Compliance Activities Related to Municipalities

Stormwater runoff is commonly transported through Municipal Separate Storm Sewer Systems (MS4s) which are subject to Phase I or Phase II NPDES permits, depending on their size.  An MS4 is a conveyance, or system of conveyances (roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, channels, or storm drains owned or operated by a state, city, town, borough, county, parish, district, association, or other public body, including university campuses, tribal lands, and military installations.  MS4s are not sewer systems, and are not combined with water going to treatment plants.  MS4s drain directly into the waters of America.

MS4 permits have six minimum control measures:

  • Public Education and Outreach
  • Public Involvement and Participation
  • Illicit Discharge Detection and Elimination
  • Construction site runoff
  • Post-construction runoff, and
  • Good Housekeeping

Our Certified Stormwater Volunteer program combines two of these measures (Public Education/Outreach and Public Involvement/Participation) to positively impact the outcomes of the other four measures (Illicit Discharges, Construction and Post-construction runoff, and Good Housekeeping).   Our team members are trained in the NPDES program, with the specific focus of identifying and reporting potential illicit discharges to their local government.  These residents may also volunteer to conduct water sampling, stencil storm drains, clean roadways, parks, and beaches, support Utility Rate increases, plus many other pollution clean-up and pollution prevention activities.

The National Stormwater Center also assists MS4s with permit compliance in several additional ways

  • Audit Services
  • Stormwater Compliance for MS4 Decision-Makers
  • International Stormwater Center
  • Certified Stormwater Inspectors