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Department of Ecology News Release - November 18, 2004
04-210
SPOKANE-Residents of the Walla Walla area will have an opportunity in early December to find out more about a study of pesticides and PCBs in the Walla Walla River.
A meeting has been planned for 7 p.m. on Thursday, Dec. 2, at the Department of Transportation, 1210 G St., in Walla Walla (at the airport). Officials from the Department of Ecology will be available to describe the results of the study and to answer questions.
The study was conducted because researchers found that chlorinated pesticides and PCBs (polychlorinated biphenyls) in fish tissue samples were above levels set to protect human health. The state Department of Health is reviewing the data to determine if a public advisory is warranted.
The report, entitled A Total Maximum Daily Load Evaluation for Chlorinated pesticides and PCBs in the Walla Walla River, contains the background needed to write a water-quality cleanup plan for the river system, sometimes called a total maximum daily load, or TMDL. It sets targets for how much pesticide and PCB pollution should be reduced in the Walla Walla River and its tributaries to meet water-quality standards.
Pesticides, such as dieldrin, DDT, chlordane and others, are no longer used in the United States. However, they persist in the environment and accumulate in river sediments and fish tissue.
"Soil cultivation is a major cause of erosion in the basin, and eroding agricultural soils is the main route for pesticides to reach the water," said study author Art Johnson. "The study shows that if we can limit erosion, we can limit the amount of pesticides in the water."
PCBs build up in the fatty tissues of the body and are a known human carcinogen. They are human-made, chlorinated chemical compounds that were once used in a variety of commercial and industrial applications. The U.S. Environmental Protection Agency banned commercial production of PCBs in 1979.
The study report shows that certain pesticides are highest in Yellowhawk Creek, Dry Creek, East Little Walla Walla River and Pine Creek. PCBs were found primarily in the urbanized Mill Creek watershed, especially in Garrison Creek. Lower Mill Creek and Yellowhawk Creek had the second-highest PCB levels.
The report can be reviewed on the Internet at http://www.ecy.wa.gov/pubs/0403032.pdf.
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Media contact: Jani Gilbert, public information manager, 509-329-3495; pager, 509-622-3073
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.html.
