Greenwire: The Supreme Court ruled today that the Obama administration unlawfully failed to consider compliance costs before it issued its landmark power plant emission limits for mercury and other hazardous pollutants.
More than 20 Republican-led states and various industry groups challenged U.S. EPA's Mercury and Air Toxics Standards, or MATS.
The rules were finalized in December 2011 and are already in effect, requiring coal-burning power plants to reduce emissions of hazardous substances like mercury,...