PolyMet, the company trying to open Minnesota's first copper-nickel mine, has formally asked the Minnesota Supreme Court to review last month's Court of Appeals decision that reversed three of its permits and sent them back to the Minnesota Department of Natural Resources for a contested-case hearing. Last month PolyMet said it would appeal the decision.

The Minnesota Department of Natural Resources has not said whether it would also appeal the decision. The agency has until the end of Wednesday to file an appeal.

Last month, the Minnesota Court of Appeals reversed PolyMet's dam safety permits and permit to mine — awarded by the DNR to the company in late 2018 — back to the DNR and said the agency must hold a contested-case hearing.

The contested-case hearing would require an administrative law judge to examine additional evidence and testimony on the project. Then, with information from the contested-case hearing in hand, the DNR must decide whether to reissue the permits.

In its appeal, PolyMet said the court's decision conflicted with the law and Supreme Court precedent. The company also argued agencies should not be required to hold a contested-case hearing if there is no "reasonable basis" that a hearing would aid in making a permit decision.

"This court's review is needed to decide whether the court of appeals correctly interpreted the contested case hearing criteria," attorneys for PolyMet wrote in the petition for review.

The Supreme Court has until mid-April to decide whether it will take up the case.

PolyMet is aiming to establish an open-pit mine, processing facility and tailings dam near Hoyt Lakes and Babbitt at the former LTV Steel Mining Co. site.

Opponents of the mine argue the project could send tainted runoff into the St. Louis River watershed and Lake Superior while supporters say the project will provide more than 300 jobs on the Iron Range and move the area's economy away from iron ore dependence.

Supporters of the PolyMet NorthMet project on Tuesday gathered at the Minnesota Capitol complex to urge the Supreme Court to take up PolyMet’s appeal and to illustrate support for the project.

Leaders from the state’s business, mining, construction and labor fields voiced support for the project along with a bipartisan group of lawmakers.

Doug Loon, president of the Minnesota Chamber of Commerce, said the Supreme Court should reinstate the project’s permits to avoid “unpredictable processes” that could be forged under the Courts of Appeals’ precedent. He said the decision could span to other businesses or municipalities of all kinds as they attempt to obtain permits moving forward.

“This is vital that the courts get this right. The implications of this decision, and then hopefully its reversal by the Supreme Court, will reset the table so that we don’t have unintended consequences for future permitting that creates more uncertainty in the area of review,” Loon said. “Simply put, our members in the business community want to understand the time and cost of compliance. This decision by the courts greatly diminishes the predictability and efficiency of that process.”

Others emphasized the 15-year review process to which the project had been subjected and argued that that should be more than enough to advance the mining project.

"No more statements, no more platitudes, we want action," Senate Majority Leader Paul Gazelka, R-Nisswa, said. "It's time to get this one done."

Democratic-Farmer-Labor lawmakers and others agreed with that sentiment and House Majority Leader Ryan Winkler, D-Golden Valley, said the decision about permitting should fall to the courts, not to the Legislature, as some members of his caucus and opponents of the PolyMet project have requested.

Opponents of the project, meanwhile, delivered a letter to Gov. Tim Walz's office on Tuesday asking his administration to accept the Minnesota Court of Appeals' January decision calling for a contested-case hearing for a set of permits for the project reversed last month.

“As people of faith and moral conviction, we must say no to this dangerous form of mining in the Lake Superior watershed," Rev. Sarah Campbell, of the Mayflower Community Congregational United Church of Christ, said in a statement. "Now is the time to listen to downstream communities — including the Fond du Lac Band of Lake Superior Chippewa and the cities of Duluth and Cloquet — who would bear the risks of toxic pollution for generations to come.”

This story was updated at 4:54 p.m. with quotes from groups opposed to and in support of PolyMet. It was originally posted at 1:35 p.m.