AZ Pollution Discharge Elimination System
The City of Prescott operates a Municipal Separate Storm Sewer System (MS4), which means that the storm sewer and the sanitary sewer are separate systems. The City’s storm sewer system consists of municipally owned streets with drainage systems comprised of a combination of catch basins, curbs, gutters, ditches, manmade channels, and storm drains. Rain, snow melt, and other substances dumped into a street, alley, gutter or storm drain enter the storm drainage system and flow into the nearest creek or lake untreated.
In Arizona, MS4s are regulated by the Arizona Department of Environmental Quality (ADEQ) through the Arizona Pollutant Discharge Elimination System (AZPDES) permit program. In accordance with the AZPDES Small MS4 General Permit, each MS4 is required to prepare and implement a Stormwater Management Program Plan (SWMP). The SWMP must reduce the discharge of pollutants to the “maximum extent practicable”, protect water quality, and satisfy the appropriate water quality requirements of the Clean Water Act. Small MS4s must design into their programs six minimum control measures including: Public Education and Outreach; Public Participation/Involvement; Illicit Discharge Detection and Elimination; Construction Site Runoff Control; and Post-Construction Runoff Control.