EPA Publishes Final Rule to Implement 1997 PM2.5 NAAQS

May 16, 2007
Client Alert Newsletter May 2007

On April 25, the U.S. Environmental Protection Agency ("EPA") published the Clean Air Fine Particle Implementation Rule to implement the 1997 fine particulate matter ("PM2.5") National Ambient Air Quality Standard ("NAAQS"). According to the new rule, states with areas in nonattainment for the PM2.5 NAAQS (including Pennsylvania and New Jersey) must submit state implementation plans ("SIPs") by April 2008 to achieve the PM2.5 standards. States are required to meet the PM2.5 NAAQS by 2010 (unless EPA approves an extension of up to five years). The SIPs will include NSR for PM2.5 sources in nonattainment areas, meaning these and other sources may have to employ more stringent pollution control technologies, including restricting emissions of PM2.5 precursors such as SO2 and NOX. In addition, EPA on October 17, 2006, published a final rule revising the 1997 PM2.5 NAAQS by tightening the 24-hour standard from 65 micrograms per cubic meter ("µg/m3") to 35 µg/m3, while retaining the annual standard of 15 µg/m3.