Washington utility puts price on closing oldest Colstrip coal plants

BILLINGS – Shutting down and cleaning up the two oldest units at the Colstrip power plant in southeast Montana would cost $130 million to $200 million, according to the Washington utility that owns most of the plant.

Puget Sound Energy, which owns half of Colstrip Units 1 and 2, said the two coal-fired plants can be shuttered and dismantled for $49.7 million. Cleaning up contaminated water and coal waste will take another $85 million to $142.7 million.

The Billings Gazette reported this is the first time since the debate about shuttering Colstrip began that real numbers have been put to paper.

However, the cost to electricity customers to complete the proposed shutdown has not been determined.

The Colstrip Power Plant is the nation’s 15th-largest producer of greenhouse gases, emitting 13.5 million metric tons annually, according to the EPA. Units 1 and 2 are its biggest polluters.

A bill before the Washington Legislature would authorize Puget Sound Energy to file a plan to decommission Colstrip’s two oldest units, and to allow the utility to buy additional ownership in one of the two newer units.

Concern has been expressed about what the impact of shutting down the units would be for the 2,300 residents of Colstrip.

“Montana needs to protect itself,” said Anne Hedges of the Montana Environmental Information Center. “The remediation of this site is critical to Colstrip. It matters more than anything else. The best economic development tool is to have clean water available.”

Colstrip has coal ash ponds that have been leaking wastewater for years. The community’s groundwater has been contaminated, and cleanup is far from over.