NC0004979_Report_20201221

44 DUKE PaulDraovitch
ENERGY® Environm Senior Vice Presides,
Environmental,Health&Safety;
Operations Support and CCP
526 S.Church Street
Mail Code:SCUP
Charlotte,NC 28202
[phone]
December 21, 2020
Via Overnight Mail
S. Daniel Smith
Director of Water Resources Ft aE 1�®
North Carolina Department of Environmental Quality
1617 Mail Service Center IN 04 242 2�
Raleigh,NC 27699-1617 0 4
t�C pEQlp�n
Rick Bolich Csntca�Office
Section Chief, Groundwater Resources Section
North Carolina Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Report Under Special Order by Consent—EMC SOC WQ S 17-009
Duke Energy Progress,LLC—Allen Steam Station
NPDES Permit NC0004979
Seep Management Amendment to Corrective Action Plan
Dear Messrs. Smith and Sledge:
On behalf of Duke Energy Carolinas, LLC (DEC), I am submitting to you the Seep Management
Amendment to Corrective Action Plan as required by the Allen Steam Station NPDES Permit
NC0004979 Special Order by Consent(SOC), SOC No. S 17-009, Section 2.d. This report follows
the Seep Characterization Report submitted on October 27, 2020 and addresses management of
non-dispositioned seeps at the Allen Plant.
Please direct any questions about this submittal to Courtney Murphy at(704) 382-7171 or Chris
Hallman at(980) 373-7892.
I certify under penalty of law that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief, true, accurate,

Messrs. Smith and Bolich
December 21, 2020
Page 2
and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fine and imprisonment for knowing violations.
ly,
Paul Draovitch
Senior Vice President
Environment, Health& Safety; Operations Support and CCP
Duke Energy
Attachment:
Allen Steam Station Seep Management Amendment to Corrective Action Plan
cc: Jim Wells, Duke Energy
Ed Sullivan, Duke Energy
Matt Hanchey,Duke Energy
Richard Baker, Duke Energy
Shannon Langley,Duke Energy
Elizabeth Glenn, Duke Energy
Courtney Murphy, Duke Energy
Chris Hallman, Duke Energy
Randy Gantt, Duke Energy
Tyler Hardin, Duke Energy
Bob Sledge,NCDEQ

4 410
.;ynTerra
SEEP MANAGEMENT PLAN AMENDMENT TO
CORRECTIVE ACTION PLAN
ALLEN STEAM STATION
253 PLANT ALLEN ROAD
BELMONT, NC 28012
DECEMBER 21, 2020
PREPARED FOR
—A%� k
DUKE ENERGY CAROLINAs, LLC
ChrX- Suttell, NC LG #2426
Project Principal
Lee Drago
Staff Scientist

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
EXECUTIVE SUMMARY
SynTerra prepared this Seep Management Plan Amendment to the Corrective Action
Plan (Plan) pertaining to the Allen Steam Station (Allen or Site) to describe plans for the
management of identified seeps in a manner that protects public health, safety, and
welfare;the environment; and natural resources. This Plan was prepared on behalf of
Duke Energy Carolinas, LLC (Duke Energy).
Special Order by Consent(SOC)WQ S17-009 was approved on April 18, 2018, and
subsequently amended on May 10, 2019. The SOC addresses the management of seeps
during the process of ash basin closure under the Coal Ash Management Act(CAMA)
of 2014, North Carolina General Statutes (G.S.) 130A-309.200 through 130A-309.231 and
the federal Coal Combustion Residuals (CCR) rule, 40 CFR Parts 257 and 261. Section
2(b)(3) of the SOC states:
Within 60 days of the submittal of the Seep Characterization Report, Duke Energy
shall submit a complete and adequate proposed amendment to the groundwater
Corrective Action Plan and/or Closure Plan as appropriate for the Facility
describing how any seeps identified in the Seep Characterization Report will be
managed in a manner that will be sufficient to protect public health, safety, and
welfare, the environment, and natural resources.
Findings in the October 2020 Seep Characterization Report (SynTerra, 2020c) indicate
identified seeps are either: (1)previously dispositioned as determined by the North
Carolina Department of Environmental Quality (NCDEQ) Division of Water Resources
(DWR) at the time of issuance of the SOC; (2) candidates for dispositioning per the SOC;
(3) covered under the National Pollutant Discharge Elimination System (NPDES) Permit
NC0004979 pertaining to the Site; or (4)not exhibiting constituent concentrations that
warrant additional corrective action at this time. Duke Energy continues to implement
ash basin closure activities to reduce groundwater seepage in a manner that is
protective of public health, safety, and welfare;the environment; and natural resources.
Completed and ongoing closure activities are summarized below.
Date Closure Activity
June 2019 Commencement of decanting of the Active Ash Basin.
June 2020 Completion of decanting of the Active Ash Basin.
June 2020 - Present Commencement of maintenance dewatering of the Active Ash
Basin. Maintenance dewatering is ongoing, along with
groundwater corrective action and landfill permitting activities.
Page ES-1

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
Evaluation of boron concentrations at non-dispositioned seep locations using the Mann-
Kendall trend test demonstrates stable to decreasing trends prior to, and since,
implementation of ash basin closure. In addition to boron, trend tests were performed
on applicable constituents with North Carolina Administrative Code (NCAC), Title
15A, Subchapter 02B-Surface Water and Wetland Standards (02B). Overall, the results
of the Mann-Kendall trend analysis indicate that the seep discharges have been
geochemically stable prior to, and since, implementation of ash basin closure with
constituent concentrations remaining stable or decreasing over time. Only one location
(S-2) exhibited increasing trends in constituent concentrations. However, S-2 has been
characterized by dry conditions, preventing sample collection at this seep location since
August 2019.
Non-dispositioned seeps are scheduled to be monitored as required by the SOC until
termination of the SOC by DWR, or not later than June 30, 2022. Upon termination of
the SOC, continued effectiveness monitoring of the two non-dispositioned seep
locations expected to remain (S-10 and S-12) is recommended until either: (1) closure of
the associated ash basin is complete or (2) sample data from two consecutive sampling
events indicate seep discharges do not contain constituents associated with ash basins
or concentrations are less than 02B standards. The contribution of flows from former
constructed seeps S-3, S-4, S-8, and S-8B-now NPDES outfalls-would continue to be
monitored as required by the NPDES permit.
Seeps would be monitored on a semiannual basis consistent with the nearby
groundwater monitoring network to correlate changing water quality and geochemical
conditions.
Page ES-2

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
TABLE OF CONTENTS
SECTION PAGE
EXECUTIVESUMMARY....................................................................................................ES-1
1.0 INTRODUCTION.........................................................................................................1-1
1.1 Background................................................................................................................1-1
1.2 Purpose and Scope....................................................................................................1-1
1.3 Previous Reporting...................................................................................................1-2
2.0 OVERVIEW OF SEEPS PROPOSED FOR MANAGEMENT..............................2-1
3.0 PROPOSED SEEP MONITORING PLAN...............................................................3-1
3.1 Seeps Associated with the Active Ash Basin........................................................3-1
3.2 Nature and Extent of Source Related Constituents and Seeps...........................3-1
3.3 Ash Basin Closure Activities...................................................................................3-2
3.4 Mann-Kendall Trend Analysis................................................................................3-2
3.5 Seep Characterization Conclusions........................................................................3-3
3.6 Potential Seep Monitoring.......................................................................................3-4
4.0 REFERENCES................................................................................................................4-1
Page i

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
LIST OF FIGURES
Figure 1-1 Site Location Map
Figure 1-2 Existing Seep Locations and Inspection Areas
Figure 3-1 Proposed Seep Dispositional Status, Locations, and Inspection Areas
LIST OF TABLES
Table 3-1 Seep Characterization Analytical Results—June 2020
LIST OF APPENDICES
Appendix A SOC WQ S17-009
Appendix B Mann-Kendall Analysis, October 2020
Page ii

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
LIST OF ACRONYMS
02B North Carolina Administrative Code, Title 15A,Subchapter 02B,
Surface Water and Wetland Standards
02L North Carolina Administrative Code, Title 15A, Subchapter 02L,
Groundwater Standards
µg/L micrograms per liter
BTV background threshold values
OCRs coal combustion residuals
COI constituent of interest
CSA comprehensive site assessment
CAP corrective action plan
DWR Division of Water Resources
EMC Environmental Management Commission
USEPA U.S. Environmental Protection Agency
FGD flue gas desulfurization
IMAC interim maximum allowable concentration
mg/L milligrams per liter
NCAC North Carolina Administrative Code
NCDEQ North Carolina Department of Environmental Quality
NC L.G. North Carolina Licensed Geologist
NPDES National Pollutant Discharge Elimination System
SOC Special Order by Consent
SOP standard operating procedure
USACE United States Army Corp of Engineers
UT Unnamed Tributary
WOS Waters of the State
WOTUS Waters of the United States
Page iii

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
1.0 INTRODUCTION
SynTerra prepared this Seep Management Plan Amendment to the Corrective Action
Plan (Plan) pertaining to the Allen Steam Station(Allen or Site) (Figure 1-1) to describe
plans to manage identified seeps in a manner that protects public health, safety, and
welfare;the environment; and natural resources. This Plan was prepared on behalf of
Duke Energy Carolinas, LLC (Duke Energy).
1.1 Background
Special Order by Consent (SOC) WQ 517-009 was approved on April 18, 2018, and
subsequently amended on May 10, 2019. The SOC addresses management of seeps
related to ash basins during the process of ash basin closure under the Coal Ash
Management Act of 2014 (CAMA),North Carolina General Statutes (G.S.) 130A-309.200
through 130A-309.231, and the federal Coal Combustion Residuals (CCR) rule, 40 CFR
Parts 257 and 261. The SOC is provided in Appendix A.
In preparation for closure of the active ash basin (AAB),wastewater inflows to the AAB
ceased on February 9, 2019. Decanting of free water from the AAB began on June 5,
2019. Duke Energy provided a Notification for Completion of Decanting letter to the
North Carolina Department of Environmental Quality (NCDEQ) Division of Water
Resources (DWR) on July 9, 2020. The notification indicated that decanting of the AAB
was completed on June 2, 2020.
1.2 Purpose and Scope
As required in Section 2.d. of the SOC, SynTerra is providing this Plan as an
amendment to the CAP Update to describe plans to manage seeps identified in the Seep
Characterization Report (SynTerra, 2020c). The Seep Characterization Report evaluated
seeps based on physical status, chemical composition, and jurisdictional determination.
To be considered in this Plan, a seep must:
1) Be non-dispositioned.
2) Constitute, or flow, to Waters of the State (WOS) or Waters of the United States
(WOTUS).
3) Exhibit constituent concentrations that are greater than applicable North
Carolina Administrative Code (NCAC), Title 15A, Subchapter 02B, Surface Water
and Wetland Standards (02B).
Page 1-1

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
1.3 Previous Reporting
Detailed descriptions of previous SOC assessments and characterizations are
documented in the following:
• Comprehensive Site Assessment Report—Allen Steam Station Ash Basin (HDR, 2015a).
• Corrective Action Plan Part 1 —Allen Steam Station Ash Basin (HDR, 2015b).
0 Corrective Action Plan Part 2 —(including Comprehensive Site Assessment
Addendum)—Allen Steam Station Ash Basin (HDR, 2016a).
• Comprehensive Site Assessment Supplement 2 —Allen Steam Station Ash Basin (HDR,
2016b).
• CAMA Annual Interim Monitoring Report,Allen Steam Station (SynTerra, 2019a).
• Surface Water Evaluation to Assess 15A NCAC 02B .0200 Compliance for
Implementation of Corrective Action Under 15A NCAC 02L .0106(k) and(l)—Allen
Steam Station (SynTerra, 2020a).
• 2019 Annual Seep Report,Allen Steam Station (SynTerra, 2020b).
• 2020 Final Seep Report,Allen Steam Station (SynTerra, 2020c).
• Seep Characterization Report,Allen Steam Station (SynTerra, 2020d).
Page 1-2

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
2.0 OVERVIEW OF SEEPS PROPOSED FOR MANAGEMENT
According to the SOC, there are eight identified non-constructed seeps at the Site
(Appendix A). Of those eight seeps, two seeps (S-1 and S-9)were dispositioned at the
time of issuance of the SOC. Four former constructed seeps -S-3 (Outfall 103), S-4
(Outfall 104), S-8 (Outfall 108), and S-8B (Outfall 108B) -are monitored per
requirements of the NPDES permit. Six non-constructed seeps (S-2, S-5, S-6, S-7, S-10,
and S-12) remain as non-dispositioned. The non-dispositioned seeps identified in the
SOC are described below and depicted on Figure 2-1.
Seep ID Associated Description
Number Ash Basin
S-2 AAB Located southeast of AAB at toe of dam. Flows to
approximately 3-foot-wide channel that flows to Lake Wylie.
S-5 AAB Located east of AAB, between dam and river bank.
Intermittent, unconfined diffuse flow toward Lake Wylie.
S-6 AAB Located east of AAB, between dam and river bank.
Intermittent, unconfined diffuse flow toward Lake Wylie.
S-7 AAB Located east of AAB, between dam and river bank.
Intermittent, unconfined diffuse flow toward Lake Wylie.
Seep located near northwest corner of Primary Pond 1. Seep
S-10 AAB flow collected in a French drain system and conveyed to a
tank from which seepage is pumped back into the AAB.
Overflow discharge of seepage collected from S-10 occurring
during temporary, infrequent power outage episodes.
S-12 AAB Seepage would flow to a stormwater drainage channel. Seep
flow is collected and pumped back into the AAB during
normal operations.
As described in the Seep Characterization Report(SynTerra, 2020c), seeps S-2, S-5, S-6,
and S-7 are candidates for dispositioning because they have been observed as dry or not
reaching WOS or WOTUS for three consecutive quarters.
Page 2-1

