1812_DukeMarshall_2023Q2_GWCR_FID1812705_20230731

(� DUKE
ENERGY
July 31, 2023
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: Groundwater Condition Quarterly Report — April 2023 through June 2023
Industrial Landfill No.1
Permit No.: 1812-INDUS-2008
Marshall Steam Station
Terrell, North Carolina 28682
Dear Ms. Moutos:
526 South Church St.
Charlotte, NC 28202
Mailing Address
P.O. Box 1006
Mail Code EC 12J.
Charlotte, NC 28201-1006
In accordance with the NCDEQ DWM September 17, 2021, Phase 2 Permit Modification Approval letter, Duke
Energy is providing the quarterly report describing groundwater conditions in the area of the Marshall Steam
Station Industrial Landfill No.1 (ILF, 1812-INDUS-2008) Phases 2, 3, and 4. The report is for the quarterly
period of April 2023 through June 2023 (Q2 2023).
The quarterly report includes an analysis of groundwater levels and dewatering pump flowrates within Phases
2, 3 and 4, with updated water level maps, hydrographs, pump flowrate plots, and well construction and water
level data tables. An evaluation of groundwater levels and pump flowrates compared to model predictions is
included. All groundwater transducer data, groundwater model trend data, and dewatering pump data are
provided in an excel file format as the report Appendices.
Groundwater conditions in the vicinity of Marshall Steam Station's Industrial Landfill No.1 continue to be
monitored and evaluated. The next quarterly report (Q3 2023) will be submitted by November 1, 2023.
If you need additional information regarding this submittal do not hesitate to email or call me at
Ashley. Healy cDduke-energy.com or [phone].
Respectfully submitted,
j4VAi
Ashley Healy, P.G.
Environmental Services
Attachments: Industrial Landfill No.1 (1812-INDUS-2008) Groundwater Conditions Quarterly Report — April
2023 through June 2023 (SynTerra; July 2023)
Appendices in excel format:
1) Appendix A Water Level Monitoring Data Files
2) Appendix B Groundwater Model Predicted Trend Files
3) Appendix C Dewatering/Underdrain Pumping Data Files
4) Appendix D Mann -Kendall Results
www.duke-energy.com Page 1 of 2

cc (via e-mail): Claire Osborn, NCDEQ
Elizabeth Werner, NCDEQ
Sherri Stanley, NCDEQ
Ed Mussler, NCDEQ
Scott Saunders, Duke Energy
Dan Zakary, Duke Energy
Chris Varner, Duke Energy
Tyler Hardin, Duke Energy
Ed Sullivan, Duke Energy
Thomas Colton, SynTerra
Craig Eady, SynTerra
www.duke-energy.com Page 2 of 2

L1
synTerra
Science & Engineering Consultants
synterracorp.com
GROUNDWATER CONDITIONS QUARTERLY REPORT -
APRIL 2023 TO JUNE 2023
INDUSTRIAL LANDFILL NO. 1
(1812-INDUS-2008)
FOR
MARSHALL STEAM STATION
8320 EAST CAROLINA HIGHWAY 150
TERRELL, NC 28682
JULY 31, 2023
PREPARED FOR
DUKE
ENERGY
DUKE ENERGY CAROLINAS, LLC
Kathryn W. Webb, LG
Senior Peer Reviewer
X J.
Thomas Colton
X%%1Cg1111f/i
• FENS X.
• SEAL =_
1599
�i'9i •'•:cOLOO •� ��
"/ 0 ••.... g ��
'/i70OUG;,P
Project Manager
:raig Eady, NC LG #1599
Senior Project Manager

