NC0038377_Mayo CAP December 2015 Figures_20151201

Corrective Action Plan Part 1
Mayo Steam Electric Plant
LIST OF FIGURES
Executive Summary
Figure ES -1 Site Conceptual Model - Plan View
Figure ES -2 Current Conditions Cross -Section Conceptual Site Model
Section 1.0
Introduction
Figure 1-1
Site Location Map
Figure 1-2
Mayo Plant Vicinity Map
Figure 1-3
Site Layout Map
Figure 1-4
Generalized Geologic Map
Figure 1-5
Drinking Water Well and Receptor Survey
December 2015
SynTerra
Section 2.0 Extent of 2L and 213 Exceedances
Figure 2-1 Areas of Exceedances of Comparative Values In Soils
Figure 2-2 Areas of Exceedances of Comparative Values In Surficial Groundwater
Figure 2-3 Areas of Exceedances of Comparative Values In Transition Zone
Groundwater
Figure 2-4 Areas of Exceedances of Comparative Values In Bedrock Groundwater
Figure 2-5 Areas of Exceedances of Comparative Values In Seeps and Surface
Water
Section 3.0 Site Conceptual Model
Figure 3-1 Generalized Potentiometric Surface Map - June 1, 2015
Figure 3-2 Potential Vertical Gradient Between Shallow and Deep Zones
Figure 3-3
Figure 3-4
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10
Figure 3-11
Figure 3-12
Figure 3-13
Figure 3-14
Figure 3-15
Isoconcentration Maps - Eh in Ash Pore Water
Isoconcentration Maps - pH in Ash Pore Water
Isoconcentration Maps -
DO in Ash Pore Water
Isoconcentration Maps - Specific Conductance in Ash Pore Water
Isoconcentration Maps
- Eh in Surficial Groundwater
Isoconcentration Maps
- pH in Surficial Groundwater
Isoconcentration Maps -
DO in Surficial Groundwater
Isoconcentration Maps -
Specific Conductance in Surficial
Groundwater
Isoconcentration Maps -
Eh in Transition Zone Groundwater
Isoconcentration Maps
- pH in Transition Zone Groundwater
Isoconcentration Maps
- DO in Transition Zone Groundwater
Isoconcentration Maps
- Specific Conductance in Transition Zone
Groundwater
Isoconcentration Maps
- Eh in Bedrock Groundwater
P:\Duke Energy Progress.1026\105. Mayo Ash Basin GW Assessment Plan\16.Corrective Action Plan\Text\Mayo CAP December
2015.docx

Corrective Action Plan Part 1
Mayo Steam Electric Plant
LIST OF FIGURES
Figure 3-16 Isoconcentration Maps - pH in Bedrock Groundwater
Figure 3-17 Isoconcentration Maps - DO in Bedrock Groundwater
Figure 3-18 Isoconcentration Maps - Specific Conductance in Bedrock
Groundwater
Figure 3-19 Time vs. Boron Concentration Graphs
Section 4.0 Modeling
Figure 4-1 Computed vs Observed Values
Figure 4-2 Draft/Preliminary Concept for Mayo Ash Basin Cap
December 2015
SynTerra
P:\Duke Energy Progress.1026\105. Mayo Ash Basin GW Assessment Plan\16.Corrective Action Plan\Text\Mayo CAP December
2015.docx

R
NORTHWEST
ASH
GROUNDWATER ABOVE 2L & IMAC
LEGEND
Q ASH
® ASH PORE WATER
GROUNDWATER ABOVE NC 2L STANDARD
0 FOR BORON
GROUNDWATER BELOW NC 2L STANDARD
FOR BORON
INFERRED OR MEASURED
APPROXIMATE WATER TABLE
INFERRED OR MEASURED APPROXIMATE ASH
PORE WATER TABLE
LITHOLOGIC CONTACT
ACTIVE ASH BASIN
(SOURCE)
ASH PORE WATER
161,
synTerra
ASH BASIN DAM
CRUTCHFIELD BRANCH
REGOLITIi
NOT TO SCALE
148 RIVER STREET, SUITE 220
GREENVILLE, SOUTH CAROLINA 29601
PHONE [phone]
www.synterracorp.com
DRAWN BY: JOHN CHASTAIN DATE: 11/09/2015
PROJECT MANAGER: JERRY WYLIE
LAYOUT: FIG ES -2 (CURRENT CONDITIONS)
11/12/2015 7:24 PM PADuke Enem Proeress.1026\105. I
SOUTHEAST
LVERT
ROAD
ELD BRANCH I
ITION
FIGURE ES -2
CURRENT CONDITIONS
CROSS-SECTION CONCEPTUAL SITE MODEL
DUKE ENERGY PROGRESS LLC
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

PROPERTY BOUNDARY
\�
--
<2
BOUNDARY
,a
�.-� �.�_ `tsor�j',l - , .jam '1�1 �-�,�� �,, .r• � ) ..
500 COMPLIANCE v
�i7,:'i 1`'`':1 1(/J ` I' 1 . r } f .BOUNDARY,
0
r\
�.s��
Ohta${7,1
a
k �
C'' n
SOURCE: 1
USGS TOPOGRAPHIC MAP OBTAINED FROM THE NRCS GEOSPATIAL DATA
GATEWAYAT http://datagateway.nres.usda.gov/ ;��•.•
J WWW;
PERSON COUNTY FIGURE 1-1
SITE LOCATION MAP
GREENSBORO• MAYO STEAM ELECTRIC PLANT
*RALEIGH
GREENVILLE • 10660 BOSTON RD
ARLG •FYETTEVILLE ROXBORO, NORTH CAROLINA,ITerra
CLUSTER SPRINGS, VA QUADRANGLE
148 RIVER STREET, SUITE 220 WILMINGTON
GREENVILLE, SOUTH CAROLINA DRAWN BY: J. CHASTAIN DATE: 2 0 1412-2 2 GRAPHIC SCALE
PHONE [phone] PROJECT MANAGER: K. WEBB CONTOUR INTERVAL: 10ft 1000 0 1000
www.synterracorp.com LAYOUT: FIG 1-1 (SITE LOCATION MAP) MAP DATE: 1987
1 29/201511:09 AM P. Duke Ener Plo ea5.1026 105. Mao — basin GW Assessment 1`11116.Co—w A-1 Plan Fi ,,, DE MAYO CAR FIG 1-1 USGS LOCATION 'AP).dlg IN FEET
20001

A
A
A
%
- —
VIRGINIA`
r
r
VIRGINIA
----------------------------- ------ ------ -
---� � .— .. — .-.—�.-.--ter.-��« -rt-� .. •_ _ ___— ______onwna.n—�_—______
zip - r -err.
NORTH CAROLINA __
NORTH' C A R 0 L I
4411
I
l000l A.
je
�1
♦�' ��� . �� MAYO ASH _ r ,, r • i
BASIN
r �
•.
•r0. _
MAYO
LAKE
MAYO
PLANT
�r-----------• '
---------- fy i
•A�•.,17
�., LOUISIANA '•�•l '� �� �/1,•
PACIFIC I
4 CORP. , • �'
r .'00".
./♦
.. co .t �• ,
_ 1. �•.�
_0
LEGEND
Y — STREAM
STATE BOUNDARY
ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
-�� DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
NOTES:
2014 NAIP AERIAL ORTHOIMAGERY OBTAINED FROM THE ARCGIS IMAGE
SERVICE, SERVICE NAME: NAIP/North_Carolina_2O14_1m. (httpsl/gis,apfo.usda.gov)
2 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS. (http:l/services.noonemap.govl)
9 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83/2O11).
synTerra
148 RIVER STREET, SUITE
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
DRAWN BY: B. YOUNG
'DUKE
ENERGY DATE: 11/10/2015
PROGRESS CHECKED BY: K.DONOVAN
MAYO STEAM ELECTRIC POWER PLANT DATE: 11/10/2015
10660 BOSTON RD
ROXBORO, NORTH CAROLINA27574
PROJECT MANAGER: J. WYLIE
NA
A
0
cn
70
w
GRAPHIC SCALE
750 0 750 1,500 2,250 3.000
IN FEET
FIGURE 1-2
MAYO PLANT VICINITY MAP

