Committee forwards consent decree and settlement agreements for Lower Duwamish Superfund cleanup; county share estimated in the tens of millions

At the March 18, 2025 Transportation, Economy and Environment Committee meeting, Council Central staff and executive branch representatives presented proposed ordinance 2025‑0084, which would authorize the King County Executive to enter into a consent decree with the U.S. Environmental Protection Agency (EPA) and the Washington State Department of Ecology and to sign related multi‑party settlements to fund the cleanup of the Lower Duwamish Waterway Superfund site.

Andy Miklow of Council Central staff summarized the site and settlement background: the 5‑mile Lower Duwamish Waterway runs from the southern tip of Harbor Island to Tukwila and was contaminated by a century of industrial and commercial activity. The county’s potential liability relates to discharges from regional sewer infrastructure, King County International Airport property, Harbor Bond facilities and stormwater from county roads. The county joined…