The Minnesota Court of Appeals has rejected a request for another environmental review for the planned PolyMet copper-nickel mine in northeastern Minnesota.
Environmental groups asked the appeals court to order the Department of Natural Resources to conduct a supplemental study of the impacts if PolyMet builds a larger mine than what regulators have approved. They point out that PolyMet has raised the possibility of a much larger mine with investors.
On Monday, the Court of Appeals said the DNR reasonably determined that the company has not changed its proposals in a way that would require a fresh environmental review.
The Minnesota Center for Environmental Advocacy says it will review the court's decision and decide on its next steps.
The case is one of several pending legal challenges to the project.