HELENA — Montana has formally adopted tougher water quality standards for Lake Koocanusa, addressing selenium contamination in the Kootenai River watershed.
The Montana Department of Environmental Quality (DEQ) has spent years analyzing selenium in the reservoir, which extends from the Libby Dam north into British Columbia.
The concern is over water quality test results in both the lake, and downstream into the Kootenai River.
Selenium is a naturally-occurring non-metal but can cause serious health risks in high concentrations.
Now, the Board of Environmental Review has adopted the new rules, which set standards for water quality in the lake, and downstream.
Since it's thought the selenium concentrations are coming from mining in British Columbia, the new standards could throw another wrinkle into negotiations over a new Columbia River Treaty, which haven't been making much progress.