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Clean Air Act

3 amendmentstracked · Side-by-side comparison of previous and amended text

August 7, 1977

1977 Amendments established the Prevention of Significant Deterioration (PSD) program and nonattainment area requirements.

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The Administrator shall establish national ambient air quality standards for each air pollutant for which air quality criteria have been issued.

Amended

The Administrator shall establish NAAQS and new requirements for areas that have not attained standards (nonattainment areas), and shall prevent significant deterioration of air quality in clean air areas.

November 15, 1990

1990 Amendments added acid rain controls, expanded toxic air pollutant regulation, and established the cap-and-trade program for sulfur dioxide.

Previous

Hazardous air pollutants shall be regulated by the Administrator on a pollutant-by-pollutant basis after listing.

Amended

The Administrator shall regulate 189 listed hazardous air pollutants using maximum achievable control technology (MACT) standards, and shall establish a market-based cap-and-trade program for sulfur dioxide emissions.

November 15, 1990

Title II amendments established stricter vehicle emission standards and required reformulated gasoline in high-pollution areas.

Previous

Automobile manufacturers shall meet emission standards for hydrocarbons, carbon monoxide, and nitrogen oxides as determined by the Administrator.

Amended

Automobile manufacturers shall reduce tailpipe emissions by an additional 35-60% from 1990 levels and vehicles must meet Tier 1 standards by 1994, with reformulated gasoline required in the nine worst ozone nonattainment areas.