Bridge No. 240245_Cumberland County_scoping comments

November 15, 2021
MEMORANDUM___________________________________________________

To: Adam Britt, NCDOT

From: Hannah Sprinkle, NC Division of Water Resources, Wilmington Office

Subject: Scoping comments on NCDOT’s proposed Bridge Replacement Project: BP6.R006. (Cumberland
County), SR 1414.

Reference your correspondence dated November 12, 2021 in which you requested comments for the referenced
project. Preliminary analysis of the project reveals the potential for multiple impacts to streams and jurisdictional
wetlands in the project area. More specifically, impacts to:
Stream Name River Basin Stream Classification(s) Stream Index
Number 303(d) Listing
Branson Creek Cape Fear C 18-27-5-1 n/a

Further investigations at a higher resolution should be undertaken to verify the presence of other streams and/or
jurisdictional wetlands in the area. In the event that any jurisdictional areas are identified, the Division of Water
Resources requests that NCDOT consider the following environmental issues for the proposed project:
Project Specific Comments:

1. To meet the requirements of NCDOT’s NPDES permit NCS000250, the road design plans shall provide
treatment of the stormwater runoff through BMPs as detailed in the most recent version of the North Carolina
Department of Transportation Stormwater Program Manual, and the Stormwater Best Management Practices
Toolbox Manual. The BMPs should, to the MEP, be selected and designed to reduce impacts of the target
pollutants of concern (POCs) for the receiving waters.

2. Any anticipated bank stabilization associated with culvert installations or extensions should be addressed in
the Categorical Exclusion (CE) document. It is understood that final designs are not determined at the time
the CE is developed. However, the CE should discuss the potential for bank stabilization necessary due to
culvert installation.

3. Any anticipated dewatering or access structures necessary for construction of bridges should be addressed in
the CE. It is understood that final designs are not determined at the time the CE is developed. However, the
CE should discuss the potential for dewatering and access measures necessary due to bridge construction.
General Project Comments:

4. The environmental document should provide a detailed and itemized presentation of the proposed impacts to
wetlands and streams with corresponding mapping. If mitigation is necessary as required by 15A NCAC
2H.0506(h), it is preferable to present a conceptual (if not finalized) mitigation plan with the environmental
documentation. Appropriate mitigation plans will be required prior to issuance of a 401 Water Quality
Certification.

5. After the selection of the preferred alternative and prior to an issuance of the 401 Water Quality Certification,
the NCDOT is respectfully reminded that they will need to demonstrate the avoidance and minimization of
impacts to wetlands (and streams) to the maximum extent practical. In accordance with the Environmental
Management Commission’s Rules (15A NCAC 2H.0506[h]), mitigation will be required for impacts of
greater than 1 acre to wetlands. In the event that mitigation is required, the mitigation plan shall be designed
to replace appropriate lost functions and values. North Carolina Division of Mitigation Services may be
available for assistance with wetland mitigation.

6. In accordance with the Environmental Management Commission’s Rules (15A NCAC 2H.0506[h]),
mitigation will be required for impacts of greater than 300 linear feet to any perennial stream. In the event
that mitigation is required, the mitigation plan shall be designed to replace appropriate lost functions and
values. The North Carolina Division of Mitigation Services may be available for assistance with stream
mitigation.

7. An analysis of cumulative and secondary impacts anticipated as a result of this project is required. The type
and detail of analysis shall conform to the NC Division of Water Resource Policy on the assessment of
secondary and cumulative impacts dated April 10, 2004.

8. The NCDOT is respectfully reminded that all impacts, including but not limited to, bridging, fill, excavation
and clearing, and rip rap to jurisdictional wetlands, streams, and riparian buffers need to be included in the
final impact calculations. These impacts, in addition to any construction impacts, temporary or otherwise,
also need to be included as part of the 401 Water Quality Certification Application.

9. Riprap shall not be placed in the active thalweg channel or placed in the streambed in a manner that precludes
aquatic life passage. Bioengineering boulders or structures should be properly designed, sized and installed.