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
3.0 PROPOSED SEEP MONITORING PLAN
3.1 Seeps Associated with the Active Ash Basin
With concurrence from the NCDEQ DWR on seep jurisdictional and dispositional status
and upon termination of the SOC, all seeps, except S-10 and S-12 would be
dispositioned (Figure 3-1). Former seeps S-3 (Outfall 103), S-4 (Outfall 104), S-8 (Outfall
108), and S-8B (Outfall 108B) would be monitored via the NPDES permit. Duke Energy
continues to implement ash basin closure activities to reduce groundwater seepage in a
manner that is protective of public health, safety, and welfare;the environment; and
natural resources. Ash basin closure activities implemented by Duke Energy to date are
detailed in Section 3.3. The nature and extent of identified seeps and the effects of
ongoing ash basin closure activities are discussed in the following sections.
3.2 Nature and Extent of Source Related Constituents and Seeps
Based on groundwater data collected through June 2020, constituents of interest (COIs)
associated with the ash basins in groundwater or surface water include:
• Boron • Strontium
• Cobalt • Sulfate
• Iron • Total Dissolved Solids (TDS)
• Manganese
Of those COIs, only sulfate and TDS are SOC Attachment B surface water constituents
with 02B standards.
Boron concentrations greater than NCAC, Title 15A, Subchapter 02L—Groundwater
Classifications and Standards (02L) generally represent the extent of affected
groundwater associated with the AAB. Because boron is non-reactive and mobile in
groundwater, it serves as a conservative indicator of the extent of constituent migration
-from the ash basins and representative of the overall plume that contains other COIs
with concentrations greater than comparison criteria [021, standard/Interim Maximum
Allowable Concentration (IMAC) or background concentrations,whichever is greater].
The boron concentration in recent seep characterization data collected from non-
dispositioned seep S-10 is less than the 02L standard (Table 3-1). Evaluation of boron
concentrations at non-dispositioned seep locations using the Mann-Kendall trend test
demonstrates stable to decreasing trends prior to, and since, implementation of ash
basin closure activities (Appendix B).
Page 3-1

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
3.3 Ash Basin Closure Activities
Duke Energy began implementation of ash basin closure activities, which contributes to
seep management and surface water protection, for the AAB in 2019. Completed and
ongoing ash basin closure activities are summarized in the table below.
Year Closure Activity
June 2019 Commencement of decanting of the active ash basin.
June 2020 Completion of decanting of the active ash basin.
June 2020 - present Commencement of maintenance dewatering of the active ash
basin. Maintenance dewatering is ongoing, along with
groundwater corrective action and landfill permitting activities.
3.4 Mann-Kendall Trend Analysis
Ash basin closure is in the early stages. Ash basin decanting was completed in June
2020, and ash basin dewatering is underway. Completion of ash basin dewatering, and
subsequent excavation of the AAB and retired ash basin (RAB), are anticipated to
further reduce seep flows and constituent concentrations.
Mann-Kendall trend tests (Appendix B) were performed on 23 constituent-location
pairs to analyze how constituent concentrations at non-dispositioned seep locations
have changed over time. The Mann-Kendall trend test evaluates data over time for each
non-dispositioned seep to develop a statistical conclusion that pertains to trends—
increasing, decreasing, or no trend—of a constituent concentration.
In addition to boron, Mann-Kendall trend tests were performed on applicable
constituents with 02B standards at non-constructed,non-dispositioned seeps. Overall,
the results of the Mann-Kendall trend analysis indicate that seep discharges have been
geochemically stable prior to, and since, implementation of ash basin closure with
constituent concentrations remaining stable or decreasing over time. Based on the June
2020 seep characterization sampling event, constituent concentrations were not greater
than 02B standards at non-constructed, non-dispositioned seeps (Table 3-1).
Results from the Mann-Kendall trend tests indicate the following:
The average percentage of non-detects for constituent-location pairs included in
the Mann-Kendall trend test is 22 percent. The large number of non-detect
measurements present in the dataset indicates that many constituent-location
pairs have concentrations less than the reporting limit and are not predicted to be
of concern.
Page 3-2

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
• 82.6 percent of constituent locations (19 constituent-location pairs out of 23
constituent-location pairs) demonstrated stable conditions with no trends.
• 8.7 percent of the constituent locations (2 constituent-location pairs out of 23
constituent-location pairs) demonstrated statistically significant decreasing
trends.
• 8.7 percent of the constituent locations (2 constituent-location pairs out of 23
constituent-location pairs) demonstrated statistically significant increasing
trends.
Although increasing trends for mercury and sulfate were identified at S-2, dry
conditions, likely due to decanting,have prevented sample collection at this seep
location since August 2019.
Overall, the results of the Mann-Kendall trend tests indicate that the constituent
concentrations in seeps have been geochemically stable or decreasing prior to, and
since,implementation of ash basin closure.
3.5 Seep Characterization Conclusions
To be considered in this management plan, a seep must:
1) Be non-dispositioned,
2) Constitute, or flow to WOS or WOTUS, and
3) Exhibit constituent concentrations that are greater than applicable 02B surface
water standards.
Based on findings from the Seep Characterization Report(SynTerra, 2020c),no seeps
meet the above criteria:
• Seeps S-2, S-5, S-6, and S-7 are candidates for dispositioning because they have
been observed as dry or not reaching WOS or WOTUS for three consecutive
quarters.
• Flow from seeps S-10 and S-12 would flow to WOS or WOTUS only if the S-10
seep collection system was not operating (an upset condition of the system).
• Former seeps and current NPDES outfalls-S-3 (Outfall 103), S-4 (Outfall 104),
S-8 (Outfall 108), and S-8B (Outfall 108B) - are monitored under the NPDES
wastewater permit.
Page 3-3

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
3.6 Potential Seep Monitoring
Non-dispositioned seeps are scheduled to be monitored as required by the SOC until
termination of the SOC by DWR, or not later than June 30, 2022. Upon termination of
the SOC, continued effectiveness monitoring of the two non-dispositioned seep
locations expected to remain (5-10 and S-12) is recommended until either: (1) closure of
the associated ash basin is complete or (2) sample data from two consecutive sampling
events indicate seep discharges do not contain constituents associated with ash basins
or concentrations are less than 02B standards. The contribution of flows from former
constructed seeps S-3, S-4, S-8, and S-8B-now NPDES outfalls-would continue to be
monitored as required by the NPDES permit.
Until that time, the seeps would be monitored on a semiannual basis consistent with the
nearby groundwater monitoring network to correlate changing water quality and
geochemical conditions.
Page 3-4

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
4.0 REFERENCES
HDR (2015a). Comprehensive Site Assessment Report, Allen Steam Station Ash Basin.
HDR (2015b). Corrective Action Plan Part 1, Allen Steam Station Ash Basin.
HDR (2016a). Corrective Action Plan Part 2, Allen Steam Station Ash Basin.
HDR (2016b). Comprehensive Site Assessment Supplement 2, Allen Steam Station Ash
Basin.
SynTerra (2019a). CAMA Annual Interim Monitoring Report, Allen Steam Station.
SynTerra (2020a). Surface Water Evaluation to Assess 15A NCAC 02B .0200 Compliance for
Implementation of Corrective Action Under 15A NCAC 02L .0106 (k) and (1), Allen
Steam Station.
SynTerra(2020b). 2019 Annual Seep Report,Allen Steam Station.
SynTerra(2020c). 2020 Final Seep Report,Allen Steam Station.
SynTerra(2020d). Seep Characterization Report, Allen Steam Station.
Page 4-1

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
FIGURES

I
DUKE ENERGY CAROLINAS
PROPERTY LINE_I
a
fA4 A�.t 1l••/ ��. _,f_—ALLEN STEAM STATION
r 4
,J
1 RETIRED ASH BASINAl
'
9�,
�.
k�L RETIRED ASH BASIN i w
WASTE BOUNDARY �—
RnQ l'. ••L� ACTIVE ASH BASIN
If
;
ACTIVE ASH BASIN,
WASTE BOUNDARY
T
ti
t tv qr lve
t.>IRr
As_
Lqr'4k
NOTES:
1.ALL BOUNDARIES ARE APPROXIMATE.
2.WATER FEATURES DEPICTED WITHIN WASTE BOUNDARIES OFTHEASH '
BASINS ON THE 2019 USGS TOPOGRAPHIC MAP DO NOT REPRESENT ` _
CURRENT CONDITIONS.THE CONDITIONS DEPICTED ARE SIMILAR TO
THOSE SHOWN ON THE 1968AND 1973 USGS TOPOGRAPHIC MAPS OFZii
THEAREA[(1968 WEST CHARLOTTE(1:24000)AND 1973 BELMONT(1:24000)]..
3.2019 USGS TOPOGRAPHIC MAP,BELMONT&CHARLOTTE WEST
QUADRANGLE,OBTAINED FROM THE USGS STORE AT
HTTPS:/INGMDB.USGS.GOV/.
FIGURE 1-1
�+ DUKE SITE LOCATION MAP
ENERGY. VNNSTON-SALEM SEEP MANAGEMENT PLAN AMENDMENT TO
CORRECTIVE ACTION PLAN
ASHEVUE • ALLEN STEAM STATION
CHARLOTTE•
GASTON COUNTY,NORTH CAROLINA
GASTON DRAWN BY:R.KIEKHAEFER DATE:09/28/2020 GRAPHIC SCALE
COUNTY REVISED BY:R.KIEKHAEFER DATE:11/05/2020 l000 0 1.0^^ 2000.
WnTena w CHECKED BY:L.L.
DRAO DATE:11/5/2020
APPROVED BY.L.DRAGO DATE:11/05/2020
ww. nterracor .com PROJECT MANAGER:C.SUITELL ON FEE

I
E
�. +�
�• -ten.—_ - 4
-�� _
IN it
1 41�"till
ti •�`Ji
1 � 1
�••q rr rw�lone!._ fir.R,T.••�s�s�
' r=�DTnDs s r,
LEGEND 1 .• r�'F+Iu Lor
L:�•_,.
NPDES TOE DRAIN OUTFACE
C NON-CONSTRUCTED SEEP
J
• DISPOSITIONED SEEP ',1.'r'�'•
_�.•` . :ACTIVE
ASH BASIN WASTE BOUNDARY
RETIREDASH BASIN WASTE BOUNDARY 1p '•
- DUKE ENERGY CAROLINAS PROPERTY LINE ^
SPECIAL ORDER BY CONSENT(SOC)
INSPECTION AREA
�--STREAM(AMEC NRTR 2015)
WETLAND(AMEC NRTR 2015)
—11 SURFACE WATER FLOW DIRECTION r `�
1DT LOCH IONSARE'E RIBEDINEMCSOCv sLTnDE - •• + - --- - 7
Rw
Cai7TEM INPOEsj
LOCATIONSARE DESCRIBED PERMIT N 9&SrOILOCATINswEREDERIVED FROMVATI111 THEREFORE
ARL
A, SUR—EDINPAPPR-IM Y
LOCATIONS
—R—MATE s.TNEREFDREs ! /
iI.S IF THEAUP v¢D ar
CREATION,
FUNNQ3ES THE—NDS AID STREAMS
BOUNDARIES WERE OBTAINED FROM STREAM AND WETLAND
_RONMENT'_wmnsrBRucruwEQiRc Hn uauEAEsouRCE
TECHNICAL REPORT INRTRI FOR ALLEN STEM STATION DATED MAV]9, �+S DUKE aaD n a5D Raa FIGURE 2-1
is ENERGY- iaAvn>C9GLEni[£I EXISTING SEEP LOCATIONS AND INSPECTION AREAS
PROPERTY BOUNDARY PRDN�DED BY DICE ENERG.LARLNNAB. c�atr,N,s SEEP MANAGEMENT PLAN AMENDMENT TO
ALL BOUNDARIES ARE APNNIXONATE. DRAwNBr:N.gNG D oA/LD/_ CORRECTIVE ACTION PLAN
�� REVEEO BN R.gEgIPEFER D1TE:11/Oi/20M
ClEM9ER' a"�RA A COLLLE.T.ONMAF NanPmfe" CHECItfD Bn.TNARDAAN WTE:LUCT— ALLEN STEAM STATION
APPRDv MANADDR C. DATE:WO m. GASTON COUNTY,NORTH CAROLINA
STATE
PLANE
COORDINATE SYSTEM FIP6E320DINADB3)RT LMOMNA T PRWECf MANAGER:C.GUTIELL
ntRIEBDD

1
I
x
I �
I
! N!•uc
r - r 4P``. R
i Eo
II � •`
p—I
t
)i
Y'-dl
LEGEND
- NPDES TOE DRAIN OUTFACE
® NON-CONSTRUCTED SEEP
DISPOSITIONED SEEP
ACTIVE ASH BASIN WASTE BOUNDARY
•—RETIRED ASH BASIN WASTE BOUNDARY
• DUKE ENERGY CAROLINAS PROPERTY LINE 1 -
SPECIAL ORDER BY CONSENT(SOC) 1 J
INSPECTIONAREA
STREAM(AMEC NRTR 2015) rJ --•^•• ••
WETLAND(AMEC NRTR 2015) T r
SURFACE WATER FLOW DIRECTION
i.SE-LOCATIONS ARE DESCRIBED IN EMI SDCwO sn Goe.
INATI EM(NPDESI
WEREVE RIVED FROM VARIOUS SOURCES AND ARE
ND AROMMATE LOCATIONS.THEREFORE,SEEP
CATIONSARETDBEDE EDA-RO%IMATE D.1
CREAH—THIS MAP IS IT­E USED FOR ILR.­
SOUNDARIMI-EREOMI
RM FROM WET REAM AND—LAND
LINEATION CONDUCTED B VAMEC FOSTER WREELER
R FOE NCIIAL RESOURCE (. Aco BDD
AL REPORT RN SAC AY20. DUE FIGURE 3-1
s
EMIM PROPOSED SEEP DISPOSITIONAL STATUS,
PROPERTY BOUNDARY PRDIIDEDBy DIKE ENERGY CARCUHAS, c.*MINAS LOCATIONS,AND INSPECTION AREAS
ILL BOUNDARIES ARE APPROAIMATE. D Y:KRING ureoA/w/2D>e SEEP MANAGEMENT PLAN AMENDMENT TO
T.AERIAL PHOTCORAPHY OBTAINED FROM"'ILE EARTH PROCH CHECKS.-ARHAEFER MTE 1]/OT/2020
DEceMBER(T.zO.s.AERaLwascoLLEITEDDNMARIH3D.zo(A. cxecAEDBv:T.HAxTMAN :wBT/zozD CORRECTIVE ACTION PLAN
IroCTAMN IEI 10 DME:ivovzo2O ALLEN STEAM STATION
CAROLINA PROTECT MANAGER:CSIITTELL
ePUNEcooRDlNAms s i F°si uo°iN1oBii" GASTON COUNTY,NORTH CAROLINA
www.s,nterracon!.com

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
TABLES

� ■ ! § ! _ _
; ! k
�
; ■ | § ! _ ® !
; ■ | ! ! _ , {
2caIc
2§ �
—
§� § �
§ix z2 is /
In
AZ
2■2E2 � ` �! ` {
§k§§ § .,
��4� � ■ � ! � ! ; , \
�Z -
§| -
.� ■ § ! ; ; ! ! /
!� }
� ]
�/ • � —
�■| • . . .
#
! : } _ �! |� !!
|§v0 E E}j�§j\{

§
# . !
■ | 7 � _ §
§ � ■ � \ )
B
k
■ . § ; , . , .
� � k
■ !$! ; �
�§
-
q� § § ; ■ � � ! ,
§O§§ §
_§§§/ § ; E ,
&E■|] \ ` §
k�B§ƒ § ` § '
§k �§ _
k|�422` - -
.
\ . `
E
IL w�
|
-
e,z | 7{
\ `]!!f ! !
` |§�t;E{}}\{ §)\!

