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The Lower Duwamish Waterway Group (LDWG) consists of The Boeing Company, the City of Seattle, and King County. We are committed to advancing the cleanup of the Lower Duwamish under EPA oversight.
The members of LDWG are implementing an effective, timely, and lasting cleanup that:
- Reduces human health risks as quickly as possible under the guidance of the EPA
- Encourages participation of potential responsible parties
- Provides greater certainty around a cleanup timeframe
- Minimizes construction impacts to the community, businesses, and the environment
- Results in an effective and permanent cleanup of the waterway
- Preserves the regional economy through implementable, cost-effective, and minimally disruptive solutions
Starting in 2000 and for over 20 years, the Lower Duwamish Waterway Group (LDWG) members worked under a consent order with the U.S. Environmental Protection Agency (EPA) and the Washington State Department of Ecology (Ecology) for a coordinated investigation of the Lower Duwamish Waterway (LDW) sediments. In fall 2024, LDWG began in-water cleanup construction of the uppermost segment of the Superfund site under an administrative order.
On September 21, 2026, the U.S. District Court for the Western District of Washington approved and entered the LDW consent decree. The consent decree now governs the sediment cleanup of the Superfund site, including long-term monitoring and maintenance of the cleanup area.
Under the terms of the consent decree, the City of Seattle, King County, and Boeing agreed to perform the cleanup. More than 40 other potentially responsible parties also signed the consent decree and agreed to pay their fair share of the cleanup costs.
The members of LDWG are committed to advancing cleanup of the LDW under EPA oversight. LDWG is also working with Ecology, which is leading efforts to control sources of contamination from areas upland of the waterway.
Cleanup will enhance the health of the LDW for tribes and community members, support a more thriving economy, and provide a healthier habitat for fish and wildlife.
About the Duwamish River
The Duwamish has a rich history as Seattle’s only river, and it continues to serve as a place for culture, recreation, wildlife and commerce. The Lower Duwamish Waterway is the last five miles of river before the water flows around Harbor Island and out to Elliott Bay and Puget Sound.
The Duwamish River once ran through tidal marshes and mudflats to meet Elliott Bay, providing ideal habitat for fish, birds, and other wildlife. It has served people, too—local Native American tribes made the river their home and thrived on its natural resources. In the early 1900s, Seattle’s economy grew, and its landscapes changed. Dredging, filling, river diversion, and rechanneling supported local industries and altered the natural flow of the Duwamish to form the Lower Duwamish Waterway that exists today.
In the late 1960s, public concern led to many initiatives to mitigate these stresses. Since the 1970s, modern environmental laws and infrastructure improvements have reduced pollution sources dramatically. In 2001, the Environmental Protection Agency (EPA) listed the Lower Duwamish Waterway as a Superfund site under federal law. While the Lower Duwamish Waterway (LDW) may never return to its pre-industrialized state, much progress has been made and there is more work yet to be completed.
Learn more about the cleanup from those leading the effort.
Debra Williston, King County Department of Natural Resources and Parks
Dave Schuchardt, Sediments Cleanup Program Manager, Seattle Public Utilities
Elly Hale, Project Manager, Environmental Protection Agency