SW1200501_Add Info_20201019

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
BRIAN WRENN
Director
Scott Burwell, PE
55 Broad Street
Asheville, NC 28801
NORTH CAROLINA
Environmental Quality
October 19, 2020
Subject: Request for Additional Information
Stormwater Permit No. SW1200501
Car Rider Improvements, Fairview Elementary School
Buncombe County
Dear Mr. Burwell:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on October 12, 2020. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
1. Original Comment 2 — The percent BUA for drainage area 2 appears to be calculated
incorrectly. The percent BUA calculation should take into consideration both the on -site
and off -site portions of the drainage area (It appears that only the on -site portion of the
drainage area was used in this calculation. Please revise here and anywhere else that
might be affected (Such as facility sizing calculations).
2. Original Comments 8a, 16, & 22biii — While the county may have more stringent
design requirements that need to be met, this is a State stormwater review and you must
demonstrate compliance with State stormwater requirements. The State requirements for
this project indicate that the design storm depth is 1.0 inches (I understand that the design
storm used in the provided calculations is larger than the State's design storm and the
facility is "oversized" to meet the more stringent County requirements, but you must
show that the State requirements are being met, even if it seems trivial). A good way to
handle this is to show/calculate the design volume using the State's 1.0" design storm and
show/calculate the peak attenuation volume using the County's more stringent
requirements. NOTE: When calculating the State required design volume, no "credit" is
given of existing BUA located in the SCM drainage area, the SCM must be designed for
the full build out potential of its drainage area.
3. Original Comment 8b & 22civ — This value should be based on the actual temporary
ponding depth of the 1 inch design storm volume (For example if the 1 inch design storm
DNorth Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources
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_ 512 North Salisbury Street 11612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA
Department oiEnvironmental aum� 0 ` 919.707.9200

volume for bioretention cell #1 is 570 cf and the stage -storage table indicates that
bioretention cell #1 has 1,742.6 cf of storage volume when the ponding depth is 12 inches
deep (@ elevation 2,307) then the actual ponding depth of the 1 inch design storm
volume (Line 20) would be closer to about 4 inches (Calculated by interpolating
information from the provided stage -storage table)).
4. Original Comment 9 — It appears that the limit of disturbance is being used as the
project area. If this is the case, the project boundary that must be delineated with bearings
and distances on the plans is the limit of disturbance, not the property area. If you are
using the limit of disturbance as the project area any part of the SCM drainage areas that
are located outside of the limit of disturbance will be considered off -site drainage and
must be handled in accordance with 15A NCAC 02H .1003(3)(b).
5. Original Comment 10 — This information must be included in the main set of plans per
Section VI, 8. The plan sheets provided in the stormwater report are acceptable, however
this information needs to be included in the main set of plans.
6. Original Comment 12 — This information must be included in the main set of plans per
Section VI, 8. The entire drainage area to the SCMs should be shown on the plans,
similar to what is shown in the Appendix H of the stormwater report.
7. Original Comment 22b — Please ensure that the correct design storm and design volume
are being used to show compliance with State stormwater requirements.
8. Original Comment 22cii — Please include the SHWT elevation, or at the very least the
ground surface elevation for borings B-5 & B-6 so that the SHWT elevations can be
determined. We require the actual SHWT elevations, not just a distance below the
existing ground surface, so that we can verify that the proposed facility will have
sufficient separation from the SHWT. NOTE: If, for example, one of the borings
terminated at elevation 100 without encountering the SHWT, you can report the SHWT
elevation as "< 100" (Since the actual SHWT elevation is not known).
9. Original Comment 23 — Please ensure that PDFs of the resubmittal information is
uploaded to Laserfiche. The link to the upload page is:
https://edocs.deq.nc.gov/Forms/SWProject Submittal (The project ID number is
SW1200501). NOTE: The following items from the prior (September 1, 2020) submittal
still need to be uploaded to Laserfiche:
- Plan set
- Stormwater narrative & calculations
10. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcopy of other
documents.
a. Pdfs must be uploaded using the form at:
hgps://edocs.deq.nc.gov/Forms/SW Project Submittal
b. Hard copies must be mailed or delivered to the following address:

Jim Farkas
512 N. Salisbury Street
1612 Mail Service Center
Raleigh, NC 27699-1612
NOTE: Per Division policy, the next review of this application will be the final review. Failure
to provide the requested information will result in the project being returned as incomplete. The
return of a project will necessitate resubmittal of all required items, including the application fee.
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 November 18, 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 SW1200501 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
[e-mail] or [phone].
Sincerely,
V "I
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Asheville Regional Office