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UNiVERSITY AT BUFFALO ,c,..
MAR 111993
COCUMENTS DEPOSITORY UBHJ\HY 0433
The U.S. Army has screened and ' evaluated alternatives to treat hazardous wastes in Basin F liquids at the Rocky Mountain Arsenal, near Commerce City, Col orado. The contaminants of concern include organic compounds (includingbyproducts of munitions and chemica1 warfare agent and pesticide manufacturing) and metals.
After . screening numerous alternatives, the Army chose the ftve most promising for detailed evaluation. As a prerequisite, all five a 1 ternat i ves had to meet a11 relevant state and federal laws, including safety standards and air emissions controls. On-site and off-site alternatives were screened. NOT TO SCALE
CONCEPTUAL
In keeping with preferences in the
Federal law for on-site treatment to
SOLIDIFICATION
avoid potential risks involved with
transporting hazardous waste, it was
assumed that the alternatives would
be located on RMA property. This
Fact Sheet which describes the
Solidification Process, is one in
the series of five.
To learn how the public can obtain
more information about the Army's
work at the Arsenal, please see the
companion EPA Fact Sheet, Rocky
Mountain Arsenal Basin F Directory.
~
How it Works
The solidification process would mix various chemicals with the Basin F liquids to immobilize the meta1 s and produce a solid. Organic compoundsin Basin F liquids would be incorporated into. the solid bu~ ~ would not be destroyed or immobilized and could be leached from the solid material. Because Basin F liqufds contain largeamounts of a111110nia and nitrogen
containing compounds, chemicals would be added to react with these compounds and prevent the release of ammonia during mixing and curing of the solid. The Basin F liquids · wou 1 d be pumped into two batch mixing units and mixed with Portland cement, fly ash, soil, and agents to reduce ammonia emissions. Mixingunits would be operated in sequenceand sealed during operation. The moist mixture would be discharged
into disposable 50-gallon drums and held in an adjacent building for 15 days to complete the curing process.The solidification process will be enclosed during mixing, transfer,and curing of the so1 i d; see the flow sheet for this process.
SOLIDIFICATION ALTERNATIVE
What is Needed
To operate the Solidification
Process a facility would be built at
the arsenal, and operational
supplies would be brought in. The equipment and supplies need·~d are listed below: -Batch •ixing units, storagevessels, bins, pipework, and processing equipment. -Air pollution control equipment. -Two separate buildings could house ·the mixing and curing
operations.
173 rail cars (100 cubic yardscapacity each) per year of phosphoric acid, plus comparablylarge quantities of magnesiumsulfate and other compounds would be used. The phophoric acid and
magnesium sulfate. are used to reduce the amount of ammonia released
during mixing.
What Would be Produced
Our ing and after the process,
certain hazardous substances would
be produced. The Army would handle
these products (listed below) in the
following ways:
Gaseous emissions: The
solidification process does not· involve a step that releases quantifiable emissions of organic or metals from a stack. Fugitiveemissions from various pieces of equipment may be released during the mechanical processing, but these emissions are not easily quantified.Moreover control measures will be used to reduce fugitive emissions.
Exhaust from mixing and curing areas wi 11 be treated by air po11 uti on control equipment to control particulates and gases. -Solid waste: The solid produced
would be approximately three times the volume of the Basin F liquids,which could be disposed of in a hazardous waste landfill.
TREATED AIR TO ATMOSPHERE
Advantages and Disadvantages ADVANTAGES/DISADVANTAGES OF SOLIDIFICATION All five alternatives were evaluated
against criteria established by the
U.S. EPA. The five key criteria are described below: Reduction of Toxicity, "obility, or Volume: The intent of this requirement is that the hazardous portions of the wastes should be reduced or destroyed; the ability of the wastes to move through the 1 ~ environment should be limited or halted; or the overall quantity of wastes containing hazardous materials should be reduced. lmplementability: This requirementfocuses on whether the alternative
2 has been proveu in other situations
•· and is commercially available. ' "ini•ization of on-or off-site ~ transport, and off-site disposal of
hazardous material: To reduce the risk of traffic accidents involvinghazardous materials, this factor seeks to 1 finit the amount of wastes and the distance that the wastes would be transported, either on-or off-site. It also seeks to limit the practice of moving hazardous waste from one locality to another. Community protection: This factor focuses on protecting the communityfrom hazards that may result duringthe remedy or afterwards. Reasonableness of cost: Finally,the costs, both of implementing the remedy and subsequent operation and maintenance, are compared amongalternatives. No alternative was considered unless it could meet all applicable or relevant and appropriateregulations.
.....
CRITERIA:
Reduction of Toxicity, Mobility, or Volume {THY)
Imp1 ementabil ity
Minimization of Onor Off-Site Transport, Off-Site Disposal of Hazardous Material
Community Protection
Reasonableness of of Cost Metals will be immobilized, but organics may be leached from the solid material. Solid producedwill be three times the volume of original Basin F
liquids.
Solidification is a well-established technology but less commonly used on liquids.
large quantities of phosphoric acid and other chemical shipped on-site. large volume of solid to be disposed of at hazardous waste landfill.
Minimal potential for off-site impact from process.
Compared to the other alternatives, the solidification
process is the most costly.
Item Estimated Cost (millions of $)
Capital Cost Operation and Maintenance ESTIMATED PROJECT TOTAl $ 5.3 $66.5 $71.8
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