1812_Duke Marshall_Phase 4 Piezometer Abandonment Request_FID1987330_20250311

(' DUKE
ENERGY-.
March 11, 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-402, CLF23-405, and CLF23-408.
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. Piezometer CLF-
402 was installed in May 2021, CLF23-405 was installed in February 2022, and CLF23-408 was installed in
February 2023, and collectively 44 months of groundwater elevation data have been collected from CLF-402,
36 months for CLF23-405, and 24 months for CLF23-408. Water level measurements were last collected on
March 10, 2025, and demonstrated substantial separation between groundwater and compacted soil liner base
grade (see Figure 2 attached). Figure 2 shows the groundwater elevation data through January 3, 2025.
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(ab_Duke-Energy.com or [phone].
Respectfully submitted,
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
Jake Muessen, Duke Energy
www.duke-energy.com Page 1 of 2

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

IL
840.38�,
F '• I
L
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i
i
s: ■� ""� '?f CLF21-10to`rf-'
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40
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r 3y 847.47 880
8 870 880 828.97
27.5 �. LEGEND
CLF21-11 a +i! MW-6S
p �, •' WELL ID
�iti■ x 825.45 0a
�r A S2s 76s.8o WATER LEVEL (NAVD 88, FEET)
BACKGROUND MONITORING WELL
g' MONITORING WELL
s 'ai, F t CLF-UD 822.5
" 811.50 18?0 0 PIEZOMETER
Yj[, CLF21-12 °y UNDERDRAIN PUMP a�� LF24 0 819.51 _ _ - -- INFERRED WATER LEVEL CONTOUR (2.5 INTERVAL)
f
828.23 5 - - - - CLF21-13R ��s T - GROUNDWATER FLOW DIRECTION
5 - r_
812.72 815 4 CLF21- / 1 R FUTURE PHASES
i
.'�� " i wpm 818.77 "o ASH BASIN WASTE BOUNDARY
GEOGRAPHIC LIMITATION
s CLF-401 so2.5 STRUCTURAL FILL BOUNDARY
. no
800.69 LANDFILL BOUNDARY
0
797.5 800 80s e6 ... LANDFILL CELL 5 AND 6 BOUNDARY
795 LANDFILL COMPLIANCE BOUNDARY
CLF24-504
810.96 1. $`'° LEACHATE BASIN
5 4 CLF23-406 DUKE ENERGY CAROLINAS PROPERTY LINE
'+ = 793.51
CLF24-503
TOPOGRAPHIC CONTOUR (10' INTERVAL)
796.46 1 yoo > STREAM (MCKIM & CREED)
' . -
�, '= CLF23-4o8 ' '' ' ' WETLAND (MCKIM & CREED)
783.13 #
NOTES:
�1 - -- 1. WATER LEVELS WERE COLLECTED ON 1/3/25.
-c CLF24-502 CLF24-50
-- 1i 795.03 790.08 = {v 2. ELEVATIONS ARE REFERENCED TO THE NORTH AMERICAN VERTICAL DATUM OF
1988 (NAVD 88).
- CLF22-306/R
3. THE STREAMS AND WETLANDS JURISDICTIONAL DETERMINATION WAS
* 787.63 APPROVED BY THE U.S. ARMY CORPS OF ENGINEERS ON OCTOBER 25, 2017
0 1 '♦a,_;+ ` 4� CLF23-405 �.' (SAW-2015-01412). WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM
781.37 AMEC FOSTER WHEELER ENVIRONMENTAL AND INFRASTRUCTURE, INC. NATURAL
RESOURCES TECHNICAL REPORT (NRTR) DATED JUNE 2015.
4. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND SHOULD
NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES. TOPOGRAPHY PROVIDED
BYTRANSASH.
r �� �■
5. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY CAROLINAS.
6. BOUNDARIES ARE APPROXIMATE.
7.AERIAL IMAGERY ISACOMBINATION OF DUKE ENERGY PROPELLER AERIAL
PHOTOGRAPHY COLLECTED ON DECEMBER 12, 2024, AND MAXAR SATELLITE
CLF22-307/R - IMAGERY OBTAINED FROM ESRI ONLINE, COLLECTED ON AUGUST 23, 2021.
,!.
779.88 _ 8. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
- - - T• ;. COORDINATE SYSTEM FIPS 3200 (NAD83).
i GRAPHIC SCALE
DUKE 200 0 200 400 FIGURE 2
l/ ENERGY® (IN FEET) AREA OF FOCUS WATER -LEVEL MAP
CAROLINAS UPPER FLOW ZONE
DRAWN BY:IKING DATE:05/12/2022 GROUNDWATER CONDITIONS QUARTERLY REPORT
REVISED BY: L. FOREMAN DATE: 01/24/2025
CHECKED BY: T.COLTON DATE: 01/24/2025 OCTOBER 2024 THROUGH DECEMBER 2024
APPROVED BY:T.COLTON DATE: 01/24/2025 MARSHALL STEAM STATION
f���� PROJECT MANAGER: T. COLTON
. TERRELL, NORTH CAROLINA
www.s nterracor .com
G:\O ARCGIS PRO PROJECTS\DUKE ENERGY\MARSHAL1\2025\GW CONDITIONS OUARTERLY REPORT\GW CONDITIONS OUARTERLY REPORTAPRX

CLF-401
CLF-402
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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
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.
CLF-401
CLF-402
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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
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
`�
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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6/1/2021 12/1/2021 6/1/2022 12/1/2022 6/1/2023 12/1/2023 6/1/2024 12/1/2024
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
CLF23-405 - 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.
CLF22-405
CLF23-406
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6/1 /2021
1 1 1
12/1 /2021 6/1 /2022 12/1 /2022 12//2023 6//2024 12//2024
1
6//2021
1 1 1/2023
12//2021 6//2022 12//20 1 1 /2023 12//2023 6//2024 112//2024
Date
Date/1
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
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
(CLF23-405 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
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
CLF23-408
818
810
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6/1/2021
12/1 /2021 6/1 /2022 12/1/2022 12/1/2023 6/1 /2024 12/1/2024
6/1/2021 12/1 1 /2021 6//2022 12/1 /20 /2023 12/1/2023 6/1 /2024 12/1/2024
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.