USGS Washington Water Science Center
|U.S. Department of the Interior
U.S. Geological Survey
Release: June 25, 1997
Luis A. Fusté, Information Officer
Low concentrations of pesticides were found in small urban and agricultural stre ams in the Puget Sound region, according to a fact sheet jointly authored by the U.S. Geological Survey (USGS) and the Washington State Department of Ecology (W DOE).
None of the concentrations exceeded drinking-water standards or guidelines, but concentrations of four pesticides exceeded maximum levels recommended for the pr otection of aquatic life. More pesticides were detected in urban than agricultur al streams. This is because the total amount of pesticides used in urban areas in the populated Puget Sound region is about three times greater than the amount used in agricultural areas, say the investigators.
"The amounts of pesticides used in urban areas and on crops explains much of wha t we found in streams, " said Gil Bortleson, USGS hydrologist and the principal author of the fact sheet. "The most commonly detected pesticides were among the most heavily applied in the basin," added co-author Dale Davis of the WDOE. Lo w levels of older-generation pesticides such as DDT were not found in water, but were found in streambed sediments. This is not surprising, according to the aut hors, because many studies nationwide report that older pesticides currently ban ned in the U.S. can still be found in sediments.
The four-page color fact sheet is a product of the USGS National Water-Quality A ssessment Program. The program is designed to assess current water-quality condi tions, describe how water quality is changing, and improve understanding of the natural and human factors that affect water quality.
Copies of Fact Sheet 067-97, "Pesticides in selected small streams in the Puget Sound Basin, 1987-95," by Gilbert C. Bortleson and Dale A. Davis, are available free from the U.S. Geological Survey, 1200 Pacific Avenue, Suite 600, Tacoma, WA , telephone (253) 593-6510, and the Washington State Department of Ecology, Publ ic Distribution Office, (360) 407-7472, or by email at firstname.lastname@example.org. Copies may be viewed on the World Wide Web at http://wa.water.usgs.gov/ps.naw qa.html and are available at most area libraries.
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Note to editors: For additional technical information, contact Jim Ebbert, Project Chief, Puget Sound NAWQA, telephone (253) 593-6530 ext. 234, or email to email@example.com.