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Phase II Stormwater Regulations

The U.S. Environmental Protection Agency (USEPA) has issued the Phase II Storm Water Rule, which requires municipalities and other public bodies that operate a separate stormwater drainage system within a U.S. Census-defined Urbanized Boundary to obtain a stormwater permit. This permit program affects over 120 communities in Southeast Michigan and is administered by the Michigan Department of Environmental Quality (DEQ).

Who Needs a Stormwater Permit? 
Owners or operators of small municipal separate storm sewer systems (MS4s) located in urbanized areas as defined by the Census Bureau (see 2010 Urbanized Area map), and those small MS4s located outside an urbanized area that are designated by the National Pollutant Discharge Elimination System (NPDES) permitting authorities are covered under the Phase II program.    

Stormwater Permit Overview and Requirements
The DEQ has revised the state application and stormwater permit for MS4s in 2013, which can be found on their Municipal Program webpage. The revised application includes new documented procedures that the municipality must develop and submit as part of their application. SEMCOG has developed template procedures that can assist communities with the preparation of their application. These template procedures are meant to serve as a framework for meeting the permit application requirements and can be adjusted for each individual community's needs. 

If you have any questions on the revised stormwater permit or application, or would like one-on-one assistance in preparing your permit application, SEMCOG can help! Please contact Amy Mangus at or 313-324-3350.