FHWA-MA-EIS-82-02-F THIRD HARBOR TUNNEL. INTERSTATE 90/CENTRAL ARTERY, INTERSTATE 93 BOSTON, MASSACHUSETTS Final Environmental Impact Statement/Report and Final Section 4(f) Evaluation Submitted Pursuant to 42 U.S.C. 4332(2)(C) and 49 U.S.C. 303 by the U.S. Department of Transportation, Federal Highway Administration and Massachusetts DeDartment of Public Works Cooperating Agencies U. S. Environmental Protection Agency U. S. Army Corps of Engineers U. S. Coast Guard U. S. Department of the Interior U. S. Department of Housing and Urban Development Federal Aviation Administration AMTRAK CONRAIL Massachusetts Executive Office of Environmental Affairs Massachusetts Department of Environmental Qual Engineering Metropolitan Area Planning Council Massachusetts Port Authority Massachusetts Turnpike Authority COLLECTION APR 271987 August 16. 1985 Federal Hig The following persons may be contacted for additional information concerning this document: Mr. Edwin Hoi ah an Assistant Division Administrator Federal Highway Administration Transportation Systems Center 55 Broadway, 10th Floor Cambridge, MA 02142 (617) 494-2255 Mr. J. William Oliver Massachusetts Department of Public Works State Transportation Building 10 Park Plaza, Room 6260 Boston, MA 02116 (617) 973-7981 This document describes and evaluates the Commonwealth's Preferred Alternative for providing increased highway capacity across Boston Harbor and improving the Central Artery in Boston, Massachusetts. The Preferred Alternative consists of construction of a four-lane Third Harbor Tunnel (1-90), from the Southeast Expressway and present terminus of the Massachusetts Turnpike Extension (1-90) at the Central Artery (1-93) in Boston to Logan Airport and Route 1A in East Boston via the Seaport Access align- ment. This alignment therefore provides a Seaport Access facility to the developing Northern Avenue industrial area of South Boston. The Preferred Alternative also includes construction of a widened (eight to ten lanes) and depressed Central Artery (1-93), from its terminus with the Southeast Expressway to the Charles River/City Square area of Charlestown. The Preferred Alternative also provides express bus/ high occupancy vehicle facilities linking the South Station Transportation Center with Logan Airport and the Southeast Expressway. This document is also prepared in accordance with the Massachusetts Environmental Policy Act (MEPA), EOEA No. 4325 Digitized by the Internet Archive in 2014 https://archive.org/details/thirdharbortunne01unit SUMMARY A. DESCRIPTION AND PURPOSE OF THE PROPOSED ACTION The Commonwealth of Massachu- setts, in cooperation with the United States Department of Transportation, Federal Highway Administration, proposes to depress and widen the Central Artery, from the Massachusetts Turnpike interchange northerly to an interchange with Interstate 93 and Route 1, and to construct an extension of Interstate 90 (Massachusetts Turnpike) from its present terminus at the Central Artery across Boston Harbor to a new terminus at Logan Airport in East Boston. The 1-90 extension will consist of a Seaport Access Roadway through the northern portion of South Boston connecting to a Third Harbor Tunnel to East Boston. Exclusive bus/high occupancy vehicle ramps will also link the South Station Transportation Center to Logan Airport and to the Southeast Expressway. This proposed action was designated as the Preferred Alternative following evaluation of a set of alternative actions. The other alternatives considered are described in Section C of this SUMMARY . Context The possibility of major investment in the Central Artery and an additional cross harbor facility has been under discussion for several decades. The Artery was constructed between 1954-1959, as part of a transportation program for the Boston region which was generated early in the post-World War II period, and which had recommended construction of numerous expressway facilities inside Route 128. This program had called for construction of additional radial and inner belt expressways which were to connect with the already congested Central Artery. The Boston Transpor- tation Planning Review concluded in 1972 that the provision of high quality radial transportation in the core area should be primarily by public transportation, with selected improvements to the regional highway network to help solve critical trans- portation problems in Boston's core area. Among the latter were the possible reconstruction of the Central Artery, and the possible addition of a third harbor crossing. Over the past decade, policy initiatives have largely carried out the ambitious public transportation construction program defined in the early 1970s. During this time, improvements to the Central Artery and an additional cross harbor facility have been under active study; these facilities have been examined in an Area Planning Study, a Corridor Planning Study, and are now the subject of this Final Environmental Impact Statement/Report (FEIS/FEIR). Purpose of Action A major purpose of the highway project is to improve the flow of traffic using the Central Artery and the numerous other regional highway facilities connecting with it. These facilities service through traffic- traffic to downtown; traffic traveling within the downtown on surface streets; traffic to and from East Boston, Logan Airport and the North Shore; and traffic destined for the developing seaport area in the vicin- ity of Northern Avenue/Commonwealth Flats in South Boston. Unless improvements are made to increase the capacity of the Artery and revise ramp connections and the surface arterial in the downtown area, Artery conges- tion will continue and worsen, severe- ly affecting the operation of Boston's regional network in the core area. Another purpose of the proposed action is to provide increased cross- harbor capacity through construction of a Third Harbor Tunnel, thus aug- menting the capacity currently avail- able via the Mystic-Tobin Bridge and Callahan/Sumner Tunnels. Still another purpose of the i proposed action is to increase acces- sibility to the Boston seaport area by constructing Interstate Route 90 easterly of its current terminus at the Massachusetts Turnpike/Central Artery interchange towards the Common- wealth Flats area at Northern Avenue and the new developments emerging there. A specific objective of this aspect of the proposed action is to establish improved connections for truck traffic seeking access to this area and by doing so, to reduce truck traffic on South Boston's residential streets . The proposed action will improve bus/transit service in the City of Boston. Exclusive bus ramps will be provided to and from the South Station Transportation Center with direct connections to points south and west, and to Logan Airport. Project Description The one-way tunnel in Fort Point* Channel will carry all north- bound traffic to a widened and de- pressed Central Artery. The Central Artery, from the north portal of the Dewey Square tunnel to the Massachu- setts Turnpike area, will be converted to southbound operation, with the exception of one lane which will continue to serve northbound traffic. This aspect of the improvements to the Central Artery — segregating north- bound traffic in the Fort Point Channel from southbound traffic in the modified Dewey Square tunnel — is referred to in this FEIS/FEIR as the "split alignment". North of Dewey Square, the Artery will be widened and constructed in a tunnel through downtown. The total length of the project on the Central Artery is approximately 3.0 miles. The depressed and widened Central Artery will have four to five lanes of traffic in each direction (in contrast with the current three) as well as improved ramp connections in the downtown area. The present elevated structure will be removed, and a continuous surface arterial will be reconstructed, connecting the expanded Artery below, along with its new ramp connections, with the city street system at the surface. The High-Level Bridge over the Charles River will be replaced as part of this project to provide an improved connec- tion between interstate Route 93, Route 1 and the Central Artery. Improved connections with Storrow Drive and with the Callahan/Sumner Tunnels will also be provided. Almost 20 acres of air rights development parcels will be created by the depression of the Central Artery. The Third Harbor Tunnel will include a two-way, four-lane, limited-access toll highway, approxi- mately 3.9 miles in length, with direct connections to the Massachu- setts Turnpike, Southeast Expressway, Central Artery, Logan Airport and Route lA to the north. This highway will follow a seaport access alignment easterly from the Massachusetts Turnpike/Central Artery interchange, across Fort Point Channel at its southerly point to the Commonwealth Flats area in South Boston. Connec- tions to Northern Avenue will be provided for both northbound and southbound traffic. The alignment continues easterly to a portal near the present location of Commercial Union, and curves north to pass between Pier 5 at the Dry Dock and the western edge of the Boston Marine industrial Park (BMIP), to continue beneath Boston Harbor to a portal at Bird island Flats. Connections are provided to Route lA north as well as to the Airport roadways. An open one-way (southbound) toll plaza will be located on Commonwealth Flats. The Seaport access route will provide access to Commonwealth Flats/ Seaport facilities and to Logan Airport from the regional highway system . Construction costs of the total project are $2.56 billion, including right-of-way acquisition costs. PREFERRED ALTERNATIVE B. OTHER SIGNIFICANT GOVERNMENT ACTIONS IN THE AREA Other significant actions or proposed actions by federal govern- mental agencies on the Boston side of the Harbor in the project area include the following: 1. Federal Highway Administration (PHWA)/Massachusetts Department of Public Works (MDPW) reconstruction of the Southeast Expressway/Central Artery south of the Massachusetts Turnpike interchange, including addition of a traffic management lane; 2. FHWA/MDPW Central Artery North Area Project, including reconstruction of the Interstate Route 93/0. S. Route 1 interchange; 3. HUD assisted urban renewal project, including site improvements, roadways and utilities in the North Station area; U.S. Urban Mass Trans- portation Administration ( UMTA ) /Massa- chusetts Bay Transportation Authority (MBTA) improvements to Green Line and commuter rail at North station; GSA Federal office building; 4. UMTA/ MBTA improvement projects in the South Cove/South Bay Area, including the South Station Transpor- tation center and the Wye Connector,- 5. FHWA/MDPW/City of Boston Transportation Systems Management improvements in the Dewey Square Area. 6. Several related combined sewer overflow (CSO) treatment, collection, and outfall facility projects by the U.S. Environmental Protection Agency ( EPA)/Metropolitan District Commission (MDC)/Boston Water and Sewer Commis- sion (BWSC) in the South Bay, Port Point Channel, and Waterfront areas; 7. FHWA/MDPW Northern Avenue Bridge Replacement Project. Within Boston Harbor, other significant proposed actions include: 8. U.S. Coast Guard Special Anchorage Area at the mouth of Fort Point Channel; 9. U.S. Army Corps of Engineers maintenance dredging and possible deepening of the Boston Harbor Ship- ping Channel. On the East Boston side of the harbor, other significant proposed Federal actions include: 10. Related EPA/MDC/BWSC Combined Sewer Overflow collection and treat- ment projects along the south water- front and on Bird island Flats at Logan Airport. 11. PAA/Mass port/ private airport- related improvements to Bird Island Flats at Logan Airport, including airfield facilities, surface access, public waterfront park and mixed-use development. Other non-federal projects in the area include the private Rowe's Wharf Development on a waterfront parcel owned by the Boston Redevelop- ment Authority (BRA); cargo and mixed use developments on Massachusetts Port Authority (Massport) property at Bird island Flats; and the East Boston Piers development being planned by the iii BRA and Massport. C. OTHER MAJOR ALTERNATIVES EVALUATED Alternative 1; No-Build With Central Artery Deck Replacement Alternative 1 involved no new construction of transportation facili- ties except for the separate projects described above in Section B. The Central Artery would be redecked, and selected modifications to existing ramps and acceleration/deceleration lanes would be made; however, no additional through capacity would result. The No-Build Alternative is the base case against which the other alternatives are compared in the Draft Environmental Impact Statement (DEIS/ DEIR), Supplemental Draft Environmental Impact Statement (SDEIS/ SDEIR) and the FEIS/FEIR. Construction cost for this alternative would be $33 million. Tolls would not change . ALTERNATIVE 1 Alternative 2; Split Alignment; Railroad Alignment Alternative 2, evaluated in the DEIS/DEIR, involved the construction of a one-way, five-lane northbound tunnel from the Massachusetts Turn- pike/Central Artery interchange through Fort Point Channel. Near the mouth of the Channel, this one-way tunnel split, with three toll-free lanes reconnecting to the Central Artery northbound and two lanes continuing across Boston Harbor to a new toll plaza in East Boston. The tunnel's two southbound lanes ran next to the northbound lanes in a single structure from the East Boston toll plaza to the mouth of the Fort Point Channel in Boston. They then split, connecting to the southbound Central Artery just before the existing Dewey Square Tunnel, which would become one-way southbound (six lanes). In East Boston, the tunnel would lie within the Conrail railroad right-of- way and industrial land next to Bremen Street, with an open toll plaza between Gove and Porter Streets. The tunnel would have connections to the Southeast Expressway, Central Artery, Massachusetts Turnpike and Frontage Road in South Boston (on ramp); Summer Street in Fort Point Channel (on ramp); and the Logan Airport access/ egress roads and Route 1A in East Boston . ALTERNATIVE 2 iv A new Dorchester Avenue would be constructed above the tunnel in Fort Point Channel, with connections to the Central Artery, Frontage Road, and cross streets. The cost of Alternative 2, including construction and property acquisition, was estimated to be $749 million . Alternative 3: Split Alignment Tunnel with Jeffries Cove Alignment Alternative 3, evaluated in the DEIS/DEIR, on the Boston side consists of the same "split" alignment as Alternative 2. However, the alignment followed a more easterly course under Boston Harbor and Jeffries Cove, surfacing at Logan Airport with connections to the Airport access/ egress roads, and terminated at Route lA near the existing Airport ramps. The cost of Alternative 3, including construction and property acquisition, was estimated to be $945 million. ALTERNATIVE 3 Alternative 3A: Central Artery Depres - sion with Split Alignment; Jeffries Cove Alignment Tunnel Alternative 3A, evaluated in the Supplemental DEIS/DEIR, included a one-way split alignment tunnel in Fort Point channel which would carry all northbound traffic to a widened and depressed Central Artery and to a cross-harbor tunnel running to the Airport via Jeffries Cove. All lanes of the Dewey Square tunnel would carry southbound traffic from the Central Artery. The Third Harbor Tunnel would be a two-way four-lane facility, connecting the depressed Central Artery with Logan Airport and Route lA in East Boston. A local on-ramp to the tunnel at Summer Street and an off-ramp (from the central Artery) at Purchase Street would be provided. A toll plaza would be located at Logan Airport. A surface arterial would be constructed above the depressed Central Artery. Ramp connections would be modified, and almost 20 acres of air rights development parcels would be created. Construction costs for this alternative were estimated to be $1,895 billion, including right-of-way acquisition costs. ALTERNATIVE 3A v Alternative 4: Two-way Tunnel Align - ment; Railroad Alignment Alternative 4, as described in the DEIS/DEIR, involved the construc- tion of a two-way four-lane tunnel from the Massachusetts Turnpike/ Central Artery interchange in Boston through Fort Point Channel, across Boston Harbor and into East Boston along the same westerly "railroad" alignment as Alternative 2. There were no direct connections with the Central Artery north of the Massachu- setts Turnpike interchange. Other connections were generally the same as those for Alternative 2, with addi- tional off-ramps at Summer Street in Fort Point Channel and Albany Street in the South End. The cost of Alter- native 4, including construction and property acquisition, were estimated to be $735 million. ALTERNATIVE 4 Alternative 5: Two-way Tunnel Align - ment; Jeffries Cove Alignment Alternative 5, as described in the DEIS/DEIR, on the Boston side consisted of the same "two-way" alignment and connections as Alterna- tive 4. The Third Harbor Tunnel continued across Boston Harbor into Logan Airport along the same easterly alignment as Alternative 3. All connections in East Boston were identical to those for Alternative 3. The cost of Alternative 5, including construction and property acquisition, was estimated to be $927 million. ALTERNATIVE 5 Alternative 5A : Central Artery Depression; Seaport Alignment Tunnel; Jeffries Cove Alignment A one-way split alignment tunnel in Fort Point Channel would carry northbound traffic to a widened and depressed Central Artery. All lanes of the Dewey Square Tunnel would carry southbound traffic on the Central Artery. A Seaport access tunnel in the South Bay area would run easterly from the Massachusetts Turnpike/Central Artery interchange, across Fort Point Channel at its southerly point to Commonwealth Flats and Northern Avenue in South Boston. Connections to Northern Avenue would be provided for northbound and southbound traffic. The tunnel alignment would continue to a portal between Commonwealth Pier 5 and Pier 6 to cross under Boston Harbor to a portal at Logan Airport vi via Jeffries Cove. A toll plaza would be located on Airport property, and connections to Route lA North would be provided, as for Alternative 3A. Modifications to the Central Artery, including the number of lanes of the depressed Artery, the align- ment, and the surface arterial street, were the same as in Alternative 3A. The Seaport access route would provide access to Commonwealth Flats/ Seaport facilities and to Logan Airport from the regional highway system. Access to and from the depressed Central Artery would be the same as in Alternative 3A. The same quantity of developable land would be created over the Central Artery. Six additional acres of air rights in the South Boston area would also be created in this alternative. Con- struction costs for this alternative were $2,187 billion including right- of-way acquisition costs. ALTERNATIVE 5A Alternative 6: Central Artery Depres- sion Without Third Harbor Tunnel A one-way split alignment tunnel in Fort Point Channel would vii carry all northbound traffic to a widened and depressed Central Artery. All lanes of the Dewey Square tunnel would carry southbound traffic from the Central Artery. The project limits extend from the vicinity of the Massachusetts Turnpike interchange to the vicinity of the interstate 93/Route 1 interchange. The depressed Central Artery would have four lanes (plus accelera- tion and deceleration lanes) in each direction. Access/egress would be the same as for Alternatives 3A and 5A except for the addition of direct ramp connections between the existing tunnels and the southbound Central Artery south of the tunnels. The number of lanes of the surface ar- terial, the ramp connections from the depressed Artery to city streets in the downtown and the creation of development parcels above the de- pressed Central Artery would be similar to Alternatives 3A and 5A. Construction costs for this alterna- tive would be $1,314 billion, includ- ing right-of-way acquisition costs. ALTERNATIVE 6 Two-Lane Tunnel Concept (Alternative 5A Modified with Two-Lane Tunnel) A one-way split alignment tunnel in Fort Point Channel would carry northbound traffic to a widened and depressed Central Artery. All lanes of the Dewey Square Tunnel would carry southbound traffic from the Central Artery. Access/egress to the depressed Central Artery would be the same as for Alternative 6, in that direct ramp connections would be provided between the Callahan/Sumner Tunnels and the southbound Central Artery south of the tunnels. The Seaport Access tunnel would follow the same alignment through South Boston as for Alternative 5A Modified, and would have four lanes through Commonwealth Flats. The cross-harbor tunnel, however, would have a two-lane cross section. The connections in East Boston would be to the Airport roadway system only, with no direct connections to Route 1A north. D. SUMMARY OF SIGNIFICANT BENEFI - CIAL AND ADVERSE IMPACTS A summary of the beneficial and adverse environmental impacts of the Preferred Alternative, compared to the No-Build Alternative, is given below. A matrix at the end of this SUMMARY includes all of the alternatives for purposes of comparison. Transportation Traffic Volumes and Queues In 2010, the Boston roadway system will carry significantly higher traffic volumes, on the order of 5 to 30 percent more than 1982 volumes. If capacity is not increased, the major links in the core area (Interstate Route 93, Mystic-Tobin Bridge, Central Artery north, Callahan/Sumner Tunnels, Central Artery south, the Massachu- setts Turnpike, and Southeast Express- way) will see a substantial increase in hours of congested operation; where these roadways are congested for 1 to 8 hours per day in 1982, congested operations would last from 5 to 14 hours per day in 2010. By providing additional lanes, the Preferred Alternative reduces the hours of congested operation signifi- cantly from 2010 No-Build or 1982 existing conditions. In 2010, the Preferred Alternative will result in congestion lasting from one to two hours per day on all key routes except the Southeast Expressway, which will experience about the same number of hours of congestion as the No-Build Alternative. Traffic volumes will be reduced on links which are currently overloaded, including the Callahan/ Sumner Tunnels and Central Artery south; links such as Interstate Route 93 and the Massachusetts Turnpike, which are currently underutilized, will carry more traffic. Furthermore, the Preferred Alternative will reduce Average Weekday Daily Traffic (AWDT) in the Callahan/Sumner Tunnels by 33 percent in 2010. Traffic volumes will decrease on the Mystic-Tobin Bridge, and will increase on Route 1A north of the Airport. The elimination of the High- Level Bridge bottleneck, the widening of the Central Artery from six to eight lanes, and the provision of a Seaport Access tunnel provide substan- tial reductions in mainline congestion and queueing over the No-Build Alter- native . Person hours of travel on an annual basis will be reduced in the year 2010 with the Preferred Alternative by 17.6 million hours as compared to the No-Build Alternative. Level of Service The Preferred Alternative results in substantial reductions in the number of roadway links and local intersections operating at Level of Service (LOS) E or F in 2010. LOS F operations are anticipated at 54 percent of the No-Build Alternative major highway links and intersections in the 2010 AM peak hour. This percentage will be reduced to 14 percent with the Preferred Alternative. viii Safety The Preferred Alternative will improve the safety of the roadway network. Accident potential on the regional highway will be significantly reduced; accident potential on local streets will be slightly reduced. The Preferred Alternative also provides benefits for the movement of hazardous cargoes, especially for vehicles with origins or destinations in South Boston. Emergency vehicle access improvements are also substantial, in accordance with predicted reductions in travel time on the regional and local highway network. Logan Airport The Preferred Alternative will reduce traffic both north of the existing tunnels on Route 1A and for Airport users approaching from Inter- state Route 93 and Storrow Drive. The Preferred Alternative will also cause substantial decreases in congestion on local East Boston routes leading to the Airport. Public Transit The Preferred Alternative provides exclusive bus ramps to and from the South Station Transportation Center, thus connecting this inter- modal transfer facility to the region- al highway network, resulting in a net increase in public transportation ridership to Logan Airport. Public transportation services will not be significantly interrupted during the construction phase of the Preferred Alternative. Construction Staging Traffic congestion during construction will be minimized by careful phasing of construction work. Six lanes will be kept in operation on the elevated Central Artery until the depressed mainline is open to traf- fic. Construction of the South Boston portion of the Third Harbor Tunnel will commence simultaneously with the work on the depression of the Central Artery. With this staging, the Third Harbor Tunnel will be available for use prior to the completion of the depressed Central Artery. This is particularly critical during the period when the Callahan/Sumner Tunnels are reduced in capacity while connections are being completed to the depressed Central Artery. The avail- ability of the Third Harbor Tunnel will thus reduce traffic demands on the Central Artery during its recon- struction . Redecking the Central Artery (No-Build Alternative) would have more significant impacts than the Preferred Alternative on the maintenance of regional expressway traffic. Although redecking involves fewer years of construction and less disruption of the surface streets under the Artery, the capacity of the elevated Central Artery would be significantly reduced during the same periods. It is not necessary to reduce capacity on the Central Artery during the construction of the Preferred Alternative. Relocation Impacts No residential units will be displaced by the Preferred Alterna- tive, and therefore no residential relocations will be required. The Preferred Alternative requires 31 partial or total takings, necessitating the relocation of 131 businesses and 4,400 employees. Of these relocations, a single property acquisition, the Anelex Building adjacent to North Station, accounts for 62 of the affected businesses and agencies, and 2,200 of the total number of employees affected by the project. (Design modifications now underway in the North Station area may reduce the number of business relocations . ) Land-Use Impacts A direct impact of the widening and depression of the Central Artery is the creation of some 20 acres of new developable land which could ix accommodate approximately 2.75 million square feet of development in downtown Boston, plus approximately 1 million square feet of parking. These parcels will be developed with land uses similar to those found on abutting parcels . The Central Artery's profile also permits construction of a new surface street system, providing better traffic circulation. Improving the Central Artery and adding a Third Harbor Tunnel may make other communities close to Boston, including Quincy, Milton, Chelsea and Revere, more attractive locations for industries depending on access to Logan Airport, as well as for service industries requiring access to downtown Boston. The Preferred Alternative will have significant impacts on land use in the northern portion of South Boston. The Seaport access route, with direct connections to Logan Airport and the regional highway system, will enhance access to indus- trial development and increase land values. Commercial and residential development planned for parcels near Fort Point Channel will benefit from improved access and enhancement of pedestrian access. Parcels which are directly affected by the project will be reduced in value due to subsurface easements which will restrict future uses . Community/Neighborhood Impacts Long-Term For most neighborhoods, the widening and depression of the Central Artery will generally improve pedes- trian access and overall environmental conditions due to elimination of the elevated structure, improvements to traffic patterns, and reduced air and noise pollution. The quality of life for resi- dents of the Waterfront area will be improved as a result of the project. For North End residents, environmental conditions will improve; overall quality of life should also improve if neighborhood cohesion is maintained. Replacement of parking spaces lost in the North End and Waterfront will be provided by the project. The final location of the ventilation buildings will be chosen in such a way as to minimize localized air quality impacts. Overall environmental condi- tions in East Boston are also expected to improve due to decreased traffic on local streets and improved air qual- ity. Access to downtown Boston will be easier . In South Boston, long term improvements in the quality of life will result from significant reduc- tions in truck traffic on local streets . Construction Period During construction, adverse community impacts will occur along the corridors where construction takes place due to increased traffic detour- ing through and around these loca- tions, and due to noise, dust, and vibration from the construction activities. Mitigating measures will be undertaken to ensure that these impacts, as well as changing traffic patterns and access points and loss of parking spaces during construction, will not pose significant problems for local residents and visitors. These measures will include prior replace- ment of parking spaces and the use of alternative traffic and pedestrian routes . Economic Impacts Long-Term The Preferred Alternative will have beneficial impacts on the Boston SMSA regional economy because it will provide better regional traffic service for through traffic on the Central Artery, and for traffic to Logan Airport. Aggregate savings in travel time and costs will generate x regional economic benefits by improv- ing accessibility for firms, employ- ees, and consumers to the regional employment base and to major market areas within and beyond the region. Improvements in regional traffic service will particularly benefit high-technology industrial growth, expected to occur in south- eastern Massachusetts and northern Rhode Island; the regional financial industry concentrated in the Boston Central Business District; auto- dependent retail sales; and a variety of industries dependent upon time- sensitive access to Logan Airport. These improvements may enhance the climate for expanded investment (and employment) in each major economic sector . Construction Period Impacts Construction expenditures from the Preferred Alternative will gener- ate significant industry sales, household earnings, and jobs through- out the regional economy. The Pre- ferred Alternative will generate an estimated $4.3 billion in industry sales and household earnings and about 77,000 person-years of employment. Net increases in income tax receipts to the Commonwealth from aggregate construction impacts are expected to total approximately $76 million. Completion of construction of the Third Harbor Tunnel will minimize adverse construction effects on access to and from Logan Airport, such as delays in air freight movement of certain manufactured and other prod- ucts . While access to the Downtown Crossing shopping area from the south, west, and north will not be signifi- cantly affected during construction, some dampening of retail sales to auto-dependent retail shoppers in the downtown area is expected. Construc- tion disruption is expected to affect employee commuting by auto, but diversions to mass transit and/or peak hour spreading are expected to mini- mize overall impact on employee access. Construction activities will temporarily affect the marketability of development projects in the immedi- ate vicinity of construction and the absorption of commercial, industrial and residential space in South Boston. Development Impacts The depression of the Central Artery will create about 20 acres of new developable land on air rights, which could accommodate approximately 2.75 million square feet of develop- ment and approximately 1 million square feet of parking. Based on preliminary urban design estimates of land use by office, commercial, and residential categories, construction costs for the full air rights develop- ment are estimated to total approxi- mately $285 million (1983 dollars) and could generate 6,100 person-years of on-site construction employment. Total direct, indirect and induced impacts of these construction expendi- tures on the regional economy would include an estimated $960,000 in industry sales and household earnings and 10,800 person-years of employ- ment. Long-term jobs attributable to the office, commercial, and residen- tial land uses assumed for the air rights are estimated to total 9,400. These workers (and new residents) would be expected to generate an estimated $9 to $10 million annual retail sales within the project area. Air Quality These impacts are measured in terms of areawide emissions and air quality at certain key receptors. Pollutants reviewed include carbon monoxide (CO), nonmethane hydrocarbons (NMHC), and nitrogen oxides (NOx). Areawide (Gross Emissions) Planned federal emission controls on automobiles will result in long-term air quality improvements with either the No-Build or the Preferred Alternatives. xi Generally, CO and NMHC emis- sions in 2010 for the Preferred Alternative will be slightly less than for the No-Build Alternative. Because of overall increases in travel speeds, however, NO x emissions will increase slightly for the Preferred Alternative. Pollutant Concentrations at Selected Receptors One-hour CO concentrations with the Preferred Alternative will de- crease at 31 out of 39 receptor locations and stay the same at 6 locations when compared with the No-Build. No violations of the one-hour CO standard established under the Clean Air Act occurred in 1982 at selected sensitive receptors in the project area. None are expected in 2010 whether the Preferred Alternative or the No-Build Alternative is cho- sen. Significant reductions in CO concentrations can be expected in Waterfront, North End and East Boston locations . With the Preferred Alternative, eight-hour CO concentrations decrease at 30 out of 39 receptor locations and stay the same at 5 locations, and no violations are expected. Violations of EPA's eight-hour CO standards do exist today at several of the selected receptors, and those violations generally continue in year 2010 in the No-Build case. Emissions from venti- lation buildings do not contribute significantly to either one-hour or eight-hour CO concentrations at any receptor locations. Eight-hour CO concentrations and one-hour NO2 concentrations at existing toll plazas can be expected to exceed applicable standards with the No-Build Alternative. The Pre- ferred Alternative provides a dramatic reduction in queues at toll plazas, with the result that these air quality measures will be well below violation levels at both the existing and new toll plazas. With respect to emissions from the ventilation buildings analyzed as part of this FEIS/FEIR, analysis shows one-hour NO2 concentrations will exceed State policy level at certain surface street or roof locations near many of these ventilation buildings with the Preferred Alternative. The Commonwealth is committed to further air quality analysis which will result in the final selection of locations for ventilation buildings, possible modifications of vent stack heights, and other modifications to the tun- nel's ventilation system to address the State's policy level on NO2 concentrations . Construction Period Impacts Air quality may also be af- fected during some periods of con- struction at locations which presently are air quality "hot spots," such as Dewey Square, Broadway station, Atlantic Avenue and the existing toll plazas for the Callahan/Sumner Tunnels in East Boston. (Air quality along local streets in East Boston is not expected to deteriorate.) The No-Build Alternative during the redecking process would have similar effects on those locations in the Central Artery corridor. Dust from construction activi- ties may have adverse impacts near construction staging areas and along truck routes. Dust control measures will be implemented during construc- tion to mitigate these impacts. Noise Noise levels will decrease by more than 5 decibels at five sensitive receptor locations with the Preferred Alternative, compared to No-Build Alternative noise levels in 2010. This is primarily due to the elimina- tion of the elevated Central Artery as a source of noise. No significant changes in noise levels are expected at other sensitive receptor sites from those predicted for the No-Build Alternative in 2010. During the construction of the xii Preferred Alternative, minor to substantial impact from construction noise is expected at some sites as compared to existing noise levels. Mitigation measures will include, for example, the use of equipment muf- flers, temporary noise barriers, and limiting the hours of noisy construc- tion in the areas of noise sensitive sites . Vibration No adverse vibration impacts are anticipated from the Preferred Alternative. Moreover, benefits can be expected after the removal of the Central Artery viaduct. During construction, minor architectural damage may occur at 26 residential buildings in the North End, 26 office or commercial buildings in the Central Area, 15 industrial buildings (2 in the North End, 5 in the South End, and 8 in northern South Boston) and at the Boston Garden. Mitigating measures and monitoring of construction work will be undertaken to minimize the risk of damage. Temporary annoyance is expected at several three-story residential buildings in Charlestown, some resi- dential buildings in the North End, as well as at office or commercial buildings, industrial buildings, institutional buildings, hotels, and the Spaulding Rehabilitation Hospi- tal. In all, about 2,600 people living in the project area would be disturbed by vibration during some portion of the construction period. Water Quality The Preferred Alternative will reduce pollutants in Boston Harbor, as vehicular pollutants which now wash off of the Central Artery viaduct would be contained in the enclosed tunnel. There will be no appreciable long-term impacts to the Charles River, as the two areas to be filled are out of the main channel and will not affect either the flow of water or water quality. (Design modifications now underway may eliminate all construction in the Charles River.) Construction impacts are minor. Potential leakage of dredged sediment from barges and turbulence from tug boats and dewatering are the only potential impacts to water quality. The loss of organisms in the sediment or caught behind the steel sheet piling walls will not be significant to the overall ecosystem. The only long-term biological impact will result from the small loss of habitat area from the new structures. Impacts from dredging for sunken-tube con- struction of the Third Harbor Tunnel will include very minor releases of contaminants. Biologic impacts will include a loss of benthic fauna and fish, but recolonization of harbor sediments and new bulkheads will commence the following spring. Navigation impacts will be minimized by careful coordination of dredging and tunnel construction with the U.S. Coast Guard, the Boston Harbormaster, and maritime interests. Currently navigable waters in Boston Harbor and the Fort Point Channel will remain navigable. Wetlands There are no Federally regu- lated wetlands in the project area. The Preferred Alternative will result in the conversion of approximately 9.1 acres of the south Bay area of the Fort Point Channel from open water to developed use. Construction of the northbound Central Artery tunnel and new Dorchester Avenue in the Fort Point Channel will result in the loss of approximately 9.5 percent of the open water. Approximately 1.18 acres along the southern banks of the Charles River between the old and new Charles River Dam and 0.5 acres in the tidal portion of the Charles River will also be converted to a developed use. (Design modifications now underway may eliminate use of land within the tidal portion of the Charles River . ) xii.i Floodplains The Preferred Alternative will result in a small amount of floodplain encroachment within the Fort Point Channel and within the Charles River. These reductions in floodplain area will have a negligible effect in the Fort Point Channel, Charles River and Boston Harbor as a whole. Vegetation and Wildlife Potential impacts to vegetation and wildlife will be negligible. Small quantities of lands of very limited wildlife habitat potential will be affected. No endangered or threatened species listed at either the Federal or State levels are known to occur in the project area. Dredged and Excavated Material Construction of the Preferred Alternative will generate approxi- mately 1,010,000 cubic yards of rock, clay and organic dredged material. Bioassay and bioaccumulation analyses indicate that these materials should be acceptable for ocean disposal under current regulations. The Massachu- setts Bay Foul Area is suitable for ocean disposal of dredge material. The depression of the Central Artery, and the construction of that portion of the Third Harbor Tunnel in land areas of East Boston and South Boston will require disposal of an additional 6.2 million cubic yards of excavated material. Historic Impacts Long-Term There will be significant beneficial effects for the entire Boston region through the removal of the Central Artery viaduct and the rejoining of the downtown with Bos- ton's historic North End and Water- front areas. There will be adverse effects as well, including the taking of xiv certain buildings which are neither on the National Register of Historic Places nor eligible for inclusion in the Register, but which are located in an area potentially eligible for designation as a National Register Historic District. These include the Charles River Building at 131 Beverly Street, and the loading dock of the Stop & shop Bakery Building on Cause- way Street, both in the Causeway/North Washington Streets District (design modification work now underway suggests that a ramp redesign in the area may obviate the need to take this building and/or the loading dock). Approximately 0.9 acres of the total 6.7 acre district will be affected. The Preferred Alternative will have impacts on the potentially eligible National Register District in the Fort Point Channel area. Impacts include slight reduction of the width of the Channel and the removal of part of the historic bulkhead. The South Bay will be filled to a new bulkhead line near the existing Dorchester Avenue Bridge due to the construction of the Seaport Access tunnel across the southernmost portion of the Fort Point Channel. Approximately 9.5 percent (or 10.3 acres) of the Fort Point Channel water area will be affected. The historic Old Colony Railroad Bridge will be removed. The Section 106 Memorandum of Agreement requires the restoration of the historic character of the Fort Point Channel through the use of granite facing in constructing the new portion of the bulkhead and landscaping improvements along the Boston side of the Channel. Construction Period During construction, the increased congestion from traffic reroutings, noise and dust, and vibration impacts will occur in historic districts adjacent to the project area. These impacts will be mitigated to avoid damage to historic properties . Utilities Utilities in the project area, which include water, storm drains, sanitary sewers, combined sewers, gas, electric, communications, etc., will be either temporarily supported or permanently relocated as part of the proposed project. Utility services are not expected to be severely interrupted, although slight disrup- tions may occur when the connections from the old to the new utility occurs. Visual Impacts Visual impacts of the depres- sion and widening of the Central Artery are expected to be positive. The removal of the viaduct will reopen views to Boston's waterfront and permit new access to light and air throughout the Artery corridor. New development will be planned appropri- ately in conjunction with community residents, public agencies and other interested groups. This development can reconnect the Waterfront and the downtown and complement the cityscape of the surrounding areas. Several new ramps and ventila- tion buildings will introduce new highway elements into the urban environment along the Artery corridor. Visual impacts in the Fort Point Channel due to a slight reduc- tion of the Channel's water surface and the loss of the continuous bulk- head line will be mitigated by provi- sions in the Section 106 Memorandum of Agreement such as those listed above. The Preferred Alternative will increase pedestrian accessibility to the Channel. Significant adverse aesthetic impacts will occur in the South Bay area, with the addition of a new ramp system much taller than the surround- ing structures. The visual quality of the lower Charles River Basin in the North Station area will be adversely af- fected by lower bridges, additional ramps and a ventilation building. These roadway elements will adversely affect views and the pedestrian environment across and along the banks of the Charles Piver. Mitigation of many of the adverse visual impacts will occur through appropriate design measures and incorporation of structures into other developments. Energy The Preferred Alternative will cause energy consumption to increase slightly, by approximately 1.4 percent, when compared to the No-Build Alternative. Total energy consumption includes vehicle operations, as well as facility construction, maintenance and operations. Section 4(f) Federal transportation law (in a provision known as "Section 4(f)") prohibits the use of land from a publicly-owned park, recreation area or wildlife or waterfowl refuge or from a significant historic site (whether publicly or privately owned) unless the U.S. Department of Trans- portation determines (1) that there are no feasible and prudent alterna- tives to the use of the land; and (2) that any use is accompanied bv all possible planning to minimize harm to the property resulting from the use. The Preferred Alternative requires the permanent use of about 500 square feet of the 17,000 acre Charles River Basin Reservation, at a point near the intersection of the Msgr. O'Brien Highway and Storrow Drive at Leverett Circle. This land is currently used for parking by t^e MDC police. Temporary construction easements for limited additional portions of the Reservation will be required; affected areas would be restored to their original condition following completion of construction. At Paul Revere Landing Park some 40,000 square feet of land located under or adjacent to the High-Level Bridge over the Charles River will be permanently taken. This xv land is currently used for parking and pedestrian access to the park, an 8.5 acre facility within the Charles River Basin Reservation. The MDC Access Road, pedestrian walk and bulkhead will be realigned, and the parking area will be reconfigured. The Preferred Alternative avoids permanent takings of any surface land in the East Boston Memorial Stadium and will make 3 acres of land available for addition to the stadium. Improvements in the air quality in the immediate vicinity of the stadium will also result from the project. Up to 34,000 square feet of land along the eastern edge of the park, including the tennis courts, may be disrupted during construction. A temporary construction easement will be required, and affected areas will be returned to their original condi- tion. In addition, the Preferred Alternative will affect the historic districts in the Fort Point Channel and Causeway/North Washington Street areas; those impacts, including takings, were outlined previously under Historic Impacts in this SUMMARY. E. ISSUES/AREAS OF CONTROVERSY Issues and areas of controversy identified during the course of the study, including those raised by agencies and the public, are listed below. FEIS/FEIR sections where the issues are addressed are identified in parentheses ( ) . o Consideration of improvements to mass transportation facilities as alternatives to a Third Harbor Tunnel and an improved Central Artery (1.3, 2.4, 4.2) o Induced traffic potential of a Third Harbor Tunnel and depressed Central Artery (1.3, 4.2). o Intrusions of regional highway traffic into South Boston, South End, North End and East Boston neighbor- hoods (1.3, 3.1, 4.2). o Sensitivity of Red Line, orange Line and Blue Line Tunnels to Third Harbor Tunnel and Central Artery construction vibration (2.3, 4.8). o Final locations of ventilation buildings (2.1, 4.4, 4.5, 4.7, 4.16). o Locations of Central Artery ramps (2.1, 2.3, 4.2, 4.4, 4.5, 4.16). o Sensitivity of the Gillette Company facilities and operations to Third Harbor Tunnel construction vibration and reduction of Fort Point Channel industrial cooling capacity (2.3, 4.8, 4.9). o Proposed dredging program and impacts to water quality (turbidity) and aquatic life (4.9, 4.12, 4.13). o Third Harbor Tunnel and Central Artery effects on quality/use of Fort Point Channel (4.4, 4.14, 4.16, 5.2). o Impacts on private and public parking (4.2, 4.3, 4.4, 4.5). o Rodent control and stabiliza- tion of the water table during con- struction (4.1) . F. SIGNIFICANT UNRESOLVED ISSUES The following issues are unresolvable until the project enters subsequent phases of project develop- ment. FEIS/FEIR sections where the issues are addressed are identified in parentheses ( ) . o The extent of federal-aid construction funding for specific project components of the Preferred Alternative (6.1, 6.2). o Selection of the materials for sunken tube tunnel construction: concrete or steel (4.1). o Selection of tunnel fabrication site, including additional analysis as needed (4.1). o Selection of site(s) for replacement parking (4.2, 4.4). xvi o Identification of disposal sites for excavated and dredged materials (4.13). o Design of the new bridges and ramps across the Charles River, and analysis of their effects on Charles River Reservation, including existing and proposed MDC park facilities, navigation, traffic on Storrow Drive, BRA North Station plans, etc. (1.4, 4.2, 4.4, 4.9, 4.10, 4.11, 4.14, 4.16, 5.1, 5.2). o Approvals of all required Federal, State, and local permits necessary for project to proceed (no specific section). o Identification of appropriate staging areas for construction (4.1). o The establishment of process to assure environmentally-sensitive future joint development activity with full citizen and agency participation (4.4). o Construction impacts on traf- fic, air quality and noise levels in the project area (4.2, 4.7, 4.8). o Location and height of ventila- tion buildings (4.4, 4.5, 4.7, 4.14, 4.16). o The extent of work for the Phase I, Step 2/Phase II Archaeologi- cal Survey and final mitigation details for impacts on archaeological resources, consistent with the Section 106 Memorandum of Agreement (4.14, 5.3). o Construction staging and sequencing of the project (4.1). and dredging in navigaole waters -- Boston Harbor) - U.S. Army Corps of Engineers. o Section 103 Permit (Marine Protection, Research and Sanctuaries Act) for ocean disposal of dredged material - U.S. Army Corps of Engi- neers. o The Section 106 (National Historic Preservation Act of 1966) Review will be completed. o Section 104 Permit (dredge spoils disposal) - U.S. Army Corps of Engineers . o Section 401 Water Quality Certification (U.S. Clean water Act) - Administered by the Massachusetts Department of Environmental Quality Engineering, Division of Water Pollu- tion Control. o Federal Aviation Regulations, Parts 77, 151, 152 - Federal Aviation Administration. o Construction agreements for railroad relocation - Amtrak and Conrail. o U.S. Coast Guard permits for new bridges over navigable waters. o U.S. Coast Guard permit for alterations of existing bridges. o U.S. Coast Guard approval for work in Boston Harbor. o Further study of business relocation impacts, including a case by case analysis of whether specific private facilities will be taken or modified (4.3). G. OTHER FEDERAL ACTIONS REQUIRED FOR IMPLEMENTATION OF PROPOSED ACTION o Section 10 Permit (construction xvii SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES TRANSPORTATION 2010 Traffic Diversions relative to Alt. 1 (AWQ ° Callahan/Sumner Tunnels 0 Mystic-Tobin Bridge ° Central Artery North of Callahan/Sumner Tunnels ° Central Artery South of Callahan/Sumner Tunnels ° Mass. Turnpike Extension " Route 1A, North of Bennington Street 2010 PM Leve l of Service (# Locations) Existing Highway Sections 0 A-D ° E ° F WAT South Boston Intersections ° A-D ° E ° F T0TAT East Boston/Revere Intersections ° A-D ° E ° F TOTAT Downtown Boston Intersections ° A-D ° E ° F TOTAT Project Roadways and Approaches 0 A-D • E ° F TOTAL 19 ( 35) 4 ( 8) 31 ( 57 54" ( 100) 7 47) 2 13) 6 T5" iool 10 63) 2 12) 4 25) T6" ' TOOT 5 25) 4 20) 11 55) 2TJ 100) NOT AVAILABLE Tunnel: Split/RR -33,200 -25,600 :-36) 1-32) - 1,300 (- 1) -29,900 +13,200 + 7,600 (-17) ( + 17) (+19) 21 48) 6 13) 17 44 8 53) 1 7) 6 40) T5" 100) 13 ( 81) 1 ( 6) 4 ( 11} te ttoot 4 0 6 TO 20 4 J5 30 ( 40) ( 0) ( 60) (TOOT ( 67) ( 13) ( 20) ITooT Tunnel: Split/Airp. -32,200 (-35) -23,700 (-30) + 2,800 (+ 2) -28,800 (-17) +12,800 (+16) + 8,600 (+22) 19 ( 44) 6 i 14) 18 42) 43 1 100) 8 53) 1 7) 6 ( 40) IE (100) 13 81) 1 6) 2 13) TE 100) 11 ( 52) 1 ' 5) 9 ( 43) 7T 100) 23 ( 70) 2 ( «) 8 ( 24) 33 ICO ) 3A Tunnel & Depressed Artery -32,600 (-36) -16,400 (-21) + 4,700 - 1,300 + 12,400 + 2,200 (+ 3) (- 1) (+16) ( + 6) 20 6 11 37 6 2 7 15" ( 54) ( 16) ( 30) TToOT ( 40) ( 13) ( 47) w 13 ( 81) 1 ( 6) TB" TTOoT 11 ( 42) ( 12) ( 46) (TOOT 3 12 7E 21 ( 53) 6 ( 15) 13 ( 32) 40 (Tooy Tunnel: 2 Way/RR -33,400 -25,200 (-36) (-32) + 400 ( 0) -27,400 +16,200 + 7,200 (-16) (+20) ( + 18) 25 ( 49) 5 ( 10) 21 ( 41) noo) 9 ( 60) 0 ( 0) 6 ( 40 ) TF (150) 81) 6) ( 13) TB" TTOOT 36) ( 18) ( 46) TT TTOOT 20 ( 80) 5 _0 25 20) ( 0) (TOOT Tunnel: 2-Way/Airp. -31,200 -23,600 (-34) (-30) + 400 ( 0) -27,200 (-16) +15,600 (+20) + 8,800 (+22) 13 ( 81) 1 ( 6) _2 _Q3) 16 (Tool 11 ( 50) 4 ( 18) 7 ( 32) 22" (TDOT 27 ( 93) 0 ( 0) _1 (J) 29 (TOO) 5A South Boston Tunnel & Depressed Artery -33,100 (-36) + 3,300 (+ 4) -15,900 (-20) + 1,800 (+ 2) + 8,700 (+ 5) + 4,200 (+ 2) + 7,400 (+ 4) +40,100 (+23) +17,400 (+22) + 5,200 (+ 7) + 400 (+ 1) - 100 ( 0) 21 42) 21 ( 57) 8 16) 4 ( ID 21 12 ( 32) 50 >S 37 (100) 9 60) 7 ( 41) 0 0) 2 ( 12) 6 100 ! 8 ( 47) T5" 17 (100) 13 ( 81) 1 ( 6) 2 ( 13) T6" TTOOT 12 ( 48) 3 ( 12) 10 ( 40) 25 (100) 34 ( 68) 4 ( 8) 12 ( 24) 50 TTooT Depressed Artery 18 47) 3 8) 17 45) 38" 100) 6 40) 1 7) 8 53) 15 (100) 10 65) 3 is; 3 16 100) 12 48) 4 13) 10 39) 26 (100) 7 28) 2 8) 16 64) ■25 100) Preferred Alternative South Boston Tunnels St Depressed Artery With Modifications (Alt. 5A Modified) -30,400 -15,400 (-33) (-19) +12,200 (+ 7) +12,900 +23,000 + 5,600 (+ 7) (+29) (+14) 20 56) 8 22) 8 36 12 60) 2 10) 6 20" 100) 14 78) 1 6) 3 16) 18 100) 17 1 68) 1) 28) 25 ■ 100) 46 ( 9 ( iil 5 i 8) 60 ] TOO) Two- Lane Tunnel Concept Incl. Depressed Artery -14,500 (-16) - 8,600 (-11) + 3,100 (+ 2) +23,800 (+14) +16,900 (+21) + 1,500 (+ 4) 20 5 14 39" 9 2 ( 52) ( 13) rm ( 47) ( ID 8 ( 42) T9 (TOTf) 12 76) 2 12) 2 , 12) 16 Tool 12 48) 2 8) 11 , 44) 25 1 toot 30 61) 7 14) 12 J5) 49 1 TOO) xviii SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT l No-Build 2 Tunnel: Split/RR 3 Tunnel: Splil/Airp. 3A Tunnel & Depressed Artery 4 Tunnel: 2 Way/RR 5 Tunnel: 2-Way/Airp. 5A South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Two- Lane Tunnel Concept Incl. Depressed Artery TRANSPORTATION (continued) H Hours Callahan/Sumner Tunnels P Level of service E or F each Weekday: 2010 1 Hours Central Artery N. of Tunnels @ Level of Service E or F each Weekday: 2010 (Average of Northbound and Southbound) 14 10 1 Not Available 1 8 0 0 1 not available 1 7 1 3 14 0 1 2 5 3 t Hours Central Artery S of Tunnels P Level of Service E or F each Weekday: 2010 (Average of Northbound and Southbound) 13 Not Available 10 0 not available 5 3 8 2 5 Construction Traffic Impacts (Affected Area) High-Level Bridge Ramp Access Surface Artery Central Artery Financial District North End Ft. Pt. Channels Bridges Central Artery Financial District North End Ft. Pt. Channel Bridges So. Boston - Andrew Square B'way/Dorch. Ave. So. End - Herald/Albany Logan Airport Roads 1 Central Artery Surface Artery Financial District North End Haymarket West End Government Center Ft. Pt. Channel Bridges So. Boston - Andrew Square B'way/Dorch. Ave. Logan Airport Roads Central Artery Ft. Pt. Channel Bridges So. Boston - Andrew Square B'way/Dorch. Ave. So. End - Herald/Albany Central Artery Surface Artery Ft. Pt. Channel Bridges So. Boston - Central Artery Surface Artery Financial District North End Haymarket West End Government Center Ft. Pt. Channel Bridges So. Boston - Andrew Square B'way/Dorch. Ave. Northern Ind'l Area Logan Airport Roads Central Artery Surface Artery Financial District North End Haymarket West End Government Center Ft. Pt. Channel Bridges So. Boston - Andrew Square B'wav/Dorch. Ave. Central Artery Surface Artery Financial District North End Haymarket Central Artery Surface Artery Financial District North End Haymarket So. Boston - Andrew Square B'way/Dorch. Ave. So. End - Herald/Albany Andrew Square B'way/Dorch. Ave. So. End - Herald/Albany Logan Airport Roads West End Government Center Ft. Pt. Channel Bridges So. Boston - Andrew Square B'way/Dorch. Ave. Northern Ind' 1 Area Logan Airport Roads Bird Island Flats West End Government Center Ft. Pt. Channel Bridges So. Boston - Andrew Square B'way/Dorch. Ave. Nnrthprn Tnd'l 11'. II LIICI II 1IIU 1 . Area Logan Airport Roads Bird Island Flats VHT diff. rel. to Alt. 1 PHT diff. rel. to Alt. 1 - +19.9 million - 6.5 million +20.8 million -8.2 million +32.3 million - 3.8 million +18.6 million - 7.9 million +27.3 million - 9.2 million +36.0 million -13.0 million +15.0 million - 1.8 million +17.7 mill ion -17.6 million +68.6 million -10.3 million 2010 Yearly Accident Reduction: Selected Locations (% change vs. Alt. 1) (Base Case) -11* -19% -26% -12% -17% 24» -12% -25% -23% xix SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT i No Build 2 Tunnel: Splil/RR 3 Tunnel: Split/Airp. 3A Tunnel & Depressed Tunnel: t ! Way/RR 5 Tunnel: 2 Way /Air p 5A South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Two- Lane Tunnel Concept Incl. Depressed Artery BUSINESS DISPLACEMENTS/RELOCATIONS Boston: # Businesses # Employees 0* 0 2* 75 2* 75 86 3,632 0* 0 0* 0 89 2,987 9 2,880 97 3,370 97 3,370 East Boston: # Businesses U Finn 1 nupp c it l ii ip l \jy ccj 0 _0 14 160 22 435 22 435 14 70 22 435 22 435 0 0 34 1.03Q 16 304 Total : # Businesses # Employees (approx. ) 0 0 16 245 24 510 108 4,570 1 14 70 22 435 111 3,420 89 2,880 131 4,400 113 3,675 LAND USE Beneficial to Existing Land Use (by area) None Some Ft. Pt Channel Sites Logan Airport Some Ft. Pt. Channel Sites Logan Airport Some Ft. Pt. Channel Sites Financial District Waterfront North End Some N. Station Some Ft. Pt. Channel Sites Logan Airport Some Ft. Pt. Channel Sites Logan Airport Some Ft. Pt. Channel Sites Financial District Waterfront North End Some N. Station Som< ft. Pt. ^nannel ' ites Financial District watt r1 rorit Nor'h End Somi. N. Station Some Ft. Pt. Channel Sites Chinatown Financial District Waterfront North End Some Ft. Pt. Channel Sites Financial District Waterfront North End Logan Airport Sites Logan Airport Sites South Boston Industrial Area Sites East Boston Logan Airport Some N. Station Sites South Boston Industrial Area Some N. Station Sites South Boston Industrial Area Adverse Effects on Existing Land Use (by area) None East Boston Some Ft. Pt. Channel Sites Some Ft. Pt. Channel Sites Some Ft. Pt. Channel Sites Some N. Station Sites East Boston Some Ft. Pt. Channel Sites Some Ft. Pt. Channel Sites Some N. Station Sites Some S. Boston Sites Some Ft. Pt. Channel Sites Some N. Station Sites Some N. Station Sites Some S. Boston Sites Some N. Station Sites Some S. Boston Sites * These do not include the 9 parking lots and the 30 employees temporarily displaced under the existing Central Artery. XX SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT i No Build 2 Tunnel: Split/RR 3 Tunnel: Spht/Airp. 3A Tunnel & Depressed Artery 4 Tunnel: 2 Way/RR 5 Tunnel: 2-Way/Airp. SA South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Two- Lane Tunnel Concept Incl. Depressed Artery NEIGHBORHOOD AND COMMUNITY FACILITIES IMPACTS Construction Period Neighborhood Disruption (by area) Moderate Financial, Waterfront North End, Government Center, North Station East Boston South Boston South Boston South Boston Waterfront Government Center North End North Station West End East Boston South Boston South Boston South Boston Waterfront Government Center North End North Station West End South Boston Waterfront Government Center North End North Station West End South Boston Waterfront Government Center North End North Station West End South Boston Waterfront Government Center North End North Station West End 1 nnn.torm ImnKfiupmpnt in LUNh lc i Mi i nip ru v cmici i \, in Neighborhood Quality of Life (by area) None Chinatown North End Chinatown North End East Boston Chinatown Waterfront Government Center North End (possible) East Boston Chinatown North End Chi natown North End East Boston South Boston Chinatown Waterfront Government Center North End (possible) East Boston Chi natown Waterfront Government Center North End (possible) South Boston Chinatown Waterfront Government Center North End (possible) East Boston South Boston Chinatown no LC l 1 1 Ull I Government Center North End (possible) Lonq-term Reduction in Some East Boston None North End (possible) East Boston None North End (possible) North End (possible) North End (possible) North End Neighborhood Cohesion (by area) (possible) xxi SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT i No-Build 2 Tunnel: Split/RR 3 Tunnel: Split/Airp. 3A Tunnel & Depressed Arteiy Tunnel: 4 2 Way/RR 5 Tunnel: 2-Way/Airp, 5A South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Two- Lane Tunnel Concept Incl. Depressed Artery ECONOMICS Project Cost ($ Million) Construction Right-of-Way Total 33 0 730 19 919 26 1,797 98 731 4 915 12 2,097 90 1,251 63 2,424 140 1,962 104 33 749 945 1,895 735 927 2,187 1,314 2,564 2,066 Construction Employment (person-years) On-site (Boston residents in parentheses) Off-site Total 697 407 1,104 4,800 (1,150) 16,000 ( 690) 20,800 5,100 (1,220) 17,000 22,100 39,378 (9,845) 15,077 54,455 1 1 4,100 (980) 3,200 (510) 7,300 5,100 (1,220) 16,500 21 ,600 45,815 (11,450) 17,542 63,357 27,360 (6,840) 10,476 37,836 55,794(13,950) 21,206 77,000 44,332 (11,083) 16,974 61 ,306 Construction-period tax losses to uty ot boston from takings (per None Not Available $125,000 $750,000 Not Avai lable $70,000 $900,000 $750,000 $1,090,000 $1,090,000 year) Construction-period tax loss to City of Boston due to development delays (per year) None None None $5-10 million None None $5-10 million $5-10 million $5-10 million $5-10 million Long-term annual tax increases over No-Build due to new development air-rights City of Boston Base Case $800,000 $800,000 $5-10 million $800,000 $800,000 $5-10 million $5-10 million $5-10 million $5-10 million One-time (non-annual) receipt due to faster absorption rate of space in new South Boston development 0 N/A N/A .$> 2-5 mi 1 1 ion N/A N/A $20-30 million $1-3 mill ion $20-30 million $20-30 million xxii SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT 1 No-Build 2 Tunnel: Split/RR 3 Tunnel: Split/ Air p. 3A Tunnel & Depressed Artery 4 Tunnel: 2 Way/RR 5 Tunnel: 2-Way/Airp. 5A South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Two- Lane Tunnel Concept Incl. Depressed Artery _ ino nnAl ITY (vear 2010) Violations of 8-hr. CO Standards 4 0 0 0 0 0 0 1 0 0 [tl locations) .. . Toll Plaza Contributions - 8-hr. CO (parts per million) < 0.2 0.2 Bremen at Gove 4.7 0.2 < 0.2 *- 0.2 < 0.2 3.7 <- o.2 1.3 Porzio Park l!l <.o'.z 0.4 0.5 < 0.2 0.4 0.5 o!9 < Q.Z o!3 Near Sumner Toll 8.0 0.3 0.3 0.2 0.3 0.3 0.2 6.3 •cO. 2 2.3 Toll Plaza Contribution - 1-hr. NO, (uq/m>) 10 22 12 Bremen at Gove 359 22 12 10 284 < 10 101 Porzio Park 56 < 10 22 24 <10 22 24 45 < 10 ' 16 Near Sumner Toll 486 19 13 11 19 13 11 384 <110 137 xxiii SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT i No-Build 2 Tunnel: Splil/RR 3 Tunnel: Split/Airp. 3A Tunnel & Depressed Artery 4 Tunnel: 2 Way/RR 5 Tunnel: 2-Way/Airp. SA South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modifiedl Two- Lane Tunnel Concept Incl. Depressed Artery NOISE Short-term/Construction Noise: Substantial Impacts (lb dBA or greater) 1 Resid. St. 1 Public Bldg. 1 Resid. St. 1 Public Bldg. 1 1 1 Hospital Resid. St. Museum 1 1 Publ Resi ic Bldg. i. St. 1 Public Bldg. 1 1 1 Hospi tal Resid. St. Museum 1 Hospital 1 Resid. St. 1 Museum 1 Hospital 1 Resid. St. 1 Museum 1 Playground 1 1 1 Hospital Resid. St. Museum Change 1n Total Noise Level (without noise abatement) 2010 0 Sensitive Receptors Base Case 3 sites minor 1 Site minor impact (5-10 dBA) 5 Sites noise 2 Sites minor impact (5-10 dBA) no impact 4 Sites decreased noi se 1 Site minor impact (5-10 dBA) 5 Sixes decreased noise 5 Sites decreased noise 5 Sites decreased noise VIBRATION Short-term/Construction Impacts ° Vibration Annoyance (jl residents) 0 Structural Damage Potential (# buildings) Not Significant none 3100 1 460 1 2,800 3 3,03 0 3 390 0 2,840 3 2,560 3 2,600 3 2,600 3 Vibration Impacts, 2010 none none none none none none none none none none xxiv SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT i No-Build 2 Tunnel: Split/RR 3 Tunnel: Split/Airp. 3A Tunnel & Depressed Artery 4 Tunnel: 2 Way/RR 5 Tunnel: 2-Way/Airp. 5A South Boston Tunnel & Depressed Artery 6 Depressed Artery Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Two- Lane Tunnel Concept Incl. Depressed Artery WATER Wetlands (Federal) none none none none none none none none none none Floodplains none insignificant insignificant insignificant insignificant insignificant insignificant insignificant insignificant insignificant Water Resources \ ft U ay b u u [ cuy mii^ wui ^ in Boston Harbor) none 170 250 250 170 250 210 none 46 30 WILDLIFE/VEGETATION Impacts on sensitive habitats or endangered species none none none none none none none none none none UTILITIES IMPACTS none moderate relocation moderate relocation major relocation moderate relocation moderate relocation major relocation major relocation major relocation major relocation ENERGY IMPACTS insignificant insignificant insignificant insignificant insignificant insignificant insignificant insignificant insignificant insignificant VISUAL none Beneficial : none Beneficial : none Beneficial : N. End Waterfront Financial Dist. Beneficial : none Beneficial : none Beneficial : N. End Waterfront Financial Dist. Beneficial : N. End Waterfront Financial Dist. Beneficial : N. End Waterfront Financial Dist. Beneficial : N. End Waterfront Financial Dist. Adverse: E. Boston Ft. Pt. Channel Adverse: Ft. Pt. Channel Adverse: N. Station/ Charles R. Ft. Pt. Channel Adverse: E. Boston Ft. Pt. Channel Adverse: Ft. Pt. Channel Adverse: N. Station/ Charles R. Adverse: N. Station/ Charles R. Adverse: N. Station/ Charles R. S. Bay Adverse: N. Station/ Charles R. S. Bay XXV SUMMARY OF ENVIRONMENTAL IMPACTS OF ALTERNATIVES (Cont.) IMPACT CULTURAL Historic (National Register) Districts' Construction - Period Adverse Effects Long-term Effects Parklands Fulton Com. St. Dist. Blackstone Block Dist. 8ulfinch Triangle Dist. Church Green Dist. N. End Dist. Old Waterfront Dist. Causeway/N. Wash. Dist. None None Tunnel: Split/RH Ft. Pt. Channel Ft. Pt. Channel (adverse) E. Bos. Mem. Stadium BIF Park (proposed) Tunnel: Split/Airp. Ft. Pt. Channel Ft. Pt. Channel (adverse) Custom House Dist. (beneficial ) E. Bos. Mem. Stadium BIF Park (proposed) 3A Tunnel & Depressed Artery Fulton Com. St. Dist. Blackstone Block Dist. Charles R. Basin Dist. Church Green Dist. Custom House Dist. N. End Dist. Old Waterfront Dist. Causeway/N. Wash. Dist. Ft. Pt. Channel (severe) Beneficial : Blackstone Dist. Church Green Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Old Waterfront Dist. Adverse : Bulfinch Tri . Dist. Causeway/N. Wash. Dist. Ft. Pt. Channel (severe) E. Bos. Mem. Stadium BIF Park (proposed) Charles R. Basin Reservation Park Revere Landing Park Tunnel: 2 Way/RR Ft. Pt. Channel Ft. Pt. Channel (adverse) E. Bos. Mem. Stadium BIF Park (proposed) Tunnel: 2-Way/Airp. Ft. Pt. Channel Ft. Pt. Channel (adverse) E. Bos. Mem. Stadium BIF Park (proposed) 5A South Boston Tunnel & Depressed Artery Blackstone Block Dist. Bulfinch Triangle Dist. Charles R. Basin Dist. Church Green Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Old Waterfront Dist. Ft. Pt. Channel S. Boston Piers Dist. Beneficial : Blackstone Dist. Church Green Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Old Waterfront Dist. Adverse : Bulfinch Tri . Dist. Causeway/N. Wash. Dist. Ft. Pt. Channel E. Bos. Mem. Stadium BIF Park (proposed) Charles R. Basin Reservation Park Revere Landing Park Depressed Artery Blackstone Block Dist. Bulfinch Triangle Dist. Charles R. Basin Dist. Church Green Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Causeway/N. Wash. Dist. Old Waterfront Dist. Beneficial : Blackstone Dist. Church Green Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Old Waterfront Dist. Adverse : Bulfinch Tri. Dist. Causeway/N. Wash. Dist. Charles R. Basin Reservation Park Revere Landing Park Preferred Alternative South Boston Tunnels & Depressed Artery With Modifications (Alt. 5A Modified) Blackstone Block (list Bulfinch Triangle Dist. Charles K . Basin Dist. Cornhill Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Causeway/N. Wash. Dist. Old Waterfront Dist. Ft. Pt. Channel Dist. Beneficial : Blackstone Dist. Bulfinch Triangle Dist. Custom House Dist. N. End Dist. Old Waterfront Dist. Fulton Com. Dist. Adverse : Causeway/N. Wash. Dist. Ft. Pt. Channel E. Bos. Mem. Stadium Charles R. Basin Reservation Paul Revere Landing Park Two- Lane Tunnel Concept Incl. Depressed Artery Blackstone Block Dist. Bulfinch Triangle Dist. Charles R. Basin Dist. Cornhill Dist. Custom House Dist. Fulton Com. Dist. N. End Dist. Causeway/N. Wash. Dist. Old Waterfront Dist. Ft. Pt. Channel Dist. Beneficial : Blackstone Dist. Bulfinch Triangle Dist. Custom House Dist. N. End Dist. Old Waterfront Dist. Fulton Com. Dist. Adverse : Causeway/N. Wash. Dist. Ft. Pt. Channel Charles R. Basin Reservation Paul Revere Landing Park xxvi TABLE OF CONTENTS Page SUMMARY 1.0 INTRODUCTION 1.1 Purpose and Need for Action 1 1.2 General Description of the Project Area 3 1.3 Major Policy Issues 5 1.3.1 The Preferred Alternative and Regional Traffic 5 1.3.2 Impact on Trip Making to Logan Airport 8 1.3.3 Effect of the Project on Trips to Downtown 10 1.3.4 Traffic Forecasting Methodology 11 1.4 Major Unresolved Issues 11 1.4.1 Air-Rights Joint Development 11 1.4.2 North Station/Charles River Basin 11 1.4.3 Ventilation of Tunnel Sections 12 1.4.4 Dredged and Excavated Material Disposal 12 1.4.5 Other Issues 12 2.0 DESCRIPTION OF ALTERNATIVES 2.1 General 13 2.2 Preferred Alternative 13 2.2.1 Description 13 2.2.2 Summary of Benefits 25 2.3 Alternatives Considered in the EIS Process 26 2.3.1 DEIS/DEIR Alternatives 26 2.3.2 SDEIS/SDEIR Alternatives 28 2.3.3 Other Concepts in the SDEIS 30 2.3.4 Other Concepts Examined in the FEIS 30 2.3.5 Pre-EIS Studies 32 2.4 Reasons for Not Selecting Other EIS Alternatives 36 2.5 Design Considerations for the Preferred Alternative 40 2.5.1 Derivation of the Preferred Alternative 40 2.5.2 Other Design Considerations 42 3.0 AFFECTED ENVIRONMENT 3.1 Transportation Facilities 54 xxvii Page 3.1.1 Existing Roadway Characteristics 54 3.1.2 Future Roadway Characteristics Without the Project 62 3.1.3 Safety 66 3.1.4 Other Transportation Facilities 66 3.2 Land Use 71 3.2.1 Overview 71 3.2.2 South End 74 3.2.3 Industrial Triangle 74 3.2.4 South Boston 75 3.2.5 Fort Point Channel 78 3.2.6 Leather District 79 3.2.7 Chinatown/South Cove 79 3.2.8 Financial District 80 3.2.9 Waterfront 80 3.2.10 Government Center 81 3.2.11 North End 81 3.2.12 North Station 82 3.2.13 West End 83 3.2.14 Charlestown 83 3.2.15 East Boston 83 3.2.16 Logan Airport 84 3.2.17 Route 1A North 84 3.3 Neighborhood Characteristics and Community Facilities 86 3.3.1 South End 86 3.3.2 South Boston 89 3.3.3 Chinatown/South Cove 91 3.3.4 Waterfront 92 3.3.5 Government Center 93 3.3.6 North End 93 3.3.7 North Station 94 3.3.8 West End 95 3.3.9 East Boston 95 3.4 Economic Activity 97 3.4.1 Overview 97 3.4.2 Economic Activities by Subarea 101 3.5 Existing Air Quality 104 3.5.1 Regional 104 3.5.2 Local 107 3.6 Noise and Vibration 111 3.6.1 Existing Noise Levels 111 3.6.2 Existing Vibration Levels 116 xxviii Page 3.7 Water Resources 122 3.7.1 Fort Point Channel 122 3.7.2 Boston Inner Harbor 123 3.7.3 Lower Charles River Basin 132 3.7.4 Industrial Water Use 138 3.8 Wetlands 138 3.8.1 Description of Existing Conditions 138 3.8.2 Evaluation of Project Area Wetlands 138 3.9 Floodplains 141 3.10 Vegetation and Wildlife 141 3.10.1 Vegetation 141 3.10.2 Wildlife 141 3.10.3 Endangered and Threatened Species 141 3.11 Historic and Archeological Resources 143 3.11.1 Historic Resources 143 3.11.2 Archaeological Resources 151 3.12 Utilities 152 3.13 Visual Characteristics 156 3.13.1 South Bay 156 3.13.2 South Boston/Fort Point Channel 157 3.13.3 Fort Point Channel/Dewey Square 157 3.13.4 Central Artery - Congress Street to High Street 158 3.13.5 Central Artery - High Street to Clinton Street 158 3.13.6 Central Artery - Clinton Street to North Washington Street 159 3.13.7 Central Artery - North Washington Street to Interstate Route 93/Route 1 Merge 160 3.13.8 Storrow Drive Ramps 161 3.13.9 Logan Airport 161 4.0 ENVIRONMENTAL CONSEQUENCES 4.1 Description of Construction 162 4.1.1 Construction Methods 162 4.1.2 Construction Sequencing 163 4.1.3 Maintenance of Traffic and Existing Utilities 166 4.1.4 Materials Movement and Staging Areas 169 4.1.5 Construction Effects and Mitigation Measures 169 xxix Page 4.2 Transportation 171 4.2.1 Comparison of Alternatives 171 4.2.2 Traffic Volumes 179 4.2.3 V/C Ratios and Levels of Service 185 4.2.4 Central Artery Bottlenecks and Congestion Points 198 4.2.5 Issues Concerning Traffic Forecasts 203 4.2.6 Vehicle Miles Travelled, Vehicle Hours of Travel, and Present Hours of Travel 204 4.2.7 Safety 206 4.2.8 Other Transportation Facilities 210 4.2.9 Construction Impacts 214 4.2.10 Parking Impacts 223 4.3 Relocation Impacts 226 4.3.1 Comparison of Alternatives 226 4.3.2 Displaced Businesses and the Availability of Comparable Relocation Space 227 4.3.3 Related Business Economic Impacts 232 4.3.4 Community Economic Impacts 234 4.3.5 Massachusetts Department of Public Works Relocation Procedures 235 4.3.6 Other Possible Sources of Assistance 236 4.4 Land Use Impacts 236 4.4.1 Comparison of Alternatives 236 4.4.2 No-Build Alternative 238 4.4.3 The Preferred Alternative 240 4.4.4 Joint Development 262 4.5 Neighborhood and Community Facilities Impacts 287 4.5.1 Comparison of Alternatives 287 4.5.2 No-Build Alternative 288 4.5.3 The Preferred Alternative 289 4.6 Economic Impacts 293 4.6.1 Comparison of Alternatives 294 4.6.2 Impacts on the Regional Economy 295 4.6.3 Impacts on the Project Area Economy 298 4.6.4 Impacts on Subarea Economics 299 4.6.5 Development and Related Fiscal Impacts 301 4.6.6 Construction Period Impacts on Development 302 4.6.7 Measures to Minimize Adverse Effects 303 4.7 Air Quality 303 4.7.1 Mesoscale Analysis 303 4.7.2 Microscale Analysis 304 4.7.3 Effects of Toll Plazas 309 4.7.4 Concentrations in the Tunnels 311 xxx Page 4.7.5 Effects of Ventilation Building Emissions 313 4.7.6 Construction Impacts 321 4.8 Noise and Vibration 326 4.8.1 Noise 326 4.8.2 Vibration 337 4.9 Water Resources 345 4.9.1 Comparison of Alternatives 345 4.9.2 No-Build Alternative 345 4.9.3 Preferred Alternative 345 4.9.4 Construction Impacts of the Preferred Alternative 352 4.9.5 Mitigating Measures 358 4.10 Wetlands 358 4.10.1 Comparison of Alternatives 358 4.10.2 Preferred Alternatives vs. No-Build Alternative 358 4.11 Floodplains 359 4.11.1 Comparison of Alternatives 359 4.11.2 Preferred Alternative vs. No-Build Alternative 359 4.12 Vegetation and Wildlife 360 4.12.1 Comparison of Alternatives 360 4.12.2 Vegetation 360 4.12.3 Wildlife 360 4.12.4 Endangered and Threatened Species 361 4.13 Dredged and Excavated Material Disposal 361 4.13.1 Comparison of Alternatives 361 4.13.2 Disposal Alternatives 361 4.13.3 Excavation, Reuse, and Disposal Volumes 362 4.13.4 Agency Coordination 362 4.13.5 Sediment Quality Requirements 365 4.13.6 Summary 366 4.14 Historical and Archaeological Impacts 366 4.14.1 Comparison of Alternatives 366 4.14.2 Effects on Historic Properties 367 4.14.3 Archaelogical Effects 376 4.15 Utilities 377 4.15.1 Comparison of Alternatives 377 4.15.2 Preferred Alternative 378 xxxi Page 4.16 Aesthetic Impacts 381 4.16.1 Comparison of Alternatives 381 4.16.2 Aesthetic Impacts 381 4.17 Energy 401 4.17.1 Comparison of Alternatives 401 4.17.2 Preferred Alternative 402 4.18 Irreversible and Irretrievable Commitments of Resources 402 4.19 Short-Term Uses of the Environment vs. Long-Term Productivity 405 4.19.1 No-Build Alternative 405 4.19.2 Preferred Alternative 406 5.0 SECTION 4(f) EVALUATION 5.1 Parklands 408 5.1.1 East Boston Memorial Stadium 408 5.1.2 Proposed Bird Island Flats Park 412 5.1.3 Charles River Basin Reservation 413 5.1.4 Paul Revere Landing Park 417 5.2 Historic Resources 421 5.2.1 Charles River Basin District 421 5.2.2 Causeway - North Washinton Streets District 422 5.2.3 Fort Point Channel District 426 5.3 Archaeological Sites 430 5.4 Consultation 431 6.0 LEGAL AND FINANCIAL CONSIDERATIONS 6.1 Third Harbor Tunnel - Interstate Route 90 433 6.2 Central Artery - Interstate Route 93 434 AGENCIES, ORGANIZATIONS, AND PERSONS TO WHOM COPIES OF THE FEIS/FEIR WERE SENT 435 COMMENTS AND COORDINATION 437 LIST OF PREPARERS 506 INDEX 512 BIBLIOGRAPHY 522 xxxii REPORTS BOUND SEPARATELY: APPENDICES Appendix 1 Appendix 2 Appendix 3 Appendix 4 Appendix 5 Public Participation Process Conceptual Relocation Plan Report Traffic Air Quality Noise and Vibration PUBLIC HEARING: SYNOPSIS OF TESTIMONY, RESPONSES TO COMMENTS, TRANSCRIPT SUPPORTIVE ENGINEERING REPORT TWO-LANE TUNNEL/OPTIONAL FORT POINT CHANNEL CONCEPTS xxxiii List of Figures Figure No. Description Page 1 Project Area 4 2 Typical Sections 15 3 Preferred Alternative - General Plan 16 3A Preferred Alternative - South Bay Area 17 3B Preferred Alternative - Central Area 19 3C Preferred Alternative - Area North of Causeway Street 20 3D Preferred Alternative - South Boston Area 23 3E Preferred Alternative - East Boston Area 24 4 South Postal Annex - Use of Dorchester Avenue 44 5 Properties Controlling Central Artery Alignment 50 6 Effect of AASHTO Standards on Existing Development - Central Area 51 7 Affected Roadway Network - Roadway Link, Ramp, and Intersection Identification Map 55 8 Pictorial Representation of Level of Service 58 9 Public Transportation Facilities 69 10 Neighborhoods in the Project Area 72 11 Major Land Uses - 1 76 12 Major Land Uses - 2 77 13 Route 1A North Major Land Uses 85 14 Community Facilities - 1 88 15 Community Facilities 90 16 Zip Code Districts Used for Economic Inventory 98 17 Carbon Monoxide Measurement Locations 110 18 Existing Noise Measurement Locations 115 19 Comparison of Typical Ground Vibration Amplitudes and Criteria 118 xxxiv List of Figures Figure No. Description Page 20 Vibration Measurement Locations 121 21 Water Quality Sampling Locations 125 22 Sediment Sampling Locations 126 23 Vertical Distribution of Metals in Fort Point Channel Sediments at Station FP-2 127 24 Flood/Ebb Excursion 129 25 100 Year Flood Zone 140 26 Historic Resources in the Project Area 144 27 Original Seventeenth Century Shoreline 145 28 Major Existing Utilities 153 29 Depressed Central Artery - Stage Construction, Typical 165 30 Preferred Alternative - Affected Roadway Network - Roadway Link, Ramp and Intersection Identification Map 186 31 Relocation Requirements - Area North of Dewey Square 229 32 Relocation Requirements - South Boston/South Bay Areas 231 33 Relocation Requirements - East Boston/Logan Airport 233 34 Land Use Impacts - South Boston 243 35 Land Use Impacts - North Station Area 253 36 Land Use Impacts - East Boston/Logan Airport 258 37 Existing Context - Central Artery from Congress Street to Causeway Street 263 38 Joint Development Opportunities - Preferred Alternative - Central Artery from Congress Street to Causeway Street 264 39 Urban Design Principles - Preferred Alternative - Central Artery from Congress Street to Causeway Street 266 XXXV List of Figures Figure No. Description Page 40 Illustrative Plan - Preferred Alternative - Central Artery from Congress Street to Causeway Street 269 41 Urban Design Objectives - Preferred Alternative - South Bay/Fort Point Channel 270 42 Illustrative Plan - Preferred Alternative - South Bay/Fort Point Channel 271 43 Cutaway View from Boardwalk Along New Dorchester Avenue (Looking North) 272 44 Illustrative Section through Fort Point Channel South of Congress Street (Looking North) 272 45 Existing: Aerial view of the Financial District from Congress Street to High Street 274 46 After Construction: Air-rights parcels available for development 274 47 Existing: View toward the harbor along Central Street 276 48 After Construction: View toward the harbor and the Aquarium along Central Street 276 49 Existing: View looking north along the Surface Artery adjacent to the Broad Street District 277 50 After Construction: View toward the harbor and the Aquarium along Central Street 277 51 Existing: View under the Central Artery toward Quincy Market from Commercial Street 279 52 After Construction: View toward Quincy Market from Commercial Street 279 53 Existing: View toward Hanover and Cross Streets from under the Central Artery 281 54 After Construction: View toward Hanover and Cross Streets 281 55 Existing: View looking south from Causeway Street 283 56 After Construction: Air-rights parcels available for development 283 xxxvi List of Figures Figure No. Description p a ge 57 Air Quality Receptor Locations 305 58 Potential Noise Barrier Locations - Central Area and East Boston 335 59 Existing and Alternative Future Gillette Cooling Water Configuration 349 60 Effect of Central Artery to Storrow Drive Connector on Charles River 351 61 Suspended Sediments 354 62 Potential Offshore Dredge Disposal Site 364 63 Historic Resources Affected by the Preferred Alternative - I 371 64 Historic Resources Affected by the Preferred Alternative - II 372 65 Existing: View looking south from the Summer Street Bridge 382 66 After Construction (Preferred Alternative): View looking south from the Summer Street Bridge 382 67 After Construction (Alternatives 2 and 3): View looking north from the Congress Street Bridge 383 68 After Construction (Alternatives 4 and 5): View looking south from the Summer Street Bridge 383 69 Existing: View looking north from the Congress Street Bridge 384 70 After Construction (Preferred Alternative): View looking north from the Congress Street Bridge 384 71 Key Plan Preferred Alternative 385 72 Summary of Aesthetic Impacts and Measures to Minimize Harm - Preferred Alternative - South Bay/Fort Point Channel 387 73 Summary of Aesthetic Impacts and Measures to Minimize Harm - Preferred Alternative - South Boston 389 74 Summary of Aesthetic Impacts and Measures to Minimize Harm - Preferred Alternative - Central Artery from Congress Street to Causeway Street 392 xxxvii List of Figures Figure No. Description Page 75 Summary of Aesthetic Impacts and Measures to Minimize Harm - Preferred Alternative - North Station/Charles River Area. 399 76 Summary of Aesthetic Impacts and Measures to Minimize Harm - Preferred Alternative - Logan Airport 400 77 East Boston Memorial Stadium - Impacts under the Preferred Alternative 409 78 Location of Proposed Bird Island Flats Park in Relation to the Preferred Alternative 414 79 Charles River Basin - Impacts 415 80 Paul Revere Landing Park - Impacts 418 81 Impacts on the Causeway/North Washington Streets Historic District 423 82 Impacts on the Fort Point Channel Historic District 427 xxxviii List of Tables Table No. Description page 1 Average Weekday Daily Traffic (AWDT) 56 2 Peak Hour Traffic Volumes, Volume-to-Capacity (V/C) Ratios, Operating Speeds (SP), & Levels of Service (LOS) 1982, 1990, 2010 60 3 Existing and Future No-Build Individual Peak Hour Queue Length Comparison (in Miles) 65 4 Yearly Accident Summary 67 5 Major Land Uses in the Project Area 73 6 Major Community Facilities in the Project Area 87 7 Study Area Employment by Sector 100 8 Number of Establishments and Employees by Type of Business within the Affected Zip Codes (1980) 102 9 Federal and Massachusetts Air Quality Standards 105 10 Measured Existing Air Quality in the Metropolitan Boston Area in 1980 106 11 Measured Carbon Monoxide Concentrations (in PPM) for the Third Harbor Tunnel and Central Artery Study Area 109 12 Relationship Between Changes in Noise Level and Loudness 112 13 FHWA Noise Criteria 112 14 Summary of Existing Noise Measurements 113 15 Variation of Hourly L e q Over a 24-Hour Period at the Callahan/Sumner Tunnel Toll Plaza 117 16 Project Vibration Criteria 119 17 Summary of Existing Vibration Measurements 120 18 Water Quality Summary - Boston Inner Harbor 124 19 Average Sediment Characteristics 128 20 Bulk Sediment Analysis 131 21 Elutriate Analysis 133 xxxix List of Tables Table No. Description Page 22 Charles River Water Quality Upstream of New Charles River Dam 134 23 Water Quality Summary - Tidal Portion of Charles River at North Washington Street Bridge 135 24 Sediment Quality Above New Charles River Dam 136 25 Sediment Quality Below New Charles River Dam 137 26 Saltwater Use in Boston Harbor 139 27 Federally Listed Endangered and Threatened Species in Massachusetts 142 28 Overall Comparison of Alternatives - Long-Term Transportation Effectiveness of Preferred Alternative 172 29 Average Weekday Daily Traffic (AWDT) 1982, 1990, 2010 - No-Build and Preferred Alternative 176 30 AM and PM Peak Hour Traffic Volumes for Links, Ramps, and Intersections Under the No-Build and Preferred Alternatives in 1982, 1990, and 2010 187 31 AM and PM Peak Hour Volume to Capacity (V/C) Ratios and Levels of Service (LOS) for Links, Ramps, and Intersections under the No-Build and Preferred Alternatives in 1982, 1990, and 2010 190 32 Level of Service Totals - Regional Highway Network 193 33 Regional Highway Network Level of Service 195 Summary Preferred vs. No-Build Alternatives 34 Number of Hours of Congested Operation 196 35 Level of Service Comparisons - South Boston Intersections 197 36 Level of Service Comparisons - East Boston/Revere Intersections (Incl. Bell Circle) 199 37 Level of Service Comparisons - Downtown Boston Intersections 200 38 Individual Queue Length Comparisons By Alternative 201 39 Future Regional Highway System Accident Summary 207 xl List of Tables Table No. Description Page 40 Future Local Roadway System Accident Summary 208 41 Existing Ramps Closed for a Period Longer Than One Month During Construction 216 42 Relocation Impacts 227 43 South Boston Land Use Impacts 242 44 North Station Area Land Use Impacts 254 45 Logan Airport Land Use Impacts 259 46 Direct and Indirect Impacts of Construction Expenditures on the Regional Economy 297 47 Total 24-Hour Emissions of Carbon Monoxide, Oxides of Nitrogen, and Nonmethane Hydrocarbons 304 48 Estimated Maximum One-Hour Carbon Monoxide Concentrations at Selected Receptor Locations 306 49 Estimated Maximum Eight-Hour Carbon Monoxide Concentrations at Selected Receptor Locations 308 50 Contributions of Toll Plaza Emissions to Maximum 8-Hour Carbon Monoxide and 1-Hour NO2 Concentra- tions for Various Analysis Years 310 51 Estimated Maximum One-Hour Carbon Monoxide Concentrations in the Various Tunnels 312 52 Estimated Maximum One-Hour Nitrogen Dioxide Concentrations in the Various Tunnels 314 53 Contributions of Ventilation Building Emissions on One-Hour Nitrogen Dioxide Concentrations 316 54 Effects of Ventilation Building Emissions on Maximum One-Hour Nitrogen Dioxide Concentrations in the Immediate Vicinity of the Vents 318 55 Receptors That May Be Affected by Noise from the Highway 328 56 Traffic Noise Summary Comparison of Alternatives, Without Noise Barriers, Year 2010 331 57 Benefit from Noise Barriers, for Sites Where Noise Barriers are Acoustically Feasible 334 58 Approximate Vibration Impact Distances 338 xli List of Tables Table No. Description Page 59 Potential Damage Effects of Construction Vibration 340 60 Residents Annoyed by Construction Vibration 340 61 Summary of Maximum Existing and Future Vibrations 343 62 Median Removal Efficiency of Primary Sedimentation 345 63 Existing Storm Water Quality in the Fort Point Channel 347 64 Future Water Quality in the Fort Point Channel 347 65 The Preferred Alternative Associated Contaminants 353 66 Maximum Concentration of Sediment-Associated Contaminants During Dredging for the Preferred Alternative 355 67 Comparison of Excavation, Dredging, and Disposal Requirements 363 68 Materials to be Excavated, Dredged, Reused, and Disposed 363 69 Summary Comparison by Alternative of Energy Consumption 403 70 Annual Equivalent Energy Consumed (BTU's) 404 xlii 1.0 INTRODUCTION 1.1 PURPOSE AND NEED FOR ACTION The proposed action, as de- scribed in detail in Section 2.2 and in Figure 3, consists of the following: (1) Construction of a widened and depressed Central Artery (1-93), from the Third Harbor Tunnel/Massachusetts Turnpike interchange to the Charles River/City Square area of Charlestown. (2) Construction of a four-lane Third Harbor Tunnel (1-90) from the Southeast Expressway and present terminus of the Massa- chusetts Turnpike Extension (1-90) at the Central Artery (1-93) in Boston, to Logan Airport and Route 1A in East Boston via the industrial area of South Boston and Boston Harbor . The need for the proposed action stems from the inability of the existing Central Artery and cross- harbor tunnels to accommodate both current and future traffic demands imposed on these regional facilities. These facilities, all constructed more than 25 years ago, were designed to handle projected traffic volumes that were approximately one half the present level. Three major improve- ments are addressed by the project: increased north-south highway capaci- ty; increased cross-harbor highway capacity; and improved access to the developing South Boston seaport area. The Central Artery was built in the early 1950s to serve as a "collec- tor-distributor" roadway whose design reflected the requirements of local- ly-oriented service, with many closely spaced on- and off -ramps. Given the design standards and service require- ments of its day, the road was consid- ered adequate for its local service function, providing access to and from the Central Business District. Over the past 30 years, the Central Artery has become part of a regional express- way system - specifically Interstate Route 93 - serving users both north and south of Boston. The Artery serves a distinctly regional function in the transportation system, while accommodating multiple traffic move- ments within a short distance which is considered inconsistent with modern Interstate design standards. Beyond the issue of design standards is the issue of present and projected traffic volumes in relation to capacity. While designed with the expectation of serving 75,000 vehicles per day, the facility now serves over 165,000 vehicles per day. The Central Artery is the most significant bottleneck in the regional highway system, causing millions of hours a year of user delay. It operates at or above capacity (i.e., traffic demand volumes equal or exceed the capacity of the roadway, resulting in congested operations) for up to eight hours a day. Congested conditions are due to several factors, including inadequate width; too many on- and off-ramps within a short distance creating weaving conditions and vehicle conflicts; and inadequate acceleration and deceleration lanes, which further add to vehicle con- flicts. The major source of signifi- cant queuing and delay during peak hours is the Charlestown High-Level Bridge. Because of congestion, motorists use alternative routes via local streets in South Boston and the South End to bypass traffic jams. Traffic congestion and queues also result in numerous accidents, and air and noise pollution. Today the Sumner and Callahan Tunnels operate at or above their capacity for five hours in the after- noon (1-6 PM) each weekday. The resulting congestion causes consider- able delays and queuing at both the Boston and East Boston approaches to the tunnels, hampers the passage of emergency (fire, police, ambulance) vehicles across the Harbor, causes 1 backups on the Central Artery, and encourages through traffic to attempt to short-cut the congestion on the expressway ramps to the tunnels by using local residential streets in East Boston. The Mystic-Tobin Bridge operates reasonably free of conges- tion, but cannot relieve the Callahan/ Sumner Tunnels problem because of the congested conditions of the Central Artery, particularly at the Charles River crossing. Traffic congestion on the Central Artery and the cross-harbor facilities, especially during peak commuter periods, attests to the need for significant highway transportation improvements. Traffic volumes (demand) on the regional highway network are projected to increase significantly by the year 2010 (design year), as a result of both regional and local development. Traffic on the Central Artery will increase by up to 10 percent, to approximately 175,000 vehicles on an average weekday. Traffic crossing Boston Harbor and the Mystic River will also increase by approximately 10 percent between 1982 and 2010 with the No-Build Alternative, to 170,000 vehicles on an average weekday. Traffic congestion and queuing will increase significantly on the Central Artery, the Mystic-Tobin Bridge, and in both existing tunnels. For the Callahan/Sumner Tunnels in particular, at-capacity or forced-flow conditions and resulting delays, queues, and backups onto the Central Artery will increase from five hours each commut- ing weekday in 1982 to 14 hours a day (generally from 6 AM to 8 PM) in 2010. On the Central Artery itself, traffic congestion and queuing will increase from up to 8 hours per day in 1982 to up to 13 hours per day in 2010. Congestion on these facilities will reach intolerable levels for travelers, residents, and businesses on both sides of the Harbor, further reinforcing the need for improvements in Central Artery and cross-harbor circulation and capacity to reduce such congestion. The purposes of widening and depressing the Central Artery are to: o eliminate the Charlestown High-Level Bridge bottleneck; o increase through capacity on the Central Artery; o improve through traffic/local traffic mix; and o result in safer operations on the ramp system. Traffic congestion on the Artery will be reduced from up to 13 hours per day in 2010 with the No- Build Alternative to 2 hours per dav with the Preferred Alternative. The project will also permit the development of a continuous surface arterial street system, and improve the expressway connections between Interstate Route 93 and the Sumner and Callahan Tunnels. Also, it will provide an opportunity to create approximately 20 acres of developable land above the highway facility. The purpose of the proposed Third Harbor Tunnel is to complete Interstate Route 90 in Massachusetts, and to provide needed additional vehicular harbor crossing capacity in Boston; it will significantly increase vehicular harbor crossing capacity. The Third Harbor Tunnel, in addition to the existing harbor crossings — the Callahan and Sumner Tunnels and the Mystic-Tobin Bridge — will satisfy vehicular harbor crossinq travel demands through the design year. The Third Harbor Tunnel will have a beneficial reroutinq, or diversionary effect on the existinq Callahan/Sumner Tunnels, reducinq potential year 2010 traffic on them by approximately 35 percent (from approx- imately 91,000 to approximately 60,000 vehicles per day). This 2010 traffic equals approximately 70 percent of the existing traffic of 83,000 vehicles per day in the two tunnels. During the peak hours, the 2 joject will reduce existing tunnel taffic by approximately 40 percent. ie 14 hours of at-or above-capacity, ( ngested operation anticipated daily i der No-Build conditions in 2010 will t reduced to 1 to 2 hours each day if « four-lane Third Harbor Tunnel is Instructed . The proposed action will also iprove access to the northern indus- trial area of South Boston. As jsscribed in the "Seaport Access ll'stem Study" completed in 1980 by the ;!)Ston Redevelopment Authority and the ijissachusetts Port Authority, there is I need to improve access to South jjston's rapidly growing northern Industrial area (generally north of Lrst Street) without increasing truck jraffic in South Boston's southern !:5sidential area. In 1979, approxi- mately 170,000 vehicle trips were made li an average weekday to and from puth Boston. Of these trips, 13,000 jere truck trips. According to that tudy, vehicle trips are expected to ncrease by 36 percent by the year 000 to 231,000 vehicles per day, with Iruck traffic accounting for nearly ,000 of the increase. Truck traffic rom this area of South Boston, herefore, is expected to grow by 54 iercent by the year 2000. A substan- tial percentage of these trucks will arry hazardous cargoes, primarily iuel oils. The proposed action provides a irect "Seaport Access" connection rom the expressway system to this rea of South Boston. A significant ortion of all vehicles, especially ruck traffic, will be removed from ocal residential streets in South oston. The combination of a direct eaport access route with a new Third arbor Tunnel to the Airport and Route A and with improved traffic service n the Central Artery will provide 'pportunities to resolve through/local raffic conflicts in South Boston. In tddition, exclusive bus ramps between >:he Third Harbor Tunnel, the Southeast Ixpressway, and the South Station "ransportation Center in Boston will .mprove bus/transit service on the regional highway system and orovide a direct transit link to the airline terminals at Logan Airport from South Station. In summarv, the propospd action will improve the flow of traffic on the Central Artery, on cross-harbor facilities, and on other regional highway facilities by increasing capacity on the Central Artery, increasing cross-harbor capacity, and providing improved connections and transit service between regional facilities and the local street system, the seaport area of South Boston, and Logan Airport. 1.2 GENERAL DESCRIPTION OF THE PROJECT AREA The project area (see Figure 1) has been generally defined to include those areas which may be directly affected by the proposed Third Harbor Tunnel/Central Artery proiect. It includes most of the central area of Boston, and extends from the existing Fitzgerald, or "Southeast," Expressway northerly along the Central Artery to the City Square area in Charlestown, and across Boston Harbor through Fast Boston, to Bell Circle in Revere. Major features of the project area are the following: H ighways : The Southeast Expressway and Central Artery (Inter- state Route 93) run north/south, intersecting the Massachusetts Turn- pike (Interstate Route 90) south of downtown Boston. Interstate Poute 93 continues north across the Charles River and interchanges with U.S Route 1, which diverges towards the north- east, crossing the Mystic River on the Mystic-Tobin Bridge. Interstate Poute 93 continues in a northerly direction through Somerville and beyond. The existing Callahan Tunnel (easthound) and Sumner Tunnel (westbound) lie under Boston Harbor, and connect t w, e Central Artery with the East Boston Expressway/State Route 1A, which continues northeast into Revere. 3 if ■ Mystic CHARLESTOWN CITY SQUARE DOWNTOWN H Mi "'V 1 1 few I #3 JOUTH BOSTON 11 sassmci mm » — Limits of Project Area Figure 1 Project Area o"^300™^80o" 3200 Feel O EIS/EIR for I-90 - Third Harbor Tunnel; I-93 - Central Artery Other Transportation Nodes ; South Station is located near the interchange of Interstate Route 90 and Interstate Route 93, in the Fort Point Channel area of Boston. It is a major rail terminus for Amtrak, Massachu- setts Bay Transportation Authority (MBTA) commuter rail, and intercity buses. MBTA rapid transit and bus lines criss-cross the area. Logan International Airport in East Boston has direct highway connections to the Callahan/Sumner Tunnels. It is the 13th busiest passenger airport in the world, and is the major air cargo terminal for southeastern New England. Water Bodies : The Charles and Mystic Rivers join to form Boston Harbor, with its major shipping channel serving the area's marine, commercial, industrial, military, and pleasure craft users. Fort Point Channel, which is approximately one mile long and of varying width (approx- imately 400 feet wide at its mid- point), empties into Boston Harbor north of the Northern Avenue Bridge. The Harbor and Channel are almost entirely bordered by piers and bulk- heads. Major Land Areas : On the Boston side of the harbor, the project area is situated in an industrial area between the residential neighborhoods of South Boston and the South End. South Boston is linked to the South- east Expressway, the Central Artery, and Boston by a series of bridges over railroad land and the Fort Point Channel. The northern half of South Boston is industrial and contains several major port facilities. The Boston side of Fort Point Channel includes Chinatown/South Cove, which is residential and institutional in character; the South Station and Leather District areas, which contain transportation, commercial, and industrial uses; the Boston Financial District; and the Waterfront, which is residential and commercial. Proceeding northerly along the Central Artery, the project area includes the Government Center, North End, North Station, West End, and City Square/Charlestown subareas of Boston, which include significant residential, office, and commercial uses. The project area on the East Boston side of the harbor includes a residential neighborhood, and indus- trial, railroad, and highway uses. The project area also includes part of Logan International Airport which occupies approximately 2,000 acres of land in East Boston. 1.3 MAJOR POLICY ISSUES During the circulation of the DEIS/DEIP and the SDEIS/SDEIP, several major policy issues were raised bv participants in the EIS process. This section of the FEIS/FEIP seeks to clarify both the policy context of the proposed action, and the consistency of the Preferred Alternative with those public policies. This section is organized into three categories: (1) Relationship Towards Regional Traffic; (2) Impact on Trip Makinq to Logan International Airport; and (3) Impact on Trip Making to Downtown Boston. Each of these subsections is organized to present the relevant policy of the Commonwealth; the conformance of the Preferred Alternative to that policy; and a discussion of those impacts associated with the project. Although not a major policy issue, a brief discussion of the traffic forecasting method and issues related to that method is also presented . 1.3.1 The Preferred Alternative and Regional Traffic Policy It is the policy of the Common- wealth's Executive Office of Transpor- tation and Construction, consistent with Federal Environmental Protection Agency policy, to minimize total Vehicle Miles of Travel (VMT) in the Boston region and to discourage the use of neighborhood streets for regional vehicular traffic. The 5 Preferred Alternative has been exam- ined in terms of its potential effect on increasing aggregate levels of vehicle travel. The Preferred Alter- native has also been analyzed in terms of potential diversion from public transportation, diversion of through trips into the area, and the possible creation of newly induced trips. This section deals with overall impacts in these areas, while sections 1.3.2 and 1.3.3, below, focus more specifically on trips to Logan Airport and downtown Boston. The alternatives were evaluated in terms of their conformance with the Commonwealth's transportation poli- cies. Minimized person hours of travel is a good "index" of the efficiency of a system, and its ability to provide "user benefit." Similarly, the Preferred Alternative will allow users to reduce their total travel time by more than 17 million person hours per year, which is the highest level of user benefit of any of the alternatives. The analysis, presented in Section 4.2 of this FEIS/FEIR, shows that each of the build alternatives can be expected to increase regional VMT somewhat. The Preferred Alternative is expected to increase the aggregate level of VMT for the region by less than 1/2 of one percent. The transportation analysis reported in Section 4.2 shows that the addition of a new tunnel is expected to have a greater propensity to "induce" new highway trips than the widening of the Central Artery. Alternative 6, "Artery-only", caused the lowest increase in VMT of the build alternatives tested. Because of its probable role in increasing regional VMT, the Preferred Alternative has been designed to include significant measures to mitigate against this impact. Specifically, the Preferred Alternative incorporates a series of Bus/HOV (high occupancy vehicle) lanes, particularly in the complex South Bay interchange area. These lanes will allow the provision of high quality public transportation services particularly to the South and to the East (Logan Airport). As discussed in Section 4.2.8, the Preferred Alternative has been designed to provide, or coordinate with other projects which provide, improved public transportation facilities. Diversion of Regional Traffic from Local Streets The Preferred Alternative will remove vehicles from local streets and arteries, diverting this traffic instead to properly designed regional highways. At present, the Central Artery is so congested that drivers who would logically use it now take elaborate by-pass routes onto local streets. The performance of the Preferred Alternative in this respect is significantly better than that of the other alternatives evaluated in the FEIS/FEIR. As is noted in Section 4.2, the Preferred Alternative significantly reduces traffic on most local streets in the network by diverting this traffic back onto the regional highway network. In the downtown and North End areas, future average weekday daily traffic (AWDT) volumes will be decreased significantly, as compared to the No-Build Alternative in the year 2010, on many local streets, including Commercial Street, Causeway Street, Atlantic Avenue, North Street, and Cross Street (see Table 29 in Section 4.2.2). In South Boston, the improved highway access and capacity will reduce traffic volumes significantly on Day Boulevard as it approaches L Street (used by South Shore commuters as an alternative to the Southeast Expressway) and on D Street, when compared with the No-Build Alternative. In East Boston, the Preferred Alternative will result in significant traffic volume reduc- tions on Porter Street, on Meridian Street, and on the Airport access road as it passes the East Boston Memorial Stadium. 6 Conversely, some local streets and intersections will receive in- creased traffic as a result of the project, as presented in Table 29 in Section 4.2.2. Traffic on Congress Street at the Fort Point Channel will increase as a result of its connection to the Seaport Access alignment. Local traffic on internal North End streets is not expected to be signifi- cantly different with either the No-Build or Preferred Alternative, as through traffic using North End streets (primarily Commercial Street) to avoid Central Artery congestion presently would be diverted back to the regional highway network. How- ever, future traffic volumes on Hanover Street will be increased from 5,300 vehicles per day (vpd) to 7,800 vpd in 2010, a 50 percent increase. Present plans allow for either a roadway or a pedestrian way linking the southbound surface arterial with the northbound arterial at Hanover Street. The ultimate decision to permit vehicles on this link will be determined with public input during the design phase. If vehicles are allowed on this link, then volumes on Hanover Street would probably be increased even more than indicated in Section 4.2, with a corresponding decrease on other North End internal streets. The project will not in- crease through trips into the North End. Traffic at Bell Circle in Revere is expected to increase slightly as a result of the project. Diversion of Regional Traffic into the Project Area A trip which has neither origin nor destination within the area defined by Route 128 should not be encouraged into the urban core area by major changes in the travel time characteristics on the highway net- work. To make highway improvements which are so major as to divert thousands of regional through trips into the downtown CBD is contrary to public policy and is not the intended purpose of the Preferred Alternative. The reconstructed Artery will not represent a high-speed, free-flowing alternative route that would divert traffic through distant parts of the region. Through-traffic diversions from Route 128 represent less than one percent of the volume on the Central Artery, at any given point. However, trips with at least one end within the Route 128 area are likely candidates for diversion back to the Central Artery. Regional Impact on Transit Ridership The Preferred Alternative includes highway facilities which will make possible an ambitious program to provide for a Downtown/Airport shuttle bus system, for direct, free-flowing bus service from airline gate to a new remote airport passenger information center to be built by the Commonwealth at the South Station Transportation Center. This improvement in Airport ground access was previously unattain- able. As part of the FEIS/FEIP, the Central Transportation Planning Staff (CTPS) prepared forecasts of the project's effects, with its improved travel times, on regional transit ridership. The details of these analyses are discussed in Section 4.2, and are documented in Appendix 3 - TRAFFIC . The analysis showed that if, as expected, the future amount of CBD parking is constrained (by a "cap" on parking supply), the Preferred Alternative would decrease regional public transportation ridership by less than one percent. If CBD parkinq is as readily available as it is today (relative to increased CBD employment) the analysis indicated that the project would reduce regional transit ridership by about 1.4 percent. As part of the Preferred Alternative, bus ramps from the South Station Transportation Center (SSTC) to the Third Harbor Tunnel, the Southeast Expressway, and the Massa- chusetts Turnpike are provided. These ramps will reduce the Preferred Alternative's effect on daily transit ridership loss. The ramps, in combination with transit service 7 improvements (not part of the project but made possible as a result of the project) which include: (1) institu- tion of shuttle bus service between the SSTC and Logan, and (2) increased frequencies of Airport express bus and Airport limousine services, will reduce the net regional transit ridership losses even further. In summary, the Preferred Alternative will have a small adverse effect on transit ridership in the region, if there were no changes in transit service. If transit services were also improved, the effect on transit ridership would be reduced further . Regional and Local Bus Service Improvements Along the Surface Artery between Essex and Kneeland Streets, an exclusive bus lane will be provided in coordination with the City's Dewey Square TSM improvements as part of the Commonwealth's larger commitment to improve the reliability of the suc- cessful Western Corridor express bus services. At the Charles River crossing, the Preferred Alternative will improve Northern Corridor express bus travel times by removing the High-Level Bridge bottleneck. From the North Shore Corridor, the project improves the possibility of new exclusive bus lane express service from Lynn to South Station and to the lower Financial District. The project will have signifi- cant indirect implications for transit services, as local downtown streets will experience major improvements in level of service, and reductions in traffic volumes on local streets critical to MBTA bus operations. Sources of Traffic on the Preferred Alternative This section has reviewed the possible impact of the Preferred Alternative on diversions from tran- sit, on diversions of through trips from outside Route 128, and on diver- sions from local streets. The results of this brief review suggest that as a result of the project: o Of the 330,000 daily vehicle trips assigned to the Artery and the Tunnels, less than one percent were generated as a result of diversion from transit; o Of the 263,000 daily vehicle trips assigned to the Artery, less than one percent have been diverted from Route 128 or beyond. o Of the additional vehicle trips assigned to the Artery, the overwhelm - ing majority have been diverted from local streets and arterials in the immediate core area. 1.3.2 Impact on Trip Making to Logan Airport Trips to Logan Airport - Policy Context It is the policy of the Common- wealth that, to the extent possible, trips to Logan Airport be made by high-occupancy vehicles. This is a strategy in which a major role must be played by: rail transit; bus transit; private bus (regional); intercity bus; vans and limousines; private car pools; and, taxis. Today, less than 15 percent of all travel to Logan is via public transportation, including bus, rail and limousine. The Common- wealth and the Massachusetts Port Authority have pursued this policy through increased promotion of shared cabs, limousines, and buses. Currently, approximately eight percent of Logan passengers arrive by bus or limousine (in addition to approximately six percent who arrive by bus from the Blue Line Station). Preliminary studies indicate that a concentrated program to make high- occupancy vehicles a major component of the ground access to the Airport holds much promise - if the new tunnel and roadway facilities are designed to provide the necessary priority access and right-of-way. 8 The Preferred Alternative reinforces this transportation stra- tegy by providing direct high- occupancy vehicle links from the regional highway network to the South Station Transportation Center and Logan Airport, and therefore supports the Commonwealth ' s program of creating remote airport passenger service centers. Airport-Related Traffic - Additional Vehicle Trips This FEIS/FEIR has concluded that construction of a new harbor tunnel will result in creation of more highway trips than would occur without the tunnel in the No-Build Alterna- tive. This conclusion was drawn after careful study of the present patterns of travel across Boston Harbor, with particular reference to traffic to and from Logan Airport. Travel data was examined for several periods, docu- menting that as traffic congestion became more of an impediment to access to the Airport, the average vehicle occupancy rate increased. Thus, for a given number of person-trips to the Airport, fewer vehicles are used in the No-Build Alternative than in the Preferred Alternative. With the No-Build Alternative, use of car pools, limousines, and other shared rides increased as compared to the Preferred Alternative. Thus, analysis included in the SDEIS/SDEIR showed that some 6,400 daily additional vehicle trips to, and 6,400 daily additional vehicle trips from (total 12,800 additional vehicle trips), Logan Airport were forecast to occur as the result of the construc- tion of a new Third Harbor Tunnel. The majority of these new vehicle trips represented diversions from other rubber tired vehicles, resulting in a lowered vehicle occupancy factor for the Airport as a whole. Transit Access to the Airport Travel forecasts show that implementation of the Preferred Alternative, including the direct ramps to South Station, will increase public transportation ridership to Logan over the No-Build Alternative. A program of direct shuttle bus to South Station, and improved bus/ limousine service, would increase public transportation use to Logan by about 20 percent. The effectiveness of transit improvements to serve cross-harbor travel demands and access to the Airport as an alternative to the proposed highway improvements has also been considered in this FEIS/FEIP (see Section 2.3 ALTERNATIVES CONST DFPED IN THE EIS PROCESS ) . The analysis addressed a Blue Line spur to the Airport, increased ferry service, and increased bus/limousine service. It was found that implementing the Blue Line spur and expanding the ferry service were not as effective as a strategy to improve access by high-occupancy rubber-tired vehicles alone . Relationship to Airport Growth Studies clearlv indicate that the rate of growth of airport activitv is determined principally by powerful regional and national economic forces, and any correlation with the quality of auto access seems weak. Transpor- tation analysts believe that as auto-access conditions deteriorate, the result is a "spreading of the peak" in which more time is allocated by the user to the task of getting to the airport. The number of hours of peak period congestion conditions subsequently grows, and the traveler plans his/her time accordingly. In short, there is no evidence that failure to improve highway access represents a meaningful strateqy to limit airport activity growth, if this is the desired action. However, there is ample evi- dence that failure to deal with problems of auto access contributes directly to the worsening of affected neighborhood environments. As highway access conditions get worse, drivers increase their use of local residen- tial streets to "by-pass" the con- 9 gested highways. Public policy actions will have to deal directly with this problem, to ensure that airport (regional) related environ- mental problems do not occur on residential streets. Land Use Impacts of increased Vehicle Trips Activity at Logan Airport will continue to grow with or without improved highway access. Therefore, it is critical that land use impacts such as intrusion of airport-related activities into adjacent residential neighborhoods be dealt with immediate- ly by appropriate public bodies. A program to review the impact of zoning and other land use control mechanisms, including various de facto licensing functions of Massport, and the cre- ation by Massport of off-Airport industrial parks in appropriately zoned areas, will be undertaken immediately by the Commonwealth as one element of a total program of mitiga- tion. 1.3.3 Effect of the Project on Trips to Downtown It is the policy of the Common- wealth to serve downtown Boston primar- ily by public transportation. This is a commitment shared by the MBTA, the MDPW, and Massport, each of which is directly involved in providing mass transportation services. Public transportation must remain the primary method for indi- vidual access to downtown Boston, making possible the use of the re- gion's highway system for those whose trips cannot be well served by public transportation. For example, goods movement and passenger trips with neither origin nor destination in the transit-rich core area are dependent upon adequate highway access. This FEIS/FEIR indicates that the Preferred Alternative will not have a significant effect on transit ridership (see Section 4.2.8 OTHER TRANSPORTATION FACILITIES). Past studies and research by others have shown that changes in public transportation ridership are best explained as a function of the quality and price of that service and the socio-economic characteristics of its ridership rather than by changes in the quality of the highway system. Impact on Transit Service for Trips to Downtown The Preferred Alternative should serve to improve the quality of transit service to downtown. At several key bottleneck locations presently impeding MBTA bus service, the Preferred Alternative will provide for significant reductions of traffic congestion, when compared with the No-Build Alternative. Locations such as Keany Square at the Charlestown (North Washington Street) Bridge, and Dewey Square at South Station, will experience significant decreases in roadway traffic volumes due to the project. Along the Surface Artery, between Essex and Kneeland Streets, the project will help to make possible a new MBTA express bus lane to serve the Western Corridor express bus system; the project includes a new express bus lane for bus service from the South Shore, with direct connec- tions to the new South Station Trans- portation Center. All of these traffic improvements should improve the quality and reliablity of transit service to the downtown. Increase in Vehicle Trips The possible impact of the project on increasing highway trips to downtown Boston has been reviewed. Based on discussions with the Boston Redevelopment Authority and other responsible organizations, it has been reaffirmed that the absolute number of vehicle trips made to the downtown area in the design year will be a direct function of the number of downtown parking spaces available and the pricing policies in force at that time and thus, not significantly affected by improvements in highway travel times. 10 It can reasonably be assumed that the improvement in highway travel time will cause some diversion from transit to car-pools, and other high occupancy vehicle situations, even though the number of vehicles parked downtown is held constant. A possible impact of the proposed highway improvement could be increasing the length of the fixed number of trips to the downtown area. Transportation analysts concur that this sort of alteration of tripmaking does occur as the result of major improvements to the highway network. However, this phenomenon would have no effect on the accuracy of highway traffic projections within the study area. It is expected that the pro- posed project would produce a minute effect on increasing the number of through trips, but would have no effect on the number of trips with origins or destinations in the down- town area. 1.3.4 Traffic Forecasting Methodology In order to calculate the value and distribution of benefits and costs of a transportation improvement, it is first necessary to predict the change in traffic which will result from any proposed transportation improvement. The calculation of traffic flows, or change in flows, is determined by the traffic forecasting process. Section 4.2.5 details strengths and weaknesses of the forecasting process, including a discussion on induced trips, use of a fixed trip table, traffic fore- casting and Logan Airport, and the relationship of traffic and land use forecasts. After review of the forecasting process and related assumptions, it is concluded that the process is totally adequate to support and clarify the decision to select a Preferred Alternative. 1.4 MAJOR UNRESOLVED ISSUES Many of the environmental issues raised during review of the SDEIS/SDEIR have been addressed during the development and refinement of the Preferred Alternative. Some of the major issues which will need addition- al attention and resolution during th< preliminary engineering design phase are summarized below. 1.4.1 Air-Rights Joint Development The SDEIS/SDEIP presented preliminary concepts for the develop- ment of the approximately 20 acres that will be created above the de- pressed Central Artery. Analysis of the Preferred Alternative in the FEIS/FEIR has stressed both the content of the joint development and the public planning process. The development potential of each parcel has been examined with respect to use building massing, subsurface structur al requirements and relationship to surrounding areas. These concepts ar presented as a starting point for the next steps in the process. This FEIS/FEIR presents propos als for the planning process itself. Major emphasis is placed on a communi ty-based task force approach to the planning of specific subareas. The Commonwealth recognizes its responsi- bility to assure the participation of community representatives, selected public agencies, and private organiza tions, and to establish financing mechanisms for developers to provide for any necessary additional founda- tion support at the time of tunnel construction. These important considerations are described in greater detail in Section 4.4.4 Joint Development . 1.4.2 North Station/Charles River Basin This area is the focus of proposals by several public agencies and private property owners. Between the old and new Metropolitan District Commission (MDC) dams, current Boston Redevelopment Authority (BRA) pro- posals for redevelopment of the area are not consistent with MDC proposals for extension of Charles River Reservation pedestrian walkways 11 along the River's edge. BRA and MDC proposals are conceptual at this time. The MDC has not yet received appropriations to purchase or improve the River banks according to its proposals, while the BRA is focusing its attentions on the Causeway Street/ Lomasney Way area of its Urban Renewal Project. Inconsistencies between these agency proposals have to be resolved before the impacts of the Preferred Alternative can be estab- lished and specific mitigation mea- sures incorporated into the project. 1.4.3 Ventilation of Tunnel Sections Analysis of the air quality impacts of the exhausts from tunnel ventilation buildings at many of the ventilation building locations indi- cates that there will be a serious violation of the Massachusetts DEQE, but not of Federal, NO 2 emisssion standards. The Commonwealth is committed to refining the proposed ventilation system and performing additional air quality analysis to assure conformance with the NO2 policy level. Preliminary analysis suggests that mitigation measures can be developed to overcome these viola- tions. Mitigation measures will be studied for all Central Artery/Third Harbor Tunnel ventilation buildings exceeding the State's policy level for NO 2 , including the ventilation buildings near the Harbor Towers, at the Callahan Tunnel portal, and Causeway Street. Possible mitigation measures include increasing the height of ventilation exhausts to be further from the air intakes and operable windows of existing nearby buildings; increasing the number of ventilation buildings to decrease the length of tunnel ventilated by each building, and achieving a more diffuse source of NO2 ; increasing the mechanical ventilation equipment in the ventila- tion buildings; etc. These and other measures to minimize NO2 emission impacts will be studied and resolved during prelim- inary engineering design based on extensive continued coordination with DEQE and EPA air quality staffs; coordination with decisions about joint development of air-rights will also take place at that time. 1.4.4 Dredged and Excavated Material Disposal Specific locations for disposal of excavated and dredged materials have not been determined, although both potential land and ocean sites have been identified. During prelimi- nary design, when the quantity and quality of this material is better known, specific sites will be analyzed and additional environmental documen- tation will be prepared as necessary. See Section 4.13 DREDGED AND EXCAVATED MATERIAL DISPOSAL for further detail on this subject. 1.4.5 Other Issues In addition to the aforemen- tioned major unresolved issues, other construction period impacts must also be evaluated in greater detail, and mitigating measures developed. For example, construction-period traffic detours, and the resulting effects on traffic operations, air quality, etc., have not been fully analyzed. These routes will be developed further during the design phase, and addi- tional traffic and air impact analvses will be prepared. Other issues have been specif- ically identified as requiring addi- tional engineering and environmental study during preliminary design to further identify and mitigate, if possible, adverse impacts. These issues are as follows: fabrication site (if applicable); parking impacts; Phase II Archaeological Survey and final mitigation details; construction staging and sequencing; and relocation impacts. Many of these issues are discussed to the extent possible based on the present level of design, in Chapter 4.0 ENVIRONMENTAL CONSEQUENCES Of this FEIS/FEIR. 12 2.0 DESCRIPTION OF ALTERNATIVES 2.1 GENERAL The following sections describe the Preferred Alternative and reasons for its selection; alternatives con- sidered during the Environmental Im- pact Statement/Environmental Impact Report (EIS/EIR) process; reasons for the Commonwealth's rejection of all alternatives other than the Preferred Alternative; and a discussion of the various considerations affecting the alignment of the Preferred Alterna- tive. It is organized as follows: o Preferred Alternative; o Alternatives Considered in the EIS/EIR Process; o Effectiveness of the EIS/EIR Alternatives in Achieving the Commonwealth's Transportation Objectives; and, o Design Considerations for the Preferred Alternative. 2.2 PREFERRED ALTERNATIVE As a result of the extensive public input received during the pub- lic review and comment period on the SDEIS/SDEIR, and a review of the en- vironmental impacts of all alterna- tives evaluated, the Commonwealth of Massachusetts has selected Alternative 5A Modified (depressed and widened Central Artery plus the Seaport Access Alignment Third Harbor Tunnel) as the Preferred Alternative. During the public review and comment period on the SDEIS/SDEIR, five formal, public informational meetings were held in the various neighborhoods directly affected by the project (South End/Chinatown, South Boston, East Boston, North End, Water- front), in addition to many meetings with citizen groups. The purpose of these informational meetings was to present the alternatives being con- sidered and discuss the concerns of area residents, businesspersons, public officials, and civic leaders. Two 12-hour public hearings were held at Faneuil Hall. During the public hearings, more than 100 individuals presented testimony on the project, with the majority of those attending voicing support for the Alternative 5A Modi- fied concept. The Public Hearing Transcript, along with a synopsis of the testimony and responses to verbal comments, has been published as a separate volume to this FEIS/FEIR. Following the public hearings, local elected officials in the area, including the (former) Mayor of the City of Boston, also endorsed the Alternative 5A Modified concept. The Metropolitan Planning Organization for the Boston area, which includes representatives from the Massachusetts Port Authority, Massachusetts Bay Transportation Authority, Metropolitan Area Planning Council, and others, has also endorsed the project (see COM - MENTS AND COORDINATION , Exhibit A). In response to the many com- ments received, the Preferred Alterna- tive incorporates further modifica- tions than those identified in the SDEIS/SDEIR as the Alternative 5A Design Modifications. Several of these modifications include: elimina- tion of a Third Harbor Tunnel exit directly to Albany Street and inclu- sion of the Herald Street Extension; inclusion of bus/high occupancy vehicles lanes and ramps to the South Station Transportation Center; and improved access, both northbound and southbound, from the Financial Dis- trict/Dewey Square area by ramp changes in the Dewey Square Tunnel. The basis for these and other addi- tional refinements are discussed in Section 2.5.1 Derivation of the Preferred Alternative . 