Municipal Separate Storm Sewer Systems (MS4)

Efforts to improve water quality in our rivers and streams have been underway since the early 1970s. A permitting system was developed called the National Pollution Discharge Elimination System (NPDES) that serves to evaluate what controls are in place to reduce polluted discharges, and attaches a monitoring and maintenance requirement onto the permit insuring that permitted discharges do not adversely impact water quality and do not exceed the limits included in the permit.  Primacy to issue permits has 

With all the work that has been done, the U.S. Environmental Protection Agency was still recording nearly 40 percent of all waterways were not meeting the current standards. Two culprits were identified as sources: Broad distribution of nonpoint source pollution such as barnyard runoff, septic system failure, erosion; Municipal separate storm sewer systems (MS4s)-the network of collection systems that convey stormwater and snow melt to waterways and are neither part of a combined sewer overflow system and are not part of a sewage treatment plant.

It was once thought that stormwater runoff was harmless--rain or snow hitting the surface of the earth and simply running into adjacent waterbodies. However, further analysis has shown that stormwater runoff serves as a vehicle for such material as heavy metals, bacteria, oils and greases, fertilizers and pesticides, and sediments associated with erosion.  As it runs off the hard surfaces, it carries with it all these contaminants that accumulate and adversely affect our water resources.

To address some of the issues of stormwater runoff, the U.S. Environmental Protection Agency phased in two permitting structures to manage stormwater runoff and the contaminants associated with it. In 1990, Phase I was issued for those municipalities or larger jurisdictions with populations over 100,000. In 1999, Phase II was issued that addresses smaller urbanized areas.

Several cities, towns and counties in the Indiana portion St. Joseph River Basin were designated as MS4 communities and mandated to take steps to control stormwater runoff in their respective communities. Referred to as "Minimum Control Measures" (MCMs) these steps include:

  • Public Education/Outreach
  • Public Participation/Involvement
  • Illicit Discharge Detection and Elimination
  • Construction Site Runoff Control
  • Post-Construction Runoff Control
  • Pollution Prevention/Good Housekeeping

Details related to these controls can be reviewed at

http://cfpub.epa.gov/npdes/stormwater/munic.cfm

For a list of local communities designated as MS4s in the St. Joseph River Basin go to SJRBC MS4 Communities.  Each designated community has developed a stormwater management plan that includes local ordinances, permitting requirements, and policies to comply with the MCMs.  Citizens are encouraged to contact the local jurisdictions to insure they meet the local requirements when involved in construction projects or other activities that deal with stormwater.