Avista Corp. is spending $36 million over six years to replace thousands of electrical transformers that contain PCBs, a cancer-causing compound found in elevated levels in the Spokane River.
Transformers built before the 1980s contain small amounts of polychlorinated biphenyls, industrial compounds once widely used in lubricants for engines and machinery.
Avista voluntarily began targeting the older transformers for changeout years ago, gradually replacing them when utility crews scheduled other maintenance work at utility poles and substations. But in 2011, Avista stepped up the work, with the goal of removing all of its transformers that contain PCBs by 2016.
The Washington Department of Ecology applauds the utility’s proactive approach, said Adriane Borgias, a water quality specialist for the Spokane River.
“Removing that potential source from the watershed is more cost-effective and less difficult than doing a cleanup if the PCBs were released into the environment,” she said.
Avista’s work is part of a bigger focus on reducing toxic compounds in the Spokane River, where state health advisories urge people to limit meals of fish from the river to reduce their exposure to PCBs and other pollutants. The Spokane-based utility is a voluntary member of a Department of Ecology-led task force working on ways to prevent industrial compounds from getting into the watershed.
In general, there’s a low risk of PCBs from the transformers getting into waterways, said Bruce Howard, Avista’s environmental affairs director. But it could occur if a vehicle struck a pole and the transformer leaked oil, he said.
Avista has 120,000 transformers in Eastern Washington and North Idaho, so just figuring out which contained PCBs was a job in itself, Howard said.
“A lot of times when the manufacturer shipped these, they didn’t tell us that it had PCBs,” he said. “We had thousands that we didn’t have information on.”
The company used a method developed by Jaco Analytical, an Ephrata company, to test the oil in active transformers for pollutants. Avista has replaced more than 8,000 transformers over the past 3 ½ years and has about 4,000 more to go.
Coordinating the transformer changeout with other work at the sites helps the utility reduce labor costs, Howard said. The new transformers are more efficient than the old ones, and the reduced environmental risk is an added benefit, he said.
PCBs are a health risk because they build up in the environment, accumulating in the tissue of fish and other aquatic animals.
In addition to causing cancer, PCBs can affect brain development and mimic the hormone estrogen.