8-Hour Ozone (2015) Nonattainment Area Summary

Data is current as of September 30, 2021

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Classification	Number of Areas	Number of Counties	2010 Population
Extreme	2	12	19,544,668
Severe 15	3	1	4,369,276
Serious	2	1	821,740
Moderate	4	31	22,634,693
Marginal	38	157	77,352,596
Marginal (Rural Transport)	2	2	17,004
SUBTOTAL	51	204	124,739,977
GRAND TOTAL	51	204	124,739,977

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