Stormwater Program for Municipal Separate Storm Sewer Systems (MS4)
Annual Report for 2014 now available
The MS4 Annual Report for 2014 is to be completed and submitted to the MPCA by June 30, 2015. For more information, visit the MS4 Annual Report page.
Who to Contact
Having trouble finding who to contact with questions regarding your MS4? Any member of the MS4 staff, listed under the Contacts tab below is available to answer your questions or direct you to the appropriate staff member. Additionally, you can find which staff member your MS4 is assigned to on the MS4 Permit Staff Assignments page. The list can be sort alphabetically by clicking on the header: MS4 Name.
According to the 1996 National Water Quality Inventory, stormwater runoff is a leading source of water pollution and can harm surface waters such as lakes, rivers, streams and wetlands. Common pollutants in stormwater runoff include pesticides, fertilizers, oils, metals, pathogens, salt, sediment, litter and other debris. These pollutants are transported via stormwater from a variety of sources including construction projects, industries and urbanized areas.
Management of stormwater runoff from urbanized areas is very important for restoring or protecting surface waters. Urbanized areas are associated with activities that contribute pollutants to stormwater runoff, such as application of anti/deicing compounds, vehicle fueling, spills, landscaping and lawn maintenance, and application of pesticides and fertilizers. Additionally, urbanized areas are characterized by large amounts of impervious surfaces, such as streets, driveways, roof tops, parking lots and sidewalks. Stormwater runoff from impervious surfaces travels faster and in larger quantities, which results in damage to rivers, streams and wetlands; destruction of aquatic habitats; and elevated pollutant levels reaching surface waters. Impervious surfaces also inhibit infiltration and subsequent groundwater recharge. Local public entities that own or operate a municipal separate storm sewer system (MS4) in urbanized areas play a key role in preventing or reducing the negative impacts stormwater runoff may have on Minnesota’s valuable water resources.
A municipal separate storm sewer system is a conveyance or system of conveyances (roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, storm drains, etc.) that is also:
- owned or operated by a public entity (which can include cities, townships, counties, military bases, hospitals, prison complexes, highway departments, universities, etc.) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage districts, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the Clean Water Act that discharges to waters of the United States;
- designed or used for collecting or conveying stormwater;
- which is not a combined sewer; and
- which is not part of a publicly owned treatment works.
The MS4 General Permit is designed to reduce the amount of sediment and pollution that enters surface and ground water from storm sewer systems to the maximum extent practicable. Stormwater discharges associated with MS4s are subject to regulation under the National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS). Through the MS4 General Permit, the system owner or operator is required to develop a stormwater pollution prevention program (SWPPP) that incorporates best management practices (BMPs) applicable to their MS4. See the following fact sheet for additional information:
What criteria make an MS4 subject to stormwater regulation?
An owner or operator of an MS4 in Minnesota is subject to stormwater regulation under the Clean Water Act due to one or more of the following reasons:
- An MS4 located in an urbanized area in whole or in part as determined by the latest Decennial Census, as regulated in accordance with Code of Federal Regulations.
- The entire jurisdiction of an MS4 owned or operated by a city or township that is located in an urbanized area in whole or in part as determined by the latest Decennial Census, as regulated in accordance with Code of Federal Regulations.
- An MS4 owned or operated by any publicly owned entity located within an urbanized area in whole or in part as determined by the latest Decennial Census, and which has a potential resident capacity or bed count occupancy of 1,000 or more.
- An MS4 owned or operated by a municipality with a population of 10,000 or more.
- An MS4 owned or operated by a municipality with a population of at least 5,000 and discharges or has potential to discharge stormwater to a water identified as an outstanding resource value water as identified in Minn R. 7050.0180, subparts 3 and 6.
- An MS4 owned or operated by a municipality with a population of at least 5,000 and discharges or has potential to discharge stormwater to a water identified as a trout lake or trout stream as identified in Minn. R. 6264.0050, subparts 2 and 4.
