Low to Moderate Pesticide Runoff
by Shannon Dininny, Associated Press
YAKIMA, Wash. -- Pesticide concentrations detected in a federal study of the Columbia Basin Irrigation Project were moderate to low compared with earlier testing, but the number of times pesticides were found was high.
The National Marine Fisheries Service ordered the study as a requirement under the Northwest salmon recovery plan, to monitor the quality of water that flows into the Columbia River to check for pesticides that might harm protected salmon and steelhead.
The Columbia Basin Irrigation Project - some 600,000 acres of irrigated farmland fed by water impounded behind Grand Coulee Dam - is managed by the U.S. Bureau of Reclamation.
The study evaluated water quality in four drainages in the project between July 2002 and October 2004: Red Rock Coulee, Crab Creek, Sand Hollow and Lind Coulee.
The four drainages vary in size from 19 to 710 square miles. Major crops in the area include alfalfa, apples and other tree fruits, onions, wheat, potatoes, corn and peas.
Researchers collected 10 samples from each drainage during the irrigation season, generally April to October, and two samples from each area during the off season, totaling 48 samples.
Each sample then was analyzed for 107 pesticides and metabolites - substances produced by the breakdown of pesticides. Pesticides or metabolites were detected 556 times - a high rate compared with previous studies of the Columbia and Yakima basins or other national agricultural studies.
But pesticide concentrations in those samples were in the moderate to low range, the report said. In all, 42 pesticides and five metabolites were detected. The herbicide Atrazine led the list, turning up in 45 of the 48 samples.
Concentrations of three insecticides and one herbicide sometimes exceeded Environmental Protection Agency or Canadian standards governing long-term exposure, but none exceeded short-term lethal levels for fish, according to the report.
Brian Gorman, a spokesman for the fisheries service, declined to comment on the study Thursday, saying researchers had not yet evaluated the results.
"At this point, we can't say what this report means for fish," he said.
Gorman said the agency's experts would be examining the level of contaminants in the mainstem Columbia River, as well as what those contaminants might mean to fish that are listed as threatened or endangered.
Conservation groups have been battling the government's salmon recovery plan for years, saying it does not go far enough to protect endangered and threatened fish.
The report comes amid new efforts to complete the Columbia Basin Irrigation Project to extend irrigation water to farmers who have been drawing water from wells. Congress initially authorized the project to irrigate about 1.1 million acres, but only 600,000 acres were developed.
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