NC0004987_Annual Report_20200423

f•, DUKE RECEIVED James Wells
Vice President
ENERGY. Environmental,Health and Safety
MAY 01 2020 Programs&Environmental Sciences
526 South Church Street
Charlotte,NC 28202
NCDEQIDWRINPDES [phone]
April 23, 2020
Via Overnight Mail
Corey Basinger
Mooresville Regional Office Regional Supervisor
North Carolina Department of Environmental Quality
Division of Water Resources
Water Resources - Water Quality Regional Operations
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Bob Sledge
North Carolina Department of Environmental Quality
Water Quality Permitting Program
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Report Under Special Order by Consent—EMC SOC WQ S 17-009
Duke Energy Carolina, LLC — Marshall Steam Station
NPDES Permit NC0004987
2019 Annual Seep Survey Report
Dear Messrs. Basinger and Sledge:
On behalf of Duke Energy Carolinas, LLC (DEC), I am submitting to you the Marshall Steam
Station Annual Seep Report summarizing the findings of the comprehensive survey as required by
the Marshall Steam Station NPDES Permit NC0004987 Special Order by Consent (SOC), SOC
No. S 17-009 Section 2.c.3).
As required by the SOC, 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.

Messrs. Basinger and Sledge
April 23, 2020
Page 2
Please direct any questions concerning the Marshall Steam Station NPDES Permit NC0004987
SOC No. S 17-009 to Robert Wylie at(704) 382-4669 and to Chris Hallman at [phone]
relative to the annual seep inspection report.
Sincerely,
James ells
Vice Pre i ent, Environment, Health & Safety-
Programs and Environmental Sciences
Duke Energy
Attachment:
Marshall Steam Station 2019 Annual Seep Survey
CC: Richard Baker, Duke Energy
Robert Wylie, Duke Energy
Chris Hallman, Duke Energy
Scott La Sala, Duke Energy
Paul Draovitch, Duke Energy
Matt Hanchey, Duke Energy

synTerra
2019 ANNUAL SEEP REPORT
MARSHALL STEAM STATION
EMC SOC WQ S17-009
8320 NC HIGHWAY 150 E
TERRELL, NC 28682
APRIL 2020
PREPARED FOR
etas DUKE
ENERGY
DUKE ENERGY CAROLINAS, LLC
�h
Eli Webster
Projec cientist
Brian Wilker, NC LG #2546
Project Manager

2019 Annual Seep Report April 2020
Marshall Steam Station- Duke Energy Carolinas, LLC SynTerra
TABLE OF CONTENTS
SECTION PAGE
1.0 INTRODUCTION 1-1
1.1 Inspection Details 1-1
2.0 FINDINGS 2-1
2.1 General Observations 2-1
2.2 Effects of Decanting 2-1
2.3 Changes to Seep Status 2-1
3.0 REFERENCES 3-1
LIST OF FIGURES
Figure 1 SOC Locations and Inspection Areas
LIST OF TABLES
Table 1 SOC Locations and Descriptions-2019 Inspection
LIST OF APPENDICES
Appendix A Photographs
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• 2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
LIST OF ACRONYMS
EMC Environmental Management Commission
SOC Special Order by Consent
Page ii

• 2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
1.0 INTRODUCTION
On March 27, 2019, Brian Wilker (NC L.G. #2546) of SynTerra inspected the Marshall
Steam Station (Marshall or Site) property for existing and potential new seeps. No
changes to seep status were observed during this inspection. Inspection activities were
performed in accordance with North Carolina Environmental Management
Commission (EMC) Special Order by Consent WQ #S17-009. The Special Order by
Consent(SOC) describes inspection requirements as follows:
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.
All locations listed in Table 1 of the SOC were observed and documented with
photographs during the inspection.
General observations include:
• No previously unidentified seeps were observed during the inspection.
• No notable changes to existing seep status were observed during this inspection.
• Decanting had not begun at the time of this inspection.
1.1 Inspection Details
The weather was clear before and during the inspection. Temperatures ranged from
approximately 46 to 58 degrees Fahrenheit(F). No precipitation was recorded on the
day of the inspection. The most recent rain event was 0.31 inches on March 25, 2019.
That total was recorded at the on-Site weather station.
The inspector reviewed previous seep inspection reports and the weekly dam safety
inspection reports pertaining to each ash basin. Dan Zakary (Duke Energy system
owner) conducted the ash basin dam safety inspections and prepared the reports. Mr.
Zakary was interviewed about recent rainfall, construction/stabilization projects
associated with the ash basin, and general Site conditions in and surrounding the ash
Page 1-1

