MS4 : A Local Program
In response to the degradation of our natural resources due to the discharge of polluted runoff, the Environmental Protection Agency developed regulations specifically targeting stormwater from industrial, construction, and municipal sources. Subsequently the Montana Department of Environmental Quality (DEQ) issued a new general permit known as the Small Municipal Separate Storm Sewer System (MS4) permit in 1995. The permit is required for urban areas within the state of Montana that have storm water drainage systems that serve a population of at least 10,000 people. Areas currently included in the permit are Billings, Missoula, Great Falls, Butte, Helena, Kalispell, and Bozeman. Cities, counties, universities, military bases, and the Montana Department of Transportation (MDT) are some of the entities required to obtain the permit for these areas. Locally, many of the regulated MS4 entities are sharing responsibilities under their permit coverage as co-permittees.
The permit requires the co-permittees to develop, implement, and enforce a Storm Water Management Program (SWMP) designed to reduce the discharge of pollutants from the Small MS4, to protect water quality, and to satisfy the appropriate requirements of the Montana Water Quality Act which was expanded to include the national EPA regulations under the Clean Water Act.
