The Wenatchee River has had some of the highest concentrations of PCBs in fish tissue measured in Washington State. This report details the findings of a study which assessed concentrations of PCBs and DDT in water, biota, and sediment throughout the Wenatchee River basin during 2014-2015. The study identified two chemically-distinct sources of PCBs to the Wenatchee River, one located near the City of Cashmere and the second near the City of Wenatchee. The main known sources of DDT to the Wenatchee River are within the Mission and Chumstick Creek sub-basins. Follow-up actions include: further source tracing for PCBs and DDT to refine locations and additional research on the bioaccumulation of toxics in the Wenatchee River.

The significant finding in this study was that PCBs in biofilms were significantly correlated with dissolved PCB concentrations in the river.  See Pages 35-39.

There will also be a second report for Phase 2 of the source assessment.

Weblinks:

Report
https://fortress.wa.gov/ecy/publications/SummaryPages/1603029.html 

QAPP
https://fortress.wa.gov/ecy/publications/SummaryPages/1403117.html

Addendum #1
https://fortress.wa.gov/ecy/publications/SummaryPages/1503107.html

Addendum #2
https://fortress.wa.gov/ecy/publications/SummaryPages/1603116.html