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Notes for the:
8-Hour Ozone Report With Classifications for Carbon Monoxide (CO), Particulate Matter-10 microns (PM-10), 1997 and 2006 Particulate Matter-2.5 microns (PM-2.5), and Previous 1-hour Ozone


8-Hour Ozone classified area designations for the 1997 standard were effective on June 15, 2004.

Thirteen (13) 8-Hour EAC areas were designated attainment on April 15, 2008.

1997 PM-2.5 area designations were effective on April 5, 2005. 2006 PM-2.5 area designations are effective on December 14, 2009.

On June 8, 2007, the United States Court of Appeals vacated the Subpart 1 portion of the Phase 1 Rule (Court Order) (PDF). On May 14, 2012, the Former Subpart 1 nonattainment areas were classified under Subpart 2 ( 77 FR 28424 (PDF)), effective June 13, 2012.

There are a few counties that are split between 8-hour ozone areas:

There are a few counties that are split between one or more previous 1-hour ozone nonattainment areas that are now in one 8-hour ozone area:


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