NCDEQ Presentation 12_13_2015 rev9_Final

1
D
NCDEQ Briefing on Groundwater
Investigations
12/14/2015

Meeting Objectives
CAMA Requirements
Site Investigations
Plume Geometry
Flow Direction
Analysis of Offsite Wells
Site Background Concentrations
Duke's Response to Comments
Conclusions

CAMA Requirements - Groundwater
N.C. Gen. Stat. § 130A-309.211 — Groundwater Assessment and Corrective Action
Subsection (a)
Submit a Groundwater Assessment Plan that includes required
elements
Begin implementation of an approved Groundwater Assessment Plan
no later than 10 days from approval
Submit a Groundwater Assessment Report no later than 180 days from
approval of Groundwater Assessment Plan
Subsection (b)
Submit a proposed Groundwater Corrective Action Plan that includes
required elements
Begin implementation of an approved Groundwater Corrective Action
Plan no later than 30 days from approval
IM
Y
Y
On Schedule
Deadline has not yet
arrived
3

Third -Party Review
The National Ash Management Advisory Board was assembled by UNC Charlotte at the
request of Duke Energy and consists of nationally and internationally recognized and
published experts. Duke Energy has engaged NAMAB to complete independent reviews
of the Comprehensive Site Assessments and the Corrective Action Plans.
John Daniels, D. Eng., P.E.
Professor and Chair, UNCC - Department of Civil and Environmental Engineering
Chairman, Ash Management Advisory Board
Susan E. Burns, Ph.D., P.E.
Georgia Power Distinguished professor, School of Civil and Environmental Engineering, Georgia
Tech
Panelist, Ash Management Advisory Board, Groundwater Subcommittee
Jeffrey C. Evans, Ph.D., P.E.
Professor of Civil and Environmental Engineering, Bucknell University
Panelist, Ash Management Advisory Board, Groundwater Subcommittee
Krishna Reddy, Ph.D., P.E.
Professor of Civil and Environmental Engineering, University of Illinois at Chicago
Panelist Ash Management Advisory Board, Groundwater Subcommittee
Joyce Tsuji, Ph.D, DABT, Fellow ATS
Principal Scientist, Exponent, Inc.
Panelist, Ash Management Advisory Board, Groundwater Subcommittee
4

Third -Party Review
Ronald Falta, Ph.D.
Professor, Clemson - Department of Environmental Engineering and Earth Sciences
Modeling
Lawrence Murdoch, Ph.D. , P.G.
Professor, Clemson - Department of Environmental Engineering and Earth Sciences
Modeling
Bill Langley, Ph.D.
Professor, UNC Charlotte - Geography and Earth Sciences
Modeling
Lisa A Bradley, Ph.D., DABT
Haley and Aldrich, Boston, MA - Vice President and Senior Toxicologist
Off-site drinking water wells; risk assessments
5

Third -Party Review
Chunmiao Zheng, Ph.D.
Professor, University of Alabama — Department of Geological Sciences
Model Reviewer
John Ewing, P.E.
Senior Water Resources Engineer, Intera, Inc.
Model Reviewer
James Rumbaugh
President at Environmental Simulations, Inc.
Model Reviewer
Bruce Hensel
EPRI (Electric Power Research Institute)
Directed and managed model review
William Linderfelt, Ph. D.
Principal Hydrogeologist, Intera, Inc.
Model Reviewer
6

Groundwater Investigation Highlights
Dr. John Daniels, Ph.D., P.E.

General hydrogeologic theory
Flow from high energy (ponds)
to low energy (surface water)
Follows topography
Historical pond monitoring
(2005-2015)
Steady State
Flow Direction
Plume generalities
(contaminant concentration range)
Comprehensive Site Assessments
Plume maps
ES1 Plan View
Cross Sections
General Principles
SYSTEM 4
-_
rt [!� "I"
Slope Aquifer Boundary and Topographic DiiAde
Discharge Boundary
- - - - - - - Compartment (C) Boundary
..............— -Water Table
r : Fractures
�► Groundwater Flow Direction
8

General Flow Direction and Plume Extent
Groundwater Flow:
General groundwater flow was as expected based on accepted
hydrogeologic theory and historical monitoring
Regional groundwater flow at each site is away from neighbors, except at
L.V. Sutton Energy Complex and Asheville Steam Electric Plant, and
towards regional water bodies in the area
Plume Extent:
The plume is generally confined to the property boundary, except at four
sites that are being addressed with accelerated remediation as required in
the Sutton Settlement
No evidence of impact to outside wells except at L.V. Sutton Energy
Complex and Asheville Steam Electric Plant.
9

Example Stations
A station was selected from Duke Energy Carolinas and
Duke Energy Progress
Allen Steam Station
Chosen because the site is a legacy Duke site, the high number of
potential receptors in close proximity to the site, and the public
interest.
Roxboro Steam Electric Plant
Chosen because the site is a legacy Progress site, the high number
of potential receptors within a half mile of the site, and due to
complexity of the site.
10

Allen Steam Station
LEGEND:
ASSUMED PR IVAYE WATER SUPPLYWPLL
FIELDIDENTIFIED PRIVATEWATER SUPPLYWELL
PUBLIC WATER SUPPLYWELL
RECORDED PRIVATE WATER MPPLY WELL
I_ly 111 ty'L{+' f.
REPQRTEO PRNATE WATER SUPPLY WELL.
VOLUNTARY GROUNDWATER MONIiORYNG WELL
_1
onTAcsP WELL
,>
APPRQ%IMATE GROUNDWATER FLAW DIRECTION
r ---_r AREAOF BORON AN D SULFATE EXCEEOANCES
j OF 2L STANDARDS
ASH BASIN CUMPdIANCE BOUNDARY
ASH BASH COMPLIANCE BOUNDARY COINCIDENT
■■ Iff DUNE ENERGY PROPERTY BOUNDARY
M 1 ASH DASN WASTE BOUNDARY
- /'�� � ,y� i` e 1 ���� pflltE fNERQY PRQPERJYBQIINQARY
srREAM
1
cl
�f
I f 7tr h,
R
b
11

Modeled boron concentration (ug/L)
in the transition zone
LEGEND]
50 Detection Limit
100
300
500
70c) 2L Standard
1,200
1,921
DUKE ENERGY
PROPERTY BOUNDARY
ASH BASIN WASTE
BOUNDARY
I -AND ILVASHSTORAGE
AREA BOUNDARY
ASH BASIAL COMPLIANCE
BOUNDARY
ASH BASIAL COMPLIANCE
BOUNDARY COINCIDENT
WTH DUKE ENERGY
PROPERTYBOUNDARY
MODEL DOMAIN
Allen Steam Station
I If
12

