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compounds such as sulfides. Dredge material can also be 

 contaminated with various metals and organic chemicals and thus 

 require special treatment or management practices to ensure there 

 is no degradation of the marine environment. However, only three 

 to five percent of dredge material can be considered seriously 

 contaminated. 



Contaminated Sediments: Facts and Figures 



No quantitative Federal criteria exist to determine when 

 sediments are contaminated enough by pollutants to require 

 special handling. However, EPA has criteria for five organic 

 pollutants under review and will soon be issuing these 

 regulations for public comment under the Federal Water Pollution 

 Control Act. Promulgation of sediment criteria has been a 

 controversial issue with environmental groups calling for strict, 

 number-based standards to help control permitting decisions, not 

 only for ocean dumping, but also, for example, industrial 

 discharge permits and to provide clean-up standards for Superfund 

 sites. 



However, under even the most stringent views, the vast 

 majority of dredge material is not contaminated and poses few 

 disposal problems. Of the 400 million cubic yards of sediment 

 dredged each year from U.S. waterways, the COE estimates three to 

 12 million cubic yards is contaminated enough to require special 

 handling or treatment. 



Most contaminated material comes from dredging ports and 

 harbors, or from areas where municipal and industrial discharges 

 have polluted estuaries and coastal waters. Riverborne clays 

 that have settled in estuaries and navigation channels also may 

 have been contaminated as they traveled down river systems. Both 

 point (direct discharge) and non-point (such as agricultural and 

 storm runoff, air emissions) pollution contribute to contaminated 

 sediments. 



Pollutants commonly found in dredge material include metals, 

 chlorinated hydrocarbons (PCBs, and DDT), polycyclic aromatic 

 hydrocarbons, and other petroleum products. Most pollutants are 

 absorbed or tightly bound to the organic material or smaller clay 

 particles in dredge material. Sand or gravel, which often makes 

 up a significant portion of dredge material, does not readily 

 absorb pollutants. However, the most abundant component of 

 dredge material, water, can be contaminated. 



The mere presence of contaminated sediment may pose a problem 

 to underwater organisms. Bottom-dwelling (benthic) creatures may 

 absorb toxic substances from the sediment itself, or pass them 

 along the food chain where they may accumulate in larger predator 

 organisms, including humans through seafood consumption. In 

 addition, when these contaminated sediments are dredged and ocean 

 dumped, they may release pollutants directly into the water 

 during both dredging and disposal operations. Dredging itself 

 may unearth "dirtier" sediments which accumulated in coastal 

 areas before water pollution controls were imposed. Finally, 

 movement of the contaminated sediments to an unexposed site may 



