Title 42 — The Public Health and WelfareRelease 119-73
§7511 Classifications and attainment dates
Title 42 › Chapter CHAPTER 85— - AIR POLLUTION PREVENTION AND CONTROL › Subchapter SUBCHAPTER I— - PROGRAMS AND ACTIVITIES › Part Part D— - Plan Requirements for Nonattainment Areas › Subpart subpart 2— - additional provisions for ozone nonattainment areas › § 7511
Summary
When a place is found to be not meeting ozone limits, it is automatically put into one of five categories based on the area's measured ozone level (the "design value" calculated the way the EPA had set before November 15, 1990). The five categories and their ozone ranges and deadlines measured from November 15, 1990, are: Marginal (0.121 up to 0.138 ppm) — 3 years; 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 (but 17 years if the area’s 1988 design value was between 0.190 and 0.280 ppm); and Extreme (0.280 ppm and above) — 20 years. The EPA must publish the area’s classification when it announces the nonattainment designation. The EPA can change a classification within 90 days if the area’s design value is within 5% of a different category, and it may consider exceedances, pollution transport, and the mix of sources. A State can ask for a one-year extension if it met its plan rules and had no more than one exceedance in the prior year. If an area later becomes nonattainment after first being listed as meeting or unclear, it gets classified the same way and faces the same rules, with any deadlines moved forward by the time between November 15, 1990, and the new classification. Within six months after an area’s deadline, the EPA will check if it met the standard. Except for Severe and Extreme areas, places that failed must be bumped up to a higher category by law. Severe areas that fail face extra requirements: fees, ongoing percent-reduction duties for certain pollutants every three years, and, if the design value is above 0.140 ppm at the deadline (or other milestones are missed), the stricter new-source controls that apply to Extreme areas. References to the category names or to the “next higher” class mean the groups and steps listed above.
Full Legal Text
Title 42, §7511
The Public Health and Welfare — Source: USLM XML via OLRC
(a)(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 classDesign value*Primary standardattainment date** *The design value is measured in parts per million (ppm). **The primary standard attainment date is measured from November 15, 1990. Marginal0.121 up to 0.1383 years after November 15, 1990 Moderate0.138 up to 0.1606 years after November 15, 1990 Serious0.160 up to 0.1809 years after November 15, 1990 Severe0.180 up to 0.28015 years after November 15, 1990 Extreme0.280 and above20 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.
(b)(1)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)(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).
(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)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)(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 11 So in original. Probably should be “terms”. “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)(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
Apr 6, 2026
Release point: 119-73