BURBANK, Wash. – Approximately 44 gallons of new transformer oil leaked into the Snake River during an oil transfer operation at Ice Harbor Lock and Dam Monday morning, Feb. 27, according to U.S. Army Corps of Engineers Walla Walla District officials.
The leak occurred while maintenance staff was replacing the oil in three of the dam’s six power transformer heat exchangers or “cooling units” -- these cooling units had been traced as the likely source of an oil sheen observed by Corps staff and reported to state officials in December and January. The transformers and cooling units are being repaired; part of the repair process is to replace clean oil into the transformers and cooling units. During a non-routine oil-flushing operation, oil escaped from an open transfer connection, onto a concrete floor in the powerhouse and into a drain running to the powerhouse drainage sump. Maintenance crews immediately shut down oil-transfer operations and used absorbent pads to recover oil on floor.
Of the 64 gallons of oil that leaked from the open transfer connection, approximately 15 gallons were recovered in the dam during Ice Harbor staffs’ spill-response actions, 5 gallons remained in the oil transfer hoses, leaving 44 gallons of oil unaccounted for and assumed to have eventually been discharged to the river.
At approximately 11:40 a.m., personnel verified a sheen in the river downstream of the drainage discharge. Corps staff made an official spill notification to the National Response Center, Washington Emergency Management and the Washington Dept. of Ecology. A collection boom was deployed at the dam’s discharge point. Two boat response crews were assembled to scout the river and deployed collection booms where a sheen was spotted. An additional spill-response team from Lower Monumental Lock and Dam joined Ice Harbor’s crew to accelerate cleanup and recovery operations continuing into Tuesday, Feb. 28.
“The Corps regrets this incident. We’re conducting an investigation to determine the appropriate actions to help prevent this particular type of incident from happening again,” said District Commander Lt. Col. David Caldwell. “We're dedicated to continuing a practice of environmental stewardship, as well as other missions such as safe hydropower generation.”
Release no. 12-13