SW6191205_AddInfoRequest_20191220

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
NORTH CAROLINA
Environmental Quality
December 20, 2019
Greg Harnish, PE
Woolpert North Carolina, PLLC
11301 Carmel Commons Blvd., Suite 300
Charlotte, NC 28226
Subject: Request for Additional Information
Stormwater Permit No. SW6191205
SOF Dining Facility, Aberdeen Training Facility, PN 82254
Hoke County
Dear Mr. Harnish:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on December 12, 2019. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
A soil investigation to determine the in -situ hydraulic conductivity is required within the
footprint of each infiltration system [ 15A NCAC 02H .1051(1)] . Please provide a soil test
within the footprint of the northwest infiltration system (listed as Infiltration Area 1 on
Sheet CG100).
2. Please provide design calculations and specifications for the riprap protection for each
inlet and outlet to show that there will not be erosion during the peak flow from the 10-
year storm event [15A NCAC 20H .1050(4)].
3. Please provide a detail of the at -grade infiltration systems including all elevations and
overflows or bypass devices for inflow volumes in excess of the design storm in
accordance with 15A NCAC 02H .1050(5).
4. Please add a note to the grading sheet or SCM details that every SCM impacted by
sedimentation and erosion control during the construction phase shall be cleaned out and
converted to its approved design state 15A NCAC 02H .1050(7).
5. Please submit a complete signed and sealed Supplement EZ form. The form can be found
on the Stormwater Design Manual website.
D EQ �� North Carolina Department of Environmental Quality Division of Energy, Mineral and Land Resources
512 North Salisbury Street 1 1612 Mail Service Center Raleigh, North Carolina 27699-1612
NORTH CAROLINA
Depadm.mofEnmmnm.maaualfty /� 919.707.9200

6. Sheet CG 100 Note 10 shows the 15" storm drain pipe entering the underground detention
system at invert 465. Detail sheet C-503 lists the invert at 465.5. Please correct the
discrepancy.
7. The calculations for the northern infiltration area, listed as Infiltration Area 2 on Sheet
CG100, use an area of 1890 sf, whereas the plans show the area as 890 sf. Please revise
the calculations to use the proper surface area.
8. The storage volume calculations for the underground system use V of stone media below
the perforated pipes, but the detail on Sheet C-503 show only 6". Please correct the
discrepancy.
9. The storage volume calculations for the underground system appear to under calculate the
storage in the stone layer by a factor of 2.
10. 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:
hltps:Hedocs.deq.nc.gov/Forms/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 January 19, 2020, 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 SW6191205 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(d),ncdenr.gov or [phone].
Sincerely,
6&u'� &I ---
Corey Anen
Environmental Engineer
Stormwater Program
cc: Fayetteville Regional Office