PRIA Logo™
Title 42, The Public Health and WelfareRelease 119-110

§7511 Classifications and Attainment Dates

Title 42 › CHAPTER 85 — AIR POLLUTION PREVENTION AND CONTROL › SUBCHAPTER I — PROGRAMS AND ACTIVITIES › Part D — Plan Requirements for Nonattainment Areas › subpart 2 — additional provisions for ozone nonattainment areas › § 7511

Last updated Sep 23, 2026|Official source

Summary

Areas that do not meet the ozone air quality limit must be put into one of five classes based on their measured ozone level (design value). The classes and their ranges are: Marginal 0.121 up to 0.138 ppm (attainment date 3 years after November 15, 1990), Moderate 0.138 up to 0.160 ppm (6 years), Serious 0.160 up to 0.180 ppm (9 years), Severe 0.180 up to 0.280 ppm (15 years), and Extreme 0.280 ppm and above (20 years). A Severe area with a 1988 design value between 0.190 and 0.280 ppm gets 17 years instead of 15. When an area is designated nonattainment, the EPA Administrator must publish its classification. The Administrator can change that class within 90 days if the area’s design value would move into a different class by increasing or decreasing it by 5%; the Administrator may consider exceedances, pollution transport, and source mix. A state can ask for a one-year extension of the attainment date if it met its plan requirements and the area had no more than one exceedance in the prior year; an area can get no more than two such one-year extensions. If an area is later redesignated to nonattainment, it gets the class from the table and its deadlines are pushed back by the time between November 15, 1990 and the new classification date. Within 6 months after an attainment date (including any extension), EPA will check whether the area met the standard and, except for Severe or Extreme areas, will reclassify failing areas to the next higher class or to the class matching the design value; EPA will publish notices of these actions. A state may also ask EPA to move an area to a higher class, and EPA must approve. If a Severe area fails to attain, fees and required percent reductions continue and must be shown every 3 years; if its design value is above 0.140 ppm at the attainment date or it missed a milestone, stricter new-source review and “major source” rules for Extreme areas apply immediately, otherwise those stricter rules apply after 3 years unless the area meets the standard. If EPA changes how compliance is measured, it will use a comparable number to 0.140 for these triggers.