Rr
hFSTF
PG
LOUISIANA PACIFIC CORPORATION
10475 BOSTON RD
i
C W 4
4j CW -3
MW-14BR
MW -O2
EDR 1 CW 5 PZ -1
r
® s-oa
ti`'rµ-� 7, Pz-1n =;os _ ^
PZ 2A
ABMW-01
ABMW-02
ABMW-02BR F
9 F
0
FG� DS /
qp Q ABMW-04
ABMW-04D /
ABMW-04BR
SB -2
_ 4 POWER PLANT w�
COAL PILE
E DFP 2
JLDCP3 - °- - -
SW-REF10 s -o7
i
MW-085."*smmgr
MW -08D
t
1 m
SB -5
�/ MW-09BR
MAYO LAKE
GRAPHIC SCALE
400 0 400 800
L IN FEET
148 RIVER STREET, SUITE 220
GREENVILLE, SOUTH CAROLINA 29601
PHONE [phone]
www.synterracorp.com
Terra
DRAWN BY: JOHNR: JERRY
DATE 11/09/2015
PROJECT IG 1-3( ITE LAYOUT) WYLIE- ----.
LAYOUT: FIG 1-3 (SITE LAYOUT)
;)m - ,
JEL
LEGEND
MW -17S SOIL BORING AND MONITORING WELL
MW-17BR LOCATION (SURVEYED)
C) ABMW-1 ASH BORING, PORE WATER, AND
ABMW-1S GROUNDWATER MONITORING WELL LOCATION
I$ SB -2 SOIL BORING LOCATION
SW-CB1 SURFACE WATER AND SEDIMENT LOCATION
FB G-11 BACKGROUND MONITORING WELL (SURVEYED)
MW -5 COMPLIANCE MONITORING WELL (SURVEYED)
IS MW -3 1 MONITORING WELL (SURVEYED)
e PZ -3 PIEZOMETER (SURVEYED)
DEP 1 DUKE ENERGY PROGRESS PRODUCTION
WELL - NOT IN SERVICE (SURVEYED)
EDR 1 EDR REPORTED SUPPLY WELL (APPROXIMATE)
O S-01 SEEP LOCATION
OUTFALL 001 NPDES OUTFALL
OUTFALL
DUKE ENERGY PROGRESS - MAYO PLANT
500 ft COMPLIANCE BOUNDARY
WASTE BOUNDARY
PARCEL LINES
FLOW DIRECTION
SOURCES:
1. 2010 AERIAL PHOTOGRAPH OF PERSON COUNTY, NORTH CAROLINA
WAS OBTAINED FROM NRCS GEOSPATIAL DATA GATEWAY AT
http://datagateway.nres.usda.gov/
2. 2012 AERIAL PHOTOGRAPH OF HALIFAX COUNTY, VIRGINIA WAS
OBTAINED FROM NRCS GEOSPATIAL
DATA GATEWAY AT http://datagateway.nres.usda.gov/
3. 2014 AERIAL PHOTOGRAPH WAS OBTAINED FROM WSP FLOWN ON
APRIL 17, 2014.
4. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA
STATE PLANE COORDINATE SYSTEM FIPS 3200 (NAD 83).
5. 2015 GROUNDWATER ASSESSMENT WELL AND BORING LOCATIONS
WERE BASED ON SURVEY DATA DATED JULY 17, 2015 PROVIDED BY
McKIM & CREED OF WILMINGTON, NORTH CAROLINA.
6. PROPERTY LINE, LANDFILL LIMITS AND BOUNDARIES
ARE FROM ARCGIS FILES PROVIDED BY S&ME AND PROGRESS
ENERGY.
7. PARCEL BOUNDARIES WERE OBTAINED FROM PERSON COUNTY (NC)
GIS DATA AT http://gis.personcounty.net
THE TOPOGRAPHY SURVEY DATA WITHIN THE PROPERTY..
FIGURE 1-3
SITE LAYOUT MAP
DUKE ENERGY PROGRESS LLC
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

. ........
CZfg
MW-13BR I I ,
— BG -01 .40'
'mI-Jqmdk-
MW -12S
I/ MW -12D
0
N
ACTIVE
ASH BASIN
CW -02
CW -02D
12
Zh
VIRGINIA
---------
NORTH CAROLINAoe'
CZfV
SR -j501 = '
MW -08S
MW -08D
-08 MW AW MW-08BR, -
1
i
MW -07D
MW-07BR
MW-09BR
J�
'r
h e s `4•
MAYL
LAKE
. 7qu".
CZfV
Cf I
LEGEND
NORTH CAROLINA GEOLOGIC UNITS'
CZfg - FELSIC MICA GNEISS (CHARLOTTE TERRANE)
CZfv - FELSIC I MARC METAVOLCANIC ROCK (CAROLINA TERRANE)
VIRGINIA GEOLOGIC UNITS2
Zh - PROTEROZOIC METAVOLCANIC SCHIST
di - PROTEROZOIC QUARTZ DIORITE
MONITORING WELL
D TOE DRAIN
ACTIVE ASH BASIN BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE
LSTATE BOUNDARY
I STREAM
NOTES:
' NORTH CAROLINA GEOLOGIC BOUNDARIES MODIFIED TO CORRESPOND WITH
SYNTERRA FIELD OBSERVATIONS. MAP BASED ON GEOLOGIC SHAPEFILES OBTAINED
FROM THE USGS. USGS OPEN -FILE REPORT 2005-1323, PRELIMINARY INTEGRATED
GEOLOGIC MAP DATABASE FOR THE UNITED STATES: ALABAMA, FLORIDA, GEORGIA,
MISSISSIPPI, NORTH CAROLINAAND SOUTH CAROLINA, DATED 2007.
(https://pubs.usgs.gov/of/2005/1323/)
2 VIRGINIA GEOLOGIC BOUNDARIES WERE NOT MODIFIED, AND ARE SHOWN FOR
REFERENCE. GEOLOGIC FEATURE CLASSES OBTAINED FROM THE USGS. OPEN -FILE
REPORT 2005-1325. PRELIMINARY INTEGRATED GEOLOGIC MAP DATABASE FOR THE
UNITED STATES: DELAWARE, MARYLAND, NEW YORK, PENNSYLVANIA, AND VIRGINIA.
(http://pubs.usgs.gov/of/2005/1325/)
] SHADED RELIEF MAP BASED ON LIDAR DEM 20 DATA FROM NORTH CAROLINA FLOOD
RISK INFORMATION SYSTEM. ACCESSED ON JANUARY 2, 2015.
4 PARCEL BOUNDARY WAS OBTAINED FROM THE INC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS. (http:llservices.nconemap.gov/)
5 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD8312011).
GRAPHIC SCALE
500 0 500 1 000 1 500 2000 2 500
IN FEET
DUKE
'' ENER Y
synTerra
PROGRESS
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC POWER PLANT
GREENVILLE, SC 29601 10660 BOSTON RD
864-421-9999 ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com
FIGURE 1.4
GENERALIZED GEOLOGIC MAP
MAYO STEAM ELECTRIC
PLANT

