The Sierra Club challenged the issuance of modified air permits to the Detroit Edison Company by the Michigan Department of Environmental Quality in 2010 and 2012. The allegations were that MDEQ failed to impose the appropriate Clean Air Act limitations on DTE's Monroe facility's coal-fired generation units in granting amended air permits which called for emission reductions due to the installation of pollution control equipment. 

All challenges had earlier been rejected by the trial court. On November 21 the Michigan Court of Appeal affirmed, citing as one of the reasons the reductions in emissions under the new air permits: "statutes should be construed to avoid absurd consequences."