Lake superior panorama

The PolyMet NorthMet open pit copper-nickel mine would be Minnesota’s first non-ferrous mine. It would include three new open pits, permanent and temporary waste rock heaps, and a permanent tailings waste dump and highly toxic hydrometallurgical residue in Minnesota’s St. Louis River watershed in the Lake Superior Basin. The open pit mine would be located on what is now public land in the Superior National Forest, containing high quality wetlands and uplands.

The tailings basin would be sited on top of an old tailings basin built in the 1950’s on top of three streams and designed to leak. The waste rock at the site is acid generating, and the combination of mercury and sulfate releases to air and water at the mine site and processing site, plus the drying and wetting cycles at both the mine site and the tailings site would result in huge increases in the production and transport to downstream waters of methylmercury – the type of mercury that bioaccumulates in the food chain and causes damage to the developing brains of fetuses, infants and children.

The PolyMet mine would be located on what is now Superior National Forest land and would require a land exchange of 6,650 acres of High Biological Diversity lands on which Indian tribes have rights to hunt, fish and gather reserved under treaties. The PolyMet project would harm endangered and listed species and would conflict with federal fiduciary responsibilities to tribes as well as state and federal statutes, regulations and policies.

WaterLegacy Has Challenged the PolyMet Land Exchange in Federal Court as a Sweetheart Deal for PolyMet in Violation of Federal Law 

On January 9, 2017, the U.S. Forest Service approved the transfer of 6,650 acres of Superior National Forest to PolyMet Mining Inc. for its proposed open pit copper-nickel mine.

Just three weeks later, WaterLegacy filed suit in Minnesota federal court challenging the PolyMet land exchange as a violation of the Federal Land Policy and Management Act and a sweetheart deal for PolyMet at the expense of users of public lands and taxpayers. WaterLegacy submitted an expert appraisal review explaining that the federal lands to be transferred to PolyMet were undervalued at only $550 by considering only their use for timber, while lands sold by private northeast Minnesota landowners to mining companies commanded much higher prices.

In February, WaterLegacy made a motion to block the PolyMet land exchange until federal land exchange law was followed, and on April 28, 2017, a federal judge heard this motion along with PolyMet’s motion to dismiss WaterLegacy’s claims.

July 4th weekend, with legal claims pending in the federal courts, Cong. Rick Nolan introduced a bill [HR 3115] to compel the PolyMet land exchange and circumvent court review of whether the exchange was an unequal exchange in violation of federal law.

As WaterLegacy Advocacy Director/Counsel Paula Maccabee explained in Minnesota Public Radio coverage:

"This kind of circumventing the courts, circumventing due process, sets a very bad precedent for PolyMet, and also leaves the potential that Minnesota taxpayers and users of public land will be ripped off by this project.”

Learn more about WaterLegacy’s opposition to the PolyMet land exchange as well as the pending lawsuit and proposed legislation to force the transfer of public lands.

Take action to oppose federal legislation to compel transfer of 6,650 acres of Superior National Forest to PolyMet and circumvent court review of the legality of the land exchange. 




Although PolyMet has yet to receive a single permit from either the state or federal government, since summer 2016 PolyMet has applied for a number of state permits from the Minnesota Department of Natural Resources and the Minnesota Pollution Control Agency.

You can read these permit applications and technical documents related to the permits on official Minnesota government sites here.



What do we know about the PolyMet NorthMet sulfide mine project?

Across the country, there is no example where a sulfide mine has been operated and closed without polluting surface and/or groundwater with acid mine drainage, sulfuric acid and/or toxic metals.


PolyMet by the Numbers:

- Proposed length of mine operations: 20 years
- Duration of pollution from mine pits and other permanent contaminant sources: perpetual
- Waste rock removed over 20 years: 308 million tons
- Percentage of waste, including waste rock and tailings waste: more than 99%
- Contaminated seepage from tailings: more than 2 billion gallons per year
- Wetland acres direct destroyed: 913.8 acres
- Potential indirect wetlands impacts acknowledged by Agencies: 7,694 acres (8,608 potential acres harmed)
- Wetlands destroyed/degraded by mine site dewatering calculated by tribal scientists: 5,720 acres.
- The PolyMet sulfide mine would result in the largest wetlands destruction ever approved by the St. Paul District of the U.S. Army Corps of Engineers.
- The Superior National Forest land exchange proposed for the PolyMet sulfide mine would be the largest ever conducted by the Forest Service.

What Happens NOW?

PolyMet has taken a great many years and tens of millions of dollars to prepare a 3,576-page Final Environmental Impact Statement that minimizes, distorts and, in some respects actually conceals the harm that its sulfide mine would cause to the environment and to human health. This document, however bulky, does not resolve the question of whether the PolyMet NorthMet mine meets the requirements for permits and other actions. Here are some of the upcoming steps:

  • The United State Forest Service issued a Final Record of Decision to approve the PolyMet Land Exchange. WaterLegacy has filed suit in federal court challenging the land exchange as a “sweetheart” deal for PolyMet in violation of federal law.

  • The Minnesota Department of Natural Resources determined that the PolyMet Final EIS meets minimum adequacy standards.