Full Legal Text

Title 42, §7511

The Public Health and Welfare, Source: USLM XML via OLRC

(a)Classification and attainment dates for 1989 nonattainment areas
(1)Each area designated nonattainment for ozone pursuant to section 7407(d) of this title shall be classified at the time of such designation, under table 1, by operation of law, as a Marginal Area, a Moderate Area, a Serious Area, a Severe Area, or an Extreme Area based on the design value for the area. The design value shall be calculated according to the interpretation methodology issued by the Administrator most recently before November 15, 1990. For each area classified under this subsection, the primary standard attainment date for ozone shall be as expeditiously as practicable but not later than the date provided in table 1.
TABLE 1
Area class | Design value* | Primary standard attainment date**
*The design value is measured in parts per million (ppm).
**The primary standard attainment date is measured from November 15, 1990.
Marginal | 0.121 up to 0.138 | 3 years after November 15, 1990
Moderate | 0.138 up to 0.160 | 6 years after November 15, 1990
Serious | 0.160 up to 0.180 | 9 years after November 15, 1990
Severe | 0.180 up to 0.280 | 15 years after November 15, 1990
Extreme | 0.280 and above | 20 years after November 15, 1990
(2)Notwithstanding table 1, in the case of a severe area with a 1988 ozone design value between 0.190 and 0.280 ppm, the attainment date shall be 17 years (in lieu of 15 years) after November 15, 1990.
(3)At the time of publication of the notice under section 7407(d)(4) of this title (relating to area designations) for each ozone nonattainment area, the Administrator shall publish a notice announcing the classification of such ozone nonattainment area. The provisions of section 7502(a)(1)(B) of this title (relating to lack of notice and comment and judicial review) shall apply to such classification.
(4)If an area classified under paragraph (1) (Table 1) would have been classified in another category if the design value in the area were 5 percent greater or 5 percent less than the level on which such classification was based, the Administrator may, in the Administrator’s discretion, within 90 days after the initial classification, by the procedure required under paragraph (3), adjust the classification to place the area in such other category. In making such adjustment, the Administrator may consider the number of exceedances of the national primary ambient air quality standard for ozone in the area, the level of pollution transport between the area and other affected areas, including both intrastate and interstate transport, and the mix of sources and air pollutants in the area.
(5)Upon application by any State, the Administrator may extend for 1 additional year (hereinafter referred to as the “Extension Year”) the date specified in table 1 of paragraph (1) of this subsection if—
(A)the State has complied with all requirements and commitments pertaining to the area in the applicable implementation plan, and
(B)no more than 1 exceedance of the national ambient air quality standard level for ozone has occurred in the area in the year preceding the Extension Year.
No more than 2 one-year extensions may be issued under this paragraph for a single nonattainment area.
(b)New designations and reclassifications
(1)New designations to nonattainment
Any area that is designated attainment or unclassifiable for ozone under section 7407(d)(4) of this title, and that is subsequently redesignated to nonattainment for ozone under section 7407(d)(3) of this title, shall, at the time of the redesignation, be classified by operation of law in accordance with table 1 under subsection (a). Upon its classification, the area shall be subject to the same requirements under section 7410 of this title, subpart 1 of this part, and this subpart that would have applied had the area been so classified at the time of the notice under subsection (a)(3), except that any absolute, fixed date applicable in connection with any such requirement is extended by operation of law by a period equal to the length of time between November 15, 1990, and the date the area is classified under this paragraph.
(2)Reclassification upon failure to attain
(A)Within 6 months following the applicable attainment date (including any extension thereof) for an ozone nonattainment area, the Administrator shall determine, based on the area’s design value (as of the attainment date), whether the area attained the standard by that date. Except for any Severe or Extreme area, any area that the Administrator finds has not attained the standard by that date shall be reclassified by operation of law in accordance with table 1 of subsection (a) to the higher of—
(i)the next higher classification for the area, or
(ii)the classification applicable to the area’s design value as determined at the time of the notice required under subparagraph (B).
No area shall be reclassified as Extreme under clause (ii).
(B)The Administrator shall publish a notice in the Federal Register, no later than 6 months following the attainment date, identifying each area that the Administrator has determined under subparagraph (A) as having failed to attain and identifying the reclassification, if any, described under subparagraph (A).
(3)Voluntary reclassification
The Administrator shall grant the request of any State to reclassify a nonattainment area in that State in accordance with table 1 of subsection (a) to a higher classification. The Administrator shall publish a notice in the Federal Register of any such request and of action by the Administrator granting the request.
(4)Failure of Severe Areas to attain standard
(A)If any Severe Area fails to achieve the national primary ambient air quality standard for ozone by the applicable attainment date (including any extension thereof), the fee provisions under section 7511d of this title shall apply within the area, the percent reduction requirements of section 7511a(c)(2)(B) and (C) of this title (relating to reasonable further progress demonstration and NOx control) shall continue to apply to the area, and the State shall demonstrate that such percent reduction has been achieved in each 3-year interval after such failure until the standard is attained. Any failure to make such a demonstration shall be subject to the sanctions provided under this part.
(B)In addition to the requirements of subparagraph (A), if the ozone design value for a Severe Area referred to in subparagraph (A) is above 0.140 ppm for the year of the applicable attainment date, or if the area has failed to achieve its most recent milestone under section 7511a(g) of this title, the new source review requirements applicable under this subpart in Extreme Areas shall apply in the area and the term “major source” and “major stationary source” shall have the same meaning as in Extreme Areas.
(C)In addition to the requirements of subparagraph (A) for those areas referred to in subparagraph (A) and not covered by subparagraph (B), the provisions referred to in subparagraph (B) shall apply after 3 years from the applicable attainment date unless the area has attained the standard by the end of such 3-year period.
(D)If, after November 15, 1990, the Administrator modifies the method of determining compliance with the national primary ambient air quality standard, a design value or other indicator comparable to 0.140 in terms of its relationship to the standard shall be used in lieu of 0.140 for purposes of applying the provisions of subparagraphs (B) and (C).
(c)References to terms
(1)Any reference in this subpart to a “Marginal Area”, a “Moderate Area”, a “Serious Area”, a “Severe Area”, or an “Extreme Area” shall be considered a reference to a Marginal Area, a Moderate Area, a Serious Area, a Severe Area, or an Extreme Area as respectively classified under this section.
(2)Any reference in this subpart to “next higher classification” or comparable terms shall be considered a reference to the classification related to the next higher set of design values in table 1.

Legislative History

Notes & Related Subsidiaries

Statutory Notes and Related Subsidiaries

Exemptions for Stripper Wells Pub. L. 101–549, title VIII, § 819, Nov. 15, 1990, 104 Stat. 2698, provided that: “Notwithstanding any other provision of law, the

Amendments

to the Clean Air Act made by section 103 of the Clean Air Act

Amendments

of 1990 [enacting this section and sections 7511a to 7511f of this title] (relating to additional provisions for ozone nonattainment areas), by section 104 of such

Amendments

[enacting section 7512 and 7512a of this title] (relating to additional provisions for carbon monoxide nonattainment areas), by section 105 of such

Amendments

[enacting sections 7513 to 7513b of this title and amending section 7476 of this title] (relating to additional provisions for PM–10 nonattainment areas), and by section 106 of such

Amendments

[enacting section 7514 and 7514a of this title] (relating to additional provisions for areas designated as nonattainment for sulfur oxides, nitrogen dioxide, and lead) shall not apply with respect to the production of and equipment used in the exploration, production, development, storage or processing of—“(1) oil from a stripper well property, within the meaning of the June 1979 energy

Regulations

(within the meaning of section 4996(b)(7) of the Internal Revenue Code of 1986 [26 U.S.C. 4996(b)(7)], as in effect before the repeal of such section); and “(2) stripper well natural gas, as defined in section 108(b) of the Natural Gas Policy Act of 1978 (15 U.S.C. 3318(b)).[,] except to the extent that provisions of such

Amendments

cover areas designated as Serious pursuant to part D of title I of the Clean Air Act [this part] and having a population of 350,000 or more, or areas designated as Severe or Extreme pursuant to such part D.”

Reference

Citations & Metadata

Citation

42 U.S.C. § 7511

Title 42, The Public Health and Welfare

Last Updated

Sep 23, 2026

Release point: 119-110