Since 1955, the Bay Area Air Quality Management District has been the public agency responsible for protecting air quality in the nine counties that surround San Francisco Bay: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, southwestern Solano, and southern Sonoma counties. Air District programs monitor air emissions sources, promote climate protection, provide clean air grants, draft rules and regulate stationary air pollution sources. The Air District’s mission is to protect and improve public health, air quality and the global climate. The Air District encourages clean commute alternatives through the Spare the Air program.