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Alternatives to Ocean Disposal of Contaminated Dredge Materials 



As stated above, only a small percentage of dredge material 

 are contaminated enough to require special handling. However, 

 given the presence of contaminated sediments in harbors and 

 navigation channels which must continue to be cleared to allow 

 safe vessel access, the growing number of coastal Superfund sites 

 which involve sediments, public opposition to marine pollution, 

 and scientific advances which allow us to detect smaller and 

 smaller quantities of pollutants, there has been considerable 

 research on ways to isolate or decontaminate contaminated 

 sediments. 



Generally, if ocean dumping of contaminated dredge material 

 is not environmentally acceptable, there are three options: 1) 

 dispose of the material on land; 2) dump but minimize the 

 environmental impact of the contaminates by capping or otherwise 

 isolating the material; and 3) decontamination to allow 

 conventional disposal or beneficial use of the dredge material. 



As follows is a discussion of some of the technologies being 

 used or tested. 



Land-Based Disposal 



1. Hazardous Waste Landfills - In several cases, contaminated 

 dredge material has been buried in dumps designed to receive 

 hazardous waste. This can be a very expensive option given the 

 large amounts of material which need to be disposed of, the cost 

 of using scarce hazardous waste landfills, and the distance that 

 the sediment must travel from the water's edge to the landfill. 

 In addition, there is a danger of exposure from the pollutants if 

 the dump leaks or the surface erodes. Removing the water from 

 the sediment can reduce the volume, but may create another 

 disposal problem if the water is contaminated. 



2. Confined Disposal Facilities - Very common in the Great 

 Lakes region is the use of Confined Disposal Facilities (CDFs) . 

 Materials are mounded in these huge structures, often located on 

 shorelines, and the materials are monitored for leaching or 

 run-off of contaminates. With appropriate capping, the 

 structures can be used for waterside parks. On the other hand, 

 local residents frequently oppose CDFs, and CDF capacities are 

 limited (most usually fill within five years) . In addition, 

 exposing sediments to oxygen in the air may cause certain 

 pollutants to react, creating even more toxic substances. 



3. Wetland/Beach Creation - Contaminated sediments have been 

 used to create wetland areas under a combined COE-EPA Field 

 Verification Program, and mildly contaminated sediment can be 

 used for erosion control along beaches. Some contaminated 

 sediments have been used to reclaim subsiding marshlands. Coarse 

 contaminated sediments could also be used to provide fill for 

 airports or other industrial uses which abut waterways, with 

 proper safeguards for the environment. The Japanese are pursuing 

 this use. 



