Municipal Separate Storm Sewer System (MS4) Program

Marshall Township’s MS4 Program was initiated in 2004 and has included mapping and inspecting stormwater infrastructure throughout the Township in an effort to detect illicit discharges.  The Township has also adopted innovative stormwater management regulations to reduce and minimize the volume of stormwater generated from new land development.  Marshall Township residents can also contribute to the improvement of water quality by reducing the amount of pollutants and stormwater generated from their property.  Potential practices that a homeowner can employ include creating rain gardens, utilizing cisterns and rain barrels, and reducing lawn fertilization.



Municipal Separate Storm Sewer Systems or MS4s

Stormwater runoff is commonly transported through Municipal Separate Storm Sewer Systems (MS4s), from which it is often discharged untreated into local waterways. These storm sewer systems are:

  • Owned by a state, city, town or other public entity that discharges to waters of the U.S.;
  • Designed or used to collect or convey stormwater (including storm drains, pipes and ditches);
  • Not a combined sewer (which carries stormwater and sewage); and
  • Not part of a Publicly Owned Treatment Works (sewage treatment plant).

To prevent harmful pollutants from being washed or dumped into an MS4, operators must obtain a National Pollutant Discharge Elimination System (NPDES) permit and develop a stormwater management program.

What is included in an MS4 Program?

Listed below are the six minimum control measures that operators of regulated small MS4s must incorporate into stormwater management programs.  These measures are expected to result in significant reductions of pollutants discharged into receiving waterbodies.

  • Public Education and Outreach – An informed and knowledgeable community is crucial to the success of a stormwater management program, since it helps to ensure greater support and program compliance as the public becomes aware of individual actions they can take to protect or improve the quality of area waters.
  • Public Participation/Involvement – An active and involved community allows for broader public support, a broader base of expertise and a connection to other local environmental programs.
  • Illicit Discharge Detection and Elimination – Illicit discharges are untreated discharges that could contribute high levels of pollutants, including heavy metals, toxics, oil and grease, solvents, nutrients, viruses and bacteria to receiving waterbodies. Operators of a regulated small MS4 are required to develop, implement and enforce an illicit discharge detection and elimination program.
  • Construction Site Runoff Control – Stormwater runoff from construction activities can have a significant impact on water quality. As stormwater flows over a construction site, it can pick up pollutants like sediment, debris, and chemicals and transport these to a nearby storm sewer system or directly to a river, lake or stream.
  • Post-Construction Runoff Control – Increased impervious surfaces, like parking lots, driveways, and rooftops, interrupt the natural cycle of gradual percolation of water through vegetation and soil. Instead, water is collected from surfaces such as asphalt and concrete and routed to drainage systems where large volumes of runoff quickly flow to the nearest receiving water. The effects of this process can include stream bank scouring and downstream flooding, which often lead to a loss of aquatic life and damage to property. Ordinances and other regulations are required to determine the appropriate best management practices and to ensure adequate long-term operation and maintenance of storm water controls.
  • Pollution Prevention/Good Housekeeping – This measure involves recognizing the benefits of pollution prevention practices and includes the development and implementation of an operation and maintenance program. Reducing pollutant runoff from municipal operations into the storm sewer system can include employee training on how to incorporate pollution prevention/good housekeeping techniques into municipal operations. These controls could also include programs that promote recycling (to reduce litter), minimize pesticide use and ensure the proper disposal of animal waste.

What is an illicit discharge?

EPA defines illicit discharges in general as any discharge into a storm drain system that is not composed entirely of stormwater. The exceptions include water from fire fighting activities, discharges from de-chlorinated waterlines, fire hydrant flushing and discharges from facilities already under an NPDES Permit.

Why are illicit discharges a problem?

Illicit discharges are a problem because unlike wastewater, which flows to a wastewater treatment plant, stormwater generally flows to waterways without any additional treatment. Illicit discharges often include pathogens, nutrients, surfactants, and various toxic pollutants.

What are examples of illicit discharges?

Illicit discharges are activities that may allow for waste water to enter into a storm drain, ditch, or waterway, for example:

  • Motor vehicle fluid spills or illegal disposal into a storm drain
  • Improper disposal of household or other hazardous materials, including paints & stains
  • Vehicle wash water from loading areas in the vicinity of storm drain inlets
  • Improper storage of oil, pesticides, dirt, or fertilizers
  • Leaking dumpsters
  • Improper pet waste disposal
  • Erosion of dirt or landscaping materials being swept into a storm drain or water body (including from construction sites)
  • Damaged sanitary sewer lines or sewer cross connections to stormwater systems
  • Septic system failure

Examples of what you might see that result from illicit discharges:

  • Oily/greasy sheen in the stream water
  • Foamy/soapy water in the waterway
  • Muddied water from sediment and dirt
  • Discoloration of water
  • Overflowing manholes

How to Report an Illicit Discharge

If you encounter what you suspect to be an illicit discharge during normal business hours (weekdays from 8:00 a.m. to 4:30 p.m.) please notify:  Bill Campbell, Manager of the Marshall Township Municipal Sanitary Authority at 724-935-3090.

For emergency situations that include hazardous waste spills, spills of raw sewage, gasoline, or other hazardous materials, dial 911.