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
TABLE OF CONTENTS
SECTION PAGE
1.0 INTRODUCTION..........................................................................................................1-1
1.1 Objectives and Purpose..............................................................................................1-1
1.2 Key Findings...............................................................................................................1-1
2.0 QUARTERLY MONITORING RESULTS........................................................................... 2-1
2.1 Current Groundwater Conditions...............................................................................2-1
2.2 Groundwater Trends..................................................................................................2-1
2.2.1 Water -Level Hydrographs and Model Trends.......................................................2-1
2.3 Dewatering and Underdrain Pump Performance.......................................................2-3
3.0 QUARTERLY WATER -LEVEL REDUCTION ACTIVITIES.................................................... 3-1
4.0 REFERENCES...............................................................................................................4-1
2023 Pagei
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
S1.1tel29LCT11Ci*1
Figure 1
Monitoring Location Map
Figure 2
Area of Focus Water -Level Map — Upper Flow Zone (May 2023)
Figure 3A
Background Monitoring Well Hydrographs (GWA-4S/D and MW-4/D)
Figure 313
Perimeter Hydrographs (MW-7 (013-3) and ILF-2S/D)
Figure 3C
Northwest of Cell 5 Hydrographs (CLF21-10 and CLF21-11)
Figure 3D
CLF-UD and Southwest of Cell 5 Hydrographs (CLF-UD and CLF21-12)
Figure 3E
East of Cell 6 Hydrographs (CLF21-14/R and CLF21-15)
Figure 3F
Future Phase 3 and 4 Hydrographs (CLF-301 and CLF-402)
Figure 3G
Cell 5 and Future Phase 5 (CLF21-13/R and CLF-401)
Figure 3H
South of Future Phase 3 Hydrographs (CLF-303 and CLF-304)
Figure 31
Phase 3 Hydrographs (CLF22-305 and CLF22-306)
Figure 3J
Within and South of Phase 4 Hydrographs (CLF22-307 and CLF23-405)
Figure 3K
Future Phase 4 and 5 Hydrographs (CLF23-406 and CLF23-407)
Figure 3L
Within Phase 4 Hydrographs (CLF23-408)
Figure 4A
Cell 5 (Underdrain) Pumping Flow Rate Vs. Simulated Flow Rate
Figure 413
Phase 3-5 Pumping Flow Rate Vs. Simulated Flow Rate
LIST OF TABLES
Table 1 Groundwater Monitoring Network Well Information and Water Levels
LIST OF APPENDICES
Appendix A Water -Level Monitoring Data Files
Appendix B Groundwater Model Predicted Trend File
Appendix C Dewatering/Underdrain Pumping Data Files
Appendix D Mann -Kendall Data
2023 Pageii
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
LIST OF ACRONYMS
CCR
coal combustion residuals
Duke Energy
Duke Energy Carolinas, LLC
DWM
Division of Waste Management
Future Phases
ILF Phases 3, 4, and 5 expansion
gpm
gallons per minute
ILF
Industrial Landfill 1812-INDUS-2008
NCDEQ
North Carolina Department of Environmental Quality
reporting period
second quarter 2023 (April 2023 to June 2023)
Site
Marshall Steam Station
2023 Page iii
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
1.0 INTRODUCTION
1.1 Objectives and Purpose
• SynTerra prepared this Groundwater Conditions Quarterly Report on behalf of Duke
Energy Carolinas, LLC (Duke Energy) to document the water -level monitoring data and
dewatering/underdrain pumping records in the vicinity of the Industrial Landfill No.1
(ILF) (Permit No. 1812-INDUS-2008) at the Marshall Steam Station (Site). This report is
prepared in response to condition #3 in the North Carolina Department of
Environmental Quality (NCDEQ) Division of Waste Management (DWM) September 17,
2021, Phase 2 Permit Modification Approval letter.
• Data collected during the second quarter of 2023 (April 2023 to June 2023) reporting
period were used to evaluate groundwater conditions for the ILF Phase 2 expansion
(includes Cell 5 and Cell 6) and ILF Future Phases 3, 4, and 5 expansion (Future Phases).
Specifically, this report evaluates the groundwater levels, dewatering/underdrain
pumping flow rates, and efforts to expedite reducing and maintaining groundwater
levels near the ILF during the reporting period.
1.2 Key Findings
Key findings of the evaluation conducted during this reporting period include:
• Groundwater levels in the area have generally stabilized.
• Water levels have been maintained at less than or approximately equal to modeled
predictions in most areas, with the exception of ten locations (CLF-301, CLF-303, CLF-
401, CLF-402, CLF21-12, CLF21-13R, CLF22-305, CLF22-306, CLF22-307, and ILF-2D).
However, during the reporting period, water levels were stable. Water levels higher
than model predictions generally represent the effects of a slower excavation rate than
assumed in the model.
The Cell 5 underdrain pump has been operational for 22 months with an average
pumping rate of 10 gallons per minute (gpm). The Future Phases dewatering pump flow
rate pumps at an average flow rate of 177 gpm. While the flow rates vary, the overall
trends reasonably match the model predictions. The model predicted the underdrain to
become dry after approximately 19 months of operation; however, the slower
excavation rate has contributed to the underdrain drying slower than predicted.
2023 Pagel-1
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
2.0 QUARTERLY MONITORING RESULTS
The established network of temporary and long-term piezometers and groundwater wells for
monitoring groundwater conditions in the ILF Phase 2 expansion area is shown on Figure 1.
Piezometer and groundwater well construction information (including water level and
groundwater elevations) for the monitoring network is included in Table 1.
2.1 Current Groundwater Conditions
Area of focus water levels were collected on May 1, 2023, for the upper (shallow) flow zone and
were used to generate a groundwater level map (Figure 2). In addition, area of focus water
levels and pressure transducer data from select groundwater monitoring wells, piezometers
and the Cell 5 underdrain pump were collected on June 28, 2023 and July 5, 2023. Site -wide
water level sweeps occur semiannually during the second and fourth quarter. Observed
groundwater levels during this reporting period indicate:
• Groundwater is generally flowing north to south through the ILF area (Figure 2).
• Some groundwater levels within and near the ILF have decreased slightly, relative to
groundwater levels from Quarter 1, 2023. However, most of the groundwater levels
near the ILF remain relatively similar in elevation to that of Quarter 1, 2023.
• Underdrain operations in Cell 5 have maintained a cone of groundwater depression
around the Cell 5 blanket underdrain sump (CLF-UD, Figure 2).
2.2 Groundwater Trends
A series of groundwater monitoring wells, piezometers, and the Cell 5 underdrain pump
transducers are used to monitor water -level trends through June 2023 (Figures 3A through 3J).
The following are key observations of overall trend data:
• Groundwater level data collected from July 2021 (when close monitoring started)
through June 2023 were evaluated using Mann -Kendall analysis to determine water -
level trends. Statistically significant decreasing trends were observed in 21 of 26
locations. Stable trends were observed at four locations (CLF21-12, CLF21-14, CLF22-
305, CLF22-306).
• Generally, decreasing trends were observed in locations downgradient of the Future
Phases area during the reporting period and decreasing trends for the overall reporting
period.
2.2.1 Water -Level Hydrographs and Model Trends
Pressure transducers are used to record high -resolution groundwater elevation data for
evaluation of groundwater conditions resulting from dewatering and excavation.
Transducer data in Excel spreadsheets are included in Appendix A. Manual water -level
measurements and transducer records were used to generate hydrographs. Predicted
groundwater level trends from the transient groundwater models are included in the
2023 Page 2-1
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
hydrographs (Figures 3A through 3L). Appendix B contains Excel spreadsheets with the
predicted transient groundwater level trends exported from the models.
Upgradient of the Phase 2 Expansion:
• Monitoring locations GWA-4S/D and CLF21-10 are west of the ILF Phase 2
expansion (Figure 1). The shallow and deep flow zone water levels at those
locations have overall decreasing trends and showed decreasing to stable trends
during the reporting period (Figures 3A and 3C).
ILF-2S/D are located north of the ILF (Figure 1). The shallow and deep flow zones
water levels have an overall decreasing trend and show stable trends during the
reporting period (Figure 313).
MW-4/41D are located east of the ILF Phase 2 expansion (Figure 1). The shallow
and deep flow zone water levels at those locations have overall decreasing
trends. MW-4 shows a significantly decreasing trend over the reporting period
whereas MW-41D is stable during the reporting period
(Figure 3A).
Within the Phase 2 Expansion:
• A transducer, identified as CLF-UD, was installed to monitor the Cell 5
underdrain sump water level with the temporary pump operations (Figure 1). In
October 2022, a permanent pump was installed; the water level in the
permanent pump is recorded manually every week. The water levels within the
sump demonstrate that the underdrain continues to operate as intended,
maintaining a steady water level controlled by the pump settings (Figure 3D).
Perimeter of the Phase 2 Expansion:
• CLF21-11, CLF21-12, and CLF21-13R are located west and south of Cell 5. Shallow
water levels at CLF21-11 and CLF21-13R have overall decreasing trends but show
a general stable trend during the reporting period. Water levels in CLF-21-12 are
stable overall since completion of the Cell 5 underdrain construction and remain
stable during the reporting period (Figures 3C, 313, and 3G).
Monitoring locations CLF21-14R and CLF21-15 are west of Cell 6
(Figure 1). Water levels in CLF21-14R have an overall stable trend since ash
excavation is complete for Cell 6 and the water levels are stabilizing. Water levels
in CLF21-15 had an overall decreasing trend (Figure 3E).
2023 Page 2-2
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
Within the Future Phase 3 Expansion:
• Monitoring locations CLF-301 and CLF22-305 are within the Future Phase 3
expansion (Figure 1). Shallow water levels at CLF-301 and CLF22-305 have an
overall decreasing trend; both locations have a decreasing trend during the
reporting period (Figures 3F and 31).
Downgradient of the Phase 2 Expansion (Future Phases Area):
Monitoring location MW-7 (OB-3) is downgradient of the ILF Phase 2 expansion
and was abandoned on April 3, 2023 to support construction of the geosynthetic
cap for the Dry Ash Landfill Phase II (1804-INDUS). Therefore, MW-7 (OB-3)
cannot be analyzed for trends during the reporting period (Figure 1). Shallow
water levels at MW-7 (OB-3) had an overall decreasing trend prior to
abandonment (Figure 3B).
• Monitoring locations CLF-401 and CLF-402 are within Future Phases 4 and 5
expansion (Figure 1). Shallow water levels at CLF-401 and CLF-402 have an
overall decreasing trend and were decreasing during the reporting period
(Figures 3G and 3F).
• Monitoring locations CLF22-306, and CLF22-307 are downgradient of the Future
Phase 3 expansion (Figure 1). Shallow water levels at CLF22-306 are stable
overall while CLF22-307 water level was decreasing overall. Both CLF22-306 and
CLF22-307 show decreasing trends during the reporting period (Figures 31 and
3J).
Monitoring locations CLF23-405, CLF23-406, CLF23-407, and CLF23-408 were
installed, in the Future Phases 3 and 4, during the previous reporting period.
Water levels in CLF23-405, CLF23-406, CLF23-407 and CLF23-408 decreased
during the reporting period. Overall water levels have a decreasing trend
(Figure 3J, 3K, and 3L).
2.3 Dewatering and Underdrain Pump Performance
A primary excavation and construction dewatering pump is located at the downgradient edge
of ILF Future Phases (Figure 1). An underdrain pump is installed within the Cell 5 underdrain
(CLF-UD). The dewatering pump removes ash pore water and precipitation runoff to support
ash excavation, while the underdrain pump removes groundwater from below the ILF Phase 2,
Cell 5. The Cell 5 underdrain pump does not receive precipitation runoff; the underdrain is
enclosed. Water removed by each pump is discharged to the lower portion of the ash basin.
The Cell 5 underdrain pumping and model -predicted dewatering rates are shown on
Figure 4A. Model -predicted and measured flow rates from the Future Phases excavation
dewatering pump are shown on Figure 4B.
2023 Page 2-3
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
The Cell 5 underdrain pump has been operational for 22 months, at an average pumping rate
for the reporting period of 10 gpm. The flow rate of the Future Phases dewatering pump
increased to an average of 177 gpm from an average of 55 gpm. ILF Cell 5 and Future Phases
pumping data, including the calculated monthly total volume pumped and monthly average
flow rate, per location, are included in Appendix C.
Combined pumping operations for Cell 5 and the Future Phases area have removed
approximately 24.5 million gallons of water during the reporting period. For each pump, the
average flow rates for the reporting period and each month are listed below.
• The Cell 5 underdrain pump had an average flow rate of 10 gpm overall during the
reporting period and monthly average flow rates of:
o 11 gpm during April 2023
o 12.4 gpm during May 2023
o 8 gpm during June 2023
• The Future Phases pump had an average flow rate of 177 gpm overall during the
reporting period and monthly average flow rates of:
o 189.8 gpm during April 2023
o 197 gpm during May 2023
o 144.6 gpm during June 2023
2023 Page 2-4
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
3.0 QUARTERLY WATER -LEVEL REDUCTION ACTIVITIES
Efforts made during the reporting period by Duke Energy to safely expedite the reduction of
groundwater levels within the ILF Phase 2 expansion and the Future Phases include:
Cell 5
• Underdrain operations continued, with an average flow rate of approximately 10 gpm.
• Cell 5 operations continue.
Cell 6
• Construction of Cell 6 is ongoing with completion of the leak detection sump, leachate
collection sump, sideslope risers, leachate pumping system, and leachate force main
connections during the reporting period.
Future Phases
• Excavation of coal combustion residuals (CCR) in the Future Phases continued during the
reporting period.
• Dewatering of excavation rim ditches is being maintained, with an average flow rate of
approximately 177 gpm.
Stability Features
The installation of approximately 136 dewatering wells began during the reporting
period to support the construction of the Structural Fill (CC130031) northern stability
feature. The dewatering wells are phase 1 of a larger scale dewatering system that is
expected to temporarily influence the groundwater elevations in the vicinity of ILF
Future Phases nearest the stability feature dewatering system. Note the dewatering
system to support construction of the stability feature was not included in the
groundwater model simulations.
2023 Page 3-1
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
4.0 REFERENCES
SynTerra (2021). Technical Memorandum: Modeling Support for the ILF Phase 2 Permit to
Construct Modification, Marshall Steam Station. October S, 2021.
2023 Page 4-1
Project: 00.0083.46.09