LEGEND
9 PRW-9 POSSIBLE WATER SUPPLY WELL
9 DW -11 OBSERVED WATER SUPPLY WELL
9 DW -14 WATER SUPPLY WELL OR SPRING REPORTED.
BY PROPERTY OWNER
HALF MILE SURVEY BOUNDARY
FB G-21 BACKGROUND MONITORING WELL (SURVEYED)
FCW--41 COMPLIANCE MONITORING WELL (SURVEYED)
■ DEP 1 DUKE ENERGY PROGRESS PRODUCTION
WELL - NOT IN SERVICE (APPROXIMATE)
EDRII EDR REPORTED WELL (APPROXIMATE)
DUKE ENERGY PROGRESS MAYO PLANT
500 ft COMPLIANCE BOUNDARY
WASTE BOUNDARY
PARCEL LINE (PERSON CO NC GIS, HALIFAX CO VA
APPROXIMATE)
FLOW DIRECTION
—w—w— CITY OF ROXBORO WATERLINE (APPROXIMATE)
FH FIRE HYDRANT LOCATION (APPROXIMATE)
POTENTIAL AREA OF INTEREST
(APPROXIMATE)
GENERALIZED GROUNDWATER FLOW
DIRECTION
SUPPORTED BY GROUNDWATER ELEVATION DATA
OR TOPOGRAPHIC DATA
SOURCES:
1. 2010 AERIAL PHOTOGRAPH OF PERSON COUNTY, NORTH
CAROLINA OBTAINED FROM THE NRCS GEOSPATIAL DATA
GATEWAY AT http://datagateway.nres.usda.gov/
2. 2012 AERIAL PHOTOGRAPH OF HALIFAX COUNTY, VIRGINIA WAS
-
OBTAINED FROM NRCS GEOSPATIAL DATA GATEWAY AT
http://datagateway.nres. usda. gov/
3. 2014 AERIAL PHOTOGRAPH WAS OBTAINED FROM WSP FLOWN ON
APRIL 17, 2014.
4. WELL SURVEY INFORMATION, PROPERTY LINE, LANDFILL LIMITS
AND BOUNDARIES ARE FROM ARCGIS FILES PROVIDED BY S&ME
AND PROGRESS ENERGY.
u 5. PARCEL BOUNDARIES WERE OBTAINED FROM PERSON COUNTY
(NC) GIS DATA AT http://gis.personcounty.net
n
6. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH
'n
` CAROLINA STATE PLANE COORDINATE SYSTEM FIPS 3200 (JARE
NOTE:
1. DISPLAYED WATER SUPPLY WELL OR SPRING LOCATIONS
r APPROXIMATE.
i
z
i1
I _
DW -16
be
(PRW-2)
/ q /
/ 1 -� l / PRW-4
/ PRW-o'; "
\� HALIFAX COUNTY
NORTH CAROLINA-VIRGI
(APPROXIMATE
— ,- - - IPERSON COUNTY
DW -3 �� CW -4_ CRUTCHFIELDBRANCH -
DW -4 – MAYO LAKE Rp F -
_�-
... D W-5 EDR 1
OCW-5 �
HFSTeRRO � - CW -2 D
FW
I 1
I ,
I
I;.
1 I
` 1 1
t j
I RA//RO
'A
1 1
1
� r
LUUIJIANA PACIFIC CORPORATION
I 10475 BOSTON RD -i
(TIED INTO TF.F C TY - R—QRO WATERLINE)
J D
CITY OF ROXBORO WATERLINE
s INSTALLED IN 2006 i
DW17
(PRW-8)
(i
POWER PLANT
,e
op
DEP 3 /
i
'r
1
1
I
1
AA
FIGURE 1-5
DRINKING WATER WELL AND RECEPTOR SURVEY
UPDATED AUGUST 11, 2015
DUKE ENERGY PROGRESS LLC
MAYO STEAM ELECTRIC PLANT
- - ROXBORO, NORTH CAROLINA
GRAPHIC SCALE
600 0 600 1200
IN FEET
148 RIVER STREET, SUITE 220
GREENVILLE, SOUTH CAROLINA 29601
PHONE [phone]
www.synterracorp.com
Terra PROJE TPIG MANAGER: DW WELLY&
RECEPTOR)DATE 11/10/2015
syn
DATE PRINTED: 11/12/2015 7:42 PM

a
0
MW-13BR
• • MW -11 BR
BG -01
ABMW-01 AB -01
AB -02
ABMW-02BR 4
AB -03 6 ABMW-03S
ABMW-02 ABMW-03
ABMW-04
ABMW-04g*"
ABMW-04D
AB -04
SB -02
BG -02
SB -03
MW-12S-PM*12D
WM
S MW-08BR '
MW -08D
— - — - -
�.
MW -04
SB -OS
CW701 D CW -01
J
A
1
SB -04 6 IMW=10BR
LEGEND
CONCENTRATION GREATER THAN COMPARATIVE VALUE
® CONCENTRATION GREATER THAN COMPARATVIE VALUE
CONCENTRATION LESS THAN COMPARATIVE VALUE
Q CONCENTRATION LESS THAN COMPARATIVE VALUE
Q ACTIVE ASH BASIN
_ ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
NOTES:
I COMPARATIVE VALUE -THE GREATER OF EITHER PSRG (PROTECTION OF GROUNDWATER)
OR PROVISIONAL BACKGROUND CONCENTRATION.
z SOIL SAMPLES OBTAINED FROM CSA MONITORING WELLINSTALLATION FEBRUARY -JULY 2015.
3SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE
NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT (httpJ/services.nconemap.govn
5PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
ANALYSIS AT (http://services.noonemap.gov/)
5 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
'DUKEa
U
ENERG o
synTerra PROGRESS
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC POWER PLANT
GREENVILLE, SC 29601 10660 BOSTON RD o
864-421-9999 ROXBORO, NORTH CAROLINA27574 w
www.synterracorp.com m
FIGURE 2-1
AREAS OF EXCEEDANCES OF COMPARATIVE
VALUES IN SOILS
MAYO STEAM ELECTRIC PLANT

,
N LEGEND
f CONCENTRATION GREATER THAN COMPARATIVE VALUE
A Y CONCENTRATION LESS THAN COMPARATIVE VALUE
APPROXIMATE DISTRIBUTION OF BORON AT CONCENTRATIONS
GREATER THAN APPLICABLE 2L OR IMAC AND PROVISIONAL
BACKGROUND CONCENTRATIONS, BASED ON 2015 DATA.
APPROXIMATE DISTRIBUTION OF CONSTITUENTS WITH
CONCENTRATIONS GREATER THAN APPLICABLE 2L OR IMAC AND
PROVISIONAL BACKGROUND VALUES, BASED ON 2015 DATA.
ACTIVE ASH BASIN
VIRGINIA ASH BASIN COMPLIANCE BOUNDARY
- DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
+ + > STREAM
NORTH CAROLINA + f
' r
MW-1 6S
rrr—
r-
MW-03
I .
♦ +�MS
r ACTIVE r t
I
ASH BASIN I 1981 ``` NOTES:
1` ;:' ✓ LANDFILL ' COMPARATIVE VALUE-THE GREATER OF EITHER 2L/IMAC OR PROVISIONAL E
t'♦` � o `: f ,� f . BACKGROUND CONCENTRATION. 3
2 CONCENTRATIONS SHOWN ARE FROM 2015 SAMPLING EVENT.
x
y A �F r + 'SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, + :••014 (OBTAINED FROM
2
ABMW-03S i t., WSP).
_ N
�� �♦� 1 i 4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012 (OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT >
(http:llservices.nconemap.gov/)).
PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC o
4 v INFORMATION AND ANALYSIS AT
o
.,
- ` ' " ' • `" httpalservices.nconemap.govl).
• • '`'•` � •�� ,� •` • a a DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
4
MAYO COORDINATE SYSTEM RIPS 3200 (NAD8312011). w
LAKE o
i GRAPHIC SCALE
■
500 0 500 1,000 1,500 2,000
+ (IN FEET) -
o
a
,
�•DUKE
dw
All ENERGY°
•
PROGRESS S 5
snerra
y
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT
GREENVILLE, SC 29601 10660 BOSTON RD a
• ♦ ♦ �� 864-421-9999 ROXBORO, NORTH CAROLINA 27574 w
♦ a <
wwwsynterracory.com
- • /DRAWN BY: A. ROBINSON DATE: 11112/2015 m
1fr
too , CHECKED BY: J. WYLIE IDATE 11/12/2015
a '�'�' '-' . ►' PROJECT MANAGER: J. WYLIE
AI
z, FIGURE 2-2
..� ,. _ W }-•a�
AREAS OF EXCEEDANCES OF COMPARATIVE
- - -�v, - � -• ;s, 71, 7, .. , - -r � -- VALUES IN SURFICIAL GROUNDWATER Q
rGAI
„y MAYO STEAM ELECTRIC PLANT
0
.: a