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
APPENDIX A
SOC WQi S 17-009

;•: ROY COOPER
Govemor
MICHAEL S.REGAN
Secretary
Water Resources LINDA CULPEPPER
Environmental Quality Interim Director
April 25,2018
Mr.Paul Draoviteh, Senior Vice President EHS
Duke Energy
526 S. Church Street
Mail Code EC3XP
Charlotte,NC 28202
Subject: SPECIAL ORDER BY CONSENT
SOC No.S17-009
Duke Energy Carolinas, LLC
Allen Steam Station,Marshall Steam Station&Rogers Energy Complex
NPDES Permits NC0004979,NC0004987&NC0005088
Gaston, Catawba&Rutherford Counties
Dear Mr.Draovitch:
Attached for your records is a copy of the Special Order by Consent(SOC) approved by the
Environmental Management Commission on April 12, 2018, and signed by the Chairman of the
Commission on April 18,2018.
The terms and conditions of the SOC are in Ul effect, including those requiring submittal of
written notice of compliance or non-compliance with any schedule date. The following items are
brought to your attention as they pertain to the terms and conditions of the SOC:
* Payment of the upfront penalty is due no later than May 25, 2018.
& Monitoring performed per the terms of the SOC shall commence during the current calendar
quarter(April—June),with results submitted to the Division of Water Resources(DWR)no
later than July 30,2018. Subsequent monitoring and reporting shall occur as specified in the
SOC.
DWR acknowledges receipt of Duke Energy's letter dated April 23, 2018,confirming the
implementation of dry fly ash handling at the Rogers Energy Complex.
With regard to concerns for the safety of personnel collecting samples,the following
locations are deemed to be acceptable for the purposes of water quality monitoring required
by the SOC near the Rogers Energy Complex:
■ Upstream in the Broad River—at the U.S.Highway 221A bridge.
■ Downstream in the Broad River—at a point along the bank approximately 1,800 feet
downstream from seep S-07.
A■ Upstream in Suck Creek—at the S.R. 1002 (McCraw Road)bridge.
State of North Carolina I Environmental Quality I water Resources
1617 Mail Service Center I Raleigh,North Carolina 27699-1617
(919)-807-6300 (919)-807-6389 FAX

Mr. Paul Draovitch
SOC WQ S 17-009 Transmittal
p.2
Pursuant to North Carolina General Statute 143-215.31), water quality fees have been revised to
include an annual fee for activities covered under a Special Order by Consent. Duke Energy will
be subject to a fee of$500.00 on a yearly basis while under the Order. The initial fee payment
will be invoiced at a later date, with future fee invoicing done on an annual basis.
If you have any questions concerning this matter,please contact Bob Sledge at(919) 807-6398.
Sincerely,
Linda Culpepper
Attachment {I�
cc: Central Files
NPDES Unit—SOC File
ec: Asheville Regional Office—DWR/Water Quality
Mooresville Regional Office—DWR/Water Quality
Shannon Langley—Duke Energy
Laurie Jones—EPA Region 4
Jeff Poupart—DWR/WQPS

NORTH CAROLINA
ENVIRONMENTAL MANAGEMENT COMMISSION
COUNTIES OF GASTON, CATAWBA,
AND RUTHERFORD
IN THE MATTER OF )
NORTH CAROLINA ) SPECIAL ORDER BY CONSENT
NPDES PERMITS NC0004979,NC0004987 ) EMC SOC WQ S17-009
&NC0005088 )
HELD BY )
DUKE ENERGY CAROLINAS, LLC )
Pursuant to the provisions of North Carolina General Statutes(G.S.) 143-215.2, this Special
Order by Consent is entered into by Duke Energy Carolinas, LLC, hereinafter referred to as
Duke Energy, and the North Carolina Environmental Management Commission, an agency of
the State of North Carolina created by G.S. 14313-282, and hereinafter referred to as the
Commission. Duke Energy and the Commission are referred to hereafter collectively as the
"Parties."
1. Stipulations: Duke Energy and the Commission hereby stipulate the following:
a. This Special Order by Consent("Special Order")addresses issues related to the
elimination of seeps(as defined in subparagraphs e, f,and g below)from Duke
Energy's coal ash basins during the separate and independent process of basin
closure under the Coal Ash Management Act, G.S. 130A-309.200 through 130A-
309.231 ("CAMA")and the Federal Coal Combustion Residuals Rule,40 CFR
Parts 257 and 261. The Environmental Protection Agency first directed permitting
authorities to consider potential impacts on surface water of seeps from earthen
impoundments in 2010. At that time,Duke Energy began discussions with the
North Carolina Department of Environmental Quality("the Department")
regarding seeps at multiple Duke Energy facilities,including identifying certain
seeps in permit applications and providing data to the Department regarding
seeps. In 2014,Duke Energy provided a comprehensive evaluation of all areas of
wetness and formally applied for NPDES permit coverage of all seeps. Since
2014,Duke Energy has performed periodic inspections and promptly notified the
Department of new seeps and sought NPDES permit coverage where appropriate.
On March 4,2016, the Department issued Notices of Violation("NOVs") to Duke
Energy related to seeps.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
p.2
Decanting (i.e.,removal of the free water on the surface of the coal ash basins),
which is required before ash basins can be closed,is expected to substantially
reduce or eliminate the seeps. In order to accomplish this goal of substantially
reducing or eliminating seeps,this Special Order affords certain relief to Duke
Energy related to the non-constructed seeps (as defined in subparagraphs f and g
below), while requiring Duke Energy to accelerate the schedule for decanting as
specified more fully below. Constructed seeps (as defined in subparagraphs a and
f below) will be addressed in the NPDES permits. After completion of decanting,
for any remaining seeps, whether constructed or non-constructed,Duke Energy
must take appropriate corrective action as specified more fully below.
b. Duke Energy has been issued North Carolina NPDES permits for operation of an
existing wastewater treatment works at each of the following coal fired, electric
generation facilities ("Duke Energy FaciIities," or in the singular, "Facility"):
Permit Issuance Receiving Water
Facility Number County for Primary
Date Outfall J
Allen NCO004979 Gaston 1/18/2011 Catawba River
Marshall NC0004987 Catawba 9/9/2016 Catawba River
Rogers NC0005088 Rutherford 2/20/2012 Broad River
C. The Duke Energy Facilities listed above will continue to operate and generate
coal ash, and each is subject to the provisions of this Special Order.
d. Wastewater treated at coal-fired electric stations includes water mixed with ash
produced through the combustion of coal for the steam generation process. Ash is
controlled and collected through the use of water, creating a slurry that is
conveyed to impoundments or basins with earthen dike walls. In the ash basin,
the solids separate from the liquid portion, with the resulting supernatant
discharged under the terms of the NPDES permit.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
p. 3
e. The coal ash basins at the Duke Energy Facilities are unlined,having no
impermeable barrier installed along their floors or sides. Earthen basins and dike
walls are prone to the movement of liquid through porous features within those
structures through a process known as seepage. Each of the Duke Energy
Facilities covered by this Special Order exhibits locations adjacent to,but beyond
the confines of, the coal ash basins where seepage of coal ash wastewater from
the coal ash basins may intermix with groundwater, reach the land surface(or
"daylight"), and may flow from that area. Once such seepage reaches the land
surface,.it is referred to as a"seep." Each of the seeps identified at the Duke
Energy Facilities and addressed in this Special Order exhibit some indication of
the presence of coal ash wastewater. Both(a) confirmed seeps and(b)areas
identified as potential seeps that were later dispositioned, are identified in
Attachment A.
f. Some of Duke Energy's coal ash impoundments contain constructed features on
or within the dam structures (such as toe drains or filter blankets)to collect
seepage. This wastewater is conveyed via a pipe or a constructed channel directly
to a receiving water. These discrete, identifiable, point source discharges are or
will be covered and regulated by the respective NPDES permits and designated as
outfaIls therein. The characteristics of these wastewater flows are similar to those
discharging from other permitted outfalls for ash basin effluent. In this Special
Order, seeps that are(1.) on or within the dam structures and(2) convey
wastewater via a pipe or constructed channel directly to a receiving water are
referred to as"constructed seeps." Seeps that are not on or within the dam
structures or that do not convey wastewater via a pipe or constructed channel
directly to a receiving stream are referred to as "non-constructed seeps."
g. Non-constructed seeps at the Duke Energy Facilities often exhibit low flow
volume and may be both transient and seasonal in nature, and may, for example,
manifest as an area of wetness that does not flow to surface waters, a point of
origin of a stream feature, or flow to an existing stream feature. These
circumstances of the non-constructed seeps make them difficult to discern,
characterize, quantify and/or monitor as discrete point source discharges. This
creates challenges in permit development and compliance monitoring because it is
difficult to accurately monitor for flow and discharge characterization. Non-
constructed seeps at the Duke Energy Facilities present significant challenges to
their inclusion in NPDES permits as point source discharges,but they do cause or
contribute to pollution of classified waters of the State. Therefore,these non-
constructed seeps are addressed in this Special Order rather than in an NPDES
permit.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
p.4
h. Investigations and observations conducted by the Department and U. S. Army
Corps of Engineers staff have concluded that some seeps emanating from Duke
Energy's coal ash ponds create and/or flow into features delineated as classified
waters of the State or Waters of the United States.
i. Collectively, the volume of non-constructed seeps is generally low compared to
the volume of permitted wastewater discharges at the Duke Energy Facilities.
j. In 2014,Duke Energy conducted a survey of each coal-fired electric generation
station to identify potential seeps from the coal ash surface impoundments. Duke
Energy included all areas of wetness identified around the impoundments as
seeps,and submitted applications to include those seeps in NPDES permits.
Beginning in 2015,Duke Energy has implemented semi-annual surveys to
identify new seeps in the vicinities of the coal ash basins. Additional seeps have
been observed and documented during these surveys and reported to the
Department pursuant to a Discharge Identification Plan mandated by CAMA.
Additional investigation has determined that not all of areas identified in 2014 are
seeps,but each Duke Energy facility does have multiple seeps.
k. The Department issued NOVs to Duke Energy on March 4, 2016 for the seeps
that emanate from the unlined coal ash surface impoundments at the Duke Energy
Facilities.
1. Non-constructed seeps create conditions such that certain surface water quality
standards may not consistently be met at all Duke Energy monitoring sites.
M. The presence of coal ash influenced water in the non-constructed seeps causes or
contributes to pollution of the waters of this State,and Duke Energy is within the
jurisdiction of the Commission as set forth in G.S. Chapter 143,Article 21.
n. A list of seeps identified in the vicinities of the coal ash surface impoundments at
the Allen,Marshall and Rogers plants, as well as their locations, and the bodies of
water those seeps may flow into (if applicable), can be found in Attachment A to
this Special Order.
o. Duke Energy must close the coal ash surface impoundments at all North Carolina
coal-fired electric generating stations in accordance with applicable requirements
set out in CAMA and the Federal Coal Combustion Residuals Rule,requirements
of which are independent of the resolution of seeps addressed in this Special
Order.
p. Decanting of wastewater performed at Duke Energy's coal ash basins is expected
to eliminate or substantially reduce the seeps from the ash basins at the Duke
Energy Facilities.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
p.5
q. Since this Special Order is by consent,the Parties acknowledge that review of the
same is not available to the Parties in the N.C. Office of Administrative Hearings.
Furthermore,neither party shall file a petition for judicial review concerning the
terms of this Special Order.
2. Duke Energy,desiring to resolve the matters causing or contributing to pollution of the
waters of the State described above, hereby agrees to do the following:
a. Penalties
1) Upfront Penalty. As settlement of all alleged violations due to seepage at
these Duke Energy Facilities,pay the Department,by check payable to the
North Carolina Department of Environmental Quality, a penalty in the
amount of$156,000,calculated based upon$12,000 each for five
constructed seeps identified prior to January 1, 2015 and$6,000 each for
sixteen non-constructed seeps identified prior to January 1, 2015.
A certified check in the amount of$156,000.00 must be made payable to
the Department of Environmental Quality and sent to the Director of the
Division of Water Resources (DWR)at 1617 Mail Service Center,
Raleigh,North Carolina 27699-1617 by no later than thirty(30)days
following the date on which this Special Order is approved and executed
by the Commission, and received by Duke Energy.
No penalty shall be assessed for seeps identified after December 31, 2014,
given Duke Energy's inclusion of seeps in permit applications and
compliance with the Discharge Identification Plan required under LAMA.
By entering into this Special Order, Duke Energy makes no admission of
liability, violation or wrongdoing. Except as otherwise provided herein,l
payment of the upfront penalty does not absolve Duke Energy of its
responsibility for the occurrence or impacts of any unauthorized
discharges in the area of the Duke Energy Facilities that may be
discovered in the future,nor does the payment preclude DWR from taking
enforcement action for additional violations of the State's environmental
laws.
2) Stipulated Penalties. Duke Energy agrees that unless excused under
paragraph 5,Duke Energy will pay the Department, by check payable to
the North Carolina Department of Environmental Quality, stipulated
penalties according to the following schedule for failure to perform
activities described in paragraphs 2(b, c, and d), or for failure to comply
with interim action levels listed in Attachment A.
1 See especially paragraph 2(a)(2) excepting newly identified seeps from future penalties under
certain conditions.

