SW5201101_Response to Comments Letter_20210210

February 10, 2021
Mr. Jim Farkas
Environmental Engineer
NCDEQ, DEMLR – Stormwater Program
512 N. Salisbury Street
Raleigh, NC 27699-1612
919-791-4200
Reference: SW5201101
Duke Energy Progress, LLC
Louisburg 115kV Capacitor Bank
Wake County
Dewberry Project No. 50130273

Dear Mr. Farkas:

Dewberry Engineers Inc. has responded to the following comments for the referenced project:
1. Comment: There is a discrepancy between the project area listed in the Supplement-EZ Form
(746,182.8 sf, Drainage Area Page, Line 5) and the project area listed in the Application (746,088 sf,
Section IV, 10). Please revise as needed for consistency. The “total drainage area” value of the
“entire site” column is taken to be the project area so these values should be the same (You may also
need to update Line 6).
Response: The project area (Drainage Area Page, lines 5 & 6) of the Supplement E-Z form has
been revised to 746,088 sf for consistency with the application (Section IV, 10).

2. Comment: Typically, there is no off-site drainage area component for low-density projects
(Supplement-EZ Form, Drainage Area Page, Line 7).
Response: The off-site area (Drainage Area Page, line 7) of the Supplement E-Z form has been
revised to show zero sf.

3. Comment: Per 15A NCAC 02H .1003(4)(e), untreated stormwater is required to be released as
dispersed flow at the edge of the vegetated setback (Supplement-EZ Form, Low Density Page, Line
12). If stormwater is released from the edge of the pavement as dispersed flow and there are no
constructed vegetated conveyances/collection system, you can assume that the flow will enter the
vegetated setbacks as dispersed flow since the flow is mimicking existing conditions.
Response: The dispersed flow (Low Density Page, line 12) of the Supplement E-Z form changed to
‘Yes’.

4. Response: The Per 15A NCAC 02H .1003(5), stormwater outlets are required to be designed so that
there is no downslope erosion (Supplement-EZ Form, Low Density Page, Line 13). If there are no
outlets you can put “N/A”.
Response: There are no outlets associated with this project; therefore, not applicable. The
Supplement E-Z form does not have the option to choose N/A for line 13. There are only ‘yes’ or
‘no’ options. We have added a comment to the last box to explain ‘NA’ was not available on the
outlets line.

The following additional information to support the Stormwater Permit Application for the referenced
project:

One (1) revised, original Supplement-EZ Form

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Mr. Jim Farkas
Louisburg 115kV Capacitor Bank
Should you have any questions or concerns, please feel free to contact me via phone [phone] or
e-mail ([e-mail]).
Sincerely,
Dewberry Engineers Inc.

Elizabeth B. Steffens, P.E.
Site/Civil Department Manager

Enclosures

Cc: Reuben Jones, PE, Duke Energy Progress, LLC
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