SW3170503 (11)

SW3170503 — Afton Ridge Industrial — Response to Comments
June 9, 2017
Page 1
Robert D. Patterson, PE
Environmental Engineer
DEMLR — Stormwater Program
North Carolina Department of Environmental Quality
Re: 4386.04 -Afton Ridge Industrial - Response Letter to 1 st NCDEQ Stormwater
Review - SW3170503
Dear Mr. Patterson,
This letter is our response to the comments dated May 23, 2017 for the above
referenced project. Please see the comments below followed by our response in bold
print.
1. Revise the supplement to reflect the plans that the internal pond side slopes
are 3:1, not 2:1.
The supplement has been revised and is enclosed, as requested.
2. Revise C-910, OCS-EC-3 section view to show 2:1 for the outer slope to be
consistent with the plan view.
The detail has been revised as requested.
3. Provide and label a SCM access easement to the nearest public right-of-way
[General MDC 9]. Since there is not a site or grading plan sheet, please show
this on the post- construction drainage plan sheet.
The required easement has been included in the plan sheets when
relevant, including on the post -development map, as requested. Please
note that the access easement has been dedicated to a proposed Right -
of -Way that will dedicated prior to the conversion of the BMP from its
erosion control to final stage.
4. Provide supporting calculations to demonstrate that the two forebays sum to
15-20% of the main pool volume [MDC 5].
The staged storage elevations table of the calculations sheet has been
revised to include the storage volume of the forebays separately from the
total BMP, as requested. A copy of this sheet has been included
separately for quick reference.
5. Provide a trash rack on the riser [MDC 10].
As discussed in our e-mail correspondence on May 2, 2017, we concluded
that the slab top outlet control structure will serve as an acceptable
alternative to the standard trash rack.
6. Provide a site specific SCM planting plan. List the species, and show where on
the shelf each species should be planted [MDC 11].
A site specific planting plan has been included as part of the BMP detail,
PASDSKPROJ\4386\Submittals\2017\0605 - NCDEQ - Stormwater - 2nd Submittal\Documents\4386 - Afton Ridge Industrial - SVV3170503 -
Response to Comments - 06.07.17.docx

SW3170503 — Afton Ridge Industrial — Response to Comments
June 9, 2017
Page 2
Sheet C-910, as requested.
7. Please note that a permit modification will be required for the future phases of
the project.
Response noted.
Please let us know if you have any questions or require any further clarifications on the
enclosed submittal.
Best Regards,
Nicholas Vesely, EI
COLEJENEST & STONE, P.A.
sac
cc: Mr. Jon Wilson — CK
Mr. Landon Wyatt, III - CK
Mr. Joel Causey, PE, LEED Green Associate — CJS
P:\SDSKPROJ\4386\Submittals\2017\0605 - NCDEQ - Stormwater - 2nd Submittal\Documents\4386 - Afton Ridge Industrial - SVV3170503 -
Response to Comments - 06.07.17.doex