For release: June 6, 2012
Portland Water Bureau to Investigate Diesel Spill at Bull Run Hydropower Project under DEQ Oversight
Portland Water Bureau says Bull Run water is unaffected; DEQ will test water to confirm
Under Oregon Department of Environmental Quality oversight, the City of Portland Water Bureau will investigate the extent of soil contamination caused by a diesel spill at the city’s hydropower facility located at the Bull Run Reservoir. Portland General Electric operates the facility and buys the power it generates.
The city and PGE have put together a DEQ-approved cleanup investigation plan that they will implement beginning Thursday, June 7. At the same time, DEQ will collect water quality samples from drinking water intakes, the reservoir and groundwater and test for chemicals commonly found in diesel fuel.
On May 16 diesel fuel was observed in a utility vault at the Portland Hydropower Project located below the Bull Run Reservoir No. 2. The diesel fuel was traced back to a spill that occurred 14 months ago during refueling of a small diesel storage tank. The fuel went into a secondary containment system, which at the time was believed to have captured the entire spill, but a hole in the system allowed a portion of the fuel to leak undetected into the soil below. Once discovered, the hole in the containment system was quickly repaired.
The city estimates that a maximum of 269 gallons of diesel – roughly equivalent to the capacity of a small residential heating-oil tank – may have spilled and seeped into the ground in an area several hundred feet uphill from of the City of Portland’s drinking water intake structure below the reservoir. The investigation will determine exactly how much fuel leaked and what action will be necessary to clean the site up.
“The Portland Water Bureau is confident that none of the diesel seeped into the drinking water supply,” said Portland Water Bureau Administrator David Shaff.
The city will continue to monitor the water quality entering the system.