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King County’s Wastewater Treatment Division and its predecessor Metro have worked for more than 40 years to restore the Lower Duwamish Waterway.

The Lower Duwamish Waterway (LDW) represents the last five miles of the Duwamish River. Historic activities such as wartime manufacturing, shipping activities and the disposal of raw sewage left the waterway polluted by contaminants including PCBs and phthalates. Now, stringent environmental laws no longer permit industries to discharge process water directly into the river. The biggest source of pollution in our waterways today comes from stormwater runoff from streets, parking lots, homes and commercial/industrial businesses.

King County has been working to clean up the Lower Duwamish for decades. But our efforts to remove historic contamination are only the start.

Learn more about the cleanup, pollution prevention, what you can do, and how to stay safe while using the river.

Library and resources: Superfund Cleanup, Early Action Reports, Source Control