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Extraction . Extraction technologies remove contaminants 

 from sediment by separating the contaminant from the sediment 

 particles and/or dissolving and concentrating the contaminant in 

 a solvent with subsequent treatment. The B.E.S.T.* process has 

 been demonstrated on a full scale, 70 tons per day, at the 

 General Refining Superfund site in Garden City, Georgia, on a 

 pilot scale for the ARCS and SITE programs for Grand Calumet 

 River, Indiana sediments, and on a bench scale for three Great 

 Lakes ARCS sediments. The CF System process was demonstrated on 

 a pilot scale for PCB removal at the New Bedford Harbor Superfund 

 Site. The BEST R process has been laboratory tested for dioxin 

 removal from New York/New Jersey sediment. Laboratory 

 evaluations of the B.E.S.T.® process have shown removals of PCBs 

 from sediments between 96 and 99.9 percent. The CF System 

 process achieved 90 to 98 percent removal efficiencies for PCBs 

 at the New Bedford pilot demonstration. Extraction processes 

 could be implemented for relatively small volume sediment 

 remediation projects. Costs for extraction processes range from 

 $100 to $500 per ton based on vendor estimates. 



Thermal Desorption . Thermal desorption is similar to 

 solvent extraction processes in that the contaminants in the 

 sediment are removed, but not destroyed. Separation of 

 contaminants is effected by heating the sediment to temperatures 

 ranging from 200 to 1,000 e F to remove volatile and some semi- 

 volatile organic contaminants. This process has been 

 demonstrated for contaminated sediments on a bench, pilot, and 

 full scale. The ARCS program evaluated ReTec ' s heated auger 

 system for two sediments. Soil Tech's Anaerobic Thermal 

 Processor was evaluated by the ARCS program on a bench and, by 

 the Superfund program, a full scale treatment of sediment from 

 Waukegan Harbor. The Soil Tech unit had a processing rate of 

 approximately 10 tons per hour, but may reach 25 tons per hour. 

 Removal efficiencies for most organic contaminants have been 

 greater than 90 percent, reducing PCB concentrations from an 

 average of 10,000 parts per million to less than 2 parts per 

 million. Thermal desorption processes can be implemented for 

 remediation of hot spot sediments, but high moisture content in 

 the sediment increases the costs. Reported costs for these 

 technologies range from $80 to $350 per ton. The cost of 

 treatment of 12,700 tons of Waukegan sediment was approximately 

 $240 per ton. 



Well Injection and Ocean Disposal in Abyssal Plains . Two 

 other treatment approaches, identified by subcommittee staff, 

 deep well injection and ocean disposal in the abyssal plains, are 

 not discussed because they appear technically infeasible or 

 uneconomic. Deep well injection of a high solids material is not 

 physically achievable. Ocean disposal of sediment that has been 

 unacceptably contaminated with London Convention Annex I 

 compounds, such as mercury,, cadmium, organohalogens and petroleum 



