"TRAVERSE CITY, Mich. — Government regulators can try to halt construction projects at power plants if they think the companies didn't properly calculate whether the changes would increase air pollution, a federal appeals court ruled Thursday, marking the latest twist in a decades-long fight over the Clean Air Act."

"The U.S. Environmental Protection Agency sued Michigan-based DTE Energy in 2010, because the company was replacing key boiler parts at its Monroe Unit 2 coal-fired power plant without installing pollution controls. The EPA said the controls were required because the utility was performing a major overhaul, but DTE argued the $65 million project was only routine maintenance and was therefore exempt.

A federal judge threw out the suit, saying the EPA went to court too soon. But the 6th U.S. Circuit Court of Appeals overturned that decision in a 2-1 ruling, saying the law doesn't block the EPA from challenging suspected violations of its regulations until long after power plants are modified."

John Flesher reports for the Associated Press March 28, 2013. [2]