What is an MS4?
MS4 stands for Municipal Separate Storm Sewer System. An MS4 entity owns or operates a system for collecting and conveying stormwater. The purpose of the MS4 program is to maintain and benefit water quality in creeks, streams and waterways by reducing pollutants in stormwater runoff.
MS4 program is an unfunded federal mandate. It is the result of the 1987 amendments to the Clean Water Act (CWA), commonly referred to as the Water Quality Act of 1987. In these amendments, Congress mandated that the U.S. Environmental Protection Agency (U.S. EPA) address non-point source pollution associated with stormwater runoff.
In response to the Congressional action, EPA developed the MS4 program to permit the discharge of the stormwater from the MS4s. In essence, EPA defined urban stormwater (previously considered a non-point source) as a point source with numerous physical locations (or points) of discharge.
The MS4s are permitted under the National Pollutant Discharge Elimination System (NPDES) program through either the U.S. EPA or the states; in Indiana, through the Indiana Department of Environmental Management (IDEM). MS4 permits are granted in five-year cycles at the end of which the permit must be renewed. The City of Valparaiso’s NPDES permit was granted in 2003, and was renewed in 2008 and 2013.
Stormwater quality management Plan
The MS4 entities are required to develop a Stormwater Quality Management Plan (SWQMP), and to implement the following six Minimum Control Measures (MCMs) to reduce polluted stormwater runoff. Click on the links to learn about these components and what we are doing.
- Public Education and Outreach
- Public Participation and Involvement
- Illicit Discharge Detection and Elimination (IDDE)
- Construction Site Run-Off Control
- Post Construction Stormwater Management
- Good Housekeeping and Pollution Prevention
The City of Valparaiso's MS4 program was recognized by Indiana Department of Environmental Management (IDEM) at the 2013, 2014 and 2015 MS4 Annual Meetings for multiple categories including illicit discharge detection and elimination, post-construction stormwater runoff control, public education/participation through rain barrel decorating competition, stormwater management utilizing trees, and programs and projects that are beyond the MS4 Stormwater Quality Management Plan. Click here to see Certificate of Recognition.
- After the Storm - by U.S. Environmental Protection Agency (EPA)
- Be the Solution to Stormwater Pollution - by EPA
- Protecting Water Quality From Urban Runoff - by EPA
- 4 Simple Steps to Clean Water - by Northwest Indiana MS4 Community Partnership
- A Citizen's Guide to the MS4 Program - by Northwest Indiana MS4 Community Partnership
- What is a Watershed? - by United States Department of Agriculture (USDA) and Natural Resources Conservation Service (NRCS)
- U.S. EPA NPDES Stormwater Program Overview
- Indiana Department of Environmental Management (IDEM) Stormwater Permitting
- EPA Nonpoint Source (NPS) Outreach Toolbox
- EPA Nitrogen and Phosphorus Pollution website
- IDEM Watersheds and Nonpoint Source Water pollution
- Avoid Hazards of Coal Tar Asphalt Sealcoats
- EPA SepticSmart Initiative