NC0005088_Report_20200131

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' ENERGY.
January 29, 2020
Via Overnight Mail
Water Quality Regional Operations
Asheville Regional Office
Landon Davidson
Asheville Regional Office Regional Supervisor
North Carolina Department of Environmental Quality
Division of Water Resources
Water Resources - Water Quality Regional Operations
2090 U.S.70 Highway
Swannanoa, NC 28778-8211
Bob Sledge
North Carolina Department of Environmental Quality
Water Quality Permitting Program
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
James Wells
Vice President
Environmental, Health and Safety
Programs & Environmental Sciences
526 South Church Street
Charlotte, NC 28202
[phone]
Subject: Report Under Special Order by Consent — EMC SOC WQ S 17-009
Duke Energy Carolinas, LLC — Rogers Energy Complex
NPDES Permit NC0005088
Quarterly Progress Report for 4th Quarter 2019
Dear Messrs. Davidson and Sledge:
On behalf of Duke Energy Carolinas, LLC (DEC), I am submitting to you the Rogers Energy
Complex quarterly progress report that summarizes the work and activities undertaken with respect
to closure of coal ash surface impoundment as required by the Rogers Energy Complex NPDES
Permit NC0005088 Special Order by Consent (SOC), SOC No. S17-009 Section 2.c.2).
As required by the SOC, I certify under penalty of law that this document and all attachments were
prepared under my direction or supervision in accordance with a system designed to assure that
qualified personnel properly gather and evaluate the information submitted. Based on my inquiry
of the person or persons who manage the system, or those persons directly responsible for
gathering the information, the information submitted is, to the best of my knowledge and belief,
true, accurate, and complete. I am aware that there are significant penalties for submitting false
information, including the possibility of fine and imprisonment for knowing violations.

Messrs. Davidson and Sledge
January 29, 2020
Page 2
Please direct any questions concerning the Rogers Energy Complex NPDES Permit NC0005088
SOC No. S 17-009 to Robert Wylie at [phone].
Sincerely,
JameslWells
Vice P sident, Environment, Health & Safety -
Programs and Environmental Sciences
Duke Energy
Attachment:
Rogers Energy.Complex Quarterly Progress Report
cc: Richard Baker, Duke Energy
Robert Wylie, Duke Energy
Steve Hodges, Duke Energy
George Hamrick, Duke Energy
Paul Draovitch, Duke Energy
Matt Hanchey, Duke Energy
Randy Hart, Duke Energy

NPDES PERMIT NC0005088
SPECIAL ORDER BY CONSENT EMC SOC 517-009
QUARTERLY PROGRESS REPORT
ROGERS ENERGY COMPLEX (CLIFFSIDE STEAM STATION)
JANUARY 29, 2020

Background and Summary
On April 18, 2018, Duke Energy Carolinas, LLC (DEC) and the North Carolina Environmental Management
Commission entered into a Special Order by Consent - EMC SOC 517-009 (SOC) applicable to the Rogers Energy
Complex (Rogers), also known as the Cliffside Steam Station. This report is submitted in accordance with
Section 2.c.2) of the SOC. In compliance with Section 2.c.2), this report summarizes the work and activities
undertaken with respect to decanting work and closure of coal ash surface impoundments at Rogers. The
quarterly reports are due no later than the last day of January, April, July, and October for the duration of the
SOC, once the decanting process has begun.
The Rogers Energy Complex is located in Mooresboro, North Carolina. The Station is located on the south side
of the Broad River approximately 55 miles west of Charlotte and about 1.5 miles south of the Town of Cliffside,
North Carolina. The power plant straddles the Cleveland and Rutherford County line. The Station began
construction and initial operation in 1939 and 1940 with Units 1-4. Unit 5 began operation in 1972, followed
by Unit 6 in 2012. Units 1-4 were retired from service in October 2011, as part of the Station decommissioning
and demolition program, and the Units 1-4 building was imploded in October 2015. Units 5 and 6 continue to
operate with a combined capacity of approximately 1387 megawatts.
The Station's ash management facilities include the Unit 5 Inactive Ash Basin, the Active Ash Basin, which
includes an ash stack area, Ash Storage Area 1, and theon-site landfill. The ash in the Units 1-4 Ash Basin has been
excavated and placed in the on -site landfill, and this area has been repurposed for stormwater and plant
process wastewater basins. Discharge from the Active Ash Basin is permitted by the NCDEQ Division of Water
Resources under the National Pollutant Discharge Elimination System Permit NC0005088.
The Active Ash Basin is located on the eastern portion of the site, east and southeast of Unit 5 and Unit 6. This
Basin began receiving sluiced ash from Unit 5 in 1975 and continued to receive fly ash until October 2017 and
sluiced bottom ash until May 2018 from Unit 5 when a conversion was completed to enable dry handling of
ash. The current ash inventory of the Active Ash Basin is approximately 5.0 million tons as of November 2019.
Decanting Status
In compliance with this SOC, Duke Energy initiated design and procurement efforts in Q3 2018 for a decanting
water treatment system at Rogers. Purchase Orders were awarded in Q4 2018 for the civil pad and electrical
infrastructure installations, as well as a Purchase Order for the water treatment supplier. Duke Energy
completed installation and commissioning of the decanting water treatment system on January 25, 2019 and
commenced decanting by gravity discharge following removal of plant operational flows on March 31, 2019.
Duke Energy provided advance notice for the projected start date of decanting to NCDEQ on March 15, 2019,
as required by the NPDES Permit, and written notification for the Initiation of Decanting per the SOC on April
8, 2019. Through December 29, 2019, approximately 34.2 feet have been decanted from an initial depth of 46
Rogers: 2

feet.
Due to the sloughing event that occurred at Cliffside on July 1, 2019, decanting ceased during the period July
1, 2019 through August 1, 2019. This resulted in a loss of the ability to lower the basin by approximately four
feet during this timeframe.
Decanting was ceased, during the Thanksgiving Holiday (i.e., from November 27, 2019 to December 1, 2019),
and, again, during the Christmas Holiday (i.e., from December 21, 2019 to December 29, 2019), due to high
TSS in the ash basin, though permit limits were not exceeded. Duke Energy has received approval to increase
basin drawdown to greater than one (1) foot per week. Currently, decanting continues with no issues.
Rogers: 3