NC0004774_Protection and Restoration Annual Report_20230120

sts DUKE EHS Environmental Programs
411 Fayetteville Street
E N E RGYR Mail Code:NC15
Raleigh,NC 27601
January 17, 2023
Mr. Richard Rogers
Director
North Carolina Division of Water Resources
1617 Mail Services Center
Raleigh, NC 27699-1617
Subject: Submittal of 2022 Surface Water
Protection and Restoration Annual Report
Duke Energy Carolinas, LLC.
Dear Mr. Rogers,
In accordance with North Carolina General Statute 130A-309.212(e), Duke Energy is required to
"...submit an Annual Surface Water Protection Report to the department no later than January
31 of each year." Duke Energy is pleased to submit the attached 2022 Surface Water
Protection and Restoration Annual Reports for Duke Energy Carolinas, LLC. The attached
report provides information for the following facilities:
Duke Energy Carolinas, LLC
Allen Steam Station, Belews Creek Steam Station, Buck Station, Rogers Steam Station
(Cliffside), Dan River Station, Marshall Steam Station and Riverbend Steam Station
If you have any questions regarding these materials, please contact Randy Hawkins at (864)
356-8257 or randy.hawkinsduke-energy.com.
Sincerely,
Cynthia Winston �IV D
Senior Manager EHS RCG �11•�
Attachment ,JAN 2 0 2C121'
Cc: WRINPDS
Randy Hawkins—via email w/attachment �CDEQID
Eric Smith —via email w/attachment
John Fischer—via email w/attachment
Kim McDaniel —via email w/attachment
EHS NC water SME's -via email w/attachment
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ENERGY®
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2022 North Carolina Surface Water
Protection and Restoration Annual
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Duke Energy Carolinas, LLC
Submitted: January 2023

Table of Contents
Page
Q
Table of Contents
Section 1 - Introduction 1
Section 2 - Site Background 1
2.1 Allen Steam Station 1
2.2 Belews Creek Steam Station 2
2.3 Buck Combined Cycle Station 3
2.4 Rogers (Cliffside) Energy Complex 4
2.5 Marshall Steam Station 5
Section 3 — Surface Water Sampling Summary 7
Section 4 — Surface Water Protection and Restoration Summary 8
Section 5 — Discharge Identification Status 9
Section 6 — Discharge Assessment Status 9
Table 3-1. Duke Energy Coal-Fired Steam Stations 2022 Surface Water Quality Sampling 7

Duke Energy Carolinas,LLC 12022 Surface Water Protection and Restoration Annual Report
Section 1 - Introduction
The purpose of this document is to address the requirements of North Carolina General
Statutes (N.C.G.S.) § 130A-309.212(e), Reporting, as established by North Carolina Senate Bill
729, the Coal Ash Management Act of 2014 (CAMA), for multiple ash basin sites operated
under National Pollutant Discharge Elimination System (NPDES) permits as referenced herein.
The following requirements are contained in N.C.G.S. § 130A-309.212:
(e) Reporting. —In addition to any other reporting required by the Department, the
owner of a coal combustion residuals surface impoundment shall submit an
annual Surface Water Protection and Restoration Report to the Department no
later than January 31 of each year. The Report shall include a summary of all
surface water sampling, protection, and restoration activities related to the
impoundment for the preceding year, including the status of the identification,
assessment, and correction of unpermitted discharges from coal combustion
residuals surface impoundments to the surface waters of the State.
CAMA establishes the submittal date of this report as no later than January 31, 2023. This
report satisfies the requirements of N.C.G.S. § 130A-309.212(e) for activities occurring in 2022
at multiple facilities with ash basin treatment units.
Section 2 - Site Descriptions
2.1 Allen Steam Station
Allen Steam Station (Allen Station) is a five-unit, coal-fired electric generating plant with a
capacity of 1,140 megawatts located on the west bank of the Catawba River on Lake Wylie in
Belmont, Gaston County, North Carolina. The site is located east of South Point Road (NC 273),
and the surrounding area generally consists of residential properties, undeveloped land, and
Lake Wylie.
