Downstream from mines, MPCA enforces limit on sulfate

map showing Hay Lake downstream of Keetac

May 5, 2024:  It seems to be a new day at the Minnesota Pollution Control Agency, where regulators are now enforcing the state’s water quality standards more stringently.

The agency has denied US Steel’s application for a more lenient site-specific standard for Hay Lake, several miles downstream of its Keetac taconite facility in Keewatin, MN. Hay Lake’s sulfate levels test at 79 parts per million, nearly 8 times the MPCA’s 10 ppm limit set for the state’s wild rice waters.  (Wild rice is particularly sensitive to sulfate, which is often discharged into water from mining operations.)  The agency called the US Steel application “scientifically indefensible,” but the company is appealing the decision.

Previously, mining companies had questioned the very validity of the state standard for wild rice waters.  Now they appear to be changing tack, saying that the standard should be flexible, with certain sites exempt. In a similar move, Cleveland Cliffs has applied for a site-specific standard for Perch Lake, in Forbes, MN. With drainage from the nearby United Taconite tailings basins, that lake’s sulfate stands at 43 times the state-set standard.

Read details in the reports by Jimmy Lovrein in the Duluth News Tribune, April 26 and April 29, 2024.