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The Commencement Bay Nearshore-Tideflats (CB/NT) Superfund site is located in the City of Tacoma and the Town of Ruston at the southern end of Puget Sound in Washington. The site encompasses an active commercial seaport and includes 12 square miles of shallow water, shoreline, and adjacent land - most of which is highly developed and industrialized.

EPA placed the site on the Superfund National Priorities List in 1983 due to widespread contamination of the water, sediments, and upland areas. EPA has divided the site into several "operable units" that are being managed as distinct cleanup sites:

  • Asarco Smelter
  • Hylebos Waterway
  • Middle Waterway
  • Sitcum Waterway
  • St. Paul Waterway
  • Thea Foss Waterway
  • Tacoma Tar Pits

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What Has Been Done to Clean Up the Site?

The site is being addressed through state, federal and potentially responsible party (PRP) actions.

The Asarco Smelter site is located in portions of north Tacoma and Ruston, Washington. It is a part of the Commencement Bay/Nearshore Tideflats Superfund Site.

From 1993 to 2011 properties in the North Tacoma/Ruston area were tested by EPA for arsenic and lead contamination from the Asarco smelter. You can search for sampling results and cleanup records for properties in the EPA Ruston and North Tacoma Study Area on the Washington State Department of Ecology's website. It will take you to the Area-wide Remediation Environmental Information System (AREIS) Database, which is a joint project with Washington Department of Ecology and EPA, with help from the Tacoma Pierce County Health Department. Information on additional cleanup by the Washington Department of Ecology will be added to this database as the work is completed.

EPA sampled 3,570 properties and cleaned up 2,436 with the worst contamination, within a one square mile area of Ruston and north Tacoma centered around the former smelter. Washington Department of Ecology will now offer voluntary yard cleanups within a larger study area. Learn more about the Department of Ecology and the Tacoma-Pierce County Health Department’s work to clean up properties:

Point Ruston LLC is cleaning up the former smelter property as part of a large housing and commercial development, under EPA’s continued oversight.

As part of remediation of the St. Paul Waterway portion of the site, PRPs restored 11 acres of shallow marine habitat for ecological reuse. Remedial activities also allowed for the construction of the colorful Chihuly Bridge of Glass public art project and the restoration of 70 acres of estuarine habitat In 2009, the site received about $5.2 million in American Reinvestment and Recovery Act (ARRA) funds. These funds supported activities at the Ruston/North Tacoma study area. These resources helped complete residential, parkland and right-of-way cleanups.

Document collections for these, and the other areas of the Commencement Bay/Nearshore Tideflats cleanup:

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What Is the Current Site Status?

The site’s long-term remedy includes demolishing remaining buildings and structures; excavating soil and slag from the five most contaminated source areas on the site; and disposing of excavated soils, slag and demolition debris in an on-site containment facility (OCF). The remedy also includes capping contaminated sediment; armoring the shoreline of the plant site and slag peninsula against erosion; monitoring impacts of Project Area cleanup on groundwater and off-shore marine sediments; integrating cleanup with future land use plans; and dredging and capping contaminated sediments in the yacht basin.

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Emergency Response and Removal

Additional remedy components include surface water controls; institutional controls; and groundwater extraction, treatment and monitoring. Remedy construction began in 1989. Investigations and remedy construction are ongoing for parts of this project area.

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