VIRGINIA
NORTH CAROLINA
14 111114
LEGEND
CONCENTRATIONS GREATER THAN COMPARATIVE VALUE
CONCENTRATIONS LESS THAN COMPARATIVE VALUE
7 APPROXIMATE DISTRIBUTION OF BORON AT CONCENTRATIONS
GREATER THAN APPLICABLE 2L OR IMAC AND PROVISIONAL
BACKGROUND CONCENTRATIONS, BASED ON 2015 DATA.
APPROXIMATE DISTRIBUTION OF CONSTITUENTS WITH
_ CONCENTRATIONS GREATER THAN APPLICABLE 2L OR IMAC AND
a PROVISIONAL BACKGROUND VALUES, BASED ON 2015 DATA.
a... m
=ACTIVE ASH
V:%_ ASH BASIN COMPLIANCE BOUNDARY
„
r--'@ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
—
----------------------------------------------------- -----------
10 STREAM
CW -04
MW -16D
CW -03
' CW 02 "SR=1501 --
ABMW-04D
BG -02
MW -12D
MW -07D
.r�
1981*^
LANDFILL '.:
+
a
NOTES:
1 COMPARATIVE VALUE -THE GREATER OF EITHER 2L/IMAC OR PROVISIONAL
BACKGROUND CONCENTRATION.
2 CONCENTRATIONS SHOWN ARE FROM 2015 SAMPLING EVENT.
3SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014 (OBTAINED FROM
WSP).
CW -01 ;; 4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012 (OBTAINED
{ FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)).
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT
- Z http://services.noonemap.gov/).
�' MAYO 6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
♦ LAKE COORDINATE SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
s ' a 500 0 500 1,000 1,500 2,000
^ (IN FEET)
DUKE
s'
..� ENERGY
a synTerm PROGRESS
r
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT
GREENVILLE, SC 29601 10660 BOSTON RD
a a 864-421-9999 ROXBORO, NORTH CAROLINA 27574
t• +
r^ + www.synterracorp.com
a DRAWN BY: A. ROBINSON DATE: 11/25/2015
• ^ �`�.., - ` r+ CHECKED BY: J.DATE: 11/25/2015
♦ a -= PROJECT MANAGER:ER: J. WYLIE
,•, FIGURE 2-3
G AREAS OF EXCEEDANCES OF COMPARATIVE
VALUES IN TRANSITION ZONE GROUNDWATER
' ";- �, + MAYO STEAM ELECTRIC PLANT
+ V a

VIRGINIA
NORTH CAROLINA
SR 134
0
0
♦#
#
a
BG -01
,1, a
ACTIVE
ASH BAS
"domi
ABMW-02BR
1
ABMW-04BR
r
CW=01 D
MAYO
LAKE
MN110BR
r
•
t..:;
*
LEGEND
CONCENTRATIONS GREATER THAN COMPARATIVE VALUE.
CONCENTRATIONS LESS THAN COMPARATIVE VALUE.
AREA OF CONCENTRATION GREATER THAN 2L I IMAC AND
CONCENTRATION FROM BACKGROUND DATA SET
AREA WHERE BACKGROUND VALUES ARE EXCEEDED. ADDITIONAL
BACKGROUND DATA OR RISK ASSESSEMENT MAY BE NEEDED TO
DETERMINE IF EVALUATION OF CORRECTIVE ACTION IS APPROPRIATE.
ACTIVE ASH
ASH BASIN COMPLIANCE BOUNDARY
r ■ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�- STREAM
NOTES:
COMPARATIVE VALUE -THE GREATER OF EITHER 2LIIMAG OR PROVISIONAL a
BACKGROUND CONCENTRATION. i
2 CONCENTRATIONS SHOWN ARE FROM 2015 SAMPLING EVENTS.
s SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014 (OBTAINED FROM
WSP). a
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012 (OBTAINED R
FROM THE INC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)).
PARCEL BOUNDARY WAS OBTAINED FROM THE INC CENTER FOR GEOGRAPHIC E
INFORMATION AND ANALYSIS AT
http://services.nconemap.gov/). a
s DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE a
COORDINATE SYSTEM RIPS 3200 (NAD8312011). u
GRAPHIC SCALE a
500 0 500 1,000 1,500 2,000 a
(IN FEET)
LL
DUKE R
All a
ENERGY
synTerra PROGRESS
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT F
GREENVILLE, SC 29601 10660 BOSTON RD a
864-421-9999 ROXBORO, NORTH CAROLINA 27574 c
u
www.synterracorp.com a
FIGURE 2-4
AREAS OF EXCEEDANCES OF COMPARATIVE
VALUES IN BEDROCK GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
VIRGINIA- - - --- - - - -
SW CB2
1
+
NORTH CAROLINA `
1094
S -01A -03 I_,t SW -061-
S-026
-08
1 �A S-02
�rno—No m -how
1
t o s
r1 r•-�►
} S-06
Z+p
' - — - - — - - SW-REF1 \ �
LEGEND
❑ SURFACE WATER CONCENTRATION GREATER THAN COMPARATIVE
VALUE
0 SEEP CONCENTRATION GREATER THAN COMPARATIVE
■ SURFACE WATER CONCENTRATION LESS THAN COMPARATIVE
® WASTEWATER SAMPLE
ACTIVE ASH
ASH BASIN COMPLIANCE BOUNDARY
-�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
> STREAM
NOTES:
COMPARATIVE VALUE -THE GREATER OF EITHER 2B OR PROVISIONAL
BACKGROUND CONCENTRATION.
2 CONCENTRATIONS SHOWN ARE FROM 2015 SAMPLING EVENT.
9 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014 (OBTAINED FROM
WSP).
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012 (OBTAINED
FROM THE INC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)).
5 PARCEL BOUNDARY WAS OBTAINED FROM THE INC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT
http://services.nconemap.gov/).
8 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD8312011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000 2,500
(IN FEET)
FIGURE 2-5
AREAS OF EXCEEDANCES OF COMPARATIVE
VALUES IN SEEPS AND SURFACE WATER
MAYO STEAM ELECTRIC PLANT
DUKE
ENERGY_
s mTerra
PROGRESS
148 RIVER STREET, SUITE 220,
MAYO STEAM ELECTRIC PLANT F
GREENVILLE, SC 29601
10660 BOSTON RD
864-421-9999
ROXBORO, NORTH CAROLINA 27574 u
www.synterracorp.com
FIGURE 2-5
AREAS OF EXCEEDANCES OF COMPARATIVE
VALUES IN SEEPS AND SURFACE WATER
MAYO STEAM ELECTRIC PLANT

