Current permit
The MPCA issued the most recent municipal stormwater general permit (MNR040000) on Nov. 16, 2020.
Upcoming: MS4 general permit reissuance
Review informal pre-public notice. Interested and affected parties may review and submit written comments on the posted informal pre-public notice draft Municipal Separate Storm Sewer System (MS4) general permit ("early draft permit"). Two versions of the early draft permit are available, one that shows markup edits and a clean copy.
- markup draft
- draft clean copy
To submit a comment, email ms4permit.pca@state.mn.us with the subject line: Early draft MS4 General Permit comment. In addition to your name, organization (if applicable), and contact information, please include:
- your interest in the permit
- the action you wish the MPCA to take, including specific references to the permit item(s) you believe should be changed
- the reasons supporting your position, stated with sufficient specificity as to allow the MPCA to investigate the merits of the position
The MPCA will not provide written responses to comments received but will post and review the comments and will consider incorporating suggested changes into the draft permit in preparation for the formal public notice, planned for spring 2026. The MPCA is accepting written comments on the early draft permit until the end of the day, Friday, Jan. 30, 2026.
Part 1 permit application past due
Permittees covered under the 2020 MS4 general permit were required to submit the Part 1 permit application and $400 application fee by May 20, 2025. If you need assistance with the application, direct questions to the MPCA MS4 staff member assigned to your organization.
Part 2 permit application requirements and process
After the next MS4 general permit is reissued, the MPCA will provide Part 2 permit application forms. MS4 permittees must provide descriptions of:
- current stormwater pollution prevention program (SWPPP)
- progress toward meeting permit requirements in the six minimum control measures
- best management practices to address total maximum daily load waste load allocations
- names or position titles responsible for implementing each component of the SWPPP
Once an MS4 permittee completes the part 2 permit application, they must submit it to the MPCA for preliminary review. If the application is incomplete, MPCA staff will notify the MS4 permittee of the deficiencies in writing. If MPCA staff determine the application is complete, the application will go on public notice for 30 days. Once the MS4 permittee has addressed any applicable public comments or hearing requests, the MPCA will make a final determination and issue coverage under the new permit. The MS4 permittee has 12 months from the date coverage is extended to meet the new permit requirements.
Reissuance overview
The MPCA plans to provide three opportunities for stakeholders to provide input throughout the MS4 General Permit reissuance process. Each opportunity will be available for at least 30 days:
- Closed May 31, 2025: Provide written feedback based on the 2020 permit. Stakeholders could provide written input on the current 2020 MS4 General Permit. This included suggested changes or areas of the permit where improvements could be made, including where additional details or guidance are desired.
- Informal pre-public notice. During this period, stakeholders will have the opportunity to review and provide written input on a preliminary version of the new draft MS4 General Permit. The MPCA will review all written comments and may make changes to the draft permit prior to the formal public notice period. The MPCA will not provide responses to written comments during the informal pre-public notice.
- Formal public notice. During this period, stakeholders will have the opportunity to review and provide written input on the new draft MS4 General Permit. The MPCA will provide responses to written comments received during the formal public notice. More information about this public participation process is available here.
Currently, the MPCA is targeting late spring 2026 to reissue the new permit. Since the new permit will not be issued by the expiration date of the 2020 permit, the 2020 permit is administratively continued, and permittees may legally discharge stormwater under the expired 2020 permit until the new permit is issued.
Notable changes
The following changes have been incorporated into the early draft MS4 general permit. Additional changes may be found in the markup version of the early draft permit.
The following concepts are planned to be incorporated into the next draft MS4 General Permit.
- Clear, specific, and measurable requirements. Changes include reorganizing the location of specific permit language, defining frequencies (e.g., education, training activities), adding and revising permit definitions, and more to further meet the EPA remand rule.
- Prohibition of PFAS-containing firefighting foams. Reducing sources and mitigating impacts of per- and polyfluoroalkyl substances (PFAS) is an MPCA priority. Two potential sources of PFAS pollution to the environment include PFAS-containing firefighting foams and pesticides. To address those potential sources, there are associated requirements in MCM 3 and MCM 6. The Minnesota Department of Agriculture website includes a list of pesticide ingredients which meet the definition of PFAS in Minnesota Statute.
- Water quality trading. Newly added Section 23 provides permittees an option to develop a water quality trading program for purposes of making progress toward achieving an applicable WLA(s). All water quality trading proposals must meet the requirements of this section.
MS4 mapping tool
Find regulated MS4s, outstanding resource value waters, drinking water supplies, and impaired waters. Click on map elements for more information.
References and resources
Water permit basics
This series of four short videos explains the basics of water permits and the important roles of select stakeholders in Minnesota.