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
FIGURES
L7
synTerra
Science & Engineering Consultants

M
J�
INDUSTRIAL
LANDFILL #1
0 950
PERMIT NO. 1812
CLF21-10 "
920
® + \ "s
900
-890
fl
CLF21-18 850 850
CLF21-19
7
CLF21-11 -m 830
T
r
CLF21-16
t i +•. CLF21-20 n
f # y
�, CLF-UD
I
`` CLF21-12 4
ral
CLF21-17
f
CLF t
' �' • ' ' " CLF21-13R
30 CLF-401
101
F
luCLF23-406�
CLF-402
- }�• °�- CLF-403
n '
F
ffiF
o•
d�
r�
*`' FUTURE
L PHASES PUMP
CLF21-14
CLF21-15 "
LEGEND
LONG-TERM PIEZOMETERAND/OR
4
GROUNDWATER MONITORING WELL
QII!)
TEMPORARY PIEZOMETER
DEWATERING OR UNDERDRAIN PUMP
ABANDONED PIEZOMETER
ASH BASIN WASTE BOUNDARY
— - — -
GEOGRAPHIC LIMITATION
LANDFILL COMPLIANCE BOUNDARY
STRUCTURAL FILL BOUNDARY
•
LANDFILL BOUNDARY
LEACHATE BASIN
— - -
DUKE ENERGY CAROLINAS PROPERTY LINE
TOPOGRAPHIC CONTOUR (10' INTERVAL)
1
STREAM (MCKIM & CREED)
L
WETLAND (MCKIM & CREED)
�� DUKE
4
GRAPHIC SCALE
200 0 200 400
ENERGY
CAROLINAS
IN FEET)
DRAWN BY. T. KING
DATE: 04/28/2022
REVISED BY: C. HARRISON
DATE: 07/24/2023
161p
CHECKED BY: T. COLTON
DATE: 07/24/2023
APPROVED BY: T. COLTON
DATE: 07/24/2023
svnTerra
PROJECT MANAGER T COLTON
NOTES:
1. THE CLF UD LOCATION WAS FORMERLY KNOWN AS CELL 5 PUMP
2. ALL BOUNDARIES ARE APPROXIMATE.
3. THE STREAMS AND WETLANDS JURISDICTIONAL DETERMINATION WAS APPROVED
BY THE US ARMY CORPS OF ENGINEERS ON OCTOBER 25, 2017 (SAW-2015-01412).
WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER
WHEELER ENVIRONMENTAL AND INFRASTRUCTURE, INC. NATURAL RESOURCES
TECHNICAL REPORT (NRTR) DATED JUNE 2015.
4. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY CAROLINAS
5. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND SHOULD
NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES. TOPOGRAPHY PROVIDED
BY TRANSASH.
6. AERIAL IMAGERY IS A COMBINATION OF DUKE ENERGY PROPELLER AERIAL
PHOTOGRAPHY COLLECTED ON MAY 8, 2023, AND MAXAR SATELLITE IMAGERY
OBTAINED FROM ESRI ONLINE, COLLECTED ON AUGUST 23, 2021.
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83).
FIGURE 1
MONITORING LOCATION MAP
GROUNDWATER CONDITIONS QUARTERLY REPORT
APRIL 2023 THROUGH JUNE 2023
MARSHALL STEAM STATION
TERRELL, NORTH CAROLINA

