2016-0418_Duke_App_C_Buck_F

4ERICH
:_'•: •►
www.haleyaldrich.com
EVALUATION OF WATER SUPPLY WELLS IN THE VICINITY OF DUKE
ENERGY COAL ASH BASINS IN NORTH CAROLINA
APPENDIXC - BUCK STEAM STATION
by Haley & Aldrich, Inc.
Boston, Massachusetts
for Duke Energy
File No. 43239
April 2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Table of Contents
Page
List of Tables
List of Figures
iii
List of Attachments
iv
List of Acronyms
v
C. Buck
1
C.1 INTRODUCTION
1
C.1.1
Facility Location and Description
1
C.1.1.1 Facility Setting
1
C.1.1.2 Past and Present Operations
2
C.1.1.3 Facility Geological/Hydrogeological Setting
3
C.1.2
Current CAMA Status
4
C.1.2.1 Receptor Survey, September 2014, updated November 2014
5
C.1.2.2 Comprehensive Site Assessment, Round 1 Sampling Event, March —
August 2015
5
C.1.2.3 Round 2 Sampling Event, September 2015
5
C.1.2.4 Corrective Action Plan — Part 1, 20 November 2015
6
C.1.2.5 Round 3 (November 2015) and Round 4 (December 2015) Background
Well Sampling
6
C.1.2.6 Corrective Action Plan — Part 2, 19 February 2016
6
C.1.3
Investigation Results
7
C.1.4
Selected Remedial Alternative and Recommended Interim Activities
8
C.1.5
Risk Classification Process
8
C.1.6
Purpose and Objectives
11
C.2 WATER SUPPLY WELL DATA EVALUATION
12
C.2.1
Data Sources
12
C.2.2
Screening Levels
13
C.2.3
Results
13
C.3 STATISTICAL EVALUATION OF BACKGROUND
14
C.3.1
Initial Data Evaluation
15
C.3.1.1 Regional Background Water Supply Well Data
15
C.3.1.2 Facility Background Monitoring Well Data
15
C.3.2
Raw Data Evaluation
16
C.3.2.1 Regional Background Water Supply Well Data
17
APRIL 2016 i %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C.5 GROUNDWATER CHARACTERISTICS EVALUATION
C.5.1
C.3.2.2 Facility Background Monitoring Well Data
C.3.3
Testing of Statistical Assumptions
C.5.3
C.3.3.1 Regional Background Water Supply Well Data
C.3.3.2 Facility Background Monitoring Well Data
C.3.4
BTV Estimates
C.3.5
Comparison of Water Supply Well Data to the Regional BTVs
C.4 GROUNDWATER FLOW EVALUATION
C.4.1
Introduction
C.4.2
Site Geology
C.4.3
Site Hydrogeology
C.5.4.1 Box Plot Comparison
C.4.3.1 Site Conceptual Model
C.5.4.2 Correlation Plot Evaluation
C.4.3.2 Groundwater Flow Direction
C.5.4.3 Piper Plot
C.4.3.3 Groundwater Seepage Velocities
Conclusions
C.4.3.4 Constituents Associated with CCR
C.7 REFERENCES
C.4.3.5 Extent of Boron Exceedances in Groundwater
C.4.3.6 Bedrock Flow and Depth of Water Supply Wells
C.4.3.7 Groundwater Mounding
C.4.3.8 Summary
C.4.4
Water Supply Well Capture Zone Analysis
C.4.5
Summary and Conclusions
C.5 GROUNDWATER CHARACTERISTICS EVALUATION
C.5.1
Evaluation Approach
C.5.2
CCR -Related Constituents Screening for Signature Development
C.5.3
Data Analysis Methods
C.5.3.1 Data Sources
C.5.3.2 Data Aggregation
C.5.3.3 Box Plot
C.5.3.4 Correlation Plot
C.5.3.5 Piper Plot
C.5.4
Evaluation Results
C.5.4.1 Box Plot Comparison
C.5.4.2 Correlation Plot Evaluation
C.5.4.3 Piper Plot
C.5.5
Conclusions
C.6 SUMMARY
C.7 REFERENCES
17
17
18
18
18
19
20
20
20
21
21
22
23
23
24
25
25
26
26
27
27
28
29
30
30
30
30
31
31
32
32
33
36
38
39
40
APRIL 2016 ii %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
List of Tables
Title
Table No.
Title
C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
C2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
C2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
C4-3
2L Screening Levels
C2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
C4-5
MCL Screening Levels
C2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
DHHS Screening Levels
C2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
RSL Screening Levels
C2-9
Do Not Drink Letter Summary
C3-1
NCDEQ and Duke Energy Background Water Supply Well Data
C3-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
C3-3
Background Data Statistical Evaluation
C3-4
Comparison of NCDEQ Water Supply Well Sampling Data to Background
Threshold Values
C3-5
Comparison of NCDEQ Water Supply Well Sampling Data to Facility Specific
Background Threshold Values
C4-1
Hydrostratigraphic Layer Properties — Horizontal Hydraulic Conductivity
C4-2
Estimated Groundwater Seepage Velocities
C5-1
Site -Specific Distribution Coefficient (Kd)
C5-2
Coal Ash Indicator Concentrations Observed in the Water Supply Wells of Low
Oxygen and High Detected Boron Concentrations
List of Figures
Figure No.
Title
C1-1
Location Map
C1-2
Key Features
C1-3
Location of Water Supply Wells and Facility Groundwater Conditions
C3-1
Facility Background Wells
C4-1
Two -Medium Groundwater System
C4-2
Slope -Aquifer System
C4-3
Regolith as Primary Groundwater Storage
C4-4
Transition Zone as Primary Transmitter of Impacted Groundwater
C4-5
Water Table Surface — Shallow Wells — Groundwater Measurement Dates 7/6
and 7/7, 2015
APRIL 2016 iii U'CH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C4-6
Potentiometric Surface — Deep Wells — Groundwater Measurement Dates 7/6
and 7/7, 2015
C4-7
Potentiometric Surface — Bedrock Groundwater Elevations — Groundwater
Measurement Dates 7/6 and 7/7, 2015
C4-8
Water Table Surface Map — Shallow Wells— Groundwater Measurement Date
9/21/2015
C4-9
Potentiometric Surface Map — Deep Wells— Groundwater Measurement Date
9/21/2015
C4-10
Potentiometric Surface Map — Bedrock Wells — Groundwater Measurement
Date 9/21/2015
C4-11
Horizontal Hydraulic Conductivity Measurements
C4-12
Site Conceptual Model — Plan View Map — Area of Boron Exceedances of
2L Standards
C4-13
Cross -Section Conceptual Site Model
C4-14
Mounding Effect
C4-15
Groundwater Affected by Pumping
C5-1
Pourbaix Diagrams for Iron and Manganese with Measured Eh and pH from Site
Monitoring Wells
C5-2
Example Box Plot and Piper Plot
C5-3
Box Plot Comparison for Major Coal Ash Constituents
C5-4
Box Plot Comparison for Barium and Cobalt
C5-5
Box Plot Comparison for Dissolved Oxygen, Iron, and Manganese
C5-6
Bedrock Groundwater Wells and Direction of Groundwater Flow
C5-7
Correlation Plot for Boron and Sulfate
C5-8
Correlation Plot for Boron and Dissolved Oxygen
C5-9
Sampled Water Supply Wells
C5-10
Piper Plot Evaluation - Ash Basin Porewater and Facility Downgradient Bedrock
Wells
C5-11
Piper Plot Evaluation - Water Supply, Regional Background, and Facility
Upgradient Bedrock Wells
C5-12
Piper Plot Evaluation - Water Supply, Regional Background, Facility Bedrock, and
Ash Basin Porewater Wells
C5-13
Concentration Variability of pH, Boron, and Sulfate in Crystalline -Rock Aquifers
List of Attachments
Attachment Title
C-1 Histograms and Probability Plots for Selected Constituents
C-2 Results of Statistical Computations
C-3 Method Computation Details
APRIL 2016 iv %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
List of Acronyms
2L Standards North Carolina Groundwater Quality Standards as specified in Title 15A NCAC.0202L
BR Bedrock
BTV Background Threshold Value
CAMA North Carolina Coal Ash Management Act of 2014
CAP Corrective Action Plan
CC Confidence Coefficient
CFR Code of Federal Regulations
CCR Coal Combustion Residuals
CSA Comprehensive Site Assessment
D Deep
EPRI Electric Power Research Institute
GOF Goodness -Of -Fit
HDR HDR, Inc.
HSL Health Screening Levels
IID Independent, Identically Distributed
IMAC Interim Maximum Allowable Concentrations
IQR Interquartile Range
KM Kaplan -Meier
pg/L Micrograms per Liter
MCL Maximum Contaminant Level
MDL Method Detection Limit
MNA Monitored Natural Attenuation
NCAC North Carolina Administrative Code
NCDEQ North Carolina Department of Environmental Quality
ND Non -Detect
NPDES National Pollutant Discharge Elimination System
NCDHHS North Carolina Department of Health and Human Services
PPBC Proposed Provisional Background Concentration
ROS Robust Regression on Order Statistics
RSL Risk -Based Screening Level
S Shallow
SCM Site Conceptual Model
SMCL Secondary Maximum Contaminant Level
TDS Total Dissolved Solids
TZ Transition Zone
UPL95 95% Upper Prediction Limit
USEPA U.S. Environmental Protection Agency
USGS U.S. Geological Survey
UTL95-95 Upper Tolerance Limit with 95% confidence and 95% coverage
APRIL 2016 v %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C. Buck
The contents of this document supplement previous work completed by Duke Energy to meet the
requirements of the North Carolina Coal Ash Management Act of 2014 (CAMA) for the Buck Steam
Station (Buck or site), a coal-fired generating station. The purpose of this document is to provide the
North Carolina Department of Environmental Quality (NCDEQ) with the additional information it needs
to develop a final risk classification for the Buck ash basin under the CAMA requirements. A technical
weight of evidence approach has been used to evaluate the available data for the Buck site, and the
evaluation demonstrates that groundwater utilized by local water supply wells near the Buck coal ash
impoundment is not impacted by coal ash sources. These results indicate that a Low classification for
the Buck Steam Station under the CAMA is warranted.
C.1 INTRODUCTION
The first section of this document provides a description of the facility location, setting, past and present
operations, a summary of activities conducted to meet the CAMA requirements, and a summary of the
on-site and background data evaluation findings and recommendations, of the following reports:
• Comprehensive Site Assessment (HDR, Inc. [HDR], 2015a);
• Corrective Action Plan Part 1 (HDR, 2015b); and
• Corrective Action Plan Part 2 (HDR, 2016).
A review of the risk classification process and the status of that process are also provided.
This report provides technical evaluations in four important assessment areas: 1) an evaluation of the
private and public water supply well data collected by the NCDEQ with respect to groundwater
standards and screening levels; 2) additional statistical analysis of regional background groundwater
data, and facility -specific background groundwater data; 3) a more comprehensive evaluation of
groundwater flow with respect to local water supply wells, including a water supply well capture zone
analysis; and 4) a detailed comparison of facility -specific coal ash groundwater chemistry, background
groundwater chemistry (both regional and facility -specific), and water supply well chemistry.
C.1.1 Facility Location and Description
Duke Energy owns and operates Buck, which is located in Rowan County near the town of Salisbury,
North Carolina (Figure C1-1).
C.1.1.1 Facility Setting
Buck occupies 640 acres of land and is located on the Yadkin River as shown on Figure C1-2. Properties
located within a 0.5 -mile radius of the Buck ash basin compliance boundary generally consist of
residential, agricultural, and undeveloped properties located in Rowan County to the west, south, and
east of the ash basin. The Yadkin River flows from west to east along the northern boundary. Hunting
APRIL 2016 1 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
and game lands are located north of the ash basin across the Yadkin River in Davidson County. Buck is
zoned as Industrial by Rowan County. Properties to the east and south are zoned Rural Agricultural.
Properties to the west are zoned as either Rural Agricultural with Agricultural Overlay or 1-85 Economic
Development District.
Per the North Carolina Administrative Code (15A NCAC 02L.0102), "Compliance Boundary' means a
boundary around a disposal system at and beyond which groundwater quality standards may not be
exceeded, and only applies to facilities that have received a permit issued under the authority of North
Carolina General Statute (G.S.) 143-215.1 or G.S. 130A. The ash basin compliance boundary is defined in
accordance with 15A NCAC 02L.0107(a) as being established at either 500 feet from the waste boundary
or at the property boundary, whichever is closer to the waste.
A total of 166 private water supply wells are located within a 0.5 -mile radius of the Buck ash basin
compliance boundary (Figure C1-3). Ten additional private water supply wells are assumed at
residences located within a 1,500 -foot radius of the Buck ash basin compliance boundary based on the
absence of municipal water lines. Two public water supply wells were identified within a 1,500 -foot
radius of the Buck ash basin compliance boundary. One water supply well was identified within the
Duke Energy property boundary that supplies drinking water to the site (Figure C1-2).
C.1.1.2 Past and Present Operations
Buck was a six -unit coal-fired electricity generating facility along the Yadkin River. Buck Units 1 and 2
operated from 1926 to 1979. Units 3 and 4 were retired in mid -2011, and Units 5 and 6 were retired
in April 2013. There are no coal-fired units currently in operation at Buck.
Construction of the Buck Combined Cycle Station natural gas facility began in 2008, and commercial
operation of the natural gas facility began in late 2011. Three combustion turbine units formerly
operated adjacent to the coal-fired units and were retired in October 2012. Buildings and other
structures associated with power production are generally located in the northwestern section of the
site. The eastern portion of the site is generally wooded with the exception of the remaining ponded
areas of the ash basin.
The major ash -related structures at Buck include Cell 1, Cell 2, and Cell 3 of the ash basin, a dry ash
storage area, and associated embankments and outlet works. The ash basin is located to the south
(Cell 1) and southeast (Cells 2 and 3) of the retired Buck Units 1 through 6 and the Buck Combined Cycle
Station (Figure C1-2).
All coal ash from Buck was disposed of in the ash basin from approximately 1957 until 2013. Fly ash
precipitated from flue gas and bottom ash collected in the bottom of the boilers were sluiced to the ash
basin using conveyance water withdrawn from the Yadkin River. The ash basin system is operated as an
integral part of the station's wastewater treatment system, which receives permitted and variable
discharges from the ash removal system, coal pile runoff, landfill leachate, the station yard drain sump,
and site stormwater.
APRIL 2016 2 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
The dry ash storage area is located between Cell 1 and Cell 2 has been utilized for storage of dredged
ash from Cell 1. This unlined storage area is located topographically upgradient and adjacent to the east
side of Cell 1. The dry ash storage area was constructed in 2009 by excavating ash within the eastern
half of Cell 1 in order to provide additional capacity for sluiced ash, and covers approximately 14 acres.
Duke Energy is authorized to discharge treated wastewater from Buck to receiving waters, designated as
the Yadkin River in the Yadkin -Pee Dee River Basin, in accordance with National Pollutant Discharge
Elimination System (NPDES) Permit NC0004774, which was most recently renewed on 1 January 2012.
Most of the discharges associated with Buck were reduced or eliminated as a result of decommissioning
Buck. There are no active or inactive permitted solid waste facilities (landfills) at the site.
C.1.1.3 Facility Geological/Hydrogeologica/ Setting
Buck is located in the geologic region known as the Piedmont Province which stretches from New Jersey
to central Alabama. The widest portion of the Piedmont is located in North Carolina. Topography at the
Buck site ranges from an approximate high elevation of 734 feet at the communications cell tower near
the southwest edge of the property to an approximate low elevation of 620 feet at the Yadkin River on
the northern margin of the site, with a total elevation change of approximately 114 feet over an
approximate distance of 0.9 miles. Surface water drainage flow generally follows site topography from
the south to north across the site except where natural drainage patterns have been modified by the
ash basin or other construction features.
Surface water features located at the Buck site are shown in Figure C1-2. The site is located within the
Yadkin -Pee Dee River basin about two miles northwest of High Rock Lake. The Yadkin River at Buck has
a classification of WS -V. Class WS -V waters are protected as water supply sources which are generally
upstream and draining to Class WS -IV waters or waters used by industry to supply their employees with
drinking water or as waters formerly used as water supply. These waters are also protected for Class C
uses which include secondary recreation, fishing, wildlife, fish consumption, aquatic life including
propagation, survival and maintenance of biological integrity, and agriculture. Secondary recreation
includes wading, boating, and other uses involving human body contact with water where such activities
take place in an infrequent, unorganized, or incidental manner.
Three small farm ponds are located on adjacent properties south of Buck. The easternmost pond is the
source of a stream that drains from south to north across the easternmost portion of the site into the
Yadkin River. The western farm ponds both drain from south to north into the southern end of Cell 1.
An unnamed stream also exists near the western edge of Buck near a transmission line corridor and
drains into the Yadkin River. Portions of Cells 1, 2, and 3 of the ash basin also currently contain ponded
areas of water. None of these ponds or streams is classified.
Based on the site investigation, the groundwater system in the natural materials (alluvium, soil,
soil/weathered bedrock, and bedrock) at Buck is a fractured bedrock system and is an unconfined,
connected system of flow layers. The Buck groundwater system is divided into three layers referred to
in this report as the shallow (S), deep transition zone (D or TZ), and bedrock (BR) flow layers to
distinguish the flow layers within the connected aquifer system.
APRIL 2016 3 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
In general, groundwater within the shallow and deep layers (S and D or TZ wells) and bedrock layer
(BR wells) flows from south radially to the northwest and northeast toward the Yadkin River. The
general direction of groundwater flow can be approximated from the ground surface topography with
groundwater discharge to streams and the Yadkin River, and from groundwater elevation
measurements. Two unnamed tributaries of the Yadkin River are located along the eastern and western
sides of the Buck site. A topographic divide is located approximately along Leonard Road, to the south
of the ash basin. The topographic divide likely also functions as a groundwater hydrologic boundary.
The Yadkin River is located to the north of Buck. The predominant direction of groundwater flow from
the ash basin is in a northerly direction, generally towards the Yadkin River, with localized components
of flow toward the unnamed tributaries on the eastern and western sides of the site.
More detail on the site hydrogeology is provided in Section C.4.
C.1.2 Current CAMA Status
The CAMA is primarily administered by the NCDEQ. The CAMA requires the NCDEQ to, as soon as
practicable, but no later than 31 December 2015, prioritize for the purpose of closure and remediation
coal combustion residuals (CCR) surface impoundments, including active and retired sites, based on
these sites' risks to public health, safety, and welfare, the environment, and natural resources.
To this end, CAMA includes the following requirements for coal -fueled facilities that manage coal ash or
CCR, the material that results from the combustion of coal for the creation of electric energy:
• An assessment of groundwater at CCR surface impoundments; and
• Corrective action for the restoration of groundwater quality at CCR surface impoundments.
Duke Energy owns and operates, or has operated, 14 coal -fueled electric generating facilities in the state
of North Carolina. Per the CAMA, the investigation reporting milestones for each facility include the
following:
• Groundwater Assessment Work Plan;
• Groundwater Assessment Report, referred to as a Comprehensive Site Assessment (CSA); and
Corrective Action Plan (CAP), Note: As agreed with NCDEQ the CAP reports were prepared in
two parts: CAP -1 and CAP -2.
Duke Energy has submitted the Groundwater Assessment Work Plans, CSAs, and CAP reports as required
by the CAMA schedule. The CSA reports were submitted for all facilities by 2 September 2015. The
CAP -1 reports were submitted for all facilities by 8 December 2015. CAP -2 reports were submitted by
7 March 2016. The CAP -2 reports include a site-specific human health and ecological risk assessment
that will be used to inform the remedial decision making for each facility.
The CAMA also requires a survey of drinking water supply wells and replacement of water supplies if
NCDEQ determines a well is contaminated by CCR -derived constituents. NCDEQ has yet to make such a
determination under the CAMA. Duke Energy provided the NCDEQ with an evaluation of the NCDEQ-
APRIL 2016 4 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
sampled water supply well (private well) data in December 2015 (Haley & Aldrich, 2015). This report
serves to augment the evaluations provided in the December 2015 report.
A brief summary of the objectives and approach for Receptor Survey, the CSA, CAP -1, CAP -2, and
multiple sampling rounds is provided below:
C.1.2.1 Receptor Survey, September 2014, updated November 2014
The receptor survey was conducted by Duke Energy for the purpose of identifying drinking water wells
within a 0.5 -mile (2,640 -foot) radius of the Buck compliance boundary. Supplemental receptor survey
information was obtained from responses to water supply well survey questionnaires mailed to property
owners within the required distance requesting information on the presence of water supply wells, well
details, and well usage (HDR, 2014a, 2014b). Figure C1-3 shows the water supply wells within this 0.5 -
mile radius.
C.1.2.2 Comprehensive Site Assessment, Round 1 Sampling Event, March —August 2015
The purpose of the Buck CSA was to collect information necessary to characterize the extent of impacts
resulting from historical production and storage of coal ash, evaluate the chemical and physical
characteristics of CCR constituents, investigate the geology and hydrogeology of the site including
factors relating to contaminant transport, and examine risk to potential receptors and exposure
pathways. The following assessment activities were performed as part of the CSA (HDR, 2015a):
• Installation of 64 groundwater monitoring wells and 44 soil borings.
• Collection of groundwater sampled from 63 groundwater monitoring wells.
• Collection of soil, ash, seep, surface water, and sediment samples.
• Completion of soil borings and installation of groundwater monitoring wells to facilitate
collection and analysis of chemical, physical, and hydrogeological parameters of subsurface
materials encountered within and beyond the waste and Compliance Boundary.
• Evaluation of laboratory analytical data to support the development of the site conceptual
model (SCM).
• Update of the receptor survey previously completed in September 2014
(updated November 2014) (HDR, 2014a, 2014b).
• Completion of a screening -level human health and ecological risk assessment.
C. 1. 2.3 Round 2 Sampling Event, September 2015
A total of 73 groundwater monitoring wells were sampled during the Round 2 event including, 63 wells
installed during the CSA, 8 voluntary monitoring wells, 1 ash basin closure well (BC -18), and 1 water
supply well (PWS -0180647). Samples were analyzed for total and dissolved CCR constituents.
APRIL 2016 5 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C. 1. 2.4 Corrective Action Plan — Part 1, 20 November 2015
The purpose of the CAP -1 report was to summarize CSA findings, evaluate background conditions by
calculating Proposed Provisional Background Concentrations (PPBCs) for soil and groundwater, evaluate
exceedances per sample medium with regard to PPBCs, refine the SCM, and present the results of the
groundwater flow and contaminant fate and transport model, and the groundwater to surface water
interaction model.
The Buck CAP -1 (HDR, 2015b) presented PPBCs for groundwater, and soil. The PPBCs and other
applicable regulatory standards were compared to the current site data from each of these media to
determine the CCR constituents to be addressed in a potential corrective action to be proposed in
CAP -2. This evaluation is updated in the subsequent CAP -2 report (HDR, 2016), as additional data were
collected and evaluated against regulatory standards for each medium.
Groundwater modeling of the fate and transport of CCR constituents identified to exceed standards was
conducted to inform the corrective action plan. Three modeling scenarios were completed to assess the
impact of potential corrective actions as follows: existing conditions; the effect of capping the CCR
source areas to reduce rainfall infiltration; and the effect of excavating CCR materials. Each scenario
was modeled over a 250 -year timeframe.
Recommendations for future work were provided at the end of the CAP -1 report as follows: additional
sampling of radiological parameters, updating the SCM with the second round of sampling in the CAP -2
report; addition of monitoring wells upgradient of the source area; collection of surface water samples
from the tributaries on the eastern and western sides of the site; and continued collection and statistical
evaluation of data from background monitoring wells.
C.1.2.5 Round 3 (November 2015) and Round 4 (December 2015) Background Well Sampling
In response to a NCDEQ request, Duke Energy collected two rounds of groundwater samples from
background wells. Facility background wells within the compliance boundary were identified and based
on the SCM during preparation of the CSA Work Plan. Groundwater sample collection and analysis were
conducted using procedures described in the CSA Report.
See Section C.3 for a statistical evaluation of background concentrations.
C.1.2.6 Corrective Action Plan — Part 2, 19 February 2016
The purpose of the CAP -2 report is to provide the following:
A description of exceedances of groundwater quality standards, surface water quality standards,
and sample results greater than the Interim Maximum Allowable Concentrations (IMAC) and
North Carolina Department of Health and Human Services (NCDHHS) health screening levels
(HSL, for hexavalent chromium only);
• Present Round 3 and Round 4 background sampling results;
• A refined SCM;
APRIL 2016 6 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
• Refined groundwater flow and fate and transport model results;
• Refined groundwater to surface water model results;
• Site geochemical model results;
• Findings of the human health and ecological risk assessment;
• Evaluation of methods for achieving groundwater quality restoration;
• Conceptual plan(s) for recommended proposed corrective action(s);
• A schedule for implementation of the proposed corrective action(s); and
• A plan for monitoring and reporting of the effectiveness of the proposed corrective action(s).
Groundwater data collected during the four sampling rounds were compared to the following standards:
• North Carolina Groundwater Quality Standards as specified in Title 15A NCAC.0202L (2L
Standards);
• IMACs;
• NCDHHS HSL (hexavalent chromium only); and/or
• Site-specific PPBCs for groundwater at Buck.
C.1.3 Investigation Results
Based on the CSA, CAP -1, and CAP -2 results, general observations regarding the spatial distribution of
constituents in groundwater at Buck are depicted in Figure C1-3 and are described as follows:
• Concentrations of constituents that exceed the applicable standard in groundwater are a result
of both naturally -occurring conditions and releases from CCR material contained in the ash basin
and ash storage area.
• Impacts from CCR -constituents in groundwater are spatially limited to areas beneath the ash
basin and ash storage area, downgradient to the north/northeast of the ash basin and ash
storage area within the compliance boundary.
• Groundwater impacts are present in the shallow soil/alluvium, deep soil/weathered bedrock
and bedrock flow layers that may be naturally -occurring.
• The groundwater to surface water interaction modeling results indicate that no surface water
quality criteria are exceeded for constituents modeled at the edge of the mixing zone in the
Yadkin River.
• Groundwater flow direction is generally in a north and northeasterly direction towards the
Yadkin River.
Constituents identified to exceed the applicable state and federal regulatory standards are listed by
location below:
• Ash samples: arsenic, barium, boron, cobalt, iron, manganese, selenium, and vanadium.
APRIL 2016 7 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
• Ash pore water samples: antimony, arsenic, barium, boron, chromium, cobalt, hexavalent
chromium, iron, lead, manganese, pH, thallium, total dissolved solids (TDS), and vanadium.
• Ash basin surface water: aluminum, antimony, arsenic, cadmium, chromium, cobalt, copper,
iron, lead, manganese, mercury, thallium, zinc, and TDS.
• Groundwater: antimony, arsenic, barium, boron, chromium, cobalt, hexavalent chromium, iron,
manganese, nickel, pH, selenium, sulfate, thallium, TDS, and vanadium.
Boron, sulfate, and TDS, exceeded their 2L Standards and PPCBs either beneath or downgradient of the
ash basin and dry ash storage area, are considered to be detection monitoring constituents in Code of
Federal Regulations Title 40 (40 CFR) Section 257 Appendix III of USEPA's Hazardous and Solid Waste
Management System; Disposal of Coal Combustion Residuals from Electric Utilities CCR Rule (USEPA,
2015a). The U.S. Environmental Protection Agency (USEPA) detection monitoring constituents are
potential indicators of groundwater contamination from CCR as these constituents are associated with
CCR and move with groundwater flow unlike other constituents whose movement is impeded by
chemical or physical interactions with soil and weathered rock.
C.1.4 Selected Remedial Alternative and Recommended Interim Activities
The recommended remedial alternative selected for Buck is the combination of two remediation
technologies: 1) capping the ash basin, and 2) monitored natural attenuation (MNA). Groundwater
modeling showed that the construction of an engineered cap to reduce infiltration would also reduce
the movement of groundwater from the ash basin.
Geochemical modeling demonstrated that CCR constituents in groundwater are removed from
groundwater with precipitation of iron and manganese. Fe -Mn -AI oxides adsorbed onto clays were
found in samples and were identified as a primary attenuation mechanism which results in the reduction
in concentration of CCR constituents in groundwater. A MNA program including collection and
evaluation of groundwater data would be implemented until remedial objectives are reached.
Installation of approximately 22 additional monitoring wells and two borings is underway to address the
additional assessment needs identified in the CSA report. The data collected from these new
explorations will be used to refine the SCM and conduct a Tier III MNA evaluation (USEPA, 2007) in 2016.
Interim and effectiveness monitoring plans are also scheduled to begin in 2016. The final closure option
may be modified based on the final risk classification proposed by the NCDEQ.
C.1.5 Risk Classification Process
Duke Energy is required by the CAMA to close the Buck ash basin system no later than 1 August 2029 or
as otherwise dictated by NCDEQ risk ranking classification. On 31 January 2016, NCDEQ released draft
proposed risk classifications for Duke Energy's coal ash impoundments in North Carolina (NCDEQ, 2016).
The proposed risk classification for the Buck ash basin was low -to -intermediate. Risk classifications were
based upon potential risk to public health and the environment. A public meeting was held by NCDEQ
regarding the proposed risk classification for the Buck ash basin. NCDEQ will release the final risk
classifications after review of public comments.
APRIL 2016 8 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Upon further review, the NCDEQ will issue either a final Low classification or a final Intermediate
classification for the Buck ash basin. The following are the classification factors as provided in the
NCDEQ (2016) document:
Groundwater Key Factor:
If either it is determined that no receptor is impacted by the coal ash impoundments or
alternate water is made available to all residents whose wells are being impacted by coal
ash impoundments, the overall groundwater risk would be low. Based on the information
received to date, there appears to be no downgradient receptors located 1,500 feet
downgradient of the impoundment compliance boundary. The following data gaps related
to groundwater uncertainty include:
- Incomplete capture zone modeling in fractured bedrock for up -gradient and side -
gradient supply wells in the immediate vicinity of the impoundments,
- Incomplete geochemical modeling, and
- Incomplete background concentration determination.
Based on the data provided in CSA Report and results of the groundwater modeling results
presented in the CAP Report, the number of down -gradient receptors (well users) 1,500 feet
from the compliance boundary that are potentially or currently known to be exposed to
impacted groundwater from source(s) or migration pathways related to the CCR
impoundments:
- Ash Basin Cell 1. LOW RISK. There are no reported supply wells within 1,500 feet
downgradient of the impoundment compliance boundary.
- Ash Basin Cell 2. LOW RISK. There are no reported supply wells within 1,500 feet
downgradient of the impoundment compliance boundary.
- Ash Basin Cell 3. LOW RISK. There are no reported supply wells within 1,500 feet
downgradient of the impoundment compliance boundary.
• Exceedance of 2L Standard or IMAC at or Beyond the Established CCR Impoundment
Compliance Boundary:
- Ash Basin Cell 1. HIGH RISK. Several constituents were detected at or beyond the
compliance boundary above the 2L Standard or IMAC including chromium, cobalt,
and vanadium.
- Ash Basin Cell 2. HIGH RISK. Several constituents were detected at or beyond the
compliance boundary above the 2L Standard or IMAC including antimony,
chromium, cobalt, and vanadium.
- Ash Basin Cell 3. HIGH RISK. Several constituents were detected at or beyond the
compliance boundary above the 2L Standard or IMAC including antimony,
chromium, cobalt, and vanadium.
• Population Served by Water Supply Wells Within 1,500 feet Up -Gradient or Side -Gradient of
the Established CCR Impoundment Compliance Boundary:
- Ash Basin Cell 1. HIGH RISK. Duke identified approximately 103 water supply wells
within 1,500 feet of the CCR impoundments. These wells are in locations spread
APRIL 2016 9 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
around all three CCR impoundments. Each CCR impoundment has at least 12 water
supply wells within 1,500 feet of it which places it in the high risk category (>30
people, assuming 2.5 persons per well). Even dividing the number of wells evenly
between the three basins, assuming 2.5 users per well, there are at least 86 persons
per basin within 1,500 feet. This totals approximately 258 persons and does not
include the Buck site's own water supply well which is also within 1,500 feet of Ash
Basin 1.
- Ash Basin Cell 2. HIGH RISK. Duke identified approximately 103 water supply wells
within 1,500 feet of the CCR impoundments. These wells are in locations spread
around all three CCR impoundments. Each CCR impoundment has at least 12 water
supply wells within 1,500 feet of it which places it in the high risk category (>30
people, assuming 2.5 persons per well). Even dividing the number of wells evenly
between the three basins, assuming 2.5 users per well, there are at least 86 persons
per basin within 1,500 feet. This totals approximately 258 persons and does not
include the Buck site's own water supply well which is also within 1,500 feet of Ash
Basin 1.
- Ash Basin Cell 3. HIGH RISK. Duke identified approximately 103 water supply wells
within 1,500 feet of the CCR impoundments. These wells are in locations spread
around all three CCR impoundments. Each CCR impoundment has at least 12 water
supply wells within 1,500 feet of it which places it in the high risk category (>30
people, assuming 2.5 persons per well). Even dividing the number of wells evenly
between the three basins, assuming 2.5 users per well, there are at least 86 persons
per basin within 1,500 feet. This totals approximately 258 persons and does not
include the Buck site's own water supply well which is also within 1,500 feet of Ash
Basin 1.
• Population Served by Water Supply Wells within 1,500 Feet Downgradient of the Established
CCR Impoundment Compliance Boundary:
- Ash Basin Cell 1. LOW RISK. Based on information in the CSA Report and
groundwater modeling presented in the CAP Report, there are no water supply wells
that are located in the overall downgradient groundwater flow direction of the
impoundment compliance boundary.
- Ash Basin Cell 2. LOW RISK. Based on information in the CSA Report and
groundwater modeling presented in the CAP Report, there are no water supply wells
that are located in the overall downgradient groundwater flow direction of the
impoundment compliance boundary.
- Ash Basin Cell 3. LOW RISK. Based on information in the CSA Report and
groundwater modeling presented in the CAP Report, there are no water supply wells
that are located in the overall downgradient groundwater flow direction of the
impoundment compliance boundary.
Proximity of 2L Standard or IMAC Exceedances Beyond the Established CCR Impoundment
Compliance Boundary with Respect to Water Supply Wells:
- Ash Basin Cell 1. HIGH RISK. There are several exceedances of the 2L Standard or
IMAC within 500 feet of a water supply well.
APRIL 2016 10 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
- Ash Basin Cell 2. HIGH RISK. There are several exceedances of the 2L Standard or
IMAC within 500 feet of a water supply well.
- Ash Basin Cell 3. HIGH RISK. There are several exceedances of the 2L Standard or
IMAC within 500 feet of a water supply well.
• Groundwater Emanating from the Impoundment that Exceeds 2L Standard or IMAC and that
Discharges into a Surface Water Body:
- Ash Basin Cell 1. HIGH RISK. Several constituents were detected above the 2L
Standard or IMAC in seeps potentially associated with the Ash Basin Cell 1, including
boron, cobalt, and vanadium that are potentially discharging to a surface water
body. Several constituents were detected above the 2L Standard or IMAC in
groundwater samples collected downgradient of the Ash Basin Cell 1 and adjacent to
surface waters. These constituents included chromium, cobalt, and vanadium.
- Ash Basin Cell 2. HIGH RISK. Several constituents were detected above the 2L
Standard or IMAC in seeps potentially associated with the Ash Basin Cell Z including
chromium, cobalt, and vanadium that are potentially discharging to a surface water
body. Several constituents were detected above the 2L Standard or IMAC in
groundwater samples collected downgradient of Ash Basin Cell 2 and adjacent to
surface waters. These constituents included chromium, cobalt, and vanadium.
- Ash Basin Cell 3. HIGH RISK. Several constituents were detected above the 2L
Standard or IMAC in seeps potentially associated with the Ash Basin Cell 3, including
chromium, cobalt, and vanadium that are potentially discharging to a surface water
body. Several constituents were detected above the 2L Standard or IMAC in
groundwater samples collected downgradient of the Ash Basin Cell 3 and adjacent to
surface waters. These constituents included boron, chromium, cobalt, and
vanadium.
• Data Gaps and Uncertainty Related to Transport of Contaminants to Potential Receptors:
- Active Ash Basin. HIGH RISK. There is a high degree of uncertainty with the data
presented in the CSA Report. Determinations of background concentrations for the
constituents of interest are still on-going. Bedrock flowpaths have not been
adequately characterized. The horizontal and vertical extent beneath the
impoundment and downgradient has not been adequately delineated. In addition,
both the closed Pine Hall Road Landfill and the onsite structural fill may contribute to
groundwater contamination, which have not been adequately assessed.
Groundwater flow direction in bedrock has not been well determined.
C.1.6 Purpose and Objectives
The purpose of this document is to provide additional detailed evaluation of Buck -related data to clarify
the subjects noted in the NCDEQ risk classification comments (see previous section). More specifically,
this appendix is written to provide a technical evaluation to determine if water supply wells in the
vicinity of Buck may be affected by CCR constituents, and provide a better understanding of whether
those metals and other constituents present in water supply wells are naturally occurring or whether
they are present due to migration from the groundwater in the vicinity of the ash basins.
APRIL 2016 11 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
This document is divided into four sections:
• Section C.2 provides an evaluation of the water supply well data with respect to regulatory
standards and health -risk-based screening levels.
• Section C.3 presents additional statistical evaluation of the water supply well data and
background data to provide a more detailed and critical evaluation of constituents that may be
present either due to the influence of nearby ash basins or are naturally occurring and
commonly found in groundwater not affected by Buck operations.
• Section C.4 provides the hydrogeologic findings of additional groundwater modeling and an
additional evaluation of groundwater flow patterns in the vicinity of Buck with respect to the
locations of the water supply wells.
• Section C.5 provides an evaluation of the geochemical fingerprint of pore water and
groundwater at the ash basin and related coal ash facilities compared to the geochemical
fingerprint of water supply wells and regional background wells. This comparison provides a
statistical evaluation of constituent data for specific data sets: ash basin pore water, facility
groundwater, facility background, water supply wells, and regional background, and identifies
where these fingerprints are the same, similar or significantly different. An interpretation of the
data is provided together with specific conclusions regarding areas that show the potential
presence of CCR constituents within and outside of the compliance boundary for Buck.
Section C.6 provides a summary of conclusions and a discussion of their potential impact on the
risk classification for this site.
C.2 WATER SUPPLY WELL DATA EVALUATION
The purpose of this section is to evaluate data for water supply wells in the vicinity of Buck with respect
to applicable screening levels.
C.2.1 Data Sources
A total of 166 private water supply wells are located within a 0.5 -mile radius of the Buck ash basin
compliance boundary (Figure C1-3). Ten additional private water supply wells are assumed at
residences located within a 0.5 -mile radius of the Buck ash basin compliance boundary based on the
absence of municipal water lines. Two public water supply wells were identified within a 0.5 -mile radius
of the Buck ash basin compliance boundary. One water supply well was identified within the Duke
Energy property boundary that supplies drinking water to the site (Figure C1-3).
This section presents an evaluation of the water supply well data from the following three sources:
A total of 89 samples collected by the NCDEQ from 89 wells within a 0.5 -mile radius of the Buck
ash basin compliance boundary;
A total of 7 samples collected by the NCDEQ from 7 reconnaissance or background water supply
wells in the vicinity of Buck, but well outside the ash basin compliance boundary; and
APRIL 2016 12 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
• A total of 17 samples collected by Duke Energy from background water supply wells located
within a 2- to 10 -mile radius of the Buck site boundary.
Where there were multiple results for a single well in the NCDEQ-sampled local water supply well
dataset, a representative value was identified to be used in the evaluation, which is defined as the
maximum of the detected values if the analytical results are not detected values. If the analytical results
are all not detected, the lowest reporting limit is defined as the representative value.
C.2.2 Screening Levels
Analytical data from the NCDEQ water supply wells and the background water supply wells were
compared to the following state and federal drinking water levels:
• North Carolina Statute 15A NCAC 02L.0202 (2L Standard) groundwater standards (NCAC, 2013),
note that IMACs are included when referring to 2L Standards in this report;
• Federal Safe Drinking Water Act maximum contaminant levels (MCLs) and secondary drinking
water standards (SMCLs) (USEPA, 2012);
• NCDHHS screening levels (NCDHHS, 2015); and
• USEPA Risk -Based Screening Levels (RSLs) (USEPA, 2015b).
As discussed in the main report, the IMAC value used by NCDEQ and the NCDHHS screening level for
vanadium has been changed, but to date the new screening level has not been released. Similarly, the
NCDHHS screening level for hexavalent chromium has been changed, but to date the new screening
level has not been released. Thus, these screening tables use the publicly available values for these two
constituents.
C.2.3 Results
Tables C2-1 through C2-4 present the comparison of the NCDEQ data for the water supply wells located
within a 0.5 -mile radius of the Buck ash basin compliance boundary to 2L standards, USEPA MCLs,
NCDHHS screening levels, and USEPA RSLs, respectively.
Tables C2-5 through C2-8 present the comparison of the NCDEQ and Duke Energy data for the
background water supply wells to 2L standards, USEPA MCLs, NCDHHS screening levels, and USEPA RSLs,
respectively.
The concentration of boron and the other potential coal ash indicators (discussed in Section 3 of the
main report) were low and not above screening levels in the water supply wells sampled by NCDEQ.
Boron was detected in 8 of the 89 NCDEQ-sampled water supply wells; boron was detected in 1 of the
7 NCDEQ background wells and in 1 of the 17 Duke Energy background wells. pH was below the drinking
water standard range in 42 of the 89 NCDEQ-sampled water supply wells. These results are not
unexpected, based on a study published by the United States Geological Survey (Chapman, et al., 2013)
and additional North Carolina specific studies (Briel, 1997) showing that groundwater pH in the state is
APRIL 2016 13 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
commonly below the MCL range of 6.5 to 8.5. Lead was above the drinking water standard in 1 of the
89 NCDEQ-sampled water supply wells.
None of the NCDEQ-sampled water supply well results were above Federal primary drinking water
standards (MCLs), with the exception of the pH results and lead result noted above. Fifteen iron results
were above the SMCL, as were 3 of the results for manganese and aluminum; however, the SMCLs are
based on aesthetics, and all results but one for iron are below the USEPA risk-based RSLs. Moreover,
the aluminum results for the NCDEQ water supply wells were within the range of concentrations from
the Duke Energy background wells.
Concentrations of sulfate, antimony, chromium, and cobalt were above the 2L Standard and NCDHHS
screening level in one or more but fewer than six samples each.
"Do Not Drink" Letters were issued by NCDHHS for 79 water supply wells at Buck Steam Station, with
hexavalent chromium and vanadium being the primary constituents listed in the letters (see Table C2-9),
though these were based on the now -outdated screening levels, and those "Do Not Drink" warnings
have been lifted for these two constituents. Letters were issued for constituents other than hexavalent
chromium and vanadium, primarily for iron (14 wells), zinc (3 wells), chromium (2 wells), lead (1 well),
manganese (1 well), and cobalt (1 well).
A detailed statistical evaluation of background and comparison to the water supply well data is provided
in the next section.
C.3 STATISTICAL EVALUATION OF BACKGROUND
The purpose of the background evaluation is to develop a site-specific or facility -specific descriptor of
background for constituents of interest, i.e., a background threshold value (BTV). If a sample result is
below the BTV, there is reasonable confidence that the constituent concentration is consistent with
background. However, a sample result above a BTV does not mean that it is not consistent with
background, only that statistically it cannot be determined based on the available background dataset.
Three datasets are available to describe background groundwater conditions in the vicinity of Buck:
• The NCDEQ-sampled background water supply well dataset;
• The Duke Energy background water supply well dataset; and
• The Buck facility background monitoring well dataset.
The water supply well data were summarized as indicated in Section C.2.1 to address wells where
resampling occurred.
The NCDEQ and the Duke Energy background water supply well datasets are referred to here as regional
background, and the Buck background monitoring wells are referred to as facility -specific background.
Twelve constituents were selected for the background evaluation studies at Buck. The subset of
constituents was defined first by whether "Do Not Drink" letters were issued for those constituents, and
second by the needs of the groundwater chemistry evaluation, which is presented in Section C.S. The
APRIL 2016 14 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
BTV values were estimated for the twelve constituents at Buck by using a stepwise approach outlined
below.
1) Initial evaluation of background input data sources.
2) Raw data evaluation by descriptive statistics, histograms, outlier tests, and trend tests.
3) Testing of statistical assumptions of the input data by checking for independent, identically
distributed (IID) measurements and goodness -of -fit (GOF) distribution tests.
4) Selection of an appropriate parametric or non -parametric analysis method to estimate
constituents BTVs.
5) Summarizing the statistical analysis results and drawing conclusions.
The statistical methodology and the conclusions for the background evaluation are presented in the
following sections.
C.3.1 Initial Data Evaluation
The initial statistical evaluation was performed to check the homogeneity of variance assumption for
multiple groups of wells included in the regional background water supply well dataset, and separately
for the Buck facility -specific background monitoring well dataset, before combining each into a single
dataset. In this step, data from discrete data sources for each background dataset were tested for
statistical variations using Levine's test. The test examines if the differences in sample variances occur
because of random sampling. Note that the original focus of the background evaluation was on
vanadium and hexavalent chromium, as these were the two constituents for which the majority of the
"Do Not Drink" letters were issued. This statistical analysis was begun prior to the lifting of the "Do Not
Drink" letters, however, the use of these two constituents for the purpose of determining whether the
datasets can be combined is appropriate.
C.3.1.1 Regional Background Water Supply Well Data
Vanadium and hexavalent chromium were used in the statistical computations to determine if the two
background datasets (NCDEQ and Duke Energy) could be combined. The results of the Levine's test are
presented in Attachment C-1.
Statistical computations revealed that there are no significant differences in the variances between the
background regional water supply well data provided by NCDEQ and Duke Energy for both vanadium
and hexavalent chromium data. Therefore, further evaluation was performed on the combined dataset.
Table C3-1 presents the combined regional background water supply well dataset for Buck.
C.3.1.2 Facility Background Monitoring Well Data
Water supply wells in this region of North Carolina are predominantly bedrock wells. Section C.4
discusses this in more detail.
APRIL 2016 15 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Background wells sampled at Buck for the CSA included BG-1BR, BG -1D, BG -2D, BG-3BRU, MW -6S, BG -
2S, BG -3S, and MW -6D. The initial facility -specific background evaluation for Buck was performed on
three background deep (transition zone) wells and two background bedrock monitoring well (BG-1BR,
BG -1D, BG -2D, BG-3BRU, and MW -6D) (see Figure C3-1). Background wells screened in the shallow
formation were excluded from the analysis to limit the data used to that same flow layer that the off-
site water supply wells draw from. The facility -specific background monitoring well data that is used in
the background data evaluation for Buck is presented in Table C3-2. The sample size for both vanadium
and hexavalent chromium consists of less than five samples per well. The results of the statistical
computations indicated that there are no significant differences between monitoring well data for
vanadium and hexavalent chromium. Although decisions based upon statistics computed using discrete
data sets of small sizes (e.g., < 8) are generally not used to make decisions, based on facility -specific
knowledge developed during the detailed environmental investigations and the limited statistical
evaluation, the data from facility -specific background monitoring wells presented in Table C3-2 and
Figure C3-1 were combined for the facility BTV estimates.
C.3.2 Raw Data Evaluation
In the raw data evaluation for Buck, the descriptive statistics for twelve constituents for both the
regional and facility -specific datasets were computed and tabulated in Table C3-3. The most common
descriptive statistics included the following: Frequency of Detection (Column 3), Percent Non -Detects
(ND) (Column 4), Range of Non -Detects (Column 5), Mean (Column 6), Variance (Column 7), Standard
Deviation (Column 8), Coefficient of Variation (Column 9), 50th percentile (Column 10), 95th Percentile
(Column 11), and Maximum Detects (Column 12). Critical information such as the requirement for a
certain minimum number of samples and percent NDs were evaluated during this step. Ideally, 8-10
background measurements would be available, and preferably more, to perform meaningful statistical
tests.
In cases where there is a small fraction of non -detects in a dataset (10-15% or less) censored at a single
reporting limit, simple substitution methods were utilized by substituting each non -detect with an
imputed value of the method detection limit (MDL). In complicated situations such as the presence of
multiple MDLs intermingled with difference non -detect levels or when the proportion of non -detects
was larger, strategies such as Kaplan -Meier (KM) and Robust Regression on Order Statistics (ROS) were
utilized.
Visual plots such as histograms and probability plots were plotted to examine the data closely and
visually determine if there were extreme outliers in the dataset. If extreme outliers were visually
identified, then outlier tests (Dixon's and Rosner's) were performed to confirm if there are outliers at a
5% significance level. The decision to include or exclude outliers in statistical computations was decided
by the project team based on constituent and facility -specific knowledge. If the presence of an outlier
was confirmed, and if there was enough evidence to remove the outlier, then the outlier was removed
from further statistical analysis. The results of the outlier tests, Outlier Presence (Column 13) and
Outlier Removal (Column 14), for twelve constituents for both regional and facility -specific datasets are
presented in Table C3-3. Attachment C-1 presents the histograms, probability plots and outlier tests for
the twelve constituents.
APRIL 2016 16 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C.3.2.1 Regional Background Water Supply Well Data
The descriptive statistics indicated the presence of a high percentage of non -detects (NDs) for boron,
cobalt, iron, and nickel; boron had 3 detects, cobalt had no detects, iron had 8 detects, and nickel had
4 detects out of a total of 24 samples. Due to the presence of a high percentage of NDs in the dataset,
the outlier test statistics were computed using the detected data alone. As presented in Table 0-3
(Columns 13-14), an analysis using visual plots and the Dixon's Outlier Test indicated the presence of
outliers in the data set. However, outliers are inevitable in most environmental data and the decisions
to exclude them need to be made based on existing knowledge about the facility and the regional
groundwater conditions. In this instance, based on existing knowledge that these are data from
background locations not adjacent to the facility no outliers were removed from the regional water
supply dataset.
C.3.2.2 Facility Background Monitoring Well Data
The descriptive statistics performed on facility -specific background data indicated that greater than
40 percent of samples had NDs for boron, cobalt, lead, manganese, and zinc. Boron and lead had
5 detects out of 26 samples, cobalt had 4 detects out of 13 samples; manganese had 10 detects out of
27 samples and zinc had 11 detects out of 26 samples. Statistical computations indicated the presence
of outliers in the data set, specifically with regard to monitoring well BG -113R. Sampling results from
BG-1BR showed significant concentration variation from the remaining sample results and, therefore,
results for this well were removed from further analysis and descriptive statistics were recalculated.
C.3.3 Testing of Statistical Assumptions
After performing the initial statistical evaluation and addressing outliers as discussed in the previous
section, two critical statistical assumptions were tested for IID measurements and normality. In general,
the background groundwater data for both the regional and facility -specific datasets were assumed to
have IID measurements for statistical analysis because the design and implementation of a monitoring
program typically results in IID measurements. The groundwater samples are not statistically
independent when analyzed as aliquots or splits from a single physical sample. Therefore, split sample
data were treated as described in Section C.2.1, such that a single value for each constituent was used in
the statistical evaluations.
To test for normality, the data was first analyzed visually by generating histograms and probability plots.
This was followed by an evaluation using GOF tests. The GOF statistics were generated using EPA
ProUCL software (USEPA, 2013), which tests for normal, lognormal and gamma distributions to establish
the appropriate distribution. If the GOF test statistics suggested the data to follow normal, lognormal or
gamma distributions, parametric methods were utilized to estimate BTV values. If the normality
assumption was not met the data was considered to be distribution free, and non -parametric statistical
methods were used to estimate BTV values.
A common difficulty in checking for normality among groundwater measurements is the frequent
presence of non -detect values, known in statistical terms as left -censored (positively skewed)
measurements. The magnitude of these sample concentrations is unknown and they fall somewhere
APRIL 2016 17 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
between zero and the detection or reporting limit. Many positively skewed data sets follow a lognormal
as well as a gamma distribution. It is well-known that for moderately skewed to highly skewed data
sets, the use of a lognormal distribution tends to yield inflated and unrealistically large values of the
decision statistics especially when the sample size is small (e.g., <20-30). In general, it has been
observed that the use of a gamma distribution tends to yield reliable and stable values. The
distributions determined by GOF tests (Column 15) for twelve constituents for both regional and facility -
specific datasets are presented in Table C3-3. Attachment C-2 presents the GOF tests statistics.
C. 3.3.1 Regional Background Water Supply Well Data
The test statistics revealed that most of the constituents follow a parametric distribution except boron,
cobalt, and manganese; hence, parametric methods were used to compute BTVs for all constituents
except boron, cobalt, and manganese. Non -parametric test methods were used to compute the BTV for
manganese. No further evaluation was performed for boron and cobalt due to the presence of very few
detects.
C.3.3.2 Facility Background Monitoring Well Data
The test statistics revealed that boron, cobalt, hexavalent chromium, iron, lead, manganese, and nickel
follow a parametric distribution; hence, parametric methods were used to compute BTVs for these
constituents. The remaining constituents did not follow a specific distribution; hence non -parametric
methods were used to compute the BTVs.
C.3.4 BTV Estimates
In this step, an appropriate parametric or non -parametric test method to estimate BTVs was selected
based on conclusions from the above sections. When selecting parametric methods or non -parametric
methods, it is implicitly assumed that the background dataset used to estimate BTVs represents an
unimpacted, single statistical population that is free from outliers. However, since outliers are
inevitable in most environmental data (high percentage of NDs), when present, outliers were treated on
a facility -specific basis using all existing knowledge about the facility, groundwater conditions, and
reference areas under investigation as discussed in the previous section. The BTVs for the constituents
were estimated using proUCL (USEPA, 2013) by using one of the following methods.
• Parametric or non -parametric 95 %Upper Prediction Limits (UPL95)
• Parametric or non -parametric Upper Tolerance Limits (UTL95-95) with 95% confidence and 95%
coverage
A prediction interval is the interval (based upon background data) within which a newly and
independently obtained (future observation) site observation (e.g., onsite, downgradient well) of the
predicted variable (e.g., boron) falls with a given probability (or Confidence Coefficient [CC]).
Prediction interval tells about the distribution of values, not the uncertainty in determining the
population mean. A UPL95 represents that statistical concentration, such that an independently -
APRIL 2016 18 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
collected new/future observation from the population will exhibit a concentration less than or equal to
the UPL95 with a CC of 0.95.
A tolerance limit is a confidence limit on a percentile of the population rather than a confidence limit on
the mean. A UTL95-95 represents that statistic such that 95% of the observations (current and future)
from the target population will be less than or equal to the UTL95-95 with a CC of 0.95. Stated
differently, the UTL95-95 represents a 95% UCL of the 95th percentile of the data distribution. A UTL95-
95 is designed to simultaneously provide coverage for 95% of all potential observations (current and
future) from the background population with a CC of 0.95. A UTL95-95 can be used when many
(unknown) current or future on-site observations need to be compared with a BTV. For moderately to
highly skewed data sets (high percentage of NDs), upper limits using KM estimates in gamma UCL and
UTL equations provide better results, if the detected observations in the left -censored data set follow a
gamma distribution.
The nonparametric upper limits (e.g., UTLs, UPLs) are computed by the higher order statistics such as
the largest, the second largest, the third largest, and so on of the background data. The order of the
statistic used to compute a nonparametric upper limit depends on the sample size, coverage probability,
and the desired CC. In practice, non -parametric upper limits do not provide the desired coverage to the
population parameter (upper threshold) unless the sample size is large.
Table C3-3 presents the estimated BTV values (Column 16) and applicable methods (Column 17) used in
estimating the upper threshold values. Attachment C-3 presents the proUCL output of the BTVs
computations.
C.3.5 Comparison of Water Supply Well Data to the Regional BTVs
The data for the water supply wells located within the 0.5 -mile radius from the ash basin compliance
boundary were compared to the regional background BTVs presented in Table C3-3. Comparison to the
regional background BTVs is provided in Table C3-4, and comparison to the facility -specific BTVs are
presented in Table C3-5.
There are 12 constituents for which regional and facility -specific BTVs were developed. Of the 89 water
supply wells sampled by NCDEQ, there are few results above the regional BTVs. There is at least one
result in this dataset above each of the regional BTVs, but no more than 15 results for any of the
constituents. Less than 10 percent (1 to 7 results) of the results for barium, boron, cobalt, manganese,
nickel, sodium, sulfate, and vanadium are above their respective regional BTVs. Less than 17 percent of
the results for hexavalent chromium, iron, lead, and zinc are above their respective regional BTVs.
Barium, boron, sulfate, vanadium, and zinc did not have any NCDEQ-sampled supply well results above
facility -specific BTVs. Less than 20 percent (1 to 18 results) of the results for cobalt, iron, nickel, and
sodium are above their respective facility -specific BTVs. Hexavalent chromium, iron, and manganese
had between 38 and 69 results above BTVs.
APRIL 2016 19 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
As noted in Section C.2.3, none of the NCDEQ-sampled water supply well results for these constituents
were above Federal primary drinking water standards (MCLs), with the exception of a single result for
lead.
C.4 GROUNDWATER FLOW EVALUATION
[The evaluation in Section E.4, including figures and tables, was provided by HDR, Inc.]
C.4.1 Introduction
The objective of this report is to expand upon site-specific groundwater flow and water quality data that
were presented in CSA report (HDR, 2015a) for Buck to demonstrate that ash impacted groundwater
associated with the ash basin system has not migrated toward water supply wells located up- and side -
gradient of the ash basin system.
The CSA was conducted to comply with CAMA. Fieldwork for the CSA was implemented in accordance
with the NCDEQ approved Groundwater Assessment Plan (Work Plan) (HDR, 2014c) and consisted of the
installation of 64 groundwater monitoring wells to complement the existing 18 monitoring wells and
subsequent sampling of the 82 total monitoring wells. The wells were installed to delineate potential
impacts to groundwater from the ash basin system; facilitate collection of geologic, geotechnical, and
hydrogeologic subsurface data; and support characterization of background groundwater conditions. To
date, two rounds of comprehensive groundwater sampling were conducted between July 2015
and September 2015. Water level measurements were recorded in each well prior to sample collection
during each of the two comprehensive sampling events. The water level data collected during the two
comprehensive sampling rounds in 2015 were used to evaluate the groundwater flow direction and
velocity at the facility. The third round of comprehensive sampling is presently being performed.
Groundwater flow within the slope -aquifer system is directly influenced by the underlying geologic
framework of the site. The geology at the site is presented in Section C.4.2, the regional groundwater
system and the hydrogeological SCM are presented in Section C.4.3.1, and the location of water supply
wells in the vicinity of the facility and hydrogeology of the site is presented in Section C.4.3.2. Detailed
data were collected to evaluate groundwater flow direction, horizontal and vertical gradients, and the
velocity of groundwater flow as described in Section C.4.3. The data were used to support the
development of a groundwater flow model, which resulted in an understanding of present and potential
future groundwater conditions. The model incorporated the effects of the water supply well pumping
adjacent to the site. The model results are discussed in Section C.4.4.
C.4.2 Site Geology
The Buck site is located in the Piedmont Province of North Carolina. In-situ materials (in addition to ash
and fill) encountered at Buck during the CSA include:
• Alluvium (S) — Alluvium is unconsolidated sediment that has been eroded by and redeposited by
streams. At some locations, alluvium was encountered beneath the ash. The alluvium is
present at the along the Broad River with thickness ranging from 0 to 32 feet.
APRIL 2016 20 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
• Residuum (Regolith -Residual Soils; M1) — Residuum is weathered soil that was derived from the
in-place weathering of bedrock. The range of residuum observed at the site is 0 to 20 feet.
• Saprolite/Weathered Rock (Regolith; M2) — Saprolite is soil developed by the in-place
weathering of bedrock and retains remnant bedrock structure. The range of
Saprolite/Weathered Rock observed at the site is 24 to 117 feet.
• Partially Weathered/Fractured Rock (TZ) — This material consists of partially weathered and/or
highly fractured bedrock that occurs below Saprolite/Weathered Rock and above bedrock. The
thickness ranges from 0 to 16 feet.
• Bedrock (BR) — Bedrock is hard rock that is unweathered to slightly weathered and relatively
unfractured. The maximum depth that borings extended into bedrock was 54 feet. The bedrock
at Buck consists of interbedded felsic, intermediate, and mafic metavolcanic rocks.
