NC0038377_02_Mayo_CAP Update 2019_Figures_20191231

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant
FIGURES
(CAP Content Section 10)
SynTerra

�- - - <-
DUKE ENERGY PROGRESS S�
PROPERTY LINE ^ iF
ASH BASIN COMPLIANCE 4
~ BOUNDARY
60' RIGHT-OF-WAY
{'--�• .'; HALIFAX COUNTY
v
C , .ram j-
NORTH CAROLINA-VIRGINIA STATE LINE
(APPROXIMATE)
`, • PER SONCOUNTY
♦ ����axw
APPROXIMATE ASH BASIN
WASTE BOUNDARY I
ir• , �' 100' HWY 501
RIGHT-OF-WAY FGD
SETTING
100' RAILROAD c I�
'` RIGHT-OF-WAY 17
BASIN
t� .. -
2
CCP MONOFILL Y� APPROXIMATE 1981
FGDf C&D LANDFILL
PONDS l' C ' f . AREA (CLOSED)
LINED RETENTION
BASIN AREA
APPROXIMATE FUTURE ASH BASIN POWER PLANT
WASTE BOUNDARY
GYPSUM STORAGE. t
COAL PAD AREA
• � n ♦ `
.......J L►! %.4 PILE
AREA -
a �.. r .' ti •� . AZF
Ire rP-=.tea
Mont
SOURCE:
2016 USGS TOPOGRAPHIC MAP, CLUSTER SPRINGS
QUADRANGLE, QUAD ID: 36078E8, OBTAINED FROM THE USGS STORE AT
https://store.usgs.gov/map-locator.
�,�a
_ _
DUKE
PERSON
COUNTY
FIGURE ES-1
USGS LOCATION MAP
ENERGY
CORRECT IVEACTION PLAN UPDATE
PROGRESS
WINSTON-SALEM
RA`EIGH •
CHARLOTTE •
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA
A MTA.�.�...
DRAWN BY: A. ROBINSON DATE: 05/02/2019
REVISED BY: A. ROBINSON DATE: 12,06/2019
CHECKED BY: P. DATE: 12/06/2019
GRAPHIC SCALE
1,000 0 1.000 2.000
(IN FEET)
,�r 1 � rd
WYLIE
APPROVED BY: J. WYLIE DATE: 12/O6/2019
PROJECT MANAGER:J.WYLIE
www.synterracorp.com

O�W
ASH BASIN COMPLIANCE
_..� t o
y DUKE ENERGY PROGRESS BOUNDARY �_• i� 4l ,�
PROPERTY LINE r
• s\ =�1 rl��l
60' RIGHT-OF-WAY NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY � st (APPROXIMATE)
PERSON • PERSON COUNTY
APPROXIMATE ASH BASIN
e �. = WASTE BOUNDARY
(100'HWY501
RIGHT-OF-WAY\ siFGD
-
�� \�.• •_'r�r�%� Z II ]► / py - I��SETTTING
100' RAILROAD "P �� BASIN
1 RIGHT -OF
CCP MONOFILL APPROXIMATE 1981
FGD C&D LANDFILL
I r jj PONDS - AREA (CLOSED)
7.
LINED RETENTION/ t�,Yq/ r :'•�
�I r V 1��-} ff � / BASIN AREA
APPROXIMATE FUTURE ASH BASIN - _ POWER PLANT
(� WASTE BOUNDARY /
'GYPSUM STORAGE-
f�!� I COAL PAD AREA:
n� STORAGE *�
.' �i.�..�. li►! �.+.j PILE
Ne., d y AREA -
Mon1a u4_ 1 � -
"
Y -
SOURCE:
2016 USGS TOPOGRAPHIC MAP, CLUSTER SPRINGS
QUADRANGLE, QUAD ID: 36078E8, OBTAINED FROM THE USGS STORE AT
hftps://store.usgs.gov/map-locator.
DUKE PERSON
COUNTY
ENERGY
PROGRESS WN,STO,-SAiEM _
AZ _17
■-
_
.-jar
FIGURE 1-1
USGS LOCATION MAP
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA
DRAWN BY: A. ROBINSON
DATE: 05/02/2019
GRAPHIC SCALE
REVISED BY: A. ROBINSON
CHECKED BY: P. ALTMAN
DATE: 12/06/2019
DATE: 12/06/2019
1,000 0 1,000
2,000
APPROVED BY: J. WYLIE
PROJECT MANAGER: J. WYLIE
DATE: 12/06/2019
(IN FEET)

I-
L��#
o
• • •
#
MW-14BR .0/
Q cW-5
r,
r,
A: SCALE 1" = 2000ft /
�i,
wpR
'� �F -•y CCR-104S y� MW-156R
MY-3 CCR-103S CW-4 CCR-104BR
7 + y CW-3 MW-16S
• �►/ MAY9IAK CCR-103D MW-1046RL MW-16D
11 CCR-103BR MW-104BRM MW-3BR
MW-103BRL' _ CCR- 009BR MW-16BR
~' MW-2 CCR-106BR PSB-2f
+ + ' • MW-103BRM PS
,r CW75 S-1 M%
i MW-5BR ® PSB-1 S 1A S-4 C
HAUFAxcouNry Y ! / PSB-2 CCR-105S
r +
PERsoN couNry / SB-1 CCR-105D
�� +CCR-102BR-
CCRCCR-ip3S / CCR-1056R
MW-105BRL S-2B
MW-105BRM PSB-25 R
PSB-26
r rr PSB-27
-
MW-13BR F
+ + AP-6 LOST IN
SETTLING EVENT
PSB-9—'"WAOSEPTEMBER 2019
, PSB-10
r I ABMW-2 AB-2 AB-1 ABMW-3
ABMW-3S
ABMW-2BR AB-3
PSB-11 LRB-2 PSB-14 PSB-16 ® •
uvv
~ MW-6B
S-2
I TREAM CCR-107BR FGD-2BR
TCHFIELD _ IVjW-7D
ANCHI MW-107BRMW­CBI MW-7BR
FGD-1D1D Q
MW-107BRL FGD j
CCR-108BR � -
3B-24 MW-4 SB-5
FGD-10BR
a FGD-9BR
LANDFILLAREA IFGD-8BR
® (CLOSED)
• MW-9BR
PSB-23 SB-6 MW-9BRL w
+ + ABMW-2BRL PSB-21
ABMW-4 -• •
• PSB-12
ABMW-4X PSB-22
BGBG_1 BGSB-3 LRB-1 PSB-15 ABMW-4D w �`
+
+ ABMW-4BR I
1 1 f • SB 2 ® PSB-17 AB-4 ....
r + � `�' � BGSB • _ __
+ r rSB-5 APPROXIMATEFUTURE
SB-18 PASH BASIN WASTE BOUNDARY
(SEE NOTE 2)
-
,1 SW-BB1 + LRB-3 ®BGSB-2 CPA-SB-6
NOTES:
1. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE U.S.
ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A
PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE PRELIMINARY WETLANDS
AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER WHEELER
ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURAL RESOURCES TECHNICAL
REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY 2014 AND
UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND
NEAR THE ASH BASIN DISCHARGE CHANNEL.
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
PRESENT IN THISAREAOF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH BASIN
WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES PERMIT
NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13, 2018.
3. SAMPLE LOCATIONS WERE DERIVED FROM VARIOUS SOURCES AND ARE A MIX OF
SURVEYED AND APPROXIMATE LOCATIONS. THEREFORE, SAMPLE LOCATIONS ARE
APPROXIMATE.
4. ALL BOUNDARIES ARE APPROXIMATE.
5. MAYO PLANT PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
6. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019. AERIAL
WAS COLLECTED ON FEBRUARY 6, 2017.
7. DRAWING HAS BEEN SET WITH PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83).
BGSB-1 BG-2PSB-19
FsB-3 CCR-101S-BG
R-101 D-BGrCICPA-2B
CPA-3D
CPA-3BR
BGSB-9
BGSB-8
CPA-4D
CPA-4BR
MW-12S
I�..MY-1001
z�
+ MY-1002 MY-1003
_ *MULLINS LN•
N
o �
O
■
CW-1 D
P
MW-18BR
MW-19D Outfall 002
MW-19BR
MW-106R
SB-4
r �
a
V Wift,
S-9
SW-REF2
S-6
0,
REF1 -
DKE
ENERGY
PROGRESS
NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY - (APPROXIMATE)
- - - _ - -- PERSON COUNTY
44
RI A
3BR t
3D `
3R
2BR ,
GRAPHIC SCALE
490 0 490 980
(IN FEET)
DRAWN BY: A. ROBINSON DATE: 06/06/201;
REVISED BY: A. ROBINSON DATE: 12/08/2019
CHECKED BY: P. ALTMAN DATE: 12/08/2019
APPROVED BY: J. WYLIE DATE: 12/08/2019
PROJECT MANAGER: J. WYLIE
I FrFnln
e WELL IN ALLUVIUM OR
WELL IN TRANSITION ZONE
WELL IN BEDROCK
WELL IN ASH PORE
MONITORING WELL (ABANDONED)
+ SOIL SAMPLE LOCATION
IN -STREAM SURFACE WATER LOCATION PER SOC/SEDIMENT
SAMPLE LOCATION
SURFACE WATER SAMPLE LOCATION
SURFACE WATER/SEDIMENT SAMPLE LOCATION
CONSTRUCTED SEEP (APPROXIMATE)
NON -CONSTRUCTED SEEP (APPROXIMATE)
♦ NPDES OUTFALL LOCATION
WATER SUPPY WELL
ASH BASIN WASTE BOUNDARY
• ASH BASIN COMPLIANCE BOUNDARY
— - — - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
DUKE ENERGY PROGRESS PROPERTY LINE
310 STREAM (AMEC NRTR)
® WETLAND (AMEC NRTR)
FIGURE 1-2
SITE LAYOUT MAP
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

_ _ _ PROGRESS
A FUTURE 60' MAYO LAKE MPROPERTY LINE
RORIGHT-OF-WAY
zz
)U N DARY
-OF-WAY
�W"
I
I
FUTURE DUKE
/ENERGY
PROGRESS
PROPERTY LINE
i
SOURCE:
MARCH 22, 1951 AERIAL PHOTOGRAPH OBTAINED FROM THE USGS EARTH EXPLORER WEB SITE AT
http://earthexplorer.usgs.gov/
GRAPHIC SCALE
E
pf D N ERGY
500 0 IN FEET 500 1000
DRAWN BY: J. CHASTAIN DATE: 5/03/2019
REVISED BY: C. NEWELL DATE: 10/2/2019
CHECKED BY: P. ALTMAN DATE: 10/2/2019
PROGRESS
APPROVED BY: J. WYLIE DATE: 10/2/2019
141P
PROJECT MANAGER: J. WYLIE
WnTem
www.synterracorp.com
FUTURE POWER
PLANT
FIGURE 1-3
1951 AERIAL PHOTOGRAPH
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

I
HALIFAX COUNTY
r
_ PERSON COUNTY
,l •
♦ T -MAY AK • ._, .
♦ I / ®� — _ O L_ E R°ADS - � - .' .. • � _ — - �Z
MW-14BR ♦ - _��----
HFSTFRRO l l ■ a ` `` ` _ - �_
l � CCR-1028R-BG
/ �, �.
/ 1 �o.�a/e.■
LANDFILL 6
" • ' ♦ MW-13BR •
�__ U ♦ I I
NORTH CAROLINA-VIRGINIA STATE LINE
(APPROXIMATE)
► ► ,�°P LEGEND
\�; \ • ♦ 41:, J GROUNDWATER BACKGROUND SAMPLE LOCATION
SOILAND GROUNDWATER SAMPLING LOCATION
BG-1 •
SOIL SAMPLE LOCATION
I ► ' • . r, . _ ■ SURFACE WATER SAMPLE LOCATION
► I • APPROXIMATEFUTURE E ASH BASIN WASTE BOUNDARY
ASH BASIN WASTE BOUNDARY ` 'd : _ . _ .
/ / ► ► (SEENOTE2) - ASH BASIN COMPLIANCE BOUNDARY
' ' ✓ — - — - - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
DUKE ENERGY PROGRESS PROPERTY LINE
I 1STORA_ \>,
/, /• �o� BG 2 - iPOWE 0 STREAM (AMEC NRTR)
I IZ, rAREA ® WETLAND (AMEC NRTR)
/ c \ ? i ' ,.7 NOTES:
• .
STORAGE + `� 1. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE US
/PILE ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A
I/ 1' PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE PRELIMINARY
AREA
/ / I `n, WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER
1 ' E WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURAL RESOURCE
I 1 RIGHT -OF -WAR`' t -,� } TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY
I , 2014 AND UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY
I I MISIDENTIFIED WETLAND NEAR THE ASH BASIN DISCHARGE CHANNEL.
/� `♦ .p 2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
= = ' PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH
a♦ ` I I •' BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES
La a I - PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13,
r a, ■ • • ' 2018.
`\, I
3. ALL BOUNDARIES ARE APPROXIMATE.
i Ail ■ n 4. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
Fir-i'll-fra• " • " • 0 MW-12S ...�
5. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019.
REFI AERIAL WAS COLLECTED ON FEBRUARY 6, 2017.
9� "'" ♦ ■ 6. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
■ GRAPHIC SCALE
,ate'♦� DUKE 500 0 500 1,000 FIGURE 4-1
= MULLINSLN `* ENERGY (IN FEET) BACKGROUND SAMPLE LOCATIONS
I PROGRESS CORRECTIVE ACTION PLAN UPDATE
y o DRAWN BY: A. ROBINSON DATE: 06/05/2019
REVISED BY: A. ROBINSON DATE:12/03/2019 MAYO STEAM ELECTRIC PLANT
CHECKED BY: P. ALTMAN DATE: 12/03/2019 ROXBORO NORTH CAROLINA
.tWOOL APPROVED BY: J. WYLIE DATE: 12/03/2019
.- •-��- :.2 - �a+'�-�•-�+• _ _ T ._._ PROJECT MANAGER: J. WYLIE

