Washington regulators deny Avista request for ratepayers to cover additional power costs after Montana coal plant closure

Avista Corp. ratepayers in Eastern Washington will not be responsible for covering $3.2 million in costs for replacement power tied to the temporary shutdown of a Montana coal plant.

The Washington Utilities and Transportation Commission issued a ruling Friday striking down requests from three investor-owned Northwest utilities which received some of their power from the Colstrip plant in southeastern Montana.

The Colstrip plant exceeded federal emission standards in June 2018, forcing Avista, PacifiCorp in Oregon and Puget Sound Energy to seek additional supplies during a partial shutdown through September of that year.

Two commissioners ruled that the utilities had not provided enough documentation to show that they would have been unaware of the abrupt loss of energy produced at the Montana facility. After two years of testing well below federal standards for pollutants, the Colstrip plant tested just at the allowable limit in February 2018. That should have served as a warning sign to the providers, a majority of the review panel argued in their decision.

But no documents were provided to the commission to determine whether the actions taken by the company were appropriate, the commissioners argued.

“We are frustrated by the lack of contemporaneous documentation from any of the Companies regarding this discussion or decision making,” the order reads.

Avista has pledged to discontinue its investment in the coal plant in Colstrip by 2025 to comply with a Washington clean energy law mandating an end to coal-produced power in the state.

The commission will allow Avista to seek compensation from its ratepayers for about a half million dollars worth of maintenance work and construction due to the outage.

In an email, a spokesman for the utility said Avista was reviewing the commission’s decision Friday and “we will have the opportunity to provide further comment after doing so.”