U.S. Steel Keetac Tailings Storage Facility Project

Project summary

U.S. Steel is proposing to modify its existing Tailings Storage Facility for its Keetac taconite mining operation in St. Louis and Itasca Counties. Activities would involve vertically raising the existing dams and dikes using downstream and modified centerline construction methods, that would extend the dam and dikes beyond the current tailings storage facility’s footprint. The Project would also involve constructing a new access road, as well as new industrial building and infrastructure for tailings separation and tailings dewatering. The infrastructure would produce coarse tailings for use in dam and dike construction and thickened fine tailings for discharge to the tailings storage facility. The project proposes revisions to the existing tailings basin, but there are no proposed revisions to mining activities or taconite processing facilities. 

Environmental Assessment Worksheet

The DNR, as the Responsible Governmental Unit (RGU) for environmental review of the project, is accepting comments on the Environmental Assessment Worksheet (EAW).

EAW documents

• EAW: U.S. Steel Keetac Tailings Storage Facility Project
• Appendices
  • A: Project Location Figure
  • B: U.S. Steel Keetac Topography 24k
  • C: MN DNR NH Review Letter
• Figures
  • 6.1 through 6.6
  • 7.1 through 7.10
  • 8.1
  • 10.1 through 10.3
  • 11.1 through 11.2
  • 12.1 through 12.8
  • 13.1
  • 14.1
  • 16.1

Public comment period

Public notice of the availability of the EAW for public comment is in the September 2, 2025, edition of the EQB Monitor. A 30-day public review and comment period will be open from September 2, 2025, until 4:30 p.m. October 2, 2025.

A hard copy of the EAW is available for public review at the following libraries:

• Keewatin Public Library, 125 W 3rd Ave, Keewatin, MN 55753
• Duluth Public Library, 520 West Superior Street Duluth, MN 55802
• DNR Library, 500 Lafayette Road North, St. Paul, MN 55155
• Hennepin County Library–Minneapolis Central Library, Government Documents, Second Floor, 300 Nicollet Mall, Minneapolis, MN  55401

A hard copy may be requested by calling 651-259-5122.

Comments must be submitted no later than 4:30 p.m. Thursday, October 2, 2025.

• Email comments should be sent to [email protected] with “Keetac” in the subject line.
• Mailed comments should be sent to the attention of Becky Horton, EAW Project Manager, Minnesota DNR, 500 Lafayette Road North, St. Paul, MN 55155.

Anyone providing a mailing address or submitting comments via email will receive a copy of the subsequent decision document, which will include responses to comments. Because all comments and related information are part of the public record for this environmental review, commenters’ names and email or postal addresses will be published and publicly available as they appear in the materials commenters submit.