^ ^ ^ O'V- ct 6 \ 
 
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 The Sewerage and Subsoil Drainage 
 
 OF NORFOLK. 
 
 To THE Drainage Committee, « 
 
 (rentlemm :—I forward herewith a map of Norfolk showing the 
 lines of the proposed sewers, with indications of skes; also a de¬ 
 tailed estimate of the cost of the same. 
 
 The general system was accurately foreshadowed in my Prelimi¬ 
 nary Report; there is no material change in the details therein sug¬ 
 gested. The Pumping Station is placed at the north-east corner of 
 Cove and Brew'er Streets. The general system is divided iido three 
 sections, as follows : 
 
 A. The district drained by the Freemason Street maim 
 
 B. The district drained bv the Brewer Street main. 
 
 C. The district drained by the Cove Street maim 
 
 The lower end of the Freemasen Street main is 10 indies in 
 diameter, and continues of that size to the intersection of Granby 
 and Courtnev Streets ; thence to the end of Freemason Street it is 
 8 inches in diameter. 
 
 The Brewer Street main is 15 inches in diameter from tlie pump¬ 
 ing station to Queen Street; thence to Cumberland Street it is 12 
 inches in diameter; thence to Smith Street it is 10 inches in diam- 
 
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 oter^ and thence to Denby Street, its upper end, it is 8 inches in 
 diameter. 
 
 The Cove Street main is 15 inches in diameter to Fenchurch St.; 
 tlience to Holt Street it is 12 inches in diameter; thence to Char¬ 
 lotte Street it is 10 inches in diameter. This main is made some¬ 
 what larger than the demands of the district now sewered by it 
 would require, in order that it may accommodate if necessary the 
 the future drainage of the north-eastern section of the City, which 
 lies too low to be connected with section B. 
 
 Section A includes the district between Granby and Newdon Sts. 
 as far south as Main Street. Section B includes the district be- 
 tw^een Chesapeake and Granby Streets as far south as Main Street, 
 and also the district south of Main Street, bounded by Marsdeii^s 
 Lane, Union Street, Newton^s Lane, East Water St. and Hutchins’ 
 Lane. 
 
 The district south of Main Street between Market Square and 
 Fayette St. is drained by gravity to the foot of Commerce St., the 
 point of outlet for the force-main of the pumping station. A small 
 district south of Main St. and west of Fayette St. is drained by an 
 independent system discharging at the foot of Matthews St. 
 
 The sub-main and lateral sew’ers are mainly of 6-inch pipe, a 
 small proportion only—about 2000 feet—of the laterals being of 
 8-inch pipe, and the Fenchurch St. submain being of 10-inch pipe. 
 
 As a rule, the minimum grade of all sew^ers, mains, submains, 
 and laterals, is 1 to 300 ; the exceptions are as follow-s : 
 
 The Cove St. main has a grade of 1 to 325 ; the Fenchurch St. 
 sub-main has a grade of 1 to 600 ; the Matthews St. sewer has a 
 grade of 1 to 400 ; the west Water and Commerce St. sewer has a 
 
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gr^ide of 1 to 450 ; tlie west Water and Union Sts. sewer to Com* 
 ) rnerce St. has a grade of 1 to 400 ; and the Cliarlotte St. sewer has 
 
 a grade of i to 450. 
 
 j,/ Taking these grades as a basis^ the sizes of the pipes have been 
 
 regulated with a view to their running at no time to more than one- 
 third of their capacity. This is rather more than the usual allow¬ 
 ance but it will add very slightly to the cost of the work) and will 
 provide for any possible future increase of density of population^ 
 also for a considerable use of the sewers for the discharge of manu¬ 
 facturing wastes. 
 