Concentrations of Boron (ug/L) in Bedrock Wells
. OF
'010
J6,
Tt
M7,
rw
IVA,
Allen Steam Station
Y3. 1.
,lux
--- ------------------------
11
13

WEST
616111., Ego] Ikq1■ TH1�7
COMPLIANCE BOUNDARY CCINCIDENT
WITH PROPERTY BOUNDARY
INACTIVE
ASH BASIN
FILL
ASH STORAGE
AREA
Allen Steam Station
RAB ASN RETIRED ASH
LANDFILL BASIN DAM
i
- - - - - �- INACTIVE ASH
REGOLITH
BEDROCK
CROSS SECTION - ALLEN INACTIVE ASH BASIN
(LOOKING NORTH)
NOTE:
TRANSECT D -D` FROM THE CSA REPORT USED FOR CROSS-SECTION SHOWN ABOVE,
DRAWING NOT TO SCALE AND IS INTENDED FOR ILLUSTRATION PURPOSES ONLY.
APPROXIMATE EXTENT OF 2L
EXCEEDANCES OF BORON
LEGENa
0 ASH
- RECOLTTH
PARTIALLY WEATHERED ROCK (PWR)
O BEDROCK
FI LL
APPROXIMATE EXTENT OF 2L
EXCEEDANCES OF BORON
APPROXIMATE ORCUNDWATER
FLOW DIRECTION
14
}
a
0
z
D
w
Z
0
ED
J
w
0
9
Iz
EAST
w
D_
J
a
0
d
0
I
I
ATAWBA
RIVER
0 ASH
- RECOLTTH
PARTIALLY WEATHERED ROCK (PWR)
O BEDROCK
FI LL
APPROXIMATE EXTENT OF 2L
EXCEEDANCES OF BORON
APPROXIMATE ORCUNDWATER
FLOW DIRECTION
14

Summary
Allen Steam Station:
Groundwater divide along Highway 273
Water flows from the topographically high area to lower elevation
towards Lake Wylie
Water flows away from neighbors
Boron was detected above the 2L Standard in bedrock at only one
location close to Lake Wylie and away from drinking water wells
No evidence of impacts to offsite receptors
No imminent hazard to human health or the environment
15

t
C1 gip,
t.
, y
.E
`4 r . "®� , , Vii • :.�
Job
%e+
sr
*4IA
1
V`
ah�.
Ak
f
w �
'Oft
a
a

Modeled boron concentrations
(ug/L) in the transition zone
40004
700
Roxboro Steam Electric Plant
2015 Current
2045 No Action 2045 Cap -In -Place
— 7 a 1
2045 Excavate

Roxboro Steam Electric Plant
Concentrations of Boron (ug/L) in Bedrock Wells
1.
2310r2290j
J"i rte• GYPSUM - -
x PAD
t � -
.�_ � �. •� 5.. r- - GMW-1 G' Gh1Vd-11' � ,-.S
Lf --\'3 `SQ {N51 5.7081N51 CW -01'
low'
IA4Y-01BR BSc INS
A
MW-06RR' 'ABMW47BR'I -- - - `
HYCO 60I` 50' 1966 35916741 I-+
SEMI -ACTIVE',
1.11KE '� MW -11 BR --BASIN I
-05BR.'
'601, 541 1
c c641 r
'ABMW,14BR' I
MYV-01BRr CYtVQOi ABMW-068R I-/ 501<501 5
51(<65) < INSF 1d1 ABFIIAP'03�' 501.641
rte. I
.1 71W
I
SO
M<5fl 0' 15 _GMW ., +t`•: cn;ti i`
<54I ABN4 �t-.�10j1
t7i 9&1
J
1973 ACTIVE
ASH BASIN
c55 NS
A
11-- MW-04BR'
MW-15BRy
60'l�SPI '^dl
Y�OIL
J' r
DO15 DUr}R-' _�
16
+_
,draw-1eea
16

voR
560
fi60
830
� 430
W
920
410
390
980
310
380
360
340
330
520
56q
560'
530'
520'
510'
500'
900
480 -
470
480
950
W — 4A0
930
920
610 -
60P -
3W -
3B0'
370'
3Bo'
350'
Roxboro Steam Electric Plant
---------- W7
. _ _ _ BEDROCK-_ PEGOLITM
--- _ ------------
- --
BEDROCK
1
T TI. $
__ ----------- --------------- -
_______________________________________________
SECTION A -A` - BORON
--R.—
GRAPHIC SCALE
a051 3QC BC9
HORIZONTAL i" 3W
9D 0 30 BD
Xf
YERTIGAL T'a
BEDRO- ------------- CK
_- _-------------
_ -
_
________ N N _______________________
__ ---------
--
_________ ---------
____
SN"' (f.0
SECTION i-8- - BORON
55fl
5ta
839
520
51©
500
bap
450
13P =Y
W-
-020
410
390
380
3M
360
340
330
326
O
LEGEND
©
COALASH/® GYPSUM
i
HEGGUTH FILLMATERWL-
n!
A3H
Ilrn In
TRAN3ITIONZONE
7
DE -OG.
F-VA—AL
— WATER LEVEL
Iwuxal
— ASH PORE WATER LEVEL
---------- W7
. _ _ _ BEDROCK-_ PEGOLITM
--- _ ------------
- --
BEDROCK
1
T TI. $
__ ----------- --------------- -
_______________________________________________
SECTION A -A` - BORON
--R.—
GRAPHIC SCALE
a051 3QC BC9
HORIZONTAL i" 3W
9D 0 30 BD
Xf
YERTIGAL T'a
BEDRO- ------------- CK
_- _-------------
_ -
_
________ N N _______________________
__ ---------
--
_________ ---------
____
SN"' (f.0
SECTION i-8- - BORON
55fl
5ta
839
520
51©
500
bap
450
13P =Y
W-
-020
410
390
380
3M
360
340
330
326
O
ASH BASIN WATER LEVEL
DOOR OCK WATERLEVEL
i
TRANSITION ZONE WATER LEVEL
n!
ZONE
.ESER D IN ROCK C
OESERVEb IN ROCK CORE
CONCENTI—DN CC -OUR
7
HASH MARKS POINTTO
DECREASING CONC ENTRATIONS
CONCENTRATION CONTOUR
DASHED MERE INFERRED
50e
CONCENRtATK)N
NA
NOTANALYZED
ND
NO DATA
NS
NOT SAMPLED
BORING SYMBOLS
���/cLL fid1EEN 5WTH
:oNLEN1MHCN
-ii":rrynrve pu IAdj
.+�,mm mle n pHf
19

