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Portland District

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News Release

Release Number: 04-075
Dated: 4/22/2004
Contact: Matt Rabe, 503-808-4510

Corps releases Bonneville Dam sediment analysis

Sediment investigation finds more PCB cleanup warranted

Portland, Ore. - An analysis of sediment samples taken from the Columbia River following the removal of discarded electrical equipment shows PCB contamination persists upstream of the Bonneville Dam.

As a result of the analysis, part of an ongoing investigation between the U.S. Army Corps of Engineers and the Oregon Department of Environmental Quality, discussions are underway to identify potential cleanup actions for the PCB-contaminated sediment along the shoreline of Bradford Island.

"The data tells us we have more work to do," said Mark Dasso, the Corps project manager. "We will seek input from the public before proceeding with any cleanup actions."

In 2003, following the 2002 removal of electrical equipment containing polychlorinated biphenyls (PCBs) from the Columbia River, the Corps collected a large number of sediment and clam samples above the dam following a work plan approved by both agencies. The Corps and DEQ recently completed an initial sediment data analysis that showed the following:

* Sediment samples collected 3,000 to 4,000 feet upstream from Bradford Island do not contain detectable levels of PCBs.

* PCBs have been found upstream of the Bonneville Dam spillway along the north, east and southeastern shore of Bradford Island. Concentrations in the area where the electrical equipment was removed, as well as adjacent areas, generally exceeded DEQs screening levels for PCBs.

* PCBs were generally not detected in areas identified as potential deposition points for sediment eroded from the equipment disposal areas, except for the south side of Bradford Island.

A final report summarizing all phases work is scheduled for completion in August 2004. The Corps is conducting the work in two phases. The phase I report and a brief summary of the phase II data results are available on the Internet at https://www.nwp.usace.army.mil/issues/bradford/cms/home.asp.

The Corps and DEQ will be contacting tribal interests, anglers and other river users about concerns they have about possible impacts to resident fish, for example bass and walleye, within the immediate vicinity of Bradford Island. Concerns do not exist for migratory fish, such as salmon or steelhead.

PCBs were used as coolants and lubricants in electrical equipment. Manufacture of PCBs stopped in the United States in 1977 because of evidence that PCBs build up in the environment and can result in harmful health effects to people and wildlife. The U.S. Environmental Protection Agency has determined that PCBs are probably carcinogenic to humans. The Corps has been working since the ban went into effect to remove PCBs from its inventory. While most equipment and oils in use today no longer contain PCBs, limited amounts of the compound remain at Corps dams. As equipment is replaced, non-PCB oils and components are installed.

The Corps entered into a Voluntary Cleanup Agreement with DEQ to address contamination at the site in February 1997.

The technical memorandum summarizing the February/March 2002 removal activities and the sediment sampling work plan, and general information about the Bradford Island Cleanup project can be viewed at https://www.nwp.usace.army.mil/issues/bradford/cms/home.asp

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Content POC: Public Affairs Office, 503-808-4510 | Technical POC: NWP Webmaster | Last updated: 2/9/2006 9:38:06 AM

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