The phrase “interstate transport” conjures images of planes, trains and trucks carrying people and goods cross-country. But, under the federal Clean Air Act (CAA), the term is often used to refer to interstate air pollution—emissions from factories, power plants, motor vehicles, refineries and other sources that are transported by prevailing winds across state lines, sometimes over hundreds of miles. The interstate transport phenomenon often has posed for the US Environmental Protection Agency (EPA) what the Supreme Court has called “a thorny causation problem: How should EPA allocate among multiple contributing upwind States responsibility for a downwind State’s excess pollution?” EPA v. EME Homer City Generation, L.P., 134 S. Ct. 1584, 1604 (2014). EPA’s efforts to address this issue have yielded, over the last two decades, a series of complex federal regulatory programs imposing increasingly stringent controls on emissions in most states in the eastern half of the country—first the “NOx SIP Call” rule in 1998, then the Clean Air Interstate Rule in 2005, followed by the Cross-State Air Pollution Rule (CSAPR) in 2011 and, most recently, the 2016 “CSAPR Update” rule. Now, however, EPA, while vigorously defending the CSAPR Update rule against pending litigation challenges, is signaling a fresh approach for potential future interstate transport regulation, an approach that may involve greater deference to states’ analyses and determinations and that may eschew additional broad regulatory mandates imposed by EPA. Continue Reading EPA Makes Room for State Flexibility in Addressing “Interstate Transport” Under the Clean Air Act

The U.S. Environmental Protection Agency (EPA) published the Cross-State Air Pollution Rule “Update” for the 2008 national ambient air quality standards for ozone – the so-called CSAPR Update Rule – on October 26, 2016.  81 Fed. Reg. 74504.  The CSAPR Update Rule regulates emissions of nitrogen oxides (NOx) from power plants located in 22 states in the eastern half of the country by establishing statewide ozone-season NOx emission budgets scheduled to take effect beginning May 1, 2017.  (Under the Clean Air Act, the regulatory “ozone season” runs from May 1 through September 30 each year.)

Continue Reading States, Industry Parties, and Environmental Groups Challenge EPA’s Latest Interstate Air Emissions “Transport” Rule in D.C. Circuit Litigation