NC0004774_Special Order By Consent_20190723

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July 23, 2019
Via Overnight Mail
Corey Basinger
Mooresville Regional Office Regional Supervisor
North Carolina Department of Environmental Quality
Division of Water Resources
Water Resources - Water Quality Regional Operations
610 East Center Avenue, Suite 301
Mooresville, NC 28115
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]
JUL 2019
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Subject: Report Under Special Order by Consent — EMC SOC WQ S 18-004
Duke Energy Carolina, LLC — Buck Steam Station
NPDES Permit NC0004774
Quarterly Progress Report for 2nd Quarter 2019
Dear Messrs. Basinger and Sledge:
On behalf of Duke Energy Carolinas, LLC (DEC), I am submitting to you the Buck Steam Station
Progress Report summarizing the work and activities undertaken with respect to closure of coal
ash surface impoundments as required by the Buck Steam Station NPDES Permit NC0004774
Special Order by Consent (SOC), SOC No. S 18-004 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. Basinger and Sledge
July 23, 2019
Page 2
Please direct any questions concerning the Buck Steam Station NPDES Permit NC0004774 SOC
No. S 18-004 to Elizabeth Glenn at [phone].
Sincerely,
13
lie
James ffells
Vice President, Environment, Health & Safety -
Programs and Environmental Sciences
Duke Energy
CC: Richard Baker, Duke Energy
Robert Wylie, Duke Energy
Elizabeth Glenn, Duke Energy
Dale Wooten, Duke Energy
George Hamrick, Duke Energy
Paul Draovitch, Duke Energy
Matt Hanchey, Duke Energy
Randy Hart, Duke Energy

JULY 23, 2019

Background and Summary
On July 12, 2018, Duke Energy Carolinas, LLC (DEC) and the North Carolina Environmental Management
Commission entered into a Special Order by Consent — EMC SOC WQ S18-004 (SOC) applicable to the Buck
Steam Station (Buck). This report is submitted in accordance with Section 2.c. of the SOC. In compliance
with Section 2.c., this report summarizes the work and activities undertaken with respect to decanting
work and closure of coal ash surface impoundments at Buck. 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.
Buck was once a six -unit coal-fired generating station located on the Yadkin River in Rowan County, NC.
The plant began operation in 1926 with two units, added a unit in 1941, another unit in 1942, and the
final two units in 1953. At its peak, the generating facility had a capacity of 440 megawatts. Units 1 and
2 retired in 1979, Units 3 and 4 retired in 2011, and Units 5 and 6 were retired in 2013. The coal plant has
been demolished through a combination of implosion and mechanical removal of plant structures. The
site is now home of the new Buck Combined Cycle Plant, a 620-megawatt natural gas facility. The
combined cycle plant came on-line in late 2011.
The approximately 150-acre Ash Basin system at Buck consists of three Basins. The Basins are designated
as Primary Pond (also referred to as Basin 2 with 57.5 acres), the Additional Primary Pond (also referred
to as Basin 1 with 71 acres), and the Secondary Pond (also referred to as Basin 3 with 21.5 acres). Basin
1 contains approximately 3.6 million tons of ash, Basin 2 contains approximately 2 million tons of ash, and
Basin 3 contains approximately 864,000 tons of ash. An ash fill area also exists, containing approximately
235,200 tons of ash.
Closure Plan
Buck was chosen on October 5, 2016, as an ash beneficiation site required by NC House Bill 630. Pursuant
to NC House Bill 630, 300,000 tons of ash from the site must be beneficiated to specifications appropriate
for cementitious products each year. NC House Bill 630 also requires that sites with ash beneficiation
products shall be closed no later than December 31, 2029. Excavation of ash from the Buck site for
beneficial use will occur over multiple years. Construction activities began in April 2017. Ash removed
from the site will be beneficiated by SEFA, with whom Duke Energy has entered into an agreement to
process and sell ash from the Buck Ash Basins for use in the concrete industry.
Decanting Status
In compliance with this SOC, Duke Energy initiated design and procurement efforts in Q3 2018 for a
decanting water treatment system at Buck. Purchase Orders were awarded in Q4 2018 for the civil pad
and electrical infrastructure installations, as well as a Purchase Order for the OEM water treatment
supplier. Wastewater flows were removed from the basin on February 7, 2019. Following installation
and commissioning of the decanting water treatment system, mechanical decanting of the basin
commenced on March 25, 2019. Duke Energy provided advance notice for the projected start date of
decanting to NCDEQ on December 20, 2018, as required by the NPDES Permit, and written notification for
the Initiation of Decanting per the SOC on February 20, 2019. Through June 30, 2019, approximately 60
million gallons has been decanted at Buck.
Buck: 1