The Clean Air Act, similar to other environmental legislation, has evolved throughout time. The Clean Air Act (CAA) started with the Air Pollution Control Act of 1955. This Act was the first Federal Legislation involving Air Pollution. Its main reason was to provide funds for Air Pollution Research.
The Clean Air Act of 1963 (CAA 1963) was the first federal legislation regarding air pollution control. This Act was to protect and enhance the quality of the nation's air so as to promote the public's health and welfare. This Act established a federal program within the US Public Health Service and authorized research into technology for monitoring and controlling Air Pollution. This Act also provided technical and financial assistance to state and local governments in connection with the development and execution of their air pollution prevention and control programs.
The Air Quality Act of 1970 was the next step toward clean air regulation. It expanded the Federal Governments activities and started enforcement proceedings in areas subject to interstate air pollution. This also initiated Federal Governments extensive ambient monitoring studies and stationary source inspections.
The Clean Air Act of 1970 (CAA 1970) was the next innovation in our quest for cleaner air. It authorized the development of Federal and State regulations to limit emissions for both stationary and mobile sources. It created four different programs for stationary sources: The National Ambient Air Quality Standard (NAAQS), State Implementation Plans (SIP), New Source Performance Standards (NSPS), and National Emissions Standard for Hazardous Air Pollutants (NESHAPs). This Act was around the same time as the National Environmental Policy Act (NEPA) which established the Environmental Protection Agency (EPA) in May of 1971. The EPA was established to implement the requirements of the CAA 1970.
There are 2 amendments to the CAA 1970, one in 1977 and one in 1990. The 1977 Amendments (CAAA 1777) created provisions for the prevention of significant deterioration, otherwise known as PSD, of air quality in areas attaining the NAAQS. It also contained requirements pertaining to the sources in non-attainment areas for NAAQS. Both of these amendments established major permit review requirements. The Amendments from 1990 increased the authorization and responsibility of the Federal Government. It also added control of acid rain, operating permits, toxic pollutants and stratospheric ozone protection.
As you can see, the Clean Air Act, and related legislation, has made enormous changes in our air quality. All of our current legislations aim towards keeping the world safe for our children and our children's children.