State and Federal Programs

National Pollutant Discharge Elimination System


The National Pollutant Discharge Elimination System (NPDES) Stormwater Program is a federal program of the Environmental Protection Agency (EPA) that regulates storm water discharges from three potential sources:

  1. Construction activities
  2. Industrial activities
  3. Municipal separate storm sewer systems (MS4s)

Most stormwater discharges are considered point sources, concentrated runoff from site, and require NPDES permits. This permitting mechanism is designed to prevent stormwater runoff from washing harmful pollutants into local surface waters such as streams, rivers, lakes or coastal waters.


South Carolina is authorized to implement the NPDES Stormwater Program through the South Carolina Department of Health and Environmental Control (SCDHEC) and administers stormwater permitting programs on behalf of the federal government.

Municipal Separate Storm Sewer System (MS4)

A municipal separate storm sewer system (MS4) is a drainage system owned by a municipality, in this case the City of Greenville, that carries stormwater runoff away from buildings, roads, and other development to alleviate flooding. More about MS4