2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
basin. Observations from the dam safety inspection reports were consistent with
observations made during the annual inspection.
The inspection included observations in the following areas (Figure 1):
• Along the northwest shore of Lake Norman
• Areas along and downgradient of the ash basin dam
• Drainage features associated with the basins
Seep locations and inspection areas are shown on Figure 1. Observations noted during
the inspection are summarized on Table 1. Photographs taken of each seep location
during the inspection are included in Appendix A.
Page 1-2

• 2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
2.0 FINDINGS
2.1 General Observations
Inspection observations of each seep are shown in Table 1. Details include:
• No new seeps were observed during the inspection.
• No previously unidentified or unreported pipes were observed during
inspection.
• Recent high-water marks (silt deposition, mud-caked vegetation) were observed
along the shoreline of Lake Norman. At the time of inspection, the elevation of
Lake Norman appeared to be a few feet below the Federal Energy Regulatory
Commission (FERC) boundary markers.
• Beaver activity was apparent in the area of S-02 and S-04 east of the ash basin
dam.
• A beaver dam was present at the mouth of the unnamed tributary, downstream
of the S-01 seep location. Heavy beaver activity in the area is apparent, as smaller
dams upstream have created terraced pools. The channelized water at the S-01
signed location appeared stagnant; however, flowing water was observed
upstream of the signed location.
2.2 Effects of Decanting
Decanting of the ash basin at Marshall had not begun at the time of this inspection.
2.3 Changes to Seep Status
Mr. Wilker inspected each seep to evaluate whether it met requirements to be
dispositioned in accordance with the SOC. The requirements for dispositioning a seep
are as follows:
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 as determined by the
Director of DWR in accord with applicable law and best professional judgment; 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. Non-constructed seeps described in paragraph 1(h) of this SOC cannot be
dispositioned through option (2) above.
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• 2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
No changes to seep status were observed during this inspection.
Page 2-2

•
2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
3.0 REFERENCES
North Carolina Department of Environmental Quality. (2018). Special Order by Consent
EMC SOC WQ S17-009.
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• 2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
FIGURES

I
• ..........
INDUSTRIAL -- - '-h • • ! ♦
LANDFILL#1 . r •
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ASBESTOS •• .♦\
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•
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r•►` \ ♦. \ l I I•
• ASH BASIN ° DRYASH ! U
LANDFILL ♦ ♦ •
-. (PHASE II) i t . / •
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STRUCTURAL BORROW .
FILL $ °N. r •>- .+ AREA LAKENORMAN
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®(PHASE I) •
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•
LEGEND
°. �" /' NON-CONSTRUCTED SEEP(APPROXIMATE)
ASH BASIN '"" • DISPOSITIONED SEEP(APPROXIMATE)
S-03 ASH BASIN WASTE BOUNDARY
LANDFILL BOUNDARY
1 e' a_ STRUCTURAL FILL BOUNDARY
- ASH BASIN COMPLIANCE BOUNDARY
`( LANDFILL COMPLIANCE BOUNDARY
�`' - DUKE ENERGY CAROLINAS PROPERTY LINE
y�
�,..5w �
STREAM(MCKIM&CREED)
1 SPECIAL ORDER BY CONSENT(SOC) INSPECTION AREA
• -- �7 WETLAND(MCKIM &CREED)
L. 17 ,
NOTES:
♦ •
• 1. SPECIAL ORDER BY CONSENT(SOC)LOCATIONS ARE DESCRIBED IN EMC SOC WQ
/ •/ 517-009.
• • ♦ „ "a STREAM AND WETLAND DELINEATION CONDUCTED BY MCKIM&CREED MARCH 2016.
♦
- ; ... PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY CAROLINAS.
AERIAL PHOTOGRAPHY OBTAINED FROM GOOGLE EARTH PRO ON JULY 26.2018.
♦ AERIAL WAS COLLECTED ON MARCH 3,2018.
/ '•r DRAWING
COORDINATE SYSTEM F PS1TH A 3200 NAD83CTIION OF NORTH CAROLINA STATE PLANE
/2011)
. S
♦ LE
/ 580 GRAPHIC SCALE 1.160
,(•,DUKE FIGURE 1
" ....... '� ENERGY- (IN FEET) SOC LOCATIONS AND INSPECTION AREAS
¢�''a°P ♦ • CAROL,NAS
DRAWN BY:A.ROBINSON DATE.03/18/2020 2019 ANNUAL SEEP REPORT
./. 0 REVISED BY:A.HARTMAN DATE:03/18/2020 MARSHALL STEAM STATION
CHECKED BY:T.HARTMAN DATE:03/18/2020
T �9 ' APPROVED BY-E.WEBSTER DATE:03/18/2020 TERRELL, NORTH CAROLINA
z �Sy / PROJECT MANAGER'B.WILKER
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2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
TABLES