NORTH
TRARR
CONCEPTUAL CROSS-SECTION OF PRE -DECANTING CONDITIONS
(NOT TO SCALE)
ASH BASIN
DAM
(FILL)
MAYO
LAKE RD.
Awl
�' DUKE
ENERGY
PROGRESS
161P
synTerra
/
GENERAL NOTES
SITE FEATURES KEY
O RIDGES EAST, WEST, AND SOUTH OF THE ASH BASIN COINCIDE
WITH GROUNDWATER DIVIDES WHICH PROVIDE HYDRAULIC
CONTROL KEEPING CONSTITUENT MIGRATION WITHIN THE
FORMER CRUTCHFIELD BRANCH STREAM VALLEY AND AWAY
FROM POTENTIAL RECEPTORS AND WATER SUPPLY WELLS
©LIMITED VERTICAL COI MIGRATION THROUGH TRANSITION ZONE
AND INTERCONNECTED BEDROCK FRACTURES
© FORMER STREAM CHANNEL IN ASH BASIN
O PONDED WATER IN THE ASH BASIN CAUSES LIMITED AREA OF
DOWNWARD VERTICAL MIGRATION OF CONSTITUENTS NEAR THE
DAM DUE TO ELEVATED HYDRAULIC HEAD
© UPWARD VERTICAL GRADIENTS IN GROUNDWATER IMMEDIATELY
DOWNGRADIENT OF THE ASH BASIN DAM LIMIT VERTICAL
MIGRATION OF CONSTITUENTS
CURRENT AREA OF BORON CONCENTRATION IN GROUNDWATER
GREATER THAN CRITERIA (SEE GENERAL NOTE 1)
FREE PONDED WATER
GENERALIZED GROUNDWATER FLOW DIRECTION
11110-► GENERALIZED ASH PORE WATER FLOW DIRECTION
STREAM
- - - INTERMITTENT STREAM
GENERALIZED BEDROCK FRACTURE
-- APPROXIMATE FORMER STREAM WITH FLOW DIRECTION
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
®GENERAL AREA OF WATER SUPPLY WELL USERS
(SEE GENERAL NOTE 2)
WATER LEVEL
1) GENERALIZED AREAL EXTENT OF BORON MIGRATION REPRESENTED BY NCAC 02L
EXCEEDANCE IN MULTIPLE FLOW ZONES BASED ON FLOW AND TRANSPORT (APPENDIX G).
2) PERMANENT WATER SUPPLY HAS BEEN IMPLEMENTED PROVIDING 16 SURROUNDING WELL
USERS WITH WATER TREATMENT SYSTEMS. THIS WORK WAS COMPLETED IN ACCORDANCE
WITH HB630 AND SUBSEQUENTLY APPROVED BY NCDEQ ON OCTOBER 12, 2018.
3) THE WATERS OF THE US DELINEATION HAS NOT BEEN APPROVED BY THE US ARMY CORPS OF
ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A PRELIMINARY JURISDICTIONAL
DETERMINATION ONLY. THE PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE
OBTAINED FROM AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC.
NATURAL RESOURCE TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED
JANUARY 2014 AND UPDATED ON JULY 11,2018 TO REMOVE ONE PREVIOUSLY MISIDENTIFIED
WETLAND NEAR THE ASH BASIN DISCHARGE CHANNEL.
4) ALL BOUNDARIES ARE APPROXIMATE.
VISUAL AID ONLY -
DEPICTION NOT TO SCALE
DRAWN BY: A. FEIGL
DATE: 6/2/2019
REVISED BY: C. NEWELL
DATE: 12/8/2019
CHECKED BY: P. ALTMAN
DATE: 12/8/2019
APPROVED BY: J. WYLIE
DATE: 12/8/2019
PROJECT MANAGER: J. WYLIE
www.synterracorp.com
FIGURE 5-1
CONCEPTUAL SITE MODEL
PRE -DECANTING CONDITIONS
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant SynTerra
Figure 5-2
Legrand Slope Aquifer System
Included in Section 5 Text

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant SynTerra
Figure 5-3
General Profile of Ash Basin Pre -
Decanting Flow Conditions in the
Piedmont
Included in Section 5 Text

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant SynTerra
Figure 5-4a
Water Level Map — Surficial Flow Zone —
April 2019
Provided in separate electronic figure file as a
large sheet size

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant SynTerra
Figure 5-4b
Water Level Map — Transition Flow
Zone — April 2019
Provided in separate electronic figure file as a
large sheet size

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant SynTerra
Figure 5-4c
Water Level Map — Bedrock Flow Zone —
April 2019
Provided in separate electronic figure file as a
large sheet size

47
NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY --
/ (APPROXIMATE)
-��.- ' f y-_� _ •-_ l �+ y PERSON COUNTY
ell
ov
elk
"'M R
; i � ��� F �+•� y. �' r 4�r ` � � � _ � � rr r ,r, r i
% _, 7~ w ! I i rrlr} t t �_FGD
SETTLING
�• f
\ ` , If
eo
0-1
k.
/*� f } � LEGEND
� � � I � ti \ ail. �►
Nk
WIL
Pv
NOTES: `!+ �♦
1. VELOCITY MAGNITUDES IN FEET PER DAY (FT/DAY).
2. VELOCITY VECTORS ARE IN THREE DIMENSIONS. I i1 a �t _ — Y�► ! `! = , f -
r
3. VELOCITY VECTOR DIRECTIONS SHOWN AS BLACK ARROWS.
4. UPDATED GROUNDWATER FLOW AND TRANSPORT MODELING REPORT FOR h ` ` l ~ r ASH BASIN WASTE BOUNDARY
MAYO STEAM ELECTRIC PLANT, ROXBORO, NORTH CAROLINA, 2019 (MURDOCH APPROXIMATE FUTURE
ET AL, 2019). _ ._ . ASHBAS(SEENOTE6)IN WASTE BOUNDARY f f ■ ■ 1 ASH BASIN COMPLIANCE BOUNDARY
y _ (SEE NOTE 6)
5. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE - — - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
U.S. ARMY CORPS OF ENGINEERS ATTHE TIME OF THE MAP CREATION. THIS e + 1, . , y _ r ti DUKE ENERGY PROGRESS PROPERTY LINE
MAP IS A PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE ; • V �, �, ` i 1 1
PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM `♦
AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURALS . y , r 1 STREAM (AMEC NRTR)
RESOURCES TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT ' _ \ •
DATED JANUARY 2014 AND UPDATED ON JULY 11, 2018 TO REMOVE ONE 1 r \ \ + f
PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH BASIN DISCHARGE CHANNEL.► GRAPHIC SCALE FIGURE 5-5a
�` y ti DUKE 380 0 380 760
�+ +� 6. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT r � � r F "-+ ` " FLOW VELOCITY VECTORS AND MAGNITUDES FOR
� ENERGY
PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH �, r� ' �` (IN FEET) PRE -DECANTING CONDITIONS
BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES PROGRESS
\ DRAWNBY: A.ROBINSON DATE:06/06/2019 TRANSITION ZONE (MODEL LAYER 13)
20E$MITNC0038377PARTI,5.A.(18.)ATTACHMENTBFIGURE1.1DATEDJULYI3, f . L REV ISEDBY: A.ROBINSON DATE:12/06/2019 CORRECTIVE ACTION PLAN UPDATE
I �' CHECKED BY: P. ALTMAN DATE: 12/06/2019
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE APPROVED BY:J. WYLIE DATE:12/06/2019 MAYO STEAM ELECTRIC PLANT
/ PROJECT MANAGER: ROXBORO NORTH CAROLINA
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). � 'IN �. � - � �/�'�Terra ,
—� " ' www.synterracorp.com

{ ! f
f f f f I
. !l "ice f `! !! 1� 11
\ t
■ ti� �: ` �, NORTH CAROLINA-VIRGINIA STATE LINE
f HALIFAX COUNTY J
/ l (APPROXIMATE)
�l-� - .Ff A -_—� f 1 ,F ��i—^"-l� f / ! �ti -__ PERSON COUNTY r
lb41
LAW
Imp
y
+ + ■
+.�.� �' LEGEND
40
; ■ - `, "�1 �`�', it �� '� •rr ; `*,`'�1w-
NOTES: +l '1 1 ' / ` Z �� ` 1 ~ 0 1
1. VELOCITY MAGNITUDES IN FEET PER DAY (FT/DAY). `�► r� ' f r ` �_ - r
2. VELOCITY VECTORS ARE IN THREE DIMENSIONS. I ` �-. ` �. 1 ►'. •1. �`
3. VELOCITY VECTOR DIRECTIONS SHOWN AS BLACK ARROWS. LINEDON
`-' : i : 1 A` j �+
t
4. UPDATED GROUNDWATER FLOW AND TRANSPORT MODELING REPORT FOR ■ t . FUTUASH BASIN WASTE BOUNDARY
MAYO STEAM ELECTRIC PLANT, ROXBORO, NORTH CAROLINA, 2019 (MURDOCH APPROXIMATE RE ` ti
AREA ASHBASINWASTE BOUNDARY
ET AL, 2019. 1 Y
_ (SEE NOTE 6) .� l 1� { J SEEN ASH BASIN COMPLIANCE BOUNDARY
�. � ► � " 5
5. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE
La RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
U.S. ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS �.� _ f►' - = L { �. �' `. 1,� r DUKE ENERGY PROGRESS PROPERTY LINE
MAP IS A PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE ► 1 I - ,...1► ti _ ` t ••' ' ► , r
PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM , �' ti 1 ` • • . �'
AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURAL �r 1 �' �_ ti t • t ` 1 STREAM (AMEC NRTR)
RESOURCES TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT �,
DATED JANUARY 2014 AND UPDATED ON JULY 11, 2018 TO REMOVE ONE + f
PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH BASIN DISCHARGE ` ` ■ '
CHANNEL. 1 I ■ ~ ` e GRAPHIC SCALE FIGURE 5-5b
DUKE 380 0 380 760
6. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT FLOW VELOCITY VECTORS AND MAGNITUDES FOR
PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH �� �.�ENERGY (IN FEET) CLOSURE -BY -EXCAVATION SCENARIO
BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES I \ - ' y --,. PROGRESS
PERMIT NCO038377PART I,5.A.(18.)ATTACHMENT BFIGURE 1.1 DATED JULY13, a - 1 DRAWN BY: A. ROBINSON DATE:06/06/2019 TRANSITION ZONE (MODEL LAYER 13)
REVISED BY: A. ROBINSON DATE: 12/06/2019
2018. \ :` ti CHECKED BY.'P.ALTMAN DATE:12/06/2019 CORRECTIVE ACTION PLAN UPDATE
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE f APPROVED BY:J. WYLIE DATE:12/06/2019 MAYO STEAM ELECTRIC PLANT
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). `.. f synTerrd PROJECT MANAGER:J. WYLIE ROXBORO, NORTH CAROLINA
' 1 www.synterracorp.com