2.2.1 Description The Preferred Alternative increases traffic capacity on the Central Artery (north-south) by widening the existing facility (total 13 length approximately 3.0 miles). Cross-harbor capacity (east-west) is increased by construction of a Third Harbor Tunnel through South Boston linking the Massachusetts Turnpike/ Central Artery interchange in Boston with Bird Island Flats, Logan Airport, and Route 1A in East Boston (total length approximately 3.9 miles). The project extends from a point on the Central Artery just north of the Southeast Exp res sway /Massachusetts Avenue interchange to a point on Interstate Route 93 in Charlestown approximately 700 feet north of the Gilmore Bridge; and from the Massa- chusetts Turnpike/Central Artery interchange to a point on Route 1A in East Boston in the vicinity of Pres- cott Street, via South Boston, Boston Harbor, and Logan Airport. The Third Harbor Tunnel alignment is also called the Seaport Access Alignment because it provides direct access to and from the regional highway system and the northern "seaport" sector of South Boston. Figure 2 presents possible typical sections of the depressed Central Artery and the Third Harbor Tunnel (not included, but also a possibility, is a binocular steel tunnel for the cross harbor sunken tube). Figure 3 presents an overview of the proposed Preferred Alternative alignment. Figures 3A through 3E present more detailed plans of the Preferred Alternative. A description of the Preferred Alternative by subarea follows. The description begins in the South Bay/Fort Point Channel area of the project, proceeding northerly with the Central Artery portion of the proj- ect. After completing the Central Artery description, the discussion returns to the South Boston area and proceeds across the Harbor with the Third Harbor Tunnel description. South Bay/Fort Point Channel Area In the southernmost section of the project, the Preferred Alternative meets the Southeast Expressway Upgrad- ing project in the vicinity of the Massachusetts Avenue interchange (see Figure 3A). A major interchange with the Massachusetts Turnpike/Central Artery/Southeast Expressway/Seaport Access Tunnel is provided, including a special purpose, two-lane, two-way bus/high occupancy vehicle (HOV) roadway located between the northbound and southbound Central Artery road- ways, and bus ramps to/from the Third Harbor Tunnel. The HOV roadway and bus ramps will enter the bus station level of the South Station Transporta- tion Center, and will provide exclu- sive bus transit links between Logan Airport, South Station, and points south and west of the City. In the vicinity of this inter- change, the northbound Central Artery roadway diverges towards the east from the existing northbound roadway, passes over the West Fourth Street Bridge, and then descends into a tunnel which passes under a new Herald Street Extension Bridge and Wye Connector. Within the tunnel, the roadway splits, with the Seaport Access tunnel diverging to the right and the Central Artery northbound tunnel to the left. Near the southern end of the South Postal Annex and within the Fort Point Channel, the Central Artery tunnel also merges with a tunnel from the Massachusetts Turnpike and from Frontage Road. This four-lane tunnel is located below the bottom and along the west edge of the Channel as it passes opposite the Gillette Company plant in South Boston. This tunnel will carry all northbound Central Artery traffic. Five of the six lanes of the Dewey Square Tunnel will carry southbound Central Artery traffic; one lane will be used by the Lincoln Street and South Street ramps. The Seaport Access tunnel (two-way, four-lanes plus weaving lanes) crosses the south end of the Fort Point Channel. The profile is set so the top of the tunnel box is near the bottom of the existing Channel. This tunnel crosses over the MBTA Red Line tunnel and the Central Artery northbound tunnel. Surface roadways are to be 14 1. Concrete Cross Harbor Tunnel r MEAN LOW WATER (EL i 84| M'-O" j ll. VARIES .I 3 .?!. W'-O 2. Steel Cross Harbor Tunnel 2 -0 OVERDREDGING ALLOWANCE L MEAN LOW WATER (EL — 4 84) cc < < I i u - EXISTING HARBOR BOTTOM ■ METAL SHELL 5 -0' STONE COVER 26 -0 RDWY 1-0 SHLDR (TYP) - PGL- FRESH AIR DUCT 3 2/-0' 3'-0" 1 2 -0' FOUNDATION MAT FIRE DOOR 250 OC 7 % O^PGL 20 q O [ 3. Depressed Central Artery OPTIONAL TIE-BACKS (TYPICAL) ^ H ^ GUIDE WALLS GROUND SURFACE "I | EXHAUST || | [~ "l l EXHAUST H i f ROADWAY (VARIES 50 -62 ) ROADWAY (VARIES 50' - 62 ) ~l l FRESHAIR | f "l l FRESH AIR || |f ~1 I 2 FOU^p/TONMAT 50-0"MIN -62 -0 MAX -777 ■■■ 777 ~^7 777~ 56 -0 MIN-68 -0 MAX .EQUALIZER PIPES ATELEV 0-5 - SLURRY WALL • TOP SLAB TO BE rt Point Channel crossing and rovides a high quality design for nproving access to and through the juth Boston industrial seaport area. : does not permanently alter existing 1| jadway circulation patterns in this icea. This profile also allows access "'?jpross the highway alignment by tacking over the depressed highway at ^elected locations. This alternative llso allows (and enhances) future jevelopment on remaining parcels in [he area by covering the majority of !f jhe highway facilities in this area, jhe extent of decking should be tinally determined during the design hase, when refinements to the design nd the tunnel ventilation system are erf ormed . Hazardous Cargoes In order to provide direct ccess from the Massachusetts Turnpike xtension and Southeast Expressway to iouth Boston for trucks carrying azardous cargoes (including fuel oil :rucks from the White Fuel/Castle island Terminal area), uncovered iections of roadway have been provided .n the South Bay area and the Fort 'oint Channel area. The openings Limit the closed tunnel segments to (approximately 1400 feet long for this purpose. In addition to the spacing [for openings in the tunnel, based on Conversations with Boston Fire Depart- ment and South Boston representatives, i:he following will also be included in i:he Seaport Access tunnel design: fleluge pumps (multi-fire sprinkler), automatic foamite dispenser system, 'refractory tiles, and appropriately- spaced emergency evacuation shafts, lit has been assumed that approvals tfould be obtained for hazardous cargo /ehicle use of this tunnel, because alternative routings would use inap- propriate local streets, thus increas- ing the potential for serious acci- dents occurring on the alternative surface routing. General Ship Drydock and Boston Marine Industrial Park 1 and 5 were rejected because of unacceptable access connections to the waterfront area. The Preferred Alternative permits access to Congress Street and Northern Avenue, and provides improved access to Logan Airport, Boston's Financial District, and the South Boston seaport area. This alternative profile provides a minimum of 7 feet of clearance below the (future) 45-foot deep main ship- ping channel of Boston Harbor. An alignment to the east of the Preferred Alternative, running through the rock fill dike of the BMIP land fill, was originally considered. It was eliminated due to the potential major adverse impacts on BMIP (dis- placing Buildings 17, 19, and 53) and the significant additional cost of removing and replacing the rock fill dike and providing a temporary sheet pile wall along the tunnel to contain the miscellaneous embankment material in the land fill. Another alignment located in the land fill east of the rock dike, while desirable from an excavation standpoint, resulted in additional property taking problems and was also rejected. The buildings that would have been taken included the Leonard Silver Company Building #19; Building #53, a support facility for the General Ship Company; and Building #39, a power plant required for the General Ship Drydock. This alignment required a large portion of land from the Economic Development and Indus- trial Corporation (EDIC). The land is used for buildings, storage, and parking, and is not replaceable within the immediate area. Harbor Crossing Two profiles were investigated for the Third Harbor Tunnel crossing under Boston Harbor: a shallow, sunken tube (high profile) tunnel, and a deep bore tunnel (low profile). The sunken tube tunnel (either reinforced concrete or steel) will consist of two parallel roadways in a 28-foot high by 88- to 98-foot wide (approximately) Tunnel alignments between Piers 47 prefabricated structure. The tunnel will have a protective stone cover and the top of the structure will be at a minimum of 7 feet below the proposed 45-foot deep shipping channel in Boston Harbor. The deep bore tunnel would consist of twin 38-foot diameter steel tubes with a minimum cover of one tube diameter. The deep bore tunnel is not feasible due to existing soil condi- tions; construction problems; and unacceptable highway design aspects, including significant speed reductions. By comparison with bored tunnel methods for this project, the sunken tube method is significantly less complex. It also involves less risk of costly delays due to construction problems. Provisions for maintaining nearly continuous shipping and other navigation in Boston Harbor can be made with the sunken tube construction method . It is conceivable that the tunnel could be constructed without having to close more than half of the 1200-foot shipping channel at any time. However, due to the precision required in placing (sinking) the tunnel sections and possible safety problems, the channel should be closed to navigation during this operation, which could be completed in approxi- mately one day per tunnel section. There will be continued coordination of this construction process with the Coast Guard and the Harbormaster. Tunnel Utilities Tunnels for this alternative will contain no hazardous transmission mains or pipelines that could create a hazard to vehicle drivers in the event of a break or rupture. The tunnels will contain deluge pumps, water lines, and foamite dispensers for fire protection as well as drainage lines and other pumps. Lighting, ventila- tion, T.V. monitoring and communica- tions facilities will be provided. The tunnel will have safety walks located on both sides of the roadways; emergency access points will be provided where appropriate, except f>: the Third Harbor Tunnel itself, when access will be from the mainline and ramp portals. Because of the addi- tional property acquisition/displace ment requirements, as well as addi- tional environmental impacts and cos 3 associated with provision of breakdo'i lanes in the new tunnels, breakdown lanes are not provided in the Centra" Artery or the Seaport Access/Third Harbor Tunnel. Central Area Split Surface Artery The northbound and southbound surface arterial roadway was initial/ considered as a single roadway. However, in order to improve traffic operations at critical intersections and to create additional parcels of land for future development, a desir of the City of Boston, the northboun and southbound roadways were sepa- rated. Continuous circulation from Atlantic Avenue to Causeway Street i provided by the Preferred Alternativ, Central Artery-Alignment In the Central Area, the Preferred Alternative was aligned to minimize land takings, underpinning impacts and demolition of buildings. Some of the design constraints along the Central Artery (see Figure 5), which are discussed in more detail i Chapter 3.0 of this report are: proposed Fort Hill development locat on Purchase Street; BRA Parcel D-10 (Marketplace Center), located betwee State Street and Commercial Street; Quincy Market, located on Commercial Street and Clinton Street; the North End residential neighborhood and shopping area; the MBTA Orange Line Tunnel, located between New Chardon and Causeway Streets; the existing Dewey Square Tunnel; and the future corridor for the Purchase Street off-ramp. Avoiding these properties while tying into the existing highwa; facilities at either end of the Central Artery corridor, essentially fixed the depressed Central Artery alignment . While initially the conceptual jlsign of the Central Artery south- :und, in the vicinity of the historic tyincy Market area, had a proposed ;00-foot radius horizontal curve with s:to- foot wide safety walks on the ijght side. This alignment resulted reduced horizontal signt distance, ijjjfour-foot walk was provided on the :ft side. As the alignment continued .uth and entered the Dewey Square innel, the horizontal radius would lain reduce the drivers' sight dis- tnce. This condition occurred again >wards the southerly end of the Dewey [uare tunnel as the alignment curved > the left. Figure 6 presents the fifect of designing the Central Artery 1 this area to meet the AASHTO stan- irds and adequate stopping sight dis- ance for a 50 mph design speed, when continuous 1500-foot radius is pro- •lided. With this design, the follow- iig additional buildings would be Ef ected: Marriot Long Wharf Hotel; i MBTA Blue Line Aquarium Station and emergency evacuation facil- ities; New England Telepnone Co. Building ; Harbor Towers Parking Garage; and Harbor Towers. Because of these potential dis- lacements, this possible realignment as been rejected. However, ongoing esign refinements at a larger engi- eering scale has allowed the proposed 'entral Artery alignment to be revised n the Quincy Market area such that a U mph design speed and adequate stop- ping signt distance can be achieved 'ithout displacing the buildings men- :ioned above. It will be the MDPW >olicy to provide sight distances i/hich conform to AASHTO standards /hile maintaining existing and pro- posed development in this area. AASHTO standards also establish a minimum vertical clearance of 16 feet 6 inches to obstructions above the roadway (such as to bridges, over- head signs, etc.). Because vertical clearances of the existing facilities are 14 feet 6 inches or less (Dewey Square Tunnel: 14*6"; Sumner and Cal- lahan Tunnels: 13 '8"; Massachusetts Turnpike Extension: 14'3"), the design of this project has a minimum vertical clearance of 14 feet 6 inches. The actual clearance to the tunnel ceil- ings has been set at 16 feet 6 inches, thus allowing overhead signs to be 2 feet high. During the design phase, if signs larger than two feet high are required, the roof of the tunnel box can be modified in the vicinity of the sign to allow for the increased height. Central Artery-Profile Consideration was given to a "high" profile crossing over the MBTA Blue Line tunnel at State Street and a "low" profile beneath it. The Blue Line tunnel is underlain by silty clays below which is glacial till. Tunneling within the soils below the tunnel poses substantial risk related to detrimental settlement of the sub- way tunnel structure. The problem is particularly severe given the width of the depressed Central Artery struc- ture. Because of these potential risks, and the possibility of signifi- cant disruption to Blue Line transit service, a "high" profile over the Blue Line tunnel is proposed. In or- der to protect the Blue Line tunnel during construction of the Central Artery project, extensive and expen- sive measures must be taken. These measures are discussed in the Support - ive Engineering Report in detail (Chapter 5.0). They include, among others: Blue Line Tunnel reinforce- ment; placement of piles on either side of the Blue Line tunnel and span- ning over the tunnel with the Central Artery structures; and placement of granular cushion material between the structures . 49 1 Fort Hill Development Area 2 BRA Parcel D- 10 3 Quincy Market 4 North End 5 MBTA Orange Line Tunnel 6 Dewey Square Tunnel 7 Purchase St. Off-ramp (proposed) Figure 5 Properties Controlling Central Artery Alignment © 0 550 '100 Feel EIS/EIR for I-90 -Third Harbor Tunnel; I-93 - Central Artery Figure 6 Effect of AASHTO Standards on Existing Development - Central Area Preferred Alternative Alignment with AASHTO _ Standards HH Affected Properties 0 200 400 Feet EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93 - Central Artery North of Causeway Street Storrow Drive Ramps to and from the Depressed Central Artery The existing ramp connections to and from storrow Drive and the Cen- tral Artery are made through a double-decked viaduct ramp system, located to the north of Boston Garden and above the MBTA's commuter rail tracks at North Station. New connec- tions from Storrow Drive to the south- bound Central Artery, and from the northbound Central Artery to Storrow Drive, are proposed to cross under the MBTA tracks. Ramp grades would be excessive (9-10 percent) if overhead crossings were used. Other alignments for these ramps were studied in the Nashua Street and the Spaulding Rehabilita- tion Hospital area. However, since the connection from Storrow Drive to the Central Artery southbound is pro- posed to take place at-grade from Leverett Circle in order to reduce the potential for increasing traffic on Storrow Drive and Back Bay residential streets, the location of the connec- tors was changed to the present loca- tion to achieve a more acceptable hor- izontal alignment and to be compatible with proposed MBTA Green Line reloca- tion plans. Further refinement to the design will occur during later stages of the project to resolve conflicts with BRA and MDC plans for this area. It now appears that design modifica- tions to be made during preliminary design to minimize impacts to the Charles River's edge may change this alignment. Leverett Circle Connections to and from Mystic-Tobin Bridge and Interstate Route 93 Leverett Circle tunnel connec- tions passing under the Charles River to and from the Mystic-Tobin Bridge and Interstate Route y3 in Charlestown were considered, as presented in the MDPW 1981 "Leverett Circle Connection - Feasibility Study." Those connec- tions replaced the existing Leverett Circle rotary with a signalized "T" :i intersection; provided a direct cc nection between the Mystic-Tobin Bridge and Storrow Drive; and elin nated the weaving section on the High-Level Bridge. The Leverett Circle tunnel connections were oppst by residents of the West End and Bj Bay because of the anticipated trafl increase on Storrow Drive (greater than 11 percent over future withou the Leverett Circle Connections). Since Leverett Circle presently lii the amount of traffic which can pa through the area, replacement of ti facility with improved tunnel conn:-' tions would attract increased trafic volumes onto Storrow Drive and thrjgl the West End and Back Bay residents areas. These connectors also woul result in permanent displacement o Section 4(f) parklands of the Charlf River Basin, and because of the tr verse crossing of the navigation c nel, construction activities would severely disrupt navigation in the Charles River. These connections » subsequently rejected by the MDPW favor of the ramps provided with t Preferred Alternative. Hi ili'i Stlf tanf Ramps to Interstate Route 9 Charlestown and the Mystic-Tobin Bridge were also studied in the sa*|" corridor as the proposed connector tunnels to the depressed Central Artery. This location would requi:' structurally infeasible long-span B 5 "-'' 1 truss with a sharp horizontal curv | •"• over the Charles River. The requi;-' ment for a truss is to avoid places* - ; of bridge piers in the navigation l&n channel. This option was therefor h. rejected. mi An option was also studied which placed the aforementioned rau between the Spaulding Rehabilitate Hospital and Nashua Street, beginnps::: as a tunnel near Leverett Circle, cending and bridging over MBTA rai road tracks at North Station and jl ing the new bridges over the Charl River. This option produced unacct able horizontal and vertical align ments (grades were approximately H percent). Because of the poor geo metrics this option was rejected, t now appears that design modificati<= 52 o be made during preliminary design |o minimize impacts to the Charles iver's edge may change this alignment. Causeway Street Off-Ramp Access from the Central Artery outhbound to Government Center is urrently provided via a ramp to New :hardon Street near the Government Renter Parking Garage. Replacement of this ramp while .voiding residential displacements is iot feasible because of insufficient i'idth between the depressed Central krtery and the existing MBTA Orange ,ine tunnel. If this ramp were to be provided, approximately 10 residences [ind 3 businesses in the North End neighborhood would be displaced. Central Artery-Profile The profile of the Central Ar- tery, as it emerges from the tunnel at [Causeway Street, rises at a +6 percent jradient to cross over the shipping :hannel of the Charles River (with a iiiinimum clearance of 30 feet). Al- :hough this profile grade is accept- able from a "design standards" per- spective, the length of the grade re- sults in speed reductions of approxi- mately 37 mph. The Causeway Street )n-ramp also merges with the north- bound Central Artery traffic in this area, compounding the effect of the steep grade on operations. Further refinements to the profile of the Cen- tral Artery will be evaluated during :he design stage to improve upon the operational aspects of this facility. Design modifications to be made during preliminary design will improve the ijrade from 6 percent to less than 5 percent . | 5ast Boston/Logan Airport Area Airport Alignment The original Jeffries Cove op- tions at Logan Airport curtailed existing boating and recreation activ- ities and detracted from the Cove's aesthetic qualities during construc- tion. It was also strongly opposed by the Jeffries Point residential commun- ity. Several other considerations also made the present alignment through Bird Island Flats (BIF) more desirable. o The ventilation building will be placed furthest from the community, on the shoreline of BIF; o Alignment avoids impact to the proposed BIF park, and elimi- nates permanent long-term im- pacts at East Boston Memorial Stadium. o The toll plaza will not be lo- cated in East Boston or at the Airport. o The alignment improves traffic movements at the Airport by allowing the Airport access and egress roads to pass under the Cross Road instead of inter- secting at-grade. 53 3.0 AFFECTED ENVIRONMENT 3.1 TRANSPORTATION FACILITIES 3.1.1 Existing Roadway Characteristics Affected Roadway Network The affected roadway network is presented on Figure 7. The major facilities crossing the harbor include the Mystic-Tobin Bridge (U.S. Route 1) and the Callahan/Sumner Tunnels (State Route 1A), which serve communities north and northeast of Boston. Both the tunnels and the bridge connect with north-south Interstate Route 93, which includes both the Central Artery and the Southeast Expressway to the south. Interstate Route 90 (Massachusetts Turnpike) and Storrow Drive provide major east-west connections between the Central Artery and communities to the west. In addition to the major roadway network, traffic conditions on 54 existing highway links and 54 key at-grade intersections are identified and evaluated . Hazardous Cargo Routes Vehicles carrying hazardous cargoes are prohibited from using the Callahan and Sumner Tunnels, and the Dewey Square Tunnel portion of the Central Artery. Because of this restriction, a number of alternative routings for such vehicles exist. Vehicles carrying hazardous cargo between East Boston or Revere and Boston presently use the Mystic-Tobin Bridge instead of the Callahan and Sumner Tunnels to cross Boston Harbor. To avoid the Dewey Square Tunnel, these vehicles use surface streets such as High Street, Purchase Street, Atlantic Avenue, Surface Artery, and Kneeland Street. In South Boston, heavy trucks are forced to use congested local residential streets to get to the industrial area generally north of First Street, because of weight restrictions on a number of bridges linking the area to the regional highway network. The designated truck route from the regional network consists of Southampton Street; Dorchester Avenue; Broadway from the Central Artery to C Street; A Street from Dorchester Avenue to West Seconc Street; West Second Street from B Street to Broadway Station; and East and West First Streets. All streets north of East and West First Streets in the northern industrial area are also accessible to truck traffic and are therefore part of the truck rout<, Existing Traffic Volumes Table 1 presents a summary oflj existing (1982) and future (1990 and HI 2010) Average Weekday Daily Traffic (AWDT) volumes and truck percentages for key major highways and city streets . It is evident from Table 1 th<: the Central Artery and Southeast Expressway carry the heaviest traffic^! volumes in the study area, with AWDT s ranging between 142,100 and 166,200 vehicles per day (vpd) between the I-93/Mystic-Tobin Bridge merge on thai Central Artery and the Columbia Road interchange on the Southeast Expressway. The Callahan/Sumner Tunnels carry a 1982 volume of 82,80( vpd, and the Massachusetts Turnpike has an AWDT volume of 71,200 vpd just west of the Central Artery interchange. While these conditions, do not reflect the new inbound-only, I one-way toll system between the Mystic-Tobin Bridge and the Callahan/Sumner Tunnels, the resultir^ traffic diversions brought about by the new system have been relatively minor. Therefore, the 1982 conditior represent the base line from which al alternatives were compared. On the streets analyzed in the downtown area, AWDT volumes range frc 44,000 vpd on the Charlestown Bridge (North Washington Street) to 4,100 ve on Hanover Street in the North End of Boston. AWDT truck percentages for selected roadways in the study area have been presented in Table 1, based on vehicle classification counts 54 \ * Beyond Map Limits: UN S.E. Expressway, Between Columbia On- and Southampton Off-Ramps. us S.E. Expressway Between Southampton On- and Columbia Off-Ramps rin Columbia Road Off-Ramp-Northbound R1S Columbia Road On-Ramp-Southbound (T) Columbia Circle (33) Bell Circle, Revere Figure 7 Affected Roadway Network - Roadway Link, Ramp, and Intersection Identification Map @ 0 450 900 1800 Feet EIS/EIR for l-90-Third Harbor Tunnel; l-93-Central Artery Legend (T) Existing Intersection L1NJ Existing Roadway LinK or Ramp ! Affected Roadway Network Table 1 AVERAGE WEEKDAY DAILY TRAFFIC (AWDT) 1982, 1990, 2010 Existing No -Bui Id Alternative 198 2 1990 2010 m % Change % % Change 1 Roadway Link AWDT Trucks AWDT vs. 1992 Truck6 AWDT vs. 1982 Tnti Sumner/Callahan Tunnels 82 800 3 83, 600 + 1 0 3 91 , 800 +11 . 0 My stic-Tobin Bridge - north of 1-93 Ramps 72 , 500 5 73, 900 + 2 0 8 79, 100 + 9. 0 1-93 - north of Mystic-Tobin Bridge Ramps 89, 450 7 102, 200 + 14 0 8 i nn n + 1 O c 3 Central Artery - between 1-93 & Storrow Drive Ramps 142, 100 7 148, 300 * 4 c g 153 800 + 8 o between Causeway St. & Sumner/Callahan Ramps 161 700 g 167, 500 + 3 c g 173 100 + 7 o between Callahan/Sumner & High St. Ramps 164 500 g 169,800 + 3 o g 173 400 + 5 5 between Atlantic Ave- & Beach St. Ramps i. Do , t U U 7 169, 500 + 2 o Q 173, 100 + 4 o between Albany St. 6 Mass Ave. Ramps i "7nn IJJ; /U U ■7 167, 200 + 9 0 8 169,400 +10 0 Southeast Expressway — between Columbia Rd. & South Hampton St • Ramps 162 ,300 7 icq nn n + 3 5 g 170 900 + 5 3 south of Columbia Rd. Ramps 151, 620 7 156 900 + 3 5 8 159, 650 + 5 3 Massachusetts Turnpike — west of Central Artery 71 200 g 79 600 + 12 o g on non o yj , uuu + 12 5 Storrow Drive - west of Copley Ramps 84 , 000 o 86, 100 + 2 5 o 90 600 + 8. o Route 1A - north of Neptune Road 30, 825 3 35, 800 + 16 0 3 40 000 + 30 o Logan Airport Access/Egress Roads (Main) 55, 450 2 66, 300 + 20 o 2 82 , 10 0 + 48 o Porter St. - between Cottage & Wellington Sts. 8, 425 5 10,000 + 18 *7 5 1 1 700 + 38 g Maverick St. - between Cottage & Orleans Sts. 4, 200* 5 4, 300* + 2 4 5 4 ( 700* + 12 o Sumner St. - between Orleans S Cottage Sts. 2,400* 5 2, 500* + 4 2 5 2, 700* +12 5 Meridian Street - northwest of Condor Street 15, 100 5 17,700 + 17 2 5 18, 300 + 21 2 Bennington Street - west of Route 1A 19, 125 5 20,000 + 4 6 5 21, 100 + 10 0 Colvimbia Road - north of Columbia Circle 21, 750 2 25,875 + 19 .0 2 27, 350 + 25 7 L Street - north of Day Boulevard 12 , 325 1 13,825 + 12 .0 1 14, 150 + 14 8 East First Street — west of Summer Street 2,900 21 4, 550 +57 0 21 4 , 800 +65 5 2 D Street ~ southwest of Summer Street 6, 500 8 9,925 +53 1 1 3 10 900 +67 7 J Sur:iner Street - east of Fort Point Channel 27, 000 10 35,475 + 74 8 8 36 , 450 + / 7 a Congress Street - east of Fort Point Channel 11,000 g 14,550 -15 9 15 15, 550 - 10 0 1 Northern Avenue - east of Foj~t Point Channel 18 050 a 30, 250 + 67 6 8 32, 250 + 79 2 Dorchester Avenue - south of A Street 23 450 c 25,450 + 8 5 - 25, 650 + 9 , \ Frontage Road — approach to W. Fourth St. Bridge 26 , 950* 1 i 27, 200* + 1 . 0 1 1 27 , 600* + 2. 3 1 West Fourth Street Bridge 11, 000 1 2 10 , 650 - 3. 2 13 10, 650 - 3. 2 1 Broadway Bridge 20 , 60 0 1 3 26, 150 + 26. 9 10 26,150 +26. 9 1 Atlantic Avenue — between Summer & Congress Sts. 16 900* 20 , 300* +20 1 10 20, 700* +22. 5 1 Scsp^rt Access Poad — southwest of Summer St. N /A 8, 300 11 9, 300 1 State St. - bet we 3 Ti Atlantic Ave. & Surface Artery 5, 100* 4 10,400* + 103 9 4 12, 500* +145 1 North St . — between Congress & Blackstone Sts. 16, 500 4 19, 800 + 20 0 4 25,800 +56 4 North Washington St. - between Keany Sq. & Cross St. 21, 550 4 34,400 + 59. 6 4 35, 100 +62. 9 Cross St. - between Hanover & No. Washington Sts. 25, 200* 3 27,800-* + 10 3 3 31, 000* +23. 0 Cross St. - between Salem & New Chardon Sts. 4,750* 3 8, 300* + 74. 7 3 11, 500* + 142 1 New Chardon - between North Washington & Merrimac Sts 17,300* 4 20, 300* + 1-7 3 4 25,000* +44. 5 Merrimac St. - between New Chardon & Sudbury Sts. 16,550 5 18, 000 +8 8 5 19,900 +20. 2 New Sudbury St. - between Congress & Blackstone Sts. 12,450* 3 13,500* + 8 4 3 20, 200* +62 2 Commercial St. - northeast of Keany Sq. 18,650 6 20, 500 +9 9 6 24,800 +33 0 Causeway St. - southwest of Keany Sq. 22,150 7 24, 500 + 10 6 7 25,600 +15 6 Hanover St. - northeast of Cross St. 4, 150 4 5,000 + 20 5 4 5,300 +27 .7 | Congress St. - between Sudbury & North Sts. 18, 500 4 27, 000 +45 9 4 29, 200 +57 S North Washington St. - south of Keany Sq. 21, 550 9 34,400 + 59 6 9 35,100 +62. 9 * One-Way Volume N/A - Not applicable for this alternative. 56 rformed as part of this study. affic Levels of Service: Definition Six discrete levels of service .OS) describe traffic operating editions along roadways and at gnalized and unsignalized itersections. The six levels, ^presented by the letters A through i ( range from free-flow to jammed pnditions. To estimate levels of isrvice, two parameters are .acessary : 12) Volume-to-capacity (v/c) ratio (for roadway links and intersections), and Operating speed (for roadway links only). I I For intersections, level of ervice is a function only of the a elationship between intersection "pproach volumes and capacities, which in turn relate to tolerable delays at given intersection. For both links 4nd intersections, a v/c ratio equal ii.o 1.0 corresponds to the upper limit 'if LOS E. A v/c ratio greater than 1.0 indicates LOS F conditions, average attainable operating speed on jn link can decrease not only due to j ncreased traffic congestion (hence ■ :he relationship between v/c and ][>perating speed), but also due to dlecreased vehicle maneuverability >hich may be independent of traffic volume. Factors such as poor roadway jeometry (horizontal and vertical alignments); significant pedestrian movements; curbside parking; double marking; pavement surface condition; and the closeness of roadside obstructions to the travel way (barriers, trees, etc.) cause notorists to drive more slowly. The let result is the same: a degradation )f level of service. Figure 8 illustrates the six levels of service. A theoretical v/c ratio greater than 1.0 is a measure of relative congestion and is indicative of a link or intersection which has vehicle demands (arrivals) that exceed the rate at which it can service them (departures) during the given hourly period, much like a toll booth operation. In actuality, traffic cannot flow through the link or intersection at a rate greater than its physical and operational capacity (i.e., v/c = 1.0). The result, when volume exceeds capacity, is congestion, queuing and actual volumes that are often less than theoretical capacity due to stop-and-go conditions. A common example of this situation is when a roadway link's capacity is greater than a downstream intersection's capacity. Traffic may be relatively free flowing on the link and may be significantly less than the link's capacity. This volume, however, may exceed the downstream intersection's ability to service it (capacity), such that the intersection experiences congestion and queuing during that period. For example, a v/c ratio of 1.2 for an intersection for a one-hour period indicates that on the average 1.2 vehicles arrived but only 1.0 vehicles were serviced, resulting in increased (lengthened) queues during this period. Vehicle arrivals in excess of departures will cause queuing and tend to prolong (or spread) the peak period. The queues will dissipate only after arrival rates of succeeding periods have decreased to below 1.0 for a length of time sufficient to service these arrivals and the queues remaining from previous periods. Because of excessive delays, motorists may change their hour of travel, if possible, or change their travel mode. Existing V/C Ratios and Levels of Service Table 2 presents peak hour traffic volumes, v/c ratios, average operating speeds, and levels of service for the affected roadway network. This section summarizes existing v/c ratios and levels of service for the affected highway links, and for streets and intersections . Highway Facilities AM Peak. Traffic on the 57 Level of Service C: Traffic volume controls speed and Level of Service D: Traffic volume affects the mair- choice of lane, to a degree, but satisfactory movement nance of speed and choice of lane, causing congeid is still maintained. Moderate delays are experienced. unstable flow. Figure 8 Pictorial Representation of Level of Service Source The Transportation Research Board. Washington, D C EIS/EIR for l-90-Third Harbor Tunnel; l-93-Central Artery rthbound Expressway/ Artery currently »erates at LOS E or F from the 'lumbia Road on-ramp to the gh-Level Bridge during the AM peak iur. Northbound, Central Artery )erating speeds during this period e typically less than 35 miles per >ur (mph). Southbound, the Central rtery also operates at LOS E or F :om the Interstate Route 93 and /stic-Tobin Bridge junction to the leeland Street on-ramp. Southbound Derating speeds range from 20 to 35 bh on this section of the Artery. lese conditions occur because of the jmerous entrance and exit ramps, ladequate acceleration and eceleration lanes, the bottleneck at (tie High-Level Bridge, and heavy emand volumes. Inbound Route 1A in East Boston s free flowing until the queue from he Sumner Tunnel is reached, utbound flow in the Callahan Tunnel or the morning peak hour is normally ithin the LOS D range. Operating peeds in the Sumner Tunnel are ypically less than 20 mph; orresponding speeds in the Callahan 'unnel range from 30 to 40 mph. PM Peak . Levels of service on :he northbound Expressway/ Artery are ypically LOS F from Massachusetts wenue to the High-Level Bridge, ixtreme congestion at several ramps to ind from the Artery create operating speeds of less than 15 mph along the ■ lorthbound downtown section of the Central Artery. The main restriction Ls the High-Level Bridge. Southbound Artery/Expressway conditions are also uOS E or F in the PM peak hour. Operating speeds southbound average Erom 20 to 30 mph on a typical weekday. The practical capacity of nany ramps is equalled or approached 'in both the northbound and southbound directions of the Central Artery. The Sumner and Callahan Tunnels also experience LOS F conditions in the PM peak hour. Back-ups originating at the Boston end of the Sumner Tunnel create inbound queues which extend back to the Airport Road/Route 1A interchange. Long queues at the Callahan Tunnel entrance are common, though recent City of Boston improvements on the approach to the Callahan Tunnel, and the elimination of the outbound Callahan Tunnel toll have had a beneficial impact on operating conditions. Some queues on the Central Artery off-ramp to the Callahan Tunnel nearly reach the Artery mainline. The Surface Artery and North Street also experience long queues approaching the Callahan Tunnel. These queues are caused primarily by the disorderly transition of eight lanes of traffic entering the two-lane tunnel. Intersections and Local Streets South Boston Intersections . Only five of the 15 South Boston intersections analyzed experience levels of service E or F in the AM peak hour. These are: Andrew Square; Congress Street/Dorchester Avenue; Congress Street/A Street; Northern Avenue/Sleeper street; and Berkeley Street/West Fourth Street/Frontage Road/Albany Street. During the PM peak hour, the following intersections operate at LOS F: Columbia Road/Day Boulevard/L Street; Dorchester Avenue/West Broadway; the Congress Street intersections with Dorchester Avenue and A Street; and Northern Avenue/Sleeper Street. East Boston Intersections . As shown in Table 2 only one intersection operates at worse than LOS D in the AM peak hour — the Porter Street/London Street intersection (LOS F) . Only the McClellan Highway (Route 1A) of f -ramp/Neptune Road intersection operates at LOS F in the PM peak hour, while one intersection pair--the intersections of the Airport access and egress roads with the Airport Cross Road, operate at LOS E. Bell Circle, Revere . Bell Circle operates at LOS F in the AM peak hour and LOS D in the PM peak hour. Although reconstructed to improve operations and safety, heavy traffic volumes continue to adversely affect traffic flow. (0%)= Percent Trucks 1902 FUTURB NO HU1LI) MAJOR HIGHWAY LINKS - NORTHBOUND 1.1N. S.E. Expressway: Btwn. Columbia On - and Southampton Off-Ramps L2N. Frontage Road: Adjacent to M.nss. Ave. Interchange L3N. S.E. Expressway: Btwn. E. Berkeley On - and Mass. Tpk. Off-Ramps LAN. Central Artery: Btwn. outh St. On - and Northern Ave. Off-Ramps L5N. Central Artery: Btwn. Atlantic On - and Callahan Off-Ramps L6N. Centra] Artery: Btwn. Sumner On - and Causeway Off -Ramps L7N. Central Artery: Btwn. Storrow On - and Tobln Off-Ramps LBN. Mystic Tobin Bridge: North of 1-93 Ramps L9N. 1-93: North of Tobln Bridge Raraps LION. Callahan Tunnel L11N. Route 1A: Btwn. Toll Plaza and Airport Off-Ramp L12N. Route 1A: Btwn. Airport On - and Neptune Off-Ramps MAJOR HIGHW AY LINKS - SOUTHBOUND LIS. S.E. Expressway: Btwn. Southampton On - and Columbia Off-Ramps L2S. S.E. Expressway: Btwn. Mass. Ave. On - and Southampton Off-Ramps LIS. S.E. Expressway: Btwn. Albany On - and Mass. Ave. Off-Ramps LAS. Central Artery: Btwn. Kneeland On - and Albany Off-Ramps L5S. Central Artery: Btwn. Congress On - and Beach Off-Ramps L6S. Central Artery: Btwn. Purchase On - and Dewey Sq. Off-Rampa L7S. Central Aicery: Btwn. Haymarket On - and High Off-Ramps L8S. Central Artery: Btwn. Causeway On - and Callahan Off-Ramps L9S. Central Artery: Btwn. Storrow On - and Haymarket Off-Ramps L10S. Central Artery: Btwn. Tobln On - and Storrow Off-Ramps L11S. Mystic Tobln Bridge: North of 1-93 Ramps L12S. 1-93: North of Tobln Bridge Ramps L13S. Sumner Tunnel L14S. Route 1A: Btwn. Airport On-Ramp and Toll Plaza L15S. Route 1A: Btwn. Neptune On - and Airport Off-Ramps MAJOR HIGHWAY LINKS - EASTBOUND AND WESTBOUND LIE. Mass. Turnpike, Eastbound: West of Expressway Ramps L1W. Mass. Turnpike, Westbound: West of Expressway Ramps L2E. Storrow Drive, Eastbound: West of Copley Sq. Ramps L2W. Storrow Drive, Westbound: West of Copley Sq . Ramps MAJOR HIGHWAY RAMPS - NORTHBOUND R1N. R2N. R3N. R4N. R5N. R6N. R7N. R8N. R9N. R10N. R11N. Columbia Road Off; from S.E. Expressway Mass. Avenue On; to S.E. Expressway Mass. Turnpike On; to Central Artery Atlantic Avenue Off; from Central Artery Atlantic Avenue On; to Central Artery Callahan Tunnel Off; from Central Artery Sumner Tunnel On; to Central Artery Storrow Drive Off; from Central Artery Storrow Drive On; to Central Artery Airport Off; from Route 1A Airport On; to Route 1A MAJOR HIGHWAY RAMPS - SOUTHBOUND R1S. R2S. R3S. R4S. R5S. R6S. R7S. R8S. R9S. R10S. R11S. R12S. Columbia Road On; to S.E. Expressway Mass. Avenue Off; from S.E. Expressway Albany Street On; to S.E. Expressway Mass. Tpk. /Albany St. Off; from Central Artery Dewey Square Off; from Central Artery High Street Off; from Central Artery Haymarket On; to Central Artery Callahan Tunnel Off; from Centra] Artery Storrow Drive On; to Central Artery Storrow Drive Off; from Central Artery Airport Off; from Route 1A Airport On; to Route 1A 7450 ( 8% ) 4350 (8%) 8780 (8%) 6030 (8* 2580 (7) 1700 ( 7) 2770 (8) 1630 (8) 5780 ( 7) 3920 (8) 7940 ( 8) 5850 (8) 64 5 0 (8) 4200 (8) 7410 (8) 5620 (8) 5030 (8) 4080 (8) 5740 ( 8) 5740 (8) 5540 ( 8) 4700 (8) 6000 (8) 5810 (8) 3 660 (9) 5350 (8) 3570 (8) 5740 (8) 1580 (9) 3120 (9) 1900 (8) 3400 (8) 2000 (8) 4290 (8) 2240 (8) 4290 (8) 2300 (3) 2850 (2) 2660 (3) 3740 (2) 2050 (3) 2580 (2) 2470 (3) 3330 (2) 9 30 (3) 2230 (2) 1220 (3) 2440 (4) 3370 (8) 53 50 (8) 5130 (8) 8290 (8) 3920 (8) 6150 (8) 5700 ( 8) 9360 (8) 4540 ( 8) 5750 (7) 5170 (8) 8360 ( 8) 4350 (8) 4570 (8) 5620 (8) 8070 (8) 4730 (8) 4500 (8) 5430 (8) 6550 (8) 50 50 (8) 3880 (7) 5590 (8) 5960 (8) 5850 ( 8) 3530 ( 5) 5740 (8) 5220 (8) 5570 (8) 3350 (8) 5470 (8) 4850 (8) 5220 (7) 2740 (9) 5170 (8) 4140 (8) 5430 (8) 3710 ( 9) 4790 ( 8) 4030 ( 8 ) 3060 2180 (9) 3 34 0 ( 8) 222 0 ( 8 ) 3 980 2150 t fl \ V o / 3460 ( 8 ) 2850 f ft ) 3160 ( 4) 264 0 ( 3 ) 3460 ( 3 ) 2810 ( 2 ) 1510 ( 3 ) 19 30 ( 2 ) i i \ I 3 1 1 780 1750 (4) 1620 \ * 1 1 «o f 1) \ J 1 1040 1 A I 4400 (9) 2080 (9) 4830 (8) 2520 (8) 1450 (9) 3180 (9) 2550 (8) 3400 (8) 3450 ( 0) 2600 ( 0 ) 3460 ( 0 ) 3000 ( 0) 2430 (0) 3440 (0) 3340 (0) 3960 (0) 500 260 570 300 460 200 1520 700 1600 700 1750 700 2 3 60 1540 3840 2110 220 800 840 1000 1330 730 1250 1410 1420 1350 1560 1520 1900 1100 1820 1 630 1 200 2000 1200 2250 1390 1270 1710 1850 270 920 460 960 400 1900 400 1980 720 500 720 64 0 600 1900 490 2290 1260 1300 1260 1410 7 50 480 720 520 1300 550 1100 560 1560 1890 1750 1740 1280 1710 1520 1370 1500 850 2050 1150 1720 1820 1630 1870 770 530 870 670 530 850 1060 1400 ■i l r. j (■ ~t r l ;. y. ho r ?■ r f ;. rn r v c i ume s , V O I ■ L' ?•' r - C • - C A I A C ] T Y (V 'C) RATIOS 01 11 A T 1 KG IT L L ( fi ) , £, LEVELS OF FLRVICE (LOS)~ ~ 19B2, 1990, 2010 KJ< I ^.'LLI^i FUTURE NO BUILD ALTERNATIVE 1 m ThUNATl ve l j~982 1990" 20T0 AM PM ~~ AM PM' ~ AM PM~ v7c s p Los "v/c sp los v/c "sp los v/c sp los "v7c sY Lbs vTc" SP ws 9650 (8*) 6590 (8*) 1.03 30 F 0.60 40 C 1.22 25 F 0.83 35 E 1. 34 20 F 0.91 35 E 2810 ( 8) 1550 (8) 0.69 30 D 0.46 40 B 0. 74 25 D 0.44 40 B 0. 76 25 D 0. 42 40 B 9420 (8) 6360 (8) 1.10 30 F 0.75 30 F 1 .10 30 F 0.81 30 F 1.31 20 F 0.88 25 F 9500 (8) 5550 (8) 1.13 20 F 0. 75 15 F 1.29 15 F 1.0] 15 F 1.62 10 F 1.00 15 F 6420 (8) 6030 (8) 0.96 30 F 0.78 15 F 1.06 25 F 1.06 15 F 1 . 19 20 F 1.11 15 F 72J0 (8) 6070 (8) 0.90 35 E 0. 79 15 F 1.06 25 F 0.99 15 F 1 .24 20 F 1 .00 15 F 4790 (8) 5850 (8) 0.89 25 F 1 . 30 15 F 0.68 40 C 1 . 46 15 F 0.91 30 E 1 .50 15 F 20 Hi (8) 3590 (8) 0.40 50 A 0. 78 45 C 0.48 45 A 0.85 40 D 0. 50 45 A 0.90 35 E 2740 (8) 4400 (8) 0.28 50 A 0. 59 50 C 0.31 50 A 0.59 50 C 0. 38 50 A 0.61 50 C 3150 (3) 4070 (2) 0.85 35 D 1.06 20 F 0.99 30 E 1 .39 20 F 1 .17 20 F 1.51 15 F 2890 (3) 3590 (2) 0. 36 35 c 0.45 30 C 0.44 30 C 0.58 20 C 0.51 25 C 0.63 20 C 1 i 10 (3) 2700 ( 5) 0. 17 15 A 0. 39 45 A 0. 22 45 A 0.43 40 B 0. 24 45 A 0.47 40 B 56 }0 (8) 8770 (8) 0.62 50 B 0.74 30 F 0.71 40 D 1.15 30 F 0. 78 40 D 1. 22 30 F 6190 (8) 10430 (8) 0.62 50 A 0.85 30 E 0.64 40 D 1.21 25 F 0. 70 30 F 1.35 20 F 5400 (8) 8700 (8) 0.73 35 D 0.95 20 F 0.60 45 B 1.13 20 F 0.63 40 C 1.17 20 F 6160 (8) 8330 (8) 0.74 40 C 0. 78 20 F 0. 78 25 F 1.13 20 F 0.85 25 F 1.16 20 F 5700 (8) 6880 (8) 0.78 35 E 0.75 20 F 0.90 25 F 1 .10 15 F 0.91 20 F 1.12 15 F 58 jU (8) ol40 (8) 0.83 30 E 0.65 25 F 0.92 25 F 1.02 20 F 0.97 20 F 1.05 20 F 61 '0 (8! 5400 (8) 1.08 30 F 0.64 25 F 1.05 25 F 0.94 25 F 1.14 20 F 0.98 25 F 60:)0 (8) 5180 (8) 0.96 30 F 0.62 25 F 0.95 25 F 0.91 25 F 1 .03 20 F 0.94 25 F 61 )0 (8) 41B0 (8) 0.96 30 E 0.51 25 F 0.96 25 E 0.77 25 F 1 .14 20 f 0.77 25 F 61 to (8) 4000 (8i 1.20 20 F 0.81 25 F 0.88 25 F 0. 74 25 F 1.14 20 F 0.75 30 F 37J0 (8) 2480 (8) 1.13 10 F 0.81 30 F 0.84 40 D 0. 56 45 C 0.93 35 E 0.46 45 C 4PH) (8) 3000 (8) 0.73 15 F 0.40 50 C 0.64 35 E 0. 53 50 C 0. 74 30 F 0. 55 50 c 3 690 ' J) 3260 (2) 1.17 20 F 0.98 20 F 1.28 20 F 1 . 04 20 F 1.37 20 F 1.21 20 F 17 ju ( 3) 2070 (2) 0. 27 5 F 0. 34 5 F 0. 30 5 F 0. 31 5 F 0. 31 5 F 0. 36 5 F 14 10 (3) 1 1 50 (5) 0.31 45 A 0.28 45 A 0.26 45 A 0.18 45 A 0. 26 45 A 0. 20 45 A 48'SO (8) 2920 (8) 27 !0 (8) 3660 (8) 39'>0 (0) 3110 (0) 3MH0 (0) 4030 (0) 0.80 40 D 0. 37 45 C 0.27 55 A 0.58 55 B 0.59 40 C 0.45 40 C 0.42 40 C 0.59 40 C 0.87 30 E 0. 45 45 C 0.46 55 B 0.62 55 B 0. 59 40 C 0.51 40 C 0.57 40 C 0.68 40 C 0.88 30 E 0. 52 45 C 0.49 55 B 0.66 50 C 0.69 40 C 0. 53 40 C 0.67 40 C 0.69 40 C 6 10 330 0. 34 35 C 0.17 35 C 0. 38 35 C 0. 20 35 C 0. 46 35 C 0. 22 35 C 20 1 0 700 0. 30 35 D 0.13 40 B 0.99 30 F 0. 46 35 D 1.31 30 F 0. 46 35 D 2 3, 0 630 1.08 20 F 0.51 30 C 1.17 20 F 0.51 30 C 1.56 10 F 0. 46 30 C 4110 1700 1.58 15 F 1.03 20 F >2.00 10 F 1.40 15 F >2.00 5 F 1.13 20 F 8!0 1150 0.16 25 F 0. 5 3 15 F 0.61 25 F 0.66 15 F 0. 59 20 F 0. 76 15 F 13 >0 1550 0.86 25 E 0.47 20 F 0.81 25 E 0.90 20 F 0.H6 20 F 0.99 15 F 21 10 1590 0.91 30 E 0.87 30 E 1 .00 15 F 0.98 15 F 1.37 10 F 0.98 15 F 2470 1670 0.62 35 C 0. 37 40 C 0.59 35 C 0.55 40 C 0.80 25 E 0. 56 40 C 14110 2300 0. 78 30 E 1.37 10 F 0. 78 30 E 1.54 10 F 0.91 30 E 1 .58 10 F 21.10 2110 0.87 30 E 0. 79 30 E 1.07 25 F 1 .14 25 F 1.33 20 F 1 . 30 20 F 5 "0 1220 0.17 40 B 0.57 40 B 0. 28 40 B 0. 59 35 C 0. 36 40 B 0.76 30 1) 4110 2050 0. 27 35 C 1.28 25 F 0. 27 35 C 1.3) 25 F 0. 32 35 C 1. 38 20 F 8l 0 720 0. 23 40 B 0.16 45 A 0. 23 40 B 0. 20 40 B 0. 27 40 B 0. 23 40 B 4' 0 1630 0.40 30 C 1.25 20 F 0. 33 30 C ] .51 20 F 0. 33 30 C. 1 .07 20 F 15)0 1670 0.85 25 E 0.88 25 E 0.85 25 E 0.95 20 F. ] .02 15 F 1.13 15 P H«0 370 0.50 30 C 0.32 35 C 0.49 30 C 0.34 35 C 0.56 30 C 0. 25 35 C 130 520 0.87 20 E 0.36 30 C 0. 74 20 E 0. 36 30 C 0.89 20 K 0. 34 30 C 20!.O 1670 1.01 15 F 1. 20 15 F 1.13 15 F 1.12 15 F 1. 32 10 F 1 . 06 15 F 19'0 1440 0.41 15 P 0.57 15 F 0.49 15 F 0. 46 15 K 0.62 15 F 0.48 15 F 21.0 1180 0.98 20 F 0. 57 30 C 1.34 20 F 0.75 25 F. 1.39 20 F 0.77 25 E 21^0 1920 1.12 20 F 1 . 22 20 F 1.06 20 F ] .25 20 F 1.39 20 F 1.29 20 F 1030 850 0.47 35 B 0. 33 40 A 0.54 30 C 0.42 35 B 0.63 30 C 0..53 30 C 1330 1780 0. 34 30 C 0. 55 25 F 0.69 30 C 0.91 20 F 0.87 25 E 1.17 15 F 60 (0%)= Percent Trucks * = Signalized Intersection Notes: 1. V/C ratios and levels of service, at unsig- nalized intersections, indicate minor street operating conditions. 2. Intersection volumes are total approach volumes . EXISTING INTERSECT IONS 1982 ■ AM ra South Boston 1. Columbia Circle 5260 {IX) A3A0 (1*) 2. Andrew Square* 2000 (1A) 1650 (8) 3. Columbia Rd./Day Blvd./L St. 1390 (1) 1450 (1) 4. L St. /East First St. /Summer St.* 1500 (6) 1550 (5) 5. Dorchester Ave./W. 5th St . Ik St.* 2 300 (5) 2140 ( 5) 6. Dorchester Ave./W. 4th St.* 22 30 (6) 2060 ( 7) 7. Dorchester Ave./W. Broadway* 2650 ( 9) 2750 ( 7) 8. Summer St . /Dorchester Ave.* 2650 (10) 2400 (6) 9. Summer St./Melcher St.* 2340 ( 7) 2040 (A) 10. Summer St . /D St .* 2380 (9) 2220 (6) 11. Congress St . /Dorchest er Ave. 2020 (8) 1730 (6) 12. Congress St ./A St . 950 (11) 1080 ( 5) 13. Northern Ave. /Sleeper St. 1270 (12) 1730 ( 3) 14. Herald St . /Broadway /Frontage Rd. /Albany St.* 3670 ( 9) 4140 (6) 15. Berkeley St./W. Fourth St. /Frontage Rd. /Albany St.* 4530 (8) AA10 (6) Ed fit Boston and Revere 16. Sumner St. /Meridian St. /Chelsea St.* 620 I 1UJ 7?n / iU 17. Sumner St . /Bremen St . 460 (7) 550 ( A) 18. Maverick St. /Meridian St. /Chelsea St. 880 (8) 990 ( A) 19. Maverick St . /Bremen St . 480 (5) 510 ( 3) 20. Maverick St. /Jeffries St. /Airport Access Rd . 380 (6) 320 (8) 21. Porter St. /Chelsea St./Viscontl Rd.* 1560 (6) 1500 ( 3) 22. Porter St. /Bremen St. 980 (4) 1290 (2) 23. Porter St. /Or leans St. 570 (5) 790 ( 2) 24. Porter St. /Cottage St. 540 (6) 670 (2) 25. Central Square (Meridian St. /Saratoga St.)* 1000 (7) 10A0 (A) 26. Porter St. /London St. 850 (4) 670 ( 5i 27. Bennington St./Prescott St. 1150 ( 5) 930 ( 4) 28. Chelsea St. /East Eagle St. 1070 ( 5) 1190 ( 5) 29. Bennington St. /Neptune Rd . 2370 (6) 1890 (6) 30. McClellan Of f -Ramp/Neptune Rd . 920 (°) 1A60 (4) 31. Condor St. /Meridian St.* 1070 (6) 1330 ( 3) 32. Airport Crossover Roads* 3630 (3) A860 (4) 33. Bell Circle (Revere)* 3860 (7) AA70 (4) Downtown Boston and Charlestovn 34. Kneeland St . /Surface Artery /S.B. On-Ramp* 2550 (9) 32A0 (13) 35. Dewey Sq.* 3770 (8) A890 (6) 36. Atlantic Ave . /Congress St.* 3040 (6) 27A0 (6) 37. Atlantic Ave. /Northern Ave. 2440 (7) 3560 (5) 38. Atlantic Ave. /Surface Artery/High St.* 32 20 (7) 3A20 (6) 39. Purchase St. /Congress St.* 2250 (7) 2970 (7) 40. North St ./Blackstone St. /S.B. Off-Ramp 2710 (4) 35A0 (4) 41. Cross St. /Hanover St. /Salem St. 2070 (A) 2110 (2) 42. Leverett Circle* 6720 6260 45. Congress St . /North St . 1920 (A) 2 300 (3) 46. City Square ( Char les town ) 3690 (11) 3680 (5) 47. Causeway St. /North Washington St . /Commerc ial St. 4260 (3) A610 (A) 48. Causeway St. /Lomasney Way/Merrlmac St . /Stan 1 ford St. 1860 (3) 1880 (3) 49. New Chardon St . /Merrimac St . 2910 (A) 2 200 (3) 50. New Chardon St. /North Washington St. 2640 (A) 2070 (3) 51. Sudbury St. /Congress St. /Merrimac St. 1760 (5) 3180 (2) 53. Commercial St. /Hanover St. 1300 (7) 1620 (4) 54. State St. /Atlantic Ave. 1560 (8) 1950 (3) 55. State St. /Surface Artery 2110 (4) 28A0 (6) 56. Sudbury St . /Blackstone St. /S.B. On-Ramp 950 (3) 1710 (2) „lc 2 (£1^ fcT^UF TRA FFIC VOLUMES, Fg^n^CA PACITY (V/C) RATIOS, fe^TTT PE EPS (SP), & fc^fj ERVICE (LOS) F7T^9or ~2Qio 61 FUTURE NO BUILD ALTERNATIVE 1 1982 EXISTING FUTURE NO BUILD ALTERNATIVE 1 1990 2010 AM PM AM PM 1990 2010 — . — — ; P" AM PM AM PM v/c sp los v/c sp Los v/c sp los v/c sp los v7c sp' Los — v7c~sTTos 6150 5030 6200 5710 0.85 D 0. 52 A 0.95 E 0.65 B 0.95 E 0.76 C 3070 2980 3160 3210 1.02 F 0.84 D 1.63 F 1.53 F 1.65 F 1.63 F 1370 1480 1370 1530 0.25 c 1.05 F 2.00 F 1.27 F 2.00 F 1.39 F 1890 1810 1910 1860 0.86 D 0.76 C 0.92 E 0.86 D 0.93 E 0.90 D 2A10 2200 2440 2550 0. 53 A 0.65 B 0.55 A 0.69 B 0.56 A 0.81 D 2390 2100 2450 2310 0. 58 A 0. 50 A 0. 50 A 0.52 A 0.52 A 0.58 A 2690 2210 2790 2460 0.87 D 1.07 F 0.92 E 0.86 D 0.96 E . 0.95 E 3120 A060 3140 4080 0.78 C 0.76 C 0.99 E 1. A6 F 0.99 E l.AA P 2800 2960 2770 3040 0.44 A 0.48 A 0. 53 A 0.69 B 0.53 A 0.67 B 2610 2570 2410 2600 0.73 C 0.69 B 0.78 C 0.75 C 0.60 B 0.76 C 2300 3390 2320 3540 2.00 F 2.00 F >2.00 F >2.00 F 2.00 F >2.00 F 12A0 2010 1240 2150 0.88 E 1.25 F 1.A7 F >2.00 F 1.A7 F >2.00 F 2660 2370 2690 2410 1.30 F 2.00 F >2.00 F >2.00 F 1.91 F >2.00 F 4910 A330 4960 5000 0.84 D 0.80 C 1.07 F 0.90 E 1.13 F 0.9A E 5910 6440 6090 5700' 1.03 F 0.76 C 1.07 F 0.77 C 1.11 F 0.80 C 690 880 690 890 0. 26 A 0.3A A 0. 44 A 0.46 A 0. 44 A 0.46 A 520 550 A60 550 0.08 B 0.12 B 0. 22 B 0.12 B 0.14 B 0.12 B 830 1030 830 1060 0.52 C 0.44 B 0. 52 C 0.63 D 0.51 C 0.69 D A80 5A0 A80 540 0.21 A 0.15 A 0. 20 A 0.17 B 0. 20 A 0.17 B 380 320 380 320 0.26 A 0.15 A 0. 26 A 0.14 A 0. 26 A 0.1A A 2120 1850 2A30 2170 0.83 D 0.65 B 0. 93 E 0.88 D « 1.27 F 1.01 F 1000 1320 1220 1510 0.52 D 0.75 E 0. 94 E 0.73 E 1.09 F 1.04 F 820 880 1020 1030 0.11 A 0.22 C 0. 27 D 0. 20 C 0. 27 D 0. 28 D 770 810 990 970 0.3A A 0. 32 A 0. 49 A 0.52 A 0.64 B 0.62 B 1170 1210 1260 1230 0.A2 A 0. 36 A 0. 46 A 0.44 A 0. 57 A 0. 54 A 930 8A0 1060 990 1.05 F 0.37 C 1. 22 F 0.60 D I. 30 F 0.99 E NO DATA AVAILABLE 0. 23 D 0.14 D NO DATA AVAILABLE 910 9A0 1020 1130 0.18 C 0.26 C 0. 22 D 0.12 A 0.28 D 0.14 A NO DATA AVAILABLE 0.68 B 0.62 B NO DATA AVAILABLE 1000 1330 11A0 1A60 0.55 C 1.27 F 0. 38 C 1.04 F 0.65 D 0.96 F 1300 1330 1A70 1630 0.A2 A 0.51 A 0. 41 A 0. 59 A 0.65 B 0.59 A 5380 6390 66A0 7870 0.6A B 0.95 E 0. 77 C 0.81 D 0.94 E 0.99 E 4760 5150 4870 5A20 1.15 F 0.89 D 1 . 33 F 1.18 F 1.37 F 1.24 F 3650 4010 3370 3990 0.69 B 6210 5970 5870 6280 0.64 F 5010 4160 4490 4790 0.94 E 4790 3860 4740 4440 2.00 F 5700 4220 6230 4070 0.89 D 2400 2960 2620 3140 0.65 B 4040 4000 4580 4400 2.00 F 2840 2 360 2680 2610 1.89 F 6860 6420 6560 6770 0.96 E 2610 2630 3010 2630 0.54 A 6570 7400 6050 7850 0.81 D 4930 5910 4410 6620 0.77 C 2170 2280 2060 2410 >2.00 F 2700 2550 2570 2630 0.65 B 2590 2480 2360 2670 0.82 D 2480 3330 2280 3350 0. 29 A 1590 1550 1670 2220 0.63 E 2130 2210 2260 2880 0. 39 A 3060 2210 2700 3450 0.51 A 1870 2890 1860 27 30 0.75 C 0.86 I ) 1.0A F 0.71 C 0.97 E 0.90 E 0.73 I >2.00 F 1.3A F 1.94 F 1.77 F 0.85 [ l 1.5A F 1.2A F 1.36 F 1.33 F 2.00 F >2.00 F 2.00 F 2.00 F >2.00 F 0.80 C 1.A2 F 0.93 F 1.42 F 0.81 F 0.82 E i 0.6A B 0.72 C 0.68 B 0.77 D 2.00 F >2.00 F >2.00 F 2.00 F >2.00 F 2.00 B >2.00 F >2.00 F 2.00 F >2.00 F 0.75 F 1.09 F 0.92 F 0.99 E 0.80 F 0.71 C 0.68 B 0.85 D 0.89 D 0.70 E 1.20 F 1.08 F 1.26 F 1.06 F 1.23 F 1.00 E 1.12 F 1.37 F 1.01 F 1.A3 F 2.00 F 0.81 D 0.91 E 0.76 C 0.85 D 0.44 A 0.65 B 0.AA A 0.65 B 0.63 B 0. 58 i 0.88 D 0.69 F 0.82 D 0.71 F 0. 54 F 0.52 A 0.57 F 0.49 A 0.60 F 0.53 E 0.93 E 0. 20 C 0.51 D 0.40 C 0.47 A 0.7A C 0.71 C 0.65 B 0.68 B 0.67 B 0.99 E 0.85 D 0.71 C 0.91 E 0. 26 F 0.85 D 0.40 F 0.85 D 0. 45 F City Sq u are, C h arle stown. The intersection of Rutherford Avenue, Chelsea Street, and North Washington Street in City Square currently operates at LOS D during the AM peak hour, with heaviest congestion on the Chelsea Street/Rutherford Avenue approaches to the North Washington Street Bridge. In the PM peak hour, this intersection operates at LOS F, with major congestion on the northbound approach of the North Washington Street Bridge towards Chelsea Street and Rutherford Avenue. Downtown Boston I n ters ections . Eight of the twenty intersections analyzed for downtown Boston presently operate at LOS E or F in the morning peak hour primarily due to heavy traffic: Atlantic Avenue/Congress Street; Atlantic Avenue/Northern Avenue; North Street/Blackstone Street/Southbound Artery off-ramp; Cross Street/Hanover Street/Salem Street; Causeway St reet/Stanif ord Street/Merr imac Street/Lomasney Way; Hanover/Commercial Street; and Leverett Circle. Dewey Square (which is actually four separate intersections) also operates at LOS F in the AM peak hour due primarily to very heavy pedestrian volumes from South Station, double parking, and passenger pick up. During the PM peak hour, the following intersections operate at LOS E or F: Atlantic Avenue/Northern Avenue; North 3treet/3lackstone Street/Southoound Artery; Cross Street/Hanover Street/Salem Street; Causeway St reet/Stanif ord Street/Merr imac Street/Lomasney Way; Hanover/Commercial Street; Sudbury Street/Blackstone Street; Sudbury St reet /Congress St reet/Mer r imac Street; New Chardon Street/North Washington Street/Cross Street/Southbound off-ramp; Keany Square (congested by outbound traffic destined for the North Washington Street Bridge, City Square, and points beyond); Leverett Circle and Dewey Squa re . Ex is t ing_ _Ce_n tr al _A_r_t_ery B ott le necks and Congest i on_ _Poi_n ts The severe bottleneck on the northbound Central Artery is the approach to the High-Level Bridge, the southbound direction, the High-Level Bridge itself is a bottleneck. On- and off-ramp merges, diverges and weaves also create numerous congestion points along the Central Artery. There is also an existing AM peak hour queue at the northbound Columbia Road on-ramp merg< area. Inlividual queues which overlaj ^ are dominated by the longest queue. These queues are discussed further in the following subsection. 3.1.2 Futu re Roadw ay Charac ter is t ics With out th e Pr oject Future Roadw ay Network Chang es Several major roadway construction projects planned for the future are assumed to be completed by the time portions of the Third Harbor Tunnel and/or Central Artery improvements are completed. These include : 1. The Central Artery North Area Proj ect. 2. Southeast Expressway upgrading project, creating four lanes in each direction to the Dewey Square Tunnel. 3. Street pattern changes associated with the proposed South Station Transportation Center . 4. Relocated Northern Avenue Bridge. 5. West Fourth Street Bridge Replacem ent . 6. Roadway improvements and street pattern changes associate! with the North Station urban Renewal Project. 62 Atlantic Avenue Phase III Project . A Seaport Connector Road, which provides a connection between B Street and Northern Avenue in South Boston. Deck replacement of the Central :tery is considered in this study as le No-Build Alternative. jture Traffic Volumes AWDT Volumes Table 1, previously presented, ummarizes AWDT volumes for the ffected roadway network for 1990 and 010 No-Build conditions. Traffic crossing Boston Harbor ill increase approximately ten ercent between 1982 and 2010 under he No-Build Alternative, to 170,000 ehicles on an average weekday, 'raffic congestion and queuing will [iccur during several hours of the day •n the Central Artery, the lystic-Tobin Bridge, and in both :xisting tunnels. For the :allahan/Sumner Tunnels in particular, it-capacity or forced-flow :onditions — and resulting delays, lueues, and backups onto the Central Artery — will increase from five hours ?ach commuting weekday in 1982 to 14 lours (generally from 6 AM to 8 PM) in iOlO . Truck percentages on the major roads are expected to be similar to L982, with the exception of D Street In South Boston, which will experience Increased truck volumes due to new development in the northern industrial Seaport area. In East Boston, traffic in 2010 is expected to increase by approximately 39 percent on Porter Street, and on Maverick and Sumner Streets by about 12 percent. For the downtown Boston streets analyzed, AWDT increases in 2010 under jthe No-Build Alternative range from a low of about 12 percent on North Washington Street to a high of about 145 percent on State Street. This increase is due to various factors, including new development and regional growth, but primarily due to motorists attempting to short-cut the severe congestion on the Central Artery. Typical increases are on the order of 30 to 60 percent over existing conditions. Truck percentages, for the most part, are expected to remain as existing for downtown Boston streets . Peak Hour Volumes Future 1990 and 2010 peak hour traffic volumes are summarized in Table 2. Growth of peak period traffic demand between 1990 and 2010 for the major links of the No-Build condition appears to be most pronounced during the PM peak hour. As can be seen by examining Table 2, peak hour growth from 1982 to 2010 on the Mystic-Tobin Bridge is projected to increase by approximately 0.5 percent per year, while the Callahan/Sumner Tunnels are projected to experience a 1.2 percent annual increase during this period. These additional demands will exacerbate the poor operating conditions currently experienced on the major highway network. Future V/C Ratios and Levels of Service Highway Facilities Future (1990, 2010) peak hour No-Build Alternative v/c ratios and levels of service are presented in Table 2. AM Peak . By 2010, northbound traffic conditions are expected to deteriorate further to LOS F on the Central Artery and Southeast Expressway from Columbia Circle to Causeway Street. Traffic flow on the High-Level Bridge will improve to LOS C because of the proposed Central Artery North Area Project by 1990, but will degrade to LOS E by 2010. Both the Sumner and Callahan Tunnels are expected to operate at LOS F in the AM peak . 63 Southbound Artery/Expressway traffic conditions during the AM peak hour will be LOS F from the Mystic-Tobin Bridge to the Albany Street on-ramp by 1990. Congested conditions and delays will be exacerbated by increasing traffic demand through 2010. PM Peak . By 2010, northbound traffic conditions will be at LOS F from the Berkeley Street/West Fourth Street interchange to the High-Level Bridge, with LOS E operations extending back to the Columbia Road ramps. LOS F conditions will prevail in 2010 in the southbound direction, from the Mystic-Tobin Bridge to Columbia Road. Both the Sumner and Callahan Tunnels will also operate at LOS F during the PM peak period, because of increasing cross-harbor traffic demand. As an indication of the increased congestion expected on -the major study highways, an estimate of the number of congested hours of operation (LOS E or F) on an average day has been made for the No-Build Alternative in 2010, compared to existing conditions. Reference is made to Table 34 presented in Section 4.2 TRANSPORTATION for a complete listing of these estimates. On the Central Artery south of the tunnels, congestion will increase from 5 hours in 1982 to 13 hours in 2010 travelling northbound and from 5 hours to 12 hours, travelling southbound. North of the tunnels, congestion will increase from 8 hours in 1982 to 12 hours in 2010 for northbound traffic, and from 4 hours to 8 hours for southbound traffic. The congestion in both the Callahan and Sumner Tunnels will increase from 5 hours per day in 1982 to 14 hours per day in 2010. On the Southeast Expressway at Southampton Street, congestion will increase from 4 hours in 1982 to 9 hours in 2010 inbound and from 4 hours to 13 hours, respectively, in the outbound direction. Likewise, congestion on the High-Level Bridge inbound will increase from 4 hours in 1982 to 5 hours in 2010, despite improvements from the Central Artery 64 North Area Project. Intersections and Local Stre b South Boston Intersections , hi shown in Table 2, 11 out of 15 of te] key intersections in South Boston wlj be operating at LOS E or F in the A peak hour by 2010, as compared to 5 intersections today. During the PM peak hour, 8 of the 15 intersection will be operating at LOS E or F undc No-Build conditions in 2010, as compared to 5 intersections current^, East Boston Intersections , y 2010, as Table 2 indicates, 4 of th 16 key intersections will be operatic at LOS E or F during the AM peak hor; as compared to 2 East Boston intersections today. During the PM peak hour, 5 of these intersections will be operating at LOS E or F, as compared to 3 intersections in 1982 Bell Circle, Revere . Bell Circle is expected to operate at LO: Pj in both 1990 and 2010, during the Al and PM peak hours, as compared to L<; F and D at present. City Square, Charlestown . Reconstruction of the City Square surface roadways (part of the Centr<. Artery North Area Project) will rest in improvements in geometry and traffic flow conditions by 1990 as compared to existing conditions. As proposed, the existing rotary at Cit; Square will be replaced by a signalized four-way intersection (Chelsea Street/Rutherford Avenue/I-: ramps) controlling traffic movements between the local roadway system anc the highway system. Although the traffic operations will be improved because of these geometric and other revisions, City Square will continu€ to be congested. Downtown Boston Intersections Of the 20 intersections analyzed in the downtown Boston area, during the AM peak hour, 2 additional intersections will operate at LOS E ' F in 2010. During the PM peak hour, three additional intersections will operate at LOS E or F in 2010 as Table 3 EXISTING AND FUTURE NO-BUILD INDIVIDUAL PEAK HOUR QUEUE LENGTH COMPARISON* ( IN MILES) Northbound Exp. /Artery Queue Sou roe 1982 1990 AM PM AM PM 2010 AM PM Columbia Road On- Ramp Mass. Ave. On-Ramp Frontage Rd./E. Berkeley On-Ramp Mass. Pike On-Ramp Northern Ave. or Atlantic Ave. On- Ramp Callahan Tunnel Of f -Ramp Storrow Drive Off- Ramp High-Level Bridge (I-93/Route 1 Merge) 0.2 0 n.c . ** 1 0.6 0 0 n.c .** 0.1 0.5 1.0 0. 3 0.9 0.5 0.5 0 0.8 0.5 0.5 1.3 0.6 1.2 0.8 0.1 0.9 0.1 0.9 0.7 2.0 1.9 2.0 Southbound Exp. /Artery Queue Source Hi gh-Le vel Br i dge (I-93/Route 1 Merge) C a us ewa y /S to r r ow Dr . Ramps Callahan Tunnel/ Haymarket Off -Ramp Haymarket On-Ramp Purchase/Cong. On-Ramp Mass. Pike On-Ramp Albany St. On-Ramp Mass. Ave On-Ramp Columbia Road On- Ramp * Queues are not additive ** Not calculated. 2.1 0 0.5 0 0.1 n.c .** n.c. ** 0.7 n.c. ** 0.6 1.4 0. 3 0.6 0 0 0 0 0. 3 0.5 0.5 1.5 0.6 0.2 0.1 3. 2 0. 3 0.8 0 0 0 0 0 0. 3 0 . 5 0.6 1.4 0.5 0.5 0.1 Where overlaps occur, the longest queue prevails 65 compared to the present conditions. Central Artery Bottlenecks and Congestion Points Year 1990 Table 3 summarizes the 1982, 1990, and 2010 individual queues expected on the Central Artery/Southeast Expressway under the No-Build Alternative. As noted previously, queues are not additive. Where they overlap, the longest queue prevails. Generally, 1990 individual queues are expected to worsen considerably in both the AM and PM peak hours, and in both directions. As in 1982, the primary queues will result from the High-Level Bridge merge with the Mystic-Tobin Bridge. Northbound in the AM peak hour, the longest individual queues are anticipated at the Massachusetts Avenue and Massachusetts Turnpike on-ramps to the Southeast Expressway — both will generate queues about one mile long, with slight overlap. In addition, the Columbia Road on-ramp merge is expected to extend the queue behind it for an additional half mile. Further north, the Northern Avenue on-ramp is expected to generate another half-mile queue. Southbound in the AM peak hour, the primary source of congestion and delay, the High-Level Bridge is expected to generate a queue extending back nearly 0.9 miles on 1-93 and 0.6 miles on Route 1. The other two southbound sources of congestion, the Haymarket on-ramp and Callahan Tunnel off -ramp, are expected to generate smaller, though significant, queues on the Central Artery between Haymarket Square and the Storrow Drive off-ramp. Northbound in the PM peak hour, the High-Level Bridge bottleneck is expected to generate a 1.1 mile queue on 1-93 and a 0.8 mile queue on the Mystic-Tobin Bridge (Route 1). This queue will then extend further southward by about a half mile, due to a queue caused by the merge of the Berkeley Street on-ramp. Southbound in the PM peak, a series of individual merge and weaving movements will combine to create a queue extending from the Massachusetts Avenue on-rap to the Haymarket Square area, a distance exceeding two miles in len'-J Year 2010 Queues anticipated on the Central Artery/Southeast Expressway L 2010 are slightly worsened or stay about the same in the northbound direction for both the AM and PM pe<: hours as compared to 1990 condition.'! Southbound, however, the queue from the primary congestion point, the High-Level Bridge, is expected to b< significantly increased, with backup of 1.9 miles towards 1-93 and 1.3 miles towards the Mystic-Tobin Bridton, with a trip time of proximately 55 minutes. Their a >sel leaves Hingham at 7:20 AM and ;ton at 5:20 PM. Finally, : jsachusetts Bay Commuter Services, :a :. schedules eight round trips on •™' 5kdays between the Hingham Shipyard .3 Rowes Wharf using a new high-speed . Lp called the "Gracious Lady." From )f :de hgham, the first trip is scheduled . leave at 7:00 AM, with the last ;ip of the day departing Hingham at -HO PM. From Boston, the day's first jparture to Hingham occurs at 7:30 AM id the last trip leaves for Hingham 7:10 PM. Scheduled trip time is iproximately 25-30 minutes. Waterfront; Government Center; North End; North Station; West End; East Boston; Logan Airport; Route 1A North; and Charlestown. These districts are shown on Figure 10. Major land uses in each area are listed in Table 5, are presented on Figures 11, 12 and 13, and are described in the following subsections . 3.2.1 Overview The project area contains a diversity of land uses. The Fort Point Channel area, Leather District, Financial District, Government Center and North Station areas house public and private offices, commercial and retail activities, transportation uses, and entertainment facilities; these areas have very small residential populations. Predominant activities in northern South Boston are manufacturing, warehousing and food distribution activities. The southern half of South Boston is a large residential community. Future development proposals in :e area are expected to result in ' c i creased traffic demand and "Ebsequently increased public and ivate transit usage. Projections of ture ground traffic generated by tivities at Logan Airport, without nstruction of a Third Harbor Tunnel, dicate an approximate 40 percent crease over existing ground affic. At South station, the amount I bus service will increase ignificantly in the future when 'Ceyhound and its affiliated companies i locate their operations to the I oposed South Station Transportation mmonwealth is also promoting : creased ferry service. : 2 LAND USE This section briefly describes ^nd use in the following districts: :ston; Leather District; linatown/South Cove; Fort Point lannel ; Financial District; The South End, Chinatown/South Cove, the Waterfront, the North End and the West End are significant downtown residential neighborhoods, with a variety of other land uses. Primary land uses in the Industrial Triangle and Route 1A North are light manufacturing, wholesaling and distribution, and storage and maintenance of transportation equipment . The Central Artery is a significant land use component of downtown Boston. The structure of this highway in many instances defines the edges of neighborhoods, and land uses on either side of the Central Artery are quite different. In some cases the physical presence of the Artery has slowed changes which were encouraged by the city; for example, the development of the waterfront south of the Harbor Towers. In other areas, the Central Artery is perceived and commonly cited as protecting the character of an area; for example, in 71 CHARLESTOWN REVERE CHELSEA Mystic River 16/ €AST BOSTON BOSTON HARBOR LOGAN INTERNATIONAL AIRPORT I SOUTH BOi ^Residential. ~ 1 - West End 2 - North Station 3 - North End 4 - Government Center 5 - Waterfront 6 -Financial District 7 - Chinatown 'South Cove 8 - Leather District 9 - South End 10 - Industrial Triangle 1 1 - Fort Point Channel 12 -S Boston 13. 14. 15 - Identified on Map 16 - Route 1A North Figure 10 Neighborhoods in the Project Area 0 800 1600 3200 Feet EIS/EIR for I-90 -Third Harbor Tunnel, I-93 - Central Artery *> O fl £ fcr W B S ft a 2 8 , w o S ET . % 5 d -» 0 * ' - a u a s « fra : " 2 a § ■OK *J v a U U at « ?a I s s u 2 fl u. h 5 s «aop ^ &. 4 3 W .J t j ii 3 -t S " i (/) 0. 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O ft) > o t S 8 £ si fl 3 i3 oo j* u> r M • ■ O c c it ftthMflaOflb 355ff = >.tii | -S?3 • T> O J "* SS5S2' 3 .3552 & 8 cScfuc8lj6a8«ijril 3 5 a . a 3d • mm c 3 M fl « C • — fl ft 0 - *J U u c « 3 k* * D fl _ • fl ■ U U a ■ ft* b 5 fl •O • V fl 11 si* Si25S ifi P CO C O •-* ( 73 the North End. East Boston is primarily residential, with some commercial and retail activity. Sections of East Boston contain airport-related uses such as car rental, parking and freight forwarding. Logan Airport is a full service national and international facility with a full complement of freight forwarding, car rental, hotel and air transport land uses. Two parallel shipping channels are maintained in Boston Harbor, one of 35 feet and one of 40 feet. The Army Corps of Engineers maintains the channels. 3.2.2 South End The South End contains several socially distinct residential neighborhoods lying mostly to the west of Harrison Avenue. These consist largely of older row houses and newer, multi-family developments. The South End's central location, good highway access, and inexpensive land and building space are the basis of its economic activity. An industrial and institutional corridor lies along the Central Artery/Southeast Expressway/ Albany Street. Activities in the industrial corridor include light manufacturing, wholesaling, distribution, and warehousing. Industrial uses are located both in older, often rehabilitated structures, of 5 to 6 stories, and in new low-rise buildings. There are several new multi-story industrial buildings, such as that of New England Nuclear on Albany Street. Most of the smaller businesses have been in their current location for over 20 years. New high tech firms entering the area occupy new or substantially renovated facilities. Major land uses in the area are shown on Figure 11 and listed in Table 5, and include two major hospital complexes, Boston City Hospital and the Boston University Medical Centei There are approximately 1,015,000 square feet of industrial building space in this area. Retail commercial, and institutional activities occupy approximately 613,000 square feet. The South End's older industrei tend to serve a regional market area i largely by truck (approximately 4300 truck trips per week). The newer, high-tech and bio-medical industries require good, primarily automobile, access to the airport and downtown areas . Retail, commercial, and institutional activities generate 21)1 truck trips per week. The two major hospitals, the principal employers i the area, serve the entire region an benefit from their central location i with good highway and reasonable airport access. The future of the South End mi- include continued growth in the institutional, high-tech, and bio-medical industries, and in associated commercial development. However, the older, established industries and commercial businesses anticipate little future expansion. It is likely that truck trips will continue to be generated by a few major sources. 3.2.3 Industrial Triangle — Th is area includes the industrial lands lying between the Southeast Expressway, the West Fourth Street Bridge, Dorchester Avenue, and Southampton Street (see Figure 10). The industries in the 230-acre area include warehousing, food and freight distribution, wholesale suppliers, an public garage and maintenance facilities; all are uses dependent on good truck access to the regional highway network. The area houses approximately 1,180,000 square feet oi space, mostly in large distribution oi warehouse facilities. Major facilities in the area 74 5: are shown on Figure 11 and listed in Table 5. The area generates large volumes of highway-dependent traffic, ooth truck and auto; there are approximately 10,000 truck trips per rfeek, and most of the area's 3150 employees drive to work. Despite 'localized areas of congestion and !t heavy rush hour traffic, the ""Industrial Triangle's central location and proximity to regional highways iS give it excellent access for the ' regional distribution system which is the basis of its economic activity. Companies in the Industrial Triangle are to some extent "interdependent, with substantial truck r volumes circulating between the food distribution centers near Southampton Street and Widett Circle via the Frontage Road, Albany Street, and Central Artery. The one proposal in the area : for future development is the Boston Service Facility, an improvement project by Amtrak at the Cabot Yards, ■Yard 5, and the Southampton Yards. [I The project is under way and ultimately, tracks will be lowered, : and inspection, maintenance, and office facilities will be built. A surface parking lot for 250 cars is planned. Access to the improved yards will be from Frontage Road and (Southampton Street. No private development plans have been identified in the Industrial Triangle. '3.2.4 South Boston South Boston is a 2400 acre peninsula connected to Boston by ten bridges across Fort Point Channel and the railroad tracks west of Dorchester Avenue. South Boston includes residential neighborhoods, heavy , industry, warehousing, transportation ■ facilities, and a large, historically significant park at Castle Island. South Boston can be divided into two distinct areas of nearly equal size: the northern industrial section, and the southern residential section. The division of these areas occurs approximately at First Street (see Figure 10). A smaller industrial area lies between Old Colony and Dorchester Avenues. Land use in the southern section is predominantly residential, with some retail and commercial activities aimed primarily at local residents with neighborhood business districts along West Broadway and East Broadway. Major facilities in the area are shown on Figure 11 and listed in Table 5. The northern section of South Boston is one of the city's largest industrial areas. The majority of land in this area is owned by Massport and the Economic Development and Industrial Corporation of Boston (EDIC), with several major parcels leased to private businesses. Industrial uses include trucking, warehousing and distribution, marine industries, fuel farms, and power plants. There are also a growing number of office buildings in the area and several commercial and retail establishments. These activities are located in South Boston because of its port facilities, large areas of relatively inexpensive land, and proximity to downtown Boston. The area immediately to the east of the Fort Point Channel contains a mix of land uses and is slowly changing from an industrial to a commercial and residential area. There are approximately 100 existing residences near Fort Point Channel; these include both developer-financed condominiums and artists' lofts. In addition there are many small businesses, including light industrial, commercial and office establishments in this area. The Gillette Company, a research and manufacturing firm with 3,200 employees, occupies a 29-acre site near the Fort Point Channel. The Boston Wharf Company has 75 I substantial land holdings in this area and plans residential and office development. Stone & Webster Engineering Corporation is converting a warehouse structure into office space for 900 employees. Cabot, Cabot & Forbes plans to develop former Penn Central properties into a major office site. Piers 1-4, owned by Anthony Athanas, are the proposed site for 1.7 million square feet of offices, two hotels, residential development and a major marina. Massport is a major land owner in South Boston. Plans for Massport property include a Computer Trade Center on Commonwealth Pier (BOSCOM) and nearby parcels; long-range plans for light industrial and office use on Commonwealth Flats; expansion of fish processing on the Fish Pier; and a container port at the Massport Marine Terminal, under lease from EDIC. The Boston Marine Industrial Park, a 101 acre area to the east of the Fish Pier (formerly the South Boston Naval Annex), is also under EDIC jurisdiction, and contains industrial and marine-related uses. Across the Reserve Channel and to the east of Commonwealth Flats is the Castle Island industrial area, including the White Fuel storage and fuel transfer facility, a major generator of hazardous cargo truck traffic. Another distinct land use area within South Boston is the South Cove area, which lies southwest of the Dorchester Avenue Bridge. The South Cove contains railroad tracks and storage, MBTA property, vacant parcels, and the back end of Fort Point Channel. 3.2.5 Fort Point Channel Fort Point Channel is located between Boston and the northern section of South Boston. The land lying between the Channel and Atlantic Avenue is described as the Fort Point Channel area. The area which lies to the east of the Channel was described above as part of South Boston. Major facilities are shown on Figure 11 and listed in Table 5. The South Station area is occupied mostly by large public facilities, including several transportation facilities undergoing I renovation. Over 3.5 million ridersi each year use the railroad and commuter rail facilities at South Station. The South Postal Annex, Boston's central mail distribution facility located adjacent to South Station generates 900 truck trips pe. week and employs 4,500 people at thi facility. Also located in the area are the Trailways bus station, and MBTA subway car storage. t Until recently the Boston sid of Fort Point Channel was dominated warehouses and vacant land used for parking. Recently, the area has beei the site of significant office development; from the Harbor Towers complex to the Stone and Webster building on Summer Street, the area almost entirely devoted to profession office space, reflecting its locatior on the periphery of the Financial District. (Although the Central Artery west of Atlantic Avenue remair a barrier to the downtown Financial District, its influence as a dividinc line has declined as more office buildings have been built or renovate east of it.) A small number of retai establishments serving office employees are located on the ground floors of several office buildings. Approximately 12,000 employees work over 3 million square feet of office space; many of them park across the Fort Point Channel in South Boston. The Channel area, a potential National Register Historic District, has been the focus of several marine oriented recreational land use concepts. The Boston Harbor Associates, Boston Educational Marine Exchange, Boston Conservation Commission, Sierra Club, and other groups have presented concept plans o voiced support for such plans. Access problems and poor water quality have hampered revitalization of the area, particularly for recreational uses. The Channel has a navigable 20-foot channel which is usable as far as the Congress Street Bridge. Neither the c i fict 78 igress nor bummer Street Bridges can opened to allow boats to go further ;o the Channel. ! .6 Leather District The Leather District is a nine )ck area of mostly five- and c-story brick loft structures built the 1880's. It is located one >ck west of Fort Point Channel. Major land uses in the area are )wn on Figure 11 and listed in Table l ^ and include office, warehousing, ^ tyiuf acturing and commercial; there /e also been some conversions to sidential use. Manufacturing uses lude the Teradyne Co., an ectronics firm with approximately 3 employees, and several small firms Irving the restaurant industry in ^larby Chinatown. Commercial uses delude warehousing, office space, and Itists' studios. Office space in the ea increased by nearly one million uare feet with the recent completion the Dewey Square Office Tower to er 1,300,000 square feet. Land use in the area is anging, from the traditional ather- and garment-oriented firms ill occupying space in the district a variety of newer businesses for ich multi-story space is suitable d proximity to downtown is portant. Proximity to South Station an additional benefit. Renovation the existing structures has arted, and will almost certainly ntinue over the next twenty years. The District's historic status both an amenity for office uses and source of investment tax advantages. Infill development (development scattered vacant lots) and some :e* development is likely; property e\lues and employment are expected to i crease. Trends indicate that future ]nd use will probably be a mixture of isidential, commercial, office, and J ght manufacturing uses. 3.2.7 Chinatown/South Cove Chinatown/South Cove is a predominantly Chinese residential neighborhood within a light industrial district. Major institutional and commercial uses are also located in the area. Buildings are typically four- to seven-story warehouses and older, medium-rise office buildings. Housing units are concentrated in three large towers and in a number of three-story brick row houses. The Tufts New England Medical Center is a major institutional land use in the district . Businesses located in the area are strongly linked to the Chinese community, both as a source of labor in the garment industries and as the primary patrons of the area's retail businesses. Clothing manufacturing, the major industrial use in this neighborhood, takes place in a number of small firms along Kneeland Street. The area to the north of Kneeland Street is primarily commercial, containing restaurants, import-export firms, and several Chinese-language movie houses. South of Kneeland Street the area is primarily residential and institutional, with a small number of retail establishments, chiefly food stores, geared to the local market. Major facilities are shown on Figure 11 and listed in Table 5. South of Kneeland Street most development activities are being initiated by Tufts University. Tufts has recently acquired two buildings occupied by garment manufacturers which it plans to convert to institutional uses. A new Tufts library is also planned. The institutional facilities have little interaction with the other businesses in the district apart from providing restaurant patrons. The BRA is trying to encourage the construction of residential buildings in Chinatown/South Cove. 79 North of Kneeland Street, however, former garment industry buildings are being converted to commercial space by private property owners. 3.2.8 Financial District The Financial District lies between Boston's downtown retail district to the west and the Central Artery to the east. It is the banking and financial center for the Boston metropolitan area and, to a large extent, for New England. The Financial District covers approximately 40 square blocks and consists of multi-story office buildings, with first floor retail activities. The Financial District comprises two fairly distinct zones separated by the High Street exit ramp from the Central Artery. Major land uses are shown on Figure 12 and listed in Table 5. One area, centered on Federal and Franklin Streets, is composed of new high-rise buildings occupied primarily by banking, insurance and related firms. Continued development of new office towers and renovation of existing buildings is occurring in this area. The largest development site is the Fort Hill Garage site, where one to two million square feet of office space is under construction. This zone also includes the new Meridien Hotel and Devonshire Towers, the first residential development to occur in the Financial District. The second area, centered around Broad Street, is characterized by five- to six-story buildings and an irregular street pattern. The Broad Street area was originally laid out by the architect Charles Bulfinch and contains many attractive commercial buildings from succeeding periods. The Custom House National Register Historic District is located within this area and includes State Street, the original main street of commercial Boston. Significant recent rehabilitation has taken place in this area, and many of the older buildings now house prime office space. Two 25-story office buildings are currently under construction near te intersection of Franklin and Oliver Streets. Downtown Crossing, Boston's retail core, is adjacent to the Financial District. Lafayette Plac^, a major retail and hotel developmem with about 225,000 square feet of retail space, opened in 1984. 3.2.9 Waterfront The Waterfront area contains commercial, office and residential uses. Faneuil Hall Market Place anc the New England Aquarium draw substantial tourist traffic to the area. Renovation activities began ii 1964, when the Waterfront was designated as an urban renewal area. Waterfront property is now extremely valuable, and most recent developmer has focused on luxury commercial anc residential markets. See Figure 12 and Table 5. West of the Central Artery tfc district is occupied by Faneuil Hall Market Place and the Blackstone Block. Buildings are primarily historic three- to five-story brick granite structures. Faneuil Hall Market Place attracts 12 million visitors per year and is a major retail center. Adjacent to the Mark is Boston Redevelopment Authority (BRA) Parcel D-10, a surface parking lot currently being developed for office and retail uses. Recent developments in the area include the 153-room Bostonian Hotel and a 680-c garage. The Haymarket area along Blackstone Street houses fresh food specialty shops, and is the site of open air market on Fridays and Saturdays. A pedestrian underpass crossing under the Central Artery links Haymarket with the North End. The area lying between North Street, the Central Artery and Atlantic Avenue is composed of four- to six-story brick and granite buildings which are primarily residential. Two large housing 80 =velopments for the elderly and a 0 jrsing home serving North End jesidents are also located in this jcea. East of Atlantic Avenue are a sries of wharves occupied by : Dmmercial, office and residential ses. Cruise, ferry and private boats :Qft ock at a variety of wharf locations, tiristopher Columbus Park is a large ark heavily used by Boston residents nd tourists. The buildings on the harves south of Long Wharf (State treet) are relatively new, and nclude the Harbor Towers condominium s uildings and the New England quarium. South of Harbor Towers is no he Rowes/Fosters Wharf, now being eveloped with office, retail and esidential uses. i North of Long Wharf, and ontinuing to Union Wharf, the wharf uildings are mostly three- to 4 our-story 19th century granite "° arehouses which have been converted o commercial, office and luxury esidential space. Further to the orth, non-residential uses, including he Bay State Lobster Company, iJ currently predominate. Two esidential development sites are inder preliminary discussion: '^argent's Wharf, owned by the BRA, and n MBTA Powerhouse being considered or rehabilitation as low-cost housing y a non-profit developer. :t 1.2.10 Government Center Government Center contains the lajority of the City of Boston's mblic offices, the major Federal >ffice buildings in Boston, and a lumber of State and County offices. ?he functional area of Government .'enter extends across Cambridge Street :o include the Suffolk County rourthouse and several State office )uildings. In addition to government )ffices, there are several large >rivate office buildings, parking facilities, and small shops and restaurants which serve the area's /orkers. There are no residential structures in the district. The physical layout of the area is quite different from most of Boston, with wide, heavily travelled streets bordering large "superblocks . " The most significant landmark in the area is City Hall Plaza, which is both the major pedestrian circulation space in the district and the site of public demonstrations, performances, and city events. Major uses are shown on Figure 12 and listed in Table 5. Boston City Hall, the State Service Center and the JFK Federal Office Building draw a great number of visitors to the area each day. Limited parking facilities cause many people to use public transportation; the Government Center MBTA Station serves area employees, people making business trips, and a significant number of tourists visiting the historic downtown and Waterfront areas . There are two publicly-owned vacant development parcels in this area: BRA Parcel 7, and the parcel at the intersection of Merrimac and New Chardon streets. 3.2.11 North End Directly north of the Waterfront and bounded by the Central Artery, North Washington Street and Boston Harbor lies the North End, one of Boston's oldest neighborhoods. Although separated from downtown Boston by the Central Artery, the North End is within walking distance of Faneuil Hall, Government Center, and the Financial District. Much of the North End is only a short walk from major public transportation services at Haymarket, Government Center and North station (Green Line, Orange Line, Blue Line, Commuter Rail, bus ) . The North End is architecturally homogeneous, with three- to five-story brick buildings lining narrow streets. It is largely residential, but also houses a significant commercial district consisting of small shops and 81 restaurants on the ground floors of residential buildings. The district is a major regional center for ethnic shopping, serving the large Italian-American population of metropolitan Boston. See Figure 12 and Table 5 for identification of major land uses in the area. Housing is the primary land use in the North End. At one time, the housing stock consisted primarily of rental units, but there are an increasing number of condominiums. The major commercial section of the North End is located around Hanover and Salem streets. Thousands of tourists visit the North End each year to follow the Freedom Trail past Paul Revere' s house, the Old North Church and other historic sites. Located on the periphery of the North End are larger businesses and institutions that are city-wide or regional in character. Expensive professional space has recently been developed on the eastern edge of the North End, essentially as an extension of the Waterfront district. 3.2.12 North Station The North Station area lies between the Charles River, the Central Artery and Government Center. It contains retail, commercial, government, office, institutional and manufacturing uses (see Figure 12 and Table 5). Major facilities are the MBTA's North Station commuter rail terminal and transit facilities, the Boston Garden sports arena, the Anelex Building, the Massachusetts Registry of Motor Vehicles, the Spaulding Rehabilitation Hospital, and the West End Pussycat Cinema. Commercial, retail, manufacturing and office uses are concentrated along Causeway Street . The Bulfinch Triangle lies south of Causeway Street between North Washington Street and Merrimac Street. Its three- to nine-story brick buildings contain primarily manufacturing, commercial and warehousing uses. Private rehabilitation of buildings in this 19th century industrial district is ongoing. The North station area presently contains a great deal of land used for surface parking; approximately 2,300 parking spaces exist. Roughly 60 percent of these are designated employee parking for the Massachusetts Department of Publ Works, Massachusetts General Hospita and the Spaulding Rehabilitation Hospital . Bra At this time, the Boston Redevelopment Authority (BRA) is undertaking a federally-assisted urb renewal project in the North Station area. Recent planning studies have divided the area into three sections Railyard and River Edge; North Station/Boston Garden Area; and Bulfinch Triangle. Redevelopment is currently in progress for the North Station/Boston Garden section (BRA Phase I), including construction of major General Services Administratio (GSA) Federal Office Building. Othe potential improvements in this area include relocation of the MBTA Green Line transit facilities; constructioi of a new Boston Sports Arena or othei facility above extended MBTA commute); rail tracks; construction of a parkiifl garage adjacent to Lomasney Way and the elevated Storrow Drive/Central Artery Connector Ramps; and discontinuance of a portion of Nashuc ■ Street (part of the GSA project). Construction of these improvements i expected to continue over the next decade. Planning is under way for tl Railyard/River Edge section (BRA Phas II). Construction of any improvement in this section are not anticipated until 1990 or later. The new Charles River Dam has two recreational and one commercial lock which allow access into the Charles River, whose 16-foot deep channel is maintained by the U.S. Arn Corps of Engineers. 82 2.13 West End The West End lies between ; aeon Hill, the Charles River, and ; : vernment Center. Until the late : 50s, the West End was composed j imarily of early 20th century I ve-story apartment buildings. These ;>w-rent buildings were razed in the urly 1960s during one of Boston's urliest and largest urban renewal |:ojects. The 45-acre site is now ccupied by Charles River Park, a uivelopment consisting of eight a li L gh-rise apartment towers, a lbsidized apartment tower for the • Lderly, an office building, a small jmmercial building, a synagogue and iree parking garages. Landscaped iths wind through the development, b .,id no through streets cross the n rea. See Figure 12 and Table 5 for ajor area land uses. South of Charles River Park, le area has primarily institutional ; ses, including Massachusetts General Dspital, Massachusetts Eye and Ear nfirmary, the Suffolk County Jail and ^wo churches. Charles River Plaza, a ] hopping center along Cambridge !: treet, contains stores, movie heaters, restaurants, a major hotel , nd a large privately-owned parking r rea. There is one undeveloped parcel it Charles River Park at the ntersection of Lomasney Way and taniford Street; no proposals are nder consideration at this time. The Remainder of the West End is fully eveloped . 1.2.14 Charlestown Existing conditions in t harlestown are described in the Final nvironmental Impact Statement for .S. Interstate Route 93 and U.S. oute 1 (Federal Highway dministration and Massachusetts epartment of Public Works, 1979). harlestown is a stable residential ommunity. The housing stock is redominantly older, two- and hree-story structures, with many iulti-family and row houses. Charlestown is also a major employment center, with industrial and warehousing activities located to the west of Interstate Route 93, along Rutherford Avenue, and along the Waterfront. Bunker Hill Community College is also located in Charlestown, north of the John F. Gilmore Bridge and east of interstate Route 93. There are local commercial establishments along Bunker Hill Street and Main Street. Several historic sites, including the USS Constitution and the Bunker Hill Monument, attract visitors to the area. 3.2.15 East Boston East Boston is primarily residential, with scattered retail activity serving local residents in Central Square, Maverick Square, along Meridian Street, and in first floor corner stores throughout the neighborhood. Industrial and commercial activities are found in Jeffries Point and in the area around the intersection of Bremen and Porter Streets . Jeffries Point, a distinct neighborhood within East Boston, lies east of the Conrail railroad right-of-way, south of Logan's Southwest Service area and west of Jeffries Cove. It is primarily a residential area. Row houses and triple-deckers cover the hill between the airport and Marginal Street. Most commercial uses in East Boston are predominantly airport- related. These include car rental agencies, parking lots, and freight forwarders. An airport-related commercial and industrial corridor parallels the Conrail railroad right-of-way and Route 1A through East Boston . Business-related traffic to the airport is heavy. Businesses located in East Boston, off the airport but accessible to it, benefit from much lower site costs than on-airport competitors. Airport-related commercial uses have grown considerably in recent years and pressure for future growth is likely to continue, constrained primarily by the lack of land with suitable access to the airport and the tunnels; property values for this type of land are likely to increase. New residential and commercial development based on excellent views of the Harbor and Boston skyline has been proposed for waterfront sites. However, the market for such development is unproven, and its occurrence is uncertain. The Massport piers property on which new commercial development may occur is dependent on negotiations yet to be resolved between that agency, the community, and the BRA. The piers and other possible development sites are shown on Figure 11 and listed in Table 5. 3.2.16 Logan Airport The project area includes portions of the Bird Island Flats development area, the Southwest Service Area, Central Area, and smaller portions of the Terminal Area and North Service Area (see Figure 11 and Table 5). Activity at Logan Airport is related to airport passenger and cargo movements. Beyond these primary functions performed by the airlines, there are a range of airline-operated support activities, such as catering and maintenance, and several businesses oriented to airline passenger services, such as parking, car rental, concessions, and a hotel. Bird Island Flats is the site of the Massachusetts Technology Center. Phase 1 of the project, a building housing 180,000 square feet of high-tech, light-industrial uses, was completed in 1984. Phases 2 and 3, scheduled to be built over the next six years, include 237,000 square feet of office space, 308,000 square feet of light-industrial space, a 270-room conference center, and 1,030 structured parking spaces. An air cargo and general aviation facility is also being constructed on Bird Island Flats. Passenger travel is forecasted to grow moderately over the next 20 years, but such forecasts are uncertain owing to basic changes in the air travel industry. Continued reliance on automobiles, including rental cars, as the primary access mode to the airport is likely. Airport growth is likely to take place in an expanded terminal area; in new car rental and support facilities in the North and Southwest Service Areas; and on Bird island Flats. 3.2.17 Route 1A North This area consists of the land with frontage on Route 1A from Curtis Street in East Boston north to Bell Circle in Revere (see Figure 13 and Table 5). Land uses are largely industrial or highway-oriented commercial, and most parcels are large, ranging upward from two to foun acres. Some residential areas lie near the highway but are separated from it by differences in elevation of 10 to 30 feet. Fuel storage, primary metals fabrication, and clothing manufacture are the principal industrial activities. Numerous airport and highway-related activities, such as freight forwarding, commercial parking, gasoline stations, hotels, and restaurants are located here as well. Two major attractions which together draw over 3 million people per year are Suffolk Downs Thoroughbred Racetrack and the Wonderland Dog Track. Approximately 310,000 vehicle trips per week are made over Route 1A North. The commercial activity which occurs in this area is dependent on this traffic. There is very little interaction with the East Boston, Chelsea or Revere neighborhoods. In the future, some infilling by industrial and airport-related uses such as freight forwarding operations 84 Match Line A Q> > 4 3 I- o CC ■ gure 13 oute 1A North lajor Land Uses ' 250 500 1000 Feet 3/EIR for l-90-Third Harbor Tunnel; l-93-Central Artery egend Suffolk Downs Race Track Entrances '. Wonderland Race Track I Ramada Inn Car Rental ; - Fuel Tank Farm . Bellesteel Fabricating Plant ' P&L Sportswear h Towle-Leonard Factory Match Line A will probably occur in this area. There will be an emphasis on airport related uses by private interests. 3.3 NEIGHBORHOOD CHARACTERISTICS AND COMMUNITY FACILITIES Neighborhood characteristics and community facilities in the neighborhoods lying closest to the tunnel alignment are described in this section. Major community facilities in these neighborhoods are listed in Table 6 and are shown on Figures 14 and 15. Neighborhood characteristics and major facilities are described below. Primary sources of information on population and housing are U.S. Census of Population and Housing (1980), the 1979 Boston Redevelopment Authority (BRA) Household Survey and BRA Neighborhood Profiles. 3.3.1 South End General Characteristics The South End was developed between 1858 and 1875 on newly filled land as a single-family row house community for the relatively affluent. In the late 1800s, the neighborhood became a working class district of rooming houses and tenements and an enclave for immigrants. By the 1950s, population had started to decline rapidly, and in 1965 over 50 percent of the existing buildings were judged by the BRA to be in substandard condition. Between 1950 and 1970 the total population of the South End decreased dramatically. The population of the South End in 1950 was 57,218; by 1960 the figure had declined 38.8 percent to 35,002. The South End suffered a further 35.2 percent population loss between 1960 and 1970, to a low of 22,680 people. This trend was reversed in the years 1970-1980 when the South End population grew to 28,254, an increase of 25 percent. The proportion of the population under age 18 decreased from 27 percent to 22 percent, a decrease of 19 percent in share; while the proportion of the population over ag< 65 decreased from 17 percent to 12 percent, a 29 percent decline in shai The total number of housing units rose by 25 percent between 197C and 1980, and the vacancy rate dropp? from 18 percent to 12 percent. Rente units made up 87 percent of the 1980 housing stock, a 4 percent drop from 1970. Home values more than tripled between 1970 and 1980, and rents more than doubled. The average 1980 home value was $67,143 and the average rer was $184 per month. According to a 1980 BRA Household Survey, the South End population has a broad ethnic mix. Only 67 percent of the residents spea English at home, as compared to 85 percent for the City of Boston as a whole. Project Study Area The South End project area includes the area bordered by Herald Street, the Central Artery/Southeast Expressway, Massachusetts Avenue and Washington Street. Its neighborhood characteristics differ not only withi: the project area boundaries, but also as compared to the South End as a whole or Boston as a whole. The South End project area encompasses an industrial corridor anc two large public housing projects which contain 46 percent of the project area's population. In 1980, 73 percent of the housing units in Boston were rental units; the rate foi the project area was 95 percent. The widespread renovations which are occurring in other parts of the South End are evident only to a very limited extent in the project area. 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H u o - n ^ in io r © cp c~> -1 i^iV^rtu \\ \\ \V3^= \S$\ \\ \\ % \ Route 1A ,>'■■• 14 1U I- o a Figure 14 Community Facilities - 1 EIS/EIR for I-90 - Third Harbor Tunnel; 0 450 900 1800 Feet Legend — Neighborhood Boundaries 1 Community Facilities Identified in Text increased by 43 percent. In 1980, 23 percent of the project area population was under age 18 and 15 percent was over age 62. The population in the two housing projects had unusually high concentrations of people under age 18. The areas experiencing renovation had significantly lower concentrations of people under age 18 and over age 62 (12 percent and 6 percent, respectively). The 1980 average rent in the project area was $191, a 105 percent increase over 1970. The 1980 vacancy rate of 17 percent represented a 42 percent increase over the 1970 rate. The 1980 vacancy rate at the Cathedral Sguare Housing Project, located between East Brookline and Maiden Streets, was 38 percent; while the Castle Square Housing Development, located between Herald and East Berkeley Streets, had only a 2 percent vacancy rate in 1980. The area south of East Concord Street is the only area with a significant number of owner-occupied homes, many of which have been renovated recently. Between 1970 and 1980, the average value of owner-occupied homes in this area increased from $14,700 to $61,300, an increase of 317 percent. The residential neighborhoods of the South End do not share a cohesive district-wide civic structure or identity. Organized by geographically distinct neighborhood areas and block associations, there is relatively little social interaction between areas. Individual neighborhoods tend to have independent positions on issues, such as gentrif ication (the renovation of residential structures by persons of higher income than those already living in the area), which affect the South End as a whole. Presently, there are nine active neighborhood associations and a dozen block associations and tenant councils. Each one tends to be relatively homogeneous in the ethnic and economic characteristics of its members. Community Facilities The South End project area contains very few community facilities; most of the facilities serving this area are located west of Washington Street . The major community facilities located within the project area are identified on Table 6 and Figure 15. 3.3.2 South Boston General Characteristics South Boston's residential community encompasses the area stretching from Dorchester Avenue on the west to the Harbor on the east and south. Its southern section is divided into six distinct neighborhoods: City Point, Telegraph Hill, Columbus Park, Andrew square, West Broadway, and D Street; the project study area includes parts of the last three neighborhoods. South Boston is a middle income neighborhood with residents of Irish descent making up 46 percent of the population. The area has long been a cohesive community. According to a 1980 BRA Survey, 93 percent of the residents have been raised as Catholics and only 2 percent of the population is non-white. The 1980 South Boston population of 30,372 was 25 percent less than the 1970 population. The proportion of the population under age 18 decreased by 26 percent and the proportion over age 62 increased by 25 percent between 1970 and 1980. The proportion of the 1980 population made up of these two age groups was 23 percent and 20 percent, respectively. The number of housing units declined by only one percent during the period between 1970 and 1980. Rental units made up a consistent 74 percent of the total units during this period, while the vacancy rate rose to 9 percent. Home values rose 121 percent while rents rose only 68 percent between 1970 and 1980. In 1980, the average home value was 89 Figure 15 Community Facilities - 2 ^"^^SC^^^^OO Fee! ^ I ^ EIS/EIR for I -90-1 hird Harbor Tunnel; l-93-^M Legend — Neighborhood Boundaries 1 Community Facilities Identified in Text 15,328 and the average monthly rent is $129. •oject Study Area The portion of South Boston .thin the project area is roughly the ea lying between G Street and the mtral Artery/Southeast Expressway, :om Southampton Street to Summer :reet. The South Boston project area y 66 percent). The proportion of the :otal housing stock made up of rental inits increased only slightly during ;':his same period. The average value )f owner-occupied homes increased 157 percent, compared to Boston's 83 percent increase, but on average, iomes in the study area were still ■forth only 46 percent of the average /alue of homes in Boston during 1980. The future of the South Boston project area will continue to be influenced to a great degree by the D Street housing project. Efforts by the Boston Housing Authority (BHA) are under way to rehabilitate the housing project and return it to full occupancy over the next five years. Probably second in importance to the influence of the D Street housing project is the effect of industrial land uses and through traffic on residential property values in the area. Community Facilities The facilities in the project area are identified in Table 6 and in Figure 14. 3.3.3 Chinatown/South Cove General Characteristics Approximately 5,000 Asian -Americans reside in the district, making it the fourth largest Chinatown in the country. The continuous influx of Asian immigrants and the expansion of commercial and institutional land uses have placed severe pressure on the limited housing resources of the area. The unique character of the Chinatown/South Cove area adds to Boston's diversity, and is a significant downtown tourist attraction. Chinatown/South Cove is a fairly homogeneous neighborhood of low to middle-income Chinese. In the 1960s the area experienced a drastic decline in population due to a reduction of housing as a result of highway, institutional and urban renewal relocation and demolition. Recent relaxation of restrictions on Asian immigration has resulted in a substantial increase in immigrants from Taiwan, Hong Kong and Southeast Asia. Most of the housing in the area is overcrowded, and a large proportion of the buildings are dilapidated. Although most immigrants live in families or are young single people, the community has between four 91 and five times as many households with elderly residents as the city as a whole. Median family income is considerably below that of the city as a whole: in 1970 it was $5100, compared to the citywide median of $9133. This may be partially accounted for by the high concentration of Chinatown/South Cove males in low-paying restaurant activities (77.3 percent) and women working as stitchers in the garment industry (72.9 percent). Some residents are well educated and highly skilled, but are underemployed due to the language barrier. It is estimated that 60 to 80 percent of the Chinese population in this district does not speak English. The Chinatown/South Cove project area encompasses the entire Chinatown/South Cove neighborhood as delineated previously. Community Facilities Major community facilities in the area are listed in Table 6 and shown on Figure 14. 3.3.4 waterfront General Characteristics The Waterfront has been a residential community since urban renewal projects began in the late 1960s. The Waterfront housing stock consists of newly constructed apartments and condominiums and older warehouse buildings that have been rehabilitated for residential use. The population of the Waterfront area increased dramatically during the period of redevelopment; from 280 in 1970 to 2,876 in 1980, an increase of 927 percent. This is in contrast to a population decline of 13 percent citywide during the same period. The average size of Waterfront households is quite small; according to a 1973 survey by the BRA, 40 percent of households in the Waterfront contain one person, and 48 percent contain two people. This 1973 survey also indicated that Waterfront households tend to have high incomes, and 68 percent of the population wer< employed in professional or technical occupations . Only 5 percent of Waterfront residents are under age 18, while th:| age group comprises 22 percent of thd Boston population. The Waterfront's elderly population increased from 4 percent in 1970 to 13 percent in 1980. This increase is attributed td the development of two elderly housir projects which are primarily occupied by residents from the North End. Residents over age 62 represented a constant 15 percent of the Boston population during this period. In keeping with the area's recent population growth, the number of housing units in the Waterfront increased by 981 percent, from 141 ii 1970 to 1,524 in 1980. The proportic] of rental units dropped from 99 percent in 1970 to 79 percent in 1980. Owner-occupied units are condominiums. The vacancy rate dropped from 11 to 6 percent, compan to an increase from 6 to 9 percent ii the city as a whole. Monthly rents increased from $299 (1970) to $697 (1980). This contrasts sharply with the 1980 Boston average of $191 per month. The period of rapid populatior and housing growth is ending as Waterfront development nears completion . Community Facilities There are no schools, churches or public service facilities in the Waterfront area, reflecting the population composition and newness of| residential use in this area. There are several parks, including Christopher Columbus Park, Dock Squar and Curley Memorial Plaza. The Faneuil Hall Market Place and the New England Aquarium are important touris 1 attractions in the Waterfront. The MBTA Blue Line Aquarium Station serve; this area, and Waterfront residents are also served by the nearby MBTA Haymarket Station (Orange and Green 92 .nes). Community facilities are .sted in Table 6 and shown on Figure ,3.5 Government Center ?neral Characteristics Government Center is not a jsidential neighborhood, and has Lmited community facilities which jrve local residents. Government snter does have a significant number k federal, state and municipal 'ffices and services, and the areas srved by these facilities range from pecific sections of Boston to all of assachusetts or New England. ommunity Facilities Governmental offices are ocated in various buildings, 'ncluding Boston City Hall, the John '. Kennedy Federal Building, and the assachusetts Departments of Social ervices, Public Welfare and mployment Security. Social and iealth services are also located in 'he Veteran's Administration 'utpatient Clinic, Jewish Social jervices Building and the Lindemann ental Health Center. The Boston olice Station, District A, serves owntown Boston, East Boston and harlestown. The Cardinal Cushing emorial Park, and City Hall Plaza are •lso found in this area (see Figure 15 nd Table 6 ) . Because this area serves as a egional service center, access is of reat importance. Due to the lack of nexpensive parking, the majority of ; isitors to the area use public ransit. The Government Center MBTA station, centrally located in City iall Plaza, is served by both the ;reen and Blue Lines. Bowdoin itation, near Cardinal Cushing lemorial Park, is the terminus of the ilue Line. Haymarket Station is ;erved by the Orange and Green Lines, ! ind is also the terminus for nine bus ines connecting Government Center ! 'ith various communities in the Boston letropolitan area, and the northern md western suburbs. 3.3.6 North End General Characteristics The North End is an historic neighborhood dating to pre-Revolutionary War days. Although largely Italian and Catholic at the present time, the North End previously housed other immigrant groups. The population of the North End declined by 22 percent between 1970 and 1980, as compared to a 13 percent decline citywide during this same period. The North End population under age 18 decreased by 48 percent from 1970 to 1980, as compared to a 21 percent decrease citywide. The proportion of the North End population over age 62 fell slightly between 1970 and 1980 (from 17 percent to 15 percent), while the senior citizen population of Boston remained constant at 15 percent. There is only one elderly housing complex located in the North End. Census figures show an increase between 1970 and 1980 in both the number of dwelling units in the North End and in housing costs. The number of units increased by 11 percent, 4 percent more than the citywide average, while the proportion of rental units declined by 1 percent. The increase in the total number of housing units is due to relatively new housing such as Casa Maria Elderly Housing (84 units), the conversion of the McLaughlin Elevator Factory into 28 dwelling units, and the subdivision of some larger units into smaller ones. A slight decrease in rental units is the result of condominium conversions, primarily in areas adjacent to the Waterfront. Average North End rents increased from $72 in 1970 to $184 in 1980. This is a 166 percent increase, compared to a 66 percent citywide increase during this same period. The average value of owner-occupied homes increased by 263 percent; citywide, owner-occupied housing values increased by 83 percent. 93 The North End is perceived as a desirable place to live, and the demand for housing has increased, especially among people aged 20-34. The market continues to respond to this demand: 58 units of luxury housing are planned on Commercial Street; over 70 rental units are being developed in an abandoned factory building on the corner of Thatcher and North Margin Streets; and smaller complexes of luxury housing are under construction or for sale on smaller North End lots. Recent census material suggests that new groups of people are moving to the North End, resulting in the escalation of housing costs beyond the reach of many North End residents. Economic pressures are one reason for the outmigration of Italian residents from the North End. Community Facilities Despite ongoing changes, the North End endures as a cohesive ethnic community. Community facilities and services geared specifically to the Italian community are in part responsible for helping to maintain the strong sense of community in the North End. Many of the facilities are located in the central section of the North End (see Figure 15). Those serving the general population are the fire department, branch library, post office and the North End Community Health Center (which has several programs geared specifically to the large elderly population). The North End also has several facilities, such as the North End Union, the Michael Nazarro Recreation Center, the North End Neighborhood Services Center, and the North Bennet Union, which serve special segments of the population including the young and elderly. The North End is a largely Roman Catholic community supporting four Catholic churches. The two largest churches, Sacred Heart and St. Leonard's, offer Masses in both Italian and English. Churches directly or indirectly sponsor several social activities for community residents. The Old North Church is Episcopalian and draws a small congregation from the North End and suburban Boston, and serves tourists and other visitors to Boston. There are both public and private schools in the North End. The North End is part of Boston's School District 7, which includes the West End, South End and Lower Roxbury. The neighborhood contains two public schools and two parochial schools. The area has many parks, playgrounds and other recreation facilities, including a tennis court, a skating rink and a sports complex. :: There are no MBTA stations in the North End; the Haymarket, North Station and Aquarium Stations are located within walking distance. One MBTA bus line connecting Haymarket anc the Army Base in South Boston stops ir the North End. While there is no large supermarket in the North End, many small stores provide Italian specialty p items, bread, cheese, meats, fruits and vegetables. A senior shuttle to the Stop and Shop on Cambridge Street in the West End is available; other residents use cars to shop in supermarkets outside the neighborhood, 3.3.7 North Station General Characteristics Like Government Center, North Station is not a residential community, and there are no schools, churches, fire or police stations or service facilities in the North Station area. There are concentrations of commerce, manufacturing and entertainment facilities, and, as the terminus of the MBTA 1 s north side commuter rail lines, North Station is a major transportation node for Boston. The North Station MBTA transit stop is served by the Green and Orange Lines. Access to these facilities is of prim 94 ; i por tance . The major pedestrian connection ttween downtown and the North Station : eea is Canal Street, which has • 3 icently been improved with widened idewalks and street trees. Other jdestrian access to North Station is la Staniford and Causeway Streets. - I mmunity Facilities Regional facilities, including .ministrative offices of the ssachusetts Department of Mental :alth and Children's Services, the >aulding Rehabilitation Hospital, the issachusetts Registry of Motor ihicles, and the Boston Garden, are '■• >cated in this area (see Figure 15 | id Table 6 ) . in Future community facilities are Lanned as part of the redevelopment :e :curring in this area. An MDC linear an irk along the Charles River 1 jnnecting the Esplanade, new Charles tver Dam and Charlestown, and a jseum or other public building, are art of these redevelopment plans. Lso, as indicated previously, the 111 !3TA Green Line facility at North jtation will be relocated. .0 5: .3.8 West End eneral Characteristics The population of the West End onsists almost entirely of the • esidents of Charles River Park. landscaping, site design and the bsence of through streets within the evelopment all serve to isolate esidents from the surrounding area, esidents of Charles River Park are •' enerally in middle- to upper-income rackets. Households tend to be mall. Many residents are assachusetts General Hospital mployees who are in the area for hort-term positions. Between 1970 and 1980, when everal of the Charles River Park uildings were completed, the West End - : population rose from 2,500 to 4,014, i»n increase of 61 percent. The proportion of the population under 18 years of age remained at 6 percent during this period. As previously indicated, in the City of Boston the total population decreased by 13 percent during this same period, while the proportion of the population under age 18 decreased slightly from 28 percent to 22 percent. The proportion of the West End population over age 62 increased slightly from 14 percent to 15 percent during this period, compared to a constant 15 percent citywide . The total number of housing units in the West End rose from 1,485 in 1970 to 2,457 in 1980, an increase of 65 percent. Rental units comprised over 99 percent of the housing stock of the West End in 1980, as compared to 73 percent in Boston. Vacancies in the West End decreased sharply between 1970 and 1980, from 11 to 1 percent; by contrast, Boston's vacancy rate increased from 6 to 9 percent durinq this period. Average monthly rents have remained higher in the West End than in Boston as a whole; the average monthly rent was $259 in 1970 in the West End, and rose by 68 percent to $438 in 1980. Boston's average monthly rent was $115 in 1970 and increased to $191 in 1980. Community Facilities Community facilities serving West End residents include two churches, a synagogue and a branch library. Massachusetts General Hospital, the Massachusetts Eye and Ear Infirmary and the Shriners Burns Institute serve a regional and national clientele and bring a large number of visitors to the neighborhood (see Figure 15 and Table 6). The Charles Street Jail is a county-wide facility. 3.3.9 East Boston General Characteristics East Boston's residential population is a fairly homogeneous group with strong Catholic and Italian identities. According to a BRA 95 survey, 57 percent of the neighborhood's population is of Italian origin; the next largest ethnic group is of Irish descent, with 17 percent of the population. The East Boston project area is roughly the area lying south of Curtis Street and bounded by Logan Airport and Boston Harbor. In the East Boston project area, population decreased by 16 percent between 1970 and 1980; in some subareas, the population decreased by as much as 25 percent (Boston's population decreased 13 percent). From 1970 to 1980 the percentage of the total population under age 18 decreased by 26 percent, and the percentage of the population over age 62 rose by 36 percent. The high average age of study area residents reflects the area's large elderly population. The actual number of elderly residents increased by 15 percent, even though the total population declined. Although decreasing, the area has a slightly larger proportion of children than Boston as a whole. The proportions of the 1980 population under age 18 and over age 62 were 23 percent and 19 percent, respectively, for the East Boston project area and Boston as a whole. Between 1970 and 1980, the number of housing units in the study area increased by 13 percent, while the vacancy rate increased from 8 percent to 12 percent. In some areas the vacancy rate went as high at 16 percent. Rents increased by 90 percent during this period, and the average value of owner-occupied homes increased by 116 percent. The rates in Boston were 66 percent and 83 percent, respectively. In 1980, rents and home values in the project area were still only about two-thirds as high as in Boston as a whole. The average 1980 value of an owner-occupied home was $24,176 (the Boston average was $36,000). The average 1980 rent was $122. The project area in East Bostoi is a relatively stable community. A large percentage of the population was born in the community and has lived there ever since. The changes shown in the census and BRA statistics for the East Boston project area are broadly similar to those which occurred in Boston as a whole: the population decline is to a great extent the result of the natural aginc i process in the area's families and th« , outmigration of young people beginning j families. However, this part of East Boston has an increasingly larger older population, while the older population of the city as a whole is remaining stable. This suggests that in the next two decades there will be a relatively high potential for neighborhood change. This potential might lead either to increased housinc, vacancies or to some form of gentr if ication which might provide housing opportunities for the area's young people to set up their own households. The outcome will probabl be influenced both by East Boston's amenities and by its environmental characteristics such as noise and air pollution, which vary significantly among East Boston neighborhoods. Community Facilities The service areas of the community facilities encompass several East Boston neighborhoods. The residential areas on each side of the Conrail railroad right-of-way are considered to be distinct neighborhoods by most residents — Central/Maverick to the west, Mt. Carmel and Jeffries Point to the east — but almost every community facility on either side of the railroad right-of-way is used by residents of both sides. This is true of schools, churches, social service agencies, recreational facilities, retail areas and places of employment. The major community facilities in the East Boston project area are identified in Table 6 and in Figure 14 As a predominantly Roman Catholic community, East Boston's I rish churches are both gathering tints for community activities and \":lineators of different r ighborhoods . There are 10 public 3 =hools in East Boston and 3 parochial shools. The majority of East Eston's public facilities and social " srvice providers are located in the Cntral/Maverick area. A number of facilities serving te general population of East Boston 3 «e in this area, including the police ; ed fire stations, the post office, fle branch library, and the MBTA : ations . ; 4 ECONOMIC ACTIVITY ";4.1 Overview Terms used in the economic 11 onditions and economic impact "Actions are defined, unless otherwise nted, as follows: Region : The (eater Boston Standard Metropolitan s j:atistical Area (SMSA), roughly all • :onomic activities within Interstate i>ute 495; City : City of Boston; ] o ject or Study Area : all project iibareas, encompassing zip codes U jil08, 02109, 02110, 02111, 02113, 1»114, 02118, 02128 and 02210 'roughly, the Boston Central Business district (CBD), plus the northern ;puth Boston industrial district and ist Boston ) . Economic subareas are based on Lp codes, the geographic unit for e lich employment statistics were ' /ailable from the U.S. Census of Dunty Business Patterns (see Figure 5). The subareas include the Eastern i etail Core (02108), Northern iterf ront/Faneuil Hall (02109), Lnancial District/Waterfront (02110), linatown/Leather District (02111), :>rth End (02113), Government u snter/West End/North Station (02114), e le South End (02118), East Boston 32128) and the northern, industrial nt 1 action of South Boston (02210). conomic sectors are defined by tandard Industrial Classification SIC ) codes, including gr iculture/f ishing ; construction; anuf actur ing ; transportation, communications, and utilities (TCU); wholesale trade; retail trade; financial, insurance, and real estate (FIRE); services; and government. The economic study area is New England's financial capital, the seat of state, city, and county government, a regional center of service industries, a significant manufacturing and wholesale base for the city, and a retail magnet. Total employment in the study area in 1980 was approximately 237,000 workers, approximately 17 percent of total employment in the Greater Boston SMSA. Government offices in the downtown area employed an estimated 50,400 workers in the government sector in 1981. This is almost 60 percent of all government employment in the City of Boston and 25 percent of all government employment in the SMSA. (East Boston and South End government employment has not been enumerated, and thus is not included. However, their shares of government employment are not likely to be significant.) The FIRE (Financial, Insurance and Real Estate), selected services, and government sectors are the dominant employers within the study area. Together, these three sectors account for nearly 160,000 jobs; approximately 67.5 percent of total study area employment. Over a third (37.6 percent) of overall SMSA employment in the FIRE sector is concentrated within the CBD study area. In addition, the study area holds approximately 46 percent of Boston's manufacturing jobs, 49 percent of the City's wholesale employment, and 34.6 percent of citywide jobs in the retail sector. Regional Access' to Logan Airport Within the past ten years, Logan Airport's importance to the regional economy has increased significantly. Over this period, the value of air freight movements for international export from the Boston Customs Region grew by 838 percent, to $245 . 