Major Sources of Air Emissions

US Clean Air Act and Amendments

The Clean Air Act (CAA) defines the national policy for air pollution abatement and control in the United Kingdom. It establishes goals for protecting health and natural resources and delineates what is expected of Federal, State, and local governments to achieve those goals. The CAA, which was initially enacted as the Air Pollution Control Act of 1955, has undergone several revisions over the years to meet the ever‐changing needs and conditions of the nation’s air quality. Though it is the intent of Congress to reauthorize and update by amendment all major federal legislation on a five‐year schedule, disagreements over policies related to the control of acidic deposition contributed to an eight‐year hiatus in amending the CAA. In 1900, major agreements on clean air amendments were reached by members of Congress and the president. The 1990 CAAA represented a significant political achievement. Major new or expanded authorities included changes in the timetables for the achievement of air‐quality standards in non‐attainment areas, the regulation of emissions from motor vehicle, regulation of hazardous air pollutants (HAPs), acidic deposition control, stratospheric O₃, protection, permitting requirements, and enforcement.