20210212-ADI_Response_Letter

ENGINEERING - SURVEYING
CORPORATE LICENSE:C-1 771
101 W. MAIN ST., SUITE 202
GARNER, NC 27529
PHONE[phone]
FAx[phone]
February 9, 2021
Adam Parr
Assistant State Mining Engineer
North Carolina Department of Environmental Quality
Division of Energy, Mineral and Land Resources
1612 Mail Service Center
Raleigh, NC 27699-1612
Subject: A&H Mine RECEIVED
Mining Permit Number 47-16
Hoke County FEB 1 2 202l
Cape Fear River Basin
LAND QUALITY
Dear Mr. Parr,
MINING PROGRAM
We have received your comments regarding the view of the mining plan and
related sedimentation and erosion control plan for the referenced site. At RWK,
P.A, it is our goal to complete this project while meeting the requirements
established by the North Carolina Department of Environmental Quality
(NCDEQ).
1. Please show how runoff will be conveyed to all basins, by detailing ditch,
etc, on map.
a. Please show and label the vegetated berm which is directing the
stormwater to Sediment Basin A.
b. Please label the diversion for Basin B and Basin E.
c. Please show and label the diversion for Basin F.
Response: The plans for the sand mine have been revised to show diversion
ditches and the berm at Sediment Basin A, and these have been
labeled. This was done after a telephone conversation with
Melissa Joyner. She discussed what she would be looking for on
the plans and how Sheet Cl should be revised. Diversions for
Basin B, E and F are shown and labeled. A note was also added

r '
to indicated that any stormwater flow that is not conveyed by a
diversion swale or ditch is conveyed by sheet flow.
2. Please verify Unit Peak Discharge for Type II Rainfall. Peak discharges
using the graphical method appear higher than what was shown in ESC
Calculations in the December 29, 2020 ADI response.
Response: The calculations were revised using the graphical method. The
sedimentation and erosion control devices were also updated in
order to handle the stormwater flows determined from Unit Peak
Discharge for Type Il Rainfall.
Please find enclosed two (2) sets of revised plans and calculations for the
referenced site. If you have any questions or need additional information, please
contact us.
Best regards,
Sean M. McLean, P.E.
cc: John A. Lindsay, 401 Sand Company, LLC
Project file