5 million in 1982. Air freight 97 Figure 16 Zip Code Districts Used for Economic Inventory C^^^"""^I00^^^^800 Feel EIS/EIR for I-90 -Third Harbor Tunnel; l-93-Ce* Zip codes 02133, 02203, 02201 , although sW map, were omitted from analysis because the Bureau does not enumerate government emp Source: Boston Redevelopment Authority svements in 1982 accounted for 54 arcent of the value of all aternational export shipments from ne Boston Customs Region, up from 30 ercent in 1972. (Source: U.S. apartment of Commerce; Highlights of .S. Export and Import Trade , FT 90/December 1972 and 1982.) Similarly, air freight ovements are significant to many of he region's manufactured products estined for distant domestic arkets. Two industry groups in articular, machinery and electric achinery and equipment are especially ependent on t ime-sens itive access to ogan. These two industry groups which comprise most of computer roduction and related firms), account or an estimated 51 percent of the alue of domestic air freight ovements from the Boston Production rea. (Source: Department of ommerce, Census of Transportation , Commodity Transportation Survey," 972, 1977.) These two industry roups now account for one- third of egional and statewide manufacturing snployment. Virtually all of these ndustries' domestic air freight •utgoing shipments require same day or iext day service. Neither shipping value nor /eight statistics fully portray the significance of t ime-sens itive air ireight shipments to the high :echnology industries, because they inderstate the importance of service commitments and critical components lelivery to overall business operations. Other regional nanuf acturing industries that are >articularly dependent on : ime-sens itive access to Logan include risheries, paper, and scientific Instruments. Of the total rargo-carrying flight arrivals and iepartures at Logan, 27 to 29 percent )ccur during AM and PM peak hours (Source: Massport). Study Area Employment by Sector Table 7 presents a summary of employment within the study area by sector . The study area's FIRE sector employed 39,975 people in 1,266 establishments in 1980, representing 69.6 percent and 37.6 percent of total financial sector employees in the city and SMSA, respectively. Citywide employment in this sector is expected to increase 22 percent between 1980 and 1990, according to recent BRA est imates . With 69,574 workers in the study area in 1980, the selected service sector employed 29.4 percent of total study area workers. This sector contains the largest number of employees in the study area. Except in the North End and South Boston (industrial) subareas, this is also the most prominent sector in terms of establishments. Although not as centralized as the FIRE sector, the selected service sector in the study area captures 46.1 percent of the city's and 17.5 percent of the SMSA's total service sector employment. Manufacturing, which is concentrated in the South Boston (north) and Chinatown/Leather District subareas generates 10.3 percent of the study area's employment (24,517 jobs). Although not as dominant an employer as the service or financial sectors, manufacturing employment in the study area constitutes 45.9 percent of all manufacturing jobs in the city, and 52.7 percent of the city's manufacturing establishments. On a regional level, manufacturing in the study area accounts for 8.3 percent of SMSA manufacturing employment. Citywide, manufacturing has declined by a small percentage since 1975, and is not expected to increase during the 1980s. Transportation, communication and public utilities employ only a small share of the study area's workers (7.2 percent), but the study area contains 48.9 percent of the city's employees in these sectors and 24 percent of the SMSA's TCU employees. These sectors are most dominant in East Boston, where they constitute 38.8 percent of East Boston's employment, and are 99 Table 7 STUDY AREA EMPLOYMENT BY SECTOR Number of Percent Employees of Sector in Study Area Total Selected Services 69,574 29.4 Government* 50,400 21.3 Finance, Insurance and Real Estate 39,975 16.9 Manufacturing 24,517 10.3 Retail | 18,168 7.7 Transportation, Communication and Utilities 16,945 7.2 Wholesale Trade 11,491 4.8 Non-classifiable 3,488 1.5 Construction 2,106 0.8 Agricultural, Forestry, Fishing and Mining 226 0 . 0 236,890 99.9 ♦Does not include government employment in the South End and East Boston, however, their shares of government employment are not significant. 100 nerally dispersed throughout the st of the study area, ranging from 2 11 percent of total employment in e other subareas. Retail trade provides 7.7 rcent of total study area iployment, with 18,168 workers in :33 establishments. With both ineuil Hall Market Place and the •wntown Crossing, the study area mtains the foremost retail center in le city, with 34.6 percent of the .ty's retail employment. Almost 7.6 jrcent of the SMSA's retail employees )rk in the study area, a fairly large hare for such a dispersed sector. ie study area contains the largest jncentration of comparison shopping atail stores in the region (an stimated $373 million sales in 1982). Central Business District (CBD) etail sales in real terms had eclined steadily for 30 years until 977. Since that time, sales have tabilized due to the addition of the aneuil Hall Market Place and the rowth in downtown office employment. BD retail sales and employment are xpected to increase over the next ecade with the addition of Lafayette lace and the continued growth in ffice employment. The study area contains an even arger share of the wholesale sector ith 49.1 percent of the city's and 4.3 percent of the region's wholesale ector employees working in the study rea. The area's importance in holesale trade is in part due to its ccess to surface, rail and water ransportation facilities. Within the tudy area, the wholesale sector :mploys 4.8 percent of the fork-force. Boston's employment in :his sector has remained static since .975, but this sector is expected to irow by 12 percent in Boston during :he 1980s, according to recent BRA ;stimates . The agriculture, forestry, lishing and mining sectors are not significant on a regional scale, with [>nly 4.5 percent of the SMSA's jmployment in these sectors in 1980. These sectors account for less than one percent of the total study area employment (226 workers). However, what little employment there is in these sectors in the city is highly concentrated in the study area; almost all of the city's employment in these categories, primarily fishing, occurs in the study area. Construction is also a relatively small sector in the overall study area, employing 0.8 percent of the study area's labor force (2,106 employees) in 1980. Of Boston's construction industry employees, 18.5 percent work in the study area, and 4.9 percent of the SMSA's construction employment is in the study area. According to BRA estimates made in 1983, almost all sectors are projected to grow between 1980 and 1990 in the City of Boston. Of the 83,020 net new jobs projected for the decade, 62 percent are expected to be in the selected services sector, and 18 percent in the FIRE sector. 3.4.2 Economic Activities by Subarea Non-government employment in the subareas is summarized by sector in Table 8; subareas are identified in Figure 16. Government employment is not available at the subarea level of detail . Eastern Retail Core (02108) Total non-government employment in this subarea numbered 32,739 in 1980. The subarea contains a relatively high percentage of the city's employment in the selected services and FIRE sectors. Specifically, the Eastern Retail Core subarea contains 14.1 percent of the total FIRE sector employment in the city and 11.5 percent of the city's selected services employment. Although the FIRE, selected services, and retail sectors are expected to grow in downtown Boston, the majority of this new growth will occur in other subareas where there is more available land for development. 101 r— in JZ -H I •D O r o — - in —i O -« -H ^ W «N «-H M i-H ^ 0> CO (0 En l 2 C ^ ^ U X •H «— 4 fN S3 -< oo t o 82 3 — < u .c — « m C — « <-H U C p 3 «j a. JJ «m (AC ~ > *j A c 5 M 102 uture development in this area will e limited mainly to renovations of xisting buildings. orthern Waterf ront/Faneuil Hall 02109) Total non-government employment n this subarea was 30,527 in 1980. The majority of the non- lovernment employment (80.6 percent) n the Northern Water f ront/Faneuil lall subarea is in two sectors: FIRE ind selected services. Retail jjmployment in this subarea is not Jominant, but does represent 22 jercent of all retail employment in ;he study area. Faneuil Hall Market Place is the center of retail •activity. This 220,000 square foot benter generated an estimated $77 million in retail sales in 1982. h 1977 survey showed that 51 percent of all Faneuil Hall Market Place shoppers arrived by auto rather than using the available public transit system, with only 24 percent City of Boston residents. Growth in this subarea will ilikely occur mainly in the FIRE and selected services sectors. Develop- ment in the Waterfront should remain stable, with the exception of housing ■development, mentioned in Section 3.2 LAND USE . Financial District/Waterfront (02110) Total non-government employment in the Financial District/Waterfront subarea was 38,576 in 1980. The majority of the employment was in FIRE and selected services. Retail activities in this subarea include part of Downtown Crossing, and retail employment represents 17 percent of all retail employment in the study I area. The Financial District/ Waterfront is currently the most active development location in downtown Boston. Major new office developments and proposals for the area, discussed previously in Section 3.2 LAND USE, and renovation and rehabilitation of existing buildings for office use, are likely to encourage growth in the selected services and financial sector employment . Chinatown/Leather District (02111) In addition to Chinatown and the Leather District, this subarea includes part of the retail core, the adult entertainment district (Boston's Combat Zone), and the retail/office zone to the south of Summer Street. Non-government employment in this subarea totals 18,585; with 75 percent of this employment in the selected services and the manufacturing sectors. Manufacturing employment in this subarea is dominated by the apparel (2,676 employees) and instruments (2,188 employees) industries, and accounts for 32 percent of manufacturing employment in the study area. Retailing in the area is dominated by the Jordan Marsh department store and smaller general merchandise, apparel, and food stores along lower Washington Street. North End (02113) The North End has very little employment (1,417 jobs). Forty-three percent of non-government employment in this area is in retail trade, and 72 percent of this retail employment is estimated to be in food markets and eating and drinking establishments. The 365 manufacturing jobs in the area are concentrated in the apparel and accessories industry (86 percent). Government Center/West End/No. Beacon Hill/North Station (02114) Non-government employment in this subarea totals 18,765. Of this employment, 56 percent is in the selected services sector, and the majority of the remaining employment is distributed in retail, FIRE, TCU, and manufacturing sectors. This subarea contains the major concentration of total study area government employment. 103 South End (02118) Businesses in the South End area employed 11,985 non-government workers in 1980, primarily in the service, wholesale and manufacturing sectors. The largest sector is services, providing 41.2 percent of the employment in the subarea. With Boston City Hospital and University Hospital located in the South End, health services account for most of the employment in the services sector. The wholesale sector provides 22.8 percent of all non-government employment in the South End. The South End houses the second largest wholesale sector in the study area, following South Boston. Almost one-quarter of all wholesale employees in the study area work in the South End. Manufacturing is nearly as large as wholesaling, employing 22.5 percent of South End non-government workers. Industrial uses include high tech manufacturing or research (Teradyne and New England Nuclear are the largest), and printing. East Boston (02128) East Boston, including Logan Airport, contains 514 business establishments employing 19,519 people, approximately 5 percent of total city non-government employment. Nearly 40 percent (7,572 employees) of the jobs in East Boston non-government employment are in the TCU sector. Clearly dominating employment in this sector is the air transportation industry, containing an estimated 6,369 employees and representing roughly 97 percent of city employment in this sector. Logan Airport is undoubtedly the source for most of the transportation employment in East Boston. Another 24 percent (4,593 employees) of East Boston non-government employment falls in the selected services sector, with business services being the dominant i industry. The retail and manufacturing sectors each hold roughly 16 percent of total non-government employment in East Boston. This compares with the wholesale trade, construction and FIF sectors, each of which contain less than 500 employees. [ Employment growth in East Boston over the next several years will likely be limited largely to airport related and/or dependent activities . The future of the Airport as a center of economic activity is likely to involve substantial growth in air cargo over the next 20 years. This i due to reliance on air travel and shipping by sectors of the regional economy such as computing equipment, instruments, and bio-medical products South Boston (02210) Total non-government employmen in the South Boston (north) subarea numbers 14,374. Sixty-three percent of this employment is in the manufacturing and wholesale sectors. In the manufacturing sector 44.7 percent of the employment is in the printing and publishing industry, followed by 14.7 percent in food products and 13.7 percent in apparel and accessories. In the future, employment in manufacturing and wholesaling is expected to increase in the South Boston Army Base and the Boston Marin Industrial Park. 3.5 EXISTING AIR QUALITY 3.5.1 Regional Five pollutants are routinely monitored by the Massachusetts Department of Environmental Quality Engineering (DEQE), Division of Air Quality Control. Based on consultations with DEQE and the U.S. Environmental Protection Agency (EPA) however, it was determined that three 104 Table 9 FEDERAL AND MASSACHUSETTS AIR QUALITY STANDARDS Pollutant Averaging Time* Primary Standards 13 Secondary Standards 53 arbon Monoxide litrogen Dioxide )zone one-hour eight-hour Annual^ 40 mg/m 3 (35 ppm) 10 mg/m3 (9 ppm) 100 ug/m 3 (0.05 ppm) one-hour d /e 470-940 ug/m 3 (0.25-0.50 ppm) 320 ug/m 3 (0.17 ppm) one-hour 240 ug/m 3 (0.12 ppm) Same as primary Same as primary Same as primary Not proposed as yet Same as primary a. Except for the annual standards, all standards are specified as not to be exceeded more than once a year. d. Standards are given in micrograms per cubic meter (ug/m 3 ), milligrams per cubic meter (mg/m 3 ), and in parts per million (ppm). Arithmetic mean. i. Proposed EPA standard. The Commonwealth of Massachusetts' DEQE has imposed a maximum one-hour policy level of 320 ug/m 3 . 105 Table 10 MEASURED EXISTING AIR QUALITY IN THE METROPOLITAN BOSTON AREA IN 1980 OZONE : No. of Site Max. Times Description Comments One -hour > Std . * E. Boston On Bremen St. 0.120+ 0 Medfield N. Meadow St. 0.159 13 SW of Boston Medford Rte. 16 0.079** 0 Somerville Tufts University 0.140 5 E. Boston Nr. Callahan 0.070** 0 NITROGEN DIOXIDE: No. of Site Max. Times Arithmetic Description Comments One-hour >Std. * Mean Boston Kenraore Sq. 338++ - 93** E. Boston Callahan Tunnel 395 - 101** Somerville Tufts University 132 - 45** E. Boston On Bremen St. 197 - 61** CARBON MONOXIDE: Site Description Comments Max. One- hour No. of Times^One hour Std.* Max No. of Eight- Times>Eight hour hour Std.* Boston E. Boston E. Boston Boston Medford Somervi lie Kenmore Sq. 16.1++ Callahan Tunnel 18.4 Bremen St. 9.2** Downtown, 28.8 600 Washington Rte. 16 19.6 Tufts University 6.9** 0 0 0 0 0 0 11.8 11.9 5.4** 13.9 12.2 4 . 4** 3 10 0 2 3 0 *One-hour standard for ozone is 0.12 parts per million (ppm) ; proposed EPA one-hour N0 2 standard is 470 to 940 micrograms per cubic meter (ug/m 3 ), although DEQE policy level is 320 ug/m 3 ; annual N0 2 standard is 100 ug/m 3 ; and the one-hour and eight-hour CO standards are respectively 40 and 10 milligrams per cubic meter (mg/m 3 ) . ++Concentrations for ozone are given in ppm; for N0 2 , in ug/m 3 ; and for CO, in mg/m 3 . ♦♦Limited number of observations. 106 these, ozone, nitrogen dioxide ) , and carbon monoxide (CO) fjld be examinea in this study for rposes of defining the existing air ility in the Metropolitan Boston . ?a. Measured air quality levels are ;nparea with applicable standards to Itermine the quality of the air and .5 potential for adverse health ;fects. Both the National Ambient h Quality Standards and the ■:ssachusetts standards for CO, NO2 , jd ozone are shown in Table 9. The .tent of the primary standards is to otect the public health, while the ,tent of the secondary standards is : protect the public welfare from any •own or anticipated effects. In 1980, DEQE operated nineteen ations statewide to measure ozone, r xteen of these stations reported . olations of the one-hour ozone tandard. This demonstrates the invasiveness of the problem of ozone 1 this state. Table 10 shows the nximum one-hour ozone concentrations ;ported by a number of stations in :ie Metropolitan Boston area, mcentrations in excess of the :andard were reported for sites in idfield ana Somerville. Monitoring Ltes in Medford and in East Boston ear the Callahan Tunnel were Lscontinued in 1980 and their ?latively low readings of maximum le-hour ozone may be a reflection of ~ie limited number of observations, ne site on Bremen Street in East oston did not record any violation, lthough the maximum one-hour reading as equal to the standard level of .12 parts per million (ppm). DEQE monitored NO2 at six tations in 1980. Four of these tations were located in Metropolitan oston. The one-hour and annual mean oncentrations for the Metropolitan rea sites are also shown in Table U. There is presently no short-term tandard for NO2. There is, owever, a proposed EPA one-hour tandard in the range of 470 to 940 g/m3. The Commonwealth has imposed stricter one-hour policy level of 320 ug/m J . when measured against the State's policy level, the Kenmore Square and Callahan Tunnel sites had one-hour concentrations in violation of this policy. The state and federal annual standard for NO2 is 100 ug/m3. Although arithmetic means were reported, the limited amount of data collected in 1980 precludes a definitive assessment of violation of the annual standard at this time. Thirteen CO monitoring stations were operated by DEQE in 1980. The maximum one-hour and eight-hour concentrations for the stations located in the Metropolitan Boston area are also presented in Table 10. No violation of the one-hour standard of 40 milligrams per cubic meter (mg/m^) was reported anywhere; the highest one-hour concentration of 28.8 mg/m^ was reported for a site at Washington Street in downtown Boston. Violations of the eight-hour standard of 10 mg/m^ were reported at Kenmore Square, Callahan Tunnel, Washington Street, and Wellington Circle. Ten separate violations were recorded at the Callahan Tunnel site. The maximum eight-hour concentration at this site was 11.9 mg/m^ . 3.5.2 Local To assist in defining the existing conditions for the purpose of assessing the impact of the proposed project, a two-month continuous monitoring of CO at one site on Kneeland Street was conducted. This continuous monitoring was supplemented by a series of short-term measurements at a number of selected intersections or traffic congested areas that are expected to be affected by the proposed project. These areas are: o Leverett Circle o North End/Callahan Tunnel o Dewey Square/South Station o Bell Circle in Revere Another area in the vicinity of 107 the Sumner Tunnel portal in East Boston is known to have frequent high traffic congestion. This area was not selected for additional CO measure- ments, however, because there is sufficient historical data from a DEQE operated monitoring site in this area to characterize the existing air quality at this location. The locations of the continuous monitor and the individual short-term measurement sites are shown in Figure 17. Although the intent of the short-term monitoring program was to establish a reasonable level of CO for background concentration, and NCHRP 2000 criteria were met, the actual measurements yielded relatively low results. After consultation with DEQE and EPA, it was agreed that the 1-hour background of 4.4 ppm for 1980 - based on MDPW's North Area Project Study - be used in the modeling analysis. Then, applying techniques approved by DEQE including an 0.8 eight-hour persistence factor, the following CO background concentrations were used: Year 1982 1990 2010 One-Hour 4.0 ppm 2 . 1 ppm 1 . 6 ppm Eight-Hour 3 . 2 ppm 1 . 7 ppm 1 . 3 ppm Because the resulting background concentrations used are higher than the results from monitoring, the air quality analysis overestimates the total CO concentrations and thus yields conservative results. The methods and instrumentation used in the continuous monitoring of CO are approved by the EPA. Guidelines developed by the EPA were followed in both site selection and probe placement. Additionally, DEQE provided advice on the final selection of the monitoring sites and in the quality assurance and field audit of the instrumentation and measured results . Table 11 shows the maximum one-hour and eight-hour CO concentrations measured by the continuous monitor at Kneeland Street for the period January 6 through Marc 29, 1982. The maximum recorded one-hour CO concentration at this sit was 7 parts per million (ppm). This concentration is well under the corresponding standard of 35 ppm. Th maximum eight-hour average CO concentration at this site was 4.4 ppm, which is also below the corresponding 9-ppm standard. No violation of either standard was recorded. Table 11 also summarizes the results of the short-term measurement conducted at Leverett Circle, the North End, Dewey Square, and Bell Circle. The short-term measurements at each site were taken during an approximately 12-hour period on two separate days. No violations of the one-hour standard were found. The highest one-hour CO concentration of I 13.6 ppm was measured at the Quincy Market garage site (CTl). The Quincy Market site also reported the highest eight-hour average CO concentration o 9.2 ppm, which exceeds the corresponding standards of 9 ppm. No other violations of the eight-hour standard were found, although the Martha Way site (LCI) at Leverett Circle, and the Gibb's Service Statio site (BC3) at Bell Circle, recorded eight-hour average concentrations tha are very close to exceeding the standard . The field measurements conducted continuously at Kneeland Street and intermittently at Leverett Circle, the North End, Dewey Square, and Bell Circle indicate that existin 1982 one-hour CO concentrations are well under the standard. However, maximum eight-hour concentrations could exceed the 9-ppm standard in a number of locations in the study area where traffic congestion is severe. To determine the impact of the project on NO2 concentrations, a one-hour background concentration of 224 ug/m 3 for the Boston proper area and 170 ug/m 3 for the East Boston 103 Table 11 MEASURED CARBON MONOXIDE CONCENTRATIONS* (IN PPM) FOR THE THIRD HARBOR TUNNEL AND CENTRAL ARTERY STUDY AREA ite D** Description Period Eight-Hour High Low One-Hour High Low 01 Kneeland Street it everett Circle ++ CI Martna way C2 MDC Police Lot C3 DPW Parking 01/06/82 through 03/29/82 4.4 01/16/82 and 04/13/82 8.5/3.9 3.7/5.4 3.3/4.9 0.5 7.2/2.2 3.4/4.1 2.0/2.9 7.0 11.3/5.8 5.7/6.6 5.4/9.3 0.5 2.6/0.5 1.4/3.1 0.9/1.1 , orth End/Callahan Tunnel ++ Tl Qumcy Market Garage 02/17/82 and :T2 Fulton Street Parking T3 Hanover/Cross Street ;t ewey Square ++ 0 (S1 Purchase Street |)S2 Lincoln/Essex Parking i 0 >S3 Federal Reserve Bank .ell Circle++ sCl Dunkin Donuts on$C2 Kappy's Parking JC3 Gibb's Service Station lal 04/14/82 02/18/82 and 04/15/82 02/19/82 and 03/26/82 9.2/4.4 1.4/6.3 7.6/3.5 4.6/3.2 6.1/2.4 3.7/4.9 7.0/4.4 5.1/3.0 9.0/3.7 2.2/2.6 1.3/4.1 5.2/2.7 3.4/1.8 4.0/2.0 2.9/3.1 2.3/3.0 3.3/2.6 1.7/0.8 13.6/6.6 3.6/8.0 9.5/5.9 8.2/7.3 8.1/4.4 6.3/6.0 7.4/5.4 7.8/3.7 10.5/4.6 1.1/1.1 0.5/3.8 3.0/0.5 2.0/0.8 2.4/0.5 1.3/0.9 0.3/1.4 1.1/1.7 3.7/0.6 *The one-hour and eight-hour standards are respectively 35 and 9 ppm. f *Refer to Figure 17 for the location of these sites. t -+Data for the two days of short-term monitoring at Leverett Circle, the North End, Dewey Square, and Bell Circle are reported separately. For J example, the eight-hour concentrations of 8.5/3.9 for the Martha way site refer to the maximum eight-hour concentrations for this site on 16 February and 13 April 1982, respectively. ie 109 area was established by DEQE. This ^as based on a review of limited Historic monitoring data which was carried out during consultation for this study. 3.6 NOISE AND VIBRATION 3.6.1 Existing Noise Levels Noise-sensitive land uses in the project area include residences, churches, schools, and parklands. The existing noise environment at these locations is generally dominated by motor vehicle traffic on expressways, major arterials or local streets, and in some cases by aircraft operations associated with Logan Airport. The basic noise unit employed in this study is the decibel (dBA). The decibel is used to measure the relative noisiness of sounds; for example, a 3 dBA increase in noise level can just barely be perceived, while a 1U dBA increase corresponds to a subjective doubling of loudness. The relationship between changes in noise level and loudness is indicated in Table 12. Since noise fluctuates from moment to moment, it is common practice to condense all this information into a single number, called the Equivalent Noise Level ( L e q ) . Many surveys show that the L e q properly predicts annoyance, and thus this descriptor is commonly used for noise measurements, prediction, and impact assessment. As prescribed by FHWA, tne L eq for the noisiest traffic hour is used throughout this document to assess roadway noise impact. The FHWA noise criteria are summarized in Table 13. Noise abatement must be considered if project noise exceeds the noise abatement criteria based on activity category, or if the project will substantially increase the noise level at sensitive locations. Noise measurements were made at 14 locations within the project area during May of 1982 in order to document the existing noise environment. These locations are shown in Figure 18 and are described in Table 14. At locations 1-13, short-term measurements were made in order to determine the existing daytime hourly L eq at representative noise sensitive receptors. These receptors were chosen so as to include residences, institutions, and parks closest to project roads. (Table 55 in Section 4.8 NOISE AND VIBRATION identifies the number of residents represented by each receptor.) At location 14, near the Callahan/Sumner Tunnel toll plaza, the Hourly L eq was monitored over a 24-hour period. The purpose of this latter measurement was to aid in the prediction of noise from the potential new toll plaza in East Boston. In April 1983, additional noise measurements were taken at locations 16-22, also presented on Figure 18. The results of the noise measurement program are summarized in Table 14. These results indicate hourly daytime L eq ranging from a low of 57 dBA to a high of 73 dBA at noise sensitive locations; such levels are typical for a daytime urban environment. Since aircraft noise is significant at some locations in the project area, measurement results in Table 14 are provided for locations 1-13 both with and without noise contribution from aircraft sources. In most instances, however, the increase in noise due to aircraft operations was measured to be less than 3 dBA, and therefore aircraft noise was not significant for most of the measurements. Existing noise levels are observed to exceed the FHWA exterior noise criterion (67 dBA for Activity Category B) at several of the measurement locations. These locations, without the addition of aircraft noise, included Rotch Playground in the South End, Dockside Place Condominiums in South Boston near the Fort Point Channel, and several locations along Bremen Street in East Boston. With the addition of aircraft noise, the FHWA criterion was also exceeded at Porzio Park in the 111 Table 12 RELATIONSHIP BETWEEN CHANGES IN NOISE LEVEL AND LOUDNESS Increase (or Decrease) in Noise Level 3 dBA 6 dBA 10 dBA 20 dBA Loudness Multiplied (or Divided) by 1. 2 1. 5 2 4 Table 13 FHWA NOISE CRITERIA NOISE ABATEMENT CRITERIA: L eq for Noisiest Activity Category Traffic Hour Desc ription of activity category 57 (Exterior) B 67 (Exterior) Lands on which serenity and quiet are of extraordinary significance and serve an impor- tant public need and where the preservation of those qualities is essential if the area is to continue to serve its intended purposes . Picnic areas, recreation areas, playgrounds, active sports areas, parks, residences, motels, hotels, schools, churches, libraries and hospitals. 72 (Exterior) D E 52 ( Interior) Developed lands, properties, or activities not included in Categories A or B above. Undeveloped lands. Residences, motels, public meeting rooms, schools, churches, libraries, hospitals, and auditoriums. CRITERIA FOR INCREASE IN NOISE LEVEL: Increase (dBA) 0-5 5-10 10 - 15 Greater than 15 Subjective Descriptor No impact Minor impact Moderate impact Serious impact (substantial) 112 Table 14 SUMMARY OF EXISTING NOISE MEASUREMENTS Site* No Description Daytime Hourly L e g Without With Aircraft Aircraft Lester J. Rotch Playground: Approx. 120 ft. from £ Albany St. 69 69 St. Peter & Paul Church: Approx. 90 ft. from £ Dorchester Ave, N.A. 63 Dockside Place Condominiums: 15 Sleeper St. (6th floor) 73 72 Boston Tea Party Museum: Approx. 100 ft. from £ Congress St, 65 64 Rear of No. 74-7 5 Frankfort St: Approx. 100 ft. from Orleans St. 57 55 Front of No. 120-122 Bremen St. (Between Porter St. & Gove St.) 68 68 Corner of Bremen St. & Porter St. (Near Residential Bldg. ) 73 73 Front of Open Lot on Bremen St. (Between Marion St & Brooks St.) 69 67 Front of Open Lot on Bremen St. (Between Brooks St. & Putnam St.) 68 68 10 East Boston Recreation Area (At home plate of West Baseball Field) 65 61 11 East Boston Recreation Area (At home plate of East Baseball Field) 67 66 12 Front of No. 347 Maverick St. (Between Ardee St. & Lamson St.) 64 58 13 14 Porzio Park (Jeffries Point - East Boston) 69 Callahan/Sumner Tunnel Toll Plaza (Tpke. Authority Parking Lot) ** 62 15 Waterfront Park at Atlantic Avenue edge 16 Waterfront Park, 110 ft. from £ Atlantic Avenue, Approx. 270 ft. from £ Central Artery 69 69 113 Table 14 (Cont.) SUMMARY OF EXISTING NOISE MEASUREMENTS Site* No Description Daytime Hourly L eq Without With Aircraft Aircraft 17 Edward Everett House, Harvard St., Charlestown, Approx. 130 ft. from £ Rutherford Avenue 69 69 18 Charles River Dam Park, City Square, Charlestown, Approx. 300 ft. from £ Charlestown Bridge 69 69 19 Apartments, Stillman Place and Stillman 72 Street, North End, Approx. 75 ft. from £ Central Artery 20 Casa Maria Housing, 7th Floor, Cooper St. 71 & Lynn St., North End, Approx. 205 ft. from £ Central Artery 21 Quincy Market, Commercial Street and 71 North Market Street, Approx. 25 ft. from £ Commercial St. and 135 ft. from £ Central Artery 22 Harbor Towers Parking Garage, 10th 71 Floor level, Approx. 200 ft. from £ Central Artery 72 71 71 71 ♦See Fig. 18. **See Table 15. ***Not Measured: future noise modeled 114 Figure 18 Existing Noise Measurement Locations 0 450 900 1800 Feel EIS/EIR for I-90 - Third Harbor Tunnel; I-93- Central Artery Jeffries Point neignborhood of East Boston. Sites 16-22 also exceed the FHWA noise level criterion. Table 15 lists the hourly L eq values measured over a 24-hour period next to the Callahan/Sumner Tunnel toll plaza (location 14). These levels were observed to vary between 62 dBA and 79 dBA, dominated by noise from accelerating vehicles. Traffic counts were also obtained for each measurement hour in order to calibrate the standard roadway noise prediction model for the special situation of a toll plaza facility. 3.6.2 Existing Vibration Levels Vibration-sensitive land uses in the project area also include residential, commercial, institutional, and industrial ouildings as well as existing MBTA subway tunnel structures. Concerns about vibration at such locations are related to potential structural damage, annoyance to building occupants, and/or interference with sensitive manufacturing processes. The basic vioration descriptor used in this study is the Peak Velocity, expressed in "inches per second" (m./sec). This descriptor refers to the largest value of the velocity of a body's surface that occurs during the motion of that oody (e.g., the ground, a building or tunnel component, etc.). The Peak Velocity has been found to relate well to structural damage, human vibration perception, and interference with the operation of very sensitive optical equipment. For example, vibration with a Peak Velocity of U.UU5 in. /sec would be just barely perceptible and could De disruptive to the operation of some sensitive precision instruments. Vibrations 1U times greater than the perception threshold (0.U5 in. /sec) would be characterized as strongly noticeable, while viorations 100 times the perception threshold, (U.5 in. /sec) would be characterized as very unpleasant. Vibrations 1UUU times tne perception threshold (b in. /sec) would begin to become intolerable to humans and wou. be likely to cause minor structural damage to buildings. Figure 19 presents examples of the type of vibrations which result from differe activities. Vibration criteria used in this study are summarized in Tabl I Vibration measurements were made during April and June of 1982 a April 1983 to document the existing vibration environment at 10 vibration-sensitive receptors within the project area (see Figure 20 and Table 17). These included a residential area located above the MBTA Blue Line Tunnel in East Boston (site A), the MBTA Red Line Tunnel below Fort Point Channel (site B), t; MBTA Blue Line Tunnel in East Boston (site C), and the Gillette Co. facilities in South Boston (site D). Vibration measurements at six sensitive receptors near the Central Artery (sites E through J) represent residential, institutional and historical building sites. The results of ground vibratii measurements near Bremen Street in East Boston (site A on Figure 20) indicate peak vertical ground vibration velocities ranging between 0.02 and 0.06 in. /sec during subway train passages in the MBTA Blue Line tunnel below. These values are representative of existing vibration experienced by some residences in trs area. Inside buildings directly abcw the subway tunnel, higher vibrations' may actually occur due to amplifications resulting from floor and wall resonances. On the other hand, lower vibration levels would occur at increasing distances from tt tunnel. In spite of these variation, the results serve as a useful reference for comparison with project-generated vibration. Vibration measurements made inside existing MBTA subway tunnels t two locations indicated vibrations ce to train passages are lowest on the tunnel ceiling. These vibration measurements will be used to determie impact, since they represent the 116 Table 15 VARIATION OF HOURLY L eq OVER A 24 -HOUR PERIOD* AT THE CALLAHAN/SUMNER TUNNEL TOLL PLAZA+ Hour of Day Midnight 1 a.m. 2 a.m. 3 a.m. 4 a.m. 5 a.m. 6 a.m. 7 a.m. 8 a.m. 9 a.m. 10 a.m. 11 a.m. 12 Noon 1 p.m. 2 p.m. 3 p.m. 4 p.m. 5 p.m. 6 p.m. 7 p.m. 8 p.m. 9 p.m. 10 p.m. 11 p.m. 1 a.m. 2 a.m. 3 a.m. 4 a.m. 5 a.m. 6 a.m. 7 a.m. ■ 8 a.m. ■ 9 a.m. 10 a.m. 11 a.m. 12 Noon 1 p.m. 2 p.m. 3 p.m. 4 p.m. 5 p.m. 6 p.m. 7 p.m. 8 p.m. 9 p.m. 10 p.m. 11 p.m. Midnight Hourly L eg (dBA) 68 65 62 65 65 68 71 71 71 73 79 74 75 74 75 71 71 70 69 68 70 72 71 70 : 14 May 1982. •Measurement Site No. 14 (See Fig. 18). 117 PEAK GROUND VELOCITY (in. /sec) 51000 -m 100 EARTHQUAKES* RICHTER MAGNITUDE MERCALLI INTENSITY TRANSPORTATION SOURCES CONSTRUCTION SOURCES BUILDING DAMAGE hum; PERCEPT 10 1.0 0.1 .01 .001 * 9 * I 8 I - 7 - - 6 - I 5 | 4 ^ ; 3 - 2 1 -t .0001 DAMAGE TOTA WAVES VISIBLE ON GROUND OBJECTS THROWN IN AIR MAG. OF 9 JAN. 1982 QUAKE AT EPICENTER II MAG OF 18 JAN. 1982 QUAKE AT EPICENTER LOWER LIMIT OF 1 BUILDING DAMAGE INTENSITY OF 9 JAN. 8. 18 JAN. 1982 QUAKE IN BOSTON NOT I XXSXX A I 12' 11 - 10 - 9 8 7 I 6 '» 5 4 - 3 - 2 i 1 STRUCTUAL >DAMAGE ■ MINOR DAMAGE M4-LOW PROBABILITY OF DAMAGE VERY SAFE TO ' BUILDINGS INTOLER LE 7 SUBWAY TRAIN (MEAS. / ABOVE MBTA TUNNEL)'/ 5i /////////////// MOTOR VEHICLE TRAFFIC AT 50 FT. FROM ROUGH ROADWAYS AND ELEVATED HIGHWAYS SLURRY WALL CONSTRUCTION AT 50 FT. EASIL NOTICE/.E rr 'MOTOR VEHICLE TRAFFIC AT 50 FT FROM SMOOTH / AT GRADE ROADWAYS . f////////////////, BARE PERCEPTLE IL. IMPERCEP •ASSUMES A PERIOD OF 0.5 sec. Figure 19 Comparison of Typical Ground Vibration Amplitudes and Criteria EIS/EIR for I-90 — Third Harbor Tunnel; I-93 — Central Artery It Table 16 PROJECT VIBRATION CRITERIA* Maximum Peak Vibration Velocity+ Type of Effect (in. /sec) Damage Effects Structural Damage 1. 9 Architectural Damage -Historical Buildings 0.08 -Non-Historical Residential Buildings 0.2 Annoyance Effects Hospital and Critical Areas 0.005 Residential/Institutional/Hotel -Construction Period 0.01 -Long Term 0 . 007 Office 0.02 Factory 0.04 ♦Maximum existing vibrations serve as supplementary criteria to the values listed in this table. + Refers to ground vibration in the case of damage effects and building vibration in the case of annoyance effects. 119 Table 17 SUMMARY OF EXISTING VIBRATION MEASUREMENTS Site No. * Description Range of Peak Vibration Velocity (in. /sec. Major Vibration Sources ) A Sidewalk outside 144 Bremen Street, above the Blue Line Subway Tunnel 0.020 - 0.060 Subway trains B Ceiling inside MBTA Red Line Subway Tunnel below Fort Point Channel 0.014 - 0.042 Subway trains C Ceiling inside MBTA Blue Line Subway Tunnel below Porter St. (East Boston) 0.016 - 0.095 Subway trains D Floors inside Gillette Company Bldgs. (South Boston) 0.004 - 0.031 Normal building activities E Sidewalk outside Baine Bldg. at 394 Atlantic Ave. 0.011 - 0.066 Street traffic, foot- steps, building construction. F Sidewalk outside bldg. at corner of State St. and Surface Artery 0.011 - 0.056 Street and expressway traffic, footsteps G Sidewalk outside North Market Bldg. at Quincy Market, near corner of Clinton St. and Commercial St. 0.010 - 0.027 Motor vehicles and pedestrian traffic H Sidewalk outside North End Nursing Home, at building corner nearest Richmond St. and Callahan Tunnel portal 0.010 - 0.040 Motor vehicle and pedestrian traffic I Sidewalk outside apartment between Nos. 2 & 3 Still- man Pi. on east side of expressway (North End) 0.007 - 0.016 Street and expressway traffic J Ground outside new wing of Mass. Rehabilitation Hos- pital, approx. 15 feet from nearest North Station railroad track 0.017 - 0.470 Commuter train movements * See Fig. 20 120 EIS/EIR for 1-90 -Third Harbor Tunnel. 1-93 - Central Artery smallest existing vibrations and since the ceiling is likely to be the part of the tunnel structure most susceptible to damage from highway tunnel construction. Therefore, these results serve as a useful baseline for comparison witn future project generated vibrations. Vibration measurements were also performed at the Gillette Company facilities in South Boston (site D on Figure 20) in order to document existing levels of building vibration at 11 locations near potentially sensitive equipment. Vibration sensitive equipment included electron microscopes, metalograpns , grinding machines, surface analyzers, blade sharpeners, hardness testers, and scales. Measurement results indicate maximum values of peak vertical floor vibration velocities ranging between 0.004 in. /sec and U.031 in. /sec, with the greatest vibrations occurring in the building closest to the Fort Point Channel. The measurement results in the vicinity of the Central Artery at sites E through J (summarized in Table 17) indicate that in most cases, maximum existing peak ground vibration velocities fall within the range between 0.01 and 0.10 in. /sec. These velocities are within the perceptible to strongly perceptible range, and are caused principally by motor vehicle traffic on surface and elevated roadways. At site J (Spaulding Rehabilitation Hospital), measured peak ground vibration velocities due to commuter train movements also fell within this range, with the exception of one event. This event consisted of an MBTA commuter train movement on the tracK closest to the measurement position (15 feet away) and resulted in a peak velocity of 0.47 in. /sec. In the absence of major identifiable vibration sources, minimum peak ground vibration velocities at sites E through J were observed to range between 0.001 and 0.U05 in. /sec, generally not perceptible to barely perceptible, depending on the measurement location. 3.7 WATER RESOURCES This section summarizes data concerning the physical, chemical, biological oceanographic environmen in the project area. Also included a discussion of industrial users of the water of Fort Point Channel and nearby parts of Boston Harbor. The data were obtained from investigati conducted during 1982 and 1983. The Massachusetts Division c Water Pollution Control (DWPC) has classified Boston Inner Harbor as Class SC. Class SC waters are suitable for aesthetic enjoyment, t> protection and propagation of marin life, and secondary contact recreat Specific water quality standards applicable to SC waters include a minimum dissolved oxygen concentratra ■ of 6.0 milligrams/liter (mg/1), a p range of 6.5 to 8.5, and maximum f el :,s coliform bacteria count of 1000 organisms per 100 milliliters of sample. The Charles River is classified as Class C water (also suitable for propagation of fish an marine life and secondary water contact recreation). 3.7.1 Fort Point Channel ■ . - ■ i.— i Tides and Currents The tidal water area of the Fort Point Channel upstream of the Northern Avenue Bridge is 2.26 mill square feet (approximately 52 acres Since the sides of the Channel are essentially vertical and consist of revetments and bulkheads, there is real difference in area between hie tide and low tide. The Channel is approximately 5600 feet in length, approximately 560 feet wide at its mouth, and the length of tidal excursion is approximately 2100 fee (Tidal excursion represents the distance a particle of water will travel on an ebb or flood tide.) 1 mean tidal prism (water volume bet* mean low and mean high tide) is 21. million cubic feet, while the sprir tidal prism is 24.9 million cubic f! (the spring tide generally occurs every two weeks when the moon is ne 122 or full). As in other harbor areas, I the range of the spring tide is approximately 11 feet, while the mean high tide range is 9.5 feet. Computations indicate that the Channel is flushed once in every 2.1 full tide 1 cycles (approximately every 26 hours). Computations also indicate I that the average current velocity of water entering or leaving the Channel at the Northern Avenue Bridge is approximately 0.1 feet per second (fps). Water Quality Water quality conditions in the Fort Point Channel are highly variable. During non-storm conditions, water quality is similar to that of the Inner Harbor (Table 18). However, during storms, combined sewer overflows contribute high levels of bacteria, solids, biochemical oxygen demand, nutrients, and metals to the water, and cause violations of Class SC water quality standards. Water in the Fort Point Channel is, however, suitable for fish and other marine life, boating, and industrial cooling water. Figure 21 presents the locations of water quality sampling sites in Boston Harbor. Sediments Figure 22 shows locations of site-specific sediment sampling locations undertaken for the proposed tunnel alignment. The chemical and physical conditions of bottom sediments in the Fort Point Channel were determined through a review of existing data as well as site-specific investigations. These show high levels of metals and petroleum residuals in the Channel. All surface sediments in the Channel are found to be Category 3 (highly contaminated) quality, with the most contaminated area located between Dorchester Avenue and Summer Street. While the quality of surface sediments is significantly degraded, this condition is only found in the upper 2-3 feet. Below this depth, sediments are relatively uncontaminated , and most are of Category 1 (uncontaminated) quality. The sediment quality at various depths at Station FP-2, as an example, is shown in Figure 23. Extraction Procedure Toxicity Testing on Fort Point Channel sediments indicated they are non-hazardous, including no hazardous levels of PCBs. A summary of sediment characteristics is presented in Table 19. Marine Life Marine life found in the Fort Point Channel includes flounder, stickleback, mummichog, smelt, alewife, eel, and others which may enter the Channel from the Harbor. The diversity of marine life living in the bottom sediments is low, with a high preponderance of pollution- tolerant worms. Filamentous algae are the dominant species of marine vegetation in the Channel. 3.7.2 Boston Inner Harbor Tides and Currents Measurements of current speed and direction were conducted at four locations on a spring (high) and neap (low) tide cycle during March 1982. Those data have been reviewed for application to the alignment for the Preferred Alternative, and the conditions have not been found to differ significantly. Data from meter Stations A and B indicate peak velocities of 1.0 feet per second (fps) during spring tides. The predominant velocities ranged from 0.10 to 0.26 fps. During ebb tide, the higher current velocities occurred near the surface. During flood tide, the higher current velocities were found to occur in the middle and bottom of the water column. Computations indicate that water within the project area will travel approximately 5600 feet on the ebb tide and approximately 7000 feet on the flood tide (see Figure 24). The flood tide excursion will carry water from the project's cross-harbor 123 Table 18 WATER QUALITY SUMMARY BOSTON INNER HARBOR (mg/1) Parameter Max imum Minimum Ave rag e pHJ. 8. 0 1 . 6 7 . 8 Suspended Solidsl 35. 0 16. 0 22.0 Oxl and Grease- 1 - 2.6 0 . 0 1.3 Total Kjeldahl Nitrogen-L 2.4 0 . 64 1. 23 Ammonia Nitrogenl 0 . 19 0 . 01 0 . 07 ouit ate J- 3, 325 1, 950 2, 488 lotai Fnospnorus- 1 - 0.10 A A A 0 . 02 0 . U5 Conducti vityl (*< mho s /cm ) ac\ nnn "K&. nnn JO , OU VJ Tnf al Crs 1 -J f avttiI lOLai ujiirunn- 1 - (# organisms/100 ml) 9 ^n 71 1 3 r ec al coiirorm 1 /ll • / -i OA — . 1 \ (# organisms/100 ml) JoU i n^3 Chloriae J - 14, 000 11, UUU to inn ±J, JUL) Arsenic ^ 0 . 001 U . UU1 Cadmium^ 0. 014 0 . 0005 A A A f\ 0.009 Chromium-' 0 . 004 0 . 004 Copper 2 0.01 0.0014 0.006 Lead 2 0 . 017 0.002 0.012 Mercury (Mg/1) 2 0.05 0.005 0.035 Nickel2 0.02 0.004 0.016 Silver2 0.08 0.08 Vanadium2 0.04 0.04 Zinc 2 0.145 0.002 0.05 Dissolved Oxygenl Surface 8.5 5.2 7.2 Middle (13' -18*) 6.8 5.4 5.9 Bottom ( 26' -40' ) 6.8 3.4 5.5 Sources : 1 Massachusetts Department of Environmental Quality Engineering from sampling locations BH03 (Boston Inner Harbor north of mouth of Charles River near U.S. Naval Reserve), BH04 (tidal portion of Charles River downstream of Charlestown Bridge) and BH05 (Main Channel of Boston Inner Harbor near mouth of Fort Point Channel) surveyed July 14-15, 1982, Personal Communication. 2 U.S. Army Corps of Engineers, 1981 and Massport Seaport Development, 1980. 3 Geometric mean of DWPC Data 124 EAST BOSTON BH-03 [IARLESTOWN • BH-04 NORTH END • BH-05 DOWNTOWN ^ SS. TURNPIKE >OUTH END Existing Gillette Cooling Water Discharge Existing Gillette Cooling Water Intake SOUTH BOSTON I Massport Station » DWPC Station Figure 21 Water Quality Sampling Locations 0 900 1800 Feet EIS/EIR for I-90 -Third Harbor Tunnel; I -93 - Central Artery NORTH S . FP - 4 BOSTON HARBOR BOSTON 5AM-1 . 5AM-2 5AM-3 5AM-4 5AM- 5 / ■ BIRD ISLAND FLATS LOGAN INTERNATIOM AIRPORT FP Fort Point Channel 5AM Third Harbor Tunnel Figure 22 Sediment Sampling Locations 0 900 1800 Feet EIS'EIR for I-90 -Third Harbor Tunnel: I-93 - Central Artery % Oil and Grease 1 2 3 4 5 6 7 8 9 10 11 12 13 14 j i i i i i i i i i ■ ■ i 1 Concentration mg/kg , , , , , , , , , , , ^_ 1 23 cal Distribution of Metals in Fort Point Channel Sediments at Station FP-2 for 1-90 — Third Harbor Tunnel; 1-93 — Central Artery Table 19 AVERAGE SEDIMENT CHARACTERISTICS FORT POINT CHANNEL SOUTH BAY DORCHESTER AVE TO SUMMER ST SUMMER ST TO NORTHERN WE PARAMETER SURFACE MUD SILT/CLAY SURFACE WJD SILT/CLAY SURFACE MJD SILT/CLAY ARSENIC rg/kg 107.65 32.2? 39. eo 125.9? 85.37 74.79 44.45 5.89 3.29 CADMIUM rg/kg ■ 12.78 6.25 3.99 £9.75 6.77 2.35 7.75 2.25 1.89 Tc/kg 107. 25 26. 65 12.89 292.45 79.63 56. e9 176.93 29.35 2.79 COPPER rg/kg 382. i? 158.49 12.89 762.85 361.83 167.49 293. 75 135.39 196.99 LEAD rg/kg 1*26. A? ♦29.79 37.99 1841.38 687.77 353. 83 431.48 147.25 22.1? MERCURY rg/tg 29. 3^ 9.68 9.97 3.94 2.18 • 3.36 3.41 3.13 5.11 NICKEL rg/kg ro.ee 39.59 16.3? 1199.35 48.73 32.25 55.83 37.69 35.29 vanadium rg/kg 157.48 32.59 16.38 595.35 55.67 34.35 197.83 4.29* 9.4? ZINC rg/kg 17e7.ro 453.99 192.48 1985.8? 892.47 595.89 495.55 417.89 223.89 PCB Big/kg (.MS (.8?5 8.91 PEST. no/kg I.MS (.995 (.895 P/TOTAL rg/kg 57.ro 17.85 2.89 181.53 44.43 55.28 44.2? 53.59 67.69 N/A"ONIfl rg/kg 115.28 169. 15 87.99 58.85 149.6? 117.35 11.7? 451.69 974.4? TKN ■g/kg 1562.58 834.15 661.39 592.35 1829.57 1851.15 278.99 2914.89 1691.29 SOLIDS/T t 27.9? 69.49 77.59 23.65 53.37 53.35 49.69 52.25 33.59 SCUDS/V I 21.48 27.65 33.63 25. 35 11.83 7. 15 19.19 9.58 3.29 GIG I 5.11 i.eo 9.17 5.35 8; 89 8.27 1.11 1.94 9.46 SILT/CLAY I 93.M 99.89 99.83 99.83 99.88 99.83 99.99 99.89 99.93 HATER CNT t 76.29 39.69 22.59 78.35 46.58 46.65 59.4? 47.75 66.59 PAcE/NEUT »g/ko (1 (1 (1 (1 (1 (1 128 tunnel alignment north to the vicinity of the Callanan/Sumner Tunnel. The ebo excursion will reach past the mouth of the Reserved Channel. Water Quality Existing water quality information on the Harbor indicates that Class SC standards are not consistently met. In past and present monitoring programs by both Massport and the Massachusetts Division of Water Pollution Control, dissolved oxygen concentrations in Inner Harbor water have been lower than the minimum 6.U mg/1 required for Class SC water. Existing water quality data are summarized in Table 18. Freshwater discharges from the Charles and Mystic Rivers can have a marked effect on salinity of the Inner Haroor. Water quality of the Inner Harbor, particularly for such parameters as bacteria, suspended solids, nutrients, and metals, is affected during storms when the discharges of combined sewer overflows are most prevalent. However, there are no CSO's in the areas of South and East Boston wnere subaqueous tunnel construction is proposed. The West Airfield drainage outfall from Logan Airport is the only source of stormwater runoff adjacent to the project. Consequently overall water quality conditions are expected to be better than those prevailing further into the Harbor. Sediments The physical and chemical characteristics of bottom sediment within the project area were determined through an evaluation of existing data as well as site-specific investigations. The overall Harbor bottom is covered with a layer of organic mud which varies in depth from almost totally absent in the main shipping channel to 4.5 feet in depth east of the mouth of the Fort Point Channel. Portions of the main shipping channel are virtually devoid of organic sediment, probably due to tide, currents, and ship traffic passing through the channel. Where :j does exist, the quality of organic sediment is variable. Lower concentrations of contaminants are found in the shipping channel, but most surface organic sediments were found to be contaminated and of Category 3 quality. Clean sediments I were found in the deeper muds and in the Harbor clay layer. Relatively uncontaminated conditions, in genera were found at depths of 2-3 feet belc the Harbor bottom. In order to characterize the material along the alignment of the Preferred Alternative, surface sediment samples were taken at five stations (see Figure 22). Deeper sediments were recovered from three (J these locations (5AM-2, 5AM-4 and 5AM-5). Table 20 presents the result of these analyses. The data for these samples confirms the general trends observed in other data on Boston Harbor sediments. Channel and pier end sediments (5AM-2, 5AM-3 and 5AM-4) ar generally cleaner than other location (5AM-1 and 5AM-5). Deeper sediments are generally cleaner than upper sediments. In general, however, the sediments between the new embankment for the Massport container port fill and the drydock at the Boston Marine Industrial Park (5AM-1 and 5AM-2) are all of Category 2 and 3 quality and are contaminated with arsenic, cadmium, and mercury. Similar conditions are found in surface sediments along the remainder of the Preferred Alternative alignment (5AM-3, 5AM-4 and 5AM-5 ) . Significan improvement in sediment quality is found in deeper materials such that a depths of three feet Category 1 sediments are found. Elutriate analyses were conducted to determine the degree to which metals and nutrients would be released to Harbor water during dredging. The analyses indicate greatest and most consistent release took place from surface sediments. The metals most consistently released include arsenic, cadmium, lead and 130 Table 20 BULK SEDIMENT ANALYSIS 1 HATER QUALITY LABORATORY 1 PROJECT: THIRD HARBOR TUNNEL ANALYSIS REPORT 244 SECOND AVENUE 1 1 PROJ/NO: 141 UALTHAM, Nfl 82154 1 1 617/898-3737 1 1 1 STATION: 5AM-1 5AM- 1 5AM-2 5AM-2 5AM-3 1 DATE: 8/2/83 8/18/83 8/2/83 8/18/83 8/2/83 1 SAMPLE*: 6887 6891 6889 6893 6898 1 TYPE OF ANALYSIS: BULK BULK BULK BULK BULK 1 SEDIMENT DEPTH: SURF 3.2-4.8' SURF 3.4-4.8' SURF 1 1 CONC CLASS CONC CLASS CONC CLASS CONC CLASS CONC CLASS 1 1 ARSENIC ■□/kg dry wt. 35. 6 3 13.84 2 37.9 3 17.42 2 25.1 3 1 1 CADMIUM ■g/kg dry wt. 7.41 2 1.78 1 3.29 1 2.58 1 3.54 1 1 1 CHROMIUM •g/kg dry Mt. 31.8 25.91 1 25.6 1 31.7 1 18.7 1 • 1 COPPER ■g/kg dry Mt. 18.1 j 18.78 1 18.5 1 25.18 1 10 1 1 1 LEAD ■g/kg dry wt. 52.2 j 44.51 1 43.6 1 51.82 1 27.2 1 1 1 MERCURY ■g/kg dry wt. .88 .59 2 .77 .61 2 Ql • 71 1 | 1 NICKEL ■g/kg dry wt. 1.82 j 1.78 1 1.74 1 2.59 1 1.18 1 VANADIUM no/kg dry wt. 51.9 j 118.61 2 38.6 1 137.47 3 39.4 1 I 1 ZINC ■g/kg dry wt. 186 1 98.81 1 71 111.26 1 56.1 1 | 1 PCB ■g/kg dry wt. .005 • WD 1 .885 .885 1 .885 1 I 1 DDT* ■g/kg dry wt. . xrc j U /A N/H 0 i r • WJ N/H • WTO N/0 . VI J N/0. .885 N/A 1 1 P/TOTAL ■g/kg dry wt. 98.9 N/H U / A N/H IOC N/A 71.52 N/A CS 1 N/H 1 1 N/ AMMONIA ■g/kg dry wt. 32.9 N/fl Job N/H bl. j N/A 229.6 N/A 63.4 N/A 1 1 PHENOLS ■g/kg dry wt. .847 N/H .381 N/A • Vc N/A .329 N/A • Vc N/H 1 1 TKN ■g/kg dry wt. 23.8 N/A 786 N/A 28.3 N/A 418 N/A 26.8 N/A 1 1 SOLIDS/T * 34.1 N/A 38.2 N/A 33.7 N/A 38.31 N/A 35.8 N/A 1 1 SOLIDS/V t 9 7 7. 1 2 7.87 2 8.73 p c Q CA J i Dt 9 C 8.25 2 1 1 0(6 t .74 2 1 17 1.1/ ■i j .7 2 1.44 3 .21 1 J 1 SILT/CLAY i 67 E i i OA 3 66 2 94 3" 1 1 WATER CNT % 65.9 3 69.8 3 66.3 3 69.69 3 64.2 3 ^1 STATION: 5AM-4 5AM-4 5AM-5 - 1 1 DATE: 8/2/83 8/18/83 8/2/63 SAMPLE*: 68 B6 6892 6838 1 TYPE OF ANALYSIS: BULK BULK BULK 1 SEDIMENT DEPTH: SURF 3.5-4.8' SURF i 1 CONC CLASS CONC CLASS CONC CLASS 1 1 ARSENIC ■g/kg dry wt. 24.2 3 17.46 2 32.2 3 1 CADMIUM eg/kg dry wt. 4.75 2. 1 1 7.53 2 1 CHROMIUM ■g/kg dry wt. 21.1 38.3 1 31.4 1 COPPER ■g/kg dry wt. 11.9 18.62 1 1.64 1 LEAD ng/kg dry wt. 48.5 49. 87 1 65.8 1 1 MERCURY ng/kg dry wt. .74 .63 2 .66 1 NICKEL ■g/kg dry wt. 1.62 3.16 1 1.64 1 1 VANADIUM ■g/kg dry wt. 41.7 189.24 2 51.6 1 ZINC ■g/kg dry wt. 62.2 115.73 1 93.3 1 1 PCB ■g/kg dry wt. .885 .885 1 .885 1 DDT* ■g/kg dry wt. ,ee5 N/A .885 N/A .885 N/A 1 P/TOTAL ng/kg ary wt. 89.5 N/A 84.52 N/A 71.6 N/A 1 N/AMMONIA ng/kg dry wt. 125 N/A 384 N/A 21.9 N/A 1 PHENOLS ■g/kg dry wt. .59 N/A .288 N/A .82 N/A 1 TKN - ng/kg dry wt. 29.3 N/A 487 N/A 19.3 N/A i solids/t t 36.4 N/A 28.15 N/A 44.3 N/A 1 SOLIDS/V t 9.16 2 7.34 2 8.45 2 1 OSG t .64 2 .76 2 1.23 3 1 SILT/CLAY t 82 2 54 1 91 3 1 HATER CNT 1 1 t 63.6 3 71.85 3 55.7 2 •INCLUDING DDT, DDD, DDE, AND ELDRIN ALL CONCENTRATIONS EXPRESSED ON DRY HEIGHT BASIS CARLTON L. NOYES 131 zinc. Total phosphorus, ammonia nitrogen, and Kjeldahl nitrogen were also released in high quantities. The data did not indicate a general decline in concentrations of released constituents as had been found in other locations in the harbor. Results of the elutriate analyses are presented in Table 21. Marine Life Ninety micro-benthic species have been found inhabiting the Inner Harbor. Polychaete worms dominate the benthic community with such pollution tolerant species as Capitella capitata and Polydora ciliata the major dominants. Samples collected for this project indicate the highest density of pollution tolerant worms are found in the Fort Point Channel and Jeffries Cove. In addition, nearly four dozen species of finfish have also been observed in Boston Harbor waters. One of the most common permanent inhabitants of the Inner Harbor is winter flounder which appears to stay in particular areas, such as the Outer Harbor, Dorchester Bay, and adjacent coves and inlets. Of the seasonal residents, rainbow smelt and blueback herring are prevalent in the early spring, with alewife present during the early summer. Flounder spawn extensively in Boston Harbor; the Boston Conservation Commission, in its Order of Conditions for several recent projects, has imposed an annual moratorium on dredging projects from February 1 to May 15 to protect the flounder's reproductive season. No harvestable shellfish beds exist within the area of the proposed tunnel alignment. A limited number of soft-shell clams are found adjacent to the CSO in Jeffries Cove. Because of the high coliform bacteria concentrations in the water, the collection of any shellfish from this area for consumption is prohibited. The closest active clam flats are those north and east of Logan International Airport, which are periodically open only to Master Diggers for commercial harvesting. Such harvesting must be followed by depuration (flushing in a clean environment ) . Both green and brown algae ar« common within the Inner Harbor. Fucu (rockweed) and Ulva (sea lettuce) are found on rocks, shells, and pilings ij , the area. Species of marine mammals periodically found in the Harbor include the harbor seal, harbor porpoise, and grampus. 3.7.3 Lower Charles River Basin Water Quality Recent water quality data upstream and downstream of the new Charles River Dam are available from the MDC and Massachusetts Division of Water Pollution Control. MDC data collected upstream of the new dam nea the MBTA railroad bridge (Table 22) indicated the water had a light amber color, with low turbidity/ and acceptable levels of pH, dissolved oxygen, BOD, and fecal coliform bacteria. Total phosphorus concentrations clearly indicate nutrient enrichment. While stratifie, testing, also conducted by the MDC, indicates isothermal conditions above the new dam, there is a clinograde oxygen curve (concentrations decreasing with depth) where at a depth of 25 feet, dissolved oxygen in July was below the 5.0 mg/1 minimum for Class C water. Specific conductance data for May 1982 indicat< somewhat more saline water at the bottom than at the surface. DWPC data for 1982 (Table 23) in the tidal portion of the Charles River below the new dam also indicate declining oxygen concentrations. Microbiological conditions between th€ two data sources are generally 132 Itl Table 21 ELUTRIATE ANALYSIS WATER QUALITY LABORATORY T: THIRD HARBOR TUNNEL ANALYSIS REPORT 244 SECOND AVENUE 1 10: 141 WALTHAC!, KA 02154 ! 617/890-3737 1 )N: 5AM-1 CAM 4 CAM 5AM-2 5AN-3 1 F flNiftLYSIS: 7/26/83 8/10/83 7/db/83 8/10/83 7/25/83 1 ; #: 6887E 689 IE 6839E 6893E 6890E 1 IF ANALYSIS: ELUTRIATE ELUTRIATE ELUTRIATE ELUTRIATE ELUTRIATE 1 •NT DEPTH: SURFACE 3. 2-4. 0 1 SURFACE 3.4-4.0' SURFACE 1 [C bid/1 .398 .914 .392 .969 .355 1 M ■g/1 .86 .008 .054 .011 .054 1 :w ng/1 <.01 .01 .01 .01 .01 1 i ■g/1 .001 .005 .001 .004 .01 1 no/1 .889 .452 ■MA .772 .45 .736 1 H in ^ o CO CO CO CO rH cn rH DO (mg/1) 11.8 o CO m cn m m cr* vD vd vO Salinity (PPt) o O O rH rH V rH rH rH rH V O O rH V Specif ic Conduct . (^mhos/cm) o in ro 700 700 2500 o o VD 1300 1500 1800 o o o o o rH o m ^* in vd Turbidity (NTU) m rH o rH in rH Color (Units) o ro in CN O CN Temperature ( C) in vo ■P O •H U +) (0 •H Q C fd +> •H rH 0 & M ■P 0) S CO o >H o to Table 23 WATER QUALITY SUMMARY TIDAL PORTION OF CHARLES RIVER AT NORTH WASHINGTON STREET BRIDGE (Concentrations in mg/1 unless noted) Parameter Average Minimum Maximum >H (units) 7. 75 7.7 7.9 Suspended Solids 20 . 5 18. 0 24. 0 )il & Grease 1.1 0.6 1.6 total Kjeldahl Nitrogen 1. 025 0 . 64 1. 5 Ammonia Nitrogen n i q n r\ i n ^uirate Z , j . ID 1 QRO 0 Pnfal PVt r"\ c i~iY"i T* n C LOLdl irllwo^JIlvj-L ud 0 15 0 . 06 0 . 24 ^fi son n "34 000 0 39 000 0 LOtal l^O -L -Li. UI 111/ X u \J HlX 1012 5 450 1.800 0 .'6cax Loiironn/ iuu mx .7*4 90 ^00 j *j u chloride Q PRO 0 4 400 0 14 000 \rsenic o n m ^ U . UUJ3 O 0 01 o nin Cadmium n nic n no n n i Chromium 0 . 0425 0.03 0 . 06 Topper 0 . 098 0 . 02 0 . 24 ^ead 0.0238 0. 22 0. 27 lercury 0 . 00012 0 . 000 0.003 Nickel 0.155 0.13 0.20 Silver 0. 035 0.03 0. 04 Sine 0.055 0.03 0.12 Dissolved Oxygen Surface (3 ft) 5.45 4.4 7.0 Middle (12-21 ft) 5.10 4.5 5.7 Bottom (25-43 ft) 3. 75 2.4 5.1 Source: Massachusetts Division of Water Pollution Control, 1982. 135 Table 24 SEDIMENT QUALITY ABOVE NEW CHARLES RIVER DAM ( Concentrations in mg/kg dry weight unless noted) Parameter Average Concentration Minimum Maximum firain Ri 70 Ciitvp /F i tip 43 . 00 7 . 00 75.00 63. 48 43 . 21 74. 98 Volatile Solids- epa (%; / . 1 z O C3 z,bz 1 R "7*3 13 » 1 A volatile boiia.s~iNriL) \t > C CI 1 1Q 1 . 15 lj . 31 luiai i\jciaani wiur uyen 1 / /uu , u **u u • u ** f A V U • V \JXX ot ul case V t> J 10 5 0 . 06 31. 4 Mercury 1.24 0.4 2.84 Lead 472.77 58.4 1,024.7 Zinc 468.57 95.4 1,189.4 Cadmium 7.43 1.1 20.1 Chromium 60.0 15.1 140.0 Copper 194.6 60.5 449.2 Source: COE GE-3, KE-3, KE-4. Collected and analyzed in 1972. 136 Table 2 5 S EDIMENT QUALITY BELOW NEW CHARLES RIVER DAM (Concentrations in mg/kg dry weight unless noted) Parameter Average Concentration Minimum Maximum Grain Size Curve/Fine (%) 71.00 64.0 78.00 Solids (%) 40. 535 31.51 49.56 Volatile Solids-EPA (%) 11.65 8.18 15.71 Volatile Solids-NED (%) 10. 01 6.5 13.52 Total Kjeldahl Nitrogen 3, 350.0 1,800.0 4,900.0 Oil & Grease (%) 2.0 0.8 3.1 Mercury 2. 34 1. 59 3.09 ucau / U Z> • JJ QA K 1 J'i O . X. Zinc 880.5 416.6 1,344.4 Cadmium 9. 35 4.1 14.6 Chromium 241.0 69.4 412.6 Copper 534.0 369.2 698.8 Source: COE GE-4, KE-7. Collected and analyzed in 1972. 137 comparable. Sediments Upstream of the new Charles River Dam, the average quality of surface sediments, presented in Table 24, indicates predominant Category 2 to Category 3 quality. The maximum sediment concentrations are highly contaminated and clearly of Category 3 quality. Minimum sediment concentrations were all in Category 1. Downstream of the new dam, the minimum, maximum, and average sediment concentrations were predominantly of Category 3 quality (see Table 25). Metals present in the highest concentrations were lead, mercury, zinc, and copper. While stratified testing was not conducted, it is reasonable to assume that sediment quality improves with depth such that at depths possibly Delow 4 feet, Category 1-2 conditions are present. Marine Life A warm water fishery is present upstream of the new Charles River Dam. The Massachusetts Division of Fisheries and Wildlife conducted a fishery survey near the Boston University Bridge during July 1981. In order of abundance, the fish found in the sampling included golden sniner, white perch, alewife, pumpkinseed, yellow perch, white sucker, white catfish, northern pike, chain pickerel, and brown bullhead. Growth rate was reported to be excellent and the condition factor was comparable to the state-wide average. Some of these species are also likely to be found between the new and old dams. Anadromous fish that pass into the Charles River include smelt, herring, and alewives. 3.7.4 Industrial Water Use A survey of industrial seawater users in the Fort Point Channel and portions of the Inner Harbor was conducted to determine whether these users would be adversely affected during construction of the proposed project or have their use of seawater restricted as a result of the presece of the tunnel. Seawater users adjacent to the tunnel alignments ae shown in Table 26. 3.8 WETLANDS 3.8.1 Description of Existing Conditions Federal and Massachusetts agencies with regulatory authority over wetlands define such areas in different terms. According to the U.S. Army Corps of Engineers (COE), federally-regulated wetlands are defined as: ". . . areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions." Based on the definition of wetlands adopted by the COE and on field observations, no Federally regulated wetlands occur in the project area. Under the Commonwealth of Massachusetts Wetlands Protection A< project area wetlands are considere< coastal wetlands. Such areas incorporate the land under the Char! River and Boston Inner Harbor, including Fort Point Channel, as we! as lands up to the limit of spring tides, and areas generally inundatec by a 100-year storm event. Figure 25 delineates the 100-year floodplain and the maximum extent of wetlands in the project ai governed by the Massachusetts Wetlar Protection Act. 3.8.2 Evaluation of Project Area Wetlands As no Federally regulated wetlands occur in the project area, and State regulated wetlands primari constitute various types of develope 138 Table 26 SALTWATER USE IN BOSTON HARBOR Name Location Primary Use Maximum Daily Use (mgd)* Gillette Company Bethlehem Steel Gillette Park Cooling South Boston 265 Marginal Way Cooling East Boston 39. 0** 0.28 Massport James Hook & Co. Bay State Lobster Hines and Smart Harbor Lobster Paul 1 s Lobster Neptune Lobster Yankee Lobster New England Aquarium Fish Pier South Boston 15 Northern Ave. South Boston 379 Commercial St, Boston 33 Mill Street East Boston Fish Pier South Boston 150 Northern Ave. South Boston 88 Sleeper St. South Boston 272 Northern Ave. South Boston Central Wharf Boston Wa shdown Lobster Support Lobster Support Lobster Support Lobster Support Lobster Support Lobster Support Lobster Support Marine Aquarium 0.43 5. 0 4.32 3.60 1.44 1.44 1. 00 0.86 0.15 *Millions of gallons per day. **Based on National Pollutant Discharge Elimination System permit; actual capacity is 57.6 mgd. 139 Figure 25 100 Year Flood Zone 0 450 900 1800 Feel EIS/EIR for l-90-Third Harbor Tunnel; land uses, water resources, floodplains, and upland vegetative communities, evaluations of these resources are addressed in Sections 3.2 LAND USE , 3.7 WATER RESOURCES , 3.9 FLOODPLAINS , and 3.10 VEGETATION AND WILDLIFE of this FEIS/FEIR. 3.9 FLOODPLAINS The extent of the 100-year flood zone is illustrated in Figure 25. The project will involve filling portions of the Fort Point Channel. This construction will involve conversion of open water areas to highway tunnel or depressed, open roadway. Construction of new bridges over the Charles River and tunnel ramp connections from Leverett Circle will also affect floodplains in the area. Impacts from changes in tnese areas are discussed in Section 4.11 FLOODPLAINS of this report. According to the Federal Emergency Management Agency (FEMA), the Charles River and the Fort Point Channel are not regulatory floodways. 3.10 VEGETATION AND WILDLIFE 3.10.1 Vegetation Due to the urbanized character of the project area, upland vegetative communities are limited, and consist of successional areas and open space. Successional areas refer to vegetated sites subject to eventual plant community replacement. These lands are primarily composed of disturbed sites, including vacant lots and areas adjacent to abandoned or infrequently used railroad corridors. Open space communities consist of maintained, landscaped sites, including recreational facilities. Successional and open space sites occur in scattered locations and exhibit a relatively low diversity of plant species. The dominant plants in successional areas are herbaceous, including such species as ragweed, milkweec, clover, dandelion, plantain, and a variety of grasses. Some woody plant species are also present. Such species typically include tree-of -heaven , black cherry, and staghorn sumac, among others. Characteristic plant species of open space sites include sycamore, Norway maple, scarlet oak, lombardy poplar, gingko, clover, dandelion, plantain, and ragweed. 3.10.2 Wildlife The wildlife habitat in the project area is quite limited. This limitation is a function of the scattered locations of the vegetative communities, as well as their relatively small size and proximity to highly developed areas. Wildlife species observed during field investigations included herring gulls, pigeons, common grackles, starlings, blue jays, American robins, and house sparrows. Additional species, however, are also likely to occur in the project area. 3.10.3 Endangered and Threatened Species Table 27 provides a list of Federally-listed endangered and threatened species for Massachusetts. Under Commonwealth regulations, only the Federally-listed species and the small whorled pogonia (a flowering plant) are protected as threatened or endangered species. According to the Massachusetts Division of Fisheries and Wildlife, the whitlow-wort (a flowering plant) is also being considered for listing in Massachusetts . The U.S. Fish and Wildlife Service and the National Marine Fisheries Service report that the occurrence of any of these species in the project area, including Boston Inner Harbor and the Charles River, is highly unlikely. Although not officially protected by special status designation, a variety of vegetative and wildlife species have been identified as uncommon in Massachusetts. None of these species 141 Table 27 FEDERALLY LISTED ENDANGERED AND THREATENED SPECIES IN MASSACHUSETTS Common Nana Scientific Name Status Distribution 1 - FISHES: Sturgeon, Acipenser brevirostrum B Connecticut River and shortnose* Atlantic Coastal waters REPTILES : Turtle, green* Chelonia mydas T Oceanic straggler in Southern New England Turtle, Eretraochelvs imbricata E Oceanic straggler in hawksbill* Southern New England Turtle, leatherback* Dermochelys coriacea E Oceanic summer resident Turtle, loggerhead* Caretca carecta T Oceanic summer resident Turtle, Leoidochelys kenraii E Oceanic summer resident Atlantic ridley* BIROS: Curlew, Eskimo** Namenius borealis E Alaska to Argentina, Southwest i Pacific Ocean: New Caledcni Eagle, Bald Raliaeetus leucoceohalus E Entire state Jj Pa Icon, Falco pecearinus anaeura E Entire state - re-establishmen , American to former breeding range peregrine in progress Falcon, Arctic Falco perearinus tundrius E Entire state-Migratory - peregrine no nesting MAMMALS: Bat, Indiana** Mvotis sodalis E Eastern i midwestern USA Cougar, eastern Felis concolor couoar E Entire state - may be extinct Whale, blue* Balaer.oDtera rausculus E Oceanic Whale, finback* BalaenoDtera physalus E Oceanic Whale, humpback* Meoaotera novaeanqliae E Oceanic Whale, right* Eubalaena spp. (all species) E Oceanic Whale, sei* Balaenootera borealis E Oceanic Whale, sperm* Physeter catodon E Oceanic MOLLUSKS: None PLANTS: Pogonia, small whorled Whitlow-wort (Silver ling). Isotria medeoloides Paronychia arovrocoma alb imontana Proposed East and Mid- Western USA Proposed Maine. Massachusetts, New Hampshire Except for sea turtle nesting habitat, principal responsibility for these species is vested with the National Marine Fisheries Service. These species are not specifically listed as present in Massachusetts by the U.S. Fish and Wildlife Service. Their inclusion in this list is based on the Massachusetts Dwision of Fisheries and wildlife, 1979 Massachusetts Species for Special Consideration . Fauna of Massachusetts, Series No. 5 Source: U.S. Fish and Wildlife Service, I960 and 1982. 142 s recorded during field vestigations. Additionally, based their nabitat requirements, none of ese species is liKely to occur in e project area. 11 HISTORIC AND ARCHAEOLOGICAL RESOURCES 11.1 Historic Resources This section identifies the stone sites within the project area ich are either listed, eligible or Itentially eligible for listing on e National Register of Historic aces. These sites have been entified through an intensive field ventory and a literature review dertaken as part of this study. The ndings of this effort are documented two separate reports "Historical ""sources inventory", prepared in cember 1982 and June 1983 as part of e DEIS/DEIR and SDEIS/SDEIR and have en discussed with the Massachusetts »t storical Commission and the Boston indmarks Commission. Consultations .th these agencies was a basis for idging the potential eligibility of sources in the project area. .storic Resources in Downtown Boston The Central Artery corridor ins through the heart of downtown >ston, an area which has seen 350 _;ars of building activity. Within lis area lie numerous historic _.stricts and many more individual Hidings either on or potentially Ligible for the National Register of istoric Places. In addition, some of ie individual buildings are National istoric Landmarks or Boston indmarks. The following designations re used next to several of the isources: ■JR): listed on the National Register : Historic Places, which includes :operties of local, state, or itional significance designated by ie U.S. Department of Interior irough the State Historic reservation Officer. ■WL) : designated a National Historic Landmark, properties of outstanding national significance designated directly by the U.S. Department of Inter ior . (BL): designated a Boston Landmark. All other buildings included here either have been determined to be eligible for the National Register, or are considered potentially eligible either individually or as part of a district, based on consultations with the Massachusetts Historical Commission and the Boston Landmarks Commission. The numbered resources are located on Figure 26. Historic Districts West of the Central Artery The following districts, which lie in whole or in part within the area of potential impact to the west of the Central Artery, are listed and described briefly below. 1. Charles River Basin District (NR) The Charles River Basin is the keystone of the metropolitan park system in Boston. The park reservations along the edge of the Basin, established in the 19th century, still provide the well-utilized recreational space that was envisioned when they were planned. The Charles River Basin National Register District incorporates the Basin and the parkways and landscaped areas on both banks for approximately six miles upstream from the old Charles River Dam to the Eliot Bridge; the District also includes Storrow Drive and Leverett Circle. The Dam, the canals, the seven bridges that cross the Charles and the numerous structures in this district display a range of architectural style and civil engineering accomplishment that reflect the evolving technology of the past one hundred years. Significant buildings and structures within the district and in the vicinity of Leverett Circle are the Charles River Dam, 1903-1910; the MBTA Green Line 143 CHARLESTOWN Legend 1 Charles River Basin District (NR) 2 Bulfmch Triangle District 3 Blackstone Block District (NR) 4 Cornhill District 5 Exchange District 6 Custom House District (NR) 7 Commercial Palace District 8 Essex/Kingston Textile District 9 Chinatown District 10 Old West Church (NR, NHL) 1 1 First Harrison Gray Otis House (NHL) 12 Boston City Hall 13 Faneuil Hall (NR) '14 Faneuil Hall Market (NR) 15 Old State House (NR, NHL) 16 Carter Winthrop Building (NR) 1 7 (Former) Federal Reserve Bank (BL) 18 272-276 Franklin Street 19 Richardson Block Buildings 20 United Shoe Machinery Corporation (NR) 21 Causeway - North Washington Streets District 22 North End District 23 Old Waterfront District 24 Fulton - Commercial Streets District (NR) 25 Long Wharf District (NR) 26 Leather District 27 Russia Wharf (NR) 28 South Station Headhouse (NR) 29 Fort Point Channel District 30 Commonwealth Pier (NR) 31 Fish Pier 32 South End National Register District 33 Albany Street Area 34 Butler Aviation Hangar 35 Streetcar Tunnel NR - Listed on the National Register of HistoricF NHL - Designated a National Historic Landmark BL - Designated a Boston Landmark Figure 26 Historic Resources in the Pr# 550 1100 Feet EIS/EIR for I-90 -Third Harbor Tunnel I-93-C*" Legend Historic Property Historic District • ■ 1 7 lh Century Shoreline M* m Preterrea Alternative Hgure 27 Original Seventeenth Century Shoreline 0 900 1800 3200 Feet EIS/EIR for I-90 -Third Harbor Tunnel; I-93 - Central Artery Viaduct , 1910; and the Metropolitan District Commission Police Headquarters and Lock Houses, 1910. 5. Exchange District 2. Bulfinch Triangle District Bounded by Causeway, Canal and Merrimac Streets, this district includes approximately half the triangular street pattern which architect Charles Bulfinch laid out for the area now commonly known as North Station. The architecture of the area is diverse, with the most distinctive structures generally four to six-story late 19th century brick warehouses in the Richardsonian Romanesque and Victorian Commercial sty les . 3. Blackstone Block District (NR) The buildings within this block, bounded by Union, Hanover, Blackstone and North Streets, are a sampler of 18th, 19th, and 20th century building types unified by their modest scale and general use of brick. The alleys which meander through the interior of the block date frcm the 17th and early 18th centuries and have been designated a Boston Landmark. Along the Blackstone Street edge is the last remaining vestige of the pushcart market called "Haymarket" . Significant buildings within this district which lie within the project corridor include Union Oyster House , 41-43 Union Street, c. 1714 (NR); and Hancock House , 10 Marshall Street, c. 1767-1776 (NR, BL ) 4. Cornhill District This grouping of diverse architectural elements is centered at the intersection of Court and Tremont Streets and includes fine examples of the Italianate, Romanesque and Federal Revival styles, several designed by well-known architects. Significant buildings within this district which lie within the project corridor include the Sears Block , 65 Cornhill Street, 1848; Sears Crescent , Cornhill Street, 1816, remodelled c. 1860; and the Ames Building , 1 Court Street, 1887-1889 (NR). CO The Exchange District is the historic center of the City's regiorl commerce, banking and insurance industries. The area is characteristic by early skyscrapers in the cla ss icajj^ | tradition, averaging eight to ten stories in height and generally constructed of light-colored materi such as limestone, granite and tan brick. A significant building withi this district which lies within the project corridor is the National Shawmut Bank, 20-42 Water Street, 1 6. Custom House District (NR) The Custom House District, centered around Broad and India Streets, is significant as one of th city's first examples of urban planning. Under the direction of architect Charles Bulfinch, the once dilapidated wharf area was redevelopj in the early 19th century into an ar| of wide streets and Federal-style warehouses, a number of which surviv today. Also located here are severa monumental structures associated wit Boston's maritime and commercial history, as well as a number of fine late 19th and early 20th century masonry buildings. Significant buildings within this district which lie within the project corridor include the Batterymarch Building , 54-68 Batterymarch Street, 1927 (NR) ; the Board of Trade Building , 2-22 Broad Street, 1901 (NR); Bulfinch Warehouses , nine buildings at 5, 7-9, 64-66, 68-70, 72-72A, and 102 Broad Street; 171, 173-175 Milk Street; anc 25-27 India Street, 1805-07 (NR) ; 5 0-5 4 Broad Street , c. 1863 (NR) ; State Street Block , McKinley Square, 1858 (NR) ; United States Custom House ■Jit ■h lldii reet, udi IH jldi If-! iters *« Ufi McKinley Square, 1837-47 and 1913-19] (NR); Central Wharf , 146-176 Milk Street, 1816 (NR) ; Chadwick Lead Works , two buildings, 172-174 and 176-184 High Street, 1875 and 1887 (NR) ; Flour and Grain Exchange/Chambe of Commerce Building , 177 Milk Street 1890-92 (NR) ; and the Richards Building , 112-116 State Street, c. 146 59 (NR). Commercial Palace District This district is located along anklin, Arch, Devonshire, Summer and dford Streets. It includes "Church een", the historic name for both the tersection of Bedford and summer reets and the polygonal Neo-Grec anite commercial building which :cupies the site. Two-thirds of the buildings in ie area date from the years mediately after the Great Fire of :72, when the city was quickly •built with 4- to 6-story masonry )mmercial buildings in the ;alianate, Neo-Grec and Panel Brick :yles. Contemporary newspaper counts called them "the new palaces : Boston merchants", and they typify ie stylistic variety and fine aftsmanship of the late 19th •"lentury. significant buildings which '"ie within the project area include lie Church Green Buildings, two it! I aildings, 101-103 and 105-113 Summer breet, 1873-74 (BL); the Bedford gilding , 89-103 Bedford Street, 374-76 (NR); and the Proctor uilding, 100-106 Bedford Street, 896-97 (BL). Essex/Kingston Textile District Centered at the Essex/Kingston ntersection, this ensemble of igh-quality late 19th century brick anufacturing and wholesale houses is ssociated historically with the ity's textile trade. Chinatown District The area centered around Beach nd Kneeland Streets and the small treets which cross them is the center f the fourth largest Chinese ommunity in the United states. Begun ith the settlement of Ping On Alley ver a century ago, the area was irmly established as Chinatown by 890, although most of its population growth has occurred since the Chinese tevolution in 1949, and the continuing nflux of new residents has kept Chinese language and customs strong. The area, developed from tidal flats beginning in the 1830s, is characterized by tiny, crowded streets and a mix of small-scale 19th century row houses and commercial buildings and larger early 20th century industrial buildings, the latter especially where the district overlaps with the Textile District. Onto this traditional Boston streetscape has been grafted a colorful overlay of Chinese signs and fanciful Chinese restaurant architecture, which gives the district a distinctive quality. It includes the Chinese Merchants Association Building , 20 Hudson Street, 1949, judged potentially eligible for the National Register despite its date, and St. James Church , 125 Harrison Avenue, c. 1900. Individual Historic Buildings West of the Central Artery 10. Old West Church , 131 Cambridge Street, 1806 (NR, NHL) This structure exemplifies the architectural principles set forth by its designer, Asher Benjamin, in his book, The American Builder's Companion (1806). 11. First Harrison Gray Otis House , 141 Cambridge Street, 1796 (NR, NHL) The first of three houses in Boston designed by Charles Bulfinch for Otis, a prominent lawyer, member of Congress and mayor of Boston. 12. Boston City Hall , One City Hall Plaza, 1961-68 Designed by Kallman, McKinnell, and Knowles, this is one of the most significant Boston buildings of the 20th century; its architectural significance makes it potentially eligible for the National Register despite its date. 13. Faneuil Hall , Faneuil Hall Square, 1740-42 (NR, NHL) 147 A rare example of Early Georgian puoiic architecture sensitively enlarged by Charles Bulfinch during the Federal period and focal point of p re-Revolutionary War protest . 14. Faneuil Hall Market , three buildings, 100-300 Faneuil Hall Marketplace, including the "Quincy Market" and North and South Market Buildings, 1824-26 (NR, NHL) Designed by Alexander Parris, these are Boston's finest remaining examples of early Greek Revival style. Also the oldest surviving trabeated granite buildings in Boston, the buildings incorporate numerous innovative construction techniques. 15. Old State House , 208 Washington Street, 1712-13 (NR, NHL) The oldest extant public building of Georgian design in the United States, it was the center of political activity in Massachusetts during Colonial and Revolutionary War periods. 16. Carter/Winthrop Building , 276-278 Washington Street, 1893 (NR) This building is a fine example of the Second Renaissance Revival style and is technologically significant as the first steel frame skyscraper in Boston. 17. (Former) Federal Reserve Bank , 22-24 Pearl Street, 1922 (BL) The culmination of Boston's classically-derived commercial architecture, this structure is among the last and most literal interpretations of the Renaissance Revival style in downtown Boston. It was the first permanent New England home of the Federal Reserve Bank. 18. 272-276 Franklin Street , 1877 A nearly intact example of the early Queen Anne style, now rare in the Central Business District. 19. Richardson Block Buildings , 113-115 Pearl Street, 1873 an< 1885 A group of rare, marble-faced post-fire buildings which form the only Neo-Grec commercial block remaining in the Financial District. 20 . United Shoe Machinery Corporation , 34-66 High Street 1928 (NR, BL) An exceptionally fine Art Dec< office building, it reflects Boston's i contemporary setback legislation, which virtually doubled the height ol the downtown Boston skyline. Historic Districts East of the Centr; . Artery 21 . Causeway-North Washington Streets District This is a district of late 19ti to early 20th century brick industrii buildings ranging in height from fiv< to nine stories. The portion of the district south of Causeway Street was originally part of the Bulfinch Triangle but is now separated from tt remainder of this street pattern by the Central Artery and MBTA Green Lir viaduct. The buildings were constructed for a variety of mercantile and manufacturing purposes. Several share common detai ling . 22 . North End District The North End is Boston's oldest extant residential neighborhood. Settled in the 1630s, it housed a cross-section of Bostonians, rich and poor, many associated with maritime activities c the neighboring waterfront. In the 19th century, it housed the successiv waves of immigrants that poured into Boston. Presently, it remains as a largely Italian neighborhood. Its narrow streets, many of them little changed from the earliest 148 i^;, are crowded with architectural . r ence from every period of its " i.ory . Significant properties within i'i district which lie within the : ect corridor include Copps's Hill 1 al Ground , Charter, Snowhill and i. Streets, 1660 (NR); St. Stephen's 'irch, Hanover Street, 1804 (NR) ; the a l Revere House , 19 North Square, 3); renovated 1908 (NR, NHL); the " i' rce-Hichborn House , 29 North lire, 1680-1710, (NR, NHL); and l ist Church (Old North) , 191 Salem j!Seet, 1723 (NR, NHL). Old Waterfront District The area of Boston waterfront : stretches between Commercial itfi i —rrrf South and Lincoln Wharf was an jortant center of Boston's maritime selopment in the mid-19th century. demolition and modernization, the issive wharf buildings still dominate »3 give clear historical form to the isa. Significant buildings within .^is district which lie within the ^oject corridor include Lewis Wharf , -32 Atlantic Avenue, 18 36-3 8; i mmercial Wharf North , 65-69 Atlantic 'enue, 1894; Commercial Wharf South , f-85 Atlantic Avenue, 1832-1834 ; _' -77 Commercial Street , (now the "tarf Restaurant) 1888; Commercial Wharf , 1834 ; 220-254 Commercia l Street , c. 1845-1870; Union Wharf , 1846-47 (NR) ; Lincoln Wharf , 36 5 Commercial Street, 1907; and Pi lot House , 38-50 Eastern Avenue, 1863. 24 . Fulton-Commercial Streets District (NR) The Fulton-Commercial Streets District, one of the last remnants of Boston's 19th century waterfront, is a unique environment of commercial architecture of the 1830s to 1860s. The brick row units, originally four stories high, with granite posts and lintels at street level, constitute what is probably the most extensive grouping of this type of shop front now extant and are significant both for their extreme coherence and as the historical and physical setting for three major architectural works: Mercantile Wharf , 1857; Commercial Block , 142 Commercial Street, 1857 ; and the McLauthlin Building , 120-1/2 Fulton Street, c. 1864. 25. Long Wharf District (NR) The original 800-foot Long Wharf (1710-1721) was for decades Boston's busiest pier. Extended to almost a half mile in length in 1740 , the wharf was then substantially reconstructed in an expansion project completed in 1857. Filling gradually landlocked the wharf, and the last traces of the 18th century structure disappeared with the construction of Atlantic Avenue in 1868-1870. Significant resources within the district are the Custom House Block , 1848 ; and the Gard iner Bui Id ing , c. 1830 . 26 . Leather District A homogeneous area of late 19th century commercial buildings related to Boston's important leather business; determined to be eligible for the National Register. Individual Historic Buildings East of the Central Artery 149 27. Russia Wharf , 518-340 Atlantic Avenue, 270-272 & 278-288 Congress Street, 1897 (NR) Pine intact trio of late 19th century commercial/industrial structures, all Classical Revival in style. 28. South Station Headhouse , 6 20-690 Atlantic Avenue, 1898 (NR) This structure is significant as Boston's first monumental public example of the Neo-Classical Revival style; as a key element in the evolution of railroad station planning; and as a prototype for the double-decker track system. Historic Resources in South Boston 2 9. Fort Point Channel District (1836 - 1930s) - potential National Register District. The Fort Point Channel area, including the Channel itself, the bridges over it, and the wharves, warehouses and transportation facilities on either side of it, comprise a physical record of the complex transportation developments which necessarily accompanied the rapid industrial expansion of Boston in the late nineteenth and early twentieth centuries, and is a symbolic vestige of the original Shawmut Peninsula. It is potentially eligible for the National Register. FHWA and the Massachusetts Historical Commission have agreed that the Congress Street, Summer Street and Old Colony Railroad Bridges are also potentially eligible for the National Register (see letters dated October 13, 1982 and June 30 , 1983 in COMMENTS AND COORDINATION ) . The district includes the following contributing elements. a. The Fort Point Channel (c. 1890s) . Historic waterway bordered by granite bulkheads, created as part of late - 19th century industrial/ transportation development of South Boston. 3 ical b . The Northern Avenue Bridge ( 1908 ) . Pivotal lift swing bridge; it has been determined eligible for the National Register. c . Congress Street Bridge (1930 ) Single-leaf bascule bridge; it represents the final period of development of the Channel and warehouse subdistrict. c;:s pi«5 Its, saite 2-St lioi d. Summer Street Bridge (1898). A retractible bridge, a design developed in Boston; although inoperable it, is one of only two remaining such bridges in the city. e. Old Colony Railroad Bridge (1899). A Scherzer rolling lift bridge perhaps the most important of South Boston's many bridges. f . Boston Wharf Co. Warehouse District (1880 - 1930 ) . trai icti' h ::.it il'JC iijit eh ijit A unified district of late 19t and early 20th century industrial buildings built by the Boston Wharf C. : g . Factory Buildings Trust/A Street Industrial Buildings :i Extension of the Boston Wharf :a Company industrial development; industrial buildings dating from 1890 > - 1930s. m Individual Historic Buildings in Sout .. Boston 30 . Commonwealth Pier, 1914 (NR) The South Boston Flats were developed in the early years of the 20th century as part of a vigorous campaign for the enlargement of Boston's port. The development included the new Fish Pier, built in 150 (1330! ty; j ise il4 to house the Boston Fish Market, ie Commonwealth Pier, and other lysical improvements to the irrounding area. Following its jmpletion, the Commonwealth Pier scame the center of the American wool :ade, as well as a port of entry for emigrants to the United States erving the Hamburg -American Line, nich brought immigrants to Boston rom Germany and intermediate European arts. The pier is impressive in its rchitecture, and includes a our-story head house, one of the few emaining major public Beaux-Arts tructures in the City. The viaduct onnection to Summer Street is an arly example of the separation of oadway, railroad, and shipping modes f transportation. Viaduct Street is unctionally part of Commonwealth ier, but is neither structurally nor rchitecturally integral to the pier, iaduct Street is constructed in a •tandard roadway design. Also, iaduct Street is not individually ;ligible for the National Register, because Commonwealtn Pier is an sligible building, not the center of in eligible district, Viaduct Street .s not a contributing feature of an ;ligible district. Fish Pier (1914-1915) Adjacent to Commonwealth Pier :: ::ind part of the development of the South Boston Flats described above, •the pier is an architecturally unified -s complex of three, three-story Duildings made of brick with terra i'i cotta classical ornamentation. It is still in its original use as the !3?: center of Boston's commercial fishing industry. South End/South Cove Area Little above-ground physical evidence of early development remains in the area whicn may be affected by the project. Further to the west is the South End National Register District and a proposed Boston LandmarK District. At the edge of these districts one small group of 19tn century warehouses remains. The following historical resources in the area have been identified and are also presented on Figure 26. 32. The South End National Register District (19th century). A district of Victorian bow-front row houses; it is the largest residential National Register district in the U.S. 33. Albany Street Area (1880s and 1890s) - a potential National Register district. An area of several long, five-story brick and granite warehouses representing the industrial development of the Albany Street warehousing area in the last decades of the 19th century. Historic Resources in East Boston 34. Butler Aviation Hangar (1930s). Logan Airport. The original Eastern Airlines Hangar; one of the earliest buildings at the Airport. 35. Streetcar Tunnel (1904, electrified 1924). MBTA Blue Line tunnel from Boston to Maverick Square, East Boston. This tunnel is the second oldest underwater vehicular tunnel in North America. 3.11.2 Archaeological Resources A Phase I, Step 1 Archaeological Survey was undertaken for this project. The reconnaissance level survey focused on the south Bay, South Cove, Fort Point Channel and Fort Hill areas of Boston; and the Conrail railroad right-of-way in East Boston and parts of Logan Airport. The survey indicated a high probability of significant historic archaeological resources being located in all of these areas, including evidence of remains of rope walks, remains of maritime trade and wharves, and refuse from industrial and institutional development. It also 151 indicated that prehistoric sites are likely to be located in the South Bay/South Cove and East Boston railroad right-of-way areas, yielding relevant climatological, geological, floral, and paleontological data and providing information on past human subsistence practices and settlement patterns. Figure 27 presents the outline of the original 17th century shoreline and its relation to the Preferred Alternative. The survey also covered the Central Artery and South Boston corridors. In the Central Artery corridor, between Dewey Square and the Causeway street area of Boston, prehistoric and nistoric archaeological sites are likely to exist within the original land mass. These sites would cover several time periods and functional or cultural affiliations, since this area is one of the most significant archaeological zones in the greater Boston area. In tne South Boston corridor, prehistoric archaeological sites inundated after their occupation by rising sea levels and subsequently filled may also be found. The remains of prehistoric sites may also be preserved within the bounds of South Boston's original land surface. Historic archaeological resources of possible significance are primarily 19th and 20th century, owing to the more recent development of this area in comparison to nearby areas of South Boston and Boston. Remnants of the out wharves, buried footings from the Atlantic Avenue elevated railway, vestiges of the 18th century timber wharves and piles, and possibly stone seawalls may be encountered. Remnants of the former Mill Creek may also be encountered. The results of the Phase I, Step 1 survey report have been reviewed by the Massachusetts Historical Commission, the State Historic Preservation Officer and the Boston Landmarks Commission; a Phase I Step 2/Phase II survey to locate and assess the significance of archaeological sites will be performed consistent with the Memorandum of Agreement (see COMMENTS AND COORDINATION ) . 3.12 UTILITIES The project area includes a maze of publicly- and privately-owi : utilities. Types of utilities encountered include storm drains, sanitary sewers, combined sewers, water mains, gas mains, telephone power lines, fuel lines, steam lin fire alarm and police communicatio systems, etc. The utilities liste below are keyed to Figure 28. 1. East Side interceptor, 32-ii| x 54-inch combined sewer (C: : located in Atlantic Avenue. 2. 72-inch CS from Purchase Sti to Oliver Street, crossing I Central Artery and Atlantic Avenue to Fort Point Channe! near Hook's Lobster. 3. Fort Point Channel outfalls Dorchester Avenue: at Congrc Street, 36-inch x 36-inch Ci at Summer Street, 60-inch Ci from Kneeland Street, 81-inci 81-inch CS. 4. 60-inch CS outfall to Fort Point Channel at Dorchester Avenue Bridge. 5. Massachusetts Turnpike Authority (MTA) pump house ♦ 6. South Bay outfalls: 72-inch at Albany street near Travel Street, 36-inch and 8-inch force mains from MTA pump ho #7, 48-inch CS near West Fom Street, two 10-inch discharg pipes from MBTA pump house a Tidal Drain Reservoir. 7. East Side interceptor in thai vicinity of the railroad yar< and crossing under the Turnp: ramps, 32-inch x 54-inch CS. " 8. Railroad Tidal Drain Reservoi in railroad yard adjacent to Broadway. 9. MBTA pump house at Tidal Drai 152 NORTH END/NORTH STATION Figure 28 Major Existing Utilities @ 0 450 900 1800 Feel EIS/EIR for I-90, The Third Harbor Tunnel Reservoi r . locations . 10. Roxbury Canal Conduit outfall, 21, twin 20-foot x 15.5-foot pipes. 11. Boston Edison utility tunnel 22, crossing Fort Point Channel between Congress Street and Summer Street . 23 12. 115,000 volt electric lines at Purchase Street and Oliver 24, Street crossing Central Artery to Boston Edison sub-station near Harbor Plaza Building. 25, 13. 115,000 volt electric lines from Boston Edison sub-station, crossing Fort Point Channel to 26 South Boston near Northern Avenue . 8-inch sanitary sewer force main in BIF access road. 20-inch water line in BIF access road. 12-foot x 10-foot Porter Stre: combined sewer outfall. 20-inch water line in vicinit; of East Boston Athletic Field, 7-foot 10-inch x 8-foot 2-inci storm drain in vicinity of Ea Boston Athletic Field. 24-inch sanitary sewer in vicinity of MBTA Airport Station. 14. 115,000 volt lines frcm Harrison Avenue suspended on Broadway Bridge crossing to South Boston at Dorchester Avenue . 15. 30-inch Intermediate Pressure gas pipe crossing area of Turnpike ramps and railroad yard from Knee land Street to Albany Street. 16. 24-inch Intermediate Pressure gas pipe crossing West Fourth Street from Albany Street to the Gillette Company. 17. Telephone submarine cable between Congress Street and Summer Street crossing Fort Point Channel from Dorchester Avenue and Sleeper Street in South Boston. 18. 16-inch and 24-inch water mains crossing Fort Point Channel from Dorchester Avenue at Congress Street to Northern Avenue in South Boston. 19. 60-inch storm drain adjacent to Bird Island Flats (BIF) access road . 20. Telephone and electric duct banks servicing several airport 27. 6-foot 6-inch x 4-foot 4-inch railroad drain in vicinity of MBTA Airport Station. 28. 60-inch storm drain in vicinil' of Emery Air Freight Building 29. 6-foot x 6-foot 4-inch combiml sewer in Porter Street in vicinity of railroad crossing and Orleans Street. 30 . 24-inch water line crossing Airport access and egress roadways, near MBTA Airport Station. 31. 12-inch gas line crossing Airport access and egress roadways near MBTA Airport Station. 32. 36-inch storm drain crossing Route 1A and Airport egress roadways . 33. Railroad drainage storage box near MBTA Station. 34 . 36-inch combined sewer (CS) siphon under Charles Street. 35. Twin 48-inch CS siphon exitinc into 39-inch x 39-inch CS at Leverett Circle. 154 Lowell Street weir structure with 48-inch and 54-inch CS exiting pipes; Charles River CS 50. junction chamber and 84-inch inlet and outlet pipe to MDC 51. Chlorination and Pumping Facility. 96-inch Charles River Marginal Conduit CS Interceptor from MDC Detention Chlorination Pumping 52. Station. 72-inch storm drain from 53. Rutherford Avenue to Millers River . 1 54-inch storm drain from Interstate Route 93 to Millers 54. River . Two major telephone services (Boston-Cambridge A Cable); one 55. with twelve, 3.5-inch conduits and one with twelve, 3-inch conduits. 56. 36-inch water main. 72-inch storm drain along Mt. Washington Avenue to Fort Point Channel. 57. In this area of A Street: 54-inch storm drain; 24-inch sanitary sewer; sixteen, 4-inch 58. New England Telephone Co. ducts; 20-inch water main; and a 12-inch high-service water main. 59. Boston Edison 115,000 volt electric lines. 60. 16-inch high service water main. 61. '. 30-inch water main. '62. In this area of Northern Avenue: 115,000 volt electric 63. lines; 16-inch water main and a 16-inch high service water main. 64. i. 66-inch combined sewer (East Side Interceptor); 16-inch 65. steam main; 30-inch gas main. 66-inch sanitary sewer; 84-inch storm drain. 24 telephone ducts. 48-inch sanitary sewer; 60-inch storm drain; 66-inch combined sewer; 96-inch storm drain; 30-inch sanitary sewer; 30-inch storm drain; 24-inch water main. 30-inch x 36-inch combined sewer; 66-inch combined sewer. 48-inch x 54-inch combined sewer; 30-inch x 36-inch combined sewer; 24-inch water main; 20 telephone ducts. 57-inch x 60-inch combined sewer; 30-inch water main; 20 telephone ducts. 10 2-inch combined sewer; 30 -inch x 36-inch combined sewer; 30-inch water main. Two 6 0- inch combined sewers (inverted siphon under MBTA Orange Line); 36-inch combined sewer. 3 2-inch x 60-inch combined sewer (West Side Interceptor), two 115,000 volt electric lines. 36-inch water main and thirty-six, 4-inch telephone ducts in the vicinity of Beverly Street. MDPW Pump House No. 1; electrical substation. MDPW Pump House No. 2. MDPW Pump House No. 4. MDPW Electrical Substation. MDPW Pump House No. 5. Pump Station at Summer Street between 7th and 8th Streets. 24-inch sanitary sewer from Northern Avenue and Trilling Way to Summer Street pump stat ion. 155 66. Telephone/electric duct banks servicing local area. 67. 115,000-volt electric lines in Massport Haul Road. 68. General Ship Power Plant near Dry Dock No. 4 at C Street and 7th Street. 69. 42-inch drain outfall. 70. 42-inch drain in C Street from 5th Street to outfall. 71. MBTA substation at Haverhill Street, south of Traverse Street . In addition to these public and private utilities, there is an extensive signalling, communications, and interlocking system for the Amtrak intercity rail facilities crossing the Fort Point Channel into the South Station terminal area. A number of new utilities have also been proposed by others within the project area. These utilities are proposed for construction, subject to funding constraints. The following summarizes the proposed utility construction by others. o Combined Sewer Overflow (CSO) Screening Facility off Causeway Street at the Charles River Estuary. o 18-inch Massport sanitary sewer in Northern Avenue in the vicinity of Piers 5 and 6. More information regarding the locations of these major utilities is contained in the Supportive Engineering Report for the FEIS/FEIR. 3.13 VISUAL CHARACTERISTICS The South Bay, South Boston and Logan Airport portions of the project area are primarily (though not exclusively) located in industrial areas. The Central Artery project corridor encompasses most of downtown Boston and includes historically significant buildings and districts, and some of Boston's most visually distinctive neighborhoods. This visual inventory highlights important visual characteristics of the project area, 3.13.1 South Bay View from the Road lis fit , in >nt s The area surrounding the Central Artery in the South Bay are is automobile and railroad-oriented industrial in character. Neighborhoods lie beyond the highwa and are remotely visible from the roadway. Immediately next to the highway, buildings are generally lotPf* 1 '" and are surrounded by large expanses of land used for parking, loading, mT rail yards. The visual environment 1 very open and flat. Several industrial landmarks are located the area: the Italianate tower of tie Pine Street Inn in the South End, tn ' ; triple smokestacks of the abandoned 1 Boston incinerator, and the railroac *• bridge and open water of the remainiig' South Bay; however, it is unlikely that any of these landmarks have muci significance to most motorists apart ' from their strong visual forms. Northbound motorists are afforded views of Boston's Financial District ,;i particularly Dewey Square Tower whia '* is the most prominent structure. f k View of the Road/Pedestrian Environim r There is little view of the road for pedestrians or other driven because the road is surrounded by industrial uses. From the upper floors of several buildings the are< appears to be open, flat and dominate by highways. The best views of this area c« obtained by rail passengers who rid< through the area bound to or from South Station. From this vantage point the view is of tidal flats, tq granite bulkhead of the back end of Fort Point Channel, and the historic railroad bridge spanning the Channel * These surviving elements from the active era of the Channel's history 156 a visual entry point to the City. ,3 .2 South Boston/Fort Point Channel of the Road/Pedestrian Environment The South Boston/Port Point innel area has four visually tinct districts within it: The district of brick lehouses along the Port Point 'SI j nnel, A Street and Congress Street ; characterized by a grid street 'tern which establishes a sense of fan ientation; a uniformity of building i ght and materials; and urban street , mities such as sidewalks and street e J|hts which make the area relatively jjifortable for pedestrians. Views of 'ntown Boston link this area sually to the rest of the city. tl The former Penn Central Rail t *ds, which lie to the east of the ^ rehouse district, are now vacant or 3(i |jd for parking. Pedestrians or nil :orists using this area lack a sense orientation or scale within this strict because of the expanse and 5 lack of an established perimeter, s Summer Street Bridge establishes j point of orientation; however, ,*:ause there are no ground- level ^ceets to which it can be compared, is one landmark gets lost in the srall environment. There are few 3tant views of recognizable idmarks from this area. The area around Northern Avenue rms the northern edge of South ston, and there is a clear visual .^nk between this area and downtown. a ,|rthern Avenue is distinguished by s intimate link with the Harbor, th pedestrians and drivers are aware i the water, and the numerous j, ter-related industries along rthern Avenue reinforce this strong sociation. The facades and bulk of J« Commonwealth Pier and the Fish ; er are strong orientation elements ich form an edge to the street. ■ ews of the Boston skyline as one is laded westbound along Northern Avenue e impressive. When the new Northern Avenue Bridge is completed and the Avenue is realigned, a dramatic vista of downtown will be created for the full length of Northern Avenue. o The area lying east of Viaduct Street, south of Northern Avenue and north of Summer Street is Commonwealth Flats, a Massport owned development area. Commonwealth Plats contains industrial buildings, surface parking lots and vacant parcels covered with scrub vegetation. The area affords distant views of the skyline and the Airport. 3.13.3 Fort Point Channel/Dewey square View from the Road The area above the Central Artery and the Dewey Square tunnel is one of complicated circulation patterns and pedestrian-vehicle conflicts which demand the attention of both motorists and pedestrians. Nonetheless, several major landmarks are easily noticed: South Station, Federal Reserve Bank, and the Dewey Square Tower. Glimpses of the retail district and the Fort Point Channel can be seen in opposite directions along Summer Street, and the towers of the Financial District are visible beyond Dewey Square. View of the Road/Pedestrian Environment Pedestrians are confined to narrow corridors between the elevated Central Artery and the rows of buildings fronting on Atlantic Avenue and Purchase Street. There are also restricted views to the Channel along cross streets and vacant parcels. The Fort Point Channel is visible to motorists or pedestrians crossing one of the three bridges in this area, but the most significant views are presented to abuttors and to the many tourist and lunchtime visitors to the Channel area. The Channel's major visual aspects are its large water surface, its views to the Harbor and East Boston, and its maritime and historic 157 character represented by its bridges, anchored or berthed ships, and by the five- to nine-story masonry buildings which line much of its shoreline from Summer street north. The Federal Reserve Bank, Stone and Webster Building, and South Postal Annex contrast in material and scale with the other buildings along the Channel. 3.13.4 Central Artery - Congress Street to High Street View f r an the Road As the northbound motorist emerges from the Dewey Square Tunnel and rises toward the elevated structure, the first views are of the roadway itself, followed by a dramatic view of the Harbor Towers buildings and Boston Harbor. Southbound motorists can look across the northbound lanes and see the Federal Reserve Building, the Dewey Square Tower, and the Fort Point Channel area. However, as the motorist approaches the Dewey Square Tunnel, the large number of merges and weaves require such concentrated attention that little notice can be given to such landmarks. View of the Road The Central Artery forms a major visual and physical barrier between the Financial District and the Fort Point Channel area. As the roadway emerges fran the Dewey Square tunnel, it is first seen as a wide, depressed roadway and then becomes a wall as it rises to become an elevated roadway. In this section the width of the roadway and ramps causes it to appear as a vast open space which is unlike the pattern of the city, and increases its impact as a barrier. Pedestrian Environment Views toward the water fran Pearl, Oliver and High Streets end abruptly at the Central Artery. A pedestrian moving along Atlantic Avenue or Purchase Street sees traffic and a concrete and steel wall. The orientation of buildings in the a is toward the streets perpend icu the Central Artery, and the sidewa which parallel the Central Artery devoid of amenities or street level commercial activities. For pedestrians in this area, there is a overwhelming sense of being surround! by vehicles, noise and fumes. For pedestrians walking adjacent to the Central Artery, the curve of the structure combined with the ramps which cut off ground level views make it impossible to see arou the road. Because of this, pedestrians cannot see their destinations and are easily confused about their location relative to cit ; landmarks and streets. 3.13.5 Central Artery - High Street Clinton Street View from the Road N ■cl tin jtl, lie ■?3 I; tie' The Central Artery in this ar curves around downtown Boston. The motorist has a dramatic view of a ri< visual environment with clear views the Custom House Tower, the Financial District skyline, Quincy Market , the Marriott Hotel, and Waterfront Park. There are distant views of the Bunke: Hill monument, Old North Church, and the expanse of Boston Harbor. The motorist gains a sense of orientation to the city and can see many destinations from the vantage point of the elevated roadway. This portion of the Central Artery provid* both north and southbound motorists with an exciting visual experience ol Boston, although concentration on th< roadway is required because of the geometry . View of the Road There are no on- and off-ramp£ in this part of the Central Artery; is therefore narrower than in other areas, and does not present impassabl barriers to either views or movement Visual impacts are largely dependent on the vantage point of the viewer. Views directly perpendicular to the 158 'i tt _ v :y.ry (e.g. fran Quincy Market, Milk .j; »et and East India Row) are not y jiLicularly restricted by the Central a.'iry. Until the viewer is near the picture itself, it appears as a band ;s*|>ss the sky with buildings, ground :::iie and sky visible both above and j|>w it . Fran those streets which ...Il?rsect at an acute angle to the ,;4iicture (e.g. Broad Street, India ;vejWset), views are considerably more j „|L rioted and the steel structure Iss up a much greater percent of the >Lzon. The BRA has estaolished a , s Jaal easement from Broad Street c; A*r the Central Artery and across aes/Fosters Wharf to the Harbor. >et| There are office buildings lated very close to the western side ■the Artery. Views of the Central tery from adjacent office buildings, Iticularly from the lower levels, a! generally unattractive because of ie | elevated structure and the heavy r | jffic on the Artery. ci! estrian Environment tlx | / : i As pedestrians approach the tii tral Artery and either pass under 3 iij or walk parallel to it, the full ect of the structure is felt. The ;a below the Central Artery ; f ucture is dark and the columns >e .ch seen quite slender from a , ;tance are large enough to make ,is rculation difficult. Noise and J >ration from traffic are acute. s ivy pedestrian traffic crosses under j » f Central Artery along the .3 ilk-to-the-Sea" connecting Quincy , rket to the Waterfront, and the BRA 3 established this corridor as a sual easement and a key location for grading the pedestrian environment. ml 1-3.6 Central Artery - Clinton Street to North Washington Street aw fran the Road Fran this portion of the itral Artery, the views for the torist are similar to those noted ave, although there are closer views of the North End and tall buildings are further away. The city seems more distant as it is viewed across a wide expanse of roadway structure owing to exit and entrance ramps in the area. This is particularly true for northbound motorists, whose view does not include many tall buildings as distant landmarks. View of the Road The Central Artery is a major visual and physical barrier disrupting the sight lines and creating an awkward street pattern in this area. The ramps to and from the Artery form walls that are largely impenetrable between the North End and Government Center. Because of this barrier affect, the BRA has established a formal visual easement which spans the Central Artery in this area, and has established design guidelines requiring that the sight line from City Hall Plaza to the steeple of Old North Church be maintained. Pedestrian Environment Pedestrian access across the Central Artery corridor is very difficult in this area. Heavy traffic and an awkward street pattern inhibit easy access between the North End and the Haymarket MBTA Station. A pedestrian underpass beneath the Central Artery connects the two ends of Hanover Street. The surface roadway system which serves the Central Artery is extremely hazardous for pedestrians, and is essentially impassable in the Callahan/Sumner Tunnel plaza area. The width and low height of the viaduct in this area creates a dark and unpleasant street level environment. The structure vibrates with overhead traffic and magnifies its noise. Automotive exhaust fumes below the viaduct aggravate an unpleasant environment. Two- to four-story brick buildings in the North End are within ten yards of the viaduct and are dwarfed by it in the vicinity of 159 Stillman Street. On the western side of Cross street, the Central Artery forms a "building wall" which is in scale with the buildings lining the east side of the street. This encloses the space and creates a feeling of intimacy, compatible with the North End street scale. The historic Blackstone Block and the outdoor market located on Blackstone Street have, as a backdrop, a ramp from the Central Artery and the viaduct above it. Traffic from the Callahan Tunnel entrance backs up on this ramp causing noise and air pollution in this active pedestrian area. In the area of the Government Center Garage and BRA Parcel 7, there are wide open spaces which focus visual emphasis on the Central Artery structure. This area has little definition of pedestrian circulation routes. 3.13.7 Central Artery - North Washington Street to Interstate Route 93/Route 1 Merge View from the Road This portion of the Central Artery rises to cross the Charles River and splits into a multi-level structure. The height of the bridge affords the motorist views across Charlestown, Boston and Boston Harbor. However, the bulk of the structure and the placement of the railings diminishes the views from an automobile. The extremely hazardous driving conditions on this portion of the Central Artery require such complete attention to other vehicles on the road that these vistas are barely noticed. Southbound motorists, approaching Boston on a lower level roadway, see the bridge structure. There is no visual gateway into Boston until the motorist reaches the vicinity of Causeway Street, where the roadway is on a single level. Here the motorist's sight is directly on the Custom House Tower, providing a dramatic entry point to the city. View of the Road Views of the road in this an vary as a viewer's vantage point shifts. In the area of the Bulfinc' Triangle, the Central Artery passes adjacent to very large buildings on the east and to the elevated MBTA Green Line and smaller buildings on' the west. These facilities block views of the Central Artery except where streets cross through the tightly built pattern. The Central Artery is always present to occupan of the buildings which it abuts. The Central Artery, as it crosses Causeway Street, is a massii steel structure which blocks views down the length of the street and visually divides the city in this area. The predominance of transportation facilities around No! Station overwhelms the character of the streets. Views toward North Station from the Haymarket area are virtually blocked by the Central Artery structure. Pedestrian Environment ill* srve bfi pas From the vicinity of the parking lots behind North Station ail the MDC's new Charles River Dam, th( Central Artery takes on a different aspect. In this area the bottom of the viaduct is 30-40 feet above ground, and the structure does not interfere with ground level circulation. ii The pedestrian walking under the Central Artery from Causeway Street to the Charles River is overwhelmed by the mass of the structure and vehicle noise. This disagreeable character causes the Charles River Dam and the river's ecjg to be an invisible part of the city,. and hides an interesting and attractive urban waterfront. Distar views of the Central Artery and Interstate Route 93 across the Charll River are almost graceful, and the river's granite bulkheads are visibl on both banks of the River. The Charles River Dam is landscaped and the combination of the dam, the MBTP.s 160 r Lling-lif t railroad bridge, the : cntral Artery's granite piers and sjlptural trusses and K-braces, and ..t» curve of the road in the distance C; :f:m a visually interesting urban ..idustrial environment. .313.8 Storrow Drive Ramps The two-level ramps which cnnect storrow Drive and Leverett , 3 Crcle to the Central Artery wind between the West End and North Station seas and cross over the MBTA's cmmuter rail tracks and platforms. ew from the Road Because of the narrow curves J td steep grades on these ramps, views lr the motorist are primarily of the , c J,adway itself. Connections from the of (;ntral Artery to storrow Drive are on e lower level ramp and little is ... sible outside of the structure. Iitorists on the upper level ramps can j|,impse buildings in the Charles River lirk complex and the Boston Garden. ew of the Road/Pedestrian Environment Views of the road in this area ' '^re perhaps more disrupted than in any :her area of the city. As the ramps "". ise from Leverett Circle, they form 1 impenetrable wall, both visually id physically. This portion of >ston is very confusing to motorists id pedestrians alike, due primarily > the fact that the roadway structure isects the area. As the ramps curve ihind North station, they are lost to Lew from most well travelled streets, ius diminishing their visual ltrusion. s The area lying between the sorrow Drive ramps and the Charles Lver is one of the largest ^developed areas in the city; it is Lso one of the least visible portions , £ Boston. The vast expanse of arking lots and the lack of clear . irculation paths make the area very laccessible to pedestrians, thus j iminishing accessibility to the River nd its interesting surroundings. 3.13.9 Logan Airport View from the Road Views from where the project will join the existing airport roadway system are of the airport's expanse of large scale structures, parking areas, and roadways. Most structures are one- to two-stories in height; exceptions are the Eastern Airlines hangar, Hilton Hotel, parking garage and control tower. Pedestrian activity is almost absent outside the termimal buildings, and views of airport structures are dominant. View of the Road/Pedestrian Environment The project area is bordered on the east by the shoreline of Bird Island Flats, currently being developed by Massport as a major mixed-use development with a wall of commercial buildings forming a visual and noise buffer along the edge of the airport, and a linear passive recreation park along Jeffries Cove. Along the west side of the Cove is Porzio Park, a neighborhood playground; several wooden piers; a variety of small- to medium-scale residential and industrial buildings; the massive structures of the Bethlehem Steel shipyard; and the row houses of the Jeffries Point neighborhood on rising ground beyond. The water surface of the Cove, anchored boats, and outstanding views of Boston and South Boston are major visual amenities. The Cove is rather narrow at its head, and views change significantly with changes in vantage point. Pedestrian activity is expected to increase following completion of the Bird Island Flats project. 161 4.0 ENVIRONMENTAL CONSEQUENCES 4.1 DESCRIPTION OF CONSTRUCTION This section describes con- struction methods and sequencing for the Preferred Alternative. Sequencing is also presented for redecking operations on the Central Artery (No-Build Alternative), for comparison of construction-period impacts. It also describes assumptions regarding the maintenance of existing utilities and traffic during construction. The effects of the proposed construction, based on these methods and assump- tions, are discussed in the appropri- ate sections of this Chapter. 4.1.1 Construction Methods The Preferred Alternative contains several major elements requiring different construction methods. manufacturers and fabricating site are: Wiley Manufacturing, Port Deposit, Maryland; General Dynamic Corporation, Quincy Massachusetts; Bethlehem Steel, Sparrows Point, Maryland; Newport News Shipbuildir^, Newport News, Virginia; Sun Ship-fr building and Drydock, Chester, Peri- sylvania; and Chicago Bridge and :jto: Pascagoula, Mississippi. A detailed study of the coi- crete and steel sunken tubes was performed as part of this study. Independent cost estimates of the r tunnel types indicated the costs re approximately equal (within five percent). Additional environments analysis and necessary documentat:>r, on the impacts of the fabrication will be performed before the tunn material is selected (during the design phase ) . :>r, Sunken-tube construction is proposed for the harbor crossing itself. Prefabricated concrete or steel sections, approximately 500 feet long and approximately 88 to 98 feet wide, will be towed to the site by barge, sunk into a trench previously dredged in the harbor bottom, joined underwater, and covered with back- fill. Fabrication of the tunnel sections will be done off-site. During preparation of the DEIS/DEIR, several potential concrete tube fabrication sites were investigated, including the proposed Lynn Marina Industrial Park area in the Port of Lynn, Massachusetts; the New London Mills area on the Thames River in New London, Connecticut; and the United Steel Buildings area on the Mill River in New Haven, Connecticut. Because it is possible to fabricate steel sunken-tube sections in shipyards and tow them (with six to nine feet of draft) long distances, the steel tube manufacturing site is rarely located near the job site, but simply depends upon where the manufac- turer is located. Several possible steel tube 162 Cut-and-cover tunnel constiic tion is necessary on land and in 1 Fort Point Channel, where sunken 1 construction is not feasible. Va types of cut-and-cover constructic will be used. In Fort Point Channel, ste«. sheet piles (or "sheeting") will :lri be driven to enclose the construct site. Within the barrier of sheeUv two methods of construction will adopted: A. Central Artery northbound, fro South Postal Annex to a point appn x mately 400 feet south of the MBTA j Line (Sta. 83+00 to 94+00). Within the barrier of shee at the south end of the Fort Point Channel where the cut-and-cover ti is deepest, temporary fill will b placed between the sheeting and t existing bulkhead of the Fort Poi Channel. Slurry walls will then constructed through the temporary to a specified depth below the turW bottom and the temporary fill mate'tt between the walls will be excavate ^ Removed from the site, silt and channel bottom materials will be , c 'ated and tentatively carried away Jirge for ocean disposal. The >1, ventilation building and a new Kl iead will then be constructed; the J'ation will be backfilled to the Jinal channel bottom elevation; and .heeting and exterior slurry wall li the channel bottom will be red . 