PORTLAND, Ore. -- Unsafe levels of the toxin PCB recently discovered in freshwater clams and crawfish were caused by electrical debris dumped in the Columbia River, a new report confirmed.

The report was released Wednesday by the U.S. Army Corps of Engineers.

The debris was discovered in 2000 at a site near the former Bradford Island landfill, where the corps dumped household waste and project debris until 1982.

Corps divers finished removing the contaminated waste from the site March 5. The divers also removed 40 cubic yards of nontoxic waste.

Divers worked in river

To measure PCB contamination, scientists looked at animal tissue and sediment samples taken last year from the Columbia River. In some cases, PCB-laden oil was found on the crawfish exoskeletons, as well as in their tissue, according to Matt McClincy, a project cleanup manager with the state Department of Environmental Quality.

McClincy said the crawfish came from an area where electrical debris holding PCB oil was dumped.

McClincy said the state will work with the corps for the next year to devise a plan to deal with the contamination.

Mark Dasso, project manager for the corps, said if samples show the area is still contaminated, the agency could remove the contaminated sediment or cap the river bottom with new fill.

Earlier this month, state officials advised against eating clams and crawfish because of unsafe PCB levels.

A team of divers spent 13 days removing the PCB-laden electrical debris -- including light bulbs, stoves, electric paneling and telephone equipment -- before young salmon began their spring migration.

The corps has spent about $1.2 million on the project since 1997 and plans to spend about $880,000 more this fiscal year, Dasso said.

------

On the Net:

U.S. Army Corps of Engineers: http://www.usace.army.mil