Storm Water Quality
On average it only rains about seven inches a year. There are two completely separate sewer systems in Gilbert and in most of the surrounding municipalities. 
- There is a sanitary sewer that collects waste from homes and businesses from the sinks, toilets, showers, and baths. From there the waste water goes through pipes to a waste water treatment plant.
- Then there is the storm sewer that includes the gutters, streets, retention basins, drywells, and other storm sewer structures. The water and other things that enter the storm sewer aren’t treated for contaminants, it goes right into the ground via infiltration into the soil or though a drywell.
The Clean Water Act (CWA), among other things, regulates storm water and urban runoff to protect water quality. The Phase II Final Rule requires small municipal storm sewer systems (MS4s) such as Gilbert to obtain a 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).
There are several requirements imposed on Gilbert by the permit including having a Storm Water Management Plan (SWMP). Gilbert is required to prohibit non-storm water discharges into the storm sewer system and to implement enforcement procedures.
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
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 measureable goals for each:
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Public Education and Outreach
- Public Participation/Involvement
- Illicit Discharge Detection and Elimination
- Construction Storm water Runoff Controls
- Post Construction Storm Water Management
- Pollution Prevention
As part of Gilbert’s SWMP, Gilbert has developed fact sheets that provide information and best management practices on how we can all reduce or eliminate pollution in the storm sewer.
Download the SWMP
Download the NOI
Download the 2009 Annual Report
Hear a message about how yard waste can affect the stormwater system and what you can do to help
Arizona Department of Environmental Quality’s Multi-Sector General Permit for Industry
ADEQ’s multi-sector general permit (MSGP) is designed for discharges of storm water 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 storm water 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 storm water 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. The operator could be the owner, developer, general contractor or an individual contractor. Information, including a Notice of Intent (NOI) form and a Construction SWPPP checklist can be found on ADEQ’s website. Information is also available on EPA’s website.
**Important: A copy of the NOI and SWPP must be submitted to the Town of Gilbert.**