Title 42 › CHAPTER 85 — AIR POLLUTION PREVENTION AND CONTROL › SUBCHAPTER I — PROGRAMS AND ACTIVITIES › Part C — Prevention of Significant Deterioration of Air Quality › subpart i — clean air › § 7475
You may not build a major pollution-emitting facility in the areas covered by this law if construction starts after August 7, 1977, unless you get a permit that sets emission limits and meets several tests. The project must have a public review and hearing. The owner must show the facility will not cause or help cause air pollution that exceeds any allowed increase in pollutant levels more than once per year, exceed any national air quality standard, or break any other required limit. The facility must use the best available control technology for each pollutant. It must protect special protected lands called Class I areas (like some national parks). The owner must analyze how the project will affect local air quality and growth, and must do any monitoring needed to check effects. If building in a Class III area would push levels above Class II limits and there is no newer pollution standard for that source type since August 7, 1977, the Environmental Protection Agency must approve the chosen control technology. There are some deadlines, exceptions, and review steps. A finished permit application must be approved or denied within one year after filing. An expansion of a major source that existed on August 7, 1977 is exempt from the Class II allowed-increase test if, after using best controls, its allowable emissions are less than fifty tons per year and it shows particulate matter and sulfur oxides will not exceed the national secondary standards. States must send permit applications to the EPA and tell the Federal Land Manager for any nearby Class I area. If that manager or certain officials say the project may hurt a Class I area, the owner must prove sulfur dioxide and particulate emissions will not exceed the Class I allowed increases. If the Federal Land Manager is convinced the project will cause harm, the permit cannot be issued; if the owner convinces the manager there will be no harm, the State may issue a permit but must meet strict emission limits. The law gives exact pollution limits in micrograms per cubic meter for particulates and sulfur dioxide, sets alternate limits for low and high terrain (high terrain is 900 feet or more above the stack base), limits how often short-term limits may be exceeded, and lets a Governor seek a variance in special cases (the President decides if the Federal Land Manager objects within 90 days). Before review, the owner or State must do an air-quality study following EPA rules. Starting one year after August 7, 1977, that study must include continuous monitoring for one calendar year before the permit application unless the State allows a shorter period. The EPA had to issue rules within six months after August 7, 1977 about what the study must cover, which models to use, and how to adjust them for special terrain.
Full Legal Text
The Public Health and Welfare, Source: USLM XML via OLRC
Legislative History
Reference
Citation
42 U.S.C. § 7475
Title 42, The Public Health and Welfare
Last Updated
Sep 23, 2026
Release point: 119-110