r — 1 \ _ ■ j
Af
t \ L
NORTH CAROLINA-VIRGINIA STATE LINE
1 ` • .� r� HALIFAX COUNTY op
�
l � } � � _ t (APPROXIMATE)
+'� -.ram,.-�•�.- ,.�.•' .-.•�� �. ,.-�� F� —.�--- — _ -7 T� �^ } -�-- -
r PERSON COUNTY --
�' r r • YAYO LAKE •..�� I 7 f �" f r, f'
eo
tw
A.
10
�• ti _ \ 1 1 ! .• A LEGEND
sk
Ad
T ti
NOTES:-
1. VELOCITY MAGNITUDES IN FEET PER DAY (FT/DAY).` a `� •� Imo' �4 ` ��
40
2. VELOCITY VECTORS ARE IN THREE DIMENSIONS. lk
3. VELOCITY VECTOR DIRECTIONS SHOWN AS BLACK ARROWS. ■ r • _ \ ` t /� 1
4. UPDATED GROUNDWATER FLOW AND TRANSPORT MODELING REPORT FOR I �' Isr • Y
\ ` `4 1 ~ { '1 \ ASH BASIN WASTE BOUNDARY
MAYO STEAM ELECTRIC PLANT, ROXBORO, NORTH CAROLINA, 2019 (MURDOCH ; APPROXIMATEFUTURE
=
�'J a ASH BASIN WASTEBOUNDARY
ET AL, 2019). (SEE NOTE 6) ■ ■ ASH BASIN COMPLIANCE BOUNDARY
1
5. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE r �I +�-• r ~ ti '\ / ti ~ .� — - — - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
U.S. ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS f - ` R
MAP IS A PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE J �' ` ` N • ' ' �. `' ti ` ' ' DUKE ENERGY PROGRESS PROPERTY LINE
PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM ' I ��
AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURAL r r r 1 ~ 1 , STREAM (AMEC NRTR)
RESOURCES TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT ■ _ ,
DATED JANUARY 2014 AND UPDATED ON JULY 11, 2018 TO REMOVE ONE I y� f •
PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH BASIN DISCHARGE r
CHANNEL. _ _ ` t' 'r 380 GORAPHICSC380 76o FIGURE 5-5c
6. AREA OFINVESTIGATION THAT DETERMINED SETTLED CCRMATERIALISNOT f 1 `� �� DUKE FLOW VELOCITY VECTORS AND MAGNITUDES FOR
PRESENT IN THIS AREA OF THE ASH BASIN. AFUTURE REPRESENTATIVEASH r1 r =ti • �. ENERGY (IN FEET) BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDCLOSURE-IN-PLACE SCENARIO
P�20GRE55 ES f ?� 1 ti • y
PERMITNC0038377PART1,5.A.(18.)ATTACHMENTBFIGUREI.1 DATEDJULYI3, I 1 DRAWN BY: A. ROBINSON DATE:06/06/2019 TRANSITION ZONE (MODEL LAYER 13)
IS BY: A. ROBINSON DATE: 12/06/2019
2018. r T.., CHECKED BY: P.ALTMAN DATE:12/06/2019 CORRECTIVE ACTION PLAN UPDATE
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE ` f = APPROVED BY:J. WYLIE DATE:12/06/2019 MAYO STEAM ELECTRIC PLANT
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). f` ` synTerra PROJECT MANAGER:J. WYLIE ROXBORO NORTH CAROLINA
—� 4 , www.synterracorp.com

NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY (APPROXIMATE)
I
I ' 1
I ♦
I♦
0♦
J#
f
PERSON COUNTY ,♦
I♦
RT NEST R
P Ro
I
1
1
CCP
MONOFILL
1
0
MY-L000
MY2018-C _ ♦ r ♦ t
' I ♦ AYO LAKE ROAO ♦ r
•1 `
I
� a
1
1 r
I
r `■
R ( •
jAREA
i ! • •
1 � 1
I
•
1 ► v 0P°
i
APPROXIMATE FUTURE
+ ASH BASIN WASTE BOUNDARY
1 (SEE NOTE 2)
1
100' HWY 501
W,dRIGHT-OF-WAYM
♦ MY-L -
♦ ! MY-2011 MY-2008
N M -2005
.,
�^ MY2007
MULLINS LN MY2009
I
I♦
I
♦I
♦I
I
I
I
I
I I♦
1
1
1
■
1
1
DUKE
�� ENERGY
650 GRAPHIC SCALE
0
(IN FEET)
650 1,300
PROGRESS
DRAWN BY: A. ROBINSON
REVISED BY: A. ROBINSON
DATE: 06/05/2019
DATE: 12/12/2019
CHECKED BY: P. ALTMAN
DATE: 12/12/2019
APPROVED BY: J. WYLIE
DATE: 12/12/2019
PROJECT MANAGER: J. WYLIE
LEGEND
WATER TREATMENT SYSTEM
0 OPT OUT OR NON -RESPONSIVE OF WATER TREATMENT
SYSTEM
LOCATION DEEMED NOT ELIGIBLE PER HOUSE BILL 630
(BUSINESS/CHURCH/SCHOOL) BUT VOLUNTARILY SUPPLIED
PERMANENT WATER SOLUTION
VACANT PARCELS PARTIALLY OR ENTIRELY WITHIN HALF -MILE
RADIUS NOT OWNED BY DUKE ENERGY
CITY OF ROXBORO WATER LINE
HALF MILE RADIUS FROM ASH BASIN COMPLIANCE
BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
— - — - - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
DUKE ENERGY PROGRESS PROPERTY LINE
STREAM (AMEC NRTR)
T� WETLAND (AMEC NRTR)
10 GENERALIZED GROUNDWATER FLOW DIRECTION
NOTES:
1. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE U.S.
ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A
PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE PRELIMINARY
WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER
WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURAL RESOURCES
TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY
2014 AND UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY
MISIDENTIFIED WETLAND NEAR THE ASH BASIN DISCHARGE CHANNEL.
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH
BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES
PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13,
2018.
3. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND SHOULD
NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES. TOPOGRAPHY IS
BASED ON LIDAR BARE EARTH DATA OBTAINED FROM THE NORTH CAROLINA
SPATIAL DATA SITE AT
https://sdd.nc.gov/sdd/DataDownload.aspx.
4. ALL BOUNDARIES ARE APPROXIMATE
0w2i]»:71va ii11LIBill :Ya,:1iP/b]A.1:17.111 /:1411ml:ZH'd,:1i1c]:1*R
6. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019.
AERIAL WAS COLLECTED ON FEBRUARY 6, 2017.
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
FIGURE 5-6
HB630 PROVISION OF PERMANENT
WATER SUPPLY COMPLETION MAP
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

HALIFAX COUNTY
PERSON COUNTY
r
---
i
♦4* �• —
I
I �♦
`.
NORTOCAROLINA-VIRGINIA STATE LINE ♦ , Iown*-ifto
(APPROXIMATE)
40 •
• ♦ S=MAYOLq `•� INSTREA
• • I LAKE RO_gp_ , CRUTCHFI 1 • _ _ __� ;
♦I �� / /i , _.� ; :Z I BRA NCWSW-CBI
I • �•♦ I S-lA S-4 r� r
♦ RT NFSTe • g_1 S-2 5-10 �'
Ro
• . • a i 1 1990 1430 0 774 ' — - - - •
` 7 / ♦ S-2B 1
. \ \ / � I / �• 1830 � � �
• sLANDFILL 1
• 1 1
II
�1 G
I �
'
1 •
11 1
1 •
�00
1' 11 � i r♦ • 9 ♦I
1 At _ APPROXIMATE FUTURE
1 1 BASIN= A)NTE BOUNDARY r
1 (SEE NOTE
^y
I 0 0
•♦ �� •00
♦�
oo
MULLINS LN
o
♦
I ♦
h ♦
I
♦
A
1.0
I
♦ Outfall 001
I -
♦ I
I
0
S6
It
ENERGY
PROGRESS
1
1
♦
I
I
I
LEGEND
■ 02L -02B SURFACE WATER SAMPLE LOCATION
BORON CONCENTRATION SURFACE WATER
IMIIIIIIII
CONSTRUCTED SEEP MONITORED UNDER THE SOC
(APPROXIMATE)
5430 BORON CONCENTRATION CONSTRUCTED SEEP
NON -CONSTRUCTED SEEP MONITORED UNDER THE SOC
(APPROXIMATE)
774 BORON CONCENTRATION NON -CONSTRUCTED SEEP
DISPOSITIONED SEEP (APPROXIMATE)
IN -STREAM SURFACE WATER LOCATION PER SOC (APPROXIMATE)
NPDES OUTFALL LOCATION
GRAPHIC SCALE
580 0 580
1,160
(IN FEET)
DRAWN BY: A. ROBINSON DATE:
06/05/2019
REVISED BY: A. ROBINSON DATE:
12/16/2019
CHECKED BY: P. ALTMAN DATE:
12/16/2019
APPROVED BY: J. WYLIE DATE:
12/16/2019
PROJECT MANAGER: J. WYLIE
�:69 :1:1_F911 \�P/_F91 � :i•11J I L7_1:>! 1
— • — - - ASH BASIN COMPLIANCE BOUNDARY
— - — - - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
- - DUKE ENERGY PROGRESS PROPERTY LINE
STREAM (AMEC NRTR)
® WETLAND (AMEC NRTR)
® ASH BASIN FREE PONDED WATER
OTHER NPDES REGULATED WATER FEATURE
:[•ii4.3
1. GROUNDWATER TO SURFACE WATER (02L-02B) SAMPLES WERE COLLECTED TO ASSESS
WHETHER GROUNDWATER MIGRATION IS CAUSING CONSTITUENT CONCENTRATIONS IN
CRUTC HFIELD BRANCH TO BE GREATER THAN THE APPLICABLE 02B STANDARDS. 02L-02B SAMPLING
WAS CONDUCTED FROM APRIL 30 - MAY 3, 2018 FOLLOWING DIVISION APPROVED PROTOCOLS. IN
THE FIVE DAYS PRIOR TO SAMPLING, A TOTAL OF 0.60 INCHES OF RAINFALL WAS OBSERVED AT
MAYO STEAM ELECTRIC PLANT. DURING THE FOUR -DAY SAMPLING EVENT, NO RAINFALL WAS
OBSERVED AT MAYO STEAM ELECTRIC PLANT. RESULTS FROM 02L-02B SAMPLING INDICATE THERE
ARE NO CONSTITUENT CONCENTRATIONS GREATER THAN THE APPLICABLE 02B STANDARDS IN
CRUTCHFIELD BRANCH.
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT PRESENT IN THIS
AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH BASIN WASTE AND COMPLIANCE
BOUNDARY IS INCLUDED IN THE MAYO NPDES PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B
FIGURE 1.1 DATED JULY 13, 2018.
3. CONSTRUCTED AND NON -CONSTRUCTED SEEPS ARE COVERED UNDER THE SPECIAL ORDER BY
CONSENT (SOC) EMC SOC WOS18-005.
4. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE U.S. ARMY CORPS OF
ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A PRELIMINARY JURISDICTIONAL
DETERMINATION ONLY. THE PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED
FROM AMEC FOSTER WHEELER ENVIRONMENTAL 8 INFRASTRUCTURE, INC. NATURAL RESOURCES
TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY 2014 AND
UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH
BASIN DISCHARGE CHANNEL.
5. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLYAND SHOULD NOT BE USED FOR
DESIGN OR ENGINEERING PURPOSES. TOPOGRAPHY IS BASED ON LIDAR BARE EARTH DATA
OBTAINED FROM THE NORTH CAROLINA SPATIAL DATA SITE AT
HTTPS:IISDD.NC.GO VISDDIDATADO W NLOAD.ASPX.
6. ALL BOUNDARIES ARE APPROXIMATE
7. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS
8. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019. AERIAL WAS COLLECTED
ON FEBRUARY 6, 2017.
9. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM PIPS 3200 (NAD83).
FIGURE 5-7
MAP OF SURFACE WATERS
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

Corrective Action Plan Update December 2019
Mayo Steam Electric Plant SynTerra
Figure 6-1
Fly Ash and Bottom Ash Interbedded
Depiction
Included in Section 6 text