EMC SOC WQ S17-009
Duke Energy Carolinas,LLC
p.6
Failure to meet a deadline in the Compliance $1,000.00/day for the first seven
Schedule in 2(b)of this Special Order days; $2,000.00/day thereafter_
Failure to meet any other deadline in this $1,000.00/day for the first seven
Special Order days; $2,000.00/day thereafter _
Exceedance of an interim action level listed in
Attachment A $4,500.00 per monitored ex.ceedance
Monitoring frequency violations $1,000,00 per violation
Failure to submit, within 210 days of the
completion of decanting at each Facility,
adequate amendments to groundwater
Corrective Action Plans or Closure Plans to $5,000.00 per day,to a maximum of
address all remaining seeps, whether $1 lity. 00.00 per electric generating
constructed or non-constructed,through facility:
corrective action as applicable under
raraera ih 2(d) of this S ecial Order.2
As long as Duke Energy remains in compliance with the terms of this Special Order, as
well as CAMA and conditions of any approvals issued thereunder,the Department shall
not assess civil penalties for newly identified seeps.
b. Compliance Schedule. Duke Energy shall undertake the following activities in
accordance with the indicated time schedule. No later than fourteen (14) calendar
days after any date identified for accomplishment of any activity,Duke Energy
shall submit to the Director of DWR written notice of compliance or
noncompliance therewith. In the case of compliance,the notice shall include the
date compliance was achieved along with supporting documentation if applicable.
In the case of noncompliance, the notice shall include a statement of the reason(s)
for noncompliance,remedial action(s) taken, and a statement identifying the
extent to which subsequent dates or times for accomplishment of listed activities
may be affected.
Duke Energy shall accelerate compliance with the requirements of G.S. 130A-
309.210(d) and(f) such that all projects necessary to eliminate discharges of
stormwater into the surface impoundments at the Duke Energy Facilities and to
convert to dry bottom ash handling shall be complete prior to the deadline for
initiating decanting set out below.
2 Failure to adequately implement any amended Corrective Action Plan or Closure Plan will be
handled in the normal course.

EMC SOC WQ S17-009
Duke Energy Carolinas,LLC
p.7
1) Complete dr►-ash handling projects in accordance with the followin::
schedule
Facilitv 171 Ash Bottom Ash
Allen Complete 3/31/2019
Marshall Complete 1/31/2019
Rogers 3/31/2018 8/31/2018
2) Initiation of Decantint,.
Allen 6/30/2019
Marshall 9/30/2019
Rogers 3/31/2019
3) Completion of Decantiny,
Allen 6/30/2020
Marshall 3/3 l/2021
Rogers 3/31/2020
This schedule is premised upon timely issuance of necessary permits or approvals,
and no requirement imposed by DWR to implement physical/chemical treatment
during decanting except as required by an NPDES permit. Should any of these
assumptions prove to be incorrect, the Parties shall renegotiate these deadlines,
provided that the final expiration date of this Special Order will not be affected by
such renegotiation.
4) Termination of S 1.i ecial Order
This Special Order shall terminate on a facility-by-facility basis on the
later of the following dates:
180 days following completion of decanting; or
30 days following the approval of an amended groundwater
Corrective Action Plan and/or Closure Plan as appropriate (if an
amendment is submitted in compliance with subparagraph d.
below).

EMC SOC WQ S17-009
Duke Energy Carolinas,LLC
p. 8
C. Additional Compliance Measures. Duke Energy shall undertake the following
additional compliance measures:
1) If the monitoring of any classified water of the State receiving flow from
seeps regulated by this Special Order indicates exceedance of any interim
action level established by the Special Order,Duke Energy shall increase
monitoring at that location from quarterly to monthly until concentrations
of monitored characteristics return to those observed at the initiation of the
Special Order. If any interim action level established by the Special Order
is exceeded by more than 20%in a single sampling event, or exceeded for
two(2)consecutive monitoring events,in addition to paying the
associated stipulated penalty, Duke Energy shall conduct a re-assessment
of the contributing seep(s), including,but not limited to,evaluation of
proposed remedial actions for treatment and/or control of the seep such
that impacts to the receiving waters are quickly mitigated. A report
compiling the findings of the re-assessment,including proposed remedial
actions, shall be provided to the Director of DWR within 60 days of any
applicable exceedance. Following its review,DWR shall notify Duke
Energy of its concurrence or disapproval of Duke Energy's proposed
remedial actions.
2) Once the decanting process is initiated, within thirty (30) days after the
end of each quarter, Duke Energy shall provide reports on the status of
decanting work and other activities undertaken with respect to closure of
each coal ash surface impoundment to DWR. The quarterly reports are
due by April 30,July 30, October 30 and January 30 while this Special
Order is in effect. The reports are to be submitted as follows: one copy
must be mailed to the appropriate Regional Office Supervisor for each
facility and one copy must be mailed to the Water Quality Permitting
Program, Division of Water Resources, 1617 Mail Service Center,
Raleigh,NC 27699-1617.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
P.9
3) Duke Energy shall conduct annual comprehensive surveys of areas down
gradient of ash basins identifying new seeps, and documenting the
physical characteristics of previously documented seeps. All
examinations of seeps must include identification of seeps by approximate
latitude and longitude and date-stamped digital photographs of their
appearance. A report summarizing the findings of the surveys, including a
section analyzing the effect decanting of the basin(s)has on seep flows,
accompanied by copies of the photographs noted above ("Annual Seep
Report"), shall be submitted to DWR in conjunction with submittal of the
April 30 quarterly report noted in 2(c)(2) above. This Annual Seep Report
must list any seep that has been dispositioned(as described below) during
the previous year,including an analysis of the manner of disposition. For
purposes of this Special Order, "dispositioned"includes the following: (1)
the seep is dry for at least three consecutive quarters; (2)the seep does not
constitute, and does not flow to,waters of the State or Waters of the
United States for three consecutive quarters; (3)the seep is no longer
impacted by flow from any coal ash basin such that concentrations of all
pollutants listed in Attachment B meet State criteria for four consecutive
sampling events with at least seven days separating each event; or(4)the
seep has been otherwise eliminated(e.g.,through an engineering solution).
If a seep that has been dispositioned through drying up reappears in any
subsequent survey, such a seep will no longer be deemed dispositioned
and can be subsequently re-dispositioned as specified above.
4) No later than 90 days following the completion of decanting at each
Facility, and in the same manner as in the annual surveys, Duke Energy
shall conduct a comprehensive survey of areas down gradient of ash
basins identifying new seeps, and documenting the physical characteristics
of previously documented seeps. All examinations of seeps must include
identification of seeps by approximate latitude and longitude and date-
stamped digital photographs of their appearance. A report summarizing
the findings of this survey,including a section analyzing the effect
decanting of the basin(s) has had on seep flows, accompanied by copies of
the photographs noted above, shall be submitted to the Director of DWR
("Final Seep Report"). This Final Seep Report must list any seep that has
been dispositioned(as described in subparagraph(3) above) during
decanting process,including an analysis of the manner of disposition. The
determination of whether a seep is dispositioned rests with the Director of
DWR. At, or at any time prior to, submission of the Final Seep Report,
Duke Energy shall seek formal certification.from the Director of DWR,
certifying the disposition of any seep that Duke Energy has characterized
as dispositioned. Any seeps not certified as dispositioned by the Director
of DWR shall not be deemed as dispositioned.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
P. 10
d. Further Corrective Action. Following completion of decanting, if any seeps
(including both constructed and non-constructed seeps) have not been certified by
the Director of DWR as dispositioned(as described in subparagraph c. above),
Duke Energy shall conduct a characterization of those seeps.3 Duke Energy shall
submit a report on the findings of these characterizations ("Seep Characterization
Report") to the Director of DWR within 150 days of completion of decanting at
each Facility(i.e., within 60 days of the submittal of the Final Seep Report). The
Seep Characterization Report must include all sampling data for each remaining
seep as well as Duke Energy's evaluation of the jurisdictional status of all seeps at
the relevant Facility. The determination regarding whether a surface water feature
is a classified water of the State rests with DWR.
Within 60 days of the submittal of the Seep Characterization Report,Duke
Energy shall submit a complete and adequate proposed amendment to the
groundwater Corrective Action Plan and/or Closure Plan as appropriate for the
Facility describing how any seeps identified in the Seep Characterization Report
will be managed in a manner that will be sufficient to protect public health, safety,
and welfare, the environment, and natural resources. This proposed amendment
will go to public comment. Duke Energy shall submit documentation that the
proposed modification has been submitted to the appropriate division within the
Department that has authority for approving modification of the groundwater
Corrective Action Plan and/or Closure.Plan. The content of, and DEQ's review
of, an amendment to a groundwater Corrective Action Plan shall be consistent
with Title 15A, Chapter 2L of the N.C. Administrative Code(specifically
including 2L.0106(h)-(o)). The amendment to the Corrective Action Plan and/or
Closure Plans shall be implemented by Duke Energy in accordance with the
deadlines contained therein, as approved or conditioned by the Department.
Failure by Duke Energy to implement the amendment will be handled in the
normal course by the Department in accordance with its enforcement procedures
(i.e., outside this Special Order).
3 If any seep is dispositioned between the time that the Final Seep Report is submitted and the
time the Seep Characterization Report is submitted, an analysis of the manner of disposition
must be included in the Seep Characterization Report, and Duke Energy must seek certification
of such a disposition from the Director of DWR. Only if such certification is received prior to
the due date of the proposed amendment described in paragraph 2(d) may such a seep, certified
as dispositioned,be omitted from the proposed amendment.

EMC SOC WQ S17-009
Duke Energy Carolinas,LLC
P. 11
For clarity,listed below is a summary of the timetable for the documents due after
completion of decanting(as described in 2(c)(4) and 2(d) above):
Document Due Date
Final Seep Report 90 days after completion of decanting
150 days after completion of
Seep Characterization Report decanting (i.e., 60 days after
submission of Final Seep Report)
Proposed amendment to groundwater 210 days after completion of
Corrective Action Plan and/or Closure decanting (i.e., 60 days after
Plan submission of Seep Characterization
Report)
e. Interim Action Levels.
1) Duke Energy shall perform monitoring of waters receiving flow from non-
constructed seeps in accordance with the schedules listed in Attachments
A and B,except as noted in paragraph 2(c)(1) above.
2) Upon the complete execution of this Special Order, with regard to non-
constructed seeps,interim action levels for the receiving waters (which are
minor tributaries)are hereby established as noted in Attachment A. The
interim action levels are site-specific. Duke.Energy shall monitor at
approved sampling sites to ensure interim action levels are met. Interim
action levels shall remain effective in the designated surface waters until
the applicable termination date in paragraph 2(b)(4)is reached.
3) Monitoring associated with seeps covered by this Special Order is exempt
from the electronic reporting requirements associated with NPDES
permits. Results of monitoring required exclusively per the terms of this
Special Order shall be reported to the Director of DWR in a
spreadsheet/worksheet format agreed to by Duke Energy and DWR.
Monitoring data shall be submitted to the Director of DWR in a digital
format no later than 30 days following the end of each calendar quarter for
as long as the Special Order is in effect. Monitoring data shall be sent to
the following email address: [e-mail]. Data from those
sites with monitoring required exclusively per the terms of the Special
Order will be posted on DWR's website to provide the public with the
opportunity for viewing.
3. Duke Energy will continue to operate its coal ash surface impoundments in such a
manner that their performance is optimized, and potential for surface waters to be
affected by seeps is minimized.

