Confused about what to document under the MS4 permit? This page provides guidance on how to comply with the documentation requirements outlined in the Minnesota Pollution Control Agency’s (MPCA) MS4 Permit. The MS4 Permit requires owners and operators of small MS4s to develop, implement, and enforce a stormwater pollution prevention program (SWPPP). The SWPPP has many components that you must document. For all documentation requirements you must retain the records for three years beyond the term of the current permit (Permit Part IV C.). Many of these materials will be requested prior to an MPCA staff auditing your MS4 program.

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Enforcement actions

Enforcement documentation needed:
The name of the party in noncompliance; date, location, and violation description; required corrective actions; date and type of enforcement action; referral to other regulatory organizations; and resolution date.

Enforcement actions are used to compel compliance with regulatory mechanisms. Each enforcement action you conduct, including verbal warnings, related to illicit discharges, active construction, and post construction must be documented (Permit Part III B.2.).

Public Education and Outreach

Public education and outreach documentation needed:
High-priority stormwater issues that are the focus of outreach material.
A Public Education and Outreach Implementation Plan and its modifications.
Description & dates of outreach activities.
Quantity & description of distributed material.

Your public education and outreach program should show the the public (residents, businesses, institutions, etc.) how they can reduce their impacts to stormwater. You need to identify issues that are a priority to your community, such as reaching your Total Maximum Daily Load (TMDL) reduction targets, specific business and residential behavior change practices, and best management practices available to residents, etc. As part of the education and outreach program, you must distribute materials, or conduct equivalent outreach, to the public on how to identify and report illicit discharges (Permit Part III D.1.).

Public Participation/Involvement

Public education and outreach documentation needed:
Written input on your SWPPP and your response.
Public notices for public events.
Date(s), location(s), description of activities, and estimated number of participants at public event.

Engaging the public and getting the public to actively contribute to your SWPPP instills the idea that everyone has a role to play in proper stormwater management. You must provide at least one yearly public involvement opportunity that allows the public to provide input on your SWPPP. In addition, you must allow the public access to the SWPPP Document, annual reports, and other information relating to the SWPPP (Permit Section 17).

Illicit Discharge Detection & Elimination

IDDE documentation needed:
Dates and locations of IDDE inspections, including inspections that incorporate IDDE.
Reports of illicit discharges, including date and follow-up actions.
Dates, locations, sources, and responses to discovered illicit discharges.

Illicit discharges, or discharges of non-stormwater to the storm sewer system, negatively impact the quality of stormwater. You are required to develop, implement, and enforce an illicit discharge detection and elimination (IDDE) program to prevent and identify illicit discharges (Permit Section 18).

Construction Site Inspections

Site inspection documentation needed:
Checklist or other written materials used to record site inspections.

Site inspections play a crucial role in ensuring construction activities are employing best management practices (BMPs) to prevent sediment and other pollutants from leaving construction sites. You must have a document, whether a checklist or other written method, used to determine compliance with your construction site stormwater runoff control regulatory mechanism (Permit Part III D.4.d.).

See the MS4 site inspection page for an example site inspection checklist.

Construction Site Plan Reviews

Site plan review documentation needed:
Project information, including name, location, total acreage to be disturbed, owner/operator of the proposed construction activity.
Comments and supporting documentation used by the permittee to support the project's approval or denial.

Site plans are required to be submitted to you for construction projects that disturb one acre or more of land. Your SWPPP must include site plan review procedures you use to determine if proposed construction activity and post-construction management practices are in compliance with your regulatory mechanisms (Permit Parts III.D.4.b. & III.D.5.b.). Site plans must include descriptions of site conditions during construction and post-construction management of stormwater volume, total suspended solids (TSS), and total phosphorus (TP) (Permit Parts III. D.4.a. & D.5.a.(2)).

See the MS4 Site Plan Review Guidance page for more information.

Mitigation Projects

Mitigation documentation needed:
Supporting documentation associated with the mitigation project, including party responsible for long-term maintenance.
Payments received in lieu of mitigation.

If post-construction requirements for TSS and TP in stormwater discharged from the site can’t be met (i.e. no net increase in TSS and TP for new development and a net reduction from pre-construction conditions for redevelopment), you may approve mitigation projects (Permit Part III.D.5.a.(4)).

Long-term Maintenance of Structural Stormwater BMPs

Long-term maintenenace documentation needed:
Legal agreement between you and the private owner or operator.
Dates and parties involved.

If a privately-owned structural stormwater BMP is installed as part of construction activity, you must have a legal agreement with the owner(s). The legal agreement will:

  • allow you to conduct inspections and perform maintenance;
  • transfer with property ownership; and
  • require the BMP to maintain proper function (Permit Part III.D.5.a.(5)).

Municipally Owned/Operated BMPs

Municipal BMP inspection documentation needed:
Dates, findings, and subsequent maintenance.
Changes to the structural stormwater BMP inspection frequency.
Pond sediment excavation/removal activities, including the pond unique ID number, volume of sediment removed, sediment test results (if any), and location of sediment disposal.

Inspecting and maintaining BMPs that are used in municipal operations is important to reducing your impacts to stormwater. Inspections must be:

  • annually, or biennially if maintenance isn’t needed for two consecutive years, for structural stormwater BMPs;
  • at least once during the permit term for ponds and outfalls; and
  • quarterly for stockpiles and storage and material handling areas (Permit Part III.D.6.e.).

IDDE inspections must be incorporated into these inspections. See IDDE Section on this document for more information.

Employee Training

Employee documentation needed:
Employee training events, including topics covered, names of employees in attendance, and dates of each event.

As part of the SWPPP, you must train employees who may encounter stormwater related issues, including those who conduct IDDE and construction site inspections, review site plans, respond to illicit discharge complaints, etc. The training program must:

  • address the importance of protecting water quality,
  • describe Permit requirements related to the employee’s job, and
  • have a training schedule for initial and recurring training (Permit Part III.D.6.f.).

Is there anything I should keep a record of?

Yes. Although not a focus of this guidance document, you must maintain the below regulatory mechanisms, maps, policies, procedures, and inventories. The MS4 Permit (citation provided in parenthesis) and other guidance documents discuss the below in more detail. Please note that if you have Alum or Ferric Chloride Phosphorus Treatment System you may have additional requirements.

  • Regulatory Mechanisms (Permit Part III.B.) for:
    • Illicit Discharges (Permit Part III.D.3.b)
    • Construction Stormwater ([Permit Part III.D.4.a), and
    • Post-construction (Permit Part III.D.5.a).
  • Enforcement Response Procedures (Permit Parts III.B./III.D.3.g.(3)/III.D.4.e).
  • Storm Sewer System Map (Permit Part III.C.1).
  • Wetland, lake, and pond inventory (Permit Part III.C.2).
  • Public Outreach Implementation Plan (Permit Part III.D.1.b).
  • Written procedures for site plan reviews (Permit Parts III.D.4.b. & III.D.5.b.).
  • Written procedures for collecting and responding to construction stormwater complaints (Permit Part III.D.4.c).
  • Written procedures for conducting site inspections (Permit Part III.D.4.d).
  • Facilities inventory and their associated BMPs (Permit Part III.D.6.a.&b).
  • Pond Assessment Procedures and schedule (Permit Part III.D.6.d).
  • The priority areas for illicit discharges and response procedures for responding to spills and reports of illicit discharges (Permit Part III D.3).

This page was last edited on 1 May 2024, at 17:37.