Programs that establish minimum standards for air quality, offer incentives which help to advance clean air goals, develop and enforce regulations that are designed to reduce and control gaseous and particulate contaminants in the air, monitor air pollution levels, investigate complaints regarding violations and, when warranted, initiate litigation against individuals and organizations who have failed to comply with air pollution control regulations.

Programs that establish minimum standards for surface and ground water quality and develop and enforce regulations to prevent or reduce water pollution and assure a reliable supply of healthy drinking water and water that is suitable for other purposes. Water quality assurance programs issue permits specifying the types and amounts of pollutants that may be discharged without violating water quality standards; identify and monitor land uses and activities such as manufacturing or farming that are potential sources of pollution; test, record and report on the quality of water in lakes, rivers, streams, underground aquifers and water supply wells upon which public water systems rely; monitor water treatment and distribution systems; issue warnings and investigate hazards related to contamination; and, when warranted, initiate litigation against individuals and organizations who have failed to comply with water pollution control regulations. These programs may also provide support for the development and oversight of wastewater treatment facilities and certify operators of those facilities. Water quality is generally defined in terms of its designated use, e.g., for drinking, swimming, farming, fish production or industrial processes.

Programs that monitor air pollution levels and notify the public when smog levels make the air unhealthy for sensitive groups or for everyone. Smog warnings are graded according to levels that may be harmful to people who are sensitive (stage I alerts), that are unhealthy for all people (stage II alerts) or that are hazardous (stage III alerts). People who are likely to be affected are advised to remain indoors, if possible, and to avoid strenuous outdoor physical activity; refrain from smoking; and avoid contact with people who are suffering from respiratory infections, traffic congested areas, and aerosols, dust, fumes and other irritants during episodes.