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Duwamish Superfund Site; Toxic History, Engineering Solutions

Rebecca Chu, EPA Duwamish Clean Up Project Manager 

SUMMARY:  Overview of the EPA process for evaluating and identifying the cleanup plan for the Lower Duwamish Waterway, as well as considerations for implementing the cleanup, including source control. It also includes discussion of the relationship between the cleanup and contaminant loading within the entire watershed, ending with the message that the overall long-term health of our waters is dependent on our individual lifestyle choices.

To see other videos in this series and to learn more about SustainabilityTALKS go to

BIO:  Rebecca Chu is a Remedial Project Manager at the United States Environmental Protection Agency, overseeing cleanups of the nation’s most polluted sites. She has also worked in EPA’s Clean Water Act program on water quality and wetland projects across Alaska, Washington, Idaho and Oregon. Prior to joining EPA, Rebecca performed laboratory research in both the environmental and medical field. Although she enjoyed scientific research, she went on to graduate school to pursue her real passion of applying environmental science to public policy. When not working to protect the environment, Rebecca can be found playing outside across the amazing Pacific Northwest with her family, friends and dog.


EPA’s cleanup plan to reduce risks to people’s health and the environment from toxic chemicals in the Duwamish River includes details of the cleanup of about 177 acres in the waterway involving dredging, capping, and natural sedimentation. The cleanup, which will cost an estimated $342 million, complements the work of state, county and city agencies. Together, these actions will remove over 90 percent of contamination in the waterway.  You can scroll down this page to learn that about half of the contamination has already been removed from the Duwamish Waterway through the completion of the Early Action Areas cleanup efforts. You can also learn more about who pays for the cleanup and how the responsibility is shared.

Fact sheet on the Duwamish River Cleanup Plan - English language version:

Fact sheet on the Duwamish River Cleanup Plan - Spanish language version:

Fact sheet on the Duwamish River Cleanup Plan - Vietnamese language version:

Duwamish River Cleanup Coalition/Technical Advisory Group is the community voice involved in all aspects of EPA’s proposed cleanup of the Duwamish River, and is working to ensure that the cleanup meets community standards. DRCC/TAG manages outreach and educational programming about the Superfund cleanup and is the successor to the community, neighborhood, environmental, tribal and small business organizations that first came together as EPA’s community advisory group for the site. DRCC/TAG receives EPA funding to hire a Technical Advisor to assist the community in reviewing and understanding all cleanup-related studies and plans.

The Department of Ecology and the Environmental Protection Agency are working together on a long term Pollutant Loading Assessment to identify, clean-up, and control sources of pollution to the lower 5.5 miles of the Green-Duwamish River. This is a crucial tool, because, existing sediment data and models completed for the Lower Duwamish Watershed cleanup indicate that sediments in this part of the river may still exceed target levels after cleanup because of pollutant concentrations in sediment coming from upstream.

The Department of Ecology is the lead on controlling sources of contamination coming in to the Lower Duwamish Waterway.

Ecology and EPA are also working on a comprehensive Pollutant Loading Assessment (PLA) of the entire Green/Duwamish Watershed.  The PLA is needed to protect and improve the effectiveness of EPA’s in-waterway cleanup by identifying upstream pollution sources as well as strategies to reduce those sources. 

King County and the City of Seattle have teamed up to establish The Green-Duwamish Strategy, to coordinate the work already being done by local, state, and federal agencies to manage habitat restoration, salmon recovery, flood control, public health, economic development, and more. This includes cleanup of the 5-mile stretch of the Lower Duwamish that is registered as a Superfund site and also addresses the need to reduce pollution that occurs upstream, such as stormwater runoff that brings motor oil, pesticides, and other contaminates into the watershed and, ultimately, into the Lower Duwamish, Elliott Bay, and Puget Sound.

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