Conservationists in two states are celebrating Montana’s new limits on the amount of selenium produced by mine-waste allowed in Lake Koocanusa and the Kootenai River.

The Board of Environmental Review, a citizen board of the Montana Department of Environmental Quality, approved water quality standards for selenium in Lake Koocanusa in northwestern Montana that are more stringent than the rest of the state, because those waters face a greater threat from Canadian coalmines just over the border.

"The transboundary pollution resulting from coal mining operations in British Columbia is a direct threat to our water quality and highly valued fisheries,” said Frank Szollosi, Montana Wildlife Federation executive director. “MWF commends Montana DEQ for ensuring a transparent and collaborative process to develop these standards.”

The concentration limit for the Kootenai River below the Libby Dam, which holds back Lake Koocanusa, is 3.1 micrograms per liter, which matches the limit set by the Environmental Protection Agency for streams. Moving water helps move contamination particles around so limits can be a little higher than those for standing water.

That’s why the concentration limit for Lake Koocanusa, which extends north from the Libby Dam over the Canadian border into British Columbia, is 0.8 micrograms per liter, about a quarter of that allowed in the river and less than the EPA standard of 1.5 micrograms per liter.

Water quality samples collected in the lake at the border already register 1.1 micrograms per liter, due to the selenium that has leached from Teck Resources’ coalmines and tailings near the Elk River for decades. The concentration of selenium at the mouth of the Elk River has risen to four times that allowed under British Columbia guidelines.

DEQ also set limits for the amount of selenium found in fish, because the fishery was a primary driver of the new standards. The international Lake Koocanusa Monitoring and Research Working Group started studying selenium contamination six years ago after Montana Fish, Wildlife & Parks found selenium levels were increasing in seven species of fish in the lake between 2008 and 2013.

“The new standards will protect Montana and downstream waters,” said DEQ Director Shaun McGrath. “We would not have achieved this outcome without the thoughtful public comments that were submitted on the proposed rules. DEQ would also like to acknowledge our state, tribal, federal and provincial partners who have helped to develop the science behind these standards.”

When the DEQ standards were proposed on Sept. 24, the mining industry and Republican legislators and county commissioners from northwest Montana tried to stall the proposed rule, accusing the DEQ of fast-tracking the process. But scientists from federal and state agencies in the U.S. and Canada had been working on setting the right standards for six years.

Montana isn’t the only state that has set site-specific standards for threatened water bodies. For example, in 2016, California created an even stricter standard of 0.2 micrograms per liter in the San Francisco Bay and Delta to save clams and animals that eat clams from selenium coming from refineries, municipal wastewater, and to a lesser extent, agricultural runoff.

The Confederated Salish and Kootenai Tribes have been very active in helping to determine the standards and then trying to finalize the DEQ rule because tribal members eat fish from the lake and river. They are actively trying to oppose the Castle Project, Teck Resources’ efforts to expand their mining operations.

People in Idaho were also keeping a close eye on the developments, because the Kootenai River flows west out of Montana into Idaho. The state is working with the EPA to list the Kootenai River as impaired due to selenium poisoning in fish, particularly mountain whitefish, the endangered Kootenai River white sturgeon and the Lower Kootenai River burbot, which is on the verge of being listed as a threatened species.

In 2018 and 2019, whitefish from the river contained selenium that exceeded EPA standards.

The more stringent Montana kept its standards, the less of an issue Idaho would likely have with the water Montana was sending downstream. So the Idaho Conservation League praised the Board of Environmental Review and DEQ for not backing down on its standards.

“We also thank the many advocates in Idaho, Montana, and British Columbia who appealed to Montana environmental officials for these new limits,” said Brad Smith, ICL’s North Idaho director. “Already we have seen alarming signs in Idaho with concentrations of selenium in the bodies of mountain whitefish in the Kootenai River exceeding EPA health thresholds. We urge our friends and neighbors up north in Canada to enforce these limits as well.”

Once the rule is published in the Montana Administrative Record on Dec. 24, it will become effective the next day. Meanwhile, DEQ will submit the rule to the EPA for approval under the Clean Water Act.

Contact reporter Laura Lundquist at