Ozone NAAQS Revisions Proposed

On Jan. 6, 2010, EPA proposed to further lower the 8-hour primary ozone standard from .075 ppm, set in 2008, to a level within the range of .060 - .070 ppm to protect public health.  EPA is also proposing a new cumulative, seasonal secondary standard, to protect sensitive vegetation and ecosystems, within the range of 7-15 ppm-hours.  Because the 2008 standards were not as restrictive as was recommended by the Clean Air Scientific Committee (CASAC), EPA elected to reconsider the standards and follow CASAC’s recommendations.  Once the standards are published in the Federal Register, EPA will accept public comment for 60 days.  Public hearings will be held on Feb. 2 in Houston and Arlington, Virginia and on Feb. 4 in Sacramento.  According to EPA, it expects to issue final standards for Aug. 31, 2010 and pursue an implementation schedule as follows:

  • By January 2011 - States make recommendations for areas to be designated attainment, nonattainment or unclassifiable
  • By July 2011 - EPA makes final area designations
  • August 2011 - Designations become effective
  • December 2013 - State Implementation Plans, outlining how states will reduce pollution to meet the standards, are due to EPA
  • 2014 to 2031 - States are required to meet the primary standard, with deadlines depending on the non-attainment status

No new monitoring requirements are proposed in this action although ozone monitoring network design changes were proposed in July 2009 that would support the proposed standards.  EPA expects to finalize the proposed changes along with the final standards in August 2010.