A group of Minnesota environmentalists, including former Natural Resources Commissioner Tom Landwehr, are calling on Gov. Tim Walz to stop the proposed Twin Metals copper-nickel mine, saying it imperils the Boundary Waters Canoe Area Wilderness, one of the state's greatest assets.

Minnesota shouldn't even be considering a project that the Obama administration scuttled in 2016 as an "unacceptable risk" to the country's most popular wilderness, Landwehr told reporters at a Capitol news conference Tuesday.

"Please stop this project right now," Landwehr said. "It was terminated once before. It should never have been resurrected."

Landwehr's forceful comments came one day before Twin Metals Minnesota will submit its long-awaited mining plan to state and federal regulators. The submission will kick off the mine's formal environmental review and regulatory process, even as the legal and political battle over hard-rock mining in northern Minnesota continues to intensify.

Responding Tuesday, Walz's office did not directly address Landwehr's request. "Like many Minnesotans and people around the world, the Boundary Waters is deeply — and personally — important to Governor Walz," spokesman Teddy Tschann said. "The governor believes that no mining project should move forward unless it passes a strict environmental review process that includes meaningful opportunities for public comment."

Twin Metals furnished a statement saying that the company "is prepared to move its project forward into a robust period of science-based scoping and environmental review, through which we will have to prove that our project can meet or exceed all environmental standards."

Expanding on environmentalists' concerns, Landwehr said Minnesota's regulatory standards are inadequate to protect a unique natural resource such as the Boundary Waters. They don't consider effects on homeowners, outdoor recreation businesses, or campers, hunters and anglers, he said, and they allow pollution. It would "be a miracle," he said, if the mine operation in a watery region of the state does not leak heavy metals and the sulfuric acid generated when sulfur-bearing ore is exposed to water and air.

He also said the mine's waste site, what will become a 120-foot-tall mound of dried processed tailings, will be a "permanent blight."

In addition, Landwehr called on state regulators to deem the Twin Metals application incomplete because it won't include the findings of an aborted federal study on hard-rock mining in Superior National Forest. The U.S. Forest Service had begun the environmental study under President Barack Obama, but the Trump administration canceled it at the 11th hour when it reinstated Twin Metals' two expired minerals leases. The findings have never been made public despite numerous requests from members of Congress, news organizations and others.

Landwehr was commissioner of the state Department of Natural Resources (DNR) when the agency gave the green light to PolyMet Mining Corp., the first company to formally propose copper-nickel mining in Minnesota. Environmentalists have argued that the Twin Metals proposal is categorically riskier because the mine would lie within the watershed of the Boundary Waters, allowing contaminated waste to flow into the pristine wilderness.

Barb Naramore, deputy DNR commissioner, said the state standards her agency implements "were carefully designed to protect human health and the environment."

"Questions about whether the existing laws are sufficiently protective rest most appropriately with the Legislature," Naramore said.

Naramore said that once the agency receives the Twin Metals mine plan, staff will assess whether the agency has the information it needs to begin preparing an environmental impact statement, a formal and time-consuming review.

"As we've stated previously, we expect to have access to relevant federal information about this project, and mining impacts more generally in the Rainy River watershed," she said. "We will request that information from the federal agencies if it is not included in the company's submittal."

A student's appeal

Joining Landwehr on Tuesday were Lukas Leaf, executive director of Sportsmen for the Boundary Waters, high school senior Julie Ruelle with Kids for the Boundary Waters, and Steve Piragis, owner of Piragis Northwoods, an Ely outfitter.

Ruelle told reporters that she grew up camping in the Boundary Waters with her family, and that the lessons she drew from those wilderness experiences helped her cope with brain cancer treatments two years ago. "We are terrified of a future in which wild places no longer exist," Ruelle said.

The group provided an audio recording of Sen. Tom Bakk, an Iron Range legislator who supports Twin Metals, discussing the regulatory process at a meeting of the Ely Area Community Economic Development Joint Powers Board last month. "The truth is the environmental review process is not intended to stop projects," Bakk said. "It's intended to mitigate impacts, so once they start down that road of applying for those permits, it's pretty hard to stop."

The group also noted that a recent Trump administration proposal to streamline federal water-quality rules could handicap state regulators overseeing new projects. In its comment letter on the proposed changes, the Minnesota Pollution Control Agency said the rules would "leave us unable to address potential water quality concerns in or near the Boundary Waters Canoe Area" stemming from Twin Metals.

Twin Metals, a subsidiary of the Chilean mining giant Antofagasta, has said it will file its project proposal Wednesday morning with the DNR and the federal Bureau of Land Management. The proposal will detail all aspects of the underground mine, processing facilities and tailings mound and set the course for further research.

The underground mine on Birch Lake near Ely would employ more than 700 people, produce 20,000 tons of ore a day and run for 25 years.

Jennifer Bjorhus • 612-673-4683