Allen Station's ash basins consist of two former ash basins. The most recently active ash basin
was commissioned in 1973 and is currently being dewatered. The inactive ash basin is located
to the north of the active ash basin and is not in operation. A large portion of the area on top of
the inactive ash basin is permitted as an industrial landfill by the North Carolina Department of
Environmental Quality (DEQ), Division of Waste Management (Permit No. 3612). The area
contained within the ash basin waste boundary is approximately 322 acres.
There are two earthen dikes impounding the active ash basin: the East Dike, located along the
west bank of Lake Wylie, and the North Dike, separating the active and inactive ash basins. The
surface area of the active ash basin is approximately 169 acres with an operating pond
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Duke Energy Carolinas,LLC 12022 Surface Water Protection and Restoration Annual Report
elevation of approximately 633.5 feet'. The full pond elevation of Lake Wylie is approximately
568.7 feet.
The ash basin was historically operated as an integral part of the Allen Station's wastewater
treatment system, receiving flows from the ash removal system, coal pile runoff, landfill
leachate, flue-gas desulfurization (FGD) wastewater, the station yard drain sump, and
stormwater flows. All wastewater inflows to the ash basin were ceased in 2019. Wastewater is
now routed to a newly commissioned Lined Retention Basin and Wastewater Treatment Facility
before being discharged through NPDES Outfall 006. The facility began the permitted activity of
decanting the ash basin in 2019 and completed decanting in 2020. Dewatering the ash basin is
maintained through a wastewater treatment facility and discharged via NPDES Outfall 002.
The Special Order of Consent for Allen (EMC-SOC-WQ S17-009) was terminated during the
reporting period of 2021, and Conditional Approval of Groundwater Corrective Action Plan has
been received. Discharge from the ash basin system is permitted and regulated by the NCDEQ
Division of Water Resources (DWR) under the NPDES Permit NC0004979. Historically,
permitted effluent from the ash basin was discharged to Lake Wylie via a discharge tower and
42-inch diameter reinforced concrete pipe (RCP). Following modifications in 2016, effluent from
the ash basin now discharges from a weir box structure located in the southeastern portion of the
ash basin via a 42-inch diameter high-density polyethylene (HDPE) pipe to a concrete vault at
the toe of the dam. The permitted effluent discharge then flows through a 42-inch reinforced
concrete pipe (RCP) to Lake Wylie. The water surface elevation in the ash basin is controlled
by the use of stop logs in the weir box structure.
2.2 Belews Creek Steam Station
Belews Creek Steam Station (Belews Creek Station) is a co-fired electric generating facility with
a capacity of 2,240 megawatts located on Belews Reservoir in Stokes County, North Carolina.
Belews Creek Station is a two-unit station, which began commercial operation in 1974. Belews
Creek, a tributary of the Dan River, was impounded by Duke Energy (Duke Power at the time of
initial impoundment) to form Belews Lake. Belews Lake is approximately 3,800 acres in area
and provides cooling water for the Belews Creek station.
The ash basin system consists of a single cell impounded by an earthen dike located on the
north end of the ash basin. The ash basin system was constructed from 1970-1972 and is
located approximately 3,200 feet northwest of Belews Creek Station. The waste boundary for
the ash basin encompasses approximately 342 acres.
The full pond elevation for the Belews Creek Station ash basin is approximately 750 feet. The
normal pond elevation of Belews Lake is approximately 725 feet.
The Special Order of Consent for Belews Creek (EMC-SOC-WQ S18-004) was terminated
during the reporting period of 2021, and Conditional Approval of Groundwater Corrective Action
Plan has been received. All wastewater inflows to the ash basin were ceased in 2019.
All elevations are reported in NAVD88.
