NCS000572_Permit Renewal Application_20191115

,10 DUKE Dan River Combined Cycle
ENERGY. Duke Energy Carolinas
864 South Edgewood Road
Eden, NC 27288
November 12,2019
Lauren Garcia
NCDEMLR Stormwater Program
1612 Mail Service Center C _
Raleigh,NC 27699-1612C� IJ
Subject: Duke Energy Carolinas,LLC NOV I 5 2019
Dan River Combined Cycle Station D' NR LAND QUALITY
NPDES Stormwater Permit NCS000572 STORMWATER PcRM1("TING
Permit Renewal Application
Dear Ms.Garcia:
Per the meeting on September 19,2019 to discuss the current and future site conditions that affect the final submittal
of the Dan River Combined Cycle Station's permit renewal application, Dan River is submitting the attached
application for your review and comments. The subject permit expires on September 30,2020. Section III Part B of
this permit requires the permit application for renewal to be submitted at least 180 days prior to the expiration date of
the permit.
With the completion of decommissioning of former steam station, final grading of the ash basins, installation of the
landfill cover,and the reestablishment of non-contact stormwater flow to the Dan River discussed and outlined in the
Significant Changes Narrative, Dan River Combined Cycle requests that SW001 and SW002 are the stormwater
outfalls in the reissued Individual Stormwater Permit.
The fish tissue monitoring results will be included with the final permit renewal application as required by the letter
dated October 2,2017 from Ms Annette Lucas of NC Division of Energy,Mineral and Land Resources to Mr.Shannon
Langley of Duke Energy.
Should you have any questions or need additional information please contact Joyce Dishmon at 336-623-0238.
Sincerely,
Michael Lanning
GM II-Regulated Stations
Dan River Combined Cycle
Power Generating Carolinas East
Attachments
Renewal Application Form
Supplemental Information
Site Maps(Current/Future)
Summary of Analytical Monitoring Results
Summary of Visual Monitoring Results
Certification of the Development and Implementation of the SPPP
,Iish Tissue Monitoring Results(Part II Section B Page 12 of 17)

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Permit Coverage
Renewal Application Form
National Pollutant Discharge Elimination System NPDES Permit Number
EnvironmentalStormwater Individual Permit NCS 000572
Quality
Please provide your permit number in box in the upper right hand corner, complete the information in the space provided
below and return the completed renewal form along with the required supplemental information to the address indicated.
Owner Information * Address to which permit correspondence will be mailed
Owner/Organization Name: Duke Energy Carolinas,LLC
Owner Contact: Paul Draovitch
Mailing Address: Charlotte,NC 28202
Charlotte,NC 28202
Phone Number: 980-373-0408
Fax Number:
E-mail address: [e-mail]
Facility Information
Facility Name: Dan River Combined Cycle Station
Facility Physical Address: 864 S.Edgewood Road
Eden,NC 27288
Facility Contact: Michael Lanning
Mailing Address: Same as Facility Address
Phone Number: 336-635-3080
Fax Number:
E-mail address: [e-mail]
Permit Information
Permit Contact: Joyce Dishmon
Mailing Address: 864 S.Edgewood Road
Eden,NC 27288
Phone Number: 336-623-0238 REC FIVEI)
Fax Number:
E-mail address: Joyce.Dishmon©duke-energy.com NOV 15 2019
Discharge Information DENR-LAND QUALITY
ReceivingStream: Dan River
STORMWATER PERMITTING
Stream Class:
Basin: Roanoke River Basin
Sub-Basin: 03-02-03
Number of Outfalls: 3
Facility/Activity Changes Please describe below any changes to your facility or activities since issuance of your permit. Attached a
separate sheet if necessary.
1.Removal of outfalls SW003,SVW03A,Sw003B.SVW04,SW005,SVW06,SVW11. Outfalls removed with decommissioning of former Steam Station.
2.Removal of outfalls SW007,SW008. Outfalls Sw007,SVV008 were removed form permit by letter dated 7/14/2017 due to no industrial activity.
3.Implementation of future outfalls SVV009,SW010.
4.Active outfalls SW001,SVV009,SW010.
CERTIFICATION
I certify that I am familiar with the information contained in the application and that to the best of my knowledge and belief
such information is true, comp ete and rate. i1 /
Signature Date
Z /GI
M L OA. Q Leal vt v1 G M i�T - aulo:cd
Print or type name of person signing above Title
DEMLR- Stormwater Program
Please return this completed application form Dept. of Environmental Quality
and requested supplemental information to: 1612 Mail Service Center
Raleigh, North Carolina 27699-1612

