Sustainable Business Network


A Municipal Separate Storm Sewer System (MS4) is a conveyance or system of conveyances that is:

  1. Owned by a state, city, town, village, or other public entity that discharges to waters in the U.S.
  2. Designed or used to collect or convey stormwater (e.g. storm drains, pipes, ditches)
  3. Not a combined sewer
  4. Not part of a sewage treatment plan, or publicly owned treatment works (POTW)


Resource Guide for MS4

This Quick Resource Guide to the PA MS4 Program includes MCM (minimum control measures) for stormwater management plans (SWMPs) to meet the conditions of the EPA’s National Pollutant Discharge Elimination System (NPDES) and the best management practices to act on them.

General information on Municipal Stormwater

Municipal Stormwater– PA Department of Environmental Protection

Addressing Stormwater Management Requirements in MS4 Communities– LandStudies, Inc.