SWA000228_Response To Comments_20240226

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5410 Trinity Road P 919.866.4951
T I M M O N S GROUP Ralte 102
e gh,NC 27607 F 919.859.5663
www.timmons.com
Date: 2024-02-26
Project: Circle K— NTI E Cumberland St & S Lehmon Ave— Dunn, NC
SWA000228
Timmons Group Project#37630.123
Subject: Response to 1st NCDEQ Stormwater Comments
Project Contact: Jacob Dooley
Phone: [phone]
Email: [e-mail]
Response to review comments have been added below each comment in bold font.
1. Please upload the electronic files for this project as indicated in the 9/26/23 email. Electronic
files are required per 15A NCAC 02H .1043(3) and must be uploaded through the following link:
https://edocs.deq.nc.gov/Forms/SW-Supplemental-Upload
Response: Electronic files have been uploaded.
2. Please ensure that the future BUA is accounted for in the Proposed New BUA in Section 5 of
the Application (this section of the Application indicates 79,022 sf of new BUA(1.81 ac)whereas
the other submittal items indicate a net increase of 1.99 ac of BUA. If you do not wish to permit
the future BUA at this time, please remove it from the submittal items (the permit will then need
to be modified to include the future BUA if/when it will be built).
Response: The future BUA is now accounted for in Section 5 of the application.
3. While not required for ATC approval, there may be some issues with the design as proposed
(The Fast-Track ATC review is not an in-depth technical review of the stormwater controls for
the site, it is more of an administrative review of the project/a review to see if the project has the
potential to meet the design requirements/rules. The SCM design and drainage area delineation
are not required submission items at this point in the Fast-Track submittal process so issues
with the SCM design or drainage area delineation do not prevent a project from getting Fast-
Track ATC approval, but if the SCM design and drainage area delineation are provided at this
point in the review, we look at them to see if the design appears to meet the rules and MDC):
a. Wet Pond #2 appears to short-circuit (Wet Pond MDC 4). Increasing the length of the
flow path from the inlet to the outlet (by either relocating the inlet and/or outlet or adding
berms/baffles) should prevent the pond from short-circuiting and better utilize the entire
wet pond.
Response: The riser structure for Wet Pond #2 has been shifted farther from the
inlet structure, and the retaining wall has been adjusted accordingly.
ENGINEERING I DESIGN I TECHNOLOGY

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5410 Trinity Road P 919.866.4951
T I M M O N S GROUP Suite 102 F 919.859.5663
Raleigh,NC 27607 www.timmons.com
b. The design volume of Wet Pond #2 does not appear to drawdown within the 2-5 day
window (Wet Pond MDC 7). The temporary pool surface elevation is set by the invert of
the lowest bypass elevation (per the plans, the top of the outlet structure at elevation
191.5') If you would like the temporary pool surface elevation to be at elevation 190.0',
you need to provide a bypass orifice or weir at that elevation.
Response: A bypass orifice has been added to the riser at 190.0' to establish the
temporary pool elevation.
105 Ashe Avenue
SUB-0053-2021, Timmons Group Project#48600.002
Response to Third City of Raleigh Review Comments Page 2 of 2