Montana is approving part of a plan to clean up groundwater contaminated by waste storage ponds at the Colstrip coal fired power plant after receiving more than 400 comments on the clean-up proposal.
The Department of Environmental Quality on June 8 announced it's conditionally approving plant operator Talen Montana’s plan to expand an existing groundwater flush-and-capture system and drain two of the ponds used to store waste from Colstrip Units 1 and 2.
Talen must submit more than $16 million as financial assurance.
DEQ still needs to sign off on a plan to address the source of contamination: unlined ponds that have been leaking elevated levels of boron, chloride and sulfate into groundwater since the 1970s. The agency is asking Talen to consider excavating the Stage 2 ponds. Talen previously proposed capping and closing them.
DEQ has already approved clean up plans for the plant site and the coal ash ponds for Units 3 and 4.