Overlying the in-situ materials are ash and earthen fill used to construct the ash basin embankment
dams and cover over ash storage areas. Additional information on the site geology was presented in
CSA report Section 6.1 (HDR, 2015a).
C.4.3 Site Hydrogeology
C. 4.3.1 Site Conceptual Model
An SCM was developed during preparation of the Work Plan to inform decisions regarding the field
exploration (i.e., monitoring well locations, screened intervals, target depths, etc.). The SCM was based
largely on the LeGrand (1988, 1989) conceptual model of the groundwater setting in the Piedmont and
incorporated Harned and Daniel's (1992) (see Figure C4-1) two -medium system described as follows: the
generalized conceptual model is a slope -aquifer system where a surface drainage basin is contained
within one or more adjacent topographic divides, located along a ridge tops serving as the upper
hydraulic boundaries and with a stream, river, or lake serving as the lower hydraulic boundary (LeGrand,
1988).
Each basin is similar to adjacent basins and the conditions are generally repetitive from basin to basin.
Within a basin, movement of groundwater is generally restricted to the area extending from the
drainage divides to a perennial stream (Slope -Aquifer System; LeGrand, 1988; 1989; 2004) (see
Figure C4-2). Rarely does groundwater move beneath a perennial stream to another more distant
stream or across drainage divides (LeGrand, 1989). The crests of the water table underneath
topographic drainage divides represent natural groundwater divides within the slope -aquifer system
and limit the area of influence of wells or contaminant plumes located within their boundaries. The
concave topographic areas between the topographic divides may be considered as flow compartments
that are open-ended down slope. In natural areas, groundwater flow paths in the Piedmont are almost
invariably restricted to the zone underlying the topographic slope extending from a topographic divide
to an adjacent stream, with the stream serving as the discharge feature. Under natural conditions, the
general direction of groundwater flow can be approximated from the surface topography (LeGrand,
2004).
APRIL 2016 21 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
The two -medium system consists of two interconnected layers, or media: 1) residual soil/saprolite and
weathered fractured rock (regolith), overlying 2) fractured crystalline bedrock (Figure C4-1) (Heath,
1980; Harned and Daniel, 1992). The residual soil grades into saprolite, a coarser grained material that
retains the structure of the parent bedrock. Beneath the saprolite, partially weathered/fractured
bedrock occurs with depth until sound bedrock is encountered. This mantle of residual soil and saprolite
(regolith) is a hydrogeologic unit that covers and crosses various types of rock (LeGrand, 1988). These
layers serve as the principal groundwater storage reservoir and provide an intergranular medium
through which the recharge and discharge of water from the underlying fractured rock occurs (Daniel
and Harned, 1998) (Figure C4-3). Within the fractured crystalline bedrock layer, the fractures control
both the hydraulic conductivity and storage capacity of the bedrock. A TZ at the base of the regolith is
present in many areas of the Piedmont. Harned and Daniel (1992) described the zone as "being the
most permeable part of the system, even slightly more permeable than the soil zone." Harned and
Daniel (1992) indicated the TZ may serve as a conduit of rapid horizontal flow and transmission of
impacted water (Figure C4-4). Additional details of the SCM are presented in Sections 5.2 and 6.2.4 of
the CSA report and Section 3.0 of the Buck Corrective Action Plan Part 1 (CAP -1) report (HDR, 2015b).
Based on the results of the CSA, the groundwater system in the in-situ materials (alluvium, soil,
soil/saprolite, and bedrock) and the overlying ash and fill at Buck is consistent with the slope-
aquifer/regolith-fractured rock groundwater model and is an unconfined, connected aquifer system.
The hydrostratigraphic layers (layers of material that have different hydraulic parameters) at the site
consist of in-situ units, Alluvium (S), Residuum (Regolith -Residual Soil; M1), Saprolite/Weathered Rock
(Regolith; M2), Partially Weathered/Fractured Rock (TZ), Bedrock (BR), and anthropogenic units, ash (A),
and fill (F), as described in Section C.4.2. These units are used in the groundwater model of the site
discussed in Section C.4.4.
Additional information concerning the development of the hydrostratigraphic layers is presented in
Section 11.1 of the CSA report (HDR, 2015a).
C.4.3.2 Groundwater Flow Direction
The Buck groundwater system is divided into three flow layers referred to as the shallow (S), deep
(D, which is representative of the TZ), and bedrock (BR) flow layers to distinguish the layers within the
connected, unconfined aquifer system. Monitoring wells were installed with screens in each of these
flow layers during the CSA.
Groundwater elevations measured in monitoring wells show that groundwater flow in all three flow
layers is from the higher topography located along the southwestern, southern, and southeastern extent
of the Buck property to the north toward the Yadkin River. There is also a component of groundwater
flow to the west of Cell 1 and there is localized flow in an area east of the source that requires further
evaluation.
APRIL 2016 22 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Water level potentiometric surfaces and directions for the three flow layers are shown on Figures C4-5
(27)1, C4-6 (21), and C4-7 (16) for water levels recorded between 6 and 71uly 2015 and on Figures C4-8
(38), C4-9 (27), and C4-10 (16) for water levels recorded on 21 September 2015. Water level data
obtained from CSA monitoring wells and existing on-site wells were used to prepare these figures. The
location of the water supply wells are also shown on these figures. The flow directions are consistent
with the slope -aquifer system and show that groundwater flow is away from off-site water supply wells
and toward the discharge feature, the Yadkin River.
Vertical gradients, as measured by differences in groundwater elevations at monitoring wells screened
in the three different flow layers, indicate that the higher topography located southwest, south, and
southeast of the ash basin systems serves as a groundwater recharge area and that Yadkin River serves
as the discharge feature for groundwater flow at Buck.
C.4.3.3 Groundwater Seepage Velocities
Groundwater seepage velocities were estimated for the hydrostratigraphic units at the site. The
seepage velocity is calculated using the average horizontal hydraulic conductivity values (permeability;
Figure C4-11; Table C4-1) obtained during field tests, the average effective porosity obtained from
laboratory testing or from technical literature (CSA report Table 11-8, and CSA Supplement #1 Table 11-
11), and measured horizontal hydraulic gradients between a number of well pairs in the same flow
layer(s) (CSA report Section 6.2.2, Table 6-9). The estimated groundwater seepage velocities are shown
in Table C4-2. These results show higher estimated groundwater velocities in the TZ than in the regolith
above and the bedrock below, which is consistent with the definition of the TZ of Harried and Daniel
(1992). Thus, the TZ serves as a conduit of relatively rapid horizontal flow and transmission of impacted
water away from the water supply wells (Figure C4-4) at Buck.
Additional details on the field testing and laboratory testing for estimating hydrogeologic parameters
are presented in Section 11.2 of the CSA report (HDR, 2015a).
C.4.3.4 Constituents Associated with CCR
The data evaluation in the previous sections of this report determined that there is greater horizontal
flow than there is vertical downward flow at the site, particularly in the TZ flow layer. This section builds
upon that knowledge to evaluate the presence of constituents in groundwater associated with a release
from the ash basins. Evaluation of constituent presence or absence in each flow layer, and the
magnitude of the concentrations provide an independent means of assessing the horizontal and vertical
flow of groundwater, and the ability of groundwater to migrate vertically between the flow layers.
Certain constituents present in coal ash can serve as indicators of a release from a coal ash management
area to groundwater; these have been used by USEPA to design the groundwater monitoring program
under the final CCR Rule (USEPA, 2015a). The USEPA defined a phased approach to groundwater
monitoring. The first phase is detection monitoring where groundwater is monitored to detect the
1 Numbers shown in parentheses represent the number of measurements used to prepare the groundwater flow
maps.
APRIL 2016 23 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
presence of specific constituents that are considered to be indicators of a release from a coal ash
management area (e.g., metals) and other monitoring parameters (e.g., pH, TDS). These data are used
to determine if there has been a release from a coal ash management area. Detection monitoring is
performed for the following list of "indicator' constituents identified in Appendix III of the CCR Rule:
• Boron;
• Calcium;
• Chloride;
• Fluoride (this constituent was not analyzed for in the CSA);
• pH;
• Sulfate; and
• TDS.
In selecting the constituents for detection monitoring, USEPA chose constituents that are present in CCR
and that are more soluble and move through the soil column and with groundwater without
retardation, relative to other constituents. Thus, groundwater monitoring for these constituents allows
for an evaluation of whether constituents are migrating from a CCR unit. Coal ash constituents dissolve
in groundwater with no measurable increase in density as compared to other constituents that would
tend to "sink" in the aquifer, such as dense non -aqueous phase liquids or saltwater. Thus, releases from
coal ash management areas tend to remain in the shallower groundwater flow layers.
C.4.3.5 Extent of Boron Exceedances in Groundwater
Groundwater at Buck was monitored for a wide range of constituents, as required by the CAMA, and
listed in the CSA report (HDR, 2015a). Boron may be one of the more common indicators for evaluation
of groundwater for releases from coal ash management areas due to boron concentrations in CCR
leachate usually being greater than in typical groundwater. Boron also tends to be highly mobile in
groundwater. For these reasons, boron is often used as an indicator constituent for CCR leachate
(Electric Power Research Institute [EPRI), 2005).
At Buck, boron exceedances of the 2L Standards reported in groundwater during the 2015 Round 2
sampling event are shown in plan view (Figure C4-12 and in cross-section view (Figure C4-13 to illustrate
where this leading indicator associated with CCR is located across the site. Boron was selected since it is
typically prevalent in CCR (USEPA, 2015a) and does generally not occur in detectable concentrations in
Piedmont groundwater. As can be seen from this cross-section, the boron exceedances of the
2L Standards in groundwater are located at the northern end of the active ash basin primary cell and the
northern end of the active ash basin secondary cell. Groundwater flow direction from these locations is
to the north to the Yadkin River. The location of the boron exceedances in groundwater are not located
at the southeastern, southern, or southwestern portions of the site near the water supply wells, and
groundwater flow is to the north, away from the water supply wells.
APRIL 2016 24 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C.4.3.6 Bedrock Flow and Depth of Water Supply Wells
Monitoring wells installed during the CSA investigation were located and screened at depths to
characterize potential vertical and horizontal extent of impacts from the ash basin system. Monitoring
wells were installed to assess groundwater in each of the three flow layers: shallow, transition zone, and
deep (bedrock). These monitoring wells are located in areas of suspected impacts, in presumed
background areas, and in areas between the ash basin system and off-site water supply wells.
Water supply wells constructed in the Piedmont province are typically drilled to greater depths than
monitoring wells installed for evaluation of inorganic constituents (i.e., constituents with specific gravity
similar to groundwater such as those found in coal ash). As described above, the groundwater levels
and groundwater seepage velocities in the TZ indicate that lateral flow predominates over downward
flow and that coal ash constituent concentrations decrease with depth.
Duke Energy mailed water supply well questionnaires to surrounding well owners during the Receptor
Survey in 2014 (HDR, 2014a, 2014b); however, very few of the returned questionnaires provided well
construction information. Those that were returned indicated that the wells were completed, or draw
water from, the bedrock groundwater zone. It is our understanding that the NCDEQ requested that
their third -party samplers record well construction information (if available) during sampling of the
supply wells, but Duke Energy has not been provided with that data.
In the absence of well -specific construction data, published literature (Daniel, 1989) was consulted to
yield an average depth of water supply wells in the North Carolina Piedmont (for domestic, commercial -
industrial, public water) as 154 feet from the ground surface with 100 feet in bedrock. Water supply
wells are generally cased though the regolith (soil/saprolite), with additional boring performed as
needed into bedrock to produce the desired well yield. Although these water supply wells may be
drilled into bedrock, the storage characteristics of the overlying saprolite and transition zone control the
sustained quantity of water available to the well (Harned, 1989). It is the regolith (soil/saprolite) that
provides the majority of water used in the water supply wells and the bedrock fractures convey that
stored groundwater to the water supply well (Harned, 1989) (see Figure C4-3).
As noted above, bedrock flow is to the north, and not toward the water supply wells. The data
collection and analysis of flow in all three groundwater flow layers at the site was conducted while the
off-site water supply wells were under normal operations. The effect of pumping of off-site water
supply wells on the direction of groundwater flow at the site is reflected in the water levels measured in
the existing network of monitoring wells. Thus, the measurements of groundwater flow velocity and
direction, and the potentiometric flow maps, reflect groundwater conditions under normal use of the
off-site water supply wells. The effect of pumping water supply wells on groundwater flow and direction
is discussed in more detail in Section C.4.4.
C.4.3.7 Groundwater Mounding
Groundwater mounding refers to the extent to which ash ponds, or any other pond, may raise or
variably influence the natural groundwater levels causing flow to leave the basin radially against the
prevailing slope -aquifer gradient (Figure C4-14). Topographical and monitoring well groundwater data
APRIL 2016 25 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
can be used establish the extent to which localized hydraulic mounding may emanate from an ash basin
and if this may affect the local groundwater flow direction.
A review of topographic and monitoring well groundwater data at Buck found no evidence of mounding
(Figures C4-5 and C4-8).
C.4.3.8 Summary
The hydrogeologic SCM presented in the CSA report (HDR, 2015a) and refined in the CAP -2 report (HDR,
2016) describes groundwater flow in the shallow (S — water table), deep (TZ — transition zone) and
bedrock (BR) groundwater zones as predominantly horizontal with flow from the southern portion of
the site to the north toward the Yadkin River, and slightly northeast and northwest to unnamed streams
on Duke Energy property that flow north to the Yadkin River. The basis for this conclusion is the analysis
of monitoring well water elevation data during the sampling events. The northern flow direction is away
from the water supply wells with average horizontal gradients of 0.037, 0.029 and 0.027 feet/foot in the
shallow, deep (TZ) and bedrock groundwater zones, respectively. The Yadkin River and unnamed
streams serve as the hydrologic discharge boundaries for groundwater at the site. There are no water
supply wells located between the ash basin system and the Yadkin River except for the Duke Power Buck
site well in the northwest portion of the site.
C.4.4 Water Supply Well Capture Zone Analysis
A well capture zone is the region of an aquifer in which water is removed by pumping wells within a
specified time period (Grubb, 1993) (see Figure A4-15). Groundwater pumping produces a low pressure
area in the groundwater flow field that induces groundwater flow towards the well.
The low pressure area due to the pumping action of the well may not propagate evenly through the
aquifer as groundwater upgradient from the well has higher potential energy and is already flowing
towards the well (positive kinetic energy). The pressure front extends outward from the well into the
aquifer until equilibrium is reached. At this point, the aquifer volume contributing water stabilizes and
the flow rate of water into the well equals the pumping rate. Consequently, the water within the
capture zone, and contaminants, if present, within the zone are captured by pumping. The shape of a
capture zone is typically portrayed as a planar shape, but is a three-dimensional volume.
A preliminary well capture zone analysis was performed and submitted to NCDEQ in December 2015,
using reverse particle tracking, to delineate well capture zones for the water supply wells near the Duke
Energy property boundary at Buck. Duke Energy is in the process of performing additional borings and
installing additional monitoring wells at the site and in off-site areas adjacent to the site. Information
from the borings and monitoring wells will be used to refine the groundwater model and to expand the
groundwater model domain. A revised capture zone analysis will be developed and submitted to
NCDEQ after completion of the refined model.
APRIL 2016 26 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C.4.5 Summary and Conclusions
Major findings from the evaluation of groundwater flow at the Buck Steam Station are as follows:
The groundwater system at Buck is consistent with the conceptual model of groundwater within
an unconfined, two -medium system (regolith consisting of soil and saprolite overlying bedrock)
separated by a transition zone of higher hydraulic conductivity (permeability) within a slope -
aquifer system. Within the basin footprint ash, fill, and alluvium are additional layers that
overlie the two -medium system. Three primary flow layers (as defined by the regolith, the
transition zone and bedrock) are present in the unconfined groundwater system at the site;
shallow (S - water table), deep (D - TZ), and bedrock (BR).
• Site-specific water level measurements confirm that groundwater flow is predominantly to the
north toward the Yadkin River from the topographic divides southwest, south, and southeast of
the ash basin system with localized flow to the west of Cell 1 and in an area east of the source
that requires further evaluation. Groundwater flow is away from the water supply wells, and
also confirms the flow model predictions.
• The transition zone that separates the regolith above from the bedrock below serves as the
primary transmitter of impacted groundwater with the regolith as the principal reservoir of
groundwater. Water level data and the groundwater modeling indicate horizontal flow
predominates over downward vertical flow. In essence, it is easier for groundwater to flow
horizontally within the transition zone than vertically down through the bedrock.
• Groundwater flow is laterally away from the water supply wells within the transition zone and
overlying saprolite and soil limiting the impact of coal ash related constituents in bedrock as
shown by analytical data and supported by groundwater modeling.
• A review of topographic and monitoring well groundwater data at Buck found no evidence of
mounding associated with the ash basin.
• Duke Energy plans to update and refine the groundwater flow model with recently collected
data and expand the model grid to include water supply wells. The revised model will be used
to perform well capture zone analysis.
• Based on this evidence, groundwater utilized by water supply wells near the coal ash
impoundments is not impacted by the coal ash sources.
C.5 GROUNDWATER CHARACTERISTICS EVALUATION
The results from the local water supply well testing conducted by the NCDEQ in the vicinity of the Buck
facility indicated that some constituents were present at concentrations above state and/or federal
standards and/or screening levels. As noted previously, these constituents are naturally occurring, and
some can be associated with releases from coal ash basins. Thus, it is critical to understand the naturally
occurring background conditions, the groundwater conditions in the tested local water supply wells, and
the conditions in groundwater at the facility where CCR -impacts have been demonstrated. A detailed
statistical evaluation of background groundwater data compared to the local water supply well data was
presented in Section C.3. As indicated in Section C.4.3.6, the local water supply wells are generally cased
through the regolith (soil/saprolite) and obtain water through the bedrock fractures that convey stored
APRIL 2016 27 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
groundwater in the regolith. Based on the hydrogeological evaluation presented in Section C.4,
groundwater utilized by local water supply wells near the coal ash impoundments is not impacted by the
coal ash sources. In this section, the chemistry of the groundwater at the facility in both CCR -impacted
areas and areas not impacted by a CCR release is compared to the chemistry of the local water supply
wells. The similarity or discrepancy in the chemistry of groundwater among various facility monitoring
well groups and the local water supply wells is expected to provide additional insights on the extent of
CCR impacted groundwater.
The objective of the evaluation is to understand, from the groundwater chemistry perspective, whether
the CCR -impacted groundwater at the facility has resulted in the water quality exceedances reported in
the local water supply wells.
The evaluation consists of the following two key steps:
• Identify site-specific CCR -related signature constituents that can effectively serve as indicators
to evaluate the extent of the CCR -impacted groundwater.
• Compare the absolute and relative abundance of major common constituents and signature
constituents among various well groups to determine whether CCR -impacted groundwater at
the site has resulted in the water quality exceedances found in the local water supply wells.
Based on the results of this evaluation, there is no relationship between the CCR -impacted groundwater
and the water quality exceedances found in the local water supply wells.
More details regarding the evaluation approach, data analysis methods, results, and conclusions are
presented below.
C.5.1 Evaluation Approach
• Screen the geochemical and transport behaviors of typical CCR -related constituents to establish
candidate constituents for further evaluation.
• Assess the presence and magnitude of candidate constituents in the groundwater beneath the
site as a result of a release from the ash basin system by comparing the concentration
magnitude of these constituents in the four major well groups below:
— Ash basin porewater monitoring wells;
— Other facility monitoring wells, including wells screened in the shallow flow layer
(shallow wells), wells screened in the transition zones (deep wells), and bedrock wells;
— Local water supply wells (data from NCDEQ); and
— Regional background wells (data from NCDEQ and from Duke Energy).
Note that the wells in a major group may be further divided into multiple subgroups in order to
evaluate the spatial trends of the groundwater data; for example, the facility bedrock wells may
be further divided into two subgroups based on the groundwater flow direction in the bedrock
unit: (a) facility bedrock wells that are likely to be within the area of CCR -impacted groundwater,
and (b) facility bedrock wells that are likely to be outside of this area.
APRIL 2016 28 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
• Identify useful reduction -oxidation (redox) constituents that can also serve as an indicator or a
signature for CCR -impacted groundwater by comparing the concentration magnitude of
dissolved oxygen, iron, and manganese, among various well groups.
• Select effective constituents that can differentiate the site -related impacts and background
conditions to serve as signature constituents to assess the potential relationship between the
facility CCR -impacted groundwater and the local water supply wells.
• Compare the relative abundance patterns of major cations and anions in groundwater among
various well groups to assess the data clustering pattern and correlation among various well
groups.
• Apply the site-specific geochemical principles and the knowledge of the groundwater flow field,
which have been developed and documented in the CSA and CAP reports (HDR, 2015a, 2015b,
2016) and summarized in Section C.4, to coherently interpret the groundwater data trends and
to verify or reject the connection between the CCR -impacted groundwater and the water quality
exceedances found in the local water supply wells.
C.5.2 CCR -Related Constituents Screening for Signature Development
The first step for the identification of the CCR -impacted signature constituents is to identify the
constituents that have the following characteristics:
• They are recalcitrant to degradation and transformation under site-specific conditions.
• They are very soluble and subject to little sorption. The site-specific sorption coefficients for
various CCR -related constituents are shown in Table C5-1.
• During the transport process, the constituents of interest are not likely subject to a mechanism
that can increase or decrease their concentrations.
• Their concentrations or values are substantially different from the background concentrations or
values.
Based on these criteria and a review of the chemical data in the CSA report (HDR, 2015a), the following
constituents are considered to be the candidates for signature development:
• Boron, calcium, sulfate, chloride, and TDS: Based on the understanding of the behavior of
constituents that can be released from coal ash into groundwater, USEPA has identified those
constituents that are considered to be indicators of a potential release from coal ash. These
constituents belong to the CCR Rule Appendix III constituents (USEPA, 2015a). Of these, boron
and sulfate are the most common constituents used to evaluate the potential for an ash
management area impact in groundwater, as will be shown in the evaluation presented below.
• Barium and cobalt: These two trace metals are less sensitive to the redox conditions and are
not readily sorbed to mineral surfaces (Table C5-1), and can be associated with CCR impacts to
groundwater (USEPA, 2015a). These two trace metals are also selected as candidate
constituents. Total barium and cobalt concentrations were used in this evaluation.
• Dissolved oxygen, dissolved iron, and dissolved manganese: Groundwater in the ash basin
system area generally contains very low concentrations of dissolved oxygen, but high
APRIL 2016 29 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
concentrations of dissolved iron and manganese concentrations (HDR, 2015a). The site-specific
geochemical analysis indicates that the groundwater in the ash basin system area is generally in
the iron or manganese reducing conditions (Figure C5-1) (HDR, 2016). It is noted that, because
groundwater samples collected from the regional background wells and local water supply wells
only analyzed for total iron, total iron concentrations were used to conservatively represent the
iron concentrations in these groundwater samples. Because the concentrations of dissolved
iron and manganese are sensitive to the presence of dissolved oxygen, including iron and
manganese in this evaluation is expected to help compare the redox conditions among different
well groups.
C.5.3 Data Analysis Methods
C.5.3.1 Data Sources
The groundwater analytical data used in this evaluation are from the following sources:
• Facility groundwater monitoring well data;
• Local water supply well data from NCDEQ;
• NCDEQ reconnaissance or background water supply well data; and
• Duke Energy background water supply well data.
C.5.3.2 Data Aggregation
The general rules for data aggregation are described here. When multiple sampling events occur for a
well, the following rules were used to find a representative concentration value for the box plot and
correlation plot evaluations:
• For boron, calcium, chloride, sulfate, TDS, barium, and cobalt, the representative value is
defined as the maximum of the detected values if the analytical results are not all NDs. If the
analytical results are all NDs, the lowest reporting limit is defined as the representative value.
Using the maximum concentrations will help not underestimate the CCR impacts to the local
water supply wells and facility monitoring wells.
• For dissolved oxygen, total and dissolved iron, and total and dissolved manganese, the average
concentration is used as the representative value for the general conditions observed in a well.
• For piper plots, the average concentration is used as the representative values for the general
conditions observed in a well.
• The reporting limits are used to represent the ND results.
C.5.3.3 Box Plot
The comparisons of the concentration magnitude among different well groups for various potential
indicators were made using the box plots produced by the ProUCL software (USEPA, 2013). Figure C5-2
defines the various components of the box plot. The location of the upper whisker is the lesser of 1.5
APRIL 2016 30 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
times the interquartile range (IQR) above the 75 percentile or the maximum value; the location of the
lower whisker is the greater of 1.5 times the IQR below the 25 percentile or the minimum value. This
analysis includes both detected and non-detected values.
C.5.3.4 Correlation Plot
The constituents found to be a signature indicator of the CCR -impacted groundwater can be used to
generate correlation plots to further evaluate the relationships among various data groups. To create a
correlation plot, different data groups can be plotted using different symbols with the concentrations of
one constituent on the x-axis and the concentrations of the other constituent on the y-axis. The
clustering patterns or trends will illustrate the correlations among data groups.
C.5.3.5 Piper Plot
Piper plots have been frequently used to assess the relative abundance of general cations (sodium,
potassium, magnesium, calcium) and anions (chloride, sulfate, bicarbonate and carbonate) in
groundwater and to differentiate different water sources in hydrogeology (Domenico and Schwartz,
1998). Groundwater resulting from different water sources or in different geologic units may exhibit
distinct clustering patterns on a piper plot. Because calcium and sulfate are common coal ash
constituents, it is expected the CCR -impacted groundwater may show a different clustering pattern than
the background groundwater or the groundwater that has not been impacted by CCR.
In the CSA report, the piper plots were used to evaluate the water chemistry between the porewater in
ash basin system and groundwater in other groups of facility monitoring wells. An example figure is
shown in Figure C5-2, which compares the general water chemistry among the porewater in the ash
basin, surface water in the ash basins, and groundwater in the bedrock wells. The piper plot consists of
three subplots: a cation composition trilinear plot in the lower left corner, an anion composition trilinear
plot in the lower right corner, and a diamond plot in between. The red lines on each subplot show how
to read the meanings of a data point in a subplot. For example, in the cation subplot, the data point of
AB -4S shows about 37 percent of the total cation charges from sodium and potassium, approximately 40
percent from calcium, and about 26 percent from magnesium. In the anion subplot, the data point of
SW-AB1 shows about 37 percent of the total anion charges from sulfate, approximately 25 percent from
chloride and nitrate related anions (NO2_ and NO3-), and 38 percent from carbonate (CO32-)plus
bicarbonate (HCO3-) anions. In the diamond subplot, the data point of AB-7BRU shows about 68
percent of the total anion charges from chloride, nitrate related anions, and sulfate, and approximately
48 percent of the total cation charges from calcium and magnesium.
The piper plots for this evaluation were generated using the GW_Chart program developed by the
United States Geological Survey (USGS) (Winston, 2000).
APRIL 2016 31 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
C.5.4 Evaluation Results
C.5.4.1 Box Plot Comparison
The box plot comparison of boron, calcium, chloride, sulfate, and TDS concentrations among various
well groups is shown in Figure C5-3. The most significant concentration differences between the results
of the ash basin porewater wells and the local water supply wells were found to be boron and sulfate.
The other constituents also show noticeable elevated concentrations in the ash basin porewater
compared to other on-site locations and compared to the local water supply wells.
The box plot comparison of barium and cobalt is provided in Figure C5-4, which shows trends similar to
those observed for other major CCR constituents in Figure C5-3. The cobalt concentration difference
between the ash basin porewater and the groundwater in local water supply wells is insignificant. The
barium concentration difference between the ash basin porewater wells and local water supply wells is
only slightly lower than the concentration difference for sulfate. Because boron, sulfate, and barium are
very mobile, subject to little sorption onto mineral surfaces, and not susceptible to degradation or
transformation, and because they show the most elevated concentrations (relative to the
concentrations found in the local water supply wells), they are thus considered to be effective signature
constituents.
The box plot comparison of dissolved oxygen, iron, and manganese is shown in Figure C5-5. The trend
of dissolved oxygen concentrations shows that the groundwater in the local water supply wells is
generally more oxygenic than the porewater in the ash basins. The observed low oxygen concentrations
in the ash basin porewater are consistent with the understanding that coal ash leachate is a chemically
reduced solution (USEPA, 1980). The depletion of dissolved oxygen in the leachate is attributed to the
occurrence of sulfite or other oxidation processes when oxygenic water contacts with coal ash (USEPA,
1980).
It is noted that dissolved oxygen occurs in groundwater through recharge by precipitation and air within
the unsaturated zone. Dissolved oxygen remains in groundwater until it is used by bacteria, organic
material, or reduced elements in minerals (Cunningham and Daniel, 2001). High dissolved oxygen
concentrations in groundwater may indicate relatively rapid groundwater recharge (Cunningham and
Daniel, 2001). The range of the dissolved oxygen concentrations observed in the local water supply
wells is consistent with the range of dissolved oxygen concentrations found in the similar geologic
environment (i.e., fractured crystalline rocks mantled with weathered regolith in the Piedmont
Physiographic Province) by the USGS (Briel, 1997).
There is some uncertainty associated with the dissolved oxygen concentrations observed in local water
supply wells and regional background wells. These concentration values may be less accurate because
the sampling protocol for these wells is not known and the dissolved oxygen measurements may be
affected by the interference from well and plumbing configurations that admit air to the sample water
(Donnahue and Kibler, 2007). Although the dissolved oxygen concentrations may be overestimated in
some cases, the trend of dissolved oxygen data collected from water supply wells have been used for
other studies to help understand the general geochemical conditions (Winograd and Robertson, 1982;
Cunningham and Daniel, 2001; Donnahue and Kibler, 2007).
APRIL 2016 32 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
The manganese concentration trend is opposite to that of dissolved oxygen. The iron concentration
trend is less significant; nevertheless, the median concentration for the ash basin porewater is
noticeably higher than that for the local water supply wells. Based on the site-specific geochemical
evaluation, the site groundwater generally favors the presence of reduced iron and manganese
(Figure C5-1), which is consistent with the low oxygen content in groundwater in that area. The results
are consistent with the iron and manganese geochemical behavior in that they tend to form precipitates
under oxygenic conditions, and are removed from the groundwater.
The lack of dissolved oxygen in the ash basin porewater can serve as a useful signature. If the
groundwater obtained by a local water supply well is primarily from the ash basin system, it is expected
that the dissolved oxygen concentration would be low because there is no effective mass transfer
process to increase the dissolved oxygen concentration during groundwater transport in the deep
overburden and bedrock units. In contrast, reduced iron and manganese ions can be re -oxidized and
form precipitates when they migrate into an aquifer system containing mineral oxides. Dissolved
oxygen is thus considered to be a useful signature constituent.
C.5.4.2 Correlation Plot Evaluation
Boron, sulfate, barium, and dissolved oxygen were identified to be useful signature constituents to
assess the extent of the CCR -impacted groundwater. The spatial patterns of boron and sulfate
concentrations were first evaluated through a correlation plot, using the data from the ash basin
monitoring, facility bedrock, local water supply, and the regional background wells.
In this correlation plot evaluation, the boron and dissolved oxygen concentration pairs are grouped as
follows:
• Ash basin porewater wells;
• Local water supply wells;
• Regional background wells; and
• Facility bedrock wells as shown in Figure C5-6, which are further divided into two subgroups:
— Subgroup 1 (Downgradient): The bedrock wells are located beneath or downgradient of
the ash basin system, or groundwater flowing through these wells is likely originated
from the ash basin system. CCR -impacted groundwater is more likely to impact these
wells based on the groundwater flow field in the deep overburden and bedrock units
(HDR, 2015b). Wells AB -213R, AB -413R, AB-4BRU, AB-5BRU, AB-6BRU, AB-7BRU, AB-
8BRU, AB -913R, AB-9BRU, GWA-213R, GWA-2BRU, GWA-313R, GWAS-3BRU, GWA-5BRU,
GWA-6BR, GWA-6BRU, GWA-913R, and GWA-12BRU belong to this subgroup.
— Subgroup 2 (Upgradient): These wells are not expected to be influenced by the ash
basin groundwater. Wells BG-1BR and BG-3BRU belong to this group.
The data obtained from the facility bedrock wells may help identify the potential groundwater chemistry
characteristics of a CCR -impacted bedrock well and help illustrate the spatial pattern of CCR -impacted
facility bedrock wells, which may be used to assess the potential impacts to the local water supply wells.
APRIL 2016 33 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
It should be noted that the subgroups formed above is to facilitate the evaluation presented below. The
final well group assignment will be based on the evaluation results, as shown in Figure C5-6.
A correlation plot of boron and sulfate concentrations was produced and shown in Figure C5-7. Panel
(a) shows the correlation plot for the ash basin porewater wells and the facility downgradient bedrock
wells. The ash basin porewater well results are distinguished by elevated boron concentrations (>100
micrograms per liter (µg/L]) and sulfate concentrations generally higher than 10,000 µg/L. Some of the
downgradient facility bedrock wells are clustered with the ash basin porewater wells; the others show
lower boron concentrations (<100 µg/L) and a variability of sulfate concentrations. Panel (b) shows the
data from the facility upgradient bedrock wells in addition to the data in Panel (a). These added wells
are clustered with the facility downgradient wells of lower boron concentrations (< 100 µg/L). The
sulfate concentrations differ significantly for the two upgradient wells. Panel (c) shows the overlay of
the data from the regional background wells and local water supply wells on the data in Panel (b). These
added wells are distinguished by generally very low to non -detect levels of boron, and a range of sulfate
concentrations.
The Panel (c) plot shows that the data are clustered in two distinct areas. Area 1 contains the data from
the ash basin porewater wells. Area 2 contains the data from the local water supply wells and regional
background wells. The facility downgradient bedrock wells are either in Area 1 or exhibit a significantly
higher sulfate concentration than most of the local water supply wells. The two upgradient bedrock
wells show similar lower boron concentrations to those observed in the local water supply wells but BG -
IBR shows a much higher sulfate concentration.
Water supply well B61 falls outside of Area 2, showing a higher degree of variability of sulfate
concentration than other local water supply wells. B61 is in fact a facility water supply well, and its
location is shown on Figure C5-9. Based on the groundwater flow direction/potentio metric surface
maps in Section C4 (C4-9 through C4-10), this location is in a downgradient direction from the Primary
Cell of the Active Ash Basin. It should be noted that B-61 is a 500 foot deep well, which could be into
very different geology from other local water supply wells due to the significant depth; therefore, the
high sulfate concentration observed in this well may be related to deep groundwater.
Based on Figure C5-5, dissolved oxygen concentration may also be a useful indicator for CCR -impacted
groundwater. The correlation plot of boron and dissolved oxygen concentrations is shown in
Figure C5-8. Panel (a) shows the correlation plot for the ash basin porewater wells and the facility
downgradient bedrock wells. These results are distinguished by elevated boron concentrations and
relatively low dissolved oxygen concentrations for the ash basin porewater wells. The downgradient
facility bedrock wells also generally show low dissolved oxygen concentrations. Panel (b) shows the
data from the facility upgradient bedrock wells in addition to the data in Panel (a). These added wells
are distinguished by lower boron concentrations (< 100 µg/L) and higher dissolved oxygen
concentrations than those in the ash basin porewater wells.
Panel (c) shows the overlay of the data from the regional background wells and local water supply wells
on the data in Panel (b). These added wells are distinguished by very low to non -detect levels of boron,
and a wide range of dissolved oxygen concentrations. The Panel (c) plot shows that the data are
clustered in two distinct areas. Area 1 contains the data from the ash basin porewater wells. Area 2
APRIL 2016 34 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
contains the data from the local water supply wells and regional background wells. Due to the
uncertainty in the dissolved oxygen concentrations in the NCDEQ-sampled water supply wells, the upper
bound of Area 2 has been truncated at approximately 7,000 µg/L dissolved oxygen. Most of the local
water supply wells have no boron detected at the reporting limit of 5 µg/L. It is noted that dissolved
oxygen concentrations in some regional background and local water supply wells are already very low
(<1,000 µg/L), suggesting that uncertainty resulting from the interference from the sampling protocol or
well and plumbing configurations that admit air to the sample water is within 1,000 µg/L for these wells.
The variability of dissolved oxygen concentrations in the local water supply wells is consistent with that
of the regional background wells. The dissolved oxygen concentration observed in two facility
downgradient bedrock wells are higher than 6,000 µg/L, indicating the background dissolved oxygen can
be naturally high in the vicinity of the site.
The variability of boron concentrations in the regional background wells (the maximum detected value is
5.5 µg/L) is much smaller than the variability of the boron concentrations observed in the local water
supply wells (up to 38 µg/L). It should be noted that, since the number of the local water supply wells
(89 in total) is significantly more than the number of the regional background wells (24 in total), the
variability of boron concentrations in groundwater is more likely to be captured by a greater number of
the wells. The groundwater quality study performed by the USGS in the Piedmont and Blue Ridge
Crystalline -Rock aquifers shows that boron concentration in the bedrock unit can be higher than
100 µg/L (Figure C5-13) (Chapman, et al., 2013).
The data pairs in Figure C5-8 for the facility bedrock wells that are classified as the downgradient group
are generally clustered toward the ash basin porewater data pairs (Area 1). In contrast, the data pairs of
the upgradient wells are generally more oxygenic and thus are not clustered toward Area 1. The
correlation plot result suggests that the low oxygen and elevated boron concentrations serve as a useful
signature pair to help identify CCR -impacted groundwater. The fact that most of the local water supply
wells are significantly more oxygenic (dissolved oxygen concentration greater than 4,000 µg/L), or do
not have boron detected at the reporting limit of 5 µg/L, suggests that most of the local water supply
wells do not obtain groundwater primarily from the ash basin. This is consistent with the fact that no
effective mass transfer mechanism can replenish oxygen during the groundwater transport from the ash
basin system to a water supply well.
It should be noted that dissolved oxygen concentration in the bedrock aquifer may be naturally low
(Briel, 1997). As can be seen in Panel (c) of Figure C5-8, low dissolved oxygen concentrations (less than
1,000 µg/L) are also present in regional background well data. Therefore, the low dissolved oxygen
concentration itself cannot be a reliable indicator. To validate the CCR impacts, concentrations of other
effective CCR indicators (such as boron and sulfate) are also needed to be higher than the background
concentration levels.
The local water supply well data that exhibit a detected boron concentration or boron ND level higher
than 5 Vg/L were further evaluated for potential to be affected by CCR -impacted groundwater.
Table C5-2 shows the comparison between the observed boron, sulfate, and barium concentrations in
these wells and the site-specific facility BTVs for these constituents. The threshold values developed
using the facility background wells are considered to be more representative of local groundwater
conditions because of their proximity to the NCDEQ-sampled local water supply wells. The results show
APRIL 2016 35 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
that the boron, sulfate, and barium concentrations observed in these wells are below the BTVs derived
in Section C.3, with the exception of the local water supply well B61. As discussed above, the sulfate
concentration in B61 is abnormally high, possibly due to its depth (500 feet), and the well is, in fact, a
facility well located downgradient of the ash basins. The location of this well is shown in Figure C5-9.
It is noted that, in Panel (c) of Figure C5-8, the water supply well B53 does not group with other local
water supply wells in Area 2. A low sulfate concentration (2,900 pg/L) in this well, as well as the local
water supply well data within the immediate vicinity (1339, B63, B69, B76, and B78) with no detections of
boron, indicate this well is not likely to be affected by CCR -impacted groundwater, and is an obvious
outlier in the correlation plot. It is noted that the boron concentration (38 µg/L) in B53 is a J -flagged
(estimated) concentration due to an reporting limit of 500 µg/L. The concentration is within the
variability of background boron concentrations (Figure C5-13) (Chapman, et al., 2013). Upgradient
bedrock well BG-3BRU similarly does not group with the local water supply wells. The boron
concentration for BG-3BRU was not detected with an elevated detection limit (50 µg/L), thus the data
point falls outside of Area 2.
Based on Figures C5-7, C5-8, and Table C5-2, CCR -impacted groundwater has been found in the facility
bedrock wells that are within or downgradient of the ash basin system footprint. Similar impacts have
not been observed in the local water supply wells. The results of the correlation plot evaluation support
the conceptual groundwater transport process that the background groundwater of higher dissolved
oxygen and lower boron and sulfate concentrations is upgradient of the ash basin system and the
groundwater becomes enriched with boron and/or sulfate and/or deprived of oxygen as it flows through
the ash basin system.
Note that this correlation plot evaluation uses groundwater concentration data under the influence of
historic pumping of the local water supply wells. The lack of elevated concentrations of CCR -related
signatures and the distinct discrepancy between the data patterns on the correlation plots indicate that
the pumping of the local water supply wells is not able to reverse the natural hydraulic gradient to the
extent that can capture the ash basin porewater.
C.5.4.3 Piper Plot
Two piper plots were created to evaluate the relative abundance patterns of major ions in the ash basin
porewater and in the facility downgradient bedrock wells. The results are shown in Figure C5-10.
Panel (a) shows the data for the ash basin porewater wells; the cation subplot shows that calcium is
generally the dominant cation in the porewater, the diamond subplot shows that the relative abundance
of calcium and magnesium in the porewater are mostly larger than 60 percent, and the anion subplot
shows that the relative abundance of chloride is generally less than 20 percent. The results also show
that these wells have a wide range of sulfate abundance.
Panel (b) shows the data for both the ash basin porewater wells and the facility downgradient bedrock
wells. The data for the facility downgradient bedrock wells are generally clustered with those of the ash
basin porewater wells, suggesting that the CCR -impacted groundwater is present in the downgradient
bedrock wells. It is noted that some data points for the facility bedrock wells (AB-9BR and AB-9BRU)
deviate from the general data distribution pattern. Note that boron was detected in both AB-9BR and
APRIL 2016 36 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
A13-913RU at concentrations of 420 and 790 µg/L, respectively. The deviation is primarily the result of the
high pH values in both wells (pH > 11), which tend to result in the formation of calcium -and -magnesium -
associated precipitates and, thus, reduce the calcium abundance among cations. These deviations show
the wide variability of bedrock groundwater quality under the ash basin system footprint, and the
potentially impacted downgradient area. It is noted that the variability of the ash basin porewater well
data is similar to the variability of the facility downgradient well data.
The piper plots for the local water supply, regional background, and upgradient bedrock wells are
provided in Figure C5-11. Panel (a) of Figure C5-11 shows the data for the local water supply and
regional background wells. As can be seen, these well data are grouped fairly tightly together in each of
the sections of the piper diagram except for an outlier in the anion subplot (see the data in blue circles,
which represents location 1361, the facility water supply well). This indicates that they have similar
major ion characteristics, and the grouping is very distinct from the ash basin related wells in
Figure C5-10. Panel (b) of Figure C5-11 shows the data for the facility upgradient bedrock wells on top
of the data of the local water supply and regional background wells in Panel (a). When viewed this way,
it is clear that the upgradient facility bedrock well, BG-3BRU, has characteristics very similar to the local
water supply wells. The other well, 13G -113R, somewhat deviates from the local water supply and
regional background well data.
Figure C5-12 shows a side-by-side comparison of the ash basin related well data in Panel (a), and the
local water supply well and facility upgradient well data in Panel (b). The apparent difference in
groundwater characteristics between the CCR -impacted wells and the local water supply wells is shown
in their diamond subplots. The area defined by the blue line in Panel (b) encloses almost all the local
water supply well data, but excludes many data in Panel (a), especially those with high relative sulfate
abundance. It is noted that some of the ash basin porewater and facility downgradient data with
characteristics low relative sulfate abundance, distribute within or in the vicinity of the blue diamond
box, indicating that the groundwater subject to less CCR impact still has the major ion composition
comparable to the local water supply and regional groundwater, although these wells are located
downgradient of the ash basin system. Some ash basin porewater and facility downgradient bedrock
well data with the characteristics of high relative sulfate abundance, representing more pronounced CCR
impacts, are distributed closer to the top portion of the diamond subplot. The separation of these two
types of data illustrates sulfate enrichment when groundwater passes through the ash basin. The
results support that the groundwater in the local water supply wells represents the background
groundwater conditions and are not impacted by the ash basin porewater.
It is noted that the facility upgradient bedrock well, 13G -113R, is also not closely associated with any ash
basin porewater and downgradient bedrock wells, strongly suggesting that its major ion composition is
likely naturally occurring.
In summary, the data for the downgradient facility bedrock wells are generally within the variability of
the ash basin porewater well data. The piper plot results are consistent with the results of the
correlation plots; both show a similarity between many of the CCR -impacted facility bedrock wells and
the ash basin porewater wells. In the piper plots, the local water supply well data show a distinct
clustering pattern in comparison to the data of the ash basin porewater wells and the impacted facility
bedrock wells. As shown in the diamond subplot, the trend of sulfate enrichment between the local
APRIL 2016 37 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
water supply well data and many of the ash basin porewater and facility downgradient well data
supports that the source water for the local water supply wells is not CCR -impacted groundwater.
C.5.5 Conclusions
This evaluation has reached the following key conclusions:
The boron and sulfate concentrations in the ash basin groundwater are considerably higher than
the maximum reported boron concentration found in the local water supply wells. Because
boron and sulfate exhibit little sorption to mineral surfaces and are not expected to precipitate
or be transformed under the site geochemical conditions, they are considered to be the most
effective signature constituents among the coal ash related constituents for evaluating the
groundwater impacts from the ash basin.
The boron and sulfate concentrations detected in the local water supply wells are within the
range of boron and sulfate concentrations found within the background conditions and within
the range of boron and sulfate concentrations found in the crystalline rock aquifers in the
Piedmont Province by the USGS (Chapman et al., 2013). Therefore, the presence of boron and
sulfate in the local water supply wells cannot be attributed to the impacts from the ash basin
porewater.
• The redox conditions in the ash basin porewater are generally anoxic, with the characteristics of
low dissolved oxygen concentrations. The redox conditions found in the local water supply wells
are generally more oxygenic. However, there is a natural range of dissolved oxygen
concentrations as evidenced in the regional background wells, and as confirmed by the USGS
data. The lack of dissolved oxygen is considered to be a useful signature of CCR -impacted
groundwater. This suggests that the local water supply wells with high dissolved oxygen
concentrations are not likely to obtain groundwater from the ash basin system because no
effective mass transfer mechanism can replenish oxygen during the groundwater transport from
the ash basin system to local water supply wells.
• The CCR -impacted facility bedrock wells identified using the correlation and piper plots are
consistent with the knowledge of the groundwater flow field in the vicinity of the facility, as
described in Section C.4. The local water supply wells are generally upgradient or side gradient
of the ash basin.
The correlation and piper plots show very different clustering patterns for the ash basin
porewater wells and the local water supply wells. The separation of the local water supply well
data and the ash basin porewater data in the correlation plots is also reflected on the piper
plots. The evaluation results using coal ash signature indicators and using major ion
compositions support each other. Both indicate that the source water for the local water supply
wells is not CCR -impacted groundwater.
• The evaluation uses groundwater concentration data under the influence of historic pumping of
the local water supply wells. The lack of elevated concentrations of CCR -related signatures and
the distinct discrepancy between the data patterns on the correlation and piper plot indicate
that the pumping of the local water supply wells is not able to reverse the natural hydraulic
gradient to the extent that can capture CCR -impacted groundwater.
APRIL 2016 38 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
It is concluded that there is no connection between the CCR -impacted groundwater and the water
quality exceedances found in the local water supply wells.
C.6 SUMMARY
This document presents the results of supplemental technical evaluations in four important assessment
areas to determine whether or not the water supply wells located within a 1,500 -foot radius of the Buck
ash basin compliance boundary could be impacted by CCR releases from the ash basin. The evaluations
in this document are based on the currently available data, which includes: generally one sampling
round from the water supply wells (note some wells had one or more re -analyses), three to four
sampling rounds from the ash basin wells, and multiple years of compliance well sampling. The
conclusion from the detailed weight of evidence demonstrates that water supply wells in the vicinity of
the Buck facility are not impacted by CCR releases from the ash basin.
The evaluation of the private and public water supply well data collected by NCDEQ, and the detailed
statistical analysis of regional background groundwater data, indicate that constituent concentrations in
the water supply wells are generally consistent with background. The concentrations of boron and the
other potential coal ash indicators were low and not above screening levels in the water supply wells
sampled by NCDEQ. None of the NCDEQ-sampled water supply well results were above Federal primary
drinking water standards (MCLs), with the exception of the pH results and a single lead result. In
general, pH in these wells (both near the facility and in the background wells) was below the state and
federal standard range. This is consistent with literature on the pH of groundwater in North Carolina
(Briel, 1997; Chapman, et al., 2013).
The comprehensive evaluation of groundwater flow with respect to local water supply wells
demonstrates that groundwater flow is predominantly to the north toward the Yadkin River from the
topographic divides southwest, south, and southeast of the ash basin system with localized flow to the
west of Cell 1 and in an area east of the source that requires further evaluation. Groundwater flow is
away from the water supply wells, and also confirms the flow model predictions. Coal ash constituents
do not measurably increase the density of groundwater or have a separate liquid phase in groundwater
as compared to other dense liquids that would "sink" in the aquifer, like saltwater. Thus, releases from
coal ash management areas tend to remain in the shallower groundwater flow layers.
This conclusion is confirmed by the detailed characterization of groundwater chemistry including
evaluation of CCR indicators, redox conditions, and correlation evaluations. The results of the chemical
correlation analyses indicate that, based on the different constituent clustering patterns from the ash
basin porewater wells and the water supply wells, the source water for the water supply wells is not
CCR -impacted groundwater.
Based on this combined weight of evidence, groundwater utilized by water supply wells near the coal
ash impoundments is not impacted by the coal ash sources.
These results indicate that a Low classification for the Buck Steam Station under the CAMA is warranted.
APRIL 2016 39 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C - Buck
C.7 REFERENCES
1. Briel, L.I. 1997. Water quality in the Appalachian Valley and Ridge, the Blue Ridge, and the
Piedmont physiographic provinces, eastern United States (Professional Paper No. 1422-D). U.S.
Geological Survey.
2. CAMA. 2014. North Carolina Coal Ash Management Act. Senate Bill S729v7. Available at:
http://www.ncleg.net/Sessions/2013/Bills/Senate/PDF/S729v7.PDF
3. Chapman, M.J., Cravotta III, C.A., Szabo, Z. and Lindsay, B.D. 2013. Naturally occurring
contaminants in the Piedmont and Blue Ridge crystalline -rock aquifers and Piedmont Early
Mesozoic basin siliciclastic-rock aquifers, eastern United States, 1994-2008 (Scientific
Investigations Report No. 2013-5072). U.S. Geological Survey.
4. Cunningham, W.L. and Daniel, C.C. 2001. Investigation of Ground -Water Availability and Quality
in Orange County, North Carolina (Water Resources Investigation No. 4286). US Department of
the Interior, U.S. Geological Survey.
5. Daniel, C.C., III. 1989. Statistical Analysis Relating Well Yield to Construction Practices and Siting
of Wells in the Piedmont and Blue Ridge Provinces of North Carolina (Water -Supply Paper
2341-A). U.S. Geological Survey.
6. Daniel, C.C., III and Harned, D.A. 1998. Ground -water recharge to and storage in the regolith -
fractured crystalline rock aquifer system, Guilford County, North Carolina: U.S. Geological
Survey Water -Resources Investigations Report 97-4140, 65p.
7. Domenico, P.A. and Schwartz, F.W. 1998. Physical and chemical hydrogeology (Vol. 44). New
York: Wiley.
8. Donnahue, J.C. and Kibler, S.R. 2007. Ground Water Quality in Piedmont/Blue Ridge Unconfined
Aquifer System of Georgia, Georgia Department of Natural Resources, Environmental Protection
Division, Watershed protection branch, regulatory support program, Circular 12U, Atlanta.
9. EPRI. 2005. Chemical Constituents in Coal Combustion Product Leachate: Boron. Electric Power
Research Institute Report 1005258. March 2005.
10. Grubb, S. 1993. Analytical Model for Estimation of Steady -State Capture Zones of Pumping
Wells in Confined and Unconfined Aquifers. Ground Water, Vol. 31, No. 1, January -February
1993.
11. Haley & Aldrich. 2015. Evaluation of NCDEQ Private Well Data. December 2015.
12. Harned, D.A. 1989. The Hydrogeologic Framework and a Reconnaissance of Ground -Water
Quality in the Piedmont Province of North Carolina, with a Design for Future Study (Water -
Resources Investigations Report 88-4130, 55p.). U.S. Geological Survey.
APRIL 2016 40 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
13. Harned, D.A. and Daniel, C.C., III. 1992. The transition zone between bedrock and regolith:
Conduit for contamination?, p. 336-348, in Daniel, C. C., III, White, R. K., and Stone, P. A., eds.,
Groundwater in the Piedmont: Proceedings of a Conference on Ground Water in the Piedmont
of the Eastern United States, October 16-18, 1989, Clemson University, 693p.
14. HDR. 2014a. Buck Steam Station —Ash Basin Drinking Water Supply Well and Receptor, Survey.
HDR, Inc. [Online] URL: http://portal.ncdenr.org/web/wq/drinking-water-receptor-surveys
15. HDR. 2014b. Buck Steam Station —Ash Basin Supplement to Drinking Water Supply Well and
Receptor Survey. HDR, Inc. [Online] URL: http://portal.ncdenr.org/web/wq/drinking-water-
receptorsurveys
16. HDR. 2014c. Buck Steam Station —Ash Basin, Proposed Groundwater Assessment Work Plan
(Rev. 1), NPDES Permit NC0004774. HDR, Inc. December 30.
17. HDR. 2015a. Comprehensive Site Assessment Report, Duke Energy Buck Steam Station Ash
Basin, August. HDR, Inc.
18. HDR. 2015b. Corrective Action Plan Part 1, Duke Energy Buck Steam Station Ash Bain,
November. HDR, Inc.
19. HDR. 2016. Corrective Action Plan Part 2, Duke Energy Buck Steam Station Ash Bain, February.
HDR, Inc.
20. Heath, R.C. 1980. Basic elements of groundwater hydrology with reference to conditions in
North Carolina (Open File Report 80-44, 86p.). U.S. Geological Survey.
21. LeGrand, H.E. 1988. Region 21, Piedmont and Blue Ridge. In Hydrogeology, The Geology of
North America, vol. 0-2, ed. W.B. Back, J.S. Rosenshein, and P.R. Seaber, 201-207. Geological
Society of America. Boulder CO: Geological Society of America.
22. LeGrand, H.E. 1989. A conceptual model of ground water settings in the Piedmont region. In
Ground Water in the Piedmont, ed. C.C. Daniel III, R.K. White, and P.A. Stone, 693. Proceedings
of a Conference on Ground Water in the Piedmont of the Eastern United States, Clemson
University, Clemson, South Carolina. Charlotte, NC: U.S. Geological Survey.
23. LeGrand, H.E. 2004. A Master Conceptual Model for Hydrogeological Site Characterization in
the Piedmont and Mountain Region of North Carolina, A Guidance Manual, North Carolina
Department of Environment and Natural Resources Division of Water Quality, Groundwater
Section.
24. NCAC. 2013. 15A NCAC 02L.0202. Groundwater Standard (2L), Classifications and Water
Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative
Code. April 1, 2013. Available at:
http://portal.ncdenr.org/c/document library/get file?uuid=laa3fa13-2cOf-45b7-ae96-
5427fb1d25b4&grouPId=38364
APRIL 2016 41 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C - Buck
25. NCDEQ. 2016. Coal Combustion Residual Impoundment Risk Classifications. North Carolina
Department of Environmental Quality. January 2016. Available at:
https://ncdenr.s3.amazonaws.com/s3fs-public/document-
library/1.29.16 Coal%20Combustion%20Residual%201mpoundment%20CIassifications.pdf
26. NCDHHS. 2015. DHHS Screening Levels. Department of Health and Human Services, Division of
Public Health, Epidemiology Section, Occupational and Environmental Epidemiology
Branch. April 24, 2015. Available at:
http://portal.ncdenr.org/c/document library/get file?p I id=1169848&folderld=24814087&na
me=DLFE-112704.PDF
27. USEPA. 1980. Effects of Coal -ash Leachate on Ground Water Quality. U.S. Environmental
Protection Agency. EPA -600/7-80-066. March.
28. USEPA. 2007. Monitored Natural Attenuation of Inorganic Contaminants in Groundwater,
Vol. 1: Technical Basis for Assessment. 2007. U.S. Environmental Protection Agency.
EPA/600/R-07/139.
29. USEPA. 2012. 2012 Edition of the Drinking Water Standards and Health Advisories. Spring
2012. U.S. Environmental Protection Agency.
http://water.epa.gov/drink/contaminants/index.cfm
30. USEPA. 2013. Statistical Software ProUCL 5.0.00 for Environmental Applications for Data Sets
with and without Nondetect Observations. U.S. Environmental Protection Agency. Software:
http://www2.epa.gov/land-research/proucl-software, and User's Guide:
https://www.epa.gov/sites/production/files/2015-03/documents/proucl v5.0 tech.pdf
31. USEPA. 2015a. Coal Combustion Residual (CCR) Rule (Hazardous and Solid Waste Management
System; Disposal of Coal Combustion Residuals From Electric Utilities; FR 80(74): 21302-
21501, April 19, 2015. U.S. Environmental Protection Agency. Available at:
http://www.gpo.gov/fdsVs/pl<g/FR-2015-04-17/PDF/2015-00257.PDF
32. USEPA. 2015b. USEPA Regional Screening Levels (RSLs). November 2015. U.S. Environmental
Protection Agency. Available at: http://www.epa.gov/reg3hwmd/risk/human/rb-
concentration table/Generic Tables/index.htm
33. Winograd, I.J. and Robertson, F.N. 1982. Deep oxygenated ground water: anomaly or common
occurrence? Science, 216(4551), pp.1227-1230.
34. Winston, R.B. 2000. Graphical User Interface for MODFLOW, Version 4 (Open -File Report 00-
315). U.S. Geological Survey. Software:
http://water.usgs.gov/nrp/gwsoftware/GW Chart/GW Chart.html
APRIL 2016 42 %UICH

