The Minnesota Court of Appeals has rejected some of the most important permits for the planned PolyMet copper-nickel mine in northeastern Minnesota in a major victory for environmentalists.

The Court ruled Monday that the state Department of Natural Resources erred when it declined to order a trial-like proceeding known as a contested case hearing to gather more information on the potential environmental impacts of the project. The court then sent the dispute back to the DNR.

Environmentalists are celebrating the decision. PolyMet says it’ll consider taking the case to the Minnesota Supreme Court, and the DNR says it’s considering its options.

By — Nathan Green