A--ow-
(SOUTHWEST)
A'
(NORTHEAST)
/ice
j
_
1 i \
♦ /\/\I/1 �/�/\I/1� / \/\I/1 �/�/\I/1� /\/\I/1 �/�/\I/1� / \/\I/1 �/ �/\I/1� /\/\I/1 �/ �/\I/1� / \/\I/1 �/ �/\I/1� /\/\I/1 �/ �/\I/1� / \/\I/1 �/�/\I/1� /\/\I/1 �/�/\I/1� / \/\I/1 �/�/\I/1� /\.
LEGEND
MW 12S
WELL IN ALLUVIUM OR SAPROLITE
MW 16D
WELL IN TRANSITION ZONE
MW 16BR
WELL IN BEDROCK
ABMW 2
WELL IN ASH PORE WATER
GENERALIZED WATER TABLE
GENERALIZED GROUNDWATER
FLOW DIRECTION
GENERALIZED SUBSURFACE ASH
PORE WATER FLOW DIRECTION
GENERALIZED VERTICAL
HYDRAULIC GRADENT
- - - GENERALIZED FRACTURE
ORIENTATIONS
0 ASH
Q ASH PORE WATER / WASTEWATER
0 SAPROLITE
® TRANSITION ZONE
BEDROCK
NOTES
ASH PORE WATER FLOW LAYER
1. WATER ELEVATIONS REPRESENT THE APRIL 2019 GAUGING EVENT FOR EACH WELL. NOTE
ELEVATIONS WITHIN EACH CLUSTER ARE MEASURED IN THE SAME DAY. REFERENCED TO NORTH
WATER LEVEL ELEVATION
AMERICAN VERTICAL DATUM 1988.
7
ALLUVIUM OR SAPROLITE FLOW LAYER
2. WATER LEVEL IN MW-105BRL IS NOT PROVIDED BECAUSE THE WATER LEVEL HAD NOT REACHED
GROUNDWATER LEVEL ELEVATION
STATIC CONDITIONS.
3. FRACTURES DEPICTED ON THIS CROSS SECTION REPRESENT THE GENERALIZED
TRANSITION ZONE FLOW LAYER GROUNDWATER
ORIENTATIONS OF THE PREVALENT FRACTURE SETS OBSERVED AT THE SITE BASED ON TELEVIEWER
LEVEL ELEVATION
LOGGING AT SITE -SPECIFIC BOREHOLES. THEY ARE SHOWN WITH APPROPRIATE APPARENT DIP, WITH
VERTICAL EXAGGERATION. THIS CROSS SECTION IS APPROXIMATELY PARALLEL TO THE
PREDOMINANT FRACTURE STRIKE DIRECTION. THE ACTUAL NUMBER OF FRACTURES IS FAR TOO
BEDROCK FLOW LAYER GROUNDWATER
NUMEROUS TO ILLUSTRATE AT THIS SCALE. IN ADDITION, THE DEPTHS AND LENGTHS OF FRACTURES
LEVEL ELEVATION
VERSUS DEPTH ARE CONCEPTUAL ONLY.
4. ALL BOUNDARIES ARE APPROXIMATE.
WELL SCREEN
5. CROSS SECTION REPRESENTATIVE OF PRE -DECANTING CONDITIONS.
381.02
WATER LEVEL ELEVATION (NAVD 88)
(LABEL COLORING BY FLOW ZONE)
DUKE ENERGY PROGRESS
GRAPHIC SCALE
PROPERTY LINE
0 135 270 540
- - -
ASH BASIN COMPLIANCE BOUNDARY
'DUKE FIGURE 6-2
HORIZONTAL SCALE: 1°=540•
A ENERGY VERTICAL 1"=
GENERAL CROSS-SECTION A
ASH BASIN WASTE BOUNDARY
TI -A'
5X VERTICAL EXAGGERATION
EXAGGERATION
PROGRESS DRAWN BY: J. CHASTAIN DATE:08/02/2019 ASH BASIN
REVISED DATE:12/2/2019 CORRECTIVE ACTION PLAN UPDATE
CHECKED BY: P. ALTMAN DATE: 12/2/2019
116rip APPROVED BY: P.ALTMAN DATE:12/2/2019 MAYO STEAM ELECTRIC PLANT
PROJECT MANAGER: J. WYLIE
LAYOUT: FIG 6-2 (ASH BASIN-WQ ROXBORO, NORTH CAROLINA
synTel'1'd
www.synterracorp.com
1501
1001

11
1 =�- MAYO
/ - L EKE ROAD-= - - _ �.- .-..
I
— _ �-
/ / ® Mqy—LAKE ROAD_
/ r 4.
♦� 4♦.
POST CLOSURE
PRE -DECANTING .
/ / CONDITIONS ° �� °
'°•♦ �:
, CONDITIONS FOR
CLOSURE
♦.
°�♦
rl `\� `` ����
-IN -PLACE
i ;
� \ ���/�, �� �,� `
.�':
,AREA
LANDFILL
Oe%`
,
r
,
4D
AREI ,
I � � lEY-�\ � � 1�� ` �///-�.%/J �`�! J � �� _
i � ; %lil, ��� �� 1 �/
� �� ✓jJ// � %//l�I� (CLOSED)
-
0.0
o%�J//� l///
%� ill`
��` i"
\� ^
_.I�,// /1{I
iIm
"1
p-� 1
1//
° {I
00
,�
��
Ao
/ w
I 1 11 1 / /L 11 .1 1+ �
APPROXIMATEFUTURE 0 ' `
/ V ASH BASIN WASTE BOUNDARY/ ♦ y '- �.
I fff'/// _ , • l (SEE NOTE 2)
1 1
1 I {�y�{ W .
, 1/ 6
1 I
/• ( I r
� APPROXIMATE FUTURE ,
/// ` 77�SS" ASH BASIN WASTE BOUNDARY t4 ^
(SEE NOTE 2)
1 1 _
1
I 'i'�a►.
80 FEET
1
1
1 - 80 FEET
dim. W_
' • - . 0 FEET
i 0 FEET
1
1
1
-
1 ­1 *0 Oft
LEGEND NOTES
1. ASH THICKNESS ISOPACH SURFACES FROM FLOW AND TRANSPORT MODELS (MURDOCH et al., 2019).
-—SATURATEDASHTHICKNESSISOPACH(FT) 2. AREA OFINVESTIGATION THAT DETERMINED SETTLED CCRMATERIAL ISNOT PRESENT INTHIS AREA OFTHE ASH BASIN. A
ASH BASIN WASTE BOUNDARY FUTURE REPRESENTATIVE ASH BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES PERMIT
NCO038377 PART 1,5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13,2018.
DUKE
ENERGY
GRAPHIC SCALE
330 0 330 660
(IN FEET)
FIGURE 6-3
SATURATED ASH THICKNESS PRE -DECANTING AND
CLOSURE -IN -PLACE SCENARIOS
SCENARIOS
DRAWN BY: A. ROBINSON
REVISEDBY: C.DAVIS
CHECKED BY: P.ALTMAN
DATE: 06/07/2019
DATE:12/15/2019
DATE:12/15/2019
_ - _ ASH BASIN COMPLIANCE BOUNDARY 3. SATURATED ASH THICKNESS BASED ON CLOSURE MODEL RESULTS WITH UNDERDRAINS.
---RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
4. ALL BOUNDARIES ARE APPROXIMATE.
• DUKE ENERGY PROGRESS PROPERTY LINE
PROGRESS
J
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
5. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
6. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019AERIAL WAS COLLECTED ON FEBRUARY 6, 2017.
APPROVED BY: J. WYLIE
PROJECT MANAGER: J. WYLIE
DATE: 12/15/2019
ROXBORO, NORTH CAROLINA
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE SYSTEM PIPS 3200
synTerra
www.s nterraco77m

A---w--
(SOUTHWEST)
now A'
ASH BASIN COMPLIANCE BOUNDARY (NORTHEAST)
0
a
0
0-1
ASH BASIN WASTE BOUNDARY
U)
ABMW-4 WELL CLUSTER LOCATED
IN THE
a
ORIGINAL CHANNEL OF CRUTCHFIELD
BRANCH BASED ON HISTORIC USGS TOPO
z v+li+\� tir
AND AERIAL PHOTOGRAPHS
N
03
N
in
N
Y'
m
m
m
2
2
2
0?
m
U
o
m
m
m
SAPROLITE
0 00 0
¢¢¢
mmm
��
a
ooLOLOLO
L
o 0 0 0
¢¢¢
TOP OF ASH
o
-1
o
0
IW-12S
3 <50
COAL PILE AREA
J J J J
00
¢¢
°�
BASIN DAM= 488
z
in
U
U
U
`
m
m
¢
EARTHEN DAM
o
0
1W-12D
TRANSITION
—
SAPROLITE
(FILL)
a
d
d
3 <5
ZONE
_
GENERALIZED GROUND TER
FLOW DIRECTION
_
-
=--_
TRANSITION -----
- -
-
- - - -
-------- -----
ABMW-3 -ASH====--_
WATER ELEVATION=480
��
���
Q
<
- -
-_
- - - - - - -
-_--- --_-_ --
-ASH---- --
195 4
N w
-4AMWa 3:BM
B 5,470 B8532 AMW1,320
g
L\1� U
\- / \ , ABM Q B 3, - TRANSITION ZONE
/ / I I.�.r \I1L /-i\I./`/_ /\ -i\I/1 /-i I./ -i\I/1 /-i\'`- ABMW-2BR -i\I/1 /-i I\/\ -/\I/\ /\ TRA MW-16S
\/\ /1, BEDROCK.\ \ 1, \/\ /1, \ /1, \/\ /1, \ /1,�\ /\, \ �\ /1, \ ,�\ _,�\ /1,�� _ /�\ / ,�_ TIO R-1055
ABMW-4BR B <5 \�/\ / _ \ / /. / _ \ . / _ E N 11
510
B <50 i,\/\/1/\i/�/1�`�/\'I/\i/\\/I�\`�/`'I/\ CW-2
CCR-105D .ALLUVIUM-
\/\I/1�/ /\I ♦/ /\I 1`/ /\I ♦/ /\I/1\/ /\I ♦/ I ♦/- _ _ /\/1 /\I ♦/ /\I/1`/-/ I ♦/_ /\I/1 /�'�T_ �I/1�/\/\I/1�/\/ B 810 B 720 SAPROLITE
7-- �1 /\-_\ 1�/�-\�\'/�-\-1�/�-\�1'/� _\-1//` -\�,�, 1//. -\�\ /�-\-\//`-\�\'/\--\-\//`-\�\�/\--\ \/'' CCR-1056R / TRANSIT'oN
ZONE MW-16D
_�\I./``_\�I•/\�-i\I /`�-`'./- -�� /\/-\ /- -��-/BEDROCK'I\i-i\I /`/_\•I./`/ i\I�\B < ��Ice\\.li; _ _i�./`�_\•I./ _i�./`BEDROCK 894 B 273
\ / \ / 1 \ / 1 , \ / \ / 1 \ / 1 . \ / 1 / \ ` / \ \ I / 1 , \ / \ / 1 \ \ I / 1
CRUTCHFIELD Mw-166R
- 1'/ - \ \'/ - \ - \'/
BRANCH \ B <50
/.--\1'/�\-1�/`=��/r/t/�4'/\-/\_1�/�
BEDROCK B 50
\/\I/ 1� �\/\I/ 1` �\/\I/ 1� �\/\I/ 1` �\/\I/1� �\/\I/ 1` �\/\I/ 1� ��-\fj 1>✓`t'��\fly /i-LL/1` �\/\I/1� �\/\I/1` �\/\I/ 1� �\/\'/ 1 � �\/\I/1� �\/\I/1` �\/\I/ 1� �\/\I/ 1` �\/\I/ 1� ��i\I/ 1` �\/\I/1 � ��i\I/ 1` �\/\I/ 1� ��i\I/ 1` �\i\I/1� ��i\I/1` �\.
\/\I/ 1; ��%\I/ 1` `\%\I/ 1; ��%\I/ 1` `\%\I/1; ��%\I/ 1` `\%\I/ 1; ��%\I/ 1` `\%\I/1; ��%\I/1` `\%\I/1; ��%\I/1` `\%\I/ 1; ��%\I/ 1` `\%\I/1; ��%\—I/1�` `\%\I/ 1; ��%\I/ 1` `\%\I/ 1; ��%\I/ 1�!r\.J��-.i+� �[i�*/ j � �\r\I/ 1; ��i\I/ 1` �\i\I/1; ��i\I/1` �\•
/. � / I� \/./\ / li \/. � / I� \/./\ / li \/. � / I� \/./\ / li \/. � / I� \/./\ / I.yL. � / li \lil\ / 1, \l• � / 1' \/ ;�\ //I, \/• � / I' \/ \�\ //I, \/ �� //1' \/ ;�\ //1, \/ �� /,I' \/ \�\ //I, \/ �� /,I' \/ \�\ //I, \/ ;� //I' \/ ;�\ //I \/ ;� /,I' \/ \�\ //I, \/ ;� //1' \/ ;�\ //1, \/�
- I � ♦ /- I ` ♦ / - I � ♦ /- I ` ♦ / - I � ♦ /- I ` \ / - I � ♦ /- I ` ♦ / - I � ♦ /- I ` \ / - I � ♦ /- I ` \ / - I � ♦ /- I ` ♦ / - I � ♦ /- I ` ♦ / - I � ♦ /- I ` ♦ / - I � ♦ /- I ` ♦ / - I � ♦ /- I ` , - I � ♦ /- I ` ♦ / - I � ♦ /- ` I . / \ � _
♦ / � / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ / \ I / 1 � � \ .
LEGEND
MW 12S
V
ASH PORE WATER FLOW LAYER
WELL IN ALLUVIUM OR SAPROLITE
WATER LEVEL ELEVATION
MW 16D
WELL IN TRANSITION ZONE
V
ALLUVIUM OR SAPROLITE FLOW LAYER
MW 16BR
WELL IN BEDROCK
GROUNDWATER LEVEL ELEVATION
ABMW 2
WELL IN ASH PORE WATER
TRANSITION ZONE FLOW LAYER GROUNDWATER
_ L
GENERALIZED WATER TABLE
LEVEL ELEVATION
BEDROCK FLOW LAYER GROUNDWATER
GENERALIZED GROUNDWATER
LEVEL ELEVATION
FLOW DIRECTION
�►
GENERALIZED SUBSURFACE ASH
WELL SCREEN
PORE WATER FLOW DIRECTION
— — — GENERALIZED FRACTURE
ORIENTATIONS
0 ASH
— ASH PORE WATER / WASTEWATER
0 SAPROLITE
® TRANSITION ZONE
BEDROCK
MW-105BRM BORON CONCENTRATION (Ng/L)
B 1 <50 (LABEL COLORING BY FLOW ZONE)
DUKE ENERGY PROGRESS
PROPERTY LINE
— — — ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN WASTE BOUNDARY
Reporting Units
Ng/L
15A NCAC 021-Standard
700
Background Threshold Values (Surficial Flow Zone)'
50
Background Threshold Values (Transition Zone)'
50
Background Threshold Values (Bedrock Flow Zone)'
S0
NOTES
1. BACKGROUND THRESHOLD VALUES WERE CALCULATED USING DATA FROM BACKGROUND GROUNDWATER
SAMPLES COLLECTED APRIL, 2010 TO DECEMBER 2018 AS SUBMITTED IN JUNE, 2019.
2. ALL CONCENTRATIONS SHOWN ARE STATISTICAL MEANS CALCULATED USING DATA RANGING FROM
JANUARY 2018 TO APRIL 2019.
3. ALL CONCENTRATIONS ARE IN MICROGRAMS PER LITER ug/L.
4. FRACTURES DEPICTED ON THIS CROSS SECTION REPRESENT THE GENERALIZED ORIENTATIONS OF
THE PREVALENT FRACTURE SETS OBSERVED AT THE SITE BASED ON TELEVIEWER LOGGING AT
SITE -SPECIFIC BOREHOLES. THEY ARE SHOWN WITH APPROPRIATE APPARENT DIP, WITH VERTICAL
EXAGGERATION. THIS CROSS SECTION IS APPROXIMATELY PARALLEL TO THE PREDOMINANT
FRACTURE STRIKE DIRECTION. THE ACTUAL NUMBER OF FRACTURES IS FAR TOO NUMEROUS TO
ILLUSTRATE AT THIS SCALE. IN ADDITION, THE DEPTHS AND LENGTHS OF FRACTURES VERSUS DEPTH
ARE CONCEPTUAL ONLY.
5. ALL BOUNDARIES ARE APPROXIMATE.
6. CROSS SECTION REPRESENTATIVE OF PRE -DECANTING CONDITIONS.
4 DUKE
ENERGY
PROGRESS
116rip
synTena
GRAPHIC SCALE
0 135 270 540
HORIZONTAL SCALE: 1" = 540' FIGURE 6-4
VERTICAL ICALEX GGERA EXAGGERATION
GENERAL CROSS-SECTION A -A'
5X VERTICAL EXAGGERATION
DRAWN BY: J. CHASTAIN DATE:08/02/2019 ASH BASIN -BORON
REVISED DATE:12/2/2019 CORRECTIVE ACTION PLAN UPDATE
CHECKED BY: P. ALTMAN DATE: 12/2/2019
APPROVED BY: P.ALTMAN DATE:12/2/2019 MAYO STEAM ELECTRIC PLANT
PROJECT MANAGER: J. WYLIE
LAYOUT: FIG 6-4(ASH BASIN -BORON) ROXBORO, NORTH CAROLINA
www.synterracorp.com

