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Notes for the:
1997 8-Hour Ozone and Previous 1-Hour Ozone Nonattainment and Maintenance Areas Report


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.

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.

8-hour and 1-hour ozone areas are listed only once in the table. Sometimes this does not give an exact account of what occurred between the 1- and 8-hour areas. Therefore, it is important to read these footnotes. For easy comparison of 8- and 1-hour ozone areas by county, see the Currently Designated 8-Hour and Previous 1-Hour Ozone Areas report.

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:

Due to the fact that this table is structured by area, the following situations are not obvious:

Counties which were part of the 1-hour ozone area, but were not included in the 8-hour ozone area:

Several Counties were moved from a 1-hour ozone area to a different 8-hour ozone area. The following are not obvious from reading the table:

Several counties in New Hampshire and Maine were completely nonattainment for the 1-hour ozone standard, but are only partially nonattainment for the 8-hour ozone standard. The following portions of 1-hour ozone areas were designated attainment for the 8-hour ozone standard:

The design value for Boston-Lawrence-Worcester (E. MA), MA was used for the classification of Boston-Manchester-Portsmouth (SE), NH.

The design value for Washington, DC-MD-VA was used for the classification of Fredericksburg, VA.


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