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Duke Energy Carolinas,LLC 12022 Surface Water Protection and Restoration Annual Report
Wastewater is now routed to a newly commissioned Lined Retention Basin. The facility began
the permitted activity of decanting the ash basin in 2019. The facility entered into dewatering for
the ash basin in 2022 and performs maintenance decanting as needed. Ceasing inflows and
decanting are the first steps towards closure of the basin. The discharge from the ash basin was
historically through a concrete discharge tower located in the northwest portion of the ash basin.
The concrete discharge tower drains through a 24-inch-diameter SDR 17 high-density
polyethylene pipe (HDPE) conduit for approximately 1,600 feet and then discharges into a
concrete flume box. Modifications to the discharge flow path have been completed which allow
for discharge from the basin to be directed to the main stem of the Dan river.
2.3 Buck Steam Station
Buck Steam Station (Buck Station) is a former coal-fired electricity generating facility with a
capacity of 256 megawatts located near the town of Salisbury in Rowan County, North Carolina.
As of April 2013, all of the coal-fired units have been retired. The site is located northwest of
Leonard Road, and the surrounding area generally consists of residential properties,
undeveloped land, and the Yadkin River. The site now contains the Buck Combined Cycle
Station (BCCS), a 620-megawatt natural gas-powered electric generating station. The entire site
is approximately 640 acres in area.
The ash basin system at the Buck Station was used to retain and settle ash generated from coal
combustion at Buck Station. The ash basin system consists of three cells, the associated
earthen dikes, discharge structures, and two canals. The cells are designated as Additional
Primary Pond (Cell 1), Primary Pond (Cell 2), and Secondary Pond (Cell 3). The ash basin is
located to the south (Cell 1) and southeast (Cells 2 and 3) of the retired Buck Steam Station
Units 1 through 6 and the BCCS.
The original ash pond at Buck Station began operation in 1957. The footprint of the original ash
pond was the approximate current footprint of Cells 2 and 3. As the ash pond capacity
diminished over time, the original pond was eventually divided into two ash ponds (Cells 2 and
3) by construction of a separator dike. In 1982, additional storage was created by construction
of Cell 1, separate from the other cells, by building a new dike up gradient from Cell 2.
Until Cell 1 was constructed, ash generated from the coal combustion process at Buck Station
was sluiced via ash discharge lines to Cell 2. Following construction of Cell 1, sluiced ash was
rerouted from Cell 2 to Cell 1. Flow from Cell 1 enters Cell 2 via the Primary Cell Discharge
Tower. Flow from Cell 2 enters Cell 3 via the Old Primary Cell Discharge Structure. Flow from
Cell 3 discharges to the Yadkin River through the Secondary Cell Discharge Tower.
The approximate pond elevations for the three ash basin cells are: Cell 1 —elevation 705 feet;
Cell 2 —elevation 682 feet; and Cell 3 —elevation 674 feet. The elevation of the Yadkin River
near the site is approximately 624 feet.
The area contained within the waste boundary for Cell 1 encompasses approximately 90 acres.
For purposes of delineating the waste boundary, Cells 2 and 3 are considered a single unit, with
the area contained within this portion of the waste boundary encompassing approximately 80.7
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Duke Energy Carolinas, LLC 12022 Surface Water Protection and Restoration Annual Report
acres. Cell 3 was developed by increasing the elevation of the earthen dike along the Yadkin
River and constructing an intermediate dike across the ash placed in Cell 2.
The ash basin system was operated as an integral part of the site's wastewater treatment
system. During operation of the coal-fired units, the ash basin received variable inflows from the
ash removal system and other permitted discharges.
The discharge from the ash basin is permitted and regulated by the NCDEQ DWR under
NPDES Permit NC0004774. Effluent from the ash basin is discharged through an above-
ground cast iron pipe spillway to the Yadkin River. During 2019, Duke Energy made
significant progress towards decanting the ash basin as a step towards ultimate closure.
Decanting was completed in 2020.
