Stormwater Management Program - MS4 Permit

Every five years, the Maine Department of Environmental Protection (MEDEP) issues a state-wide General Permit to all communities designated as small Municipal Separate Storm Sewer Systems (MS4s). The MS4 designation is based on the decennial U.S. census data for "Urbanized Areas," which are generally defined as densely developed census tracts or blocks with populations of at least 50,000. (Certain non-residential urban land uses with lower populations that are linked to more densely developed cores are also listed as Urbanized Areas). The 2013-18 General Permit identifies thirty MS4 communities in Maine and requires them all to implement Minimum Control Measures (MCMs) to reduce pollution from stormwater runoff. South Portland's Urbanized Area encompasses nearly all of the land in the City except for the area west of the Maine Mall (which is regulated under a separate permitting system).


Stormwater Program Coordinator Presentation to Council on MS4 Permit


Minimum Control Measures

State and federal regulations require more urbanized communities like South Portland to implement the following six Minimum Control Measures (MCMs) to significantly reduce the discharge of pollutants into local waterways. The City is required to develop a detailed Stormwater Program Management Plan that describes how each of the MCMs will be implemented over the five year permit period. Each of these MCMs is targeted towards specific audiences and activities as briefly described below.

MCM1. Public Education and Outreach: distribute educational materials and conduct public outreach to inform citizens about the impacts polluted stormwater on receiving water quality.

MCM2. Public Participation and Involvement: provide opportunities for citizens to participate in stormwater management program development and implementation.

MCM3. Illicit Discharge Detection and Elimination: develop and implement an enforceable plan to conduct routine inspections of stormwater systems to eliminate illicit pollutant discharges to receiving waters.

MCM4. Construction Site Runoff Control: develop and implement an enforceable plan to minimize sediment transport to receiving waters from construction activities disturbing more than 1 acre of land.

MCM5. Post-Construction Runoff Control: develop and implement an enforceable program to minimize polluted stormwater runoff to receiving waters from new development or redevelopment projects.

MCM6. Pollution Prevention and Good Housekeeping: develop and implement a training program to minimize stormwater pollution from municipal activities.