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8-Hour Ozone Area Summary

As of November 13, 2009
8-Hr Ozone classified area designations for the 1997 standard were effective on June 15, 2004. Thirteen (13) 8-Hr EAC areas were designated attainment on April 15, 2008.


  Number of   Attainment
Category/Classification Areas  Counties   Population   Date

Severe 17 1   4   14,593,587   06/2021
Severe-15 1   8   4,669,571   06/2019
Serious 4   16   6,247,662   06/2013
Moderate 23   171   71,118,075   06/2010
Marginal 1   9   6,541,828   06/2007
 
   SUBTOTAL: 30   204   103,170,723    
 
Former Subpart 1 22   66   19,173,364   06/2009
 
   SUBTOTAL: 22   66   19,173,364    
 

   GRAND TOTAL: 52   268   122,344,087    


8-hour Ozone counties are also in:
 
  No. of
Counties
  Population  
 
Previous 1-hr Ozone nonattainment areas 169   95,824,751  
 
Previous 1-hr Ozone maintenance areas 54   21,278,450  
 
New 8-hr Ozone counties not presently in previous 1-hr Ozone nonattainment or maintenance areas 45   5,240,886  

TOTAL: 268   122,344,087  
 
8-hr Ozone counties in CO, or PM-10 nonattainment or maintenance areas or previous 1-hr Ozone nonattainment or maintenance areas 238   119,651,092  

County subtotals and grand totals may not equal sum of parts. Part counties are only counted one time within groupings. Previous 1-hr Ozone maintenance county counts and population do not include counties that are also in a nonattainment area e.g., Kern Co, CA.

For simplicity, Greensboro, NC, Nashville, TN, and Denver, CO are included in the in the "Previous 1-hr Ozone" nonattainment and maintenance area county and population.

On June 8, 2007, the United States Court of Appeals vacated the Subpart 1 portion of the Phase 1 Rule (Court Order). The Subpart 1 areas in the Greenbook are listed as "Former Subpart 1" until reclassification of the areas is finalized. Proposed reclassifications were published on January 16, 2009 (74 FR 2936).


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