SW6240205_Response To Comments_20241016

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10-16-2024
ROY COOPER (( , : (i To: Brianna Holland
Governor �3 ■,4: O'
ELIZABETH S.BISER �,;�,, a?f
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Secretaryf�owMvuE°__-
"� - I have reviewed these comments below and
WILLIAM E.TOBY VINSON,JR NORTH CAROLINA have provided responses in blue along with
Interim Director Environmental Quality revised forms, drawings, and supporting
calculations. Please call me on my cell if you
September 18, 2024 have any questions or need additional
information.
Crawford Design Company •
Attn: Kevin Lindsay, PE / -414b
116 N. Cool Spring Street Kevin S. Lindsay, PE
Fayetteville,NC 28301 [e-mail]
Cell: 910-920-7661
AND
Hoke County Board of Education
Attn: Kenneth Spells, Superintendent
310 Wooley Street
Raeford,NC 28376
Subject: Request for Additional Information
Stormwater Permit No. SW6240205
Hoke County High School Replacement
Hoke County
Dear Mr. Lindsay and Mr. Spells
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on February 20, 2024. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
1. Calculations must be signed, sealed, and dated, the revised calculations are missing this
(Required per Section VI, 7). Revised calculations have been sealed.
2. Previous Comment: When determining the SHWT elevation or in-situ infiltration rate for
an SCM with multiple provided borings, do not average the measured values, but rather
use the more conservative of the values form the borings. For example, if there are two
borings for an SCM and boring#1 indicates that the SHWT is at elevation 99'and boring
#2 indicates that it is at elevation 101'the SHWT should be assumed to be at elevation
101', not at elevation 100'. Please revise as needed. Revise the Supplement-EZ
accordingly. Higher SHWT values were used,but note on narrative was not changed. Note has been changed.
3. Previous Comment: Please correct the following issues with the Supplement-EZ Form:
a. Cover Page:
i. Line 7-Please include the width of the vegetated setback from surface waters
required per 15A NCAC 02H.1017(10). It is noted that there are no surface
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waters located on-site, however we ask that this value be included on this form
(Lines 8 & 9 can remain as "N/A"to indicate that there are no surface waters
located on-site). Width has been added.
b. Drainage Areas Page:
i. Line 15/Line 22—Please indicate (at least for the entire site column) the amount of
existing BUA that will remain on-site (it does not matter if it will be relocated or
changed from one type of BUA to another). It is understood that this form isn't
really well suited for showing the BUA accounting for projects that are mostly
redevelopment, so if you want to,you can just include the amount of existing BUA
for the entire site in the additional information box (and leave the columns as final
BUA allocations by type for each DA/the entire site).Form revised accordingly,also see design calcs.
forbreakdown by watershed of BUA.
ii. Entire Site Column, Line 18 & Section IV, 8 of the Appication— ease note that,
for a site with existing BUA, the existing BUA may be excluded from the project
area percent BUA calculation per 15A NCAC 02H.1003(1)(b). [Percent BUA]=
[Net Increase in BUA]/([Total Project Area]—[Existing BUA]). Please revise if
needed. Form revised accordingly,also see design calcs.
for breakdown by watershed of BUA.
c. Bioretention Cell Page:
i. Line 2— The minimum required treatment volume is calculated using either the
Simple Method or Discrete Runoff Volume Method for the area draining to the
SCM. For example, if the DA to an SCM is 3.37 ac and the BUA draining to the
SCM is 2.11 ac, then, using the Simple Method, the minimum required treatment
volume would be 7,505 cf[DV= Rd*Rv * DA * 3630= 1.0" * (0.05+ 0.9*(2.11
ac/3.37 ac)) * 3.37 ac * 3630= 7,505 c . Please revise as needed.
ii. Line 9—See earlier comment. Norm revisedaccordingly,also see design calcs.
for breakdown by watershed of BUA.
iii. Line 24— The peak attenuation elevation over the planting surface would be
measured from the planting surface (251.0) to the highest ponding elevation
associated with the design storm (for the 100-year storm for SCM 1, the plans
show this value as 252.2). Please revise as needed(it is unclear where the
provided values came from). SCM 1 has been raised 0.4'to ensure 2'of separation.
iv. Please revise the information on the other lines as needed in accordance with the
other comments.
A revised Supplement-EZ was not provided for review. Revised Supplemental is attached.
4. Please correct the following issues with the design of the bioretention cells:
a. Previous Comment: General MDC 6—Per the Supplement-EZ Form, the dewatering
method is listed as drawdown orifice, however the detail does not indicate a
drawdown orifice capable of dewatering the SCM. Please revise as needed. To
provide clarification, this is to completely dewater the entire SCM (instead of setting
the permanent pool). A pump (recommended) or drawdown orifice located at the
bottom of the SCM is typically utilized to achieve this.
SCM 1 can be drained by unscrewing the caps at the base of the upturned TEE which will gravity flow out of
the 18"outlet pipe. SCM 2 will require a pump to be connected to the pipe after unscrewing the cap to
totally drain the SCM. There are at least two drain lines running to the riser for each SCM.w

5. 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). The responses shown here are intended as the response.
6. 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. Provided
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:
Brianna Holland
512 N. Salisbury Street, Office 625Y
Raleigh,NC 27604
ii. For USPS:
Brianna Holland
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.
To ensure a fair, timely, and transparent review process, any disagreement with provided
comments will need to be addressed in writing as part of the requested information resubmission,
within the required resubmittal window. The merits of the disagreement will be reviewed during
the next scheduled technical review and, if applicable, will be addressed in further requests for
additional information. If the resolution provided by the reviewer is found to be unsatisfactory,
the applicant can agree in writing to a longer review period, during which the dispute will be
brought to the technical review committee and a final determination will be made.
Due to staffing limitations and to ensure an efficient project review, requests for individual
meetings to discuss provided comments are decided at the discretion of the reviewer. We
encourage you to carefully review the written feedback provided and the applicable rules. The
NCDEQ Stormwater Design Manual provides additional insight into design criteria. Any
questions or further requests for clarification should be submitted in writing in the requested
information resubmission, within the required resubmittal window. We appreciate your
understanding and cooperation in this streamlined process.
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 October 18,2024, 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 SW6240205 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 30 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(919) 707-3646.
Sincerely,
Brianna Holland
Stormwater Engineer
DEMLR Post-Construction Stormwater Program
cc: Fayetteville Regional Office