News Release
| Release Number: | 01-007 |
| Dated: | 1/31/2001 |
| Contact: | Public Affairs Office, 503-808-4510 |
Portland, Ore. — Test results show PCBs (polychlorinated biphenyls) are present in sediment samples gathered from the Columbia River near Bonneville Dam. The U.S. Army Corps of Engineers took the samples in December 2000, during a dive to recover power transmission system components.
Of four samples gathered, three were above screening levels (benchmarks) developed by regional regulatory agencies and the Corps for dredged material (sand or sediment) to be deposited in water. The screening level for PCBs in materials deposited in water is .13 parts per million (ppm). Results above screening levels mean additional factors such as proximity to people, potential for release beyond the sample location and risk of intake by plant and wildlife species should be evaluated to find out whether or not there is a concern for human health or the environment, and whether further action is warranted.
The sample from the outer surface of an electrical panel tested at 8.3 ppm, a second sample retrieved from beneath a capacitor tested 5 ppm, and the third, from inside a broken lightning arrester, tested .15 ppm. The fourth sample, gathered five feet from the capacitor, was clean. Results from samples taken from or adjacent to components are most significant in determining future actions.
Tests to detect hydrocarbons showed no contamination. Tests for various other chemical substances, such as metals and semi-volatiles, were planned. The river bottom is very rocky in that area, however, and so little sediment was found that additional tests were not possible.
A new diving contract is currently being prepared. "During November and December dives we recovered six components that tested above screening levels for PCB content: three capacitors and three ballasts. Based on November tests, the rest of the pieces we recovered are not considered hazardous. We plan to have divers back in the water to get the remaining transmission components out of the river during February," said Dawn Edwards, Corps public affairs specialist. "We are working with the National Marine Fisheries Service and U.S. Fish and Wildlife to make sure we meet ESA requirements and that they agree with the recovery plans," Edwards said, "and with the Environmental Protection Agency and the Oregon Department of Environmental Quality (DEQ) to assure we comply with CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) requirements."
In November 2000 Advanced American Diving Service, Oregon City, under contract to the Corps, retrieved two capacitors, lightning arresters, ballasts, relays, and miscellaneous porcelain and metal pieces from the river near Bradford Island, just upstream of the Bonneville spillway. Six samples of equipment that could contain PCBs, five solids and one liquid, were tested for asbestos and PCBs. While no asbestos was detected, PCB levels in two of the six samples were above screening levels.
The Corps had hoped to retrieve all remaining power transmission system components from the river during the December 2000 dive, when one capacitor and various other components were recovered from the river. Further work, however, was put on hold because of weather conditions.
The materials in the river are adjacent to an historic landfill. The Corps identified the landfill site, used by the Corps to dispose of household and project waste materials from 1942 until about 1982, as an area of concern during routine internal inspections. A primary concern was contaminant migration into the sediments or water of the Columbia River. In 1996, following further internal investigations and confirmation of contents, the Corps notified DEQ about the landfill and the Corps' intent to investigate potential contamination at the site. To assure that the Corps' plans comply with regulatory agency requirements, a Voluntary Cleanup Program (VCP) agreement was signed in 1998 between DEQ and the Corps. The VCP makes the two agencies partners in the investigation, and any necessary cleanup or remediation, of the Bradford Island landfill. That agreement extends to materials being retrieved from the river. The Corps is coordinating closely with DEQ as the current work progresses.
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.