NC0004774_SOC (Acknowledgement)_20220426

RECEIVED/NCDEQ/DWR
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MOORESVILLE REGIONAL OFFICE
April 26, 2022
Corey asinger;
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]
Subject: Report Under Special Order by Consent — EMC SOC WQ S18-004
Duke Energy Carolinas, LLC — Buck Steam Station
NPDES Permit NC0004774
Quarterly Progress Report for 1st Quarter 2022
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. S18-004 Section 2.c.2).
Please direct any questions concerning the Buck Steam Station NPDES Permit NC0004774 SOC
No. S18-004 to Shannon Langley at [phone] or [e-mail].
As required by the SOC, I cent/ 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

Messrs. Basinger and Sledge
April 26, 2022
Page 2
true, accurate, and complete. I am aware that there are significant penalties for submitting false
information, including the possibility ofJne and imprisonment for knowing violations.
Sincerely,
James Wells
Vice President, Environmental, Health & Safety
Programs and Environmental Sciences
Duke Energy
Attachment
Buck Steam Station Quarterly Progress Report
CC: Richard Baker — via email, Duke Energy
Steve Cahoon — via email, Duke Energy
Dale Wooten — via email, Duke Energy
Jessica Bednarcik — via email, Duke Energy
Matt Hanchey — via email, Duke Energy
Shannon Langley — via email, Duke Energy
Randy Hart — via email, Duke Energy

NPDES PERMIT NC0004774
SPECIAL ORDER BY CONSENT EMC SOC WQ S18-004
QUARTERLY EXCAVATION PROGRESS REPORT
BUCK STEAM STATION
APRIL 26, 2022

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 - EMCSOC WQS18-004 (SOC) applicable to the Buck
Steam Station (Buck). 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 Buck. The quarterly reports are due no later than
the 30th 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).
Buck was chosen on October 5, 2016, as an ash beneficiation site required by NC House Bill 630. NC House
Bill 630 also requires that these sites be closed no later than December 31, 2029. The Consent Order, Civil
Action No. 13-CVS-14661 requires the site to be closed no later than December 31, 2035. Proper exemption
requests will be filed if the site closure date exceeds the requirements of NC House Bill 630. 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 all the usable ash from the Buck Ash Basins for use in the concrete industry.
Construction was completed in Q3 2020. Basin activities have commenced, including temporary haul road
and screening pad construction, as well as ash -screening activities.
Excavation of Buck's Ash Basin 1 began on August 1, 2020 and is ongoing. As of March 31, 2022, total ash
excavated at Buck is estimated at 411,340 tons.
Buck: 2

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 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 27, 2019. Duke Energy provided advanced notice for the projected start date of decanting to
NCDEQon December 20, 2018, as required by the NPDES Permit, and written notification for the Initiation of
Decanting per the SOC on February 20, 2019. Decanting was completed on March 2, 2020. Following
completion of decanting, the project entered the dewatering phase. Duke Energy continues to dewater the
ash basin as needed to support the ash basin closure and ash beneficiation activities.
On September 21, 2020, Duke Energy submitted a SEEP MANAGEMENT PLAN AMENDMENT TO CORRECTIVE
ACTION PLAN (CAP) for the Buck site. Approval of the plan and notice of SOC termination was issued by the NC DEQ
on April 18, 2022.
Buck: 3