Table C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 1 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
April 2016
15A NCAC 02L.0202
d(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal MCL/SMCL(b):
(• denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
"500
6
30
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Appendix III
App
endix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B10
< 5
11600
4.1
6.6
2.8
168
< 0.5
< 0.5
28.4
< 0.2
< 0.08
5.1
< 0.5
0.14
< 0.2
0.58
< 0.5
< 0.1
Buck
8100
< 5
10200
1.4
7.5
4.8
118
< 0.5
< 0.5
14.1
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
3.3
< 0.5
< 0.1
Buck
8101
<5
5490
1.1
7.1
<2
81
<0.5
<0.5
6.9
<0.2
<0.08
2.9
<0.5
0.14
<0.2
<0.5
<0.5
<0.1
Buck
B11
< 5
7160
3.8
6.62
< 2
102
< 0.5
< 0.5
8.53
< 0.2
< 0.08
< 0.5
< 0.5
0.7
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B12
< 5
8560
2.3
6.1
< 1
93
< 0.5
< 0.5
23
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B13
5.8
21300
10.3
6.7
6.5
161
<0.5
<0.5
39.3
<0.2
<0.08
0.58
<0.5
0.17
<0.2
2.4
<0.5
<0.1
Buck
B14-630
<5
4700
2
6.2
<2
38
<0.5
<0.5
29.5
<0.2
<0.08
2.5
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Buck
B14-640
< 5
41300
3.2
7.7
6.4
164
< 0.5
< 0.5
5.5
< 0.2
< 0.08
< 0.5
< 0.5
0.11
< 0.2
2.6
< 0.5
< 0.1
Buck
B15
< 5
7040
2.8
6.3
2.2
84
< 0.5
< 0.5
14.8
< 0.2
< 0.08
< 0.5
< 0.5
0.56
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B16
10.4
12000
2.4
9.4
27.8
139
< 0.5
< 0.5
1.5
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
5.1
< 0.5
< 0.1
Buck
B17
<5
11100
13.5
6.35
<2
121
<0.5
<0.5
73.5
<0.2
1.4
0.55
<0.5
0.42
<0.2
1.2
<0.5
<0.1
Buck
B18
<5
10300
3.1
6.3
2.3
99
<0.5
<0.5
50.8
<0.2
<0.08
3.5
<0.5
0.55
<0.2
<0.5
<0.5
<0.1
Buck
B19
<5
12200
9.3
6.92
2.1
143
<0.5
<0.5
15.8
<0.2
<0,08
0.66
<0.5
0.92
<0.2
<0.5
<0.5
<0.1
Buck
B2
<5
19000
4.7
6.36
2.2
136
<0.5
2.2
22
<0.2
<0.08
0.75
0.25
0.52
<0.1
0.24
<0.5
<0.1
Buck
B21
18.4
8010
3.9
6.6
< 1
109
< 0.5
< 0.5
26
< 0.2
0.6
1.7
< 0.5
11
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B22
<5
7050
2
6.5
<2
96
<0.5
<0.5
13
<0.2
0.14
0.88
<0.5
0.5
<0.2
0.59
<0.5
<0.1
Buck
B24
< 5
6760
2.5
6.4
< 2
107
< 0.5
< 0.5
11.9
< 0.2
< 0.08
1
< 0.5
0.39
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B25
<5
6490
2
6.4
<2
109
<0.5
<0.5
12.9
<0.2
<0.08
1.5
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B26
<5
12600
8.8
6.07
<2
138
<0.5
<0.5
81.3
<0.2
<0.08
2.7
<0.5
3.3
<0.2
<0.5
<0.5
<0.1
Buck
B27
<5
6130
3.7
6
<2
29
<0.5
<0.5
11.2
<0.2
<0.08
0.52
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B28
< 5
9800
1.5
7.1
2.8
93
< 0.5
< 0.5
5.8
< 0.2
0.29
6.5
< 0.5
1.2
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B29
< 5
8510
2
6.8
< 2
60
< 0.5
< 0.5
9.5
< 0.2
< 0.08
7.4
< 0.5
0.23
< 0.2
0.69
< 0.5
< 0.1
Buck
B3
< 5
10900
4.9
6.5
< 2
107
< 0.5
< 0.5
11.3
< 0.2
0.099
< 0.5
< 0.5
9
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B31
<5
12200
8
6.1
<2
98
<0.5
<0.5
22.3
<0.2
<0.08
<0.5
<0.5
0.29
<0.2
<0.5
<0.5
<0.1
Buck
B32
< 5
13700
2.1
6.9
2.7
112
< 0.5
< 0.5
9.4
< 0.2
< 0.08
< 0.5
< 0.5
0.17
< 0.2
1.3
< 0.5
< 0.1
Buck
B33
<5
13300
2
6.7
2.8
117
<0.5
<0.5
19
<0.2
<0.08
0.85
<0.5
0.82
<0.2
0.68
<0.5
<0.1
Buck
B34
<5
7280
4.28
6.2
2.1
87
<0.5
<0.5
13.4
<0.2
<0.08
0.63
<0.5
0.11
<0.2
<0.5
<0.5
<0.1
Buck
B35
<20
7210
5
6.24
7
81
<0.5
<0.08
11.1
<0.11
<0.06
2.53
<0.03
1.23
<0.01
0.17
<0.16
<0.06
Buck
B37
<5
5730
1.4
6.6
2.1
89
<0.5
<0.5
26.6
<0.2
<0.8
2.7
<0.5
0.49
<0.2
0.51
<0.5
<0.1
Buck
B38
< 5
13000
11.1
5.4
< 2
131
< 0.5
< 0.5
45
< 0.2
< 0.08
< 0.5
< 0.5
0.89
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B39
< 5
6150
2.3
6.8
< 2
100
< 0.5
< 0.5
16.7
< 0.2
< 0.08
17.1
< 0.5
0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B4
<5
10500
7.6
6.3
2.3
95
<0.5
<0.5
20.7
<0.2
<0.08
0.56
<0.5
0.69
<0.2
<0.5
<0.5
<0.1
Buck
B40
<5
7500
3.1
6.3
<1
118
<0.5
<0.5
25.7
<0.2
<0.08
1.5
0.33
0.19
<0.1
<0.5
<0.5
<0.1
Buck
B41
<5
21100
2.1
8.1
2.9
127
<0.5
<0.5
4.9
<0.2
<0.08
0.58
<0.5
<0.1
<0.2
2.5
<0.5
<0.1
Buck
B42
<100
7520
5.22
6.16
<10
71
<3
<10
10.3
<1
<1
<10
<5
36.5
<0.2
<10
<10
<1
Buck
B43
< 5
4950
4
5.2
< 2
63
< 0.5
< 0.5
18.4
< 0.2
< 0.08
2.1
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B44
< 5
6340
1.8
6.5
< 2
70
< 0.5
< 0.5
10.6
< 0.2
0.8
2
< 0.5
1.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B48
<5
15900
5.9
6.7
<1
135
0.031
<0.5
11.4
<0.2
<0.08
11.5
<0.5
0.12
<0.2
<0.5
<0.5
<0.1
Buck
B49
< 5
6060
2.7
6.2
2.3
60
< 0.5
< 0.5
15.1
< 0.2
< 0.08
< 0.5
< 0.5
3.1
< 0.2
< 0.5
< 0.5
0.15
Buck
B50
<5
8500
4.9
6.2
2.1
96
<0.5
<0.5
9.4
<0.2
<0.08
1.2
<0.5
0.27
<0.2
<0.5
<0.5
<0.1
Buck
B51
<5
3320
1.7
6.5
<2
127
<0.5
<0.5
8.2
<0.2
<0.08
1.1
<0.5
0.49
<0.2
1.3
<0.5
<0.1
Buck
B53
38
18000
3.2
6.1
2.9
130
0.057
< 1
15
< 1
0.15
< 10
< 1
0.23
< 0.2
1.1
< 1
< 1
Buck
B54
25
7760
4.9
5.69
<5
116
0.5
<0.08
30.2
<0.11
<0.06
4.84
<0.03
0.34
<0.2
0.86
<0.16
<0.06
Buck
B55
<5
23000
7.3
6.6
3.2
95
<0.5
<0.5
27
<0.2
<0.08
2.2
0.33
0.71
<0.1
2.7
<0.5
<0.1
Buck
B56
<5
6610
1.9
6.9
4.8
70
<0.5
<0.5
84.7
<0.2
<0.08
<0.5
<0.5
2
<0.2
0.59
<0.5
<0.1
Buck
B57
<5
8400
5.3
6.2
0.46
78
<0.5
<0.5
7.3
<0.2
<0.08
0.82
<0.5
3.7
0.017
<0.5
<0.5
<0.1
Buck
B58-2
28
63000
6.2
7.4
22
230
0.21
1.7
41
< 2
0.44
< 25
1.4
8.4
0.047
0.064
< 5
< 0.5
Buck
859
<5
14400
3.1
7
2.3
144
<0.5
<0.5
4.9
<0.2
<0.08
21.8
<0.5
7 .1
<0.2
<0.5
<0.5
<0.1
Buck
B6
< 5
8980
5.7
6.4
2.4
132
< 0.5
< 0.5
5.3
< 0.2
< 0.08
< 0.5
< 0.5
0.59
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B60
<5
11000
2.1
6.6
2.3
98
<0.5
1.8
47
<0.2
0.12
1.3
<0.5
1.5
0.034
1
<0.5
<0.1
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
April 2016

Table C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 2 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
d(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal MCL/SMCL(b):
(' denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
"500
6
30
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Appendix III
App
endix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
mg1L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B61
13.2
246000
20.5
7.75
711
1220
1.87
< 0.5
3.9
< 0.2
< 0.08
0.89
< 0.5
0.21
< 0.2
2
< 0.5
< 0.1
Buck
B62
<5
5770
2.3
6.6
2.3
59
<0.5
<0.5
12.6
<0.2
<0.08
<0.5
<0.5
0.74
<0.2
<0.5
<0.5
<0.1
Buck
B63
<S
7200
6.1
6.7
<1
110
0.053
<0.5
11.9
<0.2
0.26
10.2
<0.5
3.1
<0.2
0.11
<0.5
<0.1
Buck
B64 1
7.7
5370
1.6
6.6
<2
46
<0.5
<0.5
5.5
<0.2
0.43
1.1
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B65
< 5
26100
5.2
7.9
4.4
191
< 0.5
< 0.5
5.6
< 0.2
< 0.08
< 0.5
< 0.5
0.14
< 0.2
5
< 0.5
< 0.1
Buck
B66-1
< 5
9770
4.8
6.4
< 2
113
< 0.5
< 0.5
12.2
< 0.2
< 0.08
1.9
< 0.5
0.82
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B66-2
< 5
5770
4.6
6
< 2
120
< 0.5
< 0.5
16.4
< 0.2
< 0.08
1.6
< 0.5
3.8
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B67
<5
10400
3.2
6.2
2.5
90
<0.5
<0.5
58.5
<0.2
<0.08
<0.5
<0.5
0.25
<01
0.6
<0.5
<0.1
Buck
B69
<5
8520
8
6.6
<2
74
<0.5
<0.5
22.5
<0.2
<0.08
16.3
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
137
<5
16500
8.4
6.4
2.9
148
<0.5
<0.5
32.3
<0.2
<0.08
5.7
<0.5
0.68
<0.2
0.67
<0.5
<0.1
Buck
B71
<5
2860
1.5
6.3
<2
74
<0.5
<0.5
12.2
<0.2
<0.08
<0.5
<0.5
1.7
<0.2
2.6
<0.5
<0.1
Buck
B72
<5
8160
4.2
6.3
<2
92
<0.5
<0.5
15.8
<01
<0.08
1.2
0.57
6.1
<0.2
<0.5
<0.5
<0.1
Buck
B73
<5
14700
2.2
7.2
5.7
125
<0.5
<0.5
12.5
<0.2
<0.08
0.81
<0.S
0.51
<0.2
0.96
<0.5
<01
Buck
B74
< 5
3120
1.3
6.4
< 2
66
< 0.5
< 0.5
5.8
< 0.2
< 0.08
1.1
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B75
<5
15500
3.5
7
<2
113
<0.5
<0.5
5
<0.2
<0.08
22.1
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B76
<5
8400
2.4
7.3
2.8
71
<0.5
<0.5
12.5
<0.2
<0.08
9.7
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B77A
<5
31500
2.2
7.9
6.8
152
<0.5
<0.5
25.4
<0.2
<0.08
<0.5
<0.5
0.18
<0.2
3.3
<0.5
<0.1
Buck
B77B
<5
5620
2.2
6
<2
83
<0.5
<0.5
23.7
<01
<0.08
1.4
<0.5
1.6
<0.2
<0.5
<0.5
<0.1
Buck
B78
<5
12900
16.9
6.1
2.2
171
<0.5
<0.5
41.4
<0.2
<0.08
1.1
<0.S
0.32
<0.2
0.51
<0.5
<0.1
Buck
B79
< 5
9510
3.5
6.5
2.5
129
< 0.5
< 0.5
37.8
< 0.2
< 0.08
< 0.5
< 0.5
1.4
< 0.2
0.78
< 0.5
< 0.1
Buck
B81
<5
3030
1.2
6.1
2.4
34
<0.5
<0.5
9.1
<0.2
<0.08
1.5
<0.5
0.56
<0.2
<0.5
<0.5
<0.1
Buck
B82
<5
5770
<1
6.2
<2
78
<0.5
<0.5
16.7
<0.2
<0.08
0.92
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Buck
B83
< 5
9310
4.8
6.3
2.2
89
< 0.5
< 0.5
14.5
< 0.2
0.14
0.94
< 0.5
0.6
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B84
< 5
9910
3.9
5.7
< 2
97
< 0.5
< 0.5
11.2
< 0.2
< 0.08
2.1
< 0.5
0.29
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B85
< 5
19900
12.7
6.5
< 2
148
< 0.5
< 0.5
6.1
< 0.2
< 0.08
9.2
< 0.5
0.44
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B86
< 5
6560
2.8
6.2
< 2
< 25
< 0.5
< 0.5
22.7
< 0.2
< 0.08
3.7
< 0.5
0.29
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B88
<5
9310
9.3
6.1
2
98
<0.5
<0.5
32.3
<0.2
<0.08
0.84
<0.5
0.35
<0.2
<0.5
<0.5
<0.1
Buck
B89
<5
30700
4.1
7.3
4.7
145
<0.5
0.9
11.1
<0.2
<0.08
<0.5
<0.5
0.36
<0.2
3.2
2.9
<0.1
Buck
B90
<5
5700
3.1
6.3
<2
118
<0.5
0.81
16
<0.2
<0.08
0.87
<0.5
2
<0.2
<0.5
<0.5
<0.1
Buck
892A
<5
4940
1.3
6.2
<2
73
<0.5
<0.5
7.3
<0.2
<0.08
1.8
<0.5
<0.1
<0.2
0.52
<0.5
<0.1
Buck
B92B
< 5
4640
1.3
5.8
< 2
67
< 0.5
< 0.5
7.3
< 0.2
< 0.08
1.8
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B93
<5
8050
5.3
6
<2
59
<0.5
<0.5
17.7
<0.2
<0.08
3.1
<0.5
0.87
<0.2
<0.5
<0.5
<0.1
Buck
B94
< 5
6420
1.9
6.2
< 2
48
< 0.5
< 0.5
14.1
< 0.2
< 0.08
1.1
< 0.5
0.56
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B95
< 5
5220
1.2
6.8
< 2
69
< 0.5
< 0.5
4.5
< 0.2
< 0.08
2.6
< 0.5
1.9
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B96
<5
1 21500
1 1.9
7.5
33.3
255
<0.5
<0.5
15.4
<01
<0.08
1.3
<0.5
0.38
<0.2
2.2
<0.5
<0.1
Buck
B97A
<5
13900
2.1
6.6
5.1
105
<0.5
<0.5
17.1
<0.2
<0.08
<0.5
<0.5
0.41
<0.2
1.7
0.63
<0.1
Buck
B97B
<5
13500
2.2
6.2
5
105
<0.5
<0.5
17
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
1.6
0.62
<0.1
Buck
898
<5
6510
1.4
6
<2
79
<0.5
<0.5
6.8
<0.2
<0.08
1.6
<0.5
0.79
<0.2
<0.5
<0.5
<0.1
Buck
899
< 5
20700
2.1
7.3
5.9
108
< 0.5
< 0.5
10.4
< 0.2
< 0.08
< 0.5
< 0.5
0.49
< 0.2
2.8
< 0.5
< 0.1
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Table C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
Page 3 of 6
April 2016
ISA NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(* denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR
Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Buck
B10
2.8
< 10
0.0027
< 50
3.6
6690
< 0.5
< 0.5
1530
7520
86.6
0.0179
95.8
89.9
6
< 2.5
Buck
8100
2.9
< 10
0.0011
< 50
0.064
3630
1.2
< 0.5
2710
4430
43.9
< 0.005
41
41
< 5
< 2.5
Buck
8101
22.4
< 10
0.0017
< 50
2.7
2000
< 0.5
< 0.5
722
4600
45
0.285
21.9
21.9
<5
< 2.5
Buck
811
1.8
<10
0.007
4600
<0.6
3530
28.9
<0.5
951
5850
77.2
0.0662
38.5
38.5
<1
8.3
Buck
B12
2
<10
0.0162
<50
0.065
3430
9
<0.5
1 1270
6600
1 110
0,0173
43
1 43
<0
<1
Buck
B13
2.5
34.8
0.0021
65
0.041
5140
3.6
0.83
3180
17100
202
0.01
88
88
<5
2.8
Buck
B14-630
1.5
30.2
0.013
454
1.8
2320
35.7
<0.5
1150
3790
43.1
0.0588
21.8
21.8
<5
<5
Buck
B14-640
2.7
22.7
0.0016
<50
0.034
5580
20
<0.5
2790
8330
123
0.258
107
107
<5
<2.5
Buck
B15
3
< 10
0.009
< 50
0.076
3140
< 0.5
< 0.5
1090
5530
74
0.007
30.8
30.8
<0
< 1
Buck
B16
4
46.7
<0.001
<50
0.081
3700
6
<0.5
1300
27000
67
1.37
65.5
57.4
42.6
<1
Buck
B17
1
< 10
0.0205
98.3
0.27
3130
11.7
2
1650
12500
101
0.62
28.5
28.5
< 1
<5
Buck
B18
6.6
49.1
0.0041
94.8
2.5
4340
2.3
<0.5
1620
7000
120
0.0076
42.6
42.6
<5
<2.5
Buck
B19
4.7
24.6
0.0077
< 50
< 0.6
5460
1 1.1
< 0.5
1270
1 7890
108
1 0.293
46.4
46.4
1 < 1
< 2.5
Buck
B2
14
9.3
0.006
1200
<0.6
7800
22
2.7
2800
10000
110
0.596
57
57
<5
0.8
Buck
B21
4.7
<10
0.007
<50
1.6
2670
1.9
0.59
1700
8740
85
0.175
36.9
36.9
<0
<1
Buck
B22
8.8
< 10
0.0072
< 50
0.68
2690
1.3
< 0.5
1200
6490
63.6
0.159
31
31
<5
< 2.5
Buck
B24
4.3
<10
0.0147
<50
0.74
2990
4.1
<0.5
1150
5510
64.4
0.0274
27.7
27.7
<5
<2.5
Buck
B25
6.6
< 10
0.0087
< 50
1.1
2890
0.63
< 0.5
1020
5280
69.2
0.0512
29
29
< 5
< 5
Buck
B26
2.4
< 10
0.137
< 50
0.99
3310
2.4
1.2
2770
11100
153
0.0869
35.9
35.9
< 1
< 2.5
Buck
B27
2
<10
0.0136
158
0.093
2570
2.3
<0.5
966
4390
63.6
0.0289
22.8
22.8
<5
<2.5
Buck
B28
14.4
25.4
<0.001
<50
6.5
4000
0.52
<0.5
1160
4130
55.5
0.414
37.7
37.7
<5
<2.5
Buck
B29
11.5
<10
0.006
<50
4.8
4090
<0.5
0.58
894
3830
53
<0.005
35.4
35.4
<5
<2.5
Buck
B3
2.8
< 10
0.0288
5720
0.038
5460
80.5
0.79
989
6900
124
0.243
42.2
42.2
<5
<5
Buck
B31
2.8
< 10
0.0211
96.9
0.093
5300
2.8
< 0.5
1400
6840
135
0.0279
35.7
35.7
<5
<5
Buck
B32
5.9
< 10
0.0035
< 50
0.11
4850
1.6
0.67
2330
6770
88.6
0.0126
62.8
62.8
<5
< 2.5
Buck
B33
11
< 10
0.0061
< 50
0.7
4170
0.91
< 0.5
2040
8200
89
< 0.005
57.4
57.4
<0
< 1
Buck
B34
2.5
< 10
0.00794
< 50
0.33
3160
< 0.5
< 0.5
1370
5490
62
< 0.005
28.5
28.5
< 1
< 2.5
Buck
B35
5.1
24.2
0.00656
1420
2.53
3050
0.83
0.27
1100
5250
67
0.0173
30
3
Buck
B37
6.7
< 10
0.0015
<50
2.5
3760
< 0.5
0.52
1560
4690
54.5
< 0.005
31.2
31.2
<5
< 2.5
Buck
B38
2.2
< 10
0.149
< 50
0.052
5160
2.5
< 0.5
1730
7010
1 139
0.118
29.3
29.3
< 5
< 2.5
Buck
B39
6.1
< 10
0.0016
< 50
16.4
3430
0.98
1
669
3950
48.6
0.212
24.6
1 24.6
<5
< 2.5
Buck
B4
1.7
< 10
0.0026
< 50
< 0.03
3980
7.4
< 0.5
1420
6360
97.1
2.09
38.2
38.2
< 5
< 2.5
Buck
B40
12
< 10
0.024
360
1.2
2010
28
1.5
1700
9700
83
0.093
25.1
25.1
<5
< 1
Buck
B41
3.9
< 10
0.0013
< 50
0.29
3490
< 0.5
< 0.5
1890
8250
72.8
0.0073
67.7
67.7
<5
< 2.5
Buck
B42
3.02
< 50
0.12
210
< 20
3310
< 10
<10
989
5260
65.7
0.399
30.6
30.6
< 1
<5
Buck
B43
2.3
<10
0.0063
135
1.8
1930
4.5
0.74
746
6660
47.1
0.0131
18.8
18.8
<5
<2.5
Buck
B44
10.7
< 30
0.019
50
1.7
3000
1.9
< 0.5
840
6070
60.1
0.163
34.4
34.4
<5
< 2.5
Buck
B48
15.6
< 10
0.0065
< 50
12.4
9020
0.99
0.2
890
6490
103
0.025
73
73
<5
< 3.1
Buck
B49
3.2
< 10
0.111
< 50
0.058
2580
0.73
< 0.5
1040
6060
60
0.019
38.4
38.4
<5
< 2.5
Buck
B50
2.5
<10
0.0237
84.7
0.9
3770
2
0.88
1110
5980
77.6
0.0182
32
32
<5
<2.5
Buck
B51
5
< 10
0.0026
< 50
0.74
916
1.4
< 0.5
789
5330
42.9
0.0068
16.8
16.8
<5
< 2.5
Buck
B53
5.9
13
0.0025
68
< 10
6500
1.6
<2
2800
6400
69
0.027
82
82
< 5
< 3.1
Buck
B54
25.6
<10
0.00791
15.7
4.8
2970
0.49
0.31
1610
6700
81
0.0102
43
<2.5
Buck
B55
14
120
0.19
1100
2.2
5900
19
4.4
2300
6900
100
0.049
62.9
62.9
<5
1.6
Buck
856
< 1
< 10
< 0.001
170
< 0.03
3490
29.6
< 0.5
4180
6320
49.5
1.18
39
39
<5
< 2.5
Buck
B57
15
< 10
0.06
430
0.64
2600
15
2
1200
10000
89.3
0.077
27
27
<5
< 1
Buck
B58-2
12
71
0.008
2900
<2
9300
23
6.6
1200
8600
160
0.54
160
150
< 10
3.2
Buck
B59
14.3
13.7
0.0011
< 50
22.3
8910
< 0.5
< 0.5
739
4590
94.1
0.0246
69.2
69.2
<5
< 2.5
Buck
B6
2.1
< 10
0.0303
< 50
0.045
1930
1.5
< 0.5
5380
16300
53.4
0.0139
44.3
44.3
<5
< 2.5
Buck
B60
15
12.7
0.0086
490
0.75
6300
11
<0.5
1700
9900
63
0.028
45
45
<5
<1
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
Page 3 of 6
April 2016

Table C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 4 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(* denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR
Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Buck
B61
2.5
< 10
< 0.001
186
0.13
38200
272
< 0.5
2110
293000
947
0.104
114
114
< 1
< 2.5
Buck
B62
4.6
<10
0.0472
<50
0.065
2850
2.9
<0.5
1090
5390
55.5
0.488
26.6
26.6
<5
<2.5
Buck
B63
7.2
< 10
0.0268
< 50
10.4
4470
1.5
2.5
775
7470
68
0.047
35
35
<5
< 2.5
Buck
B64
5.7
< 10
0.0054
< 50
0.81
2420
7
< 0.5
786
4500
48.5
0.581
27.4
27.4
<5
< 2.5
Buck
B65
< 1
< 10
< 0.001
< 50
< 0.03
4940
18.9
< 0.5
2920
8590
124
1 0.106
82.5
82.5
<5
< 2.5
Buck
B66-1
2.6
18.1
0.0232
2700
1
4200
18
0.58
1520
5050
73.5
0.193
40.8
40.8
<5
5.6
Buck
B66-2
1.4
< 10
0.0724
5330
0.081
2870
20.5
1.2
1400
5340
59.1
0.28
20.4
20.4
<5
22.6
Buck
B67
3.4
< 10
0.0063
< 50
0.082
2310
1.4
< 0.5
2600
8520
94.9
0.0302
29.7
29.7
<5
< 2.5
Buck
B69
8.5
< 10
0.0011
< 50
10.6
6900
1.6
3
681
4410
70
0.0161
31.6
31.6
<5
< 2.5
Buck
B7
8.1
< 10
0.0077
< 50
4.6
7120
< 0.5
0.58
2340
9300
131
0.0187
59.5
59.5
<5
< 25
Buck
B71
1.2
< 10
0.0021
< 50
< 0.3
656
< 0.5
< 0.5
898
6140
44.4
0.0328
17
17
<5
< 2.5
Buck
B72
1.4
< 10
0.0123
18200
< 0.03
3440
128
0.71
1220
4550
68
1.41
42.2
42.2
< 5
26.2
Buck
B73
8.4
13.4
0.005
<50
0.24
3690
11.2
<0.5
2110
7220
66.9
1.54
53
53
<5
<2.5
Buck
874
5.5
< 10
0.0073
< 50
1.1
1450
1.2
< 0.5
980
4120
29.5
0.0157
16.5
16.5
<5
< 2.5
Buck
B75
14.1
< 10
0.0021
< 50
21.2
9590
< 0.5
< 0.5
751
4900
94.4
0.0235
74.9
74.9
<5
< 2.5
Buck
B76
13.3
<10
<0.001
<50
6.3
5620
<0.5
0.97
1070
5150
50.6
<0.005
41.7
41.7
<5
<2.5
Buck
B77A
< 1
< 10
< 0.001
< 50
< 0.03
5740
10.7
< 0.5
3230
8820
119
0.0476
106
106
<5
< 2.5
Buck
B77B
3.3
<10
0.0453
<50
1.2
2140
0.88
<0.5
929
6520
76.4
0.0306
26.8
26.8
<5
<2.5
Buck
B78
3.2
< 10
0.0051
<50
0.31
6400
2
1.3
1770
8080
108
0.633
39.3
39.3
<5
< 2.5
Buck
B79
4
14.7
0.0043
< 50
0.054
5110
5.9
< 0.5
1910
8550
116
< 0.005
28.5
28.5
<5
< 2.5
Buck
B81
3.4
< 30
0.0148
< 50
0.85
1400
0.77
< 0.5
757
3750
32.1
< 0.005
14.1
14.1
<5
< 2.5
Buck
882
5.5
23.9
0.0019
< 50
0.73
2850
3.5
< 0.5
1680
5520
44.6
0.642
30.4
30.4
< 5
5.5
Buck
B83
3.6
<10
0.024
112
0.65
4520
4
<0.5
1440
6910
86.3
0.176
33.6
33.6
<5
<2.5
Buck
B84
10.1
< 10
< 0.001
< 50
1.9
4040
< 0.5
< 0.5
1070
6530
84.7
< 0.005
39.1
39.1
<5
< 2.5
Buck
B85
11.2
< 10
0.0055
< 50
7.3
12600
2.6
< 0.5
656
5230
116
0.0271
64.4
64.4
<5
< 5
Buck
B86
4.7
< 10
0.0123
< 50
2.9
2800
0.96
< 0.5
835
7190
143
0.0302
29.3
29.3
< 5
< 2.5
Buck
B88
3
< 10
0.0121
134
0.49
4850
1.5
0.58
1770
6500
98.2
0.0143
24.2
24.2
<5
< 2.5
Buck
B89
3.1
< 10
< 0.001
< 50
1.7
4400
40.3
< 0.5
3510
7960
151
0.0108
85.6
85.6
< 5
< 2.5
Buck
B90
3.5
<10
0.0219
1720
0.086
2770
4.8
<0.5
1070
4460
58.3
2.34
34.4
34.4
<5
<2.5
Buck
B92A
11.5
<10
<0.001
<50
0.35
1920
2.4
<0.5
895
5180
38.3
1.08
21.6
21.6
<5
<2.5
Buck
B92B
10.8
<10
0.002
<50
1.7
1780
2
<0.5
838
4960
36.5
0.822
22.6
22.6
<5
<2.5
Buck
B93
3.4
< 10
0.0106
3050
0.55
4120
43.5
1.7
705
5680
66.2
0.0663
31.6
31.6
<5
5.1
Buck
B94
3
< 10
0.024
< 50
0.82
2850
3.2
0.51
1370
5390
56.8
0.0125
30.6
30.6
<5
< 2.5
Buck
B95
9.2
< 10
< 0.001
< 50
2.2
3070
< 0.5
0.96
848
4320
42.6
0.228
26.7
26.7
< 5
< 2.5
Buck
B96
11.4
117
0.0013
240
0.5
3580
4.8
<0.5
3050
6590
109
0.15
44.8
44.8
<5
<2.5
Buck
897A
6.3
<10
0.0041
<50
0.36
4140
9.6
<0.5
3640
7270
62.6
0.0064
49
49
<5
<2.5
Buck
B97B
6.5
<30
0.0036
<50
0.35
4160
9.7
<0.5
3650
6720
60.3
<0.005
46.6
46.6
<5
<2.5
Buck
B98
6.5
< 10
0.0025
< 50
1.5
2170
0.65
< 0.5
965
5920
43.9
0.276
27.6
27.6
< 5<
2.5
Buck
B99
4.6
<10
<0.001
<50
0.042
3330
8.7
<0.5
3050
5800
75.9
0.0282
59.4
59.4
<5
<2.5
Page 4 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Table C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
Page 5 of 6
April 2016
ISA NCAC 02L.0202
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Buck
B10
<1
16.3
144.7
2
145.4
Buck
8100
<1
17.7
103
0.31
256.8
Buck
8101
<1
17.7
91.5
6.59
245.2
Buck
811
28.1
20.3
114
5.01
44.2
Buck
B12
<1
18
94
5.5
232.2
Buck
B13
<1
18.8
209.4
1.8
183.5
Buck
B14-630
3.5
17.1
63.7
3.4
285.1
Buck
B14-640
< 1
18.5
263.2
0.1
115.8
Buck
B15
<1
18.5
81.7
5.5
270
Buck
B16
<1
24.1
203.7
0.5
76.2
Buck
B17
< 1
19.3
190
6
235.1
Buck
B18
<1
17.7
122.3
3.8
310.5
Buck
B19
<1
18
189
6.84
255.7
Buck
B2
2
16.2
148
6.35
268.4
Buck
B21
< 1
19.1
105.3
5.6
202.1
Buck
B22
<1
16.4
85.1
4.8
26.9
Buck
B24
<1
16.6
82.7
5.2
218
Buck
B25
<1
16.5
78.5
6
225.8
Buck
B26
<1
17.8
192
7.4
194.8
Buck
B27
1.3
16.8
80.2
6.5
222
Buck
B28
<1
16.3
91.6
5.6
167.1
Buck
B29
<1
16.9
93.5
5.7
326.5
Buck
B3
33.8
16
134.5
0.4
131.7
Buck
B31
<1
16.2
140.4
5.5
269.1
Buck
B32
<1
16.8
142
2.3
204.1
Buck
B33
<1
21
129.1
3.4
226
Buck
B34
<1
19.7
116
6.59
195.3
Buck
B35
11.6
14
107
7.33
Buck
B37
<1
17.2
85.5
5.5
178
Buck
B38
< 1
23.6
145.9
5.2
231.6
Buck
B39
<1
16.8
79.4
6.6
160.9
Buck
B4
< 1
18.1
137.4
5.61
213.9
Buck
B40
<1
17.4
81
7.71
190
Buck
B41
<1
16.7
165.3
1.1
123
Buck
B42
<1
14.7
118
5.95
Buck
B43
<1
19.3
72.1
6.7
238.2
Buck
B44
<1
17.4
80.7
6.4
277.6
Buck
B48
0.3
17.3
172.3
5.7
198.5
Buck
B49
<1
16.9
79.3
6.2
93.5
Buck
B50
< 1
16.8
100.1
5.8
198.2
Buck
B51
1.2
14.5
50
7.7
170.2
Buck
B53
1
17.9
130
3.1
157
Buck
B54
<1
16.4
121
7.41
Buck
B55
1
17.6
178.4
7.71
198.9
Buck
B56
1.6
17
105.3
1
52.9
Buck
B57
<1
19
93.8
7.7
220
Buck
B58-2
2
14
298
6.41
160
Buck
B59
<1
17.2
161.9
5.2
304
Buck
B6
<1
17.6
140.3
7.6
312.3
Buck
B60
<1
20.7
103
5.84
210
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
Page 5 of 6
April 2016

Table C2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 6 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Buck
B61
< 1
21.2
1770
6.16
711.2
Buck
B62
<1
15
77.6
5.7
155.6
Buck
B63
0.63
14.9
101.1
11
227
Buck
B64
< 1
20.2
64.7
6.3
217.7
Buck
B65
<1
16.9
207
0.3
<
Buck
B66-1
38.5
15.6
106
3.1
105.9
Buck
B66-2
121
16.1
90.4
5
135.8
Buck
B67
<1
16.2
119.3
6.4
205.8
Buck
B69
<1
16.9
119
5.6
197
Buck
B7
<1
16.7
185.3
4.1
196.2
Buck
B71
<1
17.9
48.9
8.73
215.9
Buck
B72
128
17.4
175.5
0.27
92.5
Buck
B73
<1
21.4
143
4.1
210.8
Buck
B74
<1
17
45.8
6.9
211.9
Buck
B75
<1
18
169.6
5.2
249.5
Buck
B76
<1
16
113.2
4.4
306.6
Buck
B77A
<1
17.9
233.2
0.19
14.8
Buck
B77B
<1
18.5
74.5
6.8
233.5
Buck
B78
<1
16.4
167.5
3.2
253.8
Buck
B79
<1
19.9
147.1
5.7
199.6
Buck
B81
<1
18
47.1
6.9
196.9
Buck
B82
<1
19.1
77.7
7.2
190.8
Buck
B83
<1
17.7
120.7
5.9
167.2
Buck
B84
<1
18.8
107.3
7.1
153.8
Buck
B85
<1
18.8
213.6
1.6
250.9
Buck
B86
< 1
17.8
87.1
6.1
193
Buck
B88
1.2
17.8
117.9
4.9
196.9
Buck
B89
<1
16.8
400.2
0.14
85
Buck
B90
25.9
18
88.3
5.2
172.1
Buck
B92A
<1
17.5
121.8
7
214.9
Buck
B92B
<1
18.3
61
7.9
206.3
Buck
B93
22.2
17.3
98.6
4.6
289.2
Buck
B94
<1
17.3
77.9
7.4
266.9
Buck
B95
<1
16.5
74.7
6.8
130.5
Buck
B96
<1
16.1
405.9
3.8
174.7
Buck
897A
<1
17.4
250.5
0.67
58.4
Buck
B97B
<1
18.3251.5
0.8
159.8
Buck
B98
<1
16.9
73.5
6.9
190.1
Buck
B99
<1
18.4
294.9
0.8
101.7
Page 6 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the Breen ing level.
_ Reporting limit is a bove the screening level.
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/9/2016