-
'
NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY (APPROXIMATE)
.
1
ri■�r-r �■r.�r�rrrr��-.���::■�
Ir-�tr
__--;� �•3dii�Y,.
;--ry �Fr�r�i
� __-__
PERSON COUNTY
WAYO LAKE
rl
► r
I CCR-103D � �
•
1
s a _
4_L+�r�
r
r
•
'
�
•
Ir r k
�ii�idlii�i �
_ _
�
r r
l l' RAILROAD-
rr
,
-
d r
r e
r
• �
I i
jk
RT
HFSTFHaD
t
ABMW-3
r I>I r
r
. I
r
■
I■ I d r rPAD
, ■ �r rAREA
■ ■ I
I 1FAL
■ ' rRAGE
I dt
a ,
1 r
I r •
I r
APPROXIMATE FUTURE
ASH BASIN WASTE BOUNDARY
(SEE NOTE 42��
r � '
r
'• 1
r •
3
= MULLINS LN
o
ENERGY
GRAPHIC SCALE
500 0 500 1,000
(IN FEET)
DRAWN BY: A. ROBINSON DATE: 05/03/2019
REVISED BY: A. ROBINSON DATE: 12/04/2019
CHECKED BY: P. ALTMAN DATE: 12/04/2019
APPROVED BY: J.WYLIE DATE: 12/04/2019
PROJECT MANAGER: J. WYLIE
LEGEND
� TRANSDUCER LOCATION
GEOCHEM ICAL SONDE LOCATION
ASH BASIN WASTE BOUNDARY
— - — - ASH BASIN COMPLIANCE BOUNDARY
— - — - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
- DUKE ENERGY PROGRESS PROPERTY LINE
� STREAM (AMEC NRTR)
0 WETLAND (AMEC NRTR)
NOTES:
1. GROUNDWATER MONITORING WELL TRANSDUCERS AND SONDES INSTALLED
MARCH 19, 2019. ASH BASIN PONDED WATER TRANSDUCERS INSTALLED APRIL 24,
2019.
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH BASIN
WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES PERMIT
NC0038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13, 2018.
3. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE U.S.
ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A
PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE PRELIMINARY WETLANDS
AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER WHEELER
ENVIRONMENTAL &INFRASTRUCTURE, INC. NATURAL RESOURCES TECHNICAL
REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY 2014 AND
UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND
NEAR THE ASH BASIN DISCHARGE CHANNEL.
4. ALL BOUNDARIES ARE APPROXIMATE
5. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
6. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019. AERIAL
WAS COLLECTED ON FEBRUARY 6, 2017.
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83).
FIGURE 6-5
SITE LAYOUT
DECANTING MONITORING NETWORK
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA
m

ABMW-3
CCR-103D
CCR-105D
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
2/1/19
7.0
3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19
9/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
8.0
6.5
7.5
6.5
6.4
Stable trend observed
>
7.0
/
/
6.0
6.3
_6.2
e.
CL
a
6.5
5.5
6.1
Stable trend observed
6.0
6-0
5.0
/
Increasing trend observed
i/
600
prior to decanting
0
commencement
600
500
600
-100
> >
400
-
400 E
200
(7
300
`-'
300
a
a
O
300
C
200
O
Decreasing tren
200
observed prior to
decanting commencement
100
-400
100
0
500
0
Total change in water level from
Total change in water level from
5
c
476
decanting is approximately -2.3
5
c
Sample event
c
decanting is approximately -1.9
O
feet between decanting start date
O 384
5
�0—,
feet between decanting start date
Z
and September 12, 2019
+'
>
484 and September 12, 2019
4
..
> .�
4
.-.
> .-. 382
4 C
^
u100
V
W pip
474
T" ' '
Sample event
C
Go
W 00
3
_
0
3
_
0 Total change in water level from
380
3
Sample event
M
> Q
decanting is approximately -0.8
Q
,M
> Q
W
c
W
c
0 feet between decanting start date
c
Z
482
2
to
Z
2
10
Z g78 and September 12, 2019
2 M
i
Y
472
�
41
M
1
3
1
3 376
1
470
ALI
0
11
480
0
374ILL
0
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
2/1/19
3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19
9/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
Date
Date
Notes:
LEGEND
DUKE
DRAWN BY: G. KHANG DATE: 10/02/2019
—
NAVD 88 - North American Vertical Datum
pH (S.U.) in - inches
ENERGY
REVISED BY:
P. ALTMAN
FIGURE 6-6
—
Oxidation Reduction Potential (ORP) (mv) pS/cm - micro Siemens per centimeter
PROGRESS
GEOCHEMICAL WATER QUALITY PLOTS
—
Water Level Elevation (NAVD 88)
CHECKED
BY:
P. ALTMAN
—
Cease Flows into Ash Basin (06/13/2019) my - millivolts
CORRECTIVE ACTION PLAN UPDATE
—
Decanting Start (06/27/2019) S.U. - standard unit
APPROVED BY: J. WYLIE
MAYO STEAM ELECTRIC PLANT
�
Daily Total Rainfall (inches)
��
See Figure 6-5 for monitoring locations.
ROXBORO NC
WnTerra
PROJECT
MANAGER:
]. WYLIE
�
www.synterracorp.com

Note: All sampling events
occur between 1/16/2018 and
4/23/2019
Ash Pore Water
Legend
ABMW-01
ABMW-02
ABMW-03
ABMW-04X
Surficial
Groundwater
Bedrock Groundwater Legend
A ABMW-02BR
❑ CCR-109BR
z
MW-09BRL
ABMW-02BRL
CW-01D
*
* ABMW-04BR
CW-02D
MW-104BRL
❑
MW 104BRM
■ BG-01
CW-04
O
MW-105BRM
■ CCR-102BR-BG
CW-05
• CCR-103BR
CW-06
a
MW-10BR
7
MW-13BR
CCR-104BR
■ MW-02
0
MW-14BR
7 CCR-105BR
• MW 036R
g
MW-1
♦ CCR-106BR
MW-04
�
8BR
MW-1BR
Z CCR-107BR
MW-056R
* CCR- 108BR
♦ MW-08BR
■
MW 19BR
Bedrock
k Groundwater
Transition Zone — c'
Groundwater
Transition Zone
\
ao
Groundwater Legend
80%
80%
■ ABMW-04D CW-03
1P
■ BG-02 ■ MW-12D
g� 60%
°� a
��0
60io so
■ CCR-103D • MW-16D
/40%
CCR-105D MW-18D
40%\
CW-02 V MW-19D
20°r°
�-�
i r
■
20%
.�
■
.
� z
i— Ca — Surficial Groundwater — CI
DUKE
DRAWN BY: R.BADUM
Legend
t� ENERGY
REVISED BY: R.BADUM
X ABMW-03S ■ MW-03
PROGRESS
CHECKED BY
■ CCR-1035 • MW-12S
APPROVED BY:
PROJECT MANAGER: J. WYLIE
• CCR-1045 MW-165
1P
■ CCR-105S
'k--Ca—
DATE: 9/3/2019
DATE: 12/2/2019
DATE:
"'y' W= 10 www.synterracorp.com
— Cl ---w
FIGURE 6-7
ASH PORE WATER AND
GROUNDWATER PIPER DIAGRAMS
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

