The quality of surface water is assessed and protected by regulations involving all levels of government. Federal authority to regulate surface water quality is derived from the U.S. constitution while state authorization is granted by state constitutions. In 1948, Congress passed the Federal Water Pollution Control Act (FWPCA) to address pollution impacts that were considered economically feasible and practical to correct.

In 1965, Congress passed the Water Quality Act that developed water quality standards for interstate waters. 1972 brought the Clean Water Act (CWA) revision to the FWPCA. This established an extensive list of water quality standards and created the National Pollutant Discharge Elimination System (NPDES) to protect the waters of the U.S. by minimizing the discharge of pollutants from point source discharges such as septic and industrial pipe outfalls and pond outfalls. Initially, the NPDES program focused on industrial process wastewater and municipal sewage. In 1977, the CWA was revised to establish best available technology limits for 65 toxic pollutants and best conventional pollutant control technology for the more common pollutants.

To address stormwater runoff pollution issues, Congress amended the CWA in 1987. The amendment required the implementation in two phases of a national program for regulating and controlling stormwater discharges.

In 1986, the Arizona legislature passed Arizona’s Environmental Quality Act (EQA) to allow for the creation of the Arizona Department of Environmental Quality (ADEQ) and the development of a comprehensive program for studying, monitoring and regulating Arizona’s water quality.

In February 2003, ADEQ began issuing general permits (AZG2003-001) for discharges from construction sites disturbing one or more acres.