Small Municipal Separate Storm Sewer System (MS4) Permits

In January 2005, the Montana Department of Environmental Quality (DEQ) issued a new permit known as the Small Municipal Separate Storm Sewer System (MS4) permit. The permit is required for urban areas within the state of Montana that have storm sewer systems that serve a population of at least 10,000 people. Areas included in the permit are Billings, Missoula, Great Falls, Butte, Helena, Kalispell, and Bozeman. Cities, counties, universities, military bases, hospitals, and MDT are some of the entities required to obtain the permit for these areas. Under the permit, they are required to regulate the discharge of potential pollutants in storm water runoff within the storm sewer system.

Each permit holder must develop, implement, and enforce a Storm Water Management Program (SWMP). Several entities are working together within each of the urban areas to cooperate in undertaking the program. This SWMP must address the following six "minimum control measures":

1. Public education and outreach on storm water impacts;
2. Public involvement/participation;
3. Illicit discharge detection and elimination;
4. Construction site storm water runoff control;
5. Post-construction storm water management in new development and redevelopment; and,
6. Pollution prevention and good housekeeping for municipal operations.

To comply with the Permit requirements and address storm water pollution related to highway planning, design, construction, and maintenance activities, MDT is working to develop and implement a Storm Water Management Program (SWMP) for each of the areas designated by DEQ .

Some goals of the Storm Water Management Program include involving the public in the storm water management program, and informing individuals and households about ways to reduce storm water pollution. In the coming months you’ll be able to find additional information on MDT's Website related to these programs.

To learn more about preventing pollution, read "A Citizens Guide to Understanding Stormwater: After the Storm". This US EPA publication covers storm water runoff, effects of pollution, and solutions for citizens and business.

For additional information on the Small Municipal Separate Storm Sewer System (MS4) Permit please see the Department of Environmental Quality's Permitting website.