484
Ash Basin Pond
5
West Ash Basin Finger Monitoring
Southwest
Ash Basin Finger Monitoring
5
5
Total change in water level from decanting is
488
—
488
00
00
482
approximately -6.9 feet between decanting
start date and September 19, 2019
4
00
00
Total change in water level from decanting is
g g
00
00
Total change in water level from decanting is
Q
Q
approximately -0.5 feet between decanting
4
Q
approximately -0.5 feet between decanting
4
>
>
start date and September 12, 2019
>
start date and September 12, 2019
V
480
V 486
.Z
486
c
3 c
c
c
c
c
y
3
r
3
y
478
-
484
c
>>i
484
c
a>i
W
W
W
-y
2 a
y
>
476
>
482
2
>
�
482
2
L
0
L
3-
W
R
3
1
R
3
O
3
474
480
1
480
1
71
II
.�� 1 I 11
1
�J . 1 ._ 1 I�L�1 ■ I I
472 0
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
478
0
478
0
Date
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Ash Basin Pond Level Elevation (NAVD 88)
Date
Date
Note:
Data with +/- 5 feet change in water elevation is not included and no
West Ash Basin Water Elevation (NAVD 88)
Southwest Ash Basin Water Elevation (NAVD 88)
data between 8/31/2019 and 9/19/2019 Is available due to faulty sensors.
Transducer elevation: 474.940 feet
Transducer elevation: 475.822 feet
South Ash Basin Finger Monitoring
ABMW-1
ABMW-2B1R
5
484
5
484
5
0000
00
488
Total in level from decanting is
0000
00
Total change in water level from decanting is
approximately-2.4feet between decanting
date September 12, 2019
0000
00
482
_ l
Q
change water
-2.0 feet between decanting
4
Q
482
start and
4
Q
4
>
Q
approximately
start date and September 12, 2019
>
a
>
a
Total
change in water level from decanting is
~�
Z
486
Z
Z
approximately
-1.8 feet between decanting
480
start date and September 12, 2019
O
O
O
m
3-
0 480
3—
W
3
>
Sample event
M
>
478
Sample event
M
y
lu
484
,M
'M
{IJ
•�
liJ
M
z
Ix
>
>
476
a>i
2
0) 478
2
J
2
L
482
L
L
mj
474
3
3
3
480
1
476
1
1
JJ
'I
472
'I
478
J r I�ill
470
0
0
474 0
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
Date
Date
South Ash Basin Water Elevation (NAVD 88)
ABMW-1 Water Elevation (NAVD 88)
ABMW-2BR Water Elevation (NAVD 88)
Transducer elevation: 465.729 feet
Transducer elevation: 470.614 feet
Transducer elevation: 395.838 feet
LEGEND Notes:
DUKE
DRAWN BY: G. KHANG
DATE: 10/04/2019
FIGURE 6-8a
NAVD 88 - North American Vertical Datum 1988
> ENERGY
REVISED BY:G.KHANG
DATE:12/02/2019
HYDROGRAPHS - WITHIN THE ASH BASIN
Cease Flows into Ash Basin (6/13/2019) in - inches
Decanting Start (6/27/2019) See Figure 6-5 for monitoring
locations.
PROGRESS
CHECKED BY: P.ALTMAN
DATE:12/07/2019
CORRECTIVE ACTION PLAN UPDATE
Daily Total Rainfall (inches) Transducer elevations are approximate.
APPROVED BY: J. WYLIE
DATE:
12/08/2019
MAYO STEAM ELECTRIC PLANT
,0
PROJECT MANAGER: J. WYLIE
ROXBORO, NC
synTerra
www.synterracorp.com

ABMW-3 I AP-6 I CCR-103 Cluster
484
W 482
3
480
Total change in water level from decanting is
approximately -1.9 feet between decanting
start date and September 12, 2019
Sample event
IM
5 1 484
00
00
4 >
Q
Z
5 c 482
3- a
M >
M W
oC y
2 v
J
v 480
m
3
1
0 I 478
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
ABMW-3 Water Elevation (NAVD 88)
Transducer elevation: 458.535 feet
CCR-104 Cluster
410
00
00
> 408
Q
Z
c
O
M 406
N
W
GJ
J 404
a�
M
3
402
M1
Total change in water level from decanting is
approximately -1.9 feet between decanting
start date and September 12, 2019
11 �l
5 1 477
00
00
4
Q 475
Z
C =
:. O
3M
M W 473
tY
a�
2 y
J
a�
3 471
1
0
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
AP-6 Water Elevation (NAVD 88)
Transducer elevation: 426.279 feet
5 1 384
00
00
4 > 382
Q
Z
c =
0
3 380
4-- _4)
M
W
tY Gl
2 J 378
O
m
3
1 376
0
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
CCR-104BR Water Elevation (NAVD 88) Transducer elevation: 369.500 feet
CCR-104S Water Elevation (NAVD 88) Transducer elevation: 400.954 feet
r%jWV
Average total change in water level from
decanting is approximately -0.8 feet between
decanting start date and September 12, 2019
Sample events
II _A ki,
LEGEND Notes:
NAVD 88 - North American Vertical
Cease Flows into Ash Basin (6/13/2019) in - inches
Decanting Start 6/27/2019 See Figure 6-5 for monitoring loca
9 ( ) Transducer elevations are approxim
Daily Total Rainfall (inches)
374
CCR-105 Cluster
Average total change in water level from
decanting is approximately -0.9 feet between
decanting start date and September 12, 2019
Sample event
469
Average total change in water level from
decanting is approximately -2.1 feet between
decanting start date and September 12, 2019
•.T t+- -.
Water level has
decreased below
transducer elevation.
Sample events
f)TI
5
4
3
M
c
M
IM
2
1
0
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
CCR-103BR Water Elevation (NAVD 88) Transducer elevation: 420.176 feet
CCR-103D Water Elevation (NAVD 88) Transducer elevation: 461.924 feet
CCR-103S Water Elevation (NAVD 88) Transducer elevation: 470.008 feet
5 1 378
00
00
4
Q
Z
c c 376
o
3 — +'
f0 >
w >
C 2
m W
2 >
O
J
374
�a
1 3
0 372
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19
tions.
7/1/19 8/1/19 9/1/19
Date
CCR-105BR Water Elevation (NAVD 88)
Transducer elevation: 357.507 feet
CCR-105D Water Elevation (NAVD 88)
Transducer elevation: 365.442 feet
CCR-105S Water Elevation (NAVD 88)
Transducer elevation: 376.211 feet
DUKE
DRAWN BY: G. KHANG
Datum 1988
401)
ENERGY
REVISED BY: G. KHANG
PROGRESS
CHECKED BY: P. ALTMAN
ate.
APPROVED BY: J. WYLIE
PROJECT MANAGER: J. WYLIE
synTerra
www.synterracorp.com
CeleffiilZ
5
4
c
3 4-
2
1
0
1/1/19 2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
CCR-106BR Water Elevation (NAVD 88)
Transducer elevation: 347.734 feet
DATE:10/04/2019 FIGURE 6-8b
DATE:12/02/2019 HYDROGRAPHS - WITHIN AND NORTH OF THE
DATE:12/07/2019 ASH BASIN
DATE:12/08/2019 CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NC
Sample event
Total change in water level from decanting is
approximately -0.1 feet between decanting
start date and September 12, 2019
I

CCR-107BR
CCR-108BR
CW-2
5
5
5
476
_-
00
Total change in water level from decanting is
approximately -1.5 feet between decanting
000
377
00
Q
438
start date and September 12, 2019
4
474
C
Q 472
4
0000
C
Q
4
Z
^
Z
..� 470
Total change in water level from decanting is
approximately -5.1 feet between decanting
^
Z
A
^
C
C
C
start date and September 12, 2019
C
C
C
Sample event
3 —
a 468
3
_
M
376
Total change in water level from decanting is
3 —
M
>
M
C
>
466
Sample event
C
>
approximately -1.2 feet between decanting
start date and September 12, 2019
C
LU
436
W
—a—
>
> 464
>
2
�
2
375
2
y 462
?�
?� 460
?�
434
1
458
1
1
374
I
456
l
I I
454
,
)
0
0
0
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19
7/1/19 8/1/19 9/1/19
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19 7/1/19 8/1/19 9/1/19
Date
Date
Date
CCR-107BR Water Elevation (NAVD 88)
CCR-108BR Water Elevation (NAVD 88)
CW-2 Water Elevation (NAVD 88)
Transducer elevation: 413.479 feet
Transducer elevation: 437.009 feet
Transducer elevation: 369.238 feet
MW-3
379
5
Total change in water level from decanting is
approximately -0.2 feet between decanting
00
start date and September 12, 2019
4
C
Q
z
378
CSample
event
3
...
4-1
W
Sample event
=
IntentionallyLeft
Blank
Intentionally Left Blank
2W
W
377
L
Y
3
�
1
376
0
1/1/19
2/1/19 3/1/19 4/1/19 5/1/19 6/1/19
7/1/19 8/1/19 9/1/19
Date
MW-3 Water Elevation (NAVD
88)
Transducer elevation: 371.412 feet
LEGEND
Notes:
% DUKE
DRAWN BY: G.KHANG
DATE:10/04/2019
NAVD 88 - North American Vertical Datum 1988
'
� ENERGY
REVISED BY: G. KHANG
DATE:
12/02/2019
FIGURE 6-8c
Cease Flows into Ash Basin (6/13/2019)
in -inches
PROGRESS
HYDROGRAPHS —NORTH OF THE ASH BASIN
Decanting Start (6/27/2019)
See Figure 6-5 for monitoring locations.
Transducer elevations are approximate.
CHECKED BY:P.ALTMAN
DATE:12/07/2019
CORRECTIVE ACTION PLAN UPDATE
Daily Total Rainfall (inches)
0
APPROVED BY: J. WYLIE
DATE:
12/OS/2019
MAYO STEAM ELECTRIC PLANT
synTerra
PROJECT MANAGER:J.WYLIE
ROXBORO, NC
www.synterracorp.com

J Sample ID (Depth)
f MW-3BR (0.8-1.2)
MW-3BR (14.75-15)
r
Sample ID (Depth)
r TA TMA PSB-1 (1-2)
ESample ID (Depth) •
PSB-2 (1-2) RDA -_ : ■ .
SamplelD(Depth) • - `�
Sample ID
PSB-30 (1-2)
Sample ID (Depth)
MW-15BR (0.5-1)
•' ' Sample ID (Depth)
SB-7 (1-2)
Sample ID (Depth) SB-7 (4.5-7.5)
PSB-27 (1-2)
fl
Sample ID (Depth)
- RTRF SB 1 (1 2)
SB-1 (13.5-14.5) Sample ID (Depth)
Sample ID (Depth) PSB-3 (1-2)
it.PSB-7 (1-2) ' Sample ID (Depth)
Sample ID (Depth) PS13-26 (1-2)
w
• t PSB-8 (1-2)
Sample ID (Depth) Sample ID (Depth) y
+ �ti PSB-9 (1-2) PSB-5 (1-2)
Sample ID (Depth)
+ + MW-13BR (0-2) ' Sample ID (Depth) Sample ID
+�, r r �, • , • i 1 - PSB-6 (1-2) TPB13 (1-2)
•✓ t I Sample ID (Depth)
Sample ID (Depth)
J ( ) PSB-14 (1-2)
SampleID(Depth)
�Rqr=Ro Sample ID (Depth) PSB-13 (1-2) Sample ID (Depth)
_qD PSB-11 (1-2) PSB-16 (1-2)
11
Sample ID (Depth)
,
BGSB-5 (4-5) Sample ID (Depth) -
BGSB-5 (9-10) PSB-12 (1-2) Sample ID (Depth)
BGSB-5 (14-15) , I PSB-15 (1-2)
Sample ID (Depth) I
+ I
' Sample ID (Depth)
PSB-29 (1-2)
ample ID (Depth)
L
Sample ID (Depth) - MW-8BR (0.75-1.25)
PSB-28 (1-2) • MW-8BR (25.5-26)
Sample ID (Depth)
PSB-25 (1-2) +
t.
Sample ID (Depth)
Sample ID
!� MW-7BR (1-2)
mple ID (Depth)
-2)
Sample7(Dept%h)PSB-21 (1-2)
o
•
Sample ID (Depth)
BGSB-3 (4-5) I I + (Depth) PSB-22 (1-2)
Sample ID (Depth) BGSB-3 (8-9) r ) r .r PSB-17 (1-2)
BGSB-4 (4-5) I � v � _
I I • Sample ID (Depth) • Sample ID De
BGSB-4 (9-10) Sample ID (Depth) p ( p )
BGSB4 (14-15) SB-2 (0.5-2) -
• PSB-20 (1-2) PSB-18 (1-2)
Sample ID (Depth) SB-2 (11.0-12.5) v.
11111wL BGSB-2 (4-5)
f+ f 1 I 7
BGSB-2 (9-10) � ,tjai
►
BGSB-2 (14-15)
I Sample ID (Depth)
� Sa
f S13-3 (5-6) -
PSB-19
SB-3 (17-18.5)
r � ,
■ f r r
I t r
Sample ID (Depth) t l I I 1
MW-11BR (0-2) r I •
MW-11BR(30-32) 1
r Sample ID (Depth)
+ r BGSB-8 (4-5)
r
'• ' � , BGSB-8 (8-9)
_ ■ . � . ■ � . ■ � . 1 r CHROMIUM
7- 1 •
LVVIWAIVA I"AGIrIG
f-
+
e ID (Depth) •
1
Sample ID
BGSB-9 (4-5)
BGSB-9 (9-10)
BGSB-9 (14-15)
1•
•.- i
•• yr
AREA
APPROXIMATE FUTURE
ASH BASIN WASTE BOUNDARY
• ' (SEE NOTE 2)
1RAGE N
r
MANGANESE
a
r
Sample ID (Depth)
-- -
MW-12D (1-2)
_
MW-12D (25-26)
s_rl
r
• y 1
ftsli`x
MULLINS LN
i
Sample ID (De
MW-10BR (0.75-1.0)
4DUKE
n ENERGY
161
synTerra
NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY ._ (APPROXIMATE)
PERSON COUNTY
a
9w EN"
AL
7 I
aI
GRAPHIC SCALE
500 0 500 1,000
(IN FEET)
DRAWN BY: A. ROBINSON DATE: 06/05/2019
REVISED BY: A. ROBINSON DATE: 12/06/2019
CHECKED BY: P. ALTMAN DATE: 12/06/2019
APPROVED BY: J. WYLIE DATE: 12/06/2019
PROJECT MANAGER: J. WYLIE
LEGEND
0 BACKGROUND LOCATION WITH NO EXCEEDANCES
• LOCATION WITH NO EXCEEDANCES
BACKGROUND LOCATION WITH ONE EXCEEDANCE OF
REGULATORY CRITERIA
O LOCATION WITH ONE OR MORE EXCEEDANCES OF
REGULATORY CRITERIA
- ■ _ ■ ■ ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
— - — - - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
DUKE ENERGY PROGRESS PROPERTY LINE
1 STREAM (AMEC NRTR)
® WETLAND (AMEC NRTR)
NOTES:
1. DISCRETE SOIL SAMPLES EXCEED COMPARATIVE CRITERIA FOR
CONSTITUENTS LISTED UNDER THE SAMPLE ID. REFER TO TABLE 6-4 FOR A
SUMMARY OF UNSATURATED SOILANALYTICAL RESULTS
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH
BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES
PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13,
2018.
3. SAMPLE DEPTH IS FEET BELOW GROUND SURFACE.
4. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
5. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE U.S.
ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A
PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE PRELIMINARY
WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER
WHEELER ENVIRONMENTAL AND INFRASTRUCTURE, INC. NATURAL RESOURCES
TECHNICAL REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY
2014 AND UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY
MISIDENTIFIED WETLAND NEAR THE ASH BASIN DISCHARGE CHANNEL.
6. ALL BOUNDARIES ARE APPROXIMATE
7. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019. AERIAL
WAS COLLECTED ON FEBRUARY 6, 2017.
8. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
FIGURE 6-9
UNSATURATED SOIL SAMPLE
LOCATIONS AND EXCEEDANCES
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