Table C2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
35A NCAC 02L .0201700
Groundwater Standard a:
NS
250
6.5-8 5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
denotes
Federal MCL/SMCL (b):
seconds standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015 (d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
35
5.7
100
100
0.2
Appendix III
Appendix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B10
<5
11600
4.1
6.6
2.8
168
<0.5
<0.5
28.4
<0.2
<0.08
5.1
<0.5
0.14
<0.2
0.58
<0.5
<0.1
Buck
8100
<5
10200
1.4
7.5
4.8
118
<0.5
<0.5
14.1
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
3.3
<0.5
<0.1
Buck
B101
<5
5490
1.1
7.1
<2
81
<0.5
<0.5
6.9
<0.2
<0.08
2.9
<0.5
0.14
<0.2
<0.5
<0.5
<0.1
Buck
Bll
<5
7160
3.8
6.62
<2
102
<0.5
<0.5
8.53
<0.2
<0.08
<0.5
<0.5
0.7
<0.2
<0.5
<0.5
<0.1
Buck
B12
<5
8560
2.3
6.1
<1
93
<0.5
<0.5
23
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B13
5.8
21300
10.3
6.7
6.5
161
<0.5
<0.5
39.3
<0.2
<0.08
0.58
<0.5
0.17
<0.2
2.4
<O.5
<0.1
Buck
B14-630
<5
4700
2
6.2
<2
38
<0.5
<0.5
29.5
<0.2
<0.08
2.5
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Buck
B14-640
<5
41300
3.2
7.7
6.4
164
<0.5
<0.5
5.5
<0.2
<0.08
<0.5
<0.5
0.11
<0.2
2.6
<0.5
<0.1
Buck
B15
<5
7040
2.8
6.3
2.2
84
<0.5
<0.5
14.8
<0.2
<0.08
<0.5
<0.5
0.56
<0.2
<0.5
<0.5
<0.1
Buck
B16
10.4
12000
2.4
9.4
27.8
139
<0.5
<0.5
1.5
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
5.1
<0.5
<0.1
Buck
B17
<5
11100
13.5
6.35
<2
121
<0.5
<0.5
73.5
<0.2
1.4
0.55
<0.5
0.42
<0.2
1.2
<0.5
<0.1
Buck
B18
<5
10300
3.1
6.3
2.3
99
<0.5
<0.5
50.8
<0.2
<0.08
3.5
<0.5
0.55
<0.2
<0.5
<0.5
<0.1
Buck
B19
<5
12200
9.3
6.92
2.1
143
<0.5
<0.5
15.8
<0.2
<0.08
0.66
<0.5
0.92
<0.2
<0.5
<0.5
<0.1
Buck
B2
<5
19000
4.7
6.36
2.2
136
<0.5
2.2
22
<0.2
<0.08
0.75
0.25
0.52
<0.1
0.24
<0.5
<0.1
Buck
B21
18.4
8010
3.9
6.6
<1
109
<0.5
<0.5
26
<0.2
0.6
1.7
<0.5
11
<0.2
<0.5
<0.5
<0.1
Buck
B22
<5
7050
2
6.5
<2
96
<0.5
<0.5
13
<0.2
0.14
0.88
<0.5
0.5
<0.2
0.59
<0.5
<0.1
Buck
B24
<5
6760
2.5
6.4
<2
107
<0.5
<0.5
11.9
<0.2
<0.08
1
<0.5
0.39
<0.2
<0.5
<0.5
<0.1
Buck
B25
<5
6490
2
6.4
<2
109
<0.5
<0.5
12.9
<0.2
<0.08
1.5
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B26
<5
12600
8.8
6.07
<2
138
<0.5
<0.5
81.3
<0.2
<0.08
2.7
<0.5
3.3
<0.2
<0.5
<0.5
<0.1
Buck
B27
<5
6130
3.7
6
<2
29
<0.5
<0.5
11.2
<0.2
<0.08
0.52
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B28
<5
9800
1.5
7.1
2.8
93
<0.5
<0.5
5.8
<0.2
0.29
6.5
<0.5
1.2
<0.2
<0.5
<0.5
<0.1
Buck
B29
<5
8510
2
6.8
<2
60
<0.5
<0.5
9.5
<0.2
<0.08
7.4
<0.5
0.23
<0.2
0.69
<0.5
<0.1
Buck
B3
<5
10900
4.9
6.5
<2
107
<0.5
<0.5
11.3
<0.2
0.099
<0.5
<0.5
9
<0.2
<0.5
<0.5
<0.1
Buck
B31
<5
12200
8
6.1
<2
98
<0.5
<0.5
22.3
<0.2
<0.08
<0.5
<0.5
0.29
<0.2
<0.5
<0.5
<0.1
Buck
B32
<5
13700
2.1
6.9
2.7
112
<0.5
<0.5
9.4
<0.2
<0.08
<0.5
<0.5
0.17
<0.2
1.3
<0.5
<0.1
Buck
B33
<5
13300
2
6.7
2.8
117
<0.5
<0.5
19
<0.2
<0.08
0.85
<0.5
0.82
<0.2
0.68
<0.5
<0.1
Buck
B34
<5
7280
4.28
6.2
2.1
87
<0.5
<0.5
13.4
<0.2
<0.08
0.63
<0.5
0.11
<0.2
<0.5
<0.5
<0.1
Buck
B35
<20
7210
5
6.24
7
81
<0.5
<0.08
11.1
<0.11
<0.06
2.53
<0.03
1.23
<0.01
0.17
<0.16
<0.06
Buck
B37
<5
5730
1.4
6.6
2.1
89
<0.5
<0.5
26.6
<0.2
<0.8
2.7
<0.5
0.49
<0.2
0.51
<0.5
<0.1
Buck
B38
<5
13000
11.1
5.4
<2
131
<0.5
<0.5
45
<0.2
<0.08
<0.5
<0.5
0.89
<0.2
<0.5
<0.5
<0.1
Buck
B39
<5
6150
2.3
6.8
<2
100
<0.5
<0.5
16.7
<0.2
<0.08
17.1
<0.5
0.1
<0.2
<0.5
<0.5
<0.1
Buck
B4
<5
10500
7.6
6.3
2.3
95
<0.5
<0.5
20.7
<0.2
<0.08
0.56
<0.5
0.69
<0.2
<0.5
<0.5
<0.1
Buck
B40
<5
7500
3.1
6.3
<1
118
<0.5
<0.5
25.7
<0.2
<0.08
1.5
0.33
0.19
<0.1
<0.5
<0.5
<0.1
Buck
B41
<5
21100
2.1
8.1
2.9
127
<0.5
<0.5
4.9
<0.2
<0.08
0.58
<0.5
<0.1
<0.2
2.5
<0.5
<0.1
Buck
B42
<100
7520
5.22
6.16
<10
71
<3
<10
10.3
<1
<1
<10
<5
36.5
<0.2
<10
<10
<1
Buck
B43
<5
4950
4
5.2
<2
63
<0.5
<0.5
18.4
<0.2
<0.08
2.1
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B44
<5
6340
1.8
6.5
<2
70
<0.5
<0.5
10.6
<0.2
0.8
2
<0.5
1.1
<0.2
<0.5
<0.5
<0.1
Buck
B48
<5
15900
5.9
6.7
<1
135
0.031
<0.5
11.4
<0.2
<0.08
11.5
<0.5
0.12
<0.2
<0.5
<0.5
<0.1
Buck
B49
<5
6060
2.7
6.2
2.3
60
<0.5
<0.5
15.1
<0.2
<0.08
<0.5
<0.5
3.1
<0.2
<0.5
<0.5
0.15
Buck
B50
<5
8500
4.9
6.2
2.1
96
<0.5
<0.5
9.4
<0.2
<0.08
1.2
<0.5
0.27
<0.2
<0.5
<0.5
<0.1
Buck
B51
<5
3320
1.7
6.5
<2
127
<0.5
<0.5
8.2
<0.2
<0.08
1.1
<0.5
0.49
<0.2
1.3
<0.5
<0.1
Buck
B53
38
18000
3.2
6.1
2.9
130
0.057
<1
15
<1
0.15
<10
<1
0.23
<0.2
1.1
<1
<1
Buck
B54
25
7760
4.9
5.69
<5
116
0.5
<0.08
30.2
<0.11
<0.06
4.84
<0.03
0.34
<0.2
0.86
<0.16
<0.06
Buck
B55
<5
23000
7.3
6.6
3.2
95
<0.5
<0.5
27
<0.2
<0.08
2.2
0.33
0.71
<0.1
2.7
<0.5
<0.1
Buck
B56
<5
6610
1.9
6.9
4.8
70
<0.5
<0.5
84.7
<0.2
<0.08
<0.5
<0.5
2
<0.2
0.59
<0.5
<0.1
Buck
B57
<5
8400
5.3
6.2
0.46
78
<0.5
<0.5
7.3
<0.2
<0.08
0.82
<0.5
3.7
0.017
<0.5
<0.5
<0.1
Buck
B58-2
28
63000
6.2
7.4
22
230
0.21
1.7
41
<2
0.44
<25
1.4
8.4
0.047
0.064
<5
<0.5
Buck
B59
<5
14400
3.1
7
2.3
144
<0.5
<0.5
4.9
<0.2
<0.08
21.8
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B6
<5
8980
5.7
6.4
2.4
132
<0.5
<0.5
5.3
<0.2
<0.08
<0.5
<0.5
0.59
<0.2
<0.5
<0.5
<0.1
Buck
B60
<5
11000
2.1
6.6
2.3
98
<0.5
1.8
47
<0.2
0.12
1.3
<0.5
1.5
0.034
1
<0.5
<0.1
Buck
B61
13.2
246000
20.5
7.75
711
1220
1.87
<0.5
3.9
<0.2
<0.08
0.89
<0.5
0.21
<0.2
2
<0.5
<0.1
Buck
B62
<5
5770
2.3
6.6
2.3
59
<0.5
<0.5
12.6
<0.2
<0.08
<0.5
<0.5
0.74
<0.2
<0.5
<0.5
<0.1
Buck
B63
<5
7200
6.1
6.7
<1
110
0.053
<0.5
11.9
<0.2
0.26
10.2
<0.5
3.1
<0.2
0.11
<0.5
<0.1
Buck
B64
7.7
5370
1.6
6.6
<2
46
<0.5
<0.5
5.5
<0.2
OA3
1.1
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B65
<5
26100
5.2
7.9
4.4
191
<0.5
<0.5
5.6
<0.2
<0.08
<0.5
<0.5
0.14
<0.2
5
<0.5
<0.1
Buck
B66-1
<5
9770
4.8
6.4
<2
113
<0.5
<0.5
12.2
<0.2
<0.08
1.9
<0.5
0.82
<0.2
<0.5
<0.5
<0.1
Buck
B66-2
<5
5770
4.6
6
<2
120
<0.5
<0.5
16.4
<0.2
<0.08
1.6
<0.5
3.8
<0.2
<0.5
<0.5
<0.1
Page 1 of 4
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Table C2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
15A NCAC 02L .020
Groundwater Standard a:
700
NS
250
6.5-8 5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal MCL/SMCL (b):
*' standard)NS
denotes seconds
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015 (d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
35
5.7
100
100
0.2
Appendix III
Appendix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B67
<5
10400
3.2
6.2
2.5
90
<0.5
<0.5
58.5
<0.2
<0.08
<0.5
<0.5
0.25
<0.2
0.6
<0.5
<0.1
Buck
B69
<5
8520
8
6.6
<2
74
<0.5
<0.5
22.5
<0.2
<0.08
16.3
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B7
<5
16500
8.4
6.4
2.9
148
<0.5
<0.5
32.3
<0.2
<0.08
5.7
<0.5
0.68
<0.2
0.67
<0.5
<0.1
Buck
B71
<5
2860
1.5
6.3
<2
74
<0.5
<0.5
12.2
<0.2
<0.08
<0.5
<0.5
1.7
<0.2
2.6
<0.5
<0.1
Buck
B72
<5
8160
4.2
6.3
<2
92
<0.5
<0.5
15.8
<0.2
<0.08
1.2
0.57
6.1
<0.2
<0.5
<0.5
<0.1
Buck
B73
<5
14700
2.2
7.2
5.7
125
<0.5
<0.5
12.5
<0.2
<0.08
0.81
<0.5
0.51
<0.2
0.96
<0.5
<0.1
Buck
B74
<5
3120
1.3
6.4
<2
66
<0.5
<0.5
5.8
<0.2
<0.08
1.1
<0.5
0.14
<0.2
<0.5
<0.5
<0.1
Buck
B75
<5
15500
3.5
7
<2
113
<0.5
<0.5
5
<0.2
<0.08
22.1
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B76
<5
8400
2.4
7.3
2.8
71
<0.5
<0.5
12.5
<0.2
<0.08
9.7
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
877A
<5
31500
2.2
7.9
6.8
152
<0.5
<0.5
25.4
<0.2
<0.08
<0.5
<0.5
0.18
<0.2
3.3
<0.5
<0.1
Buck
B778
<5
5620
2.2
6
<2
83
<0.5
<0.5
23.7
<0.2
<0.08
1.4
<0.5
1.6
<0.2
<0.5
<0.5
<0.1
Buck
B78
<5
12900
16.9
6.1
2.2
171
<0.5
<0.5
41.4
<0.2
<0.08
1.1
<0.5
0.32
<0.2
0.51
<0.5
<0.1
Buck
B79
<5
9510
3.5
6.5
2.5
129
<0.5
<0.5
37.8
<0.2
<0.08
<0.5
<0.5
1.4
<0.2
0.78
<0.5
<0.1
Buck
B81
<5
3030
1.2
6.1
2.4
34
<0.5
<0.5
9.1
<0.2
<0.08
1.5
<0.5
0.56
<0.2
<0.5
<0.5
<0.1
Buck
B82
<5
5770
<1
6.2
<2
78
<0.5
<0.5
16.7
<0.2
<0.08
0.92
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Buck
B83
<5
9310
4.8
6.3
2.2
89
<0.5
<0.5
14.5
<0.2
0.14
0.94
<0.5
0.6
<0.2
<0.5
<0.5
<0.1
Buck
B84
<5
9910
3.9
5.7
<2
97
<0.5
<0.5
11.2
<0.2
<0.08
2.1
<0.5
0.29
<0.2
<0.5
<0.5
<0.1
Buck
B85
<5
19900
12.7
6.5
<2
148
<0.5
<0.5
6.1
<0.2
<0.08
9.2
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Buck
B86
<5
6560
2.8
6.2
<2
<25
<0.5
<0.5
22.7
<0.2
<0.08
3.7
<0.5
0.29
<0.2
<0.5
<0.5
<0.1
Buck
B88
<5
9310
9.3
6.1
2
98
<0.5
<0.5
32.3
<0.2
<0.08
0.84
<0.5
0.35
<0.2
<0.5
<0.5
<0.1
Buck
B89
<5
30700
4.1
7.3
4.7
145
<0.5
0.9
11.1
<0.2
<0.08
<0.5
<0.5
0.36
<0.2
3.2
2.9
<0.1
Buck
B90
<5
5700
3.1
6.3
<2
118
<0.5
0.81
16
<0.2
<0.08
0.87
<0.5
2
<0.2
<0.5
<0.5
<0.1
Buck
B92A
<5
4940
1.3
6.2
<2
73
<0.5
<0.5
7.3
<0.2
<0.08
1.8
<0.5
<0.1
<0.2
0.52
<0.5
<0.1
Buck
B92B
<5
4640
1.3
5.8
<2
67
<0.5
<0.5
7.3
<0.2
<0.08
1.8
<0.5
0.14
<0.2
<0.5
<0.5
<0.1
Buck
B93
<5
8050
5.3
6
<2
59
<0.5
<0.5
17.7
<0.2
<0.08
3.1
<0.5
0.87
<0.2
<0.5
<0.5
<0.1
Buck
B94
<5
6420
1.9
6.2
<2
48
<0.5
<0.5
14.1
<0.2
<0.08
1.1
<0.5
0.56
<0.2
<0.5
<0.5
<0.1
Buck
B95
<5
5220
1.2
6.8
<2
69
<0.5
<0.5
4.5
<0.2
<0.08
2.6
<0.5
1.9
<0.2
<0.5
<0.5
<0.1
Buck
B96
<5
21500
1.9
7.5
33.3
255
<0.5
<0.5
15.4
<0.2
<0.08
1.3
<0.5
0.38
<0.2
2.2
<0.5
<0.1
Buck
B97A
<5
13900
2.1
6.6
5.1
105
<0.5
<0.5
17.1
<0.2
<0.08
<0.5
<0.5
0.41
<0.2
1.7
0.63
<0.1
Buck
B97B
<5
13500
2.2
6.2
5
105
<0.5
<0.5
17
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
1.6
0.62
<0.1
Buck
B98
<5
6510
1.4
6
<2
79
<0.5
<0.5
6.8
<0.2
<0.08
1.6
<0.5
0.79
<0.2
<0.5
<0.5
<0.1
Buck
B99
<5
20700
2.1
7.3
5.9
108
<0.5
<0.5
10.4
<0.2
<0.08
<0.5
<0.5
0.49
<0.2
2.8
Page 2 of 4
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Table C2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
10
Page 3 of 4
15A NCAC 02L.020
Groundwater Standard (a),
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
N5
• denotes
Federal MCL/SMCL(b):
secondary standard
NS
•50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*S
NS
NS
NS
NS
NS
NS
N5
NS
N5
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents
Not Identified in the CCR Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Turbidity
Temperature
Specific
Conductance
Dissolved
Oxygen
Oxidation
Reduction
Potential
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
.911.
m L
m L
m L
NTU
'C
umhos cm
m L
mV
Buck
B10
2.8
110
0.0027
<50
3.6
6690
10.5
<0.5
1530
7520
86.6
0.0179
95.8
89.9
6
<2.5
<1
16.3
144.7
2
145.4
Buck
13100
2.9
<10
0.0011
<50
0.064
3630
1.2
<0.5
2710
4430
43.9
<0.005
41
41
<5
<2.5
<1
17.7
103
0.31
256.8
Buck
8101
22.4
< 10
0.0017
< 50
2.7
2000
< 0.5
< 0.5
722
4600
45
0.285
21.9
21.9
< 5
< 2.5
< 1
17.7
91.5
6.59
245.2
Buck
Bll
1.8
<10
0.007
4600
<0.6
3530
28.9
<0.5
951
5850
77.2
0.0662
38.5
38.5
<1
8.3
28.1
20.3
114
5.01
44.2
Buck
B12
2
<10
0.0162
<50
0.065
3430
9
<0.5
1270
6600
110
0.0173
43
43
<0
<1
<1
18
94
5.5
232.2
Buck
B13
2.5
34.8 1
0.0021
65
0.041
5140
3.6
0.83
3180
17100
202
0.01
88
88
<5
2.8
<1
18.8
209.4
1 1.8
183.5
Buck
B14-630
1.5
30.2
0.013
454
1.8
2320
35.7
<0.5
1150
3790
43.1
0.0588
21.8
21.8
<5
<5
3.5
17.1
63.7
3.4
285.1
Buck
814-640
2.7
22.7
0.0016
150
0.034
5580
20
<0.5
2790
8330
123
0.258
107
107
<5
<2.5
<1
18.5
263.2
0.1
115.8
Buck
B15
3
<10
0.009
<50
0.076
3140
<0.5
<0.5
1090
5530
74
0.007
30.8
30.8
<0
<1
<1
18.5
81.7
5.5
270
Buck
B16
4
46.7
10.001
<50
0.081
3700
6
<0.5
1300
27000
67
1.37
65.5
57.4
42.6
<1
<1
24.1
2033
0.5
76.2
Buck
B17
1
<10
0.0205
98.3
0.27
3130
11.7
2
1650
12500
101
0.62
28.5
28.5
<1
<5
<1
19.3
190
6
235.1
Buck
B18
6.6
49.1
0.0041
94.8
2.5
4340
2.3
<0.5
1620
7000
120
0.0076
42.6
42.6
<5
12.5
<1
17.7
122.3
3.8
310.5
Buck
B19
4.7
24.6
0.0077
<50
<0.6
5460
1.1
<0.5
1270
7890
108
0.293
46.4
46.4
<1
<2.5
<1
18
189
6.84
255.7
Buck
B2
14
9.3
0.006
1200
<0.6
7800
22
2.7
2800
10000
110
0.596
57
57
<5
0.8
2
16.2
148
6.35
268.4
Buck
B21
4.7
< 10
0.007
< 50
1.6
2670
1.9
0.59
1700
8740
85
0.175
36.9
36.9
< 0
< 1
< 1
19.1
105.3
5.6
202.1
Buck
B22
8.8
<10
0.0072
<50
0.68
2690
1.3
<0.5
1200
6490
63.6
0.159
31
31
<5
12.5
<1
16.4
85.1
4.8
26.9
Buck
B24
4.3
<10
0.0147
<50
0.74
2990
4.1
<0.5
1150
5510
64.4
0.0274
27.7
27.7
<5
<2.5
<1
16.6
82.7
5.2
218
Buck
B25
6.6
<10
0.0087
<50
1.1
2890
0.63
<0.5
1020
5280
69.2
0.0512
29
29
<5
<5
<1
16.5
78.5
6
225.8
Buck
B26
2.4
< 10
0.137
< 50
0.99
3310
2.4
1.2
2770
11100
153
0.0869
35.9
35.9
< 1
< 2.5
< 1
17.8
192
7.4
1 194.8
Buck
B27
2
<10
0.0136
158
0.093
2570
2.3
<0.5
966
4390
63.6
0.0289
22.8
22.8
<5
<2.5
1.3
16.8
80.2
6.5
222
Buck
B28
14.4
25.4
<0.001
<50
6.5
4000
0.52
<0.5
1160
4130
55.5
0.414
37.7
37.7
<5
<2.5
<1
16.3
91.6
5.6
167.1
Buck
B29
11.5
<10
0.006
<50
4.8
4090
<0.5
0.58
894
3830
53
<0.005
35.4
35.4
<5
<2.5
<1
16.9
93.5
5.7
326.5
Buck
B3
2.8
110
0.0288
5720
0.038
5460
80.5
0.79
989
6900
124
0.243
42.2
42.2
<5
<5
33.8
16
134.5
0.4
131.7
Buck
B31
2.8
<10
0.0211
96.9
0.093
5300
2.8
<0.5
1400
6840
135
0.0279
35.7
35.7
<5
<5
<1
16.2
140.4
5.5
269.1
Buck
B32
5.9
<10
0.0035
<50
0.11
4850
1.6
0.67
2330
6770
88.6
0.0126
62.8
62.8
<5
<2.5
<1
16.8
142
2.3
204.1
Buck
B33
11
<10
0.0061
150
0.7
4170
0.91
<0.5
2040
8200
89
<0.005
57.4
57.4
<0
<1
<1
21
129.1
3.4
226
Buck
B34
2.5
<10
0.00794
<50
0.33
3160
10.5
<0.5
1370
5490
62
<0.005
28.5
28.5
<1
<2.5
<1
19.7
116
6.59
195.3
Buck
B35
5.1
24.2
0.00656
1420
2.53
3050
0.83
0.27
1100
5250
67
0.0173
30
3
11.6
14
107
7.33
Buck
B37
6.7
< 10
0.0015
< 50
2.5
3760
< 0.5
0.52
1560
4690
54.5
< 0.005
31.2
31.2
< 5
< 2.5
< 1
17.2
85.5
5.5
178
Buck
B38
2.2
<10
0.149
<50
0.052
5160
2.5
<0.5
1730
7010
139
0.118
29.3
29.3
<5
12.5
<1
23.6
145.9
5.2
231.6
Buck
B39
6.1
< 10
0.0016
< 50
16.4
3430
0.98
1
669
3950
48.6
0.212
24.6
24.6
< 5
< 2.5
< 1
16.8
79.4
6.6
160.9
Buck
B4
1.7
< 10
0.0026
< 50
< 0.03
3980
7.4
< 0.5
1420
6360
97.1
2.09
38.2
38.2
< 5
< 2.5
< 1
18.1
137.4
5.61
213.9
Buck
B40
12
< 10
0.024
360
1.2
2010
28
1.5
1700
9700
83
0.093
25.1
25.1
< 5
< 1
< 1
17.4
81
7.71
190
Buck
B41
3.9
< 10
0.0013
< 50
0.29
3490
< 0.5
< 0.5
1890
8250
72.8
0.0073
67.7
67.7
< 5
< 2.5
< 1
16.7
165.3
1.1
123
Buck
B42
3.02
< 50
0.12
210
< 20
3310
< 10
< 10
989
5260
65.7
0.399
30.6
30.6
< 1
< 5
< 1
14.7
118
5.95
Buck
B43
2.3
< 10
0.0063
135
1.8
1930
4.5
0.74
746
6660
47.1
0.0131
18.8
18.8
< 5
< 2.5
< 1
19.3
72.1
6.7
238.2
Buck
B44
10.7
<10
0.019
50
1.7
3000
1.9
<0.5
840
6070
60.1
0.163
34.4
34.4
<5
<2.5
<1
17.4
80.7
6.4
277.6
Buck
B48
15.6
<10
0.0065
<50
12.4
9020
0.99
0.2
890
6490
103
0.025
73
73
<5
13.1
0.3
17.3
172.3
5.7
198.5
Buck
B49
3.2
< 10
0.111
< 50
0.058
2580
0.73
< 0.5
1040
6060
60
0.019
38.4
38.4
< 5
< 2.5
< 1
16.9
79.3
6.2
93.5
Buck
850
2.5
< 10
0.0237
84.7
0.9
3770
2
0.88
1110
5980
77.6
0.0182
32
32
< 5
< 2.5
< 1
16.8
100.1
5.8
198.2
Buck
B51
5
<10
0.0026
<50
0.74
916
1.4
<0.5
789
5330
42.9
0.0068
16.8
16.8
<5
<2.5
1.2
14.5
50
7.7
170.2
Buck
653
5.9
13
0.0025
68
< 10
6500
1.6
< 2
2800
6400
69
0.027
82
82
< 5
< 3.1
1
17.9
130
3.1
157
Buck
B54
25.6
<10
0.00791
15.7
4.8
2970
0.49
0.31
1610
6700
81
0.0102
43
12.5
<1
16.4
121
7.41
Buck
855
14
120
0.19
1100
2.2
5900
19
4.4
2300
6900
100
0.049
62.9
62.9
<5
1.6
1
17.6
178.4
7.71
198.9
Buck
B56
< 1
< 10
< 0.001
170
< 0.03
3490
29.6
< 0.5
4180
6320
49.5
1.18
39
39
< 5
< 2.5
1.6
17
105.3
1
52.9
Buck
B57
15
<10
0.06
430
0.64
2600
15
2
1200
10000
89.3
0.077
27
27
<5
<1
<1
19
93.8
7.7
220
Buck
B58-2
12
71
0.008
2900
<20
9300
23
6.6
1200
8600
160
0.54
160
150
<10
3.2
2
14
298
6.41
160
Buck
B59
14.3
13.7
0.0011
<50
22.3
8910
<0.5
<0.5
739
4590
94.1
0.0246
69.2
69.2
<5
<2.5
<1
17.2
161.9
5.2
304
Buck
B6
2.1
<10
0.0303
<50
0.045
1930
1.5
<0.5
5380
16300
53.4
0.0139
44.3
44.3
<5
<2.5
<1
17.6
140.3
7.6
312.3
Buck
B60
15
12.7
0.0086
490
0.75
6300
11
<0.5
1700
9900
63
0.028
45
45
<5
<1
<1
20.7
103
5.84
210
Buck
B61
2.5
<10
<0.001
186
0.13
38200
272
<0.5
2110
293000
947
0.104
114
114
<1
<2.5
<1
21.2
1770
6.16
711.2
Buck
B62
4.6
110
0.0472
<50
0.065
2850
2.9
<0.5
1090
5390
55.5
0.488
26.6
26.6
<5
<2.5
<1
15
77.6
5.7
155.6
Buck
B63
7.2
110
0.0268
<50
10.4
4470
1.5
2.5
775
7470
68
0.047
35
35
<5
<2.5
0.63
14.9
101.1
11
227
Buck
B64
5.7
110
0.0054
<50
0.81
2420
7
<0.5
786
4500
48.5
0.581
27.4
27.4
<5
12.5
<1
20.2
64.7
6.3
217.7
Buck
B65
< 1
110
10.001
< 50
< 0.03
4940
18.9
< 0.5
2920
8590
124
0.106
82.5
82.5
< 5
< 2.5
< 1
16.9
207
0.3
<
Buck
B66-1
2.6
18.1
0.0232
2700
1
4200
18
0.58
1520
5050
73.5
0.193
40.8
40.8
<5
5.6
38.5
15.6
106
3.1
105.9
Buck
B66-2
1.4
<10
0.0724
5330
0.081
2870
20.5
1.2
1400
5340
59.1
0.28
20.4
20.4
<5
22.6
121
16.1
90.4
5
1 135.8
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Table C2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 4 of 4
35A NCAC 02L.020
Groundwater Standard a:
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
N5
Federal MCL/SMCL(b):
• denotesseconda standard
NS
•50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*S
NS
NS
NS
NS
NS
NS
N5
NS
N5
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents
Not Identified in the CCR Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Turbidity
Temperature
Specific
Conductance
Dissolved
Oxygen
Oxidation
Reduction
Potential
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
.91L
m L
m L
m L
NTU
'C
umhos cm
.9/L
mV
Buck
B67
3.4
<10
0.0063
<50
0.082
2310
1.4
<0.5
2600
8520
94.9
0.0302
29.7
29.7
<5
<2.5
<1
16.2
119.3
6.4
205.8
Buck
B69
8.5
<10
0.0011
<50
10.6
6900
1.6
3
681
4410
70
0.0161
31.6
31.6
<5
<2.5
<1
16.9
119
5.6
197
Buck
B7
8.1
< 10
0.0077
< 50
4.6
7120
< 0.5
0.58
2340
9300
131
0.0187
59.5
59.5
< 5
< 2.5
< 1
16.7
185.3
4.1
196.2
Buck
B71
1.2
<10
0.0021
<50
<0.3
656
<0.5
<0.5
898
6140
44.4
0.0328
17
17
<5
<2.5
<1
17.9
48.9
8.73
215.9
Buck
B72
1.4
<10
0.0123
18200
'0.03
3440
128
0.71
1220
4550
68
1.41
42.2
42.2
<5
26.2
128
17.4
175.5
0.27
92.5
Buck
B73
8.4
13.4
0.005
<50
0.24
3690
11.2
<0.5
2110
7220
66.9
1.54
53
53
<5
<2.5
<1
21.4
143
4.1
210.8
Buck
B74
5.5
<10
0.0073
<50
1.1
1450
1.2
<0.5
980
4120
29.5
0.0157
16.5
16.5
'5
<2.5
<1
17
45.8
6.9
211.9
Buck
B75
14.1
< 10
0.0021
< 50
21.2
9590
< 0.5
< 0.5
751
4900
94.4
0.0235
74.9
74.9
< 5
< 2.5
< 1
18
169.6
5.2
249.5
Buck
B76
13.3
<10
'0.001
<50
6.3
5620
<0.5
0.97
1070
5150
50.6
<0.005
41.7
41.7
<5
<2.5
<1
16
113.2
4.4
306.6
Buck
B77A
< 1
< 10
< 0.001
< 50
< 0.03
5740
10.7
< 0.5
3230
8820
119
0.0476
106
106
< 5
< 2.5
< 1
17.9
233.2
0.19
14.8
Buck
B778
3.3
< 10
0.0453
< 50
1.2
2140
0.88
< 0.5
929
6520
76.4
0.0306
26.8
26.8
< 5
< 2.5
< 1
18.5
74.5
6.8
233.5
Buck
B78
3.2
<10
0.0051
<50
0.31
6400
2
1.3
1770
8080
108
0.633
39.3
39.3
<5
<2.5
<1
16.4
167.5
3.2
253.8
Buck
B79
4
14.7
0.0043
<50
0.054
5110
5.9
<0.5
1910
8550
116
<0.005
28.5
28.5
<5
<2.5
<1
19.9
147.1
5.7
199.6
Buck
B81
3.4
<10
0.0148
<50
0.85
1400
0.77
<0.5
757
3750
32.1
<0.005
14.1
14.1
<5
<2.5
<1
18
47.1
6.9
196.9
Buck
B82
5.5
23.9
0.0019
<50
0.73
2850
3.5
<0.5
1680
5520
44.6
0.642
30.4
30.4
<5
5.5
<1
19.1
77.7
7.2
190.8
Buck
B83
3.6
<10
0.024
112
0.65
4520
4
<0.5
1440
6910
86.3
0.176
33.6
33.6
<5
<2.5
<1
17.7
120.7
5.9
167.2
Buck
B84
10.1
<10
<0.001
<50
1.9
4040
'0.5
<0.5
1070
6530
84.7
<0.005
39.1
39.1
<5
<2.5
<1
18.8
107.3
7.1
153.8
Buck
B85
11.2
<10
0.0055
<50
7.3
12600
2.6
<0.5
656
5230
116
0.0271
64.4
64.4
<5
<5
<1
18.8
213.6
1.6
250.9
Buck
B86
4.7
<10
0.0123
<50
2.9
2800
0.96
<0.5
835
7190
143
0.0302
29.3
29.3
<5
<2.5
<1
17.8
87.1
6.1
193
Buck
B88
3
<10
0.0121
134
0.49
4850
1.5
0.58
1770
6500
98.2
0.0143
24.2
24.2
<5
<2.5
1.2
17.8
117.9
4.9
196.9
Buck
B89
3.1
< 10
< 0.001
< 50
1.7
4400
40.3
< 0.5
3510
7960
151
0.0108
85.6
85.6
< 5
< 2.5
< 1
16.8
400.2
0.14
85
Buck
B90
3.5
<10
0.0219
1720
0.086
2770
4.8
<0.5
1070
4460
58.3
2.34
34.4
34.4
<5
<2.5
25.9
18
88.3
5.2
172.1
Buck
B92A
11.5
<10
'0.001
<50
0.35
1920
2.4
<0.5
895
5180
38.3
1.08
21.6
21.6
<5
<2.5
<1
17.5
121.8
7
214.9
Buck
8928
10.8
< 10
0.002
< 50
1.7
1780
2
< 0.5
838
4960
36.5
0.822
22.6
22.6
< 5
< 2.5
< 1
18.3
61
7.9
206.3
Buck
B93
3.4
<10
0.0106
3050
0.55
4120
43.5
1.7
705
5680
66.2
0.0663
31.6
31.6
<5
5.1
22.2
17.3
98.6
4.6
289.2
Buck
B94
3
< 10
0.024
< 50
0.82
2850
3.2
0.51
1370
5390
56.8
0.0125
30.6
30.6
< 5
< 2.5
< 1
17.3
77.9
7.4
266.9
Buck
B95
9.2
< 10
< 0.001
< 50
2.2
3070
< 0.5
0.96
848
4320
42.6
0.228
26.7
26.7
< 5
< 2.5
< 1
16.5
74.7
6.8
130.5
Buck
B96
11.4
117
0.0013
240
0.5
3580
4.8
<0.5
3050
6590
109
0.15
44.8
44.8
<5
<2.5
<1
16.1
405.9
3.8
174.7
Buck
B97A
6.3
<10
0.0041
<50
0.36
4140
9.6
<0.5
3640
7270
62.6
0.0064
49
49
<5
<2.5
<1
17.4
250.5
0.67
58.4
Buck
B97B
6.5
<10
0.0036
<50
0.35
4160
9.7
<0.5
3650
6720
60.3
<0.005
46.6
46.6
<5
<2.5
<1
18.3
251.5
0.8
159.8
Buck
B98
6.5
<10
0.0025
<50
1.5
2170
0.65
<0.5
965
5920
43.9
0.276
27.6
27.6
<5
<2.5
<1
16.9
73.5
6.9
190.1
Buck
B99
4.6
< 10
10.001
1 < 50
1 0.042
3330
1 8.7
1 < 0.5
3050
1 5800
75.9
0.0282
59.4
59.4
< 5
12.5
< 1
1 18.4
294.9
0.8
101.7
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

