Municipal Separate Storm Sewer System (MS4) General Permit

Program Update - What's New
MS4 Specific Materials
Permit Background
Permit Documents and Forms
What is an MS4
MS4 Permit Requirements
Links to Additional Information
Links to MS4 Stormwater Websites
Links to Previous Documents and Permits

Program Update - What's New

  • Stormwater Impaired Waters Flow Monitoring:
  • Residual Designation Authority (RDA) designations for impervious surface that discharges directly to the stormwater impaired streams: In 2009, the Department issued General Permit 3-9030 for designated discharges to Bartlett, Centennial, Englesby, Morehouse, and Potash Brook watersheds. The Department designated discharges to these receiving waters if the discharge is not covered under the NPDES municipal separate storm sewer system (MS4), another NPDES permit covering stormwater discharges, or has been issued a state stormwater discharge permit resulting in no net contribution to the receiving water.  The Department plans to designate dischargers in the remaining stormwater impaired watersheds: Allen, Indian, Munroe, Rugg, Stevens, and Sunderland.
  • Expired Stormwater Operational Permits within the stormwater impaired watersheds: It is the Department’s intention that all expired permits will be required to obtain coverage under a valid permit.  As a result of the Environmental Court’s decision in the Residual Designation Authority (RDA) petition, all such permits shall be National Pollutant Discharge Elimination System (NPDES) permits. Under the MS4 General permit (IV.C.e.3), MS4 permittees are required to submit a plan to the Department for addressing expired permits that discharge into the permittee’s separate storm sewer system.  The intent of this requirement is to provide municipalities the option of providing permit coverage for these discharges under the municipalities’ MS4 Permit coverage.  Alternatively, a municipality may choose to petition the Department to issue permit coverage to these discharges separately from the MS4 permit coverage.  In such a case the Department will use its RDA permitting mechanism to issue NPDES permits to these discharges.  The Department has developed two guidance documents to further explain the permit language:

MS4 Guidance for the Renewal of Expired Permits
MS4 Guidance for Accepting Expired Stormwater Permits

Permittees covered under the MS4 General Permit (3-9014)

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MS4 Specific Materials

City of St Albans (new 2012)

Town of St Albans (new 2012)

Town of Rutland (new 2012)

City of Burlington

Burlington International Airport (BTV)

Town of Colchester

Town of Essex

Village of Essex Junction

Town of Milton

Town of Shelburne

City of South Burlington

University of Vermont

Town of Williston

City of Winooski

Vermont Agency of Transportation

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Permit Background

On Wednesday, December 5, 2012, Vermont's MS4 Permit was issued.  This MS4 permit is the second MS4 General Permit issued by the State of Vermont.  The first MS4 permit was issued in 2003 and amended in 2004.  Both the 2004 and 2012 permits authorize stormwater discharges within the Urbanized Areas of the following small MS4s: Burlington, Colchester, Essex, Essex Junction, Milton, Shelburne, South Burlington, Williston, and Winooski, the University of Vermont, the Burlington International Airport and the Vermont Agency of Transportation (VTrans).   The VTrans small MS4 includes state highways within the Urbanized Areas in the above mentioned municipalities and in the towns of Jericho and Underhill. Click here for the Press Release and Permit Q&A.

Concurrent with the 2012 MS4 permit issuance, the Department is designating those portions of Municipal Separate Storm Sewer Systems that discharge to the stormwater impaired waters. The designated small MS4s, within the stormwater impaired watersheds, are operated by the City of Rutland, the Town of Rutland, the City of St. Albans, the Town of St. Albans, and the Vermont Agency of Transportation within the geographic boundaries of the stormwater impaired watersheds in the municipalities listed above. 

The most significant change in the 2012 MS4 permit is the requirement for municipalities to develop Flow Restoration Plans (FRPs) to implement the stormwater TMDLs.  The FRPs must be developed for each impaired watershed within 3 years and must include the following elements: 1) an identification of the required controls, 2) a design and construction schedule, 3) a financial plan, 4) a regulatory analysis, 5) the identification of regulatory assistance, and 6) identification of any third party implementation.  The schedule shall provide for implementation of the required BMPs as soon as possible, but no later than 20 years from the effective date of the permit.

For more information on the MS4 permit, contact Christy Witters at (802) 490-6173 or via email at

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Permit Documents and Forms

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What is an MS4?

A municipal separate storm sewer system is a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains):

Owned or operated by a State, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law) 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 district, or similar entity, or a designated and approved management agency under Section 208 of the CWA that discharges to waters of the State and 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

MS4 Map small

Types of small MS4s

Small MS4s include cities, towns, counties, airports, highway departments, and universities. There are four ways by which a small MS4 may be designated as a "regulated" small MS4 and thus require permit coverage:

Automatic designation - Small MS4s located within the boundaries of a Census Bureau-defined Urbanized Area (UA) based on the 2000 Census or any subsequent decennial census. Urbanized Areas include areas with populations of at least 50,000 people with an overall population density of at least 1,000 people per square mile.

These communities are Burlington, Colchester, Essex, Essex Junction, Milton, Shelburne, South Burlington, Williston, and Winooski. Three publicly owned 'non-traditional' separate storm sewer systems were also designated. These systems are owned or operated by the University of Vermont, Burlington International Airport and the Vermont Agency of Transportation. The regulations apply to areas served by each MS4 that are located either within the UA or watersheds that are principally impaired by stormwater.

Potential designation by permit authority - Small MS4s that are located outside of UAs determined to result in, or have the potential to, result in significant water quality impacts;

These MS4s are those areas that discharge to waters listed as impaired due to stormwater runoff within the municipal separate storm sewer systems of the City of St. Albans, the Town of St. Albans, the City of Rutland, the Town of Rutland, and the Vermont Agency of Transportation within these areas.

Contributes to an interconnected "regulated" MS4 - Small MS4s that contribute substantially to pollutant loadings of a physically interconnected MS4 regulated by the NPDES storm water program;

Petition for designation - Small MS4s may be designated following a final determination by the Department on a petition, or request, for designation.

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MS4 Permit Requirements

There are six minimum measures required of each designated municipality under the Rule. These measures are:

(1) Public Education and Outreach,

(2) Public Participation/Involvement

(3) Illicit Discharge Detection and Elimination

(4) Construction Site Runoff Control

(5) Post-Construction Runoff Control and

(6) Pollution Prevention/Good Housekeeping.

In addition, municipalities that discharge to stormwater impaired waters must prepare and implement a Flow Restoration Plan for their portion of the stormwater impaired watershed.

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Links to Additional Information

Logo of Rethink Runoff

Rethink Runoff is an ongoing campaign managed by the Chittenden County Regional Planning Commission to assist several municipalities and entities to meet Minimum Control Measures 1 and 2 of the Vermont MS4 Permit. The effort represents the unification of two previously separate permit-driven efforts: the Regional Stormwater Education Program (RSEP) and the Chittenden County Stream Team (CCST).  More information can be found at:

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Links to MS4 Stormwater Websites

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Draft General Permit 3-9014 (2010)

Previously Issued MS4 Permit (2003)

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WSMD - Stormwater Home