Public notice for the U.S. Environmental Protection Agency

Cleanup to be reviewed for Harbor Island Superfund Site (Seattle, WA)

Harbor Island is a 420-acre island located in the Duwamish River and Elliot Bay in Seattle, Washington. Harbor Island was listed as a Superfund Site (a highly contaminated toxic waste site) by the U.S. Environmental Protection Agency in 1983 after discovering that previous commercial and industrial operations contaminated soil, groundwater, and sediment in the adjacent waterways. Polychlorinated biphenyls are the most widespread contaminant of concern in the sediment, but others include arsenic, polycyclic aromatic hydrocarbons, mercury, and dioxins/furans.

The Harbor Island Superfund Site has been divided up into smaller areas (called Operable Units, or OUs) to help organize the cleanup work. There are seven active OUs. Cleanup decisions were made by EPA at six OUs and by the Washington Department of Ecology at the Tank Farm OU.

The EPA is working on the sixth Five-Year Review for the Harbor Island Superfund Site (due in September 2025). A Five-Year Review provides a routine check-up to make sure that the cleanup continues to protect people and the environment. The most recent Five-Year Review (from 2020) showed that the Harbor Island Superfund Site cleanup remains protective of human health and the environment. To ensure the cleanup continues to be protective of human health and the environment, the EPA performs this comprehensive review every five years.

Do you have information on how the cleanup is working? Have you witnessed any damage to the signage or fencing? Do you have other information? If so, the EPA wants to hear from you by June 2, 2025. Please contact:

Ravi Sanga, EPA Remedial Project Manager at sanga.ravi@epa.gov or 206-553-4092

For more information about the Harbor Island Superfund Site (including previous Five-Year Review documents), please visit:

EPA’s website: www.epa.gov/superfund/harbor-island

If you need materials in an alternative format or language, please contact EPA Community Involvement Coordinator Laura Knudsen at knudsen.laura@epa.gov or 206-643-4299.