The Minnesota Court of Appeals reversed a state regulator decision Monday to renew a wastewater discharge permit for US Steel's Minntac iron ore mine in the state, according to a report from Fox Business. The dispute will be sent back to the Minnesota Pollution Control Agency (MPCA) for further proceedings. The permit was first issued in 1987 and renewed in 2018.
The mine’s iron ore processing facility includes a 13.6-square-mile (35.2-square-kilometer) tailings basin to hold mine waste and wastewater, which is recycled for further iron ore processing. As a result, sulfate levels accumulate in the basin and then leaks into local ground and surface waters. Minnesota law restricts discharges of sulfates into waters near agricultural areas, including a nearby area that grows wild rice. The state has allowed the mine to exceed the 10 milligrams per liter restriction for years.
The MPCA and US Steel have 30 days to request a hearing before the Minnesota Supreme Court.