8-Hour Ozone (2015) Clean Data Determination/Attainment Determinations For Areas with Current Nonattainment Status

Data is current as of February 28, 2026
Ordered by Area Name

Click on the 'FR' link to view the Federal Register Notice

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SERIOUS
Baltimore, MD
Clean Data Determination
Proposed Approval	01/23/2026	91 FR 2887
Cleveland, OH
Clean Data Determination
Proposed Approval	02/27/2026	91 FR 9800
Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE
Clean Data Determination
Proposed Approval	01/02/2026	91 FR 98
St. Louis, MO-IL
Clean Data Determination
Proposed Approval	02/26/2026	91 FR 9516
Proposed Approval	02/26/2026	91 FR 9519
MODERATE
Louisville, KY-IN
Determination of Attainment by Attainment Date
Proposed Approval	01/29/2026	91 FR 3847
Mariposa County, CA
Determination of Attainment by Attainment Date
Proposed Approval	06/03/2025	90 FR 23501
Final Approval	10/30/2025	90 FR 48820	Effective: 12/01/2025
Uinta Basin, UT
Determination of Attainment by Attainment Date
Proposed Approval	04/10/2024	89 FR 25223
Washington, DC-MD-VA
Clean Data Determination
Proposed Approval	02/01/2023	88 FR 6688
Both Clean Data Determination and Determination of Attainment by Attainment Date
Proposed Approval	11/15/2024	89 FR 90249
Final Approval	04/04/2025	90 FR 14730	Effective: 05/05/2025
MARGINAL
Amador County, CA
Determination of Attainment by Attainment Date
Proposed Approval	04/13/2022	87 FR 21842
Final Approval	10/07/2022	87 FR 60897	Effective: 11/07/2022
Butte County, CA
Determination of Attainment by Attainment Date
Proposed Approval	07/14/2022	87 FR 42126
Final Approval	10/20/2022	87 FR 63698	Effective: 11/21/2022
Calaveras County, CA
Determination of Attainment by Attainment Date
Proposed Approval	07/14/2022	87 FR 42126
Final Approval	10/20/2022	87 FR 63698	Effective: 11/21/2022
San Francisco Bay Area, CA
Determination of Attainment by Attainment Date
Proposed Approval	04/13/2022	87 FR 21842
Final Approval	10/07/2022	87 FR 60897	Effective: 11/07/2022
San Luis Obispo (Eastern part), CA
Determination of Attainment by Attainment Date
Proposed Approval	07/14/2022	87 FR 42126
Final Approval	10/20/2022	87 FR 63698	Effective: 11/21/2022
Southern Wasatch Front, UT
Determination of Attainment by Attainment Date
Proposed Approval	04/13/2022	87 FR 21842
Final Approval	10/07/2022	87 FR 60897	Effective: 11/07/2022
Sutter Buttes, CA
Determination of Attainment by Attainment Date
Proposed Approval	07/14/2022	87 FR 42126
Final Approval	10/20/2022	87 FR 63698	Effective: 11/21/2022
Tuolumne County, CA
Determination of Attainment by Attainment Date
Proposed Approval	07/14/2022	87 FR 42126
Final Approval	10/20/2022	87 FR 63698	Effective: 11/21/2022
MARGINAL (RURAL TRANSPORT)
Tuscan Buttes, CA
Determination of Attainment by Attainment Date
Proposed Approval	07/14/2022	87 FR 42126
Final Approval	10/20/2022	87 FR 63698	Effective: 11/21/2022

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