Municipal Separate Storm Sewer (MS4) Permit

The Clean Water Act (CWA), among other things, regulates stormwater and urban runoff to protect water quality. The Phase II Final Rule requires small municipal separate storm sewer systems (MS4s) such as Gilbert to obtain a National Pollutant Discharge Elimination System (NPDES) permit which specifies the measures that will be taken to prevent pollution from entering the storm system. In Arizona, Phase II permits are administered by the Arizona Department of Environmental Quality (ADEQ).  

This permit requires the Town of Gilbert to prohibit non-stormwater discharges into the storm sewer system and perform enforcement response through the implementation of a Stormwater Management Plan (SWMP). In order to meet these requirements, the Gilbert Town Council adopted Ordinance 1590 on August 3, 2004. The SWMP includes six Minimum Control Measures with best management practices (BMPs) and measurable goals for each:

1. Public Education and Outreach
2. Public Participation/Involvement
3. Illicit Discharge Detection and Elimination
4. Construction Stormwater Runoff Controls
5. Post Construction Stormwater Management
6. Pollution Prevention

Important Links 

• Stormwater Management Plan (SWMP)
• Environmental Compliance Division Organizational Chart
• Enforcement Response Plan (ERP)
• Notice of Intent (NOI)
• Ordinance 1590
• Gilbert Municipal Code Chapter 30-54
• FY21 Annual Report

Please send comments or suggestions for the Stormwater Management Plan to Environmental.Compliance@GilbertAZ.gov. 

ADEQ's Multi-Sector General Permit for Industry

ADEQ's multi-sector general permit (MSGP) is designed for discharges of stormwater from certain industrial sites that are of a non-construction nature. The MSGP is one large permit divided into numerous separate sectors. Each sector represents a different type of activity and is dependent on its standard industrial classification (SIC) code or narrative description. Information on Facilities required to apply for a stormwater permit and SIC codes can be found in 40 CDF 122.25(b)(14). The Environment Protection Agency (EPA) and the Arizona Department of Environmental Quality (ADEQ) provide further information on the MSGP.

ADEQ's General Permit for Construction

The construction general permit authorizes stormwater discharges from large and small construction-related activities that result in a total land disturbance of equal to or greater than 1 acre (including smaller parcels that are part of a larger common plan of development or sale that are equal or greater than 1 acre) where those discharges enter surface waters of the U.S. or a storm drain.

Under the Arizona Pollutant Discharge Elimination System (AZPDES), the operator of a construction site is responsible for obtaining coverage for their site. Information can be found on ADEQ's website, including a Notice of Intent (NOI).

**Important: A copy of the NOI and SWPPP must be submitted to the Town of Gilbert.**

The SWMP also mandates that Gilbert require construction sites to:

• implement erosion, sediment, and waste control measures
• address post construction runoff from new development and redeveloped projects

• Construction Best Management Practices
• Construction BMP Brochure
• Construction Tips from STORM