PolyMet’s NorthMet mining project

MPCA sends PolyMet revised permit documents for EPA review

The MPCA considered the nearly 700 public comment submittals which resulted in the addition of numerous conditions to the draft permits to ensure compliance with air and water regulations.  The revised permit documents have been sent to EPA for review in accordance with applicable permitting rules and agreements.

The revised permits are not open for public comment. This notification is intended to serve only as a progress report on the current status of the MPCA draft air quality and water quality permits.

Aerial view of proposed mining project area

Poly Met Mining, Inc. (PolyMet) is proposing to develop a mine and processing plant to extract copper, nickel, and precious metals from the NorthMet Deposit in northeastern Minnesota.

PolyMet’s proposed NorthMet project would be located in the St. Louis River watershed on the eastern end of the Mesabi Iron Range, about six miles south of Babbitt and one mile south of the existing Northshore (iron ore) Mine. Processing of the ore would take place at the former LTV taconite plant near Hoyt Lakes.

The total project area would include a new open pit mine, temporary and permanent waste rock disposal areas, recommissioning of an existing processing plant and tailings basin, and refurbishment of an existing seven-mile railroad and utilities corridor between the mine and plant sites.

Environmental Review

The Minnesota Department of Natural Resources, US Forest Service, and US Army Corps of Engineers have conducted a comprehensive environmental review of the proposed project.


PolyMet would need multiple approvals from state agencies, primarily the MPCA and DNR, in order to proceed. The MPCA's role is to protect water and air, which it does, in part, through the issuance of environmental permits. The major permits the company would need from the MPCA are described below.

Contact DNR for more information on its Permit to Mine, Water Appropriations Permit, Dam Safety Permit, Wetland Replacement Permit, Burning Permit, Endangered Species Taking Permit, and Permit for Work in Public Waters.

When any facility submits an application to MPCA to obtain a permit, technical staff review the application and evaluate whether the facility can meet applicable environmental regulations and standards. The MPCA then develops facility-specific permit conditions. Permit conditions ensure that all standards are met by specifying how the facility must be operated, describing monitoring that must be conducted, and limiting the type and amount of water discharges or air emissions.

Once drafted, most permits require a formal public notice where the draft permits are made available for public review and comment.  (See timelines below.)  After public notice, the permits are revised to reflect any changes that result from comments from the public. To issue the permit, the MPCA must be satisfied that the permit provides for meeting all applicable rules and regulations and that the agency anticipates the applicant will comply with all conditions of the permit.

For more information about permits the NorthMet project will need from the MPCA, see the following:


MPCA permitting process

* includes coordination with EPA


Public participation

The public is encouraged to provide comments on draft permits during the formal public comment periods. All written comments received during the comment periods are considered. Comments can and often do result in changes to the final permit.