News Release
| Release Number: | 01-154 |
| Dated: | 11/28/2001 |
| Contact: | Public Affairs Office, 503-808-4510 |
Portland, Ore.-The U.S. Army Corps of Engineers and the Oregon Department of Environmental Quality (DEQ) are discussing options for removing electrical equipment containing polychlorinated biphenyls (PCBs) from the Columbia River near Bonneville Dam in a way that also will protect the environment.
Final work is underway to validate the raw data compiled from sediment, water and tissue samples taken last spring by URS Consulting and Advanced American Diving under contract to the Corps. A final report detailing last spring's effort will be issued after the data are validated and evaluated. The final report is expected to be available by February 2002. Enough information is available, however, to indicate the general nature of contamination in the local environment caused by equipment in the river off Bradford Island at Bonneville. The new data confirms earlier detections of PCBs in sediment and also identifies PCBs in the tissue of local clams and crayfish.
Divers who surveyed underwater debris mounds estimate about 313 cubic yards of electrical debris are in the river. That's roughly equivalent to 31 10-cubic-yard dumpsters. Most of the electrical debris, switchgear, cable, etc., has never contained contaminants. Other debris, such as culverts and fencing materials, also is in the mounds.
"The Corps is responsible for the materials being in the river," said Mark Dasso, Corps project manager. "Although this happened decades ago, it doesn't diminish our responsibility to clean the area."
Testing indicated that over 98 percent of the river bottom in this area is gravel or cobbles. The remaining 1 to 2 percent of finer-grained sediment has been contaminated with PCBs. That presents the Corps and DEQ with a difficult choice: remove the components this winter, disturbing some sediment in the process, and possibly also remove sediment later, or wait and remove the sediments with the components later, a much more complex task.
"Everybody agrees that we need to remove the equipment," Dasso said. "We just want to be as sure as possible we aren't going to do more harm than good. "
The Corps and DEQ plan to discuss a strategy for retrieving the debris with the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS). The two regulatory agencies are responsible for assuring cleanup plans meet Endangered Species Act (ESA) requirements.
"We think we have enough information to work with NMFS and USFWS to decide the best solution to the problem," said Dasso, "and hopefully all agencies can agree on a plan and schedule that will let us get the equipment out of the water."
The regulatory agencies expressed a concern during earlier discussions that contamination would be stirred up if debris were removed, thus potentially worsening the situation. Plans being developed include placement of a silt curtain to minimize sediment movement out of the immediate area during removal.
During last spring's investigation, sediment, water column and biological tissue samples (clams and crayfish) were collected. Samples were taken at Bradford Island and about one-third of a mile upriver at Goose Island. The Goose Island samples were used to establish background contaminant levels for comparison with those samples gathered near Bonneville Dam. This comparison helps researchers determine contaminant sources.
PCBs were used as coolants and lubricants in electrical equipment until 1977. In the United States, manufacture of PCBs was stopped because of evidence that PCBs build up in the environment and can cause harmful health effects to people and wildlife. The Environmental Protection Agency has determined that PCBs are probably carcinogenic to humans.
PCBs enter the food chain, thus effects on fish (including fish listed under the ESA) and bald eagles are of concern. Clams and crayfish are part of the food chain; contaminants can accumulate in their tissue and thus can be passed to other species. Sediment contamination near Bradford Island appears to be greatest in and very close to the mounds. The clams and crayfish stay in localized areas. Thus the overall food supply for larger fish and birds may only be minimally affected by the release of PCBs.
DEQ is concerned about the presence of PCBs in clams and crayfish. The agency is requesting additional sampling and evaluation to confirm the extent of the contamination in the river and to understand the risk to wildlife and the potential public health risk from consuming fish and other wildlife from this portion of the river. Once the report is finalized, DEQ, the Corps and other affected parties will discuss future requirements for these assessments.
The materials in the river are adjacent to an historic landfill used by the Corps to dispose of household and project waste materials from 1942 until about 1982. In 1996, the Corps notified DEQ about the landfill and the Corps' intent to investigate potential contamination at the site. To assure the landfill investigation would comply with regulatory agency requirements, a Voluntary Cleanup Program (VCP) agreement was signed in 1998 between DEQ and the Corps. Under the VCP Agreement, the Corps is working cooperatively with DEQ to complete the investigation, and any necessary cleanup or remediation, of the Bradford Island landfill. That agreement extends to materials being retrieved from the river.
The landfill site investigation is continuing and a final evaluation report is expected in spring 2002. Remedial actions, if needed, will follow when the investigation is completed. The landfill is in a part of Bradford Island that is not open to the public. It is forested and managed as wildlife habitat.