NC0003425_Report_20190723

• t DUKE Vice PresidentE N E RGY� Environmental,Health and Safety
Programs&Environmental Sciences
526 South Church Street
Mail Code EC13K
Charlotte,NC 28202
[phone]
July 23, 2019
Via Overnight Mail
DG © HflWE
Linda Culpepper —) 1n
Director of Water Resources `1 J U L 2 5 2019L-))
North Carolina Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617 DIVISION OF WATER RESOURCES
DIRECTOR'S OFFICE
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
Dear Ms. Culpepper and Mr. 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.

Ms. Culpepper and Mr. Sledge
July 23, 2019
Page 2
Please direct any questions concerning the Roxboro Steam Electric Plant SOC No. S 18-005 to
Lori Tollie at [phone].
Sincerely,
James ells
Vice President, Environment, Health & Safety-
Programs and Environmental Sciences
Duke Energy
CC: Richard Baker, Duke Energy
Lori Tollie, Duke Energy
Robert Howard, Duke Energy
George Hamrick, Duke Energy
Paul Draovitch, Duke Energy
Matt Hanchey, Duke Energy
Randy Hart, Duke Energy

41,
Background and Summary
On August 16, 2018, Duke Energy Carolinas, LLC (DEC) and the North Carolina Environmental Management
Commission entered into a Special Order by Consent—EMC SOC S18-005 (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. The ash basin system covers approximately 250 acres with a current ash inventory of
approximately 20 million tons of ash as of May 2019.
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
will commence mechanical decanting and treatment once it receives a revised NPDES permit.
In parallel, 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 has commenced and the water level
within the area of the basin north of the internal filter dike has lowered approximately 8 feet ("'50-million
gallons)from its normal operational level.
While gravity-driven decanting of the basin has commenced, this is the maximum rate of decanting authorized
by the current permit. Duke has all necessary equipment in place to commence further mechanical decanting
upon permit approval and/or authorization. Delays in issuance of the NPDES permit or authorization to
mechanically decant under the existing permit coverage will determine the stations ability to comply with the
completion of decanting date currently in the Order (6/30/2020). Should delays continue, Duke anticipates
submitting a formal request to re-negotiate the decant completion date in accordance with condition 2.) b.3.)
of the Order.
Roxboro: 1