On September 16, 2009 the EPA announced plans to review the current NAAQS (national ambient air quality standard) for ozone and make proposed revisions by December 21, 2009.  EPA is expected to reduce the current 2008 ozone standard rate of 0.075 ppm to between 0.060 ppm and 0.070 ppm  based on findings of the EPA’s independent Clean Air Scientific Advisory Committee, which had recommended stricter ozone standards.

EPA’s proposed timeline for rule development and implementation is as follows:

* Proposed Reconsidered NAAQS – December 2009
* Final Reconsidered NAAQS  - August 2010
* Final Designations – August 2011
* State Implementation Plans (SIPs) due – December 2013

EPA says that it is planning to postpone the March 2010 deadline for designation of non-attainment areas under the 0.075 ppm standard in order to reduce the workload for states during the interim period of reassessment.  However,EPA will expedite the date for any new standard to August 2011, which would require states to submit their implementation plans of the new standard by the end of 2013.