SW3180305_6028-MCC-Comment Response_6/28/2019

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Interim Director
Ms. Griselda Ruan
LandDesign
223 N. Graham St.
Charlotte, NC 28202
NORTH CAROLINA
Environmental Quality
May 14, 2019
Subject: Request for Additional Information
Stormwater Permit No. SW3180305
Mitchell Community College — Health Sciences Building
Iredell County
Dear Ms. Ruan:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on March 27, 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. The sand filter must provide sufficient volume below the first outlet to hold the entire
water quality volume without taking into account routing through the sand media.
RESPONSE: SAND FILTER REMOVED IN WATER QUALITY CALCULATIONS. REFER TO SHEET C4.02 AND REVISED
CALCULATIONS BOOK.
2. The area of the sand filter listed in the Supplement EZ form is greater than shown on the
plans and in the calculations.
RESPONSE: AREA OF SAND FILTER UPDATED IN CALCULATIONS. REFER TO SHEET C4.02 AND REVISED
CALCULATIONS BOOK.
3. The scale on the hardcopy Stormwater Management Plan sheet (C4.00) is incorrect. It
appears to be correct in the electronic document. Please resubmit two revised hardcopies
of this sheet with the correct scale.
RESPONSE: SCALE SHOULD BE 1"=20'. REFER TO SHEET C4.00.
4. Sand filters are not required to be designed as off-line systems. We recommend removing
the flow splitter and using the outlet riser to control storm events greater than the water
quality volume to reduce future maintenance.
RESPONSE: PER OUR PHONE CALL, FLOW SPUTTER TO STAY TO DIVERT OFF -SITE RUNOFF GOING INTO
ROP SED TO YSTEJVI,
5. rovl e pd s o all revisions, 2 hardcopies of revised plan sheets, and I hardcopy of other
documents. Pdfs must be uploaded using the form at:
https:Hedocs.deq.nc.gov/Forms/SW Project Submittal
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
DepadmamofEnmmnmemlQuslfty /� 919.707.9200

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 SW3180305 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.Anengncdenr.gov or [phone].
Sincerely,
C&v� a, —
Corey Anen
Environmental Engineer
Stormwater Program
cc: Mooresville Regional Office