Municipal Separate Storm Sewer Systems (MS4s) are defined by the U.S. Environmental Protection Agency (EPA) as a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels or storm drains) which are designed or used for collecting or conveying stormwater and are neither a combined sewer system nor part of a publicly owned treatment system. NPDES Phase I required that municipalities operating MS4s within large or medium urbanized areas, obtain an MS4 General Permit. NPDES Phase II increased this requirement to include small urbanized areas as well. In the State of Vermont, the Agency of Natural Resources – Department of Environmental Conservation (Vermont DEC) is the permitting authority and administers the MS4 GP on behalf of the EPA.
If an MS4 falls within an urbanized area, NPDES Phase II requires coverage under the MS4 General Permit. In order to obtain coverage under the General Permit submission or implementation of three (3) major components are required. The first component is the submission of a Notice-of-Intent (NOI) which requires general information about the owner and operator of the MS4, location of the MS4, and into what surface waters the MS4 discharges. The second component is the design and implementation of a Storm Water Management Plan (SWMP). The operator's SWMP is required to include measurable goals addressing Best Management Practices (BMPs) and the following six (6) minimum control measures:
- Public Education and Outreach
- Public Participation/Involvement
- Illicit Discharge Detection and Elimination
- Construction Site Runoff Control
- Post-Construction Runoff Control
- Pollution Prevention/Good Housekeeping
The third component is to document achievements in an annual report to Vermont DEC.
In Vermont there are currently eight municipalities with Municipal Separate Storm Sewer Systems (MS4) required to come into compliance with this regulation. 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 (VTrans).
VTrans has been designated as an operator of a non-traditional Municipal Separate Storm Sewer System (MS4) under the Permit for Stormwater Discharges from Small Municipal Separate Storm Sewer Systems administered by the Vermont DEC. As such, VTrans is required to comply with the conditions of the Permit on State Highways, other transportation facilities, and VTrans maintenance facilities that are located in the 2000 Census Urbanized Areas (UAs) and in the watersheds of waters that are principally impaired by collected stormwater runoff when the watersheds are located entirely or partially in the UAs.
VTrans operates MS4 systems to various extents in every one of the urbanized areas and associated impaired watersheds identified above. As a result, VTrans has created and implemented an extensive SWMP to meet the requirements of the MS4 General Permit. For VTrans, coverage under this permit is required for all State owned and operated roadways and facilities within the defined coverage area. The VTrans MS4, which is regulated by the Permit, is approximately two (2) square miles. The area includes approximately 90 miles of State Highway and one Maintenance Garage located within the UAs and the associated impaired watersheds. Click on this link to see a map of the VTrans MS4 coverage area .
As part of VTrans’ Notice of Intent for coverage under General Permit 3-9014 (as amended from time to time), the VTrans Stormwater Management Plan (SWMP) was established on July 23, 2003 and is updated as needed to respond to MS4 Permit 5-year cycles and changes in measurable goals addressing the Best Management Practices (BMPs) proposed to comply with the required six minimum measures. Annual Reports to Vermont DEC are a permit requirement and are used to document achievements and areas needing improvement.
The SWMP will advance and evolve through the cyclic terms of the Permit, under the direction of the VTrans Operations Environmental Coordinator in consultation with the VTrans Stormwater Steering Committee. VTrans coordinates the implementation of the VTrans SWMP internally across VTrans Divisions and all other MS4s in Vermont.
VTrans is committed to the full implementation and enforcement of the SWMP which has been designed to reduce the discharge of pollutants from the VTrans non-traditional small MS4 to the maximum extent practicable, to protect water quality, and to satisfy the appropriate water quality requirements of the Clean Water Act. The Permit states that the implementation of best management practices, consistent with the provisions of the SWMP required pursuant to this permit, constitutes compliance with the standard of reducing pollutants to the "maximum extent practicable.”
Related Documents - For more informative documents, including VTrans MS4 Stormwater Management Plan (SWMP); NOI's; Annual Reports, Maps and more.