New Ecology publication: Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2006-2008 Triennial Report

 This report is a product of interagency cooperation between the Washington State Departments of Agriculture and Ecology.  It is available online at  


The report summarizes data collected from 2006 through 2008.  Laboratory analyses were conducted for over 160 pesticides and degradates as well as total suspended solids.  Field data were collected for streamflow, temperature, pH, conductivity, and dissolved oxygen.  Trends in water quality parameters were examined, and water quality data were compared to salmon habitat requirements, Washington State numeric water quality standards, and EPA assessment criteria.  


Monitoring was conducted in five basins: Thornton Creek in the Cedar-Sammamish basin representing urban land use; the lower Skagit-Samish basin representing western Washington agricultural practices; the lower Yakima basin representing irrigated agriculture; and the Wenatchee and Entiat basins representing tree-fruit agriculture.

A total of 74 pesticides were detected.  Seven of these did not meet a water quality standard or assessment criterion: permethrin, chlorpyrifos, diazinon, azinphos-methyl, malathion, endosulfan, and total DDT.  Detected pesticide concentrations likely do not directly affect salmonids, but at some sites may affect aquatic invertebrate populations.


However, at some sites, water temperature and dissolved oxygen levels are of concern for salmonids.


If you have questions, please contact Debby Sargeant at 360-407-6139 or