Bridge No. 420015 Replacement Scoping Comments

September 13, 2022
MEMORANDUM ____

TO: Adam Britt, NCDOT

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

SUBJECT: Scoping Review of NCDOT’s Proposed Bridge Replacement Projects: Bridge No. 420015
(Harnett County), SR1532.

In reply to your correspondence dated September 7, 2022 in which you requested comments for the above
referenced projects, the NC Division of Water Resources offers the following comments:

Bridge No. 420015 over Black River, Harnett County

Stream Name River Basin Stream Classification(s) Stream Index
Number 303(d) Listing
Black River Cape Fear C; SW 18-68-12-1 n/a

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 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 Comments

4. 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.

5. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved
under General 401 Certification Number 4132/Nationwide Permit No. 6 for Survey Activities.

6. 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).

7. 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.

8. 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.

9. 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.

10. 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.

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

12. 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.

13. Sediment and erosion control measures sufficient to protect water resources must be implemented and
maintained in accordance with the most recent version of North Carolina Sediment and Erosion Control
Planning and Design Manual and the most recent version of NCS000250.

14. 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.

15. 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.

16. 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 DOT 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
Gregory Price, NCDOT
Jason Hatfield, NCDOT