Construction stormwater best management practice – Linear Utility Projects
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Construction stormwater best management practice – Linear Utility Projects

Use this guidance to determine whether a National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) construction stormwater permit is needed for your linear underground/ overhead project. Linear facilities include conduits, substructures, pipelines, towers, poles cables, wires, connectors, switching, regulating and transforming equipment, and associated ancillary facilities.

Background

Construction activities including clearing, grading, and excavating that will disturb one or more acres of land, or that are part of a larger common plan of development or sale that will disturb one or more acres of land, requires coverage under a NPDES/SDS construction stormwater permit.

How do I determine land disturbance area for my linear project?

Depending on the project type, to determine if the land area to be disturbed will be one acre or more, include the following areas in calculating the disturbed area:

Surface areas of trenches and associated laterals. Backhoe or trencher work, including excavation width and stockpile area, and vehicle width if soil will be exposed during operation. The area of trenching impact should be determined by the width of trench, side casted material pile, and depending on level of disturbance, the width of the installation equipment. Trench spoils on a paved surface that are either returned to the trench or excavation or hauled away from the project daily for disposal or reuse are not included in the disturbed area calculation.
Soil areas outside the surface area of trenches, laterals, and ancillary facilities that will be graded or disturbed by the use of construction equipment, vehicles, and machinery during construction activities. This includes tracked vehicles that cause rutting that disturbs the vegetative cover exposing soil the length of a vehicle traverse. (In general, work with tracked vehicles can result in minimal soil disturbance, as long as slope, soils, and weather are favorable).
Surface area of soil stockpiles located onsite or immediately adjacent to the project if the stockpile is not on a paved surface.
Surface area of borrow areas located onsite or immediately adjacent to the project.
Surface area of structure installation and other ancillary facilities (e.g. poles, pull boxes, fuse boxes, splice boxes, pads, etc.).
Paved surface areas constructed for the purpose of the project.
New roads constructed or major reconstruction to existing roads (e.g. improvements to two-track surfaces or road widening) for the purpose of accessing construction activities or as part of the final project.
Staging, preparation, equipment and material storage areas not on paved surfaces.

How do I determine if my linear project is part of a common plan?

A common plan of development or sale means a contiguous area where multiple, separate and distinct land disturbing activities may be taking place at different times, on different schedules, under one proposed plan. A “common plan” may consist of non-contiguous separate projects. In this case, for discrete construction projects that are located within a larger common plan that are at least one fourth mile apart, each project (e.g. individual structure) can be treated as a separate plan of development or sale provided no land disturbing activity is proposed between the projects.

Example: Two oil and gas well pads separated by one half mile could be treated as separate development plans if no land disturbing activity is proposed between the pads. However, if the same two well pads are connected by an access road or other land disturbing activity, all three areas would be considered part of a "common plan" for permitting purposes even if the construction activity is occurring at separate times.

Example: If a utility company were constructing new trunk lines off an existing transmission line to serve separate residential subdivisions located more than one fourth mile apart, the two trunk line projects could be considered to be separate projects

What if conditions change during construction and the disturbed area is greater than originally estimated?

If you originally determined that NPDES/SDS construction stormwater permit coverage was not required for your project, appropriate best management practices (BMPs) should be used for erosion prevention and sediment control to avoid transport of sediment and associated contaminants that would violate water quality standards downstream from the project area during project construction.

During dry or frozen ground conditions with snow cover, soil disturbance from installation of linear facilities is generally expected to be minimal. Under these conditions, the need for BMPs is dependent on the proximity of the project to waters of the state, the amount of soil disturbance, and the potential to violate state water quality standards during construction.

However, if unexpected rainfall or wet soil conditions occur that will result in larger exposure of soil, one acre or more, or your area of disturbance is greater than you originally calculated, you will need to meet the requirements for permit application and obtain NPDES/SDS construction stormwater permit coverage.

What is required for linear projects and wetlands?

The project should be in compliance with state and federal wetland regulations, including the Minnesota Wetland Conservation Act, and Section 404 of the Clean Water Act, as applicable.

Application materials

To get an application form and find more information about applying for permit coverage, visit the Minnesota Pollution Control Agency (MPCA) construction stormwater website at: www.pca.state.mn.us/water/stormwater/stormwater-c.html.

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