A new U.S. study has confirmed that coal mines in southeastern British Columbia are contaminating waters shared by Canada and the United States, adding that miners’ attempts to remove selenium from wastewater are not doing much difference in the quantity flowing south.
“It makes a little dent,” said Meryl Storb of the United States Geological Survey, lead author of the recently published study.
“However, water treatment is much less successful in reducing the total annual ma*s moving downstream.”
Selenium, an element toxic to fish found in coal deposits, has long been a source of conflict between British Columbia, Canada and the U.S. government. The contaminant comes from the steelmaking coal mines of Elk Valley, British Columbia, where mining has continued for decades.
Storb said his teams looked at selenium levels in the Kootenay River, which runs through similar geography but has no coal mines. Selenium levels in the Kootenay River are one-tenth those in the Elk River, where selenium consistently exceeds British Columbia and Canadian environmental protection standards.
She said the overall annual amount of selenium flowing down the Elk River and into Lake Koocanusa has more than quadrupled since measurements began in 1985.
Teck says it has installed a $1.4 billion water treatment system at the mine and is structuring new operations to minimize the amount of runoff. It claims to capture at least 95 percent of the selenium from its current operations.
Company spokesperson Chris Stannell said Teck has quadrupled its water treatment capacity since 2020 and plans to double it again by 2027. He also noted that the rate of increase in Total selenium in the Elk River had slowed.
“Monitoring shows that selenium concentrations have stabilized and are decreasing downstream,” he said in a statement. “We expect further significant reductions in selenium… as more facilities come online. »
Stannell said Montana government data shows selenium concentrations in Lake Koocanusa water have been stable since at least 2012.
Storb acknowledged that Teck’s water treatment has been effective in reducing toxin concentrations in late fall and winter, when river levels are low.
“This is the time when they can be most effective,” she said. “They can treat the greatest proportion of water (in the river) and that’s when the concentrations are highest.”
But when flow is high, Teck’s facilities handle a smaller proportion of the river’s flow. Although selenium concentrations during these periods of high flow are lower, the greater volume of moving water means that the overall selenium flux downstream is increased.
“Most of the selenium ma*s is carried downstream during periods of high flow – snowmelt, mainly,” Storb said. “They don’t have much impact on ma*s reduction.”
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In 1985, the report estimated that just under two tons of selenium flowed from the Elk River into Lake Koocanusa. Last year, this figure had increased to almost 11 tonnes.
Teck said the new mining operations are designed to prevent rain and snow from entering the waste rock and to channel any runoff to processing plants.
But Storb said these new operations would create increasingly larger piles of waste rock, increasing the risks of selenium leaching into the environment.
“This provides a longer path and more material for the water to flow over, potentially picking up more selenium as it goes,” she said.
“We’ve seen these really big upward trends. We do not yet know whether or not treatment will address these tendencies.
U.S. officials have for years called for a joint U.S.-Canada investigation into the situation, under the aegis of the International Joint Commission, which deals with cross-border water issues. Canada has not yet accepted any.
This month, Montana Sen. Jon Tester wrote to U.S. Secretary of State Anthony Blinken asking him to either involve Canada in such an investigation or launch one without its northern neighbor.
“Our drinking water is too important to stand idly by while Canada fails to meet its commitments under the agreement,” Tester wrote on November 14.
Tester said he has been trying to do something about this problem since 2015.
First Nations on both sides of the border have also called for a joint Canadian-American investigation.
Teck is in the process of selling its Canadian coal mines to Swiss company Glencore PLC.
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