12
Comparison of NCDEQ Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/9/2016

Table C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
13
Page 1 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
d(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal MCL/SMCL(b):
(• denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
"500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
30
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Appendix III
App
endix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B10
< 5
11600
4.1
6.6
2.8
168
< 0.5
< 0.5
28.4
< 0.2
< 0.08
5.1
< 0.5
0.14
< 0.2
0.58
< 0.5
< 0.1
Buck
8100
< 5
10200
1.4
7.5
4.8
118
< 0.5
< 0.5
14.1
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
3.3
< 0.5
< 0.1
Buck
8101
<5
5490
1.1
7.1
<2
81
<0.5
<0.5
6.9
<0.2
<0.08
2.9
<0.5
0.14
<0.2
<0.5
<0.5
<0.1
Buck
811
< 5
7160
3.8
6.62
< 2
102
< 0.5
< 0.5
8.53
< 0.2
< 0.08
< 0.5
< 0.5
0.7
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B12
< 5
8560
2.3
6.1
< 1
93
< 0.5
< 0.5
23
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B13
5.8
21300
10.3
6.7
6.5
161
<0.5
<0.5
39.3
<0.2
<0.08
0.58
<0.5
0.17
<0.2
2.4
<0.5
<0.1
Buck
B14-630
<5
4700
2
6.2
<2
38
<0.5
<0.5
29.5
<0.2
<0.08
2.5
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Buck
B14-640
< 5
41300
3.2
7.7
6.4
164
< 0.5
< 0.5
5.5
< 0.2
< 0.08
< 0.5
< 0.5
0.11
< 0.2
2.6
< 0.5
< 0.1
Buck
B15
< 5
7040
2.8
6.3
2.2
84
< 0.5
< 0.5
14.8
< 0.2
< 0.08
< 0.5
< 0.5
0.56
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B16
10.4
12000
2.4
9.4
27.8
139
< 0.5
< 0.5
1.5
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
5.1
< 0.5
< 0.1
Buck
B17
<5
11100
13.5
6.35
<2
121
<0.5
<0.5
73.5
<0.2
1.4
0.55
<0.5
0.42
<0.2
1.2
<0.5
<0.1
Buck
B18
<5
10300
3.1
6.3
2.3
99
<0.5
<0.5
50.8
<0.2
<0.08
3.5
<0.5
0.55
<0.2
<0.5
<0.5
<0.1
Buck
B19
<5
12200
9.3
6.92
2.1
143
<0.5
<0.5
15.8
<0.2
<0,08
0.66
<0.5
0.92
<0.2
<0.5
<0.5
<0.1
Buck
B2
<5
19000
4.7
6.36
2.2
136
<0.5
2.2
22
<0.2
<0.08
0.75
0.25
0.52
<0.1
0.24
<0.5
<0.1
Buck
B21
18.4
8010
3.9
6.6
< 1
109
< 0.5
< 0.5
26
< 0.2
0.6
1.7
< 0.5
11
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B22
<5
7050
2
6.5
<2
96
<0.5
<0.5
13
<0.2
0.14
0.88
<0.5
0.5
<0.2
0.59
<0.5
<0.1
Buck
B24
< 5
6760
2.5
6.4
< 2
107
< 0.5
< 0.5
11.9
< 0.2
< 0.08
1
< 0.5
0.39
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B25
<5
6490
2
6.4
<2
109
<0.5
<0.5
12.9
<0.2
<0.08
1.5
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B26
<5
12600
8.8
6.07
<2
138
<0.5
<0.5
81.3
<0.2
<0.08
2.7
<0.5
3.3
<0.2
<0.5
<0.5
<0.1
Buck
B27
<5
6130
3.7
6
<2
29
<0.5
<0.5
11.2
<0.2
<0.08
0.52
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B28
< 5
9800
1.5
7.1
2.8
93
< 0.5
< 0.5
5.8
< 0.2
0.29
6.5
< 0.5
1.2
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B29
< 5
8510
2
6.8
< 2
60
< 0.5
< 0.5
9.5
< 0.2
< 0.08
7.4
< 0.5
0.23
< 0.2
0.69
< 0.5
< 0.1
Buck
B3
< 5
10900
4.9
6.5
< 2
107
< 0.5
< 0.5
11.3
< 0.2
0.099
< 0.5
< 0.5
9
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B31
<5
12200
8
6.1
<2
98
<0.5
<0.5
22.3
<0.2
<0.08
<0.5
<0.5
0.29
<0.2
<0.5
<0.5
<0.1
Buck
B32
< 5
13700
2.1
6.9
2.7
112
< 0.5
< 0.5
9.4
< 0.2
< 0.08
< 0.5
< 0.5
0.17
< 0.2
1.3
< 0.5
< 0.1
Buck
B33
<5
13300
2
6.7
2.8
117
<0.5
<0.5
19
<0.2
<0.08
0.85
<0.5
0.82
<0.2
0.68
<0.5
<0.1
Buck
B34
<5
7280
4.28
6.2
2.1
87
<0.5
<0.5
13.4
<0.2
<0.08
0.63
<0.5
0.11
<0.2
<0.5
<0.5
<0.1
Buck
B35
<20
7210
5
6.24
7
81
<0.5
<0.08
11.1
<0.11
<0.06
2.53
<0.03
1.23
<0.01
0.17
<0.16
<0.06
Buck
B37
<5
5730
1.4
6.6
2.1
89
<0.5
<0.5
26.6
<0.2
<0.8
2.7
<0.5
0.49
<0.2
0.51
<0.5
<0.1
Buck
B38
< 5
13000
11.1
5.4
< 2
131
< 0.5
< 0.5
45
< 0.2
< 0.08
< 0.5
< 0.5
0.89
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B39
< 5
6150
2.3
6.8
< 2
100
< 0.5
< 0.5
16.7
< 0.2
< 0.08
17.1
< 0.5
0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B4
<5
10500
7.6
6.3
2.3
95
<0.5
<0.5
20.7
<0.2
<0.08
0.56
<0.5
0.69
<0.2
<0.5
<0.5
<0.1
Buck
B40
<5
7500
3.1
6.3
<1
118
<0.5
<0.5
25.7
<0.2
<0.08
1.5
0.33
0.19
<0.1
<0.5
<0.5
<0.1
Buck
B41
<5
21100
2.1
8.1
2.9
127
<0.5
<0.5
4.9
<0.2
<0.08
0.58
<0.5
<0.1
<0.2
2.5
<0.5
<0.1
Buck
B42
<100
7520
5.22
6.16
<10
71
<3
<10
10.3
<1
<1
<10
<5
36.5
<0.2
<10
<10
<1
Buck
B43
< 5
4950
4
5.2
< 2
63
< 0.5
< 0.5
18.4
< 0.2
< 0.08
2.1
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B44
< 5
6340
1.8
6.5
< 2
70
< 0.5
< 0.5
10.6
< 0.2
0.8
2
< 0.5
1.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B48
<5
15900
5.9
6.7
<1
135
0.031
<0.5
11.4
<0.2
<0.08
11.5
<0.5
0.12
<0.2
<0.5
<0.5
<0.1
Buck
B49
< 5
6060
2.7
6.2
2.3
60
< 0.5
< 0.5
15.1
< 0.2
< 0.08
< 0.5
< 0.5
3.1
< 0.2
< 0.5
< 0.5
0.15
Buck
B50
<5
8500
4.9
6.2
2.1
96
<0.5
<0.5
9.4
<0.2
<0.08
1.2
<0.5
0.27
<0.2
<0.5
<0.5
<0.1
Buck
B51
<5
3320
1.7
6.5
<2
127
<0.5
<0.5
8.2
<0.2
<0.08
1.1
<0.5
0.49
<0.2
1.3
<0.5
<0.1
Buck
B53
38
18000
3.2
6.1
2.9
130
0.057
< 1
15
< 1
0.15
< 10
< 1
0.23
< 0.2
1.1
< 1
< 1
Buck
B54
25
7760
4.9
5.69
<5
116
0.5
<0.08
30.2
<0.11
<0.06
4.84
<0.03
0.34
<0.2
0.86
<0.16
<0.06
Buck
B55
<5
23000
7.3
6.6
3.2
95
<0.5
<0.5
27
<0.2
<0.08
2.2
0.33
0.71
<0.1
2.7
<0.5
<0.1
Buck
B56
<5
6610
1.9
6.9
4.8
70
<0.5
<0.5
84.7
<0.2
<0.08
<0.5
<0.5
2
<0.2
0.59
<0.5
<0.1
Buck
B57
<5
8400
5.3
6.2
0.46
78
<0.5
<0.5
7.3
<0.2
<0.08
0.82
<0.5
3.7
0.017
<0.5
<0.5
<0.1
Buck
B58-2
28
63000
6.2
7.4
22
230
0.21
1.7
41
< 2
0.44
< 25
1.4
8.4
0.047
0.064
< 5
< 0.5
Buck
859
<5
14400
3.1
7
2.3
144
<0.5
<0.5
4.9
<0.2
<0.08
21.8
<0.5
7 .1
<0.2
<0.5
<0.5
<0.1
Buck
B6
< 5
8980
5.7
6.4
2.4
132
< 0.5
< 0.5
5.3
< 0.2
< 0.08
< 0.5
< 0.5
0.59
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B60
< 5
11000
2.1
6.6
2.3
98
< 0.5
1.8
47
< 0.2
0.12
1.3
< 0.5
1.5
0.034
1
< 0.5
< 0.1
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
14
Page 2 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
d(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
1s
1
NS
20
0.2
Federal MCL/SMCL(b):
(* denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
1s
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
30
1
1s
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
is
5.7
100
100
0.2
Appendix III
App
endix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B61
13.2
246000
20.5
7.75
711
1220
1.87
< 0.5
3.9
< 0.2
< 0.08
0.89
< 0.5
0.21
< 0.2
2
< 0.5
< 0.1
Buck
B62
<5
5770
2.3
6.6
2.3
59
<0.5
<0.5
12.6
<0.2
<0.08
<0.5
<0.5
0.74
<0.2
<0.5
<0.5
<0.1
Buck
B63
<S
7200
6.1
6.7
<1
110
0.053
<0.5
11.9
<0.2
0.26
10.2
<0.5
3.1
<0.2
0.11
<0.5
<0.1
Buck
B64 1
7.7
5370
1.6
6.6
<2
46
<0.5
<0.5
5.5
<0.2
0.43
1.1
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B65
< 5
26100
5.2
7.9
4.4
191
< 0.5
< 0.5
5.6
< 0.2
< 0.08
< 0.5
< 0.5
0.14
< 0.2
5
< 0.5
< 0.1
Buck
B66-1
< 5
9770
4.8
6.4
< 2
113
< 0.5
< 0.5
12.2
< 0.2
< 0.08
1.9
< 0.5
0.82
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B66-2
< 5
5770
4.6
6
< 2
120
< 0.5
< 0.5
16.4
< 0.2
< 0.08
1.6
< 0.5
3.8
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B67
<5
10400
3.2
6.2
2.5
90
<0.5
<0.5
58.5
<0.2
<0.08
<0.5
<0.5
0.25
<01
0.6
<0.5
<0.1
Buck
B69
<5
8520
8
6.6
<2
74
<0.5
<0.5
22.5
<0.2
<0.08
16.3
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
137
<5
16500
8.4
6.4
2.9
148
<0.5
<0.5
32.3
<0.2
<0.08
5.7
<0.5
0.68
<0.2
0.67
<0.5
<0.1
Buck
B71
<5
2860
1.5
6.3
<2
74
<0.5
<0.5
12.2
<0.2
<0.08
<0.5
<0.5
1.7
<0.2
2.6
<0.5
<0.1
Buck
B72
<5
8160
4.2
6.3
<2
92
<0.5
<0.5
15.8
<01
<0.08
1.2
0.57
6.1
<0.2
<0.5
<0.5
<0.1
Buck
B73
<5
14700
2.2
7.2
5.7
125
<0.5
<0.5
12.5
<0.2
<0.08
0.81
<0.S
0.51
<0.2
0.96
<0.5
<01
Buck
B74
< 5
3120
1.3
6.4
< 2
66
< 0.5
< 0.5
5.8
< 0.2
< 0.08
1.1
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B75
<5
15500
3.5
7
<2
113
<0.5
<0.5
5
<0.2
<0.08
22.1
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B76
< 5
8400
2.4
7.3
2.8
71
< 0.5
< 0.5
12.5
< 0.2
< 0.08
9.7
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B77A
<5
31500
2.2
7.9
6.8
152
<0.5
<0.5
25.4
<0.2
<0.08
<0.5
<0.5
0.18
<0.2
3.3
<0.5
<0.1
Buck
B77B
<5
5620
2.2
6
<2
83
<0.5
<0.5
23.7
<01
<0.08
1.4
<0.5
1.6
<0.2
<0.5
<0.5
<0.1
Buck
B78
<5
12900
16.9
6.1
2.2
171
<0.5
<0.5
41.4
<0.2
<0.08
1.1
<0.5
0.32
<0.2
0.51
<0.5
<0.1
Buck
B79
< 5
9510
3.5
6.5
2.5
129
< 0.5
< 0.5
37.8
< 0.2
< 0.08
< 0.5
< 0.5
1.4
< 0.2
0.78
< 0.5
< 0.1
Buck
B81
<5
3030
1.2
6.1
2.4
34
<0.5
<0.5
9.1
<0.2
<0.08
1.5
<0.5
0.56
<0.2
<0.5
<0.5
<0.1
Buck
B82
<5
5770
<1
6.2
<2
78
<0.5
<0.5
16.7
<0.2
<0.08
0.92
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Buck
B83
< 5
9310
4.8
6.3
2.2
89
< 0.5
< 0.5
14.5
< 0.2
0.14
0.94
< 0.5
0.6
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B84
< 5
9910
3.9
5.7
< 2
97
< 0.5
< 0.5
11.2
< 0.2
< 0.08
2.1
< 0.5
0.29
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B85
< 5
19900
12.7
6.5
< 2
148
< 0.5
< 0.5
6.1
< 0.2
< 0.08
9.2
< 0.5
0.44
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B86
< 5
6560
2.8
6.2
< 2
< 25
< 0.5
< 0.5
22.7
< 0.2
< 0.08
3.7
< 0.5
0.29
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B88
<5
9310
9.3
6.1
2
98
<0.5
<0.5
32.3
<0.2
<0.08
0.84
<0.5
0.35
<0.2
<0.5
<0.5
<0.1
Buck
B89
<5
30700
4.1
7.3
4.7
145
<0.5
0.9
11.1
<0.2
<0.08
<0.5
<0.5
0.36
<0.2
3.2
2.9
<0.1
Buck
B90
<5
5700
3.1
6.3
<2
118
<0.5
0.81
16
<0.2
<0.08
0.87
<0.5
2
<0.2
<0.5
<0.5
<0.1
Buck
892A
<5
4940
1.3
6.2
<2
73
<0.5
<0.5
7.3
<0.2
<0.08
1.8
<0.5
<0.1
<0.2
0.52
<0.5
<0.1
Buck
B92B
< 5
4640
1.3
5.8
< 2
67
< 0.5
< 0.5
7.3
< 0.2
< 0.08
1.8
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B93
<5
8050
5.3
6
<2
59
<0.5
<0.5
17.7
<0.2
<0.08
3.1
<0.5
0.87
<0.2
<0.5
<0.5
<0.1
Buck
B94
< 5
6420
1.9
6.2
< 2
48
< 0.5
< 0.5
14.1
< 0.2
< 0.08
1.1
< 0.5
0.56
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B95
< 5
5220
1.2
6.8
< 2
69
< 0.5
< 0.5
4.5
< 0.2
< 0.08
2.6
< 0.5
1.9
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B96
<5
1 21500
1 1.9
7.5
33.3
255
<0.5
<0.5
15.4
<01
<0.08
1.3
<0.5
0.38
<0.2
2.2
<0.5
<0.1
Buck
B97A
<5
13900
2.1
6.6
5.1
105
<0.5
<0.5
17.1
<0.2
<0.08
<0.5
<0.5
0.41
<0.2
1.7
0.63
<0.1
Buck
B97B
<5
13500
2.2
6.2
5
105
<0.5
<0.5
17
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
1.6
0.62
<0.1
Buck
898
<5
6510
1.4
6
<2
79
<0.5
<0.5
6.8
<0.2
<0.08
1.6
<0.5
0.79
<0.2
<0.5
<0.5
<0.1
Buck
899
< 5
20700
2.1
7.3
5.9
108
< 0.5
< 0.5
10.4
< 0.2
< 0.08
< 0.5
< 0.5
0.49
< 0.2
2.8
< 0.5
< 0.1
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
15
Page 3 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016
ISA NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(* denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR
Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Buck
B10
2.8
< 10
0.0027
< 50
3.6
6690
< 0.5
< 0.5
1530
7520
86.6
0.0179
95.8
89.9
6
< 2.5
Buck
8100
2.9
< 10
0.0011
< 50
0.064
3630
1.2
< 0.5
2710
4430
43.9
< 0.005
41
41
< 5
< 2.5
Buck
8101
22.4
< 10
0.0017
< 50
2.7
2000
< 0.5
< 0.5
722
4600
45
0.285
21.9
21.9
<5
< 2.5
Buck
811
1.8
<10
0.007
4600
<0.6
3530
28.9
<0.5
951
5850
77.2
0.0662
38.5
38.5
<1
8.3
Buck
B12
2
<10
0.0162
<50
0.065
3430
9
<0.5
1270
6600
110
0,0173
43
43
<0
<1
Buck
B13
2.5
34.8
0.0021
65
0.041
5140
3.6
0.83
3180
17100
202
0.01
88
88
<5
2.8
Buck
B14-630
1.5
30.2
0.013
454
1.8
2320
35.7
<0.5
1150
3790
43.1
0.0588
21.8
21.8
<5
<5
Buck
B14-640
2.7
22.7
0.0016
<50
0.034
5580
20
<0.5
2790
8330
123
0.258
107
107
<5
<2.5
Buck
B15
3
< 10
0.009
< 50
0.076
3140
< 0.5
< 0.5
1090
5530
74
0.007
30.8
30.8
<0
< 1
Buck
B16
4
46.7
<0.001
<50
0.081
3700
6
<0.5
1300
27000
67
1.37
65.5
57.4
42.6
<1
Buck
B17
1
< 10
0.0205
98.3
0.27
3130
11.7
2
1650
12500
101
0.62
28.5
28.5
< 1
<5
Buck
B18
6.6
49.1
0.0041
94.8
2.5
4340
2.3
<0.5
1620
7000
120
0.0076
42.6
42.6
<5
<2.5
Buck
B19
4.7
24.6
0.0077
< 50
< 0.6
5460
1.1
< 0.5
1270
7890
108
0.293
46.4
46.4
< 1
< 2.5
Buck
B2
14
9.3
0.006
1200
<0.6
7800
22
2.7
2800
10000
110
0.596
57
57
<5
0.8
Buck
B21
4.7
<10
0.007
<50
1.6
2670
1.9
0.59
1700
8740
85
0.175
36.9
36.9
<0
<1
Buck
B22
8.8
< 10
0.0072
< 50
0.68
2690
1.3
< 0.5
1200
6490
63.6
0.159
31
31
<5
< 2.5
Buck
B24
4.3
<10
0.0147
<50
0.74
2990
4.1
<0.5
1150
5510
64.4
0.0274
27.7
27.7
<5
<2.5
Buck
B25
6.6
< 10
0.0087
< 50
1.1
2890
0.63
< 0.5
1020
5280
69.2
0.0512
29
29
< 5
< 5
Buck
B26
2.4
< 10
0.137
< 50
0.99
3310
2.4
1.2
2770
11100
153
0.0869
35.9
35.9
< 1
< 2.5
Buck
B27
2
<10
0.0136
158
0.093
2570
2.3
<0.5
966
4390
63.6
0.0289
22.8
22.8
<5
<2.5
Buck
B28
14.4
25.4
<0.001
<50
6.5
4000
0.52
<0.5
1160
4130
55.5
0.414
37.7
37.7
<5
<2.5
Buck
B29
11.5
<10
0.006
<50
4.8
4090
<0.5
0.58
894
3830
53
<0.005
35.4
35.4
<5
<2.5
Buck
B3
2.8
< 10
0.0288
5720
0.038
5460
80.5
0.79
989
6900
124
0.243
42.2
42.2
<5
<5
Buck
B31
2.8
< 10
0.0211
96.9
0.093
5300
2.8
< 0.5
1400
6840
135
0.0279
35.7
35.7
<5
< 5
Buck
B32
5.9
< 10
0.0035
< 50
0.11
4850
1.6
0.67
2330
6770
88.6
0.0126
62.8
62.8
<5
< 2.5
Buck
B33
11
< 10
0.0061
< 50
0.7
4170
0.91
< 0.5
2040
8200
89
< 0.005
57.4
57.4
<0
< 1
Buck
B34
2.5
< 10
0.00794
< 50
0.33
3160
< 0.5
< 0.5
1370
5490
62
< 0.005
28.5
28.5
< 1
< 2.5
Buck
B35
5.1
24.2
0.00656
1420
2.53
3050
0.83
0.27
1100
5250
67
0.0173
30
3
Buck
B37
6.7
< 10
0.0015
< 50
2.5
3760
< 0.5
0.52
1560
4690
54.5
< 0.005
31.2
31.2
<5
< 2.5
Buck
B38
2.2
< 10
0.149
< 50
0.052
5160
2.5
< 0.5
1730
7010
139
0.118
29.3
29.3
< 5
< 2.5
Buck
B39
6.1
< 10
0.0016
< 50
16.4
3430
0.98
1
669
3950
48.6
0.212
24.6
24.6
<5
< 2.5
Buck
B4
1.7
< 10
0.0026
< 50
< 0.03
3980
7.4
< 0.5
1420
6360
97.1
2.09
38.2
38.2
< 5
< 2.5
Buck
B40
12
< 10
0.024
360
1.2
2010
28
1.5
1700
9700
83
0.093
25.1
25.1
<5
< 1
Buck
B41
3.9
< 10
0.0013
< 50
0.29
3490
< 0.5
< 0.5
1890
8250
72.8
0.0073
67.7
67.7
<5
< 2.5
Buck
B42
3.02
< 50
0.12
210
< 20
3310
< 10
<10
989
5260
65.7
0.399
30.6
30.6
< 1
<5
Buck
B43
2.3
<10
0.0063
135
1.8
1930
4.5
0.74
746
6660
47.1
0.0131
18.8
18.8
<5
<2.5
Buck
B44
10.7
< 30
0.019
50
1.7
3000
1.9
< 0.5
840
6070
60.1
0.163
34.4
34.4
<5
< 2.5
Buck
B48
15.6
< 10
0.0065
< 50
12.4
9020
0.99
0.2
890
6490
103
0.025
73
73
<5
< 3.1
Buck
B49
3.2
< 10
0.111
< 50
0.058
2580
0.73
< 0.5
1040
6060
60
0.019
38.4
38.4
<5
< 2.5
Buck
B50
2.5
<10
0.0237
84.7
0.9
3770
2
0.88
1110
5980
77.6
0.0182
32
32
<5
<2.5
Buck
B51
5
< 10
0.0026
< 50
0.74
916
1.4
< 0.5
789
5330
42.9
0.0068
16.8
16.8
<5
< 2.5
Buck
B53
5.9
13
0.0025
68
< 10
6500
1.6
<2
2800
6400
69
0.027
82
82
< 5
< 3.1
Buck
B54
25.6
<10
0.00791
15.7
4.8
2970
0.49
0.31
1610
6700
81
0.0102
43
<2.5
Buck
B55
14
120
0.19
1100
2.2
5900
19
4.4
2300
6900
100
0.049
62.9
62.9
<5
1.6
Buck
856
< 1
< 10
< 0.001
170
< 0.03
3490
29.6
< 0.5
4180
6320
49.5
1.18
39
39
<5
< 2.5
Buck
B57
15
< 10
0.06
430
0.64
2600
15
2
1200
10000
89.3
0.077
27
27
<5
< 1
Buck
858-2
12
71
0.0082900
< 20
9300
23
6.6
1200
8600
160
0.54
160
150
< 10
3.2
Buck
B59
14.3
13.7
0.0011
<50
22.3
8910
<0.5
<0.5
739
4590
94.1
0.0246
69.2
69.2
<5
<2.5
Buck
B6
2.1
< 10
0.0303
< 50
0.045
1930
1.5
< 0.5
5380
16300
53.4
0.0139
44.3
44.3
< 5
< 2.5
Buck
B60
15
12.7
0.0086
490
0.75
6300
11
<0.5
1700
9900
63
0.028
45
45
<5
<1
15
Page 3 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
16
Page 4 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR
Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Buck
B61
2.5
< 10
< 0.001
186
0.13
38200
272
< 0.5
2110
293000
947
0.104
114
114
< 1
< 2.5
Buck
B62
4.6
<10
0.0472
<50
0.065
2850
2.9
<0.5
1090
5390
55.5
0.488
26.6
26.6
<5
<2.5
Buck
B63
7.2
< 10
0.0268
< 50
10.4
4470
1.5
2.5
775
7470
68
0.047
35
35
<5
< 2.5
Buck
B64
5.7
< 10
0.0054
< 50
0.81
2420
7
< 0.5
786
4500
48.5
0.581
27.4
27.4
<5
< 2.5
Buck
B65
< 1
< 10
< 0.001
< 50
< 0.03
4940
18.9
< 0.5
2920
8590
124
1 0.106
82.5
82.5
<5
< 2.5
Buck
B66-1
2.6
18.1
0.0232
2700
1
4200
18
0.58
1520
5050
73.5
0.193
40.8
40.8
<5
5.6
Buck
B66-2
1.4
< 10
0.0724
5330
0.081
2870
20.5
1.2
1400
5340
59.1
0.28
20.4
20.4
<5
22.6
Buck
B67
3.4
< 10
0.0063
< 50
0.082
2310
1.4
< 0.5
2600
8520
94.9
0.0302
29.7
29.7
<5
< 2.5
Buck
B69
8.5
< 10
0.0011
< 50
10.6
6900
1.6
3
681
4410
70
0.0161
31.6
31.6
<5
< 2.5
Buck
B7
8.1
< 10
0.0077
< 50
4.6
7120
< 0.5
0.58
2340
9300
131
0.0187
59.5
59.5
<5
< 25
Buck
B71
1.2
< 10
0.0021
< 50
< 0.3
656
< 0.5
< 0.5
898
6140
44.4
0.0328
17
17
<5
< 2.5
Buck
B72
1.4
< 10
0.0123
18200
< 0.03
3440
128
0.71
1220
4550
68
1.41
42.2
42.2
< 5
26.2
Buck
B73
8.4
13.4
0.005
<50
0.24
3690
11.2
<0.5
2110
7220
66.9
1.54
53
53
<5
<2.5
Buck
874
5.5
< 10
0.0073
< 50
1.1
1450
1.2
< 0.5
980
4120
29.5
0.0157
16.5
16.5
<5
< 2.5
Buck
B75
14.1
< 10
0.0021
< 50
21.2
9590
< 0.5
< 0.5
751
4900
94.4
0.0235
74.9
74.9
<5
< 2.5
Buck
B76
13.3
<10
<0.001
<50
6.3
5620
<0.5
0.97
1070
5150
50.6
<0.005
41.7
41.7
<5
<2.5
Buck
B77A
< 1
< 10
< 0.001
< 50
< 0.03
5740
10.7
< 0.5
3230
8820
119
0.0476
106
106
<5
< 2.5
Buck
B77B
3.3
<10
0.0453
<50
1.2
2140
0.88
<0.5
929
6520
76.4
0.0306
26.8
26.8
<5
<2.5
Buck
B78
3.2
< 10
0.0051
<50
0.31
6400
2
1.3
1770
8080
108
0.633
39.3
39.3
<5
< 2.5
Buck
B79
4
14.7
0.0043
< 50
0.054
5110
5.9
< 0.5
1910
8550
116
< 0.005
28.5
28.5
<5
< 2.5
Buck
B81
3.4
< 30
0.0148
< 50
0.85
1400
0.77
< 0.5
757
3750
32.1
< 0.005
14.1
14.1
<5
< 2.5
Buck
882
5.5
23.9
0.0019
< 50
0.73
2850
3.5
< 0.5
1680
5520
44.6
0.642
30.4
30.4
< 5
5.5
Buck
B83
3.6
<10
0.024
112
0.65
4520
4
<0.5
1440
6910
86.3
0.176
33.6
33.6
<5
<2.5
Buck
B84
10.1
< 10
< 0.001
< 50
1.9
4040
< 0.5
< 0.5
1070
6530
84.7
< 0.005
39.1
39.1
<5
< 2.5
Buck
B85
11.2
< 10
0.0055
< 50
7.3
12600
2.6
< 0.5
656
5230
116
0.0271
64.4
64.4
<5
< 5
Buck
B86
4.7
< 10
0.0123
< 50
2.9
2800
0.96
< 0.5
835
7190
143
0.0302
29.3
29.3
< 5
< 2.5
Buck
B88
3
< 10
0.0121
134
0.49
4850
1.5
0.58
1770
6500
98.2
0.0143
24.2
24.2
<5
< 2.5
Buck
B89
3.1
< 10
< 0.001
< 50
1.7
4400
40.3
< 0.5
3510
7960
151
0.0108
85.6
85.6
< 5
< 2.5
Buck
B90
3.5
<10
0.0219
1720
0.086
2770
4.8
<0.5
1070
4460
58.3
2.34
34.4
34.4
<5
<2.5
Buck
B92A
11.5
<10
<0.001
<50
0.35
1920
2.4
<0.5
895
5180
38.3
1.08
21.6
21.6
<5
<2.5
Buck
B92B
10.8
<10
0.002
<50
1.7
1780
2
<0.5
838
4960
36.5
0.822
22.6
22.6
<5
<2.5
Buck
B93
3.4
< 10
0.0106
3050
0.55
4120
43.5
1.7
705
5680
66.2
0.0663
31.6
31.6
<5
5.1
Buck
B94
3
< 10
0.024
< 50
0.82
2850
3.2
0.51
1370
5390
56.8
0.0125
30.6
30.6
<5
< 2.5
Buck
B95
9.2
< 10
< 0.001
< 50
2.2
3070
< 0.5
0.96
848
4320
42.6
0.228
26.7
26.7
< 5
< 2.5
Buck
B96
11.4
117
0.0013
240
0.5
3580
4.8
<0.5
3050
6590
109
0.15
44.8
44.8
<5
<2.5
Buck
897A
6.3
<10
0.0041
<50
0.36
4140
9.6
<0.5
3640
7270
62.6
0.0064
49
49
<5
<2.5
Buck
B97B
6.5
<30
0.0036
<50
0.35
4160
9.7
<0.5
3650
6720
60.3
<0.005
46.6
46.6
<5
<2.5
Buck
B98
6.5
< 10
0.0025
< 50
1.5
2170
0.65
< 0.5
965
5920
43.9
0.276
27.6
27.6
< 5<
2.5
Buck
B99
4.6
<10
<0.001
<50
0.042
3330
8.7
<0.5
3050
5800
75.9
0.0282
59.4
59.4
<5
<2.5
16
Page 4 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
17
Page 5 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016
ISA NCAC 02L .020
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Buck
B10
<1
16.3
144.7
2
145.4
Buck
8100
<1
17.7
103
0.31
256.8
Buck
8101
<1
17.7
91.5
6.59
245.2
Buck
811
28.1
20.3
114
5.01
44.2
Buck
B12
<1
18
94
5.5
232.2
Buck
B13
<1
18.8
209.4
1.8
183.5
Buck
B14-630
3.5
17.1
63.7
3.4
285.1
Buck
B14-640
< 1
18.5
263.2
0.1
115.8
Buck
B15
<1
18.5
81.7
5.5
270
Buck
B16
<1
24.1
203.7
0.5
76.2
Buck
B17
< 1
19.3
190
6
235.1
Buck
B18
<1
17.7
122.3
3.8
310.5
Buck
B19
<1
18
189
6.84
255.7
Buck
B2
2
16.2
148
6.35
268.4
Buck
B21
< 1
19.1
105.3
5.6
202.1
Buck
B22
<1
16.4
85.1
4.8
26.9
Buck
B24
<1
16.6
82.7
5.2
218
Buck
B25
<1
16.5
78.5
6
225.8
Buck
B26
<1
17.8
192
7.4
194.8
Buck
B27
1.3
16.8
80.2
6.5
222
Buck
B28
<1
16.3
91.6
5.6
167.1
Buck
B29
<1
16.9
93.5
5.7
326.5
Buck
B3
33.8
16
134.5
0.4
131.7
Buck
B31
<1
16.2
140.4
5.5
269.1
Buck
B32
<1
16.8
142
2.3
204.1
Buck
B33
<1
21
129.1
3.4
226
Buck
B34
<1
19.7
116
6.59
195.3
Buck
B35
11.6
14
107
7.33
Buck
B37
<1
17.2
85.5
5.5
178
Buck
B38
< 1
23.6
145.9
5.2
231.6
Buck
B39
<1
16.8
79.4
6.6
160.9
Buck
B4
< 1
18.1
137.4
5.61
213.9
Buck
B40
<1
17.4
81
7.71
190
Buck
B41
<1
16.7
165.3
1.1
123
Buck
B42
<1
14.7
118
5.95
Buck
B43
<1
19.3
72.1
6.7
238.2
Buck
B44
<1
17.4
80.7
6.4
277.6
Buck
B48
0.3
17.3
172.3
5.7
198.5
Buck
B49
<1
16.9
79.3
6.2
93.5
Buck
B50
< 1
16.8
100.1
5.8
198.2
Buck
B51
1.2
14.5
50
7.7
170.2
Buck
B53
1
17.9
130
3.1
157
Buck
B54
<1
16.4
121
7.41
Buck
B55
1
17.6
178.4
7.71
198.9
Buck
B56
1.6
17
105.3
1
52.9
Buck
B57
<1
19
93.8
7.7
220
Buck
B58-2
2
14
298
6.41
160
Buck
B59
<1
17.2
161.9
5.2
304
Buck
B6
<1
17.6
140.3
7.6
312.3
Buck
B60
<1
20.7
103
5.84
210
17
Page 5 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table C2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
18
Page 6 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L .020
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Buck
B61
< 1
21.2
1770
6.16
711.2
Buck
B62
<1
15
77.6
5.7
155.6
Buck
B63
0.63
14.9
101.1
11
227
Buck
B64
< 1
20.2
64.7
6.3
217.7
Buck
B65
<1
16.9
207
0.3
<
Buck
B66-1
38.5
15.6
106
3.1
105.9
Buck
B66-2
121
16.1
90.4
5
135.8
Buck
B67
<1
16.2
119.3
6.4
205.8
Buck
B69
<1
16.9
119
5.6
197
Buck
B7
<1
16.7
185.3
4.1
196.2
Buck
B71
<1
17.9
48.9
8.73
215.9
Buck
B72
128
17.4
175.5
0.27
92.5
Buck
B73
<1
21.4
143
4.1
210.8
Buck
B74
<1
17
45.8
6.9
211.9
Buck
B75
<1
18
169.6
5.2
249.5
Buck
B76
<1
16
113.2
4.4
306.6
Buck
B77A
<1
17.9
233.2
0.19
14.8
Buck
B77B
<1
18.5
74.5
6.8
233.5
Buck
B78
<1
16.4
167.5
3.2
253.8
Buck
B79
<1
19.9
147.1
5.7
199.6
Buck
B81
<1
18
47.1
6.9
196.9
Buck
B82
<1
19.1
77.7
7.2
190.8
Buck
B83
<1
17.7
120.7
5.9
167.2
Buck
B84
<1
18.8
107.3
7.1
153.8
Buck
B85
<1
18.8
213.6
1.6
250.9
Buck
B86
< 1
17.8
87.1
6.1
193
Buck
B88
1.2
17.8
117.9
4.9
196.9
Buck
B89
<1
16.8
400.2
0.14
85
Buck
B90
25.9
18
88.3
5.2
172.1
Buck
B92A
<1
17.5
121.8
7
214.9
Buck
B92B
<1
18.3
61
7.9
206.3
Buck
B93
22.2
17.3
98.6
4.6
289.2
Buck
B94
<1
17.3
77.9
7.4
266.9
Buck
B95
<1
16.5
74.7
6.8
130.5
Buck
B96
<1
16.1
405.9
3.8
174.7
Buck
897A
<1
17.4
250.5
0.67
58.4
Buck
B97B
<1
18.3251.5
0.8
159.8
Buck
B98
<1
16.9
73.5
6.9
190.1
Buck
B99
<1
18.4
294.9
0.8
101.7
18
Page 6 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

19
Comparison of NCDEQ Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/9/2016

Table C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
20
Page 1 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016
15A NCAC d(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal M L(b):
(* denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Append x III f
Appendix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B10
< 5
11600
4.1
6.6
2.8
168
< 0.5
< 0.5
28.4
< 0.2
< 0.08
5.1
< 0.5
0.14
< 0.2
0.58
< 0.5
< 0.1
Buck
8100
< 5
10200
1.4
7.5
4.8
118
< 0.5
< 0.5
14.1
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
3.3
< 0.5
< 0.1
Buck
B101
< 5
5490
1.1
7.1
< 2
81
< 0.5
< 0.5
6.9
< 0.2
< 0.08
2.9
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B11
<5
7160
3.8
6.62
<2
102
<0.5
<0.5
8.53
<0.2
<0.08
<0.5
<0.5
0.7
<0.2
<0.5
<0.5
<0.1
Buck
B12
< 5
8560 1
2.3
6.1 1
< 1
93
< 0.5
< 0.5
23
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B13
5.8
21300
10.3
6.7
6.5
161
<0.5
<0.5
39.3
<0.2
<0.08
0.58
<0.5
0.17
<0.2
2.4
<0.5
<0.1
Buck
B14-630
<5
4700
2
6.2
<2
38
<0.5
<0.5
29.5
<0.2
<0.08
2.5
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Buck
B14-640
< 5
41300
3.2
7.7
6.4
164
< 0.5
< 0.5
5.5
< 0.2
< 0.08
< 0.5
< 0.5
0.11
< 0.2
2.6
< 0.5
< 0.1
Buck
B15
< 5
7040
2.8
6.3
2.2
84
< 0.5
< 0.5
14.8
< 0.2
< 0.08
< 0.5
< 0.5
0.56
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B16
10.4
12000
2.4
9.4
27.8
139
< 0.5
< 0.5
1.5
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
5.1
< 0.5
< 0.1
Buck
B17
<5
11100
13.5
6.35
<2
121
<0.5
<0.5
73.5
<0.2
1.4
0.55
<0.5
0.42
<0.2
1.2
<0.5
<0.1
Buck
B18
<5
10300
3.1
6.3
2.3
99
<0.5
<0.5
50.8
<0.2
<0.08
3.5
<0.5
0.55
<0.2
<0.5
<0.5
<0.1
Buck
B19
<5
12200
9.3
6.92
2.1
143
<0.5
<0.5
15.8
<0.2
<0.08
0.66
<0.5
0.92
<0.2
<0.5
<0.5
<0.1
Buck
B2
<5
19000
4.7
6.36
2.2
136
<0.5
2.2
22
<0.2
<0.08
0.75
0.25
0.52
<0.1
0.24
<0.5
<0.1
Buck
B21
18.4
8010
3.9
6.6
< 1
109
< 0.5
< 0.5
26
< 0.2
0.6
1.7
< 0.5
11
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B22
<5
7050
2
6.5
<2
96
<0.5
<0.5
13
<0.2
0.14
0.88
<0.5
0.5
<0.2
0.59
<0.5
<0.1
Buck
B24
< 5
6760
2.5
6.4
< 2
107
< 0.5
< 0.5
11.9
< 0.2
< 0.08
1
< 0.5
0.39
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B25
<5
6490
2
6.4
<2
109
<0.5
<0.5
12.9
<0.2
<0.08
1.5
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B26
<5
12600
8.8
6.07
<2
138
<0.5
<0.5
81.3
<0.2
<0.08
2.7
<0.5
3.3
<0.2
<0.5
<0.5
<0.1
Buck
B27
<5
6130
3.7
6
<2
29
<0.5
<0.5
11.2
<0.2
<0.08
0.52
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B28
< 5
9800
1.5
7.1
2.8
93
< 0.5
< 0.5
5.8
< 0.2
0.29
6.5
< 0.5
1.2
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B29
<5
8510
2
6.8
<2
60
<0.5
<0.5
9.5
<0.2
<0.08
7.4
<0.5
0.23
<0.2
0.69
<0.5
<0A
Buck
B3
< 5
10900
4.9
6.5
< 2
107
< 0.5
< 0.5
11.3
< 0.2
0.099
< 0.5
< 0.5
9
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B31
<5
12200
8
6.1
<2
98
<0.5
<0.5
22.3
<0.2
<0.08
<0.5
<0.5
0.29
<0.2
<0.5
<0.5
<0.1
Buck
B32
< 5
13700
2.1
6.9
2.7
112
< 0.5
< 0.5
9.4
< 0.2
< 0.08
< 0.5
< 0.5
0.17
< 0.2
1.3
< 0.5
< 0.1
Buck
B33
<5
13300
2
6.7
2.8
117
<0.5
<0.5
19
<0.2
<0.08
0.85
<0.5
0.82
<0.2
0.68
<0.5
<0.1
Buck
B34
<5
7280
4.28
6.2
2.1
87
<0.5
<0.5
13.4
<0.2
<0.08
0.63
<0.5
0.11
<0.2
<0.5
<0.5
<0.1
Buck
B35
<20
7210
5
6.24
7
81
<0.5
<0.08
11.1
<0.11
<0.06
2.53
<0.03
1.23
<0.01
0.17
<0.16
<0.06
Buck
B37
<5
5730
1.4
6.6
2.1
89
<0.5
<0.5
26.6
<0.2
<0.8
2.7
<0.5
0.49
<0.2
0.51
<0.5
<0.1
Buck
B38
<5
13000
11.1
5.4
<2
131
<0.5
<0.5
45
<0.2
<0.08
<0.5
<0.5
0.89
<0.2
<0.5
<0.5
<0.1
Buck
B39
< 5
6150
2.3
6.8
< 2
100
< 0.5
< 0.5
16.7
< 0.2
< 0.08
17.1
< 0.5
0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B4
<5
10500
7.6
6.3
2.3
95
<0.5
<0.5
20.7
<0.2
<0.08
0.56
<0.5
0.69
<0.2
<0.5
<0.5
<0.1
Buck
B40
<5
7500
3.1
6.3
<1
118
<0.5
<0.5
25.7
<0.2
<0.08
1.5
0.33
0.19
<0.1
<0.5
<0.5
<0.1
Buck
B41
< 5
21100
2.1
8.1
2.9
127
< 0.5
< 0.5
4.9
< 0.2
< 0.08
0.58
< 0.5
< 0.1
< 0.2
2.5
< 0.5
< 0.1
Buck
B42
<100
7520
5.22
6.16
<10
71
<3
<10
10.3
<1
<1
<10
<5
36.5
<0.2
<10
<10
<1
Buck
B43
< 5
4950
4
5.2
< 2
63
< 0.5
< 0.5
18.4
< 0.2
< 0.08
2.1
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B44
< 5
6340
1.8
6.5
< 2
70
< 0.5
< 0.5
10.6
< 0.2
0.8
2
< 0.5
1.1
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B48
< 5
15900
5.9
6.7
< 1
135
0.031
< 0.5
11.4
< 0.2
< 0.08
11.5
< 0.5
0.12
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B49
< 5
6060
2.7
1 6.2 1
2.3
60
< 0.5
< 0.5
15.1
< 0.2
< 0.08
< 0.5
< 0.5
3.1
< 0.2
< 0.5
< 0.5
0.15
Buck
B50
< 5
8500
4.9
6.2
2.1
96
< 0.5
< 0.5
9.4
< 0.2
< 0.08
1.2
< 0.5
0.27
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B51
<5
3320
1.7
6.5
<2
127
<0.5
<0.5
8.2
<0.2
<0.08
1.1
<0.5
0.49
<0.2
1.3
<0.5
<0.1
Buck
B53
38
18000
3.2
6.1
2.9
130
0.057
<1
15
<1
0.15
<10
<1
0.23
<0.2
1.1
<1
<1
Buck
B54
25
7760
4.9
5.69
<5
116
0.5
<0.08
30.2
<0.11
<0.06
4.84
<0.03
0.34
<0.2
0.86
<0.16
<0.06
Buck
B55
<5
23000
7.3
6.6
3.2
95
<0.5
<0.5
27
<0.2
<0.08
2.2
0.33
0.71
<0.1
2.7
<0.5
<0.1
Buck
B56
<5
6610
1.9
6.9
4.8
70
<0.5
<0.5
84.7
<0.2
<0.08
<0.5
<0.5
2
<0.2
0.59
<0.5
<0.1
Buck
B57
<5
8400
5.3
6.2
0.46
78
<0.5
<0.5
7.3
<0.2
<0.08
0.82
<0.5
3.7
0.017
<0.5
<0.5
<0.1
Buck
B58-2
2863000
6.2
7.4
22
230
0.21
1.7
41
< 2
0.44
< 25
1.4
8.4
0.047
0.064
< 5
< 0.5
Buck
859
<5
14400
3.1
7
2.3
144
<0.5
<0.5
4.9
<0.2
<0.08
21.8
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B6
< 5
8980
5.7
6.4
2.4
132
< 0.5
< 0.5
5.3
< 0.2
< 0.08
< 0.5
< 0.5
0.59
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B60
<5
11000
2.1
6.6 1
2.3
1 98
<0.5
1.8
47
<0.2
0.12
1.3
<0.5
1.5
1 0.034
1
<0.5
<0.1
20
Page 1 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
21
Page 2 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
d(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal M L(b):
(' denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Append x III f
Appendix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Buck
B61
13.2
246000
20.5
7.75
711
1220
1.87
< 0.5
3.9
< 0.2
< 0.08
0.89
< 0.5
0.21
< 0.2
2
< 0.5
< 0.1
Buck
B62
<5
5770
2.3
6.6
2.3
59
<0.5
<0.5
12.6
<0.2
<0.08
<0.5
<0.5
0.74
<0.2
<0.5
<0.5
<0.1
Buck
B63
<5
7200
6.1
6.7
<1
110
0.053
<0.5
11.9
<0.2
0.26
10.2
<0.5
3.1
<0.2
0.11
<0.5
<0.1
Buck
B64
7.7
5370
1.6
6.6
<2
46
<0.5
<0.5
5.5
<0.2
0.43
1 1.1
<0.5
0.26
<0.2
<0.5
<0.5
<0.1
Buck
B65
<5
26100 1
5.2
7.9 1
4.4
191
<0.5
<0.5
5.6
<0.2
<0.08
<0.5
<0.5
0.14
<0.2
5
<0.5
<0.1
Buck
B66-1
<5
9770
4.8
6.4
<2
113
<0.5
<0.5
12.2
<0.2
<0.08
1.9
<0.5
0.82
<0.2
<0.5
<0.5
<0.1
Buck
B66-2
< 5
5770
4.6
6
< 2
120
< 0.5
< 0.5
16.4
< 0.2
< 0.08
1.6
< 0.5
3.8
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B67
<5
10400
3.2
6.2
2.5
90
<0.5
<0.5
58.5
<0.2
<0.08
<0.5
<0.5
0.25
<0.2
0.6
<0.5
<0.1
Buck
B69
<5
8520
8
6.6
<2
74
<0.5
<0.5
22.5
<0.2
<0.08
16.3
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B7
< 5
16500
8.4
6.4
2.9
148
< 0.5
< 0.5
32.3
< 0.2
< 0.08
5.7
< 0.5
0.68
< 0.2
0.67
< 0.5
< 0.1
Buck
B71
< 5
2860
1.5
6.3
< 2
74
< 0.5
< 0.5
12.2
< 0.2
< 0.08
< 0.5
< 0.5
1.7
< 0.2
2.6
< 0.5
< 0.1
Buck
B72
<5
8160
4.2
6.3
<2
92
<0.5
<0.5
15.8
<0.2
<0.08
1.2
0.57
6.1
<0.2
<0.5
<0.5
<0.1
Buck
B73
<5
14700
2.2
7.2
5.7
125
<0.5
<0.5
12.5
<0.2
<0.08
0.81
<0.5
0.51
<0.2
0.96
<0.5
<0.1
Buck
B74
< 5
3120
1.3
6.4
< 2
66
< 0.5
< 0.5
5.8
< 0.2
< 0.08
1.1
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B75
<5
15500
3.5
7
<2
113
<0.5
<0.5
5
<0.2
<0.08
22.1
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B76
<5
8400
2.4
7.3
2.8
71
<0.5
<0.5
12.5
<0.2
<0.08
9.7
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Buck
B77A
<5
31500
2.2
7.9
6.8
152
<0.5
<0.5
25.4
<0.2
<0.08
<0.5
<0.5
0.18
<0.2
3.3
<0.5
<0.1
Buck
B77B
<5
5620
2.2
6
<2
83
<0.5
<0.5
23.7
<0.2
<0.08
1.4
<0.5
1.6
<0.2
<0.5
<0.5
<0.1
Buck
B78
<5
12900
16.9
6.1
2.2
171
<0.5
<0.5
41.4
<0.2
<0.08
1.1
<0.5
0.32
<0.2
0.51
<0.5
<0.1
Buck
B79
<5
9510
3.5
6.5
2.5
129
<0.5
<0.5
37.8
<0.2
<0.08
<0.5
<0.5
1.4
<0.2
0.78
<0.5
<0.1
Buck
B81
< 5
3030
1.2
6.1
2.4
34
< 0.5
< 0.5
9.1
< 0.2
< 0.08
1.5
< 0.5
0.56
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B82
<5
5770
<1
6.2
<2
78
<0.5
<0.5
16.7
<0.2
<0.08
0.92
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Buck
B83
<5
9310
4.8
6.3
2.2
89
<0.5
<0.5
14.5
<0.2
0.14
0.94
<0.5
0.6
<0.2
<0.5
<0.5
<0.1
Buck
B84
< 5
9910
3.9
5.7
< 2
97
< 0.5
< 0.5
11.2
< 0.2
< 0.08
2.1
< 0.5
0.29
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B85
< 5
19900
12.7
6.5
< 2
148
< 0.5
< 0.5
6.1
< 0.2
< 0.08
9.2
< 0.5
0.44
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B86
< 5
6560
2.8
6.2
< 2
< 25
< 0.5
< 0.5
22.7
< 0.2
< 0.08
3.7
< 0.5
0.29
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B88
<5
9310
9.3
6.1
2
98
<0.5
<0.5
32.3
<0.2
<0.08
0.84
<0.5
0.35
<0.2
<0.5
<0.5
<0.1
Buck
B89
<5
30700
4.1
7.3
4.7
145
<0.5 1
0.9
11.1
<0.2
<0.08
<0.5
<0.5
0.36
<0.2
3.2
2.9
<0.1
Buck
B90
<5
5700
3.1
6.3
<2
118
<0.5
0.81
16
<0.2
<0.08
0.87
<0.5
2
<0.2
<0.5
<0.5
<0.1
Buck
892A
<5
4940
1.3
6.2
<2
73
<0.5
<0.5
7.3
<0.2
<0.08
1.8
<0.5
<0.1
<0.2
0.52
<0.5
<0.1
Buck
B92B
< 5
4640
1.3
5.8
< 2
67
< 0.5
< 0.5
7.3
< 0.2
< 0.08
1.8
< 0.5
0.14
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B93
<5
8050
5.3
6
<2
59
<0.5
<0.5
17.7
<0.2
<0.08
3.1
<0.5
0.87
<0.2
<0.5
<0.5
<0.1
Buck
B94
<5
6420
1.9
6.2
<2
48
<0.5
<0.5
14.1
<0.2
<0.08
1.1
<0.5
0.56
<0.2
<0.5
<0.5
<0.1
Buck
B95
< 5
5220
1.2
6.8
< 2
69
< 0.5
< 0.5
4.5
< 0.2
< 0.08
2.6
< 0.5
1.9
< 0.2
< 0.5
< 0.5
< 0.1
Buck
B96
<5
21500
1.9
7.5
33.3
255
<0.5
<0.5
15.4
<0.2
<0.08
1.3
<0.5
0.38
<0.2
2.2
<0.5
<0.1
Buck
697A
<5
13900
2.1
6.6
5.1
105
<0.5
<0.5
17.1
<0.2
<0.08
<0.5
<0.5
0.41
<0.2
1.7
0.63
<0.1
Buck
B97B
< 5
13500
2.2
6.2
5
105
< 0.5
< 0.5
17
< 0.2
< O 1
< 0.5
< 0.5
< 0.1
< 0.2
1.6
0.62
< 0.1
Buck
B98
< 5
6510
1.4
6
< 2
79
< 0.5
< 0.5
6.8
< 0.2
< 0.08
1.6
< 0.5
0.79
< 0.2
< 0.5
< 0.5
< 0.1
Buck
899
< 5
20700
2.1
7.3
5.9
108
< 0.5
< 0.5
10.4
< 0.2
< 0.08
< 0.5
< 0.5
0.49
< 0.2
2.8
< 0.5
< 0.1
21
Page 2 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
22
Page 3 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016
15A NCA02L.0202
Groundwater Standard ((aa):
)
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(* denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the
CCR Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Buck
B10
2.8
<10
0.0027
<50
3.6
6690
<0.5
<0.5
1530
7520
86.6
0.0179
95.8
89.9
6
<2.5
Buck
8100
2.9
< 10
0.0011
< 50
0.064
3630
1.2
< 0.5
2710
4430
43.9
< 0.005
41
41
< 5
< 2.5
Buck
B101
22.4
< 10
0.0017
< 50
2.7
2000
< 0.5
< 0.5
722
4600
45
0.285
21.9
21.9
<5
< 2.5
Buck
I 811
1.8
< 10
0.007
4600
< 0.6
3530
28.9
< 0.5
951
5850
77.2
0.0662
38.5
38.5
< 1
8.3
Buck
B12
2
< 10
0.0162
< 50
0.065
1 3430
9 1
< 0.5
1270
6600
110
0.0173
43
43 1
<0
< 1
Buck
B13
2.5
34.8
0.0021
65
0.041
5140
3.6
0.83
3180
17100
202
0.01
88
88
<5
2.8
Buck
B14-630
1.5
30.2
0.013
454
1.8
2320
35.7
<0.5
1150
3790
43.1
0.0588
21.8
21.8
<5
<5
Buck
B14-640
2.7
22.7
0.0016
<50
0.034
5580
20
<0.5
2790
8330
123
0.258
107
107
<5
<2.5
Buck
B15
3
< 10
0.009
< 50
0.076
3140
< 0.5
< 0.5
1090
5530
74
0.007
30.8
30.8
< 0
< 1
Buck
B16
4
46.7
<0.001
<50
0.081
3700
6
<0.5
1300
27000
67
1.37
65.5
57.4
42.6
<1
Buck
B17
1
< 10
0.0205
98.3
0.27
3130
11.7
2
1650
12500
101
0.62
28.5
28.5
< 1
<5
Buck
B18
6.6
49.1
0.0041
94.8
2.5
4340
2.3
<0.5
1620
7000
120
0.0076
42.6
42.6
<5
<2.5
Buck
B19
4.7
24.6
0.0077
<50
<0.6
5460
1.1
<0.5
1270
7890
108
0.293
46.4
46.4
<1
<2.5
Buck
B2
14
9.3 1
0.006
1200
<0.6
1 7800
22
2.7
2800
10000
110
0.596
57
57
<5
0.8
Buck
B21
4.7
< 10
0.007
< 50
1.6
2670
1.9 1
0.59
1700
8740
85
0.175
36.9
36.9
<0
< 1
Buck
B22
8.8
< 10
0.0072
< 50
0.68
2690
1.3
< 0.5
1200
6490
63.6
0.159
31
31
<S
< 2.5
Buck
B24
4.3
< 10
0.0147
< 50
0.74
2990
4.1
< 0.5
1150
5510
64.4
0.0274
27.7
27.7
<5
< 2.5
Buck
B25
6.6
< 10
0.0087
< 50
1.1
2890
0.63
< 0.5
1020
5280
69.2
0.0512
29
29
<S
<S
Buck
B26
2.4
< 10
0.137
< 50
0.99
3310
2.4
1.2
2770
11100
153
0.0869
35.9
35.9
< 1
< 2.5
Buck
B27
2
<10
0.0136
158
0.093
2570
2.3
<0.5
966
4390
63.6
0.0289
22.8
22.8
<5
<2.5
Buck
B28
14.4
25.4
< 0.001
< 50
6.5
4000
0.52
< 0.5
1160
4130
55.5
0.414
37.7
37.7
< 5
< 2.5
Buck
B29
11.5
<10
0.006
<50
4.8
4090
<0.5
0.58
894
3830
53
<0.005
35.4
35.4
<5
<2.5
Buck
B3
2.8
< 10
0.0288
5720
1 0.038
5460
80.5
0.79
1 989
6900
124
0.243
42.2
42.2 1
<5
<5
Buck
B31
2.8
< 10
0.0211
96.9
0.093
5300
2.8
< 0.5
1400
6840
135
0.0279
35.7
35.7
< 5
< 5
Buck
B32
5.9
< 10
0.0035
< 50
0.11
4850
1.6
0.67
2330
6770
88.6
0.0126
62.8
62.8
<5
< 2.5
Buck
B33
11
< 10
0.0061
< 50
0.7
4170
0.91
< 0.5
2040
8200
89
< 0.005
57.4
57.4
<0
< 1
Buck
B34
2.5
< 10
0.00794
< 50
0.33
3160
< 0.5
< 0.5
1370
5490
62
< 0.005
28.5
28.5
< 1
< 2.5
Buck
B35
5.1
24.2
0.00656
1420
2.53
3050
0.83
0.27
1100
5250
67
0.0173
30
3
Buck
B37
6.7
< 10
0.0015
< 50
2.5
3760
< 0.5
0.52
1560
4690
54.5
< 0.005
31.2
31.2
<5
< 2.5
Buck
B38
2.2
< 10
0.149
< 50
0.052
5160
2.5
< 0.5
1730
7010
139
0.118
29.3
29.3
< 5
< 2.5
Buck
B39
6.1
< 10
0.0016
< 50
16.4
3430
0.98
1
669
3950
48.6
0.212
24.6
24.6
<5
< 2.5
Buck
64
1.7
< 10
0.0026
< 50
< 0.03
3980
7.4
< 0.5
1420
6360
97.1
2.09
38.2
38.2 1
<S
< 2.5
Buck
B40
12
< 10
0.024
360
1.2
2010
28
1.5
1700
9700
83
0.093
25.1
25.1
<5
< 1
Buck
B41
3.9
< 10
0.0013
< 50
0.29
3490
< 0.5
< 0.5
1890
8250
72.8
0.0073
67.7
67.7
< 5
< 2.5
Buck
B42
3.02
< 50
0.12
210
<20
3310
< 10
<10
989
5260
65.7
0.399
30.6
30.6
< 1
<5
Buck
B43
2.3
<10
0.0063
135
1.8
1930
4.5
0.74
746
6660
47.1
0.0131
18.8
18.8
<5
<2.5
Buck
B44
10.7
< 10
0.019
50
1.7
3000
1.9
< 0.5
840
6070
60.1
0.163
34.4
34.4
<5
< 2.5
Buck
B48
15.6
< 10
0.0065
< 50
12.4
9020
0.99
0.2
890
6490
103
0.025
73
73
< 5
< 3.1
Buck
B49
3.2
< 10
0.111
< 50
0.058
2580
0.73 1
< 0.5
1040
6060
60
0.019
38.4
38.4
<5
< 2.5
Buck
B50
2.5
<10
0.0237
84.7
0.9
3770
2
0.88
1110
5980
77.6
0.0182
32
32
<S
<2.5
Buck
B51
5
< 10
0.0026
< 50
0.74
916
1.4
< 0.5
789
5330
42.9
0.0068
16.8
16.8
<5
< 2.5
Buck
B53
5.9
13
0.0025
68
< 10
6500
1.6
<2
2800
6400
69
0.027
82
82
<S
< 3.1
Buck
B54
25.6
<10
0.00791
15.7
4.8
2970
0.49
0.31
1610
6700
81
0.0102
43
<2.5
Buck
B55
14
120
0.19
1100
2.2
5900
19
4.4
2300
6900
100
0.049
62.9
62.9
<5
1.6
Buck
B56
< 1
< 10
< 0.001
170
< 0.03
3490
29.6
< 0.5
4180
6320
49.5
1.18
39
39
<5
< 2.5
Buck
B57
15
< 10
0.06
430
0.64
2600
15
2
1200
10000
89.3
0.077
27
27
<5
< 1
Buck
B58-2
12
71
0.008
2900
< 20
9300
23
6.6
1200
8600
160
0.54
160
150
< 10
3.2
Buck
859
14.3
13.7
0.0011
< 50
22.3
8910
< 0.5
< 0.5
739
4590
94.1
0.0246
69.2
69.2
<S
< 2.5
Buck
B6
2.1
< 10
0.0303
< 50
0.045
1930
1.5
< 0.5
5380
16300
53.4
0.0139
44.3
44.3
<5
Buck
B60
15
12.7
0.0086
490
1 0.75
1 6300
11
<0.5
1 1700
9900
63
0.028
45
45
<5
<1
22
Page 3 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
23
Page 4 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(* denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bici
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
Buck
B61
2.5
< 10
< 0.001
186
0.13
38200
272
< 0.5
2110
293000
947
0.104
114
< 1
< 2.5
Buck
B62
4.6
< 10
0.0472
< 50
0.065
2850
2.9
< 0.5
1090
5390
55.5
0.488
26.6
<5
< 2.5
Buck
B63
7.2
< 10
0.0268
< 50
10.4
4470
1.5
2.5
775
7470
68
0.047
35
<5
< 2.5
Buck
I B64
5.7
< 10
0.0054
< 50
0.81
2420
7
< 0.5
786
4500
48.5
0.581
27.4
27.4
<5
1 < 2.5
Buck
B65
< 1
< 30
< 0.001
< 50
< 0.03
4940
1 18.9
< 0.5
1 2920
8590
124
1 0.106
82.5
82.5
<5
< 2.5
Buck
B66-1
2.6
18.1
0.0232
2700
1
4200
18
0.58
1520
5050
73.5
0.193
40.8
40.8
<5
5.6
Buck
B66-2
1.4
< 10
0.0724
5330
0.081
2870
20.5
1.2
1400
5340
59.1
0.28
20.4
20.4
<5
22.6
Buck
B67
3.4
< 10
0.0063
< 50
0.082
2310
1.4
< 0.5
2600
8520
94.9
0.0302
29.7
29.7
< 5
< 2.5
Buck
B69
8.5
< 10
0.0011
< 50
10.6
6900
1.6
3
681
4410
70
0.0161
31.6
31.6
<5
< 2.5
Buck
B7
8.1
< 10
0.0077
< 50
4.6
7120
< 0.5
0.58
2340
9300
131
0.0187
59.5
59.5
<5
< 2.5
Buck
B71
1.2
<10
0.0021
<50
<0.3
656
<0.5
<0.5
898
6140
44.4
0.0328
17
17
<5
<2.5
Buck
B72
1.4
< 10
0.0123
18200
< 0.03
3440
128
0.71
1220
4550
68
1.41
42.2
42.2
< 5
26.2
Buck
B73
8.4
13.4
0.005
< 50
0.24
3690
11.2
< 0.5
2110
7220
66.9
1.54
53
53 1
<5
< 2.5
Buck
B74
5.5
< 10
0.0073
< 50
1.1
1450
1.2
< 0.5
980
4120
29.5
0.0157
16.5
16.5
< 5
< 25
Buck
B75
14.1
<10
0.0021
< 50
21.2
9590
< 0.5
< 0.5
751
4900
94.4
0.0235
74.9
74.9
<5
< 2.5
Buck
B76
13.3
< 10
< 0.001
<50
6.3
5620
< 0.5
0.97
1070
5150
50.6
< 0.005
41.7
41.7
<5
< 2.5
Buck
B77A
< 1
< 10
< 0.001
< 50
< 0.03
5740
10.7
< 0.5
3230
8820
119
0.0476
106
106
<5
< 2.5
Buck
B77B
3.3
< 10
0.0453
<50
1.2
2140
0.88
< 0.5
929
6520
76.4
0.0306
26.8
26.8
< 5
< 2.5
Buck
B78
3.2
< 10
0.0051
< 50
0.31
6400
2
1.3
1770
8080
108
0.633
39.3
39.3
<5
< 2.5
Buck
B79
4
14.7
0.0043
< 50
0.054
5110
5.9
< 0.5
1910
8550
116
< 0.005
28.5
28.5
<5
< 2.5
Buck
B81
3.4
< 10
0.0148
< 50
0.85
1400
0.77
< 0.5
757 1
3750
32.1
< 0.005
14.1
14.1
<5
< 2.5
Buck
B82
5.5
23.9
0.0019
< 50
0.73
2850
3.5
< 0.5
1680
5520
44.6
0.642
30.4
30.4
< 5
5.5
Buck
B83
3.6
<10
0.024
112
0.65
4520
4
<0.5
1440
6910
86.3
0.176
33.6
33.6
<5
<2.5
Buck
B84
10.1
< 10
< 0.001
< 50
1.9
4040
< 0.5
< 0.5
1070
6530
84.7
< 0.005
39.1
39.1
< 5
< 2.5
Buck
B85
11.2
< 10
0.0055
< 50
7.3
12600
2.6
< 0.5
656
5230
116
0.0271
64.4
64.4
<5
<5
Buck
B86
4.7
< 10
0.0123
< 50
2.9
2800
0.96
< 0.5
835
7190
143
0.0302
29.3
29.3
<5
< 2.5
Buck
B88
3
< 10
0.0121
134
0.49
4850
1.5
0.58
1770
6500
98.2
0.0143
24.2
24.2
<5
< 2.5
Buck
B89
3.1
< 10
< 0.001
< 50
1.7
4400
40.3
< 0.5
3510
7960
151
0.0108
85.6
85.6
< 5
< 2.5
Buck
B90
3.5
<10
0.0219
1720
0.086
2770
4.8
<0.5
1070
4460
58.3
2.34
34.4
34.4
<5
<2.5
Buck
B92A
11.5
< 10
< 0.001
< 50
0.35
1920
2.4
< 0.5
895
5180
38.3
1.08
21.6
21.6
< 5
< 2.5
Buck
B92B
10.8
< 10
0.002
< 50
1.7
1780
2
< 0.5
838
4960
36.5
0.822
22.6
22.6
<5
< 2.5
Buck
B93
3.4
< 10
0.0106
3050
0.55
4120
43.5
1.7
705
5680
66.2
0.0663
31.6
31.6
< 5
5.1
Buck
B94
3
< 10
0.024
< 50
0.82
2850
3.2
0.51
1370
5390
56.8
0.0125
30.6
30.6
<5
< 2.5
Buck
B95
9.2
< 10
< 0.001
< 50
2.2
3070
< 0.5
0.96
848
4320
42.6
0.228
26.7
26.7
< 5
< 2.5
Buck
B96
11.4
117
0.0013
240
0.5
3580
4.8
<0.5
3050
6590
109
0.15
44.8
44.8
<5
<2.5
Buck
697A
6.3
< 10
0.0041
< 50
0.36
4140
9.6
< 0.5
3640
7270
62.6
0.0064
49
49
<5
< 2.5
Buck
B97B
6.5
< 10
0.0036
< 50
0.35
4160
9.7
< 0.5
3650
6720
60.3
< 0.005
46.6
46.6
<5
< 2.5
Buck
698
6.5
< 10
0.0025
< 50
1.5
2170
0.65
< 0.5
965
5920
43.9
0.276
27.6
27.6
<5
< 2.5
Buck
B99
4.6
<10
<0.001
<50
0.042
3330
8.7
<0.5
3050
5800
75.9
0.0282
1 59.4
1 59.4
<5
<2.5
23
Page 4 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
24
Page 5 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L .020
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Buck
B10
<1
16.3
144.7
2
145.4
Buck
8100
<1
17.7
103
0.31
256.8
Buck
B101
<1
17.7
91.5
6.59
245.2
Buck
B11
28.1
20.3
114
5.01
44.2
Buck
B12
<1
18
94
5.5
232.2
Buck
B13
<1
18.8
209.4
1.8
183.5
Buck
B14-630
3.5
17.1
63.7
3.4
285.1
Buck
B14-640
< 1
18.5
263.2
0.1
115.8
Buck
B15
<1
18.5
81.7
5.5
270
Buck
B16
< 1
24.1
203.7
0.5
76.2
Buck
B17
<1
19.3
190
6
235.1
Buck
B18
<1
17.7
122.3
3.8
310.5
Buck
B19
<1
18
189
6.84
255.7
Buck
B2
2
16.2
148
6.35
268.4
Buck
B21
<1
19.1
105.3
5.6
202.1
Buck
B22
< 1
16.4
85.1
4.8
26.9
Buck
B24
<1
16.6
82.7
5.2
218
Buck
B25
<1
16.5
78.5
6
225.8
Buck
B26
< 1
17.8
192
7.4
194.8
Buck
B27
1.3
16.8
80.2
6.5
222
Buck
B28
< 1
16.3
91.6
5.6
167.1
Buck
B29
<1
16.9
93.5
5.7
326.5
Buck
B3
33.8
16
134.5
0.4
131.7
Buck
B31
< 1
16.2
140.4
5.5
269.1
Buck
B32
<1
16.8
142
2.3
204.1
Buck
B33
<1
21
129.1
3.4
226
Buck
B34
<1
19.7
116
6.59
195.3
Buck
B35
11.6
14
107
7.33
Buck
B37
< 1
17.2
85.5
5.5
178
Buck
B38
< 1
23.6
145.9
5.2
231.6
Buck
B39
<1
16.8
79.4
6.6
160.9
Buck
64
< 1
18.1
137.4
5.61
213.9
Buck
B40
< 1
17.4
81
7.71
190
Buck
B41
<1
16.7
165.3
1.1
123
Buck
B42
<1
14.7
118
1 5.95
Buck
B43
<1
19.3
72.1
6.7
238.2
Buck
B44
<1
17.4
80.7
6.4
277.6
Buck
B48
0.3
17.3
172.3
5.7
198.5
Buck
B49
<1
16.9
79.3
6.2
93.5
Buck
B50
< 1
16.8
100.1
5.8
198.2
Buck
B51
1.2
14.5
50
7.7
170.2
Buck
B53
1
17.9
130
3.1
157
Buck
B54
<1
16.4
121
7.41
Buck
B55
1
17.6
178.4
7.71
198.9
Buck
B56
1.6
17
105.3
1
52.9
Buck
B57
< 1
19
93.8
7.7
220
Buck
B58-2
2
14
298
6.41
160
Buck
B59
< 1
17.2
161.9
5.2
304
Buck
B6
<1
17.6
140.3
7.6
312.3
Buck
B60
<1
20.7
103
5.84
210
24
Page 5 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table C2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
25
Page 6 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L .020
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 201S (d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Buck
B61
< 1
21.2
1770
6.16
711.2
Buck
B62
< 1
15
77.6
5.7
155.6
Buck
B63
0.63
14.9
101.1
11
227
Buck
B64
< 1
20.2
64.7
6.3
217.7
Buck
B65
<1
16.9
207
0.3
<
Buck
B66-1
38.5
15.6
106
3.1
105.9
Buck
B66-2
121
16.1
90.4
5
135.8
Buck
B67
< 1
16.2
119.3
6.4
205.8
Buck
B69
< 1
16.9
119
5.6
197
Buck
B7
< 1
16.7
185.3
4.1
196.2
Buck
B71
<1
17.9
48.9
8.73
215.9
Buck
B72
128
17.4
175.5
0.27
92.5
Buck
B73
<1
21.4
143
4.1
210.8
Buck
B74
< 1
17
45.8
6.9
211.9
Buck
B75
< 1
18
169.6
5.2
249.5
Buck
B76
< 1
16
113.2
4.4
306.6
Buck
B77A
< 1
17.9
233.2
1 0.19
14.8
Buck
B77B
<1
18.5
74.5
6.8
233.5
Buck
B78
< 1
16.4
167.5
3.2
253.8
Buck
B79
< 1
19.9
147.1
5.7
199.6
Buck
B81
<1
18
47.1
6.9
196.9
Buck
B82
< 1
19.1
77.7
7.2
190.8
Buck
B83
< 1
17.7
120.7
5.9
167.2
Buck
B84
< 1
18.8
107.3
7.1
153.8
Buck
B85
< 1
18.8
213.6
1.6
250.9
Buck
B86
< 1
17.8
87.1
6.1
193
Buck
B88
1.2
17.8
117.9
4.9
196.9
Buck
B89
<1
16.8
400.2
0.14
85
Buck
B90
25.9
18
88.3
5.2
172.1
Buck
B92A
< 1
17.5
121.8
7
214.9
Buck
B92B
<1
18.3
61
7.9
206.3
Buck
B93
22.2
17.3
98.6
4.6
289.2
Buck
B94
< 1
17.3
77.9
7.4
266.9
Buck
B95
<1
16.5
74.7
6.8
130.5
Buck
B96
< 1
16.1
405.9
3.8
174.7
Buck
B97A
<1
17.4
250.5
0.67
58.4
Buck
B97B
<1
18.3
251.5
0.8
159.8
Buck
698
<1
16.9
73.5
6.9
190.1
Buck
B99
<1
18.4
294.9
0.8
101.7
25
Page 6 of 6
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

