What is the National Pollutant Discharge Elimination System (NPDES) program?
• This is the federal stormwater program. In 1972, the NPDES program was essentially the regulatory mechanism of the Clean Water Act (CWA) which the Environmental Protection Agency (EPA) used to focus on industrial process wastewater and municipal sewage discharges. These sources were identified as being responsible for severely degraded water quality. In 1987, in an effort to mitigate diffuse sources of pollution conveyed in stormwater runoff, Congress enacted the Water Quality Act, an amendment to the CWA a comprehensive program to regulate stormwater. EPA promulgated the Phase I stormwater rule on November 16, 1990. This rule targeted stormwater discharges from communities with a population of at least 100,000 (termed by EPA as medium and large municipal separate storm sewer systems or MS4s), as well as stormwater discharges associated with certain industrial activities and construction sites impacting five acres or more of land. In Arizona, there were 8 entities targeted by the Pha
