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EPA Issues Final NAAQS Rule

On April 30, 2012, the Environmental Protection Agency (“EPA”) issued a final rule for the implementation of the 2008 National Ambient Air Quality Standards (“NAAQS”) for ground-level ozone.  The final NAAQS rule identifies nonattainment areas, establishes nonattainment parameters and sets compliance deadlines for states to come into attainment.  The final standards for attainment were set at 0.075 parts per million in June of 2008.

The final rule:

  • Establishes air quality thresholds for each of the five Clean Air Act (”CAA”) nonattainment classifications;
  • Establishes December 31 of each relevant calendar year as the attainment date for each classification; and
  • Revokes the 1997 ozone NAAQS for purposes of transportation conformity.

In this action, areas of nonattainment are classified based of the severity of their level of ozone problem.   The classifications are: Marginal, Moderate, Serious, Severe, or Extreme.  The EPA will use a “percent-above-the-standard” approach to determine what classification an area of nonattainment will fall under.  Under the “percent-above-the standard” approach, EPA will use the same percentages that the CAA uses to determine classifications for one hour ozone NAAQS.

In addition to the classifications of nonattainment areas, the final rule sets deadlines for areas to meet the NAAQS.  These deadlines vary depending upon how an area of nonattainment is classified.  NAAQS implements a graduated system in which areas with the worst air quality will have the most time to come into attainment, in addition to the most mandatory planning and emission control requirements.  Each area of nonattainment must comply with the standards by December 31 of the year as defined by the classification. 

This is the first of two rules that EPA will issue based on the 2008 ozone standards. 

A copy of the final rule is available here.