26
Comparison of NCDEQ Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is a hove the Breen ing level.
_Reporting limit isabove the screening level.
Haley & Aldrich, Inc.
Tables C2 -1-C2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/9/2016

Table C2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to 21. Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
27
Page 1 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
Groundwater Standard a
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL(b):
* denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedAntimony
Solids
mg/L
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1 NCDEQ
<5
54200
38
6.74
27.7
351
<0.5
<0.5
20.5
<0.2
<0.08
<0.5
<0.5
<0.1
Buck
BBKG-2 NCDEQ
5.3
59900
12.8
7.19
31.5
317
<0.5
<0.5
15.6
<0.2
<0.08
<0.5
<0.5
3.2
Buck
BBKG-3 NCDEQ
<5
19700
5
7.07
2.8
171
<0.5
<0.5
6.9
<0.2
<0.08
1.2
<0.5
<0.1
Buck
BBKG-5 NCDEQ
<5
31400
23.2 1
6.61
4.5
172
<0.5
<0.5
9.4
<0.2
<0.08
1.8
<0.5
<0.1
Buck
BBKG-7 NCDEQ
<5
31400
10.5
6.69
15
165
<0.5
<0.5
4.7
<0.2
<0.08
<0.5
<0.5
0.2
Buck
BBKG-8 NCDEQ
<5
10800
7.1
6.48
5.4
85
<0.5
<0.5
0.89
<0.2
<0.08
1.6
<0.5
0.38
Buck
BBKG-14 NCDEQ
6
19800
4.3
6.23
6.9
98
<0.5
<0.5
0.9
<0.2
<0.08
0.53
<0.5
0.12
Buck
DBKG-Bl Duke
<50
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B2 Duke
<5
16400
1.2
<0.5
37.2
<0.2
<0.08
2.9
<0.5
<0.1
Buck
DBKG-B3 Duke
<50
3850
<1
<1
74
<1
<1
<5
<1
<1
Buck
DBKG-B4 Duke
<5
13100
0.88
<0.5
7.3
<0.2
0.081
2.3
<0.5
3.9
Buck
DBKG-B5 Duke
<5
4460
0.94
<0.5
46.4
<0.2
<0.08
<0.5
<0.5
1.4
Buck
DBKG-B6 Duke
<5
10400
0.98
<0.5
2
<0.2
<0.08
0.97
<0.5
0.83
Buck
DBKG-B7 Duke
<5
7500
0.93
<0.5
33
<0.2
<0.08
<0.5
<0.5
0.85
Buck
DBKG-B8 Duke
5.5
6070
0.88
<0.5
2.2
<0.2
0.19
<0.5
<0.5
0.93
Buck
DBKG-B9 Duke
<5
8360
0.97
<0.5
4.7
<0.2
<0.08
0.52
<0.5
0.12
Buck
DBKG-B10 Duke
<5
16000
<0.5
<0.5
9.9
<0.2
<0.08
2.1
<0.5
0.4
Buck
DBKG-B11 Duke
<5
6800
0.96
<0.5
2.5
<0.2
<0.08
<0.5
<0.5
1.2
Buck
DBKG-B12 Duke
<50
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B13 Duke
<50
33600
<1
<1
7
<1
<1
<5
<1
<1
Buck
DBKG-B14 Duke
<50
52700
1.21
<1
<5
<1
<1
<5
<1
<1
Buck
DBKG-B15 Duke
<5
6280
0.97
<0.5
48.9
<0.2
<0.08
<0.5
<0.5
0.52
Buck
DBKG-B16 Duke
<5
9910
3.6
6.67
0.26
110
0.58
<0.5
38.6
<0.2
<0.08
2.5
<0.5
0.49
Buck
DBKG-B17 Duke
<50
12100
2.8
6.56
0.45
<1
<1
19
<1
<1
<5
<1
<1
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016

Table C2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to 21. Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
28
Page 2 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
Groundwater Standard a
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
* denotes
Federal MCL/SMCL (b):
secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
1L
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Magnesium
Hexavalent
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1
NCDEQ
<0.2
<0.5
0.52
<0.1
4.6
<10
0.001
<50
<0.6
23800
0.73
<0.5
3000
23000
Buck
BBKG-2
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0073
64.2
<0.6
15600
13.4
<0.5
1740
20400
Buck
BBKG-3
NCDEQ
<0.2
<0.5
<0.5
<0.1
9
<10
<0.001
<50
1.0 M1
8150
<0.5
0.9
1040
7060
Buck
BBKG-S
NCDEQ
<0.2
<0.5
<0.5
<0.1
12.4
<10
0.0014
<50 1
1.5
12100
<0.5
<0.5
1140 1
9880
Buck
BBKG-7
NCDEQ
<0.2
<0.5
<0.5
<0.1
15.6
12.1
0.0028
<50
0.22
11300
<0.5
<0.5
997
8410
Buck
BBKG-8
NCDEQ
<0.2
<O.5
<O.5
<0.1
7.9
<10
0.0021
<50
1.5
6970
<0.S
<0.S
26S
6770
Buck
BBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
S
213 M1
0.0022
244
0.14
8500
2.4
<0.5
352
4610
Buck
DBKG-Bl
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<S
<S
938
10300
Buck
DBKG-B2
Duke
<0.2
0.92
<0.5
<0.1
5.2
60.6
0.0754
151
1.6
3970
66.4
4.1
4340
7270
Buck
DBKG-B3
Duke
<0.05
<1
<1
<0.2
1.93
147
0.023
209
2.9
2450
8
<S
1570
4380
Buck
DBKG-B4
Duke
<0.2
<0.5
<0.5
<0.1
10
<10
0.0081
1510
1.6
6180
1
1.2
527
6590
Buck
DBKG-B5
Duke
< 0.2
< 0.5
< 0.5
< 0.1
< 1
< 10
0.0477
< SO
0.092
483
0.89
< 0.5
1390
6820
Buck
DBKG-B6
Duke
<0.2
<0.5
<0.5
<0.1
2.6
<10
0.0032
<50
0.74
4620
2.3
<0.5
311
8140
Buck
DBKG-B7
Duke
<0.2
<0.5
<0.5
<0.1
16.4
<10
0.0031
<SO
0.13
2470
<0.5
<0.5
1120
4920
Buck
DBKG-B8
Duke
<0.2
<0.5
<0.5
<0.1
2.8
<10
0.0015
<50
0.23
2240
2.S
<0.5
776
5990
Buck
DBKG-B9
Duke
<0.2
<0.5
<0.5
<0.1
4.7
<10
<0.001
<SO
0.46
3810
1.2
<0.5
514
5010
Buck
DBKG-B10
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0083
<50
1.9
6830
0.65
0.59
731
8180
Buck
DBKG-B11
Duke
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0036
<50
<0.03
938
<0.5
<0.5
1140
13200
Buck
DBKG-B12
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<5
<5
938
10300
Buck
DBKG-B13
Duke
< 0.05
< 1
< 1
< 0.2
1.19
< S
0.005
< 10
0.063
5940
< S
< S
2060
8410
Buck
DBKG-B14
Duke
<0.05
<1
<1
<0.2
2.96
<5
<O.005
30
0.14
12500
49
<5
695
12300
Buck
DBKG-B15
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0016
<SO
0.24
1890
<0.5
<0.5
1290
4640
Buck
DBKG-B16
Duke
<0.2
<0.S
<0.S
<0.1
3.8
<10
0.0552
<SO
2.6
3200
0.56
<0.S
1660
7410
Buck
DBKG-B17
Duke
< 0.05
< 1
< 1
< 0.2 jr
7.81
< S
0.018
< 10
0.25
5760
< S
< S
582
4870
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016

Table C2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to 21. Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
29
Page 3 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
Groundwater Standard a
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
*5
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c(:
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015 (d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the
CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
'C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
mV
Buck
BBKG-1 NCDEQ
293
<0.005
192 M1
192
<5
11.6
<1
16.18
0.574
5.22
176
Buck
BBKG-2 NCDEQ
514
0.0108
209
209
<5
<2.5
<1
15.79
0.51
0.96
-28
Buck
BBKG-3 NCDEQ
100
0.0085
70.6
70.6
<5
<2.5
<1
15.93
0.207
3.71
97
Buck
BBKG-5 NCDEQ
209
<0.005
97.2
97.2
<5
<2.5
<1
16.46
0.314
9.86
141
Buck
BBKG-7 NCDEQ
170
0.147
87.6
87.6
<5
<2.5
<1
16.76
0.288
5.53
132
Buck
BBKG-8 NCDEQ
93.6
<0.005
47.2
47.2
<5
<2.5
<1
16.96
0.145
4.03
143
Buck
BBKG-14 NCDEQ
121
<0.005
77.5
77.5
<5
<2.5
3.2
16.38
0.189
0.8
147
Buck
DBKG-B1 Duke
125
0.385
Buck
DBKG-B2 Duke
140
0.645
Buck
DBKG-B3 Duke
39
0.019
Buck
DBKG-B4 Duke
101
0.0424
Buck
DBKG-B5 Duke
138
0.0617
Buck
DBKG-B6 Duke
87.5
0.592
Buck
DBKG-B7 Duke
90.9
0.181
Buck
DBKG-B8 Duke
57.8
0.415
Buck
DBKG-B9 Duke
67
0.0148
Buck
DBKG-B10 Duke
122
0.0079
Buck
DBKG-B11 Duke
84
<0.005
Buck
DBKG-B12 Duke
125
0.385
Buck
DBKG-B13 Duke
146
0.013
Buck
DBKG-B14 Duke
232
0.043
Buck
DBKG-B15 Duke
64.2
<0.005
Buck
DBKG-B16 Duke
118
0.0106
<5
Buck
DBKG-B17 Duke
123
0.074
<5
29
Page 3 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016

30
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated VOL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
Reporting limit is a hove the sueening level.
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table C2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
31
Page 1 of 3
Haley Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016
15A NCAC 02L.0202
Groundwater Standard a
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL(b):
* denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedAntimony
Solids
mg/L
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1 NCDEQ
<5
54200
38
6.74
27.7
351
<O.5
<O.5
20.5
<0.2
<0.08
<0.5
<0.5
<0.1
Buck
BBKG-2 NCDEQ
5.3
59900
12.8
7.19
31.5
317
<0.5
<0.5
15.6
<0.2
<0.08
<0.5
<0.5
3.2
Buck
BBKG-3 NCDEQ
<5
19700
5
7.07
2.8
171
<O.5
<O.5
6.9
<0.2
<0.08
1.2
<0.5
<0.1
Buck
BBKG-5 NCDEQ
<5
31400
23.2
6.61
4.5
172
<0.5
<0.5
9.4
<0.2
<0.08
1.8
<0.5
<0.1
Buck
BBKG-7 NCDEQ
<5
31400
10.5
6.69
15
165
<0.5
<0.5
4.7
<0.2
<0.08
<0.5
<0.5
0.2
Buck
BBKG-8 NCDEQ
<5
10800
7.1
6.48
5.4
85
<0.5
<0.5
0.89
<0.2
<0.08
1.6
<0.5
0.38
Buck
BBKG-14 NCDEQ
6
19800
4.3
6.23
6.9
98
<0.5
<0.5
0.9
<0.2
<0.08
0.53
<0.5
0.12
Buck
DBKG-Bl Duke
<50
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B2 Duke
<5
16400
1.2
<0.5
37.2
<0.2
<0.08
2.9
<0.5
<0.1
Buck
DBKG-B3 Duke
<50
3850
<1
<1
74
<1
<1
<5
<1
<1
Buck
DBKG-B4 Duke
<5
13100
0.88
<0.5
7.3
<0.2
0.081
2.3
<0.5
3.9
Buck
DBKG-B5 Duke
<5
4460
0.94
<0.5
46.4
<0.2
<0.08
<0.5
<0.5
1.4
Buck
DBKG-B6 Duke
<5
10400
0.98
<0.5
2
<0.2
<0.08
0.97
<0.5
0.83
Buck
DBKG-B7 Duke
<5
7500
0.93
<0.5
33
<0.2
<0.08
<0.5
<0.5
0.85
Buck
DBKG-B8 Duke
5.5
6070
0.88
<0.5
2.2
<0.2
0.19
<0.5
<0.5
0.93
Buck
DBKG-B9 Duke
<5
8360
0.97
<0.5
4.7
<0.2
<0.08
0.52
<0.5
0.12
Buck
DBKG-B10 Duke
<5
16000
<0.5
<0.5
9.9
<0.2
<0.08
2.1
<0.5
0.4
Buck
DBKG-B11 Duke
<5
6800
0.96
<0.5
2.5
<0.2
<0.08
<0.5
<0.5
1.2
Buck
DBKG-B12 Duke
<SO
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B13 Duke
<SO
33600
<1
<1
7
<1
<1
<5
<1
<1
Buck
DBKG-B14 Duke
<50
52700
1.21
<1
<5
<1
<1
<5
<1
<1
Buck
DBKG-B15 Duke
<S
6280
0.97
<0.5
48.9
<0.2
<0.08
<0.5
<0.5
0.52
Buck
DBKG-B16 Duke
<S
9910
3.6
6.67
0.26
110
0.58
<O.5
38.6
<0.2
<0.08
2.5
<O.5
0.49
Buck
DBKG-B17 Duke
<SO
12100
2.8
6.56
0.45
<1
<1
19
<1
<1
<5
<1
<1
Haley Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016

Table C2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
32
Page 2 of 3
Haley Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016
ISA NCAC 02L.0202
Groundwater Standard a
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
11.
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Magnesium
Hexavalent
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1
NCDEQ
<0.2
<0.5
0.52
<0.1
4.6
<10
0.001
<50
<0.6
23800
0.73
<0.5
3000
23000
Buck
BBKG-2
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0073
64.2
<0.6
15600
13.4
<0.5
1740
20400
Buck
BBKG-3
NCDEQ
<0.2
<0.5
<0.5
<0.1
9
<10
<0.001
<50
1.0 M1
8150
<0.5
0.9
1040
7060
Buck
BBKG-5
NCDEQ
<0.2
<0.5
<0.5
<0.1
12.4
<10
0.0014
<50 1
1.5
12100
<0.5
<0.5
1140 1
9880
Buck
BBKG-7
NCDEQ
<0.2
<0.5
<0.5
<0.1
15.6
12.1
0.0028
<50
0.22
11300
<0.5
<0.5
997
8410
Buck
BBKG-8
NCDEQ
<0.2
<0.5
<0.5
<0.1
7.9
<10
0.0021
<50
1.5
6970
<0.5
<0.5
265
6770
Buck
BBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
S
213 M1
0.0022
244
0.14
8500
2.4
<0.5
352
4610
Buck
DBKG-Bl
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<5
<5
938
10300
Buck
DBKG-B2
Duke
<0.2
0.92
<0.5
<0.1
5.2
60.6
0.0754
151
1.6
3970
66.4
4.1
4340
7270
Buck
DBKG-B3
Duke
<0.05
<1
<1
<0.2
1.93
147
0.023
209
2.9
2450
8
<5
1570
4380
Buck
DBKG-B4
Duke
<0.2
<0.5
<0.5
<0.1
10
<10
0.0081
1510
1.6
6180
1
1.2
527
6590
Buck
DBKG-B5
Duke
< 0.2
< 0.5
< 0.5
< 0.1
< 1
< 10
0.0477
< SO
0.092
483
0.89
< 0.5
1390
6820
Buck
DBKG-B6
Duke
<0.2
<0.5
<0.5
<0.1
2.6
<10
0.0032
<50
0.74
4620
2.3
<0.5
311
8140
Buck
DBKG-B7
Duke
<0.2
<0.5
<0.5
<0.1
16.4
<10
0.0031
<SO
0.13
2470
<0.5
<0.5
1120
4920
Buck
DBKG-B8
Duke
<0.2
<0.5
<0.5
<0.1
2.8
<10
0.0015
<50
0.23
2240
2.5
<0.5
776
5990
Buck
DBKG-B9
Duke
<0.2
<0.5
<0.5
<0.1
4.7
<10
<0.001
<SO
0.46
3810
1.2
<0.5
514
5010
Buck
DBKG-B10
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0083
<50
1.9
6830
0.65
0.59
731
8180
Buck
DBKG-B11
Duke
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0036
<50
<0.03
938
<0.5
<0.5
1140
13200
Buck
DBKG-B12
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<5
<5
938
10300
Buck
DBKG-B13
Duke
<0.05
<1
<1
<0.2
1.19
<5
0.005
<10
0.063
5940
<5
<5
2060
8410
Buck
DBKG-B14
Duke
<0.05
<1
<1
<0.2
2.96
<5
<O.005
30
0.14
12500
49
<5
695
12300
Buck
DBKG-B15
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0016
<SO
0.24
1890
<0.5
<0.5
1290
4640
Buck
DBKG-B16
Duke
<0.2
<O.5
<O.5
<0.1
3.8
<10
0.0552
<SO
2.6
3200
0.56
<O.5
1660
7410
Buck
DBKG-B17
Duke
<0.05
<1
<1
<0.2
7.81
<S
0.018
<10
0.25
5760
<-5
<S
582
4870
Haley Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016

Table C2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to MCL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
33
Page 3 of 3
Haley Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016
15A NCAC 02L.0202
Groundwater Standard a
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
*5
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015 (d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the
CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
'C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
my
Buck
BBKG-1 NCDEQ
293
<0.005
192 M1
192
<5
11.6
<1
16.18
0.574
5.22
176
Buck
BBKG-2 NCDEQ
514
0.0108
209
209
<5
<2.5
<1
15.79
0.51
0.96
-28
Buck
BBKG-3 NCDEQ
100
0.0085
70.6
70.6
<5
<2.5
<1
15.93
0.207
3.71
97
Buck
BBKG-5 NCDEQ
209
<0.005
97.2
97.2
<5
<2.5
<1
16.46
0.314
9.86
141
Buck
BBKG-7 NCDEQ
170
0.147
87.6
87.6
<5
<2.5
<1
16.76
0.288
5.53
132
Buck
BBKG-8 NCDEQ
93.6
<0.005
47.2
47.2
<5
<2.5
<1
16.96
0.145
4.03
143
Buck
BBKG-14 NCDEQ
121
<0.005
77.5
77.5
<5
<2.5
3.2
16.38
0.189
0.8
147
Buck
DBKG-B1 Duke
125
0.385
Buck
DBKG-B2 Duke
140
0.645
Buck
DBKG-B3 Duke
39
0.019
Buck
DBKG-B4 Duke
101
0.0424
Buck
DBKG-B5 Duke
138
0.0617
Buck
DBKG-B6 Duke
87.5
0.592
Buck
DBKG-B7 Duke
90.9
0.181
Buck
DBKG-B8 Duke
57.8
0.415
Buck
DBKG-B9 Duke
67
0.0148
Buck
DBKG-B10 Duke
122
0.0079
Buck
DBKG-B11 Duke
84
<0.005
Buck
DBKG-B12 Duke
125
0.385
Buck
DBKG-B13 Duke
146
0.013
Buck
DBKG-B14 Duke
232
0.043
Buck
DBKG-B15 Duke
64.2
<0.005
Buck
DBKG-B16 Duke
118
0.0106
<5
Buck
DBKG-B17 Duke
123
0.074
<5
33
Page 3 of 3
Haley Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016

34
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated VOL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreeni ng level.
_Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table C2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
35
Page 1 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
Groundwater Standard a
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL(b):
* denotes secondary standard
NS
NS
•250
6.5-8.5
'250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedAntimony
Solids
mg/L
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1 NCDEQ
<5
54200
38
6.74
27.7
351
<O.5
<O.5
20.5
<0.2
<0.08
<0.5
<0.5
<0.1
Buck
BBKG-2 NCDEQ
5.3
59900
12.8
7.19
31.5
317
<0.5
<0.5
15.6
<0.2
<0.08
<0.5
<0.5
3.2
Buck
BBKG-3 NCDEQ
<5
19700
5
7.07
2.8
171
<O.5
<O.5
6.9
<0.2
<0.08
1.2
<0.5
<0.1
Buck
BBKG-5 NCDEQ
<5
31400
23.2 1
6.61
4.5
172
<0.5
<0.5
9.4
<0.2
<0.08
1.8
<0.5
<0.1
Buck
BBKG-7 NCDEQ
<5
31400
10.5
6.69
15
165
<0.5
<0.5
4.7
<0.2
<0.08
<0.5
<0.5
0.2
Buck
BBKG-8 NCDEQ
<5
10800
7.1
6.48
5.4
85
<0.5
<0.5
0.89
<0.2
<0.08
1.6
<0.5
0.38
Buck
BBKG-14 NCDEQ
6
19800
4.3
6.23
6.9
98
<0.5
<0.5
0.9
<0.2
<0.08
0.53
<0.5
0.12
Buck
DBKG-Bl Duke
<50
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B2 Duke
<5
16400
1.2
<0.5
37.2
<0.2
<0.08
2.9
<0.5
<0.1
Buck
DBKG-B3 Duke
<50
3850
<1
<1
74
<1
<1
<5
<1
<1
Buck
DBKG-B4 Duke
<5
13100
0.88
<0.5
7.3
<0.2
0.081
2.3
<0.5
3.9
Buck
DBKG-B5 Duke
<5
4460
0.94
<0.5
46.4
<0.2
<0.08
<0.5
<0.5
1.4
Buck
DBKG-B6 Duke
<5
10400
0.98
<0.5
2
<0.2
<0.08
0.97
<0.5
0.83
Buck
DBKG-B7 Duke
<5
7500
0.93
<0.5
33
<0.2
<0.08
<0.5
<0.5
0.85
Buck
DBKG-B8 Duke
5.5
6070
0.88
<0.5
2.2
<0.2
0.19
<0.5
<0.5
0.93
Buck
DBKG-B9 Duke
<5
8360
0.97
<0.5
4.7
<0.2
<0.08
0.52
<0.5
0.12
Buck
DBKG-B10 Duke
<5
16000
<0.5
<0.5
9.9
<0.2
<0.08
2.1
<0.5
0.4
Buck
DBKG-B11 Duke
<5
6800
0.96
<0.5
2.5
<0.2
<0.08
<0.5
<0.5
1.2
Buck
DBKG-B12 Duke
<SO
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B13 Duke
<SO
33600
<1
<1
7
<1
<1
<5
<1
<1
Buck
DBKG-B14 Duke
<50
52700
1.21
<1
<5
<1
<1
<5
<1
<1
Buck
DBKG-B15 Duke
<S
6280
0.97
<0.5
48.9
<0.2
<0.08
<0.5
<0.5
0.52
Buck
DBKG-B16 Duke
<S
9910
3.6
6.67
0.26
110
0.58
<O.5
38.6
<0.2
<0.08
2.5
<O.5
0.49
Buck
DBKG-B17 Duke
<SO
12100
2.8
6.56
0.45
<1
<1
19
<1
<1
<5
<1
<1
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016

Table C2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
36
Page 2 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQand Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016
ISA NCAC 02L.0202
Groundwater Standard a
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
1L
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Magnesium
Hexavalent
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1
NCDEQ
<0.2
<0.5
0.52
<0.1
4.6
<10
0.001
<50
<0.6
23800
0.73
<0.5
3000
23000
Buck
BBKG-2
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0073
64.2
<0.6
15600
13.4
<0.5
1740
20400
Buck
BBKG-3
NCDEQ
<0.2
<0.5
<0.5
<0.1
9
<10
<0.001
<50
1.0 M1
8150
<0.5
0.9
1040
7060
Buck
BBKG-S
NCDEQ
<0.2
<0.5
<0.5
<0.1
12.4
<10
0.0014
<50 1
1.5
12100
<0.5
<0.5
1140 1
9880
Buck
BBKG-7
NCDEQ
<0.2
<0.5
<0.5
<0.1
15.6
12.1
0.0028
<50
0.22
11300
<0.5
<0.5
997
8410
Buck
BBKG-8
NCDEQ
<0.2
<O.5
<O.5
<0.1
7.9
<10
0.0021
<50
1.5
6970
<0.S
<0.S
26S
6770
Buck
BBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
S
213 M1
0.0022
244
0.14
8500
2.4
<0.5
352
4610
Buck
DBKG-Bl
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<S
<S
938
10300
Buck
DBKG-B2
Duke
<0.2
0.92
<0.5
<0.1
5.2
60.6
0.0754
151
1.6
3970
66.4
4.1
4340
7270
Buck
DBKG-B3
Duke
<0.05
<1
<1
<0.2
1.93
147
0.023
209
2.9
2450
8
<S
1570
4380
Buck
DBKG-B4
Duke
<0.2
<0.5
<0.5
<0.1
10
<10
0.0081
1510
1.6
6180
1
1.2
527
6590
Buck
DBKG-B5
Duke
< 0.2
< 0.5
< 0.5
< 0.1
< 1
< 10
0.0477
< 50
0.092
483
0.89
< 0.5
1390
6820
Buck
DBKG-B6
Duke
<0.2
<0.5
<0.5
<0.1
2.6
<10
0.0032
<50
0.74
4620
2.3
<0.5
311
8140
Buck
DBKG-B7
Duke
<0.2
<0.5
<0.5
<0.1
16.4
<10
0.0031
<SO
0.13
2470
<0.5
<0.5
1120
4920
Buck
DBKG-B8
Duke
<0.2
<0.5
<0.5
<0.1
2.8
<10
0.0015
<50
0.23
2240
2.S
<0.5
776
5990
Buck
DBKG-B9
Duke
<0.2
<0.5
<0.5
<0.1
4.7
<10
<0.001
<SO
0.46
3810
1.2
<0.5
514
5010
Buck
DBKG-B10
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0083
<50
1.9
6830
0.65
0.59
731
8180
Buck
DBKG-B11
Duke
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0036
<50
<0.03
938
<0.5
<0.5
1140
13200
Buck
DBKG-B12
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<5
<5
938
10300
Buck
DBKG-B13
Duke
<0.05
<1
<1
<0.2
1.19
<S
0.005
<10
0.063
5940
<S
<S
2060
8410
Buck
DBKG-B14
Duke
<0.05
<1
<1
<0.2
2.96
<5
<O.005
30
0.14
12500
49
<5
695
12300
Buck
DBKG-B1S
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0016
<SO
0.24
1890
<0.5
<0.5
1290
4640
Buck
DBKG-B16
Duke
<0.2
<0.S
<0.S
<0.1
3.8
<10
0.0552
<SO
2.6
3200
0.56
<0.S
1660
7410
Buck
DBKG-B17
Duke
<0.05
<1
<1
<0.2
7.81
<S
0.018
<10
0.25
5760
<S
<S
582
4870
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQand Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016

Table C2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to DHHS Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
37
Page 3 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
Groundwater Standard a
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
*5
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015 (d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the
CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
'C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
my
Buck
BBKG-1 NCDEQ
293
<0.005
192 M1
192
<5
11.6
<1
16.18
0.574
5.22
176
Buck
BBKG-2 NCDEQ
514
0.0108
209
209
<5
<2.5
<1
15.79
0.51
0.96
-28
Buck
BBKG-3 NCDEQ
100
0.0085
70.6
70.6
<5
<2.5
<1
15.93
0.207
3.71
97
Buck
BBKG-5 NCDEQ
209
<0.005
97.2
97.2
<5
<2.5
<1
16.46
0.314
9.86
141
Buck
BBKG-7 NCDEQ
170
0.147
87.6
87.6
<5
<2.5
<1
16.76
0.288
5.53
132
Buck
BBKG-8 NCDEQ
93.6
<0.005
47.2
47.2
<5
<2.5
<1
16.96
0.145
4.03
143
Buck
BBKG-14 NCDEQ
121
<0.005
77.5
77.5
<5
<2.5
3.2
16.38
0.189
0.8
147
Buck
DBKG-B1 Duke
125
0.385
Buck
DBKG-B2 Duke
140
0.645
Buck
DBKG-B3 Duke
39
0.019
Buck
DBKG-B4 Duke
101
0.0424
Buck
DBKG-B5 Duke
138
0.0617
Buck
DBKG-B6 Duke
87.5
0.592
Buck
DBKG-B7 Duke
90.9
0.181
Buck
DBKG-B8 Duke
57.8
0.415
Buck
DBKG-B9 Duke
67
0.0148
Buck
DBKG-B10 Duke
122
0.0079
Buck
DBKG-B11 Duke
84
<0.005
Buck
DBKG-B12 Duke
125
0.385
Buck
DBKG-B13 Duke
146
0.013
Buck
DBKG-B14 Duke
232
0.043
Buck
DBKG-B15 Duke
64.2
<0.005
Buck
DBKG-B16 Duke
118
0.0106
<5
Buck
DBKG-B17 Duke
123
0.074
<5
37
Page 3 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016

38
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated VOL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table C2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
39
Page 1 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
Groundwater Standard a
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL(b):
* denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedAntimony
Solids
mg/L
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1 NCDEQ
<5
54200
38
6.74
27.7
351
<O.5
<0.5
20.5
<0.2
<0.08
<0.5
<0.5
<0.1
Buck
BBKG-2 NCDEQ
5.3
59900
12.8
7.19
31.5
317
<0.5
<0.5
15.6
<0.2
<0.08
<0.5
<0.5
3.2
Buck
BBKG-3 NCDEQ
<5
19700
5
7.07
2.8
171
<O.5
<0.5
6.9
<0.2
<0.08
1.2
<0.5
<0.1
Buck
BBKG-5 NCDEQ
<5
31400
23.2 1
6.61
4.5
172
<0.5
<O.5
9.4
<0.2
<0.08
1.8
<0.5
<0.1
Buck
BBKG-7 NCDEQ
<5
31400
10.5
6.69
15
165
<0.5
<0.5
4.7
<0.2
<0.08
<0.5
<0.5
0.2
Buck
BBKG-8 NCDEQ
<5
10800
7.1
6.48
5.4
85
<0.5
<0.5
0.89
<0.2
<0.08
1.6
<0.5
0.38
Buck
BBKG-14 NCDEQ
6
19800
4.3
6.23
6.9
98
<0.5
<0.5
0.9
<0.2
<0.08
0.53
<0.5
0.12
Buck
DBKG-Bl Duke
<50
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B2 Duke
<5
16400
1.2
<0.5
37.2
<0.2
<0.08
2.9
<0.5
<0.1
Buck
DBKG-B3 Duke
<50
3850
<1
<1
74
<1
<1
<5
<1
<1
Buck
DBKG-B4 Duke
<5
13100
0.88
<0.5
7.3
<0.2
0.081
2.3
<0.5
3.9
Buck
DBKG-B5 Duke
<5
4460
0.94
<0.5
46.4
<0.2
<0.08
<0.5
<0.5
1.4
Buck
DBKG-B6 Duke
<5
10400
0.98
<0.5
2
<0.2
<0.08
0.97
<0.5
0.83
Buck
DBKG-B7 Duke
<5
7500
0.93
<0.5
33
<0.2
<0.08
<0.5
<0.5
0.85
Buck
DBKG-B8 Duke
5.5
6070
0.88
<0.5
2.2
<0.2
0.19
<0.5
<0.5
0.93
Buck
DBKG-B9 Duke
<5
8360
0.97
<0.5
4.7
<0.2
<0.08
0.52
<0.5
0.12
Buck
DBKG-B10 Duke
<5
16000
<0.5
<0.5
9.9
<0.2
<0.08
2.1
<0.5
0.4
Buck
DBKG-B11 Duke
<5
6800
0.96
<0.5
2.5
<0.2
<0.08
<0.5
<0.5
1.2
Buck
DBKG-B12 Duke
<SO
31100
<1
1.01
<5
<1
<1
<5
<1
1.6
Buck
DBKG-B13 Duke
<SO
33600
<1
<1
7
<1
<1
<5
<1
<1
Buck
DBKG-B14 Duke
<50
52700
1.21
<1
<5
<1
<1
<5
<1
<1
Buck
DBKG-B15 Duke
<S
6280
0.97
<0.5
48.9
<0.2
<0.08
<0.5
<0.5
0.52
Buck
DBKG-B16 Duke
<S
9910
3.6
6.67
0.26
110
0.58
<O.5
38.6
<0.2
<0.08
2.5
<O.5
0.49
Buck
DBKG-B17 Duke
<SO
12100
2.8
6.56
0.45
<1
<1
19
<1
<1
<5
<1
<1
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016

Table C2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
40
Page 2 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016
ISA NCAC 02L.0202
Groundwater Standard a
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
11.
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Magnesium
Hexavalent
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Buck
BBKG-1
NCDEQ
<0.2
<0.5
0.52
<0.1
4.6
<10
0.001
<50
<0.6
23800
0.73
<0.5
3000
23000
Buck
BBKG-2
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0073
64.2
<0.6
15600
13.4
<0.5
1740
20400
Buck
BBKG-3
NCDEQ
<0.2
<0.5
<0.5
<0.1
9
<10
<0.001
<50
1.0 M1
8150
<0.5
0.9
1040
7060
Buck
BBKG-5
NCDEQ
<0.2
<0.5
<0.5
<0.1
12.4
<10
0.0014
<50 1
1.5
12100
<0.5
<0.5
1140 1
9880
Buck
BBKG-7
NCDEQ
<0.2
<0.5
<0.5
<0.1
15.6
12.1
0.0028
<50
0.22
11300
<0.5
<0.5
997
8410
Buck
BBKG-8
NCDEQ
<0.2
<0.5
<0.5
<0.1
7.9
<10
0.0021
<50
1.5
6970
<0.5
<0.5
265
6770
Buck
BBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
S
213 M1
0.0022
244
0.14
8500
2.4
<0.5
352
4610
Buck
DBKG-Bl
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<5
<5
938
10300
Buck
DBKG-B2
Duke
<0.2
0.92
<0.5
<0.1
5.2
60.6
0.0754
151
1.6
3970
66.4
4.1
4340
7270
Buck
DBKG-B3
Duke
<0.05
<1
<1
<0.2
1.93
147
0.023
209
2.9
2450
8
<5
1570
4380
Buck
DBKG-B4
Duke
<0.2
<0.5
<0.5
<0.1
10
<10
0.0081
1510
1.6
6180
1
1.2
527
6590
Buck
DBKG-B5
Duke
< 0.2
< 0.5
< 0.5
< 0.1
< 1
< 10
0.0477
< 50
0.092
483
0.89
< 0.5
1390
6820
Buck
DBKG-B6
Duke
<0.2
<0.5
<0.5
<0.1
2.6
<10
0.0032
<50
0.74
4620
2.3
<0.5
311
8140
Buck
DBKG-B7
Duke
<0.2
<0.5
<0.5
<0.1
16.4
<10
0.0031
<SO
0.13
2470
<0.5
<0.5
1120
4920
Buck
DBKG-B8
Duke
<0.2
<0.5
<0.5
<0.1
2.8
<10
0.0015
<50
0.23
2240
2.5
<0.5
776
5990
Buck
DBKG-B9
Duke
<0.2
<0.5
<0.5
<0.1
4.7
<10
<0.001
<SO
0.46
3810
1.2
<0.5
514
5010
Buck
DBKG-B10
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0083
<50
1.9
6830
0.65
0.59
731
8180
Buck
DBKG-B11
Duke
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0036
<50
<0.03
938
<0.5
<0.5
1140
13200
Buck
DBKG-B12
Duke
<0.05
5.96
<1
<0.2
2.05
12
0.006
14
0.073
7020
<5
<5
938
10300
Buck
DBKG-B13
Duke
<0.05
<1
<1
<0.2
1.19
<5
0.005
<10
0.063
5940
<5
<5
2060
8410
Buck
DBKG-B14
Duke
<0.05
<1
<1
<0.2
2.96
<5
<O.005
30
0.14
12500
49
<5
695
12300
Buck
DBKG-B15
Duke
<0.2
<0.5
<0.5
<0.1
13.2
<10
0.0016
<SO
0.24
1890
<0.5
<0.5
1290
4640
Buck
DBKG-B16
Duke
<0.2
<O.5
<O.5
<0.1
3.8
<10
0.0552
<SO
2.6
3200
0.56
<O.5
1660
7410
Buck
DBKG-B17
Duke
<0.05
<1
<1
<0.2
7.81
<S
0.018
<10
0.25
5760
<-5
<S
582
4870
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016

Table C2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to RSL Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
41
Page 3 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
Groundwater Standard a
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
*S
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015 (d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the
CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
'C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
my
Buck
BBKG-1 NCDEQ
293
<0.005
192 M1
192
<5
11.6
<1
16.18
0.574
5.22
176
Buck
BBKG-2 NCDEQ
514
0.0108
209
209
<5
<2.5
<1
15.79
0.51
0.96
-28
Buck
BBKG-3 NCDEQ
100
0.0085
70.6
70.6
<5
<2.5
<1
15.93
0.207
3.71
97
Buck
BBKG-5 NCDEQ
209
<0.005
97.2
97.2
<5
<2.5
<1
16.46
0.314
9.86
141
Buck
BBKG-7 NCDEQ
170
0.147
87.6
87.6
<5
<2.5
<1
16.76
0.288
5.53
132
Buck
BBKG-8 NCDEQ
93.6
<0.005
47.2
47.2
<5
<2.5
<1
16.96
0.145
4.03
143
Buck
BBKG-14 NCDEQ
121
<0.005
77.5
77.5
<5
<2.5
3.2
16.38
0.189
0.8
147
Buck
DBKG-B1 Duke
125
0.385
Buck
DBKG-B2 Duke
140
0.645
Buck
DBKG-B3 Duke
39
0.019
Buck
DBKG-B4 Duke
101
0.0424
Buck
DBKG-B5 Duke
138
0.0617
Buck
DBKG-B6 Duke
87.5
0.592
Buck
DBKG-B7 Duke
90.9
0.181
Buck
DBKG-B8 Duke
57.8
0.415
Buck
DBKG-B9 Duke
67
0.0148
Buck
DBKG-B10 Duke
122
0.0079
Buck
DBKG-B11 Duke
84
<0.005
Buck
DBKG-B12 Duke
125
0.385
Buck
DBKG-B13 Duke
146
0.013
Buck
DBKG-B14 Duke
232
0.043
Buck
DBKG-B15 Duke
64.2
<0.005
Buck
DBKG-B16 Duke
118
0.0106
<5
Buck
DBKG-B17 Duke
123
0.074
<5
41
Page 3 of 3
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016

42
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated VOL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the Breen ing level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables C2 -5-C2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Page 1 of 3
43
Table C2-9
Do Not Drink Letter Summary
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Table C2-9 Do Not Drink Summary.xlsx April 2016
Constituents Listed in Part I of Letter
Hex
Chromium
Haley & Aldrich, Inc.
Table C2-9 Do Not Drink Summary.xlsx April 2016

Page 2 of 3
44
Table C2-9
Do Not Drink Letter Summary
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Table C2-9 Do Not Drink Summary.xlsx April 2016

Page 3 of 3
45
Table C2-9
Do Not Drink Letter Summary
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Constituents Listed in Part 1 of Letter
Hex
Facility
Well ID
Vanadium
Chromium
Chloride
Chromium
Cobalt
Iron
Lead
Manganese
Sodium
Strontium
Sulfate
Thallium
Zinc
X
Buck
B-56
Total number of Constituent Letters
77
48
0
2
1
14
1
1
0
0
0
0
3
Total Number of "Do Not Drink" Letters
(Excluding Hexavalent Chromium and
19
Vanadium)
Total Number of "Do Not Drink" Letters
(Including Hexavalent Chromium and
79
Vanadium)
Total Number of "Do Not Drink" Letters
48
for Hexavalent Chromium
Total Number of "Do Not Drink" Letters
77
for Vanadium
Haley & Aldrich, Inc.
Table C2-9 Do Not Drink Summary.xlsx April 2016

46
Table C3-1 Page 1 of 2
NCDEQ and Duke Energy Background Water Supply Well Data
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
<- Not detected, value is the reporting limit.
°C - Degrees Celsius.
DEQ- Department of Environmental Quality.
M3 - Matrix spike recovery exceeded QC limits.
Batch accepted based on laboratory control
ample (.S) recovery.
mg/L - milligrams/liter.
mV - millivolts.
INC - North Carolina.
NTU - Nephelometric Turbidity Units.
su- standard units.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Haley & Aldrich, Inc.
Table C3-1 NCDEQ and Duke Energy Background Well Data_2016-04.xlsx April 2016

47
Table C3-1 Page 2 of 2
NCDEQ and Duke Energy Background Water Supply Well Data
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
MMMOMMMMMOMOMM
=mom
Notes:
<- Not detected, value is the reporting limit.
°C - Degrees Celsius.
DEQ - Department of Environmental Quality.
M3 - Matrix spike recovery exceeded QC limits.
Batch accepted based on laboratory control
ample (LCS) recovery.
mg/L - milligrams/liter.
mV - millivolts.
INC - North Carolina.
NTU - Nephelometric Turbidity Units.
su- standard units.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Haley & Aldrich, Inc.
Table C3-1 NCDEQ and Duke Energy Background Well Data_2016-04.xlsx April 2016

48
Page 1 of 1
Table C3-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Well ID
Sample ID
Date Sampled
Barium
(ug/L)
Boron
(ug/L)
Cobalt
(ug/L)
Hexavalent Chromium
(ug/L)
Iron
(ug/L)
Lead
(ug/L)
Manganese
(ug/L)
Nckel, Dissolved
(ug/L)
Sodium
(ug/L)
Sulfate
(ug/L)
Vanadium
(ug/L)
Zinc
(ug/L)
MW -6D
BU -MW -6D -NS -4Q15-2
10 -Dec -15
87
<50
0.13
0.47
140
0.07
5.1
0.29
6900
2200
8.7
<10
MW -6D
MW-6D_WG_20110307
07 -Mar -11
63
<50
31
<1
<5
1300
<5
MW -6D
MW -6D WG 20110705
05 -Jul -11
64
<50
<10
<1
<5
1400
<5
MW -61)
MW-6D_WG_20111102
02 -Nov -11
62
< 50
< 10
< 1
< 5
1200
< 5
MW -61)
MW-6D_WG_20120307
07 -Mar -12
65
<50
26
<1
<5
1300
<5
MW -6D
MW-6D_WG_20120703
03 -Jul -12
70
<50
18
<1
<5
1500
<5
MW -61)
MW-6D_WG_20121107
07 -Nov -12
70
< 50
25
< 1
< 5
5860
1400
< 5
MW -61)
MW-6D_WG_20130306
06 -Mar -13
73
< 50
62
< 1
< 5
5630
1400
< 5
MW -6D
MW-6D_WG_20130708
08 -Jul -13
84
<50
127
<1
<5
<5
6210
1600
<5
MW -6D
MW-6D_WG_20131104
04 -Nov -13
81
< 50
55
< 1
< 5
6080
1500
< 5
MW -61)
MW-6D_WG_20140303
03 -Mar -14
83
<50
47
<1
<5
6240
170
7
MW -61)
MW-6D_WG_20140701
01 -Jul -14
86
<50
78
<1
<5
6140
1800
<5
MW -6D
MW-6D_WG_20141103
03 -Nov -14
76
< 50
25
< 1
< 5
5840
1700
< 5
MW -61)
MW-6D_WG_20150304
04 -Mar -15
77
<50
33
<1
<5
6000
1700
<5
MW -61)
MW-6D_WG_20150701
01 -Jul -15
86
<50
<0.5
110
0.055
3.1
<0.5
6360
2400
8.8
<10
BG -1D
BG-1D_N_WG_20150629
29 -Jun -15
131
2.34
BG -1D
BG-1D_WG_20150618
18 -Jun -15
21
38
<0.5
130
<0.1
3.1
0.25
26800
12600
26.6
4.8
BG -1D
BU -BG -ID -FD -4Q15-1
18 -Nov -15
27
26
<0.5
0.58
80
<0.1
2.9
0.55
75000
88000
157
4.4
BG -11)
BU -BG -1D -NS -3Q15
21 -Sep -15
28
31
0.23
130
0.073
3.6
0.73
64300
91800
128
4.4
BG -1D
BU -BG -ID -NS -4Q15-1
18 -Nov -15
30
25
<0.5
0.074
79
<0.1
2.7
0.39
80400
105000
167
4.6
BG -1D
BU -BG -ID -NS -4Q15-2
10 -Dec -15
17
<50
<0.5
0.52
90
0.051
<5
0.23
60700
69600
151
5.9
BG -21)
BG -2D WG 20150624
24 -Jun -15
6.4
49
0.15
110
<0.1
3.3
0.41
16600
22700
7.3
5.2
BG -2D
BU -BG -2D -FD -4Q15-2
10 -Dec -15
6.1
< 50
< 0.5
0.29
< 50
< 0.1
< 5
< 0.5
23300
20500
10
2.8
BG -21)
BU -BG -2D -NS -3Q15
22 -Sep -15
6.4
< 50
< 0.5
44
< 0.1
< 5
< 0.5
14800
20400
8.5
< 10
BG -21)
BU -BG -2D -NS -4Q15-1
18 -Nov -15
7.7
<50
<0.5
0.27
57
<0.1
2.7
<0.5
18200
22100
7.5
4.3
BG -2D
BU -BG -2D -NS -4Q15-2
10 -Dec -15
6.3
< 50
< 0.5
0.5
< 50
< 0.1
< 5
0.24
22400
17600
10.3
7.3
BG-36RU
BG-36RU WG 20150612
12 -Jun -15
11
<50
0.31
306
0.23
9.1
1.8
9290
11500
10.3
26
Notes:
<- Not Detected, value is the reporting limit.
ug/L- Microgram per liter.
Haley & Aldrich, Inc.
Table C3.2 -Facility Bkg Data.xlsx April 2016

