The Montana Department of Environmental Quality is seeking public comment for next month on the mitigation of Colstrip groundwater contamination.
The state has determined that Units 3 and 4 of the coal-fired power plant in Colstrip are connected to leaking ash ponds that caused groundwater pollution.
Under state law, DEQ requires owner Talen Energy to provide a remedy.
Earlier this month, DEQ opened public comment on the latest cleanup evaluation report.
Talen proposes a system to capture contaminated groundwater and flush out contaminants.
The company is estimating a cost of around $111 million dollars according to DEQ Project Manager Sara Edinburg.
She says this remedy won’t necessarily change how Colstrip operates moving forward. What will is a 2016 settlement requiring Talen to switch to dry stack storage by 2022.
“That’s not part of the remedy. It’ll help the remedy, because they won’t be storing wet ash anymore as of then, but that is a pretty big operational change at that area," Edinburg says.