Publication Summary

Twelve freshwater sites statewide were sampled for persistent, bioaccumulative, toxic (PBT) chemicals during 2007, the first year of the trend monitoring program. Semipermeable membrane devices (passive samplers) were deployed for a one-month period during both the spring and fall.

Contaminants frequently detected were PCBs, PBDEs, DDT and endosulfan compounds, dieldrin, and pentachloroanisole. Contaminant levels for toxaphene, dieldrin, and PCBs did not meet Washington or EPA water quality criteria at five sites.

Recommendations include (1) program changes to improve identification of baseline concentrations, (2) adding other PBTs to the study, and (3) exploring potential sampling sites for future studies.

The Washington State Department of Ecology began implementing a trend monitoring program for persistent, bioaccumulative, toxic (PBT) chemicals in the spring of 2007. Semipermeable membrane devices (passive samplers) were deployed at 12 sites statewide for a one-month period during spring high-flow conditions and fall low-flow conditions. Sample sites represented a range of land use types including urban, agricultural, and mixed use, subject to present and historical contamination. Target analytes included chlorinated pesticides (CPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ether flame retardants (PBDEs).

The PBT Trends Study is one component of the Washington State Toxics Monitoring Program. This report presents the results for 2007, the first year of monitoring.

Many chemicals were detected at high frequencies. PCBs were found in 100% of the samples. DDT and its metabolites, dieldrin, and endosulfan and its metabolites were found in over half of the samples. PBDEs were detected in 96% of the samples, primarily as penta-BDE (BDE-47, -99, -100). Pentachloroanisole (PCA) was found in 74% of the samples.

The widest varieties of chemicals were detected in the Walla Walla and Yakima Rivers. These rivers had higher concentrations of DDT compounds, dieldrin, toxaphene, chlorpyrifos, and endosulfan than most of the other sites sampled. The highest concentration of PCBs and PBDEs were found in the Spokane River.

Several samples did not meet (exceeded) one or more Washington State or EPA water quality criteria for the protection of human health or aquatic life. These were toxaphene in the Walla Walla River, dieldrin in the Yakima River, and PCBs in the Lower Columbia, Duwamish, and Spokane Rivers.

Recommendations include: