The Minnesota Court of Appeals reversed a decision to renew US Steel’s (USS) wastewater discharge permit for its Minntac iron ore mine.
Minntac is located in Mountain Iron, a city in the state’s northeast, and has a 13.6 square mile tailings basin for mine waste that is subsequently recycled for ore processing. Consequently, sulfate build up makes its way into local ground and surface waters.
With the Court of Appeals’ decision, the Minnesota Pollution Control Agency (MPCA)—which first granted the permit in 1987, then renewed in 2018—must submit a new decision regarding permitting.
Minnesota law proscribes sulfate discharge into water where wild rice grows to be less than 10 milligrams per litre, but the state hadn’t enforced the law against USS until recently. Moreover, the state legislature put a moratorium on the law eight years ago while it researched and drafted new rules pertaining to acceptable sulfate limits, which were rejected by an administrative judge in 2018.
WaterLegacy, an eco group and the Fond du Lac Band of Lake Superior Chippewa have argued MPCA improperly interpreted the Clean Water Act, a federal law, and set forth permit conditions that did not adequate protect surface waters.