4.1.2 Construction Sequencing No-Build Alternative The following is a discussion of possible construction sequencing for redecking the Central Artery if the No-Build Alternative is imple- mented. The estimated time of con- struction required to redeck the Central Artery is three years. :entral Artery northbound, near northerly end of the Fort Point e , iel beyond the MBTA Red Line 94+00 to 105+00). Within the barrier of sheeting le north end of the Fort Point nel, where the cut-and-cover al is shallowest, water will be sd out; silt and other materials be excavated from the Channel om and tentatively carried away by e for ocean disposal; the tunnel ventilation building and a new head will be constructed; the .vation will be backfilled; and the ting will be removed. At the Airport, the construc- method will involve sheeting, vation and dewatering within the ct -ted area; construction of the Jel and ventilation building; ^filling; and restoring the origi- iground surface (paving, etc.). In many areas, tunnel sidewalls rt | be constructed using the slurry method. This method has been osed because it can be accom- hed in a narrow construction area, minimizing disruption. In this od, the proposed tunnel walls are isely excavated with special ching machinery, and the deep >ch excavation is temporarily orted by filling it with a water/ mixture called bentonite (or rry"). Reinforced concrete walls then poured in place while the ry is pumped out and removed from site. The material between the .s is then excavated, bottom and concrete slabs are constructed, the tunnel is finally backfilled. The deck would be replaced using three construction crews. Two crews would work on the Central Artery starting at the midpoint of the construction, with one crew moving north and the other south. The third crew would work on deck replacement for the ramps. The existing deck would be cut and removed in large pieces, to be lowered into trucks below the viaduct (on the Surface Artery or in the existing parking lots) for transport to a disposal site(s). Precast concrete deck panels would be installed rather than being cast-in-place to minimize construc- tion-period disruption. Between the Dewey Square Tunnel and Causeway Street, the construction could take place one lane at a time, keeping six reduced width (approxi- mately 11 feet wide) lanes available for normal traffic. Eight sequences would be required to redeck the total width of the Central Artery. Redecking the portion of the Central Artery north of Causeway Street would require different sequencing. If the deck for each level were to be replaced while providing three lanes for traffic, the temporary lanes would be nine feet wide, which is below the minimum acceptable lane width of ten feet. For this portion of the Central Artery, therefore, the redecking for each level would be done in three phases, closing one lane to traffic and keeping only two lanes open in each direction. During construction, all ramps would be kept open for traffic, although during the actual redecking 163 of the ramp, the useable lane width would be reduced to approximatey 11 feet. Preferred Alternative Approximately 12 years will be required for construction of this alternative. Assuming construction is commenced in late-1986, the availa- bility of adequate Federal funding and ideal conditions (i.e., no material shortages, labor strikes, etc.), the overall project would be expected to be completed in approximately late- 1997 or early-1998. Although the total construction period is approximately 12 years, not all areas will be affected or dis- rupted during this 12-year period. The length of time that each area is affected during construction is as follows: South Bay Area - 4 years, then no construction for approximately 4 years, followed by 2-1/2 years of construction for connection to the contra-flow bus lanes; Central Area - 12 years; Area north of Causeway Street - 7 1/2 years; South Boston Area - 3 1/2 years; Boston Harbor - 3 1/2 years; Logan Airport Area - 3 1/2 years. An extensive evaluation of the construction sequences associated with this alternative is documented in the Supportive Engineering Report of this FEIS/FEIR. In order to minimize the disruptive effects of construction in any particular area, construction contracts will be prepared which require completion of specific seg- ments of the contract within a single construction season or less (i.e., although a particular contract may involve several years of work, certain portions of that contract will be required to be completed within a specified time frame). These com- pleted segments of the project may subsequently be used to carry traffic while other facilities are closed to traffic. Third Harbor Tunnel Construction of the Third Harbor Tunnel tube sections off-sie will require a three- to four-year construction period, primarily fortk| fabrication of the tunnel sections Actual placement of the tunnel secil tions in the harbor will require approximately one month per secticfl'* and one day for sinking. Approxi- mately 9 tunnel sections are requi for the Third Harbor Tunnel. Dredging activities in Bosti Harbor will be performed using the clam shell method. Hydraulic dredi| methods were analyzed and rejected because of the following reasons: substantial dewatering requirement;* requirement for a spoils area withafr containment dike; need for a treaty— area for 490,000 cubic yards of dredged material; disruptions on navigation and shipping; required increased depth of excavation; andl potential for increased environmem impacts and costs compared to clam shell dredging. Recreational boati activities as well as commercial navigation requirements in the Han have also been considered in devel) ing the construction sequencing fo this alternative. Underwater excavation for t sunken tube will require some bedr removal near Boston Marine Industr Park in South Boston. To remove t rock, controlled underwater blasti techniques will be used. Depressed Central Artery Stage construction for the depressed Central Artery tunnel wi proceed as follows, (see Figure 29 1. Existing Condition The existing elevated struct is supported on steel bents set on concrete footings and piles. The Surface Artery is located beneath elevated structure. 2. Slurry Wall - Slurry Piles Transverse Grade Beam-Surf ac jg Decking The slurry walls will be It 164 Existing Condition Slurry Wall Slurry Piles Transverse Grade Beam Surface Decking Needle Beam Longitudinal Grade Anchors Excavate Pile Removal Intermediate Bracing Section -n -1B --. The construction will be timed jo that the completion of the Third iarbor Tunnel, Logan Airport, South 3oston and south Bay areas construc- . :ion will occur simultaneously. H 5. Ramps to the Central Artery and Massachusetts Turnpike will be main- lined at all times. , 7. Except for the new Northern Avenue Bridge, all of the bridges crossing the Fort Point Channel will be affected by tunnel construction. 8. A temporary railroad bridge will be built to maintain rail service during the construction period when the existing Wye Connector (presently under construction by the MBTA) is shut down. 9. Five tracks into South Station and two tracks across the Dorchester Branch railroad bridge over Fort Point Channel, serving MBTA commuter rail and Amtrak intercity rail services, will be provided at all times by use of temporary tracks. 10. The West Fourth Street Bridge, presently closed, will be recon- structed as a separate project prior to construction of the Preferred Alternative, and will remain open at all times. 11. The Herald Street Extension Bridge will accommodate the MBTA 1 s needs, including possible commuter rail service or a reconfiguration of MBTA Red Line trackage, and will be constructed prior to removal of ! Broadway Bridge. 167 12. The Harbor Plaza Building will be underpinned, permitting businesses to remain during construction. Central Area 13. During construction a minimum of six lanes for local surface traffic will be available at all times between High Street and North Street where eight lanes of surface roads are presently available. Parking along the Surface Artery and Atlantic Avenue will not be permitted during construc- tion. 14. Under the existing viaduct: (from High Street to Causeway Street), a 40-foot wide construction haul road will be provided for the Contractor's transport of construction materials. 15. Construction will be phased in such a manner to: Maintain six lanes of traffic on the elevated Central Artery during the construction of the depressed Central Artery, including use of the High-Level Bridge. Maintain six express lanes of traffic in the depressed Central Artery and on the new Charles River bridges, and reserve the elevated Central Artery as a collector- distributor road for local access. After local connections are made to the depressed Central Artery, remove traffic from the elevated Central Artery and then remove the elevated structure and the High-Level Bridge. 16. Connections between the exist- ing elevated and proposed depressed Central Artery and the Sumner and Callahan Tunnels, Atlantic Avenue and Purchase Street will be maintained. 17. Service on the MBTA Blue Line at State Street and the Orange Line below Haverhill Street will be main- tained. Area North of Causeway Street 18. Completion of the separate Central Artery North Area Project, including the connectors to the Mystic-Tobin Bridge, will precede the start of construction of the depressed Central Artery. 19. Three lanes of Interstate Route 93 (south of the Mystic-Tobin Bridge connection) and ramp access to the Mystic-Tobin Bridge and City Square will be maintained. Two lanes of Interstate Route 93 (north of the Mystic-Tobin Bridge connection) will be maintained. 20. The ramp connection from Interstate Route 93 southbound to Leverett Circle will be unavailable for approximately 3 months, and the ramp connection from Leverett Circle to Interstate Route 93 northbound will be unavailable for approximately one year. Detour routes across the old Charles River Dam and Gilmore Bridge, with appropriate traffic management controls, will be instituted to serve this traffic. 21. A minimum of two lanes through Leverett Circle will be maintained at all times. 22. During construction, ten commuter rail tracks will be main- tained at North Station. 23. Service on the MBTA's Orange Line under Interstate Route 93 in Charlestown, and the MBTA's Green Line at Leverett Circle will be maintained. 24. Access through the MDC locks at the new Charles River Dam and naviga- tion in the channel will be maintained. South Boston 25. Railroad access (one track) to the Army Base will be maintained at all times during construction. 26. A minimum of four lanes on Summer Street will be maintained during construction by means of a temporary bridge. 27. Temporary detour routes will be constructed at A Street, B Street, and Northern Avenue. 28. Relocated Northern Avenue frc "B" Street to Atlantic Avenue will completed as a separate project pric to the start of the Third Harbor Tunnel construction. Boston Harbor 29. Half of the 1200-foot wide shipping channel will remain open t< navigation at all times, except as noted below. These activities must coordinated with the Coast Guard Captain of the Port. 30. During the tunnel sinking operations (approximately one day pe tube), the channel should be closed navigation. Again, these activities^: must be coordinated with the Cost Guard Captain of the Port. - lal ■:;! 31. Dredging operations will be coordinated with general shipping activities and with the Coast Guard i Captain of the Port in Boston. East Boston 32. The same number of lanes thatt exist today on the Airport roadways will be maintained at all times. 33. Access to East Boston Memori, Stadium will be maintained at all times. 34. Access to Bird Island Flats (BIF), although disrupted during the entire construction phase, will be maintained by constructing temporary roads. 35. The existing number of lanes the Route 1A ramps to and from the Airport will be maintained during construction, with temporary struc- tures. 36. Aircraft access to the Easter Airlines Terminal and Hangar will be maintained, even if constructing a temporary satellite terminal and relocating the taxiway are required. (Underpinning the existing building, and further alignment refinements, m render the temporary satellite termi nal to be unnecessary.) 168 Service on the MBTA Blue Line DL not be significantly interrupted. ii i . .4 Materials Movement and Staging Areas a srials Disposal Disposal of dredged and Kavated materials from corresponding cstruction sites is discussed in :etion 4.13 DREDGED AND EXCAVATED S ERIAL DISPOSAL . Use of local East Boston teets for construction activities i#l be restricted by construction if cif ications. In the South Bay ma, truck access to the Turnpike and ctral Artery will be via the isting Turnpike/Central Artery rerchange, using the Broadway and it Fourth Street Bridges, Frontage e Cod, Massachusetts (see Section ■ .3 DREDGED AND EXCAVATED MATERIAL I JPOSAL ) . In addition to these materials, • loval of the Central Artery and the I |h -Level Bridge structures will also :'eral local highway contractors, Isposal of the steel viaduct will )se no difficulties because of its Hvage value; this steel can be : >rocessed and thus reused. Disposal 3 the reinforced concrete deck of the -ltral Artery could be more diffi- Mt. As discussed in this study, i «fever, it is proposed that the deck a cut into panels rather than pul- •Irized; the panels can potentially be tfsd for shore protection or some flier beneficial use (see Section 413) . Staging Areas These areas would be used for purposes such as material stockpiling, equipment storage, parking, and contractor field offices. Locations cannot be specified in advance, but their use will be controlled by contract specifications to reduce impacts on adjacent properties. Potential staging areas include, but are not limited to, portions of the parking areas under the existing Central Artery viaduct, which are to be acquired as part of the project. Demolition of existing buildings (such as the Anelex, Charles River, and Hook Lobster buildings) will occur soon after tenants have been relocated to provide additional staging areas to the contractors. 4.1.5 Construction Effects and Mitigation Measures Rodent Control The construction activities are expected to affect the existing rodent population in the area, particularly during the excavation and utility relocation phase of the work. State- of-the-art construction management techniques used in other cities have been able to control this problem. These techniques will be implemented, and are briefly described below. Extermination operations tc be specified during construction shall be in accordance with the rules and regulations of the City of Boston and State Health Departments and will consist of two phases, "Blitz" and "Maintenance". The "Blitz" phase occurs prior to the start of construc- tion and consists of applying toxic materials to all utility, drain, and sewer lines and manholes within the project area where rodents gather or may gather during the construction period. This operation usually will kill large portions of the rodent population before construction work begins . The "Maintenance" phase con- sists of placing a toxic material 169 combined with a suitable bait in all suspected habitat areas twice a month for the duration of the construction period. This phase will rid the area of any remaining rodents and their carcasses, and will prevent any rodent migration to adjacent buildings. Water Table Control It is extremely important to limit groundwater drawdown outside excavations to minimize settlements as well as to protect the wood piles which support many of the adjacent buildings. Slurry wall lateral support systems will be used where necessary to prevent "near surface" groundwater levels from falling below normal ranges. Since the lateral support systems will typically be constructed down to glacial till or clay, the potential exists for interruption of usual groundwater flow patterns. Consideration will be given to providing for flow of groundwater across the excavation width, through installation of groundwater equalizer pipes in the slurry walls. This will be necessary to prevent development of elevated water levels on any one side of the excavation. Some locations along the construction will require wells to be drilled into the rock in order to stabilize water pressures. Further engineering studies will determine what type of action will be required, such as grouting of the rock and/or groundwater recharge techniques. Observation wells, piezometers, and deep settlement points will be used to monitor water levels and pressures during construction. The key features of any groundwater level control and monitoring program are: Criteria During project design, criteria for minimum allowable water levels or maximum tolerable drawdown are estab- lished. These are safe levels which, if not exceeded, will avoid deteriora- tion of wood piles, excessive settle- ments of compressible soils and othr problems related to groundwater lowering. Water level criteria are written into the contract specifica tions, with the requirement that thi Contractor take remedial action to I restore water levels as necessary. Remedial action may include pumping water back into the ground ("rechar- ing") or reducing the drawdown by cutting off inflow of groundwater t the excavation. I Instrumentation Prior to the start of excav tion, an instrumentation system is planned and installed. Instruments' will measure the elevation of grour' water. Groundwater levels may be different in the various soil strat The system will include various typ of instruments designed to effecti\ monitor water levels in differing types. Observation wells will be us to monitor the more pervious strate including fill, sands, glacial till i and decomposed rock. The water le\l in the 1-1/4"+ diameter well is measured by sounding. Piezometers (hydraulic, pnet matic or electric type) are used tc measure water levels in less pervicj soils (organic silt, clay). Pie- zometers consist of a typically 1-^ diameter, 12-inch long sensor in- stalled in a borehole, within the £ stratum to be monitored. The sense generally provides for measurement water pressure in the ground at th< sensor level. Groundwater levels < then calculated from pressure data. Readings are made remotely, at groi surface, through wires or tubing extending up the borehole from the sensor to a manhole or roadway box ground surface. Instruments will be located near adjacent structures sensitive groundwater level drawdown, near ai where possible drawdown is antici- pated, and in other areas as necesi to measure water levels over the m 170 >eral area of influence. Instruments will be installed :5tore construction to measure exist- :a» water levels. Thus, baseline data :hj 1 be obtained for comparison during instruction; areas where existing ■ iwdown is occurring may be identi- i«id, and tidal fluctuations, if any, ill be determined. Data Collection and Evaluation Water levels in the instruments II be measured periodically during ustruction, and following construc- tion until levels have stabilized, jiidings will be typically made weekly J: may be increased or decreased pending on the construction activi- :»s in progress. Water levels will be graphical- i) presented on time plots to facili- ty review of the data and evaluation : trends in fluctuations. Water i'els are compared with the criteria it the contract documents to determine :ii remedial action is required. 1 1 i! i Corrective Action If construction modifications jls required to correct excessive ;iawdown, the wells and piezometers ■LI continue to be monitored to Icermine that water levels have been : stored or to identify if further 'Inedial action is necessary. Re- :irge or groundwater curtain cutoff Iij the more common types of correc- mre actions that would be used. I 2 TRANSPORTATION This section examines in detail IUr 1990 and 2010 transportation ipacts of the Preferred Alternative, compared to the No-Build Alterna- te. This section has been organized ujer the following categories: o Traffic Volumes o Volume-to-Capacity Ratios I o Levels of Service/Operating Speeds : I o Central Artery Bottlenecks and Congestion Points o Issues Concerning Traffic Forecasts o Vehicle Miles and Vehicle Hours Travelled o Safety o Other Transportation Facilities o Construction Impacts o Parking Impacts The long-term (1990 and 2010) impacts of the No-Build Alternative with a redecked Central Artery, are identical to those of a Do-Nothing Alternative, because redecking must be undertaken if the Central Artery remains in its current alignment. Since redecking is required with the No-Build Alternative, but not the Preferred Alternative, both have significant construction impacts which are discussed below. The Third Harbor Tunnel pro- posed to be constructed with the Preferred Alternative assumes a one-way (inbound) toll facility, consistent with the permanent one-way (inbound) toll system which now exists for the Mystic-Tobin Bridge and Callahan/Sumner Tunnels. 4.2.1 Comparison of Alternatives Table 28 provides a summary comparison of the transportation effectiveness of all build alterna- tives considered during the DEIS/DEIR and SDEIS/SDEIR process. The various indices in Table 28 as well as the hazardous cargo, public transporta- tion, and construction period impacts are highlighted below. Regional Highway Network No-Build Alternative In 2010 with the No-Build Alternative, the roadway system serving downtown Boston, East Boston, and South Boston will carry higher traffic volumes, on the order of 5 to 30 percent more than 1982 volumes, depending on the particular roadway link . The major links in the core area: Interstate Route 93, 171 c th •0 p 0 rH r- c •H (0 ■H CM o 0) p to G ■0 o a) ffl •H rH ro u 0 u dP z < 2 ro o CM CO o CM o CM VO 00 CN in oo to (Q 0) c 0) > •H p O d) m 4-1 w H vh o X (0 (Q I* 10 4H X o c 3 £ 00 vD (N VO cm m vo m CM VD in m m t*» m in ro in in vo vo VD CO in cm m at vo m CM m vo rH c c (Q U (1) & 0> 3 u a> G "0 P 0> 0 d) u VO r» 00 rH >1 r- CM CM c rH 0) \ O • rH 0 0) u rH CN O in in rH en rH CM tn > rH in ft) •H 0) JH rH ON r«- VD ro in CM 00 Cu Eh n >1 p •0 \ in rH o m rH •H rH rH rH rH 7 CM CM ro in •H s 1 o + + + + i I VM n >4-l i rH in VD ro vt» CO CM •rH 0 0) D z > Eh C G 0 0 •H •H 4-> P w U d) * cn c (0 c 0 Vh •H u rG tn VD ro in CM oo +J rH P rt rH •0 a) M rH rH •H CM 0) G VM m a> i 4-> M 0 rH a, z p rH rt CO •P rH < P rH in < in vo P P p rH rH r-t < < < 172 Mystic-Tobin Bridge, Central Artery north, Callahan/Sumner Tunnels, Central Artery south, the Massachusetts Turnpike, and Southeast Expressway will see a substantial increase in hours of congested operation; where these roadways are congested for 1 to 8 hours per day in 1982, congested operations will last from 5 to 14 hours per day in 2010 with the No- Build Alternative, with 14 hours of congestion occurring within the Callahan/Sumner Tunnels and on the northbound Central Artery south of the existing tunnels. Build Alternatives The Preferred Alternative is the most effective of the build alternatives examined during the EIS/EIR process at reducing the hours of congested operation compared to the 2010 No-Build Alternative or 1982 existing conditions. In 2010, the Preferred Alternative will result in congestion lasting from 1 to 2 hours per day on all key routes except the Southeast Expressway, which will experience about the same hours of congestion expected with the No-Build Alternative. Alternatives that feature a Third Harbor Tunnel, elimination of the High-Level Bridge bottleneck, and the widening of a depressed Central Artery from 6 to 8 (10 in some sec- tions) lanes (Alternatives 3A and 5A as well as the Preferred Alternative) provide substantial reductions in Central Artery hours of congestion relative to the No-Build Alternative. With Alternatives 2, 3, 4, and 5, the northbound Central Artery south of the Callahan/Sumner Tunnels, and the southbound side of the Central Artery north of the tunnels both benefit, though not as much as with Alternatives 3A, 5A, and the Preferred Alternative. However, with Alterna- tive 6, the Callahan/Sumner Tunnels will not experience congestion reduc- tion, although the Central Artery both north and south of the Callahan/Sumner Tunnels will benefit due to its increased capacity. In 2010, all build alternatives will redistribute traffic significant- ly as compared to the No-Build Alter- native. With the Preferred Alterna- tive, traffic volumes will be reduced on currently overloaded links, includ- ing the Callahan/Sumner Tunnels and Central Artery south; links such as Interstate Route 93 (north of the Charles River) and the Massachusetts Turnpike, which are currently under- utilized, will carry more traffic. Furthermore, the Preferred Alternative will reduce the Callahan/Sumner Tunnels' AWDT by 33 percent in 2010. The Preferred Alternative will also decrease volumes on the Mystic-Tobin Bridge, but increase volumes on Route 1A north of the Airport, including at Bell Circle. Central Artery Queues Traffic benefits of each build alternative on Central Artery bottle- necks and queuing, and benefits on local streets, reflect the effective- ness of each alternative in achieving an overall transportation improve- ment. Because of its widened Central Artery, Third Harbor Tunnel, and improved connections between major highways, the Preferred Alternative provides major traffic benefits and is more effective at reducing queues than the remaining build alternatives. In 2010, the Preferred Alternative will provide 80 percent shorter individual queues than expected in 2010 with the No-Build Alternative. Vehicle Miles Travelled (VMT) In 2010 Alternative 6, the Artery only alternative, is the most effective of the build alternatives evaluated in this FEIS/FEIR at minimizing VMT compared to the No-Build Alternative. It generates approximately 15 million more VMT per year than the No-Build Alternative. The Preferred Alternative is the next most effective, generating 17.7 million more VMT than the No-Build Alternative. Of the remaining build alternatives, Alternatives 4, 2, 3, 5, 3A and 5A all increase VMT over the Preferred Alternative. 173 Person Hours Travelled (PHT) In 2010, the Preferred Alterna- tive is the most effective of the build alternatives at producing annual travel time savings relative to the No-Build Alternative. It reduces PHT by 17.6 million hours of travel per year. The best of the other build alternatives (Alternative 5) produced slightly more than half the travel time savings of the Preferred Alternative. Levels of Service (LOS) In 2010, the Preferred Alterna- tive provides more substantial reduc- tions in the number of roadway links and local intersections operating at LOS E or F than any of the other build alternatives. The Preferred Alterna- tive produces a higher percentage of highway links and ramps operating at the acceptable range of LOS A-D than any of the build alternatives evalu- ated . In the 2010 PM peak hour, the No-Build Alternative results in only 35 percent of the analyzed regional highway links operating at LOS A-D, while the Preferred Alternative results in 68 percent of all links and ramps analyzed operating at LOS A-D. Similarly, the Preferred Alternative produces more significant LOS improvements on local streets and intersections in South Boston, East Boston and downtown Boston than any of the other build alternatives. For the intersections analyzed in East Boston, South Boston and downtown Boston, 43 percent will operate at LOS A-D in the 2010 PM peak hour with the No-Build Alternative. With the Preferred Alternative, the percentage of LOS A-D intersections will increase to 71 percent . Safety Of the build alternatives, Alternative 3A results in the most significant reductions in accident potential on the regional highway system compared to the No-Build Alternative (by 30 percent in 2010! | The remaining build alternatives reduce accident potential in 2010 b i 15-28 percent. Accident experience on loca'i i streets is expected to be reduced Mtf slightly, or stay about the same wi.h the No-Build Alternative and build i * alternatives. Hazardous Cargoes Benefits to the movement of I hazardous cargo result from the special routing features incorporai;d into each build alternative. Genenl- ly, the build alternatives benefit!* movement of hazardous cargoes in tlf i same order as presented above for i j vehicle miles travelled. The Pre- ferred Alternative, which results m the least amount of regional highwe and surface street congestion in tli long term, provides the most signi:i-t cant benefits for the movement of j.^ hazardous cargoes, especially for . t vehicles with origins or destinatias. in South Boston. Emergency Vehicle Access Emergency vehicle access improvements directly result from ie design features of each alternative which promote regional travel time* 4 savings (e.g., a depressed, widened* Central Artery, Third Harbor Tunne r < and improved connections between mj* highways). The Preferred Alternat/e provides more substantial travel tne savings than any of the other buiL alternatives and, therefore, provide the most benefits to emergency veh;l« access. The other build alternates rank according to travel time savijs listed previously in Table 28. Logan Airport The No-Build Alternative results in increased congestion on) ; local East Boston routes leading tj^ the Airport. Of the build alternaW tives, the Preferred Alternative il the most effective at providing congestion relief both north of thWi existing tunnels on Route 1A and f 174 Wort users approaching from Inter- ne Route 93 and Storrow Drive who merge onto the Central Artery, iddition, the proposed new South I interchange with exclusive bus m connections to the South Station asportation Center (SSTC) allows n SSTC to become a remote passenger : linal for Logan Airport. Of the jiining build alternatives, Alterna- •»s 3A and 5A are more effective It Alternatives 2, 3, 4 and 5 "iuse they provide congestion relief [ :h of the tunnels for Airport users r.oaching from Interstate Route 93 4 Storrow Drive. Alternative 6 and ei No-Build Alternative are less • :;ctive because they result in ireased congestion on local East con routes leading to the Airport. I' lic Transportation Public transportation services 1 not be significantly interrupted ling construction of the Preferred .er native. In the long term, some port-related trips will be diverted :m higher occupancy vehicles such as licabs, limousines, etc. back to the :vate automobile due to the regional ihway improvements resulting from ■ project. However, exclusive bus ies have been incorporated into the ¥f erred Alternative's proposed South e s interchange (allowing the SSTC to ; n CO CN r» CT> o r» o % ** 00 >H* n r» o\ in VO CO 0> ft VO tH SO vD 10 fH 00 CO 00 VO m © m •H fH fH fH fH fH fH rH tH < O o O O o o O o O o o o o \ o o o o o o o o o in o o o Z 03 00 fH fH CT* VO © vO o f* *• •a iH 10 m m m o o\ o o o cn r- o in r» vo in CO in 00 CN cr> in o •H fH vO CN CO ** 00 CN cn fH n o o CO fH r- tH in in m tH r» 00 *T CO vO in VT> r~ in fH fH fH fH tH rH fH fH < o o O O O O O o O o O o o \ o o o o o o o o O o o o o Z 10 CN m in n in CN o G\ VO fH 00 •* n m IN 00 r- o\ 00 VO vO in 00 O 10 lO 10 vo vO in 00 n fH fH fH fH tH fH iH iH < o o O O O © o O o o o o in \ O o in O © o o o o CN o o CN Z 00 m "J fH in CN VO CN o 00 % CN CN o\ CN •H lO n CN rH iH o 00 00 *T vO 10 VO in VO in 00 CO fH fH rH tH •H fH fH to §n co a > (0 E < c S u x • -u CO 4J c h w m fH fH « x -p o < •H W C 32 C fH CD CD CO CO l8 CO C 5 5 a, to E >i c (0 • XI *J rH CO < X c U CU a) co a> 3 0) l9 Xt en a E 2 K CO .§ (0 04 cn X m w • w CO ■a 3 fH o u c CU 0) 4) X ■P CO c o 04 04 5 E 3 n 0 « (0 VM 0 4J CO II) B M 04 z CO « OS • CO CO vw o 4J CO 0) • O s Q CO 0 CU E X 3 tJ o >, c (1) I fH f< Oi «H o u w T3 in CO vo Z o VO 1 H vO o D CN H CO rH o VO in CN in o z ffl 00 rH CN i—t CN CN rH rH co rH co CN CN rH • o o * * o O in in o o o o O o * * o fa OS o o o o o O r» CN O o in o o o o o o w CN o o o CN VO 00 in r- in ON CO rH o o CO in VO o o Cm in rH CN CO CN in CO r» o a vO CN rH CN CN rH CM rH CM CM in CN rH rH co o o * * o O in in o m in o o o < * O o o o o o o r» CN in CN in m m o in Q CO o o o o CO CO •n en m CM z o vO h3 CO in CN 1 H VO o r» o in CO <* in O in o o D rH CN rH CN CN rH co rH CO CN rH z pa CN z H b* CO H X w o in « * o m O m O o o o O O < * O in CN o O o CN in CM o o o o m m \ o o ^ o o rH rH CO cy> in o o o Z m o CM Oi in CO in rH CN CM vo r> rH CD CO rH in CM rH rH CN rH CM rH rH CM vO rH CM 177 a •j M W D O (Q Z I < o K Z u <*> CO > W CC 2 e-< < CM n I * o o oo < z z o m m vO in o 00 O CO o © CM cn vo CM in n rH CM cn vD in rH 1 I l + i I l 1 1 1 1 + 1 « O o o o * * O * o o O o O o o o o o o O o o o o o O CM VD cn CM o o «* o CM cn CO VO CM t* CM in cn % »> CM ■* IX) ■* VO o in rH i-i rH CM cn rH •> rH rH rr CM rH rH CM o * o * o o o o * * © * O O O o o in O o o o o o o O o o O o o o o i-3 .-i o cn © 00 f-l rH CM o o o CO vo cn CM i M in «* o o CM ■A o vO cn in in in o ON in in z 03 CM o CM CM iH CM cn cn rH cn in CM rH O CM CM CM CM • • o * < « o O o r- o Z o 3 CM rH • s m ■P < m rH C rH o u o CT> VT> cn rH o * o * CM in O o O a rH o cn o ►j cn *> rH 1 M vO 00 XI o D CM o o o CM CM O * o o O o © O o o O o o »> cn in CM m in o cn rH cn rH rH CM CM o * o o O o o O o o o o o o in in o o in 00 o in rH cn CM CM CM o o * < * o O O O * * O 41 O O O o z o o o o in in o o O in O m in in o CM M vO o z o m in in o o o vo in vo rH rH in CD rH CM cn % cn co o vo rH rH vo 00 CM CO rH EXI CM vo rH in rH CM CM in CM rH rH CM rH rH CM rH c £U 9) 3 P 4) W XI O I Q • a < u M z < 0) P CO n CO a; i CO 0) o X) i 10 1 • • 0) • P E-« CO CO tr p CO CO 178 However, the No-Build Alterna- te involves significantly fewer . rs of construction and less disrup- m of the Surface Artery and surface eet system than any of the build ;ernatives. There will, however, be le disruption of local street iffic as congestion on the Central :ery will result in much more >rt-cutting through areas in South >ton, downtown Boston, Charlestown, i East Boston than at present. The suit of this construction period >ruption would be a Central Artery ch the same vehicular capacity as 3ay and even more congestion due to ; higher traffic volumes anticipated the long term. In addition to the impacts Iscribed in the DEIS/DEIR, Alterna- tes 2, 3, 4, and 5 (which involve :th the construction of a Third rbor Tunnel and redecking of the ntral Artery) will have construction pacts similar to those described :ove for the No-Build Alternative. The Preferred Alternative, as '11 as Alternatives 5A and 3A, all ve substantial construction period :pacts on the local street network, nstruction of the South Boston rtion of the Third Harbor Tunnel 11 commence simultaneously with provements (i.e., widening and pression) to the Central Artery with ese alternatives. The Third Harbor innel will be available for use prior 1 the completion of Central Artery iprovements and can divert traffic cm the Artery while construction is iderway. This feature of the de- essed Central Artery/Third Harbor innel alternatives is particularly ijineficial during the period when the :jillahan/Sumner tunnels are reduced in J ipacity as connections are being »mpleted to the depressed Central tery (through the closure of one tne alternately for each tunnel for a ;riod of six months each). In Idition, the depressed Central "tery/Third Harbor Tunnel alterna- tes allow for the maintenance of affic on the existing Central Artery »ile the depressed Central Artery is iinq constructed. The construction of Alternative 6 has the most severe traffic impacts of the build alternatives because it involves a longer period of disruption for the Callahan/Sumner Tunnels, since traffic demand cannot be diverted to a Third Harbor Tunnel. Parking Impacts All alternatives have substan- tial impacts on public parking spaces in the project area, particularly due to loss of the surface lots under the Central Artery. All alternatives, including the No-Build Alternative, will displace these surface lots due to the construction activities which would take place at the ground level. Private parking spaces in the Fort Point Channel/South Boston area will be displaced by tunnel construction associated with the Preferred Alterna- tive and Alternative 5A. Measures to mitigate parking losses have been included in the Preferred Alternative. The following presents the transportation impacts of the Pre- ferred Alternative and the No-Build Alternative. 4.2.2 Traffic Volumes Average Weekday Daily Traffic (AWDT) Average weekday daily traffic (AWDT) volumes for regional and local roadway links are summarized in Table 29 for existing conditions and for the forecast years of 1990 and 2010 for both the No-Build and the Preferred Alternatives. To account for changes in the Preferred Alternative since the SDEIS/SDEIR analyses were completed, additional roadway links have been analyzed in this document (see Table 29). Unlike existing volumes, which are based on actual manual and auto- matic traffic recorder counts, future traffic volumes are "demand" volumes. These demand volumes, in some cases, exceed service or actual volumes that will occur at individual roadway locations. Where demand volumes are lower than capacity, they represent 179 anticipated traffic flow conditions; where demand volumes exceed the ability of a roadway to handle them, the implication is that peak hour congestion will spread into earlier and later hours of the day. The higher the demand volume to capacity ratio, the longer peak congestion will prevail. Highway Network AWDT Traffic Growth Without the Project . Section 3.1 TRANSPORTATION FACILITIES detailed anticipated traffic growth without the project (No-Build Alternative) between 1982 and 2010. Anticipated AWDT traffic growth on the regional highway network is as follows: Typical 1982 - 2010 AWDT Increase (No-Build Alternative) Interstate Route 93: 19% Mystic-Tobin Bridge: 9% Storrow Drive: 8% Callahan/Sumner Tunnels: 11% Central Artery: 10% Massachusetts Turnpike: 12% Southeast Expressway: 5% Route 1A (north of the Airport): 30% The high traffic increase on Route 1A reflects both the availabil- ity of excess highway capacity on this route and anticipated significant increases in airport-related traffic. Similarly, the increase in 2010 traffic on Interstate Route 93 re- flects its excess capacity and antici- pated population growth in the corri- dor it serves. Future AWDT With the Preferred Alternative . Also given in Table 29 are percentage comparisons of the Preferred Alternative versus the No-Build Alternative AWDT's for the year 2010. On a typical weekday, the Preferred Alternative will reduce AWDT by 33 percent in the existing Calla- han/Sumner Tunnels when compared to the No-Build Alternative. The Mystic-Tobin Bridge is also expected to experience a reduction f 19 percent in AWDT with the PreferrJ Alternative. Compared to the No-Build Alternative, the Preferred Alternat/e increases AWDT by 7 percent on the Central Artery south of the existim tunnels but north of High Street. Volumes on the Central Artery to th north of the existing tunnels will increase by about 7 percent with th Preferred Alternative as well. However, this additional traffic ca be handled with the Preferred Altera- tive, since the capacity of the Central Artery will be increased by 3? percent by being widened from 6 to lanes in this area. At the Revere/East Boston li», Route 1A is expected to carry aboutll percent more traffic with the Pre- ferred Alternative than with the No-Build Alternative. South of the Route 1A/ Bennington Street ramps, AWDT with the Preferred Alternativeis about 28 percent higher than in the No-Build Alternative. This suggest that cross-harbor traffic, includin airport traffic, will not divert to East Boston and Chelsea local strees as much with the Preferred Alternat/e as it would with the No-Build Altera- tive. This traffic will instead us Route 1A, staying on the major high^ network because the advantage of usu local streets to bypass congestion i Route 1A will be lost due to the reduced congestion on Route 1A in ta vicinity of the Callahan/Sumner Tunnels. AWDT on the Massachusetts Turnpike (Interstate Route 90) is expected to increase by 29 percent with the Preferred Alternative. Th3 is due to its direct connections toa Third Harbor Tunnel. It is also du to the increased capacity of the Central Artery which diverts trips from Storrow Drive to the Massachu- setts Turnpike. Storrow Drive AWDT is expected to decrease by 15 percent when compared to the No-Build Altera- tive. AWDT changes on the remainin regional highway network will be 7 percent or less, expressed as a 180 ^rcentage of anticipated 2010 traffic \lumes with the No-Build Alternative. Total harbor crossings lystic-Tobin Bridge, Callahan/Sumner innels, and the Third Harbor Tunnel) % ll increase with the Preferred iternative by 13 percent — 22,600 ■hides per day. This increase i presents both new traffic and taffic diverted from other routes, irthermore, it reflects the extra oss-harbor capacity created through fee combination of the existing ; innels with the Third Harbor Tunnel, : iprovements at the existing tunnel utrance, plus the increased capacity ■ the Central Artery. Local Street AWDT AWDT Growth without the Proj - t To summarize findings provided 1 Section 3.1 TRANSPORTATION vCILITIES , anticipated traffic growth ! l local streets in South Boston, jwntown Boston, and East Boston ! Lthout the proposed project between 982 and 2010 are the follow- ing: 1 South Boston AWDT: Substantial AWDT increases (up to 52 percent) will occur on the selected roadway links between 1982 and 2010. The greatest AWDT increases (in excess of 35 percent) will occur on the Fort Point Channel bridges (Northern Avenue, Congress Street, and Summer Street) and streets which provide access to the northern industrial sector of South Boston (East First Street, D Street). This area is expected to experience a significant increase in development. AWDT increases on the remaining selected roadway links will be less than 30 percent; negligi- ble changes (less than 10 percent) will occur on Dorches- ter Avenue south of A Street, Frontage Road, and West Fourth Street . o The future Seaport Access Connector (to be constructed by others with the No-Build Alternative only) will connect Northern Avenue with West Second Street and will carry 9,300 vpd in 2010 south of Summer Street. Downtown Boston AWDT: o Due to increased density of employment generators in many different parts of Downtown Boston, as well as diversions from limited access highways operating at or near capacity conditions, traffic on selected local streets is expected to increase substantially in the future — on the average about 43 percent — with the No-Build Alternative. o The largest increases in volumes for selected local streets with the No-Build Alternative are expected on North Washington Street (13,500 vpd) between Keany Square and Cross Street and on Congress Street (10,700 vpd) between Sudbury and North Streets. o The lowest anticipated volume increases (15 to 20 percent range) were found on Merrimac and Causeway Streets (3,350 to 3,450 vpd). East Boston AWDT: o Airport access/egress roads will experience a 48 percent increase in AWDT between 198 2 and 2010 because of significant increases in air travel demand as well as future airport development (specifically, Bird Island Flats). o Selected roadway links (Ben- nington, Maverick, Sumner, and Meridian Streets) will experi- ence AWDT increases ranging from 10 to 21 percent. o Porter Street (assuming airport 181 connections), would experience a 39 percent increase in traffic. Comparison of Future AWDT's With the Preferred and No-Build Alter natives South Boston AWDT . AWDT's on selected links in South Boston gener- ally decrease with the Preferred Alternative. AWDT projections indicate that the Preferred Alternative diverts a substantial amount of truck and automobile traffic from South Boston streets when compared to the No-Build Alternative. Projections for 2010 AWDT are 9,300 vehicles per day for a small-scale Seaport Connector with the No-Build Alternative. These vehicles represent diversions from alternative South Boston street routings. With the Preferred Alternative, the two new South Boston interchanges would carry 41,100 vehicles per day. Of these vehicles, only 15,200 would be using the interchanges to gain access to the Third Harbor Tunnel. The remaining 25,900 vehicles would be using the interchange as access to and from the limited access roadway connecting the Central Artery with the Third Harbor Tunnel — not the Tunnel itself. Therefore, compared to the No-Build Alternative, about 13,600 additional automobiles and 3,000 trucks will be diverted from South Boston Streets due to 1) the availability of direct access into the northern EDIC/Marine industrial area of South Boston via the Third Harbor Tunnel and proposed ramp connections to Congress Street, Summer Street, and Northern Avenue, and 2) the relocated Dorchester Avenue which provides better access to the downtown Boston Financial District from the south as well as access to the northern industrial area of South Boston . Compared to the No-Build Alternative, the Preferred Alternative also decreases volumes slightly on Columbia Road north of Columbia Circle. Furthermore, the segment of relocated Dorchester Avenue between Broadway and Congress Street carris some traffic which would otherwise.^ A, D, or L Streets in South Boston thereby reducing traffic on these streets. Traffic on the Summer Steel Bridge and the Congress Street Brige across the Fort Point Channel, wil increase by 16 percent and 5 percet respectively. These increases are caused by traffic which will be usjngi the South Boston interchanges to te downtown Boston Financial District from the Seaport Access Tunnel anc from the new Third Harbor Tunnel. East Boston AWDT . In East Boston, traffic will generally be reduced or stay the same with the Preferred Alternative relative to jhfJ No-Build Alternative. In 2010, th Logan Airport access/egress roads, Meridian Street northwest of Condc Street, and Porter Street between Cottage and Wellington Streets wi] benefit most. Meridian Street trcfii decreases by 3,300 vehicles per d< c 18 percent. Porter Street trafficis expected to decrease approximately 26 percent. Bennington Street, west >f Route 1A, will experience a slight I percent) increase in AWDT. The oler selected street links are expectecto have volumes similar to the No-Bu:d Alternative. Downtown Boston AWDT . Tralic volumes on downtown Boston street: with the Preferred Alternative, w:h the exception of the streets ment >rv below, are expected to be lower tltn or equal to those found with the No-Build Alternative. In downtown Boston, future* volumes on many of the streets se lected for analysis are also heavly influenced by the design features >f the Preferred Alternative. These design features include a relocate Dorchester Avenue to Congress Str-M a widened, depressed Central Arte'» and an improved Surface Artery. For example, with the Pref ^ Alternative, 2010 AWDT volumes on North Street are 33 percent lower ^ the No-Build Alternative because m Street will no longer have direct 182 ccess to Interstate Route 93 north- .ound. State Street volumes are 90 ■ercent lower than with the No-Build .lternative, primarily because of the lew Pearl Street connection across the lurface Artery to the downtown Boston 'inancial District. North Washington ;treet in the Haymarket Square area is >6 percent higher than the No-Build alternative due to the addition of :amp traffic from the Sumner Tunnel to Surface Artery traffic. South of e 1A with the No-Build Alterna- Porter Street particularly ■fits from the presence of a Third Kot Tunnel. However, with the rterred Alternative, traffic through i Circle is 5 percent greater than No-Build Alternative. Downtown Boston Peak Hours . r;tantial increases in AM and PM ».. hour traffic will occur at > ;ral downtown intersections without i project between 1982 and 2010, ?cially at some intersections along :intic Avenue where peak hour ::fic is expected to increase by proximately 24 percent in the AM : hour and approximately 44 percent ;he PM peak hour . Generally, in downtown Boston, rail peak hour traffic volumes with '■a Preferred Alternative are slightly o=r when compared to the No-Build ?rnative. As indicated in Table the Preferred Alternative general- reduces downtown Boston local eet traffic by diverting through i^ffic from local streets and the ! u'face Artery back to the Central tery — where congestion is less in that found with the No-Build : fer native . ! I At Leverett Circle, peak hour ffic volumes will increase with the Build Alternative, causing even ger back-ups in peak hours than sently occur. Peak hour volumes congestion at Leverett Circle are uced with the Preferred Alternative. ; I • 3 V/C Ratios and Levels of Service Volume/capacity (v/c) ratios, rating speeds, and levels of vice (LOS) for all alternatives ing the AM and PM peak hour for 2, 1990, and 2010 are summarized in le 31 for the selected major highway link, ramp sections, and local i nter sect ions . The computed levels of service during the AM and PM peak hours for selected regional highway links, ramps, and intersections have been tabulated for the No-Build and Pre- ferred Alternatives. This was done to offer an overview of total regional highway network impacts of the pro- posed project. They are summarized in Table 32. For the purpose of this study, three classes of level of service, as generally defined in the Traffic and Transportation Engineering Handbook, by the Institute of Trans- portation Engineers, were evaluated. Figure 8 in Section 3.1 TRANSPORTAT ION FACILITIE S presented a pictorial representation of level of service. 1. A-D: Acceptable operating conditions in densely developed urban conditions; flow condi- tions range from free flow to near unstable; traffic densi- ties increase from LOS A to LOS D. 2. E: Unacceptable highly con- gested operating conditions, as traffic volumes are equal to, or below, capacity, and speeds are slow but moving. 3. F: Intolerable, forced-flow conditions, as traffic opera- tions break down causing stop-and-go traffic; demand volume exceeds capacity. The degree to which the Pre- ferred Alternative minimizes overall network LOS E to LOS F operations and achieves LOS A to LOS D operating conditions is a key traffic measure of effectiveness . Major Highway Links V/C's and LOS Table 33 summarizes the level of service computations for individual highway links and ramps contained in Table 31. Table 33 provides a more simplified analysis of the critical regional highway links affected by the proposed project. 185 Figure 30 Preferred Alternative-Affects Roadway Network-RoaW Link, Ramp, and Intersection Identification Map (^^^"^ftC^^^SOO Feel ^ EIS/EIR for 1-90 -Third Harbor Tunnel 1-9 Legend Cl) Intersection Roadway Link or Ramp Table 30 TRAFFIC VOLUMES AM AND PM PEAK HOURS 1982, 1990, 2010 MAJOR HIGHWAY LINKS - NORTHBOUND EXISTING 1982 NO-BUILD 1990 ALTERNATIVE 2010 PREFERRED 1990 — ALTERN AT I VE 2010 AM PM AM PM AM — PM ~ AM — PM L IN . o . Cj . txpressway: titwn. t-oiumpia un ana oouunaiujjujii j. 7450 4350 8780 6030 9650 6590 9960 6330 10120 6700 L2N . Frontage Road: Adjacent to Mass. Ave. Interchange 2580 1700 2770 16 30 2810 16 30 2703 1150 27 00 1520 L33N . S.E. Expressway: Before South Bay Connector /Herald St. Off-Ramp NA NA NA NA NA NA 930° 5030 9080 5070 L34N . Central Artery:. Btwn. Mass. Ave. On-Ramp and Connector CN-AT NA NA NA NA NA NA 41 00 3370 5430 3630 L32N. South Bay Connector: Btwn. W. Fourth On - and Mass. Tpk. Off-Ramps NA NA NA NA NA NA 3190 2810 3500 3030 L16N. Fort Point Channel Tunnel: Before Merge with Central Artery Roadway NA NA NA NA NA NA 2660 1920 2660 2070 L19N. Third Harbor Tunnel NA NA NA NA NA 1 37 0 3150 1820 2520 L3N. S.E. Expressway: Btwn. E. Berkeley On - and Mass. Tpk. Off-Ramps 5780 39 20 7940 5850 9 420 6 360 NA NA NA NA L4N. Central Artery: Btwn. South St. On - and Northern Ave. Off-Ramps 6450 420 0 741 0 562 0 9500 562 0 NA NA NA NA L5N. Central Artery: Btwn. Atlantic On - and Callahan Off -Ramps 5030 4080 5740 5740 6420 60 30 NA NA NA L6N . Central Artery: Btwn. Sumner On - and Causeway Off -Ramps 5540 47 00 6000 581 0 7220 6070 NA NA NA NA L7N. Central Artery: Btwn. Storrow On - and Tobin Off-Ramps 3660 5350 3570 5740 - 4790 5850 5 ?S i 6030 59 30 6140 L8N . Mystic Tobin Bridge: North of 1-93 Ramps 1 580 3120 1900 3400 2010 3590 1 98 J 3290 1980 3480 L9N . 1—93: North of Tobin Bridge Ramps 2000 4 290 2240 4290 2740 4400 27"';') Clin JliU 3230 5 220 LION . Callahan Tunnel 2300 2850 2660 3740 3150 4070 171) 2150 220 0 2480 L2 5N . Central Arterv Tunnel: Before Atlantic Ave. /South St. On— Ramp N A N A N A 5591 4140 6000 4290 L26N . Central Artery: Btwn. Atlantic On- and Surface Off -Ramps NA NA NA NA NA NA 6880 6620 7410 6620 L27N . Central Artery: Btwn. Sumner On— and Storrow Off-Ramps NA NA NA NA NA NA 597") 5810 69 20 5990 L28N. Central Artery: Btwn. Causeway On- and Storrow On-Ramps NA NA NA NA NA NA 4670 4770 5020 5110 L30N. Connector: Mass. Turnpike to Third Harbor Tunnel NA NA NA NA NA NA 167.1 670 1820 890 L31N. Third Harbor Tunnel: Btwn. Conn. CN-AT and Off-Ramp to Congress/S. Boston Access Rd. NA NA NA NA NA NA 304 ) 2150 3550 2550 L11N. Route 1A: Btwn. Callahan Toll Plaza and Airport Off -Ramp 2050 2580 2470 3330 2890 3590 1710 2 330 2520 2430 L24N . Airport Tunnel: Btwn. Off -Ramp to Airport and Off -Ramp to Route 1A NA NA NA NA NA NA 570 1030 610 1180 L12N. Route 1A: Btwn. Airport On - and Neptune Off -Ramps 9 30 2230 1 220 2440 1330 2700 L52') 3110 1630 3770 MAJOR HIGHWAY LINKS - EASTBOUND AND WESTBOUND LIE. Mass. Turnpike, Eastbound; West of Expressway Ramps 4400 2080 48 3 0 2520 4860 2920 509't 2810 5280 3070 L 1W . Mass. Turnpike, Westbound; West of Expressway Ramps 1450 3180 2 550 3400 2~'00 3660 41 40 3380 43^0 L2E . Storrow Drive, Eastbound; West of Copley Square Ramps 3450 2600 3460 3000 3990 3110 353 ) 2740 3990 2890 L2W . Storrow Drive, Westbound; West of Copley Square Ramps 2430 3440 3340 3960 3150 4030 338 ) 4110 4180 4400 MAJOR HIGHWAY LINKS - SOUTHBOUND LIS. S.E. Expressway: Btwn. Southampton On - and Columbia Off-Ramps 3370 5350 5130 8290 5660 8770 ! )280 8580 5660 9180 L2S . S.E. Expressway: Btwn. Mass. Ave. On - and Southampton Off -Ramps 3920 6150 5700 9360 6190 i.0430 5780 9660 6270 10180 L3S. S.E. Expressway: Btwn. Albany On - and Mass. Ave. Off-Ramps 4540 5750 5170 8360 5400 8700 5470 9290 5740 9440 L4S . Central Artery: Btwn. Kneeland On - and Albany Off-Ramps 4350 4570 5620 8070 6160 8330 NA NA NA NA L16S . Central Artery: South of Kneeland St. /Mass. Tpk. On-Ramp NA NA NA NA NA NA 3990 6850 4100 6850 L 1 7S Central Artery: South of Thru Rdwy. /Local Rdwy. Merge NA NA NA NA NA NA 1380 5550 3420 5550 L5S . Central Artery: Btwn. Congress On and Beach Off— Ramps 47 30 4500 5430 6550 5700 6880 NA NA NA NA L18S . Central Artery Local Rdwy: Btwn. Purchase On — and Beach Off Ramps NA NA NA NA NA NA >70() 3370 2 700 3700 L19S . Third Harbor Tunnel NA NA NA NA NA NA ' \ .750 1700 1860 2150 L20S . NA NA NA NA NA NA >47'> 2180 2470 2330 L2 IS Central Artery Thru Rdwy: South of Thru Rdwy. /Local Rdwy. Split NA NA NA NA NA na ; !36i) 2810 2430 2810 L33S Central Artery Thru Rdwy: South of Essex St. On— RamD NA NA NA NA NA na : !93D 4590 3040 4590 L6S . Central Artery: Btwn. Purchase On - and Dewey Square Off -Ramps 5050 3880 5590 5960 5850 6140 NA NA NA NA L7S . Central Artery: Btwn. Haymarket On - and High Off-Ramps 5850 3530 5740 5220 6190 5400 NA NA NA NA L22S . Central Artery: Btwn. Haymarket On - and Purchase Off -Ramps NA NA NA NA NA na e ,161 5960 6230 6030 L8S . Central Artery: Btwn. Causeway On - and Callahan Off -Ramps 5570 3550 5470 4850 6080 5180 NA NA NA NA L9S . Central Artery: Btwn. Storrow On - and Haymarket Off -Ramps 5220 2740 5170 4140 6190 4180 NA NA NA NA L10S . Central Artery: Btwn. Tobin On - and Storrow Off-Ramps 5430 3710 4790 4030 6190 4030 i 74f 5180 7940 5370 LI IS . Mystic Tobin Bridge: North of 1-93 Ramps 3060 2180 3340 2220 37 20 2480 319C 2000 3350 2110 L 1 2S 1-93: North of Tobin Bridge Ramps 3980 2150 3460 2850 40 30 3000 4Q3( 3530 5210 3850 L 1 3S Sumner Tunnel 3160 2640 3460 2810 3690 3260 j 20( L590 262 0 2000 L30S . Central Artery: Btwn. Storrow On- and Callahan Off-Ramps NA NA NA NA NA NA 547( 5180 6230 5510 L23S. Fort Point Channel Tunnel: Btwn. Mass. Tpk. Off - and Herald Off-Ramps NA NA NA NA NA NA 1 141 1590 1290 1890 L31S. Third Harbor Tunnel: Btwn. Congress On- and Mass. Tpk. Off-Ramps NA NA NA NA NA NA 670 2330 1820 2780 L14S . Route 1A: Btwn. Airport On-Ramp and Sumner Toll Plaza 1510 1930 1630 1780 1750 2070 1 90( 1910 2240 1910 L25S.- Route 1A: Btwn. Airport/Third Harbor Off - and Airport On-Ramps NA NA NA NA NA NA 990 870 990 870 L15S. Route 1A: Btwn. Neptune On - and Airport Off -Ramps 1750 1620 1440 1040 1440 L150 NA NA NA NA L28S. Route IA: Btwn. Neptune On-Ramp S Off-Ramp to Airport & Third Harbor Tunnel NA NA NA NA NA NA 2 96(i 2200 3120 2200 L29S. Connector: Route 1A to Third Harbor Tunnel and Airport NA NA NA NA NA NA 1 98( 1330 2130 1650 L32S. Airport Access Rdwy. : Btwn. Rte. 1A Ramps and Off-Ramp to Third Harbor Tunnel NA NA NA NA NA NA 3 15C 2750 4150 3360 MAJOR HIGHWAY RAMPS - NORTHBOUND R1N. Columbia Rd . Off; from S.E. Expressway R2N. Mass. Avenun On; to S.E. Expressway R13N. Ramp: Frontage Rd . to Central Artery R37N. Ramp: Herald St. to Central Artery/Third Harbor Tunnel R3N. Mass Tpk. On; to Central Artery R4N. Atlantic Ave. Off; from Central Artery R5N. Atlantic Ave. On; to Central Artery R36N. Atlantic Ave. /Essex St. On; to Central Artery R6N. Callahan Tunnel Off; from Central Artery R7N . Sumner Tunnol On; to Central Artery R8N. Storrow Drive Off; from Central Artery R9N . Storrow Drive On; to Central Artery R24N. Causeway St. On; to Central Artery R25N. Surface Artery Off; from Central Artery R17N. Ramp: Central Artery to Herald St. /South Bay Connector R38N. W. Fourth St. On; to South Bay Connector R27N. Mass. Turnpike On; to Fori: Point Channel Tunnel R28N. Connector: Central Artery to Third Harbor Tunnel R31N. Ramp: Third Harbor Tunnel to Congress St./S. Boston Acc R29N. Congress St. Off; from Third Harbor Tunnel R30N . Congress St. On; to Third Harbor Tunnel R32N. South Boston Access Road R33N. Ramp: South Boston Access Road to Summer St. R34N. Ramp: South Boston Access Road to Northern Ave. R10N. Airport Off; from Route 1A RUN. Airport On; to Route 1A R20N. Ramp: Third Harbor Tunnel to Airport R21N. Ramp: Third Harbor Tunnel to Route 1A R22N. Airport/Third Harbor Tunnel On; to Route 1A R35N. Ramp: Third Harbor Tunnel to Bird Island Flats. MAJOR HIGHWAY RAMPS - SOUTHBOUND R1S. Columbia Rd. On; to S.E. Expressway R2S. Mass. Ave. Off; from S.E. Expressway R3S. Albany St. On; to S.E. Expressway R13S. Ramp: Fort Point Channel Tunnel to S.E. Expressway R30S. Ramp: Fort Point Channel Tunnel to Herald St. R15S. Ramp: Fort Point Channel Tunnel to Mass. Tpk. R4S. Mass. Tpk. /Albany St. Off; from Central Artery R17S. Ramp: Mass. Tpk . /Knee land St. to Central Artery R31S. Surface Artery/Essex St. On; to Central Artery R5S. Dewey Sq. Off; from Central Artery R6S. High St. Off; from Central Artery R18S. Purchase St. On; to Central Artery R19S. Ramp: Central Artery to Purchase St. R7S. Haymarket On; to Central Artery R8S. Callahan Tunnel Off; from Central Artery R9S. Storrow Drive On; to Central Artery R10S. Storrow Drive Off; from Central Artery R24S. Storrow Drive/Causeway St. Off; from Central Artery R25S. Congress St. Off; from Third Harbor Tunnel R27S. Summer St. /Northern Ave. On; to Third Harbor Tunnel R26S. Congress St. On; to Third Harbor Tunnel R11S. Airport Off; from Route LA R12S. Airport On; to Route 1A R21S. Ramp: Airport to Third Harbor Tunnel R28S. Ramp: Bird Island Flats to Third Harbor Tunnel R29S. Ramp: Airport Access Road to Third Harbor Tunnel EXISTING NO-BUILD ALTERNATIVE PREFERRED ALTERNATIVE 1982 1990 2010 1990 2010 AM PM AM PM AM PM AM PM AM PM ./ u u i An J 1 u 300 680 330 5 30 1 50 680 150 460 200 l ^?n 1 J*i u 7nn 'UU inn /UU 1000 580 1620 800 NA NA N A N A vt a N A 1 560 1 040 1 560 1180 NA NA NA NA NA NA 720 930 720 930 1600 7 00 1 7 50 700 2 320 700 N A NA NA NA 2 360 1540 3840 211 0 4940 2110 N A NA NA NA 220 800 840 1000 840 11 50 910 1 7 40 990 1740 N A NA NA NA N A N A 1 290 2440 1410 2440 1 Tin , 7 3Q i o cn L Z DU 1 410 i 1 1 n 1 J JU i ^^n L J jU NA NA NA NA I 420 1 350 1560 1520 21 30 1 590 1220 1040 1710 1260 1 900 11 00 1820 1630 2470 1670 1820 2110 2470 2260 1200 2000 1200 2250 1400 2300 650 1260 950 1260 N A NA NA NA NA NA 5 30 1070 530 1 370 NA NA NA NA 2130 1850 2200 1850 NA NA S A N A NA N A 4200 2240 5270 2240 NA NA NA NA N A 1030 740 1030 960 NA N A NA NA NA N A 650 290 680 330 NA NA NA NA NA NA 1 1 80 1110 1520 1440 NA NA NA NA NA NA L o ZU A Aft i oou 440 NA NA NA NA NA NA 340 150 950 210 NA NA NA NA NA NA 190 440 270 440 NA NA NA NA NA NA 990 300 990 300 NA NA NA NA NA NA 670 190 670 210 NA NA NA NA NA NA 320 70 320 •30 1390 1270 1710 1850 2130 2110 1180 1180 1820 1480 270 -^20 460 960 570 1220 NA NA NA NA N A NA NA NA NA NA 590 320 790 410 NA NA NA NA NA NA 570 10 30 61 0 1180 NA NA NA NA NA NA 990 2070 1030 2730 NA NA NA NA NA NA 210 710 430 920 /inn 1900 480 1980 480 20 50 810 1 90 810 720 500 720 640 sa£n OO u 720 340 670 340 670 600 1900 490 2290 2290 i on 16 30 2700 NA NA NA NA NA NA l n i n 1 U JU 1140 141 0 NA NA NA NA NA N A 110 J JU i en 1 JU 480 NA NA NA NA NA NA 530 780 c in 890 1260 1300 1260 1410 1510 1670 1 560 2180 * a "7 n 2 220 NA NA NA NA NA NA 610 960 720 i ia n 1 ZD u NA NA NA NA NA NA 610 L 780 610 l Ton I /OU 750 480 720 520 840 520 1030 670 10 30 r> / U 1300 550 1100 560 1 330 560 NA NA N A NA NA NA NA NA NA NA 1220 1850 LZZU ~)ftAft NA NA NA NA NA N A 1 330 ' i in L J ->U 960 1560 1890 1750 1740 20 50 1740 ioiu 1 560 1890 1280 1710 1520 1 370 1940 1 440 O / u 1 0 40 1 2 20 1 260 i Qnn (J)U 2050 1150 21 30 1180 2280 1700 2280 2000 1720 1820 1630 1870 2130 1920 NA NA NA NA NA NA NA NA NA NA 2550 1700 3570 1850 NA NA NA NA NA NA 420 330 420 370 NA NA NA NA NA NA 190 480 230 560 NA NA NA NA NA NA 190 480 190 520 ^70 530 870 670 1030 850 NA NA NA NA 530 850 1060 1400 1300 1780 910 1040 1250 1370 NA NA NA NA NA NA 570 1000 620 1160 NA NA NA NA NA NA 60 150 60 180 NA NA NA NA NA NA 1120 550 1180 810 INTERSECTIONS EXISTING South Boston 1982 1. Columbia Circle 5260 4340 6150 2 . Andrew Square 2000 1650 3070 3 . Columbia Rd./Day Blvd./L St. 1390 1450 1370 4_ L St. /East First St. /Summer St. 1500 1550 1390 5 , Dorchester Ave./W. 5th St. /A St. 2300 2140 2410 Dorchester Ave./W. 4th St. 2230 2060 2390 7 Dorchester Ave /W B r oadwa y (Herald St. Ext. ) 2650 2750 2690 8 . 2650 2400 3120 Q o umme r . / nciLiici ou. 2340 2040 2800 10. Summer St./D St. 2380 2220 2610 li. Congress St. /Dorchester Ave. 2020 1730 2300 12. Congress St. /A St. 950 1080 1240 13. Northern Ave. /Sleeper St. 1270 1730 2660 14. Herald St. /Herald St. Ext. /Albany St. 3670 4140 4910 15. Berkeley St./W. Fourth St. /Frontage Rd. /Albany St. 4530 4410 5910 61. Congress St. /Third Harbor Tunnel Ramps NA NA NA 62. Northern Ave. /Third Harbor Tunnel Ramps Ext. NA NA NA 63. Northern Ave. /Third Harbor Tunnel Ramps at General Ship NA NA NA 64. Summer St. /Third Harbor Tunnel Ramps NA NA NA 65. Herald St. Ext . /Relocated Dorchester Ave . /Expressway Off-Ramp NA NA NA East Boston and Revere 16. Sumner St. /Meridian St. /Chelsea St. 620 720 690 17. Sumner St. /Bremen St. 460 550 520 18. Maverick St. /Meridian St. /Chelsea St. 1080 1130 1030 19. Maverick St. /Bremen St. 480 510 480 20 . Maverick St. /Jeffries St. /Airport Access Rd. 380 320 380 21. Porter St. /Chelsea St./Visconti Rd. 1560 1500 2120 22. Porter St. /Bremen St. 980 1290 1000 23. Porter St. /Or leans St. 570 790 320 24. Porter St. /Cottage St. 540 670 770 25. Central Square (Meridian St. /Saratoga St.) 1000 1040 1170 26. Porter St. /London St. 850 670 930 27. Bennington St./Prescott St. 1150 930 — 28. Chelsea St. /East Eagle St. 1070 1190 910 29. Bennington St. /Neptune Rd. 2370 1890 30. McClellan Of f -Ramp/Neptune Rd. 920 1460 1000 31. Condor St. /Meridian St. 1070 1330 1300 32. Airport Crossover Roads 3630 4860 5 380 33. Bell Circle (Revere) 3860 4470 4760 66. Connector Rd. /Airport Crossover Rd. NA NA NA 67. Service Rd. /Airport Crossover Rd. NA NA NA 68. American Airline Frontage Rd. /Airport Egress Rd. NA NA NA Downtown Boston and Charlestown 34. Kneeland St. /Surface Artery/S.B. On-Ramp 2550 3240 3650 35. Dewey Sq. 3770 4890 6210 36. Atlantic Ave. /Congress St. 3040 2740 5010 37. Atlantic Ave . /Northern Ave. 2440 3560 4790 38. Atlantic Ave. /Surface Artery /High St. 3220 3420 5700 39. Purchase St. /Congress St. 2250 2970 2400 40. North St./Blackstone St./S.B. Off -Ramp 2710 3540 4040 41. Cross St. /Hanover St. /Salem St. 2070 2110 2840 42. Leverett Circle 6 720 6260 6860 45. Congress St. /North St. 1920 2300 2610 46. City Square (Charlestown) 3690 3680 6570 47. Causeway St. /North Washington St . /Commerc ial St. 4260 461 0 49 30 48. Causeway St. /Lomasney Way/Merrimac St. /Stanif ord St. 1 860 1880 2170 49. New Chardon St./Merrimac St. 2910 2200 2700 50. New Chardon St. /North Washington St. 2070 2590 51. Sudbury St. /Congress St./Merrimac St. 1760 3180 2480 52. Surface Artery/Hanover St. NA NA NA 53. Commercial St. /Hanover St. 1300 1620 1590 54. State St. /Atlantic Ave. 1560 1950 2130 55. State St. /Surface Artery 2110 2840 3060 56. Sudbury St./Blackstone St./S.B. On-Ramp 950 1710 1870 57. Causeway St./S.B. Off-Ramp NA NA NA 58. North Washington St. (S.B. Roadway ) /S . B . Off-Ramp Ext. NA NA NA 59. North Washington St. (S.B. Roadway ) /N . B . On-Ramp Ext. NA NA NA 60. Causeway St./N.B. On-Ramp NA NA NA Table 30 (Cont'd.) TRAFFIC V OLUMES NO-BUILD ALTERNATIVE PREFERRED ALTERNATIVE AM AND PM PEAK HOURS 1 £°I2 " pom 1982 , 1990, 2010 PM A" PM AM PM m wT* ' ~ 5030 6200 5710 50 20 46 40 4970 4990 2980 3160 3210 2740 2840 2730 2870 1480 1370 1530 1300 1470 1 300 1510 1810 1910 1860 1900 ■ ■ ]_9X0 1930 1880 2200 2440 2550 2270 2200 2 320 2100 2450 2310 2660 2150 2440 237 0 2210 2790 2460 3490 2110 3700 22 30 4060 3140 408 0 4380 4060 46 40 41 00 2960 2770 3040 2610 3070 2750 3110 2570 2410 , 2600 1880 2450 1950 2490 3390 2320 3540 2670 3550 2920 3680 2010 1240 2150 ' 1730 2070 1920 2240 2370 2690 2410 2460 2 420 2740 2490 4330 4960 cnnn 5 310 5430 5780 6000 6440 6090 5700 3490 3300 3690 4110 NA NA NA 1 780 1610 1860 2010 NA NA NA 2060 2080 1660 NA NA NA 1 260 11 50 1230 1190 NA NA NA 2190 2380 2 330 2420 NA NA NA 5760 3130 66 0 0 3470 380 690 R90 7 40 870 760 890 550 460 550 560 550 560 550 1 2 50 10 30 1280 1130 1 230 1 030 1160 540 480 540 48 0 540 480 510 320 380 320 310 320 380 300 1350 2430 21 70 1090 1010 1 460 1270 1320 1220 1 5 1 0 790 890 8 50 1 060 380 1020 1030 640 620 770 810 990 970 550 510 "20 680 1210 1260 1230 1260 1210 1340 1230 * 840 1060 . 990 500 410 610 460 NO DATA AVAILABLE NO DATA AVAILABLE 940 1020 1130 1040 850 1160 ' 620 NO DATA AVAILABLE MO DATA AVAILABLE 13 30 1 1 40 1 460 1170 1 1 60 1320 1330 1 3 3 0 1 47 0 1630 1180 1 3oo 1 380 1520 6 390 •5640 787 0 NA NA NA N A 5150 48 7 0 5420 5130 5360 5190 570 0 NA NA N A 22 00 i 910 2 8 40 2 240 NA NA NA 650 80 0 830 100 0 NA NA N A 2 400 38 00 2 880 4860 4010 3370 3990 2 1 90 39 ) 0 2050 326 0 5970 5870 6280 ■ 3530 3820 3450 3 4 L 0 41 60 4490 4790 2 340 2050 3 860 47 40 4440 2640 3 560 3590 4220 6230 4070 10 50 1 47 0 1020 1950 2960 2620 3140 1 380 3560 1 470 3480 4000 4580 4400 2480 i860 2990 206 0 2360 2680 2610 2940 2450 3 590 2 7 40 6420 6560 6770 6040 5350 61 00 5660 2630 3010 2630 2450 1960 26 30 2220 7400 6050 7850 6030 6720 5590 720 0 5910 4410 6620 4180 5470 3 330 5880 2280 2060 2410 2510 2400 L 7 80 2550 2550 2570 2630 3110 19 L 0 31 30 20 90 2480 2360 2670 4250 4990 4870 5320 3330 2280 3350 ' 3140 3780 3640 3880 NA NA NA 2630 1930 3150 2050 2260 1670 2220 ■ 1180 1450 990 9 30 2950 2260 2880 610 1-440 . 610 1540 3110 2700 .3450 2300 1470 2300 1520 2480 1860 2730 3720 4270 3030 4150 NA NA NA 3140 3040 3160 3160 NA SA NA 2760 2040 2250 2040 NA NA NA 2750 2290 2330 2320 NA NA NA 2380 2730 2050 3120 Table 31 AM AND PM PEAK HOURS VQLUME-TQ-CAPACITtTrATIO (V/C) , AND LEVELS O F SER VICE (LOS ) 1982, 1990, 2010 MAJOR HIGHWAY LINKS - NORTHBOUND LIN. S.E. Expressway: Btwn. Columbia On - and Southampton Off-Ramps L2N. Frontage Road: Adjacent to Mass. Ave. Interchange L33N. S.E. Expressway: Before South Bay Connector/Herald St. Off -Ramp L34N. Central Artery: Btwn. Mass. Ave. On-Ramp and Connector CN -AT L32N. South Bay Connector: Btwn. W. Fourth On - and Mass. Tpk. Off-Ramps L16N. Fort Point Channel Tunnel: Before Merge with Central Artery Roadway L19N. Third Harbor Tunnel L3N. S.E. Expressway: Btwn. E. Berkeley On - and Mass. Tpk. Off-Ramps L4N. Central Artery: Btwn. South St. On - and Northern Ave. Off -Ramps L5N . Central Artery: Btwn. Atlantic On - and Callahan Off -Ramps L6N. Central Artery: Btwn. Sumner On - and Causeway Off -Ramps L7N. Central Artery: Btwn. Storrow On - and Tobin Off-Ramps L8N. Mystic Tobin Bridge: North of 1-93 Ramps L9N. 1-93: North of Tobin Bridge Ramps LION. Callahan Tunnel L25N. Central Artery Tunnel: Before Atlantic Ave. /South St. On-Ramp L26N. Central Artery: Btwn. Atlantic On- and Surface Off-Ramps L27N. Central Artery: Btwn. Sumner On- and Storrow Off -Ramps L28N. Central Artery: Btwn. Causeway On- and Storrow On-Ramps L30N. Connector: Mass. Turnpike to Third Harbor Tunnel L31N. Third Harbor Tunnel: Btwn. Conn. CN-AT and Off-Ramp to Congress/S. Boston Access L11N. Route 1A: Btwn. Callahan Toll Plaza and Airport Off -Ramp L24N. Airport Tunnel: Btwn. Off -Ramp to Airport and Off-Ramp to Route 1A L12N. Route 1A: Btwn. Airport On - and Neptune Off -Ramps MAJOR HIGHWAY LINKS - EASTBOUND AND WESTBOUND LIE. Mass. Turnpike, Eastbound; West of Expressway Ramps L1W. Mass. Turnpike, Westbound; West of Expressway Ramps L2E. Storrow Drive, Eastbound; West of Copley Square Ramps L2W. Storrow Drive, Westbound; West of Copley Square Ramps MAJOR HIGHWAY LINKS - SOUTHBOUND LIS. S.E. Expressway: Btwn. Southampton On - and Columbia Off-Ramps L2S. S.E. Expressway: Btwn. Mass. Ave. On - and Southampton Off -Ramps L3S. S.E. Expressway: Btwn. Albany On - and Mass. Ave. Off-Ramps L4S. Central Artery: Btwn. Kneeland On - and Albany Off-Ramps L16S. Central Artery: South of Kneeland St. /Mass. Tpk. On-Ramp L17S. Central Artery: South of Thru Rdwy. /Local Rdwy. Merge L5S. Central Artery: Btwn. Congress On - and Beach Off-Ramps L18S. Central Artery Local Rdwy: Btwn. Purchase On - and Beach Off-Ramps L19S. Third Harbor Tunnel L20S. Central Artery Local Rdwy: South of Thru Rdwy. /Local Rdwy. Split L21S. Central Artery Thru Rdwy: South of Thru Rdwy. /Local Rdwy. Split L33S. Central Artery Thru Rdwy: South of Essex St. On-Ramp L6S. Central Artery: Btwn. Purchase On - and Dewey Square Off-Ramps L7S. Central Artery: Btwn. Haymarket On - and High Off-Ramps L22S. Central Artery: Btwn. Haymarket On - and Purchase Off-Ramps L8S. Central Artery: Btwn. Causeway On - and Callahan Off -Ramps L9S. Central Artery: Btwn. Storrow On - and Haymarket Off-Ramps L10S. Central Artery: Btwn. Tobin On - and Storrow Off -Ramps L11S. Mystic Tobin Bridge: North of 1-93 Ramps L12S. 1-93: North of Tobin Bridge Ramps L13S. Sumner Tunnel L30S. Central Artery: Btwn. Storrow On- and Callahan Off -Ramps L23S. Fort Point Channel Tunnel: Btwn. Mass. Tpk. Off - and Herald Off-Ramps L31S. Third Harbor Tunnel: Btwn. Congress On- and Mass. Tpk. Off -Ramps L14S. Route 1A: Btwn. Airport On-Ramp and Sumner Toll Plaza L25S. Route 1A : Btwn. Airport/Third Harbor Off - and Airport On-Ramps L15S. Route 1A: Btwn. Neptune On - and Airport Off -Ramps L28S. Route LA: Btwn. Neptune On-Ramp & Off-Ramp to Airport & Third Harbor Tunnel Connector: Route 1A to Third Harbor Tunnel and Airport L32S. Airport Access Rdwy.: Btwn. Rte. 1A Ramps and Off-Ramp to Third Harbor Tunnel EXISTING NO-BUILD ALTERNATIVE 198 2 1990 2010 AM PM AM PM AM PM V/C SP LOS V/C SP LOS V/C SP LOS V/C SP LOS V/C SP LOS V/C SP LOS PREFERRED ALTERN ATIVE L990 V/C AM SP PM 1.03 30 F 0.60 40 C 1. 22 25 F 0.83 35 E 1. 34 20 F 0.91 35 E 1 38 20 F 0 88 35 E 1. 40 20 0. 69 30 D 0.46 40 B 0. 74 25 D 0. 44 40 B 0. 76 25 D 0. 42 40 B 0 . 74 35 C 0 32 40 B 0 74 35 NA NA NA NA NA NA 1 .01 30 F 0 70 35 D 1 26 30 NA NA NA NA NA NA 0 . 64 40 C 0 . 54 40 C 0 86 35 NA NA NA NA NA NA 0 . 68 30 E 0 68 30 E 0. 77 30 NA NA NA NA NA NA 0 . 76 35 D 0 .55 40 C 0 76 35 NA NA NA NA NA NA 0 . 40 40 C 0 62 40 C 0 72 40 1.10 30 F 0. 75 30 F 1.10 30 F 0.81 30 F 1. 31 20 F 0. 88 25 F NA NA NA 1.13 20 F 0.75 ,15 F 1. 29 15 F 1. 01 15 F 1. 62 10 "F 1. 00 15 F NA NA NA 0.96 30 F 0.78 15 F 1. 06 25 F 1.06 15 F 1.19 20 F 1.11 15 F NA NA NA 0.90 35 E 0.79 15 F 1. 06 25 F 0.99 15 F 1. 24 20 F 1. 00 15 F NA NA NA 0.89 25 F 1.30 15 F 0.68 40 C 1. 46 15 F 0.91 30 C 1. 50 15 F 0 . 71 40 C 0 76 40 C 0 79 40 0.40 50 A 0.78 45 C 0.48 45 A 0.85 40 D 0.50 45 A 0.90 35 E 0 37 50 A 0 62 45 B 0 37 50 0.28 50 A 0. 59 50 C 0. 31 50 A 0. 59 50 Q 0. 38 50 A 0.61 50 C 0 . 38 50 A 0 70 40 C 0 44 45 0.85 35 D 1. 06 20 F 0.99 30 E 1. 39 20 F 1. 17 20 F 1. 51 15 F 0 . 59 35 C 0 74 35 c 0 76 35 NA NA NA NA NA NA 0 .80 35 D 0 . 59 40 c 0 86 35 NA NA NA NA NA NA 0 . 78 40 C 0 . 76 35 D 0 83 35 NA NA NA NA NA NA 0 . 76 40 C 0 .75 40 n 0 90 35 NA NA NA NA NA NA 0 . 67 40 C 0 . 68 40 C 0 72 40 NA NA NA NA NA NA 0 .90 30 E 0 . 34 40 0 98 30 NA NA NA NA NA NA 0 . 62 40 C 0 . 45 40 c 0 72 35 0. 36 35 C 0. 45 30 C 0. 44 30 C 0. 58 20 C 0. 51 25 C 0.63 20 r* 0 .31 40 C 0 .42 40 r 0 46 40 NA NA NA NA NA NA 0 16 35 C 0 28 35 c 0 17 35 0.17 45 A 0.39 40 B 0. 22 45 A 0. 43 40 B 0. 24 45 A 0. 47 35 C 0 .25 35 C 0 . 51 40 B 0 26 35 2010 LOS V/C SP LOS V/C SP LPs" v/C 0.93 0.42 0.70 0.57 0.68 0.59 0.73 NA NA NA NA 0.77 0.65 0.72 0.85 0.61 0.76 0.78 0.73 0.48 0.55 0.44 0.32 0.62 0 80 40 D 0 37 45 c 0. 87 30 E 0 45 45 C 0 88 30 E a 52 45 C 0 92 30 C 0. 50 40 C 0. 96 30 £ 0 55 40 0 27 55 A 0. 58 55 B 0 46 55 B 0 62 55 B 0 49 55 B 0 66 50 C 0 56 55 B 0 74 50 C 0 61 55 8 0 78 50 0 59 40 c 0 45 40 c 0 59 40 C 0 51 40 C 0 69 40 C 0 53 40 c 0 61 40 C 0 47 40 0 69 40 0 50 40 0 42 40 C 0. 59 40 c 0. 57 40 C 0 68 40 C 0 67 40 n 0 69 40 Q 0 58 40 C 0 71 35 D 0 72 35 D 0 76 15 0.62 50 B 0.74 30 F 0.71 40 D 1.15 30 F 0.78 40 D 1. 22 30 F 0. 73 40 D 1.19 30 F 0. 79 40 D 1.27 I 0. 62 50 A 0.85 30 E 0.64 40 D 1. 21 25 F 0.70 30 F 1. 35 20 F 0 .67 40 D 1.12 25 F 0.73 30 p 1.19 25 0.73 35 D 0.95 20 F 0.60 45 B 1.13 20 F 0.63 40 C 1. 17 20 F 0. 65 35 D 1.10 20 F 0. 68 35 D 1.12 20 0.74 40 C 0.72 20 F 0. 78 25 F 1.13 20 F 0.85 25 F 1. 16 20 F NA NA NA NA NA NA NA NA NA NA 0.61 45 C 1. 05 30 F 0. 63 45 C 1.05 30 NA NA NA NA NA NA 0.52 45 C 0.85 30 F 0. 52 45 0.95 10 0.78 35 E 0.75 20 F 0.90 25 F 1. 10 15 F 0.91 20 F 1. 12 15 F NA NA NA NA 35 NA NA NA NA NA NA 0.41 45 C 0.53 35 E 0 . 41 45 0.59 NA NA NA NA NA NA 0. 51 40 C 0.49 40 C 0. 55 40 c 0.62 41 NA NA NA NA NA NA 0 . 45 40 C 0.40 40 C 0.45 40 0.43 4) NA NA NA NA NA NA 0. 65 40 c 0. 77 35 D 0. 67 40 c 0.77 35 NA NA NA NA NA NA 0 . 54 40 c 0.84 35 E 0. 56 40 c 0.84 !! 0.83 30 E 0.65 25 F 0.92 25 F 1. 02 20 F 0.97 20 F 1.05 20 F NA NA NA NA 1.08 30 F 0.64 25 F 1.05 25 F 0.94 25 F 1.14 20 F 0.98 25 F NA NA NA NA 35 NA NA NA NA NA NA 0. 77 40 c 0. 74 40 C 0. 77 35 E 0.75 0.96 30 F 0.62 25 F 0.95 25 F 0.91 25 F 1. 03 20 F 0. 94 25 F NA NA NA NA 0.96 30 E 0.51 25 F 0.96 25 E 0.77 25 F 1.14 20 F 0.77 25 F NA NA NA NA 41 1.20 20 F 0.81 25 F 0. 88 25 F 0. 74 25 F 1.14 20 F 0. 75 30 F 0.69 35 E 0.62 40 C 0. 95 30 F 0.64 50 1.13 10 F 0.81 30 F 0.84 40 D 0. 56 45 C 0.93 35 E 0.62 45 C 0.60 45 B 0.37 50 A 0.63 45 B 0.39 40 0.73 15 F 0. 40 50 B 0.64 35 E 0.53 50 B 0.74 30 F 0. 55 50 B 0.55 40 Q 0.49 40 C 0.71 30 F 0.53 1.17 20 F 0.98 20 F 1.28 20 F 1. 04 20 F 1. 37 20 F 1. 21 20 F 0.82 35 D 0. 59 35 c 0. 97 35 E 0. 74 NA NA NA NA NA NA 0.63 40 c 0.64 40 c 0. 76 40 c 0.69 NA NA NA NA NA NA 0. 37 40 c 0.49 40 c 0. 42 40 C 0.5B NA NA NA NA NA NA 0 . 33 40 0.45 40 c 0.35 40 0.53 0.27 5 F 0.34 5 F 0 . 30 5 F 0.31 5 F 0. 31 5 F 0.36 5 F 0. 35 40 c 0.34 40 c 0 . 41 40 c 0.35 NA NA NA NA NA NA 0.27 40 c 0.23 40 c 0.27 40 c 0.23 0.31 45 A 0.28 45 A 0.26 45 A 0.18 45 A 0.26 45 A 0.20 45 A NA NA NA NA NA NA NA NA NA NA 0.41 40 c 0.31 40 0. 42 40 c 0.31 0.15 NA NA NA NA NA NA 0. 54 40 c 0. 37 40 0. 58 35 D NA NA NA NA NA NA 0.69 40 c 0. 54 40 0. 88 35 D 0.68 Table 31 (Cont'd.) AM AND PM PEAK HOURS VOLUME-TO-CAPACITY RATIO (V/ AND LEVELS OF SERVICE (LOS) 1982, 1990, 2010 NO-BUILD ALTERNATIVE MAJOR HIGHWAY RAMPS - NORTHBOUND 1982 1990 2010 AM PM AM PM AM PM V/C SP LOS V/C SP LOS V/C SP LOS v/c SP LOS v/c SP LOS V/C SP LOS R1N. Columbia Rd. Off; from S.E. Expressway 0 . 34 35 C 0.17 35 C 0. 38 35 C 0. 20 35 C 0.46 35 C 0.22 35 C R2N. Mass. Avenue On; to S.E. Expressway 0. 30 30 F 0.13 40 B 0. 99 30 F 0. 46 30 F 1. 31 30 F 0. 46 35 F R13N. Ramp: Frontage Rd. to Central Artery NA NA NA NA NA NA P.37N . Ramp: Herald St. to Central Artery/Third Harbor Tunnel NA NA NA NA NA NA R3N. Mass Tpk. On; to Central Artery 1. 08 20 F 0.51 30 C 1.17 20 F 0.51 30 C 1. 56 10 F 0.51 30 C R4N. Atlantic Ave. Off; from Central Artery 1.58 15 F 1. 03 20 F 2 . 00 10 F 1. 40 15 F 2.00 5 F 1. 40 15 F R5N. Atlantic Ave. On; to Central Artery 0.16 25 F 0 . 53 15 F 0.61 25 F 0.66 15 F 0.61 20 F 0. 76 15 F R36N. Atlantic Ave. /Essex St. On; to Central Artery NA NA NA NA NA NA R6N . Callahan Tunnel Off; from Central Artery 0.86 25 F 0.47 20 F 0.81 25 E 0.90 20 F 0.86 20 F 0.99 15 F R7N. Sumner Tunnel On; to Central Artery 0.91 30 E 0. 87 30 E 1. 00 15 F 0. 98 15 F 1.37 10 F 0. 98 15 F R8N. Storrow Drive Off; from Central Artery 0.62 35 C 0.37 40 C 0. 59 35 c 0. 55 40 C 0. 80 25 E 0.56 40 C R9N. Storrow Drive On; to Central Artery 0. 78 30 E 1.37 10 F 0. 78 30 E 1. 54 10 F 0.91 30 E 1.58 10 F R24N. Causeway St. On; to Central Artery NA NA NA NA NA NA R25N. Surface Artery Off; from Central Artery NA NA NA NA NA NA R17N. Ramp: Central Artery to Herald St. /South Bay Connector NA NA NA NA NA NA R38K. W. Fourth St. On; to South Bay Connector NA NA NA NA NA NA R27N. Mass. Turnpike On; to Fort Point Channel Tunnel NA NA NA NA NA NA R28N. Connector: Central Artery to Third Harbor Tunnel NA NA NA NA NA NA R31N. Ramp: Third Harbor Tunnel to Congress St./S. Boston Access Rd. NA NA NA NA NA NA R29N. Congress St. Off; from Third Harbor Tunnel NA NA NA NA NA NA R30N. Congress St. On; to Third Harbor Tunnel NA NA NA NA NA NA R32N. South Boston Access Road NA NA NA NA NA NA R33N. Ramp : South Boston Access Road to Summer St . NA NA NA NA NA NA R34N. Ramp: South Boston Access Road to Northern Ave. NA NA NA NA NA NA R10N . Airport Off; from Route 1A 0.87 30 E 0.79 30 E 1. 07 25 F 1. 14 25 F 1. 33 20 I. 30 20 F RUN. Airport On; to Route LA 0.17 40 B 0. 57 40 B 0.28 40 B 0. 59 35 C 0. 36 40 B 0. 76 30 D R20N . Ramp: Third Harbor Tunnel to Airport NA NA NA NA NA NA R21N. Ramp: Third Harbor Tunnel to Route 1A NA NA NA NA NA NA R22N. Airport/Third Harbor Tunnel On; to Route 1A NA 8A~~ NA NA NA NA R35N. Ramp: Third Harbor Tunnel to Bird Island Flats. NA NA NA NA NA NA PREFERRED ALTERNATIVE 1990 — 2010 AM AM PM V/C SP LOS v/c _LOS_ v/c S P LOS v/c SP LOS 0 . 36 35 C 0. 10 40 C 0 . 46 35 C 0 .10 40 C 0 . 65 40 c 0. 38 45 B 1. , 05 30 F 0 . 52 45 B 0.73 25 E 0. 58 30 c 0\ 73 25 E 0 .62 30 C 0 . 49 30 0 0. 62 30 D 0 .49 30 D 0 . 62 30 D NA NA NA NA NA NA NA NA 0 . 67 35 C 1. 16 20 0, . 73 3 5 C 1 . 16 20 F 0 . 46 35 c 0. 87 25 0. . 50 35 c 0 .87 25 E N A NA NA NA 0 . 90 20 E 0. 77 20 1. . 27 i 5 F 0 . 93 20 E 0 . 65 35 C 0. 75 25 0 . 88 25 E 0 . 81 25 0 . 42 -i c jj ° 0. 86 25 0 .62 35 c 0 . 86 25 0 . 36 35 c 0. 72 30 D 0 . 36 35 c 0 .92 25 0 76 25 E 0. 66 35 0 .79 25 E 0 .66 35 0.83 30 D 0. 80 35 1 . 04 25 F 0 .80 35 r 0.69 30 D 0. 50 35 0 .69 3 0 D 0 .65 35 C 0. 43 35 D 0. 20 40 0. . 46 35 D 0 . 22 40 C 0.32 45 B 0. 30 45 B 0 . 42 45 0 . 40 45 B 0. 58 45 B 0. 15 50 A 0. . 59 45 B 0 .15 50 A 0.63 35 C 0. 12 40 c 0 .72 30 D 0 .17 40 C 0. 12 40 c 0. 28 40 C 0, . 17 40 c 0 . 28 40 C 0.62 40 c 0. 20 50 A 0 . 62 40 c 0 .20 50 A 0. 43 35 c 0. 13 40 C 0. . 43 35 c 0 .15 40 C 0.20 40 c 0. 05 40 C 0 . 20 40 c 0 . 06 40 C 0. 74 30 0 0. 73 35 c 1 .14 25 F 0 .92 30 E NA NA NA NA 0.38 35 c 0. 21 35 c 0 . 51 35 c 0 . 27 35 C 0.37 35 c 0. 65 35 c 0 .39 35 0 .76 30 E 0.39 45 B 0. 82 40 c 0 . 40 45 B 1 . 08 30 F 0.13 40 c 0. 46 35 c 0 . 27 35 r 0 . 59 35 C MAJOR HIGHWAY RAMPS - SOUTHBOUND R1S. Columbia Rd. On; to S.E. Expressway 0.27 35 C 1.28 25 F 0.27 R2S. Mass. Ave. Off; from S.E. Expressway 0.23 40 B 0.16 45 0.23 R3S. Albany St. On; to S.E. Expressway 0.40 30 C 1.25 20 F 0. 33 R13S. Ramp: Fort Point Channel Tunnel to S.E. Expressway NA NA NA R30S. Ramp: Fort Point Channel Tunnel to Herald St. NA NA NA R15S. Ramp: Fort Point Channel Tunnel to Mass. Tpk. NA NA NA R4S. Mass. Tpk. /Albany St. Off; from Central Artery 0.85 25 E 0.88 25 E 0. 85 R17S. Ramp: Mass. Tpk . /Kneeland St. to Central Artery NA NA NA R31S. Surface Artery /Essex St. On; to Central Artery NA NA NA R5S. Dewey Sq. Off; from Central Artery 0. 50 30 C 0 . 32 30 C 0.49 R6S. High St. Off; from Central Artery 0.87 20 E 0. 36 30 C 0.74 R18S. Purchase St. On; to Central Artery NA NA NA R19S. Ramp: Central Artery to Purchase St. NA NA NA R7S. Haymarket On; to Central Artery v 1.01 15 F 1.20 15 F 1.13 R8S. Callahan Tunnel Off; from Central Artery 0 . 41 15 F 0. 57 15 F 0.49 R9S. Storrow Drive On; to Central Artery 0. 98 20 F 0. 57 30 C 1. 34 R10S. Storrow Drive Off; from Central Artery 1.12 20 F 1. 22 20 F 1. 06 R24S. Storrow Drive/Causeway St. Off; from Central Artery NA NA NA R25S. Congress St. Off; from Third Harbor Tunnel NA NA NA R27S. Summer St. /Northern Ave. On; to Third Harbor Tunnel NA NA NA R26S. Congress St. On; to Third Harbor Tunnel NA NA NA R11S. Airport Off; from Route 1A 0. 47 35 B 0. 33 40 A 0. 54 R12S. Airport On; to Route 1A 0.34 30 C 0. 55 25 F 0.69 R21S. Ramp: Airport to Third Harbor Tunnel NA NA NA R28S. Ramp: Bird Island Flats to Third Harbor Tunnel NA NA NA R29S. Ramp: Airport Access Road to Third Harbor Tunnel NA NA NA 35 1. 33 25 F 0. 32 35 C 1. 38 20 F 0 .10 40 C 0 . 54 25 F 0 .13 40 C 0 . 55 25 F 40 B 0. 20 40 B 0.27 40 B 0.23 40 B 0 . 22 50 A 0 .42 50 A 0 . 22 50 A 0 . 42 50 A 30 C 1. 51 20 F 0. 33 30 C 1.51 20 F . 03 25 F 1 . 69 15 F 1. .11 25 F .84 15 F NA NA NA 0 .66 30 D 0 .80 25 E 0 . 73 25 E 0 .90 25 E NA NA NA 0 . 08 40 C 0 . 22 35 C 0 .10 40 C 0 . 32 35 NA NA NA 0 . 33 40 0 .49 40 C 0 . 33 40 0 . 55 40 25 E 0.95 20 B 1.02 15 F 1.13 15 F 0 . 52 35 C 0 . 74 30 F 0 . 56 35 c 0 . 75 30 E NA NA NA 0 . 41 35 c 0 .65 25 F 0 . 49 35 c 0 .85 25 F NA NA NA 0 . 41 35 c 1 .19 25 F 0 . 41 35 c 1 . 19 25 F 30 C 0. 34 30 C 0. 56 30 C 0. 34 30 C 0 .69 30 c 0 .44 30 C 0 .69 30 c 0 .44 30 20 E 0. 36 30 C 0.89 20 E 0 . 36 30 C NA NA NA NA NA NA NA 0. .44 35 C 0. .66 25 E 0. . 44 35 c 0 . 73 25 E NA NA NA 0. . 89 25 E 0. 65 35 C 0. 89 25 E 0. . 65 35 C 15 F 1.12 15 F 1. 32 10 F 1.12 15 F 1. 00 25 F 1. 16 20 F »i; 00 25 F 1. 20 20 F 15 F 0.46 15 F 0.62 15 F 0. 48 15 F 0. 62 30 C 0. 77 30 D 0. 86 25 E 0. 93 25 E 20 F 0. 75 25 E 1.39 20 0.77 25 E 48 20 F 1. 14 20 F 2_ m 48 20 F 1. 34 20 F 20 F 1.25 20 F 1. 39 20 F 1. 29 20 F NA NA NA NA NA NA NA 0 . 91 30 E 0. 61 35 C 1. 28 25 F 0. 66 35 C NA NA NA 0. 30 25 D 0. 23 25 D 0. 30 25 D 0. 26 25 . D NA NA NA 0 . .14 40 0. 35 35 C 0. 14 40 c 0. . 37 35 c NA NA NA 0. 14 40 C 0. 35 35 C 0. 14 40 c 0. ,37 35 30 C 0. 42 35 B 0. 63 30 C 0.53 30 C NA NA NA NA 30 C 0.91 20 F 0.87 25 E 1.17 15 F 0. 59 30 C 0. 67 30 C 0. 81 25 E 0. 88 25 E NA NA NA 0 . .37 35 0. 65 35 C 0. 40 35 C 0. . 75 25 E NA NA NA 0. 04 40 c 0. 10 40 C 0. 39 35 C 0. 11 40 C NA NA NA 0. 72 30 D 0. 35 35 c 0. 76 25 E 0. 52 35 c Table 31 (Cont'd.) AM AND PM PEAK HOURS VOLUME-TO-CAPACITY RATIO (V/C) , AND LEVFLS OF SERVICE (LOS) :;prs . 1982, 1990, 201C 1. Columbia Circle 2 . Andrew Square* 3. Columbia Rd./Day Blvd./L St. 4. L St. /East First St. /Summer St.* 5. Dorchester Ave./W. 5th St. /A St.* 6. Dorchester Ave./W. 4th St.* 7 . Dorchester Ave./W. Broadway (Herald St. Ext.)* 8. Summer St . /Dorchester Ave.* 9 . Summer St./Melcher St.* 10. ^nmmor ^t /D "-It * 11. Congress St. /Dorchester Ave. 12. Congress St. /A St. 13. Northern Ave. /Sleeper St. 14. Herald St. /Herald St. Ext. /Albany St.* 15. Berkeley St./W. Fourth St. /Frontage Rd. /Albany St.* 61. Congress St. /Third Harbor Tunnel Ramps (Assumed *) 62. Northern Ave. /Third Harbor Tunnel Ramps Ext. (Assumed *) 63. Northern Ave. /Third Harbor Tunnel Ramps at General Ship (Assumed *) 64. Summer St. /Third Harbor Tunnel Ramps (Assumed *) 65. Herald St. Ext . /Relocated Dorchester Ave . /Expressway Off-Ramp (Assumed* East Boston and Revere 16. Sumner St. /Meridian St. /Chelsea St.* 17. Sumner St. /Bremen St. 18. Maverick St. /Meridian St. /Chelsea St. 19. Maverick St. /Bremen St. 20. Maverick St. /Jeffries St. /Airport Access Rd. 21. Porter St. /Chelsea St./Visconti Rd.* 22. Porter St. /Bremen St. 23. Porter St. /Orleans St. 24. Porter St. /Cottage St. 25. Central Square (Meridian St. /Saratoga St.)* 26. Porter St. /London St. 27. Bennington St./Prescott St. 28. Chelsea St. /East Eagle St. 29. Bennington St. /Neptune Rd. 30. McClellan Of f -Ramp/Neptune Rd. 31. Condor St. /Meridian St.* 32. Airport Crossover Roads* 33. Bell Circle (Revere)* 66. Connector Rd. /Airport Crossover Rd. (Assumed *) 67. Service Rd. /Airport Crossover Rd. 68. American Airline Frontage Rd. /Airport Egress Rd. Downtown Boston and Charlestown Kneeland St. /Surface Artery /S.B. On-Ramp* Dewey Sq.* Atlantic Ave. /Congress St.* Atlantic Ave . /Northern Ave.* Atlantic Ave. /Surface Artery /High St.* Purchase St. /Congress St.* North St./Blackstone St. /S.B. Off -Ramp (Assumed *) Cross St. /Hanover St. /Salem St. (Assumed *) Leverett Circle* Congress St. /North St.* City Square (Charlestown)* Causeway St. /North Washington St . /Commercial St.* Causeway St. /Lomasney Way/Merrimac St. /Stanif ord St. (Assumed *) New Chardon St./Merrimac St.* New Chardon St. /North Washington St.* Sudbury St. /Congress St./Merrimac St.* Surface Artery /Hanover St. Commercial St./Hanovet St. State St. /Atlantic Ave.* State St. /Surf ace Artery* Sudbury St./Blackstone St. /S.B. On-Ramp* Causeway St. /S.B. Off-Ramp (Assumed *) North Washington St. (S.B. Roadway ) /S . B . Off-Ramo Ext. (Assumed *) North Washington St. (S.B. Roadway ) /N . B . On-Ramp Ext. (Assumed *) Causeway St./N.B. On-Ramp (Assumed *) 34. 35. 36. 37. 38. 39. 40. 41. 42. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. EXISTING NO-BUILD ALTERNATIVE 1982 PREFFERRED ALTERNATIVE 1990 2010 1990 AM PM AM PM AM PM AM PM AM PM V/C LOS V/C LOS V/C LOS V/C I .OS V/C LOS V/C LOS V/C LOS V/C LOS_ V/C LOS V/C LOS 0.85 D 0. 52 A 0 . 95 E 0 . 65 B 0 . 95 E o . 76 C Q E 0 . 7 7 0 . 92 0. 78 C 1. 02 F 0. 84 D 1 .63 F 1 . 53 F 1 . 65 F 1 . 63 F V 48 F J. ■ F 1 . 49 F 1. 47 F 0.25 C 1. 05 F 2 . 00 F 1 . 27 F 2 . 00 F 1 . 39 F o 57 D L . ">A F 0 . 58 D 1 , 30 p 0. 86 D 0 . 76 c 0 . 92 E 0 . 86 D o . 93 E o . 90 D 0 93 E o 86 D n u . . ?j E 0 . 91 F 0.53 A 0 . 65 B o . 55 A o . 69 B o 56 A Q . O L D Q 60 B n U . 7 1 C 0 . 6 3 B 0 . 74 0. 58 A o t 50 o 50 A Q 52 A n u ^ 7 A 0 . 58 A o 82 D Q 7Q C 0 . . 79 D 0 . . 90 0. 87 D 1. 07 0 .92 E d . 86 D 0 .96 E 0 .95 F Q 69 B Q -17 A 0 . 7 7 c 0 . . 39 0. 78 C 0. 76 Q 0 . 99 E i . 46 F 0 . 99 E 1 . 44 F Q QQ E 0 . . 91 E 1 . . 05 F 0 , . 91 0 . 44 A 0. 48 0 . 53 A 0 .69 B 0 . 53 0 .67 B n u . . JO A 0 . 76 c 0 . 61 B 0 . . 78 0. 73 C 0. 69 B 0 . 78 c 0 . 75 Q 0 .60 Q 0 . 76 C 0 , . 45 A 0 . . 70 0 . . 47 0. . 71 C 2. 00 F 2. 00 F 2. . 00 F 2 . 00 F 2 . 00 F 2 . 00 F 0 , 7 4 c 0 . 96 0 . 82 1. 02 F 0. 88 E 1. 25 F 1 . 47 F 2 . 00 F 1 . 47 F 2 . 00 2. . 00 F 2. 00 F 2. 00 p 2. 00 F 1. 30 F 2. 00 F 2 . 00 F 2 . 00 F 1 . 91 F 2 . 00 2. . 00 F 2, . 00 F 2. 00 2. . 00 F 0.84 D 0. 80 C 1 . 07 F 0. . 90 E 1 .13 F 0 .94 E 0. .97 E i. 25 F 1. 17 F 1. 39 F 1.03 F 0. 76 C 1. . 07 F 0 . 77 C 1 . 11 F 0 .80 C 0. .95 E 0. 65 B 0. 84 E 0. 75 C NA NA NA NA NA NA 0. .60 A 0. 53 A 0. ,72 C 0. 60 B NA NA NA NA NA NA 0. . 42 A 0. . 48 A 0. 42 A 0, .48 A NA NA NA NA NA NA 0. .61 B 0. . 47 A 0. , 59 B 0. . 50 A NA NA NA NA NA NA 0. . 68 B 0. .48 A 0. .72 C 0. . 48 A NA NA NA NA NA NA 1. . 32 F 0 .62 B mi, .52 F 0 . 73 C 0.26 A 0. 34 A 0. .44 A 0. 46 A 0. . 44 A 0. . 46 A 0 . 31 A 0 . 44 A 0 . 36 A 0 . 46 A 0.08 B 1 0. 12 B 0 . 22 B 0. 12 B 0 .14 B 0 . .12 B 0 .20 B 0 .12 B 0 .15 B or .12 B 0. 52 C 0, 44 B 0. . 52 C 0. 63 0 0. . 51 C 0. .69 D 0 . 69 D 0 . 57 C 0 . 51 D 0 . 57 C 0. 21 A 0. 15 A 0. . 20 A 0. 17 B 0. . 20 A 0. .17 B 0 .13 B 0 . 17 B 0 .21 B 0 .15 B 0.26 A 0. 15 A 0. 26 A 0. 14 A 0. . 26 A 0. .14 A 0 .19 A 0 .14 A •OS .26 A 0. .15 A 0.83 D 0. 65 B 0. 93 E 0. 88 D 1. .27 F 1. 01 F 0 .66 B 0. . 34 A 0 . 59 B 0. . 54 A 0.52 D 0. 75 E 0. .94 E 0. 73 E 1. . 09 F 1. 04 F 0 . 79 E 0 . 42 e 0, . 87 E 0. .93 E 0.11 A 0 . 22 C 0. . 27 D 0. 20 D 0. . 27 D 0. . 28 D 0 . 16 A 0 .13 B 0, .10 A 0. .25 D 0.34 A 0. 32 A 0. . 49 A 0. 52 A 0. . 64 B 0. .62 B 0 . 34 A 0 . 30 A 0. . 47 A 0. . 42 A 0 . 42 A 0 . 36 A 0 . 46 A 0. 44 A 0. . 57 A 0. . 54 A 0 .46 A 0 . 41 A 0. .66 B 0 . 38 A 1. 05 F 0. 37 C 1. . 22 F 0. 60 D 1. . 30 F 0 .99 E 0 . 46 C 0 .16 A 0. .63 C 0 .17 A 0. 23 D 0 . 14 D NO DATA AVAILABLE NO DATA AVAILABLE 0.18 C 0. 26 C 0. .22 D 0. 12 A 0. . 28 D 0. .14 A 0 .27 D 0 . 25 C 0 . 33 D 0 . 35 C 0. 68 B 0. 62 B NC > DATA AVAILABLE NO DA' TA AVAILABLE 0. 55 C 1. 27 F 0. 38 C 1. 04 F 0. 56 D 0. 96 F 0 . 83 E 1 .01 F 0. .83 E 1, . 07 F 0. 50 A 0. 63 B 0. 60 A 0. 71 C 0. 69 B 0. 78 C 0 . 58 A 0 .68 B 0 .69 B 0. .76 C 0 . 64 B 0. 95 E 0. 77 C 0. 81 D 0. 94 E 0. 99 E NA NA NA NA 1.15 F 0. 89 D 1. 33 F 1. 20 F 1. 37 F 1. 24 F 1. . 40 F 1. 26 F 1 .45 F 1. 41 F NA NA NA NA NA NA 0. . 64 B 0. 51 A a. 83 D 0. 59 A NA HA NA NA NA NA 0. . 44 B 0. 67 C 0. 78 C 1. 18 D NA NA NA NA NA NA 0. . 47 C 1. 45 F 0. 84 E 2. 00 F 0. 69 B 0. 86 D 1. 04 F 0. 71 C 0. 97 F 0. 90 E 0 . 38 A 0 . 55 A 0 . 37 A 0 .59 A 0.57 F 0.73 F 2. 00 F 1. 34 F 1. 73 F 1. 77 F 0 .64 B 0 . 67 B 0 . 67 B 0 . 58 B 0.94 E 0.34 D 1. 54 F 1. 24 F 1. 36 F 1. 33 F 0 .79 C 0 .65 B 0 .81 D 0 .65 B 2. 00 F 2.00 F 2. 00 F 2.00 F 2. 00 F 2. 00 F 0 . 59 A 0 . 79 C 0 . 60 B 0 .80 0. 89 D 0.30 C 1. 42 F 0.93 F 1. 42 F 0. 81 F 0 .19 A 0 . 35 A 0 . 23 A 0 . 37 A 0.65 B 0.32 D 0.64 B 0.72 C 0.68 B 0.77 D 0 . 39 A 1 . 18 F 0 . 42 A 1 . 13 F 2. 00 F 2.00 F 2. 00 F 2. 00 F 2. 00 F 2. 00 F 0 .91 E 0 .65 B 1. .12 F 0 .73 C 1. 89 F 2.00 F 2. 00 F 2. 00 F 2. 00 F 2.00 F 0 . 65 B 0 .52 A 0 . 79 C 0 .59 A 0.96 E 0. 75 C 1.09 F 0.92 E 0. 99 F 0.80 E 0 . 92 E 0 . 76 C 0 .87 E 0 .80 D 0.54 A 0.71 c 0.68 B 0.85 D 0.89 D 0.70 D 0. . 58 A 0 . 33 A 0. 63 B 0. . 38 A 0. 81 D 1. 20 F 1. 08 F 1.26 F 1. 06 F 1.28 F 1. 03 F 1. 45 F 1. 22 F 13 F 0. 77 C 1. 00 E 1. 12 F 1. 37 F 1. 01 F 1.43 F 0. 86 D 1. 04 F 0. 67 D 1 . 13 F 2. 00 F 2 . 00 F 0. 81 D 0.91 0. 76 D 0.85 E 0 . 83 D 0. 87 D 0 . 85 D 0. 89 D 0.65 B 0.44 A 0.65 B 0.44 A 0.65 B 0.63 B 0. 58 A 0. 38 A 0. 75 C 0. 42 A 0.82 D 0. 58 F 0. 88 D 0. 69 F 0.82 D 0. 71 2 00 F 1. 91 F 1. 78 F 2 , 00 F 0.29 A 0. 54 F 0.52 A 0.57 F 0. 49 A 0.60 F 0. 62 B 0. 73 C 0. 75 C 0. 75 C NA NA NA NA NA NA 2 . 00 F 2. 00 F 2. 00 F 2. 00 F 0 . 63 E 0.53 E 0.93 E 0.20 C 0. 51 E 0. 40 C 0 . 23 B 0. 22 C 0. 24 B 0 . 20 C 0. 39 A 0. 47 A 0. 74 C 0.71 C 0. 65 C 0. 68 C 0. . 16 A 0. 36 A 0. 17 A 0. 38 A 0. 51 A 0.67 B 0.99 E 0.85 D 0.71 E 0.91 E 0. 55 A 0. 32 A 0. 50 A 0. 33 A 0. 75 C 0.26 F 0. 85 D 0 . 40 F 0.85 D 0. 45 F 1. 65 F 1 . 39 F 33 F 1. 40 F NA NA NA NA NA NA 0. 99 E 0. 94 E 1. 22 F 0. 99 E NA NA NA NA NA NA 0. 92 E 0. 68 B 0. 75 E 0. 70 C NA NA NA NA NA NA 0. 91 E 0. 76 C 1 04 F 0. 84 D NA NA NA NA NA NA 0 . 63 B 0. 90 D 0 . 53 B 05 F Table 32 LEVEL OF SERVICE TOTALS REGIONAL HIGHWAY NETWORK* 1990 AM PEAK Level of No- Build Alt. Preferred Alternative Service 1982 Exist. Rdwys. Proj. Rdwys. A-D 24 (44) 23 (42) 30 (84) 52 (87) E 9 (17) 8 (15) 4 (11) 5 ( 8) F 21 (39) 23 (43) 2 ( 6) 3 ( 5) TOTAL 54 (100) 54 (100) 36 (100) 60 (100) 1990 PM PEAK Level of No-Build Alt. Preferred Alternative Service 1982 Exist. Rdwys. Proj. Rdwys. A-D 22 (41) 21 (39) 23 (64) 50 (83) E 4 (7) 2 (4) 5 (14) 6 (10) F 28 (52) 31 (57) 8 (22) 4 ( 7) TOTAL 54 (100) 54 (100) 36 (100) 60 (100) 2010 AM PEAK Level of No-Build Alt. Preferred Alternative Service 1982 Exist. Rdwys. Proj. Rdwys. A-D 24 (44) 19 (35) 22 (61) 47 (79) E 9 (17) 6 (11) 6 (17) 8 (13) F 21 (39) 29 (54) 8 (22) 5 ( 8) TOTAL 54 (100) 54 (100) 36 (100) 60 (100) 2010 PM PEAK Level of No-Build Alt. Preferred Alternative vice 1982 Exist. Rdwys . Proj . Rdwys . A-D 22 (41) 19 (35) 20 (56) 46 (77) E 4 (7) 3 (6) 8 (22) 9 (15) F 28 (52) 32 (59) 8 (22) 5 ( 8) TOTAL 54 (100) 54 (100) 36 (100) 60 (100) * xx = No. of intersections in the category; (xx) = % of intersections in the category. 193 As summarized in Table 33, without the project, 2010 AM and PM peak hour levels of service and v/c's will remain the same or degrade further on the selected highway links, as traffic increases. The one excep- tion will be the Mystic-Tobin Bridge. Its AM peak hour level of service will improve from LOS F to LOS E due to the MDPW's Central Artery North Area Project . In 2010 with the No-Build Alternative, both the Callahan and Sumner Tunnels will operate at LOS F during the AM and PM peak hours. The Preferred Alternative will improve this operation to LOS D or better in the Callahan Tunnel during both peak hours; in the Sumner Tunnel, AM peak operations will improve to LOS E; PM peak operations to LOS C. On the Central Artery/Southeast Expressway, in both the 2010 AM and PM peak hours, current LOS E or LOS F conditions will still prevail with the No-Build Alternative, but with higher v/c ratios and more traffic diversions to parallel roadways. With the Preferred Alternative, Central Artery operations will improve generally to LOS C or LOS D in the peak hours by 2010. A few locations will still experience LOS E operations during the peak hours, but the dura- tion of congestion at these locations will be reduced considerably compared to the No-Build Alternative. As an indication of the in- creased congestion expected on the major study area facilities, an estimate of the number of congested hours of operation (LOS E or LOS F) has been made for the No-Build Alter- native in 2010, and is presented in Table 34; also presented in Table 34 are similar estimates of congested hours of operation with the Preferred Alternative. With the exception of the Southeast Expressway (which is not being improved with this project), in 2010, the Preferred Alternative substantially reduces the hours of congested operations on major highways in the project area. South Boston Intersections V/C's ai l LOS A summary tabulation of the South Boston study area intersecti cause some traffic to divert to loil streets in an effort to avoid this congestion. East Boston and Revere Intersectio n V/C and LOS A summary tabulation of the East Boston and Bell Circle (Rever) study area intersections, by levels service values, is contained in Tale 36. This summary table was preparJ from Table 31. From Table 36, overall leveB of service and v/c's without proje: improvements will degrade between M and 2010 during both peak hours. ii» new traffic, primarily related to airport growth, is expected to spil 194 Table 33 REGIONAL HIGHWAY NETWORK LEVEL OF SERVICE SUMMARY PREFERRED VS. NO-BUILD ALTERNATIVES 1982 2010 No-Build Alt Pref . Alt. AM Ppalc PM Peak AM Peak PM Peak AM Peak PM Peak IJ *t6u nignway ijiruvo r jtional Level of ir .ce ~ worst case t rstate Route 93 F C F c F C s LC-Tobin Bridge F C E E B B 0 row Drive, W. of Copley Sq. C C C C D D r. -al Artery, No. of Tunnels E-F E -F E-F E-F D C 1 ihan Tunnel pi i? r F F c U IT jr Tunnel TP Ei r F F E T. :al Artery, So. of Tunnels T? — V £ F F El n .1 1 Harbor Tunnel — c c m achusetts Turnpike n B E C E c >u least Expressway F E -F F F F F e 1A, No. of Airport A A A A-B c c cted Highway Ramps :lntic Ave. On-Ramp id Central Artery NB F F F F c E ahan Tunnel Off-Ramp :: m Central Artery NB F F F F :crow Drive Off-Ramp 7r m Central Artery NB C C E C E* E* :c row Drive Off -Ramp 1 m Central Artery SB F F F F F C i ah an Tunnel Off -Ramp ti m Central Artery SB F F F F E E lamp to Storrow Drive and Causeway Street. : 195 Table 34 NUMBER OF HOURS OF CONGESTED OPERATIONS 1982 2010 Existing No-Build Preferre - ROADWAY Alternative Alternatie Sumner Tunnel 5 14 1 Callahan Tunnel 5 14 0 Third Harbor Tunnel (Inbnd) - NA 0 Third Harbor Tunnel (Outbnd) - NA 0 Mystic-Tobin Bridge (Inbnd) 1 1 0 Mystic-Tobin Bridge (Outbnd) 0 0 0 Interstate 1-932 (inbnd) 0 0 0 Interstate 1-93 (Outbnd) 0 0 0 S.E. Xway @ Southampton St (Inbnd) 4 9 10 S.E. Xway @ Southampton St (Outbnd) 4 13 16 Mass. Tpk.b (inbnd) 0 0 1 Mass. Tpk. (Outbnd) 0 0 0 Artery, No. of Tunnels (NB) 8 12 2 Artery, No. of Tunnels (SB) 4 8 2 Artery, So. of Tunnels (NB) c 5 13 2 Artery, So. of Tunnels (SB) c 5 12 2 Storrow Dr., W. of Copley Sq. (Inbnd) 2 2 2 Storrow Dr., W. of Copley Sq. (Outbnd) 0 0 0 Route 1A, No. of Airport (Inbnd) c 0 0 0 Route 1A, No. of Airport (Outbnd) 0 0 0 High-Level Bridge (Inbnd) 4 5 0 High-Level Bridge (Outbnd) 8 6 0 a LOS E or F b Beyond influence of Xway/Artery c Beyond influence of downstream congestion 196 Table 35 LEVEL OF SERVICE COMPARISONS SOUTH BOSTON INTERSECTIONS* 1982 AM PEAK iyy u am PEAK Level of Service Existing No -Build Pref . Alt. A-D 10 (67) 4 (26) 11 (55) E 1 (7) 4 (27) 5 (25) F 4 (26) 7 (47) 4 (20) TOTAL 15 (100) 15 (100) 20 (100) 1982 PM PEAK 1 QQn PM PIT AV Level of Service Existing No- -Build Pref. Alt. A-D 10 (67) 8 (53) 13 (65) E 0 (0) 1 (7) 2 (10) F 5 (33) 6 (40) 5 (25) TOTAL 15 (100) 15 (100) To (TOO) 1982 AM PEAK 2010 AM PEAK Level of Service Existing No -Build Pref. Alt. A-D 10 (67) 4 (26) 11 (55) E 1 (7) 4 (27) 3 (15) F 4 (26) 7 (47) 6 (30) TOTAL 15 (100) 15 (100) 20 (100) 1982 PM PEAK 2010 PM PEAK Level of Service Existing No -Build Pref. Alt. A-D 10 (67) 7 (47) 12 ( 60) E 0 (0) 2 (13) 2 (10) F 5 (33) 6 (40) 6 (30) TOTAL 15 (100) 15 (100) 20~ (100) * xx = No. of intersections in the category; (xx) = % of intersec- tions in the category. 197 over onto local streets in East Boston. Bell Circle in Revere will continue to operate at LOS F with the Preferred Alternative, but congestion will last longer due to its higher v/c ratio. The Preferred Alternative will produce an overall improvement in LOS at selected East Boston and Revere intersections. Much of this improve- ment results from the removal of through traffic from the local streets of East Boston which would otherwise be taking short-cuts to the Sumner Tunnel, from the Callahan Tunnel, and to and from Logan Airport. This traffic is diverted back onto Route 1A and the main Logan Airport access roads. Downtown Boston Intersections V/C's and LOS Level of service values for study area intersections in downtown Boston are contained in Table 37. This tabulation was prepared from Table 31. From Table 37, without the project, selected intersections in downtown Boston will experience an overall degradation in level of service and v/c's between 1982 and 2010 during both peak hours, as traffic increases in the downtown Boston area. In 2010, the Preferred Alterna- tive reduces the percentage of se- lected intersections operating at LOS F during both AM and PM peak hours. In addition, Leverett Circle operates at an improved LOS relative to the No-Build Alternative. In the 2010 AM peak hour, an improvement from LOS F to LOS E is realized, while the improvement in the PM peak is from LOS F to LOS D . 4.2.4 Central Artery Bottlenecks and Congestion Points Without the Project Existing and future Central Artery/Southeast Expressway bottle necks and congestion points with ti No-Build Alternative were discusse* 1 Section 3.1. The Preferred Alternative vs. the No-Build Alternative Table 38 lists the individu, queue lengths, in miles, for the Preferred Alternative and the No-Bi 1 Alternative at each major congestiu point along the Central Artery and Southeast Expressway between the High-Level Bridge and Columbia Cir.e for 1990 and 2010 AM and PM peak h'.ft as well as by direction (northboun and southbound) . As Table 38 indicates, bott - necks and congestion points differ considerably by direction and peak hour. Each individual queue lengt! represents a calculated build-up o vehicles behind a congestion point The calculations for queue lengths were based on the geometric roadwa; configuration, number of lanes, anticipated traffic volumes, lengtl of traffic weaving sections, and r| locations. While these individual queues are not additive where they overlap, overall queue formations develop due to the interaction of various congestion points, with th< longest queue prevailing. However obtaining information about the individual congestion point queues s also critical to the analysis of biK alternatives. It not only provided basis for comparing the overall effectiveness of each alternative » reducing individual queues, but is required for optimizing a highway design under the situation where secondary queues would remain aftei primary queue source is mitigated (e.g., elimination of the High-Lev< Bridge bottleneck, the primary quei source on the Central Artery). This section discusses and compares individual queues and cone tion points for the Preferred and No-Build Alternatives in 1990 and $ Table 36 LEVEL OF SERVICE COMPARISONS EAST BOSTON/REVERE INTERSECTIONS (INCL. BELL CIRCLE)* 1982 AM PEAK 1990 AM PEAK Level of Service Existing No -Build Pref . Alt. A-D 16 (89) 12 (75) 15 (83) E 0 (0) 2 (13) 2 (11) E 2 (11) •5 A nil i X TOTAL 18 (100) 16 (100) 18 (Too) 1982 PM PEAK 1990 PM PEAK Level of Service Existing No- -Build Pref. Alt. A-D 15 (83) 13 (81) 15 (83) E 2 (11) 1 (6) 0 (0) F 1 (6) 2 (13) 3 (17) TOTAL 18 (100) 16 (Too) Tb (Too) 1982 AM PEAK 2010 AM PEAK Level of Service Existing No- -Build Pref. Alt. A-D 16 (89) 11 (69) 14 (77) E 0 (0) 1 (6) 3 (17) F 2 (11) 4 ( 25) 1 (6) TOTAL 18 (100) 16 (100) Ti (Too") 1982 PM PEAK 2010 PM PEAK Level of Service Existing No -Build Pref. Alt. A-D 15 (83) 10 (62) 14 (77) E 2 (11) 2 (13) 1 (6) F 1 (6) 4 (25) 3 (17) TOTAL 18 (100) 16 (100) 18 (Too") * xx = No. of intersections in the category; (xx) = % of intersec- tions in the category. 199 Table 37 LEVEL OF SERVICE COMPARISONS DOWNTOWN BOSTON INTERSECTIONS* 1982 AM PEAK 1990 AM PEAK Level of Service Existing No -Build Pref . Alt. A-D 12 (60) 8 (40) 16 (64) E 3 (15) 2 (10) 5 (20) F 5 (25) 10 (50) 4 (16) TOTAL To (100) 20 (100) 25* (100) 1982 PM PEAK 1990 PM PEAK Level of Service Existing No -Build Pref. Alt. A-D 9 (45) 7 (35) 18 (72) E 2 (10) 2 (10) 1 (4) F 9 (45) 11 (55) 6 ( 24) TOTAL To (Too) 20 (TOO) 25 (100) 1982 AM PEAK ZU1U AM Level of Service Existing No -Build Pref. Alt. A-D 12 (60) 8 (40) 16 (64) E 3 (15) 2 (10) 2 (8) F 5 (25) 10 (50) 7 (28) TOTAL 20 (100) 20 (Too) 25 (100) 1982 PM PEAK 2010 PM PEAK Level of Service Existing No -Build Pref. Alt. A-D 9 (45) 5 (25) 17 (68) E 2 (10) 4 (20) 1 (4) F 9 (45) 11 (55) 7 (28) TOTAL To (100) To (100) ~25 (TOO) * xx = No. of intersections in the category; (xx) = % of intersec- tions in the category. 200 Table 38 INDIVIDUAL QUEUE LENGTH COMPARISONS BY ALTERNATIVE* 1990 QUEUES (in miles) 2010 QUEUES (in miles) 2 sway /Artery ; Source jound :nbia Rd. On-Ramp 3. Ave. On-Ramp i. Pike Off -Ramp 5. Pike On-Ramp nern Ave. or -lantic Ave. On-Ramp AM 0.5 1.0 0.9 0.9 0.5 ahan Tunnel Off-Ramp** 0 :row Drive Off -Ramp 0 Level Bridge (1-93) 0 0.6 0 1.2 0 0 0 0 0 PM AM 0 0 0 0 0.8 0.5 0 1.9 0 0 0 0 0 0 0 0 0.5 1.3 0.9 1.2 0.8 0.1 0 0 0.6 0 1.2 0 0 0 0 0 PM No- Pref. No- Pref. No- Pref. No- Pref Build Alt. Build Alt. Build Alt. Build Alt. 0 0 0.1 0.1 0.9 0.7 0 2.0 Bound -Level Bridge (1-93) 1.4 row Dr. Ramps 0 •ahan Tunnel/ ymarket Off -Ramp 5 arket On-Ramp hase/Congress -Ramp I . Pike On-Ramp ^ny St. On-Ramp . Ave. On-Ramp •mbia Rd. On-Ramp 0.3 0.6 0 0 0 0 0 0 0 0.3 0.5 0.5 1.5 0.6 0.5 0.1 0 0 0 0 0 0.2 0.6 0.6 0.1 3.2 0.3 0.3 0.8 0 0 0 0 0 0 0.7 0 0 0 0 0 0 0 0 0 0.3 0.5 0.6 1.5 0.6 0.5 0.1 0 0 0 0.1 0 0.2 0.6 0.9 0.2 l s are not additive where overlaps occur. See text for further explanation, |r the Preferred Alternative, this ramp exits to the Surface Artery. 201 Year 1990 Northbound in the AM peak hour, the only source of congestion with the Preferred Alternative is the Columbia Road on-ramp which creates a 0.6 mile queue on the Southeast Expressway. The No-Build Alternative generates a similar 0.5 mile queue at this location. In addition, the No-Build Alternative generates queues at both Massachusetts Turnpike on- and off- ramps (0.9 miles each), as well as a 1.0 mile queue at the Massachusetts Avenue on-ramp, and a half mile queue at the Northern Avenue or Atlantic Avenue on-ramp. Northbound in the PM peak hour, the Preferred Alternative does not generate any queues. With the No- Build Alternative, the High-Level Bridge generates the longest queue of any location and time period in 1990 — 1.9 miles. Also, northbound in the PM peak hour, a substantial queue of 0.8 miles is generated at the Northern Avenue on-ramp with the No-Build Alternative. These queues are elim- inated with the Preferred Alterna- tive. While non-existent with the Preferred Alternative, the No-Build Alternative generates a half mile queue at the Callahan Tunnel off-ramp. Southbound in the AM peak hour, again no queues will be generated with the Preferred Alternative. The High-Level Bridge (as it does north- bound in the PM peak hour) generates a long queue with the No-Build Alter- native. This queue is distributed approximately 40 percent to the Mystic-Tobin Bridge (0.6 miles) and 60 percent to Interstate Route 93 south- bound (0.8 miles). This bottleneck and its associated queue are elim- inated with the Preferred Alterna- tive. The Preferred Alternative eliminates a 0.3 mile queue at the Callahan Tunnel/Haymarket Square off-ramp as well as a 0.6 mile queue expected at the Haymarket Square on-ramp with the No-Build Alternative. Southbound in the PM peak hour, the primary 1.5 mile queue found at the Massachusetts Turnpike on-ramp with the No-Build Alternative is reduced to 0.2 miles with the Pre- ferred Alternative. The No-Build Alternative and the Preferred Alterii tive will generate roughly equivalei queues at the Massachusetts Avenue, Albany Street, and Columbia Road on-ramps. Queues of 0.5 mile each produced with the No-Build Alternat at the Haymarket and Purchase Streei' Congress Street on-ramp merges are eliminated with the Preferred Alteri tive. A 0.3 mile queue at the CalL han/Sumner Tunnels and Haymarket off-ramp is also eliminated with th< Preferred Alternative. Year 2010 As noted previously, Table 3! lists the primary individual conges tion points and queue lengths for 2(0 traffic conditions. With few excep- tions, year 2010 traffic conditions will generate queues that are eithei longer or approximately equivalent t 1990 queues. The discussion below focuses on the most significant changes between the analysis years. Northbound in the AM peak hoi, again, the only queue that will be generated with the Preferred Alternc tive will occur at the Columbia Roac on-ramp; the queues generated at thi location with both the Preferred Alternative and the No-Build Alternc tive are the same length as expected- in 1990. Other queues anticipated with the No-Build Alternative either lengthen or remain the same as ex- pected in 1990. A 0.1 mile queue nc expected in 1990 will be generated with the No-Build Alternative at the Callahan Tunnel entrance from the Central Artery. Northbound in the PM peak hou, again, the Preferred Alternative doe not generate any queues. However, No-Build Alternative queues from the High-Level Bridge, as well as the Northern Avenue on-ramp, lengthen considerably . Southbound in the AM peak hou the High-Level Bridge is again ex- pected to generate a very long queue 202 i;ributed between Interstate Route 3 1.9 miles) and the Mystic-Tobin r;ge (1.3 miles) with the No-Build Urnative. This queue is eliminated it the Preferred Alternative. o»ver, the Storrow Drive ramps with h< Preferred Alternative are expected 0 enerate a 0.7 mile queue, distri- uld 60 percent to Interstate Route 3|nd 40 percent to the Mystic-Tobin r:jge, not found in 1990. Southbound in the PM peak hour, s hown in Table 38, queues are 1 lar to those generated in 1990, ui slightly longer in some cases for o: alternatives. . 5 Issues Concerning Traffic Forecasts This subsection has been r. I uded to clarify the technical e sion made during the EIS/EIR cung process to examine all alter- aives in the context of a fixed e 3l of economic activity in the Lysis years; this assumption ; jits in a fixed number of person : as for all alternatives. To generate future traffic oames, the methodology used to =cast future traffic assumes the «fs land use or socio-economic 'aterns with the Preferred and lo3uild Alternatives. For the trip lesration and trip distribution phase •fthe traffic assignment process, re is a technical consensus that icitional information obtained by ing new variables (i.e., differing i use and socio-economic variables ^alternative) into the process is warranted. The actual differences ween separately created trip tables relatively minor. An early :ehnical decision was therefore made, I confirmed in the EIS/EIR scoping cess, not to try to incorporate o the trip tables the effect of ferent land use and socio-economic i jections that may result from ferent highway alternatives. Traffic assignments were "^refore based on a fixed land use if socio-economic scenario for each analysis year. Results obtained by applying the traffic assignment model in this manner reflect traffic opera- tions under traffic demands which would occur with all other things being equal. This approach maintains a supportable, internally consistent basis for decision making. It is important to realize that the results of the fixed land use/ socio-economic data traffic assign- ments have been coordinated closely with — and have had an effect on — the land use and socio-economic analyses documented in other subsec- tions of this FEIS/FEIR. The land use/economic activity forecasts implicitly assume that the future transportation system will be able to serve the forecasted land use/economic activities. Such an assumption is consistent with the characteristics of the Preferred Alternative. However, there is a strong possibility that the severe congestion projected with the No-Build Alternative will constrain expected land use changes and economic growth in downtown Boston. Thus, with the No-Build Alternative, the level of trip-making may be constrained by the lack of capacity within the highway network feeding the Boston core area. Additional Vehicle Trips The fixed socio-economic conditions assumed for 1990 and 2010 analysis years result in a fixed number of person trips (i.e., a fixed trip table) occurring within the study area for each analysis year. For the Preferred Alternative (and all alter- natives which include a new tunnel), this means that a fixed number of additional vehicle trips were assigned to the regional and local highway network, while keeping the number of person trips the same as with the No-Build Alternative. While the Preferred Alternative increases the number of vehicle trips to and from Logan Airport, the number of trips to and from locations in downtown Boston, East Boston and South Boston are not expected to increase compared to the No-Build Alternative. 203 Consequently, the reduced cross-harbor congestion resulting from the Pre- ferred Alternative is expected to divert Logan Airport traffic away from higher occupancy vehicles (i.e., from carpools, vanpools, taxis, and limou- sines) to the private automobile by an estimated 12,800 additional vehicles daily (6,400 vehicles going to the Airport and 6,400 vehicles coming from the Airport). However, preferential treatments for high occupancy vehicles have been incorporated into the design of the Preferred Alternative to minimize diversions from transit and Airport limousines. Improvements to the regional highway system with the Preferred Alternative actually will reduce the amount of short-cutting which now occurs in East Boston, south Boston, and downtown Boston. Therefore, vehicle trips overall, on the study area local street system with the Preferred Alternative, are expected to be reduced compared to the No-Build Alternative. These vehicle trip reductions are accounted for in vehicle diversions to the regional highway network. Impact of Diverted Trips With the Preferred Alternative, of the 534,000 daily vehicle trips assigned to and through downtown Boston, less than one percent would be diversions from transit. However, due to the provision of the new bus lanes to and from the Airport, and to and from South Station, there will be significant opportunity to develop new highway dependent transit services (i.e., bus services) which will partially offset this initial loss. In addition, of the 263,000 daily trips assigned to the Central Artery, less than one percent have been diverted from Route 128 and beyond. Of the additional trips assigned to the Artery, the overwhelming majority will be diverted from local streets and arterials in the immediate study area — East Boston, South Boston and Downtown Boston. The traffic diversion component (8,800 vehicles per day) of the cross-harbor traffic increase (22,60 vehicles per day) with the Prefers Alternative primarily results from more traffic using the harbor facili- ties to gain access to the Airport, rather than local streets in East Boston or Chelsea because of the increased capacity, and improved traffic service potential (i.e., decreased travel times) on main lir routes versus local streets. As outlined in the preceding subsections, with the Preferred Alternative, traffic volumes calculated for the year 2010 will fow under somewhat less congested conditions than volumes recorded ir 1982. The expected level of congestion in the year 2010 with th Preferred Alternative is similar tc what has been experienced over the past two decades — a period of substantial economic growth in downtown Boston. 4.2.6 Vehicle Miles Travelled , Vehicle Hours of Travel, and Person Hours of Travel Vehicle Miles of Travel (VMT, Vehicle Hours of Travel (VHT) and Person Hours of Travel (PHT) are thee very important indices with which t evaluate the effectiveness of alternative transportation improvements. The study area for ec of these three indices includes the communities of Boston, Brookline, Cambridge, Chelsea, Everett and Somerville. These are the community most likely to be affected by the proposed changes in the highway network. [In the EIS process, calculations for these three indice were also made for a "full region" network, which covers a geographic area generally defined by the Route 128 communities.] All calculations are based on the year 2010 "design year " . Vehicle Miles of Travel (VMT is a measure of the total distance travelled by all vehicles on a stud area roadway system. Public policy 204 particularly since the oil shortages f the early 1970's] tends to seek to minimize the amount of vehicle miles - ravelled. However, by virtue of the :. mp roved characteristics of "supply" t, temming from a major highway mprovement, increased "demand" for ravel often results from major ighway improvements. Changes in VMT re an index of the increased amount if vehicular travel expected as the esult of a major highway improvement. Vehicle Hours of Travel (VHT) .s a summary of the change (usually :he decrease) in the total hours of ■ ravel of all the vehicles on a study irea roadway system. VHT calculations ire utilized in the calculations of inergy consumption, and can be used in :: macro-scale air quality impacts. To ;: calculate changes in Vehicle Hours of ! Travel, the aggregate hours of travel jf all the vehicles on the "build" letwork [including those vehicles "induced" or added to the network by virtue of its improved characteristics] are compared with the aggregate hours of the vehicles on the "no-build" network. In the Preferred Alternative, it has been forecast that I there will be 12,80U more vehicle trips on the "build" network than on : 'the "no-build" network. Person Hours of Travel (PHT) is an index which allows the summary -comparison of the effectiveness of 'alternative highway improvements, examined in terms of their ability to carry a common (fixed) number of trips. While vehicle hours of travel (VHT) calculations summarize the change in total hours of vehicle operation, PHT calculations are designed to reveal the efficiency of a candidate highway improvement to accommodate a given number of person trips. In the study area, the average vehicle carries 1.46 persons . PHT summaries show how well each alternative performs the task of carrying a fixed number of trips. For the purposes of this analysis, the "build" trip table is used throughout. Tne Preferred Alternative is compared with the Base Case for each of the three indices, below: Base Case Annual VMT = 3,302.9 million miles Annual VHT = 150.1 million hours Annual PHT = 223.4 million hours Preferred Alternative Annual VMT = 3,320.6 million miles Annual VHT = 140.9 million hours Annual PHT = 205.8 million hours Differences - Preferred Alternative vs. the Base Case Annual VMT = +17.7 million miles Annual VHT = -9.2 million hours Annual PHT = -17.6 million hours The Results . Consistent with most highway improvements, implementation of the Preferred Alternative will increase total VMT in the study area by about 17.7 million miles per year. This increase represents about 1-1/2 percent of the study area VMT, and about 1/2 of 1 percent of the full (128 region) network. in terms of VHT, it is forecast that, even with the addition of 12,800 new trips daily to the highway network, total number of hours of vehicle operation will decrease by 9.2 million in the study area. These two findings (VMT increases, while VHT decreases) are not inconsistent. The data shows that some individual motorists will change their routes in order to minimize travel time, using the new highway segments, in some cases, these new routes will be longer in terms of distance than the previous routes taken. In addition, some 12,800 new vehicle trips are added to the system, further contributing to the increase in VMT. The VHT statistics show that the total number of vehicle hours of operation will decrease by 9.2 million per year, in spite of the fact that there are 12,800 new trips being taken in the Preferred Alternative. This implies that the reduction in travel 205 time for the original vehicles (i.e., those in the base case) is 9.2 million hours greater than the additional hours of operation of the new vehicles to the system. The PHT statistics show that the Preferred Alternative carries its projected volume of vehicles with 17.6 million fewer person hours of travel than the Base Case highway network would carry that same number of vehicles, as shown previously in Table 28. The PHT statistics are used in calculating the level of travel time savings, or "user benefit", for each of the alternative highway improvements tested. The Preferred Alternative also shows a decrease of approximately 6.1 percent in total vehicle hours of travel and a 7.9 percent decrease in person hours travelled when compared to the No-Build Alternative. This reduction results from increased travel speeds made possible because of increased capacity (and resulting improved levels of service). In addition, the increased capacity and improved service of a depressed Central Artery also encourages "through" motorists to stay on the Central Artery, rather than divert to parallel local streets. 4.2.7 safety Accident Potential Highway System Table 39 summarizes predicted yearly accidents along the Central Artery/Southeast Expressway, including approaches to the existing and Third Haroor Tunnels, and to the existing and proposed tunnel approaches in East Boston for the No-Build and Preferred Alternatives. For comparison pur- poses, the average annual number of accidents occurring at these locations between 197b and 1980 is also con- tained in Table 39. Discussions of existing acci- dent history on these major highway sections, as well as predicted 1990 and 2010 accident potential withot the project (No-Build Alternative, are contained in Section 3.1.3 SAFETY . in summary, total accidets on the major highway sections are estimated to increase over existig levels by 9 percent in 1990 and 2 percent in 2010. The increases rs from increased traffic on the roaw: network . The Preferred Alternative reduces accident potential on the regional highway system in 1990 b percent, and in 2010 by 27 percen compared to the No-Build Alternatve Local Roadway System Projections of future acciet potential at local intersections n- ; South Boston, East Boston, and don- town Boston are summarized in Tabe 40. Existing accidents (1978-198 average) are also included in Tabe for comparison purposes. Discussions of existing aci- dent history and predicted accidet potential for 1990 and 2010 withot the project (No-Build Alternative* were also contained in Section 3..: In summary, total annual accident I the selected intersections in Soun Boston will increase by 17 percen 1990 and 24 percent 2010 with the i No-Build Alternative. increases c« due to predicted regional traffic, \ growth and new traffic generated p proposed developments in South Bo- ton. In East Boston, the growth l total number of accidents at the selected intersections will be mosij modest, with values of 5 percent 3t 1990 and 12 percent in 2010. The I highest percentage growth in the I number of accidents expected to o:l will be for the selected intersecil in downtown Boston, reflecting th major increases in traffic predicij for local streets in that area, m percentage growth in accidents pr>l dieted in downtown Boston is 24 percent by 1990 and 32 percent by ! 2010. For the selected intersect* in South Boston, East Boston, and i Downtown Boston combined, acciden' . potential with the No-Build AlterM 206 "0 ■'6 :e re :ii Table 39 FUTURE REGIONAL HIGHWAY SYSTEM ACCIDENT SUMMARY Average No-Build Preferred Existing Alternative Alternative 1978-1980 1990 2010 1990 2010 . Artery Section 1* 381 454 470 337 360 Section 2* 235 260 284 165 186 Section 3* 197 201 232 134 151 Section 4* 200 203 206 181 199 SUBTOTAL 1013 1118 1192 817 896 : st Boston nnel Approaches TOTAL Section 1 Section 2 Section 3 Section 4 159 1172 164 226 91* * 141* * 1282 1418 908 1037 Rte I-93/Rte 1 to Causeway Street South of Causeway Street to Callahan/Sumner Tunnels South of Tunnels to Beach Street Kneeland Street to Southampton Street Includes estimated future accidents on Third Harbor Tunnel and its approaches . 