7
{
. ILF 2S
840 10
.•
Ile -n
l0000
SID
4
LEGEND
CLF21-10 "g325 - 940
840.70 930 �`920
-6s WELL ID
GWA-4S SK 4 910-930 g00 � - c - - 765.80 WATER LEVEL (NAVD 88, FEET)
( /
a r 847.19 ., / 8j°_-- 880 r - _ MW-4 " � BACKGROUND MONITORING WELL
.100,
aso'� 8275__ ��� 825.97 , MONITORING WELL
/sso �a PIEZOMETER
I,.,,CLF21-11 a30-��E25� 1 a' '•'.
�/r .��' 825.79 ,^z 7--p ���� '. •. ABANDONED PIEZOMETER
\v WELLABANDONED
/ �+ ' ; �u R DEWATERING OR UNDERDRAIN PUMP
822.5
x ���
L r! t 82o 21-15 a -INFERRED WATER LEVEL CONTOUR (2.5' INTERVAL)
CLF-UD `� ` CLF-
823.02
�. /CLF21-12 1♦ e°o ��. '' GROUNDWATER FLOW DIRECTION
820.85 �25 �h� §'� . �\ �� FUTURE PHASES
/t
- •' F;, �® �' � ,r.CLF21-13Rc 1 J b _� ° p� ��� ���`� 10 z' ASH BASIN WASTE BOUNDARY
818.92CLF2- - - GEOGRAPHIC LIMITATION
/'r ' �s17.5•�'�� 817.4 9 R
-- 4 7.48 0 ��L� ;� � � LANDFILL COMPLIANCE BOUNDARY
i CLF-301 "'` / , 81 r - STRUCTURAL FILL BOUNDARY A
815, 1 2 N -. - -
83.5
�♦ 850 / - MW-3 LANDFILL BOUNDARY
s50 / - �_�•�812.5• CLF23-407 _ i ) gLo 803.69
f LANDFILL CELL 5 AND 6 BOUNDARY
-- / f -- --- aoJJ® �w' -'
��� �t 810.13 �'-.�\ 7 ` t .;1�N�J�J�$ e % \ �o LEACHATE BASIN
sQ° /CLF 401 809.48 T•.
s2o l ♦02 <�♦ o ; - - DUKE ENERGY CAROLINAS PROPERTY LINE
� I -' a `-�, "Z ,, -" �� > .ram `a ����,§" a*°bI� 1'1��➢d; � ' 90 `n
aa° ;�. I j `•.� mot '�1.� C��;>1�,� /:a -'' .. e1 '' TOPOGRAPHIC CONTOUR (10' INTERVAL)
�sJ ti � aW' STREAM (MCKIM &CREED)
o �0 / / CLF23-406 ` '4: �� �$ 1 -.1 1 t l AL-3S
> , o WETLAND MCKIM &CREED
' 804.49 i 'Y A m ° ( )
,, p / / / /� CLF-402 �C{��fiP7 xr�iy,Y �' i> , h No 9
807.24 ®� Aa$ F' a iCI F 3O; ^° NOTES:
� � / CLF-403) � 1 JQ�n � �! ' • MW 7 (OB-3) �
/ _ �J i•� 0 i s a _ - - -1. WATER LEVELS WERE COLLECTED ON MAY 1, 2023.
80, CLF23-408--
• ,ti, f.; V S 803.67 ;; 3; 2. * - UNDERDRAIN/DEWATERING PUMP ELEVATION. WATER LEVEL CONTROL POINT.
V' �, ♦ / ��-i ` ,. CLF22-305 3. ** - FUTURE PHASES PUMP LOCATION IS FOR REFERENCE ONLY. NOT WATER
w.
-g�� 807.69 807.5�".•-- LEVEL CONTROL POINT.
vo C ,� °• 9 L\ _�'� �� - - 4. ELEVATIONS ARE REFERENCED TO THE NORTH AMERICAN VERTICAL DATUM OF
CLF22-306 3� 1988 (NAVD 88).
3 )1 CLF-404 802.37
- J oz 5 o - 5. THE STREAMS AND WETLANDS JURISDICTIONAL DETERMINATION WAS
m 'k, 8 CLF-303 `90 APPROVED BY THE US ARMY CORPS OF ENGINEERS ON OCTOBER 25, 2017
CLF23-405 ; ' °�. (SAW-2015-01412 . WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM
L 4'� PVSF 2S� �x- ti. 803.56 AMEC FOSTER WHEELER ENVIRONMENTAL AND INFRASTRUCTURE, INC. NATURAL
,' RESOURCES TECHNICAL REPORT (NRTR) DATED JUNE 2015.
gg c c
i ABA 5S
ti;.•.` yse :,° r �:. ��\ / 6. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND SHOULD
NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES. TOPOGRAPHY PROVIDED
BY TRANSASH.
7. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY CAROLINAS.
�'y a l '` _ �Z`' ix` �� •{f,' L� PHASES PUM �� 8. ALL BOUNDARIES ARE APPROXIMATE.
� CLF23-307' � ,
9. AERIAL IMAGERY IS A COMBINATION OF DUKE ENERGY PROPELLER AERIAL
PHOTOGRAPHY COLLECTED ON MAY 8, 2023, AND MAXAR SATELLITE IMAGERY
CLF-304 / . - OBTAINED FROM ESRI ONLINE, COLLECTED ON AUGUST 23, 2021.
cl.( �,�` _ � � P ��`"• 10. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE
C r : �Naa �, • 1 R '•`t PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
�- 1
,'� DUDE GRAPHIC SCALE
• C� zoo o zoo 400 FIGURE 2
ENERGY® N FEET)
AREA OF FOCUS WATER -LEVEL MAP
S CAROLINAS UPPER FLOW ZONE MAY 2023
DRAWN BYT KING DATE: 05/12/2022 GROUNDWATER CONDITIONS QUARTERLY REPORT
REVISED BY C. HARRISON DATE' 01/25/2023
CHECKED BY.T.COLTON DATE:07/25/2023 APRIL 2023 THROUGH JUNE 2023
APPROVED BY:T.CGLTON DATE:07/25/2023 MARSHALL STEAM STATION
PROJECT MANAGER T. COLTON
(� > synTero TERRELL, NORTH CAROLINA
www.s nterracor .com
P:\O ARCGIS PRO PROJECTS\DUKE ENERGY\MARSHAL1\2023\GW CONDITIONS OUARTERLY REPORT\GW CONDITIONS OUARTERLY REPORT 02 APR%

GWA-04S/D
M W-04/D
833
4
852
4
O
851
832
00
3
00 ♦
3
Q 850
Q 831
Z
'O
Z
O
♦
�♦
c 849
2
c 830
O
2
>
.7
�
c
v
°C
u' 848
LL' 829
847
°�' 828 I'
M
M
827 L
0
846 0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
Date
GWA-04S - Total water level change from transducer installation on 07/30/2021 to 06/28/2023 is -3.2 feet.
MW-04 - Total water level change from transducer installation on 07/30/2021 to 06/28/2023 is -3.6 feet.
GWA-04D - Total water level change from transducer installation on 07/30/2021 to 06/28/2023 is -3.6 feet.
MW-04D - Total water level change from transducer installation on 07/30/2021 to 06/28/2023 is -3.9 feet.
GWA-04S/D
MW-04/D
837
858
855
00
o
a 834
a
I
Z —
Z
i O
v 852
p
O
c
---
—
a 831
>
I
p
Uj
849
0 O D
� DO O
w
Op
p O p0 O
J
O O O O O
J
0
�' O'
1 828
L
(I; 846
�•
c0
825
843 T
6/1 /2021 12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
6/1 /2021 12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
Date
LEGEND Notes:
Cell 5 construction start (05/31/2021) NAVD 88 —North American Vertical
DUKE
r�
DRAWN BY: D.AVARD DATE:07/21/2021
FIGURE 3A
BACKGROUND MONTIORING WELL HYDROGRAPHS—
Future Phases 3 through 5 CCR excavation start (06/18/2021) Datum 1988
ENERGY,
REVISED BY: D. AVARD DATE:07/05/2023
INDUSTRIAL LANDFILL NO 1.
Cell 5 Blanket Underdrain construction start (9/20/2021) Ft - Feet
ROLINAS
CHECKED BY: T. COLTON DATE:07/10/2023
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction completion (10/22/2021)
in - inches
APPROVED BY:T. COLTON DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Shallow Groundwater Flow Zone (Transducer Data)
APRIL 2023 —JUNE 2023
Deep Groundwater Flow Zone (Transducer Data) ♦ Manual Water Level Measurement
PROJECT MANAGER:T. COLTON
MARSHALL STEAM STATION
Bedrock Groundwater Flow Zone (Transducer Data) Daily Total Rainfall (inches)1Ta
TERRELL NORTH CAROLINA
— — - Transient Groundwater Model Water Level Predicted Trend
www.synterracorp.com

