Poly Met Mining, Corp. (PolyMet) is proposing a mine and associated processing facilities for the extraction of copper, nickel, and platinum group elements (PGE) in northeastern Minnesota. The mine would be the first of its kind in the state.
The Minnesota DNR's review of PolyMet's NorthMet proposal has followed a rigorous environmental review process and extensive evaluation of the company's permit applications, beginning in 2005. This included careful review of more than 22,000 public comments on draft permits in 2017 and early 2018.
July 2025
Dam safety permit amendment on existing taconite tailings basin
On July 1, the Minnesota Department of Natural Resources (DNR) issued a dam safety permit amendment authorizing NewRange Copper Nickel (formerly PolyMet Mining) to make safety-related improvements to the existing inactive LTV Steel Mining Company taconite tailings basin. The DNR sent a GovDelivery email notification on January 31, informing subscribers when the application for this amendment was submitted.
While this tailings basin is also the site of the proposed non-ferrous NorthMet mining project, the amendment request is not part of that project. The NorthMet project is currently on hold pending the result of legal challenges.
This amendment permits the construction of a new spillway at the top of the existing inactive tailings basin, the addition of coarse tailings fill to keep water away from the edge of the dam, and the construction of a rock-lined channel directing any water that leaves the spillway to an existing storage pond.
Adding the spillway/diversion ditch and adding fill to keep water away from the dam will improve dam stability by preventing ponded water from encroaching upon the perimeter dam during extreme precipitation events. These new features will replace the existing water management structure at the tailings basin that is no longer functional.
This amendment does not expand the capacity or increase the footprint of the existing tailings basin. The project will increase stability of the existing embankments (tailings basin cells) by ensuring water is able to be channeled safely away during extreme precipitation events.
DNR dam safety experts met with representatives of the Fond du Lac Band of Lake Superior Chippewa and considered the Band’s comments as part of the DNR’s review of the NewRange amendment application. The DNR also considered all other comments received on the proposed amendment. The DNR’s review of the proposed amendment determined that the planned construction meets all requirements of Minnesota’s dam safety laws and that it would increase the safety of the dam.
Permitting updates
January 2025
Dam safety amendment requested on existing taconite tailings basin
NewRange Copper Nickel (formerly PolyMet Mining) has applied for a dam safety permit amendment to modify an existing inactive LTV Steel Mining Company taconite tailings basin to enhance safety of that dam. NewRange has responsibility for managing the tailings basin under a permit issued in November 2018.
While this tailings basin is also the site of the proposed non-ferrous NorthMet mining project, the amendment request is not part of that project. The NorthMet project is currently on hold pending the result of legal challenges.
The applicant intends to construct a new spillway at the top of the existing inactive tailings basin, add coarse tailings fill to keep water away from the edge of the dam, and construct a rock-lined channel directing any water that leaves the spillway to an existing storage pond.
The tailings basin has an existing water management structure that is no longer functional. Adding the spillway/diversion ditch and adding fill to keep water away from the dam would improve dam stability by preventing ponded water from encroaching upon the perimeter dam during extreme precipitation events.
The proposal does not expand the capacity or increase the footprint of the existing tailings basin. If approved, the project will increase stability of the existing embankments (tailings basin cells) by ensuring water is able to be channeled safely away during extreme precipitation events. With the existing water management structure no longer in use, the only way for excess water to leave the cell is to flow over the embankment and down a roadside ditch to another tailings basin cell. The proposal would upgrade the tailings basin to comply with Global Industry Standard on Tailings Management (GISTM) that represents the most recent industry safety standards.
The DNR has a prescribed process for review of dam safety permit amendments that includes a 30-day government agency comment period. Comments on this application will be accepted from local governments, the Minnesota Board of Water and Soil Resources, the US Army Corps of Engineers and the Fond du Lac, Bois Forte and Grand Portage Tribal Nations until 4:30 p.m. Monday, March 3, 2025.
DNR dam safety technical experts will consider any comments provided as part of its technical review of the proposal. The DNR will need to determine that the proposal meets the regulatory requirements for dam safety in order to issue the amendment.
A link to sign up for email updates on this proposal as well as the NorthMet Mining project is at the top of this webpage.
November 2024
Statement from the Minnesota Department of Natural Resources
After careful consideration of the positions of each party to the case, the Minnesota Department of Natural Resources’ (DNR) final agency decision-maker has stayed the contested case hearing process regarding the NorthMet permit to mine until August 14, 2025. The primary reason for the stay is NewRange Copper Nickel’s (NewRange) publicly stated plans to consider changes to some elements of the NorthMet project design. The NorthMet permit to mine was originally issued to PolyMet.
On August 14, 2024, NewRange issued a press release stating its intent to study, over the next year, potential changes to the NorthMet project design ranging from tailings storage to production levels of the mine. The scope of potential changes could have a direct impact on specific issues under consideration in the contested case hearing process related to the NorthMet permit to mine. It was determined by the final decision-maker that the implementation of a stay will prevent significant expenditure of time and resources in the contested case process for a project design that may become moot if the company amends or withdraws its current permit application.
