Over the course of six years, the Department of Environmental Quality's Water Quality Planning Bureau has maintained an innovative collaboration with the British Columbia Ministry of the Environment to address rising selenium levels in Lake Koocanusa in northwest Montana.
Lake Koocanusa was formed by construction of Libby Dam, which was dedicated in 1975 by President Gerald Ford. The Kootenai River and the reservoir are part of the Columbia River Treaty between the U.S. and Canada. The dam was built and is maintained by the Army Corps of Engineers and the lake extends 109 miles north, 42 miles of which are in British Columbia. The lake was named in a contest and is a combination of Kootenai River, Canada, and the U.S.A. Hydroelectric generation on the dam is measured at 600 Megawatts.
Rising levels of selenium in the lake were identified in about 2005.
Southern British Columbia has large reserves of high-grade coal, which is shipped globally for steel making by the mining company, Teck Resources. While of metallurgical quality, the coal resides deep within mountainous terrain along the Elk River Valley, which means large quantities of overburden remain as part of the mining. The selenium leaches out of this waste rock and into the Elk River, a tributary of the Kootenai River which forms Lake Koocanusa behind Libby Dam.
Selenium is a micronutrient and while minute quantities of it are essential to biological functions in animals and certain plants, at critical levels it adversely affects a broad range of aquatic life. Selenium also becomes concentrated in the food chain, particularly in lakes, and is known to compromise reproduction in certain species of fish.
A July 2014 DRAFT Memorandum of Understanding has been developed by Montana's Department of Environmental Quality and British Columbia's Ministry of the Environment to jointly study Lake Koocanusa. It establishes a Monitoring and Research Working Group with subcommittees for Steering, Stakeholders, and Technical aspects.
The Monitoring and Research Working Group includes the U.S. Environmental Protection Agency, the U.S. Army Corps of Engineers, Montana Fish, Wildlife & Parks, and the U.S. Fish & Wildlife Service among others.
The goal of the technical subcommittee is to identify water quality standards for selenium levels in the lake that will be protective of sensitive fish and other aquatic species. Any recommended water quality criteria and/or objectives must be submitted for approval before both Montana's Board of Environmental Review and B.C.'s Ministry of the Environment.