SW3220306_Add Info_20220922

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ROY COOPER
Governor
ELIZABETH S.BISER
Secretary *Eaf QUAMNVEw x
BRIAN WRENN NORTH CAROLINA
Director Environmental Quality
September 22, 2022
LandDesign, Inc.
Attn: Frank McMahan, PE
223 North Graham Street
Charlotte, NC 28202
AND
Lennar Carolinas, LLC
Attn: Mark Henninger, Division President
PO BOX 748
Charlotte, NC 28226
Subject: Second Request for Additional Information
Stormwater Permit No. SW3220306
Preserves at Forest Creek,Phase I
Union County
Dear Mr. McMahan and Mr. Henninger:
The Division of Energy, Mineral and Land Resources (DEMLR), received additional
information for a Stormwater Management Permit Application for the subject project on June 24,
2022. A review of that information has determined that the application is not complete. The
following information is needed to continue the stormwater review:
1. Prior Comment La.ii— "Offsite portions of the drainage area to an SCM must be
accounted for at their full build-out potential(15A NCAC 02H.1003(3)(b))..." Updated
SCM sizing calculations do not appear to have been provided (taking into account the more
impervious drainage areas. Please provide the updated SCM sizing calculations based on the
most recent SCM drainage area information.
2. Prior Comment 1.a.iii.1 — "Supplement-EZ Form, Wet Pond Page, Line 2..." As indicated
above, the minimum required treatment volumes do not appear to be recalculated based on
the most recent drainage area information. For example, Wet Pond 1 shows a minimum
required treatment volume of 18,580 cf(taken from the March 16, 2022 submission
calculations)but calculating the minimum required treatment volume for this SCM based on
the most recent DA information (Drainage Area=491,598 sf, Impervious Area= 302,101 sf)
results in a minimum design volume of approximately 24,700 cf(%BUA = 61.5%, Rv =
North Carolina Department of Environmental Quality I Division of Energy,Mineral and Land Resources
512 North Salisbury Street 1 1612 Mail Service Center I Raleigh,North Carolina 27699-1612
NORTH CAROLINA _
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0.603, Volume z 24,700 cf), this issue is also present with the other SCMs. Please revise as
needed. NOTE: Revised sizing calculations were provided for Wet Pond 6 in the revised
calculation booklet (Revised June 2022), however, they indicate that the drainage area to this
SCM is 8.31 ac (z361,980 sf) and that the impervious are within this drainage area is 2.49 ac
(z108,460 sf). These calculations were not reviewed since they do not appear to be related to
the drainage area information for Wet Pond 6 as shown in the other submittal documents
(Drainage Area= 291,243 sf&Impervious Area=259,543 sf).
3. Prior Comment 1.a.iii.3— "Supplement-EZ Form, Wet Pond Page, Line 26..." The main
concern with the original comment appears to be addressed, however, there still appears to be
issues with the information shown for Wet Ponds 2, 3, 5, & 6. For example, the form shows
the surface area of the main pool at the permanent pool elevation for Wet Pond 2 as 6,076 sf
while the provided stage-storage tables indicate 6,266 sf. This issue is also present with the
other noted SCMs. Please revise as needed.
4. Prior Comment l.a.iii.4— "Supplement-EZ Form, Wet Pond Page, Line 27..." Similar to
the prior comment, the original comment appears to be addressed, but there still appear to be
issues with the values shown for Wet Ponds 2, 3, 5, & 6. For example, the form shows the
permanent volume of the main pool for Wet Pond 2 as 19,756 cf while the provided stage-
storage tables indicate 20,418 cf. This issue is also present with the other noted SCMs. Please
revise as needed.
5. Prior Comment 2— "It appears as though some of the plans... are not signed(Section VI,8
and 15A NCAC 02H.1042(2)(g)). Please provide signed copies of the applicable plans."
Please provide 2x hard copies and I electronic copy of signed plan sheets C104, C 200,
C208, C500-506, & C708-713. These items were not provided with the prior submission.
6. Prior Comment 4— "Please ensure that the SCM maintenance access and easements are
sufficiently large to allow for access and maintenance to the entire SCM(General MDCs 8 &
9)..." The SCM maintenance access and easements do not appear to include the entire SCM
systems, most of the outlet structures and emergency spillways are not included within the
easement. Please revise as needed. The entire footprint of the SCM system must be included
in the access and maintenance easement, plus an additional 10 ft or more (25 ft is
recommended for wet ponds due to the nature of their maintenance requirements) around the
SCM to provide enough room to complete maintenance tasks. This SCM system includes the
side slopes, forebay, riser structure, SCM device, and basin outlet, dam embankment, outlet,
and emergency spillway.
7. Prior Comment 7.d.i— "Please correct the following issues with the Application, Section
IV, 10—Please ensure that the off-site portions of the drainage areas are accounted for."
The off-site drainage area information for Wet Pond 6 does not appear to be correct, the off-
site drainage area is shown as 58,500 sf and the off-site BUA is shown as 95,929 sf. Please
revise as needed.
8. Prior Comment 8.b.i.1 — "Please correct the following issues with the Supplement-EZ
Form, Drainage Area Page, Lines 7, 5, & II..." As noted above, please revise the off-site
drainage area information for Wet Pond 6 as needed. Please also remove the off-site

