U.S. EPA gives PolyMet mine proposal low marks

The U.S. Environmental Protection Agency has released an analysis of the draft Environmental Impact Statement (DEIS) for the PolyMet copper-nickel mine proposed for Minnesota’s Eastern Iron Range.  The agency says the mining operation would result in “unacceptable and long-term water quality impacts,” and should not proceed as proposed.

The EPA cites more than two dozen “inadequacies,” in the draft Environmental Impact Statement and has given the document the lowest EPA rating possible, “Environmentally Unsatisfactory and Inadequate.”  In a 29 page review of document, the EPA identified three main areas of concern: water quality, wetland impacts, and financial assurance. 

The EPA says wastewater discharge from the project would increase mercury emissions into the Lake Superior watershed, exceed water quality standards, and result in unacceptable, long-term water quality impacts.  The EPA says that if water quality standards can not be met, it would not recommend issuing a permit for the mining operation.

According to the EPA, the project will also impact more than a thousand acres of high quality wetlands, which the EPA considers “aquatic resources of national importance”. The EPA says these wetlands provide unique habitat, biodiversity, downstream water quality, and flood control specifically to the Lake Superior Watershed and the Great Lakes Basin.  The EPA states the PolyMet project, as proposed, would have substantial and unacceptable adverse impacts on these resources.

The EPA recommends that additional information, alternatives, and mitigation measures are needed for the PolyMet proposal and should be made available for public comment in a revised or supplemental draft Environmental Impact Statement.  The EPA also says that because long-term water treatment will be necessary after the mine closes, details about financial assurance, or what the mining company will set aside to pay those costs, should be included in the Environmental Impact Statement. 

Critics of sulfide mining say the long term health of Minnesota’s water resources, including Lake Superior, are at risk. Sulfide mines have caused major environmental damage in other states, leaving persistent pollution and ongoing cleanup costs.  Supporters point out the economic benefits of the project which include job creation.