EMC SOC WQ S17-009
Duke Energy Carolinas,LLC
p. 12
4 Duke Energy shall make available on.its external website the NPDES permits,this
Special Order and all reports required under this Special Order for each of the Duke
Energy Facilities no later than thirty(30) days following their effective or submittal
dates.
5. Duke Energy and the Commission agree that the stipulated penalties specified in
paragraph 2(a)(2) are not due if Duke Energy satisfies DWR that noncompliance was
caused solely by:
a. An act of God;
b. An act of war;
C. An intentional act or omission of a third party,but this defense shall not be
available if the act or omission is that of an employee or agent of Duke Energy or
if the act or omission occurs in connection with a contractual relationship with
Duke Energy;
d. An extraordinary event beyond the Duke Energy's control, specifically including
any court order staying the effectiveness of any necessary permit or approval.
Contractor delays or failure to obtain funding will not be considered as events
beyond Duke Energy's control; or
e. Any combination of the above causes.
6. Failure within thirty(30) days of receipt of written demand by DWR to pay the stipulated
penalties,or challenge them by a contested case petition pursuant to G.S. 15013-23, will
be grounds for a collection action, which the Attorney General is hereby authorized to
initiate. The only issue in such an action will be whether the thirty(30) days has elapsed.
7. Any non-constructed seeps causing or contributing to pollution of waters of the State
associated with the coal ash impoundments at Duke Energy's Allen,Marshall and Rogers
electric generation stations, and listed in Attachment A to this Special Order,are hereby
deemed covered by this Special Order. Any newly-identified non-constructed seeps
discovered during the annual investigations for seeps referenced in paragraph 2(c)(3)
above, or at any other time while this Special Order is in effect, and timely reported to the
Department per the terms of LAMA and this Special Order, shall be deemed covered by
the terms of the Special Order,retroactive to the time of their discovery. Newly-
identified non-constructed seeps must be sampled for the presence of those characteristics
listed in Attachment B to this Order. Newly-identified non-constructed seeps found to be
causing or contributing to pollution of the waters of the State, with the effect of causing a
violation of water quality standards in surface waters not already referenced in the
Special Order,may require modification of the Special Order to address those
circumstances.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
p. 13
8. Noncompliance with the terms of this Special Order is subject to enforcement action in
addition to the above stipulated penalties, including,but not limited to injunctive relief
pursuant to G.S. 143-215.6C or termination of this Special Order by the Director of DWR
upon ten (10) days' notice to Duke Energy. Noncompliance with the terms of this
Special Order will not be subject to civil penalties in addition to the above stipulated
penalties.
9. This Special Order and any terms or conditions contained herein, hereby supersede any
and all previous Special Orders,Enforcement Compliance Schedule Letters,terms,
conditions, and limits contained therein issued in connection with NPDES permits
NC0004979,NC0004987 and NC0005088.
10. This Special Order may be modified at the Commission's discretion,provided the
Commission is satisfied that Duke Energy has made good faith efforts to secure funding,
complete all construction, and achieve compliance within the dates specified. In
accordance with applicable law,modification of this Special Order will go to public
notice prior to becoming effective.
11. Failure to pay the up-front penalty within thirty(30) days of execution of this Special
Order will terminate this Special Order.
12. In addition to any other applicable requirement,each report required to be submitted by
Duke Energy under this Special Order shall be signed by a plant manager or a corporate
official responsible for environmental management and compliance, and shall include the
following certification:
I certify under penalty of law that this document and all
attachments were prepared under my direction or supervision in
accordance with a system designed to assure that qualified
personnel properly gather and evaluate the information submitted.
Based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my
knowledge and belief, true, accurate, and complete. I am aware
that there are significant penalties for submitting false information,
including the possibility of fine and imprisonment for knowing
violations.
13. This Special Order shall become effective in accordance with state law, and once
effective,Duke Energy shall comply with all schedule dates, terms, and conditions
herein.

EMC SOC WQ S 17-009
Duke Energy Carolinas,LLC
p. 14
This Special Order by Consent shall expire no later than June 30,2022.
R ike Energy Carolinas,LLC:
Paul Draovitch Date
Senior Vice President,Environmental, Health & Safety
Athe
' Envi mental Management Commission:
Solomon, Ll /� g
ssion Date

II a E a n n a
> N C O Q Q Q CL N C
E a o
c v, N � `t � m Qm Qm I
a c
CL o v z Z Z Q a
Q z ^ ,n c :3 « Z -^
i p a I ,n cn ,n a
Q N N N
tw +N3+
moQ=a pL Ym O Oc cO
N
�vE OA 00 vEO a
C
6O OD pac 00 0) V)E >
Q C L LQ a a O
o, r c a
Z O Z
o w Qc N
Q
V)
to" m m m m m m
p �
o � u > > > > >
a CD
H � 3 3 3 3 3 0
3 o °c
E Ln
'O m Y _ m Y _ m X _ c0 Y _ c0 Y _ m Y _ E a
.; o m m cu .G m -0 m .O m .Q m O .0
3 rJ °' 3 Jr °' 3 `J- g 3 a' 3 .J- °' 3 Jr °' u o d
m L ? m L a m > m L '> m L '> m L m L m
•� L
< °' " v > 's > s u > 3u > 3u > 3 > 3 pE
a O U JI y }p -a =
lU6 N V1 4_en C_ Z C •T C ?� C ? d V m O
+. ,C j 3 m a3, d Zi N2 �i a r O. ami m m
cu U c c E .0 m ai C C y c N ° y '° c E
aA c c u 5 a m E 3 -0 E 3 E � o a a m
> E a c L o c L o c L o L Q m
Q a 3 v v a m e 3' co c 3 m c 3
w u > o a o a o 3 d •- c c v
w o a Cl- > w � > O a v
.x p 03 m '^ u c °1 c a C u a r= Q a i c o'
.0 $ o v > v > v � ? v m E O to a
v o t E cu a v y 4c v c w m 41 n 0 3 m
a ai c m e m e m e 0 E
j u CL u o u Y up u Y u Y o a c o a
o a o 0 4- c o c� o c i c o o a o L
J m "A U J O u J 'O 7 J 'a 7 J -v 7 u. u OD a C Q
y o i+
a m I� 00 V Ln y ' a a)
1 o o r4 m Ln m c Y a
C) 0 ko 0 0 0 o N M a
"n p o " p p •m c"i
a J Oo OP 00 Oo OP OP m c
O. a > c6 u
H pal ° nu 000
V m m ay co' �
n ,n Tn c a —
` Q -' m m Ln^ m m I en cu o c
++ LCL
I Q N d0-%
C �.. C •O E-
-
Oa p a C
V a .-i N In ,G h '� a t 0
O ,aj n ,n ,n ,i, ,n ei) u A c E
H O 0 —

a
a
� a
E a; m
.c C ` Q �
C O Z Z
V C
Q V)
CO
N
i
C y O CD
O a) E c --
C Q
O w
0
Oo
of
oo T o
o
m
o u Q o
m
V O C
E Y
y y
m
N 0 U E .T
Y
C Q N u " o Cl
(� •� /J
i p � y !� ��,
< Q m " _0 CA E 3 a _ o o E
°' 4- vi 01 U
o. a a; c c m A ate,
E O J �° = w � � 'aao � � � O 0
u r N I O a Y O E N ,ai ,C
m cJj I aui = c Z u m CL a u O
ac z �° 3 u a ° m m
L- 3 >- C
m a ca
V CL r- 'o v c u - C E
_ O t
N •� m G. m C: C N N V N N
a) C a
' j O
O O N!
.0 `i u o m a a� ` a m m c y a c o Q
LJJ O O p H y 4 o C •p O N L O C C C
"" a+ a) C 'II
0 0 c `° o z `� ` m 6 c — o
a) a � v u y a N E o w a u �e m
o +� a c u Y o o 3 m E O t O y
ns 4_ a5 r- o +, o o " C y E
000 o +; ° f0 03
CL c u E � C a� Q. E fl a c E o
.r ; E x o
aoi `o o j. o m y o o cv = = d o O v
in u A y -0 O u -0 n. vn 0 Wn Q•a a�i 0 OL c
L C
m O
ov Ln 'A c a
M en m a
m r+ ri -a •o
J ice+ Q r7 M 00 to M "a u
OL
a m o
x O a � a O a)
.a O U D O rt y u .Q
CL :Ll O Ci
is
Q m m iri O = — CA
m ` p N
fA — a Q' 'n
G n b N O O 'C O
a E a C
O ,n Z `n uo v°J a E i
O _
z 4 * as

y �
.1
4 ' S •
4--,
•
tt •

O a a
a a a m Q
o a c
a; f%j o a a o v
C' c N n Z - N o zv
0
4 c � a m
LA
G �^ cn z O v
cc co co
a S N N
Cm ° a 0 C '° C
4+ Y
`o (U to " C E to E a c E ou f0
4' E c o ,� c L a o m c E
c �- 't- tw
a �C+ Jo 4QA ?irA Ya oYa c YZI OZY
c cu Ca a -EY2 'A X c
Zd C a a
Q C J
d0 p O U U ta3 u iD
cmi m m m m o
cn
U ia+ > N -d
N a m a V1 1N uh vi a
E m l� � c
m N N
c 7 m
can oo-a a ° m Y m -14 m x m °e E `m
E m 3 � fO 3 .Jm fD 3 � `° 3 � m c°i 0
a c v az ° t wv° YEQ � u z u z z co
SE
o � N �
y O an N c v O
U 3 m a ami c o u v c
M-
CC `°
Q 1 _0 i c6 41 C C °o ` m °OO m
CNQ Y E 4NcC d a U C
m
0 ai o E E E E c w
O G4,
O
E D au° aE. oa � z v o m c
I 'A o m
m a -0Y -0 ' mo 4+ -0 C p D d Q L t 0acuc-i,
C u m 4S a W +a.+ `� am y o
lil.pae 4 'm3a N LmCLrya > d apC 0
° m+ , m � mOr o.
om m = 3 aC .:N i r- m v ° 00
c 3 u ° coZ o o u
acu
mi y n Y y a ra a E m m E
` `� o 3 m
v °.' a p cr
p > p � m p 0 c Q. o a v
0 m ? ++ Z J o al J O .0mIJ Q m J cu 0 m
o m rn 0 (c0 C Y Q
p
y c m y
m J o 000 000 - a a i +J a
OL m m 'a o
d rq
° a N r-4 d c -0 u �
o {j ° n �o n to a
`_ _' m m m I m (u o Co ou
cr ° a t
CL
ao
a o o ro o a $
c a = LA vn o J� u ,°n' c E

+ It 1. r ,
�. Catawba River
AL
• `• -t •.P. �r I JI `
� r
+ i Y
• (Lake Norman)
+ � r r ! � b4ra'+ r` k+ }
r''

a O�i 13
CL
E °� � q a O�i a a) [iL w
7 a c o F• aai 0 O tl1 O
E J N O O i-t CS Nl -� j rn
Y Op I n Q O tOn o O z a I o pv 10 I 0
a z o j) L vi 'm n z o Ln z o z a
a
aid vOial�- eq a
On a aj
x a
` c n a t0oo ^ c o.w 'Dop CLw CLai
Q. C E N a 0) 0rn c y 0 sn of t O N 0
O I '4 h `0 `p N C 1 O 0 w O I O I O
C u Ob CL
i z Q O m w 0 m C z ¢ O rya w cO z a z
Ln rr ❑ v E o E o a
V)
E A y
t0
'N > u 7 > > > > > >
a o o
-a m O
x tto'a
c o > a Q > , -o v aai o r
_a ss E +° '' ac ix it m a U uu A o
a ro O c O O O +' u u u Q
C 01 O oC m ~ N aa, O
O
co � o
0 ` y
a
3 a a .�
U r1 C C u o f0 C m O
i
u co
Q NtOW e•! .0 = Ot � O O-
*' .
'p
A u v++a
NN OWw 6 CO
C: v ++
?" N t : _ `-5cm o ° E
y E CL
QO ro CC M C `O 4a > } IV
.s
am O 1. a
aa ra
LD a ;� c E v ° M aa) C a +� o v c
a c V) +, m O rO m 3 ao C° v c c
vs N aC. 0 N W mn 00 D a m '7 U C L 'Vf m y 0 ° 0 N O C
C 0 C. `'r "0 �+ l� qp ++ O .O O 3 L m O
N C N V) N o q c ` `w w- -Q .o � M m C O m L i p
a C rO M Q Ln a m a of a �„ c a C o rO �- � oA c
O 3 a u Ln o m` a Ln aao 3 -f w c ro `aj `° T 'M " w '- -C u u c
V o o c _ t bjD m 0 a c 3 3 v y �° o °' _ °�,' OEi
+.. a •O OO.E O ++ L O u
?'O •g > 0 a x } N O 1 a u m A m M sn is 'O O O rO
41 �. 7 , cr
� •O
C LU N V H a •O a L Q ro C u ++ Cp +' N m > 3 +O-' C C G O a
O « O m fl 0 L
v ° m 0 3 °„' °c m 5 �: `�°, 'u m o o V) 5 m LL z ° a C at
a
C «,
a v oo a �n .�� v `,�° a s
p C d cr r. r� I* r- Oo It C C fl
OD at Ln Ln
rO a
ram- w Pn v Ln Ln L m a
r. r� �q ra r. r•. r. m 'ra Q u
FA OP OP oO oo ao co Z; M C
s: cc '0 > > c
N E o a M '~ �f N C 'O O a
u a N c 14 ta Ln - A a
u M
a N m m 0 � O iO
41 N rV ui ry N N rrl O EP -O
a J M Ln M M M M M M y O .CC m
CL
of C
N ` C M bCD O
o a
V CL N M Ln ~ 00 O1 O N �_ O
o vasz "' 4 4 V 4 4 4 utA c E
j Q o _

>T T T
a a a a a a a
> N a c w e aa) c Q ¢ ¢
E a a o w o a o a o ^
Ln cn
a c I 0 'o t o l o a z 13 z •g z 13
� a � N JCL y � Cl. C
� � � C za z O v"i ) rn
N N N
p0
C 4' a s a a) O. a) O. a Y pp I Y pp Y w
y a) a N p c a) c a c a c a E c E C a E c
a a a+_ o o a o o a m p a m c a a c
a c N N 'n := U L V a Y U a
O I a I 'H I vi I �- '-
C {[ o. ¢ a ¢ a Q o u `"'� cO U C co c o
a < a � 5 > >
0 0W zo zo zo zo („ yr — � vi
crs
V)
E C
m to-P O m
m C p m > > > > > > >
a a a t
u M o a
or U 0 C
N y
7 m
L
X C p > > > > (VOai N I P L
K ... ... u o �.
Qa `a a a a a Y Y Y m L m
Q E a m O O O O U u u 0 o E
� 0 m m` m` co in V) V) o aa+ a8
CJ �
<n Ln 0 -0
N �
U Q
Q m ¢ CY �► Oa C a c
W N N O M a > y myO
%- >,a L C
a a C P a m
, C a a
m C m m w CO p (n
O =
mLL m 2L; y Q Y3 a w C
cc
Em O b Yp_Y ` C N
+' m 0 a+ 0 +' m u m a m 0 O m m
c E C� M. o a L a 4-1
m s U i 4- P + O ay Q0 Q
4)au m OC-0 M OD
Lap a u >L t O p r+uM m O a C ' > S a
IA v O
' LL
OU m O O
0 o O m
a a a - O -0 ro a C ,ONaa op
O 3 O a+ a o O C '
o yw 0 Na O
a
3 a 3 0 m m p E as m ao o 0 Y o U o y
U ° N c a ° s' c a a o "' 3 m ° a o s , 8 a Y y u a a a) 3 = Y c a E
� +-„ Q o m ¢ o �, a ,�, o a p o .r 0 M 0 a a -0 0 v) c ' +- a
3 a > m Q O. > m p• N C Q y m LL Mn p a �} C O C coil ` O 3 m s.
c y E m y o m `. c y m 3 0 Y 3 > cC0 d c_ 3 c x cr
o (D
vai 1 vai axi a 0 3 c g m s vai 3 vi a o Q FL- $ E a c a
Y - L m
N rl 00 'a a
o a h LD °ram° coo N c Rr a
lD 4o rr at Ln W �D a m .+ a
,mj ,)y f r ram., n Ln n h n n n ,4; i m a
O tp a
J aa+ p PI ei e-1 ri a-i �-I pmp G. a 7
a c ao op oo ao 0o ao 0o uv - " c
o 'a a m ' o
L 7 '> C u
'c D a N LA N e-1 L V
O U io
Ql '1 n 00 a y C a -�
Q 4.. N N N N N wi 1-4
N O 0 .0 =
L
Q J Ln rn Ln 1n Ln Ln M a 'O m tA
Wm m m M m i a ,n c
a v_n W
o c o
� o C

