Oil spill at Grant County dam prompts cleanup, scrutiny of past spills

State and federal agencies are investigating a recent mineral oil spill at Priest Rapids Dam as cleanup efforts conclude. Newly released records show a history of similar spills at Grant County Public Utility District dams over the past decade.

Grant PUD estimates that about 84 gallons of mineral oil entered the Columbia River on Dec. 3 during maintenance work on one of the dam’s turbine generator units. The Washington Department of Ecology said oil sheen was observed downriver through Richland and further downstream, including as far as McNary Dam on both the Washington and Oregon sides.

Grant PUD said crews discovered the spill around 12:30 p.m. while performing maintenance on Unit P6, one of the dam’s turbine generating units.

Ecology closed the boating and fishing on the Columbia and Grant PUD deployed containment booms and cleanup crews along the river from the Vernita Bridge area and downstream to Pasco.

According to Ecology, they placed absorbent booms in the Columbia River around Richland, Pasco, Columbia Point Marina, and Hanford water intakes during the cleanup operation. The agency lifted river use advisories on Dec. 8 after reporting no additional visible oil sheen and no confirmed reports of impacts to drinking water or wildlife.

“No oiled wildlife or impacts to drinking water have been reported,” Ecology said in a public update announcing the completion of cleanup.

Emily Tasaka, public information officer for Ecology in Eastern Washington, said even small spills are taken seriously.

“Any amount of oil into the waterways is concerning, and even a small amount has an impact on the water and the environment,” Tasaka said.

She confirmed the oil was mineral oil used as a lubricant in the dam’s turbine system.

Tasaka said Ecology collected oil samples at the dam and coordinated cleanup efforts with Grant PUD, its environmental contractor, GrayMar Environmental, and other state and federal agencies. Absorbent materials used during the response will be weighed to estimate how much oil was recovered.

With the emergency phase complete, Ecology is now investigating the cause of the spill, documenting response costs and reviewing the incident for possible enforcement action.

“Washington law requires enforcement action any time a hazardous substance is spilled into water,” Tasaka said. “We will investigate the incident and use that information to determine what level of enforcement is appropriate.”

Potential enforcement actions range from warning letters to monetary penalties, according to Ecology. The agency will also bill Grant PUD for staff time, equipment and state resources used during the response.

Grant PUD said the spill occurred during routine maintenance work and emphasized that crews responded quickly, working with the Department of Ecology and cleanup contractors to contain the oil and prevent contamination of water supply intakes.

“Our teams at the dam receive spill-response training, which really kicked in following this unfortunate incident,” said Jeff Grizzel, Grant PUD’s senior vice president of power and marketing operations.

History of spills

Public records released this month by the Washington Department of Ecology show at least six other reported oil spills involving Grant PUD dams on the Columbia River between 2015 and 2021, affecting both Priest Rapids and Wanapum dams upstream from the Tri-Cities.

According to Ecology spill response records, reported incidents occurred on:

• Jan. 8, 2015 at Wanapum Dam.

• Feb. 25, 2015 at Priest Rapids Dam.

• Jan. 11, 2016 at Priest Rapids Dam.

• Feb. 17, 2017 at Wanapum Dam.

• Nov. 10, 2020 at Wanapum Dam.

• July 10, 2021 at Priest Rapids Dam.

Ecology issued a warning letter to Grant PUD on June 24, 2022, citing the 2020 and 2021 spills. The letter noted delayed reporting in both cases, stating that the 2020 spill was reported 13 days after it occurred and the 2021 spill was reported eight hours late.

Washington law requires immediate notification of oil or hazardous substance spills to state waters within one hour to both the U.S. Coast Guard and the Washington Emergency Management Division, according to the warning letter.

Records related to the Dec. 3 spill are still under review and were not included in the historical reports.

Environmental concerns

According to Grant PUD, the spill occurred during maintenance on the turbine’s guide bearing, when oil was being pumped out for inspection and then pumped back into the unit.

Environmental groups say the most recent spill underscores ongoing concerns about aging hydroelectric infrastructure along the Columbia River.

“No one should be dumping or spilling oil into the Columbia River,” said Miles Johnson, legal director for Columbia Riverkeeper, an environmental watchdog group that monitors pollution in the river. “Unfortunately, oil spills from Priest Rapids and other aging dams are a persistent problem.”

Johnson said Columbia Riverkeeper’s 2019 Clean Water Act litigation against Grant PUD resulted in the utility obtaining a permit intended to reduce and report oil leaks and discharges.

“This recent spill appears to violate that permit,” Johnson said. “Ecology should impose a significant penalty to encourage Grant PUD and other dam operators to do a better job keeping oil out of the Columbia River.”

In a follow-up interview, Johnson said enforcement decisions will be critical in determining whether similar spills continue.

“This is an ongoing problem, an ongoing issue, and ongoing attention from PUD is needed to prevent this,” Johnson said. “The level of vigilance is related to the level of enforcement by Ecology.”

Johnson said warning letters alone may not be sufficient to change behavior.

“If the only consequence is that you pay for cleanup, there is not much incentive to prevent the spill in the first place,” he said. “That creates a perverse incentive.”

He also emphasized the importance of timely reporting.

“Immediate reporting is required so agencies can respond quickly and limit harm,” Johnson said. “When spills are reported late, that undermines the entire spill response system.”

Johnson said cleanup efforts, while important, do not fully undo the damage caused by oil entering the river.

“The unfortunate reality is that oil spilled into the river doesn’t come out of the river,” he said.

The U.S. Fish and Wildlife Service’s Mid-Columbia River National Wildlife Refuge Complex reported light oil sheen near McNary Dam earlier in the response but said no wildlife impacts were documented. Monitoring continues.

Records still pending

The records released so far consist primarily of Ecology situation reports, interagency communications and public updates. Grant PUD has not yet released internal investigation documents, maintenance reports, or detailed cost records related to the spill.

Grant PUD said it worked with Ecology and its environmental contractor to contain and recover the oil and that the affected turbine unit will return to normal operation after maintenance is complete.