8-Hour Ozone (2015) Maintenance Area (Redesignated from Nonattainment) Summary

Data is current as of June 30, 2026

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Classification	Number of Areas	Number of Counties	2010 Population
Extreme	0	0	0
Severe 15	0	0	0
Serious	1	7	2,780,440
Moderate	1	7	1,928,528
Marginal	4	13	5,463,529
Marginal (Rural Transport)	2	1	17,035
SUBTOTAL	8	28	10,189,532
GRAND TOTAL	8	28	10,189,532

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.