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PM-2.5 (1997) Maintenance Area (Redesignated from Nonattainment) Summary

Data is current as of May 31, 2023

The 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 15 91 28,072,111
SUBTOTAL 15 91 28,072,111
 
Former Subpart 1 20 103 46,455,248
SUBTOTAL 20 103 46,455,248
 
GRAND TOTAL 35 194 74,527,359

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 .