NC0003425_SOC WQ S18-005_20200423

DUKEJames Wells
Vice President
ENERGY, Environmental,Health and Safety
Programs&Environmental Sciences
526 South Church Street
Chartotte,NC 28202
[phone]
April 23, 2020 RECEIVED
Via Overnight Mail MAY 0 1 2020
NCDEQIDWRINPDES
S. Daniel Smith
Director of Water Resources
North Carolina Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Bob Sledge
Division of Water Resources
North Carolina Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Report Under Special Order by Consent—EMC SOC WQ S 18-005
Duke Energy Progress, LLC—Roxboro Steam Electric Plant
NPDES Permit NC0003425
Quarterly Progress Report for 1st Quarter 2020
Dear Messrs. Smith and Sledge:
On behalf of Duke Energy Progress, LLC (DEP), I am submitting to you the Roxboro Steam
Electric Plant Progress Report summarizing the work and activities undertaken with respect to
closure of coal ash surface impoundments as required Special Order by Consent(SOC), SOC No.
S 18-005 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. Smith and Sledge
April 23, 2020
Page 2
Please direct any questions concerning the Roxboro Steam Electric Plant SOC No. S 18-005 to
Lori Tollie at [phone].
Sincerely,
Jame)Vells
Vice President, Environment, Health & Safety
Programs and Environmental Sciences
Duke Energy
CC: Richard Baker, Duke Energy
Lori To11ie, Duke Energy
Robert Howard, Duke Energy
George Hamrick, Duke Energy
Paul Draovitch, Duke Energy
Matt Hanchey, Duke Energy
Randy Hart, Duke Energy

NPDES PERMIT NC0003425
SPECIAL ORDER BY CONSENT EMC SOC S18-005
QUARTERLY PROGRESS REPORT
ROXBORO STEAM ELECTRIC PLANT
APRIL 23, 2020

Background and Summary
On August 16, 2018, Duke Energy Progress, LLC (DEP) and the North Carolina Environmental Management
Commission entered into a Special Order by Consent - EMC SOC 518-005 (SOC) applicable to the Roxboro Steam
Electric Plant (Roxboro). 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 Roxboro.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 Roxboro Steam Electric Plant is located in Semora, NC(Person County),on Hyco Lake. Hyco Lake is a man-made
reservoir constructed by the impoundment of the Hyco River. Roxboro is a four-unit, 2422 megawatts, coal-fired
generating facility. Roxboro began commercial operation in 1966,with additions in 1973 and 1980.
Roxboro's ash basin system has two impoundments, which are regulated by the North Carolina Department of
Environmental Quality(NCDEQ): The West Ash Basin and the East Ash Basin. The West Ash Basin is approximately
225 acres and contains nearly 13.0 million tons of coal ash,while the East Ash Basin is approximately 71 (excluding
the limits of the landfill) acres and contains 7.1 million tons of coal ash. Therefore, the ash basin system covers
nearly 300 acres with a current ash inventory of approximately 20 million tons of ash,as of February, 2020.
Underneath the landfills, there is ash that is not required to be moved, per the Settlement Agreement with the
NCDEQ. Therefore, nearly 3.9 million tons of ash from the East Ash Basin meet that requirement, making the
applicable total nearly 16.9 million tons.
Roxboro historically wet sluiced coal combustion residual (CCR)products into surface impoundments located on the
property.These surface impoundments are known as the East and West Ash Basins.The East Basin became inactive
in 1986 when the West Basin was placed in service.The Basins are impounded by the following dams:
• Inactive(East)Ash Basin (PERSO-033)
• Active(West)Ash Basin (PERSO-038 and PERSO-039)
The Active(West)Ash Basin received CCR products from its initial operation in 1973 until 2019,when wet sluicing of
bottom ash ceased. In the mid-1980s, Roxboro replaced its routine fly ash wet sluicing operation with a dry ash
handling system and began placing dry fly ash into a landfill. Roxboro ceased wet sluicing of bottom ash to the West
Ash Basin in April 2019 when the dry bottom ash system became operational. The Active (West) Ash Basin was
removed from service in April 2019 upon the completion of dry bottom ash handling and diversion of all other
wastewater flow to a newly lined retention basin.
Decanting Status
In compliance with this SOC,Duke Energy initiated design and procurement efforts in Q3 2018 for a decanting water
treatment system at Roxboro. Construction of the infrastructure and water treatment system commenced in Q1
2019,and the system was commissioned and ready for operation in June 2019. Duke Energy planned to commence
mechanical decanting and treatment, once it received a revised NPDES permit. However,wastewater flows from
the station were removed from the ash basin on April 10,2019. With the removal of flows to the basin,except for
stormwater,natural decanting commenced and the water level within the area of the basin,north of the internal
filter dike, lowered approximately 13 feet(in excess of 90-million gallons)from its normal operational level to an
Roxboro: 2

approximate elevation of 447 feet, which is equalized with the water level north of the filter dike. Therefore,
decanting is complete, as discussed with NC DWR staff and documented in the Notification from Duke Energy
to the North Carolina Division of Water Resources, regarding EMC SOC S18-005, dated February 11, 2020. The
basin will be maintained at the equalized level and no mechanical removal of water will commence prior to NPDES
receipt.
Roxboro: 3