20230477 Ver 1_More Info Requested_20230503

Moore, Andrew W
From: Moore, Andrew W
Sent: Wednesday, May 3, 2023 9:16 AM
To: Mularski, Eric
Cc: Fuemmeler, Amanda J CIV (US); Leslie, Andrea J; Hamstead, Byron A
Subject: Request for Additional Information, Carrier Bridge Pump Station Replacement Project, Buncombe
County (DWR Project #20230477)
Eric,
On March 29, 2023, the Division of Water Resources (Division) received your application requesting a 401 Water Quality
Certification from the Division for the subject project. The Division has determined that your application is incomplete
and cannot be processed. The application is on -hold until all of the following information is received:
1. Please provide a figure that depicts the future extension of the 60-inch diameter gravity sewer interceptor pipe
from the South River Crossing and extending upgradient/south. The Division understands these plans may not
be finalized at this time, so conceptual plans are acceptable. [15A NCAC 02H .0502(a)(9) and 15A NCAC 02H
.0506(b)(1)]
2. Please clarify if the current proposed plans include upgrading the 48-inch diameter South French Broad
interceptor from the South River Crossing to the Amboy Road Bridge (i.e. through Carrier Park, former Edaco
junkyard, etc.). The PCN Supplemental Information narrative indicates this is not part of the current plans.
However, previous meetings and a number of figures included with the PCN (e.g. Three Oaks PJD, Environmental
Management Plan) indicate this upgrade is part of the project scope. [15A NCAC 02H .0502(a)(9)]
3. During a site meeting conducted on April 27, 2023, with staff from the Division, NCWRC, MSD, and HDR, there
we discussions that indicated the rockfill cofferdam was still in consideration for the project. The PCN narrative
indicates a sheet pile cofferdam will be implemented for the project. Please clarify if the rockfill cofferdam is still
being considered for the project. [15A NCAC 02H .0502(a)(9)]
4. The PCN project narrative indicates either a sheet pile with king piles or the brace box sheet pile construction
will be implemented for the cofferdam.
a. The Division understands the king piles will require drilling into bedrock along the riverbed prior to
setting the sheet piles. Please provide a construction sequence that details how this work will be
conducted so that the river flow does not come in contact with the disturbed area and/or how the river
will be protected from turbidity during the drilling process.
b. Both the sheet pile with king piles and brace box sheet pile construction are likely to require grouting to
seal the sheet piles from seepage. Please note that cement that contains lime and comes in contact with
water can have detrimental effects on aquatic life due to changes in pH. Please explain how the grouting
will occur to preclude contact with the river flow. [15A NCAC 02H .0506(b)(2)]
5. Will the proposed South River Crossing cofferdam block or impede flow from stream SA's channel with its
confluence with the French Broad River? [15A NCAC 02H .0506(b)(1) and (2)]
6. There is a stream in the vicinity of the North River Crossing that is not depicted on any of the figures or in the
PJD request package. Please revise the figures to include the stream. Please also clarify if any impacts,
temporary or permanent, to the stream will be required to complete the North River Crossing. [15A NCAC 02H
.0502(a)(9)]

Based on the April 27, 2023 site meeting, the Division understands that rather than preemptively installing the
temporary streambank stabilization measures downstream of the proposed cofferdam locations, which would
involve extensive disturbance to the well -established woody riparian buffer, the applicant is considering a
contingency bank stabilization plan approach in which permanent bank stabilization measures consisting or rip
rap would be installed only after indications of bank instability or degradation were observed. Please provide a
narrative description of the contingency bank stabilization plan. The plan should include a qualitative evaluation
of the riverbanks downstream of the two river crossing locations as well as a routine assessment of the
riverbanks during construction. [15A NCAC 02H .0506(b)(1) an (2)]
8. Please provide construction details for the permanent natural bank stabilization that will be installed in the
vicinity of the cofferdams after installation of the gravity sewer and force main are installed. [15A NCAC 02H
.0502(a)(9)]
Pursuant to Title 15A NCAC 02H .0502(e), the applicant shall furnish all of the above requested information for the
proper consideration of the application. Please provide your response by June 2, 2023. If all of the requested
information is not received, the Division will be unable to approve the application and it will be denied as incomplete.
The denial of this project will necessitate reapplication to the Division for approval, including a complete application
package and appropriate fee.
Feel free to contact me if you have any questions.
Andrew W Moore, P.G.
Environmental Specialist ll, Division of Water Resources
North Carolina Department of Environmental Quality
Office: [phone]
[e-mail]
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NORTH CAROLINA 7d� Q
Department of Environmental Quality
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