MW-07 (013-3)
ILF-02S/D
819
818
00
a
> 817
z
c 816
O
u' 815
a�
>
a�
814
co
813
4
3
C
2
c
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
MW-07 (013-3) - Total water level change from transducer installation on 07/30/2021 to 04/03/2023 is -3.5 feet.
MW-07 (013-3) was abandoned April 3, 2023.
MW-07 (013-3)
822
0 819
a
z
W
0 816
>
N
W
G1
>
813
v
M
00
0- O-
p
O
O p
O
I
Q- J I .�
HII, 1 111.11
n
U
846
845
844
843
842
841
840
4
3
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
ILF-02S - Total water level change from transducer installation on 07/30/2021 to 06/28/2023 is -0.6 feet.
ILF-02D - Total water level change from transducer installation on 07/30/2021 to 06/28/2023 is -0.6 feet.
ILF-02S/D
849
840
■
810
837 -L+—
6/1 /2021 12/1 /2021 6/1 /2022
12/1 /2022 6/1 /2023
6/1 /2021
12/1 /2021
6/1 /2022 12/1 /2022 6/1 /2023
Date
Date
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
NAVD 88 — North American Vertical
DUKE
DRAWN BY: D. AVARD
DATE:07/21/2021
FIGURE 3B
PERIMETER HYDROGRAPHS — INDUSTRIAL LANDFILL NO 1.
ENERGY.
REVISED BY: D. AVARD
DATE:07/05/2023
Future Phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROLINAS
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CHECKED BY: T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
`�
Cell 5 Blanket Underdrain construction completion (10/22/2021)
in -inches
APPROVED BY: T. COLTON
DATE: 07/10/2023
APRIL 2023 — J U N E 2023
Shallow Groundwater Flow Zone (Transducer Data)
♦
Manual Water Level Measurement
PROJECT MANAGER:T. COLTON
MARSHALL STEAM STATION
Deep Groundwater Flow Zone (Transducer Data)
— — - Transient Groundwater Model Water Level Predicted Trend
Daily Total Rainfall (inches)
synTerra
TERRELL, NORTH CAROLINA
www.synterracorp.com

CLF21-10
843
842
00
00
a
> 841
z
LLLL
O
m
Qj
�iD2•J
a�
v
838
c�
837
4
3
C
2
4-
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF21-10 - Total water level change from transducer installation on 08/10/2021 to 06/28/2023 is -0.5 feet.
CLF21-10
846
0 843
a
z
LPL
00
0 840
>
N
LU
Gl
>
837
a�
M
834 -L+--
6/1 /2021
12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
-
CLF21-11
832
830
828
826
824
822
820
4
3
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF21-11- Total water level change from transducer installation on 08/09/2021 to 6/28/2023 is -4.2 feet.
834
831
828
825
I
CLF21-11
�O
'Q �
822 11
6/1 /2021
12/1/2021 6/1/2022 12/1/2022 6/1/2023
Date
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
NAVD 88 - North American Vertical
DUKE
DRAWN BY: D.AVARD
DATE:07/21/2021
FIGURE 3C
NORTHWEST OF CELL 5 HYDROGRAPHS- INDUSTRIAL LANDFILL NO 1.
ENERGY.
REVISED BY: D. AVARD
DATE:07/05/2023
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROI INAS
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CHECKED BY: T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
APPROVED BY: T. COLTON
DATE:07/10/2023
APRIL 2023 -JUNE 2023
Shallow Groundwater Flow Zone (Transducer Data)
�
Manual Water Level Measurement
10,
PROJECT MANAGER: T. COLTON
MARSHALL STEAM STATION
-Transient Groundwater Model water level predicted trend
Daily Total Rainfall (inches)
synTerra
www.synterracorp.com
TERRELL, NORTH CAROLINA

818 -
1.15IIT
00
00
0
a
z 814
+.
LL
C
0
> 812
v
W
Gl
>
810 -
c�
CLF-LID
oil
711�1
0
3
%i
1
C
4-
C
808 0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF-UD— Water level is stable during underdrain operations. Water levels spikes represent when pump was temporarily out of service.
CLF-LID
819
0 816
a
z
LLLL
C
813
>
N
LU
Gl
>
N
810
a�
M
807 ' 1 11 1 1 1 1 '
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023
Date
00
a
z
.LL-.
C
0
co
>
a�
LL!
GJ
>
a�
J
L
M
-
CLF21-12
824
823
822
821
820
819
818
4
3
C
2
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF21-12 - Total water level change from transducer installation on 10/03/2021 to 06/28/2023 is -2.2 feet.
CLF21-12
825
820
815
810
805
6/1/2021 12/1/2021 6/1/2022 12/1/2022 6/1/2023
Date
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
DUKE
DRAWN BY: D. AVARD
DATE:07/21/2021
FIGURE 3D
CLII AND SOUTHWEST OF CELL 5 HYDROGRAPHS —
NAVD 88 — North American Vertical
ENERGY
REVISED BY: D. AVARD
DATE:07/12/2023
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
INDUSTRIAL LANDFILL NO 1.
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CAROLINAS
CHECKED BY: T. COLTON
DATE:07/10/2023
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction completion (10/22/2021)
in -inches
APPROVED BY:T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Shallow Groundwater Flow Zone (Transducer Data)
`�
PROJECT MANAGER: T. COLTON
APRIL 2023 —JUNE 2023
- Transient Groundwater Model water level predicted trend
Manual Water Level Measurement
MARSHALL STEAM STATION
www.synterracorp.com
Daily Total Rainfall (inches)
Ta
TERRELL, NORTH CAROLINA

CLF21-14/R
CLF21-15
823
822
00
a
Q 821
z
LL
c 820
O
a�
d
818 -
c0
4
3
KA
1
817-1 0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF21-14R - Total water level change from transducer installation on 04/08/2022 to 06/28/2023 is +2.8 feet.
• • • • • CLF21-14 - Total water level change from transducer installation on 08/13/2021 to 03/22/2022 is -3.3 feet.
CLF21-14/R
830
00 825
0
a
z
LLLL
0 820
>
N
LU
Gl
>
815
a�
M
810 -L+--
6/1 /2021
0
12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
C
00
Q
z
4.:
.LLL
O
>
LL!
v
N
J
L
M
-
827
826
825
824
823
822
3
1
821 0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF21-15 - Total water level change from transducer installation on 08/13/2021 to 03/30/2023 is -3.5 feet.
CLF21-15
828
825
822
819
816 ' 1 1-
6/1 /2021
90
0
o
0
�� o
0 0 0 0 0 0 .yL�Y�l41
12/1 /2021 6/1 /2022 12/1 /2022
Date
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
NAVD 88 - North American Vertical
DUKE
DRAWN BY: D.AVARD
DATE:07/21/2021
FIGURE 3E
EAST OF CELL 6 HYDROGRAPHS - INDUSTRIAL LANDFILL NO 1.
ENERGY.
REVISED BY: D. AVARD
DATE:07/05/2023
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROI INAS
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CHECKED BY: T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
�
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
APPROVED BY: T. COLTON
DATE:07/10/2023
APRIL 2023 -JUNE 2023
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
www.synterracorp.com
TERRELL, NORTH CAROLINA

CLF-301
818
817
00
a
> 816
z
LL
c 815
0
m
d
u' 814
Gl
>
v
°�' 813
c�
812
4
3
C
2 ._
c
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF-301- Total water level change from transducer installation on 07/27/2021 to 06/28/2023 is -4.4 feet.
CLF-301
819
0 816
a
z
LPL
0 813
>
N
LU
Gl
>
J 810
L
GJ
M
42
807 -L+--
6/1 /2021
>oo
00 0
O Q
O O'
12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
00
Q
z
LL
C
2
a�
W
GJ
>
aj
J
a�
M
-
i
813
811
:I•
807
o.J
CLF-402
n
4
3
1
805 0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF-402 - Total water level change from transducer installation on 07/27/2021 to 06/28/2023 is -6.4 feet.
CLF-402
815
810
805
:
795 ' 1 L
6/1 /2021
12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
NAVD 88 — North American Vertical
DUKE
DRAWN BY: D. AVARD
DATE:07/21/2021
FIGURE 3F
FUTURE PHASE 3 AND 4 HYDROGRAPHS — INDUSTRIAL LANDFILL NO 1.
ENERGY.
REVISED BY: D. AVARD
DATE:07/05/2023
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROI INAS
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CHECKED BY: T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
APPROVED BY: T. COLTON
DATE:07/10/2023
APRIL 2023 —JUNE 2023
Shallow Groundwater Flow Zone (Transducer Data)
�
Manual Water Level Measurement
10,
PROJECT MANAGER: T. COLTON
MARSHALL STEAM STATION
-Transient Groundwater Model water level predicted trend
Daily Total Rainfall (inches)
synTerra
www.synterracorp.com
TERRELL, NORTH CAROLINA