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Dan River Combined Cycle Station
Stormwater Permit NCS000572
Individual Permit Application
Supplemental Information

SUPPLEMENTAL INFORMATION REQUIRED FOR RENEWAL OF INDIVIDUAL
NPDES STORMWATER PERMIT
Two copies of each of the following shall accompany this submittal in order for the application
to be considered complete:
(Do not submit the site Stormwater Pollution Prevention Plan)
Initials
JMD I A current Site Map from the Stormwater Pollution Prevention Plan. The location of
industrial activities(including storage of materials, disposal areas,process areas and
loading and unloading areas), drainage structures, drainage areas for each outfall,
building locations and impervious surfaces should be clearly noted.
JMD 2 A summary of Analytical Monitoring results during the term of the existing permit
(if your permit required analytical sampling). Do not submit individual lab reports.
The summary can consist of a table including such items as outfall number,
parameters sampled, lab results, date sampled, and storm event data.
JMD 3. A summary of the Visual Monitoring results. Do not submit individual monitoring
reports. The summary can consist of a table including such items as outfall number,
parameters surveyed, observations, and date monitoring conducted.
JMD 4. A summary of the Best Management Practices utilized at the permitted facility.
Summary should consist of a short narrative description of each BMP's in place at
the facility. If the implementation of any BMP's is planned,please include
information on these BMP's.
JMD
5. A short narrative describing any significant changes in industrial activities at the
permitted facility. Significant changes could include the addition or deletion of
work processes, changes in material handling practices, changes in material storage
practices, and/or changes in the raw materials used by the facility.
JMD 6. Certification of the development and implementation of a Stormwater Pollution
Prevention Plan for the permitted facility(Sign and return attached form).
If the final year analytical monitoring of the existing permit term has not been completed
prior to filing the renewal submittal,then the last years monitoring results should be submitted
within 30 days of receipt of the laboratory reports. (i.e. do not withhold renewal submittal
waiting on lab results)

Dan River Combined Cycle Station
Stormwater Supplemental Information
Draft Renewal Application - 2019
General Facility Description
The Dan River Combined Cycle Station is a 620-megawatt (MW) natural gas facility located in
Rockingham County, NC near the city of Eden. Commercial operation of the Dan River
Combined Cycle began on December 10, 2012.
Current stormwater outfalls are SW001, SW009, SW010, and (former SW002—pumped to
outfall SW009).
Facility Changes Since Permit Issuance
Decommissioning of the retired Dan River Steam Station, combustion turbines, and remaining
facilities was completed in 2017. The final grading of the west yard of the steam station
allowed removal of outfalls SW003, SW003A, SW003B, SW004, SW005, SW006, and SW011.
These outfalls were removed by letter dated 1/29/2018 from Winston Salem Regional Office.
The use of outfall SW009 identified in the NPDES stormwater permit as a future outfall was
approved by Winston Salem Regional Office on 6/27/2016. The drainage area consists of the
decommissioned coal yard, switchyard and powerhouse, decommissioned combustion turbine
area and portion of combined cycle plant (former SW002). This area was remediated along
with the decommissioning of the retired steam station facilities.
The ash has been removed from the primary and secondary ash basins, ash stack 1 and ash
stack 2. Ash from ash stack 1 was shipped offsite to a third-party privately-owned landfill. The
remaining ash has been placed in an onsite landfill. The landfill is projected to have final cover
by third quarter 2020.
Stormwater was re-routed away from the ash basins in 2018 to meet Coal Combustion Residual
Regulatory requirements and to allow ash removal from the basins. The re-routing consisted of
collection of stormwater in two wetland areas (wetland at 36" culvert and wetland at the
former loadout pad). stormwater is pumped from these wetlands to the former Dredge Pool
(WSA-1) located between ash Stack 1 and 2 and ultimately to City of Eden under Industrial User
Permit. These impacts were permitted under 404/401 Individual Permits (IP).
A diversion berm was built at WSA1 to separate the non-contact stormwater from the contact
water collected in WSA1. The use of SW010 identified in the NPDES stormwater permit as a
future outfall was approved by Winston-Salem Regional Office on 6/28/2018. SW010 is being

