NCC230818_MODIFICATION Supporting Documents_20230913

M73 Cardinal to NC State Pipeline Project
Dominion Energy
Raleigh, North Carolina
Erosion and Sediment Control Narrative
Project Scope: This narrative is intended to supplement the Notification Form being resubmitted
for the installation of the M73 Cardinal to NC State natural gas pipeline in Raleigh, North Carolina
by Dominion Energy (Dominion) in Wake County. The proposed project includes installation via
a combination of open trench and horizontal directional drill (HDD) methods of approximately
55,820 linear feet of 12-inch steel natural gas pipeline. The pipeline area generally encompasses
the area between the southern edge of the road right of way (ROW) and the northern edge of the
first traffic lane, and the replacement of the natural gas regulator station falls within the private
easement on the south end of the pipeline. The attached erosion and sediment control plans
provide a summary of the work, including best management practices.
Due to the small linear work areas proposed and limited amount of earthwork, proposed erosion
and sediment control measures for this project include perimeter compost filter socks and silt
fencing at the edge of private landowner parcels, or easements, and erosion control blankets
within an existing grass lined swale and proposed station slopes to facilitate access and work
within the right-of-way. The project area falls within the Upper Neuse River basin. There are
floodplains within the existing natural gas pipeline portion of the project, however there will be no
excavation or grade change within the floodplain. There are no floodplains within the proposed
regulator station area. Note that there will be no change in impervious surface area from pre-to
post-development conditions throughout the pipeline installation portion of the project. The
regulation station development portion of the project is small and has a Built Upon Area (BUA) of
1.1%, well below the thresholds for a low-density development area. Disturbed areas will be
stabilized sequentially as construction proceeds within the proposed limits of disturbance. Access
improvement, including the clearing of trees, will take place, however, clearing will be outside of
the tree conservations areas. Excavation generated by installation of underground facilities will
be returned in place upon equipment abandonment and installation.
Peak Rate: The Project will not result in a change in impervious surface, pre-construction
contours, or peak runoff rates. The regulation station development portion of the project is small
and has a Built Upon Area (BUA)of 1.1%,well below the thresholds for a low-density development
area. Additionally, the entire area of permanent grading will maximize water dispersion through
vegetated slopes and shallow perimeter swales as well as pads being stabilized with porous 57
stone. Therefore, the impacts due to the regulation station should have little to no impact on
existing flows in the area.
Post Construction Water Quality: The Erosion and Sediment Control Plan has been designed
to control pollution and protect water quality during all stages or phases of development. The
project will not result in a change in the physical, chemical, biological, or radiological integrity of
downstream waters.
Sedimentology: The total disturbed area of the Project is approximately 52.8 54.18 acres in NC.
Site soils consist of urban land and sandy loams based on a review of USDA NRCS soils survey
attached to this narrative. Applicable soils are mostly overlain by existing pavement and grass
and vary from 2 percent to 25 percent slope.