Lake superior panorama

The PolyMet NorthMet open pit copper-nickel mine, waste rock heaps and tailings basin dumps would be located in Minnesota’s 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.

Tuslequah Chief Mine
 Acid mine drainage from the Tuslequah Chief Copper-

 Lead Mine in British Columbia.
Photo by Chris Miller -

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.

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. Read more about the Mount Polley mine collapse here.

  • For a summary of how pollution from PolyMet’s proposed open-pit mine, waste rock piles and tailings waste threatens Minnesota's clean water, public health, and natural resources, see WaterLegacy's PolyMet Water Resources Fact Sheet. 
  • For a quick summary of the PolyMet project threats to human health and the need for a rigorous assessment of health risks see WaterLegacy's PolyMet Health Assessment Fact Sheet.

The PolyMet tailings disposal facility is being designed by the same engineering firm that designed the failed Mount Polley tailings dam. Let's avoid a similar disaster here in Minnesota. Read WaterLegacy's request to federal and state agencies to evaluate Best Available Technology for tailings disposal rather than using the current PolyMet plan.

What Can You Do?

  • Learn what WaterLegacy, scientific experts, state and federal agencies have to say about the problems with PolyMet’s most recent sulfide mine plan. Read Comments on the PolyMet SDEIS.
  • Read more about the PolyMet NorthMet sulfide mine plan, including more than 2,100 pages of the SDEIS and thousands of additional pages in reference documents from the Minnesota Department of Natural Resources NorthMet SDEIS PolyMet Mining web site.
  • Support  WaterLegacy and stay engaged as state and federal agencies prepare to complete their environmental review and move into a permitting phase for the PolyMet sulfide mine project.  Your involvement is critical to protect Minnesota clean water from sulfide mining pollution.

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WaterLegacy:  Protecting Minnesota's waters and the communities who rely on them.