207 Table 40 FUTURE LOCAL ROADWAY SYSTEM ACCIDENT SUMMARY Average No- ■Build Preferred Existing Alternative Alternativ< 1978-1980 1990 2010 1990 201(1 South Boston Columbia Road/Old Colony Ave./ Day Blvd. 11 14 15 9 9 j 1 Andrew Square 8 11 12 8 9 Columbia Road/Day Blvd./L St. 5 5 5 4 4 L St. /Summer St./E. First St. 7 9 9 9 9 Dorchester Ave./W. Broadway 9 9 10 14 15 Summer St - /T) St 10 10 10 11 12 Dorchester Ave./W. Fifth St. /A St. 10 9 10 11 14 Dorchester Ave./W. Fourth St. 10 10 10 14 15 Congress St. /A St. 4 6 7 9 9 Northern Ave. /Sleeper St. 8 13 14 8 Q y SUBTOTAL 82 yo 53 1U3 East Boston uonaor St. /Meridian bt. 13 13 14 16 16 Bennington St. /Bremen St. 7 7 8 7 8 23 24 25 24 Meridian St . /Bennington St. 13 14 15 14 "2 Porter St. /Cottage St. 2 3 3 2 SUBTOTAL 58 bl bo Oj Downtown Boston Causeway St. /No. Washington St 26 31 34 18 21 Congress St. /North St. 11 14 15 10 11 New Chardon St./Merrimac St. 10 10 10 9 io A New Chardon St. /No. Washington St. 5 6 6 7 7 Sudbury St. /Congress St. 22 31 33 35 38 SUBTOTAL 74 92 98 78 86 TOTAL 214 249 265 237 257 208 I ive will increase by 16 percent by J90 and 24 percent by 2010 over cisting conditions. In general, for South Boston, le Preferred Alternative will slight- / increase the total number of :cidents in 2010 for the analyzed itersections by 3 percent when smpared to the No-Build Alternative. Within East Boston, the total umber of accidents for intersections aalyzed for the year 2010 will be the ame for both the No-Build Alternative nd the Preferred Alternative. The total number of accidents or the year 2010 in downtown Boston or the selected intersections studied ill decrease by 11 percent compared o the No-Build Alternative. Overall, for the local street etwork analyzed in South Boston, East oston, and Downtown Boston, the total umber of annual accidents for the referred Alternative in 2010 is stimated at 257 as shown in Table 0. The total for the No-Build .lternative is estimated at 265. This epresents a 3 percent improvement in afety at local intersections within he study area. Regional Highways and Local Roadways Combined Combining the accident poten- ial estimates for selected regional lighway and local roadway sections :ontained in Tables 39 and 40, acci- lent potential will be reduced by 25 >ercent in 1990 and 23 percent in 2010 :or the Preferred Alternative compared :o the No-Build Alternative. iazardous Cargoes The Preferred Alternative will iffect both the routing and safety of lazardous cargo vehicle movements ihrough downtown Boston. Routing :hanges mainly result from the depres- sion of the Central Artery into a :unnel through which passage of such 'ehicles will be prohibited. The Code of Federal Regulations (Part 397) states that "...unless there is no practicable alternative, a motor vehicle which contains hazardous materials must be operated over routes which do not go through or near heavily populated areas; places where crowds are assembled, tunnels, narrow streets, or alleys". Adhering to this code in heavily congested areas, such as downtown Boston, often involves making trade-offs. With both the Preferred and No-Build Alternatives, hazardous cargo vehicles must use existing surface streets through heavily populated areas in downtown Boston to avoid the Dewey Square Tunnel. In addition, with the Pre- ferred Alternative, hazardous cargo vehicles must also use the new Surface Artery north of the Dewey Square Tunnel to avoid the depressed Central Artery in downtown Boston. Southbound hazardous cargoes will exit the Central Artery using the Causeway Street off-ramp, and join the southbound Surface Artery traffic at Haymarket Square. Between Dewey Square and Kneeland Street, southbound hazardous cargoes will use the new Surface Artery. Northbound hazardous cargoes will also use the new Surface Artery between Kneeland Street and the Causeway Street northbound Central Artery on-ramp. The improved design features of the Preferred Alternative's new Surface Artery generally will have a beneficial impact on safety. Even though (with the Preferred Alterna- tive) hazardous cargo vehicles will encounter large numbers of pedestrians and more vehicle conflicts than on the elevated Central Artery (due to intersections and off-street access) with the No-Build Alternative, there is a higher potential for more severe accidents involving hazardous cargoes on the elevated Central Artery, particularly during the off-peak hours when speeds will be higher on the Central Artery than on the Surface Artery. Unlike downtown Boston, there 209 is no practicable, well-designed surface street routing that can be used to avoid heavily populated areas in South Boston. Rather than using local streets in South Boston, hazard- ous cargo vehicles (with the Preferred Alternative) will be using the new Seaport Access Tunnel through South Boston. The design of the new Seaport Access Tunnel incorporates various safety features which will mitigate potential problems involving hazardous cargoes (e.g., deluge pumps, automatic foamite dispenser system). These features are described in section 2.5.2 OTHER DESIGN CONSIDERATIONS . The use of this tunnel will, overall, reduce the potential for hazardous cargo vehicle accidents on local South Boston streets compared to the No-Build Alternative. Compared to a Seaport Connector, which is assumed to be constructed as a separate project with the No-Build Alternative, the Preferred Alternative diverts some 13,601) additional vehicles per day from the local streets, including some 3,000 trucks, many of which will carry hazardous cargoes. Emergency Vehicle Access The Preferred Alternative will improve access across Boston Harbor for fire, police, ambulance, and other emergency vehicles. Emergency vehi- cles, with the Preferred Alternative, will be able to respond to calls faster due to reductions in travel times on major highways, as mentioned previously. A Third Harbor Tunnel will provide an alternative travel route for emergency vehicles in the event that one or both of the existing tunnels become blocked temporarily due to an accident or other reasons. The Preferred Alternative will add one travel lane in each direction along the Central Artery. This additional capacity will serve to decrease congestion and increase travel speeds for emergency vehicles needing to use this facility. Addi- tionally, the new South Bay inter- change connections between the Central Artery/Third Harbor Tunnel/Southeast Expressway/Herald Street Extension, as well as improved connections betwen the Callahan/Sumner Tunnels, the Central Artery, and the surface stsei system with the Preferred Alternate will, in general, offer improved travel times for emergency vehicle which will also be allowed to use these ramps. The No-Build Alternative doe not offer these improved connection and resulting travel time improve- ments, since the redecking of the i existing Central Artery will not increase capacity in the project asa 4.2.8 Other Transportation Facili it Ferry Services In the long term, the No-B Alternative will most likely incr patronage on harbor ferry services used for commuter purposes. That as congestion and delays on the Central Artery and Southeast Expr way become more severe with the No-Build Alternative, additional motorists can be expected to chang modes from the private automobile commuter ferry. Since the Southea Expressway will continue to be co gested with the Preferred Alternat commuter ferry patronage should increase in a similar fashion. Logan Airport As detailed in Section 3.1 TRANSPORTATION FACILITIES , roadway connections between Boston and the airport will become more congested through 2010 with the No-Build Alt:- native. This situation will occuns traffic volumes equal or exceed capacity on Central Artery approach to the existing tunnels, the tunne; themselves, the Route 1A ramps con necting the tunnels with the Airpo access/egress roads, and the Airpo roadway system, itself. In addition, with the No-Bu d Alternative, average vehicle occu- pancies (i.e., the number of persoi per vehicle) in the tunnels bound Logan Airport will increase as mon persons divert to alternative travi 210 ;odes (e.g., the Blue Line rapid ransit system, bus services, taxis, id airport limousines), rather than . intend with the intensifying conges- Lon in one or two occupant vehicles. The traffic forecasting proce- are for this EIS/EIR assumed that the referred Alternative (as was assumed or all build alternatives including a nird Harbor Tunnel) will generate ome 12,800 more vehicle trips (6,400 o and 6,400 from Logan Airport) per ay than the No-Build Alternative in ihe year 2010; some 600 of these trips 300 each way) were assumed to be iversions from public transportation, hile the rest were diverted from ther rubber-tired vehicles. In order o deal with this forecasted impact, ihe project was redesigned to include Several features to promote and ncourage the use of public ransportation to Logan Airport, ravel forecasts show that the use of :he direct ramp connections from Logan o South Station will result in a net ncrease in public transportation idership to Logan over the No-Build Jternative. This service, combined i'ith an increase in bus/limousine service using the Preferred alternative's facilities, would ncrease total public transportation idership to the Airport by 20 percent m an average day. The Preferred Alternative will iave a major positive impact on raffic circulation and access to jogan Airport because it provides: • A more direct connection into the passenger terminal area of the Airport than does the No-Build Alternative, and eliminates the necessity of all traffic bound to and from the terminal area to pass through the signalized intersections at the existing north-south Cross Road (the No-Build Alternative defined for this EIS/EIR assumed the existence of the Cross Road intersections; Massport is currently operating an experiment to redirect traffic and eliminate the need for these two signals), and; o A new South Bay interchange, featuring an exclusive bus lane to and from the Third Harbor Tunnel, which will allow direct public transportation connec- tions to Logan Airport. These connections will allow Airport passengers to use ground transportation services which would terminate at or originate from the South Station Trans- portation Center (SSTC). The SSTC could, therefore, be developed by the Commonwealth as a separate project to serve as a remote transfer terminal to the Airport. Given that buses and Airport limousines will be given preferential treatment on ramps connecting the tunnel with South Station, the airlines could conceivably operate baggage checking operations out of the SSTC. With the Preferred Alternative, a grade separation will be provided between the future Airport Cross Road and the Airport access/egress roads. Motorists entering or leaving the Airport via Route 1A will experience reduced travel times and less conges- tion due to improved traffic flow on the main Airport roadway as well as Third Harbor Tunnel roadways to the west of the terminal area. One disadvantage of the Preferred Alterna- tive is the longer access route from the Callahan Tunnel to Bird Island Flats. While access from the Callahan Tunnel to Bird Island Flats will be more circuitous than with the No-Build Alternative, reduced congestion on the Airport access/egress roads will result in acceptable traffic operating conditions for the longer trip. Continued study of design refinements indicates that it may be possible to retain this direct right turn to Bird Island Flats. The Massport master plan for Logan Airport calls for double-decking the access to the Airport terminals to separate arrivals and departures. The Preferred Alternative design features at Logan Airport can be incorporated into future Massport double-decking roadway circulation improvements J 211 through the use of "switch back" ramps or other down-ramping schemes to gain access to lower-level Airport services (e.g., arrivals), the Third Harbor Tunnel, or Route 1A ramps. The development of the Preferred Alterna- tive has been coordinated with Mass- port throughout this EIS/EIR process to provide consistency, to the extent possible, with future Airport develop- ment plans. Public Transportation As indicated in Section 3.1 TRANSPORTATION FACILITIES , the No-Build Alternative will increase long-term demands for cross-harbor public transportation as a result of increased congestion on the highway network . A manual sensitivity analysis (excluding Airport trips) incorporating such factors as parking availability, the quality of services offered by competing transportation modes, congestion, out-of-pocket costs, and travel times was undertaken by the Central Transportation Planning Staff (CTPS). This analysis concluded that if, as expected, CBD parking is less available in the design year than it is today, the Preferred Alternative would result in a drop of public transit usage of less than one percent. Alternatively, if parking is not more constrained than at present by the design year, the analysis indicates that the Preferred Alternative will decrease public transportation trips in the region by about 1.4 percent as compared to the No-Build Alternative. This reduction in regional transit trips will be partially offset by improvements in airport-related public transportation allowed by the Preferred Alternative. The key findings of the analysis, as they pertain to the Preferred Alterna- tive, are summarized below: o To and from areas to the north and northeast of downtown Boston, a slight decline in rail public transportation ridership will occur while bus service will improve; o To and from areas to the wes and southwest of downtown Boston, ridership on express bus services is expected to increase, and; o To and from areas south and southeast of downtown Boston rail public transportation ridership is expected to decline. This will be offse, somewhat, by a slight increa; in express bus ridership attributable to the busway improvements in the South Ba area. Bus ridership would further increase with the implementation of a separate project that would include a planned bus lane along the Southeast Expressway. The long-term impacts of the Preferred Alternative on the many M bus routes within the study area wi be minor in terms of required routi changes resulting from changes in t roadway network configuration. Mos of these changes will affect bus routes serving Broadway and Haymark Stations as well as the South Stati Transportation Center. At the Broadway Station in South Boston, with the Preferred Alternative, the Broadway Bridge wi be replaced by a new Herald Street Extension that will intersect Dorch ter Avenue north of the existing Broadway alignment. The Herald Str Extension design has been coordinat with an on-going MBTA Broadway Stat Modernization project. In addition the proposed new South Bay interchaje between the Massachusetts Turnpike/ Third Harbor Tunnel/Southeast Expre;* way/Central Artery/Herald Street Extension will provide new options >i improving South Boston bus services It is expected that future bus cona- tions to the MBTA Red Line Broadway Station will improve with the Pre- ferred Alternative. All bus routes to be consoli dated at the South Station Transposi- tion Center will benefit with the Preferred Alternative. Exclusive bs 212 anes incorporated into the proposed DUth Bay interchange discussed above [ill result in savings for regional BTA and private carrier bus services erving Northern New England. These us lanes will provide direct connec- ions between the South Station ransportation Center and the Central rtery, the Southeast Expressway, the assachusetts Turnpike, and the Third arbor Tunnel. In addition, buses enefit from reduced congestion on ummer Street and in the Dewey Square rea. The Third Harbor Tunnel, as ell as the depressed and widened :entral Artery provided with the 'referred Alternative, will reduce .ravel times for all bus connections :o and from the north for private jperators such as Greyhound, [■railways, and Vermont Transit. Buses entering Boston via Interstate Route 93 to Haymarket Station will be required to use the lew Causeway street off-ramp rather zhan the previously-used Haymarket Square off-ramp. While some delays ■nay be experienced by buses using this ramp at the Causeway Street intersec- tion, buses entering Haymarket Station previously were delayed on the Central Artery and on the Haymarket exit ramp because of heavy traffic volumes on the highway and on the local roads. In addition, the construction of a replacement parking garage by the MBTA, possibly at Canal Street/Haver- .hill Street (see Section 4.2.10 | PARKING IMPACTS ), may offer a significant opportunity to create a ,new, enclosed bus-to-transit .intermodal transportation center at Haymarket Square. MBTA buses will .generally benefit from improved downtown Boston traffic circulation. Certain bus services to and from the MBTA Haymarket Station in downtown Boston will also benefit with the Preferred Alternative. Specifi- cally, a new on-ramp to the Central Artery northbound will be provided from Causeway Street. Combined with Surface Artery improvements, this new ramp will make bus travel between Haymarket Station and the northbound Central Artery much easier. Bus routes to the north will also be able to avoid City Square in Charlestown by using this new on-ramp. Express bus services to other North Shore communi- ties will also benefit from proposed roadway configuration changes. These bus routes will be able to use a new on-ramp from Haymarket Square directly into the Callahan Tunnel, thus bypass- ing the existing heavily congested intersection of Blackstone Street/ North Street/Central Artery off-ramp. Other than those routes that terminate at South Station Transporta- tion Center and at Broadway Station in South Boston, as mentioned above, MBTA bus routes in South Boston will not be directly affected by the tunnel construction through South Boston. Buses will be able to use the same streets as they do today. However, the Third Harbor Tunnel's proposed interchanges in South Boston will provide the MBTA with new routing options which may improve its South Boston bus services. Overall, particularly due to the direct ramp connections provided at the South Bay interchange, highway- dependent public transportation services in the study area will improve over the No-Build Alternative with the Preferred Alternative. Commuter rail services to and from Boston's North and South Stations will not be directly affected in the long term by the Preferred Alternative because of provisions to relocate tracks and maintain services. Amtrak and MBTA services to South Station, and MBTA service to North Station, will be affected during construction. Temporary track will be provided to maintain service. There will be close coordination with Amtrak, the Federal Railway Administration (FRA), and the MBTA during the construction stage. In the long term, Amtrak and MBTA services will not be adversely affected, although occasional relevel- ing of the track beds in the South Bay area may be necessary to correct long term settlement in this area. 213 4.2.9 Construction Impacts No-Build Alternative The No-Build Alternative, with redecking, will require a construction period of about three years. The No-Build Alternative, like the Pre- ferred Alternative, will have several construction impacts. The redecking construction staging procedure for the No-Build Alternative in the High-Level Bridge area calls for travel lanes on the Central Artery to be reduced from 6 to 4 (see Section 4.1 DESCRIPTION OF CONSTRUCTION ) . This reduction in lane capacity will degrade traffic levels of service, on occasion extending congested peak operating conditions into what are normally off-peak hours. On the Central Artery south of Causeway Street, one lane at a time will be out of service, with temporary by-pass lanes used to maintain six through lanes. The Central Artery currently operates above its theoreti- cal capacity — i.e., at peak condi- tions — for 4 to 8 hours of the day. Traffic flow is subject to break down from relatively minor disruptions during these hours. During the redecking, along with the slowing of traffic resulting from the normal curiosity factor (i.e., "rubber- necking") associated with any roadside disturbance, the capacity of the Artery will be reduced at construction zone bypasses as 12-foot lanes are channelized into narrower 11-foot lanes. Vehicle operating speeds will decrease sharply in these areas. The resulting lu percent reduction in capacity will cause additional bottle- necks with lengthier queues. The impact of the increased traffic on the Central Artery will be realized on its connecting expressways (particularly Interstate Route 93 to the north and the Southeast Expressway to the south). With respect to regional traffic flow, redecking the High-Level Bridge area is of greater concern. Due to the bottleneck at this location and doubledecking of the northbound and southbound directions of the Central Artery on the bridge, it wi be impossible to maintain three lane in each direction during peak hours Increased congestion and queuing woid occur for at least an eighteen-montl period while the bridge and Leveretl Circle connections are being redecki ; detour routes would be developed to reduce this congestion. Also during the redecking construction period, traffic diver- sions from the Southeast Expressway Central Artery to parallel local roadways will occur during the peak and off-peak hours, adding to conge tion on adjacent surface streets in South Boston, downtown Boston, and East Boston. Traffic flow on all Central Artery ramps will be maintained at times during redecking. At least h the width of each ramp (11 feet) wi be available for use at all times while the remaining half is being reconstructed. Also, one or two lai of the Surface Artery, depending up< location of the redecking operation will be closed in the immediate area(s) under the construction zone These closures will result in some additional congestion on the Surface Artery as traffic attempts to move through the construction area. Onc< traffic has bypassed the construct area, normal capacity (i.e, number lanes) on the Surface Artery will available for traffic movements. These impacts will be most notable during the peak periods, but will cause motorists inconvenience durinc the off-peak hours of the day. Overall, the Preferred Alterr tive will have more significant loce street network traffic impacts dur construction than the No-Build Alter native. The redecking, however, requires construction activity throughout the full length of the Central Artery through downtown Boston. Therefore, when examining construction period impacts on re- gional expressway traffic, the Pre ferred Alternative has the benefit leaving the existing Central Artery 214 service throughout the construction >eriod (including a phase, starting in >:he eighth year of construction, in /hich the viaduct is in use in addi- :ion to portions of new underground jroadway). At the end of the Preferred alternative construction period, all izraffic will be transferred to the new depressed Central Artery, allowing the jemolition of the existing viaduct. In short, while the construc- tion time period is longer for the Preferred Alternative and the disrup- tion to traffic using the local street network is more severe, the provision 'of continuous through service for the heavy component (60-65 percent) of regional traffic on the Central Artery is better handled by the Preferred Alternative than by redecking with the No-Build Alternative. Preferred Alternative The Preferred Alternative requires a construction period of about 12 years. The analysis of construction traffic impacts over the 12-year construction period for the Preferred Alternative covers five corridors: o South Boston; o South Bay/Fort Point Channel corridor ; o Central Artery/Surface Artery corridor from Dewey Square north to Causeway Street; o The storrow Dr ive/Leverett Circle connector ramps from Causeway Street to the Central Artery North Area Project; and o Logan Airport (East Boston). Proposed phasing for the Preferred Alternative calls for the depression of the Central Artery to be initiated simultaneously with the construction of the South Boston and South Bay/Fort Point Channel sections. Table 41 lists the existing Central Artery ramps that will be closed for a period longer than a month during construction of the Preferred Alternative. Also provided in Table 41 are the 1982 traffic volumes on each of the facilities and possible alternative routes for traffic during the periods the ramps will be closed. Each of the five construction corridors has construction sequences described in Section 4.1.2 CONSTRUCTION SEQUENCING and in the Supportive Engineering Report . Construction staging sequences have been organized to maximize maintenance of major traffic flows throughout construction. This section focuses on the critical traffic implications of those construction periods. Construction of the South Boston, South Bay/Fort Point Channel, and Central Artery corridors is assumed to begin in January 1987. Construction of the Third Harbor Tunnel is expected to be completed by January 1991. This date also marks the expected start of construction of the Storrow Dr ive/Leverett Circle ramp connections to the Central Artery; within the overall 12 year construc- tion framework, this construction schedule may be revised to accommodate land development considerations. Construction period impacts are summarized below by corridor. The discussion of each corridor includes, where appropriate, a description of the traffic implications of construc- tion activities in other adjacent corridors that interact with activi- ties in the corridor being discussed. There are a number of measures which will be taken to reduce disrup- tion during construction of the proposed improvements. Specific details will be developed during the design phase, based on input received from all affected groups, including residents, commuters, and merchants. The MDPW is committed to providing measures to mitigate construction impacts and disruption, to the extent possible. 215 Table 41 EXISTING RAMPS CLOSED FOR A PERIOD LONGER THAN ONE MONTH DURING CONSTRUCTION OF PREFERRED ALTERNATIVE Ramp 1982 AWDT Route 1-93 SB Off -Ramp 22,200 to Storrow Drive Route 1-93 NB On -Ramp from 23,600 Storrow Drive Alternative Route 1-93 SB to Ramp CS-W to Causeway Sullivan Square, Rutherford Avem and Gilmore Bridge and through Leverett Circle & It! I ft ■ ■■ fa ti Leverett Circle to old Charles Rie: Dam to Gilmore Bridge and Rutherfrc Avenue Central Artery SB On-Ramp 11,600 from High Street/Purchase Street Central Artery NB Off-Ramp 10,350 to Causeway Street Purchase Street to Congress Stree On-Ramp Leverett Circle to Lomasney Way Causeway Street 216 Some of these measures in- lude: extensive use of the media inouncing traffic or access changes id displays describing the snstruction activities, etc. use of :her transportation modes to commute b the City could also be promoted. Tiplementing these measures, however, ill require extensive coordination nd cooperation from various public City of Boston, MBTA, etc.) and rivate (local newspapers, radio tations, etc.) concerns, since many ossible measures are beyond the urisdiction of the Massachusetts epartment of Public Works and the ederal Highway Administration. These nd other impact mitigating measures 're discussed, as appropriate, in the ollowing sections. South Boston The Preferred Alternative irectly affects the interior of South oston to the east of the Fort Point hannel. The construction of the eaport Alignment Tunnel will require se of temporary detour roads at everal locations. Of particular importance is the need to replace the ummer Street bridge over the railroad racks. (It is important to note, owever, that the Summer street bridge s currently posted for weight re- trictions and will need to be re- laced with or without the project.) he existing bridge will first be eplaced by an adjacent temporary our-lane bridge for approximately one ear. Adverse traffic impacts during his period should be minimal, as ither the existing or the temporary ridge will be in service at all imes. However, for two months prior o the use of this temporary struc- ure, repairs to the retaining walls f the existing bridge, required as art of Summer Street bridge replace- ent, will reduce the capacity of the ridge by 50 percent. This can be xpected to cause some delays to ummer street traffic, especially uring peak hours. When the new ridge is completed, Summer Street raffic will be switched from the emporary bridge to the new structure, with no interruptions in traffic service. A short segment of A Street will be replaced for five months by a temporary two-lane bypass while construction of the tunnel proceeds beneath it. Later in the construction process, traffic on the easternmost segment of Northern Avenue and the private EDIC access road (also re- ferred to as "A" Street, though not the same "A" Street as mentioned above) to the east of Commonwealth Pier will operate over a short four- lane temporary bypass during Third Harbor Tunnel construction for a four-month period. Travel delays on both detours will be minimal. Viaduct-Ramp Street will be closed to traffic for an estimated two-year period. An elaborate detour will be required. B Street, in the vicinity of its intersection with Congress Street, will remain open, serving as part of the detour to maintain access to the Commonwealth Pier area via local streets from the south. While motorists who formerly used Viaduct-Ramp Street in this area will find the detour circuitous, the discouragement of north-south local traffic movements is consistent with local South Boston traffic planning objectives. Only Congress Street between B Street and the new on- and off-ramps to the Third Harbor Tunnel will be closed permanently as a result of the construction of the Preferred Alterna- tive. This portion of Congress Streetis upaved and privately-owned. While this closure will inconvenience motorists presently using Congress Street (the 1982 AWDT volume in this unpaved section of roadway is 35u0 vpd ) , they will be able to divert to Northern Avenue, which has the capa- city to accommodate the additional traffic at an acceptable level of service. During construction of the Preferred Alternative, it is antici- pated that the following roadways will 217 be ready for use about 3 to 4 years into construction: o The new project service road between Congress Street and Northern Avenue; o The new easterly on- and off- ramp system connecting the Seaport Access Alignment Tunnel and Third Harbor Tunnel with Summer Street and Northern Avenue, and; o The Seaport Access Alignment Tunnel between the Third Harbor Tunnel and the Southeast Expressway/Massachusetts Turnpike and these interchanges. The availability of these roadways and interchanges as well as a relocated Dorcnester Avenue will improve access from the south and southwest to the northern sections of South Boston (and downtown Boston) while work on the Central Artery depression proceeds. Simultaneously, they will remove truck and automobile traffic from various South Boston local streets and connecting roadways during and after the construction period. South Bay/Fort Point Channel Crossings Construction of the Preferred Alternative will proceed with the objective of placing northbound traffic in the new Fort Point Channel tunnel section and on the relocated Dorchester Avenue as soon as possi- ble. Traffic now using the Broadway Bridge will be able to cross the railroad tracks throughout the con- struction period. The Broadway Bridge will not be closed permanently until the Herald Street Extension nas been completed. Tne West Fourth Street Bridge, currently closed, is assumed to be reconstructed prior to the initiation of this project. It will, therefore, be available to traffic throughout the South Bay/Fort Point Channel construction period. Further north in the Fort Point Channel, the Summer Street, Congress Street, and Northern Avenue bridges will also remain open to traffic throughout construction. By using constructs techniques outlined previously, th tunnel for the relocated Dorcheste Avenue will be constructed beneath these bridges without interrupting traffic. Several temporary bypass detours with capacities similar to those of the replaced roads will b constructed to maintain the flow o traffic on the interchange of the Massachusetts Turnpike with the Southeast Expressway. These required roadway chanas will redistribute traffic from brigei and ramps closed or reduced in cap- city to those which remain open. Sue. resulting increases in traffic on local streets in South Boston near:ht : Central Artery can be expected. Additional congestion will occur a the intersections of bridges which remain open and roadways parallel d the Southeast Expressway/Central Artery. Because several constructio contracts will be necessary with t5 Preferred Alternative, constructio a the complicated South Bay interchaje will be closely coordinated with t? Central Artery construction so tha continuous flow between the MassacJ- setts Turnpike and the Central Artry will be maintained at all times. Central Artery/Surface Arte . Corridor At all times, six or more travel lanes will be available for Central Artery traffic with the Preferred Alternative. The construction period for depression of the Central Artery wll generate from 500 to 1,000 truck tip: per day during excavation. During:!: excavation phase of construction, temporary haul road will be providi along the Central Artery work area t minimize the impact these trucks wl have on local streets in downtown Boston. Otherwise, project-relate trucks will generally have an advene impact on local and regional traff : flow. Most of these trucks (as 218 ruckers are inclined to do in con- jsted areas) will be using the street /stem in off-peak hours to avoid peak jriod congestion. Construction of the Central rtery depression will proceed in five :eas at once as shown in the support- /e Engineering Report . The first 15 Dnths of construction (September 1986 d January 1988), primarily utilities elocation, will result in traffic isruptions on streets crossing the entral Artery corridor. In all ases, at least two traffic lanes will 'e maintained on each cross street hrough temporary crossings, allowing raffic to flow across the Surface rtery. If possible, only one street rossing will be affected at any given ime. Primary adverse traffic impacts : ill occur on cross streets in the eak hours. Detours will result in ottlenecks at the Surface Artery and tlantic Avenue, and occasionally ause back-ups on intersecting streets. The most serious impacts on ocal downtown Boston traffic during [.he Central Artery depression will ; >egin to occur during the second year ■>f construction, and will last until : :he middle of the fifth year of construction (January 1988 to July .992). Construction of the slurry /alls paralleling the Artery will require the closure of certain lanes bn the existing Surface Artery/ Atlantic Avenue corridor. A study of :raffic operations along the Surface Artery/Atlantic Avenue corridor was nade to address traffic impacts during :he slurry wall construction phase. Che study (see Appendix 3) indicated :hat even though travel lane capacity ilong the corridor will be reduced by i maximum of two lanes in each direc- :ion, through the removal of on-street parking (replaced by off-street parking), the key constricting inter- sections will handle peak period traffic volumes at levels of service comparable to what will occur with the to-Build Alternative in 1990. During :his period, six lanes of through traffic will be maintained on the existing Central Artery. Summer Street, Pearl Street, Congress 219 Streets, High Street, Franklin Street, Federal Street, and Milk Street will carry heavier volumes than usual. Transit ridership is expected to increase. Access to properties adjacent to Atlantic Avenue will be maintained. Also during this time period, the Atlantic Avenue on-ramp will be closed and replaced with a temporary on-ramp at State Street. At six-month intervals over a two-year period, these ramps will alternately be closed and opened to maintain northbound access to the Central Artery. At the end of the slurry wall and utilities relocation construction sequences, with the Preferred Alterna- tive, both Atlantic Avenue and the Surface Artery will again be open to traffic. Excavation and construction of the depressed Central Artery will proceed. The elevated Central Artery, underpinned during the previous construction sequence, will remain in operation until the depressed Artery and its connections are completed. The next period of significant traffic disruption with the Preferred Alternative lasts for approximately two years. It requires the alternate closing of one traffic lane at a time in both the Callahan and Sumner Tunnels. Callahan Tunnel (Outbound) Lane Closure The Third Harbor Tunnel will be opened at this time. At the outset of this construction sequence, the short section of Cross Street between Fulton Street and the Callahan Tunnel will be removed. For one year (i.e., six months for each of the lanes), only one lane of the approach to the Callahan Tunnel will be open to traffic from local streets. The tunnel itself will retain two lanes. Effectively, three outbound and four inbound tunnel lanes will be available for cross-harbor traffic, as compared to the four existing cross- harbor tunnel lanes. During this period, some cross-harbor traffic coming from downtown Boston on the Central Artery that would otherwise have been using the Callahan Tunnel, will probably divert to the new tunnel via Northern Avenue or Congress street. Sumner Tunnel (Inbound) Lane Closure During the succeeding period of construction, one lane of the exit from the Sumner Tunnel will be closed for a period of approximately one year (again, six months for each of the two lanes). While two lanes could be maintained inside the Sumner Tunnel, in this case, traffic will be merged into one lane at the entrance of the tunnel (the other lane being used as an emergency or breakdown lane). This will eliminate the need for a conges- tion producing and hazardous merge at the exit. As mentioned above, the Third Harbor Tunnel will be available to accommodate cross-harbor traffic. Traffic from East Boston and the North Shore area using the Central Artery both north and south of the existing tunnels will be able to use the Third Harbor Tunnel. Motorists who use the Third Harbor Tunnel to go to the downtown Boston Financial District during this period will be able to exit in South Boston at the Congress Street/Northern Avenue ramps. The increase in traffic at these ramps will probably result in peak period congestion on the ramps and increased traffic volumes on Summer Street, Congress Street, and Northern Avenue. Central Artery Ramp Impacts Throughout construction of the Preferred Alternative, access to the Central Artery will be maintained either through existing ramps or replacement ramps. Replacement ramps will be necessary at three locations: Atlantic Avenue/State Street on-ramp; New Chardon street off-ramp; and North Street off-ramp. Access to these ramps will be alternated over about a six month period. During the final stages of construction, major traffic routing changes are required to complete the Storrow Drive/Leverett Circle Connec tions to the new depressed Central Artery. The construction activities in the two areas will be coordinatec to minimize adverse impacts associate] with ramp closures in the two areas, Storrow Drive/Leverett Circlt Connecting Ramps from Causewr Street to the MDPW's North Ai ;a Project Limits Construction of the Storrow Drive/Leverett Circle connecting rans is assumed to begin in the fifth yer of construction. With the exceptioi of a three month period while Leveret Circle construction takes place, traffic impacts during the first th;>e years of construction should be minimal. Construction trucks are t. 1 . primary source of traffic impacts during this period. Construction of proposed improvements at Leverett Circle wil reduce capacity of the Circle by abit one-third for about three months, a. the new off-ramp from the Central Artery to Storrow Drive westbound i; completed. Completion of this conn:- tion is necessary before the depress Central Artery can be opened to traffic. During these periods, traffic congestion at Leverett Circ? will increase in duration, perhaps extending another hour during both le morning and evening peak periods. Once the depressed Central Artery is completed, but before the Central Artery viaduct has been removed, two of the existing on- an off-ramps to Storrow Drive will be removed and replaced to complete construction of the new storrow Dri; ramp system. The first three month of this period will be critical because all of the vehicles which formerly used these ramps will be forced to use alternative routes, the two ramps, the most critical is 220 the southbound Central Artery off-ramp to Storrow Drive, whose three month closure will cause major traffic diversions and disruptions on poten- tial detour routes. These routes are expected to include Interstate Route 93 southbound to Sullivan Square, Rutherford Avenue, and the Gilmore Bridge to the Charles River Dam, and Mystic Bridge to City Square to Rutherford Avenue. The Massachusetts Turnpike will also be a major rerout- ing alternative for much of this traffic bound to and from the downtown Boston area. Diversions to the •Massachusetts Turnpike will increase traffic on the Central Artery between Storrow Drive and the Massachusetts Turnpike. While the Central Artery 'will have the increased capacity of two additional lanes (a total of four in each direction), some peak period congestion will likely occur. Like- wise, much of the eastbound traffic ' from the storrow Drive off-ramp to the northbound Central Artery which must be rerouted due to closure of that rarnp for about a year will be able to use the alternative Massachusetts Turnpike routing in the reverse direction. During the preliminary design phase, refined construction ' staging techniques will be developed to minimize both the impact and duration of this ramp closure. Once this ramp is reopened, major construc- tion traffic impacts will cease in this area. Logan Airport (East Boston) Construction at Logan Airport and East Boston with the Preferred Alternative is to proceed concurrently with construction activities in South Boston to assure that the Third Harbor Tunnel is available when lane closures on the Callahan/Sumner Tunnels are required as described above. Construction of the cut-and- 1 cover tunnel section through Airport ; property will require both the main Airport access and egress roads as well as the Cross Road to be replaced by temporary roads of similar capacity for short periods of time, resulting in minor delays to traffic. Other- wise, traffic to and from the Airport will generally be maintained. All construction at Logan Airport is expected to be completed by 1991. Public Transportation No-Build Alternative The No-Build Alternative should have minimal impacts on public trans- portation services during redecking. Only public and private bus carriers who use the Central Artery would be affected. As indicated earlier, a 33 percent reduction in Central Artery capacity at the High-Level Bridge (5-10 percent reduction south of Causeway Street) would cause signifi- cantly increased delays and longer travel times for buses. Except for the reconstruction of the Summer Street Bridge over the Conrail yards, the No-Build Alternative does not affect bus services in South Boston. Preferred Alternative It is probable that ridership on all MBTA rapid transit lines serving downtown Boston will increase during construction of the depressed Central Artery. Many motorists who have the option will divert to transit because of increased delays to automo- bile traffic. Red Line Rapid Transit . Operation of the MBTA's Red Line service under the Fort Point Channel will be affected by construction of the Preferred Alternative. Construc- tion of the Herald Street Extension above the MBTA Cabot Yards will require the temporary relocation of about four tracks. Service will be maintained on replacement tracks. Appropriate rail speed restrictions will be in effect during construction, as required. Generally, the Red Line impacts will be minimized by a re- quirement that any sensitive construc- tion be accomplished during night periods (e.g., 1:00 to 5:00 AM) when the rapid transit line does not operate. 221 Blue Line Rapid Transit . Construction of tne Preferred Alterna- tive will, however, cause some slight disruption to Blue Line service in East Boston as a result of the need to relocate approximately 1000 feet of track immediately to the north of the ramps to and from Logan Airport. Service disruptions will be minimized since tie-ins and final connections will occur during night-time (no service) or weekend (off-peak) pe- riods. In downtown Boston, the de- pressed Central Artery will pass directly over the Blue Line tunnel under State Street. Disruptions brought about by interior tunnel strengthening will again be minimized by a requirement tnat all sensitive construction occur during night periods when there is no Blue Line service. Orange and Green Lines Rapid Transit . Botn the MBTA's Green and Orange Lines are located adjacent to the central Artery in the North Station/Haymarket Square area. At the Haymarket portal, a temporary ramp passing over the Green Line is to be constructed to serve traffic diverted from the closure of the New Chardon Street ramp. An MBTA power substation now under construction may be affected by this temporary ramp. Every attempt will be made to minimize the impact this ramp will have on the substa- tion. It is not expected that service on either the Green or Orange Lines will be directly affected by construc- tion of a depressed Central Artery in that location. Also, a replacement parking facility may be built in this same Canal/Haverhill Street area by the MBTA. No major disruptions to MBTA service are expected during the construction of this garage. Bus Services . The Preferred Alternative's construction within the Fort Point Channel will temporarily reduce the capacity of the bridges across this waterway. Several MBTA local bus routes use these bridges to provide service between South Boston and other locations. These routes will be affected by construction w.h detours to temporary bridges as necessary. Increased delays due t< increased congestion will result ii an overall degradation in the quality bus service in South Boston during construction period. Within downtown Boston, it expected that express bus services, particular, will experience an in- crease in ridership during construe tion of the Preferred Alternative. The MBTA operates numerous local and regional bus routes with:, downtown Boston. Many of these rotes will be disrupted during constructs of the depressed Central Artery, particularly those serving the Hay- market Square area. These disrupt, will arise from increased traffic congestion in this area caused by construction, resulting in delays c longer trip times, as well as from possible changes in routings due tc various roadways being taken out o service either temporarily or perm nently. Some delays or reroutings f services provided by other bus comf- nies which use the Southeast Expres- way and/or the Central Artery can Market, the Waterfront, and Governmet Center, will be taken by the project in the first year of construction, s discussed below under Mitigating Measures , replacement parking for l\ surface lots serving the general public will be provided by the proje: prior to the loss of the existing spaces. The existing lots are bordered by the following streets: Blackstone Street/North street/Cross Street lot - 200 spaces; North Wash- ington Street/Cross Street/New Chardi 224 treet lot (2 parcels) - 70 spaces; nd North Washington Street lot - 60 paces. The two lots bordered by the ollowing streets will be taken during he third year of construction: ndicott Street/Stillman Street lot - 0 spaces; and Cooper Street/Stillman lace lot - 20 spaces. Thirty metered m-street spaces, spaces for 20 fish md produce trucks which park under Lhe existing Central Artery on Fridays md Saturdays when Haymarket is open, ind a 20-space lot operated under the Artery by the City of Boston's Public torks Department for city employees tfill be taken. Mitigating Measures . The Commonwealth is committed to ensuring che availability of parking for North :End residents and visitors and will provide permanent parking facilities prior to displacing the approximately 370 lot spaces taken under the Artery. Prior to tneir being displaced, all lot spaces taken by the project will be replaced at locations such as in a new garage above state-owned property in the vicinity of Haverhill and Canal streets (above the MBTA's Orange and Green Lines), or possibly ;on city-owned property lying between ;Fulton Street and the approach to the Callahan Tunnel. Other parking options under consideration include an agreement to allocate space at nearby :garages (i.e., Quincy Market Garage, Harbor Tower Garage, Hertz Garage, Government Center Garage) for North End residents and visitors, and providing (via MET A or a private service) shuttle service between various parking garages and the North End. These possibilities will be i pursued with the appropriate owners during the design phase to guarantee adequate replacement parking for North End residents and businesses. To mitigate impacts on Hay- market vendors, truck storage space will be provided in the immediate area, both during and after construc- I tion. Areas near the construction corridor, such as BRA parcel 7 or an area adjacent to Waterfront Park, may in part be designated for this use. North Station Temporary Takings . The Spauld- ing Rehabilitation Hospital will lose 80 spaces and the state-owned lot (currently used by MDPW employees and Registry of Motor Vehicle employees) will lose 100 spaces during the fifth and sixth years of construction. Fifty spaces will be taken from the Massachusetts General Hospital parking lot during the tenth year of construc- tion. Permanent Takings . Two lots located under the existing Central Artery and fronting on the following Streets will be taken in the first year of construction: Causeway Street lot - 120 spaces; Haverhill Street lot (one of two parcels) - 50 spaces. The Beverly Street lot (also under the Central Artery) - 70 spaces, will be taken in the third year of construction. A parking lot behind the Anelex Building accommodating 440 vehicles is also taken by the project during the first year of construc- tion. Twenty spaces from the MDPW parking lot on Nashua Street are taken in the fifth year of construction. Mitigating Measures . As a result of the planned relocation of the MDPW to the new state Transporta- tion Building, the demand for state- vehicle or employee parking in this area may be reduced. Because of the anticipated reduced demand and excess supply on this state-owned parcel, temporary parking for the hospitals may be accommodated at this site. The spaces taken at the Cause- way Street lot, Beverly Street lot, and that portion of the Haverhill Street lot affected by the Preferred Alternative will be replaced prior to their being displaced, possibly through the parking garage previously mentioned or through agreements with other garage owners. Logan Airport Temporary Takings . There are no temporary takings. 225 Permanent Takings , sixty spaces serving the Delta Reservations Center, 6U serving the American Airlines hangar building, and 50 serving the Williams Air Freight employee parking area will be taken in the first year of construction. No other takings exclusively accommodat- ing parking uses result. Mitigating Measures . Parking displaced by the project will be replaced on Airport lands to be determined in consultation with Massport . 4.3 RELOCATION IMPACTS In the discussions which follow, all references to acquisition of properties or buildings refer only to those properties or buildings whose tenants ' /owners ' businesses will be displaced by the proposed project. Other property acquisitions will occur as part of this project, but will not involve business displacements. Where mitigating measures are necessary to ensure the continuance of business operations during the construction phase, they are discussed in Section 4.4 LAND USE IMPACTS of the FEIS. Appendix 2 - CONCEPTUAL RELOCATION PLAN REPORT elaborates on the reloca- tion requirements of the Preferred Alternative. 4.3.1 Comparison of Alternatives The relocation impacts of all alternatives considered during the EIS process are summarized in Table 42 and discussed briefly below. o No residential properties would be acquired for any of the alterna- tives; therefore, no residential relocations would be necessary. o The Preferred Alternative necessitates 31 partial or total takings. This alternative displaces 131 businesses and public agencies, affecting 4,400 employees. Tax losses per year are estimated at $767,000. This alternative takes the most businesses and has the most impacts on relocation of manufacturing and distributing businesses. o Alternatives 3A and 5A woul cause the next largest relocation impact. Partial or total takings range from 23 to 27; 108 to 111 businesses or agencies would be displaced. The number of employes . affected by business displacement range from 3,420 to 4,570, and ta losses are in the vicinity of $75' per year. o Alternative 6 would requii. partial or total takings and woul displace 89 businesses and agenci<; 2,880 employees would be affected annual tax losses are estimated a $685,500. o Alternatives 2, 3, 4, and would have fewer takings overall, primarily because the Anelex buil is not acquired (the Anelex buildi accounts for 62 businesses and 2, employees.) Partial or total tak range from 8 to 12; 14 to 24 busi nesses or agencies would be dis- placed. The number of employees affected by business displacement ranges from 170 to 510. o The No-Build Alternative a;l Alternatives 2, 3, 4, and 5 would temporarily affect the nine parki lots located under the Central Artery. It is expected that not of the lots would be affected at same time, but all would be close parking at some time during the three-year construction period re quired for redecking of the Centr Artery. o Alternatives 3A, 5A, 6 and Preferred Alternative would requi that the nine lots under the exis Central Artery be permanently takf the lot bordered by Blackstone, ;ross, and North Streets may cause the I jaost adverse economic impacts because )f its convenient location to North ind activities. If comparable space iuring weekdays is unavailable some people may be discouraged from dining Dr shopping in this area upon removal of this lot. As noted previously, however, the Commonwealth is already exploring other parking alternatives in order to avoid adverse economic impacts to this community and has made a commitment to provide replacement parking prior to the commencement of construction. Plans for replacement parking are discussed in Section 4.4 LAND USE IMPACTS . For the remainder of the takings in the central area, South Bay, and South Boston, numerous locations near the existing busi- nesses are available; therefore, adverse economic impacts are not expected to result. In South Boston manufacturing and industrial jobs are actually expected to increase due to the current redevelopment of space at the Boston Army Base and due to roadway improvements built as a result of the Preferred Alternative. These improvements will also increase revenues in the long term. In East Boston there are no significant community economic impacts because it is anticipated that most businesses would relocate at the Airport, thereby preserving existing jobs for East Boston residents. The relocation interviews conducted for this study indicate that the number of minority-owned busi- nesses to be relocated by the project is negligible. The percentage of minority employment at Logan Airport is lower than for the City of Boston as a whole. Business relocations at the Airport are not expected to affect a significant number of these employ- ees. Minority representation in certain areas, however, is higher. In South Boston, the number of minority employees affected by relocation is approximately 16 percent of the total affected work force. This percentage is comparable to the total number of employed minorities who reside in the City of Boston (18 percent). 4.3.5 Massachusetts Department of Public Works Relocation Proce - dures A business relocation agent will be assigned by the MDPW to assist each relocating business in all phases of relocation and in the preparation of documentation required to process payment claims. The relocation agents will inform all business owners of their benefits and entitlements, courses of action which are open to them, any special provisions designed to encourage businesses to relocate within the city, and other public or private programs that may provide them with assistance. Relocation Benefits Depending on the type of ownership and the business options one chooses, displaced businesses are eligible for several payments: 1. Actual reasonable costs of moving and related expenses. 2. Direct loss of tangible per- sonal property for items that are not moved and cannot be sold. 3. Actual reasonable expenses in searching for a replacement business, not to exceed $500. 4. A fixed payment in lieu of the payment for actual expenses and losses, not to exceed $10,000. In addition, the property owners are reimbursed for the full fair market value of the business property. If any business or property owner has been denied a payment or 235 disagrees with a computed amount, an administrative appeal process is available through the Hearing Examiner of the MDPW. Functional Replacement FHWA policies provide for functional replacement of publicly- owned facilities displaced by the project where such replacement is in the public interest, as determined by consultation with FHWA. Functional replacement involves compensation beyond appraised market value of public property taken for highway projects if replacement cost exceeds appraised value. FHWA must approve actual replacement cost and review site selection design and construc- tion, in the context of relocation, functional replacement may apply, for example, to the General Aviation Building at Logan Airport depending on the composition of its tenants at the time the buiiding is acquired by eminent domain. See Appendix 2 CON - CEPTUAL RELOCATION PLAN REPORT for a discussion of the building's current tenants. The applicability of func- tional replacement will be pursued further during the design phase. 4.3.6 Other Possible Sources of Assistance Other potential resources to minimize economic harm to displaced business establishments, and to increase the likelihood of their remaining within city limits, were also explored. Sources contacted include state and local agencies; the U.S. Small Business Administration (SBA); Economic Development and Industrial Corporation of Boston ( EDIC/Boston ) , Boston's Neighborhood Development and Employment Agency (NDEA); the Massachusetts Government Land Bank; and local banks. In some cases, the SBA will guarantee loans or issue a debenture in conjunction with other lenders. Several other agencies have programs which could assist relocating businesses. These include: NDEA of Boston operates a program for retail and co- mercial businesses in nin targeted sections of Bostj Ljai For eligible businesses, program provides loans at reduced interest rates fo facade improvements or cor mercial development throu participating commercial banks. This program also provides loan packaging ai architectural assistance. o EDIC/Boston assists in re viewing the financial neei businesses, provides dire loan packaging assistance referral to other financi. assistance programs, and i tains listings of availab industrial sites includin< parks developed by EDIC, information on Boston's 1 force. o Massachusetts Government ] Bank can sell or rent spa< businesses at below market interest rates. It may w( directly with businesses through EDIC/Boston. In order to minimize incor veniences and impacts to busines displaced by the project, the Cor wealth of Massachusetts will pro\ assistance to affected businesse attempting to secure additional 4.4 LAND USE IMPACTS 4.4.1 Comparison of Alternatives o The Preferred Alternative change land use in downtown Bostc adding approximately 20 acres to stock of land available for devel ment. It will improve the envirc mental quality of downtown to sue extent that there may be shifts land use from less expensive Clas office use and industr ial/warehoui uses to prime Class A office, ret and possibly, residential use. Tl is consistent with the City's plai goals for downtown. Alternatives) 236 id 6 would have similar impacts, lo- Build Alternative and Alterna- ; 2, 3, 4 and 5 would not cause jes in land use in downtown Boston. The Preferred Alternative will /e the barrier of the elevated :al Artery which has dampened actions between the Financial ict and the Waterfront; connec- s which are an important element le City's development plans, rnatives 3A, 5A and 6 would have lar impacts. The No-Build Alter- y/e and Alternatives 2, 3, 4 and 5 d leave the Central Artery in its ting configuration, thus maintain- the barrier between these dis- ts. The Preferred Alternative will a more positive impact on the re land use of northern South on because of the additional rchange provided; it also involves ter land takings in South Boston other alternatives. Alternative ould have positive impacts on hern South Boston, although access ovements are less than those red by the Preferred Alternative, rnatives 2, 3, 3A, 4, and 5 would lesser positive impacts on future i use in northern South Boston; the luild Alternative and Alternative 6 .d not have land use impacts on :hern South Boston. The Preferred Alternative .licts with some aspects of BRA and plans in the North Station area. :e will De continued coordination i these two agencies to minimize impacts of the project. Alterna- js 3A, 5A and 6 would have similar icts. The No-Build Alternative and irnatives 2, 3, 4 and 5 would not jet plans in the North Station area, The Preferred Alternative ifits residential land use in East Boston by improving access via the existing tunnels to the Central Artery northbound and Boston, and by reducing traffic on local streets. Alterna- tives 3A and 5A would have similar impacts. Alternatives 2, 3, 4 and 5 would cause improvements in access to the south and west from East Boston; improvements would be less significant to the north and northwest corridors. With Alternative 6, and to a greater extent with the No-Build Alternative, access from East Boston would degrade over time because of the lack of a Third Harbor Tunnel, and land use could shift away from current residen- tial patterns. o The Preferred Alternative will benefit future water-related uses in the Fort Point Channel, notwithstand- ing its aesthetic impacts. See Section 4.14.2 Effects on Historic Pr oper t ies for a description of mitigating measures in Fort Point Channel required under the Section 106 Memorandum of Agreement . Alternatives 2, 3, 3A, 4, 5 and 6 would have serious negative aesthetic impacts on Fort Point Channel which would dis- courage future water-related land uses; Alternative 3A would have additional negative land use impacts because it requires taking the U.S. Customs Building; Alternative 3 would have long-term negative impacts on the Rowes/Fosters Wharf parcel. Alterna- tive 5A would have less significant aesthetic impacts on the northern portion of Fort Point Channel than the other build alternatives. The No- Build Alternative does not affect land use in Fort Point Channel. o The Preferred Alternative will cause significant construction period land use impacts at Logan Airport. Alternatives 2, 3, 3A, 4, 5 and 5A would cause less significant constru- tion period impacts on Logan Airport. The No-Build Alternative and Alterna- 237 tive 6 would not have direct impacts on Logan Airport. 4.4.2 No-Build Alternative Long-Term Impacts The Region Vehicular access to the Boston Central Business District and Logan Airport is presently difficult at times. This condition will be exacer- bated with the No-Build Alternative as traffic volumes and congestion in- creases on both the Central Artery and the cross-harbor facilities. This traffic congestion may marginally reduce development potential in some areas as compared to the Preferred Alternative, but is not expected to significantly change existing regional land use patterns. In the Central Artery corridor, office development will continue, but the elevated Central Artery will continue to dampen change and impede development of land uses compatible with those of adjacent districts because of degraded access, the poor pedestrian environment, obstructed views, and noise and vibration from traffic on the Central Artery. Rehabilitation of historic structures in the Broad Street area will con- tinue, although perhaps at a slower pace and with lower market rents than would occur with the Preferred Alter- native. South End Development potential in the institutional/industrial area along Albany Street will oe less with the No-Build Alternative than with the Preferred Alternative, because access to the Airport will not be improved. Property values in the area are expected to increase gradually. Industrial Triangle There will be no long-term ltf use impacts from the No-Build Altera- tive in this area. South Boston With the No-Build Alternativ^ development of the northern, indus- trial, portion of South Boston will continue, but at a lesser pace than with the Preferred Alternative. Fort Point Channel Growth in development potentil will continue but will be less than! with the Preferred Alternative becaj regional access is not improved. There are no impacts on individual parcels with the No-Build Alternati; Leather District Development potential in thi district may be slightly less than with the Preferred Alternative, whiii improves access. Continued gradual conversion of buildings to office a residential uses is expected. Chinatown/South Cove Through traffic on Kneeland .">d Beach Streets will continue to hind: circulation within this district to the detriment of local land uses. Some institutional and residential redevelopment is likely to occur. Financial District No significant changes in th s district are expected with the No- Build Alternative; however, the Cenjl| tral Artery will continue to have s : - tunnel will require the re-parcelia- tion of this area, and will resulti- 'm the removal of approximately 14 acta*;:;:', from future development use. Seveal large tenants will be displaced byth project (see Section 4.3), includig the Pappas Building (167 employees and the Commercial Union insurance Company (67 employees). The northern half of Common — wealth Flats is currently planned b accommodate buildings and parking related to the BOSCOM development ,thi- : cruise ship terminal and the Fish Pier. The southeastern portion oftto site, with access via the Massport Haul Road, is scheduled to be usedfo: storage parking and washing of im-' ; ported cars. The project does not intrinsically interfere with these planned uses; however, site circuit tion will require adjustments, and:h> total quantity of land taken for tli : project may require the constructs • of a parking garage to provide an adequate number of parking spaces a Commonwealth Flats. Parcel depth r sufficient from both Summer Street im Northern Avenue to accommodate devil*:: opment, but service access may be ijp difficult to achieve. Any changes tn specific parcel configuration will*: addressed in the preliminary desigi phases of the project. There will be a permanent lcs of 340 parking spaces at the U.S. 1st Office parking and vehicle maintenace facility in South Boston (see Mitig t- ing Measures below). The primary access point to the facility will hve to be relocated. The Post Office hs 244 s to construct an operations/main- • :i nce building on its south Boston erty. The project will not ilude construction of this Post -ice facility, but coordination of =2to|siting and design of the new Welding with the project is necessary. )e In the South Bay area, the strejject will result in the creation of tj lall development parcel abutting ! Gillette Company headquarters, jss to the Tolman Manufacturing i.-.h jany will be shifted from Dor- ptyster Avenue to Foundry Street, the hough land use does not change. sultl The project will not cause land 4 aca impacts which affect the long-term ;-:ivities of the Gillette Company. fees ana At the present time, Dorchester nue is closed to the public and re is no pedestrian access between Broadway Station area and South tion. Access between these areas ->1 be significantly improved with provision of a new northbound Chester Avenue and a pedestrian kway connecting to Summer and gress Streets. i of I lortj The project will not have ^ C 'ig-term land use impacts on South J;ton's residential area. ese Construction impacts will :lude congestion caused by increased an jUffic, both in the northern indus- . Lai area and in the southern resi- ..j^itiai area. In the northern area, . ? temporary narrowing of the Summer >:eet and Congress Street Bridges, \i construction on Northern Avenue tjd Summer street will cause conges- on and impair access. This could aiporarily slow development during s e four year construction period in ; is area. The West Fourth Street Bridge -11 be rebuilt as a separate project l^ior to the construction of the ' ieferred Alternative; the new Herald ^reet Extension will be built as part "J this project while the existing -Roadway Bridge is open. Therefore, :,^cess to the southern half of South ,1 Boston will not be seriously affected by construction. For approximately one year, construction activities would preclude General ship, Inc., located at BMIP, from using several of its facilities, including Pier 5, the facility's steam plant, and parking areas. (Building 53, which the company has been using for material assembly operations, is expected to be given up by General Ship and leased to another entity for activites that would not require access to Pier 5. This new com- pany(ies) will also suffer due to the loss of parking areas, and will therefore require replacement of this park ing area . ) Viaduct Street, between Summer and Ramp Streets, will be closed for approximately 18 months. This will inconvenience BOSCOM and will require special provisions for a ground-level pedestrian entry from Northern Avenue. The project will require the temporary taking of approximately half of a BMIP owned, 250-car parking lot for 12-18 months. BMIP tenants of Buildings 19, 32 and 17 will be affected by construction noise and dust; however, access to these build- ings from Northern Avenue will be maintained at all times, and no disruptions in business activities will be caused. Construction period loss of 460 parking spaces (in addition to the 340 spaces permanently lost) at the U.S. Post Office South Boston facility will occur. Construction period displace- ment of approximately 220 spaces on the Boston Wharf site, and 130 spaces at the Solomon surface parking lot, will also occur. During construction, approximately 125 spaces will be temporarily displaced at the Gillette Company . Mitigating measures will be implemented to ensure the availability of facilities for the continued operation of General Ship, Inc. during the construction period. At BMIP this would require the construction of a 245 temporary parking lot, relocation of steam lines, and the temporary reloca- tion of drydock operations to the BMIP's large drydock number 3 (Pier 6, an alternative to Pier 5 considered earlier, will largely be used under an easement agreement by General Ship's neighbor, Pier 7 Corp., for expansion of its commercial fishing operation.) During preliminary design, alterna- tives to accomplish this will be explored. Access along Northern Avenue will be maintained at all times to ensure access to all facilities at BMIP. Temporary parking may be provided on sites such as the western portion of the container shipping area which Massport plans to construct (if it is not in use for containerport activities ) . Construction staging areas located on Commonwealth Flats will be provided away from areas used by BOSCOM and Fish Pier for surface parking to minimize disruption of their activities. The Turner Fisher- ies (located at Commonwealth Flats) loading dock will be moved, and their internal space reconfigured to ensure their continued operations during and after construction. These adjustments to the operations of Turner Fisheries may not conform to the plans which Massport has made for this area, which call for servicing to occur from the rear yards of structures rather than front or side yards; project design refinements will address the need to achieve consistency with land use plans for the area. Construction period parking replacement for the Post Office will be provided through such mechanisms as short-term use of designated parking spaces in the South station Transpor- tation Center garage. In the long- term, Post Office parking will be replaced on sites near the existing parking area. It is expected that the private sector market for commuter parking will spur earlier development of other proposed parking structures in South Boston, which will accommo- date any displacement of privately- owned, publicly available parking areas in South Boston. The pedestrian connection between the Broadway Station area South Station will be as direct a possible, and must be carefully integrated into the development o: new parcel between the present an<| proposed locations of Dorchester Avenue. This may require maintem 1 of a public pedestrian easement a described in Section 4.5 COMMUNITY ' :ILITIES AND NEIGHBORHOOD CHARACTER- irics. Long-term land use changes will csur on the newly created air-rights prcels and near the entrance and exit seas to the existing tunnels. The ■wly created parcels and continuous ireet frontage will accommodate the cvelopment of land uses compatible vth existing North End uses. The "fecific type and size of development •^11 be determined during the prelim- inary design phase. Construction impacts will iclude disruption to local commercial id residential land uses due to ; mstruction-related dust, noise, ibration and traffic, and will lerefore require mitigating measures ach as dust control, muffling of Disy machinery, slurry wall construc- ion to reduce noise and vibration, nd traffic management schemes. * instruction period traffic pattern hanges will make both pedestrian and ehicular access more difficult than t is under existing conditions, onstruction disruption, particularly n Cross Street, may discourage people rom coming into the North End and may ake it more difficult for North End esidents to get to the Haymarket MBTA tation. Traffic management will be esigned to mitigate these impacts. The loss of approximately 370 parking spaces under the elevated Central Artery is a significant mpact, but these spaces will be eplaced prior to their loss from :onstruction activities. Mitigating measures in the torth End will include state sponsored programs geared to the maintenance of Local businesses during the construc- :ion period, particularly merchants on :ross and Salem Streets. in the long-term, there can be similar programs to encourage stability. Vibration and groundwater table levels will be monitored during construction; see Section 4.1 and 4.8, respectively, for a discussion of the measures to mitigate impacts. Section 4.1 also includes a discussion on how rodents will be controlled during construction. in order to minimize impacts on residential land uses, construction period noise will be controlled by a variety of measures including contrac- tual limitations on the hours of noisy work permitted, adherence to city of Boston noise regulations, construction of temporary noise barriers, use of mufflers on noisy equipment and use of construction methods (such as slurry wall construction) that are the least noisy possible (see Section 4.8). The Commonwealth is examining a possible program to provide soundproofing (double glazed windows and air condi- tioning) for adversely affected private properties. (The program would be similar to one being current- ly undertaken by Massport in East Boston. ) Provisions to assure pedestrian access to and from the area will be carried out. Traffic controls will be instituted to minimize the diversion of traffic to North End streets; programs will be developed to control construction vehicles and prohibit their use of local, residential streets wherever possible. Heavy construction vehicles will be re- stricted to the project haul road which will run from High street to Causeway street. The Commonwealth is committed to ensuring the availability of parking for North End residents and visitors. Permanent parking facili- ties may also be developed on the air-rights above the depressed Artery. During the construction period, all spaces displaced by the project will be replaced prior to their dislocation, at locations such as state-owned property in the vicin- ity of Haverhill Street (above the MBTA Orange and Green Lines) or city-owned property lying between Fulton Street and the approach to the Callahan Tunnel. if necessary, replacement parking will be located in specially constructed parking struc- tures . The state is exploring other parking options such as an agreement to allocate space at nearby garages (i.e., Government Center Garage, Quincy Market Garage, Harbor Tower Garage, Hertz Garage) for North End residents and visitors, and providing (via MBTA or a private service) snuttle service between various parking garages and the North End. These possibilities will be pursued during design to guarantee adequate replacement parking for North End residents and businesses. North End residents will be consulted in the process which will determine tne disposition of air- rights parcels (see section 4.4.4 Joint Development ) . The Commonwealth will work with the City of Boston on programs to provide local residents with opportun- ities to stay in the neighborhood througn municipal controls on condo- minium conversions and through access to new housing on parcels over the depressed Central Artery. The scope of sucn programs will be determined in consultation with the City of Boston. North station Long-term impacts in the North Station area may result from changes in the local traffic pattern. Access to the area to and from the north will improve due to new ramps at Causeway Street. Access from the south, however, will become less direct due to the removal of the existing Causeway Street ramps. Traffic coming from the south will exit from the Central Artery to Leverett Circle and travel along Lomasney Way to get to the area. The project is not consistent with the BRA's initial proposed redevelopment plans for subarea II of the North Station area or with the MDC's preliminary proposals for a continuation of the MDC riverfront park; see Figure 35 and Table 44. should be noted that these two majc plans are not entirely consistent wt each other, and that reconciliatior would be required with or without te construction of the Preferred Altera- tive. Elements of the BRA's proposd plan would have to be redesigned di to tunnel and ramp locations. Acce to potential development parcels wc be affected by below-grade ramp connections. It is likely that the plans for Subarea II will be recon- sidered in the light of changing circumstances in the North Station area. This process would occur in conjunction with preliminary desigr for the depressed Central Artery. The MDC plan for the Boston side of this section of the Charles River proposes park use of land nov occupied by parking lots for the MIW the Spaulding Rehabilitation Hospitl and the Anelex Building. The propcec MDC greenbelt along the river is currently interrupted by the MBTA' £ commuter rail tracks entering Nortr Station. The Preferred Alternative will not prevent construction of public open space at the river's ece from the new Charles River Dam to te railroad tracks, but an open, de- pressed ramp, located approximatel}- feet inland would constrain the with of such open space. Upstream of th railroad tracks, the private parkir area behind the Spaulding Rehabilit- tion Hospital will again be availate for either parking or open space at the river's edge. Further upstrean an open depressed ramp rising to surface grade at Leverett Circle wil block access to the river's edge (design refinements currently under for this area indicate that it may e possible to move the ramp inland, tus eliminating this impact). This are is now occupied by MDPW parking andis shown as open space (including an island and lagoon) in the MDC plan.; j This area will also be crossed by t; 252 ■ WW Tunnel or New Roadway Boundary ot Affected Parcel Identided m Table 44 Areas are shown m approximate locations: exact boundaries are not known m all cases Figure 35 Land Use Impacts North Station Area 200 EIS EIR for 1-90 -Third Harbor Tunnel. 1-93 - Central Artery Table 44 NORTH STATION AREA LAND USE IMPACTS SITE IMPACT BRA Subarea II Elements of the BRA's plan will ha; , be redesigned due to tunnel and ra|| locations . Proposed MDC greenbelt along Charles River, Boston side Proposed MDC greenbelt along Charles River, Charlestown side New Charles River Dam Proposed new arena/garage Proposed Green Line relocation General Services Administration Office Building Public open space along river edge from Charles River Dam to railroad tracks uninterrupted. An open depressed ramp rising to surface a, . Leverett Circle will block access > river's edge (design refinements currently underway for this area indicate that it may be possible b move the ramp inland, thus elimina.n: ; this impact). Two low level bridgi; will have adverse visual, air qual.:y, and noise impacts for pedestrians ad' bicyclists. Not adversely affected. Access will be maintained via new access road, walkway across dam wi^ t adversely affected by shadows and uis from low bridge structure. Building site not affected by the project, but service access as pro^se will require modifications. Could supply replacement parking for that taken for the Central Artery projec. If new complex not built, replacenut storage space will have to be builttc the rear of the existing Boston Gaie due to the taking of the Anelex Building. Not directly affected by project. Not directly affected by project. 254 ci ocated Nashua Street. MDC open space plans on the D rlestown side of the river are not i> ersely affected by the Preferred k ernative. Impacts to the new Cirles River Dam and the Paul Revere Liding Park are described in Section jL 3 Of the SECTION 4(f) EVALUATION . Access to the new Charles River Di will be maintained via a replace- lit road built parallel to existing B/erly Street. Replacement of the fcgh-Level Bridge with two, lower- 1/el bridges will also have adverse vsual, air quality, and noise impacts o the environment for pedestrians and D:yclists on the downtown Boston side v the Charles River in the vicinity o the new Charles River Dam. Impacts 'V this MDC property are addressed in •t'e SECTION 4(f) EVALUATION in chapter ; 50, and in Section 4.16 AESTHETIC ] PACTS . The project will eliminate fblicly-owned parking under the tisting elevated Central Artery, *ich could be replaced as part of a iw Garden/Arena parking structure. Takings which will occur in the tisrs) should be completed by the let of tunnel construction in this u a; that development has been leigned to act as a buffer between Airport and residential areas, it : t jl also serve as a buffer during .jestruction of the tunnel. All of ■ Hi businesses that are displaced by -■'Si project in East Boston are located ai Massport property (with the excep- ts of a taking at Robie Airport P. k). The Third Harbor Tunnel will be c-ipleted four years after project c .imencement in late 1986. Traffic o.ginating from the southwest of Bston will then be able to divert f)m the Callahan/Sumner Tunnels to ■ti Third Harbor Tunnel, in order to *Did the Central Artery construc- tion. This will reduce traffic on the Arport access road and on local sreets. East Boston residents should tnefit from improved air quality as -11 as decreased congestion. Mitigating measures are being frsued to reduce the potential for Vrport spillover to the East Boston c'mmunity. A program to review the ipact of zoning and other land use cntrol mechanisms (including various ' - BIRD ISLAND FLATS 1^ — Boundary of Affected Parcel Identified in Table 45 Note: Boundaries are approximate. and are based on land use issues and impacts. Figure 36 Land Use Impacts East Boston / LoganAgl 400 Feel EIS/EIR for 1-90 -Third HarboT^^ Table 45 LOG AM AIRPORT LAND USE IMPACTS T 3WNER/ > JUL- c. :/future part ? cargo area c :/f uture part if cargo area ■ cn Airline* « /at Ion Center i irking TAXING full temp. full BUSINESS RELOCATION yea SUMMARY OF IMPACTS Ventilation building will permanently occupy the site precluding other uses. Permanent subsurface easement, will not affect una aa a roadway and cargo area. Business will be relocated on adjacent land, subsurface easement will not affect una of area for surface parking. n il Aviation full yea The occupants of this structure were planning to relocate regardlese of the project. Future use of the parcel will bo constrained in only one small corner by a subsurface tunnel easement. •rn Airlines ir Jatway very temp. no During approximately 18 months use of the jetway will bo constrained, there are no long-term impacts on the parcel. 1 Mr Cargo and m Air Freight i. lnga full yea Buildings will be taken, following construction similar structure a could be built over permanent subsurface easements. itnal Car Rental full yea Similar use could occur following construction; over permanent sub- surface easements. m t parcel h Car Rental H Car Rental partial perm. ' minor perm. partial Temporary and permanent taking* will reduce parcel size. Future uae of the remainder of the parcel could remain in ita current uae. no Minor permanent taking, will not affect uae of the parcel. > 259 or who missed their destinations. The National Car Rental facil- ity will be taken, as will the Hertz Express Car facility. A small portion of the Avis Car Rental site will be taken. New parcels will be less suitable for commercial tenants due to their irregular shape. Vehicular access to the Eastern Airlines hangar and the Massport taxi pool will be altered. The Eastern Airlines fuel farm will be slightly modified, and fuel truck access to this facility will be relocated. Access to the Airport BayBank branch office will be shifted from the egress roadway to a new central service road. Access to the Airport Hilton Hotel will be consolidated at the central service road. Two new parcels now occupied by roadways or land- scaping will be created in the central service area, with access from the new service road. The Exxon service station will oe removed and relocated to a site on the central service road. Access to the above uses will be somewhat less convenient than at present, but should be adequate for their operations. Access to the American Airlines air freight building will become more circuitous from the north and require trucks to use the new central service roaa and to cross outbound terminal traffic. Glycol storage tanks at the American Airlines hangar will be relocated; the landscaped pedestrian entrance to this ouilding will be reduced in size and associated parking will be reduced by approximately 60 spaces. The united Airlines Flight Kitchen and ABC air freight building will be removed; other sites are available at the Airport for reloca- tion of these facilities. Employee parking at the Williams air freight building will be reduced by approxi- mately 45 spaces. The Eastern Airlines Reserva- tions Center will be taken or under- pinned during construction, and adjacent employee parking will be temporarily reduced by 200 spaces. If a taking proves necessary, the bu ing will be reconstructed adjacen its present location and connects made to existing telephone lines essential for its operation so th< there is no interruption in servi< employee parking will be provided Parking at the Delta Airlii reservations center will be reduc< approximately 55 spaces. The cent building at Robie Airport Park wi shortened by two structural bays, requiring relocation of two tenant an adjacent air freight building be removed. The increase in vehicle tri to the Airport may generate additi parking demand at the Airport, whi may require the construction of additional parking facilities. Lifting the current EPA ban on in creasing Airport parking is being pursued by the state and Massport an effort to minimize possible spi over effects on the East Boston community. Construction impacts includ the removal of the Eastern Airline and Hill air freight buildings and Edson general aviation building. Following construction of the pro] these sites will be available for similar uses. There is adequate building area at Logan Airport to relocate the occupants of these buildings in a manner consistent the Logan Airport Master Plan. Th construction of replacement facil will be completed prior to the tak of these structures. The west satellite on the Eastern Airlines terminal (Southwe Terminal) will not be usable by lai turbojet passenger aircraft for a period of approximately 15 months during construction. The adjacent taxiway must be relocated closer t< the terminal during the constructic of the tunnel in this tightly con- strained area. The satellite termi can be used by smaller commuter aircraft during this period with adequate clearance for continued aircraft access to the Eastern Air- 260 .-en lectin nan 9 ar « Tne terminal can ■"tS iO tl iervi 'ided iue to operate normally by means . :emporary six-gate satellite jnal (see Mitigating Measures ). nrlii educi lenj »ij ays, enant e tti Mid , whi )f J I m !ing :::t i spi HI Minor detours of the Bird j Flats access road will be red during three phases of the to-four year construction period is area. These detours will not ficantly affect access to Bird d Flats. It appears that it will ssible to route the BIF access in such a way that it will not over the tunnel construction site g any phase of construction, ruction of air freight facilities he Bird island Flats mixed-use opment will be inconvenienced ig the three-year period when a on of the freight facilities site ied for construction staging. Disruptions to traffic on the >rt access and egress roads and ervice roadways will occur during of the construction period, but icluhnot significantly affect Airport ine LC e or operations, and Construction staging areas can pro] rcommodated on sites temporarily 1 for construction and on vacant at Bird island Flats. for te to Mitigating Measures include nt I tic management and measures to :e noise, vibration, and disrup- at the Hilton Hotel and at ine terminals near the construc- area. be t 1 : a ths rent it ! id :oii' :efl Construction will be staged, staging areas located, to avoid cts on the Massachusetts Techno- Center development. Construction cles will use a separate haul road llel to the Bird island Flats ss road and will use the Airport ice roads connecting to the onal highway system (Route 1A). majority of excavated material be removed from the Airport via a ice roaa east of the tunnel nment. Additional sites and/or build- ings are available at Bird island Flats, the Southwest Service Area, and the North Service Area to accommodate car rental, air freight, airline reservations, airline kitchen opera- tions, and parking permanently or temporarily displaced by the project (see Section 4.3 RELOCATION IMPACTS ). Parking displaced by the project will be replaced at other on-Airport locations with input from Massport on the final locations. Project construction disruption to Eastern Airlines passenger service, particularly the shuttle service, will be avoided through construction of a temporary six-gate satellite in the center of the Southwest Terminal, facing Bird Island Flats; commuter service which currently uses this apron area will be relocated to the west satellite, as described above. Modifications to the Airport circulation system will be needed to mitigate less convenient terminal circulation, less direct access to the Southwest Service Area and Bird Island Flats and less convenient access to the North Service Area. A specific design requirement is the replacement of the direct right turn movement to the Southwest Service Area/Bird Island Flats from the Aiport access road. Modifications to the North Service Road near Robie Airport Park may also have the potential to mitigate con- struction period and long-term impacts to uses relocated to the North Service Area. Any such modifications will be coordinated with Massport during preliminary and final design of the project. The Airport signage system which provides orientation to airline locations using several large overhead signs on the approach from the Calla- han Tunnel will have to be modified for users of the new Third Harbor Tunnel, who will enter the Airport roadway system downstream of these signs . Route 1A North Long-term impacts on the area 261 will be predominantly positive. Some displaced businesses from the Airport may relocate to this area. Increased traffic on Route 1A could be benefi- cial to businesses which depend on good access and to highway-oriented commercial businesses. Those busi- nesses with time-sensitive deliveries to Logan Airport may have slightly impaired access due to the increased traffic. Impacts on land use in Revere will be minor, with some increase in business expected because of improved access from Boston. Construction impacts on land use in this area will be minimal. Charlestown Long-term impacts of the project will not cause land use changes in this area. Construction impacts will not affect land use in Charlestown. 4.4.4 Joint Development The Preferred Alternative creates a unique opportunity for new development on air rights over the depressed Central Artery (see Figures 37 and 3b). The creation of 20 acres of new land for development and the opportunity to rebuild a significant portion of the city severed by the existing Artery are major positive impacts of the transportation proj- ect. Realizing the potential benefits of this unprecedented opportunity will require a complex development process involving many public and private interests over a 10 to 15 year period. Possible land uses include recreation, office, retail, residen- tial, parking, and open space. Careful planning will be required to assure that future uses of Artery air rights are viable and compatible with tne character of the adjacent neigh- borhoods. This section describes the steps involved in establishing an effective joint development process and the key issues and constraints to De dealt with in establishing a planning and decision-making mechai The need to establish a con uing joint development planning ani design process has been emphasized numerous public meetings throughout the EIS/EIR process and in testimoi at the public hearings. The Commoi wealth recognizes the importance o the issue and is committed to an ongoing open participatory processis concepts discussed in this sections refined and carried through details design and execution. Joint development is discus;ri in the following order: 1. Design objectives and consisr ations including: urban design, structural, historic, and economic issues used in developing an illusra tive joint development scheme. 2. Descriptions of specific isies and illustrative design concepts f: individual parcels, grouped by geo graphical subarea. 3. Description of the proposed joint development process. Related discussion of devel> ment on currently existing parcels adjacent to the project, particular in the North Station area and in Sit Boston, is contained in Section 4.4.3. For assessment of the secoi- ary impacts of the illustrative development possible within these assumptions, see Sections 4.2 TRAE - PORTATION , 4.4 LAND USE IMPACTS , 45 NEIGHBORHOOD AND COMMUNITY FACILIl K IMPACTS , 4.6 ECONOMICS , 4.14 HISTC Ij RESOURCES , and 4.16 AESTHETIC IMP* r5 DESIGN OBJECTIVES This general statement of design objectives for potential development of the 20 acres of airl rights is based upon known public I policies and on public input from H community participation phase of tfl project. While specific design guidelines for air-rights developirit will be established during the desp phase, these design objectives hav 262 Legend 1 . Entry & exit ramps and the transition section from the elevated Central Artery to the Dewey Square tunnel act as a visual and pedestrian barrier between the Financial District and the Waterfront/Fort Point Channel Area. 2. Visual and pedestrian connections between the historic Broad Street District and the Waterfront are complicated by the overhead roadway and its supporting piers and columns. The highway structure is close to the historic brick & granite buildings and conflicts with the scale and character of the district. 3. The Walk-To-The-Sea is affected by the dark environment under the highway structure and by the combined width of the Surface Artery and Atlantic Avenue. 4. The open expanse of surface roadways and the combination of surface, Central Artery, and tunnel connections present a confusing and dangerous situation for pedestrians 5. The Blackstone block and the Cross St. /Hanover SI /Salem St. area of the North End share a common street scale, architecture, and pattern of commercial ground floor activities The artery and its three ramps separate these areas; views across the Artery Corridor are severely limited and pedestrian connections (including the Freedom Trail) are difficult. 6. The width and layout of the surface street system and the isolation of this section under the artery contribute to a hazardous condition for North End residents walking to the Haymarkel MBTA station. 7. Street and building pattern of historic Bullfinch Triangle is severed by the artery and ramps. < - Pedestrian and Visual Figure 37 Corridor Existing Context Visual Corridor Central Artery from Congress Existing Central Artery and Ramps St. to Causeway St. i Pedestrian Connection ^^^^^^O^^^^^OO Feel Blocked EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93 - Central Artery Air-Rights Parcels Parcel 1 Congress Street - Pearl Street 32.000SF ■Parcel 2 Pearl Street - Oliver Street 62.000SF •Parcel 3 Oliver Street - High Street 90.000$* Parcel 4 High Street - India Street 66.O00SF Parcel 5 India Street - Milk Street 36.000SF Parcel 6 Milk Street -State Street 37.000SF Parcel 7 State Street - Clinton Street 80.000SF 'Parcel 8 Clinton Street - North Street 4S.OO0 S F •Parcel 9 Fulton Street - North Street 50 000SF •Parcel 10 North Street - Hanover Street 22.000SF 'Parcel 1 1 North Street - Hanover Street 90.000SF •Parcel 12 Hanover Street - Haymarket Square 85.000S.F Parcel 13 Endicott Street - Cooper Street 32.000SF Parcel 14 Haymarket Square - Traverse Street 35.000SF Parcel 15 Bounded by North Washington Street, Beverly Street and Traverse Street 12,000 ST. Parcel 16 Traverse Street - Causeway Street _65 ! O0OSF TOTAL 842.000 S.F. (Approximate •Parcel partially encumbered by ramp(s). Air-Rights available for development on 2nd floor taMat New Air Rights Parcels Figure 38 Joint Development Opportune Preferred Alternative Central Artery from Congress^ to Causeway st. EIS/EIR lor 1-90 400 Feel r -Third Harbor Tunnel^ used to illustrate joint develop- potential and are illustrated in re 39. Street and block patterns Id be in scale with that of ting neighborhoods or districts should re-establish a city circu- on system similar to that which ated the construction of the ral Artery. Maintain the major existing strian links connecting activity .ers across the corridor's surface ;ets, such as the "Walk-to-the-Sea" the Haymarket to North End connec- Establish parcels of sufficient depth, and configuration to lit flexibility in potential ;lopment, and to allow for com- wble land uses and densities. Where necessary within develop- : parcels, development should )mmodate or incorporate ramps or ;ilation buildings above the ressed Central Artery. Design building forms and open ):es to re-establish the visual ks between functional areas rsently severed by the Artery. Develop open spaces to assist in esstrian orientation. Provide visual n physical settings for important clvities and prominent buildings. the actual construction. Subsidy of certain uses will also have to be considered. While specific uses of most parcels cannot be preestablished , planning and decisions about founda- tions, access, and to some extent the type and massing/building envelopes of air-rights structures must be worked out during the highway design phase for incorporation in construction. Final engineering and other design phase decisions may modify specific assumptions. On the basis of current conceptual engineering, at least four kinds of issues must be addressed, as follows: 1. Structural Considerations. Based on the conceptual structural design of the tunnel, air-rights development capability differs signi- ficantly from parcel to parcel. Each parcel has been assessed to establish its capacity to accommodate buildings with and without structural modifica- tions of the tunnel. In almost all instances, the ability to develop more than one to five stories on air-rights will require one or more of the following modifications: a strengthening of the tunnel box top and bottom sections, strengthening of the center wall, and strengthening of the center slurry pile system. Additional structural support in the existing transfer beams spanning the outside slurry wall system could also be required in some locations for some building types. The effort of reconstructing portion of the city should center developing each parcel in harmony Wi its immediate environment; thus, 't= corridor" effect would disappear. >E IGN CONSIDERATIONS A number of air rights develop- issues must be resolved. Devel- 3 Fng air rights over the tunnel and =ps will present significant struc- ^al design considerations, founda- -in premiums, and legal and financial wks of long term decisions and estments some 10-15 years prior to All such decisions have to be made during preliminary design. Each parcel is unique in terms of its lateral alignment with the tunnel, the depth between the ground surface and top of the tunnel box, slurry wall and grade beam depth, and soil conditions. Each parcel will require further study as engineering work progresses, to determine the maximum carrying capac- ity and the structural modifications, if any, required to achieve the type of development planned for this parcel. This ongoing process may produce minor design changes in the tunnel, or in specific construction 265 These urban design guidelines were established to develop a base case analysis ola The process of developing design guidelines will be on-going and involve all appr 0 n r " ,"* ,s - attected neighborhoods, and other interested parties. la ' e P*t 1 . Reestablish a city circulation system similar to that which existed prior to the coin Central Artery to produce a street and block pattern that is in scale with that of mi* ' uc ' w tf or district. Mai ™iqu e „ 2. Respect the maior pedestrian links connecting activity centers across the corrida such as the "Walk-lo-the-Sea" and the Haymarket to North End connection SSui ' 3 t! 3. Establish parcels ot sufficient size, depth, and configuration to permit flexibility m n ment, and to allow for land uses and densities compatible with the ad|acent functional j,^ 4. Develop general guidelines for new buildings which stress scale and lorm relationsh the old and new by maintaining facade planes, emphasizing lateral continuity across tri * respecting the architectural character and detailing of adpcent buildings and districts 6 C0 ' n< ' remely costly, but minor modifica- ns to the tunnel design could allow horter span. Building height is uo constrained by the lack of grade space for structural stiffen- against wind loads, mechanical terns and elevator shafts. More nisticated analysis will be needed later design stages to determine i feasibility of buildings higher n 15 stories. Ventilation Buildings. following additional detailed air quality analysis. The ventilation buildings may be accommodated in air rights parcels above the depressed Central Artery, or they may be located on parcels adjacent to the right-of- way. The height and appearance of the structures will be guided by air quality requirements and by the requirements of the Section 106 Memorandum of Agreement. 3. Section 106 Memorandum of -rights development may accommodate 'tilation buildings. The specific ation and configuration of ventila- - n buildings will be determined Agreement . The Memorandum of Agree- ment (MOA) between the Federal Highway Administration (FHWA), Advisory Council on Historic Preservation (ACHP), Massachusetts Historical Commission (MHC), and Boston Landmarks Commission (BLC) describes mitigation measures which must be implemented to minimize impacts of the project on adjacent historic districts. The architectural and visual character of air-rights development will have to satisfy these Section 106 requirements. 4. Economic Feasibility . Selected parcels were examined to assess the economic feasibility of their develop- ment at a range of densities and uses consistent with the urban design objectives described above. Selected parcels were tested using 1983 market data to determine if the required foundation premium exceeds the market value of the "land". The preliminary analysis suggests that the potential return from leasing the air-rights could cover the foundation premium, financing, and administrative costs incurred by the necessary public involvement. As provision of addi- tional subsurface structure to support air-rights buildings must be built at the time the tunnel is constructed, an appropriate public agency or authority will be required to provide the front-end costs and subsequently lease the air-rights to private developers. ILLUSTRATIVE JOINT DEVELOPMENT A parcel-by-parcel illustration of possible air-rights development has been prepared on the basis of the design objectives and considerations discussed above. Parcels have been 267 grouped into seven distinct subareas on the basis of several factors: (1) constituencies that emerged during the preparation of the DEIS/DEIR (for example, Fort Point Channel); (2) constituencies that are well identi- fied from decades of involvement in public issues (for example, the North End); (3) geographic and historic definition (for example, the Bulfinch Triangle); (4) patterns of activity (for example, the Financial District), and distinct problems or opportunities (for example, Haymarket Square). See Figure 40 for a graphic description. Fort Point Channel a landscaped vehicular entrance tc downtown via New Dorchester Avenue (4) the continuation of the City' Waterfront Walk to allow public a to the waterfront from Christopher Columbus Park to the head of the ! Point Channel (see Figure 41). With the Preferred Alternat development opportunities created reinforce the Channel's attractive (see Figures 42, 43, and 44). New Dorchester Avenue will allow the entire Channel to be accessible to public use, providing an alternate route to downtown for the South Bo! community. Upper Fort Point Channel, from the existing Dorchester Avenue bridge to the summer Street bridge, is inaccessible to pedestrians and surrounded by industrial uses. This area, as seen from the Summer Street bridge, is a calm water surface with continuous granite bulkheads that accentuate its length. In contrast, the Fort Point Channel between the Summer Street and Congress street bridges is small and well-defined. This area does not have good public access to the water and has not been developed for marine- related commercial or open space uses. The section north of the Congress Street bridge to the existing Northern Avenue bridge is very differ- ent. This is a high activity area and its edges are used for both public and private uses. The public uses include the Tea Party Museum and Children's Museum. Lobster boats, public leisure boat marina and commercial marine activity represent the private uses. The relocation of Dorcheste Avenue will result in the creation two new parcels of land. One of t parcels is at the head of the Chan and could be developed for a publi use, such as a park or boat landin The other parcel, about one acre i size, is adjacent to Gillette Comp. property. This parcel could be acquired by Gillette to provide lai to build a new headquarters, furthi improving the quality of developmei. around the Channel. Consistent with the Section Memorandum of Agreement , a boardwa! below the New Dorchester Avenue sti level would be designed within the Channel, thus providing a separatic between vehicular and pedestrian traffic. This boardwalk would ext« from the headwall at the existing Dorchester Avenue Bridge along the bulkhead. From the lowered boardws pedestrians would have the opportur to relate more directly to the wat based activities which contribute the Channel's historic character. i The major joint development opportunities afforded by the project are: (1) The creation of water- related open spaces that will provide stages for activities, i.e., open spaces for lunching, (2) the re-estab- lishment of a pedestrian connection from South Boston to downtown via New Dorchester Avenue, (3) the creation of As the boardwalk approaches Summer Street Bridge, the tunnel b(J (which had been under the Channel)|| emerges and causes a shift of the? bulkhead and creates a surface deckj area of 35,000 square feet. This tunnel box provides the opportunity for a recreational open space easily accessible to downtown Boston office workers. Lightweight 268 Urban Design Objectives - Fort Point Channel 1 . Provide architectural treatment and reduce scale of ventilation building to lessen visual imp^ 2. Create public open space with access from Dorchester Avenue for recreation andposahu 3. Provide visual landmark at focal point on pedestrian walkway. 4. Provide landscaping as visual buffer between Post Office loading docks and New Dm*™ 5. Provide landscaping, pedestrian level lighting, architectural railings and steps and ram boardwalk along street level sidewalk to improve pedestrian experience. 6. Lower pedestrian boardwalk to provide visual separation from vehicular traffic and to h closer proximity to the water ^WWn 7. Pedestrian bridge could connect boardwalk to existing and planned activities on then the Channel. "sssftci 8. Design public recreation decks with outdoor commercial activities to be buill over lunneltv. linear plane of granite bulkhead line to preserve the symmetry of the Channel south olih»« Street Bridge. 9. Design decks over the tunnel box for public recreation use. Elevation and material of the den minimize impact on existing bulkhead and bridges. 1 0. Completing pedestrian link between Harbor Plaza building and U.S Customs buildinq™ waterfront pedestrian walkway from South Boston to Waterfront Park, 1 1 . Louvers and landscape screening lessen impact of tunnel open section. New structures on am* would be possible if side louvers are provided for ventilation "mm — Proposed Pedestrian Link ooo Grade Separated Pedestrian Link HI Existing Open Space PI Proposed Open Space Figure 41 Urban Design Objectives Preferred Alternative South Bay/Fort Point Channel " "q o^^^oo^^Tx) f«i ^ J EIS/EIR for I-90 -Third Harbor jug^^ / View from Boardwalk Along New Dorchester Avenue (Looking North) 1-90 -Third Harbor Tunnel; 1-93 -Central Artery Figure 44 Illustrative Section through Fort Point Channel South of Congress Street (Looking North) POSt Office New uctures could be located here to |se food services catering to the chtime users. As the tunnel box ceeds north along the Channel knead, another deck is created ween the Summer Street and Congress eet bridges. Due to the proximity the decked area to the Federal ;erve Bank, the opportunity would .st to extend the Bank's Sculpture den to the waterfront, tying the j open spaces together. The tunnel c continues north, curving into the isting bulkhead line. Nortn of the lgress Street bridge, the tunnel :ges into the existing bulkhead line i has a minimal impact on this area the waterway. Construction of a new granite lkhead in this section allows for e extension of the public walkway to e northern limit of the project, tough coordination with the property ners along the western edge of the annel, the public walkway could tend further providing continuous terfront access from the Fort Point annel to the Waterfront Park and the uarium. The potential for marina velopment is limited by the availa- lity of accessible parking. How- •er, a pedestrian bridge over the ;annel could be designed that would ovide access to the eastern side of le Channel at the Boston Wharf operty. This bridge could provide :cess to parking areas in the Fort )int Channel warehousing area. inancial District The transition from an elevated antral Artery to the Dewey Square annel occurs in this subarea; this transition section, together with the any on- and off -ramps, creates the ongest barrier in the corridor tretching from Congress to High treets. Removing all of these lements will allow the reestablish- ent of the street and block pattern hat existed prior to the Artery onstruction in the 1950s; the Finan- ial District will again be connected o the Harbor, Fort Point Channel and the industrial/waterfront section of South Boston (see Figures 45 and 46). However, the physical character and land uses in the area have changed dramatically in the interim and will continue to change as the new Northern Avenue Bridge, Rowes/Fosters wharf, and proposed Fort Hill developments proceed into construction over the next few years. This distinguishes the Financial District subarea from the others in that any planning for joint development over the tunnel must be carried out in concert with plan- ning efforts for adjoining parcels and public improvements to a greater degree than in other subareas. o Parcel 1 is approximately 32,000 square feet. Although it is free of any ramps or ventilation buildings, more analysis will be required to determine the nature of structural constraints placed on any air-rights development by the reten- tion of the existing tunnel walls in contrast to the rest of the corridor where a new slurry wall system will be in place. o Parcel 2 , between Pearl and Oliver Streets, is 62,000 square feet, but is constrained by the placement of a southbound exit ramp and an opening in the new tunnel roof for ventilation of the existing Dewey Square Tunnel. o Parcel 3 is the largest at 90,000 square feet and, like Parcel 2, is similarly constrained by a north- bound on-ramp and currently by the combined mass of two ventilation buildings in the center of the parcel. The context of all three parcels is similar in some respects: the buildings on adjacent sites vary from 6 to 30 stories in height and there are still some large undeveloped sites; the predominant land use is office with some retail at the ground level; and proximity to the Waterfront would allow views of the Harbor and Fort Point Channel from potential future buildings on the air-rights parcels . 273 Figure 45 Existing: Aerial view of the Financial District from Congress Street to High Street. Figure 46 After Construction: Air-rights parcels available for development. Financial District streets reco nected to the Waterfront and South Boston. EIS EIR for 1-90 — Third Harbor Tunnel; 1-93 — Central Arterv 1-4. Newly created air-rights parcels A. Buildings not taken; they are shown in outline form to illustrate new surface street pattern B. Fort Hill Development Site C. Rowes and Fosters Wharf Develops It is reasonable to assume that lar uses would be proposed for the parcels and tnat housing might oe iible on the north end of Parcel 3 • Rowes/Fosters Wharf. One of the ; positive changes is the possibil- of providing active retail uses on major pedestrian corridors from - Financial District down Congress jet to the Fort Point Channel, Tea \ ty Ship, and Children's Museum; jn Oliver Street to the new Northern inue Bridge and South Boston water- _cnt development area; and down High Jjeet to the public ferry landing on lies/Fosters Wharf. The neight and density of telopment on Parcel 1 will be (ermined in part by its structural «ring capacity and on Parcel 2 by A ability to maintain an open y.tilation section and ramp while rting the ground floor access and i tical circulation requirements of a Tl-rise office tower. Parcel 3 presents a very liferent opportunity. It is an i:remely long parcel and can accom- odate the ramp and ventilation sructures within a development ulding envelope, possibly in a ;:age structure. The parcel is Icated at a sharp bend in the cor- rJor, and this, coupled with its lngth, suggests that the relationship I building forms to open space and pdestrian paths must be carefully Krked out so that the disorienting trrier effect of the existing transi- tion section is not repeated. Provi- ■on of second level connections ttween the Fort Hill and Rowes/ fsters wharf developments across this {reel is also possible. r oad street This historic area developed i.pidly with Boston's growing impor- .nce as a port city in the 19th ':ntury. Many of the buildings •sociated with this era remain, but ney are severed from the harbor by ie Central Artery; those adjacent to ie Artery are altered in scale and jpearance by the proximity of the large steel structure. Removing the Artery presents an opportunity to reconnect this district to the water- front, create a series of small open spaces around and between these buildings, and expand the mixed use neighborhood on three new air-rights parcels . Parcels 4, 5 and 6 extend from High Street to State Street. A ventilation building has been proposed to be located in the general vicinity of these parcels. The specific location and configuration of the required ventilation structure will be determined following additional detailed air quality modeling and analysis . Each of the three parcels could be developed for office or residential use on the upper floors and office or retail use on the ground floor with parking provided in each or all of the parcels as needed. There are estab- lished markets for both office and residential space in this area, and the creation of new mini-parks and pedestrian walkways to the waterfront should enhance the marketability of the three air-rights parcels. There are two types of public open space opportunities: (1) Land- scaped pedestrian "links" across the parcels at High, Broad, India, Milk, and Central Streets (see Figures 47 and 48) and/ (2) A linear sequence of small parks along the irregular edge of buildings parallel to the south- bound surface Artery (see Figures 49 and 50). Many of these are buildings which were truncated, during the Central Artery construction in the 1950s with the notable exception of the Grain Exchange Building whose windows face directly into the high- way's columns and girders. Removing the viaduct will allow the development of a radically different environment for these older historic buildings. o On Parcel 4 , the building forms could define new plazas at the impor- tant pedestrian crossing where High and Broad Streets intersect and at the other end of the parcel where India 275 Figure 47 Existing: View toward the harbor along Central Street. Figure 48 After Construction: View toward the harbor and the Aquarium along Central Street, illustrating air-rights development - one option. EIS/EIR for 1-90 - Third Harbor Tunnel: 1-93 - Central Artery i 49 < ting: View looking north along the Surface Artery adjacent to the Broad Street District. t) Construction: View toward the harbor and the Aquarium along Central Street, illustrating '-j }hts development - one option. 'A I for 1-90 - Third Harbor Tunnel: 1-93 - Central Artery Street crosses to the Waterfront. Broad and India Streets intersect the new parcels at an oblique angle, creating an interesting design opportunity for both buildings and open spaces. o A building on Parcel 5 should respect the diagonal geometry of India Street at one end and the 90 degree geometry of Milk Street at the other end; its design should respect the preeminence of the Grain Exchange Building. o Parcel 6 offers an opportunity to create a pedestrian mall at the end of Central Street connecting McKinley Square ana the U.S. Customs House area with the Waterfront and the Aquarium Plaza. Building forms on this parcel could replicate those of the remaining sections of the State Street block and Central Wharf, thus, reestablishing visual continuity between the historic Broad Street District and the Harbor that generated its development. Waterfront This subarea extends from North Street to High Street and includes two large parcels. Parcel 7, between High and Clinton Streets, is approximately 80,000 square feet and is not encum- bered by any new tunnel elements; the smaller Parcel 8 (40,000 square feet), however, accommodates a northbound exit ramp, the Callahan Tunnel en- trance ramp, and possibly a ventila- tion building. These elements, plus the narrow width of the parcel, make it consideraoly more difficult to develop than Parcel 7. The context of the two parcels is quite different in terms of both the physical character of adjacent blocks and the types of uses within. Parcel 7 offers an opportunity to strengthen two important pedestrian connections and retail corridors: State Street to Long Wharf and Quincy Market to the Waterfront Park, Marri- ott Hotel and Mercantile Wharf. The parcel is flanked by heavily used public spaces and active ground floor stores and restaurants including the new Marketplace Center, now unde construction. o Parcel 7 offers a very di ent type of opportunity. The to-the-Sea" could be extended th a skylit gallery or an open mid- pedestrian walkway with ground f retail space on either side. A block to the north could be used office space or housing on the u floors as could those of a highe building to the south parallel tl State Street. The gallery or wa| would be the last link of the pe trian axis from Government Cente Plaza to the harbor, occupying a pivotal location along that axis could extend the linear path fro South Market Street through Mark place Center and then open out t afford views of the Waterfront ?% As viewed from the Park, it woul appear as an entrance to the cit i underlining the importance of th] major pedestrian walk. o Parcel 8 is flanked by th blank masonry facade of the Quin Market garage on one side and th walls of residential buildings a Commerical and Fulton Streets on other side. The many constraint, placed on this parcel suggest th might be a logical candidate for small parking garage, possibly I bined with a recreation deck. A garage could span the tunnel ram] incorporate the ventilation stru< more easily than other building | and could be connected to the ex parking garage or to a new repla< parking structure on Parcel 9. south end of Parcel 8, at the intersec- tion of Clinton Street the new Surface Artery, a mini-pi; connecting Commercial street wit! Quincy Market is a possibility (! Figures 51 and 52 ) . North End The North End extends fron Fulton to Endicott Streets and ir: porates two large new parcels, bd Blackstone and Cross Streets, anct* smaller parcels within existing tX on the North side of Cross street 278 igure 51 xisting: View under the Central Artery toward Quincy Market from Commercial Street. Figure 52 After Construction: View toward Quincy Market from Commercial Street across a land- scaped pedestrian walkway - one option. EIS/EIR for I-90 - Third Harbor Tunnel: I-93 - Central Artery The principal joint development opportunities afforded by the project in this subarea are: (1) the reestab- lishment of a connecting network of streets and pedestrian walkways between the North End and Downtown; (2) sufficient ground floor space in potential buildings on Parcels 11 and 12 to expand the area's existing food-related commercial activities and to connect the Blackstone Street Markets witn the Cross, Salem, and Hanover streets commercial area; (3) upper floor space on all four parcels which could be used for offices, housing, recreation and other community facilities; and, (4) a series of small plazas which could enhance the neighborhood and be used for botn recreation and outdoor commercial activities. It has been assumed in examin- ing the range of possibilities for reuse of the land on these parcels that new buildings would be in scale with existing North End buildings, and that new streets and plazas would reflect the scale and character of the North End. The Artery as a barrier would disappear and, although the North End and Downtown would be physically reconnected, the placement of new buildings and the uses in these buildings could provide a new and staoilizing edge to the North End. o Parcels 9 and 10 : These two parcels could accommodate buildings, garages, or public open space on air-rights over the existing tunnel entrances. New buildings in the general height range of adjacent structures on Hanover and Fulton Streets would allow 100,000 square feet of space for retail, housing or other commercial activities. An open plaza in front of the handsome neo- classical Police Academy Building would provide a better setting for this building and would facilitate pedestrian movement along Cross Street where today tne open tunnel entrances inniDit safe passage. o Parcel 11 : This block could be the connecting link between Downtown and the North End. A diagonal pedes- trian walkway from Hanover stre« ; the Haymarket could tie together.- commercial activities now severe; the Artery (see Figures 53 and 3) 1 ground floor retail stores in ne buildings flanking this walkways further reinforce this connectic, Low-rise, walk-up housing or off* space could be developed on uppe floors; the total square footagejf all floors would be in the rangof 200,000 square feet. On the dovti side, a widened sidewalk and pecs- trian island would provide a nevg enlarged home for the Haymarket pushcarts; and on the North End I a small plaza could serve as an entrance to the North End at the important intersection of Hanove Cross streets. o Parcel 12 : Two new ramps bisect this block restricting qi^ level circulation across the coii« dor. However, there is sufficiet] depth between the ramps and parclj surface streets to accommodate iti uses; Cross Street would then be conventional two-sided shopping tl with additional food markets, r additional ramps (the Sumner Tur exit ramp and a southbound surfc Central Artery entrance ramp) wi connect directly to the Square. 280 Existing: View toward Hanover and Cross Streets from under the Central Artery. III' 11 » ,'i Figure 54 After Construction: View toward Hanover and Cross Streets across a small plaza - one option. EIS/EIR for 1-90 - Third Harbor Tunnel: 1-93 - Central Artery new roadways, added to the existing street network, Government Center Garage, MBTA bus station, Green Line, and Orange Line Stations, focus on a small but visually prominent corner of downtown Boston. In fact, Haymarket Square is the visual entry point into Boston for several routes and for all of the approaches from the North. Four issues are paramount from a joint development, surface area design point of view: (1) how to buffer the North End residential area from this busy intersection; (2) how to facilitate pedestrian circulation through the Square, especially the connection between the North End and MBTA stations; (3) how to avoid visual clutter disorienting to motorists and pedestrians; and (4) how to design the new elements within the Square to serve as an appropriate "entrance" into downtown. o Parcel 13 , approximately 30,000 square feet, extending from Endicott and Cooper Streets between the North End and Haymarket Square, offers an opportunity to design a noise and visual buffer between the two areas. This could take the form of an archi- tectural wall - perhaps characteristic of North End homes replicated on the surface. Landscaping or a small recreation area on the parcel could be incorporated into the design. Pedestrians would be able to cross at grade between the North End and the Haymarket MBTA station, but a grade-separated crossing would be possible. There is sufficient verti- cal clearance between the tunnel roof and street level to construct a new pedestrian entrance from Parcel 13 in the North End to the Orange and Green line platforms at Haymarket. Sky- lights could be placed in traffic islands above this pedestrian connec- tion which, in effect, would be a new entrance to the station for North End residents. The surface street system in Haymarket Square will receive much more attention in the preliminary design phase and a parallel effc: will focus on the visual charactr the surface environment. There various approaches to finding a solution for the problem of creai "order" within this environment t traffic islands dominated by sigi signals, and lights. In some wa area is analogous to Boston's Ke Square; the search for a design solution appropriate to this ga into Boston should center on an which signifies the historic anci vital importance of Haymarket Sql Bulfinch Triangle The Central Artery viaduc spans two large parcels which, o covered, could be redeveloped to reestablish the physical charact: the historic Bulfinch Triangle, provide over 2.5 acres for new 1 uses (see Figures 55 and 56). H portion of the Triangle between and Beverly Streets has always b severed by transportation corrid a canal, a railroad, the Orange Green Lines, and finally the Cen Artery. The canal and railroad i removed many years ago, the Oran Line was depressed in the 1970s, an alternative for reconstructin Green Line in a tunnel is under study. Removing the Artery woul allow the North Station/Bulf inch Triangle area to grow back toget over this corridor and to connec the rest of the city. The area is characterized! mix of office and industrial use: some retail and restaurants on ti ground floor level. The buildin principally late 19th and early j century masonry structures which' in height; most are in the six t story range. o Parcels 14 and 16 can be developed at comparable densitie provide between 500,000 and 750, square feet. Office and light i trial uses would be possible; th large floor areas attainable on i parcels would be suitable for eii although the area is far removed 5 282 View looking south from Causeway Street. 3D QOO 0 QQi 0 000 QOflDb" i ij m r."* 'ii'Ti i ur: M Ik _ EM l*iiS3 £l¥:f?3 pS?l(fx^ i , ' i 'v' 1 ''"iUv.v-v /.Ifr:-;-:-:';-:-: i l:o.v. Ul "itl 1-5! f\" X^v onstruction: Air-rights parcels available for development. Bulfinch Triangle surface street restored. 1-90 — Third Harbor Tunnel; 1-93 — Central Artery the Financial District and perhaps not marketable for Class A office space. A new housing complex is another possibility. Although it is difficult to envision today, the environment will be radically altered when the Artery is removed, and there are several good reasons to consider housing: access to public transporta- tion; proximity to the North End, and its convenience and service retail areas; views from upper floors of the Charles River Basin, Harbor, North End, and Charlestown Waterfront; and proximity to the potential amenity of two new landscaped parks. o Parcel 15 : a small urban square is a likely use for this triangular parcel bound by North Washington, Traverse, and Beverly Streets; it would be comparable in scale to Post Office Square and would face the tallest building in the North End as well as the two new development parcels. On the other side of these parcels, a linear parcel extending from Causeway Street to Haymarket Square would replace the existing Haverill Street. This long, narrow parcel rests on top of the Orange Line tunnel and could be developed as a landscaped mall linking the North Station area with Haymarket Square and Government Center. It has also been identified as a possible site for a new garage providing replacement parking for lost spaces under the Artery. JOINT DEVELOPMENT PROCESS General Policies The illustrative design work completed during the EIS/EIR process is the first step in a process that must continue through the project construction period and subsequent availability of development parcels. This work is an essential part of the task of preparing imaginative and realistic plans, and of designing an effective mechanism for facilitating and controlling development. What follows represents an initial state- ment of the Commonwealth's policies 284 regarding this important joint opment process. o Continuity , whatever ti disposition of development par;l the state will continue an ongln open process involving the cit'ai other public agencies and priv;e citizens, especially those in ;»i borhoods adjacent to the Arter corridor. The need for this c\tl ity was emphasized in comments 1 on the SDEIS/SDEIR and in testw presented at the public hearing, is particularly important to mi.na activity between the publicatiu this FEIS/FEIR and the start o: preliminary design work. o Coordination and Qveral. Responsibility . Continuing sti.e involvement will be required t< develop mechanisms to finance te costs of future building foundcic* and to enforce design guideline 5 the new development. As the prnd proponent of this project, the f oi> monwealth will be responsible ft' coordinating and implementing snA tive and environmentally sound on development within the project op dor. The new land created by he Artery depression will be ownectr Commonwealth, and the ongoing cert tion and maintenance of the higwa facility will be a Commonwealth responsibility. State leadershp be required in pursuing any neee: legislation. Close coordinatio « be maintained with the City of br as various city departments wil p' a central role in this process. 1* Boston Redevelopment Authority W indicated the project's general conformance with both specific W| plans and more general planning activities, and has expressed afl interest in participating activly the continuing planning process o Local involvement . ReprW tives of affected neighborhoods vi. have an active role throughout ie process. Participation should If* organized around geographic sub.:« containing groups of parcels wilH :>n development issues and of n=rn to neighborhood groups. ;-cedures for membership and partici- : : .t3n will be defined, primarily to -.gee continuity of participation .rughout the process of planning, -• sgn, construction and development. ..6,specific responsibilities of these ....c,ps, and the mechanisms by which .,jb will interact with public offi- : ...cS, public agencies and with ...!cect designers, are covered further r .„,he following discussion of a .. .cosed three-stage planning process. The Executive Office of Trans- ition and Construction (EOTC), and i Massachusetts Department of Public ;s (MDPW) will be responsible for "TTCiding appropriate technical .stance to these groups. Prospec- y .y. developers will be required to be -. )lved in the public participatory •:.; s ;ess for development of the air ■ -„its. Selection of the developers : L likely be by the Commwonwealth ; i significant input from the City local interests. :nd ; ■ cinuing Development Planning The joint development process Id extend over the course of .1 liminary design, final design, , istruction, and into an implementa- phase that would last as long as . takes to develop each of the new i..;cels - a minimum of 15 years from ' a; r commencement of project construc- ,.|n. The phasing of development inning activities is based on the ..;ietable for design and construction .'the project. The Preliminary ign Phase takes the project to the 3 ||.nt at which design is 25 percent . uplete, and all major technical ..Mies have been resolved. Detailed ; ';ign and the working drawings can n be commenced. At preliminary :: ;ign completion, plans for joint 'elopment must be sufficiently J 'anced sucn that all necessary : .'>visions for the design of the • inel and surface street system have l>(;n identified and approved. By this ^ae, the process for agency and ^amunity participation must be well i:ablished; design guidelines, mechanisms for managing the develop- ment planning process, and for funding any necessary extra project costs must be determined. The first phase of development ("short-term") would begin as soon as reasonable assurance of project approval and funding is received and continue to the start of preliminary design. The second phase ("mid-term") would begin with the preliminary design phase and end with the comple- tion of preliminary design. The final phase ("long-term") would continue through the design phase until completion of construction and disposition of development parcels had occurred . Short-Term Process Between the publication of the FEIS/FEIR and commencement of prelim- inary design, the state will take steps to establish a responsive planning process. The "agenda" will include land use issues, minor refine- ments to surface street design, building scale, land disposition, job creation, public improvements and open spaces. The basic purpose of this stage will be to identify the full and specific range of issues to be addressed during preliminary design. Community-based task forces will be established to provide for direct involvement in the planning as it affects specific subareas. The process will also include the partici- pation of public agencies, organiza- tions and individuals with relevant technical expertise in such areas as real estate development and finance, architecture and urban design, as well as community-based development. To accomplish this, strategic, task- oriented project-wide committees will be organized as necessary to address specific technical issues. Because the Central Artery corridor passes through very distinct neighborhoods, historic districts and commercial areas, the issues and constituent groups vary by location. Accordingly, community-based task 285 forces will focus on geographic subareas. Membership will be open to all interested parties and the struc- ture of the task forces will be formalized as the issues become more specific. Workshops will be conducted in each of the subareas as part of the preliminary design phase. The product of these meetings will be joint development reports (issues papers) to guide the early phases of preliminary design. An understanding of community and agency concerns should precede detailed preliminary engineering in order for these concerns to be incor- porated into the project design. Mid-Term Process This stage will be concurrent with the detailed design phase. The critical decisions regarding details of surface street design, open space, and design guidelines for development will be reached during this stage. Subarea tasK forces established to generate joint development issues papers will provide guidance for the design work of the various project design teams. The proposed air-rights devel- opment scheme will be shaped in this period, ana it is expected that numerous meetings, workshops, and other means of dialogue between the community, tne city, the state, and the designers will occur. Interim products, including drawings, models and other illustrative devices will be prepared for task force review. The product of tnis work will be a set of joint development guidelines, a public improvements plan for each parcel, and a state policy plan for implementing the concepts developed by the process. At the completion of prelim- inary design, specific products will include an overall land use plan for all parcels; a description of the mecnanism for managing the ongoing process of development planning and developer selection; a description of the process for funding front-end structural and foundation costs; preliminary criteria for deve.tpei selection; and a plan for the levr ment of proposed public open ;>aci These would be linked to the iina] structural designs and the suia street system. Long-Term Process After the basic decisics regarding land uses and desigrgm lines have been made, there wil ^ continuing planning and implennta process to ensure that: (1) te detailed designs follow the d€isj reached during the preliminaries phase; and (2) the selection c . developers for air-rights parcls the refinement of their proposd development plans are consistet established design guidelines. It is likely that the cs.: guidelines for each parcel wil, quite specific, reflecting thed*.. which emerges from the subareatcs force review process. As the &s\ guidelines and criteria for dee., selection are finalized, advic wi be sought from appropriate proec- advisory groups. Financing and Development Mech.iu Providing a structural for larger air-rights building wi require a front-end investments^: must be carried for 10 to 15 y^rs, state-backed development mechais will be necessary to provide f :i. development capability, assistin developer selection, finance sine the public open space improvermit and enforce the subarea design pai lines. The specific developmei: mechanism cannot be determined io» but must be established at an ur point in the overall process. The mechanism ultimately selected must provide the avaijbi of needed front-end public fincici be responsive to the plans prodw through working with the subart. t forces; have direct access to ky state and city policy makers; ad directly tied to the design prces and thus able to assure that plnn 286 ,r tne development parcels is fully if grated with the detailed design of if depressed roadway and of the : irace street system. The mechanism may combine rents of more than one approach, ii of the specific problems likely i e encountered include: (1) to :i eve the desired land uses, build- , scale, and open space improvements ; : \ iome parcels, it may be necessary iubsidize some portion of the cost i revenues realized from the leases >ther more profitable parcels; (2) i of the front-end costs, such as lc alterations to slurry wall or lei box construction, are system- i and not just related to a single :el or subarea; (3) the designated elopers of individual parcels could required to contribute to the struction and maintenance costs of lie open space improvements oughout the corridor; and, (4) -traditional public and private Jing sources will probably be ded to assist in financing open ce and other public improvements. vie i Among the possible approaches r: (1) establishing within the ponsible state agency (EOTC and the -W), the staff capability to execute se responsibilities in conjunction h general or specific state bonding ".hority; (2) utilizing an existing : te agency with appropriate powers experience (e.g., the Massachu- ■ ts state Land Bank); and, (3) bating a special purpose public ^■telopment authority to oversee all ^elopment planning and implementa- »<>n. go I : erim Land Uses During the two-year period [uired for dismantling the Central ery viaduct, new surface area will :ome available for other uses. The 3 '|' surface street system will be It in increments. Parcel avail- lity will parallel this effort, but i timing of new development will be iunction of market demand. Interim !S for these parcels, prior to development for buildings or public open space, could include surface parking, recreation, and temporary landscaping. Some parcels will probably be loamed, seeded and fenced until such time as permanent develop- ment is underway. 