SW3210301_27842.0002 - Response Letter_20210602

M
. G
14THOMAS&HUTTON
020 EUCLID AVENUE
"""TTE, NC 28203 1 980.201.5505
WWW.TH0 MASAN MH UTTON.COM
June 1, 2021
Attn: Jim Farkas
NCDEQ - Division of Energy, Mineral, and Land Resources
512 N. Salisbury Street
1612 Mail Service Center
Raleigh NC 27699-1612
Re: Request for Additional Information
Stormwater Permit No. SW3210301
Cresswind - Phase 2
J-27842.0002
Union County
To whom it may concern:
This letter serves as acknowledgement that we have revised the previously submitted package to
address all comments below as follows:
It appears as though the Applicant, KH Wesley Chapel, -1-C, is also the Property Owner. If
this is the case, please change Section 111, 1 c of the Application to indicate that the
Applicant is the Property Owner (not the Developer).
Revised per comment.
2. Please do one of the following:
a. Please provide official documentation from KH Wesley Chapel, LLC indicating
that the Applicant, Mike McLendon, is able to sign on behalf of KH Wesley
Chapel, LLC (Section VI, 11). As discussed in an earlier email, since the
Secretary of State documentation does not list a company official by name
you will have to provide some other form of official documentation. If Mike
McLendon can sign on behalf of KH Wesley Chapel, LLC then the Property
Owner Authorization (Section IX) is not required and should be revised in the
Application.
Documentation for the authorized signatory of Mike McLendon to sign on behalf
of KH Wesley Chapel, LLC is included in this resubmission.
b. Please clarify the Applicant/Property Owner relationship and provide
official documentation for both the Property Owner, Robert A.
Rademacher, and Applicant, Mike McLendon.
Please refer to deeds provided in original submittal for proof of ownership.
3. Please show the drainage area to the proposed wet pond based on the current phase
being permitted (Phase 2). You are allowed to oversize this wet pond with the specific
intent to treat BUA that will be built at some future time (We can even put specific
language in the permit stating the maximum drainage area size and impervious area that
the wet pond can handle in the future), however what is currently being permitted must
meet all of the applicable requirements as a standalone project (Phase 2 should still be
able to meet all of the treatment requirements if, theoretically, Phase 3 never gets built).
What you are asking to have permitted (A wet pond that treats all of the impervious area

from Phase 2 and some of the impervious area from Phase 3) is not what is being
constructed per the submitted plans (An oversized wet pond that treats some of the
impervious area from Phase 2 and a diversion ditch that diverts part of the wet pond's
future drainage area around it). For clarity, you may want to show the " Phase 2" drainage
area to the wet pond and the "Phase 3" drainage area to the wet pond in the
Application (Section IV, 10) and in the Supplement-EZ Form (Or you can just oversize the
wet pond now, state your intentions to use this oversized wet pond to treat some future
BUA, and provide the future drainage area/sizing calculations when Phase 3 gets
submitted for approval). Let me know if you would like to set up a meeting to discuss this
further.
Stormwater Report has been revised to reflect this request.
NOTE: The following comments are based on what was provided in this submission,
they may or may not be applicable to the resubmission.
4. The proposed impervious area information (Section IV, 10) does not appear to be
correct. The sum of all of the individual types of BUA (1,224,710) does not add up to the
shown total BUA (1,319,710 sf). Based on the provided deed restriction document, the
BUA associated with lots appears to be too large or account for lots not included in this
phase of construction.
This section has been revised to reflect accurate BUA values.
Please provide calculations showing that all outlets are stable during the 1 0-year
storm (Section VI, 7).
Erosion control report has been included in this resubmission. Outlet protection
calculations are within this report.
The main pool is too small (Wet Pond MDC 1 b). The SA/DA tables relate the surface
area of the main pool (not the entire wet pond) to the drainage area. Per the
provided calculations, the minimum surface area of the main pool of the wet pond is
40,968 sf whereas only 38,860 sf are provided. NOTE: Table values should be
interpolated based on the actual average depth of the main pool and actual
percent impervious of the drainage area.
Pond size and calculations have been revised per comment.
7. The stage -storage table for forebay 2 appears to be incorrect. The cross -sectional
area at elevation 564 is smaller than the cross -sectional area at elevation 563.
Revised per comment.
8. The 4 ft wide weir at elevation 566.8 is located below the temporary poncling elevation
(approximately at elevation 566.99 per the provided stage -storage table (which is
different than the provided water quality elevation calculation)) and should be
accounted for in the drawdown equation (or, preferably, moved above the
temporary poncling elevation).
TPE elevation calculated using average end area method is 566.76 therefore the weir
has been set.24' above this elevation.
9. The following issues were noted with the Supplement-EZ Form:
a. Drainage Area Page:
i. Entire Site Column - This column should be an accounting of all of the

BUA located within the project area. This column would include and BUA
that is located outside of the drainage area to the SCM (Line 5 of this
column should show the entire site area since the entire site doesn't have
a "drainage area").
EZ Form updated to include additional column for Future SUB-01 C to
account for breakdown of future BUA.
Line 10 - These items should add up to Line 7 (since Line 10 is a
breakdown by type of the impervious area shown on Line 7), but it
does not.
Revised per comment.
b. Wet Pond Page:
i. Line 25 - This value (565.51) differs from the water quality elevation
calculation (565.71) and the value interpolated from the provided
stage- storage table (approximately 566.99). This value should be
based on the design volume.
TIRE elevation calculated using average end area method is 566.76.
Line 25 has been updated to reflect this calculation.
ii. Line 28 - This value (2.89) appears to be calculated incorrectly (Average
depth calculation is only for the main pool) in the calculations and must
be greater than 3.0 ft per Wet Pond MIDC 2.
Revised per comment.
10. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and I hardcopy of
other documents.
a. Pdfs must be uploaded using the form at:
httips://edocs.deg.nc.gov/Forms/SW Proiect Submittal
b. Hard copies must be mailed or delivered to the following address:
Jim Farkas
512 N. Salisbury Street
1612 Mail Service
Center Raleigh, NC
27699-1612
We look forward to receiving the approved certification for the referenced project to
allow us to proceed. If you have any questions, comments, or desire additional information, please
contact our office at [phone].
Sincerely,
THOMAS & HUTTON
Matthew S. Kiker, PE
MSK