The state Court of Appeals on Monday turned back PolyMet's wastewater permit, saying state regulators erred in not considering whether seepage from the proposed mine's tailings dam into the groundwater should be governed by the federal Clean Water Act.
The decision sent the reversed permit back to the Minnesota Pollution Control Agency (MPCA) for more work.
The practical impact of the decision isn't clear as the $1 billion mine that PolyMet Mining Corp. wants to build near Babbitt and Hoyt Lakes is already stalled, with major permits in various states of review, reworking or litigation.
Nearly all parties declared a win in Monday's decision, with the MPCA downplaying the significance.
The MPCA and environmental lawyers clashed on interpretations of the reversal. MPCA spokesman Darin Broton said the agency's interpretation is that the decision only partly reverses the permit without striking it down. The reversal was on narrow grounds for the groundwater analysis, he argued, and it does not reopen the entire permit to debate.
The agency is reviewing the court's directive to do analysis that the law didn't require before the permit's issuance, he said. The wastewater permit protects Minnesota's waters.
"For a second time, a Minnesota court has firmly decided that the MPCA's permitting processes for the PolyMet project were rigorous and prudent," Broton said.
PolyMet Mining Corp. spokesman Bruce Richardson downplayed the court's reversal of its water permit and said the company is "very pleased" with the decision. The decision overruled six of seven challenges that mine opponents made, the company said in a news release.