During the period of the stay, the company will provide periodic status updates to the parties on project-wide internal studies mentioned in its August 14, 2024, press release. If, before the expiration of the stay, the company chooses to proceed with the design as set forth in its current permit application, specifically the use of a bentonite clay amendment, or otherwise believes new circumstances warrant a lifting of the stay, it may petition to have the stay lifted. The DNR's internal decision-maker retains the discretion to lift the stay prior to August 14, 2025, and to seek additional briefing from the parties to the contested case hearing as necessary and appropriate.
Additional Background:
In November 2023, an Administrative Law Judge issued a recommendation to the DNR following the contested case hearing on the proposed bentonite amendment for the tailings basin that was included in the NorthMet permit to mine, issued to PolyMet. In accordance with established laws for reaching a final decision, the ALJ’s recommendations were forwarded to the DNR’s final agency decision-maker, along with their legal counsel, for review. The final agency decision-maker is a senior leader in the department who had no role in the original permit decision and has been walled off from the team that worked on the permit. The final agency decision-maker is charged with reviewing the ALJ’s report, the existing case record, and providing an opportunity for all parties to the contested case hearing to provide any exceptions they may have to the ALJ’s report, prior to making a final decision. This process was underway when NewRange issued the August 14, 2024, press release.
March 2023
Following a number of court decisions that upheld most of the conclusions made by DNR throughout the review process, the Minnesota Supreme Court only directed the DNR to add a fixed term (set in years) to the permit to mine and to hold a contested case hearing on whether using bentonite clay to reduce oxygen and water infiltration into the proposed tailings basin is a practical and workable reclamation technique. The contested case hearing is set for March 27. Following the hearing and after review of the recommendation of the administrative law judge, the DNR will make a final permit decision on the permit to mine application.
DNR GovDelivery bulletin on notice of hearing »
April 2021
On April 28, 2021, the Minnesota Supreme Court issued its ruling on the Court of Appeals decision regarding the permit to mine issued to PolyMet in November 2018. The Court offered a clarifying interpretation of who has standing to request a contested case hearing, but concurred with the DNR's application of the standards for granting a contested case hearing. The Court found ample evidence in the permit records to support the DNR's decisions on the critical issues of dam safety and tailings basin closure and found that DNR did not need to hold a contested case hearing on financial assurance or whether Glencore was required to be on the permit to mine at the time of permit issuance. The Court instructed DNR to establish a fixed term for the permit to mine and to hold a contested case hearing on whether the use of bentonite is a practicable and workable technology to reduce oxygen infiltration into the project tailings.
Minnesota Supreme Court Ruling »
February 2020
On February 12, 2020, the DNR submitted a petition to the Minnesota Supreme Court seeking review of the Minnesota Court of Appeals' January 13, 2020 decision regarding three DNR-issued permits for PolyMet's NorthMet project.
Petition for review »
Addendum to petition for review »This addendum contains the NorthMet project Permit to Mine Findings of Fact, originally posted November 2018.
August 2019
On August 7, 2019, the DNR issued the following order regarding requests for reconsideration of the Dam Safety Permit 2016-1380 and the nonferrous Permit to Mine.
Order of Commissioner »
Dam Safety Memo »The DNR has issued PolyMet's Permit to Mine, Wetland Replacement Plan, Water Appropriation, Dam Safety, Endangered Species Taking Permit, and Public Waters Work permits. You can find these permits, along with supporting documentation, using the navigation menu above or below.
Permit to Mine »
Water Appropriation Permit »
Dam Safety Permit »
Other DNR Permits »Environmental review process
Prior to the current permitting phase, the proposed NorthMet Mining Project went through an extensive environmental review process. PolyMet submitted its initial project proposal to the DNR in February 2005. In accordance with state and federal laws, an Environmental Impact Statement (EIS) was prepared under the leadership of the DNR, U.S. Army Corps of Engineers (USACE), and the U.S. Forest Service (USFS). The Final EIS was deemed adequate by the DNR in March 2016 marking the end of the state's environmental review process. On January 9, 2017, the USFS signed the Final Record of Decision authorizing a land exchange with PolyMet. This exchange will transfer the surface property owned by the Forest Service to PolyMet, who controls the sub-surface (mineral) rights. The land exchange is presently being challenged in federal lawsuits. On March 21, 2019, the USACE completed its Record of Decision and issued an individual permit to PolyMet for its NorthMet project.
- Project location
The NorthMet Mining Project will be located in the St. Louis River watershed on the eastern edge of the Mesabi Iron Range, about 6 miles south of Babbitt.
Partner links
Minnesota Pollution Control Agency »
U.S. Forest Service (USFS) »
U.S. Army Corps of Engineers (USACE) »News
News releases