4.5 NEIGHBORHOOD AND COMMUNITY FACILITIES IMPACTS 4.5.1 Comparison of Alternatives o South Boston will benefit from the Preferred Alternative through a reduction in truck and auto traffic on local streets. Removal of through trucks will improve the safety on local streets, and reduce traffic noise. Alternative 5A would reduce truck traffic on South Boston streets to a slightly lesser extent than the Preferred Alternative because it does not provide the same level of access as the Preferred Alternative. Alter- natives 2, 3, 3A, 4, and 5 would have minor positive impacts on South Boston traffic. The No-Build Alternative and Alternative 6 would not provide traffic benefits in South Boston. o The Preferred Alternative will result in the Waterfront having a significantly improved quality of life following the removal of the elevated Central Artery, with aesthetic, air quality, noise and access benefits. Alternatives 3A, 5A and 6 will have similar benefits; the No-Build Alter- native and Alternatives 2, 3, 4 and 5 would not provide these benefits. o The North End will have im- proved environmental quality following the construction of the Preferred Alternative. The long-term impacts on community cohesion are not based solely on the physical impacts of the project, but rather are also dependent on management of construction, and disposition of air-rights parcels. Alternatives 3A, 5A and 6 would have similar impacts. Alternatives 2, 3, 4 and 5 would provide only minor benefits to the community. With the No-Build Alternative, air quality and congestion caused by regional traffic 287 on local streets would continue to get worse over time. o East Boston air quality will improve and traffic on most local streets will decrease with the con- struction of the Preferred Alterna- tive. Alternatives 3, 3A, 5, and 5A would also cause these benefits, but would place the tunnel much closer to the community and would result in a permanent open space taking. No benefits would result from the No-Build Alternative or Alternative 6, and air quality and traffic would get worse over time. Alternatives 2 and 4 would have significant negative im- pacts on the East Boston community. o Construction period impacts of the Preferred Alternative on the neighborhoods on the Boston side of the harbor are similar to those of Alternatives 3A, 5A and 6; and are of longer duration and more disruptive than those of the No-Build Alternative or Alternatives 3 and 5. The Pre- ferred Alternative has the least construction period impact on East Boston, followed by Alternatives 3, 3A, 5, and 5A. Alternatives 2 and 4 are similar to Alternatives 3 and 5 on the Boston side of the harbor, but are significantly worse than all other alternatives in East Boston. 4.5.2 No-Build Alternative South End Long-term impacts are not expected with the No-Build Alternative. Construction impacts may result from a small increase in traffic on local streets during portions of the three year construction period. South Boston Long term impacts will result from increased traffic on local streets. Heavy trucks will continue to find shortcuts through residential areas rather than staying on truck routes. This will further degrade the quality of life for residents. 288 Construction impacts ma' oc as a result of increased traf f ; diversions to local streets. Chinatown/South Cove, Waterfroi ., North End, North Station, West fro Long-term impacts will r»t cause changes in existing or pup 0 land use patterns and trends irjth neighborhoods. Increased traflc congestion, air and noise pollii; will reduce the quality of lifcfo residents and visitors. Construction impacts wiJ inconvenience residents, shoppes, tourists for the three years dcin which redecking would occur. ;ce from one side of the Artery to he other will become more difficul a inconvenient as residents and vs use alternative routes. This pob will be most acute for Waterfrot North End residents and visitor, temporary relocation of parkingar, pushcart storage from under theAr will affect residents and shopprs Cross Street businesses will alD I disrupted by noise and dust dune construction. East Boston Long-term impacts in Eas Boston may result because the lrgf proportion of elderly residents In East Boston, coupled with a risig vacancy rate (already higher th.i Boston average), indicate that le area will experience considerab.; demographic change over the next 2i years. This makes the community sensitive to changes which affe<. neighborhood cohesion, as well <: t character of the community. With the No-Build Alternciv traffic increases in the existir tunnels, and Airport growth whioji projected to occur as the regiorl national economy continue to grc, will tend to increase traffic ar related impacts in East Boston rs. dential areas abutting the existng tunnels and the Airport. Noise ev related to traffic will increase a le air quality improvements due to eral emission controls are ex- ted, pollutant concentrations will ' (near or aoove standards at several ations, reducing the quality of — e in these areas and increasing the Dability of disinvestment and ociated community impacts. Land conflicts between Airport-related •Sj residential uses may also tend to ede neighborhood preservation orts in localized areas. Construction impacts will occur a result of congestion resulting ira redecking the Central Artery ch will cause backups at the sting tunnel toll plaza. This will lporarily degrade local air quality. M 1.3 Tne Preferred Alternative Mitigating measures are briefly ; i5cussed below; for greater detail > Section 4.4 LAND USE IMPACTS where ; ighborhood related mitigating isures are spelled out. :: ?Jth End Long-term impacts on the South i neighborhood will be positive. "aor decreases in through traffic on jth End streets, as a result of the ocald Street Extension and Expressway up relocations, are expected to prove the quality of life on resi- ntial streets. Construction impacts of the eferred Alternative will have little feet on community facilities and ighborhood cohesion in the South End. uth Boston Long-term impacts of the eferred Alternative will be positive r South Boston neighborhoods. The eferred Alternative will remove rough truck and commuter traffic om South Boston's streets. In rticular, traffic on A and D Streets d on Day Boulevard will decrease. Pedestrian access between South ston and downtown will be signifi- ntly improved with the construction of a continuous walkway from Broadway to Summer and Congress Streets along Fort Point Channel. Construction impacts are expected to be relatively minor. A new West Fourth Street Bridge will be built as a separate project prior to the commencement of the Central Artery/Third Harbor Tunnel project. The Broadway Bridge will remain open while Herald Street Extension is being built. Therefore, access to the residential community will not be reduced during the construction period. During construction of the depressed Central Artery, the in- creased congestion on downtown Boston surface streets may increase diver- sions of through traffic into the community to a minor extent. Mitigating measures include traffic management and construction staging to minimize detours, and to prevent through traffic from detouring to residential streets. The new Herald Street Extension will be completed prior to the closing of the Broadway Bridge so that residents will always have access to Expressways and other parts of Boston. Chinatown/South Cove Long-term impacts will be positive as a result of decreased traffic on Kneeland Street and the removal of through traffic from Beach Street. The project is compatible with the proposed Dewey Square TSM project which will precede the central Artery/Third Harbor Tunnel project. The TSM project will close the three northbound lanes of the Surface Artery and shift southbound traffic to those lanes, thus providing the opportunity to construct open space areas adjacent to the Chinese community and to create an appropriate setting for the china- town Gate area. Pagoda Park, an open space area near Chinatown consisting of two basketball courts and a volleyball court, had been leased on a short-term basis by the Boston Parks and Recre- 289 ation Department from the Massachu- setts Turnpike Authority. The site is currently under lease to the Wang Corporation. The site of this park will be displaced by the project (FHWA has determined that Section 4(f) requirements do not apply to Pagoda Park — see COMMENTS AND COORDINA- TION ) . These facilities will be provided on a site made possible by the separate TSM project noted above, in the vicinity of the Chinatown Gate. Construction impacts in this area will be caused by increased traffic on Kneeland street. Actual construction activities in the immedi- ate vicinity of the community will not be significant. Mitigating measures will include traffic management techniques to minimize disruption during the construction period. Beach Street will be prevented from being used as a detour route. Waterfront Long-term impacts are primarily positive. Removal of the Central Artery structure will improve the pedestrian environment and reduce traffic-related air and noise pollu- tion. The "Walk-to-the-Sea " will be greatly enhanced. Pedestrians walking along the waterfront on Atlantic Avenue will have views of their destinations. Pedestrian access between various Waterfront attrac- tions, as well as between the Water- front and surrounding neighborhoods, will be improved as traffic on Atlan- tic Avenue is reduced. Parking spaces botn under and alongside the existing Central Artery that are taken by the project will be replaced. Tour bus parking will continue to be provided on local streets. Construction impacts , including dust, noise, vibration and congestion, will reduce the quality of the pedes- trian environment, and will be disrup- tive for area residents and tour Noise, dust and traffic managemer mitigating measures will reduce t impacts. Increased traffic on At tic Avenue and Commercial street iJ] impair access to public faciliti? such as Christopher Columbus Park t\ New England Aquarium and the Aqueiu- MBTA station. It will be more difi- cult for residents of the east sie t Atlantic Avenue, and for tourists visiting waterfront attractions, o get to surrounding areas. Atlantc Avenue will be rebuilt by the Masa- chusetts Department of Public Wois • make it safer, prior to the startof this project. Pedestrian access ill be assured at all times during cc- struction. As detailed in the led use section, the open-air Haymarkt pushcart area, a community faciliy which depends on pedestrian acces, will be affected by the construct specific noise and dust control measures will be undertaken. The ventilation building i tt vicinity of the Harbor Towers wi] affect air quality in that area. Further air quality modeling and analysis of the ventilation syste will be performed to assure confcm- ance with appropriate air quality standards and to minimize air quair impacts on neighborhood residents Mitigating measures specifc I the Waterfront include provisions^ ensuring Haymarket's operations (ee Section 4.4.3 Waterfront ) and prci- sion of designated areas for the unloading and parking of tour buss local streets. Government Center Long-term impacts will res! in more circuitous access to the re from the Central Artery. The eliif!' tion of the southbound Central Arer exit ramp at New chardon street wll require drivers coming from the ikti to use the Causeway Street exit rmp and follow surface streets into te Government Center area. Drivers coming from the south will exit a< North Street and make a U-turn ono 290 :. nton street or continue on the gi face Artery to New chardon Street. The environment will be im- I >ved for pedestrians moving between tl! neighborhoods across the Artery c ridor . Construction impacts will be c Lated to access. Confusion result- il from the relocation of access 1 pints and streets will be a problem f: the many visitors to Government Citer who are only slightly familiar w;h the area. Changes in street and tiffic patterns will also incon- vuence the MBTA and commuter buses cuing in and out of Haymarket station. Construction related noise a'i dust will inconvenience the large nber of pedestrians in the area. Mitigating measures include taffic management techniques to esure pedestrian and vehicular access t the Haymarket MBTA station, partic- -arly across the construction corri- dr from the North End. Parking which I lost from lots under the elevated Cntral Artery will be replaced nearby. Urth End Long-term impacts include both tual physical changes and the jrception by residents that the ighborhood has changed. Removing the existing Central /tery structure will improve the 'Stern edge of the North End aes- tetically. Pedestrian routes between le North End and other downtown r ighborhoods will be more open and < tractive. Convenient access between 'e North End and the Haymarket MBTA ation will be provided. Predicting the ultimate impact * the physical and perceptual bene- ts of removing the Central Artery on social fabric of the North End is ' ry difficult. For a number of ■lars, new private development and fblic improvements in the adjacent l terf ront area have been attracting jw residents to the North End commun- y, with resulting increases in housing costs and condominium conver- sions. A growing proportion of North End housing is less affordable to long-term North End residents. Development pressures on the North End are expected to continue in this direction independent of this proj- ect. Over the next decade, unless active policy intervention is under- taken by the City, these changes can be expected to continue and acceler- ate. The prospect of improved overall neighborhood conditions due to elimination of the viaduct may re- inforce this trend. Conversely, commencement of a relatively extended construction period may dampen real estate speculation and pressures on the North End housing market. At the conclusion of construction of the Artery depression, the improved environmental quality of the area may encourage existing residents to stay, help to strengthen the neighborhood economy, and, therefore, reinforce the existing community. Business at North End restau- rants and stores could improve as visitors to surrounding neighborhoods find it easier to walk into the North End. These businesses are an integral component of the community's ethnic cohesiveness . A depressed Central Artery and new cross-harbor tunnel will reduce traffic-related air and noise pollution in the area. All parking spaces which are displaced by the project will be replaced nearby so that lack of parking does not discour- age visitors and shoppers. A key variable affecting the direction of the North End community in this regard will be the actions of state and city government. Programs to assist long-term residents to continue to own or rent housing in the North End, condominium conversion and rent controls, public improvements targeted to the needs of existing residents, and parking and development controls, generally, are types o r measures which would tend to stabilize the community. The State, in cooperation with the city, will ensure the adherence to 291 sensitive development controls for adjacent air-rights joint development, and the participation by neighborhood residents in the planning process for sucn joint development. This will promote future joint development uses that are compatible with the North End neighborhood . Construction impacts will be substantial for the entire construc- tion period. A large number of residences, restaurants and food shops are located very close to the con- struction area, and will be particu- larly affected by construction period noise, vibration and dust. Open-air produce markets on Cross street are particularly sensitive, and any loss in sales may be difficult for them to absorb. Local residents are dependent on these shops and have few neighbor- hood shopping alternatives. The State will sponsor programs for the mainte- nance of local businesses during construction, and will carry out measures to mitigate noise, dust and vibration impacts. Street closings and traffic detours may exacerbate existing circulation and congestion problems. Access to other parts of the city will be impaired. Delays and less conveni- ent bus service at Haymarket will pose a hardship for transit-dependent North End residents. Traffic detouring via Commercial Street, to avoid the construction zone, will make it more difficult for neighborhood children to cross to the two large waterfront recreation areas. Traffic management programs to mitigate these impacts will be undertaken for the duration of the construction period. A ventilation building will be located in the North End area which may affect air quality in the neigh- borhood. Further air quality modeling and analysis will be performed to determine the final location and configuration of the building to assure conformance with air quality standards and to minimize air quality impacts on neighborhood residents. Mitigating measures in the North End include measures to re noise, dust, vibration, parking, traffic and other impacts, see Section 4.4 LAND USE IMPACTS for complete description of these mi ing measures. North station Long-term impacts on comm facilities in this area will occ because access to existing facil such as the Boston Garden will b affected. Access from the north be improved; however, access fro south will be more circuitous. Garden's office and service faci in the Anelex Building will be t by the project, but replacement facilities will be provided, if Arena is not built in the interi Construction impacts incl loss of parking spaces, and diff pedestrian access during some st of construction. Mitigating measures inclu traffic management to facilitate pedestrian access across causewa Street and replacement of Boston Garden support facilities. West End Long-term impacts will be minor. A smoother flow of traff through Leverett Circle will imp air quality and reduce traffic-rn noise at Charles River Park. Construction impacts will result from the construction of ij tunnel leading into Storrow Drive Traffic congestion will increase s the connection from storrow Driv 296 The Preferred Alternative v>ll add four traffic lanes of capacitor Logan Airport four years after cor struction commences. This will uif south and west originating trips t Logan (15 to 20 percent of all tra- fic) from the central Artery. The No-Build Alternative will have a negative impact on regional personan goods movements during the four ye' £ that Central Artery capacity and service are constrained, and impac? in CN Tfr O <£> ro r- CN o CN Tfr vO 00 m ft ft o o *X> CN Tfr in m o CN ■fft o o o < in O ft Eh W Z 8 ft O U & s H in 2 w z o 2 D M Q Z W ft X w > H Z ft w Eh •J < (N r- CN ■w in n Tfr in CO m -w- Tfr CN n C 0 •H P O iw 3 0 in P W to c C 0 O -H U rH \ rH CO -H CD £ P •H £ 5 C rH CO CO n o in oo is CN o CN co r- o r- (0 c P. 0 it •H •P u c P, 0 P to (0 0) u p c rd 0 H u rH c l> n CN CN CN rH CN CN Tfr r» O rH VP -te- rH -0 rH 0 to A U 01 IT) US ye 0 en 53 (3 § 0 13 •H CO s rH u rH -~ • H CO & (0 E P 0) CD c rH C rH p •H m •H rH •H to CO ~3 1 CO to c XI & cr> m o 0 p c co •h cn rH C rH as U p c trj U-l 0 •H H W 0 Eh to 297 are also expected to be more severe over this period for through-trip movements. Certain industries, such as freight and parcel delivery establish- ments, emergency hospital delivery services, and time-sensitive busi- nesses will experience travel time and cost increases during limited con- struction phases of either the Pre- ferred or the No-Build Alternative. 4.6.3 Impacts on the Project Area Economy Long-Term Impacts The Preferred Alternative will improve both north-south (Central Artery) and east-west (cross-harbor) access by removing existing bottle- necks and increasing capacity. It will also enhance accessibility to and within downtown Boston, with signifi- cant traffic service improvements expected in general, on the downtown streets. Such improvements in downtown access would be expected to produce general long-term benefits to the study area economy, including travel time (and cost) savings for both person trips and goods movements and reduced congestion which will improve auto-dependent retail sales. Such improvements may also enhance the climate for expanded investment (and employment) in each major economic sector. The No-Build Alternative provides no comparable long-term benefits to the study area economy. Construction Period Impacts Retail sales, goods movement, attendance at leisure-oriented facili- ties, and time-sensitive deliveries of public and private services within the CBD study area will be negatively affected during construction of the Preferred Alternative. However, the degree of disruption varies by eco- nomic sector and by location within downtown. The No-Build Alternative will also affect the above industries, although the extent of disruption is lessened by a shorter constructor The transportation indus:y within downtown, including freint forwarders, courier and other p: services, is expected to incur n creased labor costs due to travil delays, and possible capital cocl cumulative delays may force addcio equipment purchases to assure r lia service. The leisure and recreatin « industry, including museums, tfr Aquarium, movie theaters, and oiei cultural facilities, is expecte t« experience some attendance and sv» declines during construction, upa are primarily subarea specific, and will be limited to those period 1 t during construction when physicl access and/or parking is temporriJ disrupted or lost in the immedize vicinity of the facility. Consruo tion staging and techniques wil ke such disruptions to a minimum, j Employee commuting by aua v be disrupted, but, with a few sdbe exceptions, most employers expe: further diversions to mass tranit. peak hour spreading, and therefre negligible impact on employee a:es Construction activities ;e expected to dampen retail sales^o shoppers, other than downtown eal» ees arriving in the study area / auto. Auto-dependent trips comris approximately 10 to 15 percent :" E retail shoppers; auto-dependent:et sales throughout the study areaire estimated to total approximate! $2 million annually (including Laf/et Place, scheduled for completion^ summer of 1984 ), or approximated percent of the $835 million estnat study area retail sales overall! Retailers are concerned »Ltb actual physical disruption in p<:ta of access and travel times, as Mil with the "perception" of difficnti by prospective customers, partial* in the case of comparison goods shopping (75 percent of all dowi.ow retail sales). Retail sales lo:;es 298 icng construction in tne project :t were forecast in a range from 2.6 ) percent of total study area *tjil sales (an annual total of $23 uion to $45 million in constant I dollars, or 10 to 20 percent of n -dependent shopper sales). The i^erred Alternative, in which the ■Third Harbor Tunnel is completed near 4, prior to the reconstruction I he approaches to the existing li. els, and which includes a Surface :• ry/Atlantic Avenue six-lane 3 and Orange Line extensions is ipcted to offset this loss in part Y.lrawing additional suburban shop- to downtown. ,:,4 Impacts on Subarea Economics a g-Term Impacts With the Preferred Alternative, r:fic circulation patterns to oitown Crossing retailers from the $:h and west will not be altered ■c the long-term, and traffic e/ice is expected to improve com- *2d to the No-Build Alternative, oass from the south and west to the asuil Hall/Waterfront area, and to h concentration of retailers located bee, is expected to improve signifi- •tly over the long-term with the rferred Alternative. The provision >£a continuous Surface Artery above depressed Artery is expected to trove local distribution of traffic. Between Faneuil Hall Market- di ce and the waterfront , the Pre- yed Alternative will improve visual * physical linkage. The overall roved appearance of the Faneuil •el/Waterfront subarea should attract n activities, particularly in the i);a immediately adjacent to the p>)ject construction. Special provi- iims will be included in the con- duction documents to assure contin- iii pedestrian access across the :istruction site to the North End. g Lnatown/ Leather District The Chinatown/Leather District soarea has a high concentration of lentific and related instruments raufacturing. Approximately 40 percent of this industry's shipments 9, to Logan Airport. Although nearly ^1 of these shipments are during c,f-peak hours, increased travel times u Logan during construction would icrease costs. j uth End Increased traffic on Albany ij reet between Herald and East rkeley Streets during construction j expected to have only a marginal ipact on business activities in the >uth End. Construction impacts in East Boston will largely be localized at Logan Airport and are thus not ex- pected to affect overall East Boston business activities. 4.6.5 Development and Related Fiscal Impacts Long-Term Regional Development Impacts The Preferred Alternative is expected to provide positive stimulus to the overall project area due to the superior access that it affords South Boston (north). in East Boston, the Massachusetts Technology Center should benefit from the tunnel over the long term, with the maintenance of clear access provided to the property. The No-Build Alternative may have a long-term negative impact on development activities due to lack of overall traffic service improvements and increased congestion. A major long-term net benefit from the Preferred Alternative will be the creation of roughly 2.75 million square feet of air-rights development opportunities, not including parking and open space. Based on estimates of office, commercial, residential and parking land use, construction costs for the full air-rights program are estimated to total approximately $285 million (1983 dollars) and would generate 6,100 person-years of on-site construction employment. Total direct, indirect, and induced impacts of these construction expenditures on the regional economy would include an estimated $960 million in industry sales and household earnings, and 10,800 person-years of employment. Long-term jobs attributable to the office, commercial and residential land uses assumed for the full air rights program are estimated to total 9,400. These workers (and new resi- dents) would be expected to generate an estimated $9 to $10 million annual retail sales within the project area. The introduction of direct access between South Boston and the Massachusetts Turnpike, the Southeast 301 Expressway, and Logan Airport is expected to accelerate development in the seaport area of South Boston. The facilities provided by the Preferred Alternative are likely to increase land values in the seaport area, and to be of particular importance to industries which will benefit from improved Airport access. Long-term impacts of the Preferred Alternative on local prop- erty taxes are estimated to include: o A |5 to $10 million annual property tax benefit after full absorption of 2.75 million square feet of potential new air rights develop- ment that will become available over the Central Artery with the Preferred Alternative (over time, additional city property tax revenues could be realized as a result of general improvements in the project area environment); and o a $20 to $30 million one-time receipt (not annual) because of faster absorption of space in new south Boston developments due to the Pre- ferred Alternative. As discussed in Section 4.4, a variety of areas where traffic service has been most seriously affected by delays on the Central Artery, includ- ing suburbs close to Boston (e.g., Quincy, Milton, Somerville, Chelsea and Revere), may experience some increase in development and related economic growth due to improved access to and through Boston with the Pre- ferred Alternative. 4.6.6 Construction Period Impacts on Development During the construction period, neither alternative, Preferred or No-Build, is assumed to affect devel- opment activities on a regional scale, but rather will influence regional development activities indirectly through the location, timing and pace of development within the study area. The Preferred Alternative will affect the marketability of develop- ment projects in the immediate (n- struction vicinity that are due o completed during 1986-1991. Nev projects not located in the imim i construction area should only b« marginally affected. After 199] negative impacts on Boston area development due to construction f , Preferred Alternative will dimirs almost entirely, due to the operr the Third Harbor Tunnel and the partial reopening of the Surface Artery. Major construction perioc impacts will be concentrated in he Financial District/Waterfront (2P 02110) and the South Boston-Nort 02210) subareas. in the Financil District/Waterfront subarea, Rous \ Fosters Wharf and the Fort Hill rea projects will have recently been completed just before major construction under the Central Jte: is beginning. With the Preferre Alternative, both projects may experience added development complexities, and space may be irr difficult to market due to the dree effects of construction activity 5 No-Build Alternative will have lss overall impact on development, bt will disrupt selected development within the immediate vicinity of construction to some extent. Co- struction activities of the Pref: Alternative could delay full leau of these projects somewhat, but not prevent their development. In South Boston (north), j initial construction disruption the Preferred Alternative would i expected to slow down absorption)! space in commercial, industrial, in residential properties that woul b< opening in the 1987-1990 construe period. During this time, South Boston will experience some loss >f access (both locally and regionay and it will become somewhat more isolated from downtown. The Pre:t Alternative will have created a it benefit to South Boston by the y< t 1995. The No-Build Alternative im have little or no construction p< i< impact on development in northerr South Boston. 302 in East Boston, the Massachu- •■■X Technology Center requires Action against potential noise and "^tion impacts during construction frmit the full tenant absorption ases II and III of this develop- ed and to avoid a negative impact derail leasehold and financing :=£ic detours and potential ramp Wings on streets providing access J aneuil Hall Marketplace and Downtown Crossing. Waterfront Land Uses - Maintain pedestrian thoroughfares underneath the elevated Central Artery. Manufacturing and Wholesaling - Maintain access to surface roads and bridges (particularly to South Bos- ton); provide advance publicity of any necessary street closings, together with suggested alternative routes; and restrict closings of important surface roadways to non-working hours. Fiscal and Development Impacts ■ Minimize construction noise and staging activities as well as disrup- tions in service road access adjacent to any proposed developments in the immediate vicinity of the construction area. Avoid major losses in access due to detours and/or ramp closings, particularly in the 1987-1991 con- struction period. 4.7 AIR QUALITY The air quality consequences of the Preferred Alternative are pre- sented in terms of their total emis- sions burden (mesoscale analysis), maximum one and eight-hour carbon monoxide (CO) concentrations (micro- scale analysis), effects of toll plaza emissions and concentrations in the tunnels, effects of ventilation building emissions, and impacts during construction. Where potential adverse impacts are identified, potential mitigating measures to alleviate these impacts are described in each of these impact categories. Within each impact category, a summary comparison of all alternatives considered in the EIS/EIR is presented, followed by a detailed assessment of the Preferred Alterna- tive relative to the No-Build Alterna- tive. 4.7.1 Mesoscale Analysis General This project is in an air quality nonattainment area for which transportation control measures are included in the State Implementation 303 Table 47 TOTAL 2 4- HOUR EMISSIONS OF CARBON MONOXIDE, OXIDES OF NITROGEN, AND NONMETHANE HYDROCARBONS Analysis Year Alternative NMHC Pollutants (kg/day) CO NO 1982 1990 Existing No-Build Preferred 4,230 1,810 1,870 60,200 39,500 41,400 6,520 4,610 5,250 2010 No-Build Preferred 1,540 1,430 36,200 34,200 4,180 4,620 4.7.2 Microscale Analysis Comparison of Alternatives CO concentrations at selected receptor locations in the project area were estimated for all of the build and the No-Build alternatives. For all alternatives examined, no one-hour CO concentrations in excess of the 35-ppm standard were found. CO concentrations at all receptors were estimated to decrease with time except with the No-Build Alternative, where CO concentrations at heavily congested areas actually show an increase in 201U after an initial decrease in 1990. There are a number of areas where eight-hour CO concentrations were estimated to be in excess of the 9-ppm standard in 1982. These viola- tions would continue into the future witn a No-Build Alternative. The excessive eight-hour CO concentrations anticipated for the area around the Sumner Tunnel portal would be allevi- ated with a new tunnel. Without a new tunnel (i.e., with the No-Build Alternative or Alternative 6), viola- tion of the 9-ppm standard is antici- pated in this area. Compared with the No-Build Alternative, one- and eight- hour CO concentrations at most of the receptor locations analyzed are expected to decrease with the build alternatives either because of the removal of the motor vehicle emissions on the street (e.g., by depressing the Central Artery) or the diversion of traffic to a different and less congested corridor (i.e., with ait tunnel). CO emissions from the ventilation buildings are not exjc to contribute significantly to e:fc the total one- or eight-hour CO concentrations. Preferred vs. No-Build Alternate Estimates of the maximum one-hour CO concentrations for t! Preferred and the No-Build Alteri- tives are shown in Table 48. No violations of the one-hour standc 35 parts per million (ppm) were estimated. With very few exceptm CO concentrations at all recepto locations examined show a decrea 1 with the Preferred Alternative win compared with the No-Build. The geographical locations of the va o receptors selected in this analy s are shown on Figure 57. With the depression of th> Central Artery, a significant po i of the emissions from the street, would be removed (and discharged through elevated exhausts in ven 1< tion buildings). This removal ii responsible for the significant reduction in CO concentrations a<» receptor locations as the Quincy Market (Receptor No. 13) and Martignetti 's (No. 14). A new h tunnel crossing is also expected relieve the existing congestion I Sumner Tunnel portal in East Bosti i 304 01 OA s SOUTH g END .: -A • if /A ' 30' 3# 18 # 17* NST#18 # >: ' , • 34. 12. ;,V>;; 19- 33 | CHARLESTOWN /c 10 # '//V X * * 5 * Gfe '35 { # 36 SOUTH BOSTON '38 20# 21* 32# ^ 23 « 33 J EAST BOSTON 24* SB •37 -5 //* ■ 18 BOSTON HARBOR 26* •28 25* 1 i LOGAN INTERNATIONAL AIRPORT Air Quality Receptor Locations— Bell Circle, Revere 0 125 250 500 Feet EIS/EIR for l-90-Third Harbor Tunnel; l-93-Central Artery Figure 57 Air Quality Receptor Locations 0 900 1800 Feet \£/ EIS/EIR for I-90 -Third Harbor Tunnel; I-93 - Central Artery Numbers Indicate Receptor Location Identified in Text NST #18 - From BRA North Station Study Table 48 ESTIMATED MAXIMUM ONE-HOUR CARBON MONOXI DE CONCENTRATIONS* AT SELECTED RECEPTOR LOCATIONS ~ 1982 1990 2010 Alternatives Alternatives Receptor Locations No-Build Preferred No-Build Pre: 1. Rotch Playground 17 13 12 11 11 2. Columbus Park 9 6 5 4 4 3. Res., Old Colony Ave. 10 7 6 6 5 4. Broadway Station 10 6 9 5 8 5. Tea Party Ship 12 10 8 9 6 6. Children's Museum 13 9 6 8 5 7. Reserve Bank 25 15 9 17 8 8. Stone & Webster 17 14 8 13 7 9. U.S. Postal Annex 13 10 6 9 5 10. CO Monitor - Kneeland 19 15 10 12 8 11. Tai Tung Park 16 13 9 11 8 12. N.E. Aquarium 15 10 6 9 5 13. Quincy Market 23 25 9 26 7 14. Mar tignetti 's 21 28 8 29 7 15. Res., nr. Vent 15 13 7 13 6 16. Playgrd., Commercial 27 19 16 18 15 17. West End Apts. 16 12 8 7 7 18. Tennis Cour ts 21 14 12 14 11 19. City Square 29 22 21 21 21 20. Heritage Apts. 11 7 4 7 3 21. Maverick Square 15 10 5 11 4 22. Paris St. Health Ctr . 16 13 5 14 4 23. Res., Havre St. 33 23 5 28 4 24. Daniel Webster School 14 8 5 8 4 25. Day Square 13 7 7 6 5 26. Porzio Park 7 6 4 4 3 27. E. Bos. Mem. Stadium 12 9 5 5 4 28. Hilton Hotel 12 9 6 6 5 29. N. End. nr. Sumner Vent. 13 8 7 6 6 30. South Bay nr. Vent VO 9 6 10 6 9 31. Sumner /Cottage @ V2 9 5 4 4 3 32. Chelsea St. nr. Sumner Vent. 15 5 4 4 3 33. Central Sq., E. Boston 24 12 5 5 5 34. Atlantic Ave., nr. VI 19 14 10 14 8 35. 259 A St. 10 7 6 6 4 36 W. 1st & E. St 10 6 4 6 4 37. Summer & E 1st 10 6 4 4 3 38. B0SC0M 10 7 4 5 4 39. Mooney (§ Bell Circle 12 8 8 8 7 *Concentr ations are given in parts per million (ppm). The one-hr standard 35 ppm. All entries include background concentrations of 4 ppm in 1982, 2.1 ppm in ]990, and 1.6 ppm in 2010. Concentrations are rounded to neare ppm. 306 ^ificant improvement in the air aity is therefore anticipated at : areas as Havre Street (No. 23) cParis street (No. 22) with the eerred Alternative. Very little cct, in terms of changes in CO 1 rentrations, is expected for .cptors located either in the -jdential area or the industrial rhwest section of South Boston, tonly area where one-hour CO rentrations are expected to in- (se with the Preferred Alternative n the South Bay (Receptor No. 30), rea used by Amtrak, Conrail, and Red Line storage, where the ild Street Extension will introduce nw intersection and bring addi- tial traffic into this area. Even 1 this additional traffic, the i, .mum one-hour CO concentration was ; .mated at 1U ppm, which is well !>w the standard. When the Central Artery is »;:essed, the emissions within the osed tunnels will be discharged i )ugh ventilation buildings. The : ;cts of the vent emissions on i imum one-hour CO concentrations are l:e insignificant - ranging from >it 0.2 to 0.7 ppm. Contributions :n these ventilation buildings to jsptor locations in South Boston are Really between 0.1 and 0.3 ppm; in II; Boston, the contributions are jveen 0.2 and 0.3 ppm. Table 49 shows the maximum iit-hour CO concentrations for the rferred and the No-Build Alterna- tes. Eight-hour CO concentrations excess of the 9-ppm standard were eimated in many areas throughout the eject corridor under baseline 1982 oditions. These excessive CO eventrations would continue into 13 and 2010 with the No-Build iernative. With the Preferred lernative, eight-hour CO concentra- ins are expected to decrease at lost every receptor location exam- lid. No violation of the standard M estimated anywhere, although the -Ipm standard was met for the recep- V at city Square in Charlestown. fls particular area is generally rffected by project alternatives. Eight-hour CO violations were esti- mated at Quincy Market (Receptor No. 13), Martignetti's (No. 14) and Leverett Circle (No. 18) with the No-Build Alternative. These viola- tions are eliminated with the Pre- ferred Alternative. The congestion at the Sumner Tunnel portal and the resulting violation of the standard (e.g., the 14 ppm concentration for a receptor at Havre Street) with the No-Build Alternative is alleviated by a new tunnel. The significant im- provement in the air quality at this site is due to dramatic reduction in queue times in the Sumner Tunnel when the new tunnel is in operation. Eight-hour CO concentrations at various receptor locations in South Boston are well below the 9-ppm standard with both the Preferred and the No-Build Alternatives. For a receptor located in the South Bay area (Receptor No. 30), the new intersec- tion and the additional traffic with the Preferred Alternative is expected to result in an increase of CO concen- tration. However, the maximum concen- tration of 7 ppm is still below the corresponding eight-hour standard. CO emissions from the ventila- tion buildings do not contribute significantly to the total eight-hour CO concentrations at any of the receptor locations examined. Contri- butions from these ventilation build- ings to receptor locations in South Boston and in East Boston are in the range of 0.1 to 0.2 ppm. The maximum contribution of about 0.5 ppm was estimated for a receptor location at Atlantic Avenue (Receptor No. 34). The total eight-hour CO concentration at this receptor location is 5 ppm, which is well below the 9-ppm standard. Mitigating Measures No excessive one- or eight-hour CO concentrations were estimated for any of the receptors analyzed with the Preferred Alternative. In fact, the estimated concentrations are conserva- tive because the emissions reduction credit for the Commonwealth's inspec- tion/Maintenance program was not included in the analysis. The I/M 307 Table 49 ESTIMATED MAXIMUM EIGHT-HOUR CARBON MONOXIDE CONCENTRATIONS* AT SELECTED RECEPTOR LOCATIONS 1982 1990 Alternatives 2010 Alternative 1NO BU1J.Q NO-BUlld Pree 1 . Rotrh Plavoround 11 6 7 5 6 2. Columhus Park 6 3 3 3 3. Res. Old Colonv Ave. 6 5 4 4 3 4. Broadwav Station 6 4 6 3 c 5. Tea Par tv Shio 7 5 4 4 k 6. Children's Museum 7 5 3 4 7. Reserve Bank 10 8 5 8 \ 8. Stone & Webster 11 7 4 7 4 9. U.S. Postal Annex 7 5 4 4 3 10. CO Monitor - Kneeland 13 9 7 9 7 11. Tai Tung Park 10 8 5 6 1 2. N.E. Acinar ium 9 6 4 5 3 13. Ouincv Market 11 10 6 10 6 14. Mar ti^netti * s 13 14 5 15 5 15. Res.* nr . Vent 10 6 4 6 3 16. Pi p vcrr H Cnmmpr c \ A 1 X lay iiL VI • ■ V> v/ LLLLUC- JL L.-LOX 9 7 5 6 5 17. X / • Wpftt" End Antft. 9 7 5 8 5 18. Tpnnl a flniirfft 14 11 8 12 7 19 X J ■ \v j. l y juucu. • 12 10 9 9 9 20. Hpt" "f f" a trp An £ ft - UCI 1 Late ^HK 7 5 3 5 2 21. Mflvpf "I r*lc Soiiarp i la V Ci J- V r\. u V£ UOJ. 8 6 3 6 3 99 Par 1ft ^t" Hpa 1 f-h CtT 9 7 3 8 3 93 17 14 3 16 3 9A Uaulcl WcDoLci OLllUOl \j A 3 •J 7 3 9^ Y\ «3 XT C/1M ay o Uciy oqudJTc a O 7 5 5 4 96 rur 6iu rax iv 5 3 3 3 2 97 1? Rnc Kfam C f- •{ 1 1 m Ej • DOSi riCUl* DLaQlUIll 7 5 3 6 2 9ft i-O . n. x x u u u nu lci 7 5 4 6 3 29. N. End. nr. Sumner Vent. 9 5 4 4 3 30. South Bay nr. Vent V0 6 4 7 3 6 31. Sumner /Cottage @ V2 5 3 3 3 2 32. Chelsea St. nr. Sumner Vent. 7 4 3 3 3 33 Central Sq., E. Boston 11 8 4 8 3 34. Atlantic Ave., nr. VI 10 7 5 6 4 35. 259 A St. 6 4 3 3 2 36. W. 1st & E. St. 6 4 3 3 2 37. Summer & E 1st 6 4 3 3 3 38. B0SC0M 6 4 3 3 2 39. Mooney @ Bell Circle 8 5 5 4 4 Concentrations are given in parts per is 9 ppm. All entries include backgr 1.7 ppm in 1990, and 1.3 ppm in 2010. ppm. million (ppm). The eight-hr standail ound concentrations of 3.2 ppm in I9!i Concentrations are rounded to nearct 308 tit would reduce the estimated rentrations presented in Tables 48 c 49 . Consequently, no mitigating aures are proposed. 3 Effects of Toll Plazas : i /in 6-5 <10 Por zi n Par k 16 -/ u 47 J o \ 1 u BIF Park (proposed) 13 40 <10 53 <10 Maverick Square 108 118 <10 171 <10 Residents, Or leans /Por ter 150 109 <10 152 <10 Residents, Bremen/Porter 383 281 <10 375 <10 Residents, Bremen/Gove 189 242 <10 359 <10 Residents near Sumner Toll 293 296 <10 486 <10 Residents on Havre St 463 485 <10 686 <10 Bldg (a 259 A St <10 <10 <10 <10 <10 W. 1st & E Sts <10 <10 <10 <10 <10 Sumner & E 1st Sts <10 <10 <10 <10 <10 Boscom <10 <10 <10 <10 <10 Pier 4 Restaurant <10 <10 <10 <10 <10 Barnes Bldg <10 <10 <10 <10 <10 *Concentr ations are given in parts per million (ppm) for CO, and microgram per cubic meter (ug/m 3 ) for N0 2 . These entries do not include background levels. The 8-hr CO standard is 9 ppm, and the state's policy level for 1-hr N0 2 is 320 ug/m 3 . To compare with these standards and criteria, the 8-hr CO background concentrations 3.2, 1.7, and 1.3 ppm for 1982, 1990 and 2010 respectively, and the 1-hr N0 2 background concentrations of 170 ug/m (for sites in East Boston) and 224 ug/m 3 (for all other sites) should be added to these tabular entries. 310 c the Commonwealth's policy level 33 ug/m 3 . With the No-Build enative, however, excessively high our NO2 concentrations are lipated for receptor locations in roximity of the existing tunnel tls in East Boston. For example, the No-Build Alternative in 1990, .plaza emissions alone will result Lce-hour NO2 concentrations that n excess of the 320 ug/m 3 jy level. No problem with respect ►cessively high one-hour NO2 icntrations is anticipated for ■ tor locations in South Boston [fr with the Preferred or the lid Alternative. :. ating Measures The air quality effects of the l. plazas associated with the ; ?rred Alternative are quite nificant when measured in terms <.ther the eight-hour CO or the ; iour NO2 concentrations. Conse- j:ly, no mitigating measures are j'id for the toll plaza emissions : the Preferred Alternative. 7 1 Concentrations in the Tunnels a uison of Alternatives Maximum one-hour CO and NO2 njntrations in the various tunnel cents were estimated for all I jet alternatives. The maximum I lour CO concentrations in the nsls under peak hour traffic rations were estimated to range about 19 to 54 mg/m 3 in 1990 the various build alternatives, concentrations are below the I estimates for the existing sis, and are within the American ciaty of Heating, Refrigerating and conditioning Engineers (ASHRAE) •sline of 143 mg/m 3 for maximum qiour CO concentration. In 2010, :oncentrations in the tunnels ui decrease further with all trnatives as compared to the responding No-Build Alternative ^titrations. With the exception of trnative 6, CO concentrations in * Sumner, Callahan, and Dewey Square I els were anticipated to decrease dramatically with all of the build alternatives. This decrease is due to diversion of cross-harbor traffic to the new harbor tunnel. Because Alternative 6 has no new cross-harbor tunnel, the CO concentrations in the Sumner and Callahan tunnels are comparable to the corresponding No-Build Alternative concentrations. Maximum one-hour NO2 concen- trations in the various tunnel seg- ments for the build alternatives were estimated to range from about 1,600 to 4,000 ug/m 3 in 1990. The higher NO2 concentration in this range is anticipated for tunnel segments of Alternative 6. There are presently no applicable standards governing maximum allowable one-hour NO2 concentra- tions in a tunnel. In all instances, however, the estimated NO2 concen- trations in the various tunnel seg- ments are comparable to or less than NO2 concentrations estimated for the existing tunnels in 1982. NO2 con- centrations in all existing tunnels were estimated to decrease signifi- cantly for all build alternatives except Alternative 6. For Alternative 6, the one-hour NO2 concentrations in the Sumner and Callahan Tunnels were estimated to be comparable to the corresponding No-Build Alternative concentrations. Preferred vs. No-Build Alternative Estimated maximum one-hour CO concentrations in the various tunnel segments during peak hour traffic con- ditions and assuming all ventilation fans in operation are shown in Table 51 for both the Preferred and the No-Build Alternatives. These concen- trations range from about 17 to 36 mg/m 3 in 1990. If a background CO of about 2.4 mg/m 3 is added to these concentrations, the CO concentration in 1990 would range from about 19 to 38 mg/m 3 . These concentrations are acceptable and are within the ASHRAE guideline of 143 mg/m 3 . Compared with the No-Build Alternative, CO con- centrations in the Sumner, Callahan, and Dewey Square Tunnels would de- crease dramatically with the Preferred Alternative. For example, the one- 311 CO > ■H O 4J •h « CO cu > •H O 4J ON CO ON S 4J 4 CN 00 ON -73 CD M M CD CD ft T) i-H ■H pa i o 2 CD U u CD IH CD U ft T3 H ■M 3 CO I O 2 CN CM cO PQ 3 O CO CD 3 l-i CD 42 4-1 CM vO 00 ON CM CM —I CM CM V0 CM r*. oo CM -H On v© CO CO cTJ O H 43 •3 C2 W 42 •u M CO cu CO 3 CO CJ 4J CO 3 CO C CO 3 CO •3 C CO o 3 "3 CO CD CO CO PQ CO > CO 4J «0 iH fx. CD C C2 3 CO 42 CO CO CD 5 CD a o •3 O T3 J3 I CD C -H O 4-1 •H U "3 O 3 •4-1 O CJ CD 3 3 bO •3 C 3 O CD CO CD 42 CJ 4-1 CO 43 6b * V H CM ■3 « C en 3 no •H > > > 3 c 4-1 c 4J O o O o C O CO o u 3 a CD O 1— I CO m 00 ON — * * > > > > > > > > t> > > > > CD U u. CD 4-4 CD U ft CD 42 4J U o 4-t iH ■H c CD CD cu 03 o 43 3 •3 CD C •H T3 CD T3 3 3 42 iH ■P ■ ' a 42 c CD CO 3 ■>* CO i-H 1-1 Tj » 4-1 CD CD V ' 3 42 CM ■P CD u 00 >H S-i CJ On CD NO ON t— ( CD 3 42 <—t > |-~» NO ITl 4-1 O 4-1 C 1 CJ ■s U 0 O 0 B 14-4 CJ CD CD •H a CO 43 * 43 •H \A a * 3 a. H l-l iH CJ a If H cu cu § o ■H 3 3 u CJ & 3 3 CU CD oo iH 3 3 a, CO o • H (U H H CD H — • CD 3 CO C 3 PQ a •3 3 3 CO CO • 3 3 H CO cO • • 6b • PQ 3 cr cr CD CO CO CO ■H a > 2 CD (0 3 tJ : CO >- CD CD Q CD CD 42 > 4-> -H 4-> 14-1 (0 3 1-1 CJ 4-> CO ft < * * 312 mr CO concentration of 62 mg/m 3 ;timated for the Callahan Tunnel with ,e No-Build Alternative, is expected i drop to about 21 mg/m 3 with the eferred Alternative. This dramatic tcrease is attributed to a shift of ;e cross-harbor traffic to the new innel. Maximum one-hour NO2 concen- ations in the various tunnel seg- >nts were also estimated under the ime set of peak hour conditions. The •suits are shown in Table 52. With ie Preferred Alternative, the maximum le-hour NO2 concentrations in 1990 >re estimated to range from 1,600 l/m 3 (or 1.6 mg/m 3 ) to 3,400 l/m 3 (or 3.4 mg/m 3 ). When a ickground NO2 concentration of >out 224 ug/m 3 for the Boston :gments and 170 ug/m 3 for the East >ston segments is added to the >deling predictions, the anticipated mcentrations in the tunnel in 1990 mid range from about 1,820 to 3,620 l/m 3 . in 2010, these concentra- .ons are expected to decrease slight- '. As mentioned previously, there :e no ASHRAE guidelines or applicable :andards governing maximum one-hour >2 concentrations in a tunnel ivironment. Under peak hour traffic mditions with all ventilation fans 1 operation, these one-hour NO2 mcentrations are lower than the >2 concentrations encountered in ie existing tunnels in 1982. When >mpared with the No-Build Alterna- te, maximum one-hour NO2 concen- ations in the Sumner, Callahan, and ;wey Square Tunnels are expected to icrease dramatically with the Pre- ;rred Alternative because of version of cross-harbor traffic to ie new tunnel. tigating Measures Air quality in the existing innels, the new tunnels, and the 'pressed Central Artery is accept- 'le, based on the peak hour traffic editions indicated in Section 4.2, id with all ventilation fans in oper- ion. However, should traffic condi- ons in the tunnels degrade, for ample, due to an accident, and/or there is mechanical malfunctioning in the ventilation fans, then excessively high CO and NO2 concentrations could result. To avoid this potential health hazard, the mechanical ventila- tion system of the proposed tunnels must be maintained in good working order at all times and a procedure for deploying the necessary number of fans in operation (as a function of the CO concentrations in the tunnel, CO in the intake air, and traffic condi- tions) must be developed. Additional- ly, a real-time CO monitoring system in the proposed tunnels must also be installed. These mitigating measures will be included in the proposed ventilation system designs for the new tunnels. 4.7.5 Effects of Ventilation Building Emissions Comparison of Alternatives The effects of ventilation building emissions on ambient air quality were evaluated using two analytical methods: (1) EPA's ISC model for the "far-field" impact and using the same set of receptors that were used for the microscale analysis; and (2) Halitsky's algorithm for the "near-field" environment for receptors that are located at pedestrian side- walk level in the immediate vicinity of the individual vents, and at air intakes on rooftops of adjacent build- ings. Maximum one- and eight-hour CO, and one-hour NO2 concentrations were estimated for all project alterna- tives. The far-field analysis sug- gests that with very few exceptions, maximum one-hour NO2 concentrations at the various receptors selected for this analysis were estimated to be less than the Commonwealth's policy level of 320 ug/m 3 . The exceptions include a receptor in the North End in the vicinity of an existing ventila- tion building, where the 1990 concen- tration with Alternative 6 was esti- mated at about 350 ug/m 3 ; and another receptor at Atlantic Avenue where concentrations in the range of 330 to 460 ug/m 3 were estimated for Alternatives 3, 3A, 5, and 6 in 1990. CO concentrations at all receptor 313 o *j a 3 u t3 cu rH u CO D a) m ai M 4J 3 CM 00 OS to OJ > •H O 4J o\ S CM CN CM CO CM 00 CM o o CO CM CN eg CM ~H 4-1 4-1 4-1 4-1 c c 3 c c OJ ai cu cu E S e 0 bO bo bO M 00 CD cu CU (U cu CO r/i CO CO CO o > co > > to > CO 3 CO TJ C CO co 4J c cu 0 bO CU CO > CO 3 CO 4 O 3 T3 CO C CU 0 00 cu CO 00 CM cn • • CO 4-1 CO rH to •3 3 CO M •H CO CO CO e cu 0 00 cu CO c CU 0 bo D CO CU c c 3 H U cu 3 CO c CU 0 00 CU CO CM > o > > CU c c 3 H 3 CO •C CO CO U 4-1 CO CO 4-1 c cu 0 00 ai CO > co CM CM CO rH C0C0OCMO\^0 COCOtMCMCMCM-H^H^^ CM CO CM CO CM > * * rH CU C c 3 H cr co CU cu Q 4J CO C CU 0 bO CU CO 00 > —4 > T3 C CU *H a) CO c/j CO CO Qj ^ C4J ^ O CO 4-1 CU -H TO U 4J W O CO co 4J CO 4-1 O C (D O CU T) •H CJ — > O 0 o \ cu CM 3 ^ CU O TJ CJ 2 O ^ C t- 3 O rH r-H 0 O CO ,C 4-» n cn 0 o o 3 4J — 0 4J •H flro c X -H 0 CU eg co N. E 0 4J tr 1 tn X E cu cu o co CO o cu o r- u £Z H H a) d jj o • CO Uh /"N rH O rH CO Qj r-1 0 > cd CO u 4-1 c 3 3 CD (0 c o u ■H 0 4J H-l CO M — > O 4-1 CO u 3 E 00 CU "N, ^! o cn C 3 . o tH X CJ 3 CU *T3 CN O T3 C E 3 E ■H (0 0 o 4-> >• i— I a (0 4J (0 4-) CO rH (0 T3 C (0 4-> CO rH o CO cu s ■H rH CU Tj •rH 3 Cn W o cj co 3 U H CU CJ a c 3 *H O O bir ^ 00 eg o E 0 4-1 co \ CO O Xi Cn bi C 6 •H O CMrT «— I T5 O CN Z CM C id 1 I TJ co cu 3 3 3 O O id K w < o c >1 rH 4-1 3 cu CO CU u a, CD u cu )H CU XI cu C c 3 4J CO t3 a 3 4J CU CO si — •u 4J c - cu E C cu cu oo c rH C 3 4-1 CO cu o • CJ CO CO 3 co CD CU O T3 3 a O 3 JZ U O 4J CU !h >H 0) cw c o u CU x cu c 3 3 Eh m CU iH 03 3 CO >1 4J -H 4-> 14H o 4J CU SH 4J n3 >H * * 314 l:ations for all project alternatives we estimated to be insignificant ir n measured against the contribu- t ms from other mobile sources or the airopriate one- and eight-hour CO s indards. The impact of the emissions f >m ventilation buildings is mostly tkt in a near-field environment. The i ir— field analysis suggests that with ff exceptions, maximum one-hour NO2 cicentrations at these close-by r;eptors would exceed the Common- wlth's policy level. All the vitilation buildings associated with t2 depression of the Central Artery, a analyzed in this EIS/EIR, are epected to result in excessive NO2 cicentrations for all build alterna- tes examined. Similarly, emissions tm the ventilation buildings in the Irth End, in the Dewey Square area, »i in South Boston are expected to rsult in one-hour NO2 concentra- tons that are in excess of the policy Jvel for all alternatives. The (ceptions are the existing ventila- ton buildings in East Boston where ^2 concentrations, even with the {-Build Alternative and Alternative ( were estimated to be below the 320 ./m 3 policy level. Further air cality modeling and analysis must be rformed to develop a ventilation sstem which conforms to the NO2 licy level. eferred vs. No-Build Alternative The Far-Field Results The effects from all ventila- lon buildings on the various receptor cations are shown in Table 53 for e Preferred and the No-Build Alter- tives. The maximum one-hour NO2 ncentrations with the Preferred ternative were estimated to range om about 12 to 82 ug/m 3 in 1990. ese concentrations do not represent «y problem with the Commonwealth's i licy level of 320 ug/m 3 , even j ter a high one-hour NO2 background I 224 ug/m 3 is added to the model- g results. The Preferred Alterna- ve includes several new ventilation ildings along the Central Artery corridor and in South Boston. Conse- quently, the maximum one-hour NO2 concentrations at a number of receptor locations in downtown Boston, the North End, and South Boston are expected to increase with the Pre- ferred Alternative. As will be noted later in this subsection, violations of the Commonwealth's policy level for NO2 emissions may require re-siting of many of the proposed ventilation buildings. During the design phase, the final locations of the required ventilation buildings will be deter- mined based on additional air quality analyses. In East Boston, on the other hand, the decrease in traffic using the Sumner and Callahan Tunnels with the Preferred Alternative is expected to result in lower NO x emissions from the existing ventilation build- ings and subsequent lower NO2 con- centrations. For example, maximum one-hour NO2 concentrations (with background) at Maverick Square were estimated to decrease from about 220 ug/m 3 with the No-Build Alternative to about 190 ug/m 3 with the Pre- ferred Alternative. The 2010 maximum one-hour NO2 concentrations are gen- erally lower than their corresponding 1990 concentrations. Therefore, no concentrations in excess of the Com- monwealth's policy level are anticipa- ted in East Boston. In 1990, the maximum one-hour CO concentrations at the various re- ceptor locations with the Preferred Alternative were estimated to range from about 0.2 to 0.7 ppm. These con- centrations are quite insignificant when measured against contributions from the mobile sources or the 35-ppm standard (see Section 4.7.2 Microscale Analysis ) . The maximum eight-hour CO concentrations were estimated to range from about 0.1 to 0.5 ppm. These con- centrations are also insignificant when compared with the 9-ppm stan- dard. CO concentrations in 2010 are generally expected to be even lower. Consequently, no problem with respect to the one- and eight-hour standards is anticipated in 2010 due to emis- sions from any of the ventilation 315 Table 53 CONTRIBUTIONS OF VENTILATION BUILDING EMISSIONS ON ONE-HOUR NITROGEN DIOXIDE CONCENTRATIONS* 1982 1990 2010 Alternatives Alternatives IP j i Jl. JUL 1 ji ■ T rt, a J *M «a Kecepcor Locat ions No-Build Preferred No-Build Pre- 1 1 . D rt, t* rt V"k D 1 O IT «Tf rt a | « J Koccn rxaygrouna 44 1 0 JZ oi Zl 07 z/ 1 Q iy o Z. l»OJ.umDUS rax K 1 A 1U oo ZZ Q y OA zo 1 J • Kesiaeucc uxo. uoj-Ouy Ave 07 Z/ 0Q CO i 7 i / o>; ZJ 4. Da. rt rt ^4 I 71 XT C h r\ f" /-V rt JJcOauway ocaLioti oo Zy 01 Zl 00 ZZ Q O 1 Q iy c J. lea r ax r_y onip OQ ZO 00 zz J J 1 fi 10 oo zy O. unxxaxeu h nuseum 0Q Zy 00 zz in 1 Q iy OA zo 7 Reserve Bank 1/i J4 07 z/ 1 Q lo 01 ZJ i j Q O . ocone a weuscer A 1 0 1 1 ^ 17 J/ in JU Q TT C Dnof fll Ann £i v u.o. rusLai Annex *t J OA OQ Z7 on zu i n 1U. i^u Monitor Mieeiana 7 C / J A 1 01 ifl JO c o jZ l/l J4 i i lax lung rax k £7 0 / ^O 11 JJ A1 • 4 J 1 1 J 1 1 o 1 Z. N.E. Aquarium 4b 0 ^ JJ ZJ OA JO Ol Zl 1 i 1 J. Quincy Market 17 J/ 1^ ZJ 01 Zl 0 0 ZZ 1 0 1 o 14. Mar tignettis jl 0 1 Jl OQ Zo 0Q Zo OA ZO ID. Tj rt rt 4 x4 A *"» rt rt M^*V rt -a— T 7 rt t- Kesiaence wear vent 1 OA 1 Zh 7 0 / Z 07 at* 00 A1 0 j 16. Playground on Commercial 0"7 27 21 o o J8 1 o 18 0 0 JJ 1 "7 17. West End Apartments 16 1 J 1 Q iy i i 1 1 i 7 1 / 1 O 18. Tennis Courts 1 o 1 2 y 1 o 18 8 16 19. City Square 32 20 o / 34 1 o 18 O 1 Jl 20. Heritage Apartments £Q 6y A A 4U OA 20 17 51 oi zl 21. Maverick Square O 0 O J 4o 0 0 ZZ 44 01 ZJ 22. Paris St. Health Center / o 42 25 16 oo 23 1 r 16 23. Residence on Havre 49 J j O A JO OQ zy 0Q zy 24. Daniel Webster School 27 21 oc 25 1 o 18 OI 21 25. Day Square 25 1 / 16 1 J 14 26. Por zio Park OA 20 12 1 J 1 1 11 1 J 27. E. Boston Mem. Stadium 44 OA JO 07 LI Ot ZO 01 ZJ 28. Hilton Hotel 1 o 1 2 o o 1 J 7 / 1 J 29. North End, near Vent 41 28 42 24 38 30. South Bay near V0 37 28 68 24 62 31. Sumner /Cottage near V2 29 17 23 15 20 32. Chelsea St., near Vent 29 19 14 17 14 33. Central Square, East Boston 36 24 32 21 30 34. Atlantic Ave., near VI 33 23 82 20 70 35. Bldg., 259 A St 35 27 28 23 24 36. W 1st & E St 15 11 18 9 16 37. Summer & E 1st St 15 11 12 9 11 38. B0SC0M 23 18 24 15 21 f er;;c Concentrations are in micrograms per cubic meter (ug/m 3 ), and do not include background concentrations. The state policy level for one-hr N0 2 is 320 ug/m 3 . To compare with this policy level, a background concentration of 224 ug/m 3 for Boston sites, and 170 ug/m 3 for East Boston sites should be added to these estimates. 316 uildings. The Near-Field Results The effects of ventilation uilding emissions in a near-field nvironment are assessed by consider- ng one vent at a time and estimating .he maximum one-hour concentrations or receptors at pedestrian sidewalk evel and at air intakes on the roofs ■f adjacent buildings. Table 54 shows he maximum one-hour NO2 concentra- ions for each of the proposed venti- .ation buildings with the Preferred ind the No-Build Alternatives. Again, lote that the final ventilation build- .ng locations will be determined luring the design phase after addi- .ional air quality analyses have been >erf ormed. The emissions from each of the 'entilation buildings associated with :he depression of the Central Artery [i.e., vent stack No. VO through V5 in Table 54) are expected to result in )ne-hour NO2 concentrations at learby receptor locations that are in ixcess of the 320 ug/m 3 policy Level. For a number of receptors Located at air intakes on the roofs of adjacent buildings, the estimated naximum one-hour NO2 concentrations in excess of the Commonwealth's policy Level are also anticipated for recep- :ors at pedestrian sidewalk level and rooftop air intakes close to these /entilation buildings. Because of a Lower background concentration (170 ig/m 3 ) assumed for East Boston, the smissions from the ventilation build- ing at Bird island Flats would not result in excessive NO2 concentra- :ions, except for the receptor at the sidewalk where the maximum one-hour concentration was estimated at about 330 ug/m 3 (just over the 320 ag/m 3 policy level). One-hour NO2 concentrations associated with the existing ventila- :ion buildings in East Boston are not sxpected to be in excess of the 3ommonwealth ' s policy level with Jither the Preferred or the No-Build Uternatives. Emissions from the Jxisting ventilation buildings in the North End and in the Dewey Square area, on the other hand, will continue to result in maximum one-hour NO2 concentrations that are in excess of the policy level. Because the Pre- ferred Alternative is expected to result in significant reduction in emissions from the ventilation build- ings serving the Dewey Square tunnels, NO2 concentrations at pedestrian level in the vicinity of these venti- lation buildings were estimated to be below the Commonwealth's policy level. However, even with this emission reduction, NO2 concen- trations at a number of rooftop air intake locations were still estimated to exceed the 320 ug/m 3 policy level. Maximum one-hour NO2 concen- trations in 2010 were estimated to be only slightly lower than the corres- ponding 1990 results. Maximum one-hour CO concentra- tions at receptors located in the immediate vicinity of the proposed ventilation buildings were estimated to range from about 3.0 to 7.7 mg/m 3 with backgound CO concentration in 1990 under the Preferred Alternative. These concentrations are well below the one-hour standard of 40 mg/m 3 . The maximum eight-hour CO concentra- tions were estimated to range from about 2.4 to 6.2 mg/m 3 , with back- ground. These concentrations are also within the eight-hour CO standard. Both maximum one- and eight-hour CO concentrations in 2010 were estimated to be less than the corresponding 1990 concentrations. Therefore, CO emis- sions from these ventilations are not expected to be a problem with respect to exceeding the applicable standards. Mitigating Measures If a one-hour NO2 background concentration of 170 ug/m 3 is assumed for East Boston receptor locations, and 224 ug/m 3 is assumed for the rest of the study area in Boston, then emissions from most of the ventilation buildings analyzed -- existing and proposed — would result in excessive one-hour NO2 concentra- tions when measured against the Commonwealth's policy level of 320 317 4) 0) > •H O u ON > on cm I I ~H 00 O v£> O 00 —t CN •— 4 CM till Eh a H 0 00 22 •H H «J U R) a> CO cj H U 4J w -H > 4-1 >+H a> • M-4 W CO .-1 H O Eh * r-f > > > a o ■H 4J a ■H b to & M 0 tt u CO CC 3 O CO o > n ifl n > > > < c & 4-1 I ON 00 o J \0 -H vO -i o oo m 00 CN 00 cn m n cm co % T3 M-i u 9 •H <4-i CO M CO O 5 — I CN CO > > > CO u u 5 o E-> o I CO > — I CN CO IO Qi (X' ^ CcJ ■ > > > > CO u CM CTJ m erf od orf m io m m > > > > i— I CN CO OS Oi eeS > > > 4J CO r CO 3 cO c_> CO •u CO 3 CO ■s CO < cs> > l a> a > — ' CO 4-1 4-1 CO Oi o 1 — 1 M • • ^ — ' v — ' U u 3 C 4J o cr 0) o Pn z x: CO CO • 4-1 M CO 4-1 H C2J <2j i— I >, •H CO 1 CO 0) CO c > o c 13 <: o CJ a CJ CU 4-1 T3 c t) T3 •H T> o CO i-H •o On CO tH CO H H tH 4-1 m o •H m o 3 CO cc rS CO CO 0_ CO CN PQ O C 00 CO 0 « 00 CM C c CM 4^ O 0 2 C a f f CD *4- C! O cr> E U O t 01 H < CO O M >N O cj o c a > CN, CD CD CD a) 4J c co a< ■u t« co c cc x» h MO CH cc3 O CO -co ° ^ -5 * 4J 1(1 c O J= ■H H M 4J c CD CJ . C -u 318 O 4J I 3 * 8 4J 3 o ON ON CM 00 On u U cm w A H a w w a o 4J s a a 4) CJ V3 «, ^ PQ *o •H CO CO u erf i— ( V Cl, • x: bO J-J T3 —I 03 C o & o •— < CM CO Crf Crf Crf oo oo oo > > > CO 3 •o c cd CO AS 2 ^ & O M 0) u co 13 DO Cu «H O CO PQ -H CM erf erf ON ON > > erf CO CO Crf 00 CO CO CO XT 13 < — < 4-1 iH c jC EX 3 PQ CQ M o m CO O c T3 o* cc u CO OJ OJ \A c CO 3 u x: 3 O % • ■H a, CJ M X tr <+-t 0) iH o CO M-l 4J •H c o CO s • x: a) a) • • OJ 0) 1 T> & T3 • CO •o CO > T3 CO T3 •H & ■H •u •H at ■H aj H CO PQ PQ CO CO CO erf CO C/3 aa •— t CM CO —1 CM CO < CM t— l CM CN sf erf Crf erf erf erf erf Crf Crf Crf erf o o o —4 CO CN CN CO > > > > > > > > > > > > 3 CO • CO Crf Crf * — ^ CO CJ ^ e 4J o x: o 4.) CO CO u to rH o CD <0 ■a CO & CQ 0) 3 0) M CQ 9d H iH CO; (2; OJ •H • OJ bO • 4-1 T3 GO -a •o cn ■x •H > > H N CI Sf Crf Crf Crf Crf m m in to > > > > b CO ■8 (0 4-1 CO O 3 •O 03 •H > ca> 5 c o 4-1 CO O PQ O co 0) CO CO CQ cc) > 2 ON > T3 C En to En c CO CO o c 4J x: o J3 4J o CO 4J PQ 4J CO 4J iH Ll o CO No • w No PQ Bo • ■a n CO • iH • • rH u O o* 4-1 CO co O CO CO M a x: x: at x: T3 4-1 4-1 CJ M > CJ cfl O •H 1 & OJ PQ SB ►J PQ c& & C2J <&> > > > > > 319 to E-t Z W > w 33 E-t En O » E-" H 2 H u 1-1 > w Eh < -M Q W f M- T5 fl) <1) <4-J a) tJ o ,— | ft* 0 ar J o CM c CQ I o •i CD flj o> ' 0) Q '-1 W i (It i-H S t> H .,_) -J 3 OQ 1 CM 00 o u a o> o N N vO S vO N * ifl Mn m h 1— I !— I .— I O H N H H If) 00 m H CI H H 00 O 00 in o in* Q> \C ON H oo m on 00 CO CO vO hOh« oo ■— < on co m oa >c in CO vO CO — i r~» co o oo vo o CO \o o oo io Ol vO N CO — t vO CM o m co m id n m oo H N H i-l 00 CM CM CM oo on cm i-^ CM CM -H Pd 00 prf 0) a! CO 3 • * — ^ CO CO 4J erf 00 ^-v pd J= / N v_x C -a o QJ iH 01 00 -j - — ^ 0) > CQ 00 w rH 3 > OJ CO a> Cb C i-l • •u • w • u c 01 M o o* v o M C *H CO H c 00 rH CO CO tO CO • X >n >> X • •U QJ 00 00 00 00 —I t— ( i— i r-1 -H ■—I 1 — 1 1— 1 > > > > > t> > > > > > > c o c o 4J o 1-t CO 4J CS u o 00 4J a O CO •H co o M PO O • n CO • A a oo 4J O OO •H u AJ Oi X c a* CO CO 00 rH 3 CO 4J 00 oo W <: > > 320 j/m3. The project must conform .th the NO2 policy level. To Ltigate this potential problem, a imber of potential options must be illy evaluated. These options iclude: the height of the exhaust >ening and/or the exit velocity of le exhaust gases could be altered to ;duce the impact on nearby receptors; ie exhaust gases from a given set of innel segments could be vented from >re than one ventilation building in lat general location (i.e., to :hieve more diffuse source environ- ;nt); the amount of exhaust gases juld be reapportioned among the fixed it of ventilation buildings. Not all I these potential mitigating measures ill be equally effective for all of ie ventilation buildings. However, :om the magnitude of these estimated le-hour NO2 concentrations, it jpears that by using these mitigating jasures — either individually or in 5me combination — the Commonwealth's jlicy level can be met at every jceptor examined. The necessary air aality analyses to determine the *asibility and effectiveness of these Ltigating measures will be performed aring the design stage of the project. CO emissions from the ventila- ion buildings are not a problem with jspect to either the one- or eight- sur standard. Consequently, no initi- ating measures are required. .7.6 construction Impacts The air quality consequences of instruction are described in terms of ie impact of traffic disruption dur- ig construction, dust emissions from instruction-related activities and tential CO problem would apply to )th the build as well as the No-Build •ternatives, because the No-Build ternative would still involve redecking of the existing viaduct. For all build alternatives, traffic disruption on local streets in the northern industrial section of South Boston is also expected. However, the traffic volumes on these streets are generally not very heavy, and existing CO concentrations are well below the standards. Consequently, no potential CO problem is likely to take place in South Boston. All alternatives, except the No-Build Alternative and Alternative 6, are expected to affect local traffic in East Boston to some extent during construction. This impact will mostly be limited to the Airport proper for the Preferred Alternative and Alternatives 3, 3A, 5, and 5A. Another potentially serious problem is impact due to dust emis- sions. Areas near construction stag- ing areas or construction haul routes are expected to be adversely af- fected. The entire Central Artery corridor will be affected with every alternative, including the No-Build Alternative. South Boston will be affected to a varying extent - for example, alternatives with a cross- harbor tunnel will affect South Boston to a greater extent and for a longer period than will Alternative 6 or the No-Build Alternative. This impact, however, is expected to be confined to the Fort Point Channel area and the industrial section. The residential section of South Boston would be unaffected. With the exception of the No-Build Alternative and Alternatives 2, 4, and 6, dust emissions from the construction activities at the Airport are also expected to adversely affect many areas at the Airport (e.g., the Southwest Service area) and the eastern portion of the Jeffries Point community. Alternatives 2 and 4 would adversely affect the East Boston residential areas adjacent to the Conrail right-of-way. Because of the proposed align- ment of the tunnel of the Preferred Alternative, aircraft operations at the Southwest Terminal will also be affected during construction. The potential impact associated with this 321 temporary change in aircraft opera- tion, however — either in terms of changes in emissions or ambient concentrations at sensitive receptor locations in Jeffries Point — is expected to be insignificant. Preferred vs. No-Build Alternative The impacts associated with traffic disruption, dust emissions and exhaust odor, and construction at Logan Airport that is applicable to the Preferred Alternative is described in greater detail below, and compared to potential impacts of the No-Build Alternative. Traffic Disruption During the construction period of the Preferred Alternative, adverse traffic effects due to reduced capa- city and detouring traffic are antici- pated for many locations in Boston, South Boston, and within Logan Air- port. However, the details of the detour routing and the resulting traffic volumes on the affected roadway network have not been fully defined beyond the construction phasing program identified in Section 4.1 and in the Supportive Engineering Report . Consequently, the air quality implications of these traffic effects are examined qualitatively — accord- ing to various geographical areas. When definitive detour routing and associated traffic volumes are devel- oped (e.g., during the design stage), more detailed analysis of the poten- tial air quality impact shall be performed to ensure compliance with applicable air quality standards and criteria. o South Bay/Fort Point Channel During the construction of the tunnel segment under the Fort Point Channel, the Congress Street Bridge will be narrowed. Traffic congestion is anticipated at intersections of bridges with roadways paralleling the Southeast Expressway and the Central Artery. If the traffic congestion is severe during some stage in the con- struction period, the potential to exceed the 9-ppm CO standard wil increase. o Downtown Boston/Waterfront During the construction of i depressed Central Artery, the over, capacities of certain ramps from tf viaduct and the Surface Artery are expected to be decreased. This lo in capacity will lead to severe co- gestion on both the viaduct and th Surface Artery. For five years du the construction period, the Surfae Artery and Atlantic Avenue will be combined into one, six-lane arteril roadway, with some resulting loss capacity. As noted in Section 4.2 however, traffic flow is not expec to be significantly affected becau of removal of on-rstreet parking an other factors which affect traffic flow. However, increased congestii in this area could exacerbate an existing CO problem. This proble also applicable to the No-Build Alternative, although the nature o the problem is different: in redecking, there will be a more serious loss of capacity on the Ce tral Artery viaduct than in the Pr ferred Alternative. On the other hand, the duration of construction.s significantly less with the No-Bui 1 Alternative. During the first year of thV construction of the Preferred Alteia tive, utilities would be relocatedm disruption of local traffic is ant:i pated on many of the cross streets This disruption is expected to rem.n during the construction of the slut|. walls. During this time, parts of Surface Artery and Atlantic Avenue will be closed, and extensive deto ing would result. The combined ei lanes of roadway from both the Sur Artery and Atlantic Avenue will be replaced by a six-lane surface roa along the length of the Central Artery; also, a 40-foot wide const tion haul road will be provided in this area, increased traffic on t viaduct and on local streets such Summer, Congress, High, Franklin, eral, and Milk Streets will be ove-J burdened. Adverse impacts on both - cs-hour and eight-hour CO concentra- tons are anticipated as a result of : is reduction in capacity and detour- Construction of the Central ztery depression is expected to gen- fate significant new truck traffic. |r example, up to 1,000 trucks per dy could be added to the surface /reets during the excavation stage, : rther affecting local traffic, ) though a separate haul road will List under the viaduct to restrict lis traffic from the local streets to lie extent possible. A similar effect on local traf- ! ic is also applicable to the No-Build Lternative due to capacity restric- 'Lons on local streets below the Cen- tal Artery, as there will be more of diversion from the viaduct to the ical streets, as well as loss of some anes of the Surface Artery, during ie redecking process. This impact, bwever, will be offset by the shorter onstruction time for the No-Build lternative. North End/West End/City Square There are a number of areas in e North End (Hanover Street, the llahan Tunnel portal, and Keany uare), the West End (at Leverett ircle), and in City Square (in harlestown) that are known to have xisting eight-hour CO concentrations hat are in excess of the 9-ppm stand- rd. Construction of the Central rtery depression or the redecking of he viaduct is expected to aggravate his existing problem. At some point n the construction of the Preferred lternative for a period of about 12 lonths, the removal of the south- bound Central Artery ramp to Storrow •rive could result in traffic being liverted to Lomasney Way and causeway itreet although a detailed traffic letour route using the Charles River >am road, Gilmore Bridge, and tutherford Avenue will be developed, increased congestion on the local itreets could ensue, leading to an ;xacerbation of the CO problem in this trea. During the construction of ramps and related improvements at Leverett Circle, capacity of the Circle is expected to be reduced by one-third. The Leverett Circle area is presently in violation of the eight-hour CO standard. Reduction in capacity would in essence extend the "peak" hour period in both the morning and evening peaks. This would aggra- vate the existing eight-hour CO prob- lem. o South Boston During the construction of the cross-harbor tunnel, Viaduct-Ramp Street, portions of B and Congress Streets would be closed. These re- placements and closures would lead to traffic diversions of other streets, principally in the northern industrial section of South Boston. Because the traffic volumes on these streets are generally not very heavy, no serious congestion and subsequent CO problems are anticipated as a result of this diversion. Potential problems, how- ever, are expected at the various Fort Point Channel bridge crossings. o East Boston The construction of the Pre- ferred Alternative is not expected to have any significant adverse traffic effects on the local streets in East Boston. Most of the impact will be felt within Logan Airport. This impact is described in a subsequent section. Dust Emissions and Exhaust Odor Dust and truck exhaust emis- sions at construction sites, staging areas, and along construction haul routes can lead to potential adverse effects (as manifested in nuisance dust, odor, and possible violation of the 24-hour total suspended particu- late Federal and State standards). The construction sites along the Cen- tral Artery corridor are located in a very urbanized area with extensive public access and with many public amenities, such as Quincy Market and the restaurants along the waterfront. 323 The potential problems associated with nuisance dust and truck exhaust odor will detract from the enjoyment of these amenities. These problems are equally applicable to both the Pre- ferred and the No-Build Alternatives. Staging areas in the Central Artery corridor (e.g., at the Anelex Building, or the parking areas by Causeway Street) can lead to increased traffic congestion and subsequent CO problems. These areas would probably be used to varying extents during the construction period. Construction activities at staging areas more re- mote from the corridor (such as those in the northern industrial portion of South Boston) can lead to nuisance dust problems and particulate standard violation at these locations. With the Preferred Alternative, these potential problems are also antici- pated in the Bird island Flats, the Southwest Terminal, and the Southwest Service areas of the Airport and the residences on the east side of the Jeffries Point community in East Boston. Final truck routes for all con- struction-related activities have not been defined as yet, but as plans for a haul road under the existing viaduct from Causeway Street to High Street are included in the project, it would appear that adjacent areas such as the Financial District, the Waterfront, the North End, the West End, the Fort Point Channel, South Bay, and parts of Charlestown and South Boston may be affected by truck exhaust and dust emissions. With the Preferred Alter- native, truck emissions could also affect portions of East Boston (e.g., along Route 1A) and some of the businesses within the Airport itself. Construction at Logan Airport At Logan Airport, the construc- tion of the tunnel and connecting ramps with the Preferred Alternative is broadly divided into three phases, progressing from the Bird island Flats area through the Southwest Terminal area to the southwest Service area. During the first phase, con- struction activity is generally limi ted to the southwest corner of Bird Island Flats, although the entire BI Access Road will be used for constru tion access to the staging area at Bird island Flats. Under certain meteorological conditions (e.g., hig wind and applicable wind directions) and without specific dust control measures, some adverse impact associ ated with high dust loading could be' anticipated at the eastern part of t Jeffries Point community, and the Southwest Terminal area. The air cargo facilities and other proposed development at Bird island Flats cou also be affected by dust emissions. Aircraft operations at the Southwest Terminal should not be significantly affected by these dust emissions. i tii The second phase of the con- struction will extend the tunnel froi Bird Island Flats through the South- west Terminal area to a point just past the Eastern Air Lines Reservatic Center. impact from dust emissions Jeffries Point will continue to be felt, and might actually intensify because the construction activity would be closer to this community an at the same time the staging area at Bird island Flats will continue to in use. The frequency of impact fron dust emissions at the Southwest Terminal would be expected to in- crease, again if specific dust contrc measures are not included in the construction specifications. During Phase 2, the Eastern Airlines shuttle operation and the commuter air lines operation at the Southwest Terminal are expected to switch positions. This temporary switch in positions of the shuttle and commuter operations could result in a small net reduction of aircraft emissions. However, in terms of ambient concentrations of th various pollutants at such sensitive receptors as Porzio Park and other areas in the Jeffries Point community this small decrease in emissions is not expected to manifest itself in an significant reduction in total pollu- tant concentrations at these receptor locations. The air cargo and other 324 le ?lopment facilities at Bird island l|:s will continue to be affected by M: emissions from construction idLVities. The third phase of the con- jtiction will extend the tunnel from io:h of the Eastern Airlines Reser- ■Lon Center to the Airport access :o3. During this final phase, a uner of existing buildings in the Sothwest Service area (e.g., the Seeral Aviation Building and the Mtern Air Freight) will be removed. \nther staging area will be estab- Lihed and the BIF Access Road will be reocated a little closer to the Jefries Point community. The poten- :il impact of dust emissions on Jefries Point would continue to be a prblem and the affected area might »>end further west into the commun- Lt. Additionally, most of the Eailities in the Southwest Service ■a (e.g., Sky Chefs, and rental car itilities) and the Hilton Hotel would xaffected by dust emissions. During ■se 3, the Eastern shuttle and the ■muter operations will again switch ;-. k to their original positions in ij Southwest Terminal. Impact from t±se aircraft operations will return tcbaseline conditions. Impact of i.t emissions at the Southwest ttminal and at Bird island Flats ■Id continue during Phase 3. Truck movements and other ■ struction-related traffic could [xentially interfere with the other iKmal Airport traffic. If this nerference were to result in loss of Bacity either on the Airport access 3i egress roads or the Cross Road, • ffic congestion would result ■ ding to potentially excessive CO a^centrations at a number of receptor illations at the Airport such as the ■ ton Hotel and the East Boston ■lorial Stadium. However, con- duction-related vehicles represent a ' 60 ■H 0) 4J 4J 4j<3 H 0) «H M *J H 3 SB as _ 0J H > P T» -H H iH 4J 3 S f S O *J a a o •H 4J a •H b CO & V * 4-1 • V5 SB CN CN CN CN CN CN CN 1 4-J m vO v£> m in in vO vO v£> m n m 3 CD 1 O CD 4J •H 3 CD 4-1 CD CO CJ B m in in sO V40 m •3 CO •v ■0 3 CD 3 C rH CJ • rH •a o O c CO CJ c o — H m m in ON CN «. oo 4-1 •H -a CO T-l 3 •H 4-1 JO CO •H CO o m m n On CN % rH 00 in 00 r-. oo X3 |_i CO u 00 -H CO 4-1 3 o C j_J C CO o ■H o -o J* a 1 1 1 1 1 I | 1 1 1 I 1 1 1 1 1 1 o c t-l -o CD CO CO CO c CO O 4-1 rH O- cO 3 J= o «t T—J o CD CO o CO o\ 00 CO m o> 00 in CT\ o^ ON CN — * ON o •H CO CD •H CU m r» in in X> in 1 X3 m Lj U CD •H V-i ■H S- CU u l_i CU I 4J CO CO 4-1 CO c c 1-4 o CU co •H 2 4-1 -H T-l ■K -K CO ^3 Ul rH X rH * e •K II r-l 4-> o 4-1 * o -K * CD •H a. m ^ jB i . 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Alteration of alignment . For a proposed new roadway, it is sometimes possible to alter the horizontal alignment to move it further from noise-sensitive receptors. The alignment of the Preferred Alternative has been developed with the intent to reduce noise impact at sensitive receptors, and has produced substan- tial noise benefits to East Boston. Further changes in alignment must at least triple the distance between receptor and roadway in order to produce additional significant bene- fits; such shifts in alignment are not feasible (see Section 2.5 DESIGN , CONSIDERATIONS FOR THE PREFERRED ALTERNATIVE ) . The project's vertical align- ment is primarily dictated by the need to connect to existing roadways. Any small changes that remain possible would have no significant effect on noise. Acquisition of buffer zones . Where unimproved property exists between noise-sensitive receptors and a roadway corridor, acquisition of this property can preempt future development close to the roadway. However, no such opportunities exist along the proposed project alignment. Noise insulation of public-use or non-profit institutional struc- tures . Noise insulation of public-use or non-profit institutional structures can be incorporated into this project, particularly in the North End areas affected by construction noise. This is primarily a construction noise mitigation measure that will be eval- uated further during the design phase. Noise Insulation for Private Buildings . The Commonwealth is committed to developing a program to help private building owners sound- proof structures immediately adjacent to construction areas, through use of double panel windows and air condi- tioning. As with the public build- ings, this is primarily a construction noise mitigation measure which will e evaluated further during the design phase. Noise barriers . Noise barries have been evaluated where the total projected noise levels approach or exceed the relevant FHWA Noise Abate ment Criterion, in total, noise barriers have been examined for all sites except 2 and 13. At these twc sites, noise increases are less thar 15 decibels and the total noise does not approach the Noise Abatement Criterion. Significant noise reduction c five decibels or more is not acousti cally feasible at sites where non- project noise exceeds project noise. At such sites, even a complete elimi nation of project noise, through noise-barrier design, would reduce total noise by a maximum of three decibels, unless non-project noise s five decibels or more below the tote noise level, noise abatement is considered acoustically not feasible since significant total noise reduc- tion is unattainable. For the Pre- ferred Alternative, noise abatement s not acoustically feasible at sites 2 4, 8, 9, 10, 12, and 20. For the remaining sites, where noise barrier are acoustically feasible, Table 57 contains the predicted noise levels, both with and without noise barriers The likelihood of implementing these barriers is discussed below. Final decisions on their implementation wil be made during the design phase of te project, when neighborhood opinion i assessed . At site 1, where the proposed project would increase noise by one decibel, a reduction of 5 decibels could be achieved with a 15-foot hig barrier along the edge of the mainlis highway structure, for a length of approximately 900 feet, plus a 12-fot high 1,100-foot long barrier along tJ ramp. The total-noise reduction woui be just five decibels due to traffic noise from surface streets. Because of the massiveness and the limited benefit of these barriers, and the limited usage of this playground, it 332 ij unlikely that the barriers will be b.lt to protect this site. For site 11, noise impacts for t; Preferred Alternative would d:rease slightly relative to the N-Build Alternative; two figures a>ear in Table 57 - one for each of H) different barrier heights, ligation of 5 decibels can be ueved with the 10-foot high, 2300-foot long barrier shown in : gure 58. With help from the stadium . ating, this barrier protects the h Lf of the park closest to the Arport tower. Mitigation of 10 d:ibels can be achieved with a i-foot high barrier in the same l:ation. It is likely that the i-foot barrier will be built (outside tj2 existing park limits) to protect tis half of the park at an estimated :st of $437,000, subject to community .put. At site 15, where the project *uld result in a perceptible decrease i noise level relative to the No- 5ild Alternative, a reduction of ^proximately 9 decibels can be thieved with a 10- to 12-foot high nrrier, approximately 600 feet in Jngth, located along the western edge c Waterfront Park. It is estimated tat such a barrier would cost approx- ately $78,000 and would also provide ^proximately a 6 decibel reduction at te 16, further into the park. Less rtigation is achieved here because 9e barrier is not as close to the :ceptor and because more sound energy ravels around the barrier ends. A :rrier along this park edge would cstruct access to waterfront Park and Juld obstruct the view of the harbor torn Quincy Market. For these rea- -'ns, this barrier is not likely to be hilt. At sites 17 and 18, where the joject would result in a slight • crease in noise relative to the ij-Build Alternative, reduction of ■ proximately 7 decibels can be I hieved witn 10- to 15-foot high I rriers on all elevated roadways and mps north of Causeway Street, as 1 11 as adjacent to some surface streets. These barriers would reduce project noise by approximately 10 decibels, although the total noise benefit would be just 7 decibels, due to noise from non-project roadways. At this time, construction of such barriers does not appear likely. For the lower floor of site 19, a reduction of approximately 11 decibels can be achieved with a 15-foot high, 300-foot long barrier along the southern and western edges of relocated Stillman Place (see Figure 58). This residence is typical of a large number of residences and other noise-sensitive land uses along this edge of the Central Artery. Although all residences along the corridor in this area would signifi- cantly benefit from a similar barrier, such a barrier would cut off access of these receptors to their local street. For this reason, such an extended barrier is not likely to be built. Since it is effective in reducing noise levels as well as providing protection through isolation to this area of the North End, the more limited barrier intended to protect only site 19 is likely to be built, subject to community input during the design phase of the pro- ject. It is estimated that this barrier would cost approximately $57,000 and would benefit approxi- mately 30 residents at this location. A 10 decibel noise reduction can be achieved in the vicinity of the MDC's roadway access to the new Charles River Dam, with a 500-foot long 15-foot high barrier along the easter- ly edge of the causeway Street on-ramp (see Figure 58). It is estimated that such a barrier would cost approxi- mately $171,000. Because of the potential for enhancing this area, which may be utilized as passive recreation space by the MDC in the future, construction of this barrier is likely. At site 21, a reduction of approximately 10 decibels was calculated with a 10- to 15-foot high, 300-foot long barrier along the western edge of Commercial street, adjacent to the Quincy Market. This 333 01 oo ij a o •h a o «< 0) gj w < u u 2 « «h a* < >H b 2 ► 5 S "H b0 Cm 4J 0) J* o 8 i-7 ►> H s •H 4J r 6, •H GO 5 a ■H U A 4J « PQ H S "H w 00 4J £2 V ■H 4J 00 •H c3 4-1 • CO \0 PQ PQ NO 00 on vO vO * * He u — • O r-~ PQ on vO NO PQ <3" vO O on nO o nO no PQ ON nO On ON vO vO rH T3 cu (0 c0 CO •H 4-1 o O 3 « M IM M O m M s « T3 iH O lO CO a C cC a. M c a Q o 3 a) X ar c 0J o 4-1 •H o •H ■H 0) u Id 4J & •H >-. o o 4-1 •H -o 4-1 u 4-> cr «0 4-1 4-1 c c0 c <4-( > I— 1 (0 o o o hZ CO (X o 8 4-1 M u o CO De PQ CO U-l 0 >4-l C o CU Xi a) M O 14-1 t-l o CNJ -a CO 0) CO o C XJ 4= CO W w CJ 4-1 3 PQ <4-l 3 cc «0 u U CVi CNI vO vO CM vO vO -H O vO CN PQ W On ON 00 — . CM CM CM 334 • Noise Measurement Location 1 Noise Barrier J Height of Noise Barrier Figure 58 Potential Noise Barrier Locations Central Area and East Boston 0 200 400 Feet EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93 - Central Artery barrier would have cost approximately $45,000 and would have been acoustically effective because it shields not only project noise, but noise from Commercial Street as well. However, a barrier in this location would separate Quincy Market from Commercial Street and would obstruct the view of the harbor. Its intrusion upon Quincy Market would have been severe and thus has been rejected. Fortunately, the Marketplace Center project now under construction will tend to shield the Quincy Market area from noise generated along the Surface Artery. The initial noise analysis for site 21 did not assume the construction of Marketplace Center between the Artery and Commercial Street, at the eastern end of Quincy Market. At site 22A, a reduction of approximately 9 decibels can be achieved with a 20- to 25-foot high, 300- to 400-foot long barrier along the Surface Artery, wrapping around the Harbor Tower Condominiums at both ends. Such mitigation would accrue only to the lowest residential floor, however. Such a barrier is imprac- tically high and is therefore not likely to be built. Construction Impacts For the Preferred Alternative, major sources of construction noise will include pile drivers, jack- hammers, trucks, cranes, excavating equipment and miscellaneous support equipment. It is anticipated that construction will proceed using two 10-hour shifts per day over a 12-year period (approximately) in downtown Boston and over a 4-year period (approximately) in East Boston, Charlestown, Fort Point Channel, South Bay, and South Boston areas. A review of the planned con- struction indicates that, compared to existing noise levels, minor impact from construction noise is ex'pected at the Edward Everett House (Charles- town), Charles River Dam Park, the Casa Maria Housing (North End), St. Peter and Paul Church, and at the Albany Street Apartments in the kx End. Moderate impact is expecte a Quincy Market, Waterfront Park, m : Tower, Rotch Playground, and at m Boston Tea Party Museum. Substat impact is expected at the Spauldn: Rehabilitation Hospital, Stillmai Place Residences (North End), th proposed Arts Building in South Boston, and at the East Boston Memorial Stadium. Construction Noise Mitiga i: Measures Potential mitigation techic for construction noise include lm: ing noisy construction activity o daytime hours near noise sensitie areas, to the extent possible; esu ing that all diesel powered equime has effective mufflers; and ereci: temporary noise barriers betweennc construction operations and near/ sensitive receptor locations. Te feasibility and effectiveness oft: mitigation measures depends upontr. specific construction equipment ad scenarios planned for the projec. Therefore, a project-specific pli mitigate construction noise willae developed during the design phas, when project-specific constructii noise computations can be made. Mitigation will be incorporated 3 required to conform with the Cit; o Boston Noise Ordinance, in addiic the Commonwealth will explore th« feasibility of undertaking a pro<:c to soundproof affected private h CO 4-1 H W IH R) •H ■H -a < M 4-1 is B CD 01 CJ ^ t-i u wa o •H 3 U aj CO 4J c "J > u o T3 CO 5C 4-1 —1 3 1 OJ c CO >, co ■H i— i bG — < O 0 c PUi 00 C 03 00 04 a o o CJ l-J * 4J o >4-l 14-1 O O I-- CM CJ 3 u 4-1 co c o o bO a > CO a >, u at t-i H 3 Oi OO I — * * T3 CO CO o X3 Oi bO 3 CJ O TJ Si U O CO (1) u c 0 u OJ H I bO c cu 4J jr CO > 4-l U-l c •H T-l u-i o o T t c a (JJ c c co t e 338 laster, etc.) is likely to occur only a those situations where impact piles ill be driven within six feet of a tructure or where slurry wall excava- ion will occur within one foot of a tructure. "Architectural damage" which refers to very fine plaster racking and the reopening of old racks) could occur at somewhat reater distances from project con- duction, particularly for historic uildings. The impact distances for [his effect are quite conservative, owever, and are based on criteria hat make allowance for the cumulative :ffects of vibration over a period of iime. With regard to annoyance Effects, Table 58 suggests that impact Jistances can be considerably greater e.g., as much as 460 feet for pile jlriving near residential buildings !?ith wooden floors that may amplify ncoming ground vibration). I Potential long-term vibration effects due to the project are related p vibration generated by motor /ehicle traffic. As indicated in :able 58, the impact distances for lamage effects from road traffic are ;'ery small (six feet or less). Thus, it is highly unlikely that traffic 'ibrations could cause even very minor Jamage, although such vibration could >e annoying to people inside buildings :hat are very close to roadways. Annoyance would be greatest near roads :hat are in poor condition and that :arry heavy truck traffic. However, since ground vibration has been observed to reach its peak with the massage of an individual vehicle, it las been found that increased traffic Volumes do not increase the magnitude )f ground vibration, but rather increase the number of peaks that 3ccur in a given time period. Furthermore, it is likely that in the Limited situations where traffic /ibrations are perceptible, annoyance iue to noise (addressed in section 3.6.1) would greatly overshadow annoyance due to vibration. There- fore, the effects of traffic vibration are assessed based on the maximum amplitude of the vibration rather than 3n traffic volumes. Comparison of Alternatives With regard to potential vibration impacts in the long-term (i.e., from traffic), the Preferred Alternative would have beneficial effects similar to Alternatives 3A, 5A and 6, with reduced levels of vibra- tion as compared to the No-Build Alternative and Alternatives 2, 3, 4 and 5 at locations near the existing Central Artery viaduct. Elsewhere in the project area, long-term vibrations are essentially unchanged over exist- ing conditions, regardless of the alternative . Potential damage effects of construction vibration are expected to be greater for the Preferred Alterna- tive than for all other alternatives, as summarized in Table 59, since vibrations during construction would affect more buildings than any other alternative. With regard to annoyance from construction vibration, the Preferred Alternative is expected to affect about the same number of residents as for Alternative 6, somewhat less than for Alternatives 2, 3A, 4 and 5A, and considerably more than for the No-Build Alternative and Alternatives 3 and 5 (see Taole 60). By geographic area, the Pre- ferred Alternative would result in impacts similar to Alternatives 3A, 5A and 6 in the Central Area and the area north of Causeway Street. In the Museum Wharf area, construction vibration impacts for the Preferred Alternative would be the same as for all other build alternatives. In the South End, the Preferred Alternative would cause the same construction vibration impacts as for Alternatives 4, 5 and 5A, but would cause greater impacts than for all other alterna- tives. In South Boston, construction vibration impacts for the Preferred Alternative would be slightly more extensive than for Alternative 5A; no such impacts would occur for any of the other alternatives in this area. Finally, in the East Boston neighbor- hoods, there would be no significant construction vibration impacts for the 339 Table 59 POTENTIAL DAMAGE EFFECTS OF CONSTRUCTION VIBRATION No. of Building s Affected by Alt ernative Type of No- Effect Build 2 3 3A 4 5 5A 6 Preferrec Structural Damage 0 1130033 3 Architectural Damage 0 8 5 57 11 8 64 57 69 Table 60 RESIDENTS ANNOYED BY CONSTRUCTION VIBRATION Approx . No . Alternative of Residents No-Build 0 2 3100 3 460 3A 2800 4 3030 5 390 5A 2840 6 2560 Preferred 2500 340 •referred Alternative at any residen- .ial location (same as for the No- luild Alternative and Alternative 6 ) ; ill other alternatives would affect .he residential neighborhoods during .•onstruction. Construction vibration .impacts at the Airport Hilton Hotel /ould be the same for the Preferred alternative as for Alternatives 3, 3A, i and 5A. Alternatives 2 and 4 would lave no effect at this Hotel. ^o-Build Alternative Long-Term Effects Future vibration impacts for the No-Build Alternative will improve DVer existing conditions because of deck replacement, roadway surface restoration, and improvements to the expansion joints. Construction Impacts Construction period vibration impacts during Central Artery deck replacement for the No-Build Alterna- tive are not expected to be signifi- cant compared to existing vibrations because of the type of construction equipment expected to be used (i.e., pavement saws, cranes, trucks, etc., rather than impact devices, pile drivers, and similar equipment). Preferred Alternative Long-Term Effects No adverse long-term (i.e., traffic) vibration effects are antici- pated from the Preferred Alternative and, therefore, no long-term mitigat- ing measures are required. In fact, some long-term vibration benefits can be expected after the Central Artery viaduct is dismantled. In particular, at locations near existing Central Artery columns, where traffic vibra- tions are now perceptible, vibrations are expected to become imperceptible after the Central Artery viaduct is removed. Construction Impacts During construction, it is anticipated that some underwater blasting of rock will be required in Boston Harbor. Vibration generated by such blasting could affect nearby land uses, but the potential for impacts would be limited to industrial and commercial areas near the shoreline in South Boston and at Bird island Flats. Of particular concern in these areas are the effects of blasting on the drydock and sensitive Navy vessel equipment at the General Ship facility in South Boston, and on electronic equipment at the Massachusetts Techno- logy Center at Bird Island Flats. These potential effects will be carefully evaluated during project design when detailed requirements for blasting are developed, and appro- priate mitigation measures will be incorporated as required to avoid impacts. Mitigation measures include the use of controlled blasting tech- niques such as the pre-spl itting or line drilling of rock, use of reduced charge weights, and limiting the depth of rock removed per blast. Assessment and mitigation of potential vibration effects for other project construction activities are discussed below. For the Preferred Alternative, the most prevalent sources of vibra- tion will be pile driving and slurry wall construction, with pile driving being the dominant source. In down- town Boston, exposure to intermittent pile driving will occur over a one to two year period for the support of relocated utilities. In addition, soldier piles will be driven over a period of about one year for site preparation in each construction section, and some sheet piles will also be driven for depressed ramps and the Blue Line subway tunnel crossing in the Central Area. The remainder of construction in the Central Area will primarily involve excavation and slurry wall construction for about 1 to 1-1/2 years in each section. In the Charlestown, South Boston, and East Boston areas of the project, exposure to pile driving vibration is generally expected to occur for periods of two to three months at nearby sensitive locations. 341 Maximum vibrations during construction along the existing Central Artery corridor are expected by be 3 to 25 times as great as the maximum vibrations measured at Sites E through I (see Table 61). At Site J (Spaulding Rehabilitation Hospital), maximum construction vibrations are not expected to exceed existing maximum vibrations from MBTA commuter rail operations, but would be continu- ous during pile driving near this location rather than the intermittent vibrations now experienced. The significance of vibration at these and other sites is discussed below. There is potential for vibra- tion-induced structural damage at the Hanover Street Post Office arid Boston Police Academy in the North End during soldier pile driving operations within six feet of these buildings. The potential for structural damage also exists at the Purity Cheese Company building in the North End and the MBTA Orange Line subway tunnel near North Washington street during slurry wall construction within one foot of these structures. Therefore, during the design phase, appropriate construction management methods will be specified to minimize the possibility of damage of these critical sites. Some of these measures, as described below under Mitigating Measures , include pre-trenching , pre-auger ing , use of low-displacement piles, controlling sequencing of pile driving, etc. For tunnel construction across the MBTA Red Line tunnel in Fort Point Channel near the Gillette Company, the potential for vibration-induced structural damage during excavation around the subway tunnel is mitigated by installation of steel ribs on the inside of the tunnel, and by other measures as described below. For construction across the MBTA Red Line tunnel in Fort Point Channel near Summer Street and across the Blue Line tunnel at State Street, vibration levels are not expected to exceed the criterion limit for structural damage (peak velocity of 1.9 in. /sec) but are expected to exceed existing vibrations due to train operations (see Table 61). Specific measures to mitigati these possible impacts are describe later in this section. In terms of minor architects damage, analysis estimates indicab that the project vibration criteri; for this effect (peak velocity of II in. /sec for historic buildings and 0.20 in. /sec for non-historic build- ings) would be exceeded at approxi mately 26 residential buildings in ;h North End, 26 office or commercial buildings in the Central Area, 15 industrial buildings (2 in the Nor i End, 5 in the South End and 8 in Sat Boston) and at the Boston Garden ail the Children's Museum. Although a maximum ground vibration velocity <: 0.35 in. /sec is expected to occur : the Spaulding Rehabilitation Hospiil during nearby pile driving, measur- ments indicate a maximum existing level of 0.47 in. /sec due to nearb commuter train traffic. Since exi: ing vibrations are greater than th maximum levels expected to occur during pile driving operations, architectural damage effects are n: anticipated at this building from i« Preferred Alternative. Temporary annoyance from construction vibration is expectedit approximately 40 three-story residi tial buildings in Charlestown, 52 residential buildings in the North End, Harbor Tower, the Dockside Condominiums, the Albany street Apartments (§©uth End), and the Ar Building in South Boston (259 A Street), in addition, annoyance effects are anticipated during con struction near approximately 40 of J or commercial buildings (primarily.n the area between the Dewey Square | Tunnel and Causeway Street), 31 industrial buildings (primarily in South Boston and the South End), 8 institutional buildings, 3 hotels,) the Spaulding Rehabilitation Hos- pital. The most severe annoyance residents is expected during pile driving in the North End, with max vibration velocities inside the nearest residential buildings as h as 1.0 in. /sec, which could be cha acterized as "very unpleasant." A 342 Table 61 SUMMARY OF MAXIMUM EXISTING AND FUTURE VIBRATIONS Maximum Peak Vibration Velocity (In. /sec) Site.* Description Existing and No-Build Alternative Preferred Alternative Construction Sidewalk outside 144 Bremen St., 0.060 (Not Applicable) above the Blue Line Subway Tunnel Ceiling Inside MBTA Red Line Sub- 0.042 1.900 way Tunnel below Fort Point Channel Ceiling inside MBTA Blue Line Sub- 0.095 (Not Applicable) way Tunnel below Porter St. (East Boston) Floors inside Gillette Company 0.031 0.045 Bldgs. (South Boston) Sidewalk outside Bain Bldg. 0.066 0.200 at 394 Atlantic Ave. F Sidewalk outside bldg. at corner 0.056 0.600 of State St. and Surface Artery G Sidewalk outside North Market 0.027 0.100 Bldg. at Quincy Market, near corner of Clinton St. and Commercial St. H Sidewalk outside North End Nurs- 0.040 0.800 ing Home, at building corner nearest Richmond St. and Calla- han Tunnel portal I Sidewalk outside apartment 0.016 0.400 between Nos. 2 & 3 Stillmar. PI. on east side of expressway (North End) J Ground outside new wing of Spauld- 0.470 0.350 inq Rehabilitation Hospital, approximately 15 feet from nearest North Station railroad track See Fig. 20 343 discussed below, measures to mitigate these impacts include use of low- displacement piles, pre-trenching or pre-augering for piles, etc. At the Spaulding Rehabilitation Hospital and at the proposed Arts Building in South Boston, maximum building vibrations during two to three months of nearby sheet pile driving are expected to be as high as 0.2 in. /sec, which could be characterized as "unpleasant." At other affected locations, maximum construction vibrations could be characterized as "easily to strongly noticeable. " Based on approximate population density, it is estimated that about 2,500 people living in the project area would be disturbed by vibration during some portion of the construction period. The effects of construction vibration on sensitive equipment operation are of particular concern at the Gillette Company facilities in South Boston. The analysis indicates that vibration from pile driving for the supports of Gillette's temporary extended water intake pipe would exceed maximum existing building vibration at only 2 of 11 sensitive locations. This effect would occur for a period of about one month, with a maximum peak floor vibration veloc- ity of about 0.045 in. /sec at the nearest sensitive building location (see Table 61). In addition, building vibrations are expected to be notice- able at the extreme north end of Gillette's facility during pile driving for tunnel construction across Fort Point Channel. It is unlikely that these levels of vibration will affect Gillette's operations. The U.S. Postal Service has also expressed concern regarding the effects of construction vibration on their computer equipment at the South Postal Annex. However, a comparison of predicted vibration levels with criteria recommended by computer equipment manufacturers indicates that project construction vibration is not likely to affect this equipment, even though such vibration could be per- ceptible inside the postal facility. Construction Impact Mitigat e. Measures Mitigation techniques for ts above vioration effects include wasr jetting and pre-trenching in the cse of sheet piling and pre-augering aj the use of low-displacement piles 1 the case of bearing pile driving, j Other mitigation measures applicabi to pile driving include controllin the sequence of pile driving, conto: ling the rate at which piles are driven and establishing minimum ofse distances for pile driving near structures. In addition, the subsi- tution of slurry wall constructionfc sheet pile driving, where possible could also be an effective mitigaton technique. Additional means to avic. adverse effects include scheduling construction to minimize sensitive activity interference (e.g., avoicna night time vibration-related constuc tion near residences). Appropriat mitigation measures will be indued in the construction documents, basd on the details of the design. Adc- tional details regarding the asses- . ment and mitigation of constructic vibration are contained in Appendi Specific measures to avoid structural damage to MBTA tunnel facilities and other nearby structr- are detailed in the Supportive Enc - neering Report . These measures, vi, will be incorporated by the projec' ' design, include the use of steel rb£ to strengthen the lining of the Re Line subway tunnel beneath Fort Pent Channel prior to excavation arounci. (2) the use of a resilient cushior between the proposed highway and te existing subway tunnels at locatics^ with small clearances between the tunnels, (3) specification of dewj ing procedures during constructior as to minimize stress concentratic in subway tunnel structures, (4) t< use of shorter than normal slurry segments where these are close to way tunnels, and (5) the specifics tion of minimum clearances betweer project slurry walls and subway ti nels. in addition, an instruments tion program will be implemented t : IS 344 onitor stress and strain inside sub- ay tunnels during nearby construc- ion. '.9 WATER RESOURCES '.9.1 Comparison of Alternatives The No-Build Alternative avoids 11 impact to water resources. Of the uild alternatives evaluated, Alterna- tes 3, 3A, and 5 result in the argest impact to water resources, rincipally due to the volume of redging required in Boston Harbor, lternatives 2 and 4, which had horter cross-harbor tunnels, had omewhat less water-related impacts 'nan these alternatives. Alternative A results in even less impact to ater quality and the Preferred Jternative has the least impact of 11 cross-harbor tunnel alternatives ■ecause of the shortest route across ;.he Harbor. Alternative 6 had the east water-related impact of the ;>uild alternatives. None of the alternatives will affect any pro- grammed improvements to sanitary ;;ewers or implementation of the Fort 'oint Channel or the East Boston :ombined sewer overflow projects. 1.9.2 No-Build Alternative There are no impacts on water Quality of the Boston Harbor from the Jo-Build alternative because of the ibsence of construction within area waterways. 1.9.3 Preferred Alternative ..ong-Term Operational Impacts • The Preferred Alternative may Contribute to some reduction of pollutants into the Harbor, since the structures will be totally enclosed. Consequently , with the exception of ^missions which are dispersed from the /entilation system, other pollutants vill be concentrated and contained within the tunnel structures. This contrasts with the present condition, vhere all pollutants from vehicles on :he viaduct are either dispersed Laterally or depositee onto the roadway surface and ultimately are carried into the Harbor by the storm- water drainage system. The Central Artery and Third Harbor Tunnel walls and ceilings will be periodically washed. This will flush accumulated solids and metals into the tunnel drainage system. Some of these solids and metals will settle in sumps within the drainage system, and will therefore result in a net capture of pollutants, washdown water will be pumped from the drainage system sumps and discharged into the sanitary sewers. (stormwater from ramps and other open roadways will not be conveyed to the sanitary sewers, but will be discharged to storm drains.) Sedimented solids and metals will periodically be removed from the drainage system sumps and disposed at an approved location. The following percentages of pollutant removal are estimated to be possible through primary sedimentation in the drainage system sump (Table 62). Table 6 2 MEDIAN REMOVAL EFFICIENCY O F PRIMARY SEDIMENTATION Median Percent Pollutant Removal Cadmium (total) 7 Chromium (total) 16 Lead 20 Mercury 21 Copper 19 Nickel 6 Zinc 25 iron 37 Manganese 8 Ammonia 16 TOC 20 COD 19 Suspended Solids 52 BOD 5 28 Source: EPA, 1977. In addition to this initial removal of pollutants, further water treatment will also be provided. The Metropolitan District Commission (MDC) has indicated that a minimum of oil/ 345 water separation will be necessary before the washdown water is dis- charged into the sanitary sewers. This separation is to prevent petro- leum fractions, flotables, and other solids from entering the wastewater collection system. During the design phase, plans will be developed for containment and control of accidental spills as required by the MDC. MDC's sewer use regulations prohibit the introduction of stormwater runoff to sanitary sewers. In summary, some minor long- term benefits to water quality of the Inner Harbor should be derived through the reduction of roadway pollutants which presently are discharged to Boston Harbor. These pollutant reductions will result from improved traffic flow and the removal of solids and metals in the tunnel and Central Artery drainage systems. Impacts to Fort Point Channel The Preferred Alternative will entail filling a portion of South Bay, with a bulkhead located at Dorchester Avenue and extending along the western edge of Fort Point Channel. This will reduce the tidal water area of Fort Point Channel from approximately 52 acres to approximately 41 acres, a reduction of approximately 21 per- cent. This reduction in tidal water area will be reflected in a propor- tional decrease in tidal prism, with the mean tidal prism falling from 21.5 million cubic feet to 17.1 million cubic feet; the spring tidal prism will decrease from 24.9 million cubic feet to 19.8 cubic feet. The tidal excursion for a particle of water beginning at the mouth of the Channel will decrease from approximately 2,100 feet to approximately 1,600 feet as a result of this filling. Computed average tidal veloci- ties at the Northern Avenue Bridge will decrease very slightly from approximately 0.1 feet per second to approximately 0.06 feet per second. The flushing time for the Channel will increase slightly, from 2.1 tidal cycles (approximately 26 hours) to 2.25 tidal cycles (approximately 26 hours ) . The design of all highway structures in or crossing the Fort Point Channel has minimized fillinc the Channel to the extent possible. However, the resulting 21 percent Is of tidal prism will have some long- term impacts on water quality in th Channel. The existing water qualit under storm conditions in the Fort Point Channel were estimated and ar shown in Table 63. Potential impacts from fillig parts of the Fort Point Channel are shown in Table 64. As shown in the tabulations, most parameters show little, if any, change in concentre tion. Those which show the greates change are bacteria, BOD and COD, a solids. None of the increased con- centrations are considered major changes to the existing concentrate There may be a 15 percent decrease of dissolved oxygen durinc storms. The decrease, however, is I expected to make the Fort Point Channel any less habitable for marie life. Water quality standards for bacteria and dissolved oxygen in tr Channel are presently violated, anc the presence of the new highway facilities will result in slight exacerbations of these conditions. Construction of the Fort Point Char; Combined sewer Overflow (CSO) treat ment facility by the MDC would sigr- ficantly improve overall water qua]: conditions . Impacts to Industrial Seawat : Users Of the 11 users of sea watei listed previously in Table 27, only are close enough to the constructic area to be of concern. These are ti New England Aquarium and the Gillet; Company. The New England Aquarium removes sediment and suspended soli' from the seawater by sedimentation 1 diatomaceous earth filtration. The Aquarium, therefore, is capable of accommodating increased suspended solids in the seawater, although it 346 Table 63 EXISTING STORM WATER QUALITY IN THE FORT POINT CHANNEL (concentrations in mg/1 unless otherwise noted) Total Coliform Bacteria 69.0 x 106/100 ml Fecal Coliform Bacteria 3.8 x 106/100 ml Biochemical Oxygen Demand (BOD) 28.1 Total Suspended Solids 84.3 Mercury 0.5 0 Lead 0.03 Copper 0.05 Zinc 0.05 Cadmium 0.00 4 Chromium 0.0 2 Total Organic Carbon 18.5 Chemical Oxygen Demand (COD) 58.3 Table 64 FUTURE WATER QUALITY IN THE FORT POINT CHANNEL (concentrations in mg/1 unless otherwise noted) Total Coliform Bacteria 78.9 x 10 6 /100 ml Fecal Coliform Bacteria 4.4 x IO6/100 ml Biochemical Oxygen Demand (BOD) 32.1 Total Suspended Solids 96.4 Mercury 0.5 7 Lead 0.04 Copper 0.06 Zinc 0.06 Cadmium 0.00 4 Chromium 0.02 Total Organic Carbon 21.2 Chemical Oxygen Demand (COD) 66.6 t 347 may require additional cleaning of sedimentation tanks and more backwash- ing of filters during the construction period. The seawater intakes of Pauls Lobster Company, Neptune Lobster Company, and Harbor Lobster Company on Northern Avenue will be monitored during construction and, if necessary, temporary filters can be installed to assure clear water for the lobster holding tanks. Hook Lobster Company will be displaced by the Preferred Alternative, and therefore will not be present during the construction period. To maintain the quality of cooling water used at the Gillette facility, a lengthy relocation of the intake was proposed in the DEIS/DEIR. Gillette objected to the relocation because of significantly increased annual costs for maintenance and access difficulties to much of the system which would have been off Gillette property. Additional infor- mation has been developed on the hydraulic characteristics of the Fort Point Channel and a series of computa- tions has been conducted to model the limits of water movement on the ebb and flood tides. The results indicate that, under existing conditions, the Gil- lette seawater intake is located in the middle of a thermal mixing zone (see Figure 59). That is, Gillette draws water into its plant which it had previously discharged; hence, the intake water for cooling purposes is actually warmer than it should be because of the proximity to the discharge pipes. The computations also indicated that filling in South Bay sufficiently reduces the volume of tidal prism such that excursion on the flood tide falls approximately 400 feet short of the existing intake as measured from the northern Gillette property line. That is to say, should the discharges be relocated to the northern property boundary, heated water from the discharge would not reach the intake on the flood tide. Field data also indicated that considerably coolei water (by approximately 4°c) is available at a depth of -11 to -l; feet mean sea level (msl). There! r< the intake could be moved to a loc- tion downstream of the discharge j the intake is low enough to allow heated water to be discharged at i elevation above the cooler water. The Preferred Alternative vu. require that either Gillette's intra*/ or discharges (2) be relocated. Gillette wanted its relocated f acui- ties to remain on its property so ihe operational and maintenance costs could be minimized. Plans in the Supportive Engineering Report shova permanent relocation of the dischcgj (also shown in Figure 59), and a temporary relocation of the intake — during construction. These are presented as a possible solution t }} Gillette's cooling water concerns. However, there are several other alternative measures which cu] be used to respond to Gillette's -tj f cooling water requirements, inclucnc o Relocating the intake to th north end of Gillette propetj o Relocating the intake to th north end of Gillette propet _ and relocate the outfall toth ^ vicinity of the Dorchester Avenue Bridge or discharge it the Roxbury Canal Conduit. o Modifying the existing inta= or designing a relocated inak ),! ' to tap the cooler water locte c at greater depth in the Cha- nel, including dredging in ie vicinity of the intake and reconstructing the adjacent seawalls, if necessary, and ~~ designing any relocated outil to limit vertical mixing. A preliminary assessment indicates that it is possible to mit Gillette's current and future cool >9 water requirements with various combinations of these measures, selection of the mitigating measure will be made during the design sta<: : PM2 348 [xisting □ r^r^' Limits of Tidal Excursion ^ looo • Figure 59 Existing and Alternative Future Gillette Cooling Water Configuration i^^O^^O^^^^^OO Feet EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93 -Central Artery of the project, based on detailed hydraulic and thermal analyses to determine thermal capacity of the Fort Point Channel. The mitigating mea- sures will be designed such that Gillette's potential for pumping 57 million gallons per day (mgd) without exceeding the intake and outfall temperature requirements (a maximum of 22.20c and 28.3°c respectively) will not be reduced. in addition, the mitigation measures will be designed so that expansion of Gillette's cooling water usage would be optimized up to 75 mgd within the current intake and outfall temperature requirements. An existing 72 inch CSO discharge near the north end of Gillette's property may have an adverse water quality impact on an intake repositioned to this location. Also, the proposed Roxbury Canal Conduit discharge in the vicinity of the Dorchester Avenue Bridge may affect the water quality at the existing intake location. These water quality impacts will also be evaluated during design and will be mitigated by modification or relocation of the discharges, as necessary. Construction staging will result in initial construction of the South Bay components of the Tunnel and Central Artery stopping short of the Red Line Tunnel. At the same time, construction of the Seaport Access portion of the tunnel will commence approximately 200 feet east of the Red Line Tunnel. After the Seaport Access Tunnel has been completed in the Fort Point Channel, either a temporary or permanent intake will be constructed over the tunnel. This will allow bridging of the Red Line Tunnel, and will require that most of the Channel at that time be blocked by steel sheeting. This sheeting will also result in temporary impacts to recre- ational navigation in this portion of the Channel. Construction activities in the Channel will result in temporary increases in turbidity and suspended solids. The construction impact on Gillette's cooling water will be mitigated by use of steel sheetincar silt curtains to contain the susp|ty of these contaminants in suspension ;,yith the sediment has been made by ]>i assuming that all of the contaminants remain with the suspended sediment at their bulk concentration. The bulk ill concentration data for the sediments ; along the alignment of the Preferred ■a Alternative are listed in Table 65 for is surface sediments. Table 65 THE PREFERRED ALTERNATIVE ASSOCIATED CONTAMINANTS Average Concentration (mg/kg dry weight) Parameter Arsenic Cadmium Chromium Copper Lead Mercury Nickel Vanadium Zinc PCB Pesticides Total Phosphorus Ammonia Nitrogen Total Kjeldahl Nitrogen Surface Mud 31.00 5.30 25.70 10.40 45.90 0.79 1.60 43.00 77.70 0.005 0.005 , 84.70 60.90 23.90 Earlier sampling programs in the Harbor have shown that the maximum concentration of contaminants is found in the surface sediments. Since dredging will disturb both the surface and deeper layers of sediment, the surface concentrations listed in Table 65 were used to estimate the maximum concentration of sediment-associated contaminants in the dredging plume. Table 66 lists the resulting concentrations of sediment-associated contaminants above background at distances from the dredge between 20 m and 1200 m. The concentration of sediment-associated metals in the dredge plume, for the most part, will be in the parts per billion range. The maximum concentrations reported will be those for lead and zinc, exhibiting concentrations of approxi- mately 0.026 and 0.045 mg/1 at 20 meters from the dredge. These will be reduced to less than 0.001 mg/1 (1 ppb) at the edge of the plume. PCBs and pesticides will not be measurably present in the plume; even at 20 m, the concentration of both will be less than 0.001 mg/1 (1 ppb) . There will, however, be higher concentrations of sediment-associated nutrients in the dredging plume. Total phosphorus could reach 0.049 mg/1 above background near the dredge. This concentration will be reduced to less than 0.001 mg/1 (1 ppb) above background at a distance of 1200 m from the dredge. These sediment-associated contaminants are not likely to enter the water as dissolved constituents, and thus, will not be present outside the plume or after the plume resettles from the water column. This is confirmed by the elutriate analyses, discussed in Section 3.7 WATER RESOURCES, EXISTING CONDITIONS , which indicate only minor releases of any contaminant, even at high sediment concentrations. Based on these analyses, the concentration of soluble metals, nutrients, and petrochemicals will be 3 to 4 orders of magnitude below the sediment-associated concen- trations listed in Table 65. 353 Table 66 MAXIMUM CONCENTRATION OF SEDIMENT- ASSOCIATED CONTAMINANTS DURING DREDGING FOR THE PREFERRED ALTERNATIVE (mg/1) Background* 20m** Am* * um o u um b u um 120 0m* Suspended Solids 22 57 3 XU D j J lb 5 Arsenic 0. 001 0. 018 u . UUJ n U . u ui n u • U U 1 0 .001 Cadmium 0. 009 0. 003 n VJ • 0 01 0 01 o 0 01 0 .001 un ronu. um 0. 004 0. 015 0 003 n 0 01 0 . 001 \J \J X 0 .001 0. 006 0. 006 0. 001 0. 001 0. 001 0 .001 Lead 0. 012 0. 026 0. 005 0. 002 0. 001 0 .001 Mercury 0. 035 0. 001 0. 001 0. 001 0. 001 0 .001 Nickel 0. 016 0. 001 0. 0 01 0. 001 0. 001 0 .001 Vanadium 0. 040 0. 025 0. 005 0. 001 0. 001 0 .001 Zinc 0. 050 0. 045 0. 008 0. 003 0. 001 0 .001 PCBs 0. 001 0. 001 0. 001 0. 001 0 .001 Pesticides 0. 001 0. 001 0. 001 0. 001 0 .001 Total Phosphorus 0. 050 0. 049 0. 009 0. 003 0. 001 0 .001 Ammonia Nitrogen 0. 070 0. 035 0. 006 0. 002 0. 001 0 .001 Total Kjeldahl Nitrogen 1. 230 0. 014 0. 003 0. 001 0. 