Roxboro Steam Electric Plant
20
LEGEND
COALASH ®./ OVFSUM
O REGOLITH FILLMATERIAL
NORTH
SOUTH
® ASH
-RANsnON ZONE
590
560
580
5B0
BEDROCK
570
MW.1dBR..
570
FILL MATERIAL
5�
5
580
WATER LEVEL
�
NMWbe:
�
� a5H PPRE WATER LEVET
© ASH MEN WATER LEVEL
53P
LAND ILL
r'OG!
530
BEDROCK WATER LEVEL
THAN5MONZONE WATER LEVEL
510
_______ ______________
510
FRACNREDIOXIOREDZONE
SW
ANSI ON ZONE __
-- - <0
--------------
5m
m
OBSERVED IN ROCK CORE
490
- - - - - - - __ _ _ _
��
_-_ _
--'-_--
Ti
CONCENTRATfDN CONTOUR
yW
- - - - - -
_ - - - - - - -
- -- I��rr_ _ --- - - -- -- -
. - _ _ - _- -- _
-_ - -�1t _ - -_ - -. .4950- __ �` -_ --_ - ---
_ __ �_- - _ -
870
mr HASH MARKS KIINTTO
DECREASING CONCENTRATIONS
NE RAMAL.:
--_ _ _ _ _ _ _BEDROCK _ _ _- -_ _ - _
____
460
WNCENTRATIONCONT R
DASHED WHERE INFERRED
450
44U
-_ _ _ _ __ _ _ _ _ _ _ _ _ _ _ ________ __ __ ____ ____________ _____________ ____ _��
--_ _ _-_'_ _ _ _'_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ �_
450
440
5,UN OONCENiR.ATION
NA NOT ANALYZED
430
1590: ----------------�� ��J
430
NP NQ DATA
dM
��yr+���~
420
NS NOT SAMPLED
410
s�����..���+••����,.r� ■
410
BORING SYMBOLS
Std1100
d91L _
�u —Y£1L 673EEN NRH
D]NCENYRAYION
SECTION C -C'
{mi[n'greml pErlM4
—NGEASS
20

Summary
Roxboro Steam Electric Plant:
Regional groundwater flow is to the west/northwest toward the Hyco
Reservoir
A discharge canal and topographic ridge located west of the Site ash
basins limits groundwater flow in that direction
Localized groundwater high zones are centered around the ash
basins, with radial flow in these areas
Boron was detected above the 2L Standard in bedrock at three
locations on site and away from drinking water wells
No evidence of impacts to offsite receptors
No imminent hazard to human health or the environment
21

Site Background Concentrations
Provisional proposed site background concentrations were included in the
CAP Part 1
These values are based off of available data and will be updated as more
sampling is completed
Alternative ways to compute site background concentrations are shown
below
Example of Alternative Site Background Concentrations: Weatherspoon
Parameter
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Chloride
Chromium
Background
Sample Size
3
3
3
3
3
3
3
3
1
Calculated
Calculated
Calculated
Calculated
Calculated
Calculated
Calculated
Background
Calculated
Method
Background
Background
Background
Background
Background
Background
Background
Concentration
Background
Concentration
Concentration
Concentration
Concentration
Concentration
Concentration
Concentration
(mg/L)
Concentration
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(ug/L)
(ug/L)
NC21- Standard
NA
1*
10
700
4*
700
2
250
10
Maximum
66
1
1
52
1
50
1
3.30
1
75% of Maximum
50
0.750
0.750
39
0.750
37.5
0.750
2.48
0.750
50% of Maximum
33
0.500
0.500
26
0.500
25
0.500
1.65
0.500
Mean
32
1
1
49.3
1
1 50
1
3.17
1
ACI -2
82.3
1
1
55.6
1
1 50
1
3.42
1
ACLS
71.7
1
1
56.8
1
1 50
1
3.45
1
Nondetects identified as ND, as opposed to the method detection limit, were omitted from calculations.
IQR (Interquartile Range) = 75th percentile - 25th percentile
ACI -2 (Alternative Concentration Limit 2): median + 1.65 x IQR
ACLS (Alternative Concentration Limit 3): median + 1.65 * IQR (where IQR = the interquartile range).
22

Duke's Response to Comments
Mounding
Deep fractures
Pumping
Depth of CSA wells versus receptor wells
Geochemical effects
Saturated Ash
Constituent Modeling
See tables on next slide
23

Modeling Constituents
Constituents selected for the fate and transport models were those:
a) determined to be source -related by professional judgment of the
university led modeling team,
b) with analytical results that exceeded applicable regulatory criteria, and
c) with a distribution that was not suggestive of naturally occurring
conditions
Certain Constituents were not selected for modeling based on one or
more of the following reasons:
a = Not modeled using MODFLOW/MT3DMS. These constituents will be included in the geochemical
modeling.
b = Only isolated exceedances and/or appear to be related to background or non -source related.
c = No 2L Standard exceedances in non-porewater monitoring wells samples.
d = No 2L Standard or IMAC exceedances; not identified as a COL
e = Found in ash and/or but not found in groundwater - ash being dewatered and removed from site.
f = Constituent is not present in ash pore water monitoring wells above the 2L or IMAC Standards
g = Constituent is not present above the 2L Standard or IMAC outside of the compliance boundary
h = There is not a discernable plume of the constituent downgradient from the ash basin(s)
24
i = The constituent is strongly adsorbed (Kd>20 mL/g; R>100) and has very low mobility

