SW5210202_Add Info_20210310

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
BRIAN WRENN
Director
Kim Denton, County Manager
113 Market Street
Louisburg, NC 27549
NORTH CAROLINA
Environmental Quality
March 10, 2021
Subject: Request for Additional Information
Stormwater Permit No. SW5210202
Franklin County E911
Franklin County
Dear Mr. Hall:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on February 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 fill out the Consultant Information and Authorization (Section VIII of the
Application). Normally, this Request for Additional Information letter is sent directly to
the engineer/consultant since it is fairly technical and deals with the design of the
proposed Stormwater Control Measure (SCM), but since no consultant was authorized to
answer questions on the Applicant's behalf, it is being sent to you, the Applicant. If you
do not wish to designate an engineer/consultant to provide information on your behalf,
please let me know. Blake Hall from Timmons Group is being Cc'd in the Request for
Additional Information email since his contact information is listed in Section III, 3 of
the Application. The remaining comments are listed in the order in which they appear in
the Application with design specific comments at the end.
2. Per the included USGS topo map, there appears to be a surface water (blue line stream)
located within the project area (Section IV, 6-8). Please include this surface area (area
between the banks) in the Application and recalculate the project area and percent
impervious area. Please also callout the surface water area in the main set of plans
(Section VI, 8h).
3. The drainage area shown in Section IV, 10 should only include the drainage area to the
proposed SCM, not the entire study point.
DNorth Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources
EQ
_ 512 North Salisbury Street 11612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA
Department oiEnvironmental aum� 0 ` 919.707.9200

4. Please show the drainage area to the proposed SCM in square feet, not acres (Section IV,
10).
5. The "Proposed Impervious Area" line of the table in Section IV, 10 should include all of
the on -site and existing BUA (It should match the "Total" from the "Impervious Surface
Area" portion of the table).
6. Please use the latest versions of the Supplement-EZ Form and O&M Agreement Form.
These forms can be found at the following location:
hgps://deq.nc. gov/about/divisions/energy-mineral-land-resources/enemy-mineral-land-
permit-guidance/stormwater-bmp-manual (Sections V & VI, 3).
NOTE: Both forms require original signatures.
7. Please provide calculations showing that the inlet and outlet for the proposed SCM are
protected from erosion (Section VI, 7 & General MDC 4).
8. Please dimension the project boundary with bearings and distances (Section VI, 8i). This
information should be shown in the main set of plans.
9. Please identify and dimension all of the BUA for this project (Section VI, 8j). This
information should be shown in the main set of plans. The information shown in Section
IV, 10 of the Application and on the Drainage Area page of the Supplement-EZ Form
should be verifiable on the plans (without the use of CAD or other computer program).
You may wish to include a BUA summary table similar to the one in Section
IV, 10/Supplement-EZ Form.
10. Please show the drainage area to the proposed SCM (Section VI, 8o). This information
should be shown in the main set of plans.
11. Section IX should only be filled out/completed if the Property Owner is designating some
other entity (such as a Lessee, Property Purchaser, or Developer) to become the
Applicant. If the Property Owner is also the Applicant (as indicated by Section III, 1c),
then Section IX should be left blank and Section X should be completed. If this is not the
case, please revise the Application to reflect the Developer as the Permittee.
12. As designed, the proposed wet pond does not have a sufficient average depth (Wet Pond
MDCs 1 & 2). The SA/DA sizing method, as outlined in Part C-3 of the Manual is used
to determine the minimum size of the main pool, not the entire permanent pool. Even
though the berm separating the forebay from the main pool is below the permanent pool
elevation the portion of the permanent pool above the forebay is not considered to be part
of the main pool (See attached drawing for clarification). Generally, we recommend that
the berm separating the forebay from the main pool is at or above the permanent pool
elevation (You can add a connection weir at or below the permanent pool elevation). This
is not an MDC requirement, but it is helpful for maintenance and will make the proposed
gate valve more accessible (It also eliminates the confusion as to the forebay/main pool
distinction line).

13. The forebay inlet invert (-249') should be at a lower elevation than the lowest connection
elevation between the forebay and main pool (-248.5') (Wet Pond MDC 5b). This helps
reduce the amount of suspended solids that enter the main pool. It should be noted that
the forebay inlet invert should not be so low as to resuspend sediment.
14. The plans (Plan sheet L1.0, possibly others) and the stormwater report (Hyrdaflow)
reference a bioretention cell as the SCM for this project whereas the calculations
reference a wet pond. Please revise the submission items to eliminate ambiguity.
15. The planting plan as shown on the plans does not match the planting plan as shown in the
stormwater report/calculations. Please revise for consistency.
16. 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:
hgps://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
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 April 9, 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 SW5210202 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