January 25, 2010 – The Center and allies gave notice of intent to file suit under the Clean Water Act to stop the ongoing pollution of waters surrounding the proposed PolyMet mine site. In response, the state of Minnesota entered into a consent decree with the mining company and requires corrective actions to address the pollution.
February 1, 2010 – The Center submitted detailed comments on the draft environmental impact statement for PolyMet's proposed NorthMet copper mine. In response to comments — including highly critical comments submitted by the EPA — the U.S. Army Corps of Engineers and Minnesota Department of Natural Resources recognized the need to prepare a supplemental draft environmental impact statement, anticipated in early 2012.
January 14, 2011 – The Center and allies filed suit against the state agency Iron Range Resources, under the Minnesota Environmental Policy Act, for providing a loan to PolyMet prior to completion of the required environmental review process. In response, the Minnesota legislature passed a new law exempting Iron Range Resources from the Minnesota Environmental Policy Act.
June 27, 2011 – The Center submitted detailed comments on the draft environmental impact statement concerning the widespread exploration of copper and other minerals on the Superior National Forest.