SW5210303_Add Info_20210430

ROY COOPER
Governor
DIONNE DELLI-GATTI
Secretary
BRIAN WRENN
Director
Matt Lowder, PE
4004 Barrett Drive, Suite 101
Raleigh, NC 27609
NORTH CAROLINA
Environmental Quality
April 30, 2021
Subject: Request for Additional Information
Stormwater Permit No. SW5210303
Burlington Park Apartments — Phase 1
Franklin County
Dear Mr. Lowder:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on March 15, 2021. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
Please clarify the project area (Section IV, 4-10). The project area can be the Phase 1
area, the limit of disturbance, the property area or some other defined area, but it should
be consistent throughout the submission. For example, the project area in Section IV, 7 is
13.99 acres, whereas the project area is 8.99 acres on the Supplement-EZ Form. Revise as
needed.
2. The drainage area information for the proposed wet pond should be based on what is
currently being permitted, not the ultimate plan for the property (Section IV, 10). The
reason for this is that what is currently being permitted should be permittable as a
standalone project (in the event that the future phases of the project do not get built). You
are allowed to oversize the proposed wet pond in anticipation for future phases (we can
even add specific language in the permit stating the maximum drainage area and BUA
that can ultimately drain to the pond), but the calculations should reflect what is currently
being permitted. Future BUA is typically reserved for BUA that will be added within the
drainage area to the SCM, not to account for increased areas draining to the SCM
(Changes to the SCM drainage area require a permit modification and review).
3. The drainage area information (Section IV, 10) shows 25,797 square feet of off -site
drainage area but does not include any off -site built upon area. Please either revise or
provide justification in accordance with 15A NCAC 02H .1003(3)(b).
D E Q�� 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 OAROLINA _
Depar ntofEnvimnmmdlDoellry 919.707.9200

4. Please provide documentation for how the off -site drainage area was determined. It is
recommended to divert any off -site drainage areas not owned by the permittee around the
proposed SCM since off -site drainage areas must be accounted for at their full build -out
potential (please refer to note about off -site drainage areas following these comments).
NOTE: If the project area will be a subset of the property area, any portion of the
drainage area that is located on the property, but not within the project area would be
considered "off -site".
5. Please identify and dimension all BUA in the main set of plans (Section VI, 8j). The
information shown in the Application and Supplement-EZ Form 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.
6. Please delineate the drainage area to the proposed SCM in the main set of plans (Section
VI, 80).
7. This project is located within a Nutrient Sensitive Watershed (NSW). Please ensure that
SCMs that reduce nutrient loading (in accordance with 15A NCAC 02H .1017(9)(c)) are
being used.
8. The Phase 1 boundary should be expanded to include the entire proposed wet pond (It's
not against the rules to do what is being proposed, it just makes permitting the SCM more
difficult if the SCM is located off -site).
9. Please provide an emergency spillway, or some other mechanism, for the proposed wet
pond to handle extreme storm events (General MDC 5). Uncontrolled overtopping of the
pond embankment can cause it to fail catastrophically.
10. Please provide the surface area of the vegetated shelf so that Wet Pond MDC 1 lb can be
verified.
11. Supplement-EZ Form, Wet Pond Page, Line 34 — The forebay cleanout depth is the
distance from the permanent pool elevation (380') to the top of the sediment storage
elevation (377'). Based on the provided design, this value appears to be 36" (This
matches the cleanout depth shown in the O&M Agreement Form).
NOTE: Aside from the earlier comments, the proposed wet pond is designed correctly
for the provided drainage area. However, as mentioned earlier, the drainage area used in
the Application and calculations should be based on what is currently being permitted.
The calculations will need to be re -done using the correct drainage area information for
this phase of construction. The Drainage Area page of the Supplement-EZ Form was not
reviewed.
12. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcopy of other
documents.

a. Pdfs must be uploaded using the form at:
https://edocs.deq.nc.gov/Forms/SW—Project 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
While it is not required, the following items are recommended:
- 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 its full build -out potential (typically 100% BUA) per 15ANCAC 02H .1003(3)(b),
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.
- The maintenance access be widened to 25 feet to accommodate the larger equipment
typically needed for wet pond maintenance.
- It is recommended to look into the possibility of using an SCM that is more well suited to
the site since the underlying soils are well -drained, HSG B soils.
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 May 31, 2021, 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 SW5210303 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 [phone].
Sincerely,

)elfM4�
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Raleigh Regional Office