BACKGROUND

The Lower Duwamish Waterway site is approximately 5.5 mile portion of the Lower Duwamish River which flows into Elliott Bay. The Washington State Department of Ecology (Ecology) and the U.S. Environmental Protection Agency (EPA) are working to clean up contaminated sediments and control sources of recontamination in the Lower Duwamish Waterway. Ecology and EPA have joined into a legal agreement(Administrative Order on Consent) with the City of Seattle, King County, the Port of Seattle, and The Boeing Company to begin work in the waterway and upland areas.

The sediments along the river contain a wide range of contaminants due to years of industrial activity and run off from residential areas. These contaminants include PCBs (polychlorinated biphenyls), PAHs (polycyclic aromatic hydrocarbons), chlorinated dioxins & furans, metals, and phthalates.

EPA is leading the sediment contamination investigation for the Lower Duwamish Waterway site with support from Ecology. Ecology is leading the efforts to control sources of sediment pollution in the Lower Duwamish Waterway in cooperation with the City of Seattle, the Port of Seattle, King County, the City of Tukwila, and EPA.

Source Control is the process of working to find and control releases of pollution to waterway sediments to prepare for cleanup and prevent sediment recontamination. Finding and controlling sources is difficult, and even with aggressive source control some recontamination may occur.

Read more about the cleanup progress in the 2021 factsheet

View more information about cleanup and source control work in the Lower Duwamish Waterway!

RELATED INFORMATION

• EPA Lower Duwamish Waterway Superfund Site  

ADDITIONAL RESOURCES

• Acronyms used by the Toxics Cleanup Program
• Cleanup Process: Major Steps & Definitions
• Data Submittal Requirements for All Cleanup Sites
• Toxics Cleanup publications