utilized to discharge non-contact stormwater from the wetland in the upland area of WSA1.
These areas will be restored per the IP prior to returning flow to the Dan River.
Outfalls 007 and 008 were removed from permit by letter dated 7/14/2017 due to no industrial
activity.
Future Changes with Landfill Closure
Figure 2 —Stormwater Figure Final Grading identifies the drainage areas that will be created
with final grading and the reestablishment of stormwater flow to the Dan River. Stormwater
will be discharged through four gabions to the Dan River.
• The drainage area to Gabion #1 will include 8.26 acres of the former primary ash basin.
The outfall coordinates will be N36 29' 10.84"/W79 43' 04.85". The ash has been
removed from the primary basin. The switchyard located in this area is currently
covered under NPDES Industrial Wastewater Permit NC0003468. This is a standalone
switchyard that is not associated with the Combined Cycle Station and would not be
considered industrial activity.
• The drainage area to Gabion #2 will be 37.03 acres and will include a portion of the
former primary ash basin, a portion of the former SW009, former SW002, gravel
laydown area, and 48" culvert area. The outfall coordinates will be N36 29' 17.87"/W79
42' 51.24".
o Future SW009 that flows to Gabion #2 drainage area will include stormwater
from the drummed oil storage building located in the southeast corner of the
combined cycle property. Storage in this building is self-contained with a sloped
and bermed concrete floor.
o Former SW002 discharges into an unnamed tributary. DRCC requests the
stormwater collection for this outfall be at this unnamed tributary.
• The drainage area to Gabion #3 will be 97.58 acres and will include the Motley Tie
switchyard (this is a standalone switchyard at the entrance to the facility. It is not
associated with DRCC), capped ash landfill, former ash fill and ash basin footprint, and
remediated wetlands. The outfall coordinates will be N36 29' 23.54"/W79 42' 47.63".
o The diversion berm that separates the non-contact stormwater from the contact
stormwater will be removed. This will allow the wetlands to return flow to the
Dan River eliminating the need for SW010. Dan River Combined Cycle requests
removal of this outfall from permit.

o Once the landfill cover is installed there will not be industrial activity in this area.
The cap installation is estimated to be complete by 3' Quarter 2020.
• The drainage area to Gabion #4 will be 16.51 acres and will include former ash basin
footprint, remediated wetland and stream from the loadout pad. The outfall
coordinates will be N36 29' 30.43"/W79 42' 40.62".
• Former SW009 will be divided once stormwater flow is reestablished through Gabion
#2. The area from SW002 and the 48" culvert will no longer be pumped to outfall
SW009. The drainage area for SW009 will include a maintenance storage building. All
maintenance activity is conducted inside the building. There will not be any industrial
activity in this new drainage area.
o Dan River Combined Cycle requests removal of SW009. With the
decommissioning of Steam Station and the maintenance building there is no
industrial activity in this area.
• DRCC requests that the reissued permit contain outfalls SW001 and SW002 that are
associated with combined cycle station.

Attachment 1
Site Maps

Current Stormwater Map