1 T
a a CL 0 CL a a a
> f!1 C N rV N N c Q l o C ¢ C. c
J N o 9 O C7 N O � A +l+to O � n to O
C ¢ 0 N N a0i Q O z 'mo €Q O z-00 Q O
z C- to tn to z CL z C, C M,
¢ Q N H Z Q1
m m
N N
tl0 dD ..N bD ..
C Q. 0) '% L O. OJ Y CO Q 0J L UO Q a)
M o di v c tw p 00 o a0 p d o a� E C 0! c > E c m e
+. m o c ._ c _ c ,r 0� p a, m L m o m L a� o
O. C to ++ �- C d L C 0J '�- C a I N L w O � i+ w O to '+_
O I v O p a+ p o a+ O p ++ I in U L #= I ti a `= 1 'v�
Q U •c Z a O N O N O N z C. to C Z 0 m C Z
O Q.
Ln
a � H I� � � h Q 4 O
E >. c
ro Fw a m
(U .°Q > > > > > > > > >
In 'p 41 E to fN N to to 1n 0} to to
m Aat 7 C N
O c
V�1 to
'p � L L Y L � �O
x c o a p L o L > > ID > > o r
a m a m v ce o= v oc a " o a
CL L I >
u o a + Om> I a -voQ aim a 'oD cOuO ° Em
++ U x 3 co ( I mL m to coL m o � L
c m O
Vl
Ol ��7lID.
0 .�
V 0) ' o (y � N r- C C @ 0 s u
to W O/ `' _ •� N V'1 ° N Q 0 U Bm O
CC
;; O o O w O O Ln w > 3 a, y 3 > o c c
d0 O 'O � m N O 00 01 C G 0 " 3 sC. CO a) a Y a m . OJ
CC 'o ° v 3 a 3 a 1p ° omLO o > `o m m +: o s
m "" ni ro _O m p �+ N f° C � O •c 2 � aa) u
m O 0 N L N `1 tL h C ¢ O r.. ¢ to U 0J O N aJ Sl C Q. m ¢
,aCD m C O m C O y.. C ` W o -p 0Y! a m Oo C > Z O 'a C
tri a v N m t � w n0 m 00 y° a '� x y n, v i3 o p o +1 °c c a
f0 a L L m O 00-0 m e •O m = 0 m a Q CJ o00 m s E '� O ,n O y C
C a ,4; p L C O y •C O .CC +-' -C L CO y Y 00 L r O Y a �- .0 ' C O
> m a 3 a 3 a 3 4 m `+ m m c u 3 m o L L o o � o ,2
m ¢ O 3 v- O aOD a
ip m � v E ,� m E m E M 3 "0 M Wpi a m CL v a tW W t •t o
U a O0 O o o c o c w 0 E y ,, +� o a, o o a c a c p 0 0,
�. 9 c '� O m �= m Y o m w 3 3 ° a, o u v w a c °;
3 m C t ? N tvwa > C > H VO 3 c N s ° p y m P
o v w a 41 ai s a°i c0 a °�' a, ai 3 0, a :E c 3 c I Q c c
o` 3 V) ¢ p` to 3 to 3 in c =o LA - � E a m to � 20 � cc v � av
Q C r` W 00 sni e-4 to to O co H _O t 0J
O ' N Ln %D N N Ol N N cf m C a+ G
;_, „ m 00 00 fT to to 00 0 c n a m a
m CD tD tD tD LO to a to v 0J " m W
G C f` r• P` h P% n h h !M1
J ++ p .-� r•1 rl ri 0D o- w 3
c J OP OP O0 OD 0a O0 OP 00 OP y7 a) V a
�+ Ln 3 C
m '0 > m a U
p N Ot ry r-q lO to 00 ct D1 C
C, N O) M w 00 to N n en -O 0-.O
V -O ri r M to 00 to N m 1-I ? 01 G
0 3 r` w to tD to Rr ap r` 00 to c 01
Q ±' .r rq '-I rq ri e+ e-i ri e-1 3 O .0 flt
O- N N y N p
I N N N N N N y — N
Q J — r'n M ' M m m m m M M 0 Ln LF) a y C
O.
C 'p ,
0 * 0o rn ¢ * r♦ m Q °LZio
N N � N O to
�1 0

a a O. a O. a
'aJ 0. °a) o. ate) Q Q. Q Q Q Q a v a BCD a v
41 c aJ C c aJ c aJ C
E a; a, o a, o M o -0 m � aJ(AuO a� o (ua
QJ C 'ifJ 'uJ \ N \ iO \ f6 \ f6 •a fO \ f0 N 'rn 41 IJ 'vl
41 c Q O Q o z a Z rs z M z a z is z c ` oLn Wp
Q ` ` oa
_ a Z a z ° rcc m m m 1 m m CL z z y
Q In n n N i n L a b o
N I co N Co N N
tw
412
C a aJ a aJ Y 4D Y WD Y h013C OD �C OD 3C OD a aJ I a w a aJ
`o ac) aJ c ar c aJ E c O E c a, E c w E c aJ E c aJ E c ar c w C v c
Q c E to o �' a `o o �' o a v o CU L. w o �' v o �^ ° '^ rn
O I '� I an U + V ` ++ U ` 41 U ` ++ U ++ U i w
c a ` CL a c o 3 c o c o c o v c o c o OL CL? a
*O� O � zD z � 0I ( � (A Mtn Ln Z � zO zO
m �+
0D p O m
ate+ > Q �° > > > > > > > > > > >
v) a 0) V) Ln cn Ln V> dJ v) vi v) LA
o 0
O @
Y �f Y Y Y 44 Y Y
X C O E 0) Cl) aJ aJ aJ 0) aJ OJ 01 O =
a �-, a u u u U` u u u u u - a
U �„� f0 Y 3Y .Y Y .Y Y Y �0 Y Y O
a N �O O L.J U U U U U U a U U U O E L-
y. O > > 7 O 7 3 p 7 7 W
{... U m in cn � CA yr to m `n `n v H '^ O
a O ( --- c O v Ln
E 9 E Y d a3 aJ aJ a) Y OJ t L
t ^ y to 7 ti4 >! CO 7 CtD t'� y7 Oj y to U ++
U 'V4 L C V 1..7 f.' •C.7 C U S� 1/1 L a7 L C7 Y
m IA W e`D U � 0 0 O ro O co a@ O (a O rD a) @ U Q fO ++
VI O i- c O 16 aJ eo a) ro aJ ra aJ ro aJ > c C Y d a M m
Q r ? y to� o w o � v m aai t'n ? aci
hD m ..- � �+ 3 ro �►- ro � m 4- M L+ ra � aJ �. . a
O m fl i o R v o a s a O a o 0. o a o o z o O Ql +, c E
cC v. a '6 C ,� (J a' m — 0) 4+ aJ — a " L_ � c Y +' m C ° u
3 c o .°)c > �' v w a aJ v a' aJ a v m `= a c l u 0) V m
U g a 'r m` w 3 ¢ m 3 3 3 al 3 w 3 0 o m c °a m q
J ++ O O SC +' •]C Y Y ++ y y Y r+ Y Y '�••' 9 7 V
J p, O +� M t aJ 'a N M O) M a) N aJ M (D M (D C m U @ ... O a c
N o Y Y OJ a 3 v 3 �J 3 v 3 3 43) c x c c -7
rmo m -0 3 (D < � u c � cU cU cv cv 41 a, m a) cn o ,n c
Q O U m OJ aIn
_ro C 5
O I y H S U O O Ln W V) dD N OD to OD N OD N w '' - a j. C C M
m m 0 1 7 01'O Cl u0i O Y A 0 -Y y 0 Y in O Y_ o `~ Y_ U O t d > u U C
U a E w = .4+ N N m O Y 'O Y a 3 Y a 7 .nt a 3 Y 'a O O m vi y c c Y bo O1
v a •a u C 3 � c c c c c c c c c E �, to m` u u c - . m
z o " 3 bD0v n '� v NJa °a � -0ra •rA f6 cc ar o 3 ro =
u C t - ns L ca rD f6 m 3 cc 3 a 4 o E 'O
a o aJ ° a c o .c o .° o ° o Q.n o a.o CL O a ° w X
C C O N 10 aJ N S O C t = C _c d C = a7 @ H m fYO r C O i
W O aJ 0 O .. r+ co +� In m w m to N LL T3 Z z N ° OQ 0)
Iv o z c to a .— E m a co 1„ m v c a r
Y N ~O m �+
v . ao w m rl to at Ln m f6 aJ
C -� 07 m r n 0) 0o V Lr) N O M "O G.
O 00 01 d• 00 Ch 00 w r, r r, C +-'
3 r-I m to m M M M m Tt m Ln
Ln Ln Ln N Ln Ln to LA Ln Ln 0) L M OJ
U N dD n t` n N n n h n h n -
r0+ p r1 e 4 r4 ri r7 i 4 rq ri rl r1 OOD O.
�0) C J O0 CO OO OO Op CO 00 OO C0 OO N ` U C
- > m � O
E -0m Ln N N to N 00 N LD M •s C U
O VaJ 00 N W r. v M co In r. Ln o .00 a,
O t0 vt to Ln ,I et N N LM N S ai O
7 r- n e-1 ei ci ri H r1 00 n 00 i/1 C aJ —
O. :Ll e-r �i rt -1 p 1-I If 1-1 r1 e-1 O 7 O .0 M
(y +� N N N N N N N N N N N O
Q J Ln Vl vi Ln Ln Ln Ln Ln ui to N
m m ") m m r m m rn m m M d o to
a ° DL
N 00 Os o r1 N + + I o o.'o C
N £ N Lo N N N M M T m M fM I4'
Iy z In rn of vJ vJ vJ vJ vJ yr yr y o In o E
{ J IF

a CL
EL a
E JLn
m Q Co m
O z 'O Z -0 z v
c
Qu m m m
N V1 VS
an co m
N N N
OD w
a L
'L C to wE C > E toO C L m L `J m V j2 M L,
C2 O ` U ` O U ay O p 0
0 O Ln
C c N C c m C c
cc
m N
41
N
> 0 v>
m tto'D m
+�+ > > > >
V
u rCA 3 �' o
0: M
U p O
C
Q. ci y U U V O Q
C L m
G u u O 0 O E L
y 0 V) V) m O j
U E 0 p a ti O
I� OJ M.0 v N 07 V 0CV) y t V �.-
++ O
N N to N c 0 O V YO s w O O a v m m
Q L y > ,L +' N u rn a+ p
4A N u :ke -0a&n O LM Y m �'
O a ami v 1 4 3 0i aa) v 3 y ° c E
L
Vp, +� c '
0 OU mC d LA u cO +a00 w 0 H O+ Qa�m O X \ >
O O O) j LL C a m
Q m ) d 4-1 y a 9 O V C Q . '+3.tn c 3 v o non 3 w° (D o �' w ° g
v ,Y L m c N 00 Zn m` 3 Q.
C 0 0 m m �; •pp m C � •Q v V y Q = 0 w
O oo L 3 Q v c c a + c '^ LSD c •4
U z +m+ ul d m y `M w. Q p Ln LO u 0 Q
7 y m 0) a� C m a@ co c c a�j
>. N .�[ "O C O) C v
o °,�' o = m vv, Q u o 3 m tf
v o �e c y Y = m Y o X 'a-
!= c c •vL L a+ L N O a) u 0
C O L
d .0 V •a t� c m a0+ N Ln 'C O � 0 C a 0]
(4 Y
M N QS \ N y
Q C 00 N �-4 en 'a
p 7 M 00 cm c aC. Q-
R Y LMfl imfl VMS 'O m M 'a
0 y c n n n I m O O u
v c w op o`p °,-° alai
�+ 0) 7 0
m I - > ; O
x p O) VAS n0 w C -p u
N N Ln A v u -0
OL U y O O 00 j p
a r, .-I ,q
a N N N _o Z3 m
Q J LA LA ui •� •� m 00
m m m v o y c
a Q a0 L
O y c `a S
a 'o n T c a o c
a m m m (Uo
VS Vt Vi V Ln C
LnZ 0 * 0 _

y 1�
' T
41
• ` s '
-_I r
r
L- •-� .S ~ r 1 1 .
r
AV - +
1
1 , �
�s
•
f:
�a

SOC S l 7-009
Duke Energy Carolinas, LLC
Attachment B
Monitoring Requirements
The following represents the parameters to be analyzed and reported at all monitoring locations
designated within this Special Order.
Parameter l Reporting Units Monitoring
Fre uenc
TSS mg/L Annually
Oil and Grease mg/L Annually
pH Standard Units(s.u.) Quarterly
Fluoride pg/L Quarterly
Total Mercury nglL Quarterly
Total Barium ug/L Quarterly
Total Zinc erg/L Quarterly
Total Arsenic _ fag/L Quarterly
Total Boron Ng/L Quarterly
Total Cadmium erg/L Quarterly
Total Chromium uglL Quarterly
Total Copper Ng/L Quarterly
Total Thallium lrg/L Quarterly
Total Lead _ Ng/L Quarterly
Total Nickel Ng/L Quarterly
Total Selenium Ng/L Quarteri
Y
Nitrate/Nitrite as N mg/L Quarterly
Bromides mg/L Quarterly
Sulfates mg/L Quarterly
Chlorides mg/L Quarterly
TDS mg/L Quarterly
Total Hardness mg/L Quarterly
[Temperature °C Quarterly
Conductivity, Nmho/cm Nmholcm Quarterly

