SW5240102_Response To Comments_20240423

Gettle Engineering and Design, PLLC
3616 Waxwing Ct.
Wake Forest, NC 27587
NC License P-2538
919.210.3934
April 17, 2024
Brianna Holland
Environmental Engineer
North Carolina Department of Environmental Quality
512 N. Salisbury Street, Office 640E
Raleigh, NC 27604
Subject: Project Name: Jeffery Way Commercial
Stormwater Permit No. SW5240102
County: Franklin
City: Youngsville
As noted in the attached Request for Additional Information Letter, dated April 11, 2024, the
following responses to comments are noted below.
Application
a. Section III, 2-Since the property owner is also the applicant, this should not be filled out. With
your permission, I can cross out the original signature on the provided hard copy, however,
you should revise the electronic copy of the form.
Response: You have our permission to cross out the original signature as requested.
Confirm the address of the property owner, as 9000 Creedmoor Rd and 900 Creedmore Road
were listed as the address in Section III 1 and III 2.
Response: 9000 Creedmoor is correct and revised on the PDF copy.
b. Section IX- Since the property owner is also the applicant, Section IX should not be filled out.
With your permission, I can cross out the original signature on the provided hard copy,
however, you should revise the electronic copy of the form.
Response: You have our permission to cross out the original signature as requested.
c. Section III, 4 - Provide the point of contact and phone number for the local jurisdiction as
requested.
Response: The Franklin County point of contact is listed with phone number on the
application.
Plans
a. There appears to be an error on the provided vicinity map and plan sheets. Per Franklin
County GIS maps, the road appears to be"Jeffery Way" instead of"Jeffrey Drive". Per 15A
NCAC 02H .1042(2) (e), a location map with street names and SR numbers to the nearest
intersection, with 1, 2, or 3 digit road numbers, legend, and north arrow is required.
Response: The name has been modified, and NCDOT SR numbers are listed. However,the
roadway along the front of the project is considered private, and is not in the NCDOT
Gettle Engineering and Design.PLLC. 3616 Waxwing Ct.,Wake Forest. NC 27587. [phone]. NC License P-2538 Page 1 of 3

system.
b. Per Section VI, 8n,o of the Application, delineated drainage areas on the main set of plans are
required. It is noted that erosion control drainage areas have been provided, but the existing
drainage and post construction drainage areas need to be delineated so that off-site drainage
area may be verified, and the total drainage area directed to the SCM may be confirmed.
Response: The pre-development and post development maps (EX1 and EX2) have been
included in the plan set.
c. The information shown in the Application, Supplement-EZ Form, and calculations should be
verifiable on the plans in the field without the use of a computer. You may wish to add a BUA
table to the plans or provide additional dimensions for easier verification of BUA. Notably, it is
currently unclear if the gravel area shown on the plans is being accounted for as BUA. 15A
NCAC 02H .1042(2) (g) (v)
Response: The summary areas (BUA and gravel) are noted on the cover sheet.
d. Provide dimensions, side slopes, and elevations on the cross section/plan view detail per
15A NCAC 02H.1042 (2) (h).
1. Include elevations such as: lowest excavated
n. point of the bioretention cell, top of planting surface, bypass elevations, top of
riser structure, peak attenuation outlet, top of internal water structure, cleanout pipes, and media.
Response: Additional info as requested noted on the Bio detail sheet (D5).
e. Revise the media mix per Bioretention Cell MDC 6: The media shall be a homogeneous
engineered media blend with approximate volumes of:
(a) 75 to 85 percent medium to coarse washed sand (ASTM C33, AASHTOM
6/M80, ASTM C330, AASHTO M195, or the equivalent);
(b) 8 to 10 percent fines (silt and clay); and
(c) 5 to 10 percent organic matter(such as pine bark fines)
Response: Additional info as requested noted on the Bio detail sheet (D5).
f. It is unclear weather the outlet of the SCM is connecting to a system or is daylighting.
Response: The discharge is daylighting and a rip rap apron added.
Demonstrate that the outlet of the Bioretention Cell does not cause erosion in the 10-year storm
per General MDC 4.
Response: the Q10 discharge is approximately .068 cfs.
Calculations
a. Per 15A NCAC 02H .1003(5), demonstrate that stormwater outlets(of the site) are designed
so that they do not cause erosion downslope of the discharge point during the peak flow from
the 10-year storm event as shown by engineering calculations.
Response: Calculations noted in the stormwater report noting the design of the rip rap
apron as previously noted.
b. Please provide calculations showing that a drawdown rate of at least 1 inch per hour can
be maintained through the media and underdrains at the planting surface
Gettle Engineering and Design.PLLC 3616 Waxwing Ct..Wake Forest. NC 27587, [phone]. NC License P-2538 Page 2 of 3

(Bioretention MDC 9).
Response: Calculations sizing the underdrain system for drawdown is noted in the
stormwater report.
c. This project drains to Richland Creek which is classed as a NSW in the Neuse River Basin.
Ensure compliance with the Neuse Nutrient Strategy 15A NCAC 02B .0711
( 5) by demonstrating nutrient treatment
Response: Snap Tool included in the resubmittal (stormwater report)and the nitrogen target
rate is met.
4 Ensure consistency across the package. In the Application Section IV, 10, it is noted that
89,733.6 SF (2.06 acres) is being treated by the SCM, but the provided calculations indicate that
the drainage area to the SCM is 1.75 acres.
Response: Drainage to the SCM is 1.60 acres and noted in the stormwater report.
5. A Supplement-EZ does not appear to have been provided, and therefore could not be
reviewed at this time. Provide Ix hard copy and one electronic copy of the complete, original signed
Supplement-EZ Form (This item is required per Sections V& VI, 3 of the Application). This form
can be found on our website at the following
address: https://deq.nc.gov/about/divisions/energy-mineral-and-land-
resources/stormwater/stormwater-program/stormwater-design. Please note that a complete
Supplement-EZ form will have 3 or more pages and uses macros to generate the relevant sheets
based on the information entered into the cover page. It appears that a bioretention cell
supplement document may have been submitted in lieu of the Supplement-EZ form, but a complete
Supplement-EZ from the provided link must be provided. Ensure that any calculations for items
requested in the Supplement-EZ are provided so that the values can be verified.
Response: EZ form included in the resubmittal.
6. Please provide a Response to Comments letter indicating, in a point-by-point manner, how
each of the above comments has been addressed. This item is required per 15A NCAC 02H
.1042(3)(b).
Response: Letter provided.
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.
Response: Noted copies submitted.
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Please advise if further information is required. ff • s;Q.. -v -%
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Sincerely = 030913
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Keith P Gettle, PE ''� �k P.G� •\
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