HALIFAX COUNTY
Jy
MAYO LAKE RD
MW -148R 0
504.61
L 1 f
':
.460 "',>0 �a�p
.�!' Q5 495.47 BRr ?• . S'
o --ILL
}« -'ABMW-01
477.93 0
BG -
j
3 `tF
• e
OP " t
0
0
MW -116R m "p -V�
488.05
4
V"
MW-15BR 0
_ k CW -04 402.68 1 1
n._4.•i /
MW -9 C
B
CW -02D CW -02
s-oi 5-oa 375.29 375.29
4033 4 3
z 377.32 ,yp
l0. p
Jo
3j
s-02A j0.?
7 ft
2IB3 �p
P3A P3 /
-A P4
\ 446t y�6pf�fr,Vr�
T 47(
ACTIVE ASH BASIN
WATER LEVEL 479.8
1 ry
ABMW-02
481.56 ABMW-03S
483.04
0
9BMW-026R iii
182.75 ABMW-03 CW -0
483.02 472
ABMW-04BRI
ABMW-04D 4ABMW-04
485.06
485.11
F*
;ofi? �'1'q`*�'t!,•{'.Z i',A, �. -- .R
\ - _ DEP 2 \••,d1 �L
1 LOUISIANA PACIFIC CORPORATION I
IPLANT ACCESS ROAD 5 6 90D ®556 60 _ <_�.�.►1
0
ELECTRIC PLANT
w t
NORTH CAROLINA-VIRGINIA STATE LINE
HALIFAX COUNTY ("PROXIMATE)
111 PERSONCOUNTY
1;
� MW -088R
r ON; 432.54 �MW-08S
♦ fa 437.02
t � MW -07D MW-07BR
MW -08D
? 444.46 445.94 433.53
1 LANDFILL
NIT NO 73 -B
l Q-
� 0MW-096R
01D
93
MAYO LAKE
WATER ELEVATION 436'
GRAPHIC SCALE
400 0 400 800
IN FEET
DEP t ■ 148 RIVER STREET, SUITE 220
GREENVILLE, SOUTH CAROLINA 29601
PHONE [phone]
www.synterracorp.com
Terra DRAWN BY JOHN CHASTAIN DATE 11/12/2015
S� PROJECT MANAGER :JERRY
LAYOUT: FIG 3-1 (GEN POTENTIOMTIOMETRIC MAP)
11/12/20159:11 PM P:\Duke Energy Pragress.1026\105.
LEGEND
ASSESSME40 015BR
ELEVATION IN FEET (msl )L
BG 02 BACKGROUND COMPLIANCE WELL
511.16 ELEVATION IN FEET (msl.)
FCW-0-6-1 DOWNGRADIENT COMPLIANCE WELL
450.81 ELEVATION IN FEET (msl.)
FM -W3--1 MONITORING WELL
377.32 ELEVATION IN FEET (msl.)
WATER LEVEL CONTOUR IN FEET (msl.)
- - INFERRED WATER LEVEL CONTOUR (msl.)
f GROUNDWATER FLOW DIRECTION
DUKE ENERGY PROGRESS
500 ft COMPLIANCE BOUNDARY
WASTE BOUNDARY
------- PARCEL LINE (APPROXIMATE)
SOURCES:
1. 2014 AERIAL PHOTOGRAPH OF PERSON COUNTY, NORTH
CAROLINA OBTAINED FROM THE NRCS GEOSPATIAL DATA
GATEWAYAT http://datagateway.nres.usda.gov/
2. 2014 AERIAL PHOTOGRAPH WAS OBTAINED FROM WSP
FLOWN ON APRIL 17, 2014.
3. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH
CAROLINA STATE PLANE COORDINATE SYSTEM RIPS 3200
(NAD 83).
WATER LEVELS:
1.) WATER LEVELS WERE COLLECTED BY SYNTERRA ON JUNE 17, 2015.
2.) NEW WELLS WERE SURVEYED BY McKIM& CREED. THE HORIZONTAL DATUM IS SET TO
NAD83 AND THE VERTICAL DATUM IS SET NGVD88.
3.) COMPLIANCE MONITORING WELL LOCATIONS AND WASTE BOUNDARYPROVIDED BU DUKE
ENERGY PROGRESS
4.) ADDITIONAL MONITORING WELL AND PIEZOMETER LOCATIONS WERE BASED ON DATA
PROVIDED BY PROGRESS ENERGY.
FIGURE 3-1
GENERALIZED POTENTIOMETRIC
SURFACE MAP
JUNE 2015
MAYO STEAM ELECTRIC PLANT
ROXBORO, NORTH CAROLINA

N .
0.(
/
L egend
/
1 POTENTIAL VERTICAL GRADIENT ( foot per foot)
MONITORING WELL
•
�
Q ACTIVE ASH BASIN
VIRGINIA
. o
ASH BASIN COMPLIANCE BOUNDARY
1
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
f
i
■
■
STREAM
NORTH CAROLINA
y
A
IJ
1
+
1
■, MW -16D to
Well ID
POTENTIAL VERTICAL GRADIENT
Direction
M1N=16BR
Transition to Bedrock
- -0.074: UPWARD (1.0 foot per foot)
+
r i
1 '
CW -3 to 0.006 '
MW-03BR_.
Downward
0
CW -2 to CW -2D 0.000
0007
�
CW -3 to MW-03BR 0.001
Downward
SQ,15p'^
"
0.074: DOWNWARD (1.0 foot per foot)
Upward
CW -2 to
MW-0&DtoMW-OGBR 0074
Down and
♦��
CW -2U
,
a
NEW
J �.
■
V
NOTES:
I WATER LEVELS WERE COLLECTED BY SYNTERRA ON JUNE 17, 2015
2SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE NC
CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT (http:11services.nconemap.gov1)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
ANALYSIS AT (http:11servioes.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM FIPS 3200 (NAD8312011).
GRAPHIC SCALE
400 0 400 800 1,200 1,600
(IN FEET)
114rip
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
'DUKE
ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD <
ROXBORO, NORTH CAROLINA27574
FIGURE 3-2
POTENTIAL VERTICAL GRADIENT
BETWEEN SHALLOW AND DEEP ZONES
MAYO STEAM ELECTRIC PLANT
0.(
/
/
•
�
. o
1
f
i
■
■
Well ID
Potential Vertical Gradient
Direction
Transition to Bedrock
CW -1 to CW -1D 0.020
Downward
CW -2 to CW -2D 0.000
CW -3 to MW-03BR 0.001
Downward
MW-07Dto MW-07BR -0.031
Upward
MW-0&DtoMW-OGBR 0074
Down and
♦��
M%V-16D to MO,-16BR 0.006
Downward
NEW
J �.
■
V
NOTES:
I WATER LEVELS WERE COLLECTED BY SYNTERRA ON JUNE 17, 2015
2SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE NC
CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT (http:11services.nconemap.gov1)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
ANALYSIS AT (http:11servioes.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM FIPS 3200 (NAD8312011).
GRAPHIC SCALE
400 0 400 800 1,200 1,600
(IN FEET)
114rip
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
'DUKE
ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD <
ROXBORO, NORTH CAROLINA27574
FIGURE 3-2
POTENTIAL VERTICAL GRADIENT
BETWEEN SHALLOW AND DEEP ZONES
MAYO STEAM ELECTRIC PLANT

•
A
ABMW-01
45.9
O�
h
ABMW-02
2 ABMW-03
' 92
ABMW-04
Legend
1 TOTAL Eh MEASUREMENT (mV)
Eh CONTOUR (Interval 50 mV)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
I STREAM
Eh MEASUREMENT
415 mV
212 mV
-7 mV
NOTES:
CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
♦ ,ry 2SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA. x
sSITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. iT WAS OBTAINED FROM WSP. ^'
•. 9
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE NC 2
CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT(http://services.nconemap.gov� m
H
s PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
ANALYSIS AT (htt)://services.nconemap.gov/) w
/e DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM FIPS 3200 (NAD83/2011).
L� „ ♦�' • GRAPHIC SCALE °
300 0 300 600 900 1,200 1,500 H
♦♦ m
♦ (IN FEET)
o
DUKE LL
m
o
:-..� ENERGY 0
synTerra PROGRESS
• 148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT
GREENVILLE, SC 29601 10660 BOSTON RD F
864-421-9999 ROXBORO, NORTH CAROLINA 27574 0
www.synterracorp.com w
d
-------------
FIGURE 3-3
ISOCONCENTRATION MAPS
Eh IN ASH PORE WATER
MAYO STEAM ELECTRIC PLANT

