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Stormwater Management Program
Stormwater is rain or snow melt that runs over impervious surfaces such as streets, parking lots, driveways, and roof tops. All properties with impervious surfaces generate stormwater runoff. In general, greater amounts of impervious surfaces result in greater volumes of stormwater and more potential pollutants.
In developed areas, stormwater must be managed because it picks up pollutants as it flows into local surface waters via storm drains or road-side ditches. These pollutants can include sediment, nutrients, toxics, bacteria and trash. Consequently, local surface waters in more developed areas often fail to meet state and federal water quality standards.
The Clean Water Act requires municipalities like South Portland, which are referred to as “municipal separate storm sewer systems” (or MS4s), to comply with permit regulations that were established to minimize the harmful effects of polluted stormwater runoff and improve local water quality. To help accomplish these overall goals, the City’s Stormwater Management Program Plan identifies specific minimum control measures that must implemented over ongoing 5 year permit periods.
2022 MS4 General Permit Now in Effect
The Maine Department of Environmental Protection's Municipal Separate Storm Sewer System ("MS4") General Permit (PDF) went into effect on July 1, 2022. There are several new provisions that provide more protection for water resources. Some of these provisions include:
- Conduct analytical water quality monitoring for stormwater outfalls to determine if prohibited discharges are occurring.
- Remove verified prohibited stormwater discharges within 60 days of discovery (or develop an expeditious mitigation plan if removal within 60 days is infeasible).
- Establish an Erosion and Sediment Control Ordinance or other regulatory mechanism to minimize sediment discharge from construction projects by July 1, 2023.
- Establish a Low Impact Development Ordinance or other regulatory mechanism to provide more stormwater treatment for redevelopment and new development projects by July 1, 2024.
For more information please review the City's Stormwater Management Plan (PDF) and/or contact the Stormwater Program Coordinator.
Review the City's 2022 Stormwater Management Plan
In compliance with the Maine Department of Environmental Protection's General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems (MS4), the City updated our Stormwater Management Plan (SWMP). Please see the City Clerk to review a printed copy of the SWMP at City Hall.
WILLARD BEACH WATER QUALITY MONITORING
Since 2003, the City has worked with the Maine Healthy Beaches Program (MHB) to conduct bacteria monitoring at Willard Beach and ensure that swimming conditions are safe for the public. Additionally, the City and MHB have collaborated to identify potential pollution sources being discharged into the municipal stormwater system.