NPDES/MS4

Stormwater Non Point Discharge System (NPDES) in Richland County

In addition to requirements Richland County landowners follow for earthmoving activities through the Richland County Stormwater and Erosion Control Program, communities that have 1000 or more people per square mile must follow the Stormwater Non Point Discharge System (National Pollutant Discharge Elimination System) (NPDES) General Permit for Small Municipal Separate Storm Sewer Systems (MS4) to further effectively manage water pollution. The Richland County Commissioners are mandated by Ohio EPA to create and manage this added accountability for stormwater runoff. The NPDES (MS4) communities in Richland County are: City of Mansfield, City of Ontario, Village of Lexington, Madison Township, Mifflin Township, Springfield Township and Washington Township.

NPDES/MS4 Areas Map

Stormwater runoff is generated when rain and snowmelt events flows over land or impervious surfaces and does not percolate into the ground. As the runoff flows over the land or impervious surfaces (paved streets, parking lots, and building rooftops), it accumulates debris, chemicals, sediment or other pollutants that could adversely affect water quality if the runoff is discharged untreated. The primary method to control stormwater discharges is the use of best management practices (BMPs). In addition, most stormwater discharges are considered point sources and require coverage under an NPDES/MS4 permit. 

Water pollution degrades surface waters making them unsafe for drinking, fishing, swimming, and other activities. Authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program for MS4 controls water pollution by regulating point sources that discharge pollutants into waters of the United States. Point sources are discrete conveyances such as pipes or man-made ditches. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES/MS4 permit; however, industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters. In most cases, the NPDES/MS4 permit program is administered Ohio EPA. Since its introduction in 1972, the NPDES permit program is responsible for significant improvements to our Nation’s water quality. These regulations require designated communities to develop and implement a storm water management plan. This is accomplished by implementing six minimum control measures.

  1. Public Education — BMPs for MS4s to inform individuals and households about ways to reduce stormwater pollution.
  2. Public Involvement — BMPs for MS4s to involve the public in the development, implementation, and review of an MS4’s stormwater management program.
  3. Illicit Discharge Detection & Elimination — BMPs for identifying and eliminating illicit discharges and spills to storm drain systems. Learn more about how to test for an IDDE.
  4. Construction — BMPs for MS4s and construction site operators to address stormwater runoff from active construction sites.
  5. Post-construction — BMPs for MS4s, developers, and property owners to address stormwater runoff after construction activities have completed. 
  6. Pollution Prevention/Good Housekeeping — BMPs for MS4s to address stormwater runoff from their own facilities and activities. 

If there is a land disturbance within the NPDES/MS4 area it may require engineered plans. Please contact us as part of your planning process to find out. Our office can provide detailed steps of how a land use change can be made while still complying and how to work with EPA (Environmental Protection Agency) directly.

Richland Soil and Water Conservation District assists communities with a variety of public education, outreach, involvement and participation programs to help meet the requirements of the local MS4 management plan. These programs include electronic newsletters, social media platforms, website updates and workshops.

2023 Stormwater Theme: Reduce Your Stormwater Footprint

For 2023 we will be looking at how to “Reduce Your Stormwater Footprint” for this year’s MS4 Theme. What is a stormwater or runoff footprint? Wikipedia has the following definition. A runoff footprint is the total surface runoff that a site produces over the course of a year. According to the United States Environmental Protection Agency (EPA) stormwater is “rainwater and melted snow that runs off streets, lawns, and other sites”. Urbanized areas with high concentrations of impervious surfaces like buildings, roads, and driveways produce large volumes of runoff which can lead to flooding, sewer overflows, and poor water quality.

Since soil in urban areas can be compacted and have a low infiltration rate, the surface runoff estimated in a runoff footprint is not just from impervious surfaces, but also pervious areas including yards. The total runoff is a measure of the site’s contribution to stormwater issues in an area, especially in urban areas with sewer overflows. Completing a runoff footprint for a site allows a property owner to understand what areas on his or her site are producing the most runoff and what scenarios of stormwater green solutions like rain barrels and rain gardens are most effective in mitigating this runoff and its costs to the community. Source

If you would like to find out how much of a stormwater footprint you have on a specific area of land, you can go to the National Stormwater Calculator located on the EPA website. This calculator will assist you in ways to reduce your stormwater footprint and then show you the positive effects Best Management Practices once installed, have on the environment.

In the upcoming months we will be providing some good examples of stormwater best management practices that will help you reduce your stormwater footprint on an area as small as where you live. We can all make a difference as long as we make an effort to reduce our own stormwater footprint.

What is one easy way to reduce your stormwater footprint if you own your own home or business? How about installing a rain barrel? Whenever there is a rain event that produces enough precipitation from gutters and downspouts, the precipitation will fill your rain barrel.

Can you name the positive results that occur within the environment when this water is captured? Let’s get you started:

  • The water that would normally go to storm drains or flow on the surface and potentially pick up pollutants that go directly into our waterways would go into the rain barrel instead.
  • This helps in slowing possible erosion and picking up water heavy with sediment.
  •  The rain barrel stores the water for you until you are ready to use it.
  •  You can use this precipitation to water your plants and garden.
  • Your plants will like the naturally soft water.

Can you think of any others?

Here at the District we sell rain barrels and have them in stock. You may purchase one online or let us know if you would like to purchase one and we will make arrangements with you to pick one up.



Learn more about the MS4 program in Richland County by contacting Dan.

Related Links

Stormwater Themes