A lawsuit filed last month by environmental groups against the Minnesota Pollution Control Agency, saying the state has failed to enforce water pollution limits on U.S. Steel's Minntac taconite plant in Mountain Iron, has been dismissed.

Online court records indicate the suit, filed in State District Court in Ramsey County by the Minnesota Center for Environmental Advocacy, the Save Lake Superior Association and Save Our Sky Blue Waters, was dismissed this week. The Minneapolis Star Tribune reported that the dismissal order includes a stipulation that the MPCA must complete a new permit for Minntac within nine months.

The state agency issued a new draft permit for Minntac last month, just days after the lawsuit was filed. It would be the first new permit for the facility in 24 years and appears to at least try to bring the largest U.S. iron ore producing facility into compliance with water pollution regulations.

Court records indicate the suit, which had asked the court to impose a new permit with specific limits, by a specific date, for pollutants in Minntac discharges, was dismissed without prejudice. An attorney for the environmental groups told the Star Tribune that if the permit completion and other conditions are not met, the groups retain the right to resume the lawsuit.

The draft permit is posted on the MPCA's website, with public comment open through Dec. 16.

Environmentalists have argued that the Minntac facility releases several problem pollutants in the discharge and groundwater seepage from its giant tailings basin, especially sulfate which at high levels is known to cause harm to wild rice.

The draft permit appears to, for the first time, call for a phased-in sulfate regulation, although it seems to apply to groundwater and not the facility's actual surface discharge.

Current state water pollution regulations require sulfate discharges be limited to just 10 milligrams per liter of water, although those limits are under review by regulators and highly criticized by the state's mining industry. But a 2015 state law also prohibits the PCA from enforcing that sulfate limit until more research is conducted on its value.

Past testing showed Minntac emitting sulfate levels as high as 1,320 milligrams per liter, with an average of 954 milligrams per liter.

Taconite industry supporters have said the sulfate pollution is not impairing local waterways and that forcing taconite plants to further treat discharge would cost millions of dollars and make the Iron Range plants noncompetitive in an increasingly global iron and steel market.