Justice Department Reaches $668M Settlement Agreement for Continued Cleanup of Lower Duwamish Waterway Superfund Site in Seattle Area
Wednesday, March 4, 2026 - Today, the Justice Department, Environmental Protection Agency (EPA), and State of Washington reached agreement on a proposed settlement with more than 100 responsible parties to address hazardous substances released into the Lower Duwamish Waterway in Seattle. Cleanup work is estimated to cost $668 million and take at least 10 years to complete.
Under the settlement, the Lower Duwamish Waterway Group — which consists of the Boeing Company, the City of Seattle and King County — agreed to design and perform the cleanup plan EPA selected for the in-water portion of the Lower Duwamish Waterway Superfund site.
The cleanup plan requires Boeing, Seattle, and King County to conduct dredging and capping and take other measures to clean up the most contaminated parts of the Waterway. To help fund the required work, the Lower Duwamish Waterway Group will receive about $130 million from other responsible parties and about $140 million from federal agencies.
“The Duwamish is a vital asset to Seattle and the surrounding community. By lodging this settlement with the court today and seeking public comment, we take a big step toward restoring the Lower Duwamish,” said Acting Deputy Assistant Attorney General Justin Heminger of the Justice Department’s Environment and Natural Resources Division. “We are proud to play an integral role in negotiating with more than one hundred other parties to achieve this milestone agreement.”
“This settlement finally ensures full-scale cleanup of the Lower Duwamish Waterway,” said Assistant Administrator Jeffrey A. Hall of EPA’s Office of Enforcement and Compliance Assurance. “The cost-sharing agreement resulting from negotiations among many parties shows that this Administration will make good on its promise to expedite cleanup of hazardous pollutants while ensuring responsible parties are held accountable and the public is not left with the bill for the cleanup.”
“This settlement demonstrates EPA’s commitment to protecting public health, cleaning up contaminated sites, and advancing cooperative federalism with our state partners,” said EPA Region 10 Administrator Emma Pokon. “Cleaning up this waterway will enhance residents’ use, support safer fishing, protect wildlife, and foster a vibrant industrial core in the heart of Seattle.”
The Lower Duwamish Waterway Superfund site is a five-mile segment of Seattle’s only river, the Duwamish. The Waterway has served as Seattle’s major industrial corridor since the early 1900s, hosting industries such as airplane manufacturing, timber operations, cement and brick manufacturing, steel mills and foundries, marine construction and repair, drum recycling and chemical production. Discharges from these industries, and combined sewage and stormwater systems and stormwater systems, contributed to sediment contamination within the waterway.
EPA identified 41 hazardous substances in sediments that pose significant risks to human health and the environment in the Waterway; these include polychlorinated biphenyls, arsenic, carcinogenic polycyclic aromatic hydrocarbons, dioxins, and furans.
This settlement demonstrates EPA’s commitment to protect public health, clean up contaminated lands, and advance cooperative federalism with our state partners. Cleaning up this vital waterway will enhance existing residential and recreational uses, support safer fishing and fish habitats, protect wildlife and foster a healthy, vibrant industrial core in the heart of Seattle.
The settlement is authorized under the Comprehensive Environmental Response, Compensation, and Liability Act (commonly known as Superfund) and Washington State’s Model Toxics Control Act for releases of hazardous substances.
More information is available on EPA’s Lower Duwamish Waterway Superfund site webpage. For more on this settlement, visit EPA’s settlement summary webpage.
Attorneys with Environment and Natural Resources Division’s Environmental Enforcement Section filed the settlement in the U.S. District Court for the Western District of Washington. It is subject to a 30-day public comment period and court approval. The proposed consent decree and information on submitting comments is available at www.justice.gov/enrd/consent-decrees.
U.S. Department of Justice
Office of Public Affairs
Source: Justice.gov
