EPA's Region 10 dive unit was asked to help plan and execute the deployment and retrieval of passive sampling devices in the Lower Duwamish River. This sampling effort, that began in November of 2012, will help scientists better understand the bioavailability of PCBs on the river bottom.

A photo from the deployment effort: www.flickr.com/photos/usepagov/8246528622/in/set-72157629...

A century of heavy industrial use has left the waterway contaminated with toxic chemicals from many sources – industries along its banks, stormwater pipes, and runoff from upland activities, streets and roads. Pollution in the river sediments includes polychlorinated biphenyls (PCBs), dioxins/furans, carcinogenic polycyclic aromatic hydrocarbons (cPAHs), and arsenic.

Many of these chemicals stay in the environment for a long time, and have built up to unsafe levels in resident fish and shellfish. Because of contamination, state and local health departments warn against eating crab, shellfish, or bottom-feeding fish from the Lower Duwamish River. Migratory salmon are considered safe as they move quickly through the waterway into the Green River watershed.

Lower Duwamish Waterway Superfund Site