1812_DukeMarshall_Phase 4 Piezometer Abandonment Request_FID1926180_20250212

(' DUKE
ENERGY-.
February 12, 2025
North Carolina Department of Environmental Quality
Division of Waste Management
Solid Waste Section
2090 U.S. Highway 70
Swannanoa, NC 28778
Attn: Ms. Sarah Moutos (submitted electronically)
Re: Request for Approval to Abandon Piezometers
Industrial Landfill No.1 - Phase 4
Permit No.: 1812-INDUS-2008
Marshall Steam Station
Terrell, North Carolina 28682
Dear Ms. Moutos:
525 South Tryon St.
Charlotte, NC 28202
Mail Code DEP-36A
Charlotte, NC 28201-1006
To progress site closure activities and future landfill construction, Duke Energy requests approval to abandon
Industrial Landfill No.1 (1812-INDUS-2008; ILF) Phase 4 piezometers CLF-401, CLF23-406, and CLF23-407,
located within the footprint of Phase 4 and Phase 5 (CLF-401). The attached Site Vicinity Plan (Figure 1) has
the piezometers requested for abandonment circled.
The piezometers were installed to support the Geotechnical Investigation for ILF Phase 4 and Phase 5 (CLF-
401). Piezometer CLF-401 was installed in May 2021, CLF23-406 was installed in February 2022, and CLF23-
407 was installed in February 2023, and collectively 44 months of groundwater elevation data have been
collected from CLF-401, 36 months for CLF23-406, and 24 months for CLF23-407. The last water level
measurements were collected on January 3, 2025, and demonstrated substantial separation between
groundwater and compacted soil liner base grade (see Figure 2 attached).
Abandonment of the piezometers will be supervised by qualified geotechnical field support that is under the
direct supervision of and in contact with a Licensed Geologist. The piezometers will be abandoned by a North
Carolina licensed well contractor in accordance with subchapter 02C of the North Carolina Administrative
Code. Duke Energy will provide well abandonment logs to the Division upon completion of the field work.
If you need additional information regarding this request do not hesitate to email or call me at
Anne.Davin(a-)Duke-Energy.com or [phone].
Respectfully submitted,
0'1v� kc>'��
Anne Davin, E.I.
Environmental Services
Attachments: Figure 1 Monitoring Location Map (SynTerra, December 2024)
Figure 2 Hydrographs (SynTerra, 2025)
cc (via e-mail): Deana Yitbarek, NCDEQ
Sherri Stanley, NCDEQ
Eliabeth Werner, NCDEQ
Dan Zakary, Duke Energy
www.duke-energy.com Page 1 of 2

Jake Muessen, Duke Energy
Scott La Sala, Duke Energy
John Metcalf, Duke Energy
Tyler Hardin, Duke Energy
Ashley Healy, Duke Energy
www.duke-energy.com Page 2 of 2

CLF-401
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Date
Date
CLF-401- Total water level change from transducer installation on 07/27/2021 to 12/31/2024 is -14.5 feet.
CLF-402 - Total water level change from transducer installation on 07/27/2021 to 12/31/2024 is -20.3 feet.
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Date
Date
LEGEND Notes:
DRAWN BY: D.AVARD DATE:07/21/2021
FIGURE3F
Cell 5 construction start (05/31/2021) NAVD 88 — North American Vertical
'DUKE
.� ENERGY.
REVISED BY: D. AVARD DATE:01/10/2025
DOWNGRADIENT OF THE PHASE 2 EXPANSION (CLF-401 AND CLF-402)
Future phases 3 through 5 CCR excavation start (06/18/2021) Datum 1988
CAR�LINAS
INDUSTRIAL LANDFILL NO 1. (1812-INDUS)
Cell 5 Blanket Underdrain construction start (9/20/2021) Ft -Feet
CHECKED BY: T. COLTON DATE:01/14/2025
GROUNDWATER CONDITIONS QUARTERLY REPORT
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Cell 5 Blanket Underdrain construction completion (10/22/2021)
in -inches
APPROVED BY: T. COLTON DATE:01/14/2025
SEPTEMBER 2024 THROUGH DECEMBER 2024
Shallow Groundwater Flow Zone ( Transducer Data)
♦ Manual Water Level Measurement
PROJECT MANAGER:T.COLTON
MARSHALL STEAM STATION
— — -Transient Groundwater Model water level predicted trend
Daily Total Rainfall (inches)
synTerra
TERRELL, NORTH CAROLINA
www.synterracorp.com

