20150266 Ver 2_More Info Requested_20171211

Moore, Andrew W
From:
Sent:
To:
Cc:
Subject:
Attachments:
Carson,
Moore, Andrew W
Monday, December 11, 2017 11:18 AM
'carson dellinger'
'Amanda Jones'; Leslie, Andrea J
Request for Additional Information, Mountain Electric Cooperative's Sugar Mountain
69kV Transmission Line, Avery County (DWR Project #20150266V2)
GC 4133.pdf
On November 27, 2017, the Division of Water Resources (Division) received your application dated November 21, 2017,
requesting a 401 Water Quality Certification from the Division for the subject project. The Division has determined that
your project is on hold until the following items are addressed:
Condition 1.4. of Water Quality Certification (WQC) 4133 (attached), which corresponds to U.S. Army Corps of
Engineers Nationwide Permit 12, requires that construction corridors in wetlands and across stream channels be
minimized to the maximum extent practicable and shall not exceed 50 feet wide for gas utility lines and 40 feet
wide for all other utility lines. The proposed construction corridor width at stream crossings for the subject
project is unclear. The Division understands that a 100 foot cleared right-of-way is required for the project.
However, it is anticipated that the construction corridor, including any land -disturbing activity, will be necked
down, or tapered, at stream and wetland crossings. Please confirm that this condition will be met or clearly
explain why it cannot be met. [15A NCAC 02H 0506 (b)(2) and (c)(2)]
Condition 1.5. of WQC 4133, requires that permanent maintained access corridors in wetlands and across stream
channels be restricted to the minimum width practicable and shall not exceed 30 feet wide for gas utility lines
and 20 feet wide for all other utility lines. The subject Pre -Construction Notification includes proposed stream
impacts ranging from 30-50 feet. Please revise the proposed culvert length to that allowed by the WQC, or
clearly explain why the additional impact length is needed. [15A NCAC 02H 0506 (b)(2) and (c)(2)]
3. Condition 11.11. of WQC 4133 requires culvert burial, with some exceptions including slope, in order to allow for
aquatic life movement. It appears that at least one culvert is proposed to be installed at a slope requiring culvert
burial. Please provide a cross section detail showing the provisions for aquatic life passage that meet Condition
11.11. of WQC 4133. [15A NCAC 02H .0506(g)]
4. Condition 11.11. of WQC 4133, also requires that, if multiple pipes or barrels are required, they shall be designed
to mimic the existing stream cross section as closely as possible including pipes or barrels at floodplain elevation
and/or sills were appropriate. Widening the stream channel should be avoided. Stream channel widening at the
inlet or outlet end of structures typically decreases water velocity causing sediment deposition that requires
increased maintenance and disrupts aquatic life passage. Please revise the permanent double culvert installation
detail to meet the noted condition. [15A NCAC 02H 0506 (b)(2) and (c)(2)]
Please explain why rip rap is necessary at the culvert inlet and outlet and include any applicable calculations
demonstrating the need for this material. If the rip rap is necessary, please provide a detail showing the proper
installation (below the streambed elevation) of the rip rap pad at the culvert inlet and outlets. In addition, if the
rip rap is proven to be necessary, please revise the stream impact table to include the permanent impacts
associated with the rip rap pads. [15A NCAC 02H .0502(b)]

Please explain why impact S9 is necessary. It appears that the utility easement could be accessed from Hickory
Nut Gap Road, thereby eliminating the need for impact S9. [15A NCAC 02H .0506(f) and (g)]
Pursuant to Title 15A NCAC 02H .0502(c), the applicant shall furnish all of the above requested information for the
proper consideration of the application. If all of the requested information is not received, the Division will be unable to
approve the application and it will be returned.
Feel free to contact me if you have questions of would like to discuss further.
Andrew W. Moore, P.G.
Environmental Specialist — Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ — Division of Water Resources
828 296 4684 office
email: [e-mail]
2090 U.S. Hwy. 70
Swannanoa, N.C. 28778
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.