- An MS4 owned or operated by a municipality with a population of at least 5,000 and discharges or has potential to discharge stormwater to a water listed as impaired under section 303(d) of the Clean Water Act, 33 U.S.C. § 1313.
Minnesota state rules also establish criteria that can be applied to designate future MS4s under a formal designation process. MS4s that are designated through the petition process under Minn. R. 7090 are required to obtain a NPDES/SDS stormwater permit. The public can petition the Commissioner for the designation of an MS4 based on the designation criteria established in the rules.
Note: The cities of Minneapolis and St. Paul are Large MS4s, and received individual NPDES/SDS permits in 2000 that are reissued on a five year cycle.
Visit the Visit the Stormwater Program Rulemaking Web page for further details.
- MS4 mapping tool:This is an interactive electronic map tool that can be used to view and explore MS4 boundaries, defined urban areas, impaired waters, outstanding resource value waters, trout waters and approved TMDL study areas. Note: This is best viewed with pop-up blockers disabled and screen resolution set to 1024x768 or higher.
- Guidance Document: Use of the MS4 Mapping Tool
MS4 Permittees with assigned Waste Load Allocations (WLA) as part of a Total Maximum Daily Load (TMDL) project approved by US EPA prior to the effective date of the latest Permit reissuance must address additional information in their Stormwater Pollution Prevention Program (SWPPP). Permittees must develop a compliance schedule that outlines interim milestones it will achieve during the permit term, strategies for continued implementation beyond the permit term, and target dates to achieve the applicable WLAs.
MS4s are required to develop and implement a stormwater pollution prevention program (SWPPP) to reduce the discharge of pollutants from their storm sewer system to the maximum extent practicable. The SWPPP must cover six minimum control measures.
The MS4 must identify best management practices (BMPs) and measurable goals associated with each minimum control measure. An annual report on the implementation of the SWPPP must be submitted each year.
The MPCA will provide public notice and opportunity for public comment and hearing on each MS4s proposed SWPPP. Information on the public notice process is available at the MPCA Web page Public Notice Process for MS4 General Permit Applications.
Fact Sheets and Instructions
2013 Reissuance of the General NPDES/SDS Permit MNR040000 for Municipal Separate Storm Sewer Systems (MS4s)
2006 Issuance of the General NPDES/SDS Permit MNR040000 for Municipal Separate Storm Sewer Systems (MS4s)
The reissued permit (MNR040000) became effective on August 1, 2013.
|Revisions to MS4 SWPPP Requirements:|
Fact Sheets and Instructions
|Part 2 Application for MS4 General Stormwater Permit (SWPPP Document) (PDF Version)||
Application for Authorization
MS4 SWPPP Application for Reauthorization (SWPPP Document) Example
Filling out the SWPPP Document - FAQs
|MS4 Permit TMDL Attachment Spreadsheet||
Application supplement for MS4s with approved TMDL with a Waste Load Allocation (WLA) prior to the effective date of Permit.
Guidance for MS4 TMDL Requirements
Master List MS4 Permit TMDLs Spreadsheet (PDF Version)
|Alum or Ferric Chloride Phosphorus Treatment Systems Form (PDF Version)||
Application supplement for MS4s with alum or ferric chloride phosphorus treatments systems.
If applicable, must be submitted with MS4 SWPPP Application for Reauthorization (SWPPP Document).
Fact sheets and instructions
Annual Reports are due June 30 of each year.
Use SWPPP Pollution Prevention Guidance on the right. To update your current SWPPP to reflect changes in needs or when completing Annual Reports to aid in assessment of appropriateness of identified BMPs.
|MS4 Inspection and Recordkeeping|
|Summary of Stormwater Pond Sediment Testing Results||
Use these forms to to meet permit requirements for stormwater pond dredging for maintenance purposes.
|Managing Stormwater Sediment Best Management Practice Guidance for Municipalities|
|MS4 Pond, Wetland and Lake Inventory Form (PDF Version)||
Inventory of all ponds, wetlands and lakes within permittee’s jurisdiction pertaining to 2009 Minnesota Session Law, Ch. 172. Sec. 28.