10. Riparian vegetation (native trees and shrubs) shall be preserved to the maximum extent possible. Riparian
vegetation must be reestablished within the construction limits of the project by the end of the growing season
following completion of construction.

11. The NCDWR is very concerned with sediment and erosion impacts that could result from this project. NC
DOT shall address these concerns by describing the potential impacts that may occur to the aquatic
environments and any mitigating factors that would reduce the impacts.

12. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved
under General 401 Certification Number 3883/Nationwide Permit No. 6 for Survey Activities.

13. If a bridge is being replaced with a hydraulic conveyance other than another bridge, the NCDWR believes the
use of a Nationwide Permit may be required. Please contact the US Army Corp of Engineers to determine the
required permit(s).

14. If the old bridge is removed, no discharge of bridge material into surface waters is allowed unless otherwise
authorized by the US ACOE. Strict adherence to the Corps of Engineers guidelines for bridge demolition will
be a condition of the 401 Water Quality Certification.

15. Whenever possible, the NCDWR prefers spanning structures. Spanning structures usually do not require
work within the stream or grubbing of the stream banks and do not require stream channel realignment. The
horizontal and vertical clearances provided by bridges allow for human and wildlife passage beneath the
structure, do not block fish passage and do not block navigation by canoeists and boaters.

16. Bridge deck drains shall not discharge directly into the stream. Stormwater shall be directed across the bridge
and pre-treated through site-appropriate means (grassed swales, pre-formed scour holes, vegetated buffers,
etc.) before entering the stream. Please refer to the most current version of NCDWR Stormwater Best
Management Practices.

17. If concrete is used during construction, a dry work area shall be maintained to prevent direct contact between
curing concrete and stream water. Water that inadvertently contacts uncured concrete shall not be discharged
to surface waters due to the potential for elevated pH and possible aquatic life and fish kills. Concrete shall be
handled in accordance with the NPDES Construction General Permit NCG010000.

18. Bridge supports (bents) shall not be placed in the stream when possible.

19. If temporary access roads or detours are constructed, the site shall be graded to its preconstruction contours
and elevations. Disturbed areas shall be seeded or mulched to stabilize the soil and appropriate native woody
species shall be planted. When using temporary structures the area shall be cleared but not grubbed. Clearing
the area with chain saws, mowers, bush-hogs, or other mechanized equipment and leaving the stumps and
root mat intact allows the area to re-vegetate naturally and minimizes soil disturbance.

20. All work in or adjacent to stream waters shall be conducted in a dry work area unless otherwise approved by
the NCDWR. Approved BMP measures from the most current version of NCDOT Construction and
Maintenance Activities manual such as sandbags, rock berms, cofferdams and other diversion structures shall
be used to prevent excavation in flowing water.

21. Heavy equipment shall be operated from the bank rather than in stream channels in order to minimize
sedimentation and reduce the likelihood of introducing other pollutants into streams. This equipment shall be
inspected daily and maintained to prevent contamination of surface waters from leaking fuels, lubricants,
hydraulic fluids, or other toxic materials.

22. In most cases, the NCDWR prefers the replacement of the existing structure at the same location with road
closure. If road closure is not feasible, a temporary detour shall be designed and located to avoid wetland
impacts, minimize the need for clearing and to avoid destabilizing stream banks. If the structure will be on a
new alignment, the old structure shall be removed and the approach fills removed from the 100-year
floodplain. Approach fills shall be removed and restored to the natural ground elevation. The area shall be
stabilized with grass and planted with native tree species. Tall fescue shall not be used in riparian areas.

Thank you for requesting our input at this time. The NCDOT is reminded that issuance of a 401 Water Quality
Certification requires that appropriate measures be instituted to ensure that water quality standards are met and
designated uses are not degraded or lost. If you have any questions or require additional information, please contact
Hannah Sprinkle at [e-mail].

Electronic copy only distribution:
Liz Hair, US Army Corps of Engineers, Wilmington Field Office
Kristi Lynn Carpenter, NCDWR
Hannah Sprinkle, NC Division of Water Resources Wilmington Regional Office
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