SWA000058_Add Info_20191018

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Shad Walters, PE
3701 Arco Corporate Drive, Suite 400
Charlotte, NC 28273
NORTH CAROLINA
Environmental Quality
October 18, 2019
Subject: Request for Additional Information
Stormwater Permit No. SWA000058
Project Cure
Catawba County
Dear Mr. Walters:
The Division of Energy, Mineral and Land Resources (DEMLR), received an Authorization to
Construct (ATC) Permit Application for the subject project on September 26, 2019. A review of
that information has determined that the application is not complete. The following information
is needed to continue the stormwater review:
Please fill out Section D4 of the application since the applicant is not the property owner.
You do not need to resubmit an entirely new, signed application, just provide the
corrected sheet.
2. The forebay is larger than 20% of the main pool (Wet Pond MDC 5). Despite the fact that
the top of the spillway separating the forebay from the main pool is six inches below the
permanent pool elevation, the forebay volume is calculated all the way up to the
permanent pool elevation. Based on the provided stage storage tables, it appears that the
surface area of the forebay at elevation 883.5 is 7,719 sf (32,662 sf — 24,943 sf), which
yields a volume of about 20,000 cf.
3. There is a small section of proposed BUA at the intersection of Lutetium Circle and
proposed Trivium Parkway that does not drain to the SCM. Per 15A NCAC 02H .1002
(43), "...the volume of stormwater runoff generated from all of the built -upon area of a
project at build -out during a storm of the required storm depth is treated in one or more
primary SCMs..." Please ensure that this BUA is directed to an SCM. If this cannot be
done, the Division reserves the right to allow projects to not meet the above requirement
if the applicant can "demonstrates that the project provides equal or better stormwater
control and equal or better protection of the waters of the State ..." [15A NCAC
02H .1003 (6)(b)]
D EQ 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 _
o.PaWnamofEnvironmental Quality /� 919.707.9200

4. The side slopes on the embankments of the SCM are too steep (General MDC 3). If you
would like to keep the side slopes as -is, please provide calculations showing that the soil
and vegetation will remain stable. NOTE: The 3:1 side slope rule only applies to the parts
of an SCM that are above the permanent water surface elevation.
5. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcopy of other
documents. Pdfs must be uploaded using the form at:
hgps://edocs.deq.nc.gov/Forms/SW Project Submittal
While it is not required, it is recommended that:
- The maintenance access be widened to 25 feet since wet ponds maintenance tends to
require larger equipment than other SCMs.
- The "Pre BMP Wetpond" CN sheet be checked for accuracy since the total drainage area
value does not equal the sum of the subareas and the composite curve number is larger
than either of the curve numbers used for the subareas.
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 November 17, 2019, 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 SWA000058 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 Authorization to Construct (ATC) 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 [phone].
Sincerely,
V "I
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Mooresville Regional Office