Efforts to slow copper-mining's advance into Minnesota are intensifying, with state lawmakers proposing a prohibitive measure that would require mining companies to show proof that a similar non-iron, hard-rock mine has operated safely elsewhere.

More is in the works, including companion state and federal bills to ban copper mining on federal lands next to the Boundary Waters Canoe Area Wilderness.

Those are slated to be introduced shortly in Minnesota and Congress. Such bans would kill the proposed Twin Metals copper mine that Chilean mining giant Antofagasta wants to build.

Efforts at the federal level may have more lift now with the advance of President-elect Joe Biden's more environmentally friendly administration and the slight Democratic edge in the U.S. Senate. Not as much has changed in Minnesota's Capitol, said Alexandra Klass, who teaches environmental law at the University of Minnesota Law School. "In Minnesota we don't really have a change that would make this more palatable," she said.

The "Prove It First" legislation, based on a similar law that was on the books in Wisconsin, was introduced in Minnesota on Wednesday. It's backed by Friends of the Boundary Waters Wilderness and 16 state lawmakers, all Democrats, some of whom spoke at a news conference.

"We are not willing in northern Minnesota to be a test case for these billionaires to do their experiments on our water and our public health. We are just not," said lead author Sen. Jen McEwen, a Duluth DFLer.

The broad bill is a moratorium of sorts and covers any kind of hard rock, or non-iron ore, mine anywhere in Minnesota. To proceed, regulators would have to demonstrate independent scientific evidence that a similar mine that operated for at least 10 years, and that has been closed for at least 10 years, did not release pollutants as defined in state statute.

Advocates say it's a common-sense way to protect all Minnesota waters, and human health, from copper mining pollution.

The Wisconsin law it was modeled after, which took effect in 1998, was later repealed in an effort led by former Republican Gov. Scott Walker.

Copper mining supporters in Minnesota immediately attacked the measure as a move to kill an industry.

"This effort, by a few misinformed legislators, will kill an opportunity for Minnesota to provide the critical minerals needed for both a green economy, as well as essential for our health care industry," said Frank Ongaro, executive director of Mining Minnesota. "Prove it first? Done! That is what our current system is designed to do."

Ban on mining

Separately, the Campaign to Save the Boundary Waters, U.S. Rep. Betty McCollum, and state lawmakers are slated to hold a news conference Thursday to discuss efforts to ban copper mining near the Boundary Waters.

That more targeted legislation would permanently ban copper mining in the Minnesota portion of the Rainy River Watershed that drains into the Boundary Waters, an area of about 11,000 square miles. It would provide more permanent protection for the Boundary Waters than the "Prove it First" moratorium, advocates said.

When McCollum, a St. Paul Democrat, introduced the ban last year it did not make it to the House floor.

But there may be a shift under the Biden administration. The incoming president's pick for secretary of agriculture, Tom Vilsack, who has say on mining in federal forests, has been public about his desire to protect the Boundary Waters. In 2018 he penned a commentary for the nonprofit news website Minn­Post calling the wilderness "priceless" and a potent economic engine for northern Minnesota.

State Rep. Kelly Morrison, DFL-Deephaven, and lead author of the proposed ban in Minnesota, said she expects to introduce the bill any day now. Morrison also supports "Prove It First," and she said she sees no conflict between them.

"I see them as complementary," she said, adding that many lawmakers support both.

The Twin Metals mine near Ely and the Glencore-backed PolyMet mine near Babbitt and Hoyt Lakes would be Minnesota's first hard-rock mines — a much riskier type of mining than iron ore and taconite mining because it exposes crushed sulfide-bearing ore to the elements, which creates toxic sulfuric acid, known as acid mine drainage.

Metals mining is highly polluting, and nearly half of all the documented toxic chemical releases into the environment last year were from this sector, according to the latest federal data.

Jennifer Bjorhus • 612-673-4683