001 0 .001 *See Table 19 ♦♦Concentrations above background 355 Biological impacts result from the increased suspended solids in the sediment plume closest to the dredge. Impacts include a total loss of benthic bottom dwelling fauna and fish mortality. Recolonization of harbor sediments and new bulkheads will commence the following spring. Thus, no significant long-term biological impacts will result from cross-harbor tunnel construction although short- term impacts will occur during con- struction. The marine dredging required for the Preferred Alternative is less than most other Third Harbor Tunnel alternatives. The impacts to water quality from the dredging are limited, similar in every way to a normal maintenance dredging project in the Harbor. The impacts projected from dredging for the Third Harbor Tunnel can be assessed qualitatively by comparison with other dredge monitor- ing information. Monitoring during dredging of the Thames River in Connecticut indicated that near field suspended solids impacts were limited to within 150 meters from the dredge. A return to background conditions occurred approximately 1000 meters from the dredge. Additionally, the vertical variation at the dredge was approximately 2 times higher at the River bottom (155 mg/1 ) than on the surface (68 mg/1). At the point where surface suspended solids were at background concentrations (5 mg/1), bottom suspended solids were 4 times greater . The previous discussions have referenced a 5 mg/1 suspended solids concentration at the end of a turbid- ity plume. In its "Order of Condi- tions" to Massport for the south Boston Naval Annex filling, DEQE (July 16, 1980; File No. 6-148) defined a turbidity plume as: "... A turbidity plume shall be defined as the area in which the effects of solids, suspended in the water column are present in concentrations in excess of 50 mg/1 over background values . " With this definition as a guideline, the length of a turbidiy plume from the Third Harbor Tunne] dredging will be significantly les than those described. The 50 mg/] concentrations will occur at apprci mately 300 meters along either alin ment . Tunnel construction will require removal of approximately 520,000 cubic yards of rock in th« vicinity of the Boston Marine indi- trial Park and General Ship Drydoc South Boston. The necessary blastn represents a potential source of adverse environmental effects, incu ing direct mortality of fish and chi organisms. The impact to biota resultig from any underwater blasting progiir is a function of several parameter These include: the type and quant t of material to be removed; its dejh below the water surface and positirv ing in relation to the shoreline; bottom configuration; the amount < explosives used; and the type and abundance of organisms in the are* The most vulnerable organiiis are fish which possess air bladdei swim bladders. These fish may ruju in response to rapid pressure changes. In general, it has been reported that the effects on fish i open water explosions are not projr tional to the size of the charge (Coker and Hollis, 1950). Instea< the most important factors appear .0 be detonation velocity, the speed f the pressure pulse, and peak pres- sure. Peak pressure has also beer found (Hubbs and Rechnitzer, 1952/to decrease exponentially with incren 4.4, 4.9, 4.11, and 4.12). The Preferred Alternative w result in the conversion of the so Bay area of Fort Point Channel fro: open water to a developed use. Th conversion of approximately 9.1 acis of open water constitutes a long-tn impact as well as a loss of open w.e wetlands as defined in Massachuset; regulations . Ill Additional impacts to exist open water communities will occur the remainder of Fort Point Channe In this area, construction of the Preferred Alternative will result : the loss of approximately 3.9 acre: 358 )pen water as the northbound Central \rtery tunnel crosses over the Red jine Tunnel. An area totaling approximately .18 acres along the southern banks of he Charles River between the old and lew Charles River Dams and 0.5 acres in the tidal portion of the Charles River, will also be converted to a developed use. As with South Bay and Fort Point Channel, this conversion constitutes a long-term impact and an irretrievable loss of open water wetlands. Mitigating Measures As discussed, the Preferred Alternative will result in no impacts "to Federally-regulated wetlands; consequently, no mitigation measures are necessary. With respect to State-regulated wetlands, impacts resulting from construction, and measures to mitigate the impacts have : been discussed in Section 4.9 WATER RESOURCES . Also, during the design phase, the requirements of the Wet- lands Protection Act (Massachusetts General Laws Chapter 131, Section 40) must also be met. The Boston Conser- vation Commission will be responsible ifor imposing specific construction methods and materials to minimize | impacts to wetlands through the Order of Conditions; the specifics of these .conditions will be incorporated into Ithe construction specifications and the contract drawings. 4.11 FLOODPLAINS 4.11.1 Comparison of Alternatives There are no significant impacts to floodplains and flooding from any of the alternatives. The Preferred Alternative, however, results in the least impact to flood- plains as compared to all build alternatives. 4.11.2 Preferred Alternative vs. No-Build Alternative Approximately 13 acres of floodplain encroachment will result from construction of the Preferred Alternative within the Fort Point Channel; an additional 1.68 acres of floodplain encroachment within the Charles River will also take place from the Central Artery to Storrow Drive Connector (1.18 acres above the new dam and 0.5 acres in the tidal Charles River). Flooding in Boston Harbor is controlled almost entirely by a combination of the high tides and storm surges which accompany hurri- canes and major winter storms. There will be no impact to flooding because there will be no significant reduction in the cross-section of the Harbor and therefore, its ability to pass flood waters will not be reduced. The mean sea level water surface area of the inner Harbor is approximately 54.5 million square feet (upstream of Pier 5, South Boston). The Preferred Alternative will occupy approximately 588,000 square feet in the Fort Point Channel and the tidal portion of the Charles River. This decrease in water plane area is one percent of the existing water plane area, and results in a negligible (uncalculable) rise in floodwater elevation within the Inner Harbor. Flooding impacts in Fort Point Channel are similarly small. The floodplain encroachment required for the Preferred Alternative will reduce the width of Fort Point Channel to approximately 360 feet at a point approximately 600 feet south of the Congress Street Bridge where the new bulkhead will be located. At Northern Avenue, the existing Channel width will be maintained. For a 100-year storm flow to pass through the reduced cross-section and reduced length of the Channel (3,700 feet), calculations indicate that the elevation increase would be 0.002 feet. While this represents a cal- culable increase over the elevation under existing conditions, it is put into appropriate perspective by comparison to the effects of atmos- pheric pressure changes. One inch of 359 barometric pressure will result in local sea level changes of up to one foot. The elevation difference resulting with the Preferred Alterna- tive is two-thousandths of one foot. The reason for such an insignificant increase in elevation is that the displacement of flood storage area is spread over an extremely large area. The reductions in floodplain area associated with the Preferred Alternative will have negligible effects on flooding both in Boston Harbor as a whole, in Fort Point Channel, and in the Charles River. Because the loss of floodplain area and storage volume in the Charles River is immediately above the regu- lating dam, no provision for compensa- tory flood storage is necessary. Mitigating Measures Since construction of the Preferred Alternative will not create significant adverse floodplain im- pacts, no mitigation measures are necessary. 4.12 VEGETATION AND WILDLIFE 4.12.1 Comparison of Alternatives There are no significant adverse impacts to vegetation and wildlife from any of the alterna- tives. 4.12.2 Vegetation Preferred Alternative vs. No-Build Alternative Potential impacts to vegetation from the Preferred Alternative will be minimal. In the vicinity of West Fourth street and the Broadway Bridge in Boston, small portions of land- scaped (City of Boston Maintenance Facility) and successional sites will be affected. A loss of approximately 1.8 acres will occur in this area. The Preferred Alternative will also result in the disturbance of scattered successional vegetation associated with the railroad tracks in South Boston in the vicinity of Congress Street, Viaduct Street, Summer Street, Ramp Street, and Massport Haul Road. Approximately, acres of disturbed successional lad will be affected in this area. Additionally, the Preferred Alternative will result in the los approximately 0.4 acres of succes- sional land immediately east of ti Charles River Dam, north of Lever? t Circle and Nashua Street; the lossof approximately 1.0 acres of open stce-;. at Paul Revere Park in Boston; ancth- temporary loss of approximately 0,5 : acres of open space at the East Be to - Memorial Stadium. Reconstruction s planned for this latter area as w€l as the addition of approximately acres of land to the East Boston Memorial Stadium. The Preferred Alternative will result in the los o approximately 0.6 acres of existir landscaped areas at Logan Airport. Mitigating Measures d Kill The Preferred Alternative results in insignificant impacts vegetation in Boston and south Bosoni- and increases the amount of vegetcio in East Boston; consequently, no measures to mitigate impacts are necessary. 4.12.3 Wildlife U Preferred Alternative vs. No-Builc Alternative ol Impacts to wildlife from ti Preferred Alternative will be very limited. As indicated in Section 3.10.2, the wildlife habitat poteri£ of vegetative communities in the project area is minimized by their scattered location, relatively smal size, proximity to densely develop! sites, relatively low diversity of plant species, and the extent to v»ic these areas have been disturbed. Consequently, the minimal loss of > vegetation is not expected to affet existing wildlife populations in ts ( overall project area significantly Effects on aquatic life have been discussed previously in Section 4.. 360 litigating Measures No measures to mitigate im- li jacts, other than those discussed in Section 4.9, are necessary because of ;he insignificant impacts to the e: wildlife population of the area. Oil s 1.12.4 Endangered and Threatened Species n No endangered or threatened nspecies listed at either the Federal i jr State levels are known to occur in } , uhe project area. Their future ! occurrence in these areas is also liiighly unlikely. Thus, no impacts to .■■these species are anticipated. No I initigation measures are necessary. 4.13 DREDGED AND EXCAVATED MATERIAL DISPOSAL M : ,4.13.1 Comparison of Alternatives Alternatives 5A, 3, 3A, and 5 result in the greatest volume of dredging and largest impact to the marine environment, because of the I length of the tunnel across the ; Harbor, as shown in Table 67. The shorter subaqueous tunnel portion of the Preferred Alternative results in less impact to water resources and less dredged material to be disposed of all Third Harbor Tunnel alterna- tives. Alternatives 2 and 4, with the shortest harbor crossing tunnels, involve the least dredging of the build alternatives. The Preferred Alternative results in greater volumes ,of upland materials to be disposed at landfills, at other upland areas, or at the Foul Area if it were to be redesignated to accept upland mate- rials. i4.13.2 Disposal Alternatives Alternatives evaluated for disposal of dredged and/or excavated materials included: (1) Fort Point Channel (2) Squantum Point (3) Boston Marine Industrial Park (4) Lynn Harbor (5) Logan Airport (6) Artificial Reefs (7) Barrier Islands (8) Quarry Reclamation (9) Massachusetts Bay Foul Area (10) Boston Harbor Islands (11) Landfill Covering Specific alternatives elimi- nated from consideration were Fort Point Channel, Squantum Point, Boston Marine Industrial Park, Lynn Harbor, and Logan Airport. Fort Point Channel was eliminated because its filling would obviously conflict with planned and programmed improvements in the area, including the Central Artery/ Third Harbor Tunnel project. Filling of shallow water areas at Squantum Point in Quincy was also rejected because of the extensive and produc- tive clam flats that would have been destroyed. Timing of the project is inappropriate for Massport, which needs additional fill for part of its Boston Marine Industrial Park. Filling activities at Logan Airport appear impractical because of the poor engineering characteristics of much of the material to be removed. Barrier island creation re- quires clean, sandy material which does not occur in the Third Harbor Tunnel and Central Artery project area, and artificial fishing reefs can only be created with rock. There is no apparent reason to construct fishing reefs or barrier islands in Massachusetts Bay. Reclamation of quarries, such as those at Quincy, is questionable, particularly with marine sediments . The remaining specific disposal alternatives offer potential for disposal of the materials from the Third Harbor Tunnel and Central Artery. The Massachusetts Bay Foul Area is suitable for the ocean dis- posal of dredged material. Landfill covering is a possible alternative and is discussed further in this section. Finally, ledge and clean material might be employed in restoration efforts on Spectacle Island in Boston Harbor and will be considered later insofar as timing and volume allow. 361 4.13.3 Excavation, Reuse, and Disposal Volumes For the Preferred Alternative, the volumes of materials to be exca- vated, reused as fill, or disposed have been calculated and are presented in Table 68. These include- both marine sediments presently underwater, which will be conventionally dredged (dredged materials), as well as fills on top of old marine sediments (exca- vate). Wherever possible, suitable materials will be reused as backfill. Most reusable materials are found in the South Boston and Bird island Flats areas, and stockpiling of suitable materials will take place at those two general locations. ' Because of poor structural quality, however, much of the excavate which consists of marine sediments will require disposal. Under the present ocean disposal regulations, only material that is dredged from navigable waters can be disposed at the Massachusetts Bay Foul Area (see Figure 62). In addition to disposal of clays and other materials excavated along the Central Artery and in South Boston and East Boston, approximately 300,000 cubic yards of bentonite slurry (from the slurry wall construc- tion) will also require disposal. Before bentonite slurry can be ac- cepted at a landfill, it must have a solids content greater than 20 percent by weight. After some solidification, the slurry can be transported by truck to any of the nearby landfills. 4.13.4 Agency Coordination The regulations for ocean disposal of waste materials were reviewed at a series of meetings with the U.S. Environmental Protection Agency (EPA), U.S. Army Corps of Engineers (COE), and the U.S. Depart- ment of the Interior, Fish and Wild- life Service (FWS). Discussions addressed both excavate and marine dredged materials from the Third Harbor Tunnel and Central Artery construction. Because the Massachu- setts Bay Foul Area is designated by 3 EPA for disposal of dredged mater ih only, other materials, including ill and marine sediments now buried uiSer Boston, or demolition debris, may lot be dumped there. Redesignation of the Foul ,:ec was also considered. Under the of ; the Foul Area is the need for sucl action, in order to determine the need for ocean disposal of excavaitd material, an evaluation was conduced to assess potential landfills or alternative sites which may be su::- able to accept the materials, as previously discussed. In consultation with the Commonwealth of Massachusetts Dep closed or remains unused for more ha .. one month. Any lateral expansion f .... landfills within the State also requires that a liner (preferably constructed of clay materials) be placed. There is also a daily re- J^ . quirement to cover compacted refus. These three requirements for relatve ly impermeable material establish potential need for marine sediment and bentonite. Consultation also took plac with the Southeast and Northeast Regional Offices of DEQE. The Souh- east Region has significantly more landfills (because of the lack of regional resource recovery facilites Table 67 COMPARISON OF EXCAVATION , DREDGING, AND DISPOSAL REQUIREMENTS • : Alternative Excavated (cubic yards) Dredged Disposed Reused ispoi 2 — 2,100,000 2,100, 000 ispsl 3 2,737,000 2,737,000 — 3A 2,568,000 2,737,000 5,305,000 — — 2, 100, 000 2,100,000 ad 5 aentil :::e:i 5A 3, 335, 000 2,700,000 3, 340, 000 2,700,000 6,675,000 •' :ef . Alt. 5,525,000 2,307,000 7,162, 000 670,000 e tkj & 2, 723, 000 240, 000 2,963, 000 cava: i y.:< : Ex I •ioili I Table 68 MATERIALS TO BE EXCAVATED, DREDGED, REUSED, AND DISPOSED (cubic yards) Source 3uth Bay Excavate buth Boston Excavate brth Area Excavate 1st Boston Excavate antral Area Excavate Dston Harbor Sediment Dredging 3Ston Harbor Rock Excavation sntonite Slurry Mass Materials 1, 297,000 1,582,000 458,000 1,430,000 2,055,000 490, 000 520,000 300, 000 Reused 181, 000 396, 000 93,000 Disposed 1,116, 000 1,186,000 458,000 1,337,000 2,055,000 490,000 520,000 300,000 )TAL 8,132, 000 670, 000 7,462. 000 [ WAKEFIELD V «~ f TOPSFIELD \ I /S HAMILTON J DAN VERS N \ J MIDDLETON — N \ / v — V . pfaBODY'** "*-.«. \ j LVNNFIELD N ' 1 X - J "S v / SALEM V v S I WE NH AM ^ _ \ GL0UI r" ^ "V. *. MANCHESTER LYNN \ SWAMPSCOTT I melrose\ -jL <\ t MALDEN ' * REVERE CHELSEA.-., Massachusetts la Foul Area 42° 25' N / 70° 35' W I ■» < .WEYMOUTH BRAINTREE ' \ \ RANDOLPH \ | L A NORWELL Foul Area Diameter = 2 Nautical Miles Figure 62 Potential Offshore Dredge Disposal Site 0 12 4 Miles EIS/EIR for I-90 - Third Harbor Tunnel; I-93 - Central Artery ian does the Northeast Region, .thin the Southeast Region, there are . commercial and 58 town-operated indfill operations, all of which mid have need for clay and other iterial. Additional uses of the clay kso include several eastern Massachu- litts hazardous waste sites. Within le Northeast Region, it was estimated |iat when excavate starts to become /ailable in 1987, there will only be few active landfills. Therefore, lere is greater need for clay and :her materials in the southeastern art of the State. Between both agions, there are approximately six andfills close enough to the marine ivironment where bulk chloride Dncentrations in the disposal mate- ials is not a major concern. 1.13.5 Sediment Quality Requirements The likely characteristics of oth upland and dredged marine sedi- ents excavate for the Preferred lternative have been determined. Materials to be used at land- ills must be relatively uncontami- ated. Marine sediments which are not ontaminated also pose a threat to round and surface water quality hrough the leaching of chloride, herefore, DEQE requires that marine ediments have a bulk chloride content f less than 250 ppm (the drinking ater standard) if the sediments are o be used at an inland landfill, his requirement is particularly important in the Southeast region here the Sole Source Aquifer designa- ion requires careful review of otential impacts by EPA. The bulk hloride requirement is less restric- ive for landfills draining to a Marine environment. The overall etallic and organic requirements, owever, are still imposed. These equirements, therefore, limit the otential locations where marine ediments (or Central Artery mate- ials) can be disposed. In order to estimate likely estraints on upland disposal of Central Artery and other excavated aterial, estimates were made on bulk chloride content of the marine sedi- ments buried under the City. This estimation made use of existing data on fill and marine sediments under Section 1 of the Southwest Corridor Project, generally under Back Bay. Within Section 1, there are 15 borings where resistivity and chloride were analyzed on bulk sediments. A corre- lation analysis was conducted on these data and bulk chloride content was projected to other sediments for which only resistivity was available. The results of these estimates suggest that the fill over marine sediments could have an average bulk chloride content of 170 ppm (range 40-520 ppm), and the native marine sediments could have an average bulk chloride content of 1,900 ppm (range 270-4,800 ppm). If these data for Back Bay are reason- ably indicative of conditions under the Central Artery and other locations in South Boston and East Boston, the materials from the Preferred Alterna- tive could only be taken to coastal landfills. There are no similar data on metallic content of these materials. Sediments to be dredged from the Fort Point Channel were tested for toxicity and bioaccumulation poten- tial. The results of the bioassays indicated that the sediments do not contribute to significant levels of toxicity or bioaccumulation and therefore are suitable for ocean disposal at the Massachusetts Bay Foul Area. Harbor sediments from the C Street bulkhead (South Boston) to Bird Island Flats have not been tested for toxicity or bioaccumulation. However, reasonable projections of acceptabil- ity for ocean disposal can be made from existing data. Bioassay and bioaccumulation testing for several Third Harbor Tunnel alternatives evaluated in the DEIS/DEIR indicated that those sediments were acceptable for ocean disposal. Additionally, Massport conducted bioassay and bioaccumulation tests on sediments off the North Jetty at the Boston Marine Industrial Park (approximately 1,500 feet from the alignment of the Pre- ferred Alternative) as well as along 365 the Bird Island Flats embankment in Jeffries Cove. The results of those analyses also indicated the sediments could be disposed at the Foul Area. Further corroboration can be obtained from the results of the EPA tests (Nolan, 1980) in which Boston Harbor shipping channel sediments across this alignment were tested and again found suitable for ocean disposal. While there is little reason to suspect the sediments along this alignment will not pass such tests, the sediments will be suitably tested during the design phase of the project. Ocean disposal is assumed for all marine sediment and most rock removed for the Third Harbor Tunnel. 4.13.6 Summary An analysis of available alternatives for disposal of spoil materials from Boston Harbor and upland excavation sites has been conducted. For materials dredged from Boston Harbor, disposal at the Massa- chusetts Bay Foul Area is the pre- ferred disposal alternative. It is recognized, however, that use of clean clays is possible at coastal landfills and partial use of these materials is not being ruled out from future consideration. Additional analyses, specifically bioassay and bioaccumula- tion tests on marine sediments from the South Boston C Street bulkhead to Bird island Flats, are required and will be conducted during design. As previously stated, however, all indications strongly suggest suitabil- ity of these sediments for ocean disposal. Existing ocean disposal regula- tions do not permit disposal of excavated spoil from upland areas at the Foul Area. Based on the foregoing assessments, it can be assumed that need for landfill cover exists. However, before any commitment can be made, the materials must be tested for chemical composition and agreements reached with landfill owners to receive material when it becomes available. During design, all suit- able landfills will be identified and agreements sought with the landowners 3 and the State to allow the clay excavate to be used for landfill capping if it is found suitable f< that purpose. Ocean disposal of upland sj may also be pursued through redes:|iv: tion of the Foul Area during desici. This is considered necessary *in th event that part or all of the uplac excavate is unsuitable for landfii.s (or no areas are available at the :i: of construction). Bioassay and bioaccumulation tests and necessa:' documentation with EPA would also >e conducted at that time. A third disposal alternati 1 ! which is still under consideratioi ai will be continued through design » the reuse of excavate at Spectaclt Island. Master planning efforts ;:e underway for improvements to the Boston Harbor islands; the need f<: suitable fill materials is being evaluated at this island as part these efforts. Finally, combinations of ti: above disposal alternatives must ,.s< be considered. It is possible th<: some spoils will not be suitable >r any beneficial use or ocean disponl and, due to chemical complexity, as. be disposed at a secure site. Otl:r more natural materials will be pui t a beneficial use. As future data become available, coordination wi!. continue with DEQE, EPA, COE, and FWS. Section 4.1.4 indicated the methods for transport of dredged ad excavated materials. 4.14 HISTORICAL AND ARCHAEOLOGIM IMPACTS 4.14.1 Comparison of Alternatives o Alternatives 3A, 5A, and 6 £ the Preferred Alternative would require a minor taking in the Chai.e River Basin Historic District; Alternatives 2, 3, 4 and 5 and th< No-Build Alternative would not afi'Ci this district. o Alternatives 3 A, 5A, and 6 , ai the Preferred Alternative, would j nclude reestablishment of the visual elationship between downtown historic roperties, reduction of traffic in istoric areas and improvement of ehicular and pedestrian access to istoric properties. With Alterna- tives 2, 3, 4, and 5, and the No-Build \lternative, existing negative effects if the Central Artery viaduct and '.raffic congestion on historic re- sources would continue. Alternatives 3A, 5A, and 6, and ;he Preferred Alternative, would lecessitate taking the Charles River iuilding (design modification work now inderway suggests that a ramp redesign in the area may obviate the need to :ake this building) and modifying the Loading facilities at the Stop and 3hop Bakery Building in the Causeway - Jorth Washington streets District; Qternatives 2, 3, 4 and 5 and the Jo-Build Alternative would not require :akings in this district. ) Adverse effects on the Fort Point Channel District are less Extensive under the Preferred Alterna- cive than under Alternatives 2, 3, 3k, i, 5, or 6; the Preferred Alternative places less structure in the Channel, but fills more of the South Bay portion of the district than the other alternatives listed above. New Dorchester Avenue will have fewer lanes with the Preferred Alternative than with Alternatives 2, 3, 3A, 4, 5 or 6. New Dorchester Avenue could also be narrowed to two northbound lanes in Alternatives 3A, 4, 5 and 6, out traffic congestion would become unacceptable; these alternatives do inot provide the same alternate routes (via ramp connections to Summer Street) as does the Preferred Alterna- tive. Alternative 5A is similar to the Preferred Alternative in the South Bay area, but does not include a new Dorchester Avenue. The impacts of Alternative 5A in the Fort Point Channel would therefore be less than those for the Preferred Alternative; however, the need for new Dorchester Avenue has been demonstrated in Section 2.5.2 Other Design Considera- tions . Also, see Section 5.2.3 Fort Point Channel District in Chapter 5.0 SECTION 4(f) EVALUATION . The No-Build Alternative would not have any adverse effects on the Fort Point Channel District. o Potential adverse effects on downtown historic properties from development of joint development parcels would be similar for Alterna- tives 3A, 5A, 6, and the Preferred Alternative. Alternatives 2, 3, 4 and 5 and the No-Build Alternative would not create joint development parcels adjacent to the downtown Historic Districts, so there would be no potential adverse effects. o Potential construction-period adverse effects on historic properties would be greater from Alternatives 3A, 5A, 6, and the Preferred Alternative than from Alternatives 2, 3, 4 and 5 because of the large number of his- toric properties immediately adjacent to the construction zone. The No- Build Alternative would have some construction-period adverse effects on historic properties, during redecking of the existing Central Artery. o Alternatives 3A, 5A and 6, and the Preferred Alternative, which include a large downtown project area, would have greater potential adverse effects on archaeological resources than would Alternatives 2, 3, 4 and 5 and the No-Build Alternative. The Phase I, Step 1 archaeological survey indicates that a number of significant sites may exist in the downtown project area; actual impacts cannot be evaluated until the Phase I, step 2/Phase II Archaeological survey is completed during the next design phase. 4.14.2 Effects on Historic Properties Effects of the Preferred Alternative on historic resources identified in Section 3.11 are evalu- ated below. Criteria of effect for historic properties have been estab- lished by the Advisory Council on Historic Preservation, which has responsibility for review under Section 106 of the National Historic Preservation Act; they include direct impacts to the property, loss of 367 access, separation from the context which contributes to its significance, and adverse changes in the property's visual or audible environment. Section 106 review has involved consultation between FHWA, MDPW, EOTC, the Massachusetts State Historic Preservation Officer (SHPO) and the Boston Landmarks Commission (BLC). Determinations of potential eligibil- ity for the National Register of Historic Places for the properties discussed below were made by concur- rence of the State Historic Preserva- tion Officer (SHPO) and the FHWA. The SHPO concurred in FHWA's finding of No Effect on several properties listed below, and a Preliminary Case Report was written to document potential adverse effects on other properties. Based on this Report, agreement was reached on the potential adverse effects and appropriate mitigating measures. A Memorandum of Agreement (MOA), detailing these mitigating measures, has been prepared, and signed by FHWA, MDPW, MHC, BLC, and the Advisory Council on Historic Preservation (see COMMENTS AND COOR- DINATION section of the report for copies of these). Properties and Districts not Affected by the Preferred Alternative It has been determined that the Preferred Alternative will have no effect on the following properties and districts identified in Section 3.11. The SHPO has concurred with FHWA's Finding of No Effect on these proper- ties (see letter dated 7 September 1983 in COMMENTS AND COORDINATION ): 1. 2. 4. 5. 7. 8. 9. 10. 11. 12. Charles River Basin District Bulfinch Triangle District Cornhill District Exchange District Commercial Palace District Essex-Kingston Textile District Chinatown District Old West Church , 131 Cambridge Street, 1806 First Harrison Gray Otis House , 141 Cambridge Streeet, 1796 Boston City Hall , One City Hall Plaza, 1961-68 15. 16. 17. 18. 20. 23. 26. 28. 30. 31. 32. 34. Old State House , 208 Washiijtc Street, 1712-13 Carter/Winthrop Building , 276-278 Washington Street, ■ (Former) Federal Reserve Ba k 22-24 Pearl Street, 1922 272-276 Franklin street , ll'T United Shoe Machinery Corpc a tion, 34-66 High Street, 1«.:S Old Waterfront District Leather District kse tin South Station Headhouse , 620-290 Atlantic Avenue, 1(8 Commonwealth Pier , 1914 Fish Pier (1914) South End National Registei District (Nineteenth Centur) Butler Aviation Hangar (1930 's), Logan Airport ■3D ,:e Properties and Districts Adversely Affected by the Preferred Alternat v Downtown Boston and the North End Owing to the large number q\ "'" historic districts and properties n the downtown portion of the projec area, adverse effects that apply t many properties in the downtown project area are described generaly in the subsections immediately belw; ' these effects and appropriate mitiat "■' ing measures are also detailed in he ' Preliminary Case Report. Specific '[ effects to individual districts or £ properties are then described in te following subsections. General Long-Term Effects The effects of depressing ts * Central Artery on downtown Boston' historic properties are best under stood in relation to the existing condition. When it was built, the ; 3j existing Central Artery cut throug - : the oldest and most densely built Ct of downtown Boston, which, becausesf - its wealth and central location, hi - the highest concentration of archiac < turally significant buildings and historic sites. In addition to th' ;i many buildings which were demolishi : the combination of an elevated higi* : ' c together with a multi-lane surface artery beneath it had a major adve> effect on historic properties, cre:uildings, ease of access is directly elated to economic viability, and .hat in turn is directly related to he ultimate preservation of the esource. Vehicular access is impor- tant, but in many cases pedestrian iccess is even more so, as the narrow ■•treets and small scale of the area lake Boston tourism a pedestrian ixercise. Reduced Traffic in Historic Areas . in addition to simplifying tccess to these areas and the individ- ual resources within them, reduced traffic congestion with the Preferred Alternative will lead to decreased noise and air pollution affecting persons using or viewing these his- toric properties. Because current and projected traffic volumes under the No-Build Alternative are heavy on nearly all streets in the downtown project area, traffic impacts are a source of adverse effect with the No-Build Alternative. Joint Development . There are several potential effects from the development of air rights parcels and the creation of ventilation structures and new surface streets by the Pre- ferred Alternative. Future develop- ment could help to rejoin adjacent neighborhoods with complementary building styles and land uses. However, the potential also exists for these future developments and street improvements to isolate or inappropri- ately alter the setting of these properties or to introduce inappropri- ate visual, audible and atmospheric elements such as new buildings out of scale with the historic buildings and districts or traffic on new streets. The actual effect for each property will depend on the design of street improvements and joint development parcel configurations and the applica- tion of appropriate design guidelines for massing, height, and surface treatment of ventilation buildings and subsequent joint development build- ings. Measures to minimize potential adverse effects and to maximize beneficial effects are included in the Section 106 Memorandum of Agreement and are described below. Except where specifically noted to the contrary in the sections below, appropriate mitigating measures can eliminate adverse effects. As stated in the Section 106 Memorandum of Agreement, FHWA will ensure that potential adverse effects from the use of air-rights and other joint develop- ment ventures, the development of ventilation structures, and surface street improvements on historic properties described in FHWA's Prelim- inary Case Report will be minimized or 369 avoided through appropriate design. Design guidelines will be developed by the Massachusetts Department of Public Works, in consultation with the Massachusetts SHPO, BLC, and other interested groups, for joint develop- ment affecting such properties. Preliminary and final design and construction specifications for joint development ventures, as they affect historic properties described in FHWA's Preliminary Case Report, will be reviewed and approved by the Massachusetts SHPO in consultation with BLC for consistency with the above design guidelines. The MDPW shall ensure, as a condition to disposal of joint development and air rights parcels, compliance with this stipulation prior to and following parcel disposition. As discussed above, the poten- tial for beneficial or adverse effects on historic properties near the project depends on the preliminary and final design of the project and related joint development. The relevant mitigating measures in the Section 106 Memorandum of Agreement address these effects through review at each phase of design. Because of the proximity of many historic properties to the construction area, the extent and nature of the construction activity and the fact that so much of the historic area is on land created by the historical process of filling land in and between wharves, construction of the Preferred Alternative could have varying degrees of adverse effect on these properties. These effects may include noise, dust and interfer- ence with pedestrian access. Vibra- tion and potential foundation damage due to construction-related lowering of the water table will be avoided through appropriate construction procedures, as described in Section 4.1 DESCRIPTION OF CONSTRUCTION . Proximity to construction may cause potential structural vibration effects, as described in Section 4.8.2 Vibration Impacts , to the Police Station and Hanover Street Post Offi> in the North End District. There wi. be potential architectural damage in the North End District, Custom House District, Faneuil Hall Markets, and the Causeway-North Washington Street District. There will also be effect due to noise and dust on these prope ties and the Richardson Block Build- ings, the western portion of the Fulton-Commercial Streets District, and Russia wharf. As stated in the Section 106 Memorandum of Agreement, FHWA will ensure that potential adverse con- struction effects on all historic properties described in this section are minimized or avoided through appropriate preliminary and final design and construction specifica- tions, reviewed and approved by the Massachusetts SHPO in consultation with the MDPW and BLC, and through appointment by the MDPW of a Project Conservator whose job description an qualifications will be reviewed and approved by the Massachusetts SHPO i consultation with the MDPW and BLC. The Project Conservator's responsibil- ities will include overseeing the development of measures for mitigati' the adverse effects of construction I standing historic properties. These mitigation measures will be included as part of the construction specific tions . Effects on Specific Propertie I K Where adverse effects will result during redecking of the exist , ing Artery with the No-Build Alterna tive, that fact is noted below. Otherwise, the No-Build Alternative assumed to continue the status quo . Numbers refer to Figures 63 and 64. 3 . Blackstone Block District Long-Term Effects . This area will benefit especially from re-estaj lishment of the downtown's visual relationship with the North End, reduced traffic, and potentially improved pedestrian access, which wi-1 be brought about by potential improv- ments such as reconnecting Hanover 370 Figure 63 Historic Resources Affected by the Preferred Alternative- 1 C^^^^OC^^^TdO Feet EIS/EIR for I-90 -Third Harbor Tunnel; I-93- Central Artery Legend H Historic Property ■ •■ Boundary of Historic District Numbers correspond to enumeration in text 33 v Albany Street ■ Area ft: PROPOSED WEST FOURTH BRIDGE ^, BY OTHERS Figure 64 Historic Resources Affected by the Preferred Alternative- 2 200 400 Feel EIS/EIRfor 1-90 -Third Harbor Tunnel; Legend EH Historic Property ■■■ Boundary of Historic District Numbers correspond to enumeration in text treet and building small-scale tructures above the depressed Artery. Custom House District Long-Term Effects . Removal of he viaduct will have the beneficial ffect of creating an improved visual elationship between this district and he waterfront. It will also allow uch important buildings within the listrict as the Grain Exchange and ;tate Street Block to be viewed from ;treet level without the adverse isual effect of the present viaduct Structure. Pedestrian access between ':his district and its historically :onnected waterfront will be improved. U . Faneuil Hall and Faneuil Hall Markets Long-Term Effects . Removal of .he viaduct will have a beneficial if feet, improving the visual connec- :ion between the Markets and the /aterfront (although this connection /ill be negated in the cases of Quincy larket and South Market, by the :onstruction of Marketplace Center on 'arcel D-10). In addition, the :haracter of pedestrian access between :he Markets and the Waterfront will be improved. .9 . Richardson Block Buildings Long-Term Effects . Removal of :he Central Artery viaduct will have :he beneficial effect of opening sight Lines and improving pedestrian access iround these buildings. The 150-foot >pening in the deck over the depressed Urtery between Pearl and Oliver streets to provide ventilation for the )ewey Square Tunnel will have an adverse effect on the context of the juildings, but this effect will be Less adverse than that of the existing :entral Artery with the No-Build Uternative. 11. Causeway - North Washington Streets District Long-Term Effects . The align- ment of the Preferred Alternative requires the taking of the Charles River Building and the loading dock at the west end of the Stop and Shop Bakery Building for construction of a connecting ramp from the depressed Central Artery northbound to Storrow Drive. Because of its position in relation to the Stop and Shop Bakery Building and the Hoffman Building, and the limited number of buildings in the area, removal of the Charles River Building will further permanently alter the historic fabric and charac- ter of this area, which has already been negatively affected by construc- tion of the original elevated central Artery. Design modification work now underway suggests that a ramp redesign in the area may obviate the need to take the Charles River Building. The Preferred Alternative will also have the beneficial effect of removing the Central Artery viaduct from the historic Bulfinch Triangle area and partially reuniting the Causeway-North Washington streets District with the Bulfinch Triangle potentially eligible National Register District to the west. A ten-story ventilation build- ing measuring approximately 60 feet by 80 feet will likely be built on the former site of the Charles River Building (the vent bulding would be relocated if design modifications eliminated the need to take this building). This new building will not be altogether out of character with the industrial nature of this historic district. Mitigating Measures . As stated in the Section 106 Memorandum of Agreement, FHWA will ensure that the loading facilities of the Stop and Shop Bakery Building will be modified either to continue present operations or to serve an alternate building use with lesser loading requirements, in order to ensure the continued economic viability of the building. Prelim- inary and final design and construc- tion specifications for the building modifications will be reviewed and approved by the Massachusetts SHPO in consultation with the BLC. 373 Design guidelines for the development of the ventilation build- ing will be developed by the MDPW, in consultation with the Massachusetts SHPO and 3LC . FHWA will ensure that prior to alteration or demolition of the Charles River Building and Stop and Shop Bakery Building loading dock, the Historic American Building survey (HABS )/Historic American Engineering Record (HAER) will be contacted to determine the level of documentation required to provide a permanent record of the properties. All documentation must be accepted by HABS/HAER prior to alteration 1 or demolition of the properties. 22. North End District Long-Term Effects . The Pre- ferred Alternative will have a benefi- cial visual effect upon the historic properties of the North End District. It will once again be visually linked with the downtown area, although not in exactly the same manner as it was prior to the construction of the Central Artery. The original Central Artery project removed a series of small irregular streets east of the Blackstone Block District connecting it with the North End. Appropriate guidelines for joint development over the depressed Artery and appropriate final design of surface street connec- tions, in locations shown at the present stage of design, will result in buildings compatible in scale and materials with those in the surround- ing districts, which though not recreating the original urban fabric, will approximate it. A wide area of traffic lanes and open space, or super-block con- struction, would not be consistent with the historic access to the North End which was through an intricate pattern of narrow streets. The principles discussed in the aesthetic mitigation measures and joint develop- ment recommendations (Section 4.4.4) of reinstating a complex pattern of sight lines and appropriately scaled buildings across the depressed Artery will be applied in the development design guidelines as required in t\ Section 106 Memorandum of Agreement and will result in an improvement ci the present and No-Build situation, Dispersing pedestrian access throuc several street connections in this a will likewise reinstate something approximating the historic approact the North End. Construction Effects. The i k North End is particularly sensitive construction effects since it is a place to live, shop, and visit. Fc this reason, construction effects v negatively affect historic structuis in that economic viability is oftera key factor in their preservation ar maintenance. Appropriate mitigatir measures will minimize these effect Mitigating Measures . Approri :r ate design guidelines regarding height, materials, and massing willll.., applied to the joint development parcels on the surface right-of-wa} and design of surface street connec , tions will be reviewed to ensure trli adverse effects to the historic context are avoided and minimized, «.... historic connections between the NctT End and downtown Boston are partialf . restored . 24. Fulton-Commercial District Long-Term Effects . Removal t the Artery viaduct will potentially improve the visual relationship between this district and the FaneuL '* Hall Markets-Blackstone Block area, with which it was historically closl] ; connected. The Preferred Alternate allows potential improvements such > those aesthetic mitigation measures and joint development recommendatio; for building over the depressed ArtJj] and reconnecting streets which are discussed in Section 4.4.4 Joint Development ; these measures will be applied to the development of desig guidelines for joint development an design review of surface improvement' to reestablish a continuity in urba fabric which will improve the chara ter of the pedestrian access betwee these two historically important an : ' : 5 . Long Wharf Long-Term Effects . Removal of he Central Artery viaduct will have a Dsitive effect on restoration of the istoric relationship between Long 'harf and State Street, with the Old tate House at its head, one of the ost important historic sightlines in oston. This visual relationship will e stronger, and pedestrian access ill be improved. 7. Russia Wharf Long-Term Effects . There will 1 e no long-term effects on Russia harf. 9 . Fort Point Channel District Long-Term Effects . Changes to '.he physical configuration of the :hannel as a result of the Preferred alternative will include introduction >f a partially visible tunnel box, emoval of part of the historic mlkhead, removal of the Old Colony tailroad Bridge and the temporary ilteration of one span of the Summer Street Bridge, and visual effects to :he historic character of the district lue to the introduction of a surface roadway and ventilation building (see figure 82 in Section 5.2.3 Fort Point :hannel District of the Section 4(f) evaluation ) . The southern end of the Channel fill be filled to a new bulkhead line Located to the east of the existing Dorchester Avenue Bridge (near the Gillette property in South Boston), rhe historic bulkhead line on the Boston side of the Fort Point Channel will be altered by construction of a two-lane, northbound new Dorchester avenue which will extend approximately ! 30 feet inside the Channel, from the Dorchester Avenue Bridge to a point approximately 400 feet south of the Summer Street Bridge. The road will oe built on slurry walls with four- foot square knock-out panels to allow 'tfater to pass through, with a false oulkhead of granite and a 10-foot adjacent pedestrian walk. In the 400 feet south of Summer Street, a deck, slightly lower than new Dorchester Avenue, will be constructed on top of the tunnel box. The deck plus Dor- chester Avenue will project 80 feet into the Channel from the existing bulkhead line, then taper toward the existing bulkhead. The existing channel is approximately 500 feet wide in this area. At Summer street, the new deck will project 40 feet from the existing bulkhead line; at Congress Street it will project 15 feet into the Channel; at a point 100 feet north of Congress street the new bulkhead will meet the existing bulkhead line. A total of 88,500 square feet, or 9.5 percent of the Channel will be occu- pied by the Preferred Alternative. Only the Old colony Railroad Bridge will be removed by the Pre- ferred Alternative. On the Boston side of the Channel, the Summer Street Bridge will have one span dismantled and reconstructed; its profile and symmetry will not be altered. Con- gress street Bridge will not be affected . The construction of a Seaport Access Tunnel through South Boston will displace two buildings (40 Wormwood Street and 293 A Street) in the Boston Wharf Company section of the Fort Point Channel District. These buildings do not contribute to the significance of the district, nor does the architectural character qualify the buildings for eligibility for the National Register. Removal of these buildings will not affect the integrity of the District. A 10-story ventilation building measuring approximately 80 feet by 90 feet is proposed on the filled portion of the Channel south of Dorchester Avenue. Construction Effects . During construction, vehicular and water access to the Fort Point Channel area will be disrupted as a result of successive closing or reduction in width of the bridges, the placement of steel sheet piling in the Channel, and the presence of barges and construc- tion equipment. The construction 375 activities themselves may also affect the area and its use as a result of construction-related noise, dust, and vibration. There will also be adverse effects due to construction in the Boston Wharf Company section of the Fort Point Channel District. The Preferred Alternative will create short-term noise, dust, and vibration affecting this area's industrial and commercial buildings, a number of which have been recently rehabilitated, Mitigating Measures . As stated in the Section 106 Memorandum of Agreement, FHWA will ensure that design development in this area will include the following: to minimize effects to the history characteristics of Fort Point charK and adjacent historic properties, including effects to pedestrian aj vehicular traffic flow. o Preliminary and final desii, and construction specifications, iij be submitted to the Massachusettssh prior to start of construction foil review and approval in consultatia with the BLC regarding consistenc with the design development guideint outlined above. 33. Albany Street Area Long-Term Effects . There i. be no significant effect on this | historic area. o Design and location of the ventilation building in a manner that is sympathetic to, and respectful of, the characteristics of surrounding historic properties with regard to massing, color, building material, detail, and scale. o Granite facing will be used in the new section of the Fort Point Channel bulkhead to make it visually consistent with the existing bulkhead in color, texture, configuration, and design. o Reconstruction of the one span of the Summer street Bridge removed during project construction will be in a manner that reuses as much original fabric as possible and results in the same configuration as the original. o Landscaping improvements along the Boston side of the Channel will be designed to enhance those characteris- tics of the historic district that make it eligible for listing in the National Register of Historic Places. o During preliminary project design, there will be continuing study and negotiation with the U.S. Postal Service concerning the use of land between the existing Dorchester Avenue and the Channel bulkhead for project right-of-way. The final design of the New Dorchester Avenue will be such as 35. Streetcar Tunnel Long-Term Effects . There il. be no significant effect on this historic structure. Construction Effects . Viba- tion could cause potential structra damage. Mitigating Measures . Consru tion period mitigating measures include tunnel reinforcement, plaa- ment of piles on either side of ta tunnel, and spanning over the tunsi with the Central Artery structure, granular cushion material will be placed between the Blue Line and Central Artery tunnels. (See the Supportive Engineering Report for a more detailed discussion of these techniques . ) 4.14.3 Archaeological Effects „ A Phase I, Step 1 archaeol cal survey was performed during ti preparation of the SDEIS/SDEIR fo'tl Preferred Alternative. The Phase! survey results indicate a high proc bility of locating archaeological properties in the following areas South Bay/South Cove (prehistoric iw historic), Fort Point Channel (hi:- toric), Fort Hill (historic), Cen :a Artery corridor from Dewey Square :o Causeway Street (prehistoric and 376 J istoric), Logan Airport (historic), -il.nd South Boston corridor (prehistoric :es i f.nd historic ) . « A AS stated in the Section 106 lemorandum of Agreement, FHWA will ^(•nsure that a Phase I, Step 2/Phase II • nvestigation is initiated 90 days : ' i iollowing ratification of the Section :; .06 Memorandum of Agreement and : elease of funds for additional : " : jlanning and design studies. This .nvestigation will include, at a ainimum, the following elements: Preparation of an appropriate research design, outlining and justi- lying important research problems that is nay be addressed by investigation of archaeological properties in the aroject area, and a proposed scope of fork and work plan for field investi- jation integrating the results of the :e following work: ) acquisition of additional nistorical documentary informa- tion on past disturbances that may preclude areas from field testing and 3 acquisition of additional historical documentary infor- mation concerning potential significance of historic and :j prehistoric archaeological remains. % This program for investigation, including the research design, scope Df work and work plan, will be e« reviewed by MDPW and the SHPO prior to implementation. Field testing and evaluation rfill be implemented based on the scope 3f work and work plan and in the : context of the research design. A written report describing the : : results of the documentary research, • ; field testing and applied National Register criteria and containing : recommendations on the significance of identified resources will be provided ito MDPW, the Massachusetts SHPO, and :; . BLC. These recommendations will be - : subject to review by MDPW and the Massachusetts SHPO in consultation with BLC. Based on the results of the documentary research and field testing work, a plan will be developed in consultation with the SHPO and BLC that includes provisions for avoidance or preservation in place of signifi- cant archaeological remains, where feasible and practical, through design and engineering development or con- struction specifications as set forth above. If avoidance or preservation in place is not feasible and practi- cal, and the SHPO concurs in this determination, the plan will include provisions for Phase III data recovery or other appropriate treatment. The plan will be submitted to the Massa- chusetts SHPO and the Advisory council for review and approval in consulta- tion with BLC prior to implementation. At such time as the nature, extent, and locations of necessary utility line relocations are known, identification, evaluation, and treatment plan preparation and imple- mentation will be done in the same manner as set forth above for any significant archaeological properties which may be affected by these activi- ties . All historic and archaeological investigations called for under these stipulations will be conducted by individuals who meet, and in a manner consistent with, the Advisory Coun- cil's standards and guidelines. 4.15 UTILITIES 4.15.1 Comparison of Alternatives All build alternatives would have significant impacts on the exist- ing utilities in the project area. However, no long-term service disrup- tions would occur with any of the alternatives. The Preferred Alterna- tive affects more major utilities than any of the other alternatives. Utility impacts of Alternative 5A would be similar to the Preferred Alternative. Alternatives 3A and 6 377 have major utility impacts in the Cen- tral Artery corridor, including South Bay, while Alternative 3A would also affect utilities in East Boston. The Tunnel-Only alternatives (Alternatives 2, 3, 4 and 5) would not affect utilities in the Central Artery corridor. Utilities in the South Bay and Fort Point Channel parts of Boston, and in East Boston, would be affected by these alternatives. The No-Build Alternative would have no effect on existing or future utilities. 4.15.2 Preferred Alternative Section 3.12 identified the extensive system of public and private utilities within the project area which will be affected by the Third Harbor Tunnel/Central Artery project. These utilities, which include water, storm drains, sanitary sewers, com- bined sewers, gas, electric lines, communications, etc., will be either temporarily supported or permanently relocated as part of this project. The proposed highway construction will have a major impact on utilities as a result of the relocations necessary. The impact will not be from service disruptions, but from the traffic con- gestion and disruption caused by their relocation. No long-term service dis- ruptions will occur, although slight service disruptions may occur when the crossover from the old to the new utility occurs. Extensive coordina- tion with utility owners will be required during the design and construction phases of the project to minimize any inconveniences caused by the construction. More detailed descriptions of these utility reloca- tions are contained in the supportive Engineering Report . The following is a brief description of the major utilities requiring relocations by geographic area: Boston - South Bay o 36-inch x 36-inch combined sewer outfall at Congress street ed .: Dorchester Avenue. Ln jr outflj ;ter Avnitf ■ o 60-inch combined sewer outf] at Summer Street and Dorchest o 60-inch combined sewer outfl] at the Dorchester Avenue Bridge. o Force mains of 36-inch and 8-inch diameters from Massachusett ;[S| Turnpike Authority Pump House No. . :; East side Interceptor at itlantic Avenue and India Street. > 60-inch storm drain at Commer- :ial Street from Clinton street to itlantic Avenue. > 30-inch x 36-inch sewer at Traverse Street and North Washington Jtreet. o 115,000 volt electric lines at Causeway Street, from Haverhill street to Medford Street. o Telephone cables at State Street, from the Surface Artery southbound to Atlantic Avenue. o 30-inch gas main at Purchase Street, from India street to High Street. o 30-inch gas main at Cross Street and Commercial Street. o Two 60-inch pipes (inverted sewer siphon) at Traverse street under the MBTA Orange Line. o 102-inch sewer, from the siphon at Traverse Street to North Washington Street. o 57-inch x 60-inch sewer, from North Washington Street and New Chardon street to Cross street. o MDPW Pump House No. 1 and electrical substation at Traverse Street near Haverhill Street. o MDPW Pump House No. 2 at Haymarket Square near Cross street and Blackstone Street. o MDPW Pump House No. 4 at Clinton street and Commercial street. o MDPW electrical substation at Atlantic Avenue near High street. o MDPW Pump House No. 5 at High Street near Purchase street. o 66-inch sewer at Cross street, from new Chardon Street to Commercial Street . o 42-inch sewer at Commercial Street, from Cross Street to Clinton Street. o 66-inch drain at Commercial Street, from Clinton street to Cross Street . o 72-inch sewer at Oliver street from Purchase Street to Fort Point Channel outfall. 379 o 16-inch LS and 16-inch HS water mains, a 12-inch gas main, six 5-inch electric (MBTA AC), sixteen 5-inch electric (Boston Edison), and twelve 4-inch telephone from Haverhill Street to Canal Street. o The Boston Edison substation located on Atlantic Avenue may require reconfiguration due to the proximity of the Central Artery northbound tunnel. o In A Street: 54-inch stor:, drain; 24-inch sanitary sewer; 16 4-inch New England Telephone Co. ducts; and a 16-inch water main. o 115,000 volt electric line;a Summer street and Congress street o 115,000 volt electric line:. 16-inch gas main, 2-16 inch water lines and an 18-inch sewer in Non Avenue near 8th Street. Boston - North of Causeway Street Area o Twin 48-inch Combined Sewer (CS) siphon exiting into 39-inch x 39-inch CS at Leverett Circle. o Lowell Street weir structure with 48-inch and 54-inch CS exiting pipes; Charles River CS river crossing structure and 84-inch inlet and outlet pipe. o Two major telephone services (Boston-Cambridge A Cable); one with 12, 3.5-inch conduits and one with 12, 3-inch conduits. o 36-inch water main parallel to Interstate Route 93 on the easterly side. o General Ship Power Plant nur Drydock No. 4 at C Street and 7th Street . o Telephone/Electric duct ban servicing local area. o 24-inch sanitary sewer froi Northern Avenue and Trilling Way » Summer Street pump station. o 115,000 volt electric line:i Massport haul road from Northern Avenue to Summer Street. East Boston - Airport Property o 60-inch storm drain locatec: the vicinity of the General Aviat:* : Building . o Thirty-six 4-inch telephone ducts and a 36-inch water main in the vicinity of Beverly Street, north of Causeway Street. o The West side Interceptor at Causeway Street from Haverhill Street to Martha Way. o Two 115KV pipe-type electric cables in Causeway Street from Haverhill Street to Canal Street. o Design modifications to eliminate impacts to the Charles River's edge may require the taking of the Boston Edison power plant located on Nashua Street. South Boston o 72-inch storm drain along Mt. Washington Avenue to Fort Point Channel . o 8-inch sanitary force main located along the easterly side oJ General Aviation Building. o 10-inch fuel line in the vicinity of the Porter Street out jtl lilt a i it I o 10-foot x 12-foot Porter ste combined sewer outfall. o 12-inch water main near the southerly end of the Eastern Air Freight Building. o 18-inch sanitary sewer in ti vicinity of the Hilton Hotel. o Major telephone line and 20-inch water main to the west of Hertz Check-In Center; a 60-inch drain, and telephone and electric ducts to the east of the Hertz CenJi o In the vicinity of the Exxo 380 :ation: major telephone lines and a 3-inch water main. At Bird Island Flats, one 10x10 oot drain and twin 12x10 foot con- crete culverts. 12-inch gas line and a 20-inch ater line in the vicinity of the MBTA ib-station. 12-inch gas line located behind le Hilton Hotel. .16 AESTHETIC IMPACTS .16.1 Comparison of Alternatives The Preferred Alternative will .. ^move the elevated Central Artery ,rom downtown Boston and significantly nprove the environment visually and -oustically. Alternatives 3A, 5A and 1 have similar aesthetic impacts in Tiis area. The No-Build Alternative id Alternatives 2, 3, 4 and 5 will Dt change the appearance or aesthetic laracter of downtown Boston. (The Preferred Alternative will Iter the appearance of Fort Point nannel and will increase pedestrian - :cessibility to the Channel. The |r>-Build Alternative has no impacts on Ibrt Point Channel; Alternative 5A has ILmilar, but lesser (due to the lack I : a new Dorchester Avenue) impacts on lr>rt Point Channel than the Preferred IlLternative ; Alternatives 2, 3, 3A, 4, r and 6 have negative aesthetic impacts on Fort Point Channel. .■ igures 65 - 70 present existing views I: the Fort Point Channel from the dimmer Street and Congress Street ! ridges, and the future views with the referred Alternative and with Alter- Ihtives 2, 3, 4, and 5 for comparison Wirposes. The Preferred Alternative will ;ive negative aesthetic impacts on the '•wer Charles River Basin in the North " :ation area. Similar impacts would il:cur with Alternatives 3A, 5A and 6. lie No-Build Alternative and Alterna- tives 2, 3, 4 and 5 would not have Irsthetic impacts in this area. o The Preferred Alternative will not have aesthetic impacts on the residential community of East Boston because the project roadways occur well within the limits of Logan Airport. Alternatives 3, 3A, 5 and 5A would place a ventilation building, toll plaza and associated support facilities on Logan Airport property, closer to the East Boston community where they would be visible to some residents of Jeffries Point. Alterna- tives 2 and 4 would have significant adverse aesthetic impacts on the East Boston community, as their alignments pass through the center of the resi- dential area along the Conrail right- of-way. The No-Build Alternative and Alternative 6 would have no aesthetic impacts on East Boston. o The Preferred Alternative will have significant adverse visual impacts on the South Bay area. The area will change from railyards, primarily below the elevation of surrounding areas, to one with major highway ramps that are much taller than surrounding structures. Alterna- tives 2, 3, 3A, 4, 5, 5A and 6 would also change the appearance of this area, although less radically. The No-Build Alternative would not affect the South Bay area. 4.16.2 Aesthetic Impacts The aesthetic impacts of the Preferred Alternative are compared to the No-Build Alternative in eleven geographic sub-areas (see Figure 71). The sub-areas reflect the patterns of land use and development activity that exist, or would be established, when the land within the Central Artery corridor becomes available for re- use. The categories for analysis are: 1) the view from the road; 2) the view of the road; and, 3) the pedestrian environment. The majority of motorists using the new transportation facilities included in the Preferred Alternative will be driving inside a tunnel. For these people the view from the road 381 Figure 65 Existing: View looking south from th Summer Street Bridge. EIS/EIR for 1-90 -Third Harbor Tunnel: 1-93— Ce Alter Construction (P^^ View looking south from the ^ Street Bridge. ..iga-o** - EIS/EIR for 1-90 -Third Harbor Tunnel, i- aaaaaa aaQBaaaaaaaa a QQlDQQQfl Q QQQQQQDQQQQQ9QQ QQIQQQQQ □DDQQQ ir: Note: The Drawings on this page depict previously rejected Alternatives. They are included for comparison with the Preferred Alternative. Figure 67 After Construction (Alternatives 2 and 3): View looking north from the Congress Street Bridge. 1 R f 1 □ □ -o Id u a n 3 a a QQ "in. QQ ET1' BQ 13 QQ QQ ea oaaaa QQQQQQD aaaaaa aaaaaa □ QQQQ QQQQQaQaQQaQQ QQQQQ Figure 69 Existing: View looking north from the Congress Street Bridge. EIS/EIR for I-90- Third Harbor Tunnel: I-93 — CentralAit aa. a a aa JU aa QQ QQ aaaaaa aaaaaa a BGBQBQB a aaoaaaa a QQQQQaQDDQQQQ Q QQQQQQQQQDQQQ QQQQQ View looking north from the uxy Street Bridge. M q 3 -ce* a EIS/EIR tor l-90-Tmrd Harbor Tunnel. W Figure 71 Key Plan Preferred Alternative Boston EIS/EIR for I-90 -Third Harbor Tunnel; I-93 - Central Artery @ will be of tiled tunnel walls and of other vehicles. Since this experience will be similar throughout the project area it is only described in some detail once in Section 4.16.2. Aesthetic impacts are compared to the No-Build Alternative; the aesthetic environment without the project is described in Section 3.13 Visual Characteristics . Mitigating measures for aes- thetic impacts are described briefly for each geographic sub-area. Addi- tional information about various enhancement measures such as landscap- ing/ joint development, engineering design modifications, and urban design improvements are discussed in greater detail in Section 4.4.4 Joint Develop - ment . South Bay Area View from the Road The experience of entering Boston from the south will be signifi- cantly altered. Those motorists exiting from the Southeast Expressway to Kneeland Street or the westbound Massachusetts Turnpike will be afforded dramatic views of Fort Point Channel, downtown Boston and Boston Harbor. The ramp which provides these connections will rise to almost 60 feet above grade and curve across the South Bay area (see Figure 72). Motorists going from the Southeast Expressway to new Dorchester Avenue will be afforded similar views, from the connecting ramp which rises to 40 feet above grade. View of the Road The South Bay area will be completely altered in appearance by the project. What is now water and railyards will become a network of ramps which are larger in scale than the existing railroad bridges, signal towers and other structures in the immediate area. A large number of ramps and realigned city streets will be at or above ground level and will be visibl from other roadways and from the windows of structures in the area. The geometry of the roadways will reduce the amount of visible ground area. Shadows cast by elevated ramps will limit the landscaping which can be planted. The scale of the highway elements, and their height (up to 60 feet above grade), will form a visual wall between South Boston and the South End. Pedestrian Environment The majority of pedestrians wh will see this area will be people walking between South Boston and downtown via Dorchester Avenue. The Herald Street extension and new Dorchester Avenue will be designed to accommodate pedestrian traffic. This will enhance pedestrian access. A pedestrian easement may be required across the parcel which is created between existing Dorchester Avenue an new Dorchester Avenue. The scale of the new highway ramps will be significantly larger than the existing elements in the landscape. The Broadway Bridge is currently the highest roadway in the South Bay area. The new connecting ramp between the northbound Artery an< the Massachusetts Turnpike will be 35, feet higher than the existing Broadwa; Bridge. Herald Street Extension will replace the existing Broadway Bridge. This ramp will be designed so as not to visually overwhelm pedestrians using the Herald Street Extension. Mitigating Measures The highway elements to be located in the South Bay area can be, visually interesting, and can create dramatic landscape with their grade changes and curving alignments. Wei designed roadways can be a form" of urban sculpture if they are designed with that as a goal. For motorists approaching Boston from the south or west, this area will provide the first image of downtown Boston; it is important that it be handsomely 386 Aesthetic Impacts - South Bay/Fort Point Channel and mitigating measures 1 . Existing South Bay area is characterized by industrial architecture, bridges, and open water. The scale and height ot the many new bridge and ramp structures will create a physical and visual barrier between South Boston and the South End. Views of the Financial District Irom the new Kneeland Street off-ramp will create a dramatic entry to the city, 2. Ventilation building will be a prominent visual landmark from relocated Dorchester Avenue, the new Herald Street Extension bridge, and new connecting ramps. Mitigating Measures: reduce height of struc- ture and use special architectural treatment Vent stack height may be altered based on additional air quality analysis. 3. Relocation of Dorchester Avenue to the west creates less direct pedestrian access from South Boston to the Fort Point Channel walkway Mitigating Measure: Provide pedestrian easement from Fort Point Channel to Foundry Street. 4. Bulkhead at location of former Dorchester Avenue bridge creates a new terminus to Fort Point Channel lessening the visible water area. 5. New bulkhead line projects 36' into the Channel from the existing bulkhead Mitigating Measure: Replace granite face on new bulkhead. 6. New Dorchester Avenue provides new pedestrian walkway connecting South Boston with downtown and offers views of the Channel. 7. Top of tunnel box is visible above the water line with the new bulkhead line projecting 60' to 80' from existing bulkhead. Mitigating Measure: Provide public open space on deck over the tunnel. 8. New bulkhead line projects 15' to 40' into the Channel from existing bulkhead. Mitigating Measure: Provide public open space on deck over the tunnel. 9. New bulkhead projects 10' into Channel at Congress Street bridge and curves back into existing bulkhead 100' to the north. Mitigating Measure: Integrate deck over tunnel into pedestrian walkway. 10. Open section of tunnel is visible from adjacent areas Mitigating Measures: Placement of louvers to visually screen roadway opening. Figure 72 ill Ramps and Open Sections Summary of Aesthetic Impacts H Ventilation Buildings, and Measures to Minimize Harm Preferred Alternative South Bay/Fort Point Channel f^"^^Oo"^^^^00 Feel EIS/EIR for I-90 -Third Harbor Tunnel; I-93 - Central Artery designed. South Boston View from the Road The experience of motorists driving on the roadway will alternate between enclosed tunnel sections and open depressed roadway sections (see Figure 73). The motorist exiting or entering the tunnel at the Congress Street exit will see the Fort Point Channel 19th century warehouse dis- trict (Boston Wharf Company) on the west, as well as new development to the north and east. View of the Road From Commonwealth Flats, the project's toll plaza, ramps and ventilation buildings will be visible in open cut from Summer Street to the eastern edge of Commonwealth Flats. Since this property is not yet fully developed, it is difficult to predict what the visual impact will be in the future. However, it is clear that the highway facilities and ventilation structure will be visually significant. If current Massport plans for parking and fish distribution are put into effect, the impact is not ex- pected to be significant because these uses are not particularly visually sensitive. The road will be most visible from Viaduct Street; the view from this point will include the toll plaza, Northern Avenue ramps, and ventilation buildings. The ventila- tion buildings located east of Viaduct Street will be placed within an industrial landscape, within which they will be the tallest elements. The ventilation building located north of Northern Avenue will be visible from the harbor and possibly from across the harbor. The ventilation building near A Street will be a noticeable element in this area of 19th century industrial buildings . The access road connecting t tunnel to Northern Avenue requires right-of-way wider than the streets parallels. The visual separation which it creates between the existi structures on Stillings Street and parcel to the east of the access ro will not allow the continuation of area's existing street and building pattern . Pedestrian Environment The area in which the Prefer Alternative is located does not presently attract a great number of pedestrians. Future plans for the area concentrate pedestrian use aloi the waterfront side of Northern Avenue, and are not affected by the project. The depressed highway will not be visible from Northern Avenue, Ventilation buildings and ramps wilj be visible, but not significant to t overall appearance of the area. In the Congress Street area, tunnel-related signing and lighting will be noticeable elements in the pedestrian environment. Mitigating Measures Architectural treatment of th ventilation building in conformance with existing buildings will minimiz visual impacts on neighboring parcel Fort Point Channel View from the Road For those motorists approachu downtown Boston on New Dorchester Avenue, views of the Fort Point Channel and the Post Office will be dominant. Views of Fort Point Chann* will be across a landscaped pedestrii walkway and will include any marina development which occurs in the Channel. The experience of entering Boston along this route will be reminiscent of the drive along Memorial Drive near the Longfellow Bridge in Cambridge. The increased visibility of 388 Legend Ramps, and Open Sections ^ Ventilation Buildings South Boston - Summary of Aesthetic Impacts and Mitigating Measures 1. Ventilation building will be a prominent visual landmark from A Street and ad|acent renovated buildings. Mitigating Measure: reduce height of structure, use special architectural treatment, and orient ventilation building to conform with existing street and building grid. Vent stack height may be altered based on additional air quality analysis. 2. Three new ramps and open tunnel section will be visible from ad|acent buildings and Summer Street Bridge. 3. Wide right-of-way for new access road connecting the tun- nel to Northern Avenue separates the existing Boston Wharf buildings from the future Cabot, Cabot & Forbes Develop- ment. Mitigating Measure (2 & 3): Modify the ramp and access the design. 4. Ventilation building will be a prominent visual landmark from Summer Street, Viaduct Street and B Street. Mitigating Mea- sure: reduce height of structure and reorientate structure to minimize impact. Vent stack height may be altered based on additional air quality analysis. 5. New ramps are visible from adiacent buildings, Summer Street, Viaduct Street, Ramp Street and Massport properties. 6. Toll plaza is an open section visible from Viaduct Street and will be visible from future Massport development. View of Adminis- tration building will be obscured from surrounding streets by ramps and existing fisheries buildings. 7. Ventilation building will be a prominent visual landmark from the Harbor and will also be visible from Northern Avenue. Miti- gating Measure: reduce height of structure and special archi- tectural treatment. Vent stack height may be altered based on additional air quality analysis. Figure 73 Summary of Aesthetic Impacts and Measures to Minimize Harm Preferred Alternative South Boston 0 250 500 Feel \£/ EIS/EIR for I-90 -Third Harbor Tunnel; I-93 - Central Artery Fort Point Channel caused by the introduction of this roadway may enhance its potential for water- related development and will introduce many people to its existence as a unique urban waterfront area. View of the Road and Pedestrian Environment The project will cause changes in the visual and pedestrian character of Fort Point Channel. Although some of these changes are visually nega- tive, the project will have the benefit of increasing accessibility to Fort -Point Channel for pedestrians and increasing the Channel's visibility as an urban waterfront. The visually negative impacts caused by the project are the loss of the existing parallel bulkhead lines, and loss of visible water area, particularly south of Summer Street. The visual character of the Channel is different in the three areas defined by the bridges over the Channel. These visual differences will remain after the project. The specific changes to the western bulkhead line are described below and are illustrated in Figure 72. o From the southern end of the Cnannel to a point 400 feet south of Summer Street, the New Dorchester Avenue and pedestrian walkway will project 40 feet further into the Channel than the existing bulkhead line . o Within the 400 feet just south of Summer Street, a deck, slightly lower than New Dorchester Avenue, will be constructed on top of the tunnel box. This deck can be used for a variety of passive recreation uses (see Section 4.4.4 Joint Develop - ment ) . Tne deck plus Dorchester Avenue will project 80 feet into the Channel from the existing bulkhead line, and then taper inward toward the existing bulkhead. (See also Figure 66.) The linear character of the ■ Channel edge south of the Summer Stree ... Bridge, which is defined by the parallel bulkhead lines, will be maintained. A new bulkhead line wil be created and a new pedestrian dec will be developed below street leve . A new bulkhead constructed of granie will be created. The introduction I '. the two-lane New Dorchester Avenue n this area will increase noise leveltw this area. o Between Summer Street and Congress Street, the Channel is a small tightly defined space, with irny bridge, utility and piling structure in the water. The project will red:e the water area slightly, but will improve pedestrian access to the water's edge, and thus facilitate t>. development of water-related uses. North of Summer Street, the roadway and pedestrian walk project feet from the existing bulkhead line adjacent to Summer Street, and tapei in to be only 15 feet from the exist ing bulkhead line at Congress Street The deck to be built in this area is similar to the one described above. o North of the Congress Street Bridge, the Channel is occupied by t« Tea Party Ship Museum, and its easte bank is used heavily by pedestrians visiting the Children's Museum. The character of this area will be essen tially unaltered by the project. The project will require the filling of a small area just east of Russia Wharf (this filling is alread planned by others), and will facili- tate the development of pedestrian access and recreational amenities in the area. In this area, new Dorches-' ter Avenue and the pedestrian walkwaj will project 10 feet into the Channel 100 feet north of Congress Street th new bulkhead meets the existing bulkhead line. The Central Artery While the Central Artery passe through a number of distinct district and neighborhoods, some effects of removing the viaduct are common to al 390 ( see Figure 74 ) : SI Today/ people walking under the ,y experience a dark environment the impact of vehicle noise and ist is frequently intensified by iaduct; in the future, the ience of crossing or walking .lei to the Artery Corridor will ke that of walking on a typical street, and the pedestrian Ironment will be greatly improved. The establishment of a pattern j.imarily rectilinear parcels and ,i:ts will provide a better sense of ■ itation for both drivers and intrians. Removal of the overhead road- ramps, piers, and columns will •;tablish visual continuity between !i of the city which were severed ie elevated highway construction jars ago. Removing ramps in the >irket/North End area, and between V'inancial and Waterfront Dis- t.:s, will open up views which do :, presently exist; removing the deck : uer supports from other areas L allow clear views along cross- i:s which intersect the corridor 3 ire presently obstructed by the cpture. Relocating the ramps connecting rice streets and the Central Artery 1 alter surface traffic patterns d/olumes. The new Surface Artery i carry the fuel and other hazard- I :argo trucks which presently use •elevated Artery, thus making them K noticeable to pedestrians. There will be several secondary il impacts when buildings are •|:ructed on parcels over the n,5l . Oblique views under the llited Artery will no longer be slble, as the new buildings will Ov diagonal sight lines and channel 1 'iews along the new surface street ri.dors. Views from existing Uings adjacent to the Artery tjidor will be affected as well; the n|i of openness over and around the iking Artery will change as devel- mt occurs and the Artery corridor sines a physical character and density much like that of the adjacent districts. o The experience of driving through or into Boston on the Central Artery will be radically altered when traffic on the existing elevated structure is placed in the new tun- nel. From a strictly visual point of view, elevated highways offer two advantages : 1) Drivers entering Boston have the opportunity to see landmarks, select an exit ramp, and drive to their destination with a sense of its character and location in mind. Travel in a tunnel clearly precludes this sense of orientation. 2) The views from the elevated structure across the North End, into the Quincy Market, out to the Harbor, and up to skyscrapers of the Financial District offer a diverse visual experience for drivers crossing the city; this experience of changing vistas has been observed and commented upon by many, and would be lost if the highway were placed in a tunnel. The aesthetic experience of driving in a tunnel is less desirable than that of driving on an elevated or surface road. Although there are examples of tunnels designed with particular concern for creating a pleasant environment, artificial lighting and views only of the road- way, tiled surfaces and other vehicles typically offer a meager experience in contrast to the open and visually rich environment on the surface. However, the use of tunnel offers a balancing opportunity to improve the visual experience of driving on the new Surface Artery. The new street system will offer clear uninterrupted views along its length and along crossing streets at inter- sections. o Today the elevated Central Artery is a continuous element in the landscape, and when it is removed, the open corridor will appear as a long linear open space. As the corridor is developed with buildings and public 391 Central Area - Aesthetic Impacts and Mitigating Measures 1 . 150' opening lor ventilation of existing Dewey Square Tunnel could be overbuilt by air-rights devel nJm which would incorporate a ventilation system lor the Dewey Square Tunnel- °Pm^B 2. Oliver Street pedestrian connection and visual corridor improved by depressing and covenna of Central Artery, 3. Ventilation building would be a prominent visual landmark as viewed from Atlantic Avenue Mitioaiinc Measure: locate structure in less prominent location, possibly combining it with ventilation buildinn aiJB Street, and incorporating the building envelope of future air-rights development, based on additional ai9 quality analysis. 4. Open ramp affects views and quality of pedestrian environment along Atlantic Avenue Miligalinq Mea-I sure: incorporate ramp into the building envelope of future air-rights development, 5. High Street visual and pedestrian corridor re-established by removal of ramps. 6. Broad Street visual and pedestrian corridor improved by the removal of ramps and overhead highway structure. 7. Ventilation building would be a landmark as viewed from Atlantic Avenue and adjacent buildings. Mili-fl gating Measure: Locate structure to the south of High Street and combine with northbound on-rampanH ventilation building at Oliver Street into the building envelope of future air-nghls development (see NoteH 8. Removal of the elevated highway allows visual relationship between the Gram Exchange BuildingiCusloM House Tower area and the Waterfront area. 9. Important visual and pedestrian links to the Waterfront improved by removal of the elevated high- way structure. 10. Visual and pedestrian corridor between Quincy Market and Commercial Street improved, 11. Open ramps affect views and quality of the pedestrian environment along Cross Street and within Iheafl rights parcel between the North End and the Blackstone Block/Quincy Market area Mitigating MeasunM incorporate ramps into the building envelope of future air-rights development. 12. Removal of elevated highway structure improves the North Street visual corridor. 1 3. Ventilation building will be a prominent visual landmark. Mitigating Measure: incorporate venlilaiion building in a building envelope constructed above depressed Central Artery, based on additional air qualilyH analysis. Give building special design treatment consistent with Section 106 Memorandum of Agreement. 1 4. Pedestrian and visual connection established between Haymarket/Quincy Market area and the Hanovm Street/Cross Street area 1 5. Direct pedestrian and visual corridor re-established. 16. Open ramps affect views and quality of the pedestrian environment. Mitigating Measure, incorporate ■ ramps into the building envelope of future air-rights development, 1 7. Pedestrian connection between the North End and Haymarkel MBTA Station improved. Grade separate pedestrian connection between North End and MBTA station could also be provided, 1 8. North Washington Street visual corridor re-established. 1 9. Restoration of the original street grid re-establishes the visual form and pattern of the Bulfinch Triangle. ■ 20. Causeway Street visual and pedestrian corridor improved by removal of elevated structure and ramps, ■ Pedestrian and Visual Corridors Visual Corridors Ramps Ventilation Buildings Preferred Location (Subject to Air Quality Analysis) Figure 74 Summary of Aesthetic Impacts and Measures to Minimize Harm Preferred Alternative Central Artery from Congress St. I to Causeway St. EIS/EIR for I-90 -Third Harbor Tunnel: l-93_ Cen „ai Artery J is, the physical character of its 0 s and streets will take the form ,e neighborhood or district 1 igh which it passes. The poten- a,y disruptive appearance of an e ;ize linear element will be [ iced by an integrated urban r ftscape. The three ventilation buildings oised along the Central Artery r dor between High Street and North s ngton Street and the permanent gr; to and from the depressed nal Artery will cause aesthetic pits on areas directly adjacent to e The final locations for these n.lation buildings will be deter- n! following additional detailed reality analysis; architectural i in will be consistent with the con 106 Memorandum of Agreement. | :ts of these ventilation buildings c litigating measures are described For further discussion of t |ating measures, see Section 4.4.4 u . Development . The description of aesthetic :ts in the area between the Dewey iu:e Tunnel and Causeway Street is I ;nted by sub-area. The two | rtant impacts noted below apply to I individual area. View from the Road . For motor- ists within the tunnel, the view will be of tiled surfaces and other vehicles, as de- scribed above. View of the Road . Views of the road will be greatly diminished as a result of the removal of the elevated Central Artery. The road will no longer be the dominant visual element in the area; rather, small portions of the project, such as ramps, will be visible from city streets. jt icial District: Central Artery - >n| :ess Street to High Street View from the Road There will be new views of the city for motorists driving on the Surface Artery or on streets perpen- dicular to the Surface Artery. This will be particularly important for motorists approaching downtown via the new Northern Avenue Bridge. Under existing conditions, views of downtown are blocked by the Central Artery structure which is in a transition section between elevated roadway and tunnel. With the project, these drivers will have unimpeded views up Oliver Street into the heart of the Financial District. View of the Road The ramps to and from the depressed Central Artery will be open depressed sections parallel to the Surface Artery. They will resemble the ramps to and from the existing Dewey Square Tunnel. The ventilation system for the Dewey Square Tunnel requires an open section 150 feet long between Pearl and Oliver Streets. This will be a negative element in terms of views from surrounding buildings. The ventilation building proposed for this area will be the most visible project element . Pedestrian Environment For pedestrians walking along the Surface Artery, the environment will be significantly improved in this area in terms of visual quality, air quality and noise levels as compared to the future No-Build Alternative. The pedestrian environment will be enhanced by the opening of new views along Pearl, Oliver and High Streets. Oliver Street will be a through street, connecting to the new Northern Avenue Bridge, allowing for an at-grade pedestrian connection along Oliver Street to the proposed new bridge. Mitigating Measures The open tunnel section between Pearl and Oliver Streets could be covered by air-rights development 393 which incorporates a ventilation system for the Dewey Square Tunnel. The on- and off-ramps designed as open sections could also be enclosed in an air rights development on the newly created parcel. The ventilation building to be ' constructed in this area will be located and designed following de- tailed air quality analyses. The design will be consistent with the Section 106 Memorandum of Agreement. The ventilation building may be incorporated into air-rights develop- ment above the depressed Central Artery. Broad Street District: Central Artery - High Street to State Street View from the Road For motorists driving on the new northbound Surface Artery, a new visual environment will be created. The road will curve to the left as it approaches Harbor Towers, as it does today. With the elevated Central Artery removed, drivers will have a dramatic view of the Grain Exchange Building and the U.S. Customs House. Design guidelines to ensure that these sight lines remain open and that the heights of new buildings do not conflict with vistas opened by the removal of the Artery will be prepared (see Section 4.4.4 Joint Development ). View of the Road The ventilation building adjacent to the northbound Surface Artery near High Street would be visible to pedestrians walking along the Surface Artery and to residents of the Harbor Towers Building. Pedestrian Environment The new Surface Artery will provide a pleasant experience for pedestrians walking above the de- pressed Central Artery, in contrast to existing conditions. Pedestrian crossings will be improved at all access points between downtown and the pedestrian esplanade along Long Wharf, the New England Aquarium, Harbor Towers and Rowes/Fosters Wharf. Mijk ! ■■■ Street will be continuous from the i center of downtown to the Waterfron,. High Street will cross the depresse . Central Artery and connect with a 30-foot wide pedestrian access corr- dor established by the BRA design guidelines for the northern edge of EL: the Rowes/Fosters Wharf parcel. Uninterrupted views of the harbor are created from the Broad Street District along High, Broad, India, Milk and State Streets. The Broad Street sight line, currently obstructed by retaining walls, will re-established in a manner consister with the BRA's design guidelines for Rowes/Fosters Wharf. The Broad Street Historic District will be visually and physi- cally reconnected with the Waterfron Mitigating Measures The ventilation building to I constructed in this area will be located and designed following de- tailed air quality analyses. The design will be consistent with the Section 106 Memorandum of Agreement. The ventilation building may be incorporated into air-rights develop- ■-, ment above the depressed Central Artery. Waterf ront/Quincy Market - State Street to Clinton Street View from the Road Removal of the existing Centra Artery structure will provide drivers on the new Surface Artery with clearei sight lines and an improved orienta- | ^ tion to the street pattern. View of the Road No visible portions of the Central Artery will be constructed in this area. Pedestrian Environment The "Walk-to-the-Sea" will be 394 :ed by a pedestrian easement 11 i the new parcel created over the 36 ssed Central Artery. Pedestrian ::)ll tted signals will allow safe and : uent access across the Surface ; {. The visual connection between ■••'•arket area and the harbor will be '■ tablished. As buildings are : ' oped on air rights over the ssed Central Artery, views will anneled along streets and itrian corridors. State Street's :ric function as an important link 1 -cting Long Wharf to Boston's " 5 ircial center will be enhanced by ■ emoval of the Central Artery. '■•'i End/Haymarket - Clinton Street - dicott Street View from the Road Motorists travelling on the 31 ice Artery will have views of >n's most historic neighborhoods, lorth End and the Blackstone New development on parcels : i the depressed Central Artery .d provide view corridors across depressed Central Artery. New Uings constructed on air-rights tils should be designed to assure •aate sight lines at intersections a:o re-establish the building tern. The new Surface Artery and is to the Sumner and Callahan icels, with proper signing, will * these areas clearer and more Krstandable to the driver. View of the Road The ramp from the Central :try northbound to the Surface rt ry (in the vicinity of North -let) is placed on the side of the net away from the North End. It ftj be visible from the street, but •jild not be very obtrusive. The Ji>s permitting access from the north ■<> the Sumner Tunnel and into the «i:ral Artery southbound will be i :ed in the center of the air-rights a:el over the depressed Central c ;ry, and their visual and noise fflticts will be masked by new develop- ment placed around them (see Section 4.4.4 Joint Development ). The ventilation building to be located in this area would be visible to pedestrians and motorists, and may be larger than most structures in the area. Pedestrian Environment This portion of the Central Artery corridor has a high volume of pedestrian movement between the North End, downtown and the Quincy Market area. Removal of the elevated struc- ture will provide the large number of residents, shoppers and tourists with more pleasant routes, open to the sky. The existing Central Artery southbound off-ramps and northbound on-ramps totally block cross-corridor views under the Artery and restrict pedestrian access. With the construc- tion of the depressed Central Artery, sight lines across the corridor will be opened at Hanover, Salem, and North Streets. A diagonal pedestrian walk connecting North and Hanover Streets will be built across a newly-created parcel. This walk will serve the large number of pedestrians wishing to cross between downtown and the North End. The 17th Century Blackstone Block will be physically and visually reconnected with the North End, and a street pattern similar to the original layout will be re-established. A significant improvement in the pedestrian environment will occur as a result of the reconfiguration of the Surface Artery which will provide pedestrians on the east side of Cross Street with a pedestrian walk over the covered portals of the Sumner and Callahan Tunnels and signalized street intersections at Commercial and Fulton Streets. This area is currently a dangerous and obstructive element to pedestrian circulation in downtown Boston. Mitigating Measures The ventilation building to be 395 constructed in this area will be located and designed following de- tailed air quality analyses. The design will be consistent with the Section 106 Memorandum of Agreement. The ventilation building may be incorporated into air-rights develop- ment above the depressed Central Artery. The exit ramp from the north- bound Central Artery tunnel to the Surface Artery/ running parallel to Cross Street, could be enclosed in a building envelope to enhance the appearance of these newly-created parcels. Haymarket Square View from the Road Haymarket Square will be the focal point for drivers entering Boston from the north via North Washington Street, Interstate Route 93 and the Mystic-Tobin Bridge, and from the Sumner Tunnel exit to downtown Boston. The strict channelization of traffic which has been built into the design of this busy intersection will clarify movements for motorists approaching from many directions. View of the Road The Haymarket intersection will carry such significant volumes of traffic that a large expanse of paved area is necessary. The many movements occurring in the area will require many directional signs which will require careful design to avoid contributing to visual clutter. The views of this area from the North End will be buffered by develop- ment on the parcel between the Surface Artery and Stillman Street. Pedestrian Environment Currently, pedestrians crossing the North End to the Haymarket MBTA station have to work their way around local and regional traffic under the Central Artery. The new Surface Artery will provide some safe, direct crossings with pedestrian traffic signals . North Station/Bulf inch Triangle - North Washington Street to Causeway Street View from the Road Motorists driving on the northbound Surface Artery will be adjacent to handsome 19th Century industrial buildings; motorists on tji southbound Surface Artery will have views of the Blackstone Block and th area around Quincy Market. On this portion of the Surface Artery driver will be on a roadway which forms a logical street pattern with adjacent city streets, thus enhancing the sen of orientation. Drivers entering Boston on North Washington Street will have improved sight lines into downtown Boston. View of the Road When the Central Artery viadu is removed, the physical and visual character of the North Station/ Bulfinch Triangle will be altered dramatically. Haverhill Street will be reconstructed to Haymarket Square which will improve vehicular circula tion and open views of the U.S. Customs House and downtown. Views will also be reopened between North Washington Street and downtown and along Traverse Street. With the reconstruction of Beverly and Travers Streets, the physical layout of the Bulfinch Triangle will be re-estab- lished. Pedestrian Environment The elevated Central Artery is a major barrier to pedestrian movemen in this area. With the removal of this structure, many impediments to sunlight, circulation, and activity will be eliminated. Causeway Street will become visually continuous, with only the single bridge of the relo- cated Green Line crossing the roadway overhead. (The MBTA is evaluating Green Line relocation options which may result in this bridge crossing 396 •being removed.) Controlled sections at Haverhill and Beverly its will ease pedestrian movement, I mtrast to the free-moving vehicle i; that exist today. Development jw parcels along Causeway Street increase street-level activity, •ler improving the pedestrian rronment. The project will provide opportunity to create a landscaped • on MBTA-owned land adjacent to '•new southbound Surface Artery. Views along North Washington ; :;t are currently obscured due to Arising of the street and the low, ijue crossing of the elevated ::ture. This important corridor '".ien Charlestown and downtown will ^-established, greatly improving >?resent pedestrian environment. /Lopment of parcels created along 13 routes will also improve the dstrian environment. i n Station/Charles River - Causeway : st to Charles River View from the Road North of Causeway Street the rral Artery will emerge from a (el and rise onto bridges over the *les River. For northbound motor- t this will be the first opportun- Ito view surrounding areas since 'ring the depressed Central Artery. Views available to drivers ring Boston on southbound Inter- ne Route 93 are presently blocked he overhead northbound structure. new northbound and southbound iges will be separated, so inbound wrists will have a dramatic vista owntown Boston before they enter ^Artery tunnel, with sightlines sed on the U.S. Customs House iv'r. Northbound motorists will have ^s across the Charles River to ^lestown and Bunker Hill, as they t«ge from the tunnel. The rising id and corrective measures taken j licessary during the construction i"X[)d to minimize the project's ef- ]W; on the groundwater table. Other :;H:ruction period effects, such as jfpotential influx of rodents to :'.:|l:ent buildings caused by the con- niption activities, will be con- ::.o|led by approved techniques de- : r >ed in this document. In the long-term, the Preferred •trnative results in significant vipovement in transportation service dievelopment opportunities for the >S3n area. This transportation ben- includes a savings of approxi- atlLy 17.6 million person hours of ;"a'2l. Tne Preferred Alternative Jbltantially improves tne movement of JoLe and goods to Logan Airport, /■Lting in economic benefits to the •«|3n. The level of Airport activity oasengers, airline operations, de- ilpment, etc.) is not expected to be •cicted by the project, but is more a iiition of regional and national eco- forces. The Preferred Alternative re- ws significant volumes of traffic :c neighborhood roadways, particu- »ry in the North End, Chinatown and Jtn Boston areas. This major bene- -tlof the project will significantly •ove the quality of life in these Ji tiborhoods. In South Boston, the cect also removes substantial vol- 407 umes of truck traffic (hazardous car- go) from the residential streets. Improvements in air quality and noise and vibration characteristics of the project area will also accrue from implementation of the Preferred Alter- native, due to improvements in traffic flow, placement of the large volumes of traffic in tunnels, and removal of the existing Central Artery viaduct. Removal of the existing Central Artery viaduct will also improve aes- thetic conditions in the area, will allow reconnection of the downtown and adjacent neighborhoods long severed by the elevated Central Artery, and will allow joint development of approxi- mately 20 acres of air rights above the depressed Central Artery. These improvements will also result in sig- nificantly increased tax revenues and employment opportunities in the area. Removal of the viaduct will also enhance the historic character of a major portion of downtown Boston. The historic Fort Point Channel will be enhanced by the public ameni- ties to be included as part of the Preferred Alternative. Public access to the waterfront area and the aes- thetic experience of walking along the Channel will also be improved. The East Boston Memorial Stadi- um at Logan Airport will also be en- larged and enhanced as a result of the Preferred Alternative. This intensively-used recreational facility will experience noise level reductions as a result of a new noise barrier to be constructed along a portion of the Airport access, egress, and Cross Roads. Landscaping improvements are also to be provided. In summary, the Preferred Al- ternative includes specific, extensive measures to mitigate potential adverse impacts and commitments to evaluate further unresolved issues. With these commitments, the construction period impacts will be minimized to the ex- tent possible while the long-term productivity of the environment is enhanced. 5.0 SECTION 4(f) EVALUATION Section 4(f) of the Department of Transportation Act of 1966 prohibits use of land from a significant publicly-owned park, recreation area, or wildlife or waterfowl refuge or any significant historic site unless it can be shown that (1) there are no feasible and prudent alternatives to the use of the land from the property; and (2) the proposed action included all possible planning to minimize harm to the property resulting from such use. 5.1 PARK LANDS There are three recreation areas affected by the Preferred Alternative which are subject to Section 4(f) requirements. 5.1.1 East Boston Memorial Stadium Description This recreation area totals 17.67 acres. It has a northwest- to-southeast orientation and is located between the inbound and outbound Airport access roads east of Route 1A. The park includes an additional parcel of 50,400 square feet located southwest of the inbound Airport roadway (see Figure 77). The latter parcel has been augmented by approximately 26,000 square feet of adjacent land leased from Massport. The facilities include a Softball field, baseball field and 4,900-seat football stadium, all of which have floodlighting for evening use. The stadium building contains offices, shower rooms, a first aid station, locker facilities and a maintenance depot for the owner, the Boston Parks and Recreation Department. A track, basketball courts and a tot lot with wading pool, swings, slide and jungle gym are also provided. Tennis courts lie at the southeastern end of the field. The parcel southwest of the inbound roadway has two street hockey courts and parking spaces demarcated. All facilities in the stadium complex are heavily used. It is the only East Boston park with a single-use football field, and one of only four East Boston parks with floodlights. The three other floodlit parks are located throughout East Boston and serve different neighborhood groups. In addition, the stadium playfields are a city-wide and regional resource. The football fiel< is the home field for East Boston Higl School games and practice. It is alsc used by eight Boston Park League football teams, and bv 1,200 bovs in the East Boston Youth Athletic Association football program. The football field is used for competitior by two state-wide soccer associations which play over four games per week ir season. It is also used for a city-wide summer recreation program for handicapped and emotionally disturbed children which daily serves over 300 children. The baseball and softball facilities are used as home fieldr r East Boston High School, by 16 baseball and 22 softball teams in the Boston Park League, and by the East Boston Girls* Softball League. Most of the airlines at Logan Airport have a team in the Massport League which has softball games two nights per week. In addition, the East Boston Little League maintains a separate baseball diamond within the stadium complex. In spite of limited play facilities, the tot lot and wadinq pool area are heavily used. East Boston Social Centers, Inc. uses the area as part of its summer Day Care Center program, which serves hundreds of children each day. The Boston Parks and Pecreation Department recently considered entering into an agreement whereby a private parking lot operator would maintain the stadium and grounds in exchange for the exclusive right to 408 Route 1A East Boston Memorial Stadium 'Parking\ 1 :cess Road iproved Land To Be Added To Park Property After Construction Proposed Noise Barrier (15) If Construction Easement (permanent subsurface easement at tunnel layout lines) ■J' Park Boundary 1 1 Tunnel or New Roadway i Figure 77 East Boston Memorial Stadium - Impacts Under the Preferred Alternative 250 Feet 9 EIS/EIR for I-90 -Third Harbor Tunnel. I-93 - Central Artery use the 140-space parking area southwest of the inbound roadway. Although parking spaces were demarcated, this arrangement was never implemented; the parking area is now closed to the public and cannot be used, as a point of access into the park. The recreation area was transferred to the City of Boston in 1954 by the Commonwealth of Massachusetts in exchange for the City-owned Amarena Playground, acquired by the Commonwealth for Airport expansion. Approximately one third of the stadium's parking area is located on a contiguous parcel leased for -an indefinite term from Massport. The Boston Parks and Recreation Department has also been given easements across the state owned land under the highway and MBTA ramps. These easements differ by parcel, but basically are for laying and maintaining utility lines and for providing pedestrian and service vehicle access to the park. Present access for both pedestrians and vehicles is at the western corner of the park, on a roadway which passes under the existing inbound Airport ramps and- runs along the edge of the park. According to the 1954 deed to the parkland, the Boston Parks and Recreation Department easement over this roadway is for pedestrians and service vehicles only, although this restriction is not enforced. The 1954 deed provides an easement for public vehicular access from Porter Street to the parcel southwest of the inbound Airport Road and a pedestrian easement between this parcel and the main field. Improvement of this connection to Porter Street is proposed as a part of the project to offset negative impacts which will occur because of the project (see Figure 77.) Although the facilities themselves do not possess any unusual characteristics, the fact that this park is a replacement for parkland previously "taken for Airport expansion makes any encroachment on this park of major concern to the community. Location and Amount of Land to be U e- No surface parkland is permanently used by the Preferred Alternative. Approximately 34,000 square feet (or 4.4 percent of the total recreation area) of land alon the southeastern end of the park wit be disrupted temporarily during construction of the underground rami connecting the outbound Airport Roa< to the Third Harbor Tunnel, and a subsurface easement will be permanently occupied by this ramp, i construction easement will include ; 40 foot wide strip inside the edge c the tennis courts. These courts art not actively used at present, perhaj: due to lack of maintenance. This ci and cover construction will last for about three months, after which time the surface of the land will be restored to its original condition. The tunnel will permanently occupy ah subsurface easement approximately 50|' feet wide and 200 feet long (1,000 square feet). Also, a temporary detour of te inbound Airport Road along the southwestern edge of the park will require the use of a 10-foot wide strip of the park occupying approximately 6000 souare feet of parkland (0.8% of the park area). This temporary taking will last for approximately two years, after which; time the land will be restored to it; original condition. No recreational facilities will be affected by this temporary service road; pedestrian ai vehicular access to the park will remain unchanged. Other Impacts Air quality at East Boston Memorial Stadium will be substantial improved by the Preferred Alternative compared to No-Build conditions in 2010 (see Section 4.7 AIR QUALITY IMPACTS ) . With the noise barrier proposed as part of this project, overall noise levels at the park will be decreased by the project relative to existing and year 2010 No-Build 410 1 Ions (see Section 4.8 NOISE AMD ON IMPACTS ) . "', Agency Funding of Improvements >j Conversion of parkland which ?n improved or acquired with th e Jl funds to non-park use requires :i 0 Jal by the funding agency; in < losses this approval is contingent splacement of the affected '2jLnd. The city has recently been 5, a A3 an Urban Parks and Recreation 2 iry Grant (UPARR) for recreation mprovements at East Boston . al Stadium. Because the red Alternative requires only ary use of parklands, ..ement of affected parkland is iquired. The National Park .... . ie is prepared to authorize a uction permit for East Boston al Stadium at the time the - (wealth of Massachusetts tes the Final Environmental i Statement/Report and Final m 4(f) Evaluation (see 7 >er 1983 letter in COMMENTS AND NATION ) . According to the U.S. :ment of the Interior and the Liaison Officer, no Land and Conservation Fund Act funds have ;sed on this property, so the .s not subject to Section 6(f) :ement requirements. (See :s from U.S. Department of the ior dated August 29, 1983, and n:he State Liaison Officer dated : 23, 1983 in COMMENTS AND - R [NATION. ) •jg iatives Which Would Avoid the 4(f) Property Although no surface parkland is fnently used by the Preferred «native, as described in the •jus subsection Location and Jj t of Land to be Used , temporary ruction and subsurface easements equired. All of the build •{'natives which include a four-lane ' Harbor Tunnel examined in the SDEIR and SDEIS/SDEIR require the ' E substantially more parkland 'Uoes the Preferred Alternative. : < natives which would avoid "trary and subsurface easements as well as permanent surface use of th» Section 4(f) property are as follows: (a) Alternative 6 and the No-Build Alternative, and (b) the Two-Lane Tunnel Concept. (a) Alternatives which did not include a Third Harbor Tunnel (Alternative 6 and the No-Build Alternative) were examined in the DEI S/DEIR and SDEIS/SDEIR; these alternatives did not satisfy the basic project objective of improving Central Artery and cross-harbor traffic flow, and were not selected. (b) The Two-Lane Tunnel Concept would avoid both temporary and permanent use of the East Boston Memorial Stadium but would not provide transportation improvements comparable to the Preferred Alternative, because the Two-Lane Tunnel Concept does not include a direct connection to Route 1A North. Without this connection, all northbound traffic with destinations beyond Logan Airport would have to continue to use the existing tunnels, or else exit from the new cross-harbor tunnel and use the Airport roadway system to reach Route 1A North, increasing travel time and adding to the congestion at Logan Airport. As a consequence, this concept does not adequately address cross-harbor travel demand, and would result in congestion in the existing and proposed tunnels and on the Central Artery south of the Callahan/Sumner Tunnels. (See the separate report volume, "Two-Lane Tunnel/Optional Fort Point Channel Concepts" for a detailed analysis of the other impacts of this concept.) For these reasons, the Two-Lane Concept does not satisfy basic transportation objectives for the design year and was not selected. Although the Preferred Alternative involves no permanent surface use of the park and will increase usable park area by 17 percent, temporary impacts remain which will affect approximately 5 percent of the park's area (tennis courts for three months and a narrow strip along the park's edge for two years). Minor design modifications to the Preferred Alternative were studied in an attempt to avoid even this temporary use of the Section 4(f) property. Complete avoidance of the temporary Section 4(f) impacts would require the underground ramp affecting the park's tennis courts (as shown in Figure 77) to be realigned to the southeast, which would have adverse impacts on the foundations of the 12-story wing of the Airport Hilton Hotel (located just east of the proposed Cross Road and south of the Airport egress road); the feasibility and cost of underpinning the hotel cannot be determined without more detailed engineering design studies . Complete avoidance of the Section 4(f) property would also require realignment of the inbound Airport Road to the southwest, both to avoid the temporary construction easement at the edge of the park and to provide necessary vertical clearances above the relocated underground ramp. Relocation of the inbound Airport Road would introduce a reverse curve. This geometry is less desirable than the alignment of the Preferred Alternative, particularly because of the heavy traffic volumes on this roadway segment, the weaving movements which would occur on this reverse curve, and the need for clear informational signing at this location for directing motorists to various airline terminals. Meeting minimum geometric design standards for the relocated inbound Airport Road and its associated ramps would require the taking of the Hertz Check-in Center and the Eastern Airlines Fuel Farm as well as leasable airport land totalling between 100,000 and 200,000 square feet and currently occupied by Hertz, the Avis Car Rental Service Center, National Car Rental, and Eastern Airlines. This less desirable alignment is not warranted to avoid a three-month period of disruption to the park's tennis courts and a two-year disruption of a 10-foot wide strip of parkland not affecting any recreation facility within the park. Measures to Minimize Impacts After construction of the tunnel and Airport service road, the tennis courts will be replaced and approximately three acres of land wil. be added to the eastern end of the stadium grounds. This land represent: a 17 percent increase in the size of the recreation area. This land will be inside the newly reconfigured Airport roadways. Improvements to the park's entrance system from Porter Street into the stadium area will also be provided. This easement, currently existing, has not been fully opera- tional in spite of its existence at the time of the various land transfers which created the park area in 1954. Standard measures to control construe tion period impacts, such as dust, construction noise, etc., will be implemented. A noise barrier approximately 15 feet high and 2,300 feet long will be constructed around the southeasterr end of the park, outside the park limits. This barrier will be a combination of earth berm and wall. The barrier, along with landscaping improvements, will buffer both visual impacts and noise impacts of the surrounding roadways. Conclusion Based upon the above considerations, a determination has been made that there is no feasible and prudent alternative to the use of land from the East Boston Memorial Stadium and that the proposed action includes all possible planning to minimize harm to the East Boston Memorial Stadium resulting from such use. 5.1.2 Proposed Bird Island Flats Park This proposed park which is to be built along the edge of Jeffries Cove was discussed in the DEIS/DEIR but will not be affected by the Preferred Alternative. The alignment of the Preferred Alternative passes to 412 st of this proposed park and es no use of Section 4(f) . ty ( see Figure 78 ) . 11: Charles River Basin Reservation fit ion nh The Metropolitan District ;sion (MDC) owns this 17,000-acre -ation along, and including, the ;s River, extending from the Old »s River Dam in Boston to :own. Chapter 524 of the Acts of jives the MDC authority over :ures on, across, over, or in the ;s River Basin. The MDC was i:ized by Chapter 550 of the Acts 52 to acquire land downstream in the old dam and the new dam •:Lbed in Section 5.1.4 below; ■?;r, acquisition of property •an the dams has not occurred. Layground extending from Leverett to Cambridge Street and the fallow Bridge along the Boston 'eaf the Charles River will be eted by the project, as will : s2tt Circle (see Figure 79). Facilities in the landscaped yround area include a pedestrian icycle path, two tennis courts, a firing pool, a wading pool, a ?all field, a tot lot and a xr/football field. Pedestrian :es to this part of the reservation torn the pedestrian overpasses at '«ett Circle, Blossom Street, and i:idge Street. The park is heavily used by ;:ents of the metropolitan area. ion and Amount of Land to be Used A strip of land up to 10 feet and approximately 50 feet long « than 500 square feet in area), the intersection of the Msgr. en Highway and Storrow Drive, •be permanently used for the ^figuration of Leverett Circle, -strip is part of an MDC Police lion parking lot. A temporary ruction easement which includes xisting roadway west of Leverett e and a 10-foot width along the roadway will be needed for a distance of approximately 500 feet, temporarily involving 5,000 square feet of parkland. This land will be used for approximately one year, while the Storrow Drive/Central Artery connections are constructed. The affected area includes the pedestrian overpass at Leverett Circle, a narrow strip of land at the edge of the MDC police parking lot and the edge of the tot lot. The pedestrian overpass will be reinforced during construction, but will remain serviceable in its present location. At the end of construction in this area, the land will be returned to its original condition. A new tunnel ramp from the Central Artery to Storrow Drive will be built through Leverett Circle, requiring temporary disruption of the Circle during construction. The interior of the existing traffic circle is presently a grass-covered area of approximately 32,000 souare feet, and contains a bridge pier and entrances to the MBTA Green Line Science Park Station, which passes over the Circle; the portion of this area which is disturbed during construction will be restored following construction. The relocation of Nashua Street to improve the geometry of the traffic circle will require the permanent use of an area within the Reservation approximately 30 feet wide and 100 feet long (3,000 square feet); this area is currently used by the Massachusetts Department of Public Works for surface parking, and is not presently available for park use. A 20-foot-wide construction easement will also be needed next to relocated Nashua Street in the parking lot. An additional ramp connection required to maintain access to Msqr. O'Brien Highway joins Nashua Street outside the park boundary and does not involve Section 4(f) land. Other Impacts During the construction period, there will be increased traffic 413 ! Jeffnes Cove Ay LOGAN INTERNATIONAL AIRPORl Preferred Alternative (4 Lane Tunnel) BOSTON HARBOR Figure 78 Location of Proposed Bird Island Flats Park in Relati- to the Preferred Alternative ^"^"^O^^^^OO Feel EIS/EIR for 1-90 Third Harbor Tunnel. 1-93 - Central Artery - • Park Boundary | Construction Easement j Tunnel or New Roadway ) MDC Land Used for MDPW Parking ) MDC Police Station Parking Figure 79 Charles River Basin — Impacts rj""~5C^^0C^^^^00 Feet EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93- Centra! Artery congestion on the portion of Storrow Drive abutting the playground, and consequent increases in air pollution in and around the playground near Leverett Circle. After construction, Leverett Circle will have decreased traffic, reducing the traffic-related air and noise pollution in and around the playground. Federal Agency Funding of Improvements Although Land and Water Conservation Fund (LWCF) funds were expended for tennis courts in the reservation, this part of the park will not be disrupted by the Preferred Alternative. Therefore, there is no conversion of Section 6(f) properties (see letters from EOEA and the National Park Service dated 5 April 1984 and 12 April 1984, respectively, in COMMENTS AND COORDINATION ) . Alternatives Which Would Avoid the Section 4(f) Property The existing connection of the Central Artery to Storrow Drive at Leverett Circle, within the Reservation, is a necessary link in the regional transportation system at present and will continue to be a necessary link following completion of the project. Two types of alternatives to the Preferred Alternative were examined: (a) those which make the connection with Storrow Drive at another location; and (b) those which do not involve construction to modify the existing connection. (a) The Preferred Alternative, while not avoiding the Section 4(f) property entirely, makes the connection with Storrow Drive in the location which involves the least impact to the Reservation. Storrow Drive lies entirely within the Reservation at its eastern edge and Leverett Circle at its northeastern corner, which is closest to the Central Artery; recreational and park facilities lie beyond these roadways. Consequently any alternative connection to Storrow Drive would lie further into the Reservation and would involve larger amounts of Section 4(1 land and impacts to more recreational facilities . (b) The No-Build Alternativp and other alternatives which include no Central Artery improvements were examined in the DEIS/DEIR and SDEIS/SDEIR; these alternatives involve no construction in the Reservation and would avoid Section 4(f) property but do not satisfy the basic transportation objective of improving traffic flow on the Central Artery and were rejected for this reason. Design modifications to the Preferred Alternative which would involve no change in the present Central Artery connection to Storrow Drive at Leverett Circle were examined. These modifications would retain the existing two-lane underpas at the Circle by connecting all northbound and southbound Central Artery traffic to the existing ramp approach to Storrow Drive and eliminate the Preferred Alternative's minor modifications in surface road geometry at the Circle. Careful examination of this alternative reveals that it may be possible to utilize the existing two-lane tunnel segment under the Leverett Circle. However, it is clea that even with this possible modification there will still remain some construction period use of Leverett Circle, particularly at those locations where new ramps to local street connections will have to tie into the existing geometrv of Leverett Circle. Use of a two-lane tunnel in this segment would have negative traffic capacity characteristics compared with the three-lane tunnel incorporated with the Preferred Alternative. Further design work mav show that the two-lane tunnel segment is the appropriate solution. Some Charles River Basin Reservation land will he used durinq the construction phase in either event, and is therefore covered under this Section 4(f) Evaluation. 416 3 to Minimize Impacts Standard measures to control iction period impacts, such as .: onstruction noise, etc., will •4 emented . The temporarily used ;=< strip of land along the edge upark and the grassy area inside •ft Circle will be restored to ■ riginal condition following - :i ction. L' .ion Based upon the above titrations, it is determined that > s no feasible and prudent . mtive to the use of land from 'lirles River Basin Reservation l.it the proposed action includes ..?<;sible planning to minimize harm I* Charles River Basin Reservation .1 .ng from such use . 4 Paul Revere Landing Park .. r ?tion .. i The MDC owns this 8.5-acre park :■ the New Charles River Dam at bid of the Charles River Basin in o. The park is part of the 0- acre Charles River Basin .'ration, but not contiguous to its TLand. Paul Revere Landing Park ins from Boston's North Station i :ross the dam and into the rlstown neighborhood. It consists » jandscaped parking and pedestrian I par North Station, the dam, and jr. area in Charlestown (see Figure A landscaped pedestrian way ing the parking area has two less, one which runs a short tare along the Boston edge of the 3 River, while the other aes across the locks of the new 1 the pumping station and ends Charlestown side of the park. Peking area accommodates cimately 100 cars. The existing 1- avel Bridge connecting the ml Artery with Interstate Route sses over part of the parking id the locKs at an elevation of Lmately 40 feet to 50 feet to bottom of structure, depending on location . Although the MDC has conceptual plans to acquire and develon more land along both banks of the Charles Piver to create a greenbelt strip, of which Paul Revere Landing Park would be part, this land has not yet been acquired by the MDC, and it is not subject to Section 4(f) regulations. However, actions to aid planned property acquisition for this greenbelt are included among the mitigating measures describe^ below. Pedestrian access to the park on the Charlestown side is bv a stairway from the existing North Washington Street Bridge; from under this bridge; and from under the existing High-Level Bridge. On the North Station side of the river, pedestrian access is from Beverly Street, under the existinq Central Artery viaduct. The pedestrian way is heavily used by area residents walking between Charlestown and downtown Boston . Location and Amount of Land to be Used The Charlestown side of the Paul Revere Landing Park is affected both by the Preferred Alternative of the present project and by the separate Central Artery North Area Project. The North Area Project involves reconstruction of the Interstate Route 93 viaduct and its approaches to Route 1. The preliminary design for the North Area Project involves surface street modifications that recruire the redesign of the Charlestown side of Paul Revere Landing Park into a larger, but reconfigured parcel. The preliminary design for the North Area Project will have to be modified as a result of the Central Artery Depression Proiect; desian coordination between the two proiects involves the transition from the new Charles River bridges constructed in the Central Artery Depression Proiect to the new Interstate Route 93 viaduct constructed in the North Area 417 CHARLESTOWN Pedestrian Walk NORTH STATION Relocated MDC Access Road and Path PROJECT CONSTRUCT Tunnel Elevated Roa Surface Road Ramps Figure 80 Paul Revere Landing Park - Impacts 0 Area to be Designed During North Area Project Final Design " ■ tmmmm Boundary Under Preliminary North Area Design 0^^^™^0o" 200 Feet EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93 - Central Artery ■ . This transition occurs in rrinity of the Paul Revere .1 Park. Construction activities (due to :< tral Artery depression) on the li town side of the Charles River I MDPW-owned land to the west of vk, part of which has previously ]. edged to become replacement ,ind following construction of S''th Area Project (see Figure ?he net effect of both projects h; part of the park will be to ese its area; the final iiration of the park will be rined following design diation between the projects and utation with the MDC. Impacts on Carlestown side of the park are gfletailed in the Section 4(f) ution for the Central Artery h\rea Project, which will be lzed during final design of the t.kzea Project, beginning in 1984. The new MDC Charles River Dam :s parking area on the Boston i f the Charles River lie south of Carlestown area just described. listing High-Level Bridge will be .