Model Constituents: Duke Energy Carolinas
X = COI
XX = C O I
included in CAP Part 1 Modeling.
added to CAP Part 2 Modeling.
W
Duke Energy
Constituents of Interest (COls) Selected for Groundwater Fate and Transport Modeling
DRAFT
COI
Allen
Belews Creek
Buck
Station
Cliffside
Dan River
Marshall
Riverbend
Aluminum
d
c
d
d
d
d
b
Antimony
X
c
X
X
XX
X
X
Arsenic
X
X
c
X
X
X
XX
Barium
X
c
c
XX
d
X
b
Beryllium
c
X
d
XX
d
X
b
Boron
X
X
X
X
X
X
XX
Cadmium
c
b
d
d
d
d
b
Chromium (VI)
X
X
X
X
X
X
XX
Chromium (Total)
X
X
X
X
X
X
X
Chloride
d
X
d
d
d
X
d
Cobalt
X
X
X
X
X
X
XX
Copper
d
c
d
d
d
d
b
Iron
a
a
a
a
a
a
a
Lead
c
c
d
X
d
d
b
Manganese
a
a
a
a
a
a
a
Mercury
c
c
d
c
d
d
b
Molybdenum
d
d
d
d
d
d
b
Nickel
c
c
e
X
d
d
b
Nitrate
d
c
d
d
d
d
b
pH
a
a
a
a
a
a
a
Selenium
X
b
d
d
XX
X
e
Strontium
d
d
d
d
d
d
b
Sulfate
X
b
X
X
X
X
X
TDS
a
a
a
a
a
a
a
Thallium
c
X
c
X
X
X
XX
Vanadium
X
b
X
X
X
X
XX
Zinc
c
c
d
d
d
d
b
X = COI
XX = C O I
included in CAP Part 1 Modeling.
added to CAP Part 2 Modeling.
W

Model Constituents: Duke Energy Progress
Duke Energy
Constituents of Interest (COls) Selected for Groundwater Fate and Transport Modeling
DRAFT
COI
Asheville
Cape Fear
H.F. Lee
Mayo
Roxboro
Sutton
Weatherspoo
n
Aluminum
a, d, f, g
a, d, f, g
a, d, f, g
a, d, f, g
a, d, f, g, h
a, f, g
a, d, f, g, h
Antimony
g, h
g, c
g
b, h
h, b
b, f
d, f, g
Arsenic
a, h, i
h, i, a
X
X
X
X
X
Barium
c, d, f, g
b, f
g, h
b, g, h
b, f, g
c, g
c, g, h,
Beryllium
f, g, h
g
d, f, g
d, f, g
c, g, h
d, f, g
f, g, h
Boron
X
X
X
X
X
X
X
Cadmium
f, h, b
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
Chromium (VI)
a
a
a
a
a
a
a
Chromium (Total)
a, g, h
a
a
a, d, f, g
a, b, f, h
a
a
Chloride
X
f, g
f, g
d, f, g
f, g
f, h
f, g
Cobalt
X
a, h, i
h, i
a, h, i
a, h, i
a, f, h, i
h, a
Copper
c, d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
Iron
a,h
a,h
X
a,h
a,h
a,h
a,h
Lead
c, d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
f, b
g, h
Manganese
a, h
a, h
X
c, h
a, h
a, h
h
Mercury
c, d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
Molybdenum
c, d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
Nickel
f, g, h
g
d, f, g
d, f, g
g, h
d, f, g
f, g, h
Nitrate
f,g,h,
f, h
d, f, g
d, f, g
d, f, g
b, f
d, f, g
pH
a
a
a
a
a
a
a
Selenium
a, f, g
a, b
c
a, f, g, d
a, f, g
a, b, f, g
a
Strontium
c, d, f, g
d, f, g
d, f, g
d, f, g
d, f, g
f, g, d
d, f, g
Sulfate
X
X
f, g
d, f, g
X
f, g
f, h
TDS
X
h
h
h
h
h
h
Thallium
h, i
X
g, h, i
h, i
h, i
f, h
h
Vanadium
a, h, i
a, h, i
a, h, i
a, b, h, i
a, h, i
X
h
Zinc
c, d, f, g
c, h
d, f, g
d, f, g
c, d, f, g
d, f, g
M

General Conclusions from the Investigations
for All Stations
Recent groundwater assessment results are consistent with previous
results from historical and routine compliance boundary monitoring
well data
No imminent hazard to human health or the environment has been
identified as a result of groundwater migration from the ash basins
No evidence of off-site impacts to private or public water supply wells
(except at Sutton and Asheville plants where residents will be
provided a water line, some are receiving bottled water)
27

General Conclusions from the Investigations
for All Stations
Minimal difference and benefit is seen for excavation over cap -in-
place in the modeling scenarios
These investigations and conclusions are conservative — no
adjustment was made for background concentrations
Addition of data gap wells will add resolution to the CSA results
28

Private Well Analysis
Dr. Lisa Bradley, Ph.D., DABT
29

Private Well Analysis
Detailed per well screening results for the following datasets was performed:
• DEQ Private Well Data
• DEQ Background Private Well Data
• Duke Energy (Duke) Background Private Well Data
Constituent concentrations in water for each well for each data set were compared to
the following:
• 2L Standards: North Carolina Groundwater Standard (2L)
• Federal Drinking Water Standards: USEPA Maximum Contaminant Levels
(MCLs) and Secondary Maximum Contaminant Levels (SMCLs)
• DHHS Screening Levels: North Carolina Department of Health and Human
Services Screening Levels
• USEPA Risk -Based Screening Levels (RSLs): November 2015
30

Summary Of NC DEQ And Duke Private Well And
Background Sample And Well Counts
Station
Sample/Well Counts
DEQ Private Wells
DEQ
Background
Duke
Background
Wells
Available
Wells
Sampled
Samples
p
Allen
142
119
182
6
16
As hevi I I e
20
8
9
0
13
Bel ews Creek
31
24
36
0
11
Buck
101
84
114
7
17
Cape Fear
2
1
1
0
18
Cliffside
26
17
29
0
9
Dan River
0
0
0
0
8
Lee
34
16
29
0
11
Marshall
47
38
57
3
29
Mayo
7
3
5
0
14
Ri verbend
1
0
0
0
11
Roxboro
14
11
18
0
26
Sutton
18
10
17
0
13
Weatherspoon
8
2
3
0
2
Total:
451
333
500
16
198
ff