TABLE 1 •
SOC LOCATIONS AND DESCRIPTIONS - 2
2019 ANNUAL SEEP REPO
MARSHALL STEAM STATI(
DUKE ENERGY CAROLINAS, LLC, TI
Location Coordinates Receiving Receiving
Facility Sample ID Waterbody Description
Latitude Longitude Waterbody Classification
General groundwater seepage formi
UT to Catawba River wet area that flows to an approximz
Marshall S-01 35.6117 -80.9604 (Lake Norman) WS-IV; B; CA 2 foot wide natural channel, locat
northeast of the active ash basin, t
flows to Lake Norman.
Located east of active ash basin, m
Catawba River area of wetness (AOW) between bE
Marshall 5-02 35.6066 -80.9589 (Lake Norman) WS-IV; B; CA dike and river bank. Intermittent fl
from culvert directs seasonal flow
Lake Norman.
Located east of active ash basin, m
Marshall S-03* 35.6067 -80.9591 Catawba River WS-IV B CA area of wetness between basin dike
(Lake Norman) river bank. AOW was determined tc
same area of wetness as S-02 abo
Located east of active ash basin, n
Catawba River flowing AOW in wetland area betwi
Marshall S-04 35.6064 -80.9590 WS-IV; B; CA basin dike and river bank. Potent

2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
APPENDIX A
PHOTOGRAPHS

•
2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
NE E SE
0101°E(T) *35°36'42"N,80°57'37"W±32.8ft ♦781ft
d, ye `T a
R
.un
Fy
a ,
•F .fit.
,7 `
S-01 View of seep location facing east
SW W NW N
zw 3s,
0 281°W(T) '*35°36'23"N,80°5732"W*16.4ft A 781ft
1 if ,
doe
4.
1,
f^ K
27 mar 2019,09:36:35
S-02 View of seep location facing west
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2019 Annual Seep Report April 2020
Marshall Steam Station-Duke Energy Carolinas,LLC SynTerra
®216°SW(T) 135°36'24"N,80°57'32"W t16.4ft ♦821ft
0
starsiesswayi;, r xamilL -k 7,..tt,":,,Alke..% '.•,;.t., tw,.,.,,41.
• \A s'a •P •
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,'3 ,,_' �7 Mar201 0042.04
S-03 View of dispositioned seep location facing southwest
SE S i SW W
120 150 180 i 210 240 270
I • 1 • l • I • l • l • l • l • l • l • l • l • l • I • l • 1 • l • i •
0193°S (T) o 35°36'23"N, 80°57'32"W ±16.4ft A 754ft
1 0 il
a.
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g 1 Agid.` E F. �, ; *{ ,�{ �n
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S-04View of seep location facing south-southwest
Page 2 of 2