 . The force-main (the outlet from the pumping station) is 12 inches 
 in diameter, and its cost is estimated at $2500. There is no doubt 
 that for a long time to come, and perhaps permanently, the pumps can 
 perfectly well force the sewage through an 8-inch pipe, and I sub¬ 
 mit to the judgment of the Committee, the decision of this question : 
 ^ whether the exigencies of economy ai*e sufficient to make it worth 
 
 while to take the very slight risk that it might be necessary at some 
 ^ remote future day, to replace this 8-inch pipe with a larger one, or 
 
 to lay a second pipe to double its capacity. Of course the risk 
 would be very much lessened by laying a 10-inch pipe at once, and 
 this would effect a material saving. In making the plan it has 
 been assumed that it may be considered advisable to expend an ex¬ 
 tra thousand dollars on this important part of the work ; but.the 
 
 recommendation is modified bv the above remarks. 
 
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 The details of the pumping station are sufficiently given in the 
 
 drawings and estimates. The drawing shows a brick chimney 67 
 
 feet high and 9 feet wide at the base; but the construction of this 
 
 chimney is not recommended at least for the present, as it is be- 
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 Kered that the smokestack furnished with the boilers will be amply 
 sufficient for active firing. 
 
 The pumps selected are Blake^s Duplex Pumps^ two sets each 
 with a double pump and double steam end. These pumps and the 
 boilers awe offered free on lx)ard in New' York for the figures given 
 in the estimate, 
 
 A Field^s Flushtank is to be built^ as shown by dots at the heads 
 of all the laterals. Their discharging capacity is generally the same 
 as those in use in Memphis (112 gallons.) Three of these tanks are 
 to be of double capacity, (diseharging about 225 gallons), because 
 of the low grade of the sewers to be flushed by them. There are in 
 all 159 flushtanks which, discharging three times in twm days, wdli 
 require for their working about 17,500 gallons per day. * 
 
 The accompanying specifications give full instructions for the 
 performance of all work connected with the construction of these 
 sewers and their appurtenances } but I desire to call especial atten¬ 
 tion to the importance of ample engineering supervision and the 
 closest possible inspection. For on the efficiency with which this 
 part of the work is performed, will depend to a very great degree 
 the efficiency and permanent value of the whole w^ork. The occa¬ 
 sion for expenditure has been restricted as much as possible, with 
 due regard to the requirements of the service. To attempt further 
 economy by cheapening or restricting the necessary supervision, 
 would be most unwise. 
 
 The profiles accompanying this report, give the exact depth to 
 wdiich each sewer is to be laid at each station along the course, as¬ 
 suming the levels upon which the plan is based to be accurate. It 
 will of course be necessary, as the work is constructed, to run new 
 
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 exact levels along the precise lines of the sewers, in order to secure 
 perfect accuracy of grade. 
 
 For the cleansing of the sewers when in actual use, two systems 
 are adopted, one for the mains and one for the laterals. The mains 
 are provided with two manholes, through which cleansing balls may 
 be introduced. These balls are of about 7-8ths the diameter of the 
 sewer, are made of metal, water-tight, and are loaded with a suffi¬ 
 cient amount of water to reduce their buoyancy to such a degree 
 that they will roll easily along the crown of the' sewer. These 
 balls, by restricting the water-way, cause a slight accumulation of 
 head behind them, and the current passes under them with suffi¬ 
 ciently increased velocity to stir up and send forward whatever de¬ 
 posit may exist,—the operation being repeated two or three times at 
 each cleaning. This system has been thoroughly tested in Mem¬ 
 phis and has been found to be most efficient. For the cleansing 
 of the laterals handholes are provided, usually at intervals of 100 
 feet. These handholes and their construction are shown in the 
 accompanying sketch; their location is exactly fixed on the map, 
 and on the occurrence of an obstruction, indicated bv the failure of 
 
 a house drain to discharge, the handhole is reached by opening the 
 street. Its elevated opening protects it against the inflow of the 
 muddy water of the excavation, and it affords ample room for the 
 introduction of the arm for working the cleansing instrument, 
 which is usually nothing more than a stout piece of telegraph wire 
 long enough to reach Irom one handhole to another. With care 
 in construction, and especial care to leave no rubbish or other for¬ 
 eign substance in the sewers, and with a strict adherence to 4 inch 
 
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 house connections in all cases, the liability to obstruction will be 
 very slight. 
 