Seep Management Plan Amendment to Corrective Action Plan December 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
APPENDIX B
MANN-KENDALL ANALYSIS, OCTOBER 2020

410
r3ynTerra
MANN-KENDALL TREND TEST ANALYSIS
ALLEN STEAM STATION
253 PLANT ALLEN ROAD
BELMONT,r NC 28012
OCTOBER 30,f 2020
PREPARED FOR
DUKE
ENERGY.
DUKE ENERGY CAROLINAS, LLC

Mann-Kendall Trend Test Analysis October 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
TABLE OF CONTENTS
SECTION PAGE
1.0 THE MANN-KENDALL TREND TEST...................................................................1-1
2.0 TIME VERSUS CONCENTRATION PLOTS .........................................................2-1
3.0 MANN-KENDALL TREND TEST RESULTS.........................................................3-1
LIST OF FIGURES
Figure 1 Time vs pH
Figure 2 Time vs total suspended solids
Figure 3 Time vs total boron concentration
Figure 4 Time vs chloride concentration
Figure 5 Time vs sulfate concentration
Figure 6 Time vs total dissolved solids
Figure 7 Time vs total arsenic concentration
Figure 8 Time vs total barium concentration
Figure 9 Time vs total cadmium concentration
Figure 10 Time vs total chromium concentration
Figure 11 Time vs total copper concentration
Figure 12 Time vs total mercury concentration
Figure 13 Time vs total nickel concentration
Figure 14 Time vs nitrate+nitrite concentration
Figure 15 Time vs total selenium concentration
Figure 16 Time vs total thallium concentration
Figure 17 Time vs total zinc concentration
Figure 18 Time vs bromide concentration
Figure 19 Time vs fluoride concentration
Figure 20 Time vs hardness
Figure 21 Time vs oil and grease
LIST OF TABLES
Table 1 Sampling Locations and Constituents Included in Concentration over Time
Plots
Table 2 Results of Mann-Kendall Trend Test
Page

Mann-Kendall Trend Test Analysis October 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
1.0 THE MANN-KENDALL TREND TEST
The Mann-Kendall trend test evaluates data over time for monotonic trends, where
monotonic indicates a trend that is solely increasing or decreasing. Mann-Kendall is a
useful trend test in that it is non-parametric and does not require normal distribution of
data.
To perform the Mann-Kendall trend test at Allen, the data must first be processed as
follows:
• Non-detects greater than regulatory values are removed. If a COI has multiple
reporting limits only the lowest reporting limit is kept.
• Non-detects are treated as the reporting limit.
• Samples with turbidity greater than 50 NTU (nephelometric turbidity units) are
removed.
• Samples with pH greater than 10 SU are removed.
• Samples have to be at least one month apart. If two samples are closer than one
month, the less complete sample is removed. If samples are equally complete,the
earliest sample is kept.
Next, the data must meet the following requirements for a Mann-Kendall trend test to
be applicable:
• There must be at least four detect measurements.
• Non-detects must make up less than or equal to 50 percent of measurements.
In a Mann-Kendall trend test, each value is compared to the proceeding values to
calculate whether the value has increased, decreased, or stayed the same over time.
These comparisons are recorded as simply 1 (increasing), -1 (decreasing), or 0 (stayed
the same). These comparisons give an S value, where S indicates the type of trend. A
negative S value indicates a decreasing trend, and a positive S value indicates an
increasing trend. Whether or not these trends are statistically significant is dependent
on the two-sided p value. A p value ranges from 0 to 1 and indicates whether the results
are due to chance or the results are statistically significant. Greater p values indicate a
trend is not statistically significant, and a p value less than 0.1 indicates a statistically
significant trend.
All Mann-Kendall trend tests are performed in the program RStudio using the
"Kendall" package.
Page 1-1

Mann-Kendall Trend Test Analysis October 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
2.0 TIME VERSUS CONCENTRATION PLOTS
Plots of concentration over time provide a visual representation of possible trends in the
data. All plots can be viewed in Figure 1 to Figure 21. Plots are grouped by constituent,
and within the figure, a plot of concentration over time is displayed for each location
that has data for that constituent. It is important to note that some constituents, such as
hardness,have limited samples in few locations. All locations and constituents included
in these plots can be found in Table 1.
Trends from the Mann-Kendall tests are displayed on plots with colored borders
representing trend conclusions. Blue indicates no trend was present, green indicates a
decreasing trend, yellow indicates an increasing trend, and no color indicates the
constituent-location pair cannot be analyzed for trends due to a lack of detect
measurements. Detect measurements are shown as a black point,whereas non-detect
measurements are shown as an open circle.
Page 2-1

Mann-Kendall Trend Test Analysis October 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
TABLE 1
SAMPLING LOCATIONS AND CONSTITUENTS INCLUDED IN PLOTS OF
CONCENTRATIONS OVER TIME
Sampling Locations Constituents
S-2 pH
S-05 Total Suspended Solids
S-6 Total Boron
S-07 Chloride
S-10 Sulfate
Total Dissolved Solids
Total Arsenic
Total Barium
Total Cadmium
Total Chromium
Total Copper
Total Mercury
Total Nickel
Nitrate + Nitrite
Total Selenium
Total Thallium
Total Zinc
Bromide
Fluoride
Hardness
Oil and grease
Note:
If a location-constituent pair does not have a plot,data was not available for that pair.
Page 2-2

Mann-Kendall Trend Test Analysis October 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
3.0 MANN-KENDALL TREND TEST RESULTS
Results of the Mann-Kendall trend tests are displayed in Table 2. Trend analysis could
be performed for only 23 location-constituent pairs due to a lack of detect
measurements. Either there are less than four samples, less than four detects, or the
number of non-detects is greater than the number of detects. The number of non-detect
measurements present in the dataset indicates that many constituent-location pairs have
concentrations less than the regulatory limit and are not predicted to be of concern at
the Site.
Locations not displayed in Table 2 are excluded due to having less than minimum
number of samples required to run the "Kendall" package in RStudio. Locations must
have at least three samples to be included,but individual location-constituent pairs
with less than three measurements can be analyzed as long as the location itself has
three samples. However, it is important to note that location-constituent pairs with less
than four detects cannot be analyzed for trends based on the criteria in Section 1.0.
Out of the 23 constituent-location pairs that have trend conclusions, 82.6 percent are
stable with no trends (19 out of 23 constituent-location pairs), 8.7 percent have
statistically significant decreasing trends (2 out of 23 constituent-location pairs), and 8.7
percent have a statistically significant increasing trend (2 out of 23 constituent-location
pairs). All of the increasing trends occur at S-2.
Overall, the results of the Mann-Kendall trend tests indicate a system that is been
geochemically stable, with the majority of concentrations of constituents remaining
stable over time.
Page 3-1

o m
N v
a r
0
Q a In a VI N N a UI a a a Ot N a a N a f/1 Vl IA Vl a In U) Ill V) 0 0 M VI N M ul y
c a c a a a c a C C a C C a C c a C a a a C a C a 'O a a a a a a a a a a
4) C KU c c C W c W W C Ll 'y c d `l c d C C c `1 C N C C c C c c c c C C C c
c N y N N L ai3 it d a+ M N y d y d v Ill y d y Ll N �7 N N N UJ 0 `1 M M
G y F F F F F y F v y F F F F F F F F F F F- H F F F F F
'y C C C C C C u C C C C C
7 Mu R w w O w _O _O 0 C w N N a R w w w R w m �O y0 w w w w w
U U U U V U � U U U U U
C .0 N C N N N C NCC N .0 c NCC N •C N N N .0 NC N N N N N N N N N N N N
O Ol_T O)_T_T T Ol_T m OI�. O U T Or OI_T O)_T T_T _T T_ _T >_A_T_ _T_T_ _T
V n R w M M M w M w m IE 'N it IO IA VI 10 0 M M M N M Ill A Q N M M R R R R R R fC
'O O C O C C C O C O O C O C c O O c O c c C O C O C C C c C C c c C c C C
C C Q C Q Q ¢ C Q c C Q C _OI Q c c ¢ C ¢ Q Q C ¢ C Q G Q Q Q Q Q Q Q Q ¢ Q
dj O y y 0 y 0 0 4 y 0 Qj O O O y 0 y 0 0 0 0 0 0 0 0 0 0 0 0
F O C z C C C C C a c C C c C C c c c C c C C C C c C c a a a a s a .q a a a a
c c c c c c c c c c c c c c c c c c c c c c c c
M M M R R y R R A i0 N N z 10 u R R R R A 10 O IO IC 10 fp Ip lO 10 IO Ip R
!n V (/� U U U y U In in U (/) y U jn U (n U V V (%� U lA U U U u u U U U U V U V
Mn
.i�
d
7
R 'a
M
r r r r i r r l l I l l l l l l r l l r l l l l l l r l
y
a
a
dy
n O O N N O M O W
A N n O M rl O M M O l!1 .-1
O O O 00 O O 00 O O
F N
v
c'Ul a
C N >R m o 0 0 0 (n o 0 0 o m o o o 0 o m o 0 0 ^ o N o 0 0 0 0 0 0 0 0 0 o O
Z F Y y z y z z z y z W 11 z } y z y y z } z z z } z lu z z z z z z z z z z z z
c
1yi Q a
F. a
J
J
a
NC �
ay. O O O N O O O O o 0 o O O o 0 0 0 O M O p o 0 0 0 Z M M O M O N M p Z G
a
Z oz
U.
S
0
O M M ti M M M It V N O ti M O N O u1 N O n M M N N O
J G
N
W
G)
a�
m 000 0 '+ o000000a0000N a 000 voo o a 0o Noo
C
c
0
z
0 N
L d
a E ti M v V M ti M I M V M 7 MIt M iF ti M -T N O ti M I ti M -0- v N O
R
zN
u
a
VI IA Ill N 1I) VI
c a a a a a 9
U) In Lf)
Ln V W y y O O Q O1 W U1 a a a C C C j j > > 7 7 7 7 _7 a a a a a s
>. 3 a a a o 0 o a 0 a -W v (l Ili ` m 11 E 'E 'E E E E a s aOi a°i ai
H oo R = x x C C C 0] !n M 'c r',°_ �° �° > > 12 T `m A `m a a a o 0 0 0 0 0
u m n a a o v m _ 0 0 `0 0 0 o a a ¢ m m CO 0 m m t L t 0 0 0
a a Cl a M M 0 U u u¢C W G ul In w m is m U U U U) U) En _y In I_n i alt; i L U U U +Ri i
y x 7 7 7 0 0 0 F F F F F F o 0 0 0 0 0 F F F F F F
N V) V) F F F
F p m m � c la m F F F F F F
G G
H H F H H F0-
� O
F jp
A �
b � �
aFi y N i0 N tD N lD N tD N t0 N t0 N t0 N 10 N 10 N l0 0O N �O 00 N �O 00
D M M w M Lh W M 6 M 06 V1 M h M M y Vl In In V) N (n N y N N y V1 fn N In cA N
m a 7
Q

N U
a
° n d d"
u
O (M M 'D 13 N Cll 0 W V -0 w 't3 N Ill N N W M M H N U H M m 13 M -0 VI N N
C C V V y V C C
Ill C N LJ C N C C C 01 C it C C C C C C `1 C H � C C C C C v C N C C C
yl V
O u u o a w _u w w 0 `0 0 o M- o 0 o w cmi o u Z
CC O �= O) �`- Ol OJ 0J 0) 0) 0) m OJ cJ w 01 0) � 0) �' 0) 0 01
O VN L c N c N N N C N C N N N N N N C N L C N N N N N C N C N N N
, m T u _T T O1 T Lm T T T > T T O1_ 1.0 rn T T T T T Lm_T CT_T_T-?I.V ir N 0 0 m m 00 - m 0m m N m m m Ill m Ic � m m m m N 0 m m m m m
C C O O C •C C C C O C O C C C C G C O CC O C C C C c O C O c c c
c 01 Q c c Q O Q Q Q c Q C Q Q Q Q Q Q C Q a C Q Q Q Q Q c Q C Q Q Q
F T C � �
C C
V (Y/7 (%J U v V V U ((n U 3; U U V U U U m U !� m m m m m m m m m 10 10 IO
'N (n LA U U U U U (ry U m U V U
N N
L Y
L Y
d
Z
> �
M
U)
IL
d
o o o m m a C, o+ rn o7 a
IA 10 O M OO H 009 O ."-I Lq n
o> 0 0 0 o O 0 0 0 0 0 0
3
H
I+
9 N d
C N
O N N o 0 o o o w O N o o o o o o 0 o o 0 0 0 0 H O N O 0 0
F m > z > > z > z z z > z > z z z z z z > z > > z z z z z > z > z z z
e
waa
a
C d M
C
O O Q Q Q N o O Q IA o Q O O O O O y
O O O O O O O 0 0 0 0 0 0 eo
0 O 2 Z Z �'-� In In Z n z 0 0 0 0
M G
as
z
r ti N 0 M - N .-1 O +-1 - - n M - - O - O O N n .-I
01
In
y0
V
d O O O .a 0 0 0 0 0 O O N .-i O M O O 0 0 0 0 0 w .-i O O O O M .-1 V
C
c
O
z
O U). d
d a ti N 7 M 7 0 0 0 00 M I- t- N O V M .-1 ti M V ID O M r-i N n .-1 M .-1 'It'
E
7�
z
a
r
c
° °= ° °1 E E E E E E m w m
m m dz z z _ „ „ > >
U A7 L V Y > > > U U U Ill Ill N m m m
•+ U_ U_ _U Z Z Z = C C C 01 01 01 01 O) 01 yl yl yl y y y
v 2 0) O) m m m
2 Z Z 0 0) Ol t + } O) Ol W L L L N N N E E c c c rn OI O1
° O m m m 1° m m L ;� w m m Vl V1 (n F F F m m m o 0 0 > > > m `m `m c c c
y Q o 0 o Y Y m 22 i :° .10. i Y F H H m m m L LL U- _ _ = m m m
o 0 0
Z z z z z z lo- I-o H F F F O O O
b
c ❑
F m
❑ cn
a E O
~ N tD O N l0 O N �O O N t0 O N lD O N l0 O N IO O N i0 O N l0 O N l0 O N ID O
.i .-I 'i 0, 0, .-I 0
d (n M M (n N !n N N N N !n M
S (n M N N N
I i

