Publication Summary

This is the study plan for the Potholes Reservoir Assessment of Dieldrin and Other Chlorinated Contaminants.

Potholes Reservoir in Grant County has been listed by Washington State under Section 303(d) of the federal Clean Water Act for dieldrin in edible fish tissue. The U.S. Environmental Protection Agency requires each state to address 303(d)-listed waterbodies by establishing Total Maximum Daily Loads (TMDLs) for each waterbody.

This study will assess Potholes Reservoir for dieldrin, other chlorinated pesticides, and PCBs. Sampling will include fish tissue, surface sediments, and water. The results will be used to (1) evaluate the extent and significance of dieldrin contamination in Potholes Reservoir and (2) make recommendations for a TMDL study (water cleanup plan), if warranted. The fish tissue data will be provided to the Washington State Department of Health for determination of risk to human health from consuming fish from the reservoir.

Each study conducted by the Washington State Department of Ecology (Ecology) must have an approved Quality Assurance (QA) Project Plan. The plan describes the objectives of the study and the procedures to be followed to achieve those objectives. After completion of the study, a final report describing the study results will be posted to the Internet.

Link to EIM data for User Study ID BERA0005