 For the more perfect ventillation of the sewers, while introdu¬ 
 cing the flow of house drains at the bottom of the main, a special 
 form of branch-piece for the connection of house drains is used. 
 [See accompanying illustration.] 
 
 As indicated in my Preliminary Report, while the immediate 
 removal of all decomposing organic matter is of the greatest impor¬ 
 tance to the sanitary condition of the City, it would be difficult to 
 overestimate the hygienic benefit to result from a perfect draining 
 of the subsoil. Much stress has been laid on this leature of the 
 case by those who have preceded me in discussing the subject, and 
 they have not overstated its importance. 
 
 Fortunately, the subsoil of Norfolk is very largely of a porous 
 character, and the simplest means of underdrainage will be much 
 
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 more effective there than they would be in a more uniformly’re¬ 
 tentive subsoil. 
 
 Proper underdrainage is secured by the use of agricultural 
 drainage tiles laid in the trenches with the sewer pipes at the time 
 of construction, adjusting their sizes to the accumulated flow they 
 may receive, and delivering their flow into manholes, sewers, or, 
 where possible, into flushtanks lying at a low’er level or at the 
 shore. By taking advantage of such means of outlet, it will be 
 easy to prevent such an accumulation of lengths as would require 
 the use of large tiles. Sizes ranging from 1J to 2 inches in diam¬ 
 eter will suffice for nearly the whole City. The cost of this portion 
 of the work is estimated at $5,130.00. This may be somewhat 
 modified in the final arrangement, which is necessarily controlled 
 
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 by the quantity of water met with in excavating the trenches ; the 
 modification, however, cannot be important one way or another. 
 
 The estimate of the cost of the work herewith submitted is based 
 on a careful, detailed computation for different depths and sizes, 
 labor being estimated at $1.50 per day; pipes and tiles at the 
 prices at which it is believed that they can be procured delivered 
 on the ground; bricks at $9 and $13 per thousand according to 
 quality ; flushtanks at $45 each ; and fresh-air inlets at $40 each. 
 
 The total cost of the work, including 10 per cent, for contin¬ 
 gencies, 10 per cent, for engineering and superintendence, and a 
 royalty of 10 cents per foot, is $141,230.42. With proper busi¬ 
 ness management, this estimate is much more likely to be dimin¬ 
 ished than to be exceeded in carrying out the work. 
 
 For the protection of the works and for general sanitary reasons 
 it is important that the use of the sewers be made compulsory on 
 thcipart of the whole population, and that all plumbing work and 
 other drainage of private dwelling houses, hotels, etc., be made 
 strictly in accordance with prescribed regulations based on the best 
 development of the art. 
 
 In closing this report, I beg to recommend as an important aid 
 to the securing of a good execution of all details, that the perfor¬ 
 mance of work by contract be rigidly excluded, all material being 
 
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 purchased by the City, and all work being done by the day. This 
 would be unimportant in the construction of sewerage works of 
 the ordinary kind, with the use of large brick sewers, but where 
 everything is so exactly adjusted to the work that it is to perform, 
 the least deviation from the best in everything may result in serious 
 permanent injury. I believe that thoroughly good workin small-pipe 
 
sewerage can be secured as cheaply by days^ labor as by contract • 
 but even if it were to cost somewhat more, it is to be remembered 
 that to provide Norfolk with a storm-water system of sewerage on 
 the plan herewith submitted, witluadequate pumping works would 
 cost at least $700,000 ; the saving, therefore, by this system is so 
 great as to justify any necessary increase of expenditure to secure 
 the very best workmanship and material. 
 
 It is also worth while to consider the fact that it will cost no 
 more to complete the whole system within three months from the 
 time of beginning the work, than it would to extend the construc¬ 
 tion over several years. 
 
 I shall forward in a fev/ days a report with estimates on the im¬ 
 provements of Newton’s Creek and the Canal -west of Granby St. 
 
 Respectfully Yours, 
 
 , GEO. T. WARING. 
 
 Newport, R. I., June 21st, 1881. »