Identification of Most Probable Stressors to Aquatic Life in the Touchet River, Washington

摘要

This is a causal assessment of a biologically impaired river in the state of Washington. The assessment was done by the Washington State Department of the Ecology (WSDE) after they listed the Walla Walla Basin including the Touchet River on 303d list of impaired waters. A determination of the total maximum daily load (TMDL) to meet water quality standards was then required. The text was reorganized and formatted for the U.S. Environmental Protection Agency (U.S. EPA) publication during a workshop at Canaan Valley, West Virginia in May of 2005. The sampling, analysis, and conclusions are those of researchers who were employed by the WSDE at the time of the assessment. Only comments indicating alternative approaches and suggestions were prepared by the National Center for Environmental Assessment (NCEA). NCEA provided editorial and formatting assistance to make the original WSDE report similar to four other case studies that were solicited as examples for other practitioners of causal assessment.