Must be submitted within 12 months of the date permit coverage is extended.
Guidance and BMPs
- Minnesota Stormwater Manual Wiki
- Minnesota Stormwater Best Management Practices Manual
- EPA: National Menu of Stormwater Best Management Practices
- International Stormwater Best Management Practices Database
- Plants for Stormwater Design
Public Education and Outreach
- EPA BMP Menu: MCM 1
- MS4 Education Toolkit - This education toolkit was funded by a grant through the MPCA to the Washington Conservation District.
Public Participation & Involvement
Illicit Discharge, Detection and Elimination
- EPA Factsheet
- EPA BMP Menu: MCM 3
- Illicit Discharge - What to look for (PDF Version) Training PowerPoint (Courtesy Rick Baird, City of Mankato MS4)
Construction Site Stormwater Runoff Control
Post Construction Stormwater Management
- Technical Support Document for the Post-Construction Stormwater Management Conditions in the General Stormwater Permit for Small MS4s
- Minimal Impact Design Standards (MIDS) Community Assistance Package
- EPA BMP Menu: MCM 5
- Minimal Impact Design Standards fact sheet
Pollution Prevention/Good Housekeeping For Municipal Operations
- EPA BMP Menu: MCM 6
- MS4 Inspection and Recordkeeping
- Pollution Prevention and the MS4 Program
- Managing Stormwater Sediment Best Management Practice Guidance for Municipalities
- Coal-tar Based Sealcoat - Environmental Concerns
- Addressing Potential Impacts of Urban Runoff on Wetlands
- Untreated Stormwater Runoff to Lakes, Streams, and Wetlands
- Municipal Stormwater Ponds
- Swimming Pool and Hot Tub Water Discharges Best Management Practices
2013 Permit Reissuance: Filling out the SWPPP document
- Filling out the SWPPP Document - PowerPoint presentation
- Addressing TMDL Requirements in the MS4 Permit - PowerPoint presentation
MPCA staff held workshops following the reissuance of the General NPDES/SDS Permit MNR040000 for Municipal Separate Storm Sewer Systems (MS4s), which became effect August 1, 2013. These events provided information to assist MS4s in filling out their SWPPP Documents, which are due for submittal on October 30 (Group 1), December 2 (Group 2) and December 30 (Group 3). See the video below for a recorded version of one of these workshops.
Video timeline guide:
- 0:06:31 - Municipal Stormwater Regulations, Revisions to 2013 MS4 Permit, SWPPP Document Format
- 0:26:18 - Application Process & Public Notice, BMP Table Examples
- 0:48:20 - Questions on SWPPP Document
- 0:58:26 - Guidance Documents on the MS4 webpage
- 1:00:23 - TMDL Requirements in MS4 Permits
- 1:55:56 - Questions on TMDL Requirements
The MPCA has various opportunities for receiving grants or loans for stormwater projects in Minnesota. Visit the following MPCA webpages for information on water-related financial assistance:
Information for MS4s
- Stormwater Phase II Final Rule Fact Sheet Series (U.S. EPA)
- National Pollutant Discharge Elimination System (NPDES) Stormwater Phase II Final Rule
- National Service Center for Environmental Publications (NSCEP)
- Stormwater Managers Resource Center
- Center for Global Environmental Education
- Stormwater Program for Construction Activity
- Stormwater Program for Industrial Activity
- University of Minnesota Impervious Cover and Updated Land Cover (2000) interactive maps
Information for citizens
For more information regarding the MS4 Stormwater Program, please contact the following staff. If outside the metro area, please call 1-800-657-3864.
Duane Duncanson, 651-757-2323
Duane Duncanson, 651-757-2323
Technical assistance and compliance enforcement:
TMDL/MS4 Permit technical assistance:
Wendy Gardner-Pritchard, 651-757-2090