49
Page 1 of 1
Table C3-3
Background Data Statistical Evaluation
Buck Stean Station
Water Supply Well Evaluation
Duke Energy
April 2016
1
2
3
4
KM - Kaplan -Meier Method.
5
6
1 7
8
9 1
10
1 11
12
13
14
15
16
17
Frequency of Percent
Detection
Non-
Detects
Range of Non-
Detects
KM
KM Mean Variance
KM
Standard
Deviation
KM Coefficient
of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Regional Background Evaluation
Distribution
BTV
Method
Barium
ug/L
26
/
Variable
Units
Frequency of Percent Non-
Detection Detects
Range of Non-
Detects
KM Mean
KM
Variance
KM
Standard
Deviation
KM Coefficient
of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Outlier Outlier
Presence* Removed
Distribution
BTV
Method
Barium
ug/L
21 / 24
13%
5
5
16.64
366.2
19.14
1.15
7.15
48.53
74
No
No
Gamma
56.09
95%Approx. Gamma UPL WH and KM
Boron
ug/L
3 / 24
88%
5
50
5.1
0.0644
0.254
0.0498
5
50
6
NA
No
NA
6
Maximum Detect
Cobalt
ug/L
0 / 24
100%
0.5
1
NA
NA
NA
NA
0.5
1
NA
NA
No
NA
1
Maximum RL
Hexavalent Chromium
ug/L
21 / 24
13%
0.03
0.6
0.742
0.722
0.85
1.145
0.355
2.495
2.9
No
No
Gamma
2.554
95%Approx. Gamma UPL WH and KM
Iron
ug/L
8 / 24
67%
10
50
103.1
90032
300.1
2.91 1
50
238.8
1510
Yes
No
Gamma
334
95%Approx. Gamma UPL WH and KM
Lead
ug/L
16 / 24
33%
0.1
1
0.818
0.917
0.958
1.171
0.84
2.96
3.9
Yes
No
Gamma
2.617
95%Approx. Gamma UPL WH and KM
Manganese
ug/L
13 / 24
46%
0.5
5
6.519
252.6
15.89
2.438
1.1
43.66
66.4
Yes
No
Distribution Free
66.4
Maximum Detect (95% UTL)
Nickel
ug/L
4 / 24
83%
0.5
5
0.766
0.686
0.828
1.081
0.5
5
4.1
No
No
Normal
2.678
95% Normal UTL and KM
Sodium
ug/L
24 / 24
0%
Yes
NA
8703
21815480
4671
0.537
7340
19320
23000
Yes
No
Lognormal
21695
95% UTL
Sulfate
mg/L
9 / 9
0%
Yes
NA
10.5
137.2
11.71
1.115
5.4
29.98
31.5
No
No
Normal
33.46
95%UPL (t)
Vanadium
ug/L
21 / 24
13%
1
1
6.141
23.48
4.845
0.789
4.65
15.24
16.4
No
No
Gamma
16.77
95%Approx. Gamma UPL WH and KM
Zinc
mg/L
18 / 24
25%
0.005
0.005
0.129
0.0378
0.194
1.512
0.0169
0.565
0.645
No
No
Gamma
0.491
95%Approx. Gamma UPL WH and KM
Notes:
* -Tested at 5% significance level.
ug/L- Microgram per liter.
BTV - Background Threshold Value.
UPLs - Upper Prediction Limits.
KM - Kaplan -Meier Method.
UTLs - Upper Tolerance Limits.
NA - Not Available.
Var - Variance.
RL - Reporting Limit.
Facility Specific Background Evaluation
Variable
Units
Frequency of Percent
Detection
Non-
Detects
Range of Non-
Detects
KM
KM Mean Variance
KM
Standard
Deviation
KM Coefficient
of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Outlier Outlier
Presence* Removed
Distribution
BTV
Method
Barium
ug/L
26
/
26
0%
NA
49.77
997
31.58
0.634
63.5
86
87
Yes
Yes
Distribution Free
87
Maximum Detect (95% UTL)
Boron
ug/L
5
/
26
81%
50 50
33.8
78.96
8.886
0.263
50
50
49
No
No
Normal
54.02
95% Normal KM UTL
Cobalt
ug/L
4
/
13
69%
0.5 0.5
0.205
0.00508
0.0712
0.348
0.5
0.5
0.31
Yes
Yes
Normal
0.395
95% Normal KM UTL
Hexavalent Chromium
ug/L
7
/
7
0%
NA
0.386
0.0326
0.181
0.467
0.47
0.562
0.58
Yes
Yes
Normal
0.761
95% Normal UPL
Iron
ug/L
23
/
27
15%
10 50
1 74.36
3798 1
61.63
0.829 1
57
137.3
306
Yes
Yes
Gamma
257.8
95%Approx. Gamma UTL WH and KM
Lead
ug/L
5
/
26
81%
0.1 1
0.0752
0.00208
0.0456
0.607
0.615
1
0.23
Yes
Yes
Gamma
0.167
95%Approx. Gamma UTL WH and KM
Manganese
ug/L
10
/
27
63%
5 5
3.274
1.593
1.262
0.386
5
5.07
9.1
Yes
Yes
Gamma
5.799
95%Approx. Gamma UTL WH and KM
Nickel
ug/L
9
/
14
36%
0.5 5
0.469
0.168
0.409
0.873
0.5
2.92
1.8
Yes
No
Gamma
1.566
95%Approx. Gamma UTL WH and KM
Sodium
ug/L
21
/
21
0%
NA
22526
6.15E+08
24803
1.101
9290
75000
80400
Yes
Yes
Distribution Free
80400
Maximum Detect (95% UTL)
Sulfate
mg/L
26
/
26
0%
NA
19399
9.89E+08
31454
1.621
2000
90850
105000
Yes
Yes
Distribution Free
105000 Maximum Detect (95% UTL)
Vanadium
ug/L
13
/
13
0%
NA
53.92
4606
67.87
1.259
10.3
161
167
No
No
Distribution Free
167
Maximum Detect (95% UTL)
Zinc
mg/L
11
/
26
58%
5 : 10
5.427
18.04
4.248
0.783
5
10
26
Yes
No
Distribution Free
26
Maximum Detect (95% UTL)
Notes:
* -Tested at 5% significance level.
ug/L- Microgram per liter.
BTV - Background Threshold Value.
UPLs - Upper Prediction Limits.
KM - Kaplan -Meier Method.
UTLs - Upper Tolerance Limits.
NA - Not Available.
Var - Variance.
RL - Reporting Limit.
WH -Wilson Hilferty Transformation.
BTV values and statistics were calculated using ProUCL v. 5.0.00
Haley & Aldrich, Inc.
Table C3-3_Background Evalua[ion_Buck.Als April 2016

50
Page 1 of 1
Table C3-4
Comparison of NCDEQ Water Supply Well Sampling Data To Regional Background Threshold Values
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Constituents
Units
Frequency of
Detection (a)
Range of Detected
Concentrations
Mean
Detect
10th
Percentile
25th
Percentile
50th
Percentile
75th
Percentile
90th
Percentile
Regional
Background Threshold
Value (BTV) (b)
Number of Samples
Above Regional
BTV
Barium
ug/L
89 / 89
1.5 - 84.7
19.19
5.58
9.4
14.1
23
39.64
56.09
4
Boron
ug/L
8 / 89
5.8 - 38
18.31
5
5
5
5
6.18
6
7
Cobalt
ug/L
5 / 89
0.25 - 1.4
0.576
0.5
0.5
0.5
0.5
0.5
1
1
Hexavalent Chromium
ug/L
77 / 89
0.034 - 22.3
2.383
0.0444
0.093
0.73
2.2
7.84
2.554
15
Iron
ug/L
31 / 89
15.7 - 18,200
1664
50
50
50
112
1244
334
15
Lead
ug/L
78 / 89
0.1 - 36.5
1.679
0.1
0.18
0.49
0.92
3.1
2.617
11
Manganese
ug/L
74 / 89
0.49 272
14.05
0.5
0.91
2.3
9.7
24
66.4
3
Nickel
ug/L
31 / 89
0.2 - 6.6
1.367
0.5
0.5
0.5
0.67
1.76
2.678
4
Sodium
ug/L
89 / 89
3,750 293,000
10,136
4426
5250
6490
7890
9740
21,695
2
Sulfate
mg/L
45 / 89
0.46 711
20.67
2
2
2.1
2.8
6
33.46
1
Vanadium
ug/L
86 / 89
1 25.6
6.456
1.78
2.8
4.6
8.8
14
16.77
2
Zinc
mg/L
79 / 89
0.0064 - 2.34
0.272
0.005
0.0143
0.0328
0.243
0.635
0.491
14
Notes:
BTV - Background Threshold Value.
DEQ- Department of Environmental Quality.
mg/L - milligrams/liter.
NC - North Carolina.
ug/L - micrograms/liter.
(a) - Frequency of Detection: number of detects / total number of results.
(b) - BTV values shown on Table C3-3.
Haley & Aldrich, Inc.
Table C3-4 NCDEQ Water Supply Well Data Compared to Regional BTVs.xlsx April 2016

51
Page 1 of 1
Table C3-5
Comparison of NCDEQ Water Supply Well Sampling Data to Facility Specific Background Threshold Values
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Constituents
Units
Frequency of
Detection (a)
Range of Detected
Concentrations
Mean
Detect
10th
Percentile
25th
Percentile
50th
Percentile
75th
Percentile
90th
Percentile
Facility Specific
Background
Threshold Value
(BTV) (b)
Number of Samples
Above Facility
Specific BTV
Barium
ug/L
89 / 89
1.5 - 84.7
19.19
5.58
9.4
14.1
23
39.64
87
0
Boron
ug/L
8 / 89
5.8 - 38
18.31
5
5
5
5
6.18
54.02
0
Cobalt
ug/L
5 / 89
0.25 - 1.4
0.576
0.5
0.5
0.5
0.5
0.5
0.395
2
Hexavalent Chromium
ug/L
77 / 89
0.034 - 22.3
2.383
0.0444
0.093
0.73
2.2
7.84
0.761
38
Iron
ug/L
31 / 89
15.7 - 18,200
1664
50
50
50
112
1244
257.8
15
Lead
ug/L
78 / 89
0.1 - 36.5
1.679
0.1
0.18
0.49
0.92
3.1
0.167
69
Manganese
ug/L
74 / 89
0.49 272
14.05
0.5
0.91
2.3
9.7
24
5.799
29
Nickel
ug/L
31 / 89
0.2 - 6.6
1.367
0.5
0.5
0.5
0.67
1.76
1.566
8
Sodium
ug/L
89 / 89
3,750 293,000
10,136
4426
5250
6490
7890
9740
80,400
1
Sulfate
mg/L
45 / 89
0.46 711
20.67
2
2
2.1
2.8
6
105000
0
Vanadium
ug/L
86 / 89
1 25.6
6.456
1.78
2.8
4.6
8.8
14
167
0
Zinc
mg/L
79 / 89
0.0064 - 2.34
0.272
0.005
0.0143
0.0328
0.243
0.635
26
0
Notes:
BTV - Background Threshold Value.
DEQ- Department of Environmental Quality.
mg/L - milligrams/liter.
NA - Not Applicable.
NC - North Carolina.
ug/L - micrograms/liter.
(a) - Frequency of Detection: number of detects / total number of results.
(b) - BTV values shown on Table C3-3.
Haley & Aldrich, Inc.
Table C3-5 NCDEQ Water Supply Well Data Compared to Facility Specific BTVs.xlsx April 2016

Table C4-1
Hydrostratigraphic Layer Properties - Horizontal Hydraulic Conductivity
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Hydrostratigraphic Unit
N
Geometric
Mean (cm/sec)
Geometric Mean
+ 1SD (cm/sec)
Geometric Mean -
1SD (cm/sec)
Median
(cm/sec)
Minimum
(cm/sec)
Maximum
(cm/sec)
Ash
16
1.2E-03
8.3E-03
1.8E-04
1.7E-03
4.5E-05
1.0E-02
Fill
14
4.8E-05
1.7E-04
1.3E-05
6.4E-05
5.4E-06
3.9E-04
Alluvium (S)
10
4.9E-04
5.2E-03
4.6E-05
1.0E-03
8.2E-06
2.6E-02
M1
23
2.5E-04
1.9E-03
3.4E-05
3.4E-04
6.7E-06
7.1E-03
M2
5
1.2E-04
4.0E-04
3.9E-05
2.1 E-04
1.9E-05
3.6E-04
Transition Zone (TZ)
20
3.4E-04
2.3E-03
5.1 E-05
3.6E-04
1.4E-05
1.0E-02
Bedrock (BR)
25
8.8E-06
1.0E-04
7.5E-07
6.9E-06
5.5E-08
7.8E-04
Notes:
1. Hydraulic Conductivity, 'k,' values have an approximate lognormal distribution. Geometric mean, median, and standard deviation
estimated by taking the log of the values and running standard statistics on the log values, then converting those values back.
2. Dataset derived from CSA Investigation and historical reports. Refer to tables 11-4 and 11-6 for historic conductivity data.
3. Fill dataset derived from CSA Investigation Sites Allen (N=5), Cliffside (N=4), Dan River (N=2), and Riverbend (N= 3)
4. Alluvium dataset derived from Riverbend CSA investigation (N=3), Allen (N=2), Cliffside (N=3), and Dan River (N=2).
5. Data derived from Dan River data (See Notes 3 and 4 above) have been updated to reflect revised slug test reports from that site.
Page 1 of 1
52

Table C4-2
Estimated Groundwater Seepage Velocities
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Well Pair
Ash
Fill
Alluvium
M1
M2
TZ5%
TZ10
BR2%
BR,%
Regolith (Swells); Seepage Velocity (ft/yr)
AB -10S / MW -9S 224.3 31.7
104.9
43.2
19.5
-
-
-
-
AS -1S / GWA-12S 163.7 23.1
76.5
31.5
14.2
-
-
-
-
AB -4S / AB -9S 60.6 8.6
28.3
11.7
5.3
-
-
-
-
Transition Zone (D Wells); Seepage Velocity (ft/yr)
AB -21D / GWA-22D - -
-
-
-
292.2
146.1
-
-
AS -1 D / GWA-7D - -
-
-
-
199.6
99.8
-
-
AS -21D / GWA-41D - -
-
-
-
114.0
57.0
-
-
Fractured Bedrock (BR Wells); Seepage Velocity (ft/yr)
AB-2BR / GWA-9BR - -
-
-
-
-
-
11.8
4.7
AB-4BR / GWA-6BR - -
-
-
-
-
-
10.0
4.0
AB-7BRU / GWA-5BRU - -
-
-
-
-
-
14.6
5.8
Notes:
1. Refer to Table 11-9 for horizontal hydraulic conductivity values.
2. Refer to Table 6-11 for horizontal hydraulic gradients.
3. Refer to Table 11-8 for effective porosity/specific yield for upper hydrostratigraphic units; refer to Table 11-11 for effective porosity/specific
yield for lower hydrostratigraphic units.
4. TZ and BR subscripts indicate effective porosities used in calculations for a range of effective porosity values.
Page 1 of 1
53

Table C5-1
Site -Specific Distribution Coefficient (Kd)
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Constituent
Mininum
(L/kg)
Mean
(L/kg)
Maximum
(L/kg)
Antimony
1.27E-05
7.75E-05
6.75E-04
Boron
1.53E-02
4.30E-02
1.59E-01
Cobalt
7.37E-01
1.63E+00
4.72E+00
Chromium
4.67E+06
9.97E+06
2.92E+07
Iron
5.21E-02
1.42E-01
5.69E-01
Manganese
5.95E-02
1.22E-01
3.40E-01
Sulfate
1.73E-01
5.20E-01
3.15E+00
Vanadium
2.42E+01
1.04E+03
8.21E+04
Notes:
L/kg - Liters per kilogram.
Table adopted from Appendix E of the CAP -2 Report by HDR.
Haley & Aldrich, Inc.
Table C5-1.xlsx
Page 1 of 1
April 2016
54

Table C5-2
Coal Ash Indicator Concentrations Observed in the Water Supply Wells of Low Oxygen and High Detected Boron Concentrations
Buck Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Water Supply Well (a)
Dissolved
Oxygen
(µg/L)
Boron (µg/L)
Boron BTV
(µg/L) (b)
Barium
(µg/L)
Barium BTV
(µg/L) (b)
Sulfate
(µg/L)
Sulfate BTV
(gg/L) (b)
B13
1,225
5.8
33.5
6,500
B16
320
10.4
5.75
27,800
B21
5,350
18.4
26
<1000
B35
7,330
<20
11.1
7,000
B42
5,950
<100
10.3
<1000
54.02
87
105,000
B53
3,100
38
15
2,900
B54
7,410
25
30.2
<5000
B58
6,410
28
41
22,000
B61
4,077
13.2
3.9
711,000
664
1 6,300
1 7.7
1
1 5.5
1
1 <2000
Notes:
BTV - Background Threshold Value.
µg/L - Micrograms per liter.
(a) - The water supply wells contain detected boron concentrations and/or boron non -detects higher than 5 µg/L.
(b) - BTV = background threshold value in the unit of pg/L determined from the facility well data.
Haley & Aldrich, Inc.
Table C5-2.xlsx
Page 1 of 1
April 2016
55

VIRGINIA
L i, I I III i
--------' --- MAYO
I --------- II• ROXBORO, NC
BELEWS CREEK R MORA, NC
O
BELEWS CREEK, NC
• I •
L u,
L II
BUCK
I + + I MARSHALL SALISBURY, NC
I, dl TERELL, NC
� =li Dile
I I •,• III•
CLIFFSIDE
MOORESBORO,NC ALLEN
BELMONT, NC
+ •ai ill
IIIIIII li 3' ff
SOUTH
CAROLINA
,III •i E
NORTH
CAROLINA

YADKIN RIVER
(HIGHROCKLAKE) I �`
/
LBUCK STEAM STATION \
COAL FIRED UNITS 1.6 `� l
I ACTIVE
LEGEND
C �
1 ASH BASIN i\
OLD CE MARY CELL 3
SECONDARY J
�\ BUCK COMBINED POND J
CYCLE STATION / NOTES
i-
\QI
CELL 2 t
PRIMARY �O�O
I ACTIVE DRY ASH POND
I ASH BASIN STORAGE f♦ v
AREA
I �
I w CELL 1 ,
ADDITIONAL
I > PRIMARY POND
Y �
SOIL GRANT
I ' STORAGE
L _ I JAMES ST
I I
I
UICH
I�
LONG FERRY RD O�
ti
�v
CRAWFORDRD

LEGEND
YADKIN RIVER
(HIGH ROCKLAKE) f
..L�
LBUCK STEAM STATION
o°
I _j
O �
LONG FERRY RD OO
O
O Q
O• (') CRAWFORD RD
COAL FIRED UNITS 1.6
r
ACTIVE
1
ASH BASIN
OLD PRIMAR CEL 3
\
BUCK COMBINED
CELLSECON ARY
D
CYCLE STATION
O NOTES
I
t
O
�+
CELL 2
PRIMARY
I
/RYASH
POND O
e
I
\ ACTIVE
ASH BASIN/STORAGER
O
o
`U
I
I
w CELL 1
� r4DDITIONAI'
4 O
O
>
PR NO
•
I
rl
SOILO
STORAGE JO GRANT RDG
O
•
•
I
1
— _
OO. O
_
•
••
I
—
%
��
OOvU
OO.
/3
O
oLo 1
� � O
jo o
O q)
:o
o°
I _j
O �
LONG FERRY RD OO
O
O Q
O• (') CRAWFORD RD

i
/ YADKIN RIVER /
(HIGH ROCK LAKE) `� \
i � 1
1 , I
l \ I
100,
,
LL I t ^/ �EONPRD RD
I �
\ I W J
I J �N4
J
GRANT RD
I J Imo,
JAMES ST
ulc
IG'Fy RD
SON O
Q-
O�
�v
� s
Y
CRAWFORD11
F
e
LEGEND
NOTES

F)l
DATE
TWO MEDIUM GROUNDWATER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-1
SOIL
Regolith
ONE'
ZONE'-
unsaturated
unsaturated
none
Water table
REGOLITH
Regolith
RESIDUUM
saturated
II
zone
JfFANSITION{
4 _
ZONE l
WEATHERED
J / BEDROCK
j�
UNWEATHERED
BEDROCK
r .�
r\
t
FRACTURED BEDROCK
SHEETJOINT
r
r��
1
�
I
BEDROCK
STRUCTURE
r
� 4 1
-
r
''
I11
I
�l FRACTURE
1
1
t
NOTES:
1. HARNED, D.A. AND DANIEL III, C.C.
1992. THE TRANSITION ZONE BETWEEN BEDROCK REGOLITH: CONDUIT FOR
CONTAMINATION?, P. 336-348, IN
DANIEL, C.C., III, WHITE,
R.K., AND STONE, P.A., EDS., GROUNDWATER IN
THE PIEDMONT: PROCEEDINGS OF A CONFERENCE ON GROUND WATER IN THE PIEDMONT OF THE EASTERN
UNITED STATES, OCTOBER 16-18,
1989, CLEMSON UNIVERSITY, 693P.
F)l
DATE
TWO MEDIUM GROUNDWATER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-1

F)l
�IffR
log A0
STEM A
Slope Aquifer Boundary and Topographic D1171de
Discharge Boundary
- - - - - - - Compartment (C) Boundary
.... 0........... Water Table
X�x> - Fractures
Groundwater Flow Direction
SOURCE: LEGRAND, 2004
DATE
SLOPE AQUIFER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4.2

WELL
--------- "+
RECDC]LITH RESlzRVOIR -----------
.
�P
`5 }
STORAGE
REDROCI{
- ERACTUR'ES BEDROCK
J F
t _ Y
1 1 Y
5 Y
m
0 r, Y
P
fTA 1 � Y
Y
1
Y
Source: Heath, 1984
DATE
REGOLITH AS PRIMARY APRIL 2016
GROUNDWATER STORAGE
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-3

REGOLITH B
z
Q
TRANSITION Ccs
700E "A
BEDROCK
LAND FILL.
Arrows indicate direction
_ of ground -water flow
,LEACHATE4
W J
J
Q
W
0
Source: Harned and Daniel, 1992
DATE
FNTRANSITION ZONE AS PRIMARY TRANSMITTER APRIL 2016
OF IMPACTED GROUNDWATER
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC c4-4

NOTES:
1. PARCEL DATA FORTH E SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE.
2. WASTE BOUNDARY IS APPROXIMATE.
3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY. 5004. COMPLIANCE SHALLOW (S) MONITORING WELLS ARE SCREENED ACROSS THE SURFICIAL AQUIFER.
5. COMPLIANCE DEEP (D) MONITORING WELLS ARE SCREENED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH.
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007.
7. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP.
8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.0107 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
0 500 1,000
SCALE (FEET)
FEZ
ROWAN COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
ASH BASIN COMPLIANCE GROUNDWATER
MONITORING WELL
ASH BASIN VOLUNTARY GROUNDWATER
MONITORING WELL
WATER TABLE CONTOUR LINE
- - - DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
_ ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
STREAM
NR - NO READING
DATE
APRIL 2016
FIGURE
C4-5

0
O
0 0 0
00 00 0
O
O
O
O
O
O
19
0 FI
0
0
0 0-
00 0
O O:
O
0 0 000 00
)
O
O O 000 00
000 00 00 00
00 00 0 000 0
NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE.
2. WASTE BOUNDARY IS APPROXIMATE. 5OO 5OO �,���
3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY.
4. COMPLIANCE SHALLOW (S) MONITORING WELLS ARE SCREENED ACROSS THE SURFICIAL AQUIFER.
5. COMPLIANCE DEEP (D) MONITORING WELLS ARE SCREENED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH.
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007. SCALE (FEET)
7. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP.
8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
FEZ
ROWAN COUNTY, NORTH CAROLINA
y'.
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
GROUNDWATER CONTOUR LINE
- - - DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
W 1�READING
DATE
APRIL 2016
FIGURE
C4-6

NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE.
2. WASTE BOUNDARY IS APPROXIMATE. 500
3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY.
4. COMPLIANCE SHALLOW (S) MONITORING WELLS ARE SCREENED ACROSS THE SURFICIAL AQUIFER.
5. COMPLIANCE DEEP (D) MONITORING WELLS ARE SCREENED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH.
& TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007.
7. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP.
8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.0107 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
0 500 1,000
SCALE (FEET)
FEZ
WELLS (BR)
ROWAN COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
GROUNDWATER CONTOUR LINE
- - - DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
_ ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
STREAM
NR - NO READING
DATE
APRIL 2016
FIGURE
C4-7

O 0
O
O
OO O
00 O O 0
O
~0
0
O 0
0
O
0. O
0 O
a 0 0 00
U 000 00 0 00
00 00 0 00 0 0
NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE.
2. WASTE BOUNDARY IS APPROXIMATE.
3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY. 5OO 5OO 1,000
4. COMPLIANCE SHALLOW (S) MONITORING WELLS ARE SCREENED ACROSS THE SURFICIAL AQUIFER.
5. COMPLIANCE DEEP (D) MONITORING WELLS ARE SCREENED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH.
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007. SCALE(FEET)
7. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP.
8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.0107 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
F)l
WATER TABLE
ROWAN COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
ASH BASIN COMPLIANCE GROUNDWATER
MONITORING WELL
ASH BASIN VOLUNTARY GROUNDWATER
MONITORING WELL
WATER TABLE CONTOUR LINE
— — — DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
STREAM
NR - NO READING
WELLS (S)
DATE
APRIL 2016
FIGURE
C4-8

OO -
000 00 0 00
00 00 0 00 0 0
NOTES'
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE.
2. WASTE BOUNDARY IS APPROXIMATE.
3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY. 5OO 5OO 1,000
4. COMPLIANCE SHALLOW (S) MONITORING WELLS ARE SCREENED ACROSS THE SURFICIAL AQUIFER.
5. COMPLIANCE DEEP (D) MONITORING WELLS ARE SCREENED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH.
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007. SCALE(FEET)
7. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP.
8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.0107 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
FEZ
ROWAN COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
ASH BASIN COMPLIANCE GROUNDWATER
MONITORING WELL
ASH BASIN VOLUNTARY GROUNDWATER
MONITORING WELL
WATER TABLE CONTOUR LINE
- - - DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
STREAM
NR - NO READING
WELLS (D)
DATE
APRIL 2016
FIGURE
C4-9

O 0
O
O
OO O
00 O O 0
O
~0
0
O 0
O O
0. O
O 0 0 0 o,
0 0 �' ll '1 Acicli:�i�r?�Il Prirn-,ry Pr)fid
0
0 0 0
0 0O O
O Op 0 O 0 0 �..
O 00
O 0 (9 O O
IN]Fb o o O Opo 00
0
0 0 0 00 00
o o pp
0.
0 p0 00 0 0
O� 0 0
O 1 0p 00 0 000 0
NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE.
2. WASTE BOUNDARY IS APPROXIMATE.
3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY.
4. COMPLIANCE SHALLOW (S) MONITORING WELLS ARE SCREENED ACROSS THE SURFICIAL AQUIFER. 500 0 500 1,000
5. COMPLIANCE DEEP (D) MONITORING WELLS ARE SCREENED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH.
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007.
7. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP. SCALE(FEET)
8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
FEZ
ROWAN COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
WATER TABLE CONTOUR LINE
DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
STREAM
NR - NO READING
WELLS (BRU AND BR)
DATE
APRIL 2016
FIGURE
C4-10

DATE
NOTES: HORIZONTAL HYDRAULIC CONDUCTIVITY
1. ONLY SITE-SPECIFIC, IN-SITU MATERIAL REPRESENTED IN THIS FIGURE.��� APRIL 2016
2. REFER TO TABLE C4-1 FOR ADDITIONAL INFORMATION. MEASUREMENTS
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-11
Horizontal Hydraulic Conductivity for Native Hydrostratigraphic Layers
1.DE-a3
NT = 73
I
1.DE-02
drm
E
a
LIRE -03
�
1.aE-04—
c
,
m
�
x
1.0E-06
a
—
N
.0
0
— —
i
1.DE-07
o
—
1.aE as
M1 (N=23) M2 (N=5) TZ (N=20) BR (N=25)
2.5E-04 1.2E-04 3.4E-04 8.8E-06
DATE
NOTES: HORIZONTAL HYDRAULIC CONDUCTIVITY
1. ONLY SITE-SPECIFIC, IN-SITU MATERIAL REPRESENTED IN THIS FIGURE.��� APRIL 2016
2. REFER TO TABLE C4-1 FOR ADDITIONAL INFORMATION. MEASUREMENTS
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-11

y. v
t r.
'A
;pr
so
O t Ga�4
QlY
r
O
O 0 O
. i
OL
r r
f I
1
O ._
.. ..._, O
:00
o
O O -
x 1 ' •., � ° C��f�� AL O
O
1
p
n
O O g g .
11 �17
O o °
�b
7
u- '
1 /
5
1 La O
O o
o f 4
f 4
.
P
ell
N
y
O 1 k
O 1 x
0 0 1 1
4
O
0.0
r O 1 1 1 ay R
a
lk
" 0
a v 01 O 1
0
1 1
/'.
O 1 ■
0
O O
O_; 1 1 O O 0 0 0 0
�00L o.
O
O 0
1 0 O0 O 0
O 1 .
1L`
O — — — .� _ 1 O
O
500 0 500 1, 000
SITE CONCEPTUAL MODEL - PLAN VIEW MAP
AREA OF BORON EXCEEDANCES OF 2L STANDARDS
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
BUCK STEAM STATION ASH BASIN
LEGEND:
O
J
NOTES:
11

FILL
Q
wa
WATER
SUPPLY MW-13D
z
�
WELL -- - _- ��
O
AB-4S
AB-4SL
A13-9S
m
-
i
AB-4BRU
AB-4BR
AB-5S
AB-5SL
AB-5BRU
AB 9D
CELE 2 PRIMARY POND AB-9BR
LTI U
- \
m Z
OQ
MW-3S
O
-�- MW-3D
MW-11 S
a _ _
MW-11D
REGOLITH
-
YADKIN
RIVER
WR
I �
APPROXIMATE
BEDROCK
EXTENT OF 2L
STANDARD
EXCEEDANCES GE
BORON N
GRAOUNDWATER
A�
EAST
CROSS SECTION CELL
2 PRIMARY POND LEGEND
(LOOKINO
WEST)
ASH
REGOLITH
PARTIALLY WEATHERED
NOTE:
ROCK/TRANSITION ZONE (PWR/TZ)
1. TRANSECT AA' FROM FIGURE X—X OF THE (REPORT) REPORT USED
FOR CROSS—SECTION
ABOVE.
BEDROCK
DRAWING NOT TO SCALE AND IS INTENDED FOR ILLUSTRATION PURPOSES
ONLY.
FILL
2. APPROXIMATE EXTENT OF 2L STANDARD EXCEEDANCES OF BORON IN
GROUNDWATER BASED
ON RESULTS
APPROXIMATE EXTENT OF 2L
FROM 2015 ROUND 2 SAMPLING EVENT.
STANDARD (700 ,Ug/L)EXCEEDANCES
3. MW-11D WAS NOT SAMPLED DURING THE ROUND 2 SAMPLING EVENT,
BUT A BORON EXCEEDANCE
WAS REPORTED
DE eORON IN GROUNDWATER
IN THIS WELL DURING THE ROUND 1 SAMPLING EVENT; THEREFORE, A BORON
EXCEEDANCE IS
DEPICTED
APPROXIMATE GROUNDWATER
N ASSOCIATED WITH THIS WELL.
FLOW DIRECTION
CROSS-SECTION CONCEPTUAL SITE MODEL
DATE
F)lDUKE
WATER SUPPLY WELL EVALUATION
ENERGY CAROLINAS, LLC
APRIL_ 2016
DUCK STEAM STATION ASH DASIIV
FIGURE
ROWAN COUNTY, NORTH F"-ILII I .
D413

F)l
Pecharge
e w
(Plan \fiew) -41
L
Vertical Per olation
Ground level
Initlal wde.r level
Y
NOTE: F IGURE F ROM NORTH CAROLINAS TATE
UNIVERSITY (1995); MODIFIED FROM DRISCOLL (1986).
DATE
MOUNDING EFFECT APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-14

�' GR�nd•�idR*
Z0f D W16M
Wow Tabic
r. 45� k �
r�LOi►O 'tvr+1K1c�rl�eFtrd :r .,tr,awtl°er
M) CROSS ,SECTION
{imrw,wo*f
+�rern Dni�e
F)l
t0b EQ 0 70 w
DJ PLAN lit€W
LEIGEND
•
Equ%omt+a: Lmn
Ground wow Dw,at
�.- FIo+ Lww
t
r �
N ; t
41 1 .
70 IN so
HEAD IFT!
tta 1w 1+0 1001
�►x o1 own .t III
r of comirmbulmn to the vwIl
r Is am Table
NOTE: FIGURE FROM NORTH CAROLINA STATE
UNIVERSITY (1995); MODIFIED FROM DRISCOLL (1986).
DATE
GROUNDWATER AFFECTED BY PUMPING APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC C4-15

I�.
—'-)
IRON
=edH
e(DH)+ 02(g)>0.21 atm
A Fe.(OH)3(a)
Fe2-AA IJ 19
© El ❑ o
CH4(9) s 1 a
OCCO3
2 4 6 8
pH
NOTE
DIAGRAMS ADOPTED FROM APPENDIX E OF THE CAP -2
REPORT FOR THE BUCK STEAM STATION BY HDR.
1.0
LLI
0.0
10 12 2
MANGANESE
a,(g) a 0.21 atm
F�IfC7iIl1S11E (S)
1Ari— rc
ita
R-00
Hau
A ❑ P
m ❑
f9huclachrosite(s)
CHt(g) 3
4 6 B
pH
❑ Shallow
0 Deep
D Bedrock
(.$) d Upgrndlent
O Source
D Dewngradlent
10 12

Panel (a): Example Box Plot
L1[611*�
1. BOX PLOT EXPLANATION DIAGRAM ADOPTED FROM
HTTP:HS ITES. GOOGLE.COM/S ITE/DAVI DSSTATI STI CS/HOME/
NOTCHED -BOX -PLOTS.
2. PIPER PLOT ADOPTED FROM CSA REPORT FOR
BUCK STEAM STATION BY HDR.
Panel (b): Example Piper Plot
Ash Basin Porewater
Ash Basin Surface Water
Dewngradient"BRU" Wells
- . Io
Caklum Chloddo*F&hogen, NO2 plus NO3
CATIONS ANIONS
Possible Outlier
Upper Whiskers
75th Percentile
aka 3,rd Quartile
The "Notch"
55% Confidence Interval of . •.
: Interquartile (IOR)
the Median
i 1557 Pereerd of Datel
Median +1- 1.57 x IQR/n°'.s
25th Percentile
aka tst Quartle
I OW9r Whiskers
L1[611*�
1. BOX PLOT EXPLANATION DIAGRAM ADOPTED FROM
HTTP:HS ITES. GOOGLE.COM/S ITE/DAVI DSSTATI STI CS/HOME/
NOTCHED -BOX -PLOTS.
2. PIPER PLOT ADOPTED FROM CSA REPORT FOR
BUCK STEAM STATION BY HDR.
Panel (b): Example Piper Plot
Ash Basin Porewater
Ash Basin Surface Water
Dewngradient"BRU" Wells
- . Io
Caklum Chloddo*F&hogen, NO2 plus NO3
CATIONS ANIONS

J
1000000 Boron
100000
10000
1000
100
10
r
1
Calcium
BUCK
Chloride
I **
Sulfate
Total Dissolved Solids
AB FM RBG WSW AB FM RBG WSW AB FM RBG WSW AB FM RBG WSW AB FM RBG WSW
NOTES
ACRONYMS:
AB =ASH BASIN POREWATER WELL
FM = OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL

AI—AUIHUK: UKANI BUWLN—UFFIUt: PHA
BUCK
Barium Cobalt
J
61
O
N 10.0
C
d
V
C
Ij
•
1.0 � •
•
•
•
0.1
AB FM RBG WSW AB FM RBG WSW
NOTE
BUCK STEAM STATION
AC N WATER SUPPLY
ABO ASH `%
BASIN POREWATER WELL U'CH DUKE ENERGY WELL EVALUATION
FM=
OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL
BOX PLOT COMPARISON FOR
BARIUM AND COBALT
APRIL 2016 FIGURE C5-4

1,000,0000
Dissolved Oxygen
100,000.0
10.0
1.0
0.1
AB
BUCK
Iron
DISSOLVED
TOTAL
DISSOLVED
TOTAL
Manganese
DISSOLVED
]K DISSOLVED
TOTAL
TOTAL
FM RBG WSW AB FM RBG WSW AB FM RBG WSW
NOTES
1. ACRONYMS:
AB = ASH BASIN POREWATER WELL
FM = OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL
2. NO DISSOLVED OXYGEN CONCENTRATION DATA FOR
THE DUKE ENERGY REGIONAL BACKGROUND WELLS.
10,000.0
J
1,000.0
C
O
C
G1
V
O
100.0
L1
10.0
1.0
0.1
AB
BUCK
Iron
DISSOLVED
TOTAL
DISSOLVED
TOTAL
Manganese
DISSOLVED
]K DISSOLVED
TOTAL
TOTAL
FM RBG WSW AB FM RBG WSW AB FM RBG WSW
NOTES
1. ACRONYMS:
AB = ASH BASIN POREWATER WELL
FM = OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL
2. NO DISSOLVED OXYGEN CONCENTRATION DATA FOR
THE DUKE ENERGY REGIONAL BACKGROUND WELLS.

YADKIN RIVER
(HIGHROCKLAKE) I
fL/� GWA56RU
GWA12BRU
/
LBUCK STEAM STATION
/ COAL FIRED UNITS 1.6 GWA6BRU
GWA6BR AB9BR AB9BRU
I ` AB6BRU \
1 R` QIII) Q� AB7BRU 4GWA3BR
GWA3BR
AB5BRU U
ACTIVE
BUCK COMBINED ASH BASIN J
CYCLE STATION LD PRIMARY
GWA96R A88BRU CELLS
\I _ AB46R ® 1 SECONDARY
POND
�I 1 AB4BRU GWA2BR�
I foie BRUT
I CELL 2 t
I AB2BR PRIMARY QO�O
AS BCTIVE
ASIN�� DRY ASH POND
I STORAGE , v
AREA
I �
I w CELL 1 ,
ADDITIONAL
I > PRIMARY POND
y J
� I SOIL STORAGE J
I II BG3BRU
I %
L _ I JAMES ST
I BG1BR1
I�
6
UICH
LONG FERRY
ti
�v
Q
U
2
L
Y CRAWFORDRD
LEGEND
C - J
NOTES
FN Tal
ITA
ulky

AI—AUIHUK: UKANI BUWLN—UFFIUt: PHA
Panel (a)
Panel (b)
1,WO,000
1,000,000
•
k a
0°
• ■ ■
0 •
• ■
• r
BG - 19R
0 ao ■
aala w0 ► ■ ■
100,060
0 0 �l ■ ■
• ■
0 ■
• ■
• ■
f
■
■
b 10,000 !
� 10,000
•
m
0 BG-3BRU
1,080
• Ash Basin Porewater Well
• Ash Basin Porewater Well
a Facility Bedrock Well (Downgradient)
@ Facility Bedrock Well (Down grad i ant)
0 Facility Bedrock Well (Upgradient)
100 _ _
100
1 10 106 1,000 10,000 1 10
100 1,000 16,666
Boron Concentration (ug/L)
Baron Concentration lug/L)
Panel (c)
10000
�
O
B61
0
O—A--------
BG-1BR O r---�---------
■
106.066
0 � 4 ■� ■
0 ■
0 r r
■
Area 1
lUaQOD
m
■ .
`BG-3BRU —_—
jif
r
o
r
- I +
1 •Asir Basin Pvrewafer Well
r
1 �
t
f ®Fadk'ity Bedrock Well (Dvwngradient)
q� O Farili y Bedrock Well (Upgradient)
I Area 2
FX4--------------
----' _ ---
♦ Water Supply Well
;
----4 Regional Background Well
100
1 10
100 1,000 18000
Boron Concentration Jug/l-)
NOTES
BUCK STEAM STATION
1. ONLY WELLS SAMPLED FOR BOTH BORON AND SULFATE ARE PLOTTED.
WELL EVALUATION
SUPPLY Oft
DWATER
UKE ENERGY
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS B35 AND B42 WERE NOT
PLOTTED BECAUSE BORON WAS NOT DETECTED ATA REPORTING LIMIT
SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER SUPPLY WELLS (20 pg/L
AND 100 Ng/L RESPECTIVELY). THE SULFATE CONCENTRATIONS FOR B35
CORRELATION PLOT FOR
AND B42 WAS 7,000 Ng/LAND 10,000 pg/L.
BORON AND SULFATE
3.AREA 1 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE ASH BASIN
POREWATER; AREA 2 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE
WATER SUPPLY AND REGIONAL BACKGROUND WELLS.
APRIL 2016 FIGURE C5-7

Panel (c)
Panel (b)
■Ashy Basin Parewater Well
—
*Facility Bedrock Well(Downgradient) --
0
O OFacilo Bedrock Well (Upgradient)
O
O
08
0 0( 0 A O 00 A Q ,► A
10D
Baron concentration (uclLl
12,000
Panel (a)
¢ &Ash Basin Porewater Well
•�
10,000
OFacili Bedro(k Well U adient
F�-----�^---p Facility { pBr )
10'0°°
I I Q
Area 2 } •water Supply Well
♦Ash Basin Porewater Well
B,DOD
.
n
8,000
Z
•Facility Bedrock Well (Downgradient)
t
8,040
v
t
B53
co
t t i
a 2,440
I " Area
1 10 100 I,ik]4 10,040
� 6,000
Boron Cancentradon (ug/L)
6'000
V
0
c
c
m
� 4,000
� 4•WO
O
�
o
08
R
2,000
'c
2,0DO
O O O
1 10 100 1,000 10,000
1 10
Boron Concentration (ug/L)
Panel (c)
Panel (b)
■Ashy Basin Parewater Well
—
*Facility Bedrock Well(Downgradient) --
0
O OFacilo Bedrock Well (Upgradient)
O
O
08
0 0( 0 A O 00 A Q ,► A
10D
Baron concentration (uclLl
12,000
¢ &Ash Basin Porewater Well
•�
/Facility Befio(k Well (OOwngradient)
OFacili Bedro(k Well U adient
F�-----�^---p Facility { pBr )
8,404
I I Q
Area 2 } •water Supply Well
�,; O C, Regional Background Well
}
B,DOD
.
n
0; B6-3BRU
t
v 4,408
t
B53
t t i
a 2,440
I " Area
1 10 100 I,ik]4 10,040
Boron Cancentradon (ug/L)
NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS B35 AND B42 WERE NOT
PLOTTED BECAUSE BORON WAS NOT DETECTED ATA REPORTING LIMIT
SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER SUPPLY WELLS (20 Ng/L
AND 100 Ng/L RESPECTIVELY). THE DISSOLVED OXYGEN CONCENTRATIONS
FOR B35 AND B42 WAS 7,330 pg/LAND 5,950 pg/L.
3. AREA 1 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE ASH BASIN
POREWATER; AREA 2 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE
WATER SUPPLY AND REGIONAL BACKGROUND WELLS.

YADKIN RIVER
(HIGH ROCKLAKE) f
LBUCK STEAM STATION
COAL FIRED UNITS 1.6 L
1 B61 ` ACTIVE �A
O ASH BASIN I`\
OLD PRIMARY CELL 3 J
CELL SECONDARY ,
BUCK COMBINED POND
CYCLE STATION O
I i o 0 0 0�
CELL 2 t O
PRIMARY
I POND 0
ACTIVE DR ASH STORAGE `
I ASH BASIN 621AREA 2O O•
I ir , B16 U
I w CELL 1 4 O
ADDITIONAL
I > PRIMARY POND !'
Lu —JSOI�� C
RAE _
• STOORAGE
• I II J OO GRANT R OO O
.• o oof o0
0 0 � I -�I I 0 0
o
B533 0 0
� B35 � � � B13 � q)
o LO I Boz O o O
I O
o I I 00 00-
• B54
o�O-
I Q B58
J
o -�.
O DI J B° 0)
o•
LONG FERRY RD OO
0
0 0
LEGEND
O NOTES
0
UICH
l . %I
NN
lor

(a) Ash Basin Porewater Wells Only (b) Ash Basin Porewater and Downgradient Facility Bedrock Wells
EXPLANATION 100 EXPLANATION 100
♦ Ash Basin Porewater Well ♦ Ash Basin Porewater Well
A Facility Bedrock Well (Downgradient)
♦ n ♦ A
�♦ i e<♦e K
Ak
0 A ;� ; A 0 0 Ae A 0
Y < x ABS 9BR
100 0 / ` / \ 0 100 100 0 , ` / \ \ 0 100
/ \ /
9BRU
\ / A o \ / \ / Ae
♦ \/ \/ /\ n \/
`--- \---y -- wx i �\ \_e y __ / `PO
\ `\ / x O \ A j ♦`\ / \ `\ / k O \ �� 1`\ /
\ /
`\ \\ i `\ i 1� ♦ \\ i `\ \ \\ i `\ �� ♦
\ `♦ ` 100 \ \ , \ / e \ A \ / AB-9BR
r-----E-------------E-----)A----F-- loo----x----F---
\ ♦ \A `\ ♦i ` / /`\ i \\ ` / ` e / ♦moi e�/ ` AB-9BRU a
0 100 100 0 0 0 too 100 0
100 0 0 100 100 0 0 100
Ca'- CI Caz+ CI
CATIONS ANIONS CATIONS ANIONS

(a) Water Supply and Regional Background Wells
(b) Water Supply and Regional Background Wells and Facility
Upgradient Bedrock Wells
EXPLANATION 100 EXPLANATION 100
• Water Supply Well • Water Supply Well
O Regional Background Well O Regional Background Well
■ Facility Bedrock Well (Upgradient) ♦ /
�� '♦% � r U� 'V% d x
n n
�� a ♦♦♦ / ♦ •� 50 a ♦♦♦ / / ♦ ��� ��
r♦♦ i ♦♦ ♦` r♦jl i♦♦ BG-1BR
1000 /♦
/ ♦ x ` � ♦` 0 100 100 0 / ` �i ♦` / ♦♦ 0 100
♦` A CO ♦♦ / ♦♦ i A UC ♦♦ i
y --- 2 '�---�B61 - ---y --- 2 '♦ ---y ---
♦� -/♦♦ dX ♦ o ♦` i ♦♦ JOS ♦♦ i ♦♦ wk / ♦ o ♦ BO -\l BRA
-w-- ;E--- loo --�� --- --- ;E--- -- ;E--- loo ��L�---�--- ;E---
0 100 100 0 0 0 100 100 0
100 0 0 100 100 0 0 100
Ca'- Cl- Caz� CI
CATIONS ANIONS CATIONS ANIONS
NOTE
BLUE CIRCLES SHOW THE DATA THAT APPARENTLY DEVIATE
FROM THE GENERAL DATA CLUSTERING PATTERN.

(a) Ash Basin Porewater and Downgradient Facility Bedrock Wells (b) Water Supply and Regional Background Wells and
Upgradient Facility Bedrock Wells
EXPLANATION 100 EXPLANATION 100
♦ Ash Basin PorewaterWell • Water Supply Well
A Facility Bedrock Well (Down gradient) O Regional Background Well
V / ■ Facility Bedrock Well (Upgradient) V /
♦ A A
00 00
/ y /
�` ,♦ \\ ♦� \`\ �\
v ♦ v
A P /
100 0i ` / \ /<\ 0 100 100 0 \ /�\ 0 100
/e`
\`�' A\
\ / n O \ / \ / w O \ /
\e 4� $� \/
---y --- / \ —A -V— --- ---y --- / \ --- v— — ——
A/ ♦`\
- a---'�---- a-- '� --
-'�-- -- - - --- - - - -
--- 100n -4— --- -- ,E--- T -- iF--- 100 -�%--- -- ,F---
\♦�/fie , \ / \ • • \ , \ �\ , \ ,
o Al 16� loo loo � o o � loo too � o
100 0 0 100 100 0 0 100
Ca'' CI Cal' CF
CATIONS ANIONS CATIONS ANIONS
NOTE
BLUE DIAMOND DEFINES THE GENERAL DATA CLUSTERING
PATTERN OF THE WATER SUPPLYAND REGIONAL
BACKGROUND WELLS.