components from the Entire Site Column (The entire Site Column is not a summation of the
values shown in the other columns, but rather an accounting of the entire site).
9. Prior Comment 8.b.ii.1 — "Please correct the following issues with the Supplement-EZ
Form, Drainage Area Page, Entire Site Column..." As noted above, the Entire Site Column
is an accounting of the entire project area (similar to how the drainage area columns are an
accounting of the drainage areas), not just a sum of the drainage area columns. All BUA
located on-site (whether it drains to an SCM or not) should be included in this column. There
are typically no off-site components to the Entire Site Column (since off-site areas are not
part of the entire site). Please refer to the other comments to address issues with Lines 5-8,
11, & 18 of this column.
10. Prior Comment 8.b.ii.2— "Please correct the following issues with the Supplement-EZ
Form, Drainage Area Page, Entire Site Column, Lines 5-7..."
a. Line 5 —The "total drainage area" of the entire site is equal to the project area. The value
shown here (4,836,757 sf z 111.04 ac) does not correspond to the project area as shown
in Section IV, 7 of the Application (101.65 ac). Please revise as needed.
b. Line 6—The "on-site drainage area" of the entire site is equal to the project area. The
value shown here (4,569,900 sf z 104.91 ac) does not correspond to the project area as
shown in Section IV, 7 of the Application (101.65 ac). Please revise as needed.
c. Line 7 —The "off-site drainage area" of the entire site is equal to zero since there are no
areas that are both part of the entire site and not located on-site. Please revise as needed.
11. Prior Comment 8.b.ii.3— "Please correct the following issues with the Supplement-EZ
Form, Drainage Area Page, Entire Site Column, Line 18..." This item (44%) should
correspond to Section IV, 8 of the Application (47.8%). Revise either as needed. Information
about calculating project density can be found in 15A NCAC 02H .1003(1).
12. Prior Comment 9.a— "Provide PDFs of all revisions..." Electronic files from the June 24,
2022 submission were not uploaded through the online portal. Please provide these files in
addition to the files needed to address these comments.
13. Wet Pond 3 —As designed, Wet Pond 3 does not appear to have a sufficiently large main
pool surface area(Wet Pond MDC 1). Per the provided drainage area information,
the %BUA for the drainage area is 67.3% and the average depth of the main pool is
calculated as 3.2 ft. This results in an SAMA table value of approximately 2.32%
(interpolated) which results in a minimum required main pool surface area of approximately
25,940 sf while only 19,510 sf of surface area is provided. Please revise
14. Wet Pond 4—The lowest bypass weir for this pond is located at elevation 586.35'.
Interpolating the storage volume that is provided by the temporary pool at this surface water
elevation results in 29,236 cf of storage. The minimum required storage volume for this Wet
Pond is approximately 33,700 cf. Please ensure that at least the minimum design volume for

this pond can be stored between the permanent pool and the lowest bypass weir (General
MDC 1).
15. Please correct the following issues with the Application:
a. Section IV, 10, Drainage Area 4—The % Impervious Area value (46.4%) does not appear
to be correct. Please revise as needed.
b. Section IV, 10, Drainage Area 6—As mentioned above, please revise the off-site
drainage area information as needed.
c. Section VIII— Since Mason Greeson is no longer associated with the project, please
update this information.
16. Please correct the following issues with the Supplement-EZ Form:
a. Cover Page:
i. Line 2—The project area information (105.5 ac) should correspond to the project area
as shown in Section IV, 7 of the Application (101.65 ac). Please revise as needed.
ii. Lines 27-32—Please update this information as needed.
b. Drainage Area Page:
i. Drainage Area 6, Lines 7 & 11 —Revise as needed in accordance with other
comments.
ii. Entire Site Column, Lines 5-8, 11, & 18 —Revise as needed in accordance with other
comments.
iii. Line 20—Revise as needed in accordance with other comments.
c. Wet Pond Page:
i. Lines 2, 26, 27, & 35 —Revise as needed in accordance with other comments.
ii. Line 25 —The temporary pool surface elevation is typically equal to the invert
elevation of the lowest bypass weir in the pond outlet structure
iii. Line 32—The forebay volume values for Wet Ponds 2, 3, 5, & 6 do not appear to
match the information provided in the stage-storage tables. For example, the form
shows the permanent volume of the forebay pool for Wet Pond 2 as 4,641 cf while the
provided stage-storage tables indicate 3,999 cf. This issue is also present with the other
noted SCMs. Please revise as needed.
iv. Line 42—There do not appear to be berms or baffles added to these ponds to increase
the flow path (berms added to separate the forebay from the main pool do not count
for this, this item is asking if there are any berms/baffles added to the pond design to
increase the flow path from the inlet to the outlet).
17. 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.
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:
Jim Farkas
512 N. Salisbury Street, Office 640E
Raleigh, NC 27604
ii. For LISPS:
Jim Farkas
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.
NOTE: Per Division policy, the next review of this application will be the final review. Failure
to provide the requested information will result in the project being returned as incomplete. The
return of a project will necessitate resubmittal of all required items, including the application fee.
While it is not required, it is recommended that the off-site drainage from upstream properties be
diverted around the SCM since the Applicant cannot maintain control over the development of
property that they do not own. If the Applicant elects to account for off-site drainage, it must
either be accounted for at 100% BUA (its full build-out potential) or there must be a recorded
legal agreement in place between the Applicant and the Owner of the upstream property in which
the Owner of the upstream property agrees to record a deed restriction limiting the
minimum/maximum amount of BUA on the upstream property that will be treated in the
Applicant's SCM, the locations and sizes of access and drainage easements, how construction
and/or ongoing maintenance costs will be handled, maintenance responsibility, a list of legal
recourses available to each party should one party fail to hold up their end of the agreement, and
any other related legal issues.
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 22,2022, 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 SW3220306 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 90 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,
v-"I
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Mooresville Regional Office