  • WaterLegacy has requested that the U.S. Army Corps of Engineers provide a supplemental EIS as well as a public hearing due to “bait-and-switch” changes to the PolyMet project design. 

  • U.S. Army Corps of Engineers and U.S. Environmental Protection Agency (EPA) must review the complete record, including PolyMet’s permit application, the Final EIS and all comments to determine if the project meets the Requirements for a Clean Water Act Section 404 permit.

  • Minnesota Pollution Control Agency and downstream States and Tribes (Fond du Lac Band) in conjunction with the EPA evaluate whether the PolyMet project would violate water quality standards and should be blocked.

  • U.S. Forest Service must determine, on the basis of the complete record and any objections made, whether the PolyMet federal land exchange sulfide project is in the public interest and meets the requirements of federal law.

  • Minnesota Department of Natural Resources must determine whether the PolyMet sulfide mine meets the requirements of Minnesota rules for a permit to mine and must set financial assurance requirements.

  • PolyMet must seek additional state permits for air pollution, water pollution, waste storage and other aspects of its sulfide mine project.

The PolyMet Sulfide Mine Would Pollute the Lake Superior Watershed and the Rainy River (Boundary Waters) Watershed

The PolyMet sulfide mine would pollute and degrade drinking water, streams and rivers and would contaminate fish with toxic methylmercury, harming the developing brains of Minnesota babies and children, as well as adversely affecting fish, wild rice and tribal rights and resources.

  • Claims that the PolyMet sulfide mine would not violate Minnesota water quality standards are based on modeling done by PolyMet and its paid consultants. None of the assumptions were independently verified.

  • PolyMet's modeling assumes that a dirt and clay trench around portions of the unlined four-and-a-half mile square tailings heaps will collect 99.5% of 2 trillion gallons per year of contaminated seepage emanating from PolyMet tailings waste. (FEIS 5-179, 5-181, 5-186).

  • PolyMet's modeling claims that it will collect 94% or more of the seepage from the permanent 526-acre unlined Category 1 waste rock pile with a compacted dirt trench. (FEIS 5-120) Not only are there fractures beneath the Category 1 waste rock pile location, but the unlined waste heap is located on top of Virginia Formation higher conductivity rock. (Barr 2014b, Large Figures 1-2)

  • PolyMet's claims are based only on models. There is no field experience where collection rate from unlined waste seepage have approached this level. The U.S. Steel pumpback system for Minntac tailings seepage, for example, captures about 50 percent. (See WaterLegacy Minntac Comment Letter).

  • The example of perfect tailings seepage collection promoted by PolyMet, the Fort McMurray tar sands tailings piles (PolyMet 2015h, Attachment D) have been proved to leak toxic seepage into the Athabasca River. Reducing this tailings seepage pollution has been projected to cost as much as $1 billion.

  • Instead of comparing PolyMet pollution to clean background waters, the Final EIS sets a low bar by comparing PolyMet pollution to a continuation of existing conditions situation (FEIS 5-94), so the Minnesota Pollution Control Agency's failure to require existing polluters, like Cliffs Erie, to meet water quality standards, is used to justify PolyMet pollution. (See WaterLegacy Petition to the EPA regarding MPCA Failure to Regulate Mining Pollution)

  • The PolyMet Final EIS fails to analyze the known impact of wetlands drawdown and rewetting on the formation of methylmercury. (FEIS 5-233). This impact on toxic mercury was emphasized by Dr. Brian Branfireun in his report on the PolyMet SDEIS and has been confirmed in Dr. Branfireun’s 2015 report on the PolyMet Final EIS.

  • The PolyMet Final EIS fails to analyze the known impact of mining pollution on fish and aquatic life as a result of the ionic pollution known as specific conductivity. A recent report shows that specific conductivity mining pollution can have adverse impacts hundreds of miles downstream in the St. Louis River.

  • The Great Lakes Fish and Wildlife Commission has to shown that when Northshore mining ceases, large volumes of contaminated seepage from the PolyMet East Pit would be drawn toward the Boundary Waters watershed. The PolyMet Final EIS admits that post hoc tactics to reduce contaminated pit seepage are "uncertain," "difficult" and "if needed, would be maintained indefinitely". No data or field experience is cited to show that any of these "mitigation" measures would protect the watershed. (FEIS 5-240 to 5-244).

We don't have to look very far to see the devastation caused by sulfide mine pollution. In August 2014, the tailings dam at a British Columbian mine collapsed, releasing over 6 billion gallons of tailings into nearby lakes and streams. Let's avoid a similar disaster here in Minnesota. Read more about the Mount Polley mine collapse here.


What Can You Do?

  • READ WaterLegacy’s comments on the PolyMet Final EIS Plan and PolyMet’s request for a Section 404 Clean Water Act permit to destroy wetlands. Find out what scientific experts and Tribal Cooperating Agencies have to say about the PolyMet sulfide mine project.

  • Support WaterLegacy and help us develop the expert and legal resources needed for the administrative permitting process and for possible litigation.Your involvement is critical to protect Minnesota clean water from sulfide mining pollution.

  • FOLLOW WaterLegacy on Facebook to keep up to date and learn of ways you can take action to protect Minnesota’s water resources.

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