46 



contaminated sediments is not feasible. Costs are estimated at $300 

 to $400 per cubic yard or ton. 



In line particle separation processes such as gravity settling, clas- 

 sifiers, and hydrocyclones have demonstrated and costs less than 

 $100 per cubic yard. 



Bioremediation processes have been evaluated only on a bench 

 and very limited field pilot scale. Implementation is difficult be- 

 cause of their developmental nature. Long time periods in large 

 systems will likely be required, and costs could well range from 

 $100 to $600 per cubic yard. 



Incineration is a proven technology for decontamination of soils 

 contaminated with dioxins, PCB's, and other organic contaminants 

 with a reduction greater than 99 percent. Costs, however, are over 

 $1,000 per cubic yard or ton. 



Extraction technologies remove contaminants from sediment by 

 separating the contaminant from the sediment particles at greater 

 than 95 percent removal, costs ranging from $100 to $500 per yard 

 or ton. 



Thermal desorption somewhat similar to extraction can remove 

 contaminants greater than 90 percent and have been demonstrated 

 at all levels. The process is useful for hot spots, and costs again 

 may range up to $350 per ton. Two other treatment technologies, 

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

 do not appear feasible. 



Mr. Chairman, in summary, there will be large amounts of sedi- 

 ments requiring cleanup. Innovative solutions will need to be devel- 

 oped or costs will escalate and inhibit any real progress. Sediment 

 remediation will be a complex and expensive task and useful only 

 for those sediments that pose an unacceptable risk if left unman- 

 aged. Otherwise, huge quantities of marginal material may be re- 

 mediated at a high cost without a commensurate benefit. 



The only long-term solution to the contaminated sediments issue 

 is the reduction of pollutants at their source and the cleanup of 

 high risk hot spots on the land as well as in the water. 



Mr. Chairman, that completes my oral statement. I would be 

 happy to answer any questions you may have. 



[The prepared statement of Dr. Engler can be found at the end of 

 the hearing.] 



Mr. Ortiz. Thank you very much. Mr. Pallone, do you have a 

 question? 



Mr. Pallone. No. 



Mr. Ortiz. Mr. Green? 



Mr. Green. I have no questions, Mr. Chairman. Thank you. 



Mr. Ortiz. I just have one question. Dr. Grassle, you mentioned 

 other countries' efforts to remediate contaminated sediments. Is 

 the United States behind in its efforts to reduce contamination? 

 What efforts can be made by the United States to improve the 

 range of technology used in the process of remediation? 



Mr. Grassle. I think that we have been slow to adopt the phased 

 process to look at intermediate containment solutions, long-term 

 remediation solutions in parallel with the immediate needs that we 

 have to solve the urgent problems of a particular port. 



Mr. Ortiz. Anybody else? Mr. Engler, would you like to 



