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PM-2.5 (1997) Maintenance Area (Redesignated from Nonattainment) Summary
PM-2.5 (1997) Maintenance Area (Redesignated from Nonattainment) Summary
Data is current as of March 31, 2025The 1997 Primary Annual PM-2.5 NAAQS (level of 15 µg/m3) is revoked in attainment and maintenance areas for that NAAQS. For additional information see the PM-2.5 NAAQS SIP Requirements Final Rule, effective October 24, 2016. (81 FR 58009)
| Classification | Number of Areas | Number of Counties | 2010 Population |
|---|---|---|---|
| Serious | 0 | 0 | 0 |
| Moderate | 16 | 92 | 28,081,540 |
| SUBTOTAL | 16 | 92 | 28,081,540 |
| Former Subpart 1 | 20 | 103 | 46,455,248 |
| SUBTOTAL | 20 | 103 | 46,455,248 |
| GRAND TOTAL | 36 | 195 | 74,536,788 |
County subtotals and grand totals may not equal sum of parts. Part counties are only counted one time across groupings. Multi-state nonattainment areas are not considered maintenance areas until all states in the area have been redesignated
The PM-2.5 (1997) Philadelphia-Wilmington, PA-NJ-DE nonattainment area, county and population are included in the Moderate classification grouping. NJ was classified as Subpart 1 at redesignation (effective September 4, 2013, 78 FR 54396), while PA and DE were classified as Moderate at redesignation. DE was redesignated effective September 4, 2014 79 FR 45350, and PA was redesignated effective April 21, 2015 80 FR 22112 .