Energy Northwest reports small silicone‑oil leak at Columbia Generating Station; heat exchanger replaced

Kelly Elsa Fagan of Energy Northwest gave the council a nonroutine environmental compliance update for July, reporting a small oil migration event at Columbia Generating Station. "We have no nonroutine updates for August. For environmental compliance on 07/18/2026, Energy Northwest environmental regulatory programs was notified that up to 10 gallons of nonhazardous silicone compressor oil ... had likely leaked through the service air compressor heat exchanger and entered the plant service water system," she said.

Fagan said operations inspected the cooling water basin on July 18 and did not observe an oil sheen; the failed heat exchanger (SAHX 2) was confirmed by pressure testing and removed from service July 17–19. The failed heat exchanger was replaced July 21 and returned to service July 22 after successful pressure testing; notifications were made to the National Response Center, Washington Department of Ecology, FSEC and Department of Natural Resources. Energy Northwest is investigating the root cause. Chair Beckett thanked Energy Northwest for the detail and diligence in reporting.