Oil Spilled at The Dalles Dam Contains PCBsby Alex Pulaski
The Oregonian, January 19, 2004
The leak is blamed on water pipes split by freezing;
wildlife officials try to assess the damage to fish and birds
Crews continued their cleanup Sunday of PCB-tainted mineral oil leaking into the Columbia River from a transformer at The Dalles Dam.
The leak, first reported Thursday, involves an undetermined amount of oil from a transformer on the powerhouse's roof. The transformer's capacity is 6,000 gallons, but authorities said it had been partially drained for winter maintenance.
The oil leak is the latest in a series of dam-related spills that have frustrated wildlife organizations and state and federal regulators.
The U.S. Army Corps of Engineers, which operates dams on the Columbia and Snake rivers, has been implicated in 35 oil spills of varying quantities during the past five years. Nearly half the spills have been reported at Bonneville Dam.
Although state agencies in Oregon and Washington have issued violation notices to the corps over past spills, it says states have no authority over the operations of its generators and related equipment.
A corps spokesman said Thursday's leak apparently resulted from the previous week's freezing temperatures, which cracked water-filled cooling pipes.
The leak has caused oil spotting as far downstream as Bonneville Dam and sent a mileslong sheen of oil downriver. The only known wildlife kill has been the discovery of more than 180 dead shad in The Dalles Dam's slot gates.
Wildlife crews searched this weekend for dead and injured birds, finding none related to the spill.
Bob Sallinger, urban conservation director of the Audubon Society of Portland, said that was not surprising, given that birds would tend to become coated with oil and die quickly in hiding from hypothermia.
"There are thousands of birds out there," he said. "There's no question that on a spill of this size there will be impacts for them, direct and indirect."
Joye Redfield-Wilder, a Washington Department of Ecology spokeswoman, said recovery operations had resulted in about 600 gallons of mineral oil being recaptured near the dam.
Although oil containing PCBs -- polychlorinated biphenyls -- has been banned for more than two decades, the mineral oil inside the dam's transformers has become contaminated through its contact with machinery predating the ban. PCBs can cause cancer and damage the immune and reproductive systems of humans and wildlife.
Redfield-Wilder said a consultant's analysis last year determined that the PCB content of the transformer's mineral oil ranged from 5 parts per million to 9 parts per million.
The U.S. Environmental Protection Agency has determined that a transformer is technically considered PCB-contaminated at levels higher than 50 parts per million.
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