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.

  • For a quick 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 and threats to Minnesota’s clean waters, see WaterLegacy’s handy Comment Card.

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