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Classifications of 8-Hour Ozone (1997) Nonattainment Areas

As of December 05, 2013
View Notes

Category/Classification (Attainment Date)

EXTREME (June 2024)
Los Angeles-South Coast Air Basin, CA
San Joaquin Valley, CA
SEVERE 17 (June 2021)
Morongo Band of Mission Indians
SEVERE 15 (June 2019)
Houston-Galveston-Brazoria, TX
Los Angeles-San Bernardino Cos. (W Mojave Desert), CA
Riverside Co. (Coachella Valley), CA
Sacramento Metro, CA
SERIOUS (June 2013)
Baltimore, MD
Dallas-Fort Worth, TX
Ventura Co, CA
MODERATE (June 2010)
Amador and Calaveras Cos. (Central Mountain Cos.), CA
Atlanta, GA
Boston-Lawrence-Worcester (E. Mass), MA
Buffalo-Niagara Falls, NY
Charlotte-Gastonia-Rock Hill, NC-SC (NC portion)
Greater Connecticut, CT
Imperial Co, CA
Jamestown, NY
Jefferson Co, NY
Kern Co (Eastern Kern), CA
Mariposa and Tuolumne Cos (Southern Mtn), CA
Nevada Co. (Western part), CA
New York-N. New Jersey-Long Island, NY-NJ-CT
Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE
Pittsburgh-Beaver Valley, PA
Poughkeepsie, NY
Providence (all of RI), RI
Sheboygan, WI
Springfield (W. Mass), MA
St Louis, MO-IL (MO portion)
Washington, DC-MD-VA
MARGINAL (June 2007)
Albany-Schenectady-Troy, NY
Chico, CA
Denver-Boulder-Greeley-Ft. Collins-Loveland, CO
Essex Co (Whiteface Mtn), NY
Phoenix-Mesa, AZ
Rochester, NY
San Francisco Bay Area, CA
Sutter Co (Sutter Buttes), CA


Details about the designations and classifications of previous 1-hour ozone nonattainment and maintenance areas can be found here.

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.

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