M
CL
w
D
h
J
ABM W-01
6.7
ACTIVE
ASH BASIN
ABMW-02/
I7.4 ABMW-03
I
ABMW-04
y
1981
LANDFILL
fix• ,��� ..
Legend
1 TOTAL pH CONCENTRATION
pH CONTOUR (Interval 1 pH UNIT)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
pH CONCENTRATION
� 14
— Neutral
0
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. iT WAS OBTAINED FROM
WSP.
4 ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http:Hservices. nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE INC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
300 0 300 600 900 1,200 1,500
(IN FEET)
PROJECT MANAGER: J, WYLIE
FIGURE 3-4
ISOCONCENTRATION MAPS
pH IN ASH PORE WATER
MAYO STEAM ELECTRIC PLANT
DUKE
o
ENERGY,
synTerra
PROGRESS
148 RIVER STREET, SUITE 220,
MAYO STEAM ELECTRIC PLANT a
GREENVILLE, SC 29601
10660 BOSTON RD o
864-421-9999
ROXBORO, NORTH CAROLINA 27574 w
www.synterracorp.com
m
DRAWN BY: B. YOUNG
ATE: 11/2312015 N
PROJECT MANAGER: J, WYLIE
FIGURE 3-4
ISOCONCENTRATION MAPS
pH IN ASH PORE WATER
MAYO STEAM ELECTRIC PLANT

A
ABMW-01
0.4
ACTIVE
ASH BASIN
ABMW-02
AB M W-04
0.S
ABMW-03
' 0.7
J
A
9
.-
------------
Legend
1 DISSOLVED OXYGEN (DO) CONCENTRATION (mg/L)
DO CONTOUR (Interval 1 mg/L)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�— STREAM
DO CONCENTRATION
– 3 mg/L
– 1.5 mg/L
– 0 mg/L
NOTES:
CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4 ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.neonemap.gov/)
8 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT (http://services.nconemap.gov/)
9 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
300 0 300 600 900 1,200 1,500
(IN FEET) @
DUKE
141P <co� c
n
ENERGY
synTerra PROGRESS
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT c
GREENVILLE, SC 29601 10660 BOSTON RD
864-421-9999 ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com LL
FIGURE 3-5
ISOCONCENTRATION MAPS
DISSOLVED OXYGEN IN ASH PORE WATER
MAYO STEAM ELECTRIC PLANT

A
/ ABMW-02
o ' ABMW-03
I '
630
ABMW-04
800 2
4 nr•:
m. v
J
,.
d
Legend
1 SPECIFIC CONDUCTANCE (SC) MEASUREMENT (pmhos/cm)
SC CONTOUR (200Nmhos/cm)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
311. STREAM
SPECIFIC CONDUCTANCE (SC) MEASUREMENT
— 2144 (Nmhos/cm)
— 1072 (Nmhos/cm)
0 (Nmhos/cm)
NOTES:
t CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.govn
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT (http://services.nconemap.gov/)
5 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
300 0 300 600 900 1,200 1,500
(IN FEET)
,410
AB
_
V ENERGYC,
2145 145
PROGRESS 11
148 RIVER STREET, SUITE 220,
MAYO STEAM ELECTRIC PLANT
GREENVILLE, SC 29601
10660 BOSTON RD <
864-421-9999
ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com
A
Amw
• �
h
•
W It
I
�
_
�i
r/
0110 mi
♦ ,,.
/ ABMW-02
o ' ABMW-03
I '
630
ABMW-04
800 2
4 nr•:
m. v
J
,.
d
Legend
1 SPECIFIC CONDUCTANCE (SC) MEASUREMENT (pmhos/cm)
SC CONTOUR (200Nmhos/cm)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
311. STREAM
SPECIFIC CONDUCTANCE (SC) MEASUREMENT
— 2144 (Nmhos/cm)
— 1072 (Nmhos/cm)
0 (Nmhos/cm)
NOTES:
t CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.govn
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT (http://services.nconemap.gov/)
5 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
300 0 300 600 900 1,200 1,500
(IN FEET)
,410
y
DUKE
V ENERGYC,
synTerra
PROGRESS 11
148 RIVER STREET, SUITE 220,
MAYO STEAM ELECTRIC PLANT
GREENVILLE, SC 29601
10660 BOSTON RD <
864-421-9999
ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com
FIGURE 3-6
ISOCONCENTRATION MAPS
SPECIFIC CONDUCTANCE IN ASH PORE WATER
MAYO STEAM ELECTRIC PLANT

VIRGINIA
NORTH CAROLINA'
1238.9
- ----------------- ---------------
LEGEND
1 TOTAL Eh MEASUREMENT (mV)
Eh CONTOUR (Interval 50 mV)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
Eh MEASUREMENT
415 mV
212 mV
-7 mV
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP,
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.govo
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
<t5ENERGY6u'
DUKE
1�lp
synTerra PROGRESS
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT a
GREENVILLE, SC 29601 10660 BOSTON RD a
864-421-9999 ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com a
FIGURE 3-7
ISOCONCENTRATION MAPS
Eh IN SURFICIAL GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
VIRGINIA
NORTH CAROLINA
J
ASH BASIN
MW -12S
15.8
I
ABMW-03S
5.4
n
J
J
LEGEND
TOTAL pH CONCENTRATION
pH CONTOUR (Interval 1 pH UNIT)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
pH CONCENTRATION
14
— Neutral
0
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. iT WAS OBTAINED FROM
WSP.
4 ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http:Hservices. nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
DRAWN BY: B. YOUNG DATE: 1112312015 1.
PROJECT MANAGER: J, WYLIE
FIGURE 3-8
ISOCONCENTRATION MAPS
pH IN SURFICIAL GROUNDWATER
MAYO STEAM ELECTRIC PLANT
DUKE
U
ENERGY°
synTerra
PROGRESS 0
148 RIVER STREET, SUITE 220,
MAYO
STEAM ELECTRIC PLANT 'a
GREENVILLE, SC 29601
864-421-9999
10660 BOSTON RD o
ROXBORO, NORTH CAROLINA 27574 w
www.synterracorp.com
e
DRAWN BY: B. YOUNG DATE: 1112312015 1.
PROJECT MANAGER: J, WYLIE
FIGURE 3-8
ISOCONCENTRATION MAPS
pH IN SURFICIAL GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
VIRGINIA
NORTH CAROLINA
3R 13>4
------' - ---- ----- ------
- — —
/ MW -16S
• 2.6
MW -03 ./••
1.7 SR 1s _
LEGEND
DISSOLVED OXYGEN (DO) CONCENTRATION (mg/L)
DO CONTOUR (Interval 1 mg/L)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�— STREAM
DO CONCENTRATION
- 3 mg/L
- 1.5 mg/L
- 0 mg/L
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
DUKE
ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
DRAWN BY: B. YOUNG DATE: 11/2 312 01 5
PROJECT MANAGER: J, WYLIE
FIGURE 3-9
ISOCONCENTRATION MAPS
DISSOLVED OXYGEN IN SURFICIAL GROUNDWATER
MAYO STEAM ELECTRIC PLANT

