SW6190504_AddInfoRequest_20190627

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Blair Pittman, PE
Bobbitt Design Build, Inc.
600 Germantown Road
Raleigh, NC 27607
NORTH CAROLINA
Environmental Quality
June 27, 2019
Subject: Request for Additional Information
Stormwater Permit No. SW6190504
Hoke County Cooperative Extension Office
Hoke County
Dear Blair Pittman:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on May 17, 2019. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
The Supplement EZ form states that the elevations of the seasonal high water table for
infiltration basins one and two are 245 and 241 respectively. These numbers appear to be
calculated using information from borings that occurred outside of the infiltration areas.
The submitted geotechnical evaluation states on Pages 8-9 that the seasonal high water
table was indicated at 3-3.5 feet below the existing ground surface. Based on the existing
conditions survey and the boring locations indicated in Figure 1 of the geotechnical
report, this indicates that the seasonal high water table in the area of the proposed
infiltration basins is significantly higher than shown in the Supplement EZ form and the
required 2 foot separation will not be achieved (Infiltration MDC 2).
2. Please provide calculations that show that the inlet and outlet protection for the SCMs is
sufficient to prevent erosion during the 10-year storm (General MDC 4).
3. Please add a detail of the spillway for infiltration basin one and a cross sectional detail
showing the flared end section outlet for infiltration basin two. These details should show
the proposed design and elevations.
4. The Supplement EZ form lists the drain time for both infiltration basins to be 4 hours. No
calculations were submitted to confirm this. Please provide these calculations and update
the Supplement EZ form as required.
D EQ �� North Carolina Department of Environmental Quality Division of Energy, Mineral and Land Resources
512 North Salisbury Street 1 1612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA
Depadm.mofEnmmnm.maaualfty /� 919.707.9200

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:
hqps:Hedocs.deg.nc.gov/Forins/SW ProjectSubmittal
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 July 26, 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 SW6190504 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
Corey.Anen&ncdenr.gov or [phone].
Sincerely,
Corey Anen
Environmental Engineer
Stormwater Program
cc: Fayetteville Regional Office