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. U.S. Steel has applied to combine its two wastewater permits into one permit that covers both the mine and tailings basin.
Our role
The Minnesota Pollution Control Agency is committed to protecting human health and the environment and supporting sustainable job growth in the state. 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 most recent air permit for the facility on June 29, 2026.
The MPCA made draft industrial wastewater permits for the facility available for public comment in the summer and fall of 2025.
During the public comment period for the Keetac wastewater discharge permits, we received more than 1,000 comments. In consideration of comments related to affordability, the MPCA requested additional information from U.S. Steel for its permits at Keetac. We continue to work with U.S. Steel to address compliance with the proposed sulfate effluent limits and on other issues raised in the public comments.
On March 4, 2026, U.S. Steel submitted an application for an industrial wastewater discharge permit that would combine its two wastewater permits into one. The agency is reviewing the application. After the MPCA completes its review and develops a single wastewater permit, we will place the permit on public notice. This will likely take place later in 2026.
We are committed to continuing to provide updates throughout this process.
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.
Air quality permit
U.S. Steel applied for an updated air permit authorizing the replacement of four wet scrubbers with dry cartridge filters (fabric filters). The existing scrubbers and new fabric filters control ore-handling equipment. After a 30-day public comment period, the MPCA issued the update on June 29, 2026.
