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sediments is not feasible due to the presence of water in the 

 sediment and the effects on the overlying water column. Cost for 

 in situ vitrification treatment of New Bedford sediment was 

 estimated at $290 to $350 per ton in 1988, not counting 

 dewatering and dredging costs. 



In Line Particle Separation and Pipeline Tniection . 

 Particle separation and pipeline slurry injection have been 

 evaluated primarily for hydraulically dredged sediment. Physical 

 separation processes such as gravity settling, spiral 

 classifiers, and hydrocyclones have been demonstrated in The 

 Netherlands and in the ARCS Program. The cost of the physical 

 separation in the ARCS Saginaw River, Michigan demonstration was 

 less than $100 per cubic yard. Injection of chemicals, such as 

 oxygen, hydrogen peroxide, and organic polymers, into the 

 discharge pipe of the dredging operation has been evaluated in 

 this country and the Netherlands with little success. Cost data 

 are not available. 



Bioremediation . Bioremediation technologies use bacteria, 

 fungi, or enzymes to break down petroleum hydrocarbons, PCBs, 

 pesticides, and other organic constituents into innocuous or less 

 toxic compounds. Metals are generally not treated by biological 

 processes. Biodegradation processes have been evaluated only on 

 a bench and limited field pilot scale. Implementation is 

 difficult because of the developmental nature of these processes. 

 Long time periods and large systems will likely be required for 

 treatment of contaminated sediments. The cost could range from 

 $100 to $300 per cubic yard. If biodegradation could be 

 conducted in a confined disposal facility, the cost could 

 decrease. 



Incineration . Incineration is the process of heating 

 contaminated materials to temperatures generally in excess 1200°F 

 in the presence of air to convert organic contaminants to 

 inorganic ash, carbon dioxide and water. Most metals remain with 

 the ash. Incineration is a proven technology for decontamination 

 of soils contaminated with dioxins, PCBs, and other organic 

 contaminants. It has been selected for remediation of hot spot 

 sediments at New Bedford Harbor, Massachusetts, and Bayou 

 Bonfouca, Louisiana, Superfund Sites. The EPA has conducted 

 incineration tests on a bench or pilot scale for New Bedford 

 sediment and for New York/New Jersey sediment. Incineration has 

 demonstrated destruction and removal efficiencies greater than 

 99.9999 percent. Incineration of New York/New Jersey Harbor 

 sediment reduced total dioxin levels in the sediment from 

 approximately 200 parts per trillion to less than 2 parts per 

 trillion. Preliminary cost estimates for removal and 

 i incineration of contaminated sediments from New York/New Jersey 

 Harbors are approximately $1300 per cubic yard. 



