AddInfoRequest2 - Knapheide Gravel

Energy, Mineral
and Land Resources
ENVIRONMENTAL QUALITY
August 24, 2018
Mr. Nicholas R. Parker
Amicus Partners, PLLC
7140 Weddington Rd. Suite 140
Concord, NC 28027
Subject: Request for Additional Information
Stormwater Permit No. SW3180601
Knapheide Gravel Storage Lot — Midland, NC
Cabarrus County
Dear Mr. Parker:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
WILLIAM E. TOBY VINSON, JR.
Interim Director
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on June 1, 2018 and additional
information on July 30, 2018. A review of that information has determined that the application
is not complete. The following information is needed to continue the stormwater review:
1. Based on the grading of the site, it appears that a significant amount of the drainage area
will bypass the sand filter.
2. The calculations that were used to size the sand filter are from the old BMP Manual and
are not consistent with the new MDCs. The interpretation of the MDCs is that the entire
bottom of the sand chamber must be sand.
3. Sand Filter MDC 2 requires that the storage volume in the sand chamber and the
sediment chamber be equal. Because sand filters may also be used for peak flow
attenuation, we allow for the sediment chamber to be larger than the sand chamber as
long as 50% of the water quality volume (after the 25% discount) can be stored in the
sand chamber below the first bypass outlet.
4. Page 1 of the Supplemental EZ form with a wet signature must be submitted.
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:
htlps:Hedoes.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 September 23, 2018, 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 SW3180601 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,
Corey Anen
Environmental Engineer
Stormwater Program
ec: Mooresville Regional Office
Chris Todd — Knapheide Truck Equipment Center
Nothing Compares.
State of North Carolina I Environmental Quality I Energy, Mineral and Land Resources
512 N. Salisbury Street 1 1612 Mai Service Center I Raleigh, NorthCaroiina27699-1612
919 707 9200