House Bill 630 of 2016 required Duke Energy to designate two North Carolina sites for ash
beneficial reuse by January 1, 2017 and a third North Carolina site for ash beneficial reuse
by July 1, 2017. Duke Energy chose Buck Steam Station as one of the three sites
designated for ash recycling in December 2016. A beneficiation system has been
constructed to process the ash onsite before shipping it for reuse purposes. The
beneficiation ash reprocessing unit at Buck started up in 2020.
2.4 James E. Rogers Energy Complex
The James E. Rogers Energy Complex (formerly known as Cliffside Steam Station) is a coal-
fired electric generating facility located along the south bank of the Broad River in Rutherford
and Cleveland Counties at 573 Duke Power Road, Mooresboro, North Carolina. Rogers Energy
Complex currently operates Units 5 and 6 only. The original Units 1-4 began commercial
operation in 1940. Units 1-4 were retired in October 2011 and have been decommissioned. The
surrounding area generally consists of residential properties, undeveloped land, and the Broad
River.
Rogers Energy Complex contained three ash basins. The newest ash basin and the Units 1-4
inactive ash basin are located in Cleveland County to the east and southeast of Cliffside Station.
The Unit 5 inactive ash basin is in Rutherford County west of Cliffside Station.
The newest ash basin is located approximately 1,700 feet to the east-southeast of Cliffside
station adjacent to the Broad River. This ash basin is impounded by earthen dikes located
between the west portion of the basin and Suck Creek and between the northeast portion of the
basin and the Broad River. The waste boundary associated with this ash basin is approximately
117 acres in area. The approximate maximum full pool water elevation of this ash basin is 770
feet. The main section of the basin was historically operated below 765 feet to leave extra
storage capacity during a heavy rain event.
The Units 1-4 inactive ash basin is located approximately 400 feet to the southeast of the
retired Units 1-4 and approximately 1,300 feet to the northeast of Unit 6, adjacent to the Broad
River. The Units 1-4 inactive ash basin is impounded by an earthen dike located along the
north and northeast side of the basin. The waste boundary associated with the Units 1-4
inactive ash basin is approximately 14.5 acres in area. The Unit 1-4 inactive ash basin is no
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Duke Energy Carolinas,LLC 12022 Surface Water Protection and Restoration Annual Report
longer used to retain storm water or plant process water. The impounded ash material within
the inactive basin was capped with a soil cover approximately two-feet thick. Excavation is
nearly complete for the Unit 1-4 basin. Two lined retention basins and a Wastewater Treatment
Plant are being constructed within the footprint of the former ash basin.
The Unit 5 inactive ash basin is located approximately 1,000 feet to the southwest of Unit 5 and
approximately 1,000 feet west of Unit 6, south of the Broad River. The Unit 5 inactive ash basin
is impounded by two earthen dikes located along the north and northeast sides of the basin.
The waste boundary associated with the Unit 5 inactive ash basin is approximately 58 acres in
area.
The ash basin system has been an integral part of the Rogers Station's wastewater treatment
system, which has received historic inflows from the ash removal system, station yard drain
sump, stormwater flows, and station wastewater. All wastewater inflows to the ash basin were
ceased in 2019. Wastewater is now routed to a newly commissioned wastewater treatment
system. The facility began the permitted activity of decanting the ash basin in 2019 and
completed decanting in 2020. Ceasing inflows and decanting were the first steps towards
closure of the basin.
The Special Order of Consent for Rodgers (Cliffside) (EMC-SOC-WQ S17-009) was
terminated during the reporting period of 2021, and Conditional Approval of Groundwater
Corrective Action Plan has been received. Effluent from the ash basin system is permitted and
regulated by NPDES permit number NC0005088. Effluent from the treatment system is
discharged from the active basin to the Broad River through a concrete inlet structure at the
left abutment of the downstream dam. The inlet structure discharges through two 42" RCP
Pipes that combine into a single 48" RCP pipe that runs along the access road at the left
abutment and then into a concrete discharge structure that discharges to the Broad River.
