A newly released report from the Environmental Protection Agency has confirmed what conservationist and scientists have suspected for years: coal mining in Southeastern British Columbia is sending harmful contaminants downstream into Montana.
Extensive coal mining in the Elk River Valley is releasing selenium and nitrates into the Elk River, which is one of the major tributaries of the Kootenai River. Selenium is naturally occurring, but toxic to humans and wildlife in large quantities.
The concern is contaminants are settling into Lake Koocanusa, the trans-boundary reservoir constructed in the early 1970s.
The study didn't find those higher levels in the Kootenai's tributaries, leading to the conclusion the contamination is coming from Canada and being discharged at Libby Dam.
Nitrate levels below the dam were three times higher than samples taken in the early 2000s.
Government and tribal interests will use the data to develop an action plan, and it could play a role in the development of a new Columbia River Treaty.