Note:
*- Indicates
sampling events
prior to 1/1/2018
All other sampling
events occur C4
4/20/2018 -
7/2/2019 goo
80%
r
60%
/40%
V*
to O°. % 10o Surface
`— Ca — Water
o 1 1
-Cl b
Upgradient Downgradient
S-6
■
S-3
�I SW-REF1
A
SW-C81
■ SW-REF2
7
SW-C82
■ SW-13132
SW-C83
Z
SW-C84
*
SW-CBT1
DUKE
ENERGY
41P
synTerra
*— Ca —
DRAWN BY: R. Badum
REVISED BY: R. Badum
CHECKED BY:
APPROVED BY:
PROJECT MANAGER:
Seeps
■ S-1*
S-2
■ S-2B
■ S-8*
DATE: 10/4/2019
www.synterracorp.com
60% U'p
Q
40%\
20%
— Cl ---*
FIGURE 6-10
SEEP AND SURFACE WATER
QUALITY PIPER DIAGRAMS
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

- yy
• �• r — - _ • ♦ MW-16S o-
_ _ • 167
�o
' ' • ♦ i� CCR-104S >ryo �� ' n o 'S ,se
• . �/ i 267
R T 3 1049 Alb - RD� .P
HEST • CCR-105$Qw388
FRgO 510 (d• -,� 0.^e ,�e°i J 3-2`237 Imo( :�'a. s• �. 7$. o 35p ' �' e ` .
.'—
�.
92 37a_
r ' �386-3390-384
/ 1
♦ 1
\ \ N
\ y
\ ♦ U
�� I ♦�� ABMW-113S • ♦ 0 4°6
` o : 1320 �• 49a
LEGEND
' x 1 MONITORING WELL - GREATER THAN 15A NCAC 2L .0202
I i ♦ 4 STANDARD (700 Ng/L) OR THE IMAC (EFFECTIVE DATE FOR 15A
NCAC 02L .0202 STANDARD AND IMAC IS APRIL 1, 2013)
1 'I f� x �♦� (� g I� Q' " " " • • " • • • • CAMA MONITORING WELL - GREATER THAN CONSTITUENT
oI/ ♦ v � r • I + BACKGROUND THRESHOLD VALUE (50 Ng/L)
y 1 / ♦ �♦ MONITORING WELL- LESS THAN BACKGROUND THRESHOLD
1 m° ' • gj� ' VALUE
I APPROXIMATE FUTURE • o' v BACKGROUND MONITORING WELL
ASH BASIN WASTE BOUNDARY, s6^43s
ll
/ (SEE NOTE4) 0 o BORON PLUME GREATER THAN THE USEPA DRINKING WATER
NOTES: / / Spa 1 EQUIVALENT LEVEL (4000Ng/L) FROM FLOW AND TRANSPORT
,r ti MODEL PREDICTED PLUME.
1. DATA INCLUDED IN THIS FIGURE ARE THE ARITHIMETIC MEAN BASED ON - I ••. , �� a`'
VALID GROUNDWATER SAMPLE DATA COLLECTED FROM JANUARY 2018 ♦ 1 ) , , • app BORON PLUME GREATER THAN NC 02L STANDARD (700 Ng/L)
THROUGH APRIL 2019. /
• FROM MEAN ANALYSIS. FLOW AND TRANSPORT MODEL
2. THE 02L FOR BORON IS 700 pg/L. 522 ♦ • PREDICTED PLUME IS USED WHERE EMPIRICAL DATA IS NOT
3. THE BACKGROUND VALUE FOR BORON IS 50 pg/L (AS SUBMITTED JUNE ♦ AVAILABLE.
2019). I ♦� sa°
BORON PLUME GREATER THAN BTV (50 Ng/L) FROM MEAN
4. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS CCR-101S-BG ANALYSIS. FLOW AND TRANSPORT PREDICTED PLUME IS USED
NOT PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE <50 ! •• ', �e e G/ WHERE EMPIRICAL DATA IS NOT AVAILABLE.
ASH BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO 1 1 • 1
NPDES PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED v • •
JULY 13, 2018. I i 540 • ♦ ASH BASIN WASTE BOUNDARY
5. GROUNDWATER FLOW AND TRANSPORT BORON PLUME IS MODIFIED FROM ' ASH BASIN COMPLIANCE BOUNDARY
MODEL LAYER 10 (MURDOCH ET AL, 2019). .°
RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
6. HYDROLOGIC DIVIDE INDENTIFIED IN CSAUPDATE (SYNTERRA, 2017)AND
UPDATED GROUNDWATER FLOW AND TRANSPORT MODELING REPORT DUKE ENERGY PROGRESS PROPERTY LINE
(MURDOCH ET AL, 2019).
7. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE ' '
1` y B TOPOGRAPHIC CONTOUR (10' INTERVAL)
U.S. ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS 536 ------ b- GROUNDWATER FLOW DIRECTION
MAP IS A PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE 1 5pq _558�
PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED
FROM AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC. I �¢sz _ STREAM (AMEC NRTR)
NATURAL RESOURCES TECHNICAL REPORT (NRTR) FOR MAYO STEAM ss
ELECTRIC PLANT DATED JANUARY 2014 AND UPDATED ON JULY 11, 2018 TO WETLAND (AMEC NRTR)
REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH BASIN
DISCHARGE CHANNEL. ) APPROXIMATE HYDROLOGIC DIVIDE
8. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND rm
SHOULD NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES. 570 j a —a.
TOPOGRAPHY IS BASED ON LIDAR BARE EARTH DATA OBTAINED FROM THE y^`D 5g2`,.586
NORTH CAROLINA SPATIAL DATA SITE AT GRAPHIC SCALE
https://sdd.nc.gov/sdd/DataDownload.aspx. 578 DUKE 390 0 390 780 FIGURE 6-11a
580 �� s° 546 MAP OF BORON DISTRIBUTION
9. ALL BOUNDARIES ARE APPROXIMATE. N f" 0�� ENERGY ° (IN FEET)
10. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS. yoo MW-12S SZa PROGRESS SURFICIAL ZONE
57a 598 <50 DRAWN BY: A. ROBINSON DATE:05/09/2019 CORRECTIVE ACTION PLAN UPDATE
11. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019. REVISED BY: A. ROBINSON DATE: 12/13/2019
AERIAL WAS COLLECTED ON FEBRUARY 6,2017. h 594 - y�'� s'9 CHECKED BY: P.ALTMAN DATE:12/13/2019 MAYO STEAM ELECTRIC PLANT
12. DRAWING HAS BEEN SET WITH PROJECTION OF NORTH CAROLINA "y •� ' APPROVED BY: J. WYLIE DATE:12/13/2019 ROXBORO, NORTH CAROLINA
STATE PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). ,�Crl� PROJECT MANAGER: J. WYLIE
606 ,02 584 www.synterracorp.com

la
NOTES:
1. DATA INCLUDED IN THIS FIGURE ARE THE ARITHIMETIC MEAN BASED ON
VALID GROUNDWATER SAMPLE DATA COLLECTED FROM JANUARY 2018
THROUGH APRIL 2019.
2. THE 02L FOR BORON IS 700 pg/L.
3. THE BACKGROUND VALUE FOR BORON IS 50 pg/L (AS SUBMITTED JUNE
2019).
4. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS
NOT PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE
ASH BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO
NPDES PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED
JULY 13, 2018.
5. GROUNDWATER FLOW AND TRANSPORT BORON PLUME IS MODIFIED FROM
MODEL LAYER 10 (MURDOCH ET AL, 2019).
6. HYDROLOGIC DIVIDE INDENTIFIED IN CSA UPDATE (SYNTERRA, 2017)AND
UPDATED GROUNDWATER FLOW AND TRANSPORT MODELING REPORT
(MURDOCH ET AL, 2019).
7. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE
U.S. ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS
MAP IS A PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE
PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED
FROM AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC.
NATURAL RESOURCES TECHNICAL REPORT (NRTR) FOR MAYO STEAM
ELECTRIC PLANT DATED JANUARY 2014 AND UPDATED ON JULY 11, 2018 TO
REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH BASIN
DISCHARGE CHANNEL.
8. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND
SHOULD NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES.
TOPOGRAPHY IS BASED ON LIDAR BARE EARTH DATA OBTAINED FROM THE
NORTH CAROLINA SPATIAL DATA SITE AT
hftps:flsdd.nc.gov/sdd/DataDownload.aspx.
9. ALL BOUNDARIES ARE APPROXIMATE.
10. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
11. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019.
AERIAL WAS COLLECTED ON FEBRUARY 6, 2017.
12. DRAWING HAS BEEN SET WITHA PROJECTION OF NORTH CAROLINA
STATE PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
1 /
I I
I
I
I
� � o
i
•
OEM
h
� it
■
n ABMW-4D
(mac' 3242
♦♦
000
APPROXIMATE FUTURE o•
ASH BASIN WASTE BOUNDARY,
(SEE NOTE 4) /7
�522
♦ � s�
0
O
v
1 ®--558
552
556
r0ll�
590
0
�j
MW-16D
<50
FA"4%
It
ENERGY
PROGRESS
O
ol
GRAPHIC SCALE
390 0 390 780
(IN FEET)
DRAWN BY: A. ROBINSON DATE: 05/09/2019
REVISED BY: A. ROBINSON DATE: 12/12/2019
CHECKED BY: E. KINSEY DATE: 12/12/2019
APPROVED BY: J. WYLIE DATE: 12/12/2019
PROJECT MANAGER: J. WYLIE
www.synterracorp.com
11 LEGEND
MONITORING WELL - GREATER THAN 15A NCAC 2L .0202
ie STANDARD (700 pg/L) OR THE IMAC (EFFECTIVE DATE FOR
15A NCAC 02L .0202 STANDARD AND IMAC IS APRIL 1, 2013)
MONITORING WELL - LESS THAN BACKGROUND THRESHOLD
VALUE
BACKGROUND MONITORING WELL
BORON PLUME GREATER THAN THE USEPA DRINKING
WATER EQUIVALENT LEVEL (4000Ng/L) FROM FLOW AND
TRANSPORT MODEL PREDICTED PLUME.
BORON PLUME GREATER THAN INC 02L STANDARD (700 Ng/L)
FROM MEAN ANALYSIS. FLOW AND TRANSPORT MODEL
PREDICTED PLUME IS USED WHERE EMPIRICAL DATA IS NOT
AVAILABLE.
BORON PLUME GREATER THAN BTV (50 pg/L) FROM MEAN
ANALYSIS. FLOW AND TRANSPORT PREDICTED PLUME IS
USED WHERE EMPIRICAL DATA IS NOTAVAILABLE.
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
- - - - - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
0
• DUKE ENERGY PROGRESS PROPERTY LINE
TOPOGRAPHIC CONTOUR (10' INTERVAL)
GROUNDWATER FLOW DIRECTION
310 STREAM (AMEC NRTR)
® WETLAND (AMEC NRTR)
APPROXIMATE HYDROLOGIC DIVIDE
FIGURE 6-11b
MAP OF BORON DISTRIBUTION
TRANSITION ZONE
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

