HELENA – The U.S. Geological Survey has recently released a Department of Environmental Quality-funded modeling framework for scientific collection and analysis of Selenium data in Lake Koocanusa in northwestern Montana and British Columbia.
The modeling framework is designed to accommodate existing and future data to support a common site-specific standard for Selenium in the reservoir, which extends 90 miles from Libby Dam, 40 miles of which are north of the border in British Columbia.
“As a lead agency for Montana, we are excited to have this scientific tool to collect pertinent data,” said DEQ’s Water Quality Administrator Tim Davis. “This framework allows us to work on both sides of the border as we collect defensible and important information that will help lead to informed standards for Selenium as a critical step in the protection of Montana’s water quality.”
Selenium levels in the lake have been rising over the past decade, largely due to metallurgical coal mining in southeastern B.C. Montana DEQ and the B.C. Ministry of the Environment have collaborated in recent years to develop a common standard for Selenium that will be protective of aquatic life in the lake. The USGS modeling framework is designed to accommodate data collection from numerous state, federal, and provincial agencies on both sides of the border.
Sensitive fish species, such as cutthroat and bull trout, as well as burbot and mountain whitefish, are identified in the framework with seasonal recommendations for sampling for Selenium. Additional water column monitoring protocols are also established. This modeling framework for Selenium has been tested elsewhere over the past 10 years by the USGS and is tailored for specific conditions in Lake Koocanusa.
Selenium is a micronutrient that in minute quantities is essential to biological functions in animals and certain plants, but at critical levels adversely affects a broad range of aquatic life. Selenium becomes concentrated in the food chain, particularly in lakes and reservoirs, and is known to compromise reproduction in certain species of fish and birds.
Montana DEQ and the B.C. Ministry of the Environment have formed the Lake Koocanusa Monitoring and Research Working Group – which comprises Selenium experts from around the world – along with subcommittees and hired contractors. Meetings of the groups have been held twice yearly in communities on both sides of the border. Data on Selenium in the lake will continue to be collected by the various parties to better understand unique local food webs with an aim toward an integrated approach to standards development.
Southern British Columbia has large reserves of high-grade coal, which is mined and shipped globally for steel making by the company Teck Resources. The coal resides deep within mountainous terrain along the Elk River Valley and large quantities of overburden remain as part of the mining. Selenium leaches out of this waste rock and into the Elk River, a tributary of the Kootenai River which forms Lake Koocanusa.
Developing a common Selenium standard will provide British Columbia regulatory programs the information necessary to establish protective strategies for the lake. Currently, Teck Resources has built a treatment plant that uses biological processes to remove Selenium and Nitrates from waste water before entering the Elk River. That plant has run intermittently and has had varying levels of success at improving environmental conditions.
The goal of a Selenium standard common to both Montana and British Columbia will better inform and enforce protective measures at the mines and treatment plants.
The USGS report is available as a PDF document here: https://pubs.usgs.gov/of/2017/1130/ofr20171130.pdf For more information about Montana DEQ’s efforts on the Lake Koocanusa collaborative, visit: http://deq.mt.gov/DEQAdmin/LakeKoocanusa