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By: Ben Gleekel, Vol. 106 Staff Member

Northeast Minnesota may soon host an industrialized corridor of copper-nickel mining operations. The region is the home of the Duluth Complex—a geological formation containing an estimated 4.4 billion tons of copper, nickel, and other precious metals,[1] making it one of the largest untapped copper deposits in the world.[2] Copper-nickel has never been mined in Minnesota, but a number of mining companies hold leases to land on the Duluth Complex[3] and two companies—PolyMet Mining Corporation and Twin Metals Minnesota—are in the process of trying to establish mining operations.[4] While proponents of copper-nickel mining are encouraged by the economic benefits the industry would bring,[5] opponents are concerned by the fact that the industry’s history demonstrates that any copper-nickel mine established in Minnesota is almost certain to pollute surrounding waters.[6]

At the center of the decision-making process for the copper-nickel mining industry is the Minnesota Department of Natural Resources (“DNR”). The DNR promulgates and enforces Minnesota’s copper-nickel mining rules,[7] oversees the environmental review process for proposed mining operations,[8] grants permits to mine (which are necessary to mine in Minnesota),[9] and oversees the reclamation process once mining operations cease.[10] In conducting those processes, the DNR has a dual mandate to both promote copper-nickel mining development and to regulate the environmental impacts of such mines that is imposed on the agency by Minnesota mining laws.[11] The DNR’s dual mandate has the potential to create serious environmental consequences for an already dangerous industry. It is important to understand these consequences and remedy them.


The DNR’s dual role in the copper-nickel mining process dates to the Mineland Reclamation Act of 1969.[12] The Act declared that the mining policy of the state is “to provide for the reclamation of certain lands subjected to the mining of metallic minerals” in order “to control possible adverse environmental effects of mining” and to “promote[] the orderly development of mining.”[13] The legislature followed up the Act by prohibiting any person from mining in the state without first obtaining a permit to mine from the commissioner of the DNR,[14] and requiring the commissioner of the DNR to determine that the reclamation plan “can be accomplished under available technology….”[15] The legislature also prohibited the DNR from issuing permits to mine until it enacted rules establishing standards for copper-nickel mining reclamation.[16] In the early 1990s, the DNR promulgated rules that imposed on itself the same roles articulated in the Mineland Reclamation Act. Specifically, the DNR was “to control possible adverse environmental effects of [copper-nickel] mining” and to “promot[e] orderly development of [copper-nickel] mining.”[17]

For the permitting and reclamation of copper-nickel mining operations, the DNR is therefore statutorily mandated to both “promote the orderly development of mining” and “control possible adverse environmental effects” by using “available technologies.”[18]


The DNR’s dual mandate has potentially serious environmental ramifications for an industry that is already likely to pollute the waters of Northeastern Minnesota. The root of the issue with the mandate is that it requires the DNR to “control possible adverse environmental effects” by using “available technologies,” but does not require the use of the “best available technologies.”[19] This distinction causes the DNR’s role in promoting the development of mining to override the role of protecting the environment.

Consider, for example, the DNR’s approval of PolyMet using the upstream construction method for its proposed tailings dam.[20] The upstream method is not the best dam construction method.[21] In fact, environmental organizations have effectively argued that it is the most dangerous construction method and is only used because it is the cheaper option.[22] So long as it is an available technology, however, there is nothing barring the DNR from allowing its use.[23] Nor is the DNR forced to require that mining operations use the best available technology, which is known as the downstream dam construction method.[24] Under the DNR’s dual mandate, the promotion of copper-nickel mining development is not affected by the use of available technologies that are more likely to fail than better available technologies.

Further, even if the DNR wanted to use the best available technologies, the dual mandate might very well require the agency to settle for lower quality technologies. The best available mining technologies are often more expensive[25] and not required by the dual mandate. When there are instances in which the DNR requires a mining company to use the best available technology, but the company expresses that the best available technology is expensive to the point where it is not economically viable and threatens the development of the mine, the DNR’s dual mandate will always require allowing for the use of an available technology that is not the best. That way the DNR is meeting its role of controlling adverse effects on the environment by requiring the use of technology that is available and sufficient, while also continuing to promote the development of the mine.

Consider a scenario in which the DNR were to require PolyMet to use the downstream dam construction method instead of the upstream method, despite the downstream method being more expensive.[26] What would happen if PolyMet told the DNR that such a requirement was likely to make the mining operation unprofitable and potentially jeopardize it? Considering its dual mandate, the DNR would recognize that the upstream construction method is in fact an available technology and that an available technology is all that the DNR is mandated to require. The DNR would also reason that potentially jeopardizing the development of the operation by requiring the downstream construction method would mean it was not fulfilling its role of promoting the development of mining operations. In the end, the dual mandate would lead DNR to rescind its requirement.


There are two potential ways to alleviate the environmental consequences of the DNR’s dual mandate. The first is to rewrite the statutes to require the use of the “best available technologies” instead of only requiring the use of “available technologies.” Rewriting the laws that way would avoid the problem of the DNR only requiring the use of the best available technologies when doing so does not jeopardize the agency’s promotion of a mining operation. One problem with the requirement is that the opposite issue that currently exists with the dual mandate would occur—the duty to control adverse environmental impacts would always override the duty to promote the development of copper-nickel mining operations because the DNR could only promote those operations that could afford the best available technologies. The issue of the DNR being unable to equally fulfill its dual mandate, however, could be addressed under a “best available technology” regulatory scheme by splitting up the authority of promoting and regulating the copper-nickel mining industry.

