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1-Hour Ozone (1979) Nonattainment Area Summary - NAAQS Revoked
1-Hour Ozone (1979) Nonattainment Area Summary - NAAQS Revoked
Data is current as of September 30, 2024| Classification | Number of Areas | Number of Counties | 2010 Population |
|---|---|---|---|
| Extreme | 2 | 12 | 17,784,954 |
| Severe-17 | 6 | 48 | 35,418,992 |
| Severe-15 | 6 | 48 | 16,736,177 |
| Serious | 8 | 36 | 16,125,782 |
| Moderate | 5 | 11 | 1,736,909 |
| Marginal | 16 | 36 | 7,367,934 |
| Rural Transport (Marginal) | 2 | 2 | 0 |
| Other | 1 | 8 | 6,541,828 |
| SUBTOTAL | 46 | 201 | 101,712,576 |
| Section 185A | 3 | 3 | 459,668 |
| Incomplete Data | 14 | 15 | 1,259,464 |
| SUBTOTAL | 17 | 18 | 1,719,132 |
| GRAND TOTAL | 63 | 219 | 103,431,708 |
County subtotals and grand totals may not equal sum of parts.
Part counties are only counted one time across groupings.
"Section 185A" was previously called "Transitional".
The former 1-hour ozone designations and classifications as of June 15, 2004, are being retained in subpart C of Part 81 for purposes of the anti backsliding provisions of 40 CFR 51.905. 40 CFR 51.905(c) references subpart C of part 81 for the areas affected by the anti-backsliding regulation.