Forest Service: Copper-nickel mining poses threat to Boundary Waters

The study will inform the federal government on whether to place a 20-year ban on that type of mining in the watershed.

Canoeists paddle the Kawishiwi River near Ely in the Boundary Waters Canoe Area Wilderness.
File / Duluth News Tribune

DULUTH โ€” Copper-nickel mining would pose an environmental risk the Boundary Waters Canoe Area Wilderness if conducted within the same watershed, the U.S. Forest Service said in a draft environmental assessment released Thursday.

The study will inform the federal government on whether it should follow through on a 20-year ban on that type of mining and mining activity within the Rainy River Watershed, which is shared with the BWCAW.

Last year, the Biden administration reinitiated an Obama-era mineral withdrawal that had been reversed by the Trump administration. The move bans new federal mineral leases within 225,500 acres of the Rainy River Watershed for two years, with the possibility of extending it to a 20-year withdrawal, or ban. Only Congress can pass a permanent withdrawal.

The 93-page environmental assessment outlines potential environmental impacts to the BWCAW if the full 20-year mineral withdrawal is not enacted and mining projects are allowed to proceed.

Water quality is particularly vulnerable, the study said.


"Development of these mineral resources could ultimately result in the creation of permanently stored waste materials upstream of the Boundary Waters Canoe Area Wilderness with the potential to generate and release water with elevated levels of acidity, metals, and other potential contaminants," the Forest Service said in the study.

A 30-day comment period on the draft environmental assessment will begin June 28. Comments can be made at

The U.S. Department of Agriculture, which oversees the Forest Service, will consider the comments and finalize the study.

The study is being prepared for the Bureau of Land Management, which is part of the Department of Interior. The bureau will make a final recommendation on whether to accept the mineral withdrawal application and pass it on to Interior Secretary Deb Haaland, who will then make a decision on the 20-year ban.

Echoing concerns by environmentalists opposed to mining there, the Forest Service said this type of mining is inherently risky, even with engineered safeguards in place.

"Existing literature suggests that hardrock minerals mining of sulfide-bearing rock, no matter how it is conducted, poses a risk of environmental contamination due to the potential failure over time of engineered mitigation technology," the Forest Service said.

In a news release, Becky Rom, national chair for the Campaign to Save the Boundary Waters, celebrated the study's release, and said it "provides a strong scientific foundation for a 20-year ban on copper mining near the Boundary Waters."

"It is deeply rooted in peer-reviewed science, law, and established federal public lands policy, and validates the concerns of local residents and the American people about the risk sulfide-ore copper mining poses to the Wilderness," Rom said. "It is clear beyond a shadow of a doubt that the watershed of the Boundary Waters is the wrong place for this risky type of mining."


Mining advocates have long said the safety of specific projects should be studied rather than an overarching study examining hypothetical scenarios across the entire watershed.

Twin Metals, which wants to build a mine near the BWCAW, said it will still push for a specific environmental review of its project.

โ€œTodayโ€™s action by the U.S. Forest Service is not informed by science and it attempts to inhibit the consideration of copper-nickel mining projects across a vast area of northeast Minnesota," Kathy Graul, a spokesperson for Twin Metals, said in an emailed statement. "It will affect the future domestic accessibility of clean energy minerals needed to combat climate change and strengthen U.S. supply chains. This action contradicts the goals of the Biden administration."

Twin Metals' plan would include an underground mine processing plant and dry-stacked tailings storage facility on the edge of Birch Lake, which flows into Kawishiwi River and then the BWCAW itself.

twin metals map.jpg
Gary Meader / Duluth News Tribune

In addition to the proposed mineral withdrawal, the Biden administration earlier this year also canceled two of Twin Metals' mineral leases.

In a news release, U.S. Rep. Pete Stauber, R-Minn., blamed Biden for choosing "the wealthy, elite, keep-it-in-the-ground lobby over our workers."

"Instead of reviewing the project-specific proposal offered by Twin Metals, the Biden Administration decided to rely on a political study to find the end result they want: to permanently ban mining in northern Minnesota," Stauber said. "Rest assured, I will fight this on behalf of northern Minnesotans, who deserve high-quality mining jobs.โ€

Jimmy Lovrien covers energy, mining and the 8th Congressional District for the Duluth News Tribune. He can be reached at or 218-723-5332.
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