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The Federal Clean Air Act

The Federal Clean Air Act (CAA) is the core and driving force for all air pollution legislation in the United States.  As it currently exists it is the framework for a wide ranging and coordinated federal/state scheme of regulation that that now pervades our social order and national economy.  It affects nearly every corporate and private citizen in the country.  The following sections summarize the structure and history of the Act, and demonstrate how it is currently applied. 


The original CAA was passed in 1963, and since that time there have been five major amendment cycles.  Prior amendments to the act have occurred in 1965, 1967, 1970, and 1977.  The latest cycle was completed November 17, 1990, when President Bush I signed the latest Clean Air Act. 

The original CAA

  • Provided grants to state and local Air Pollution Control Districts.

1965 Amendments

  • Added Title II - The Motor Vehicle Pollution Control Act, authorizing federal emissions standards for new vehicles. [40CFR89]

1967 Amendments

  • Registration of fuel additives (Sec. 211) [40CFR79] - Coupled with the amendments of 1970 allowing citizen suits led to the lead phase-out regulations [40CFR80.20] and special nozzles with matching inlets for cars.  The latest lead regulations were promulgated in 1985 [50 FR 9386 (3/7/85)].

  • Aircraft engine emissions controls [40CFR87]

  • New Source Performance Standards (NSPS) (Sec. 111) [40CFR60] - Among other things, sets test methods, and requires states to regulate existing sources in any category for which EPA sets NSPSs.

1970 Amendments

  • Establishes air quality criteria pollutants (Sec. 108) [40CFR50].

  • Requires EPA to set National Ambient Air Quality Standards (NAAQS) and goals with deadlines (Sec. 109) [40CFR50].

  • Required establishment of air quality control regions (Sec. 107) -by default settled on county boundaries and formalized regions in 1977 amendments.

  • Required preparation of State Implementation Plans (SIPs) to achieve NAAQS (Sec. 110) [40CFR51].

  • Required that National Emissions Standards for Hazardous Air Pollutants (NESHAPs) be set (Sec. 112) [40CFR61]

  • Required the preparation of Transportation Control Plans (TCPs) in ozone non-attainment areas.

  • Mandated New Source Reviews in non-attainment areas (Sec. 110 (a) (2) (D)) including authorization of off-set rules (41 FR 5524-30 and 44 FR 3274).

  • Set vehicle emissions limits with compliance schedule [40CFR86].

  • Allowed citizen suits (Sec. 304) - Citizens suits led to the Prevention of Significant Deterioration (PSD) policy and amendments in 1977, a TCP for the Los Angeles basin, and a NAAQS for lead.

  • Required public disclosure of emissions (Sec. 114) - A source could not claim company proprietary rights to prevent public disclosure of emissions data.

1977 Amendments

  • Prevention of Significant Deterioration (PSD) of air quality (Sec. 163) (45 FR 52676 (8/7/80) and 48 FR 38745 (8/25/83)) [40CFR52.21].

  • Ozone protection (Sec. 150-159).

  • Forbids use of intermittent controls or dispersion to control air pollution (Sec. 123)

  • Establishes Emissions 0ff-sets and "bubble" approach (51 FR 43814 (12/4/86)).

  • Puts carcinogenic air pollutants into NESHAPs (Sec. 112)

1990 Amendments

The 1990 Federal CAA was a complete rewrite of the old clean air act.  Revises the Titles and requires EPA to issue 175 new regulations, 30 guidance documents, and 22 reports.  It also establishes 6 panels and initiates 53 research projects.  Formalizes congressionally mandated regulations.  Following are some of the items covered:

  • Drops automotive emissions limits for HCs to 0.25 g/mi and for NOx to 0.4 g/mi from 0.41 and 1.0 g/mi respectively

  • Mandates gasoline reformulation in "dirtiest cities".

  • Mandates fleet clean fuels and lowers CAFE levels

  • Sets diesel particulate standards.

  • EPA may prohibit highway grants to states

  • EPA must establish interstate air pollution transport regions.

  • Mandates maximum achievable control technology (MACT) for 189 airborne toxics by 2003.

  • Mandates reduction of SOx emissions by 8.9 million tons per year by 2000.

  • EPA to establish an allowance trading and tracking system for SOx emissions.

  • Mandates complete phase-out of CCl4 and TCA by 2000 and 2002 respectively.

  • Bans non-essential uses of ozone depleting chemicals

  • Requires recycling of CFCs from air conditioners and refrigerators by 1992

  • Mandates permit and emissions fee system for acid rain emissions

  • Sets new SIP requirements

  • By 1992 states must require owner/operators of >10 ton per year emitters to submit inventories of NOx and VOC emissions.

The 1990 Clean Air Act

The CAA is constructed of titles, each addressing a specific air pollution issue.  The CAA  currently has nine titles, covering National Ambient Air Quality Standards, Mobile Sources, Air Toxics, Acid Rain, Permitting, CFCs, Enforcement Issues, Miscellaneous Topics, and Research.  An individual Title may require the appropriate agency (usually the EPA) to write certain regulations, prepare reports, issue guidance documents, or conduct studies.  For example, under Title 1, Sec.176A(a), The EPA must by rule establish interstate transport regions whenever interstate transport of air pollutants contribute significantly to a violation of a national ambient air quality standard.  The individual titles with their major requirements are listed below.

Title I - Attainment of National Ambient Air Quality Standards

Title II -Mobile Sources

Title III - Hazardous Air Pollutants (Air Toxics)

Title IV -Acid Rain

Title V - Permits

Title VI - CFCs Phaseout/Global Warming

Title VII - Enforcement

Title VIII - Miscellaneous Issues

Title IX - Research



Last Update 11/03/2009