To implement the strict new Clean Air Act of 1970, during his first term as EPA Administrator William Ruckelshaus spent 60% of his time on the automobile industry, whose emissions were to be reduced 90% under the new law. Senators had been frustrated at the industry's failure to cut emissions under previous, weaker air laws. The Clean Air Act Amendments of 1977 required Prevention of Significant Deterioration (PSD) of air quality for areas attaining the NAAQS and added requirements for non-attainment areas. The 1990 Clean Air Act added regulatory programs for control of acid deposition (acid rain) and stationary source operating permits. The provisions aimed at reducing sulfur dioxide emissions included a cap-and-trade program, which gave power companies more flexibility in meeting the law's goals compared to earlier iterations of the Clean Air Act. The amendments moved considerably beyond the original criteria pollutants, expanding the NESHAP program with a list of 189 hazardous air pollutants to be controlled within hundreds of source categories, according to a specific schedule. The NAAQS program was also expanded. Other new provisions covered stratospheric ozone protection, increased enforcement authority and expanded research programs. The legal authority for federal programs regarding air pollution control is based on the 1990 Clean Air Act Amendments (1990 CAAA). These are the latest in a series of amendments made to the Clean Air Act (CAA), often referred to as "the Act." This legislation modified and extended federal legal authority provided by the earlier Clean Air Acts of 1963 and 1970. The 1955 Air Pollution Control Act was the first federal legislation involving air pollution; it authorized $3 million per year to the U.S. Public Health Service for five years to fund federal level air pollution research, air pollution control research, and technical and training assistance to the states. Subsequently, the act was extended for four years in 1959 with funding levels at $5 million per year. The act was then amended in 1960 and 1962. Although the 1955 act brought the air pollution issue to the federal level, no federal regulations were formulated. Control and prevention of air pollution was instead delegated to state and local agencies. The Clean Air Act of 1963 was the first federal legislation regarding air pollution control. It established a federal program within the U.S. Public Health Service and authorized research into techniques for monitoring and controlling air pollution. In 1967, the Air Quality Act was enacted in order to expand federal government activities. In accordance with this law, enforcement proceedings were initiated in areas subject to interstate air pollution transport. As part of these proceedings, the federal government for the first time conducted extensive ambient monitoring studies and stationary source inspections.