SW4220602_Response To Comments_20220921

DAMS • MARTIN • POWELL dmpENGINEERS & SURVEYORS
September 22, 2022
Re: Nordfab Systems, Inc.
Building Expansion Project
Davidson County
DMP Project 210238 (BF)
Stormwater Permit # SW4220602
Mr. Jim Farkas
NCDEQ— DEMLR
Stormwater Program
512 N. Salisbury Street, Office 640E
Raleigh, NC 27604
via UPS
Dear Mr. Farkas,
We are in receipt of your September 21, 2022 email providing comments and requesting additional
information on the subject project. We have reviewed the comments and offer the following:
Please provide outlet stability calculations for the proposed piping/culverts (Required per 15A
NCAC 02H .1003(5)). It is noted that the riprap sizing information is provided in the plans,
however, we need the calculations verifying that the provided riprap is adequately sized and that
the 15" RCPs do not require outlet protection.
The pipe outlet stability calculations are enclosed. Please note the following:
- Pipe outlet velocities for pipes P-1 and P-3 are within the allowable velocity limits for
the receiving soil/vegetated cover class, therefore protection is not required.
- We have added and outlet protection measure for pipe P-4 to the plan — this
protection was inadvertently omitted with the original submittal. The revised plan
sheet showing this addition is attached (plan sheet C5.1)
Supplement-EZ Form, Cover Page:
- Line 2 — Please do not include the surface water area in the project area. This value
should correspond to the value shown in Section IV, 7 of the Application.
- Line 2 has been revised to match the Application
- Line 4 — The information shown here (1.14 cc) does not correspond to the information
shown in Section IV, 6 of the Application (1.15 cc). Please revise as needed.
- Line 4 has been revised to match the Application
As requested, we are enclosing the following hardcopies:
- One (1) copy of the pipe outlet stability calculations
- One (1) copy of the revised Supplement EZ form Cover Page
- Two (2) copies of revised plan sheet C5.1
We have also uploaded electronic copies of the attachments to the NCDEQ Laserfiche portal.
T: 336-886-4821 • F: 336-886-4458 • License: F-0245
6415 Old Plank Road, High Point, NC 27265 • www.dmp-inc.com

Mr. Jim Farkas
Nordfab Building Expansion September 22, 2022 Page 2 of 2
We trust this information is complete and will allow approval at an early date. Should you have questions
or require additional information, please let us know.
Sincerely,
DAVIS • MARTIN • POWELL & ASSOCIATES, INC
Z,--- Pqr--,
Ben Palmer, PE
C. Mr. Erik Olshall, Nordfab — [e-mail]
Mr. Rick Doss, Nordfab — [e-mail]
Mr. Keven Masten, Fourth Elm Construction - kmasten@fourth elm. com
Mr. Wally Samuels, Fourth Elm Construction - [e-mail]
File (enc)
P:1202112102381PermitslStormwaterl210238_DEQ Stormwaterxmittal(9-22-2022).docx