Splitting the two authorities in the dual mandate between the DNR and one other agency—rather than housing both in the DNR—is likely the best way to bring both mandates to a level playing field. Doing so would allow the DNR to commit itself fully to one of the roles while the other agency commits itself fully to the other. Without the conflict of interest from the dual mandate resting in one agency, the issue of either mandate overriding the other under one decision-maker would not be a concern.

The Minnesota Pollution Control Agency (“MPCA”) would perhaps be the most sensible agency to split the authority with. Under this scheme, the DNR would continue to have the role of promoting the development of copper-nickel mining, while the MPCA would fully take over the role of regulating the adverse environmental impacts of industry. This would work well considering the MPCA already participates in the environmental review process and oversees the granting of air and water permits for mining operations.[27] Fully transferring the role of regulating the industry would mean involving the MPCA more in the planning process. Most of the DNR’s role in environmental regulation occurs at the beginning of the process when mining operations are being planned and approved.[28] Currently, the MPCA begins its regulatory role after those mine plans have been approved.[29] If the MPCA were to have the primary role of controlling “possible adverse environmental effects of mining”  from the start, alongside the DNR in its promotion of the  “orderly development of mining,” then neither agency would have a dual mandate that leads to unavoidable conflict and the likelihood of further environmental consequences.


[1] Minn. Dep’t of Nat. Res., U.S. Army Corps of Eng’rs, U.S. Forest Serv., NorthMet Mining Project and Land Exchange: Final Environmental Impact Statement 3–33 (2015), [][hereinafter NorthMet Mining Project: Final Environmental Impact Statement].

[2] Paul Tosto, MPR News Primer: Copper-Nickel Mining, MPR (Apr. 11, 2021), [].

[3] Minn. Dep’t of Nat. Res., State Nonferrous Metallic Mineral Leasing: January 2022, [].

[4] See Twin Metals Minn., Mine Plan of Operations (Dec. 18, 2019), []; Minn. Dep’t of Nat. Res., PolyMet’s NorthMet Mining Project, [].

[5] PolyMet Mining, Economic Benefits and the Importance of Mining, [] (claiming that PolyMet’s proposed mining operation will bring 360 full-time jobs, 2 million construction hours, a $515 million annual boost to the St. Louis County economy, and 600 indirect jobs to the region).

[6] See Letter from Thomas Tidwell, Chief of Forest Serv., to Neil Kornze, Dir. of Bureau of Land Mgmt., U.S. Forest Serv. (Dec. 14, 2016), lease_renewal_with_bibliography.pdf [] (explaining that any copper-nickel nickel mine is extremely likely to pollute surrounding environs and that such pollution poses a “serious and irreparable” risks the in the region); U.S. Env’t Prot. Agency, An Assessment of Potential Mining Impacts on Salmon Ecosystems of Bristol Bay, Alaska: Volume 1—Main Report (Jan. 2014), [] (finding that 13 of the 14 porphyry copper mines that have operated for at least 5 years in the United States, experienced reportable aqueous releases, with the number of events ranging from 3 to 54) (citing Earthworks, U.S. Copper Porphyry Mines Report: The Track Record of Water Quality Impacts Resulting from Pipeline Spills, Tailings Failures and Water Collection and Treatment Failure (July 2012), uploads/2012/08/Porphyry_Copper_Mines_Track_Record_-_8-2012.pdf []).

[7] Minn. R. 6132 (2013).

[8] NorthMet Mining Project: Final Environmental Impact Statement, supra note 1, at 2–3; see also Minn. R. 4410.4400, subpts. 1, 8 (requiring the preparation of an EIS because one is mandatory for projects involving the “construction of a new facility for mining metallic minerals or for the disposal of tailings from a metallic mineral mine”); id. subpt. 8 (designating the DNR as the responsible government unit for the development of an EIS for metallic mineral mining and processing operations).

[9]  Minn. Stat. § 93.481.

[10] Minn. R. 6132 (2013).

[11] Infra Part I.

[12] Minn. Stat. §§ 93.44–93.51.

[13] Minn. Stat. § 93.44.

[14] Minn. Stat. § 93.481, subdiv. 1.

[15] Id. subdiv. 2.

[16] Minn. Stat. § 93.47.

[17] Minn. R. 6132.0200 (2008).

[18] Supra notes 12–17 and accompanying text.

[19] Id.

[20] Minn. Dep’t of Nat. Res., NorthMet Project Dam Safety Permits: Findings of Fact, Conclusions, and Order of Commissioner (Nov. 1, 2018), [].

[21] U.S. Env’t Prot. Agency, Technical Report: Design and Evaluation of Tailings Dams 24 (Aug. 1994), [].

[22] Minn. Ctr. for Env’t Advocacy, Comments on Dam Safety Permits 11–14, []; see also U.S. Env’t Prot. Agency, supra note 6, at 24.

[23] Supra Part I.

[24] U.S. Env’t Prot. Agency, supra note 21.

[25] Id.

[26] Id.

[27] Minn. Pollution Control Agency, PolyMet’s NorthMet Mining Project, [] (tracking all MPCA permitting and status).

[28] Supra notes 7–9 and accompanying text.

[29] Minn. Pollution Control Agency, supra note 27.