MS4 Annual Meeting

Each year, an annual meeting is held to review the Municipal Separate Storm Sewer System in Hanover.  Residents are able to review the information from the annual meeting and provide feedback using the Comment Sheet under Additional Information.  This information is also posted at City Hall.

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 Stormwater Pollution Prevention and MS4

When rain falls or when snow melts in our communities, the water flows on impervious surfaces. Impervious surfaces do not allow water to soak into them. Examples of these surfaces include roads, sidewalks/trails, driveways, rooftops, and more.

The water travels on these surfaces and eventually enters a system of storm drains which directly discharge into our lakes, rivers, streams, and wetlands. As the water travels, it can pick up various pollutants such as oils, metals, road salt, trash, and other contaminants.

The system of storm drains you observe in your community is referred to as a Municipal Separate Storm Sewer System (MS4). It consists of roads with drainage systems, catch basins, curbs, gutters, ditches, channels, and similar components.

These systems are owned and operated by a public entity. This can include cities, counties, military bases, universities, and others. In Minnesota, these systems must comply with the MS4 permit if they meet at least one of the following criteria:

1. Located in an urbanized area and used by a population of 1,000 or more.
2. Owned by a municipality with a population of 10,000 or more.
3. Has a population of at least 5,000 and the system discharges to specially classified bodies of water.

The MS4 permit is designed to reduce the introduction of pollutants into state waters from stormwater systems. Public entities that own and operate an MS4 permit are required to establish a Stormwater Pollution Prevention Program (SWPPP) to minimize the number of pollutants entering the system. An effective SWPPP is comprised of six components known as Minimum Control Measures (MCMs):

1. Public Education and Outreach
2. Public Participation/Involvement
3. Illicit Discharge Detection and Elimination
4. Construction Site Stormwater Control
5. Post-Construction Stormwater Management
6. Pollution Prevention/Good Housekeeping