U.S. EPA Issues Final New Source Review Rule for Fine Particulate Matter

U.S. EPA has issued final rules regarding how emissions of particulate matter less than 2.5 micrometers in diameter (PM2.5) will be regulated under the New Source Review (NSR) permitting programs. The new rule will impact most, if not all, major stationary sources that emit PM2.5. The rule identifies requirements for direct emissions of PM2.5 and includes requirements for PM2.5 precursors.  The precursors identified for PM2.5 formation in the atmosphere include sulfur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (VOC), and ammonia (NH3).  SO2 emissions will be regulated as a PM2.5 precursor. NOx emissions will be regulated as a PM2.5 precursor unless states can demonstrate that NOx emissions are not a significant contributor to PM2.5 formation.  VOC and NH3 will not be regulated as PM2.5 precursors unless states can demonstrate that VOC and NH3 are significant contributors to PM2.5 formation for specific areas in their state.

States are initially not required to account for gaseous emissions that could form condensable particulate matter in establishing PM2.5 emission limits.  The significant emission rate for PM2.5 emissions is 10 tpy.  The significant emission rate for the precursors NOx and SO2 is 40 tpy each.  The final rule also allows interpollutant offset trading and establishes offset trading ratios for major projects located in PM2.5 nonattainment areas.   U.S. EPA published the final rule in the Federal Register on May 16, 2008.  The final rule has a July 15, 2008 effective date.  ALL4 will include a full analysis of the PM2.5 NSR rule in the June 2008 edition of 4 The Record.