CLF21-13/R
822
820
00
> 818
z
LL
c 816
0
v
u' 814
Gl
>
v
°�' 812
c�
810
4
3
2
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF21-13R - Total water level change from transducer installation on 11/08/2021 to 03/31/2023 is +0.5 feet.
CLF21-13 - Total water level change from transducer installation on 08/09/2021 to 10/01/2021 is -0.2 feet.
CLF21-13/R
0 820
a
z
LL
C
815
>
N
W
Gl
>
810
M
CLF21-13 was abandoned and replaced on
November 4, 2021.
O< O
� O O
I
O �
II
805 -L+--
6/1 /2021
o ° °* o ° o
O'
12/1 /2021 6/1 /2022
Date
12/1/2022 6/1/2023
-
816
814
812
810
CLF-401
M
3
KA
1
808 0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF-401- Total water level change from transducer installation on 07/27/2021 to 06/28/2023 is -6.5 feet.
CLF-401
820
I-I&S
810
TM
795 ' 1 L
6/1 /2021
�000 o _ -M
12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
C
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
DUKE
DRAWN BY: D. AVARD
DATE:07/21/2021
FIGURE 3G
CELL 5 AND FUTURE PHASE 5 HYDROGRAPHS—
NAVD 88 — North American Vertical
ENERGY
REVISED BY: D. AVARD
DATE:
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
INDUSTRIAL LANDFILL NO 1.
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CAROLINAS
CHECKED BY: T. COLTON
DATE:07/10/2023
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction completion (10/22/2021)
in -inches
APPROVED BY: T. COLTON
DATE: 07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Shallow Groundwater Flow Zone (Transducer Data)
`�
PROJECT MANAGER: T. COLTON
APRIL 2023 —JUNE 2023
- Transient Groundwater Model water level predicted trend
Manual Water Level Measurement
MARSHALL STEAM STATION
www.synterracorp.com
Daily Total Rainfall (inches)
Ta
TERRELL, NORTH CAROLINA

CLF-303
802
801
00
a
> 800
z
c 799
0
v
W 798
v
v
J
L
797
c0
796
4
3
c
2 _
�a
c
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF-303 - Total water level change from transducer installation on 07/27/2021 to 01/11/2023 is +0.5 feet.
CLF-303
810
00 805
a
z
LA.
0 800
>
N
W
Gl
>
795
a�
M
790 -L+--
6/1 /2021
12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
-
CLF-304
801
800
799
798
797
796
795
4
3
1
0
6/1 /2021 10/1 /2021 2/1 /2022 6/1 /2022 10/1 /2022 2/1 /2023 6/1 /2023
Date
CLF-304 - Total water level change from transducer installation on 07/27/2021 to 01/18/2023 is +0.2 feet.
CLF-304
807
804
801
798
o �0 IrA,�
• 0•• OO O aw
795 ' 1 L
6/1 /2021
12/1/2021 6/1/2022 12/1/2022 6/1/2023
Date
LEGEND
Cell 5 05/31/2021
Notes:
DUKE
DRAWN BY: D. AVARD
DATE:07/21/2021
FIGURE 3H
SOUTH OF FUTURE PHASE 3 HYDROGRAPHS-
construction start ( )
NAVD 88 -North American Vertical
ENERGY
REVISED BY: D. AVARD
DATE:07/OS/2023
INDUSTRIAL LANDFILL NO 1.
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROLINAS
CHECKED BY: T. COLTON
DATE:07/10/2023
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
Cell 5 Blanket Underdrain construction completion (10/22/2021)
in - inches
APPROVED BY: T. COLTON
DATE: 07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Shallow Groundwater Flow Zone (Transducer Data)
�
PROJECT MANAGER: T. COLTON
APRIL 2023 —JUNE 2023
- Transient Groundwater Model water level predicted trend ♦
Manual Water Level Measurement
MARSHALL STEAM STATION
www.synterracorp.com
Daily Total Rainfall (inches)
synTem
TERRELL, NORTH CAROLINA

CLF22-305
CLF22-306
i�
813
810
807
804
4
3
1
801 0
6/1 /2021 12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
816
E:5191
804
792
786
Date
CLF22-305 - Total water level change from transducer installation on 08/10/2021 to 06/28/2023 is -2.8 feet.
CLF22-305
6/1 /2021 12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
CLF22-305 was not used in the Transient Groundwater Model calibration, water level predictions were prepared following installation of
CLF22-305 (after Transient Groundwater Model calibration)
LEGEND Notes: DUKE
Cell 5 construction start (05/31/2021) NAVD 88 — North American Vertical ENERGY.
Future phases 3 through 5 CCR excavation start (06/18/2021) Datum 1988
Cell 5 Blanket Underdrain construction start (9/20/2021) CAROI INAS
Ft -Feet
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
Shallow Groundwater Flow Zone (Transducer Data)
-Transient Groundwater Model water level predicted trend � Manual Water Level Measurement 110
Daily Total Rainfall (inches) synTem
00
Q
z
C
0
c�
>
a�
W
GJ
>
aj
J
L
M
i
807
804
801
798
�o ti
jilull I..11 I I ,,, -L
795 0
6/1 /2021 9/1 /2021 12/1 /20213/1 /2022 6/1 /2022 9/1 /202212/1 /20223/1 /2023 6/1 /2023
Date
CLF22-306 - Total water level change from transducer installation on 08/13/2021 to 06/28/2023 is -1.6 feet.
M
3
:e1
792
784 -
CLF22-306
C
�a
4-
1
776
6/1/2021 12/1/2021 6/1/2022 12/1/2022 6/1/2023
Date
CLF22-306 was not used in the Transient Groundwater Model calibration, water level predictions were prepared following installation of
CLF22-306 (after Transient Groundwater Model calibration)
DRAWN BY: D. AVARD DATE:07/21/2021 FIGURE 31
REVISED BY: D. AVARD DATE:07/05/2023 PHASE 3 HYDROGRAPHS — INDUSTRIAL LANDFILL NO 1.
CHECKED BY: T. COLTON DATE:07/10/2023 (1812-INDUS) PHASE 2 EXPANSION
GROUNDWATER CONDITIONS QUARTERLY REPORT
APPROVED BY: T. COLTON DATE: 07/10/2023 APRI L 2023 — J U N E 2023
PROJECT MANAGER: T. COLTON MARSHALL STEAM STATION
www.synterracorp.com TERRELL, NORTH CAROLINA

CLF22-307
CLF23-405
00 804
0
Q
z
LLLL
c 802
0
v
LLI
G1
a>i 800 -
J
L
i�
4
3
KA
1
798 0
6/1 /2021 12/1 /2021 6/1 /2022 12/1 /2022 6/1 /2023
Date
CLF22-307 - Total water level change from transducer installation on 04/08/2022 to 06/28/2023 is -2.6 feet.
CLF22-307
810
1
\ O
00 800
a
z
ILL.
0 790
>
N
LU
Gl
>
J 780
i
GJ
M
U
C
4-
c
i
i
807
804
801
798
4
3
1
795 0
6/1/2021 12/1/2021 6/1/2022 12/1/2022 6/1/2023
Date
CLF23-405 - Total water level change from transducer installation on 03/01/2023 to 06/28/2023 is -3.8 feet.
812 -
804 -
796 -
788 -
770 780
6/1/2021 12/1/2021 6/1/2022 12/1/2022 6/1/2023 6/1/2021 12/1/2021
Date
CLF22-307 was not used in the Transient Groundwater Model calibration, water level predictions were prepared following installation of
CLF22-307 (after Transient Groundwater Model calibration)
LEGEND Notes:
Cell 5 construction start (05/31/2021) NAVD 88 — North American Vertical
DUKE
DRAWN BY: D.AVARD
ENERGY.
REVISED BY: D. AVARD
Future phases 3 through 5 CCR excavation start (06/18/2021) Datum 1988
CAROI INAS
CHECKED BY: T. COLTON
Cell 5 Blanket Underdrain construction start (9/20/2021) Ft -Feet
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
APPROVED BY: T. COLTON
Shallow Groundwater Flow Zone (Transducer Data)
� Manual Water Level Measurement
110
PROJECT MANAGER: T. COLTON
-Transient Groundwater Model water level predicted trend
p
www.synterracorp.com
Daily Total Rainfall (inches)
synTei ery
�
CLF23-405
O
6/1 /2022 12/1 /2022 6/1 /2023
Date
DATE:07/21/2021
FIGURE 3.11
WITHIN AND SOUTH OF PHASE 4 HYDROGRAPHS —
DATE: 07/05/2023
INDUSTRIAL LANDFILL NO 1.
DATE:07/10/2023
(1812-INDUS) PHASE 2 EXPANSION
DATE: 07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
APRIL 2023 — JUNE 2023
MARSHALL STEAM STATION
TERRELL, NORTH CAROLINA

