Each MS4 community must develop a Stormwater Management Plan that will guide its activities under the General Permit. There are 6 Minimum Control Measures that form the basis of what communities must do to manage stormwater and its impacts. Those measures are:
Each MS4 community must identify ways to educate the public about stormwater and its impacts on water quality, as well as share information on how to prevent pollutants like nitrogen, phosphorus and bacteria from getting into stormwater runoff.
Ensure the community has the opportunity to engage and participate in stormwater management planning and implementation.
Efforts must be made to identify and eliminate non-stormwater discharges to the storm sewer system. Illicit discharges inlcude nearly anything that isn't stormwater such as illegal dumping in storm drains, animal wastes, fertilizers, industrial and commercial waste, sewage, leaves, etc.
MS4 communities must put safeguards in place to prevent runoff of sediment and other materials from construction sites.
This measure focuses on mitigating stormwater impacts from new and re-development by requiring practices that treat, store, and infiltrate stormwater onsite.
The section covers best management practices for municipal operations (municipal land, facility, and equipment maintenance; salt/sand storage; employee training; etc.) and other activities aimed at preventing pollutants from entering the stormwater drainage system.