An MS4 is a Municipal Separate Storm Sewer System that grants a municipality or a municipal like entity permission to develop and implement a storm management program. This storm management program is designed to prohibit illicit discharges and stop the contamination of stormwater runoff.
MS4 permit requirements stipulate that an approved storm management program must include a minimum of six (6) minimum storm control measurements (MCMs) to properly support the running of a stormwater management program. Two of these MCMs include public education and outreach, as well as public involvement and participation to ensure that the stormwater management program is properly integrated into the life of the municipality and the people who live there.
The other four MCMs speak to the physical aspects and technical operations of the stormwater management program and include the following:
1. Illicit Discharge and Detection Elimination
2. Construction Site Runoff Control
3. Post Construction Stormwater Management
4. Good Housekeeping/Pollution Prevention