8-Hour Ozone Nonattainment Area Summary

As of August 30, 2011
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

Extreme	2	12	17,784,954	06/2024
Severe 15	3	15	6,972,669	06/2019
Serious	2	10	5,784,025	06/2013
Moderate	20	157	64,753,819	06/2010
Marginal	1	9	6,541,828	06/2007

SUBTOTAL:	28	199	101,837,295

Former Subpart 1	16	45	16,351,290	06/2009

SUBTOTAL:	16	45	16,351,290


GRAND TOTAL:	44	242	118,188,585

8-hour Ozone counties are also in:

		No. of Counties	Population

Previous 1-hr Ozone nonattainment areas		166	95,439,661

Previous 1-hr Ozone maintenance areas		41	17,901,349

New 8-hr Ozone counties not presently in previous 1-hr Ozone nonattainment or maintenance areas		35	4,847,575

TOTAL:		242	118,188,585

8-hr Ozone counties in CO, or PM-10 nonattainment or maintenance areas or previous 1-hr Ozone nonattainment or maintenance areas		218	115,662,228

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.

Multi-state nonattainment areas are not considered maintenance areas until all state in the area have been redesignated.

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

8-Hour Ozone Nonattainment Area Summary

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