CLF22-405
CLF23-406
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6/1/2022 12/1/2022 6/1/2023 12/1/2023 6/1/2024 12/1/2024
Date
Date
CLF23-405 - Total water level change from transducer installation on 03/01/2023 to 12/31/2024 is -23.5
feet.
CLF23-406 - Total water level change from transducer installation on 03/01/2023 to 12/31/2024 is -13.6
feet.
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LEGEND
Notes:
The modeled water levels are truncated
�� DUKE
DRAWN BY: D. AVARD DATE:07/21/2021
FIGURE 3H
Cell 5 construction start 05/31/2021
( )
NAVD 88 — North American Vertical
based upon the expected shutdown of
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REVISED BY: D. AVARD DATE: Ol/10/2025
DOWNGRADIENT OF THE PHASE 2 EXPANSION
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
the Cell 5 underdrain pumping
CAROLINAS
(CLF23-405 AND CLF23-406)
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft - Feet
operation. The slower basin excavation
CHECKED BY: T. COLTON DATE:01/14/2025
INDUSTRIAL LANDFILL NO 1. (1812-INDUS)
Cell 5 Blanket Underdrain construction completion (10/22/2021) in -inches rate has extended the period needed to
APPROVED BY: T. COLTON DATE: 01/14/2025
GROUNDWATER CONDITIONS QUARTERLY REPORT
— — -
Shallow Groundwater Flow Zone (Transducer Data)
Manual Water Level Measurement
operate the underdrain and will delay
10
PROJECT MANAGER:T. COLTON
SEPTEMBER 2024 THROUGH DECEMBER 2024
Transient Groundwater Model water level predicted trend
the shutdown of the Cell 5 underdrain
MARSHALL STEAM STATION
Daily Total Rainfall (inches)
synTerld
TERRELL NORTH CAROLINA
www.s nterracor com
y p.

CLF23-407
CLF23-408
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6/1/2021 12/1/2021
6/1/2022 12/1/2022 6/1/2023 12/1/2023 6/1/2024 12/1/2024
Date
Date
CLF23-407 - Total water level change from transducer installation on 03/01/2023 to 12/31/2024 is -10.4 feet.
CLF23-408 - Total water level change from transducer installation on 03/21/2023 to 12/31/2024 is -22.1 feet.
CLF23-407
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Date/2023
Date/1
LEGEND
Notes:
The modeled water levels are truncated
�� DUKE
DRAWN BY: D. AVARD DATE:07/21/2021
FIGURE 31
Cell 5 construction start 05/31/2021
( )
NAVD 88 — North American Vertical
based upon the expected shutdown of
p p
<. r ENERGY::
REVISED BY: D. AVARD DATE: Ol/10/2025
DOWNGRADIENT OF THE PHASE 2 EXPANSION
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
the Cell 5 underdrain pumping
CAROLINAS
(CLF23-407 AND CLF23-408)
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft - Feet
operation. The slower basin excavation
CHECKED BY: T. COLTON DATE:01/14/2025
INDUSTRIAL LANDFILL NO 1. (1812-INDUS)
Cell 5 Blanket Underdrain construction completion (10/22/2021) in -inches rate has extended the period needed to
APPROVED BY: T. COLTON DATE: 01/14/2025
GROUNDWATER CONDITIONS QUARTERLY REPORT
— — -
Shallow Groundwater Flow Zone (Transducer Data)
Manual Water Level Measurement
operate the underdrain and will delay
10
PROJECT MANAGER:T. COLTON
SEPTEMBER 2024 THROUGH DECEMBER 2024
Transient Groundwater Model water level predicted trend
the shutdown of the Cell 5 underdrain
MARSHALL STEAM STATION
Daily Total Rainfall (inches)
synTerld
TERRELL NORTH CAROLINA
www.s nterracor com
y p.