CLF23-406
CLF23-407
810
4
810
4
0
O
00 807
3
00
809
3
o
a
>
>
Q
Q
Z
Z
c 804
2
c
808
o
—
o
—
fa
>
c
>
v
W
ca
W
W
ca
d
W 801
1
GJ
W
807
1
J
J
f0
M
798
14k
0
806
0
12/1 /2022
2/1 /2023 4/1 /2023 6/1 /2023
12/1 /2022
2/1 /2023
4/1 /2023 6/1 /2023
Date
Date
CLF23-406 - Total water level change from transducer installation on 03/01/2023 to 03/30/2023 is -1.7 feet.
CLF23-407
- Total water level change from transducer installation on 03/01/2023 to 06/28/2023 is -1.1 feet.
CLF23-406
CLF23-407
818
818
�
I
o0
00
00 810
>
812
>
\
Z
LPL
i
O
\
0 802
>
806
\
>
`
W
W
\
;
N
J
>
794
—
+;
800
o
-
786
794
6/1 /2021
12/1 /2021 6/1 /2022
12/1 /2022 6/1 /2023
6/1 /2021
12/1 /2021
6/1 /2022 12/1 /2022 6/1 /2023
Date
Date
CLF22-307 was
not used in the Transient Groundwater Model calibration, water
level predictions were prepared following installation of
CLF22-307 (after
Transient Groundwater Model calibration)
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
NAVD 88 — North American Vertical
DUKE
DRAWN BY: D. AVARD
DATE:07/21/2021
FIGURE 3K
FUTURE PHASE 4 AND 5 HYDROGRAPHS — INDUSTRIAL LANDFILL NO 1.
ENERGY.
REVISED BY: D. AVARD
DATE:07/12/2023
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROI INAS
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CHECKED BY: T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
APPROVED BY: T. COLTON
DATE:07/10/2023
APRIL 2023 —JUNE 2023
Shallow Groundwater Flow Zone (Transducer Data)
�
Manual Water Level Measurement
101
PROJECT MANAGER: T. COLTON
MARSHALL STEAM STATION
-Transient Groundwater Model water level predicted trend
Daily Total Rainfall (inches)
synTerra
www.synterracorp.com
TERRELL, NORTH CAROLINA

CLF23-408
807
4
00 00
804
3
t7
Q
Z
+;
c
801
2
=
Space Not Used
o
—
>
'ca
v
W
GJ
0>i
798
1
J
N
f0
795
0
12/1 /2022
2/1 /2023 4/1 /2023 6/1 /2023
Date
CLF23-408 - Total water level change from transducer installation on 03/21/2023 to 06/28/2023 is -3.4 feet.
CLF23-408
812
e
00
805
Q
Z
L4L
°
798
Space Not Used
v
W
Gl
\>
791
a�
M
784
6/1/2021
12/1/2021 6/1/2022
12/1/2022 6/1/2023
Date
LEGEND
Cell 5 construction start (05/31/2021)
Notes:
NAVD 88 — North American Vertical
DUKE
DRAWN BY: D.AVARD
DATE:07/21/2021
FIGURE 3L
WITHIN PHASE 4 HYDROGRAPHS — INDUSTRIAL LANDFILL NO 1.
ENERGY.
REVISED BY: D. AVARD
DATE:07/12/2023
Future phases 3 through 5 CCR excavation start (06/18/2021)
Datum 1988
CAROI INAS
(1812-INDUS) PHASE 2 EXPANSION
Cell 5 Blanket Underdrain construction start (9/20/2021)
Ft -Feet
CHECKED BY: T. COLTON
DATE:07/10/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
Cell 5 Blanket Underdrain construction completion (10/22/2021) in - inches
APPROVED BY: T. COLTON
DATE:07/10/2023
APRIL 2023 —JUNE 2023
Shallow Groundwater Flow Zone (Transducer Data)
�
Manual Water Level Measurement
10,
PROJECT MANAGER: T. COLTON
MARSHALL STEAM STATION
-Transient
Groundwater Model water level predicted trend
Daily Total Rainfall (inches)
synTerra
www.synterracorp.com
TERRELL, NORTH CAROLINA

CL
wo
a�
co
re
O
LL
N
c-
Ln
0)
U
140
120
100
:1
M
20
I
3
2
1
Ic
9/1/2021
3/1/2022
9/1/2022 3/1/2023
Years
of Operation
Notes:
1. gpm = gallons per
minute.
2. Flow data from
the first day following a period of no flow
were not plotted.
DUKE
DRAWN BY: T. COLTON
DATE: 10/13/2021
FIGURE 4A
4 ENERGY
c
REVISED BY: D. AVARD
CHECKED BY: T. COLTON
DATE: 07/12/2023
DATE: 07/05/2023
CELL 5 (UNDERDRAIN) PUMPING FLOW RATE VS. SIMULATED FLOW RATE
APPROVED BY: T. COLTON
DATE: 07/05/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
��
PROJECT MANAGER: T. COLTON
APRIL 2023 THROUGH JUNE 2023
synTena
MARSHALL STEAM STATION
TERRELL, NORTH CAROLINA
www.synterracorp.com

500
A
CL
aA
a) 300
ca
oC
_O
LL 200
Ln
W
cN
ca
v 100
40
S
LL
■
x x X x
x
x ■ ■ Xx
x x �� ■ ■
XX ■ ■
X x is
x °
0 Xx X
x i_i
■ x X ■
XX � ��
■ X � x
X x
X X
X Xx CC x � x x �
J
3
2
V)
U
O
1 ro
Q
X
0
0
9/1/2021
3/1/2022
9/1/2022 3/1/2023
X Actual Pumping Flow Rate (gpm)
Years of Operation
■ Model Flow Rate (gpm)
Rainfall Daily Total (in)
Notes:
1. gpm = gallons per minute.
2. Flow data from the first day following a period of no flow were not plotted.
DUKE
DRAWN BY: T. COLTON
DATE: 10/13/2021
FIGURE 413
4 ENERGY
c
REVISED BY: D. AVARD
CHECKED BY: T. COLTON
DATE: 07/12/2023
DATE: 07/05/2023
PHASE 3-5 PUMPING FLOW RATE VS. SIMULATED FLOW RATE
APPROVED BY: T. COLTON
DATE: 07/05/2023
GROUNDWATER CONDITIONS QUARTERLY REPORT
��
PROJECT MANAGER: T. COLTON
APRIL 2023 THROUGH JUNE 2023
synTena
MARSHALL STEAM STATION
TERRELL, NORTH CAROLINA
www.synterracorp.com

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
TABLE
L7
synTerra
Science & Engineering Consultants

