In passing the Clean Air Act of 1970, Congress noted that the predominant part of the nation's population was centered in rapidly expanding metropolitan and other urban areas. The continuing urbanization of America, along with industrial development and increasing use of automobiles, had greatly increased the amount and complexity of air pollution. Increased air pollution endangered public health and welfare, including damage to agricultural crops, livestock, and property. Hazards to air and ground transportation also resulted from concentrated air contaminants.

Congress stated that the prevention and control of air pollution at its source was the primary responsibility of state and local governments, and that Federal financial assistance and leadership was essential for the development of cooperative Federal, state, regional, and local programs to prevent and control air pollution.

The Clean Air Act of 1970 was an attempt to protect and enhance the quality of national air resources for the public interest. The Act set forth requirements for air quality standards, emission limitations, motor vehicle emissions and fuel standards, and aircraft emissions.

National ambient air quality standar9s were designed to protect public health and welfare. Motor vehicle emission standards were established to assist in reducing pollution levels below ambient standards. These. air quality standards and emission standards comprised the fundamental approach to air pollution control, with the basic mechanism for the application of this approach being the state implementation plan. The Clean Air Act Amendments of 1977 retained the basic approach and mechanism for air pollution control, while pushing back attainment deadlines and detailing appropriate control measures. Passage of the 1977 amendments necessitated action by the Virginia General Assembly and other state legislatures as well.

The General Assembly acted by creating the State Air Pollution Control Study Commission pursuant to Senate Joint Resolution No. 37.