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EPA Announces Cleanup Plan for Terminal 117 on Duwamish River in Seattle
Release Date: 8/4/2005
Contact Information: Ravi Sanga
August 4, 2005
Marking another step forward in cleaning up Seattle’s working waterways; the U.S. Environmental Protection Agency has announced a plan to clean up contaminated soil and sediments in Seattle’s Duwamish River. The plan will cover the area of the Duwamish known as Terminal 117, an approximately 3 acre parcel, 6 miles from the heart of downtown Seattle.
EPA’s decision, made in coordination with the Washington State Department of Ecology (Ecology), sets a course for cleaning up the urban river’s bed and banks, which have been contaminated with a variety of substances and industrial by-products for decades.
Site-specific cleanup action will include:
- Riverbank: Soil contaminated with polychlorinated biphenyls (PCBs) will be removed from the bank and the upland area near the bank, including the drainage ditch at the south end of the property. Creosote treated timber and piles, asphalt, and debris will also be removed. A cap of clean material will be constructed to cover the excavated area and continue down the mudflat to protect the mud from recontamination. Further upland sampling in the northern part of T-117 has been done and more upland soils could be removed depending on the results of the additional sampling.
- South Park Marina: At the north end of the site, the cap will end before the mudflat in order to maintain the water depth needed for boat traffic.
- Submerged mud: This area has lower levels of PCBs than the mudflat. A dredge will remove mud until the surface of the submerged area meets state standards. This area and the dredged area of the mudflat will be filled with clean material to restore habitat for fish and mud-dwelling organisms.
EPA believes that disposing of the contaminated material in appropriate landfills – rather than performing on or offsite treatment -- is protective of people and the environment. The Agency also believes that this strategy will speed up the cleanup, reduce project costs and prevent the possibility of having to dispose of material even after treatment.
The Lower Duwamish Waterway has served as Seattle’s major industrial corridor since it was created by the widening and straightening of the Lower Duwamish River, completed in the early 1900s. Past and present discharges to the waterway include boat manufacturing and repair, marina operations, airplane parts manufacturing, and metals fabrication. In addition, twelve combined sewer overflows and over one hundred storm drains discharge to the waterway.
EPA added the Lower Duwamish Waterway site to the Superfund list on September 13, 2001.
The Port of Seattle and the City of Seattle plan to begin designing the cleanup of T-117 this month. The cleanup work is expected to begin in the spring of 2006 and continue through the following winter.
- Lower Duwamish Superfund Site (yosemite.epa.gov/r10/cleanup.nsf/sites/lduwamish)
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