Summary of NC DEQ Private Well Sampling Data
32
Frequency of
Frequency of
Range of Detected
Frequency Detected Above:
Frequency of Reporting Limits Above:
Frequency of
Detection
Detects Below All
Constituents
Units
Detection
Percent
Concentrations
2L (a)
DHHS (b)
MCL c
()
RSL(d)2L
a
()
DHHS b
()
MCL c
()
RSL(d)
()
Screening Levels
Constituents Listed in Appendix III Detection Mon itori ng) of the CCR Rule e
Boron
ug/L
115
/ 500
23%
1.8 690
0
0
0
0
0
0
115
Calcium
ug/L
497
/ 500
99%
553 246,000
--
--
--
--
--
--
--
-
Chloride
mg/L
491
/ 499
98%
0.92 - 335
1
1
1
0
0
0
490
pH
su
496
/ 496
100%
2.13 9.4
256
--
256
0
--
0
240
Sulfate
mg/L
304
/ 499
61%
0.15 711
7
7
7
0
0
0
297
Total Dissolved Solids
m /L
492
/ 494
100%
21.3 2,040
9
--
9
0
--
0
--
483
Constituents Listed in Appendix IV (Assessment Monitoring) of the CCR RuIe(f)
Antimony
ug/L
37
/ 500
7%
0.031 - 1.87
2
2
0
0
60
60
23
23
35
Arsenic
ug/L
79
/ 500
16%
0.1 - 108
5
5
5
79
0
0
0
421
0
Barium
ug/L
482
/ 499
97%
0.46 400
0
0
0
0
0
0
0
0
482
Beryllium
ug/L
20
/ 500
4%
0.04 0.78
0
0
0
0
23
23
23
0
20
Cadmium
ug/L
33
/ 500
7%
0.063 1.4
0
0
0
0
0
0
0
0
33
Chromium
ug/L
281
/ 500
56%
0.176 - 22.1
7
7
0
0
11
11
0
0
274
Cobalt
ug/L
79
/ 500
16%
0.03 12
35
35
--
3
59
59
--
29
44
Lead
ug/L
380
/ 500
76%
0.073 75.S
8
8
8
8
0
0
0
0
372
Mercury
ug/L
25
/ 499
5%
0.017 0.12
0
0
0
0
0
0
0
0
25
Molybdenum
ug/L
167
/ 500
33%
0.064 20.2
--
1
--
0
--
4
--
0
166
Selenium
ug/L
42
/ 500
8%
0.1643 3.4
0
0
0
0
0
0
0
0
42
Thallium
u /L
14
/ 500
3%
0.057 - 0.24
1
1
0
1
118
118
5
118
13
Constituents Not Identified in the CCR Rule
Vanadium
ug/L
351
/ 500
70%
0.197 - 26.5
344
344
--
0
134
134
--
0
7
Aluminum
ug/L
158
/ 500
32%
0.0018 5,000
--
1
71
0
--
0
9
0
87
Copper
mg/L
424
/ 500
85%
0.0002 29
4
4
3
4
0
0
0
0
420
Iron
ug/L
199
/ 500
40%
14.5 8,500
76
16
76
0
2
0
2
0
123
Hexa vaIentChromium
ug/L
263
/ 484
54%
0.033 22.3
--
239
--
0
--
159
--
0
24
Magnesium
ug/L
497
/ 500
99%
101 - 61,200
--
--
--
--
--
--
--
-
Manganese
ug/L
376
/ S00
7S%
0.49 1,010
39
16
39
5
0
0
0
0
337
Nickel
ug/L
179
/ 500
36%
0.18 15
0
0
--
0
0
0
--
0
179
Potassium
ug/L
499
/ 500
100%
96.1 21,200
--
--
--
--
--
--
--
Sodium
ug/L
500
/ 500
100%
570 370,000
34
--
0
--
466
Strontium
ug/L
495
/ 500
99%
2.3 3400
1
0
--
0
--
0
494
Zinc
mg/L
413
/ 500
83%
0.0021 - S.26
11
11
1
0
1
1
1
1
402
Total Number of
14,970
Total Number
of Exceedances:
805
733
476
100
408
569
63
592
5,670
Analyses:
32

Summary of NC DEQ Background Private Well
Sampling Data
Total Number 544 Total Number of Exceedances: 13 23 2 1 0 0 0 15 162 33
of Anal ses:
Frequency
Fre uen of
q �
Range of Detected
Frequency Detected Above:
Frequency of Reporting Limits Above:
Frequency of
Background
g
Detection
Detects Below All
Threshold Value
Constituents
Units
of Detection
percent
Concentrations
2L (a)
DHHS (b)
MCL (c)
RSL (d)
2L (a)
DHHS (b)
MCL (c)
RSL (d)
Screening Levels
(BTV) (g)
Constituents Listed in Append ix III (Detection Mon itori ng) of the CCR Rule (e)
Boron
ug/L
4/ 16
25%
5.3 12.7
0
0
0
0
0
0
4
12.56
Calcium
ug/L
16 / 16
100%
1,680 - 59,900
--
--
--
-
--
--
--
69,922
Chloride
mg/L
16 / 16
100%
1.8 38
0
0
0
0
0
0
16
37.02
pH
su
NA
NA
NA
--
--
--
--
--
--
--
NA
Sulfate
mg/L
13 / 16
81%
2.8 - 39.4
0
0
0
0
0
0
13
39.45
Total Dissolved Solids
m /L
16 / 16
100%
51 - 351
0
--
0
0
--
0
16
572.9
Constituents Listed in Appendix IV (Assessment Monitoring) of the CCR Rule (f)
Antimony
ug/L
0/ 16
0%
NA
0
0
0
0
0
0
0
0
0
NA
Arsenic
ug/L
1/ 16
6%
4.4 - 4.4
0
0
0
1
0
0
0
15
0
NA
Barium
ug/L
16 / 16
100%
0.89 77.3
0
0
0
0
0
0
0
0
16
67.75
Beryllium
ug/L
0/ 16
0%
NA
0
0
0
0
0
0
0
0
0
NA
Cadmium
ug/L
0/ 16
0%
NA
0
0
0
0
0
0
0
0
0
NA
Chromium
ug/L
11 / 16
69%
0.53 - 5
0
0
0
0
0
0
0
0
11
7.478
Cobalt
ug/L
0/ 16
0%
NA
0
0
--
0
0
0
--
0
0
NA
Lead
ug/L
11 / 16
69%
0.12 - 3.2
0
0
0
0
0
0
0
0
11
3.385
Mercury
ug/L
0/ 16
0%
NA
0
0
0
0
0
0
0
0
0
NA
Molybdenum
ug/L
4 / 16
25%
0.85 - 2.9
--
0
--
0
--
0
--
0
4
2.488
Selenium
ug/L
2/ 16
13%
0.52 - 0.72
0
0
0
0
0
0
0
0
2
0.72
Thallium
ug/L
0/ 16
0%
NA
0
0
0
0
0
0
0
0
0
NA
Constituents Not Identified in the CCR Rule
Vanadium
ug/L
13 / 16
81%
1 - 23.7
13
13
--
0
0
0
--
0
0
21.39
Aluminum
ug/L
4 / 16
25%
12.1 - 213
--
0
2
0
--
0
0
0
2
156.1
Copper
mg/L
13 / 16
81%
0.001 - 0.0116
0
0
0
0
0
0
0
0
13
0.0213
Iron
ug/L
4/ 16
25%
57.5 - 244
0
0
0
0
0
0
0
0
4
189.2
Hexavalent Chromium
ug/L
8 / 16
50%
0.14 - 4.5
--
8
--
0
--
0
--
0
0
3.533
Magnesium
ug/L
16 / 16
100%
808 - 28,800
--
--
--
--
--
--
--
--
--
28,204
Manganese
ug/L
8/ 16
50%
0.73 43.3
0
0
0
0
0
0
0
0
8
31.23
Nickel
ug/L
3/ 16
19%
0.53 1
0
0
--
0
0
0
--
0
3
0.942
Potassium
ug/L
16 / 16
100%
265 - 3,360
--
--
--
--
3,908
Sodium
ug/L
16 / 16
100%
4,610 - 23,000
2
0
14
23,000
Strontium
ug/L
16 / 16
100%
12.2 - 760
0
--
0
--
0
--
0
16
908
Zinc
ug/L
9/ 16
56%
6.5 147
0
0
0
0
0
0
0
0
9
149
Alkalinity
mg/L
16 / 16
100%
7.4 - 226
--
--
--
--
--
--
--
--
--
324.3
Bicarbonate
mg/L
16 / 16
100%
7.4 - 226
324.3
Carbonate
mg/L
0 / 16
0%
NA
NA
Total Suspended Solids
mg/L
2 / 16
13%
4.2 - 11.6
11.6
Turbidity
NTU
2 / 16
13%
2 - 3.2
3.2
Temperature
°C
NA
NA
NA
NA
Specific Conductance
umhos/c
NA
NA
NANA
--
--
--
--
--
--
--
-
m--
Dissolved Oxygen
mg/L
NA
NA
NA
NA
Oxidation Reduction Potentia
mV
NA
NA
NA
NA
Total Number 544 Total Number of Exceedances: 13 23 2 1 0 0 0 15 162 33
of Anal ses:

