Clean Air Act Overview

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Enacted in 1970, the Clean Air Act (CAA) is the most complex, comprehensive, and costly environmental statute in existence. Amended in 1977 and again in 1990, the CAA has spawned thousands of pages of regulations covering numerous sources of air emissions. The CAA is divided into the following six titles: 

Title I regulates the six so-called criteria pollutants (particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, ozone, and lead). The U.S. Environmental Protection Agency (EPA) sets National Ambient Air Quality Standards (NAAQS) for these six pollutants. Each state must submit State Implementation Plans to the EPA spelling out how it will meet the NAAQS. States with areas that exceed these standards are subject to additional requirements and potential penalties. Title I also contains the air toxics program, which deals with a long list of so-called hazardous pollutants. 

Title II covers mobile sources of pollution: motor vehicles and fuels. The EPA has promulgated a large number of costly rules affecting the composition of motor fuels and vehicle emissions. 

Title III contains general provisions and authorizes lawsuits against the agency for failing to meet the statute’s hundreds of requirements. 

Title IV addresses industrial emissions that are believed to contribute to acid rain.

Title V created an air emissions permitting program, which is operated by the states under EPA supervision. 

Title VI regulates the production and use of chemicals that are believed to deplete the stratospheric ozone layer, such as chlorofluorocarbons (CFCs). 

During the 30-year existence of this federal regulatory scheme, the quality of air has improved dramatically. These gains improve on trends that had begun prior to 1970, indicating that technological advances and state and local controls were having a positive effect before federal involvement. The extent to which air quality improvements likely would have continued (under state and local law and through private sector efficiency improvements) had Congress not passed the CAA is subject to debate. What is clear is that the law has proved very costly— quite possibly more than necessary to achieve its goals. The EPA estimates direct costs at approximately $21 billion annually, increasing to $28 billion annually by 2010. Others believe the actual costs, including the indirect ones, may be much higher.