U.S. Steel Corp. operates a taconite mine and processing plant known as Keetac north of Keewatin, where it produces taconite pellets for use at iron and steel mills.
Keetac operates under an existing air permit and two industrial wastewater permits: one for the discharges from the mining area and one for the tailings basin.
Our role
The MPCA is responsible for issuing and enforcing permits that limit emissions and discharges from Keetac’s operations to protect the environment and health of Minnesotans. Those permits reflect current state law and regulations.
The MPCA issued the facility’s air permit on Jan. 16, 2025. In September 2023, Keetac submitted updated permit applications for both of its industrial wastewater permits, which the MPCA reviewed to develop draft permits.
Open for public comment
The draft wastewater permits for the U.S. Steel Keetac facility's mine and tailings basin are now available for public comment.
Project information
U.S. Steel has operated the Keetac facility since 1967 and produces about 6 million tons of taconite pellets per year. The facility consists of the Keetac plant area and a nearby tailings basin.
The industrial wastewater permits for the facility limit sulfate to 14 milligrams per liter as a monthly average and 24 milligrams per liter as a monthly maximum. Those limits are derived from the water quality standard that protects waters in which wild rice grows and is harvested. Currently, the facility is not designed to treat its discharges for sulfate. Keetac must comply with the final sulfate limits as soon as possible but no later than April 30, 2030.
Additional pollutants of concern from this facility include dissolved iron, total suspended solids, pH, oil, grease, and mercury. In addition to the sulfate limits and compliance schedule, the permits require Keetac to:
- test wastewater toxicity at the mine pit and tailings basin
- conduct a PFAS inventory at each site
- monitor for additional nutrients
- monitor for mercury
- conduct an annual public meeting
At the tailings basin, the permit also requires:
- the addition of eight surface-water monitoring locations
- biological monitoring for the Hay Creek watershed
- the addition of two internal waste-stream monitoring locations
- U.S. Steel to evaluate whether the seepage to groundwater from the tailings basin is equivalent to a point-source discharge to surface waters
In May 2025, U.S. Steel requested a variance from the sulfate water quality standard for waters used for the production of wild rice. Upon review of the documents, the MPCA has made the preliminary decision to deny the variance request.
Public meeting
The MPCA will host an informational meeting to discuss the draft permits and the preliminary variance denial from 6-7:30 p.m. on Sept. 3 at the Iron Trail Motors Event Center in Virginia, Minnesota.
Next steps and timeline
The draft industrial wastewater permits are available for public notice through Sept. 8, 2025. The MPCA will host a public meeting on Sept. 3 in Virginia, Minnesota, to discuss the draft permits.
