Publication Summary

Initiated in 1991 by the Department of Ecology, the Washington State Pesticide Monitoring Program (WSPMP) analyzes ground water, surface water, fish tissue, and sediments for pesticide residues. The results of these analyses are used to provide information on how these residues are distributed in the environment and if these patterns are changing over time.

Initiated in 1991 by the Department of Ecology, the Washington State Pesticide Monitoring Program (WSPMP) analyzes ground water, surface water, fish tissue, and sediments for pesticide residues. The results of these analyses are used to provide information on how these residues are distributed in the environment and if these patterns are changing over time.

WSPMP surface water samples were collected at eight sites in April, June, and August of 1996. Sites were selected to represent various pesticide uses, including use (1) in urban and suburban areas in King County, (2) on cranberry farms on the Washington coast, (3) by orchards and berry farms north of Spokane, and (4) by dry-land agriculture and on range land south of Spokane. Samples were analyzed for 161 pesticides and breakdown products in the following chemical groups: chlorinated pesticides, organo-phosphorus pesticides, nitrogen-containing pesticides, pyrethroid pesticides, chlorinated herbicides, and carbamates. Conventional parameters measured included total suspended solids, total organic carbon, conductivity, nitrate+nitrite, temperature, pH, and flow.

Thirty-two pesticides and breakdown products were detected in 1996 WSPMP samples. The most frequently detected pesticides were 2,4-D, MCPP, dichlobenil, bromacil, and pentachlorophenol; each was found at four or more sample sites. Washington State and/or USEPA aquatic life criteria were exceeded at two sites. Pesticides above criteria were total DDT, azinphos-methyl (Guthion), and chlorpyrifos (Dursban, Lorsban). Levels of diazinon exceeded the National Academy of Sciences (NAS) recommended maximum concentration to protect aquatic life and wildlife at three sites.

High concentrations of five insecticides were found in WSPMP samples collected in 1994 and 1995 from Grays Harbor County Drainage Ditch No.1 (GHCDD-1). These results prompted an intensive survey in 1996 to assess pesticide contamination from cranberry bog drainage in the Grayland area. Results from water samples collected from GHCDD-1 and Pacific County Drainage Ditch No.1 (PCDD-1) for the WSPMP were also used for the intensive survey. All of the insecticide detections above water quality criteria were at these two sites.

Springbrook, Big Soos, and Newaukum Creeks were sampled in conjunction with the U.S. Geological Survey (USGS) as a part of the National Water Quality Assessment Program, Puget Sound Basin Study Unit. These three creeks are major tributaries to the Green/Duwamish River, which was sampled for pesticides by the USGS on the same dates as the creeks for the WSPMP. Many of the same pesticides were found in the creeks and the river in April, but not in June and August.

Twelve herbicides were detected in samples from Latah (Hangman) Creek, eight from Swamp Creek, and four from Deadman Creek; none exceeded water quality criteria.

Link to EIM data for User Study ID WSPMP96W