PUGET SOUND SEDIMENTS: 
A SOURCE AND SINK OF CONTMINANTS 
Robert C. Barrick 
Tetra Tech Inc. 
Bellevue, Washington 
Introduction 
Why be concerned with Puget Sound sediments? In general, they are 
some of the cleanest sediments found in estuaries of the east and west 
coasts of the United States. Nevertheless, highly contaminated sediments 
are found in some parts of Puget Sound, including the most toxic marine 
sediment ever tested (Swartz et al., in preparation). Concern over the 
potential biological effects of these sediments has prompted extensive 
studies by the National Oceanic and Atmospheric Agency (NOAA), U.S. 
Environmental Protection Agency (EPA), Washington Department of Ecology, 
the University of Washington (UW), the Municipality of Metropolitan 
Seattle (Metro), and other agencies. The wide concentration range and 
diversity in contamination has made Puget Sound especially useful for 
studying biological effects of sediment contamination. 
Puget Sound sediments are a sink for contaminants from three major 
kinds of sources: direct discharges from human activities, natural 
discharges, and relocation of contaminated sediments. Much of the 
contamination derives from people, as either industrial or municipal 
discharges. Natural contaminants eroded from geologic material within the 
drainage basin enter Puget Sound through river discharges. These 
contaminants include organic compounds [e.g., polynuclear aromatic 
hydrocarbons (PAH)] from coal deposits (Barrick et al. 1984; Furlong and 
Carpenter 1982) and metals from a variety of source rocks. Dredged 
material relocated to open-water disposal sites is yet another source of 
contaminants to Puget Sound. Fourteen active and inactive disposal sites 
have been located throughout Puget Sound (Figure 1). Three major sites 
are located next to the cities of Tacoma, Seattle, and Everett. 
Contamination and potential biological effects at these disposal 
sites are not well characterized but will receive additional attention 
through the Puget Sound Dredged Disposal Analysis (PSDDA) program 
administered by the U.S. Army Corps of Engineers (COE), U.S. EPA, 
Washington Department of Ecology, and Washington Department of Natural 
Resources. The current policy for these sites is to not permit disposal 
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