298 



The ocean disposal testing evaluation process emphasizes potential biological 

 effects, rather than chemical presence of possible contaminants. Bioassays 

 are used to evaluate the effects of the sediment on appropriate sensitive 

 organisms, to record any mortality, and to determine if dredge material is 

 suitable for ocean disposal. 



Bioaccumulation indicates the biological availability of contaminants in the 

 dredge material to marine organisms. Bioaccumulation also assesses the 

 potential for long-term accumulation of contaminants in aquatic food webs at 

 levels that might be harmful to consumers. Bioaccumulation is used to 

 determine a cause-and-effect relationship between a marine organisms' presence 

 in the dredge material and any adverse elevation of contaminant levels in 

 tissues greater than that in similar marine organisms not exposed to the 

 dredge material . 



Biological evaluations serve to integrate the chemical and biological 

 interactions of the contaminants present in dredge materials by measuring 

 their effects on test organisms. Biological evaluations are more direct and 

 specific than are chemical evaluations, which have to infer interactions and 

 effects based on sediment contaminant data alone. 



Bioassays and bioaccumulation tests indicate a direct and specific biological 

 effect under test conditions and, therefore, have the potential to detect any 

 ecologically unacceptable impact. Thus, the results can be used to determine 

 the acceptability of the material for ocean disposal. Because of the strict 

 testing requirements for ocean disposal, it is very difficult to obtain 

 permits. Dredge material may be considered unsuitable for ocean disposal 

 because of bioassay and bioaccumulation results, but this material, once 

 placed on land, could be considered non-hazardous. If material does not 

 qualify for ocean disposal, other alternatives need to be found. 



If dredged material is not hazardous and of suitable granularity, it is more 

 beneficially used for beach replenishment than disposed of in the ocean. All 

 beach replenishment activities are also regulated by the U.S. EPA, but under a 

 different standard of suitability than exists for ocean disposal. There are a 

 number of other beneficial uses of dredge material provided it is not 

 hazardous. The difficulties of dredging occur when the material is deemed 

 unsuitable for any of the beneficial uses listed previously. 



More time, research, and money need to be spent investigating alternative 

 dredge spoil remediation methods for contaminated sediments. Remediation 

 options for dredged sediments containing hazardous materials are expensive and 

 include, but are not limited to the following: 



1. Confined disposal facilities 



2. Capping 



3. Chemical fixation/stabilization 



4. Size screening/separation 



5. Chemical extraction 



Confined disposal facilities (CDF) are used frequently on the East Coast as a 

 disposal option for contaminated dredge spoils. A CDF is an enclosed area 



-2- 



