New selenium standards for Lake Koocanusa, Kootenai River

New standards could affect upstream coal mining in nearby Canada

HELENA—The Board of Environmental Review adopted rules to establish site-specific water quality standards for selenium in Lake Koocanusa and the Kootenai River.

The rule adoption follows a request made by the Montana Department of Environmental Quality (DEQ) and comes after a 45-day public comment period and a public hearing, in addition to numerous presentations to interested parties. 

HELENA—The Board of Environmental Review adopted rules to establish site-specific water quality standards for selenium in Lake Koocanusa and the Kootenai River.

Lake Koocanusa gets its name from "Kootenai, Canada, USA." Photo by David Reese/Montana Living
“The department is extremely pleased that after an extensive multi-year process that included public engagement and collaboration, the proposed selenium standards have been passed. The new standards will protect Montana and downstream waters,” said DEQ Director Shaun McGrath. “We would not have achieved this outcome without the thoughtful public comments that were submitted on the proposed rules. The standards adopted today reflect amendments made as a result of those comments. DEQ would also like to acknowledge our state, tribal, federal and provincial partners who have helped to develop the science behind these standards.”
The Board of Environmental Review passed new water column and fish tissue selenium standards for both Lake Koocanusa and the Kootenai River. The new water column standard for Lake Koocanusa is 0.8 µg/L. This standard was developed based on the unique, site-specific aquatic ecosystem of the water body. The new standard for the Kootenai River is 3.1 µg/L and based on EPA's recommended national criteria
The new fish tissue standards are broken down into egg-ovary (15.1 mg/kg), muscle (11.3 mg/kg) and whole-body (8.5 mg/kg) selenium values for both water bodies. 
The standards are a culmination of more than six years of collaboration with leading selenium scientific experts and the Lake Koocanusa Monitoring and Research Working Group that included public meetings, data collection and a peer-reviewed modeling report.

The selenium standards for Lake Koocanusa and the Kootenai River are designed to protect water quality and the health of aquatic life.  
For more information, visit DEQ’s website at:

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