2.5 arshall Steam Station
Marshall Steam Station (Marshall Station) is a four-unit, co-fired electric generating plant with a
capacity of 2,090 megawatts located in Catawba County, North Carolina, near the community of
Terrell. The site is located north of NC Hwy 150, east of Sherrills Ford Road and south of Island
Point Road, and the surrounding area generally consists of residential properties, undeveloped
land, and Lake Norman.
The ash basin system consists of a single cell impounded by an earthen dike located on the
southeast end of the ash basin. The ash basin system was constructed in 1965 and is located
approximately 2,000 feet northeast of Marshall Station.
The full pond elevation for the Marshall Steam Station ash basin is approximately 790 feet. The
normal pond elevation of Lake Norman is approximately 760 feet.
The ash basin was operated as an integral part of Marshall Steam Station's wastewater
treatment system and received inflows from the ash removal system, coal pile runoff, landfill
leachate, FGD wastewater, the station yard drain sump, stormwater flows, and station
wastewater. All wastewater inflows to the ash basin were ceased in 2018. Wastewater is routed
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Duke Energy Carolinas, LLC 12022 Surface Water Protection and Restoration Annual Report
to a lined Retention Basin (LRB). The facility began the permitted activity of decanting the ash
basin in 2019 and completed decanting in 2020.
The Special Order of Consent for Marshall (EMC-SOC-WQ S17-009) was terminated during
the reporting period of 2021, and Conditional Approval of Groundwater Corrective Action Plan
has been received. The discharge from the ash basin is permitted and regulated by NPDES
permit number NC0004987. Treated effluent is released through a 36-inch HDPE pipe into Lake
Norman.
RECEIVE
JAN 2 0 2023
NCDEQIDWRJNPDES
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Duke Energy Carolinas, LLC 12022 Surface Water Protection and Restoration Annual Report
Section 3 — Surface Water Sampling Summary
The NPDES program regulates wastewater discharges from ash basins to surface waters to
ensure that surface water quality standards are maintained. Surface water discharges are
identified and evaluated to locate potential outfalls for inclusion in the permit. The NPDES
permitting program requires that permits be renewed at least every five years.
Routine surface water monitoring was performed in 2022 in accordance with each site's NPDES
permit conditions and CAMA. Table 3-1 below summarizes the 2022 routine surface water
quality sampling conducted at the five Duke Energy Carolinas, LLC coal-fired steam stations
described in Section 2. Sample results are submitted to the Department of Environmental
Quality in accordance with timelines and procedures identified in each site's respective NPDES
permit. Some additional site-specific sampling events were undertaken associated with the
requirements of various consent orders and groundwater to surface water interaction
demonstrations. Those results were also submitted to the Department in accordance with the
requirement timeframes and protocols.
Table 3-1. Duke Energy Coal-Fired Steam Stations 2022 Surface Water Quality Sampling
Station Water Quality Water Chemistry2 Trace Elements3
Allen Station X X Fish muscle tissues
Belews Creek Station X X Fish muscle tissues
Buck Station X X Fish muscle tissues
Rogers Steam Station X X Fish muscle tissues
Marshall Station X X Fish muscle tissues
'Temperature, dissolved oxygen, conductivity, pH, secchi disk transparency depth (at lake stations only).
2 Water Chemistry constituents analyzed
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F- U U) c0 U Q < F- co. c0_ m 0 0 0 0 ELJ 2 F- F- Z F- U) F- I— N I H I—.. Z <
Allen XXXXXXX XXXXXX XX XXXXXXXXXXXXXXXX
Belews XXXXXX XXXXXXX XX X X X X XXXXXXXXXXX
Creek
Buck XXXXX XXXX X XXX X XXX XX XXXXXXXX
Rogers XXXXXX X XX X XX XXXXXXXX XXXXXXX
(Cliffside)
Marshall XXXXXX XX XXX XX XXX X XXXXXXXXXX
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Duke Energy Carolinas, LLC 2022 Surface Water Protection and Restoration Annual Report
Section 4 — Surface Water Protection and Restoration Summary
In 2022, Duke Energy identified and submitted several documents and undertook a number of
actions to comply with the CAMA requirements. Documents submitted and additional activities
of note undertaken are listed below:
• Allen
o Conducted weekly and annual dam inspections.
o Continued implementation of NPDES permit coverage for industrial stormwater
discharges.
o Continued dewatering of ash basins.
