- Construction Activities
- Multi-Sector (Industrial Activities)
- Municipal Separate Storm Sewer System (MS4)
The U. S. Environmental Protection Agency (EPA) continues to be the permitting authority for all regulated stormwater discharges on Indian Lands. For more information on stormwater permitting on Indian Lands within Arizona, please visit: U.S. EPA Region 9 NPDES Stormwater Program .
U.S. EPA has estimated that about 30 percent of known pollution to our nation's waters is attributable to stormwater runoff. In 1987, Congress directed U.S. EPA to develop a regulatory program to address the stormwater problem. U.S. EPA issued regulations in 1990 authorizing the creation of a NPDES permitting system for stormwater discharges from a select group of industrial activities. The National Pollutant Discharge Elimination System (NPDES) is the administrative mechanism chosen for the stormwater permitting program. In Arizona, this program is called Arizona Pollutant Discharge Elimination System (AZPDES). An AZPDES permit is required for any point source discharge of pollutants to a water of the United States. Because stormwater runoff can transport pollutants to either a municipal separate storm sewer system or to a water of the United States, permits are required for those discharges.
Most stormwater discharges are permitted under various general permits. However, an individual permit is required when the general permit requirements do not accurately represent the activity at a facility and a permit is customized to the site.
An individual permit may be necessary if the limitations of coverage section of a general permit does not allow the facility's discharge to be covered within the general permit. It is the responsibility of every applicant to determine if any of the limitations of coverage apply to the facility seeking a general permit.
The following waterbodies (commonly referred to as the 303(d) list) were assessed by ADEQ as having impaired uses that require more than existing technology and permit controls to achieve or maintain water quality standards. The links below provide a list and map of these impaired waters.
Outstanding Arizona Waters (OAW)
ADEQ established, under A.A.C. R18-11-112, the following surface waters have been classified as outstanding Arizona waters.