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Department of Ecology News Release - December 6, 2007
07-360
OLYMPIA - The Washington Department of Ecology today announced a preliminary agreement with Alcoa over cleanup goals that the company will achieve when removing polluted sediments from the Columbia River next fall. The agreement will be finalized when the cleanup action plan, being developed this winter, is complete.
The agreement calls for Alcoa to dredge up to 95 percent of known polychlorinated biphenyl (PCBs) contamination from the river bed at its former smelter site near Vancouver. When the dredging is finished and the ecosystem has had time to restore itself, the residual contamination should not exceed 98 parts per billion (ppb) PCBs.
Current sampling indicates most of the contamination in the top layers of the riverbed generally ranges from 100 ppb to 1,000 ppb PCBs. There is a hot spot with a concentration as high as 300,000 ppb, with some contamination as deep as three feet.
Ecology and Alcoa agree that dredging is the best option for reducing the level of contamination. The cleanup goal represents the residual level of contamination that will remain after dredging is complete, sand is brought in to fill holes and the site returns to equilibrium.
"This will be a very aggressive cleanup to remove as much contamination as physically possible," said Carol Kraege, whose Ecology team oversees the Alcoa site. "Unfortunately, the Columbia River is besieged with contamination from many sources. This cleanup is just one of many important steps in the long-term efforts to restore the river's health."
PCBs can cause a variety of health effects and have been linked to cancer. The dredging will lessen the risk to human health and will be protective of wildlife.
Alcoa recently announced its intention to dig and dispose of all clams on its site as soon as feasible. High levels of PCBs were found in clam tissue collected around the Alcoa property and throughout the river. While harvesting freshwater clams in the Columbia is illegal, some have expressed concern that people may ignore the prohibition and dig for clams.
Then Alcoa will complete the remedial investigation and a feasibility study report for the entire site by the end of December. In early January, Alcoa will submit the sediment cleanup engineering plans for Ecology review and approval. Ecology will also begin work on a cleanup action plan for the site, including the sediments. The public will have an opportunity to comment on the cleanup action plan when the draft is published in early spring.
To learn more about Alcoa's cleanup progress to date: http://www.ecy.wa.gov/programs/swfa/industrial/pdf/AlcoaFocusSheet.pdf.
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Media Contacts: Kim Schmanke, Ecology media relations, 360-407-6239
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.html.
