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    State of Arizona

    Arizona Stormwater Laws and Regulations

    The state operates under the Arizona Pollutant Discharge Elimination System, through NPDES Permit (AZG2002-002) and state regulation Arizona Administrative Code (A.A.C.) R18-9-A905. There is a phase II MS4 general permit to address stormwater runoff from new development and redevelopment projects that "disturb greater than or equal to one acre, including projects less than one acre that are part of a larger common plan of development or sale, and discharge into the small MS4." The standards are only applicable in regulated MS4 areas, and Indian Lands are exempted.

    Excerpt- Arizona Department of Environmental Quality Stormwater Page

    On December 05, 2002, Arizona became one of 45 states with authorization from EPA to operate the NPDES Permit Program (Section 402 of the Clean Water Act) on the state level under the Arizona Pollutant Discharge Elimination System (AZPDES) Permit Program. All facilities that discharge pollutants from any point source into waters of the United States (navigable waters) are required to obtain or seek coverage under an AZPDES permit. Pollutants can enter waters of the United States from a variety of pathways, including agricultural, domestic and industrial sources. For regulatory purposes these sources are generally categorized as either point source or nonpoint sources.

    Arizona is authorized to issue NOIs for construction and industrial activities under 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.

    Excerpt - ADOT Municipal Separate Storm Sewer System Permit

    3.2 Maintain Adequate Legal Authority 

    ADOT shall utilize the powers delegated to it by the Arizona Legislature to control and enforce the release of pollutants to and discharges from the MS4 that is owned or operated by ADOT through rules and regulations regulating encroachments (e.g., A.A.C. R17-3-501 – 509), permits, contracts or similar means. 

    Where necessary to assist in implementing this legal authority, ADOT shall develop and/ or revise procedures, agreements, and/or memorandums of understanding with other agencies, such as the Arizona Office of the Attorney General and the Arizona Department of Public Safety. These procedures/ agreements/ memorandums shall be documented in the SWMP. 

    To be considered adequate, this legal authority shall, at a minimum, address the following: 

    1. Authority to Prohibit Illicit Discharges: Prohibit and eliminate illicit connections and discharges to the MS4. Illicit connections include pipes, drains, open channels, or other conveyances that have the potential to allow an illicit discharge to enter the MS4. Illicit discharges include all non-stormwater discharges except firefighting discharges, discharges from NPDES permitted industrial sources and discharges not otherwise allowed under Part 3.2(b) of this permit. 
    2. Allowable Non-Stormwater Discharges: Exceptions to the prohibition in Part 3.2(a) may include the allowable non-stormwater discharges described in Part 1.3, only if they are nonsignificant contributors of pollutants (i.e., do not result in the discharge of pollutants above a numeric or narrative SWQS). 
    3. Authority to Prohibit Spills or Other Releases: Control the discharge of spills, and prohibit dumping or disposal of materials other than stormwater into the MS4. 
    4. Authority to Require Compliance: Require compliance with conditions in ADOT’s statutes, rules, permits, contracts, or orders (i.e., hold dischargers accountable for their contributions of pollutants and flows). 
    5. Authority to Require Installation, Implementation, and Maintenance of Control Measures: Require owners/operators of construction sites, new or redeveloped land, and industrial and commercial facilities that discharge to ADOT’s MS4 to minimize the discharge of pollutants through the installation, implementation, and maintenance of stormwater control measures. 
    6. Authority to Receive and Collect Information: Require from operators of construction sites that discharge to ADOT’s municipal storm sewer system information such as stormwater plans, inspection reports, and monitoring results, and other information deemed necessary to assess compliance with this permit. Permit No. AZS000018 – 2015 [6] Arizona Department of Transportation AZPDES Municipal Separate Storm Sewer System Permit 
    7. Authority to Inspect: To the extent allowable under state law, ADOT shall have authority to inspect facilities or activities that result in a discharge to its municipal storm sewer system. 
    8. Response to Violations: Establish written procedures to promptly require that violators cease and desist illicit discharges or discharges of stormwater in violation of any ADOT-specific statute, rule, permit or other mechanisms and abate such discharges, including the ability to: 
      1. Require the responsible person to abate the illicit discharge, spill, or pollutant release immediately and initiate remedial activities as soon as practicable; 
      2. If a situation persists where pollutant-causing sources or activities are not abated, provide the option to order the cessation of activities until such problems are adequately addressed.
      3. When all parties agree that remedial activities cannot be initiated immediately, ADOT shall determine a new timeframe and notify ADEQ within 14 days of becoming aware of the illicit discharge, spill, or pollutant release. 
    9. Interagency Agreements: As necessary, establish agreements (memorandum of agreement, etc.) with other MS4s to abate, control, or reduce the discharge of pollutants to ADOT’s municipal storm sewer system 


    Arizona DEQ Stormwater Page

    ADOT Municipal Separate Storm Sewer System Permit