' . .
VIRGINIA
NORTH CAROLINA y
SR 13)¢
C
MW -12S
I47
ACTIVE
ASH BASIN
LEGEND
1 SPECIFIC CONDUCTANCE (SC) MEASUREMENT (umhos/cm)
SC CONTOUR (200Nmhos/cm)
r
MONITORING WELL
GQJ 0� Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
---------------------------------------------
• � V
7 MW -03 ••- �/•`�
372/ i SR.150
ABMW-03S
165.9
n
M
I►
A
1981 `s
LANDFILL
SPECIFIC CONDUCTANCE (SC) MEASUREMENT
— 2144 (Nmhos/cm)
— 1072 (Nmhos/cm)
0 (Nmhos/cm)
NOTES:
CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM WSP.
'ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE I
CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT (http://services.noonemap.gov�
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
ANALYSIS AT (http://services.nconemap.govo
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM FPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
1�lp
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
DUKE
V ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
FIGURE 3-10
ISOCONCENTRATION MAPS
SPECIFIC CONDUCTANCE IN SURFICIAL GROUNDWATER
MAYO STEAM ELECTRIC PLANT

VIRGINIA
NORTH CAROLINA
284.3
Op
• '7S0 . / .
CW -02
387 •�-• /'�/•
i7,11114
LEGEND
1 TOTAL Eh MEASUREMENT (mV)
Eh CONTOUR (Interval 50 mV)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
Eh MEASUREMENT
415 mV
212 mV
.7 mV
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP,
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.govo
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM FIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
%DUKE
0
o.
ENERGY.
synTerra PROGRESS
148 RIVER STREET, SUITE 220, MAYO STEAM ELECTRIC PLANT a
GREENVILLE, SC 29601 10660 BOSTON RD a
864-421-9999 ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com a
FIGURE 3-11
ISOCONCENTRATION MAPS
Eh IN TRANSITION ZONE GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
VIRGINIA
NORTH CAROLINA
BG -02
/ 6A
------------------------------------
CW'04'
�6'
5.9
L
-03
ACTIVE
ASH BASIN
ABMW-04D
6.6
MW -12D
I 6.2
I
n
7
6131
181 1
LANDFILL
MW-07D� .c..—. —..
6.3 '.��•
s
♦
LEGEND
TOTAL pH CONCENTRATION
pH CONTOUR (Interval 1 pH UNIT)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
pH CONCENTRATION
14
Neutral
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. iT WAS OBTAINED FROM
WSP.
4 ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http:Hservices. nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
4!DUKE
V ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
DRAWN BY: B. YOUNG DATE: 11/2312015
PROJECT MANAGER: J, WYLIE
FIGURE 3-12
ISOCONCENTRATION MAPS
pH IN TRANSITION ZONE GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
VIRGINIA
NORTH CAROLINA
41 5 '
CW -03
� I a.s
r
4
LEGEND
DISSOLVED OXYGEN (DO) CONCENTRATION (mg/L)
DO CONTOUR (Interval 1 mg/L)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�- STREAM
DO CONCENTRATION
- 3 mg/L
MW -07D
10.6
_L
�\ NOTES:
7
• -.*-,\
♦
- 1.5 mg/L
- 0 mg/L
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
DUKE
ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
DRAWN BY: B. YOUNG DATE: 11/2 312 01 5
PROJECT MANAGER: J, WYLIE
FIGURE 3-13
ISOCONCENTRATION MAPS
DISSOLVED OXYGEN IN TRANSITION ZONE
GROUNDWATER
MAYO STEAM ELECTRIC PLANT

r
VIRGINIA
NORTH CAROLINA y
• r
SR 73)¢
h
C
A,
CW=04_ .. —:
—
�1903 1
U / CW -03
648
7
ACTIVE
ASH BASIN
L(i-245
o
o
BG -02
537
W -12D
---.125 -.---
♦ I
MW -16D
233.8
326a
c, SR -1501' -
A
1981
LANDFILL
MW -07D
1171
7ppp_
1 'J
8�0 f
7
'• MAYO
• �� LAKE
f •
M
LEGEND
1 SPECIFIC CONDUCTANCE (SC) MEASUREMENT (pmhos/cm)
SC CONTOUR (200Nmhos/cm)
MONITORING WELL
ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�— STREAM
SPECIFIC CONDUCTANCE (SC) MEASUREMENT
- 2144 (Nmhos/cm)
- 1072 (Nmhos/cm)
0 (Nmhos/cm)
NOTES:
CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE I
CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT (http://services.noonemap.gov�
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
ANALYSIS AT (http://services.nconemap.govo
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
SYSTEM FPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
A (i
VIP
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
IL%�DUKE
V ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
FIGURE 3-14
ISOCONCENTRATION MAPS
SPECIFIC CONDUCTANCE IN TRANSITION ZONE
GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
VIRGINIA
NORTH CAROLINA
• r
MW-03BR
115.<.
• MW-14BR
189.3
MW 02
CW -05
•. • MW-05BR ) c'
�+ 89.5�� s0�/ CV
o /
' \ ASH BAE
rABMW-02BR
96 \
�ABMW-04BR
/ O
0
'o \
in o
0
n
MW-16BR
CW -06, .
11 53.9
-MW-04
258:8
\1981
LANDFILL
CW -01 D
C,312.6
300
A
�. LEGEND
1 TOTAL Eh MEASUREMENT (mV)
Eh CONTOUR (Interval 50 mV)
# MONITORING WELL
j ® ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
Eh MEASUREMENT
415 mV
212 mV
-7 mV
MW-08BR'
/MW\07131R / 167:6
I/47:61 I;fi
0
M 9BR •�
2501271.1 \ 0,000.10
-. r\•
0-MW-10BR . ..,,
219 ,
♦
0.0�'
♦
N.
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE INC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
DUKE
ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
DRAWN BY: B. YOUNG DATE: 11/2312015 IO1
PROJECT MANAGER: J, WYLIE
FIGURE 3-15
ISOCONCENTRATION MAPS
Eh IN BEDROCK GROUNDWATER
MAYO STEAM ELECTRIC PLANT

LEGEND
rN
Yr La'
n 1 TOTAL pH CONCENTRATION
pH CONTOUR (Interval 1 pH UNIT)
MONITORING WELL
ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
STREAM
VIRGINIA pH CONCENTRATION
14
_.
--- -- --
_— 7 • — . —. - - Neutral
NORTH CAROLINA
0
o �.MW-03BR\MW-16BR a
CW -05 \ '6'9... 8.8
6.7•
rMW--05BR � CW -02D
7.2
�0'Sa 6.4
CW -06
�♦ 6.5
! • �'
MW -041981
• LANDFILL
♦ 6.5
MW' -13BR ACTIVE
6.9 ASH BASIN
•.• • %♦ ABMW-02BR
�•••. / 7.3 CW -01D
�� . • `1D • 6.9, rD
•. '� ABMW-04BR
�� • 7.5 ,
BG -01
• 5.3
t 11 .�•
/ • • o' MW-10BR
• 6.1
6 \
r i j I
• • B
MW-11BR
/ 9.2
nr •
•� Ir
L.
•
A
MW-08BR 4
MW-OZBR .5• • — .
MW-09BR
.tel
n
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. iT WAS OBTAINED FROM
WSP.
4 ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http:Hservices. nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
4!DUKE
V ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
DRAWN BY: B. YOUNG DATE: 11/2312015
PROJECT MANAGER: J, WYLIE
FIGURE 3-16
ISOCONCENTRATION MAPS
pH IN BEDROCK GROUNDWATER
MAYO STEAM ELECTRIC PLANT

