States defend push to consider 'background' ozone in NAAQS

A coalition of states opposed to EPA's tougher 2015 ozone standard is defending its position that EPA should have considered naturally occurring "background" ozone when setting the standard, which they argue should result in a weaker limit because it would account for background ozone levels states are powerless to reduce. In a Jan. 11 filing with the U.S. Court of Appeals for the District of Columbia Circuit, Arizona on behalf of state petitioners in Murray Energy Corp. v. EPA...