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 › § 7511a
Require each State with any area that fails the ozone air quality standard to send the EPA revised air-quality plans and rules. The exact steps depend on how bad the area’s ozone problem is: Marginal, Moderate, Serious, Severe, or Extreme. For all areas, States must make and update a complete emissions inventory (first due within 2 years after November 15, 1990, then every 3 years), fix plan items on reasonably available controls, put in permit programs (within 2 years), and require owners of big stationary sources to report actual NOx and VOC emissions (the first statements due within 3 years after November 15, 1990, then at least yearly). Marginal areas have simpler rules, including a 1.1-to-1 emissions offset ratio and specific short deadlines (some fixes due within 6 months or immediately after November 15, 1990); vehicle inspection rules must meet EPA guidance (EPA will update guidance within 12 months). Higher classifications add stronger steps and stricter deadlines. Moderate areas must plan for at least a 15% VOC cut from 1990 levels within 6 years after November 15, 1990 (less only with EPA approval), install RACT for listed source categories, require gasoline vapor recovery at larger stations, and use a 1.15-to-1 offset ratio. Serious areas add enhanced monitoring rules (EPA to issue within 18 months), formal attainment and reasonable-progress demonstrations due within 4 years, tougher vehicle inspection programs and other controls, and a 1.2-to-1 offset ratio; for Serious areas “major source” includes sources at or above 50 tons per year of VOC. Severe areas must adopt travel and traffic controls to offset growth in vehicle miles within 2 years and use a 1.3-to-1 offset ratio (or 1.2-to-1 if best available controls apply); for Severe areas “major source” is 25 tons per year. Extreme areas face the strictest limits, including higher offsets (1.5-to-1 unless best controls are required), specific NOx fuel or control requirements for boilers and power plants (plan due in 3 years; rules effective 8 years after November 15, 1990), and a 10-ton major-source threshold. States must check progress every 3 years starting 6 years after November 15, 1990, and send proof to EPA within 90 days that milestones were met. If a Serious, Severe, or Extreme area misses a milestone or fails to report, the State must choose within 90 days to be reclassified, add extra measures, or adopt an EPA-approved economic incentive program; stricter deadlines apply for Extreme areas. EPA may treat some rural transport areas as Marginal if local sources are not a major cause. For areas that cross State lines, the States must coordinate and use EPA-approved modeling; a State that fails because other States did not act can ask EPA for relief.
Full Legal Text
The Public Health and Welfare, Source: USLM XML via OLRC
Legislative History
Reference
Citation
42 U.S.C. § 7511a
Title 42, The Public Health and Welfare
Last Updated
Sep 23, 2026
Release point: 119-110