A
♦
``♦ MW-13BR /
` ♦` 0.5
VIRGINIA
NORTH CAROLINA
SR 13j4
MW 1413R .�MW-0313MW-166R�
1\ CW -05 0,5 • • 0:5
• 1.3� MW -02 `.
7 �
O.3
/sE
MW-OSBR
fS_6i
w
A
ACTIVE
ASH BASIN
n
^/ CW -06 /
C W-02 D 0.3
1.6
MW -04 11 f8
®0 LANDFILL
1
CW -01D
0.5
J
J
MW-10BR
0.5
7
MW-08BR
fW-07BR/
��•--• —••
0.3
�.
MW-09BR'
1.6
,
•.1"4" of
1
MAYO
• ��
LAKE
LEGEND
DISSOLVED OXYGEN (DO) CONCENTRATION (mg/L)
DO CONTOUR (Interval 1 mg/L)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�— STREAM
DO CONCENTRATION
- 3 mg/L
- 1.5 mg/L
- 0 mg/L
NOTES:
1 CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
2 SURFACE/CONTOUR BOUNDARY TRUNCATED AT EXTENT OF SAMPLING DATA.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT
(http://services.nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS AT(http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD83/2011).
GRAPHIC SCALE
500 0 500 1,000 1,500 2,000
(IN FEET)
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE, SC 29601
864-421-9999
www.synterracorp.com
DUKE
ENERGY
PROGRESS
MAYO STEAM ELECTRIC PLANT
10660 BOSTON RD
ROXBORO, NORTH CAROLINA 27574
DRAWN BY: B. YOUNG DATE: 11/2 312 01 5
PROJECT MANAGER: J, WYLIE
FIGURE 3-17
ISOCONCENTRATION MAPS
DISSOLVED OXYGEN IN BEDROCK GROUNDWATER
MAYO STEAM ELECTRIC PLANT

VIRGINIA
NORTH CAROLINA
SR 73)¢
MW,13BR
``♦ 571
♦ ♦ r
•
A ..
� r i •
r , MW-11BR
282
co
nr ♦
`T '
9 L:
• .
/i,
• • MW-14BR
• • 413
600
MW-05BR4 EcW-05
6246
h
J
h
D
BG -01
168
Ill
----------_-------_ ----
954
M W-02
329.4 , �p0 .�"--•
800
CCW- 2D 900'SR=1501
75
600 M W-08 BR
(C)06 836
eo 865,
O c
ACTIVE
ASH BASIN
'aoOABMW-02BR
603
ABMW-04BR
523
n
LEGEND
1 SPECIFIC CONDUCTANCE (SC) MEASUREMENT (umhos/cm)
SC CONTOUR (200Nmhos/cm)
MONITORING WELL
Q ACTIVE ASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
�^ DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
�- STREAM
SPECIFIC CONDUCTANCE (SC) MEASUREMENT
- 2144 (Nmhos/cm)
- 1072 (Nmhos/cm)
0 (Nmhos/cm)
MW,0 8426
4 MW-07BR •�.-
.7 ,A �•
1981 MW-09BR
LANDFILL 219'7 !�-•�■
• NOTES:
CONCENTRATIONS SHOWN ARE FROM THE SEPTEMBER 2015 SAMPLING EVENT.
CW -01 D4 . �� • 'SURFACE/CONTOUR BOUNDARY TRUNCATEDAT EXTENT OF SAMPLING DATA.
1341.2 '
�♦ 'SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM WSP.
J , 'ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED FROM THE I
CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS AT (http://services.noonemap.gov�
�� ••` �• e PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC INFORMATION AND
♦ ` • ANALYSIS AT(http://services.nconemap.govo
c DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE COORDINATE
• ` SYSTEM FPS 3200 (NAD83/2011).
MW-10BR „ MAYO
1.452 •.�• LAKE
♦ . GRAPHIC SCALE
f ` 500 0 500 1,000 1,500 2,000
♦ (IN FEET)
,41P
0
L' DUKE
V ENERGY.
synTerra
PROGRESS
148 RIVER STREET, SUITE 220,
MAYO STEAM ELECTRIC PLANT a
GREENVILLE, SC 29601
10660 BOSTON RD a
864-421-9999
ROXBORO, NORTH CAROLINA 27574
www.synterracorp.com
a
FIGURE 3-18
ISOCONCENTRATION MAPS
SPECIFIC CONDUCTANCE IN BEDROCK GROUNDWATER
MAYO STEAM ELECTRIC PLANT

ma
250
m
m 200
c
0
150
c
v
V
p 100
u
0 50
c
a
a
Well BG -1: Boron
0 0 0 0 0 0 0 .i .i .+ N N N M M M It I a N N
O D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
N N N N N N N N N N N N N N N N N N N N N
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
O N b O N b O N b O N N O N V) O N 10 O N N
t♦ �
SR 1`728
SR. 1400 SR•
250
J
c 200
2 150
i+
c
w 100
0
U
0
50
m
c
Q
0
O .d w .4 N N N M M M a s -t M
N N N N �i N 4 H N 0
O O O O O O O O O O O O O O
N N N N N N N N N N N N N N
\ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \
N 7 W N 7 OD N 7 0) N 7 O N 7
N N N N N
Well BG -2: Boron
A
,BSG -01
C
N ..
MW -02 mw_us-
CW -02D -CW -06`x` -
1981`" MW-06BR'
L NDFILL
VE
NIW-0
ZkAS N '
W:04...
MW-09BR N
ABMW-02
ABMW 33
W -01D
V -046R u-
M 10BR� 1
SR X141
SR -1
Well CW -21): Boron
G!
400
350
\
m
300
0
250
Y
T
200
E
c 150
01
0
u
3 100
0
3 50
Detection
Limit
= 50
ug/L
Q
0
0
.+
N
N
NM
M
M
R
a
a N
N N
N
.i
N
N
N
N
N
N
N
N
N N
O O
O
O
O
O
O
O
O
O
O
O
O O
N N
N
N
N
N
N
N
N
N
N
N
N N
\ \
N It
N
\
co
\
N
H
\
V
\
W
\
N
N
\
er
\
co
\
N
H
\
11
\
W
\ \
N V
H
1000
J
7 Soo
0
600
c
v
c 400
0
U
°y 200
a
a
0
i
• ' Well CW -2: Boron
Detection Limit = 50 ug/L
O .4 A '1 N N N M M M 7 7 7 N
N N N N N
D D D D D D D D D D D O D O
N N N N N N N N N N N N N N
\ \ \ \ \ \ \ \ \ \ \ \ \ \
N � W N 7 00 N C 00 N 7 OD N 7
N N N N N
LEGEND
MONITORING WELL
p� —73 ACTIVEASH BASIN
ASH BASIN COMPLIANCE BOUNDARY
DUKE ENERGY PROGRESS MAYO PLANT SITE BOUNDARY
- — - DITCH
STREAM
THE NORTH CAROLINA 2L STANDARD FOR BORON IS 700 uglL
NOTES:
1 DATA FROM HISTORICAL NPDES COMPLIANCE GROUNDWATER MONITORING.
2 BORON NOT DETECTED ABOVE REPORTING LIMIT IN COMPLIANCE WELLS
CW-01,CW-01D,CW-03,CW-04,CW-05, AND CW -06.
3 SITE AERIAL ORTHOPHOTOGRAPHY IS DATED APRIL 17, 2014. IT WAS OBTAINED FROM
WSP.
4 ADDITIONAL OFFSITE AERIAL ORTHOPHOTOGRAPHY IS DATED 2012. IT WAS OBTAINED
FROM THE INC CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS.
(http://services.nconemap.gov/)
5 PARCEL BOUNDARY WAS OBTAINEDFROM THE INC CENTER FOR GEOGRAPHIC
INFORMATION AND ANALYSIS (http://services.nconemap.gov/)
6 DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
COORDINATE SYSTEM RIPS 3200 (NAD8312011).
GRAPHIC SCALE
1,000 0 1,000 2,000 3,000 4,000 5,000
(IN FEET)
SR -1507.
synTerra
148 RIVER STREET, SUITE 220,
GREENVILLE,SC 29601
864-421-9999
® www.synterracorp.com
DUKEC
ENERGY,
PROGRESS
MAYO STEAM ELECTRIC PLANT 4
10660 BOSTON RD
ROXBORO, NORTH CAROLINA27574
FIGURE 3-19
TIME vs BORON CONCENTRATION GRAPHS
MAYO STEAM ELECTRIC PLANT