Minnesota Statewide Rule

Minnesota MS4 Stormwater Permit Program Statewide Standards

Heavy RestrictionsApplies statewide across Minnesota (2026)

Key Facts

Permitting agency: MN Pollution Control Agency
Construction threshold: 1 acre disturbed
Maximum civil penalty: $15,000 per day
Minimum measures: Six federal MCMs

Last verified: September 5, 2026Source: Minnesota Revisor of Statutes

Summary

The Minnesota Pollution Control Agency administers the federal NPDES MS4 general permit under Minn. Stat. Ch. 115. Regulated cities and counties must adopt construction, post-construction, and illicit discharge controls meeting statewide minimum measures.

MS4's that meet the following criteria must submit a complete application for a permit within 18 months of meeting the criteria: § (1) the entire jurisdiction of a city or township that is partially regulated in accordance with Code of Federal Regulations, title 40, section 122.26(a)(9)(i)(A); § (2) the MS4 is owned or operated by a municipality with a population of 10,000 or more based on the most recent decennial census or approved municipal boundary adjustment under the provisions of Minnesota Statutes, chapter 414; or § (3) the MS4 is owned or operated by a municipality with a population of at least 5,000 based on the most recent decennial census or approved municipal boundary adjustment under the provisions o

Source: Minnesota Revisor of StatutesView official code

Full Breakdown

Under the federal Clean Water Act and Minn. Stat. 115.03, MPCA issues a general MS4 permit to municipal separate storm sewer systems serving urbanized areas. Permittees must implement six minimum control measures: public education, public participation, illicit discharge detection, construction site runoff control, post-construction stormwater management, and pollution prevention for municipal operations. Cities must adopt ordinances regulating sediment, erosion, and volume control on construction sites disturbing one acre or more, generally requiring 1.0 inch volume retention in many areas. Local rules may be stricter but must meet MPCA's permit baseline.

Violations & Penalties

MPCA may issue administrative penalty orders, civil fines up to $15,000 per day per violation under Minn. Stat. 115.071, and require corrective discharge controls.

Frequently Asked Questions

Who regulates stormwater discharges in Minnesota?

The Minnesota Pollution Control Agency administers the NPDES program statewide, issuing MS4 permits to qualifying municipalities and a separate Construction Stormwater General Permit for sites disturbing one or more acres.

What sites need a Construction Stormwater Permit?

Any construction project disturbing one acre or more, or part of a larger common plan of development totaling one acre, must obtain coverage under MPCA's Construction Stormwater General Permit before earthwork begins.

Sources

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