• Belews Creek
o Conducted weekly and annual dam inspections.
o Continued implementation of NPDES permit coverage for industrial stormwater
discharges.
o Began dewatering of ash basins in June, 2022.
• Buck
o Conducted weekly and annual dam inspections.
o Continued implementation of NPDES permit coverage for industrial stormwater
discharges.
o Continued dewatering of ash basins.
o Aproximately 721k tons of ash have been sent to the Buck beneficiation facility
as of October 31, 2022.
• Rodgers (Cliffside)
o Conducted weekly and annual dam inspections.
o Continued implementation of NPDES permit coverage for industrial stormwater
discharges.
o Continued dewatering of ash basins.
o Continued excavation of Rodgers (Cliffside) Station Unit 5 Inactive Ash Basin.
o Over 3M tons of ash been removed from the inactive ash basin at Rogers
(Cliffside) Station as of October 31, 2022.
• Marshall
o Conducted weekly and annual dam inspections.
o Continued implementation of NPDES permit coverage for industrial stormwater
discharges.
o Continued dewatering of ash basins.
o A total of 1.3M tons of ash have been excavated from Marshall ash basin as of
October 31, 2022.
o Received NPDES Wastewater permit renewal April 11, 2022.
• Dan River and Riverbend have met all CAMA closure requirements
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Duke Energy Carolinas, LLC 12022 Surface Water Protection and Restoration Annual Report
Upcoming commitments and activities related to the CAMA include:
• Close basins as required by CAMA and in accordance with performance standards set
out in the federal coal combustion residuals rule to the extent of its applicability to a
particular station.
Section 5 — Discharge Identification Status
The Discharge Identification Plans submitted in September 2014 for all seven (7) DEC sites
addressed the requirements of N.C.G.S. § 130A-309.212(d), Identification and assessment of
discharges; correction of unpermitted discharges. Inspection procedures developed to satisfy
the requirements of N.C.G.S. § 130A-309.212(d) were presented in these plans and used as the
basis for developing the topographic map required by N.C.G.S § 130A-309.212(a)(2). These
documents were submitted to DEQ on September 30, 2014 for all seven (7) DEC stations
described in Section 2. In 2019, Duke Energy implemented the procedures outlined in the
previously submitted Discharge Identification plans.
With the termination of seep management consent orders and removal of seep-related NPDES
requirements for sites with closed ash basins, NCDEQ approved seep management
amendments to site specific groundwater Corrective Action Plans now govern required activities
for future identification and assessment of discharges.
Section 6 — Discharge Assessment Status
Duke Energy submitted the required Topographic Map and Discharge Assessment Plans to
DEQ on December 30, 2014. The plan addressed the requirements of N.C.G.S. § 130A-
309.212(a)(2), topographic map, and (b), Assessment of Discharges from Coal Combustion
Residuals Surface Impoundments to the Surface Waters of the State. The elements required in
N.C.G.S. § 130A-309.212(a) were incorporated into the plan. These documents were submitted
to DEQ on December 30, 2014 for all seven (7) stations described in Section 2. During 2019,
Duke Energy provided sampling data to DEQ of potential discharges from coal combustion
residuals surface impoundments. Duke Energy participated in numerous meetings and site
visits with DEQ staff in evaluating such potential discharges.
With the termination of seep management consent orders and removal of seep-related NPDES
requirements for sites with closed ash basins, NCDEQ approved seep management
amendments to site specific groundwater Corrective Action Plans now govern required activities
for future identification and assessment of discharges.
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