TABLE 1
GROUNDWATER MONITORING NETWORK WELL INFORMATION AND WATER LEVELS
GROUNDWATER CONDITIONS QUARTERLY REPORT
APRIL 2023 THROUGH JUNE 2023
MARSHALL STEAM STATION
DUKE ENERGY CAROLINAS, LLC, TERRELL, NC
Well ID
Date Well/
Piezometer
Installed
Date
Transducer
Installed
Monitoring
Zone
Northing
(Ft-NAD 83)
Easting
(Ft-NAD 83)
Measuring Point
TOC Elevation
(Ft-NAVD 88)
Ground Surface
Elevation
(Ft-NAVD 88)
Total Well
2,3
Depth
(Ft-BGS)
Measured
i
Well Depth
(Ft-TOC)
Screened
3
Interval
(Ft TOC)
Top of
Screen
Elevation
(Ft-NAVD 88)
Bottom
of Screen
Elevation
(Ft-NAVD 88)
Water Level
Measurement
(Ft-TOC)
5/01/2023
Groundwater
Elevation
(Ft -NAND 88)
5/01/2023
Water Level
Measurement
(Ft-TOC)
6/28/2023
Groundwater
Elevation
(Ft -NAND 88)
6/28/2023
CLF-301
5/21/2021
7/27/2021
Shallow
685838.40
1413513.30
847.46
844.46
62.00
65.00
52.00
62.00
795.46
785.46
34.21
813.25
34.55
812.91
CLF-303
5/12/2021
7/27/2021
Shallow
684951.10
1413840.30
824.31
822.31
40.00
42.00
30.00
40.00
794.31
784.31
Abandoned
Abandoned
CLF-304
5/24/2021
7/27/2021
Shallow
684062.20
1413563.40
823.28
821.28
60.00
62.00
50.00
60.00
773.28
763.28
Abandoned
Abandoned
CLF-401
5/17/2021
7/27/2021
Shallow
685783.50
1412779.50
832.44
830.44
39.00
41.00
29.00
39.00
803.44
793.44
22.31
810.13
23.50
808.94
CLF-402
5/21/2021
7/27/2021
Shallow
685598.80
1413217.80
818.41
816.41
50.00
52.00
40.00
50.00
778.41
768.41
11.17
807.24
12.90
805.51
CLF21-10
8/6/2021
8/6/2021
Shallow
687020.10
1412353.40
857.75
857.75
32.00
32.00
22.00
32.00
835.75
825.75
17.05
840.70
17.16
840.59
CLF21-11
8/5/2021
8/5/2021
Shallow
686572.30
1412572.20
850.17
850.08
40.00
41.64
31.64
41.64
818.53
808.53
24.38
825.79
23.96
826.21
CLF21-12
8/5/2021
8/5/2021
Shallow
686217.40
1412518.20
839.06
838.96
40.00
43.22
31.22
41.22
807.84
797.84
18.21
820.85
18.45
820.61
CLF21-13R
11/4/2021
11/8/2021
Shallow
686085.92
1412818.66
836.21
836.2
35.00
37.46
25.46
35.46
810.75
800.75
17.29
818.92
16.95
819.26
CLF21-14R
4/18/2022
4/18/2022
Shallow
686027.10
1414268.70
847.54
844.0
41.50
38.19
28.19
38.19
819.35
809.35
26.75
820.79
26.60
820.94
CLF21-15
8/10/2021
8/10/2021
Shallow
686307.70
1414410.00
864.37
864.37
55.00
55.00
45.00
55.00
819.37
809.37
41.35
823.02
Abandoned
CLF22-305
3/22/2022
4/8/2022
Shallow
685228.95
1413445.92
819.21
816.94
16.00
16.00
6.00
16.00
813.21
803.21
11.52
807.69
15.20*
804.01
CLF22-306
3/22/2022
4/8/2022
Shallow
685033.00
1413752.34
816.36
813.57
25.00
25.00
15.00
25.00
801.36
791.36
13.99
802.37
15.67*
800.69
CLF22-307
3/22/2022
4/8/2022
Shallow
684539.89
1413247.50
825.96
823.40
40.00
40.00
30.00
40.00
795.96
785.96
24.83
801.13
26.17*
799.79
CLF23-405
2/14/2022
3/1/2022
Shallow
684920.61
1413022.90
810.29
807.29
42.00
42.00
32.00
42.00
778.29
768.29
7.04
803.25
9.55*
800.74
CLF23-406
2/14/2022
3/1/2022
Shallow
685463.34
1412717.51
813.96
810.77
43.00
43.00
33.00
43.00
780.96
770.96
9.71
804.25
12.30
801.66
CLF23-407
2/15/2023
3/1/2022
Shallow
685796.44
1413229.69
828.87
826.33
43.00
43.00
33.00
43.00
795.87
785.87
19.82
809.05
20.80
808.07
CLF23-408
2/15/2023
3/1/2022
Shallow
685262.35
1413270.88
810.81
808.07
35.00
35.00
25.00
35.00
785.81
775.81
7.31
803.50
10.75
800.06
GWA-4D
6/12/2015
7/30/2021
Deep
686783.39
1411776.91
902.45
899.38
90.07
93.14
84.07
89.07
818.38
813.38
54.38
848.07
NM
NM
GWA-4S
5/19/2015
7/30/2021
Shallow
686776.57
1411777.34
901.97
898.98
67.99
70.98
52.19
67.19
849.78
834.78
54.78
847.19
NM
NM
MW-4
6/30/1989
7/30/2021
Shallow
686723.00
1414467.00
867.15
863.81
50.20
49.93
49.93
49.93
823.55
813.55
38.24
825.97
NM
NM
MW-41)
10/12/2006
7/30/2021
Bedrock
686715.00
1414462.00
866.74
863.42
64.18
67.55
56.65
61.65
807.87
802.87
38.64
828.10
38.80
827.94
MW-7 (06-3)
12/16/2010
7/30/2021
Shallow
685380.10
1414418.00
859.16
856.56
51.40
54.00
39.00
54.00
820.16
805.16
Abandoned
Abandoned
ILF-21)
3/31/2019
7/30/2021
Deep
687699.24
1413205.78
885.14
885.57
107.00
106.57
91.57
101.57
793.57
783.57
41.32
843.82
43.66
841.48
ILF-2S
3/31/2019
7/30/2021
Shallow
687699.26
1413214.68
884.79
885.21
52.00
51.58
41.58
51.58
843.21
833.21
43.69
841.10
41.30
843.49 11
Notes:
1 Well depths initially measured during well installation and updated as new wells are installed.
Z "Total Well Depth" is the depth to the bottom of the filter pack.
3 Values measured during well installation
* - Water level measured on July S, 2023.
BGS - Below ground surface
TOC - Top of casing
Ft - Feet
NAD 83 - North American Datum of 1983
NAVD 88 - North American Vertical Datum of 1988
NM - Not measured
Prepared by: KCO Checked by: DAA
Page 1 of 1

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
APPENDIX A
WATER -LEVEL MONITORING DATA FILES
INCLUDED AS EXCEL FILE)
L7
synTerra
Science & Engineering Consultants

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
APPENDIX B
GROUNDWATER MODEL PREDICTED TREND FILES
INCLUDED AS EXCEL FILE)
t
L7
synTerra
Science & Engineering Consultants

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
APPENDIX C
DEWATERING/UNDERDRAIN PUMPING DATA FILES
INCLUDED AS EXCEL FILE)
141
synTerra
Science & Engineering Consultants

Groundwater Conditions Quarterly Report — April 2023 to June 2023
Duke Energy Carolinas, LLC - Marshall Steam Station - Industrial Landfill No. 1
Terrell, North Carolina
APPENDIX D
MANN-KENDALL DATA
INCLUDED AS EXCEL FILE)
L7
synTerra
Science & Engineering Consultants