«ed by two lower-level bridges uting the depressed Central to the Interstate Route 93 Kt and its approaches to the :i-Tobin Bridge in Charlestown. w connections will be r.ucted as open cut sections with Cioot walls, rising to ramps on JJed fill, and then to low-level ■s 8 to 30 feet above the land fi water. The land extending from (■ginning of the open cut sections tl point at which the clearance I the bridges reaches eight feet I to longer be available for k v ig or pedestrian use which occurs Ptsent. The area to be taken is rrimately 40,000 square feet. At iter's edge, there will be a f',»t vertical clearance between the i of the bridges and the •Irian path along the river's •I which presently terminates at astern property line of the MDC d see Figure 80 ) . Within the 40,000 square foot area just described, construction of the open cut sections and lower-level bridges also will result in the permanent taking and replacement in a new alignment of the existing park access road and the pedestrian v/alk leading to the dam. The Preferred Alternative also includes construction of subsurface ramps between the Central Artery and Storrow Drive which will require realignment of the existing Charles River bulkhead and the existing path along the river edge. Other Impacts A Leverett Circle ramp to Interstate Route 93 northbound will cross above the parking area (at a measured height of approximately 40 feet from bottom of structure); this ramp will cross over approximately 14,400 square feet of parkland. Cars and pedestrians will be able to move freely under this ramp. The two new bridges across the Charles River will be approximately 23 feet above mean high water at the dam's recreational boat locks and 30 feet above mean high water at the large commercial boat lock; this is lower than the existing High-Level Bridge, which is approximately 40 and 50 feet above mean high water at these respective locks. Navigation will not be affected by the new bridges. The northbound bridge will be 60 to 100 feet closer to the locks and pedestrian walkway over the pumping station than the existing High-Level Bridge. It will occupy approximately 1,600 square feet of air rights over the corner of the park on the Charlestown side of the river, and 29,400 square feet of air rights over the dam and property on the Boston side of the river, casting shadows on the dam. (The current High-Level Bridge casts shadows further upstream.) Additionally, each new bridge structure, as currently designed, will be 58 feet from the underside of bridge to the top of truss, contributing to their visual impact. The shadow effect, and the closer proximity of the pedestrian walkway to traffic on the northbound 419 bridge, will reduce the aesthetic quality of the walk and its public recreational value. Northbound traffic on the ramps to the new bridges across the Charles River will increase noise levels at the park. The construction of a ventilation structure on the site of the Charles River Building, adjacent to the park will also have potential visual impacts in the park. During the construction period, the MDC parking lot will be reduced to approximately one half its capacity for approximately one year. Alternatives Which Would Avoid the Section 4(f) Property Alternatives to the Preferred Alternative which would avoid or reduce impact on the Section 4(f) property are as follows: (a) alternatives which involve no improvements to the Central Artery, (b) modifications to the alignment of the Preferred Alternative, and (c) modifications to the profile of the Preferred Alternative. (a) Removal of the existing bottleneck caused by the High-Level Bridge is one of the major objectives of the project. The No-Build Alternative and alternatives which do not include depressing the Central Artery and replacing the High-Level Bridge were examined in the DEIS/DEIR and SDEIS/SDEIR; these alternatives did not satisfy the basic project objective of improving Central Artery traffic flow, and were rejected. ( b) The alignment for the proposed bridges closely parallels that of the existing bridge in a corridor that is tightly constrained by the need to connect the Central Artery to the south with the Interstate Route 93 viaduct and Route 1 to the north within a distance of less than 2,000 feet; the short distance between these points makes alternative bridge alignments to the west or east of this park impossible. The existence of the Orange Line tunnel makes it impossible to shift the bridges to the west. Shiftinq the bridges to the east would cause greater impacts to the Charles Piver Dam, which is part of the Section 4(f) property, as well as to the Stop and Shop Bakery Building and other buildings in the Causeway-North Washington Streets District, which is a separate Section 4(f) area described below. (c) The bridge profile is similarly constrained. If the Central Artery crossing of the Charles River were placed in a tunnel underneath the river, to completely avoid surface and air rights use of Section 4(f) parkland, connection to the Mystic-Tobin Bridge (Route 1) would be impossible, owing to the vertical differences between them. For the same reason, the depressed roadwav's profile would not meet that of the existing Interstate Route 93 until the Sullivan Square area in Somerville, approximately 5,000 feet north of the Preferred Alternative's northern limit. In addition the Central Artery crossing could not be placed in a tunnel beneath the river without major construction impacts to the river basin, its navigation channel, and the Charles River Dam. Higher profiles for the Charles River bridges were considered and rejected because they would not avoid the Section 4(f) property. Although higher bridge profiles would reduce some of the visual impacts to the Section 4(f) property, this modification would cause other impacts, including impacts to Section 4(f) historic districts, dispropor- tionate to their benefit to the Paul Revere Landing Park. Higher bridges would require relocation of Causeway Street and the removal of the existing Central Artery structure prior to the construction of the new bridges; maintaining continuous operation of the Central Artery during construction would therefore not be possible. Mitigating Measures A new MDC access road with a 420 w.k for pedestrians will be built hist of the existing access . A reconfigured bulkhead will ; built far enough into the r :o accommodate a new riverfront srian walk. The parking lot will onfigured to accommodate 100 e. the number in the existing Replacement facilties will be siped to mitigate visual impacts h project. Final design of the two bridges *sult in more attractive icares, reducing shadows on the sarian walk. Design solutions .dinclude the use of a cable >esion design to lighten the lg superstructure or improvements I underside of the bridge icure such as lighting. The Hility of bridge design •ratives will be studied during •rdesign phases. Work on the ildesign will involve consultation ten the MDPW, MDC, FHWA, the U.S. I orps of Engineers, and the U.S. l jnd Wildlife Service. The ventilation building «int to the park will receive ^ectural and landscape treatment niimize visual impacts on the park. A noise barrier constructed ncthe western edge of the park « road and pedestrian walk will vie a noise and visual buffer *«n this road and the adjacent t:l Artery northbound on-ramp. As discussed above in the c:ption of the Section 4(f) ?e/acated during the complicated and .ejthy underpinning operations; and :o.3truction of the depressed Central Arary and the MDC Access Road would it LI require taking the access and losing area for the building, lesssitating changes in the use of :h building, and possibly harming the jcnomic feasibility of maintaining :.h. building. The location of the : posed ventilation building would ila have to be revised because it is prsently proposed for the Charles iier Building site. The MBTA's Drnge Line Tunnel prohibits - structing the ventilation building of the Central Artery. As iricated in Section 4.7.5, violations olthe Commonwealth's policy level for NC emissions from the proposed vetilation buildings require acitional detailed air quality mceling and analysis to mitigate this ir'act. The final location of this d lding will be determined in or dance with these analyses, and •Jo in conformance with the Section Memorandum of Agreement . It st uld be noted, however, that a I ferent site would also lie either * hin this District, possibly □iring taking another building, or - the Charles River. igating Measures Further design activity should us on actions which allow the - irles River Building to remain. ' ign refinements as noted above s igest that modifications to the - r lius of curvature of the ramp from t ■ Central Artery northbound to I >rrow Drive westbound may obviate the need for the taking of the Charles River Building. The Stop and Shop Bakery Building loading facilities will be modified either to allow continued operations or to serve an alternative building use with lesser loading requirements, such as office or lighter industrial uses, which occupy the adjacent Hoffman Building. (Stop and Shop has announced that the bakery will be relocated, independent of this project. The building will be available for a number of other possible uses which require less extensive loading facilities.) Historic documentation of these two buildings will be done as approved by the Historic American Building Survey/Historic American Engineering Record (HABS/HAER) prior to alteration or dislocation (see the Section 106 Memorandum of Agreement in COMMENTS AND COORDINATION ) . Construction staging and traffic management measures will be used to reduce impacts during construction. Vibration impacts within the District will be mitigated through measures such as water jetting, pre-trenching , and pre-augering of piles and maximum use of slurry wall construction, as described in Section 4.8.2 Vibration Impacts , and through appropriate design of construction staging and contract specifications to avoid structural damage, as provided in the Section 106 Memorandum of Agreement . Design guidelines for the development of the ventilation structure will be developed by the MDPW, in consultation with the Massachusetts SHPO and BLC, as provided in the Section 106 Memorandum of Agreement . Conclusion Based upon the above considerations, it is determined that there is no feasible and prudent alternative to the use of land from the Causeway-North Washington Streets District and that the proposed action includes all possible planning to 425 minimize harm to the Causeway-North Washington Streets District resulting from such use. 5.2.3 Fort Point Channel District Description Fort Point Channel, a potentially eligible National Register District, is fully described in Section 3.11.1 of this report. It includes the Channel waterway and bulkhead, four significant bridges, and the subarea of brick warehouses in South Boston developed (1880-1930) by the Boston Wharf Company. Location and Amount of Land to be Used and Other Impacts Changes to the physical configuration of the Channel as a result of the Preferred Alternative will include introduction of a partially visible tunnel box, removal of part of the historic bulkhead, removal of the Old Colony Railroad Bridge and the temporary alteration of the Summer Street Bridge, and associated visual impacts due to the introduction of a surface roadway and ventilation building (see Figure 82). Approximately 10.3 acres (or 9.5 percent) of the Fort Point Channel area will be affected. The southern end of the Channel will be filled to a new bulkhead line located near the existing Dorchester Avenue Bridge (south of the Gillette property in South Boston). The historic bulkhead line on the Boston side of the Fort Point Channel will be altered by construction of a two-lane, northbound new Dorchester Avenue which will extend approximately 30 feet inside the Channel, from the Dorchester Avenue Bridge to a point approximately 400 feet south of the Summer Street Bridge. The road will be built on slurry walls with four-foot square knock-out panels to allow water to pass through, with a false bulkhead of granite and a 10-foot adjacent pedestrian walk. In the 400 feet south of Summer Street, a deck, slightly lower than new Dorchester Avenue, will be construct on top of the tunnel box. The deck plus Dorchester Avenue will project }0 feet into the Channel from the existing bulkhead line, then taper toward the existing bulkhead. The existing channel is approximately 50 feet wide in this area. At Summer Street, the new deck will project 4( feet from the existing bulkhead line at Congress Street it will project '.i feet into the Channel; at a point 10 feet north of Congress street the n«i bulkhead will meet the existing bulkhead line. A total of 88,500 square feet, or 9.5 percent of the Channel will be occupied by the Preferred Alternative. Of the structures which span the Channel, only the Old Colony Railroad Bridge will be removed by te Preferred Alternative. On the Bostc side of the Channel, the Summer Str€t Bridge will have one span dismantled and reconstructed; following construction, the bridge's profile cd symmetry will be the same as at present. Congress street Bridge wi] not be affected. The construction of a Seaport Access Tunnel through South Boston will displace two buildings (40 Wormwood Street and 293 A Street) in the Boston Wharf Company section of the Fort Point Channel District. These buildings do not contribute to the significance of the district, no does the architectural significance f the buildings qualify them for eligibility for the National Registe. Removal of these buildings will not affect the integrity of the District A 10-story ventilation buildig measuring approximately 80 feet by 9 feet will be constructed on the proposed filled portion of the ChannL south of Dorchester Avenue. During construction, vehicula and water access to the Fort Point Channel area will be disrupted as a result of successive closing or reduction in width of the bridges, t placement of steel sheeting in the Channel, and the presence of barges 426 i: ' .r" Boundary of Historic District Figure 82 Impacts on the Fort Point Channel Historic District 0 800 Feet EIS/EIR for 1-90 -Third Harbor Tunnel; 1-93 - Central Artery friend of the Channel filled "U)ny Railroad Bridge removed ■-story buildings in Boston Wharf Company section of fcct removed; buildings do not contribute to significance fl khead line at southern end of Channel located near * Dorchester Avenue Bridge W bulkhead line on Boston side of Channel altered by con- ti • of two-lane, northbound new Dorchester Avenue which ! W 30 feet inside existing bulkhead line from Dorchester H 'o a point 400 feet south of Summer Street Bridge, pedes- *"jk hung on new bulkhead proiects additional 10 feet •dnnel ■ •I mt 5. new Dorchester Avenue built on slurry walls with ■ut panels to allow water to pass through, and a false bulk- granite with a 10 fool adjacent pedestrian walk hung above e l irface 7. In 400 feet south of Summer Street, pedestrian deck constructed on top of tunnel box as it rises above low water line False bulkhead follows perimeter of deck, projecting maximum of 80 feet beyond existing bulkhead line One span of Summer Street Bndge on Boston side of Channel dismantled and reconstructed; final profile and symmetry same as existing 8. Between Summer and Congress Street Bridges, the deck and Dorchester Avenue taper toward existing bulkhead False bulk- head at perimeter of deck projects 40 feet from existing bulkhead line at Summer Street and 15 feet from existing bulkhead line at Congress Street Congress Street Bridge not altered 9. New bulkhead meets existing bulkhead line 100 feet north of Congress Street and construction equipment. The construction activities themselves may also affect the area and its use as a result of construction-related noise, dust, and vibration. There will be additional construction impacts in the Boston Wharf Company section of the Fort Point Channel District, including construction noise, dust, and vibration impacts on this area's industrial and commercial buildings, a number of which have been recently rehabilitated. Alternatives which would Avoid the Section 4(f) Property No alternative which provides a cross-harbor tunnel connection can entirely avoid the southern end of the Fort Point Channel District and the historic Old Colony Railroad Bridge because of the need to connect with the Massachusetts Turnpike, whose terminus lies immediately west of the Channel District. An alignment which crossed the Fort Point Channel area at a location south of the Gillette property was examined and rejected. This alternative is operationally infeasible, since it required the highway tunnel to pass under the MBTA Red Line tunnel and then rise to connect to the Massachusetts Turnpike. This alignment is not possible in the short distance allowed for this connection. Alternatives which did not include a cross-harbor tunnel connection were examined in the DEIS/DEIR and SDEIS/SDEIR; they did not provide the desired traffic improvements on the Central Artery and in the existing tunnels, and were rejected. A second major objective of the project, providing additional north-south expressway capacity in this segment of the Central Artery corridor, requires construction in the Channel District under all build alternatives studied in both the DEIS/DEIR and the SDEIS/SDEIR. Alternatives which did not include providing additional capacity in this segment of the Central Artery were examined in the DEIS/DEIR and SDEIS/SDEIR; they did not provide desired traffic improvements on tr Central Artery, and were rejected. Other alternatives which would avcd or reduce this use of land within he district were considered. Specifically, conceptual feasibiliy studies were made during the preparation of the SDEIS/SDEIR of a widening the Dewey Square Tunnel, b) construction of a new four-lane tunel beneath Atlantic Avenue, (c) construction of the Central Artery northbound tunnel under existing Dorchester Avenue on Postal Servic land, and (d) elimination from the project of additional Central Arte; capacity in the Dewey Square area. (a) Widening of Dewey Squar Tunnel was considered and rejected because widening this tunnel would cause extensive commercial relocates in the Leather District and Chinatw and residential relocations in Chinatown (a total of 27 relocation and/or underpinnings); these takin*; would occur within the potentially eligible Chinatown Historic Distric and the eligible Leather District, which experience no effect under tb Preferred Alternative. There woulc also be Section 4(f) impacts to th< Chinese Gate park and the adjacent basketball court. (b) A tunnel under Atlantic Avenue was also considered and rejected because it poses major engineering difficulties. It woulc involve major disruption to the MB1 Red Line mezzanine at South Statior and the proposed intermodal transit connection; greater utility relocations, including the need to relocate the Boston Water and Sewer Commission 96-inch combined sewer fsr Atlantic Avenue into the Channel; a3 alignment problems at the Turnpike/Expressway/local street interchange and the South Station garage ramps. In addition, because'f downtown Boston access needs, new Dorchester Avenue would also be required in this avoidance alternate in order to avoid serious traffic congestion on local streets as in t' 428 rred Alternative; it would ifore involve land within the Fort Channel District. See the ate volume of this report -Lane Tunnel/Optional Fort Point " iel Concepts" for a detailed 'sis of this concept. iir (c) A tunnel under existing lester Avenue, which is owned by .' >ostal Service and closed to other :ic south of Summer Street, was considered and rejected for the )wing reasons. Construction )d disruption to operations at the i Postal Annex would be :antial; this facility processes J.S. Mail for the Boston region .requires access to its loading :s directly from Dorchester je. The Postal Service also 'jires the provision of northbound ss to the Central Artery and race Artery from the South Cove 'e; in order to provide access for Postal Annex trucks and general afic, a new Dorchester Avenue would 1 to be built on pile supports and cted in the Channel. With this nrnative, Postal Service operations : ud be disrupted by construction of ; :nnel under Dorchester Avenue, and eproject would still involve the toduction of a roadway within the anel; therefore, disruptions would ubstantially greater than from the terred Alternative, and the .nment would still involve impacts : i his section of the Channel rict. An analysis of the concept tunnel under Dorchester Avenue is -wained in the separate volume of m report, "Two-Lane Tunnel/Optional Point Channel Concepts". (d) The concept of not nding north-south capacity in this ent of the Central Artery corridor ^studied; i.e., leaving the titing Dewey Square tunnel with six «rs and omitting the northbound *js from Fort Point Channel. This nept would fail to satisfy the asportation objective of improving •Aral Artery traffic flow and Wcing congestion. Demand at Dewey Mte would exceed capacity by 25 -'ent during peak hours and by 10 to 15 percent in the hours immediately before and after peak. Significant queuing would result and traffic flows would be disrupted throughout the Central Artery and on local streets in Downtown Boston and South Boston due to substantial traffic diversion from the Central Artery. Also, this concept does not avoid construction along the Fort Point Channel, since a pile-supported new Dorchester Avenue would still be above the Channel to provide access from the south to the Central Business District. As noted above, all build alternatives studied involved the use of potential Section 4(f) property in the Fort Point Channel District. The Preferred Alternative has substantially less impact on the Fort Point Channel area than any of the other build alternatives examined, except for Alternative 5A. Alternative 5A, which did not include a new Dorchester Avenue, failed to satisfy basic transportation objectives for improving Central Artery traffic flow and access to downtown Boston; for these reasons it was rejected. In comparison with the remaining alternatives, the Preferred Alternative reduces the width of the new Dorchester Avenue from four lanes to two lanes. The new Dorchester Avenue would extend only 30 feet into the Channel (plus the 10 foot pedestrian deck); in other alternatives it extended into the Channel as far as 110 feet. New Dorchester Avenue extends north only to Summer Street with the Preferred Alternative; in other alternatives it extended as far as Northern Avenue. The exposed area of the tunnel structure is also reduced with the Preferred Alternative, extending to a point 400 feet south of the Summer Street Bridge rather than to the Dorchester Avenue Bridge as with other alternatives. Additionally, the Preferred Alternative does not require ramps crossing the Channel at Summer Street which were required under several of the other build alterna- tives. For these reasons the Preferred Alternative represents the best alignment while minimizinq 429 impacts in the Fort Point Channel area. Mitigating Measures Long-term mitigating measures include configuration of the ventilation building to reduce visual impact, use of granite facing to make the new bulkhead sections visually consistent with the existing bulkhead, reconstruction of existing bridges, and the creation of landscaping improvements and a pedestrian walkway along the Boston side of the Channel. During preliminary and final design, there will be continuing exploration of the possible use of up to 10 feet of Postal Service land now used for parking between the existing bulkhead south of Summer Street and the section • of existing Dorchester Avenue used for Postal Service operations; the use of this land would further reduce the width of new Dorchester Avenue within the Channel. Conclusion Based upon the above considerations, it is determined that there is no feasible and prudent alternative to the use of land from the Fort Point Channel District and that the proposed action includes all possible planning to minimize harm to the Fort Point Channel District resulting from such use. 5.3 ARCHAEOLOGICAL SITES A Phase I, Step 1 archaeo- logical survey was performed during the preparation of the SDEIS/DEIR for the Preferred Alternative. The Phase I (Step 1) survey results indicated a high probability of locating archaeological resources in the following areas: South Bay/South Cove (prehistoric and historic), Fort Point Channel (historic), Fort Hill (historic), Central Artery corridor from Dewey Square to Causeway Street (prehistoric and historic), Logan Airport (historic), and South Boston corridor (prehistoric and historic). As stated in the Section 106 Memorandum of Agreement , FHWA will ensure that a Phase I, Step 2/Phas investigation is initiated 90 days following ratification of the Sector 106 Memorandum of Agreement and release of funds for additional planning and design studies. This investigation will include, at a minimum, the following elements: o preparation of an appropria> research design, outlining and justifying important research prob:ems that may be addressed by investiga* of archaeological properties in th< project area; and o a proposed scope of work an< work plan for field investigation integrating the results of the following work: - acquisition of additional historical documentary information on past disturbances that may preclie areas from field testing, ar - acquisition of additional historical documentary information concerning potential significance of historic and prehistoric archaeological remains. This program for investigation, including the research design, scop of work, and work plan will be reviewed by MDPW and the SHPO priorto implementation. Field testing and evaluation will be implemented based on the sc of work and work plan and in the context of the research design. A written report describing ie results of the documentary research field testing and applied National Register criteria and containing recommendations on the significance >f identified resources, will be provic>d to MDPW, the Massachusetts SHPO, an< BLC. These recommendations will be subject to review by MDPW and the Massachusetts SHPO in consultation with BLC. Based on the results of the 430 lentary research and field testing a plan will be developed in Sect iltation with the SHPO and BLC includes provisions for avoidance reservation in place of IMsjRf icant archaeological remains, > feasible and practical, through jn and engineering development or rr.ruction specifications as set ::i *r|i above. If avoidance or e;rvation in place is not feasible practical, and the SHPO concurs in determination, the plan will voide provisions for Phase III data c/ery or other appropriate etment. The plan will be submitted 3i ne Massachusetts SHPO and the sory Council for review and coval in consultation with BLC it to implementation. At such time as the nature, tnt, and locations of necessary iity line relocations are known, -- €>t if ication , evaluation, and -etment plan preparation and ementation will be done in the manner as set forth above for any ificant archaeological properties h may be affected by these vities. All historic and archaeological l'stigations called for under these ::ulations will be conducted by jcoBViduals who meet, and in a manner distent with, the Advisory ::*cil's standards and guidelines. lusion A determination has been made i i his time that there are no ible and prudent locations or i'rnatives for the action to avoid -•to use of Section 4(f) land. This •- rmination has considered all : - ible planning to minimize harm to ""extent that the level of detail '•lable at the publication of this : IVEIR allows. Upon completion of 0" Phase I, step 2/Phase II f'aeological Survey, and in : c rdance with the Section 106 : -*j randum of Agreement , appropriate •< ures will be developed to avoid, t' erve in place or recover data from i ificant archaeological sites. 5.4 CONSULTATION Consultation regarding the above parkland and historic sites, as required by federal Section 4(f) regulations, was initiated during the DEIS/DEIR through meetings and discussions with Federal, State and local agencies. This consultation process has continued during the preparation of this FEIS/FEIR as follows : o Section 106 Memorandum of Agreement : developed through consultation with, and signed by, Massachusetts State Historic Preservation Officer, Boston Landmarks Commission, Massachusetts Department of Public Works, and FHWA; sent to the Advisory Council on Historic Preservation on 21 September 1983; revised by the Advisory Council and signed by FHWA on 24 February 1984, by the Advisory Council on 11 April 1984 and by MDPW on 28 February 1984. Design guidelines for joint development, preliminary and final design and construction specifications affecting historic areas for the project and joint development, and treatment of archaeological properties are subject to review by the Massachusetts State Historic Preservation Officer in consultation with Boston Landmarks Commission (see COMMENTS AND COORDINATION ), o City of Boston Parks and Recreation Department and Department of Environment: 9 August 1983 letter states concurrence with impact analysis and satisfaction with mitigating measures (see COMMENTS AND COORDINATION ) . o Boston Landmarks Commission: meetings held 2 June 1983 regarding eligibility of properties, and on 27 July, 26 August, and 1 September 1983 regarding impacts and 431 mitigating measures. Section 106 Memorandum of Agreement signed 21 September 1983; Agreement revised and approved by the Advisory Council and signed by BLC 28 February 1984. Massachusetts Historical Commission (State Historic Preservation Officer): meeting held on 2 June 1983 regarding eligibility of properties; exchange of correspondence between FHWA and SHPO initiated on 21 June 1983; consultation on impacts and mitigating measures on 27 July, 26 August, and 1 September 1983; Section 106 Memorandum of Agreement signed 21 September 1983 ; Agreement revised and approved by the Advisory Council and signed by MHC 27 February 1984. Massachusetts Metropolitan District Commission: meetings held on 25 May 1983 and 26 July 1983; comments received from MDC Commissioner on 15 August 1983 indicating general concurrence and requesting mitigating measures which were subsequently incorporated in this FEIS/FEIR (see COMMENTS AND COORDINATION ) . U.S. Department of Housing and Urban Development: corre- spondence to HUD initiated on 12 May 1983; HUD response 19* May 1983 and 1 August 1983 indicating concurrence with impact assessment and appro- priate mitigating measures (see COMMENTS AND COORDINATION ) . U.S. Department of the Inter- ior, National Park Service: technical assistance review and comments requested, 12 May 1983 ; UPARR approval received 7 November 1983; Section 6(f) approval received 5 April 1984 (see COMMENTS AND COORDINATION ) U.S. Department of the Inter- ior: comments received 7 April 1983, 29 August 1983 and 4 October 1983 (see COMMENT S 2D COORDINATION ) . o Massachusetts Executive Offi|*r; of Environmental Affairs, stte Liaison Officer: Section 6()t approval received 12 April lffl (see COMMENTS AND COORDINA - TION ) . The results of this consulta tion process are reflected in the discussions in this Chapter 5.0 of FEIS/FEIR. 432 6.0 LEGAL AND FINANCIAL CONSIDERATIONS The proposed financing of i(truction and operating costs for '-^Preferred Alternative is briefly rented below. THIRD HARBOR TUNNEL - INTERSTATE ROUTE 90 The Commonwealth of Massachu- i s, through its designated agen- f, proposes to finance, construct coperate the Third Harbor Tunnel lion of the Preferred Alternative toll facility. As an extension he easterly terminus of Interstate te 90 (the Massachusetts Turnpike), (Third Harbor Tunnel will be iible for federal aid under the cral-Aid Interstate Highway Program i up to 90 percent of the construc- i-related costs. Federal partici- t on in the construction of the id Harbor Tunnel as a toll facility onditioned upon compliance with (following provisions of Title 23 he United States Code. The tunnel and approaches to c tunnel must be publicly-owned and « ated . The Commonwealth must enter M> an agreement with the United ^.es Secretary of Transportation, t iding that (a) all tunnel tolls, 1: the actual cost of operation and B.tenance of the tunnel, shall be g. ied to the payment of the local ■ e of the cost of construction of M tunnel, and (b) no tunnel tolls ■.1 be charged after the local share Hi have been repaid, and (c) the fuel shall be operated as a free *iel after the date of such repay- ■ . The 10 percent local share of Third Harbor Tunnel construction s, along with operating costs, may inanced by a variety of mecha- ts. Among the possibilities are: s from the tunnels or other State lities, State general obligation s, general State revenues, or some ination thereof. The Common- wealth's specific toll policy with respect to the Third Harbor Tunnel will be developed at a later, appro- priate time, and may also change from time to time. As a matter of policy, the Commonwealth may charge different tolls for the new Third Harbor Tunnel than for the existing Callahan/Sumner Tunnels and Mystic-Tobin Bridge. For purposes of illustration only, an analysis of estimated Third Harbor Tunnel tolls has been prepared assuming that the 10 percent local share and operating costs would be covered by tolls, and assuming equal tolls for the Third Tunnel and the Callahan/summer Tunnels. 3ased on these assumptions, and using present day costs, a toll of approximately $0.45 per vehicle in each direction would be required with the implementa- tion of one-way tolls; $0.90 per vehicle would be collected inbound onl y. The specific assumptions used in estimating this illustrative toll figure were as follows. It was assumed that the Common- wealth's 10 percent share of the construction costs (including funds as may be necessary to redeem the then outstanding existing tunnel revenue bonds) would be financed through the sale of revenue bonds. The bond issue evaluated was based on 40 -year revenue bonds at an interest rate of 7 percent. It included the Commonwealth's 10 percent share of construction costs, capital- ized interest payments between the date of the bond issue and the time that revenues are available fran the operation of the Third Tunnel, and financing and legal costs incurred in the preparation and sale of the bond issue . The toll schedule required to finance this illustrative bond issue is dependent on the 1990 traffic forecasts (opening year) for the 433 existing tunnels and the Third Harbor Tunnel; estimated costs of operation and maintenance of the three tunnels; provision for a replacement reserve fund to cover the costs of insurance, equipment and major non-recurring repairs; and debt service costs. In addition, investors in revenue bonds require, as a safety cushion, coverage above the level annual debt service requirements to retire the bonds by maturity . 6.2 CENTRAL ARTERY - INTERSTATE ROUTE 93 The depressed Central Artery portion of the Preferred Alternative will be eligible for federal aid funding for up to 90 percent of the construction-related costs. The Central Artery will remain a toll-free facility. The Commonwealth's 10 percent share of the construction cost is anticipated to be financed through bonds issued by the Commonwealth. Financing of operating costs is expected to be undertaken by the Commonwealth in a manner similar to all other state facilities. AGENCIES, ORGANIZATIONS, AND PERSONS TO WHOM THE FEIS/FEIR WERE SENT The following list of Federal, [1 , regional and local agencies and i* parties were sent copies of this FEIR. Those who commented >;antively on the DEIS/DEIR and ::/SDEIR have been identified by u of an asterisk(*). lal: I Environmental Protection Agency : Department of Transportation - ::cretarial Representative Department of Health and Human •rvices, Public Health Service sural Aviation Administration .! Department of the Interior r.onal Marine Fisheries Services Army Corps of Engineers Coast Guard Department of Housing and *ban Development Ijtn Mass Transportation iministration e;ral Emergency Management Agency e;ral Railroad Administration iLsory Council on Historic reservation e;ral Services Administration .. Postal Service :ted Officials: mator Edward M. Kennedy mator Paul E. Tsongas ipresentative Thomas P. O'Neill, Jr, ipresentative Edward J. Markey ipresentative John J. Moakley ipresentative Brian 0' Donnelly ipresentative Nicholas Mavroules State : (Cont.) *Department of Environmental Quality Engineering/Division of Air Quality Control Department of Environmental Quality Engineering/Division of Water Pollution Control Massachusetts Aeronautics Commission *Metropolitan Area Planning Council *Metropolitan District Commission Massachusetts Bay Transportation Authority Massachusetts Turnpike Authority *Massachusett s Port Authority Central Transportation Planning Staff ♦Massachusetts Historical Commission Massachusetts Division of Marine Fisheries Massachusetts Department of Environmental Management Special Commission for the Development of Boston Harbor Senator William J. Bulger Senator Michael LoPresti, Jr. Senator William Owens Senator Joseph Walsh Senator Royal Boiling, Sr. Speaker Thomas McGee Representative Emanuel "Gus" Serra ♦Representative Michael F. Flaherty Representative Salvatore DiMasi Representative Angelo Marotta Representative Byron Rushing Suffolk County Sheriff Dennis Kearney Local : Lee of the Governor :utive Office of Administration and Finance rutive Office of Environmental ffairs xrutive Office of Communities id Development *:utive Office of Economic ■ fairs *:utive Office of Public Safety .ce of Coastal Zone Management ■eirtment of Environmental Quality igineering/Northeast Region Office of the Mayor - Boston Office of the Mayor - Cambridge Office of the Mayor - Chelsea Office of the Mayor - Revere Office of the Mayor - Some rvi lie Office of the Mayor - Lynn ♦Boston Conservation Commission ♦Boston Redevelopment Authority ♦Boston Traffic and Parking Department ♦Boston Water and Sewer Commission Boston Public Works Department Boston Parks and Recreation Department ♦Boston Economic Development and Industrial Commission Boston Department of the Environment 435 Local: ( Cont . ) Private: (Cont.) ♦Boston Landmarks Commission Boston Police Department Boston Fire Department Boston City Clerk Boston City Council Boston Neighborhood Development Agency Private : *Greater Boston Chamber of Commerce East Boston Chamber of Commerce Greater Boston Community Development Corporation South Boston Citizens Association South Boston/Neighborhood House South Boston Information Center South Boston Residents Group South Boston Community Development Corporation South End Committee on Transportation Ellis Neighborhood Association East Boston Fair Share East Boston Jets Club East Boston Veterans Council Jeffries Point Harborside Association Chinatown Housing and Land Development Task Force Chinese Merchants Association Chinese Economic Development Council Haymarket Pushcart Association North End Health Center Sons of Italy Boston Educational Marine Exchange Boston Harbor Association The Harbor Associates Harbor Design ♦Boston Preservation Alliance • Fort Point Arts Community *Boston Society of Architects Boston Aviation Council ♦Coalition Against The Third Harbor Tunnel *League of Women Voters League of American Wheelmen Association for Public Transportation, Inc. *Sierra Club Massachusetts Audubon Society ♦American Lung Association ♦Eastern Airlines ♦The Gillette Co. Bay State Spray & Provincetown Steamship Co. ♦Boston Wharf Company Museum Wharf Company New Boston Garden Corporation 150 (Causeway) Trust Cabot, Cabot & Forbes Paul Revere House North End Neighborhood Council Stone and Webster Engineering ♦Macomber Development Co. Bo scorn Standex International Corporation ♦Boston Tea Party Museum ♦The Stop & Shop Company Boston Edison Company ♦Conservation Law Foundation Conrail ♦Marullo and Barnes ♦Mr. Justin Gray 436 COMMENTS AND COORDINATION : Committees/Participation An important part of the :ination efforts for this study was inity participation. Public input during the EIS/EIR I was obtained by the use of two ittees : The Interagency Committee's rsis was on the technical aspects te study, and included the iwing agencies: Federal - Environmental t ction Agency, Federal Aviation jistration, Federal Highway istration, Fish and Wildlife \ce, National Marine Fisheries tee, Army Corps of Engineers, Coast t . State - Central Transportation ring Staff, Office of Coastal Zone l ement , Department of Environ- tl Quality Engineering/Northeast :n, Department of Environmental !ty Engineering/Division of Air '.ty Control, Executive Office of mities and Development, Executive :e of Economic Affairs, Executive :e of Environmental Affairs, utive Office of Transportation and i ruction, Massachusetts Aero- tcs Commission, Massachusetts : tment of Public Works, Metro- : an Area Planning Council, spolitan District Commission, schusetts Bay Transportation rrity, Massachusetts Port Irity, Massachusetts Turnpike trity . City of Boston - Boston celopment Authority, Boston Traffic • 'arking Department, Boston Water ; ewer Commission, Department of ' c Works. (The Interagency I ttee also included two community i sentatives (one from East Boston ne from South Boston) that are < members of the Working Committee.) The Interagency Committee met 15 ■ through preparation of the ' FEIR. At each meeting the agencies were updated as to the study progress, were briefed on the alternatives, and were presented information on existing conditions in the project area. Potential impacts of the project were also presented as they were identified and quantified in the areas of urban design/ joint development, traffic projections, air quality, water quality, noise and vibration, relocation of businesses, construction staging costs, historical/archaeo- logical resources, neighborhood facilities, land use, Section 4(f) lands, and economic impacts. The Working Committee provided close contact with community and neighborhood representatives for input on technical matters about the study. This Committee was formed from interested community groups, private individuals and business interests in the project area. The Committee was open to all residents, community organizations, individuals, business interests, and agency representatives. The Working Committee met 13 times through preparation of the FEIS/FEIR. Meetings were announced by mailing notices to over 800 individuals. Ongoing Agency Coordination Additional meetings for continual coordination were held with many of the previously listed agencies. The following agencies not on the Interagency Committee were contacted for data on their facilities and/or their concerns relating to the project: Boston Educational Marine Exchange, Boston Harbor Associates, Boston Landmarks Commission, City of Boston Department of the Environment, Boston Conservation Commission, Boston' Fire Department, Boston Neighborhood Development Agency, Boston Parks and Recreation Department, Boston Police Department, Federal Census Bureau, General Services Administration, Greater Boston Chamber of Commerce, Massachusetts Historical Commission, U.S. Post Office, East Boston Land Use Advisory Council, and the East Boston Chamber of Commerce. Ongoing Private Group Coordination Also involved in coordination efforts for the project were the following private companies: Amtrak; Conrail; Boston & Maine Railroad; Eastern Airlines; Boston Edison Co.; Jung/Brannen Associates; The Gillette Co.; New England Aquarium; Camp Dresser & McKee, Inc.; America East Corporation; Bethlehem Steel Co. (East Boston); New England Medical Center; New England Telephone Co.; Boston Gas Co.; Cabot, Cabot & Forbes; Boston Wharf Co.; Macomber Development Associates; and Stone and Webster. Other Community Participation Besides the Working Committee meetings mentioned previously, community participation activities included seven public meetings, three open houses, and a two-day public hearing on the project. All public meetings were advertised in the local newpapers . A newletter was also developed which was published three times during the course of the study. Three thousand copies of each addition of Update were published. Each edition of Update had a broad mailing list of approximately 800 individuals and organizations, besides being distributed at public libraries, meetings and by other means. Five thousand copies of a fourth newsletter, IN BRIEF , were printed and were widely distributed through the mail, to libraries, and at public meetings. This last newletter provided a concise summary of the DEIS/DEIR and SDEIS/SDEIR findings and process. During the DEIS/DEIR phase, two project field offices were maintained in downtown Boston and East Boston. During the SDEIS/SDEIR phase, two project field offices were also maintained, one in downtown Boston and another in South Boston. At the field offices, plans of the alternatives were on display, along with other project material. Each office was staffed two to three afternoons per week. The participation staff mai !i>perties listed below, HABS/ HAER (National Park Service, Mid Atlantic Clonal Office, 143 South Third Street, Philadelphia, PA., 19106; Mr. John rk:dak (215) 597-1577) will be contacted to determine the level of d«:umentation required to provide a permanent record of the properties. ?l:st, a list of the properties, with a summary of their National Register sd;nificance (the description given in the case report), will be forwarded ccHABS/HAER. All documentation must be accepted by HABS/HAER and the M j sachusetts State Historic Preservation Officer (SHPO) prior to alteration 3i demolition of the properties. lis stipulation refers to the following list of properties: •tt Point Channel omer Street Bridge '] Colony Railroad Bridge tries River Building t p and Shop Building 447 Page -2- Memorandum of Agreement Third Harbor Tunnel/Central Artery Boston, Massachusetts 2. FORT POINT CHANNEL DESIGN DEVELOPMENT GUIDELINES FHWA will ensure that design development in this area will include the following: a. Design and location of the ventilation building in a manner that is sympathetic to, and respectful of, the characteristics of surrounding historic properties with regard to massing, color, building material, detail, -and scale. b. Granite facing will be used in the new section of the Fort Point ChanneZ . bulkhead to make it visually consistent with the existing bulkhead in color, texture, configuration, and design. c. Reconstruction of the one span of the Summer Street Bridge removed during project construction will be in a manner that reuses as much original fabric as possible and results in the same configuration as the original. d. Landscaping improvements along the Boston side of the Channel will be designed to enhance those characteristics of the historic district that make It eligible for listing in the National Register of Historic Places. e. During preliminary project design, there will be continuing study and negotiation with the U.S. Postal Service concerning the use of land between the existing Dorchester Avenue and the Channel bulkhead for project right-of-way. The final design of the new Dorchester Avenue will b such as to minimize impacts to the historic characteristics of Fort Point Channel and adjacent historic resources, including impacts related to pedestrian and vehicular traffic flow. f. Preliminary and final design, and construction specifications, will be submitted to the Massachusetts SHPO, prior to start of construction for review and approval in consultation with the Boston Landmarks Commission (BLC) regarding consistency with the design development guidelines outlined above . 3. STOP AND SHOP BAKERY BUILDING LOADING DOCK RELOCATION . FHWA will ensure that the loading facilities of the Stop and Shop Bakery Building, a building included in the Causeway/North Washington Streets District, a property eligible for listing in the National Register, will be modified either to continue present operations or to serve an alternative building use with lesser loading requirements, in order to 448 i'age -3- lemorandum of Agreement Third Harbor Tunnel/ Central Artery Joston, Massachusetts insure the continued economic viability of the building. Preliminary and :inal design and construction specifications for the building modification shall be reviewed and approved by the SHPO in consultation with the BLC. 4. REVIEW OF DESIGN AND CONSTRUCTION SPECIFICATIONS FHWA will ensure that potential adverse construction effects on all historic properties described in its Preliminary Case Report are minimized jr avoided through appropriate preliminary and final design and construction specifications, reviewed-andrapp roved =>by the SHPO in consultation with the 3LC, and through the appointment to the project design team by the MDPW a 'roject Conservator. The Project Conservator's job description and |ualif ications shall be approved and his/her ongoing responsibilities eviewed by the SHPO in consultation with the BLC. The Conservator's esponsibilities shall involve overseeing the development of measures for Itigating the adverse effects of construction on standing historic roperties. These mitigation measures shall be included as part of the onstruction specifications. 5. JOINT DEVELOPMENT DESIGN GUIDELINES a. FHWA will ensure that potential adverse effects (as efined in Section 800.3(b) of the Council's Regulations, "Protection of istoric and Cultural Properties" (36 CFR Part 800)) from the use of ir-rights and other joint development ventures, and the development of entilation structures, and surface street improvements on historic roperties described in FHWA' s Preliminary Case Report will be minimized or voided through appropriate design. Design guidelines will be developed by he Massachusetts Department of Public Works, in consultation with the assachusetts SHPO, BLC, and other interested groups, for joint development ffecting such properties. b. Preliminary and final design and construction pecif ications for joint development ventures, as they affect historic roperties described in FHWA's Preliminary Case Report, will be reviewed and >proved by the Massachusetts SHPO in consultation with BLC for consistency Lth the above design guidelines. The MDPW shall ensure, as a condition to sposal of joint development and air rights parcels, compliance with this :ipulation prior to and following parcel disposition. 449 Memorandum of Agreement Third Harbor Tunnel/ Central Artery Boston, Massachusetts 6. ARCHAEOLOGY A. Identification and Evaluation 1. Based on the preliminary Phase I (Step 1) survey work already conducted, FHWA shall ensure that a Phase I, Step 2/Phase II archaeological investigation of the project's proposed area of environmental impact be conducted in consultation with the MDPW, SHPO and BLC. This investigation will be initiated 90 days following ratification of this Agreement and release of funds for additional planning and design studies. This investigation shall include, at a minimum, the following elements : (a) Preparation of an appropriate research design, outlining and justifying important research problems that may be addressed by investigation of archaeological resources in the project area, and a proposed scope of work and work plan for field investigation integrating the results of the following : (1) Acquisition of additional historical and engineering/utility documentaton on past disturbances that may preclude areas from field testing; (2) Acquisition of additional historical documentary information concerning potential significance of historic and prehistoric archaeological sites and their eligibility for nomination to the National Register of Historic Places. (b) This program for investigation including the research design, scope of work and work plan will be reviewed by MDPW and the SHPO prior to implementation. 2. Implementation of field testing and evaluation based on the scope of work and work plan and in the context of the research design. 450 age -5- emorandum of Agreement hird Harbor Tunnel/Central Artery oston, Massachusetts 3. A written report describing the results of the documentary research, field testing and applied National Register criteria 36 CFR Part 63 and containing recommendations on the significance of identified resources, will be provided to MDPW, the Massachusetts SHPO, and BLC. These recommendations will be subject to review by MDPW and the Massachusetts SHPO in consultation with BLC. B. Treatment and Additional Studies Based on the results of the documentary research and field testing work, a plan will be developed in consultation with MDPW, the Massachusetts SHPO and BLC that includes provisions for avoidance or preservation in place of significant archeological remains, where feasible and practical, through design and engineering development or construction specifications as set forth in Stipulation 4 above. If avoidance or preservation in place is not. feasible and practical, and the Massachusetts SHPO concurs in this determination, the plan will include provisions for Phase III data recovery or other appropriate treatment consistent with the Council's Handbook, Treatment of Archaeological Properties (Attachment 1) . The plan will be submitted to the Massachusetts SHPO and the Council for review and approval in consultation with BLC prior to implementation. C. Performance Standards 1. All historic and archaeological investigations called for under Stipulation 5. a. and b. above will be conducted by qualified individuals who meet, at a minimum, the appropriate qualifications in "Professional . Qualifications" contained in the Secretary of the Interior' s Standards and Guidelines for Archeology and Historic Preservation (Attachment 2) and in a manner consistent with those Standards and Guidelines and the Council's Handbook (Attachment 1). 2. Curatlon arrangements and materials conservation will be agreed upon by the MDPW and Massachusetts SHPO in consultation with BLC. Copies of final technical reports and papers resulting from the investigations will be provided to the Massachusetts SHPO, the National Park 451 Page -6- Memorandum of Agreement Third Harbor Tunnel/ Central Artery Boston, Massachusetts Service, BLC, interested local academic institutions, and the Council. A camera ready copy of a popular report suitable for local public dissemination describing the results of any significant archaeological data recovery will be prepared for the project. 7. The Massachuse tts SHPQ shall r eview within 30 days of -receipt J any documents submitted by FHWA in accordance with any of the stipulations written .above. Failure by the Massachusetts SHPO to respond within 30 days of receipt of anyrcomplete documents from FHWA shall be deemed to constitute full approval of such documents under the stipulations written above. If the Mar -,achusetts SHPO and FHWA fail to agree, then the agency shall submit documentation to the Council and request consultation under 36 CFR 800.6. Execution of this Memorandum of Agreement evidences that FHWA has afforded the Council a reasonable opportunity to comment on the Third Harbor Tunnel, Interstate 90/Central Artery, Interstate 93 and its effects on historic properties and the FHWA has taken into account the effects of its undertaking on historic properties. (date) ederal Highway Administration (date) z/wfc Massachusetts State Historic Preservation Officer Executive Director 0 Boston Landmarks Commission (date) _'■ (date) Chief^ngineer U ;sachusetts Department of Public Works Executive Director Advisory Council on Historic Preservation infin ity Chairman Advisory Council on Historic Preservation 452 EXHIBIT D 453 PRELIMINARY CASE REPORT ON HISTORIC PROPERTIES Third Harbor Tunnel, Interstate 90 Central Artery, Interstate 93 Boston Massachusetts 19 September 1983 1. From Title 23, United States Code, "Highways", the Federal Highway Administration (FHWA) is authorized to expend funds appropriated from the Highway Trust Fund for Construction of Federal-Aid Highways. Applicable implementing regulations, procedures, and guidelines are contained in the Federal-Aid Highway Program Manual Volumes 1 through 7. 2. No decisions made yet on location approval or extent of Federal Aid 3. Both DEIS and Supplemental DEIS have been circulated. The target date for completion of the FEIS is 30 September 1983. 4. Summary description of project from FEIS is attached. A. Properties which will be adversely affected through permanent destruction or alteration are as follows (numbers correspond to attached project area map): 1. Fort Point Channel District (1880 - 1930' s) - potentially eligible National Register District, based on SHPO/FHWA consultation, with input from the Boston Landmarks Commission. The Fort Point Channel area, including the Channel itself, the bridges over it, and the wharves, warehouses and transportation facilities on either side of it, comprise a physical record of the complex transportation developments which necessarily accompanied the rapid industrial expansion of Boston in the late nineteenth and early twentieth centuries, and is a symbolic vestige of the original Shawmut Peninsula. It is potentially eligible for the National Register. The district includes the following contributing elements. a. The Fort Point Channel (ca. 1890* s) . Historic waterway bordered by granite bulkheads, created as part of late nineteenth century industrial/ transportation development of South Boston. b. The Northern Avenue Bridge (1908). Pivotal lift swing bridge; it has been determined eligible for the National Register. funding . 5. Description of National Register and Eligible Properties 454 • DESCR IPTION OF TilE PRE FERRED A LTEF NATIVE A 1 1 e rnative 5 A Modi fi r- d; Ce ntral Art e r y_ Depress ion W ith Third Harbor Tunn el Via S outh Boston _ ( Seaport Alignme nt ) _ This alternative increases traffic capacity on the Central Artery (north-south) by widening and depressing the existing viaduct (total length approximately 3.6 miles); cross-harbor vehicular capacity (east-west.) is increased by construction of a Third Harbor Tunnel through South Boston linking the Massachusetts Turnpike/Central Artery interchange in Boston with Bird Island Flats, Logan Airport, and Route 1A in East Boston (total length approximately 3.6 miles). The Third Harbor Tunnel alignment is also called the Seaport Alignment because it provides direct access to and from the regional highway system and the northern "seaport" sector of South Boston. Figure 2 presents the proposed Alternative 5A Modified alignment. Figure 3 presents typical sections of the depressed Central Artery and the Third Harbor Tunnel, (not included but also a possibility is a binocular steel tunnel for the cross harbor sunken tube). Central Artery Corridor In the South Bay and Fort Point Channel areas, this alternative proposes construction of a four-lane tunnel within and along the west edge of the Channel from the Massachusetts Turnpike/Central Artery /Southeast Expressway interchange area to north of Dewey Square. This new tunnel will carry all northbound Central Artery traffic while five lanes of the Dewey Square Tunnel will be converted to southbound operation (serving both local access and through traffic). The profile of the Central Artery tunnel has been designed so that the tunnel box is below the bottom of the Fort Point Channel except where it crosses over the Massachusetts Bay Transportation Authority's (MBTA's) Red Line Tunnel. In plan view, the alignment curves to the west, north of Summer Street, to further avoid encroachment and impacts to the Fort Point Channel . North of the Dewey Square Tunnel, the existing six-lane Central Artery will be depressed and widened to eight lanes (four lanes in each direction plus weaving lanes), in a new tunnel structure, to the vicinity of Causeway Street at North Station; it will be located principally within the existing Central Artery corridor, and will pass over the MBTA's Blue Line Tunnel at State Street. North of Causeway Street, the depressed Artery emerges through a portal and transitions to a viaduct, crossing over the Charles River on two truss bridges, rejoining the existing elevated Interstate Route 93 double-decked viaduct approximately 700 feet north of the Gilmore Bridge in Charlestown. 455 The existing Central Artery viaduct, the double-decked High-Level bridge over the Charles River, and portions of the recently constructed double-decked Interstate Route 93 structure in Charlestown will be removed after the new bridges become operational. A major interchange with the Massachusetts Turnpike/Central Artery /Southeast Expressway/Third Harbor Tunnel is included. This interchange provides exclusive bus ramps to and from the South Station Transportation Center. These ramps therefore provide direct connections to points south and west of the City as well as to Logan Airport. This interchange also includes ramps to and from the local roadway system, including a ramp from the Third Harbor Tunnel to Herald Street Extension. On-ramps to the Central Artery northbound will be provided from Essex Street, Atlantic Avenue (two- lane), the Sumner Tunnel, Causeway Street, Storrow Drive, and Leverett Circle; off-ramps from the Central Artery northbound will be provided • to the Surface Artery (two-lane), Storrow Drive, and Leverett Circle. In the southbound direction, on-ramps to the Central Artery will be provided from Storrow Drive/Leverett Circle, from the Surface Artery, and from Essex Street; off -ramps from the Central Artery will be provided to Leverett Circle/Storrow Drive, Causeway Street, Callahan Tunnel, and Purchase Street. Surface roadways are also proposed to be constructed and/or modified in this area as part of this project. Broadway Bridge will be replaced by a new bridge realigned slightly to the north and designated as Herald Street Extension. Herald Street Extension (four lanes, median separated) will extend from Albany Street to Broadway at Dorchester Avenue in South Boston. (Existing Herald Street is to be improved by the City of Boston to match the Herald Street Extension cross-section. ) A two-way, four-lane relocated Dorchester Avenue will connect Herald Street Extension with the South Postal Annex, providing driveway access to the Annex and existing (privately-owned) Dorchester Avenue. From that point, relocated Dorchester Avenue will continue as a one-way two-lane northbound roadway, constructed above the northbound Central Artery Tunnel in the Channel, intersecting with Summer Street. Between Summer Street and Congress Street, existing Dorchester Avenue (four-lanes with angle parking), will be reconstructed as a two-way six-lane roadway (with no parking). A ramp from the Central Artery northbound will connect with Herald Street Extension, opposite relocated Dorchester Avenue. The surface roadways along and crossing under the Central Artery will be rebuilt in their approximate present location, where possible. A surface arterial route connecting Atlantic Avenue (one-way northbound) and Purchase Street (one-way southbound) with Causeway Street is also proposed. English-style U-turns will be provided at Pearl Street to 456 • Atlantic Avenue, and from Atlantic Avenue to Purchase St. v < • t and Pearl Street. A one-way east bound connection from Oliver Street to Atlantic Avenue and to Northern Avenue will also be provided. Other U-turns are also selectively located to allow efficient traffic flow between the northbound and southbound surface arterial. Nashua Street will be realigned from the Massachusett s Rehabilitation Hospital, passing over the new Storrcw Drive ramp terminals, and into Leverett Circle. Five ventilation buildings have tentatively been proposed in the following areas: South Bay area south of Herald Street Extension; at Northern Avenue; at Atlantic Avenue (just north of High Street); at North Street; and along the rear of the Hoffman Building near North Station (Causeway Street). All ventilation structures are expected to be approximately 100 feet high. South Boston/Seaport Acce ss _C o r r idor The Seaport Access tunnel (two-way; four-lane, plus weaving lanes) will interchange with the Massachusetts Turnpike/Central Artery /Southeast Expressway in the South Bay area, crossing the south end of the Fort Point Channel and into South Boston. This tunnel crosses Gillette Company and Boston Wharf Company properties and passes under A Street, Summer Street, B Street, and Viaduct Street to an open one-way (southbound) toll plaza (no toll plaza for northbound travel) in the Commonwealth Flats area (Massport property). From the toll plaza area, the roadway enters a portal and curves towards the north, passing through Economic Development and Industrial Corporation (EDIC) property as it approaches Boston Harbor at the west edge of Boston Marine Industrial Park (BMIP). The profile of the roadway as it crosses the end of the Fort Point Channel is set so the top of the tunnel structure is near the bottom of the existing Channel. The following ramps to and from the Seaport Access Tunnel will be provided: o Congress Street, with a surface street connection to Northern Avenue; o Summer Street; and, o Northern Avenue. The Summer Street and Northern Avenue on- ramps to the southbound tunnel will be toll free, providing free access to this facility by all vehicles including trucks. Ventilation buildings will be located in the vicinity of A Street; between B Street and Viaduct Street; and at the B".IP 457 near C Street. A Massachusetts Turnpike Authority administration building will be located in Commonwealth Flats overlooking the toll plaza. Harbor Crossing/Logan Airport Corridor After passing to the west c-.f 3MIP in South Boston, the Third Harbor Tunnel (two-way, four-lanes) approaches Boston Harbor and crosses directly to the Bird Island Flats area of Logan Airport, passing under the main shipping channels. The profile provides a minimum of 7 feet of clearance below the possible future 45-foot deep rain shipping channel. At Bird Island Flats, the four-lane tunnel continues in a north-east direction, providing tunnel ramps to and from the Airport roadway system, generally south of the East Boston Memorial Stadium, although encroachment into the park is not avoided. A ramp is also provided for northbound traffic to the Airport parking garage. Northbound traffic will continue in a tunnel, merging with a relocated egress roadway to the cast of the East Boston Memorial Stadium. This roadway to Route 1A northbound continues, requiring modifications to Route 1A, south of Bennington Street and relocation of the MBTA ' s Blue Line tracks south of Prescott Street. Modifications to Route 1A southbound are also provided to permit traffic to got to the southbound portion of the Third Harbor Tunnel. This alternative also proposes significant changes to the Airport's roadway system. The existing Cross Road will be relocated slightly to the south; the Airport access road and relocated egress road will be grade-separated, passing under the Cross Road. The existing egress road will be removed, and direct connections to and from the parking garage will be constructed from Cross Road. A two-way relocated Service Road from the air cargo area near Route 1A will also be provided, intersecting with Cross Road, and thus providing connections to Bird Island Flats. A direct connection to the southbound Tiiird Harbor Tunnel is also provided from relocated Cross Road for traffic exiting the Bird Island Flats development. A ventilation building will be constructed on Bird Island Flats, where the Third Harbor Tunnel enters Airport property at the pier and bulkhead line of Eoston Harbor. 458 PsUSSSA V WHARF *f* COMPANY 28flCoogr«t»Str««i (617) 4A2-70W Boston, M*»iacnu»elt» 02210 August 22, 1983 Mr. James A. Walsh Division Administrator Federal Highway Administration Transportation Systems Center 55 Broadway, 10th Floor Cambridge, Ma. 02142 Mr. Robert J. McDonagh, P. E. Chief Engineer Massachusetts Department of Public V.'orks 100 Nashua Street Room 530 Boston, Ma. 02114 RE: FHWA - MA - EIS - 82-02-DS Gentlemen: This letter i^ to express my support for Alternative 5-A Modified as descried in :r ; -:- er :-j : ::r. . I wish to express my strenuous objection to all other alternates for any proposal which would construct a third harbor tunnel other than on the proposed Sea Port Access alignment or without depressing and widening the Central Artery. To the best of my knowledge, Russia Wharf is the only privately owned property abutting directly on the Fort Point Channel's West Bank which will have the proposed Northbound Depressed Central Artery aligned between its' buildings and the water. The potential exists for serious dimunition of the value of our property if the proposed construction is at all intrusive on our views, marina, parking facilities or water edge access. Accordingly, my su pport of 5A Modified is based on the final design of the NorthbounTtenTra i Artery tunnel located in the Ft. Point Channel achieving the minimal impacts on the Channel and Russia Wharf implied in the "Lhannel Preservation Design Refinement" plan winch was exh-.FTted to me on august is, maj. -cont mioH. 459 (Uub Ki^Q ^^C^L- CM^-Xk^ l&Xi^ Au^^ jl projected passenger ferries. all around the harbor, as well as ; recreational boating and entertainment cruises. The harbor is also the center of commercial marine transportation in the state Fishing and lobstering are very important eco nor, i ca 11 y to Massachusetts. In addition, mar.} of these marine activities arefcir historically significant. K v es list! It is hoped that the Central Artery project, could bring better H^i coordination between the MDC Charles River basin plans and the other development plans in the adjacent area. The Sierra Club requests that disruption in the Leverer.t Circle area (p. 288) be minimized. Pedestrian access and walkways must be a priority i nH.' | this area, and all modifications which could make the new bridge more attractive and reduce shadows should be implemented. HISTORIC IMPACTS The description of the historic aspects of the project were all- inclusive and excellent. There was, however, very little consideration of the impacts' of the artery project. Boston is a historic city, not made to accommodate automobiles and trucks. That's what has created the ambiance that makes Boston ir commercially and financially desirable. That is the quality of ^ life that attracts business. To create easy access for cars - roadways and parking - would destroy the ambiance that has made n[f Boston successful. Kor Btt For example, Fort Point Channel is eligible for the National Historic Register. It is inviolable, and should not be touched. The highway should be underground at the head of the Channel, ant ; c also depressed under Old Dorchester Avenue. These is no | -. m convincing need for a New Dorchester Avenue, for locationg a tunnel in the Channel, nor for a new Northern Avenue bridge. Aim/ the bridges over the Channel should be put in decent condition sc the Channel will be navigable as it always has been historically As the project area includes some of the oldest sections of Boston, the archeaolog ical findings are goi-ng to be impressive and numerous. Advance commitment should be make for preserving these sites and publishing their implications. This material will be tremendously exciting for all citizens of the United States. CHARLESTOWN With the depression of the Central Artery there is a most beneficial visual improvement to the connection between Charlestown and the downtown districts of Boston. However, thi£ ! " :e; is created at the expense of worsening the impact on the Charles m River water passage and the potential pedestrian walkway on each bank. The width of the bridges with their ramp connections, the clearances underneath the river crossing, the design of the substructure and superstructure of the bridges, and the space between them all need reassessment if the approach to this famous river corridor is to be saved. 460 piames A. Walsh 2 jral_R e_so_u£C_es fated in our letter of April 7, 1983, we concur that there are no feasible and prudent •natives to the use of land in the Fort Point Channel Historic District should the A determine that one of the tunnel alternatives is necessary to satisfy the ■a;portation needs of the Boston area. We also concur that there are no feasible and isnt alternatives to the use of land in the Charles River Basin Historic District, and use of land and properties in the Causeway-North Washington Historic District and it Bullfinch-Triangle Historic District by the proposed Central Artery Depression, Kid the FH W A determine that such im provem ent is necessary. e:oncur with your proposed measures to minimize harm to these four historic districts lUith the proviso that adequate recordation be undertaken for any demolished historic x:tures, and that the recommendations of the Massachusetts Historical Commission ithe Boston Landmarks Commission be included in project planning and evidenced in jhquent project documentation. eroncur that data recovery and/or protection of data in situ is appropriate for any ;qcted archeological resources that may be discovered in your Phase n survey. t~eational development at the Charles River Basin Reservation has been assisted rjgh the Land and Water Conservation Fund Act (L&WCF), Public Law 88-578, a tram administered by the NPS. Any conversion of park property to a non-park use in rcBasin may require compliance with the Section 6(f) replacement provisions of the Coordination with the NPS and the State Liaison Officer (SLO) should be Krtaken to determine the applicability of Section 6(f). The SLO in Massachusetts is |3S S. Hoyte, Secretary of Environmental Affairs, State Office Building, 100 I bridge Street, Boston, M A 02202. kid any Section 6(f) conversions be involved in this project, the NPS would be willing Dnsider a request for such conversion upon submission by the SLO. Any conversion ideration under Section 6(f) first requires Section 4(f) approval of the project by A. In addition, the conversion must be in accord with the State's comprehensive lioor recreation plan, and appropriate replacement land of at least equal fair market is and of reasonably equivalent usefulness and location must be provided. ■K IRONMENTAL STATEMENT COMMENTS hicom ments provided in our letter of April 7, 1983, on the draft statem ent, with regard » he environmental impacts of tunnel fabrication sites and sites for disposal of xtvated material—, arejtffl applicable to the present supplemental draft statement, 'dote, ho wever, your firm co m mitm ent that further environm ental analysis and xavated material means (a) the "muck" which would be excavated from the harbor ' for the Third Harbor Tunnel trench and (b) the overburden which would be removed he I-90/Central Artery Depression. 461 3 The Boston Preservation Alliance A n Association of Preservation Organizations P.0.BQrll65,BO8tOn,Ma88achu»e.»ts 02103 Phone: 617-242-56 56 *" August 9, 1983 Mr. Jamas A. Walsh Division Administrator Federal Highway Administration Transportation Systems Center 55 Broadway, 10th Floor Cambridge, MA 02142 Dear Mr. Walsh: The Boston Preservation Alliance welcomes the opportunity to comment on the Environmental Impact statement and its supplement for the Third Harbor Tunnell, Interstate 90/Central Artery, Interstate 93. As a coalition of thirty-one preservation groups and historical societies in the City of Boston, the Alliance has deep concern for issues such as this that affect the built environment and the well being of Boston's citizens. The Alliance appreciates the scope of this project whose objective will undoubtedly resull in better transportation for the city and the region. However, the Alliance opposes certain aspects of this project which wil. have a negative impact on historic resources in the central city and beyond. The first of these is the way in which the Fort Point Channel will be affect^ A historic body of water (and potentially eligible for the National Register of Historic Places), the Fort Point Channel is the last remaining body of wa that defines the old Shawmut Peninsula. The Channel will be severely compro mised unless modifications to this project are made. The only alternative tit the Preservation Alliance sould support with modifications would be number 5A. The other alternatives diminish the Channel drastically because of -he introduction of rarnps and roadways on the surface. The Alliance opposes rn< extent to which the bulkhead of the new Dorchester Avenue projects into the Channel under alternative 5A and feels that the bulkhead should be diminish^ to the minimum. The Alliance would also like to see the roadways at the hel of the Channel made entirely inconspicuous. Associated with this project is the building of a fixed span bridge to replace the current Nortlu-rn Av< bridge. The headway of this bridge will be roo low to allow sailboats through. The Alliance believes that this will have a negative iit:p:,ct on Channel ab a recreational facility. Second, the Alliance is concerned .^ont the traffic impart liie e 'jfl on the South Fnd during and after construction, ''lie Allia.K' 1. ■ I ' • ■ •'• ; . hii: Me raid Street should I ! widened in order to help nmeli-'i ito : he '•■ '1 - f vehicles predicted to v-.ss through this Nati »nal ;< i ; li lief, ..'■!■'■ also trie largest Victorian residential ivii'hbovhooil in this <• i.cv. 462 I EXHIBIT E 463 MICHAEL S DUKAKIS Governor JAMES S. HOYTE Secretary fat Srfffa J 00 ^loamiyu/ye !$reet Soriton, ^{lattac/iaiefo 02202 April 12, 1984 Robert J. McDonagh Chief Engineer Executive Office of Transportation and Construction Department of Public Works 100 Nashua Street Boston, MA 022 04 Re: L&WCF Project* 25-00099, Charles Rivei Tennis Courts - Central Artery 6(f) (3) Review Dear Mr. McDonagh: This office has received the enclosed correspondence from National Park Service relative to the referenced project and t! Central Artery proposal. We have reviewed the enclosed response from the National I Service and subsequently concur with their opinion. Sincerely, diati.'?s S. Hoyte Secretary JSH : DFS : rhl 464 3 United States Department of the Interior f REFTR TO NATIONAL PARK SERVICE MID- A TLA A' T/C RECIOS . 143 SOUTH THIRD STREET PHILADELPHIA. PA. 19106 } APR 1334 * P « 9)984 Mr. Joel Lerner Executive Cffice of Environmental Affairs 100 Cambridge St. Boston, MA 02202 Subject: L&WCF Project #25-00099, Charles River Tennis Courts - • Central Artery 6(f)(3) Review Dear Joel: la have reviewed our files as well as the supplemental materials recently provided regarding the transportation proposal 3 .nd the dedicated park area it the Charles River project site. J We note the following: .) The proposed Preferred Alternative will only have a short term temporary effect on the park (during actual construct:-. on) '.) The construction will not impact the major developed recreation facilities nor recreator use of them ) The current alignment of the Preferred Alternative provides for the maintenance of recreator/pedestrian access during project construction ) The highway revisions, if approved, will clearly serve a public purpose (in contrast to the private proposal regarding #25-00221, Charlestown Water front Park) t ) Precautions will be taken to adequately protect the public during the project ) Given the Preferred Alternative, there would be no permanent loss of dedicated park area which will be restored and returned to full use following construction ) Your staff are located in close proximity to the project and will be able to monitor it regularly. ; therefore provisionally find no conversion. We emphasize this is only i interim opinion. Any final opinion must await final project routing and •mpletion of the 4(f) review and determination. I ncerely, 9, Iristine McCoy 'ief, Planning & Grants stance 465 L7619 (MAR-PW Rece?vedI M r. Robert J. ^cDonaoh Chief Engineer Co*nrtom*ealth of Massachusetts ^ecutive Office of Transportation and Construction Department of Public Works 100 Nashua Street Boston, "assachusetts 02114 Dear Wr. McDonaght This is in res pons* to vour letter of Oc t obe r 16 , 1983 , pertaining to the Section 4 < f ) evaluation from the Preliminary Final Environmental Impact Statement/Report for the Third Harbor Tunnel, Interstate 90/ Central Artery, Interstate 93, Boston, As you are aware, the National Park Service (MPS) is r es pon s ible for any construction permits issued at the East Boston "emorial Stadium as It has been assisted through the Urban Park and Recreation Recovery Act of 19*78, a program administered by HPS. The draft report adequately addresses the extent and nature of the impacts on the Fast Boston Recreation Center. We are pleased that there is no permanent conversion of parkland involved. The mitigation treasures, including the replacement land, are satisfactory to thi? agency, fine concern we do have is the provisions for safety neasures during the construction period. The design phase of this project should carefully consider safety factors since this park is in both a heavily trafficed area and receives intensive community use. Thus, kp<; is prepared to authorise a construction permit for East Boston Memorial Ptadium at the time the fi omwow * e alth of Massachusetts completes the environmental/5»ection 4(f) impact statement. These comments are pro- vided on a technical assistance basis only and should not be construed as reflecting a position on the pr o ject or the environmental /Section 4 ( fl statement by the Secretary of the Interior. Any formal or official comments on the project by the Department of the Interior are to be initiated through the Office of Environmental Project Review, United States Department of the Interior. NOV 1 7 1983 ■■■CZQCfiVZS , 466 2 Should you have further question* on impacts at the East Boriton Heereation Center, please contact Joseph Karhan, Chief, r*iviron»ental Quality Division (215-597-2785) . we appreciate your cooperation in this matter, sincerely. Anthony M. Corbisiero Associate Regional Director Planning and Development CCT HASO 762 BBECKERtjy: 11/7/83 General Dally Area Project File 467 (executive (Office Environmental £$^awi 400 ^QamSridpe ^Street £$otfon, tdlattacbitetb 02202 MICHAEL S. DUKAKIS Governor JAMES S. HOYTE Secretary October 26, 1983 ,...»rF FLO' 1 - James S. Coleman, Jr. Regional Director National Park Service 600 Arch Street Philadelphia, PA 19106 Dear Director Coleman: Re: Projects* 25-00099 UPARR #25CTY 0120-83-08, 4(f)Evalu In accordance with the attached Massachusetts Department f Public Works request, this office is seeking your comments andai of the proposed Third Harbor Tunnel, Interstate 90/Central Artr and Interstate 93 projects. Sincerely, JSH/rhl v cc: Robert J. McDonagh, Chief Engineer 468 6 October 1983 / *0 Mr. Joel Lerner State Liaison Office Department of Conservation Services : -. r 100 Cambridge Street . -£.v». Boston, MA 02202 ' Dear Mr. Lerner: As per your telephone conversation with Carole Schlessinger of our consultants, HFMW, on 14 September 1983, I am forwarding a copy of the Section 4(f) Evaluation from the preliminary Final Environmental Impact Statement/Report for the Third Harbor Tunnel, Interstate 90/Central Artery, Interstate 93 in Boston. As noted in the Section 4(f) Evaluation, the Charles River Basin Reservation recreation facilities will be affected only on a short-term basis during the construction period. There will be no permanent conversion of recreational property to a non-park use. The construction period right-of-way has been realigned so that the tennis courts are no longer affected. The pedestrian overpass will be braced, rather than removed. In compliance with Section 6(f) of the Land and Water Conservation Fund Act, we hereby request State Liaison Officer authorization to conduct construction activities at the Charles River Basin Reser- vation, an L&WCF grant recipient. I would appreciate your response at your earliest possible con- venience, as we are working on a very tight schedule. Our con- sultants are available to answer any questions for you or your staff. Please feel free to contact Ms. Carole Schlessinger at (617) 423-4440. Thank you for your cooperation. I look forward to hearing from you. Sincerely, Robert J. McDonagh Chief Engineer Enclosure 469 JCP. 93/944 OCT 4 1983 *r* Janes >.* welsh division Administrator Pe***ral Hl«rh»*ay Adrvlnlstraticm ^rnnoportatiorf :»v?l*tj Center 55 Broadway, 10th floor Ca*brldye, HaKMChuMttA 6214/ Dear Mr* Welsh! Tbie is to supplement the Department of the Interior's previous eaosaentn on t>>% •opplesseotal draft enriroa*eutal/3nction 4(f) stateausnt for Third Barbor tunn*l, I -^0 /Central Artery, end 1-93, Suffolk County, Massachusetts* The draft vupplwrental document end the Departmental letter of August 29, 19S3, did not disease the status of the S-nct Boston Recreation Centex* e part of the Cast Sostcn Ke*»orial Stadltn* On tagaet 31, 1923, e rnhabilitation «jx«t f *25CTY01 20-63 -0*) wi approved by the Rational Pari Service, Hid -Atlantic Regional Office (RPC, xarc) through the Urbar. Park and Recreation Recovery Program (UPAFJ!) to rehabilitate the Joseph Lee Playground, Col unban Park, end the £ast Sostoo f<« creation Center* The nature #ff the rehabilitation at the Last property includes a running track, turf, drainage, paring, play areas, landscaping, shelter, fencing, end player benches ■ _ Planning for and compliance with the provisions of the Br baa Perk end Recreation Bnoev«ry *ct of 197S should be incorporated into design plane* Ton shoal 6 be aware that any conversion at the 2a«t Boston Recreation Centex wnld retire the approval of the national Perk Service (HPS), es delegated by the Secretary of the Interior and subject to f ulf illsmnt ef the 07AXK Section 1© 18 criteria a Me property lsproved or developed with esai stance under this title •hall, vdtbeut the approval of the Secretary, be converted to ether then penile recreation use** The Secretary shall s ppro ne such eonverslon only if he find* it to be in accord with the; current local park and recreation recovery act lor- program end only upon each conditio* a as be <3eesa wreiwry to assure the provlalea of adequate reersatloa properties and opportunities of reasonably equivalent location end usafulnees* 470 ^»»W» UIUWJI * *-^3ruce Blanchard, Director Environmental Project Review cc: (next page) ' ; : . L ■ 476 mes A. Walsh Mr. Robert J. McDonagh, P,E. Chief Engineer MA Departm ent of Public Works 100 Nashua Street, Room 530 Boston, MA 02114 Mr. James S. Hoyte Secretary of Environmental Affairs State Office Building 100 Cambridge Street Boston, M A 02202 Mrs. Patricia L. Weslowski Executive Director MA Historical Commission 294 W as hi ngton Street Boston, MA 02108 Mr. Robert E. Tern pie Acting Regional Director, Northeast Region National Marine Fisheries Service Fall Bldg Gloucester, M A 01930 Colonel C. B. Sciple Division Engineer, New England Division U.S. Corps of Engineers 424 Trapelo Road Waltham, MA 02254 477 vj to/ Srffat'rS /OO^a/utfr/Jyr !//scrf. ^#S/<,/t 02202 •I August 23, i98foruT^i; r 2 9 AUG 1033 o\*'"** _ Robert J. McDonagh Chief Engineer Executive Office of Transportation & Construction \~ Department of Public Works 100 Nashua 'Street Boston^ WA 02114 Dear Mr. McDonagh: Thank you for the opportunity to comment upon the 4(f)statyp« from the Supplemental Draft Environmental Impact S tatement/Repct for the Third Harbor Island, Interstate 90/Central Artery, Inters* 93 in Boston. As far as I can determine this office has 6(f) concerns ovff ' M.D.C.'s Charles River Tennis Courts, proj ect#25-00099 located to : Charles River Basin Reservation. Funds for rehabilitating the *C were granted, through this office, to the M.D.C. from the Natiofc* Park Service Land and Water Conservation Fund Program. Although difficult to judge impact, if any, Jeffries Pointfc project 125-00161 also received National Park Service funding.. Ir? this case the City of Boston received the financial assistance. Finally, you should also be advised that the National ParkS« and the Commonwealth have just committed in excess of $1.3 milloi for the restoration of Lee Playground, Colombia Playground^ te East Boston Recreation Center. Funding for the renovations corns from the federal and state Urban Park And Pecreatiorj Recovery (UP programs (P. L. 95-625 and M.G.L. c.132, S.llE) and wojrk is schedlf to start this Fall. Alternatives 3A and 5A involving the Third He Tunnel would impact the latter UPARR project site. Please contact me if I can be of further assistance Sincerely , JAL/rhl 478 >el A. Lerne Director — i ark Service ONIA J$ [AA-D. 30. c August 22, 1983 ___:iarks jfr fission ' Boston ' ^Itts 02201 ~ ..:;850 iiton Vhite, Mayor ase Harrell, n K. Allen Anderson \. Bianchi k >avis Hynes, Jr. -ang Wood Sea:. int on, Idrich f lander ■he Mice |L Gorin la ibea osebrock Jv rllner :e. : fers, ^Director.'- fti), .rdh Robert T. Tiemey, Commissioner Department of Public Works Commonwealth of Massachusetts 100 Nashua Street Boston, MA 02114 Dear Commissioner Tierney: C/1 Thank you for the opportunity to comment on the draft Environ- mental Impact Statement "on the Central Artery /Third Harbor Tunnel project. -. ~. The Boston Landmarks Commission is sympathetic to the goals of this project and commends the Secretary of Transportation and the project team for exploring alternatives which would attempt to minimize disruption of the Central -Business District and residential neighborhoods while upgrading the regional - transportation system- : The Landmarks Commission, as the City of Boston's agency concerned with the preservation and enhancement of the city's historic resources, has reviewed the draft EIS/EXR including the suplemental report dated June., 1983, in order to assess the potential impacts on the historic resources of the City. BjflnhajaffEeaG! t ^" iT igg. rnrirpl ' n which has emerged from this revi ew pertains to the potentially devastating impact of the "build"" alternatives on the. Fort Point Channel. The channel is the last remnant of the water body that defined the old Shawmut Peninsula. With the gradual filling in of the South Bay, a process which would continue under this project, the channel becomes even more important as a vestige of that feature which gave form to the city. The channel, its bridges and the older commercial buildings flanking the channel have been identified as a district potentially eligible for listing in the National Register of Historic Place. While the channel has, for many years, been neglected, it nonetheless represents an important visual and recreational resource for the City, as well as a link with its past. In general, the Boston Landmarks Commission opposes the use of the channel for roadway purposes - whether for the Third Harbor Crossing, the Central Artery or for Dorchester Avenue. The Commission's specific concerns regarding the channel, are as follows (in rough order of priority: 479 • •• • I JlLl. Tiemey C'^ W page 2 Cook of Mass 1. " Reduction in the absolute and visual dimension* of" the ,channe"l • by construction which narrows, shortens of s'pan-s itv (Narrowing -and spanning activities being more objectionable" than s^oYrening its length.) 2. Intrusion of street level traffic between 1 the channel and" the headland. -3. Reconstruction of historic bridges result-frig" fh losV of oYiginal . ii, .ic as well as disruption of symmetry in design when recons true td. * • - - ---- ■ t 4-. Removal, replacement or visually obscuring the hisrVric bulkhead.' 5i Removal of the Old Colony. Bridge.. 6-. Taking of buildings^ in the. South Boston Industrial' arffaV •» . _ . j 7v installation of Vent buildings- in the channel near the 3 existing . ITor the rn Avenue Bridge. Of the "build" alternatives currently under' consideration," Alternative -5a is the least disruptive witK respect to the Fort Point; ChaUheT.' -Alternatives 3, 3a, and S are. the, most objectionable." The Commission is disturbed- to. see- the re-iritrVdoiction of _aV new Dorchestr Avenue connection in Alternative 5a- modified.- Etr seems* particularly ?i unfortunate that, if this connection- is important', it must" be' re-e's"t'abliie t outside of the old al ignment and the old' bulkhead. ti " ' ... I U The -Boston Landmarks Commission, has. no objection per se to the* .concept o a third harbor crossings seaport, access? r oedrpri;depr ession of. the Central . \ Artery. There are many and varied- benefits to be accrued by these pro j erst: Sbvever, the Commission must state its opposition to the aspects, of. thes. ii projects which would "adversely, affect the Fort Point Channel and other historic resources, unless, these negative impacts can be reduced" or mitigated. The Commission would like to see the following: -1-. 'Adoption by the Mass.. D.P-.W. and Federal Highway of design ' s'oTutioni which would minimize the narrowing or shortening of the channel. Such solutions would include use of part or all of the old" .Dorchestr Avenue alignment or Atlantic Avenue for northbound artery traffic. 2. -Elimination of ramps crossing the channel. 3. -El-imnation of a new Dorchester Avenue conncection. . A. -Public access, appropriate landscaping and provision of water relate ''activities aJ.ong the. channel edge. 480 R.T. Tierney .DPW Co mm of Mass •8/22/83 5. Mitigation of the negative impacts by positive ;artiQirs aimed at improving the environment of the channel. Such -measures migirt Include facilities to i-oprpve .water ojual.it y j.n the channel and redesign of the Northern Avenue bridge -to allow full arr.es s by pleasure crafts and working boats. 6. A process for continued review of more detailed plans frcr rhe treatment of the channel, its bridges and bulkhead. With respect to impacts on resources other than the Fort Point nha-rmpl the Commission would like to see: (Alternatives _3a, 5a, & 6) 1. A process for anticipating and monitoring construction impacts on historic resources adjacent to the Central Artery, and a plan for shoring and stabilizing such properties in the event of anticipated or unanticipated damage. 2. •* A process for continued review of the location and design of vent buildings, new highway ramps and new surface streets adjacent to historic properties and other development on parcels to be created. This can be handled through the Advisory Council procedures established pursuant to Seetion 106 of. the Historic Preservation Act of 1966. . " While the draft EIS/EIR does not adequately evaluate the effects of the project on archaelogical resources ». it is the understanding of this office that a field investigation of the preferred alternative will be undertaken this fall and that the Advisory Council procedures for protection of historic and cultural properties will be followed. We look forward to continued discussions with the Executive Office of Transportation concerning this project and measures to reduce its negative impacts on the city's historic resources. Marcia Myers Executive Director Boston Landmarks Commission cc: Secretary James S.Hoyte Exec. Office of Environmental Affairs 100 Nashua Street Boston, MA 02202 :page 3 481 2o£f&me*te*£/?nr*t. 02/0$ WILLIAM J. GEARY Commissioner August 15, 1983 Mr. James A. Walsh Division Administrator Federal Highway Administration 55 Broadway Cambridge, Massachusetts 02TJ2 Dear Mr. Walsh: The Metropolitian District Commission is the agency with the primary responsibility for the police and emergency services on the Central Artery the management of traffic on nearby parkways; the preservation and en- hancement of the parklands Charles River Basin Historic District; and the water quality, recreational and navigational use and flood management of the Charles River. With these responsibilities the agency is directly im- pacted by the proposed projects. It is the Metropolitian District Commission's opinion that a depressed and widened Central Artery and new tunnel will provide the citizens of this city and this region with a safer and more efficient highway system. TheCentral Artery now experiences 2i'times the national accident rate for urban highways. In 1981 Metropolitian District Commission Statistics indicated a total of 682 accidents in the are^frol^hlfr^t^FSaJjare on-ramp through the Dewey Square Tunnel; 1982 resulted in similiar statistics. Ninety percent of these accidents involved personal injury. The congestion and outdated design of this short stretch of road are the reasons for the alarming number of accidents. The many access ramps merge on to a highway that has inadequate deceleration and ac- celeration lanes and no breakdown lanes. It is our judgement that mere reconstruction of the artery will not remove the causes of the many ac- cidents. Construction of the tunnel and depression of the artery create a once-in-a-generation opportunity to significantly improve the quality of life for metropolitian Boston residents. Our challenge is to maximize that opportunity. The following comments are directed to that end. I. WATER QUALITY Section 4.9 raises some serious questions concerning drainage. M.D.C. rules and regulations prohibit storm drain connections into san- itary sewers. A connection to an existing combined sewer is allowed, but is subject to pretreatment requirements. The removals of heavy metals and and sediments in Table 97 appear low. Further discussion of pretreatment approaches should be presented. Apparently construction in the Charles River will be behind sheet steel refraining walls. The effect of this approach on the Dam, locks and basin water quality should be more fully discussed as it relates to the construction of the two new bridges as well as for the construction of the Central Artery to Storrow Drive connection. II. CONSTRUCTION PHASING It is difficult to clearly understand construction phasing and deviation for specific segments of the project. Clarification of timing is needed for the construction of the Central Artery to Storrow Drive connection, and the two new bridges. III. TRAFFIC It is stated (p. 170) that ramp connections between I-93 and ; Leverett Circle will be unavailable for one year. A brief description jf detour routes for this extremely heavy traffic* movement should be sresented. New rerouting of Charles Street traffic has changed volumes ind congestion on Storrow Drive between Arlington Street and Leverett lircle. Was this included in the traffic assignment network and does it iffect the Storrow Drive on-ramp volumes (p. 139) and queueing pp. 147-149)? The Storrow Drive /Leverett Circle connecting ramp construction > stated to have major impacts for a two year period (p. 164) mitigating ip teasures and full description of alternative routes and impacts should e presented. The impact on the Craigie Bridge (Charles River Dam) > of particular concern. /. NOISE (LONC TERM EFFECTS) No noise abatement proposals are made for the Charles River Dam ark. It is unclear from the text if any are proposed. If proposals exist »ey should be described; if not the impacts should be more fully des- ibed. * The effects of pile driving for new bridge piers (both noise and bration) on the Charles River Dam and Park should be presented I'p. 236-237). ^ _ -FLOODPLAIN Apparently the Charles River will be filled in by .7 acre. This fill, » location, effect, construction techniques, finished embankment des- ertions etc. should be clearly described. Final elevations and river- . fank configuration are particularly important. 483 -3- VI. PEDESTRIAN CIRCULATION Pedestrian access to Charles River Dam was a major design objective in its construction. Mitigating measures (p. 1 94) do not address the need to preserve this pedestrian connection to the Dam. Police vehicles must als have constant access as the Dam is the station for the MDC Police Harbor Patrol. Pedestrians must also have constant access to Science Park Station. In the absence of the pedestrian bridge at Leverett Circle, how will this station function, for Museum of -Science, Hospitals etc? VII. CHARLES RIVER DAM The impacts on the Charles River Dam are significant. . The Commission recgonizes the challenge of the design problem and acknowledges that some impact is inevitable. However 15' or less of clearane under twelve lanes of high volume traffic, in addition to the 40,000 square feet of land with less than 8' of clearance requires extensive, detailed, and innovative design measures to mitigate the current proposal. Such measures should be possible to develop. In the design phase of the project the Commission has a major park improvement plan for the Basin extension and the thoughtful incorporation of this plan into the construction program would be appropriate. Alternatives to the truss bridge design and to the spacing of the two bridge structures should be fully explored. The view from the Dam for the operators, police and recreational users must be considered. The Commission is anxious to work closely with the Department to deveiop a comprehensive program for impact mitigation in this area. VII I .- —FACTUAL-ERROR ." - ^4 The boundry of the National Register District does include Storrqw Drive and Leverett Circle (p. 292). The review process for National Register properties should be described. The Commission appreciates the opportunity to comment on this EIS/E1R. And is confident that it can work closely with the Department of Public Works and EOTC on the aforementioned issues. The p *oposal project is vital and we believe can be designed to be a lasting benefit to the use and enjoyment of the areas to be/impacted by its cor struction / WJfliam J. Qcary v/ Commissioner S~ S.' WJC:cao 484 THE COMMONWEALTH OF MASSACHUSETTS METROPOLITAN DISTRICT COMMISSION 20 SOMERSET STREET. BOSTON 02 108 JBLIC INFORMATION OFFICE 727-321 5 CONTACT: Cheryl Yaffe 727-5215 FOR IMMEDIATE RELEASE 9 August 1983 METROPOLITAN DISTRICT COMMISSIONER WILLIAM J. GEARY TODAY TESTIFIED IN SUPPORT OF THE DEPRESSION OF THE CENTRAL ARTERY AND THE THIRD HARBOR TUNNEL Metropolitan District Commissioner William J. Geary today testified in strong support of the depression of the Central Artery and the third harbor crossing. The Metropolitan District Commission is the agency with the primary responsibility for police and emergency services on the Central Artery, as well as the agency responsible for the preservation, protect- ion and enhancement of the region's parks and open spaces. Commissioner Geary focused on the issues of public safety and environmental improve- The Central Artery is Boston's major North - South Connector as well as a major route to Logan Airport. It is the region's most important transportation facility and the region's number one traffic congestion problem. At present the Artery is far exceeding its capacity, with 160,000 cars per day using the road and traffic projections of a ten percent increase over the next twenty years. This aging and overburdened struc- ture will have to be rebuilt or replaced within the next ten years in order to keep the route operational. more - 485 - 2 - The Central Artery now experiences 24 times the national accident rate for urban highways. In 1981 Metropolitan District Commission Sta- tistics indicated a total of 682 accidents in the area from the City Square on-ramp through the Dewey Square Tunnel; 1982 resulted in similar statistics. Ninety percent of these accidents involved personal injury. The enormous congestion and hazardous design of this short stretch of road is the reason for the alarming amount of accidents. The many access ramps merge on to a highway that has inadequate deceleration and accele- ration lanes and no breakdown lanes. Commissioner Geary explained the role of the Metropolitan District Commission Division of Central Services, which provides motorist aid, emergency services and unique capabilities to handle critical accident situations. The Commissioner showed dramatic photographs of serious truck accidents along the Artery responded to by Metropolitan Police and the Metropolitan District Commission Central Services Special Emergency Opera- tions Unit. He estimated that this unit responds to similar accidents on this stretch of road 55 times a year. Also, the Division's Motorist Aid Patrol, which operates daily, assists thousands of disabled vehicles per year. The public safety concerns when the Central Artery is jammed from 6 a.m. to 8 p.m. as projected in the Environmental Impact Statement is startling. As it is now, there is grave concern in this city for the ability of emergency vehicles to get through city streets. Commissioner Geary stated, "It is the Metropolitan District Commis- sion's opinion that a depressed and widened Central Artery will provide the citizens of this city and this region with a safer and more efficient highway system. As the agency responsible for policing the Central Artery during construction, it is our judgement that mere reconstruction of the artery will not remove the causes of the many accidents." 486 - 3 - Commissioner Geary emphasized chat one of his agency's strongest mandates is to preserve, enhance and develop the urban park characteris- tics within the Metropolitan area. The depression of the Central Artery will eliminate the horrendous elevated structure which for years has been the dark cloud over Boston's streets as well as an obstruction to the city's historic waterfront area. The Metropolitan District Commission will be working in cooperation with the Department of Public Works on design improvement for the proposed twin bridges over the Charles River Dam. Commissioner Geary said, "In conclusion, it is my hope that the Metro- politan District Commission can work with state and federal agencies to not only provide the region with a safer transportation system, but also improve and enhance the environment and liveability of the city." 487 August 9,1983 Mr. Robert T. Tierney Commissioner Department 7 Public Works 100 Nashua Street Boston, Massachusetts 02114 Dear Commissioner Tierney: In review of the proposal for the Third Harbor Tunnel, the East Boston Recreation Center, which is the largest outdoor multi-use recreation area for the East Boston Community, will be affected in several of the plan versions. The East Boston Recreation Center is located adjacent to Airp'ort property on Porter Street and is owned and operated by the Boston Parks and Recreation Department. It is essential that this recreation facility not be adversely affected or altered due to the construction of the Third Harbor Tunnel. Because of the variety of recreation activities offered at the East Boston Recreation Center and because of the transportation difficulties involved in leaving East Boston for recreation, the East Boston Recreation Center is the single most important neighborhood recreation facility within walking, bicycling or public transit distance to East Boston residents. Specifically, in the Alternative 5A Modified which seems to have wide community support, the AP-3 Ramp appears to be constructed under the southeast portion of the East Boston Recreation Center. This area of the facility provides basketball and tennis courts for community use. If there were to be underground construction in this area, we would require that these courts and perimeter area be completely reconstructed, that the interruption of facility use be as limted as possible, that a construction schedule be closely followed and that the adverse affect of noise and dust during construction be mitigated to the greatest extent possible so as not to effect park users in other areas of the facility. The East Boston Recreation Center is an important open space resource to the community and I welcome the opportunity to work with you in the Third Harbor Tunnel project in order to preserve this recreation facility as your project progresses. Commissioner 488 Kevin H. White, Mayor/PARKS AND RECREATION DEPARTMENT/Boston City Hall/City Hall PlazO Coimr.il On 1322 K Street NW Washington. DC 20005 MB I 1983 Mr. James A- Walsh Division Administrator Federal Highway Administration Transportation Systems Center 55 Broadway, 10th Floor Cambridge, MA 02142 RZF: Third Harbor Tunnel, Interstate 90 and Central Artery, Interstate 3. •-, Boston, Massachusetts Kti Dear Mr. Walsh: The Massachusetts Department of Public Works (MDPW) has provided us wit a copy of the Supplemental, Draft Environmental Impact Statement/Report for the referenced project. The Supplemental DEIS identifies adverse and other possible effects on many historic p r o p erties eligible or potentially eligible for the Natiail Register of Hi srrvrf c Places. "These properties include Faneuil Hall Mar Long Wharf, and Russia Wharf, and the following Historic Districts: Blackstone Block, Bulf inch Triangle,. Charles River Basin, Custom House, Causeway-North Washington Streets, North End, Old Waterfront, Fulton Commercial, and Fort Point Channel/South Boston. We understand that the Federal Highway Administration and MDPW are curr working with the Massachusetts State Historic Preservation Office to identify historic resources and to make specific findings of effect on historic structures and archeological properties. ' Thereafter, we note your expressed intention to seek the Council's comments pursuant to Section 106 of the National Historic Preservation Act of 1966, as amendii. At that time we would appreciate copies of the Historic Resources Repon and Archaeolgical Survey Report referenced in the Supplemental DEIS' TaU of Contents. In the meantime, we will maintain a file on this project. If you have any questions, please contact Kate M. Perry at FTS 254.-3495. 490 of Project Review z KrPRbbefr '^r*teDSnaugE7~P . E*. Chief Engineer *' Massachusetts Department of Public Works 100 Nashua Street Room 530 Boston, MA 02114 James S. Hoyte Secretary Executive Office of Environmental Affairs 100 Cambridge Street Boston, MA 02202 l 491 Ilil Utr rtll i mun I V^r IIuuoiku ni.u uhunn w w « kuui kiwi i • BOSTON AREA OFFICE BULF INCH BUILDING. 15 NEW CHAROON STREET BOSTON. MASSACHUSETTS 02114 REGION I IN REPLY R AUG J Mr. James A. Walsh, Division Administrator Federal Highway Administration U.S. Department of Transportation 55 Broadway Street - 10th Floor Cambridge, Massachusetts 02142 Mr. Robert J. McDonagh/ Chief Engineer Massach . tts Department of Public Works 100 Nasnua Street Boston, Massachusetts 02114 Dear Sirs: SUBJECT: Supplemental Draft Environmental Impact Statement/Report for The Department of Housing and Urban Development is making limited observations to assist Boston and the larger metropolitan region in en- vironmental matters with regard to their obligations under HUD assisted Community Development and assisted Housing Programs; Under the no-build alternative, to include redecking of the Central Artery only, the core roadway system must carry significantly higher volumes of traffic, thereby, creating longer hours of congestion. From the HUD prespective, air and noise quality, in particular, would r come progressively worse. With an exacerbation of regional traffic movement community and housing development in the built environment will continue to suffer under the no-build alternative. Not either of the build alternatives (depressing the Central Artery and constructing a third harbor tunnel in either the existing railroad or airport alignments) would interfere adversely with any of HUD's goals and objectives. Either of the build alternatives should produce improv- ed traffic movement which will have positive impacts on community and housing development in the metropolitan region. Depressing the Central Artery will greatly improve visual contact downtown, toward the waterfront, and the North End* 3 historic resources; which are much desired attributes of the city's built environment. The final designs must include mitigating measures to minimize unwanted traffic snarls; so that the improved access through the city will have a positive impact on locational housing choices throughout the region. Boston - Interstate Route 90 - Third Harbor Tunnel and Interstate Route 93 - Central Artery 492 It would be preferable that tunnel traffic surface on Logan Airport pro- perty than in East Boston's residential neighborhoods. This Office does not object to the proposed treatment of. the four publicly-owned recreation areas under either of the build alternatives with respect to the required 4(f) analysis. There does not appear to be any other viable alternative with less of an impact, on the East Boston Memorial c tadium, the Bird Island Flats Park, The Paul Revere Landing Park or l..e Charles River Basin Reservation. Thank you for the opportunity to comment on the Draft Environmental Impact Statement/Report for the proposed Central Artery improvements, the proposed Third Harbor Tunnel and the effects on publicly-owned recreation areas. Sincerely, Carl Ji^r/ers / Environmental Clearance Officer 493 3 * *M- _.Q* Boston Area Office, Region I Bulfinch Building, 15 NewChardon Street Boston, Massachusetts 021 14 MAY j 0 uta RECi JUN 1 E|0f J. William Oliver Commonwealth of Massachusetts Executive Office of. Transportation vV.MLA-'i. FLCYIM and Construction Department of Public Works 100 Nashua Street Boston, MA 02114 Dear Mr. Oliver: SUBJECT: Third Harbor Tunnel Draft EIS/EIR This is in response to your May 12, 1983 letter regard- ing the required 4 (f) analysis of the cited study which has been expanded to include three new alternative alignments. As in our September 30, 1982 letter regarding the East Boston Memorial Stadium and the Bird Island Flats Park; we also find that the Paul Revere Landing Park in Charlestown can be included; and no conflicts to HUD assisted programs and goals v/ill result. Thank you for the opportunity to comment. Sincerely , iff Carl J. Byers Environmental Officer 1.1CP cc : • Gordon H. Slaney HFM W-60 First Avenue Waltham, MA "NIC Will tic 494 United States Department of the Interior OFFICE OF THE SECRETARY WASHINGTON, D.C. 20240 ER 83/162 APR 7 1963 Mr. Norman J. Van Ness Division Administrator Federal Highway Administration Transportation Systems Building 55 Broadway Cambridge, MA 02142 Dear Mr. Van Ness: This responds to a request for the Department of the Interior's comments on the draft environmental/Section 4(f) statement for Third Harbor Tunnel Project (1-90 extension from 1-93 to East Boston), Suffolk County, Massachusetts. SECTION 4(f) STATEMENT COMMENTS We concur that there are no feasible and prudent alternatives to the use of land from the East Boston Memorial Stadium, Bird bland Flats Park, and the Fort Point Channel Historic District, should the Federal Highway Administration determine that one of the build alternatives is necessary to satisfy the transportation needs of the Boston area. We also concur that the measures to minimize harm addressed in the draft statement are adequate. We especially recommend mitigation of impacts to the Old Colony Railroad Bridge by rebuilding the structure as noted on page 288. The recommendations of the Massachusetts Historical Commission, the Boston Landmarks Commission, and the Boston Parks and Recreation Department, should be incorporated into mitigation design plans, ancL.the results of continuing consultations with these agencies reported in the final statement. ENVIRONMENTAL STATEMENT COMMENTS Since the Third Harbor Tunnel Project may ultimately generate increased local traffic loadings, the final statement should address possible future actions that may result from such increases. These actions might include major reconstruction of the Central Artery, new highways connecting the Northshore with East Boston and/or 1-90, and new Interstate or expressway Jinks near or in the old 1-95 on other corridors. The proposed Lynn Harbor fabrication site will have far greater impacts to fish and wildlife resources than the proposed tunneL Although the draft statement gives a qualitative sketch of species found in the area, it does not contain sufficient data to provide an assessment on how the biological productivity of the Lynn Harbor area [including the Pines and Saugus Rivers) will be impacted by the removal of 5 million cubic yards of material from 75 acres of productive shallow water/intertidal habitat. The draft statement also fails to emphasize the importance of the area for waterfowl wintering habitat, especially black duck. The black duck is an important waterfowl 495 Mr. Norman d. van Ness species in the Northeast whose population has been declining. Although all the reascs for this decline have not been identified, the loss of critical wintering habitat is a ma;r factor. • New London, Connecticut and New Haven, Connecticut were identified as other possite fabrication sites for concrete tubes. If steel tubes are eventually chosen over concre* tubes, these could be fabricated at one of several East Coast shipyards. The draft cj not identify any specific locations. The New England River Basins Commission September 1981 Ports and Harbors Study identifies potential environmental constrains for both New London and New Haven. The New London Mills area is some distance frci the navigation channel and contains highly valuable fish and wildlife resources whir and highway design engineer with 33 years of experience at the MDPW. H holds a degree in civil engineering In the Third Harbor Tunnel/Central Artery study, Mr. Gardner assisted \ the review and critique of the documents. He also supervised revic of the project's engineering submissions to the Department of Public Works. Robert M. Horigan, P.E. Environmental Engineer, Massachusetts Department of Public Works (MDPW) Mr. Horigan heads the MDPW's Environmental Section. Mr. Horigan has prepared and supervised many environmental documents during the past ten years. For this study, he :::; ;iei 506 as involved in the review of the raft document at the State level. ames Allen, P.E. MPal upervising Transportation Planning ngineer, Massachusetts Department of ublic Works (MDPW) planning. In this study, Mr. Plourde was responsible for the overall content and production of the environmental document and related reports and for directing the traffic studies . Leonard J. Barbieri, P.E. Mr. Allen has 34 years of ' 'xperience in highway engineering and ransportation planning and has irected numerous transportation rojects for the MDPW involving raffic analysis and traffic . orecasting. He holds a Masters egree in Civil Engineering. In this ; : tudy, Mr. Allen assisted in the upervision of the Central transportation Planning Staff's ' (fforts in transportation forecasting. : lordon H. Slaney, P.E. cts " 'roject Manager, HFMW - A Joint Venture Mr. Slaney is a civil engineer m ind an Associate with Howard Needles • : 'ammen & Bergendoff. He has 17 years if project management, administration, ind design experience in environmental md highway projects, including banning, environmental impact inalysis, preliminary and final 1C iesign, and construction. As Project lanager of the current study, Mr. ilaney had overall responsibility for project budgeting, administration, and " coordination, and was also responsible : lor the overall technical quality and •■ content of the environmental ~~- locument . Mr. Slaney holds a Masters iegree in civil engineering. ; todney P. Plourde, P.E., Ph.D. >eputy Project Manager - Environmental IFMW - A Joint Venture Deputy Project Manager - Engineering, HFMW - A Joint Venture Mr. Barbieri has 27 years of experience evaluating and designing large-scale transportation engineering projects. A Senior Engineer with CE Maguire, Inc., Mr. Barbieri holds a Bachelor of Science degree in industrial technology. As Deputy Project Manager for Engineering, Mr. Barbieri was responsible for directing and coordinating all engineering aspects related to the Third Harbor Tunnel and Central Artery projects, including preparation of engineering-related portions of the environmental document. Gordon Brigham Deputy Project Manager - Planning, HFMW - A Joint Venture Mr. Brigham, a planner with experience in both the public and private sectors, specializes in the management of large-scale development projects. He worked for the City of Boston as Director of the Boston Plan. Currently on the staff of Wallace, Floyd, Associates inc., Mr. Brigham's responsibilities included coordination of the planning efforts with traffic and engineering disciplines, and supervision of preparation of land use, community facilities, and visual portions of the environmental document. An Associate and Vice President 'ith Fay, Spofford & Thorndike, inc., lr. Plourde has 15 years of experience n the field of transportation ilanning and engineering, and has /orked on more than 25 environmental .mpact statements and reports. He oofholds a doctorate degree in ■ransportation with a minor in city he I ■M Adel Foz Deputy Project Manager - Urban Design, HFWM - A Joint Venture Mr. Foz, an Associate with Wallace, Floyd, Associates Inc., has extensive experience in highway-related impact studies, regional impact studies, and urban design and neighborhood planning. Mr. Foz holds advanced degrees in architecture, urban design, and planning. His responsibilities in the present study included coordination of the urban design efforts with traffic and engineering disciplines, and assistance in the supervision of preparation of land use, community facilities and visual portions of the environmental document. Lydia E. Mercado Deputy Project Manager - Community Participation, HFMW - A Joint Venture Ms. Mercado, a planner with Wallace, Floyd, Associates Inc., has extensive experience in designing and implementing community participation programs, including programs for several major transportation projects. Ms. Mercado holds a Masters degree in city and regional planning. For this project, she was responsible for overall coordination of the community participation efforts. Thomas E. Lisco, Ph.D. Central Transportation Planning Staff (CTPS) - Traffic Forecasts Mr. Lisco is a systems planning manager at CTPS. He has 15 years of experience in travel demand analysis and transportation project evaluation, and holds a doctorate degree in economics. For this project, Mr. Lisco was responsible for CTPS' development of traffic forecasts for all alternatives and participated in the evaluation of queuing on the highway facilities. K. Meng Chng Bolt Beranek & Newman Inc. - Air Quality Assessment Mr. Chng has 17 years of experience in performing air quality analyses for various transportation and private industry projects, and has participated in more than two dozen environmental impact studies. He holds a Bachelor of Science degree in earth sciences. For this project, Mrl' Chng was responsible for preparation j of the air quality analysis of the proposed project, including documentation of existing conditions and modelling the future air quality characteristics of the area. David A. Towers, P.E. Bolt Beranek & Newman Inc. - Noise ant Vibration Assessment Mr. Towers is an acoustical engineer with more than nine years of experience. He has been involved in environmental assessments for noise and vibration control, community nois« evaluation and assessment, and noise and vibration control for surface transportation systems. Mr. Towers holds advanced degrees in mechanical engineering and acoustics. For this project, Mr. Towers supervised noise and vibration tasks which involved data collection and analysis, evaluation of impacts, and preparation of those portions of the documents. Carlton Noyes Jason M. Cortell and Associates inc. (JMCA) - Water Resources Mr. Noyes, Director of the Water Quality Group at Jason M. Cortell and Associates Inc., has 16 years of experience in environmental consulting, principally in preparation of environmental impact statements, feasibility studies, and site plan documents. Mr. Noyes holds a Masters degree in zoology. For this project, Mr. Noyes was project manager for JMCA, responsible for documenting existing conditions and evaluating impacts on water resources, wetlands, vegetation and wildlife, and Harbor sediment characteristics. Edward B. Kinner, Sc. P., P.E. Haley & Aldrich, Inc. - Geotechnical Studies Mr. Kinner is a geotechnical engineer and a principal and Senior 508 • ice President of Haley & Aldrich, • nc. As project manager for Haley & :- ldrich's geotechnical efforts for his study, Mr. Kinner's esponsibilities included determining ; he technical requirements for nderpinning the existing elevated Itructure, the lateral support equirements of the Artery's xcavation, and underpinning equirements for affected buildings, ie also studied groundwater effects rom the project and evaluated oundation requirements for the iroposed structures. Mr. Kinner holds ■. Doctorate in civil engineering. 'rancis X. Mahady a iconomics Research Associates, Inc. ERA) - Economic Assessment Mr. Mahady, a Vice President - ind Boston Manager of ERA, has . :onducted numerous projects or studies .n economic development, transporta- :ion, tourism and recreation, and real j» istate. For this project, Mr. Mahady directed ERA's economic assessment of .impacts from all project alterna- tes. He holds a Masters degree in )lanning and economics. Victor Impemba Jryant Associates, Inc. - Right-of-Way Investigation Mr. Impemba is a civil engineer nth 15 years of experience working on i variety of projects involving lighway and transit design, property Investigation, and preparation of instruction specifications and ?stimates. In this study, Mr. Impemba vas involved in property research and preparation of right-of-way plans for :he various alternatives. 'auline C. Harrell experience. She holds a Masters degree in history and is on the faculty at Boston University in the graduate program for preservation studies. Ms. Harrell supervised the historical resources inventory and impact assessment in the Third Harbor Tunnel and Central Artery study. Russell J. Barber, Ph.D. Institute of Conservation Archaeology (ICA) - Archaeological Resources As Director of ICA, Dr. Barber was responsible for the overall review, research, and documentation for the Phase I archaeological investigation for the Third Harbor Tunnel and Central Artery study. Dr. Barber holds a Doctorate in archaeology. He has specialized in New England archaeology since 1971, and has published 20 articles and two books on the subject. Neil Farmer Ryan, Elliott Appraisal and Consulting Company, Inc. - Conceptual Appraisal and Real Estate Analysis Mr. Farmer, Vice President of Ryan, Elliott Appraisal and Consulting Co. Inc., has over ten years of experience in real estate consulting and appraisal. He has worked with a wide variety of public and private clients throughout New England. For this project, Mr. Farmer supervised the firm's estimates of probable acquisition costs for various properties, estimated relocation resources, and helped to identify the availability of relocation space. Anthony DiSarcina, P.E. Segal/DiSarcina Associates Consultant ioston Affiliates, Inc. - Historical Resources Ms. Harrell, Vice President of Boston Affiliates, Inc., is a social t ^nd architectural historian with 13 t ifears of teaching and consulting A former director of CTPS , Mr. DiSarcina is currently a partner of Segal/DiSarcina Associates and specializes in traffic impact studies, preliminary design studies, traffic operations analyses, etc. He assisted the Joint Venture in the preparation of the traffic analysis and highway design analyses for the Supplemental DEIS/DEIR. He holds a Masters degree in civil engineering. The following individuals of HFMW A Joint Venture were also extensively involved in the engineering and environmental/planning analyses of the Third Harbor Tunnel/Depressed Central Artery study. Administration Robert Yarsites, HNTB Carl Anderson, HNTB Agency Liaison Robert Kelly, FST Engineering Roy Andersen, HNTB Francis Astone, CEM Richard Azzalina, FST Brian Barry, HNTB Ed Chisholm, CEM Brian Connolly, CEM Gino Cosimini, FST Fred Douglas, CEM Robert Fuller, FST Sceva Johnson, FST Sergiu Luchian, HNTB Edward Machnik, CEM Ed Mahoney, CEM John Mansolillo, HNTB Leonard Marino, HNTB Sal Mirabella, CEM Ed Moresco, CEM Steve Potter, CEM Bill Reed, FST James Rourke, FST Joe San Clemente, HNTB Jeff Sheldon, FST Peter Sizer, HNTB Eugene Skelton, CEM Ben Slusarze, CEM Ray surrette, CEM Sergey Vikdorchik, CEM Andy Warot, CEM Tarysh Waterfield, HNTB Alan Webb, CEM Environmental/Traffic Richard Bessom, FST Robert Dunn, FST Joseph Grilli, HNTB Dean Groves, FST Cathy Hanley, HNTB Gary Hebert, FST Patrick Ita, FST Ken Cram, HNTB Jay Pease, WFA Leonid Velichansky, HNTB John Yaney, FST Graphics Andrea Cioccolanti, WFA Alfred Christopher, FST Joan Driebeek, WFA Jean Piccosi, FST Estelle Shuman, FST Henry Tycner, CEM Planning/Urban Design Irene Carlson, WFA Deneen Crosby, WFA Allison Harper, WFA Tim Koele, WFA Ruth Kolodney, FST Mary Konsoulis, WFA Wendy Landman , WFA Tom Maistros, WFA Lynda Naanes , WFA James Purdy, WFA Linda Ross, WFA Enzo Satta, WFA Mariangela Satta, WFA Carole Schlessinger , WFA H. H. Smallridge, WFA Word Processing Roberta Arcoleo, FST Dawn Barkans, CEM Rosemary Filosi, FST Elizabeth Martin, WFA Sharon Samek , FST In addition, the consulting firm of Sverdrup & Parcel and Associates, Inc. in conjunction with Skidmore, Owings & Merrill, Vanasse/Hangen Associates, Inc., and Planning Innovations, Inc. was responsible for providing HFMW with preliminary supplemental engineering and traffic data for this project related to Alternative 5A Modified. Thomas Regan, P.E. Sverdrup & Parcel and Associates, inc 510 Mr. Regan, a Vice President of verdrup & Parcel and Associates, Inc. erved as project executive and oordinator for his team's work on reliminary Alternative 5A iodif ications , and was responsible for ts tunnel design portions. Mr. Regan •.as 35 years of engineering experience i.nd holds a Masters degree in tructural engineering. Richard E. Hangen, P.E. 'anasse/Hangen Associates, inc. Mr. Hangen is a principal at 'anasse/Hangen Associates, Inc. and specializes in traffic engineering, 'or the preliminary study of iodif ications to Alternative 5A, he lirected Vanasse/Hangen 1 s efforts in formulating the conceptual development )f the proposed modification and the subsequent traffic analyses performed :n assistance of CTPS's traffic forecasts during the SDEIS/SDEIR and r EIS/FEIR phases. Mr. Hangen holds a Masters degree in Civil Engineering.