On March 12 the Sierra Club filed a lawsuit in Federal District Court against DTE Energy Company alleging violations of the federal Clean Air Act. The complaint cited 1499 instances between January 1, 2007 and June 30, 2012 in which the coal-fired plants of Belle River, River Rouge, St. Clair and Trenton Channel exceeded permitted opacity limits. These exceedances were measured by automatic continuous emission monitors and reported by the company in its required periodic reporting. For relief the Sierra Club is asking the Court to order that these plants:

• comply with their opacity limits 100 percent of the time;
• either install additional pollution control equipment or switch operations to natural gas, and;
• pay civil penalties.

Each of the plants except Belle River is more than 50 years old.