Mann-Kendall Trend Test Analysis October 2020
Allen Steam Station-Duke Energy Carolinas,LLC SynTerra
FIGURES

(A
U)
}
Z ?
a=J
O
xaiF-C
V)
N
�W w<
f7>PPZ
LL Lu
J z H
Fo-o
wa-j
OZOZ z m
z
a
6LOZ
940Z ui
0
L WZ t
U
.. Q
940Z
m W y W U
O W
tt W S a 0
0 K U Q
OZOZ '^
V�
6LOZ =Z v^
Ousu
� ' y
R 9LOZ m
EnC
I vo
1LOZ he
w u
H m
9LOZ a
ref yt+
ao
o
,'o 0
i
OZOZ a
a
o«
o`o
6LOZ 0
x
a c
v
N
nt,
•q 9LOZ Lu na`
W >y a
z p��
LLOZ a =
a y
HF
m�
940Z a �a
v � v
_ oS�
w t- ro N v ro ti co
y
o = _
(ns)Hd
aLn En
f
cI
-u V
V N VI G
m V
Z
W
L"
Z O m
WI 2 O
J ��

§§
k� «
§)§)
z0)pw
WLU
���u
�§LUaIr
■Z
ca
�0-1
�A§§
�z-i■
U)Lu«-1
ozz §I LU
in
§§
�
eW
§
} Mz /
` [
\ � *
. °` §
� ) \ \§ §
o ,lz
)-
e� zo §§\ /
§ § ego
z� za )k
� \{
{/<
oezz #;f
MZ )j\
\ § �&2 - )f\
>ro
o /\)
z F««
�L O k/
QE
to \ \ ) CD
2 ( \ \
{gem @Sp��sSAo \\\/
L-Jwj§
t
z k

y
}
Z a Z
Z
Z
O ► 00
owaa
cF F.
waw
m US U-jU)
1.O J Z Z
>Uo_3O
J
ozoZ Y a m
Z
z
a
6LOZ
�j 8 60Z
w
r
0 8
LLOZ E
t
U
9LOZ Y m $
3
m m
oa w �
Z o w
S N
o ¢ ¢ a
oZOZ
WO Z
SLOZ x o e,�r
W z�4
vs 9Lod G
LLOZ
�t
I �
9 LOZ 8
_T N
=v
3 m
c
OZOZ a
o u y
—x c
�L«
SLOZ aa�
`o'v>
N � ace
N y 8LOZ
Y�a
W > n c
01 m a u
LLOZ Z i=�
c F,
r
r9LOZ N a
O InO LOj O � C0 O O CDO
u.
h N 2 f o
y
y C L
(-116d)UoJo81L,3a1
ra Do
%
' o
�V
Z
W
a ti
� � w
W�i Z17♦�
T

■
§
o k �
B§ §
§�k
�141"u
zzz�Ruo
�U)W Z
—wL)
>§gwz
ua-Jo
k Lu
GZOZ i m
k
e� zo
q
U) e� ao \ .
;
LW f
§ m /
^°
f » & : !
\ ai
oozz
�k
eWZ
a i
ZGz /o
Mz 2.2
oezz .2
!«
6LOZ
o \
rE .2
` uj
o f�2
z FE
z� z,
• /{
Mz
w ° * cli
�ee A�ltio�
)§)\
k,
2 !m
�

k§
Kd ■
Z«Z:1
C)
§P��
eLU�§��
e-Lu
:3-2J
§8k
§LU -1 ozaz ; ■
k�
a0z
/ eL
< ;
zLa §
| ! (
� .&E 67 `
. � @B
oz z
d7
16M AzI
° a °4
cn ; &r
62
/\
\ e1 zQ _
\}
� oolz $!
sL �/
£
k
� !#
§ 2 a� !f)
U)
�
of
a2 z r�@
Mz -!
� o o a))
_ ® 27#
/ƒƒz
;2u
§!a (
2 !$
}�

C N
J �
Y
w Z Z
z
� H0o
o O wpw
U)FF-�c�
WoRzz.x
O J LLI Z K W O
LL~V~N Z
�Z J Z F
j U O J 0
K aW
OZOZ j Y Z m
F
6LOZ
gg
n3
aLOZ w
❑ o
EL
LLOZ
U 2
W
940Z
m m o w
Y U W
4a � i a rc
OZoZ
MZ ?t
9M
O
LLOZ v
m
u
�o
t c
9LOZ
�v
3=
o:
Ag
`p`xa
OZOZ a`w
ny
aT�
s
640Z v o
W
�9
�qa
ti
0
N pq SW o c v
N m�
H
O E
LLOZ z ~�9
as
•
9LOZ
• a w a
c
O O O O O O O O O F
O O O O O O
co N M N
43 cE c2
t'i/r)LLD SP!!oS POA!OSSIQ!poi
T Ty,
C=N O
Ill VI VI `o
Z
w
a t'i
I

■
° ) _
Z Z z
f «00IXzo
«p.L
LU I- C§ §\ w
o
o(ALUI.-wZ
MDu,u) .
W Z ZZ -
SS;-i§
LU mǤ
20! § J w
5
aLOZ
;
a ;
©° /
} = m
&E
Gala
�7
eWZ ))\ /
%
k . ee
LO
@� aq /-
,z � )
o o
,f 222
/ &2 .
CO) )\j
i�
k )
9L
2 \\/
o o §\!
(-lBmmmsVAoin-gi
�z
2
2 kz
LLJI
)

�
§
) kzk
« ego
�0Lu
§§§§aw
22§§U)k
Liz-J*
az § w�w
� $ m
5
ee
n
e@z
! §
&2 (
} ! (
,L
\ \ ) � §
, , ! !
o z
b¥
eGz 263 V/
k #2 m `
,L \-
� \/
oQ& z #\
�)k
ems ®-#
E
( �c
® sL
2 >
� �,�
� §Z� k k!
T
G � a C & ' � � u\k
m w _ r e ))!
mpe jejol §f\
\/\k
�/
;
§ \'
)�

e
} Z
B -00
v§2a�
w�-
ee�
-LUo
oV)w��Z
�mu�C .
Lkk§k
» z-j2
s @`w
e� zo z
�
§
^ ;
g Li
| U) -
! . ■
� ! m
I `
Mz
LU
§. 44
k
\{
\/
\§¥
; 7 &E
/xof
!�2
� \k§
\ zB
l
� 9 Wz
� |)�
/£2
))#
(]Bm mmw�a mo ///ƒ
z
LU
§ }

■
Z
)zZk)
�Rr�vo
zE
§R�■LU§
@U)
AWL)o
¥ ]]§
0,70Z § $
�
§
2 ego /
� §
L ~ a 5
! ƒ
aE § . � & 7 ,
,
ozz
�!
eLze $33
/I■ %
. 4 #2 v
aE k§
_ _�-- M §§
� \a /\
Bozo {!!
2
2 § «tea d
Lu )'
§\
,
r ,
B=
=a2 ;#B
@tea )
/ \
!! °
s @n�oy Ao /ƒƒ<] ƒ
�\
� \m
z '
§ }�

■
L ) «
LLI
Z Z
oz�oo
°0Lua■
�0Kw
GOF)§�P§
M.MoLuZ u�U .
�
LLJ
>uo-10
a;
LU §■§
z
�
B2
(
BLOZ
a ;
6E
) ! \
®® ® ® )
\ } \ . }
Glz
e� §§\ /
�& MZ
&2 `
ego k�
\k
oz z ){
$®f
e2 I
kq{
§ @� /
. � V)
0
a2
gk/u
° §§�
( Ili) addo a Ao.L i7i M
mm
\\}k
/
!
2
LU
; ?�

T
U)
aZM
2Owaa
�_F~~v
aaDom
D Z K W Q
0 y W�H Z
Ii�O Zi
UO W 0
9 z J E
W ui Yaw
OZOZ F z m
z
a
Mz
s
c_
9
y B WZ m
a
❑ o
L40Z e
❑
9 '
940Z m m
m o w
N Y O W
U tt
W 2 �
❑ R' U Q LL
OZOZ
Y�
6lOZ Y��
a
0
d, 4 9 wz J'
c
i
f MZ
Y9
aY
m 8
a o
9LOZ �8
�t
�w
OZOz _o 0
-u '
w n w
oL«
660Z —
it a
a
q >
fh E
9lOZ
Ya
N o
H >Aa
L WZ Z
�a
960Z m N
O O O O y
It.
('716d)tinoaaW 19no1 a
v in in
T Ty,
N N VI C
iT.
0
z
0
LU
W

■
§
k �00
z 0Lu
�■re-
)§13 z§
w l--
�cnzmLU0
22§�§�
>S9L-uj§
w L■�
9ozz § I ;
�
&E
§
� ego
!W zo §
kOZ > \
\ } \ / /
oz z
eA «�k
8Lu V
r
w 8�oz 2
ZL `
)/
oozz a
,\'o
B £±j
§ 9L
=�f
/)!
se
B2 .-
f \{\
�; .
(-lBmPOPIN mO
�kk §
�)
2
� {|
m
§

�
� § «
& z
z 200
L,0 ul
_����u
§§LUkit
zWLu0
0�0-jUZ
Ezjuz�
2Go-j§
2 ma-j° `
z
s
-Ez
s §
. & Mz :
! §
|
zt _
ƒ
| ! §
Mz
oozz
§F
«2 E§\ /
fmz 2
4L )§
gqz /!
�\
oozz --�
6 2$]
, ;27
§ 2 &7
� ®�@
R
ZW z,
2 k/!
- -
ci
# !/F
0 0 §§#
{-l/N-ew mAN+mom w Cn n/�
}\kk
�/
o /2
z
§ \

■
� j «
2 zz§
EDZWP
®P�-
�k■§W2I.-
§pzWw§
�§§_j§�
Lu-j0
» z/�
ego k $ ■, f
�2 LLO
§ §
f � t § 2
Mz b!
«Ea
833
a Art
�
MZ `
t{
)\
aE
\/§
�
w .�!
-��
G / )
. t2 )7
ib
- - - - kkto a CD
w 2 w 6 e w A w a a q {
(-I/am wniuslas lino \\//
�j
2
2 )
(�

■
§ } ;
¥zU)k0
�PRLu-
v
M0§-w<
D�-zWLu0
@cn§PP?
�§S8§k
» z-i■
e� zo a ■`m
z _
§
$ a2
aj
ge
/ }
e� zo
)
2
\/ V%
� § I uE �
�M /o
\%'
!LQ _
GPS
SEC
- - L�
\ \ § \ \ § §/\
§)a
(�Bm LumR�m!o \\\/
a \g
Z
§ }�

■
§
Z $z2
~zto§�
�0Lu««
U)
°■2■�
�_t-Lu«W-
=:3zwwo
�2U\UZ
�wU_30
�Lu`w
�z �
k
■
eL zo
eL zo
L2 §
§ ■ |
9WZ ® 2 `
f � & m !
\ } } / }
�
Qo� z
§.
e@z ii' /
a ) \
� &e
ZWo k k
§,
,L zo \
|{
oozz ){
#B2
e� �)/
` 7 2 #S §!$
w
| 2
zLOZ
eL \
r m
(/Bmou!10401 \\\\
/)kj
Dal/
§ :m
§ }�

k§
§z ■
�«§�
Z(a
�o■�v
wLUz2
w0LU«12
:3■�Lu0
LL U)
m�z�
§z_3k
2■�w
LU m
kZ
oz ! j
3 !
f » ! m §
ee \ } \ / }
Gk�
RI
k
oa z /ƒ
k\ .
EE
Lu
e ��!
o
z
_ p
/ § ) / /)
!!!
(]Bm A!woe \/ƒƒ
�/
;
o
z •
}§

�
Z £
)00
B§aaa
Ix Wg im
w
S$wPPz
-LUu�z .
��z�z�
�S§-3§
■ z-j2
�«�
e� z
�
§
IaW
�
iW ze !
� ® �
\ & § )
= 22r
- ' \ woT1
� ! � & E
�
Mz
b9
Vba
RM \
- �
J/
#!
o
MZ )}
o
Rm -
2 §)�
of
z PEE
!M
o = e o §§a
(-lBma mmi \\/
})/k
k
� )�

■
§
§�o0
§maa
cm aU°
■U)ma§
��-Luo
�§�U�
»«LUZ
§�<k
o Z ILU
m
2
G2 §
� La
2 ■
a2 ! !
| § �
K � & \ ;
B2
\ } \ � )
Gozz
§.
60Z /ƒ /
3 -
eG� �
!G!
19LO q]
o z �f
)(
ee \/#
� )/\
&E 2 §|E
o |��
z ;�e
aE
/\� �
(■k©®�� \\\/
&ƒd1
�)
;jt

y
N
cn
LLI
W Q Z J
0 y 0
ZLu
I. F U
w�waw
70Wwp
aU)) -F-Z
fq
C ZZ
LLwLuO
9 Z J M
LuWQJ
OZOZ F zz m
Z
Q
6M
c
� C
W w
Mz o
6
L WZ a
a �
Y > m a
m m m ❑ �
940Z w
aa a
0 K U Q
OZOZ
Lug4
-.--
610Zv
EP
R
Mz
�D
LIOZ 9 a
a�
O m°
c
960Z
�v
o«
OzOZ 20
-o .
1p xa
�av
0 t
a or`
Mz as
ova
aY
°G
v A
an
860Z ml °
a
Z rFu
L MZ a
:a
�F
94Oz `"-
o �n u� ""o C.
O 1� if1 N22
O
(-I/6w)aseai6 pue In a
aY
lid
N N N O
G
Z
G1
LU Z 0
J ��