Summary of Duke Energy Background Private
Well Sampling Data
Total Number of 4,995 Total Number of Exceedances: 271 293 123 48 42 55 0 160 1,514 34
Analyses:
Frequenty
Frequency of
q ty
Range of Detected
Frequency Detected Above:
Frequency of Reporting Limits Above:
Frequency of
Background
�
Detection
Detects Below All
Threshold Value
Constituents
Units
of Detection
Percent
Concentrations
2L (a)
DHHS (b)
MCL (c)
RSL (d)
2L (a)
DHHS (b)
MCL (c)
RSL (d)
Screening Levels
(BTV) (g)
Constituents Listed in Appendix III (Detection Monitoring) of the CCR Rule (e)
Boron
ug/L
27 / 185
15%
5.1 113
0
0
0
0
0
0
27
113
Calcium
ug/L
185 / 185
100%
14 195,000
--
--
--
150,923
Chloride
mg/L
54 / 54
100%
0.62 40
0
0
0
0
0
0
54
47.01
pH
su
52 / 52
100%
4.88 11.7
5
--
5
0
--
0
47
11.7
Sulfate
mg/L
52 / 54
96%
0.26 170
0
0
0
0
0
0
52
275.3
Total Dissolved Solids
mg/L
40 / 40
100%
42 520
1
--
1
0
--
0
39
584.9
Constituents Listed in Appendix IV (Assessment Monitori ng) of the CCR Rule (f)
Antimony
ug/L
94 / 185
51%
0.5 1.5
48
48
0
0
0
0
0
0
46
1.5
Arsenic
ug/L
25 / 185
14%
0.52 14.1
1
1
1
25
0
0
0
160
0
3.968
Barium
ug/L
164 / 185
89%
1.5 486
0
0
0
0
0
0
0
0
164
486
Beryllium
ug/L
6/ 185
3%
0.31 0.5
0
0
0
0
0
0
0
0
6
0.385
Cadmium
ug/L
7/ 185
4%
0.01 1.17
0
0
0
0
0
0
0
0
7
0.345
Chromium
ug/L
31 / 185
17%
0.5 157
3
3
2
0
0
0
0
0
28
157
Cobalt
ug/L
20 / 185
11%
0.58 25.9
15
15
--
2
0
0
--
0
5
25.9
Lead
ug/L
104 / 185
56%
0.12 73.2
5
5
5
5
0
0
0
0
99
73.2
Mercury
ug/L
1/ 185
1%
0.27 0.27
0
0
0
0
0
0
0
0
1
NA
Molybdenum
ug/L
48 / 185
26%
0.52 10.8
--
0
--
0
--
0
--
0
48
14.16
Selenium
ug/L
10 / 185
5%
0.59 1.7
0
0
0
0
0
0
0
0
10
1.135
Thallium
ug/L
2/ 185
1%
0.354 0.554
2
2
0
2
0
0
0
0
0
0.554
Constituents Not Identified in the CCR Rule
Vanadium
ug/L
106 / 185
57%
0.318 112
106
106
--
1
42
42
--
0
0
127.8
Aluminum
ug/L
93 / 185
50%
5 32,200
--
3
30
2
--
0
0
0
63
32,200
Copper
mg/L
121 / 185
65%
0.0011 0.992
0
0
0
1
0
0
0
0
120
1.443
Iron
ug/L
119 / 185
64%
10 45,000
42
13
42
2
0
0
0
0
77
45,000
Hexavalent Chromium
ug/L
72 / 115
63%
0.033 73.5
--
61
--
1
--
13
--
0
11
73.5
Magnesium
ug/L
184 / 185
99%
128 46,300
--
--
--
--
88,964
Manganese
ug/L
119 / 185
64%
0.56 4,820
37
13
37
7
0
0
0
0
82
5,915
Nickel
ug/L
37 / 185
20%
0.53 380
1
1
--
0
0
0
--
0
36
380
Potassium
ug/L
185 / 185
100%
123 8,060
--
--
9,555
Sodium
ug/L
185 / 185
100%
763 151,000
16
0
169
151,000
Strontium
ug/L
180 / 181
99%
1.3 2,210
1
--
0
--
0
--
0
179
3,561
Zinc
ug/L
149 / 185
81%
5 2,990
5
5
0
0
0
0
0
0
144
2,990
Total Number of 4,995 Total Number of Exceedances: 271 293 123 48 42 55 0 160 1,514 34
Analyses:

