Nonattainment and Maintenance Area Dashboard
The Nonattainment and Maintenance Area Dashboard provides information about nonattainment and maintenance areas for current and revoked National Ambient Air Quality Standards (NAAQS). Information in the dashboard can be filtered by state, NAAQS, area name, area status, area classification, and other fields. When viewing information about a specific area, the history of EPA actions on the area is displayed at the bottom of the page. For more information about a particular nonattainment or maintenance area, please visit the EPA Green Book and the Nonattainment and Maintenance Population Tool.
Reports Last Updated:
1 On June 8, 2007, the United States Court of Appeals vacated the Subpart 1 portion of the Phase 1 Rule for the 1997 8-hr ozone NAAQS (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.
2 On January 4, 2013, the D.C. Circuit Court of Appeals held that the EPA must implement the PM2.5 NAAQS pursuant to the requirements specific to particulate matter in subpart 4 (of part D of title I of the CAA), in conjunction with the general requirements in subpart 1. [NRDC v. EPA, 706 F.3d 428 (D.C. Cir. 2013).] After this decision, EPA classified all PM2.5 nonattainment areas as either Moderate or Serious, pursuant to subpart 4.
3 For nonattainment or maintenance areas that include partial counties, only the portion of the population living within the nonattainment or maintenance area is included in the total population number.
4 See the Air Quality Design Value site spreadsheet footnotes for information about "Insufficient Data" Meets NAAQS Determinations.
* On February 27, 2020, the EPA determined, based on an analysis from California, that the Imperial County nonattainment area would have attained the 2008 ozone NAAQS by the 'Moderate' area attainment date of July 20, 2018, but for emissions emanating from Mexico, and therefore is not subject to the CAA requirements pertaining to reclassification upon failure to attain. (85 FR 11817)
* Multi-state areas are counted in maintenance totals when all states in the area have been redesignated.
* Current and historical design value data can be found on the Air Quality Design Value site and the EPA Green Book contains comprehensive nonattainment area, designation status, and historical information.
* Entire 40 CFR Part 81 area designation notices for all states can be found on the 40 CFR Part 81 - Designation of Areas for Air Quality Planning Purposes site. Additional area designation can be found on the Green Book Related Air Quality and Designation Websites page.
* Multi-state areas are counted in maintenance totals when all states in the area have been redesignated.
* Maintenance areas – Total number of maintenance areas for current NAAQS. Does not include maintenance areas for revoked NAAQS, or portions of maintenance areas.
* Nonattainment areas – Total number of nonattainment areas for current NAAQS. Does not include nonattainment areas for revoked NAAQS. Includes nonattainment areas for which a portion may already be redesignated to attainment (i.e., maintenance).
* Maintenance (NAAQS revoked) – Total number of maintenance areas for revoked NAAQS only.
* Nonattainment (NAAQS revoked) – Total number of nonattainment areas for revoked NAAQS only.