The Kootenai River originates from glaciers in Canada and its watershed spans over 19,000 square miles across British Columbia, Montana, and Idaho. The river crosses the US-Canada border twice. Residents on both sides of the border share its waters and its pollution.
Researchers have recently launched a $4.9 million transboundary study aimed at promoting “a common understanding” of longstanding pollution concerns in the Kootenai River system. The International Joint Commission initiated this study in March 2024 amid concerns about British Columbia's mining operations. Mine runoff flows into the Elk River, a major tributary of the Kootenai, impacting water quality.
Increasing selenium concentration downstream of the mines is of particular concern. While harmless in small amounts, large exposures cause neurological defects and reproductive failure in fish. In humans, excessive levels can lead to severe health issues. Selenium concentrations have increased by over 550% in parts of the watershed over the past 40 years, with fish tissue samples frequently exceeding recommended levels.
Waste rock piles near British Columbia's open-pit mines likely contribute to this toxic pollution. Rainwater flushes selenium into streams, which then travels downstream into Montana and Idaho.
The study will not target mines specifically, but will aim to produce a detailed report on the Kootenai watershed with 4 main areas of focus:
1. Water quality status and trends
2. Impacts to human health and wellbeing
3. Impacts to ecosystems including cumulative effects
4. Mitigation
Funding for the study will be split equally between the US and Canadian governments and a final report is expected within the next two years.
You can learn more about the study and how to get involved here.
