The latest legal challenge to a proposed copper-nickel mine on Minnesota's Iron Range is underway in St. Paul.
A state judge is conducting a fact-finding hearing into accusations against the Minnesota Pollution Control Agency that it improperly tried to suppress serious concerns by federal regulators about the PolyMet project's risks.
Findings from the hearing will be forwarded by the judge to the Minnesota Court of Appeals.
The high count would then consider that information as it weighs a broader legal challenge to a water quality permit that the state issued for the project in 2018.
The MPCA denies any procedural irregularities about how it handled the permit.
Environmentalists and others have long claimed that the project near the town of Babbit would have adverse affects on the area's water resources.
PolyMet officials say the mine would create hundreds of new jobs.