SW5190201_AddInfo_20190514

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Interim Director
Mr. David H. Blevins, PE
Development Engineering, Inc.
244 W. Millbrook Road
Raleigh, NC 27609
NORTH CAROLINA
Environmental Quality
May 14, 2019
Subject: Request for Additional Information
Stormwater Permit No. SW5190201
Cambridge Southeast Estates
Chatham County
Dear Mr. Blevins:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on February 28, 2019. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
1. In Section 10 of the application, the proposed impervious area in the two tables don't
match. The first table states that the proposed impervious area is 71,560 sf and the second
states that it is 76,830 (excluding existing). If the actual impervious surface is 76,830 sf,
the total BUA will be over 7% and will trigger local peak flow requirements according to
the stormwater narrative.
2. The narrative states that no local peak flow requirements apply. State regulations do not
require mitigation of peak flows and the low density regulations promote diffuse flow
and vegetated conveyances. Therefore, the dry ponds are not necessary, unless the actual
proposed BUA exceeds 7% as a result of the previous comment.
3. If the dry ponds are to remain on the plan, the maintenance agreement must be signed and
notarized.
4. Please complete all applicable sections of the low density supplement and provide
calculations for the swales showing that they will not erode during the 10-year storm.
5. Please provide calculations for any outlet showing that the rip rap apron is designed to
prevent erosion during the 10-year storm.
DNorth Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources
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_ 512 North Salisbury Street 1 1612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA
Department or Emironmeatal mail� 919.707.9200

6. 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 June 13, 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 SW5190201 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: Raleigh Regional Office