60' RIGHT-OF-WAYSIT
�---- I - plerK //
w,
APPROXIMATE HYDROL . ®i
\ ® APPROXIMATE 1981 I
LANDFILL
AREA
100'RAILROAD� • i (CLOSED)
�RI_GH/T-OF-WAY
<50
474 � LEGEND
' 1�11• ABMW-46R \ • • 0 MONITORING WELL- GREATER THAN 15A NCAC 2L.0202
` o� <50 a MW-196R lie STANDARD (700 Ng/L) OR THE IMAC (EFFECTIVE DATE FOR
r
BG-1 <50 15A NCAC 02L .0202 STANDARD AND IMAC IS APRIL 1, 2013)
ImI
<50 `� �t CAMA MONITORING WELL -GREATER THAN CONSTITUENT
� � � �h I {"�-�g !d % Q � ' " " " • • " • • • • BACKGROUND THRESHOLD VALUE (50 Ng/L)
3 ♦ ♦ �• ` MONITORING WELL -LESS THAN BACKGROUND THRESHOLD
' _� • '000VALUE
NOTES:
/
/ ''a•I
1. DATA INCLUDED IN THIS FIGURE ARE THE ARITHIMETIC MEAN BASED ON
VALID GROUNDWATER SAMPLE DATA COLLECTED FROM JANUARY 2018
THROUGH APRIL 2019.
2. THE 02L FOR BORON IS 700 pg/L.
3. THE BACKGROUND VALUE FOR BORON IS 50 pg/L (AS SUBMITTED JUNE
2019).
4. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS
NOT PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE
ASH BASIN WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO
NPDES PERMIT NCO038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED
v
JULY 13, 2018.
I I
5. GROUNDWATER FLOW AND TRANSPORT BORON PLUME IS MODIFIED FROM
MODEL LAYER 10 (MURDOCH ET AL, 2019).
6. HYDROLOGIC DIVIDE INDENTIFIED IN CSA UPDATE (SYNTERRA, 2017)AND
UPDATED GROUNDWATER FLOW AND TRANSPORT MODELING REPORT
(MURDOCH ET AL, 2019)
7. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE
U.S. ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS
5
MAP IS A PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE
PRELIMINARY WETLANDS AND STREAMS BOUNDARIES WERE OBTAINED
FROM AMEC FOSTER WHEELER ENVIRONMENTAL & INFRASTRUCTURE, INC.
NATURAL RESOURCES TECHNICAL REPORT (NRTR) FOR MAYO STEAM
ELECTRIC PLANT DATED JANUARY 2014 AND UPDATED ON JULY 11, 2018 TO
REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND NEAR THE ASH BASIN
DISCHARGE CHANNEL.
I
8. THE TOPOGRAPHY IS SHOWN FOR REFERENCE PURPOSES ONLY AND
SHOULD NOT BE USED FOR DESIGN OR ENGINEERING PURPOSES.
TOPOGRAPHY IS BASED ON LIDAR BARE EARTH DATA OBTAINED FROM THE
NORTH CAROLINA SPATIAL DATA SITE AT
hftps:flsdd.nc.gov/sdd/DataDownload.aspx.
9. ALL BOUNDARIES ARE APPROXIMATE.
10. PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS.
11. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019.
AERIAL WAS COLLECTED ON FEBRUARY 6, 2017.
12. DRAWING HAS BEEN SET WITHA PROJECTION OF NORTH CAROLINA
STATE PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
606
• `� soa BACKGROUND MONITORING WELL
APPROXIMATE FUTURE v
sus ASH BASIN WASTE BOUNDARY, MW-106R es 4ae BORON PLUME GREATER THAN THE USEPA DRINKING
sa (SEE NOTE4) 0 0 <56 WATER EQUIVALENT LEVEL (4000Ng/L) FROM FLOW AND
�a aao TRANSPORT MODEL PREDICTED PLUME.
• "' �' �a °yam BORON PLUME GREATER THAN NC 02L STANDARD (700 Ng/L)
• q9• FROM MEAN ANALYSIS. FLOW AND TRANSPORT MODEL
���✓✓✓ • 522 PREDICTED PLUME IS USED WHERE EMPIRICAL DATA IS NOT
•
AVAILABLE.
♦� s�o O o BORON PLUME GREATER THAN BTV (50 Ng/L) FROM MEAN
O ANALYSIS. FLOW AND TRANSPORT PREDICTED PLUME IS
♦ j • ' USED WHERE EMPIRICAL DATA IS NOT AVAILABLE.
♦� • i • . ASH BASIN WASTE BOUNDARY
I
ASH BASIN COMPLIANCE BOUNDARY
— - — - - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
a DUKE ENERGY PROGRESS PROPERTY LINE
�° a• "� TOPOGRAPHIC CONTOUR (10' INTERVAL)
--556=146 GROUNDWATER FLOW DIRECTION
Ssa 0 STREAM (AMEC NRTR)
556 ® WETLAND (AMEC NRTR)
APPROXIMATE HYDROLOGIC DIVIDE
570 yb S a ...6
$a''�`� GRAPHIC SCALE
%� DUKE 390 0 390 780 FIGURE 6-11c
ENERGY (IN MAP OF BORON DISTRIBUTION
PROGRESS DRAWN BY: A. ROBINSON DATE: 05/09/2019 BEDROCK ZONE
REVISED BY: A. ROBINSON DATE: 12/17/2019 CORRECTIVE ACTION PLAN UPDATE
CHECKED BY: E.KINSEY DATE:12/17/2019 MAYO STEAM ELECTRIC PLANT
• APPROVED BY: J.WYLIE DATE:12/17/2019 ROXBORO NORTH CAROLINA
s)mTerra PROJECT MANAGER: A. ALBERT
www.synterracorp.com

.�.,.-.�.���r��-.-����.��-.--.-�tt— % ,, • «-�tt - y CCR-104S
•/ C W-4
CCR-103S _ CCR-104BR CW-3
r • ��MA.��IAKE CCR-103D MW-1046RL
•/ —CCR-103BR MW-104BRM -1
• •� � _ _ _ _ cc R-109B
—MW-2 CCR
L •� ��
� ♦ MW-.
r
Herr ,
CCR-105S
r CCR-105D
7 CCR-102BR-BG ��♦ CCR-105BR
MW-105BRM
� � - „ - - • • MW-136R ' �
Rq)`RO,q `� 1
•
r06BR
� _
a
CCR-107BR
X
CCR-108BR
PPROXIMAT
C&D
LANDFILL
AREA o
(CLOSED)
'RE ON
BASIN APPROXIMATE FUTURE y
='AREA ASH BASIN WASTE BOUNDARY
/ / ji , •j (SEE NOTE 2) Q
CCR-101 S-BG � �� • ' ^ '� � �- �
CCR-101D-BG
• I I I - i
,
NOTES:
1. THE WATERS OF THE U.S. DELINEATION HAS NOT BEEN APPROVED BY THE U.S.
ARMY CORPS OF ENGINEERS AT THE TIME OF THE MAP CREATION. THIS MAP IS A
PRELIMINARY JURISDICTIONAL DETERMINATION ONLY. THE PRELIMINARY WETLANDS
AND STREAMS BOUNDARIES WERE OBTAINED FROM AMEC FOSTER WHEELER
ENVIRONMENTAL & INFRASTRUCTURE, INC. NATURAL RESOURCES TECHNICAL
REPORT (NRTR) FOR MAYO STEAM ELECTRIC PLANT DATED JANUARY 2014 AND
UPDATED ON JULY 11, 2018 TO REMOVE ONE PREVIOUSLY MISIDENTIFIED WETLAND
NEAR THE ASH BASIN DISCHARGE CHANNEL.
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
PRESENT IN THISAREAOF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH BASIN
WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES PERMIT
N00038377 PART I, 5.A.(18.) ATTACHMENT B FIGURE 1.1 DATED JULY 13, 2018.
3. SAMPLE LOCATIONS WERE DERIVED FROM VARIOUS SOURCES AND ARE A MIX OF
SURVEYED AND APPROXIMATE LOCATIONS. THEREFORE, SAMPLE LOCATIONS ARE
APPROXIMATE.
4. ALL BOUNDARIES ARE APPROXIMATE.
5. MAYO PLANT PROPERTY BOUNDARY PROVIDED BY DUKE ENERGY PROGRESS
6. AERIAL PHOTOGRAPHY OBTAINED FROM ESRI ONLINE ON JUNE 10, 2019. AERIAL
WAS COLLECTED ON FEBRUARY 6, 2017.
7. DRAWING HAS BEEN SET WITH PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83).
MW-12D �'
I
I
3
= MULLINS LN
h
o �
O
Outfall 002
V, 4
It
ENERGY
PROGRESS
Outfall 001
NORTH CAROLINA-VIRGINIA STATE LINE
IF HALIFAX COUNTY . (APPROXIMATE)
PERSON COUNTY
I
.I
l
GRAPHIC SCALE
500 0 500 1,000
(IN FEET)
DRAWN BY: A. ROBINSON DATE: 06/06/201;
REVISED BY: A. ROBINSON DATE: 12/10/2019
CHECKED BY: P. ALTMAN DATE: 12/10/2019
APPROVED BY: J. WYLIE DATE: 12/10/2019
PROJECT MANAGER: J. WYLIE
i
LEGEND
WELL IN ALLUVIUM OR SAPROLITE
WELL IN TRANSITION ZONE
WELL IN BEDROCK
ccR-loss WELLS INDICATED WITH RED FONT WILL HAVE GEOCHEMICAL
SONDES
NPDES OUTFALL LOCATION
ASH BASIN WASTE BOUNDARY
• ASH BASIN COMPLIANCE BOUNDARY
— - — - RIGHT-OF-WAY (DUKE ENERGY PROPERTY)
DUKE ENERGY PROGRESS PROPERTY LINE
310 STREAM (AMEC NRTR)
WETLAND (AMEC NRTR)
FIGURE 6-12
CONFIRMATION MONITORING PLAN NETWORK
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

Interim
Monitoring Plan Corrective Action
(IMP) sampling H
Plan Approval
Confirmation Monitoring Plan (CMP)
monitor downgradient and
background groundwater in
accordance with G.S. 130A-
309.214(a)(4)k for compliance with
NCAC 02L .0202 Groundwater Quality
applicable Standards
Based on
annual evaluation,
is the boron plume
stable at the
compliance
boundary?/
1►[7
Evaluate contingency to determine
if additional data needed to
validate conditions and/or to
update CAP; continue with CMP
Notes:
1 - For well locations to be monitored see Figure 6-12 and Table 6-11
2 - For parameters to be monitored and frequency see Table 6-11
NCAC - North Carolina Administrative Code
02L - NCAC Title 15A, Subchapter 02L. Groundwater Classification and
Standards
Yes
Continue CMP sampling Continue PCMP sampling
and Annual Review and and Annual Review and
Reporting I I Reporting
""I\
Is the ash basin
certified closed?
No
Are the groundwater
monitoring results
below applicable
standards at the
compliance boundary
for three years?
Post -Closure Monitoring Plan (PCMP)
Post -closure monitoring to begin
Yes following closure certification.
Monitoring parameters and locations
to be determined at that time and in
accordance with G.S. 130A-
309.214(a)(4)k.2.
Yes
Based on \
annual evaluation,
is the plume stable
at the compliance
boundary?
No
Yes Request completion of CMP
corrective action plan monitoring
or
Request completion of PCMP post -closure monitoring
in accordance with G.S. 130A-309.214(a)(3)b
(' DUKE
ENERGY
DRAWN BY: T. PLATING
REVISED SHECK BY: J. WYLIE &
K
DATE: 10/112019
DATE: 12/16/2019
PROGRESS
CHECKED BY: P. ALTMAN
DATE: 12116/2019
APPROVED BY: J. WYLIE
DATE: 12/16/2019
PROJECT MANAGER: J. WYLIE
s)"Terra
www.synterracorp.com
FIGURE 6-13
CONFIRMATION MONITORING
PLAN WORK FLOW DIAGRAM
CORRECTIVE ACTION PLAN UPDATE
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA