The developer of the NorthMet copper/nickel/palladium project, in north-eastern Minnesota, has secured another court victory, this time in the Minnesota Supreme Court, which ruled in favour of the Clean Air Act permit issued to PolyMet Mining.

The court ruling overturned an order by the state Court of Appeals that remanded the permit back to the Minnesota Pollution Control Agency (MPCA).

Rejecting the central legal argument relied on by opponents of PolyMet’s project, the court ruled that the lower court had “relied on an erroneous interpretation of federal law” when it remanded the permit.

This is the second court victory in as many days. Last week, a federal judge dismissed a challenge by the Fond du Lac Band of Lake Superior Chippewa to the US Environmental Protection Agency’s oversight of a water quality permit issued to PolyMet.

PolyMet chairperson, president and CEO Jon Cherry said the latest court decision was a major step forward in the defence of NorthMet’s air permit.

 “We believe strongly that the facts and the law are on our side, and we are pleased that the court agreed with us on the law. This is a victory for the company, our many stakeholders and for everyone that supports responsible mining in Minnesota.”

The ruling endorses the MPCA’s permitting process which involved a years-long review of the project and its potential effects on air quality, Cherry said.

“The decision provides additional clarity that will enable the company to move closer to mining the metals that are needed for improvement to US infrastructure projects and production of electric vehicles and renewable energy technologies,” he said.

Now that the Minnesota Supreme Court has ruled on the most significant legal issue, the case will return to the court of appeals for resolution of a few remaining items that the court did not specifically address in its original decision. “We are confident that the record in the court of appeals supports the MPCA’s decision to issue the permit,” Cherry said.

When operational, NorthMet will become one of the leading producers of nickel, palladium and cobalt in the US, which is increasingly searching for locally mined sources of critical minerals.

Located within Minnesota’s Mesabi Iron Range, the NorthMet project has a measured and indicated resource of 649-million tonnes. PolyMet plans to develop the mining operation in two phases, the first of which involves development of 225-million tons – nearly one-third of NorthMet’s known resource – into an operating mine processing 32 000 t/d over a 20-year mine life. It also includes rehabilitating the former LTV Steel Mining Company processing plant.