SW5140801_Add Info_20220830

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
BRIAN WRENN
Director
Timmons Group
Attn: Francis Slinsky, PE
5410 Trinity Road, Suite 102
Raleigh, NC 27607
AND
North Carolina National Guard
Attn: Col. Rodney D. Newton
1636 Gold Star Drive, Suite 2600
Raleigh, NC 27607
NORTH CAROLINA
Environmental Quality
August 30, 2022
Subject: Request for Additional Information
Stormwater Permit No. SW5140801
NCNG Camp Butner Training Center ACFT
Granville County
Dear Mr. Slinsky and Col. Newton:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on June 1, 2022. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
This project is located within the Falls watershed and the project is owned by a federal
entity. Please ensure that the requirements outlined in 15A NCAC 02B .0281 are being
met.
2. Please clarify how much BUA will exist on -site in both existing and proposed conditions
(so that the %BUA calculation may be verified since this project is located within a
critical WS-III watershed (per 15A NCAC 02B .0275(2) and is limited to a maximum of
30% BUA). Plan sheet C3.1 indicates that there is 26,671 sf (z 0.61 ac) of BUA on -site
in proposed conditions (but does not show the location of this BUA (the layer may be
turned off?)), but the BUA summary in the stormwater narrative indicates that there is
only 0.06 ac of existing BUA on -site. Similarly, plan sheet C3.2 indicates that there will
be 72,313 sf (z 1.66 ac) of on -site BUA draining to the SCMs and there appears to be
additional BUA located on -site, but not draining to the SCMs (Portions of the gravel area
North Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources
512 North Salisbury Street 1 1612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA _
oepm nt of EnvimnmwUl uwl ry 919.707.9200

& road in the north, northeast, and east parts of the project area) that would increase the
on -site BUA in proposed conditions above 1.66 ac (the amount shown in the stormwater
narrative). Please revise as needed. You may wish to include a bypass area on the
plans/stormwater narrative indicating how much BUA is located on -site but bypassing
the SCM so that the total amount of BUA on -site in proposed conditions can be
determined.
3. There appears to be a BUA mismatch between the information shown in Section IV, 10
of the Application and as shown on the Drainage Area Page of the Supplement-EZ Form.
The BUA in the Application is all shown under the "Other" type while the Supplement-
EZ form breaks it down into "Sidewalk" and "Future" BUA. Please revise as needed.
4. Wet Pond MDC 1, 2, & 3 — Please do not include the sediment storage zone in the main
pool calculations. Plan sheet C5.4 indicates that the excavated bottom of the pond
(bottom of the sediment storage zone) for the main pool is at elevation 478.0' and that the
top of the sediment storage zone is at elevation 479.0'. The sediment storage table in the
calculation booklet indicates that the top of the sediment storage zone is at elevation
478.0'. Please revise as needed. NOTE: The pond cross-section on plan sheet C5.4
indicates that the top of the sediment storage zone for the forebay is at elevation 478.0'
but the plans (cross-section on sheet C5.4 and grading on sheet C3.0 seem to indicate that
the forebay and main pool bottoms/sediment storage zones would be at the same
elevation. Please revises if needed.
5. Wet Pond MDC 4 — Please indicate the location of the forebay weir on the plans. The
detail provided on plan sheet C5.4 indicates that there is a riprap lined weir on the
forebay berm, but the plan views of the pond do not appear to show this. It is
recommended to place the weir as far away from the outlet structure as possible to
increase the flow path of the pond and prevent short-circuiting. Please also increase the
elevation of the forebay embankment so that the pond does not short-circuit since the
inlet and outlet are located fairly close to each other and the top of the forebay
embankment is at the permanent pool elevation (it does not currently impact the flow
path of the temporary pool).
6. Please correct the following information for the Supplement-EZ Form:
a. Drainage Area Page:
i. Please complete the entire site column. The entire site column is an
accounting of all of the BUA located within the project area (not just a
sum of the DA columns). The entire site column should include the on -site
BUA that drains to the SCMs plus the BUA that is located on -site but
bypasses the SCMs.
b. Wet Pond Page:
i. Lines 20 & 21 — Revise if needed (see earlier comment).
ii. Lines 27 & 28 — Revise if needed (see earlier comment).
iii. Lines 43 & 44 — Per the provided plans, the bottom of the forebay at the
entrance is shown to be at elevation 477.0', the bottom of the forebay at

the exit is shown to be at elevation 477.5' and the permanent pool surface
elevation is shown to be at elevation 484.0'. This results in a depth to the
forebay entrance of 84" (484.0' — 477.0') and a depth to the forebay exit
of 78" (484.0' — 477.5'). Please revise as needed.
7. Provide PDFs of all revisions, 2 hardcopies of revised plan sheets, 1 hardcopy of other
documents, and a response to comments letter briefly describing how the comments have
been addressed.
a. PDFs must be uploaded using the form at:
https://edocs.deq.nc.gov/Forms/SW-Supplemental-Upload
b. Hard copies must be mailed or delivered to the following address:
i. For FedEx/UPS:
Jim Farkas
512 N. Salisbury Street, Office 640E
Raleigh, NC 27604
ii. For LISPS:
Jim Farkas
1612 Mail Service Center
Raleigh, NC 27699-1612
iii. Hand Delivery:
Please reach out to me prior to hand delivering a submission to make
sure that I (or someone else in my group) will be able to receive the
submission. Do not leave the package in the foyer with the
security guard.
NOTE: Hard copies should not be sent to a Regional Office. Doing so
will delay the review process and the submission package may be lost
while being sent from the Regional Office to me in the Central Office.
Please note that this request for additional information is in response to a preliminary review.
The requested information should be received by this Office prior to September 29, 2022,
or the application will be returned as incomplete. The return of a project will necessitate
resubmittal of all required items, including the application fee. Please reference the State
assigned project number SW5140801 on all correspondence.
If you need additional time to submit the information, please submit your request for a time
extension to the Division at the contact below. The request must indicate the date by which you
expect to submit the required information. The Division is allowed 90 days from the receipt of
a completed application to issue the permit.
The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject
to enforcement action pursuant to NCGS 143-215.6A.

If you have any questions concerning this matter please feel free to contact me at
[e-mail] or [phone].
Sincerely,
V- "I
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Raleigh Regional Office