The Clean Air Act gives primary responsibility for implementing our nation’s clean air programs to state and local air pollution control agencies. In order for these agencies to work toward the goal of healthful air quality, they have to carry out a variety of programs and activities designed to reduce and limit air pollution. For example, in order to plan their activities and determine their effectiveness, agencies must measure and predict the amount of pollution in the air. State and local air agencies also must enforce the air quality rules and laws, train their staffs, issue permits to sources that may emit air contaminants and obtain the funding necessary to conduct these activities.