20170172 Ver 1_More Info Received - Email_20170314

Strickland, Bev
From: Jordan Isenhour <[e-mail]>
Sent: Tuesday, March 14, 2017 10:57 AM
To: Price, Zan (George)
Cc: [e-mail]; Elliott, William A CIV USARMY CESAW (US); Annino, Amy
M; '[e-mail]'; Chad Pierce; Ryan Hager
Subject: RE: Request for Additional Information - Asheville 2015 Water Distribution Projects -
Buncombe County - DWR 17-0158
Attachments: 2017-03-14 - NEP Area 2 -Revised Stream Stabilization Details.pdf
Mr. Price,
Please see the responses to your comments below. Let us know if you have any questions.
Thank you,
Jordan Isenhour, PE
Project Engineer
WK Dickson & Co., Inc.
From: Price, Zan (George) [mailto:[e-mail]]
Sent: Friday, March 10, 2017 9:20 AM
To: Jordan Isenhour <[e-mail]>
Cc: [e-mail]; Elliott, William A CIV USARMY CESAW (US) <[e-mail]>; Annino,
Amy M <[e-mail]>
Subject: Request for Additional Information - Asheville 2015 Water Distribution Projects - Buncombe County - DWR 17-
0158
The Division of Water Resources (DWR) has performed a review of a 401 Water Quality Certification application dated
February 2, 2017 for the above referenced project. The DWR has determined that your application is incomplete and
cannot be processed. The application is on -hold until the following information is received:
1. Condition number #6 of Water Quality Certification (WQC) No. 3884 states that work must be performed in the
dry. Specifically, it states, "All work in or adjacent to stream waters shall be conducted so that the flowing
stream does not come in contact with the disturbed area. Approved best management practices from the most
current version of the NC Sediment and Erosion Control Manual, or the NC DOT Construction and Maintenance
Activities Manual, such as sand bags, rock berms, cofferdams, and other diversion structures shall be used to
minimize excavation in flowing water. Exceptions to this condition require application submittal to and written
approval by the Division."
Please provide appropriate construction sequence information and associated details describing how the project
will meet condition #6 of WQC 3884.
The attached sheet, D.7 -Stream Stabilization Details, from the project plan set has been revised
to include a stream bypass detail which also includes a sequence of construction. During
construction, the work area will be kept dry through the suggested means.

2. The proposed project includes the use of a 50/50 mix of in-situ soil and #5 stone on the bed of the channel and a
mix of Class B and Class 1 riprap on the streambank. Please provide appropriate calculations (e.g. shear stress)
demonstrating long term stability of the proposed stream bed and bank materials.
The riffle grade control structure is intended to return the reach to pre -construction condition.
The bottom IS of this structure will be composed of mixed riprap on filter fabric and will be
located below the stream bed. An additional foot of native soil salvaged from the existing
stream bed mixed with #5 stone (gravel) will be installed above the rip rap to insure that the
reach is returned to its pre -construction condition. Once installed, the riffle will act as a grade
control, which will protect the channel from being undercut.
The soil/gravel mix layer will be positioned between native soil both upstream and
downstream. This native soil in the established channel bottom is stable as part of existing
natural channel function and the short length of riffle grade control used to restore the pipe
trench will provide the same or better resistance to scour as the existing channel bottom, while
providing similar biological habitat to the existing channel bed.
Pursuant to Title 15A NCAC 02H .0502, 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 within 30 calendar days of receipt of
this email, the DWR will be unable to approve the application and it will be returned. The return of this project will
necessitate reapplication to the DWR for approval, including a complete application package and the appropriate fee.
Feel free to submit the above requested information to me via email.
Contact me if you have any questions or concerns.
Regards,
Zan Price, P.E.
Assistant Regional Supervisor — Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ — Division of Water Resources
828 296 4662 office
828 231 9634 mobile
zan. price(cDncdenr.gov
2090 U.S. Hwy. 70
Swannanoa, N.C. 28711
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