10,00©,
000
Boron - Background Data Comparison
10
DEQ Private Wells USGS Data Duke Background DEQ Background AWWA
(1992 - 2003) Private Wells Primate Wells
35

1040
100
Vanadium - Background Data Comparison
Vanadium Background Concentrations
Detecte:; 351
ND, 149
MATS
75th Percentile
5,7th Percentile
25th Percentile
1
0.1
DEQ Prfvate We IIs USGS Data Duke Background DEQ Background
(1992 - 2403) Private We IIs Private 'Wells
36

Vanadium in Groundwater
Vanadium in Groundwater
u .LUU
❑ .50
0 1
Grid Cell Interpolated Thematic
Grid Cell =1.5 miles
Source:
a as loci
miles
http://portal.ncdenr.org/image/image_gallery?uuid=eb8495e2-b440-4dOa-9998-3d95e6ce5Oab&groupld=38334&t=1391110519151
37

100
10
1
0.1
0,01
Hexavalent Chromium - Background Data
Comparison
Hexavalent Chromium Background Concentrations
MAX
Detected: 252
ND: 222
cted: 52
2
75th Percentile
54th Percentile
25th Percentile
161IN
V
0.001 u_
DEQ Private Wells Duke Background DEQ Background AWWA UCMR3
Private Wells Private Wells Porth Carolina
38

Summary of Background Levels from AWWA and
USEPA UCIVIR3
Background Levels for Boron and Hexavalent
Chromium from American Water Works Association
(AWWA)
Background Levels for Hexavalent Chromium from
USEPA Third Unregulated Contaminant Monitoring
Rule (UCMR3)
AWWA
AWWA
AWWA
Constituents Units
Average
Median
Maximum
Boron (b) ug/L
167.9
40
3321.3
,Hexavalent Chromium (c) ug/L
1.1
0 (d)
52.6
Background Levels for Hexavalent Chromium from
USEPA Third Unregulated Contaminant Monitoring
Rule (UCMR3)
39
Avg Conc
Min
Max
State/Region
Samples
Detects
(ug/L)
(ug/L)
(ug/L)
North Carolina
1519
1019
0.13
0.015
9.1
U.S.
49079
36934
0.58
0.015
97.38
39

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213

Allen Correlation Charts - Boron
Boron vs. Sulfate
Boron vs. Arsenic
400
4
O
0
m 6
c
3.5
350
5
V
300
3
920
0
E
0 2.5
0
250
0
c 2
d
c
u°
1.5
W
♦♦
200
u
1
0
u
E
v 150
m
0.5
0 20 40 60 80 100 120 140
Boron Concentration ([WL)
0
100
0
20 40 60 80 100 120 140
Boron Concentration (µg/L)
50
♦
0 ��—
0 20 40 60 80 100 120 140
Boron Concentration (Ng/L)
Boron vs. Hexavalent Chromium
Boron vs. Arsenic
Boron vs. Vanadium
4
30
0
m 6
c
3.5
5
V
E
3
920
0
z
Y
0 2.5
0
♦
c 2
d
c
u°
1.5
W
♦♦
N ♦
1
E
♦
0.5
0 20 40 60 80 100 120 140
Boron Concentration ([WL)
0
s ♦
0
20 40 60 80 100 120 140
Boron Concentration (µg/L)
Boron vs. Hexavalent Chromium
Boron vs. Vanadium
8
30
0
m 6
c
25
5
V
E
♦
920
0
z
Y
3
2
15
L
♦♦
v
E
0
0 20 40 60 80 100 120 140
Boron Concentration ([WL)
m 10
5
j
0
0
20
40 60 80 100 120 140
Boron Concentration (WJL)
Boron vs. Hexavalent Chromium
9
8
2
c
0
m 6
c
v
c
5
V
E
E 4
0
z
Y
3
2
x2
x
♦♦
1
0
0 20 40 60 80 100 120 140
Boron Concentration ([WL)

Allen Correlation Chart —Boron and Calcium
1 &1-1 DO 0
140DOO
120DOO
100DOO
.2
L.
4-P
SDDOO
60000
40DOO
2aDOO
0
Boron vs. Calcium
0 20 40 0 go 100 1,20 140
Boron Concentration (pg/L)
42

Allen Correlation Charts - Calcium
Calcium vs. Sulfate
400
350
M
300
c
0
250
O
c 200
u
♦
c
m
V
C
a 150
m
m 15
N
♦
c
o♦
100
E
♦
10
i
0
s`
50
♦♦
5
40
♦ ♦ ♦♦
0
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
Calcium vs. Vanadium
30
8
M
25
c
0
20
c
0
♦
c
m
C
♦
m 15
♦
c
o♦
E
♦
10
i
0
s`
♦♦
5
40
♦ ♦ ♦♦
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
Calcium vs. Hexavalent Chromium
9
8
M
2
c
0
m 6
c
m
c 5
0
v
E
E4
0
s`
v
3
c
x
2
v
x
1
0
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
M

ire" •

Roxboro Correlation Charts - Boron
Boron vs. Sulfate
Boron vs. Vanadium
90
80
12
70
10
60
8
c
50
c
c 40
0
6
a
° 30
N
20
4
>
10
0
0 10 20 30 40 50 60 70 80 90 100
Boron Concentration (pg/L)
0.25
0.2
e 0.15
m
Boron vs. Arsenic
0.05
0 +--+-+-
0 10 20 30 40 50 60 70 80 90 100
Boron Concentration (µg/L)
3
2.5
c
0
2
0
v
E 1.5
E
0
Y 1
c
a
v
= 0.5
Boron vs. Hexavalent Chromium
00
0
0 10 20 30 40 50 60 70 80 90 100
Boron Concentration (µg/L)
Boron vs. Vanadium
12
10
i
c
0
8
c
$
c
6
u°
E
m
A
4
>
2
0
0 10 20 30 40 50 60 70 80 90 1
Boron Concentration (µg/L)
3
2.5
c
0
2
0
v
E 1.5
E
0
Y 1
c
a
v
= 0.5
Boron vs. Hexavalent Chromium
00
0
0 10 20 30 40 50 60 70 80 90 100
Boron Concentration (µg/L)

