Pollutants in the air of state 1 travel downwind and pollute the air of state 2. How do we solve that problem? The Clean Air Act sets up a federal system in which the federal government sets up national air-quality standards, with the states left to implement those standards. In particular, “upwind” states – who generate the bulk of the nation’s power, have to be responsible for their own emissions, lest they pollute the “downwind” states unduly. The EPA, that engine of a massive rules-emitting machine, believes it gets to have the final, and full, say. But the DC Circuit disagreed. The EPA issued rules that not only enforced upwind state’s federally-mandated standards, but the rules also would require upwind states to care of pollutants that came from other upwind states. As Judge Kavanaugh stated,
“Absent a claim of constitutional authority (and there is none here), executive agencies may exercise only the authority conferred by statute, and agencies may not transgress statutory limits on that authority.”
A principle worth remembering, in areas well beyond environmental regulation.
The opinion can be found here: http://www.cadc.uscourts.gov/internet/opinions.nsf/19346B280C78405C85257A61004DC0E5/$file/11-1302-1390314.pdf