SW3210602_Add Info_20210720

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
BRIAN WRENN
Director
Chris Mettler, PE
300 W. Summit Avenue, Suite 330
Charlotte, NC 28203
NORTH CAROLINA
Environmental Quality
July 20, 2021
Subject: Request for Additional Information
Stormwater Permit No. SW3210602
Blackburn Solar Point of Interconnect
Catawba County
Dear Mr. Mettler:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on June 29, 2021. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
Please indicate the county in which this project is located (Section I, 2). The county is
currently listed as "NC".
2. Please list the correct major river basin that this project is located within (Section IV, 3).
The river basin shown in this section of the application should be one of the 17 major
river basins located throughout North Carolina (which can be found here:
https://ncdenr.mgps. arc gis.comlgpps/PublicInformationlindex.html?gppid=ad3 a85aOc6d6
44aOb97cd069db238ac3). This project appears to be located within the Catawba River
Basin.
3. Please include a USGS topographic map clearly showing the extent of the project area
(Section VI, 6). It is noted that there was a survey map and some maps showing the
project area, however we require a USGS topographic map showing the project area (The
reasoning behind this is that the USGS topographic map is used to determine if there are
any surface waters located within the project area).
4. Please provide calculations showing that the riprap placed downstream of the culverts has
been adequately sized to prevent erosion during the 10-year storm (Section VI, 7). Design
charts for riprap apron sizing can be found in the Erosion and Sediment Control Planning
and Design Manual (ht!ps:Hdeq.nc.gov/about/divisions/energy-mineral-land-
North Q North Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources
512 North Salisbury Street 11612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA _
De"dm,tomD,im mUlDwnry 919.707.9200

resources/energy-mineral-land-permit-guidance/erosion-sediment-control-planning=
design -manual).
5. Please show the surface area and required vegetated setbacks for the on -site surface
waters in the main set of plans (Section VI, 8h & p). It is noted that the on -site surface
water is shown on plan sheet BB 1-D-P002-CVR, however the surface area (it is not
practical to delineate the banks of the stream at this scale so you can just indicate the
surface area of the surface water as a callout) and required vegetated buffer (as required
per 15A NCAC 02H .1003(4) & .1017(10)) are not shown.
6. Please dimension the project area boundary with bearings and distances (Section VI, 8i).
NOTE: You can select an appropriate smaller subset of the property area (such as the
limit of disturbance) to use as the project area if you so choose. If you choose to do this,
please adjust the other application items accordingly.
7. Please identify the surface area of all on -site BUA (Section VI, 8j). The surface area
information shown in the application/supplement form of all proposed BUA should be
able to be verified on the plans. Certain regular geometric shapes (such as the switchyard
pad) can be verified solely based on the provided dimensions whereas areas of irregular
shapes (such as the access road) cannot easily be determined solely from the provided
plans. You may wish to provided surface area callouts, add surface areas to existing
callouts, or add a table, similar to the one in Section IV, 10 of the application.
8. Per the information shown in the Supplement-EZ Form, some of the vegetated
conveyances have side slopes of 4:1 whereas the detail on plan sheet BB1-D-P002-5 only
indicates ditches with 3:1 side slopes. Please adjust this detail to indicate the various
cross -slopes that will be used and indicate which ditches will have which cross -slopes
(Section VI, 81).
9. Please provide official documentation showing that Mr. Stempowski can sign on behalf
of the applicant, Blackburn Solar, LLC (Section VI 11). Since Mr. Stempowski's name is
not listed in the Secretary of State documentation, you need to provide some form of
additional documentation showing Mr. Stempowski's position/signing authority within
Blackburn Solar, LLC and/or ESI Energy, LLC.
10. Please correct the following issues with the Supplement-EZ Form:
a. Cover Page:
i. Line 7 — Vegetated setbacks are required from all surface waters in
accordance with 15A NCAC 02H .1003(4) & .1017(10).
b. Low -Density Page:
i. Pervious Area Column — The information in this column appears to be
incorrect (It appears as though the information from the "BUA" column
was duplicated in this column).

ii. Ditch 1 — The provided calculations indicate that the flowrate in this ditch
is 1.0 cfs whereas the Supplement-EZ Form indicates that the flow is 4.9
cfs. Please revise either as needed for consistency (It appears as though the
intensity is incorrect in the calculations).
iii. Ditch 3 — The provided calculations indicate that the flowrate in this ditch
is 4.7 cfs whereas the Supplement-EZ Form indicates that the flow is 4.9
cfs. Please revise either as needed for consistency.
NOTE: New original signatures are only required if information on the signature page
needs to be corrected. For example, if the only page of the application that needs to be
revised is page 3, then a new signature page is not needed (I will add the revised page 3
into the otherwise correct application to create a complete correct version).
11. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, 1 hardcopy of other
documents, and a response to comments letter briefly describing how the comments have
been addressed.
a. Pdfs must be uploaded using the form at:
https:.//edocs.deq.nc.gov/Forms/SW-Supplemental-Upload
b. Hard copies must be mailed or delivered to the following address:
i. For FedEx/UPS:
Suzanne McCoy
512 N. Salisbury Street, Office 640K
Raleigh, NC 27604
ii. For LISPS:
Suzanne McCoy
1612 Mail Service Center
Raleigh, NC 27699-1612
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 August 19, 2021, 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 SW3210602 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,
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Mooresville Regional Office