Roxboro C Chart — Boron a n d Calcium
1 000
140000
120000
�
k
100000
g
#
80000
�
0
U
2 £0000
:
_
�
20000
0
Boron vs. Calcium
O 10 20 30 40 50 §O 70 aO 90 100
Boron Concentration (µ L
46
. �
� m
O 10 20 30 40 50 §O 70 aO 90 100
Boron Concentration (µ L
46

Roxboro Correlation Charts - Calcium
Calcium vs. Sulfate
90
80
70
£ 60
c
50
c
a
c 40
V
a
w° 30
VI
20
10
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
Calcium vs. Arsenic
♦
0.25
A
0.2
♦
c 0.15
L
a
c
O
U
♦
0.1
c
d
♦
Q
♦
0.05
♦
0
♦
Calcium Concentration (Ng/L)
♦
Calcium vs. Arsenic
♦
0.25
0.2
♦
c 0.15
L
a
c
O
U
♦
0.1
c
d
♦
Q
♦
0.05
♦
0
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (Ng/L)
Calcium vs. Vanadium
12
10
s
c
0
c
v 6
c
v°
E
m 4
N
2
0
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
Calcium vs. Hexavalent Chromium
3
,.., 2.5
c
m 2
c
v
c
O
V
E 1.5
J
E
0
t
V
c 1
d
N
N
d
0.5
0
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
♦
♦
♦
♦
♦
♦
♦
♦
Calcium vs. Hexavalent Chromium
3
,.., 2.5
c
m 2
c
v
c
O
V
E 1.5
J
E
0
t
V
c 1
d
N
N
d
0.5
0
0 20000 40000 60000 80000 100000 120000 140000 160000
Calcium Concentration (µg/L)
♦
♦
♦
♦
♦

Sutton Well Map
48
MLAI�
MIN
HEW A;E A
k
tee. eA E:IF:,k
Sutton Well Map
48

Sutton Correlation Charts - Boron
2.5
8
u°
1
L
a
Q
0.5
Boron vs. Arsenic
0 100 200 300 400 500 600 700 800
Boron Concentration (µg/L)
Boron vs. Vanadium
1.4
1.2
1
0
0
0.8
c
v
—
c
O
U
0.6
E
a
c
>- 0.4
0.6
c
s
0
u
E 0.5
0.2
E -_-
°
0.4
L
u
0
0 100 200 300 400 500 600 700 800
Boron Concentration (Ng/L)
Boron vs. Hexavalent Chromium
1
0.9
0.8
0
0.7
0.6
c
0
u
E 0.5
°
0.4
L
u
nv 0.3
m
a 0.2
x
0.1
0
0 100 200 300 400 500 600 700 800
Boron Concentration (Ng/L)
49

Sutton Correlation Charts —Boron and Calcium
700 DO
600 DO
50000
400 DO
30000
20000
.10000
a
Boron vs. Calcium
0 100 200 WO 400 500 600 700 800
Boron Concentration (pg/L}
50

Sutton Correlation Charts - Calcium
Calcium vs. Arsenic
2.s
1.2
2
1
i
°
0.8
a 1.5
.2
d
0
0
u
c
c
u°
m
c
1
E
> 0.4
a
a`
s
o.s
♦
0.3
0
0 10000 20000 30000 40000 50000 60000 70(
Calcium Concentration (pg/L)
= 0.2
0
0 10000 20000 30000 40000 50000 60000 70000
Calcium Concentration (pg/L)
Calcium vs. Vanadium
1.4
1.2
0.9
1
0
°
0.8
c
0 0.7
d
0
0
u
0.6
E
'v
m
c
U
E 0.5
> 0.4
E
°
s
0.2
0.3
0
0 10000 20000 30000 40000 50000 60000 70(
Calcium Concentration (pg/L)
Calcium vs. Hexavalent Chromium
1
0.9
0.8
c
0 0.7
0.6
0
U
E 0.5
E
°
0.4
L
v
w
0.3
x
= 0.2
0.1
0
0 10000 20000 30000 40000 50000 60000 70000
Calcium Concentration (pg/L)

Summary
The DEQ private well data set is very similar in results to the DEQ background data set and
to the Duke background data set:
Of the 14,970 DEQ private well analyses, approximately 7% are above a NC screening level
Of the 544 DEQ background well analyses, approximately 4% are above a NC screening level
Of the 4995 Duke background well analyses, approximately 7% are above a NC screening level
The main drivers for the NC screening levels are vanadium and hexavalent chromium
Comparison of the DEQ private well results for both constituents to background levels from various
sources (local, state, national) indicate that the results are consistent with these background data
sets
Correlation evaluations for a subset of the facilities demonstrate that other than Sutton,
there is no demonstrated signature of coal ash -derived constituent impacts on the private
wells in the vicinity of the Duke facilities
Overall conclusion — the private well results are consistent with background and do not
exhibit a coal ash signature
52

LAMA Requirements
GAPs met CAMA groundwater assessment requirements
Contained required elements:
Description of receptors and significant exposure pathways
Assessment of the horizontal and vertical extent of contamination
Description of all significant factors affecting movement and transport
Description of features influencing the chemical and physical character
Approved by the Department
Effectively implemented
Department has valid information to prioritize the basins
No reason to disregard information now available
Opportunities to collect information for increased resolution of the
CSA results
53

Conclusion
Site investigation concludes groundwater flow is away from receptors
No imminent hazard to human health or the environment
No offsite migration to receptors
No appreciable benefit between excavation and cap -in-place
Duke Energy
believes
this
supports a low risk determination for the
groundwater
factors
in
the
CAMA
analysis
54

Conclusion
Correlation evaluations for a subset of the facilities demonstrate that other
than Sutton, there is no demonstrated signature of coal ash -derived
constituent impacts on the private wells in the vicinity of the Duke facilities
Overall conclusion — the private well results are consistent with background
and do not exhibit a coal ash signature
NCDEQ's duty is a proposed classification on 12/31/2015 based on the
evidence before it
CAMA by design contemplates additional data, including public review,
should continue to be developed and considered before DEQ issues it's
proposed classifications to the Commission on May 20, 2016
Duke agrees to continue to refine the analysis, including installation of data
gap wells and completion of the CAP Part 2 to further validate those
conclusions
Duke stands ready to provide additional data and analysis as requested by
NCDEQ throughout the evaluation process contemplated by CAMA to occur
over the next six months at a minimum
55

� DUKE
ENERGY
56