AI-AUIHUK: UKANI BUWLN-UFFIUt: PHA
1,000------------- -------- 700 `00 1J.
EXPLANATION 500 EXPLANATION
500 Crystalline---------------------------------------------- 8.0 Crystallin:
Siliciclastic �...t��, Siliciclastic
EXPLANATION c�
100 Crystalline 7.5
200 50
a Siliciclastic
100 Q 7.0
E E
a 50 10 6.5
E 5
E C
Q
l? C
m 10 1 5.5
0.5 �.
5 ��
5.0
0.1 41
2 4.5
0 0.5 1.0 0 0.5 1.0 0 0.5 1.0
Frequency concentration was exceeded Frequency concentration was exceeded Frequency concentration was exceeded
NOTES
�y BUCK STEAM STATION
WATER SUPPLY
REPORT 201D3-05072 BY UNITED (STATES G EO CAAL SURVEY.-%UICIH DUKE ENERGY WELL EVALUATION
1. IMAGES AED FROSCENTIFIC INVESTIGTIONS
2. PROBABILITY PLOTS INDICATE THE FREQUENCY (X-AXIS),
OR THE PROPORTION, OF SAMPLES WITHIN THE CRYSTALLINE- CONCENTRATION VARIABILITY OF
AND SILICICLASTIC-ROCK AQUIFERS THAT EXCEEDED THE
CONSTITUENT CONCENTRATION IN GROUNDWATER (Y-AXIS) pH, BORON, AND SULFATE IN
OR OTHER PLOTTED PARAMETER VALUES. CRYSTALLINE-ROCK AQUIFERS
APRIL 2016 FIGURE C5-13

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
ATTACHMENT C-1
Histograms and Probability Plots for Selected Constituents
APRIL 2016 U'CH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -1: Buck Regional Background Water Supply Well
Data Test for Equal Variances
APRIL 2016 U'CH

BUCK REGIONAL BACKGROUND WATER SUPPLY WELL DATA
Test for Equal Variances: Hexavalent Chromium (ug/L) versus Data Source
Method
Null hypothesis All variances are equal
Alternative hypothesis At least one variance is different
Significance level a = 0.05
95% Bonferroni Confidence Intervals for Standard Deviations
Data
Source N StDev
Duke 17 0.960651
NC DEQ 7 0.558536
CI
(0.570325, 1.86386)
(0.322991, 1.42079)
Individual confidence level = 97.5%
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.307
0.43 0.520
Test for Equal Variances: Hexavalent Chromium (ug/L) vs Data Source
Multiple comparison intervals for the standard deviation, a = 0.05
Multiple Comparisons
P -Value 0.307
Levene's Test
Duke P -Value 0.520
v
V
i
3
0
N
(0
f6
NC DEQ -
T T
0.50 0.75 1.00 1.25 1.50
If intervals do not overlap, the corresponding stdevs are significantly different.

Test for Equal Variances: Vanadium (ug/L) versus Data Source
Method
Null hypothesis All variances are equal
Alternative hypothesis At least one variance is different
Significance level a = 0.05
95% Bonferroni Confidence Intervals for Standard Deviations
Data
Source N StDev CI
Duke 17 4.90039 (3.00593, 9.2021)
NC DEQ 7 4.96075 (2.50064, 14.4765)
Individual confidence level = 97.50
Tests
Method
Multiple comparisons
Levene
v
0
V)
M
4-1M
r.,
Test
Statistic P -Value
— 0.973
0.02 0.881
Test for Equal Variances: Vanadium (ug/L) vs Data Source
Multiple comparison intervals for the standard deviation, (X = 0.05
Multiple Comparisons
P -Value 0.973
Levene's Test
Duke P -Value 0.881
I
NC DEQ
3 4 5 6 7 8 9 10
If intervals do not overlap, the corresponding stdevs are significantly different.

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -2: Buck Facility Background Monitoring Well
Data Test for Equal Variances
APRIL 2016 U'CH

BUCK FACILITY BACKGROUND MONITORING WELL DATA
Test for Equal Variances: Chromium (VI) - ug/L - T versus sys_loc_code
Method
Null hypothesis All variances are equal
Alternative hypothesis At least one variance is different
Significance level a = 0.05
95% Bonferroni Confidence Intervals for Standard Deviations
sys loc code N StDev CI
BG-1BR 1 * ( * *)
BG -1D 3 0.276451 (0.0118373, 25.5325)
BG -2D 3 0.127410 (0.0054556, 11.7674)
MW -6D 1 * (
Individual confidence level = 97.5%
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
1.13 0.289
0.35 0.585
Test for Equal Variances: Chromium (VI) - ug/L - T vs sys_loc_code
Multiple comparison intervals for the standard deviation, a = 0.05
BG -1D1
BG -2D
L I
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
If intervals do not overlap, the corresponding stdevs are significantly different.
Multiple Comparisons
P -Value 0.289
Levene's Test
P -Value 0.585
Test for Equal Variances: Vanadium - ug/L - T versus sys_loc_code

Method
Null hypothesis All variances are equal
Alternative hypothesis At least one variance is different
Significance level a = 0.05
95% Bonferroni Confidence Intervals for Standard Deviations
sys loc code N StDev CI
BG-1BR 1 * ( * *)
BG -1D 5 57.3396 (12.7682, 494.051)
BG -2D 5 1.3864 ( 0.6516, 5.659)
BG-3BRU 1 *
MW -6D 2 0.0707
Individual confidence level = 98.3333%
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.000
1.36 0.305
* NOTE * The graphical summary cannot be displayed because the multiple comparison
intervals
cannot be calculated.

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -3: Histograms and Probability Plots for Background Regional Background
Water Supply Well Data and Facility Background Monitoring Well Data
APRIL 2016 U'CH

Histogram of Background Constituents - Buck (Regional)
Barium u Boron u L Co6aU u Hexavalent Chromiu
8
4 1 10 a
00 0
p ti N A P� 6 1 ti ti '> P 5 O O d p� pg 4' O� pP O$ lry hb ti '4p N�
Histogram of Background Constituents - Buck (Facility)
Barium - u /L -T Boron - u -T 10 Cohah-u L - T Chromium -u./L-T
3.0-
5.0 20 � IIIIIn
2.5 ` 10 GI�I--L—I�LJ 15
0.0 �t 0- 0 0 00
M1 P N Po ti 1 AS P P S O�SO�Oti O' O O OP"pti o Ory p7, Cp p O6
y 20 Uon u Lead uq/1) 16 Mangan (u /L 16.Nickel u V Iron-uq/L-T Lead -u -T 20,
B Man an u /L -T Nickel-uq/L - D
C C
10 30 5.0
C 10 4 8 5 5 10 25
LLLL
0 0 0 0 0 0.0
p' ti p
10 4
Sodium u /L Sulfate (-A) /L 10 Vanadium(ug/L) 16 Zinc m
5 2-
0 0 0 0 0
�cP ycP BryycA �5B gptiScP O s .,p ti 'L rye 'h0 i P e s .,p v 'vP ti o p� pry p' pP ps pe
ti h
Probability Plot of Background Constituents- Buck
Normal - 95% CI (Regional)
99
C 90
O1
V 50
a�
10
MOM
I Al I 1 /09
Sodium -u /L -T 16- Sulfate -u /L -N
10
51 B
0 0
pp O OOOpppO g0 pp p0 8p O 'L e 8p O°°ppbp 8
'rpOti A P ti � 1� 0 p.�p
Vanadium u /L -T Zinc -u /L -T
20
4
2 1
0
O Pp A ,ti � P �' S 5p ti ti ry
Probability Plot of Background Constituents - Buck
Normal - 95% CI (Facility)
99Barium-u /L -T 99: Boron -u /L -T 99 Cobalt -u /L -T Chrom. m(V�-u -T
99
. - 96 -
5o 5o 5D So
10 10 . 10 10
1 1 1- 1
0 BO 160 20 40 60 0.0 0.5 10 0.0' 0.5 10
Uon-u -T 99. Lead -u -T 99 Mangane - -T 99 Nickel -u -D
90 90 90 90
s0 50 50 s0
a 10 10 10 10
1 1 1 1
0 Iso Sao -z.z 6.0 lz o s 1a v o a
99 Sodium -u L -T 99 Sulfate -u -N 99. Vanadium -u /L -T 99 Zinc -u -T
•
90 90 90 90
50 50 50 50
10 10 10 10
1 • 1 • 1 1 •
-60000 0 60000 -100000 0 100000 -200 0 200 0 10 20
PRIVLEGED & CONFIDENTIAL—ATTORNEY-CLIENT COMMUNICATION —ATTORNEY
WORK PRODUCT — DO NOT DISTRIBUTE WITHOUT APPROVAL OF COUNSEL

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part 4: Buck Regional Background Water Supply Well
Data Outlier Test Statistics
APRIL 2016 U'CH

Attachment C-1: Buck Regional Background Water Supply Well Data Outlier Test Statistics
Outlier Tests for Selected Uncensored Variables
User Selected Options
Date/Time of Computation 4/2/2016 6:08:00 PM
From File WorkSheet.xls
Full Precision OFF
Dixon's Outlier Test for Barium (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 74 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.383
For 10% significance level, 74 is an outlier.
For 5% significance level, 74 is not an outlier.
For 1 % significance level, 74 is not an outlier.
2. Observation Value 0.89 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.024
For 10% significance level, 0.89 is not an outlier.
For 5% significance level, 0.89 is not an outlier.
For 1 % significance level, 0.89 is not an outlier.
Dixon's Outlier Test for Hexavalent Chromium (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 2.9 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.354
For 10% significance level, 2.9 is not an outlier.
For 5% significance level, 2.9 is not an outlier.
For 1 % significance level, 2.9 is not an outlier.
2. Observation Value 0.03 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.023
For 10% significance level, 0.03 is not an outlier.
For 5% significance level, 0.03 is not an outlier.
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 1 of 5
4/8/2016

Attachment C-1: Buck Regional Background Water Supply Well Data Outlier Test Statistics
For 1 % significance level, 0.03 is not an outlier.
Dixon's Outlier Test for Iron (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 1510 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.870
For 10% significance level, 1510 is an outlier.
For 5% significance level, 1510 is an outlier.
For 1 % significance level, 1510 is an outlier.
2. Observation Value 10 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.020
For 10% significance level, 10 is not an outlier.
For 5% significance level, 10 is not an outlier.
For 1 % significance level, 10 is not an outlier.
Dixon's Outlier Test for Lead (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 3.9 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.605
For 10% significance level, 3.9 is an outlier.
For 5% significance level, 3.9 is an outlier.
For 1 % significance level, 3.9 is an outlier.
2. Observation Value 0.1 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
For 10% significance level, 0.1 is not an outlier.
For 5% significance level, 0.1 is not an outlier.
For 1 % significance level, 0.1 is not an outlier.
Dixon's Outlier Test for Manganese (ug/L)
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 2 of 5
4/8/2016

Attachment C-1: Buck Regional Background Water Supply Well Data Outlier Test Statistics
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 66.4 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.804
For 10% significance level, 66.4 is an outlier.
For 5% significance level, 66.4 is an outlier.
For 1 % significance level, 66.4 is an outlier.
2. Observation Value 0.5 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
For 10% significance level, 0.5 is not an outlier.
For 5% significance level, 0.5 is not an outlier.
For 1 % significance level, 0.5 is not an outlier.
Dixon's Outlier Test for Nickel (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 5 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.000
For 10% significance level, 5 is not an outlier.
For 5% significance level, 5 is not an outlier.
For 1 % significance level, 5 is not an outlier.
2. Observation Value 0.5 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
For 10% significance level, 0.5 is not an outlier.
For 5% significance level, 0.5 is not an outlier.
For 1 % significance level, 0.5 is not an outlier.
Dixon's Outlier Test for Sodium (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 3 of 5
4/8/2016

Attachment C-1: Buck Regional Background Water Supply Well Data Outlier Test Statistics
1. Observation Value 23000 is a Potential Outlier (Upper Tail)
Test Statistic: 0.534
For 10% significance level, 23000 is an outlier.
For 5% significance level, 23000 is an outlier.
For 1 % significance level, 23000 is an outlier.
2. Observation Value 4380 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.029
For 10% significance level, 4380 is not an outlier.
For 5% significance level, 4380 is not an outlier.
For 1 % significance level, 4380 is not an outlier.
Dixon's Outlier Test for Sulfate (mg/L)
Number of Observations = 9
10% critical value: 0.441
5% critical value: 0.512
1 % critical value: 0.635
1. Observation Value 31.5 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.122
For 10% significance level, 31.5 is not an outlier.
For 5% significance level, 31.5 is not an outlier.
For 1 % significance level, 31.5 is not an outlier.
2. Observation Value 0.26 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.007
For 10% significance level, 0.26 is not an outlier.
For 5% significance level, 0.26 is not an outlier.
For 1 % significance level, 0.26 is not an outlier.
Dixon's Outlier Test for Vanadium (ug/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 16.4 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.208
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 4 of 5
4/8/2016

Attachment C-1: Buck Regional Background Water Supply Well Data Outlier Test Statistics
For 10% significance level, 16.4 is not an outlier.
For 5% significance level, 16.4 is not an outlier.
For 1 % significance level, 16.4 is not an outlier.
2. Observation Value 1 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
For 10% significance level, 1 is not an outlier.
For 5% significance level, 1 is not an outlier.
For 1 % significance level, 1 is not an outlier.
Dixon's Outlier Test for Zinc (mg/L)
Number of Observations = 24
10% critical value: 0.367
5% critical value: 0.413
1 % critical value: 0.497
1. Observation Value 0.645 is a Potential Outlier (Upper Tail)',
Test Statistic: 0.359
For 10% significance level, 0.645 is not an outlier.
For 5% significance level, 0.645 is not an outlier.
For 1 % significance level, 0.645 is not an outlier.
2. Observation Value 0.005 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
For 10% significance level, 0.005 is not an outlier.
For 5% significance level, 0.005 is not an outlier.
For 1 % significance level, 0.005 is not an outlier.
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 5 of 5
4/8/2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part 5: Buck Facility Background Monitoring Well Data Outlier Test Statistics
APRIL 2016 U'CH

Attachment C-1: Buck Facility Background Monitoring Well Data Outlier Test Statistics
Outlier Tests for Selected Uncensored Variables
User Selected Options
Date/Time of Computation 4/4/2016 11:30:58 AM
From File WorkSheet a.xls
Full Precision OFF
Rosner's Outlier Test for Barium - ug/L - T
Mean 63.85
Standard Deviation 79.46
Number of data 27
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 63.85 77.97 430 27 4.696 2.86 3.18
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 430
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 430
Rosner's Outlier Test for Boron - ug/L - T
Mean 46.19
Standard Deviation 8.316
Number of data 27
Number of suspected outliers 1
Potential Obs.
# Mean sd outlier Number
1 46.19 8.161 25 19
For 5% Significance Level, there is no Potential Outlier
For 1% Significance Level, there is no Potential Outlier
Dixon's Outlier Test for Cobalt - ug/L - T
Number of Observations = 14
10% critical value: 0.492
5% critical value: 0.546
1 % critical value: 0.641
1. Observation Value 1.8 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.828
For 10% significance level, 1.8 is an outlier.
Haley & Aldrich, Inc.
Outlier test stats before removing outliers.xlsx
Test Critical Critical
value value (5%) value (1%)
2.596 2.86 3.18
Page 1 of 5
4/8/2016

Attachment C-1: Buck Facility Background Monitoring Well Data Outlier Test Statistics
For 5% significance level, 1.8 is an outlier.
For 1 % significance level, 1.8 is an outlier.
2. Observation Value 0.13 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.270
For 10% significance level, 0.13 is not an outlier.
For 5% significance level, 0.13 is not an outlier.
For 1 % significance level, 0.13 is not an outlier.
Dixon's Outlier Test for Chromium (VI) - ug/L - T
Number of Observations = 8
10% critical value: 0.479
5% critical value: 0.554
1 % critical value: 0.683
1. Observation Value 6.5 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.950
For 10% significance level, 6.5 is an outlier.
For 5% significance level, 6.5 is an outlier.
For 1 % significance level, 6.5 is an outlier.
2. Observation Value 0.074 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.387
For 10% significance level, 0.074 is not an outlier.
For 5% significance level, 0.074 is not an outlier.
For 1 % significance level, 0.074 is not an outlier.
Rosner's Outlier Test for Iron - ug/L - T
Mean 529.8
Standard Deviation 1700
Number of data 29
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 529.8 1671 7000 29 3.873 2.89 3.22
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 7000
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 7000
Haley & Aldrich, Inc.
Outlier test stats before removing outliers.xlsx
Page 2 of 5
4/8/2016

Attachment C-1: Buck Facility Background Monitoring Well Data Outlier Test Statistics
Rosner's Outlier Test for Lead - ug/L - T
Mean 0.614
Standard Deviation 0.564
Number of data 27
Number of suspected outliers 1
Potential Obs. Test
Critical Critical
# Mean sd outlier Number value
value (5%) value (1%)
1 0.614 0.553 2.3 27 3.048
2.86 3.18
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 2.3
For 1% Significance Level, there is no Potential Outlier
Rosner's Outlier Test for Manganese - ug/L - T
Mean 9.705
Standard Deviation 19.32
Number of data 29
Number of suspected outliers 1
Potential Obs. Test
Critical Critical
# Mean sd outlier Number value
value (5%) value (1%)
1 9.705 18.98 82 29 3.808
2.89 3.22
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 82
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 82
Dixon's Outlier Test for Nickel - ug/L - D
Number of Observations = 16
10% critical value: 0.454
5% critical value: 0.507
1 % critical value: 0.595
1. Observation Value 5 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.737
For 10% significance level, 5 is an outlier.
For 5% significance level, 5 is an outlier.
For 1 % significance level, 5 is an outlier.
2. Observation Value 0.23 is a Potential Outlier (Lower Tail)?
Haley & Aldrich, Inc.
Outlier test stats before removing outliers.xlsx
Page 3 of 5
4/8/2016

Attachment C-1: Buck Facility Background Monitoring Well Data Outlier Test Statistics
Test Statistic: 0.016
For 10% significance level, 0.23 is not an outlier.
For 5% significance level, 0.23 is not an outlier.
For 1 % significance level, 0.23 is not an outlier.
Dixon's Outlier Test for Sodium - ug/L - T
Number of Observations = 22
10% critical value: 0.382
5% critical value: 0.43
1 % critical value: 0.514
1. Observation Value 239000 is a Potential Outlier (Upper Tail
Test Statistic: 0.703
For 10% significance level, 239000 is an outlier.
For 5% significance level, 239000 is an outlier.
For 1 % significance level, 239000 is an outlier.
2. Observation Value 5630 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.003
For 10% significance level, 5630 is not an outlier.
For 5% significance level, 5630 is not an outlier.
For 1 % significance level, 5630 is not an outlier.
Rosner's Outlier Test for Sulfate - ug/L - N
Mean 27791
Standard Deviation 53414
Number of data 27
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 27791 52416 246000 27 4.163 2.86 3.18
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 246000
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 246000
Dixon's Outlier Test for Vanadium - ug/L - T
Number of Observations = 14
Haley & Aldrich, Inc.
Outlier test stats before removing outliers.xlsx
Page 4 of 5
4/8/2016

Attachment C-1: Buck Facility Background Monitoring Well Data Outlier Test Statistics
10% critical value: 0.492
5% critical value: 0.546
1 % critical value: 0.641
1. Observation Value 167 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.101
For 10% significance level, 167 is not an outlier.
For 5% significance level, 167 is not an outlier.
For 1 % significance level, 167 is not an outlier.
2. Observation Value 7.3 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.008
For 10% significance level, 7.3 is not an outlier.
For 5% significance level, 7.3 is not an outlier.
For 1 % significance level, 7.3 is not an outlier.
Rosner's Outlier Test for Zinc - ug/L - T
Mean 10.62
Standard Deviation 22.28
Number of data 27
Number of suspected outliers 1
Potential Obs.
# Mean sd outlier Number
1 10.62 21.86 120 27
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 120
For 1% Significance Level, there is 1 Potential Outlier
Potential outliers is: 120
Haley & Aldrich, Inc.
Outlier test stats before removing outliers.xlsx
Test Critical Critical
value value (5%) value (1%)
5.003 2.86 3.18
Page 5 of 5
4/8/2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
ATTACHMENT C-2
Results of Statistical Computations
APRIL 2016 U'CH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -1: Buck Regional Background Water Supply Well Data GOF Statistics
APRIL 2016 U'CH

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Goodness -of -Fit Test Statistics for Data Sets with Non -Detects
User Selected Options
Date/Time of Computation 4/2/2016 6:09:49 PM
From File WorkSheet.xls
Full Precision OFF
Confidence Coefficient 0.95
Barium (ug/L)
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.907 0.883 0.883 0.557
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Num Obs
Num Miss
Num Valid
Detects
NDs
% NDs
Raw Statistics
24
0
24
21
3
12.50%
Data Not Normal
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
3
5
5
5
5
0
Statistics (Detects Only)
21
0.89
74
18.65
9.4
20.13
Statistics (All: NDs treated as DL value)
24
0.89
74
16.94
7.15
19.33
Statistics (All: NDs treated as DL/2 value)
24
0.89
74
16.63
7.15
19.55
Statistics (Normal ROS Imputed Data)
24
-8.994
74
16.2
7.15
20.03
Statistics (Gamma ROS Imputed Data)
24
0.01
74
16.46
7.15
19.69
Statistics (Lognormal ROS Imputed Data)
24
0.89
74
16.63
7.15
19.55
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.865
0.773
21.55
2.247
1.321
0.588
Statistics (NDs = DL)
0.884
0.801
19.16
2.167
1.25
0.577
Statistics (NDs = DL/2)
0.811
0.737
20.51
2.08
1.311
0.63
Statistics (Gamma ROS Estimates)
0.594
0.547
27.72
Statistics (Lognormal ROS Estimates)
2.068
1.333
0.645
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.907 0.883 0.883 0.557
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.822
0.908
Data Not Normal
0.239
0.193
Data Not Normal
0.781
0.916
Data Not Normal
0.267
0.181
Data Not Normal
0.781
0.916
Data Not Normal
0.26
0.181
Data Not Normal
0.839
0.916
Data Not Normal
0.248
0.181
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO:
Correlation Coefficient R 0.986 0.986 0.986 0.983
Anderson -Darling (Detects Only)
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Test value Crit. (0.05) Conclusion with Alpha(0.05)
0.362 0.777
Page 1 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Kolmogorov-Smirnov (Detects Only)
0.134
0.196
Detected Data Appear Gamma Distributed
Anderson -Darling (NDs = DL)
0.62
0.777
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.167
0.184
Data Appear Gamma Distributed
Anderson -Darling (NDs = DL/2)
0.682
0.78
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.149
0.184
Data Appear Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
0.206
0.797
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.0963
0.187
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.984 0.986 0.982 0.986
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.957
0.908
Data Appear Lognormal
Lilliefors (Detects Only)
0.114
0.193
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.96
0.916
Data Appear Lognormal
Lilliefors (NDs = DL)
0.106
0.181
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.949
0.916
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.146
0.181
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.956
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.108
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
0.245
Hexavalent Chromium (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 24 0 24 21 3 12.50%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
3
0.03
0.6
0.41
0.6
0.329
21
0.063
2.9
0.831
0.25
0.893
24
0.03
2.9
0.778
0.355
0.851
24
0.015
2.9
0.753
0.275
0.861
24
-1.209
2.9
0.693
0.245
0.947
24
0.01
2.9
0.742
0.245
0.868
24
0.0172
2.9
0.742
0.24
0.868
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.831
0.744
1
-0.896
1.311
-1.463
0.819
0.745
0.95
-0.973
1.341
-1.379
0.769
0.701
0.978
-1.059
1.397
-1.318
0.699
0.639
1.062
-1.11
1.409
-1.27
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.906 0.906 0.892 0.918
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 2 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.813
0.908
Data Not Normal
0.266
0.193
Data Not Normal
0.813
0.916
Data Not Normal
0.233
0.181
Data Not Normal
0.789
0.916
Data Not Normal
0.284
0.181
Data Not Normal
0.892
0.916
Data Not Normal
0.222
0.181
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.963 0.974 0.968 0.965
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.92
0.779
0.173
0.223
0.196
Data Not Gamma Distributed
0.638
0.78
Data Appear Lognormal
0.181
0.184
Data Appear Gamma Distributed
0.779
0.782
0.95
0.2
0.185
Detected Data appear Approximate Gamma Distri
0.711
0.787
Data Appear Lognormal
0.177
0.186
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.962 0.98 0.978 0.974
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.908
0.908
Data Not Lognormal
Lilliefors (Detects Only)
0.173
0.193
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.947
0.916
Data Appear Lognormal
Lilliefors (NDs = DL)
0.14
0.181
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.95
0.916
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.145
0.181
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.94
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.161
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
505.2
Iron (ug/L)
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 3 of 13
4/8/2016
Num Obs
Num Miss
Num Valid
Detects
NDs
% NDs
Raw Statistics
24
0
24
8
16
66.67%
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
16
10
50
45
50
13.66
Statistics (Detects Only)
8
14
1510
279.5
107.6
505.2
Statistics (All: NDs treated as DL value)
24
10
1510
123.2
50
300.9
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 3 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Statistics (All: NDs treated as DL/2 value)
24
5
1510
108.2
25
305
Statistics (Normal ROS Imputed Data)
24
-983.1
1510
-157
-94.46
503.2
Statistics (Gamma ROS Imputed Data)
24
0.01
1510
95.8
0.01
308.9
Statistics (Lognormal ROS Imputed Data)
24
0.3
1510
101
14
307.3
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.553
0.429
505.4
4.502
1.611
0.358
Statistics (NDs = DL)
0.718
0.656
171.6
3.975
1.064
0.268
Statistics (NDs = DL/2)
0.536
0.497
201.6
3.513
1.224
0.348
Statistics (Gamma ROS Estimates)
0.135
0.146
708.3
Statistics (Lognormal ROS Estimates)
2.529
2.092
0.827
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.741 0.55 0.546 0.511
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.576
0.818
Data Not Normal
0.403
0.313
Data Not Normal
0.332
0.916
Data Not Normal
0.411
0.181
Data Not Normal
0.328
0.916
Data Not Normal
0.393
0.181
Data Not Normal
0.882
0.916
Data Not Normal
0.171
0.181
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO'
Correlation Coefficient R 0.948 0.796 0.828 0.945
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.508
0.759
0.235
0.308
Detected Data Appear Gamma Distributed
3.513
0.786
0.39
0.185
Data Not Gamma Distributed
4.109
0.803
0.407
0.188
Data Not Gamma Distributed
3.111
0.959
0.39
0.202
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.972 0.888 0.87 0.993
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only) 0.936 0.818 Data Appear Lognormal
Lilliefors (Detects Only) 0.143 0.313 Data Appear Lognormal
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 4 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (NDs = DL)
0.806
0.916
Data Not Lognormal
Lilliefors (NDs = DL)
0.315
0.181
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.775
0.916
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.345
0.181
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.985
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0639
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
3.9
Lead (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 24 0 24 16 8 33.33%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
8
0.1
1
0.55
0.55
0.481
16
0.12
3.9
1.109
0.84
1.079
24
0.1
3.9
0.923
0.84
0.95
24
0.05
3.9
0.831
0.5
0.968
24
-1.806
3.9
0.542
0.445
1.292
24
0.01
3.9
0.784
0.445
0.999
24
0.0364
3.9
0.8
0.445
0.984
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
1.253
1.06
0.885
-0.346
1.04
-3.005
1.072
0.966
0.86
-0.615
1.148
-1.867
0.887
0.804
0.937
-0.846
1.299
-1.536
0.525
0.487
1.495
-0.923
1.284
-1.391
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.897 0.878 0.857 0.894
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.807
0.887
Data Not Normal
0.199
0.222
Data Appear Normal
0.777
0.916
Data Not Normal
0.217
0.181
Data Not Normal
0.742
0.916
Data Not Normal
0.251
0.181
Data Not Normal
0.944
0.916
Data Appear Normal
0.132
0.181
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.983 0.976 0.981 0.987
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 5 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Anderson -Darling (Detects Only)
0.238
0.759
Data Appear Lognormal
Kolmogorov-Smirnov (Detects Only)
0.108
0.22
Detected Data Appear Gamma Distributed
Anderson -Darling (NDs = DL)
0.617
0.77
Data Not Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.141
0.183
Data Appear Gamma Distributed
Anderson -Darling (NDs = DL/2)
0.456
0.777
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.141
0.184
Data Appear Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
0.592
0.804
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.169
0.188
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.986 0.96 0.969 0.991
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.961
0.887
Data Appear Lognormal
Lilliefors (Detects Only)
0.124
0.222
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.906
0.916
Data Not Lognormal
Lilliefors (NDs = DL)
0.187
0.181
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.927
0.916
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.171
0.181
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.972
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.116
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
0.69
Manganese (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 24 0 24 13 11 45.83%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
11
0.5
5
2.136
0.5
2.27
13
0.56
66.4
11.46
2.3
21.15
24
0.5
66.4
7.189
1.1
16.07
24
0.25
66.4
6.699
1.1
16.18
24
-50.24
66.4
-4.843
0.69
25.91
24
0.01
66.4
6.319
0.69
16.32
24
0.0102
66.4
6.35
0.69
16.3
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.474
0.416
24.2
1.087
1.618
1.489
0.484
0.452
14.84
0.655
1.478
2.257
0.418
0.393
16.04
0.337
1.627
4.827
0.23
0.229
27.51
-0.412
2.251
-5.461
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.755 0.666 0.648 0.503
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 6 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.581
0.866
Data Not Normal
0.356
0.246
Data Not Normal
0.461
0.916
Data Not Normal
0.388
0.181
Data Not Normal
0.438
0.916
Data Not Normal
0.436
0.181
Data Not Normal
0.902
0.916
Data Not Normal
0.185
0.181
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO:
Correlation Coefficient R 0.961 0.925 0.924 0.957
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
1.302
0.795
0.234
0.319
0.251
Data Not Gamma Distributed
2.397
0.81
Data Not Lognormal
0.233
0.189
Data Not Gamma Distributed
2.446
0.825
0.876
0.337
0.19
Data Not Gamma Distributed
1.649
0.885
Data Not Lognormal
0.239
0.196
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.937 0.926 0.941 0.991
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.864
0.866
Data Not Lognormal
Lilliefors (Detects Only)
0.234
0.246
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.847
0.916
Data Not Lognormal
Lilliefors (NDs = DL)
0.181
0.181
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.876
0.916
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.194
0.181
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.977
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.111
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Nickel(ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 24 0 24 4 20 83.33%
Number Minimum Maximum Mean Median SD
Statistics (Non -Detects Only) 20 0.5 5 1.85 0.5 2.116
Statistics (Detects Only) 4 0.59 4.1 1.698 1.05 1.621
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 7 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Statistics (All: NDs treated as DL value)
24
0.5
5
1.825
0.5
2.011
Statistics (All: NDs treated as DL/2 value)
24
0.25
4.1
1.054
0.25
1.163
Statistics (Normal ROS Imputed Data)
24
-11.26
4.1
-3.955
-4.069
3.878
Statistics (Gamma ROS Imputed Data)
24
0.01
4.1
0.322
0.01
0.872
Statistics (Lognormal ROS Imputed Data)
24
0.00109
4.1
0.366
0.0557
0.859
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
1.879
0.636
0.903
0.24
0.833
3.471
Statistics (NDs = DL)
1.022
0.922
1.785
0.038
1.033
27.16
Statistics (NDs = DL/2)
0.978
0.883
1.078
-0.54
1.089
-2.018
Statistics (Gamma ROS Estimates)
0.281
0.273
1.149
Statistics (Lognormal ROS Estimates)
-2.838
2.109
-0.743
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.871 0.796 0.84 0.7
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.769
0.748
Data Appear Normal
0.371
0.443
Data Appear Normal
0.617
0.916
Data Not Normal
0.355
0.181
Data Not Normal
0.702
0.916
Data Not Normal
0.338
0.181
Data Not Normal
0.987
0.916
Data Appear Normal
0.0877
0.181
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.979 0.85 0.926 0.948
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.445
0.661
0.328
0.398
Detected Data Appear Gamma Distributed
4.174
0.771
0.353
0.183
Data Not Gamma Distributed
3.276
0.773
0.367
0.183
Data Not Gamma Distributed
5.613
0.86
0.499
0.194
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.952 0.819 0.853 0.997
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only) 0.915 0.748 Data Appear Lognormal
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 8 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Lilliefors (Detects Only)
0.278
0.443
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.651
0.916
Data Not Lognormal
Lilliefors (NDs = DL)
0.344
0.181
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.711
0.916
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.365
0.181
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.989
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0717
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
24
Vanadium (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 24 0 24 21 3 12.50%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
3
1
1
1
1
0
21
1.19
16.4
6.876
5
4.862
24
1
16.4
6.141
4.65
4.95
24
0.5
16.4
6.079
4.65
5.02
24
-6.201
16.4
5.47
4.65
5.937
24
0.01
16.4
6.022
4.65
5.087
24
0.635
16.4
6.126
4.65
4.967
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
2.013
1.757
3.416
1.659
0.784
0.472
1.523
1.36
4.033
1.452
0.921
0.634
1.279
1.147
4.753
1.365
1.08
0.791
0.735
0.671
8.19
1.432
0.958
0.669
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.951 0.942 0.95 0.956
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.892
0.908
Data Not Normal
0.206
0.193
Data Not Normal
0.872
0.916
Data Not Normal
0.2
0.181
Data Not Normal
0.887
0.916
Data Not Normal
0.194
0.181
Data Not Normal
0.964
0.916
Data Appear Normal
0.143
0.181
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma ROc
Correlation Coefficient R 0.97 0.969 0.965 0.939
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 9 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.441
0.754
0.122
0.126
0.192
Detected Data Appear Gamma Distributed
0.463
0.761
Data Appear Lognormal
0.114
0.181
Data Appear Gamma Distributed
0.324
0.766
0.923
0.0968
0.182
Data Appear Gamma Distributed
0.87
0.784
Data Appear Lognormal
0.176
0.185
Detected Data appear Approximate Gamma Distri
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.982 0.977 0.969 0.984
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.952
0.908
Data Appear Lognormal
Lilliefors (Detects Only)
0.122
0.193
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.935
0.916
Data Appear Lognormal
Lilliefors (NDs = DL)
0.119
0.181
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.923
0.916
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.114
0.181
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.954
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.117
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
0.0169
Zinc (mg/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 24 0 24 18 6 25.00%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
6
0.005
0.005
0.005
0.005
0
18
0.0079
0.645
0.17
0.0524
0.215
24
0.005
0.645
0.129
0.0169
0.199
24
0.0025
0.645
0.128
0.0169
0.199
24
-0.495
0.645
0.0479
0.0169
0.289
24
0.0079
0.645
0.13
0.0169
0.198
24
3.4731 E-4
0.645
0.128
0.0169
0.199
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.605
0.541
0.281
-2.793
1.596
-0.571
0.469
0.438
0.274
-3.419
1.764
-0.516
0.424
0.399
0.302
-3.593
1.971
-0.549
0.524
0.486
0.248
-
-
-3.741
2.205
-0.589
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Page 10 of 13
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx 4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Correlation Coefficient R
0.877
0.823
0.825 0.918
0.791
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.759
0.897
Data Not Normal
Lilliefors (Detects Only)
0.283
0.209
Data Not Normal
Shapiro -Wilk (NDs = DL)
0.673
0.916
Data Not Normal
Lilliefors (NDs = DL)
0.317
0.181
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.677
0.916
Data Not Normal
Lilliefors (NDs = DL/2)
0.315
0.181
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.944
0.916
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.195
0.181
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.953 0.959 0.957 0.959
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.851
0.791
0.897
0.175
0.214
Detected Data appear Approximate Gamma Distri
1.621
0.813
Data Appear Lognormal
0.226
0.189
Data Not Gamma Distributed
1.209
0.823
0.174
0.199
0.19
Data Not Gamma Distributed
2.149
0.804
Data Not Lognormal
0.256
0.188
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.96 0.943 0.96 0.986
User Selected Options
Date/Time of Computation
From File
Full Precision
Confidence Coefficient
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Goodness -of -Fit Test Statistics for Uncensored Full Data Sets without Non -Detects
4/2/2016 6:09:21 PM
WorkSheet.xls
OFF
0.95
Page 11 of 13
4/8/2016
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.897
0.897
Data Appear Lognormal
Lilliefors (Detects Only)
0.157
0.209
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.868
0.916
Data Not Lognormal
Lilliefors (NDs = DL)
0.174
0.181
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.899
0.916
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.138
0.181
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.959
0.916
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.105
0.181
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are not recommended.
User Selected Options
Date/Time of Computation
From File
Full Precision
Confidence Coefficient
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Goodness -of -Fit Test Statistics for Uncensored Full Data Sets without Non -Detects
4/2/2016 6:09:21 PM
WorkSheet.xls
OFF
0.95
Page 11 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Sodium (ug/L)
Raw Statistics
0.877
Number of Valid Observations
24
Number of Distinct Observations
22
Minimum
4380
Maximum
23000
Mean of Raw Data
8703
Standard Deviation of Raw Data
4671
Khat
4.967
Theta hat
1752
Kstar
4.374
Theta star
1990
Mean of Log Transformed Data
8.967
Standard Deviation of Log Transformed Data
0.441
Normal GOF Test Results
Correlation Coefficient R
0.877
Shapiro Wilk Test Statistic
0.774
Shapiro Wilk Critical (0.05) Value
0.916
Approximate Shapiro Wilk P Value 5.6886E-5
0.0742
Lilliefors Test Statistic
0.233
Lilliefors Critical (0.05) Value
0.181
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.945
A -D Test Statistic 0.83
A -D Critical (0.05) Value 0.746
K -S Test Statistic 0.178
K -S Critical(0.05) Value 0.178
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.964
Shapiro Wilk Test Statistic
0.924
Shapiro Wilk Critical (0.05) Value
0.916
Approximate Shapiro Wilk P Value
0.0742
Lilliefors Test Statistic
0.145
Lilliefors Critical (0.05) Value
0.181
Data appear Lognormal at (0.05) Significance Level
Sulfate (mg/L)
Raw Statistics
Number of Valid Observations
9
Number of Missing Observations
15
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 12 of 13
4/8/2016

Attachment C-2: Buck Regional Background Water Supply Well Data GOF Statistics
Number of Distinct Observations
9
Minimum
0.26
Maximum
31.5
Mean of Raw Data
10.5
Standard Deviation of Raw Data
11.71
Khat
0.707
Theta hat
14.85
Kstar
0.546
Theta star
19.24
Mean of Log Transformed Data
1.498
Standard Deviation of Log Transformed Data
1.674
Normal GOF Test Results
Correlation Coefficient R
0.909
Shapiro Wilk Test Statistic
0.813
Shapiro Wilk Critical (0.05) Value
0.829
Approximate Shapiro Wilk P Value
0.0386
Lilliefors Test Statistic
0.287
Lilliefors Critical (0.05) Value
0.295
Data appear Approximate Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R
0.957
A -D Test Statistic
0.249
A -D Critical (0.05) Value
0.755
K -S Test Statistic
0.134
K -S Critical(0.05) Value
0.29
Data appear Gamma Distributed at (0.05) Significance Level
0.295
Lognormal GOF Test Results
Correlation Coefficient R
0.964
Shapiro Wilk Test Statistic
0.917
Shapiro Wilk Critical (0.05) Value
0.829
Approximate Shapiro Wilk P Value
0.455
Lilliefors Test Statistic
0.168
Lilliefors Critical (0.05) Value
0.295
Data appear Lognormal at (0.05) Significance Level
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 13 of 13
4/8/2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -2: Buck Facility Background Monitoring Well Data GOF Statistics
APRIL 2016 U'CH

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Goodness -of -Fit Test Statistics for Uncensored Full Data Sets without Non -Detects
User Selected Options
0.928
Date/Time of Computation 4/4/2016 11:47:17 AM
0.835
From File WorkSheet a.xls
0.92
Full Precision OFF
Confidence Coefficient 0.95
0.228
Barium - ug/L - T
0.174
Raw Statistics
Number of Valid Observations
26
Number of Missing Observations
1
Number of Distinct Observations
23
Minimum
6.1
Maximum
87
Mean of Raw Data
49.77
Standard Deviation of Raw Data
31.58
Khat
1.559
Theta hat
31.92
Kstar
1.405
Theta star
35.43
Mean of Log Transformed Data
3.554
Standard Deviation of Log Transformed Data
1.003
Normal GOF Test Results
Correlation Coefficient R
0.928
Shapiro Wilk Test Statistic
0.835
Shapiro Wilk Critical (0.05) Value
0.92
Approximate Shapiro Wilk P Value 5.3264E-4
Lilliefors Test Statistic
0.228
Lilliefors Critical (0.05) Value
0.174
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.83
A -D Test Statistic 1.979
A -D Critical (0.05) Value 0.761
K -S Test Statistic 0.286
K -S Critical(0.05) Value 0.174
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.901
Shapiro Wilk Test Statistic
0.79
Shapiro Wilk Critical (0.05) Value
0.92
Approximate Shapiro Wilk P Value 6.4663E-5
Lilliefors Test Statistic
0.293
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 1 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Lilliefors Critical (0.05) Value 0.174
Data not Lognormal at (0.05) Significance Level
Chromium (VI) - ug/L - T
Raw Statistics
0.953
Number of Valid Observations
7
Number of Missing Observations
19
Number of Distinct Observations
7
Minimum
0.074
Maximum
0.58
Mean of Raw Data
0.386
Standard Deviation of Raw Data
0.181
Khat
3.229
Theta hat
0.12
Kstar
1.94
Theta star
0.199
Mean of Log Transformed Data
-1.114
Standard Deviation of Log Transformed Data
0.72
Normal GOF Test Results
Correlation Coefficient R
0.953
Shapiro Wilk Test Statistic
0.904
Shapiro Wilk Critical (0.05) Value
0.803
Approximate Shapiro Wilk P Value
0.399
Lilliefors Test Statistic
0.25
Lilliefors Critical (0.05) Value
0.335
Data appear Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R
0.871
A -D Test Statistic
0.607
A -D Critical (0.05) Value
0.712
K -S Test Statistic
0.28
K -S Critical(0.05) Value
0.314
Data appear Gamma Distributed at (0.05) Significance Level
0.335
Lognormal GOF Test Results
Correlation Coefficient R
0.876
Shapiro Wilk Test Statistic
0.78
Shapiro Wilk Critical (0.05) Value
0.803
Approximate Shapiro Wilk P Value
0.0191
Lilliefors Test Statistic
0.262
Lilliefors Critical (0.05) Value
0.335
Data appear Approximate -Lognormal at (0.05) Significance Level
Sodium - ug/L - T
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 2 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Raw Statistics
Number of Valid Observations 21
Number of Missing Observations 6
Number of Distinct Observations 21
Minimum 5630
Maximum 80400
Mean of Raw Data 22526
Standard Deviation of Raw Data 24803
Khat 1.174
Theta hat 19190
Kstar 1.038
Theta star 21703
Mean of Log Transformed Data 9.539
Standard Deviation of Log Transformed Data 0.959
Normal GOF Test Results
Correlation Coefficient R
0.841
Shapiro Wilk Test Statistic
0.701
Shapiro Wilk Critical (0.05) Value
0.908
Approximate Shapiro Wilk P Value 9.9538E-6
0.00113
Lilliefors Test Statistic
0.249
Lilliefors Critical (0.05) Value
0.193
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.949
A -D Test Statistic 1.761
A -D Critical (0.05) Value 0.766
K -S Test Statistic 0.247
K -S Critical(0.05) Value 0.194
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.918
Shapiro Wilk Test Statistic
0.825
Shapiro Wilk Critical (0.05) Value
0.908
Approximate Shapiro Wilk P Value
0.00113
Lilliefors Test Statistic
0.243
Lilliefors Critical (0.05) Value
0.193
Data not Lognormal at (0.05) Significance Level
Sulfate - ug/L - N
Raw Statistics
Number of Valid Observations
26
Number of Missing Observations
1
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 3 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Number of Distinct Observations 21
Minimum 170
Maximum 105000
Mean of Raw Data 19399
Standard Deviation of Raw Data 31454
Khat 0.481
Theta hat 40354
Kstar 0.451
Theta star 43024
Mean of Log Transformed Data 8.544
Standard Deviation of Log Transformed Data 1.735
Normal GOF Test Results
Correlation Coefficient R
0.794
Shapiro Wilk Test Statistic
0.629
Shapiro Wilk Critical (0.05) Value
0.92
Approximate Shapiro Wilk P Value 1.0284E-7
0.00409
Lilliefors Test Statistic
0.304
Lilliefors Critical (0.05) Value
0.174
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.951
A -D Test Statistic 2.038
A -D Critical (0.05) Value 0.813
K -S Test Statistic 0.292
K -S Critical(0.05) Value 0.182
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.938
Shapiro Wilk Test Statistic
0.875
Shapiro Wilk Critical (0.05) Value
0.92
Approximate Shapiro Wilk P Value
0.00409
Lilliefors Test Statistic
0.246
Lilliefors Critical (0.05) Value
0.174
Data not Lognormal at (0.05) Significance Level
Vanadium - ug/L - T
Raw Statistics
Number of Valid Observations
13
Number of Missing Observations
14
Number of Distinct Observations
12
Minimum
7.3
Maximum
167
Mean of Raw Data
53.92
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 4 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Standard Deviation of Raw Data
67.87
Khat
0.709
Theta hat
76.08
Kstar
0.596
Theta star
90.4
Mean of Log Transformed Data
3.136
Standard Deviation of Log Transformed Data
1.34
Normal GOF Test Results
Correlation Coefficient R
0.828
Shapiro Wilk Test Statistic
0.667
Shapiro Wilk Critical (0.05) Value
0.866
Approximate Shapiro Wilk P Value 1.9409E-4
0.00115
Lilliefors Test Statistic
0.355
Lilliefors Critical (0.05) Value
0.246
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.885
A -D Test Statistic 1.857
A -D Critical (0.05) Value 0.774
K -S Test Statistic 0.363
K -S Critical(0.05) Value 0.247
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.868
Shapiro Wilk Test Statistic
0.73
Shapiro Wilk Critical (0.05) Value
0.866
Approximate Shapiro Wilk P Value
0.00115
Lilliefors Test Statistic
0.341
Lilliefors Critical (0.05) Value
0.246
Data not Lognormal at (0.05) Significance Level
Goodness -of -Fit Test Statistics for Data Sets with Non -Detects
User Selected Options
Date/Time of Computation 4/4/2016 11:47:53 AM
From File Worksheet a.xls
Full Precision OFF
Confidence Coefficient 0.95
Boron - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 1 26 5 21 80.77%
Number Minimum Maximum Mean Median SD
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 5 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Statistics (Non -Detects Only)
21
50
50
50
50
0
Statistics (Detects Only)
5
25
49
33.8
31
9.935
Statistics (All: NDs treated as DL value)
26
25
50
46.88
50
7.628
Statistics (All: NDs treated as DL/2 value)
26
25
49
26.69
25
5.32
Statistics (Normal ROS Imputed Data)
26
12.4
55.2
33.8
33.08
10.88
Statistics (Gamma ROS Imputed Data)
26
14.66
58.19
34.08
32.59
11.06
Statistics (Lognormal ROS Imputed Data)
26
17.71
60.46
34.28
32.06
10.8
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
15.6
6.374
2.166
3.488
0.28
0.0803
Statistics (NDs = DL)
29.24
25.89
1.603
3.83
0.204
0.0532
Statistics (NDs = DL/2)
36.58
32.39
0.73
3.271
0.156
0.0476
Statistics (Gamma ROS Estimates)
9.557
8.48
3.566
-
-
Statistics (Lognormal ROS Estimates)
3.488
0.311
0.0893
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.953 0.675 0.592 0.421
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.9
0.762
Data Appear Normal
0.211
0.396
Data Appear Normal
0.461
0.92
Data Not Normal
0.466
0.174
Data Not Normal
0.374
0.92
Data Not Normal
0.471
0.174
Data Not Normal
0.989
0.92
Data Appear Normal
0.0668
0.174
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.979 0.628 0.643 0.996
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.313
0.679
0.218
0.357
Detected Data Appear Gamma Distributed
7.003
0.743
0.468
0.171
Data Not Gamma Distributed
7.409
0.743
0.478
0.171
Data Not Gamma Distributed
0.0955
0.744
0.0625
0.171
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.969 0.669 0.608 0.998
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 6 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.926
0.762
Data Appear Lognormal
Lilliefors (Detects Only)
0.194
0.396
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.456
0.92
Data Not Lognormal
Lilliefors (NDs = DL)
0.464
0.174
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.391
0.92
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.476
0.174
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.989
0.92
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0673
0.174
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
0.205
Cobalt - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 14 13 4 9 69.23%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
9
0.5
0.5
0.5
0.5
0
4
0.13
0.31
0.205
0.19
0.0823
13
0.13
0.5
0.409
0.5
0.148
13
0.13
0.31
0.236
0.25
0.0465
13
0.0625
0.347
0.205
0.205
0.085
13
0.0771
0.366
0.207
0.2
0.0861
13
0.0962
0.387
0.209
0.193
0.0867
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
8.524
2.298
0.0241
-1.645
0.398
-0.242
5.572
4.337
0.0734
-0.986
0.498
-0.506
22.4
17.28
0.0105
-1.466
0.234
-0.16
5.892
4.583
0.0351
-1.645
0.415
-0.252
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.968 0.814 0.82 0.889
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.926
0.748
Data Appear Normal
0.248
0.443
Data Appear Normal
0.65
0.866
Data Not Normal
0.423
0.246
Data Not Normal
0.699
0.866
Data Not Normal
0.386
0.246
Data Not Normal
0.978
0.866
Data Appear Normal
0.126
0.246
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Page 7 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Correlation Coefficient R 0.988 0.72 0.795 0.989
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.301
0.658
0.237
0.273
0.395
Detected Data Appear Gamma Distributed
2.287
0.736
Data Not Lognormal
0.427
0.237
Data Not Gamma Distributed
2.358
0.733
0.652
0.403
0.236
Data Not Gamma Distributed
0.167
0.736
Data Not Lognormal
0.113
0.237
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.978 0.809 0.792 0.993
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.942
0.748
Data Appear Lognormal
Lilliefors (Detects Only)
0.237
0.443
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.649
0.866
Data Not Lognormal
Lilliefors (NDs = DL)
0.414
0.246
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.652
0.866
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.402
0.246
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.978
0.866
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.113
0.246
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are
not recommended.
Iron - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 0 27 23 4 14.81%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number Minimum Maximum Mean Median SD
4 10 50 30 30 23.09
23 18 306 84.09 78 62.99
27 10 306 76.07 57 61.66
27 5 306 73.85 57 63.23
27 -64.32 306 68.68 57 70.54
27 0.01 306 73.13 57 64.02
27 10.46 306 74.61 57 62.5
K hat K Star Theta hat Log Mean Log Stdv Log CV
2.253 1.988 37.32 4.194 0.716 0.171
1.822 1.644 41.76 4.033 0.83 0.206
1.489 1.348 49.59 3.93 0.974 0.248
0.71 0.656 103
4.002 0.827 0.207
Normal GOF Test Results
Page 8 of 15
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx 4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.89 0.892 0.896 0.411
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.808
0.914
Data Not Normal
Lilliefors (Detects Only)
0.147
0.185
Data Appear Normal
Shapiro -Wilk (NDs = DL)
0.814
0.923
Data Not Normal
Lilliefors (NDs = DL)
0.146
0.171
Data Appear Normal
Shapiro -Wilk (NDs = DL/2)
0.819
0.923
Data Not Normal
Lilliefors (NDs = DL/2)
0.138
0.171
Data Appear Normal
Shapiro -Wilk (Normal ROS Estimates)
0.907
0.923
Data Not Normal
Lilliefors (Normal ROS Estimates)
0.125
0.171
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.955 0.962 0.965 0.96
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value Crit. (0.05)
0.373
0.754
0.103
0.184
0.269
0.759
0.0876
0.171
0.37
0.763
0.0929
0.171
1.631
0.788
0.216
0.175
Conclusion with Alpha(0.05)
Detected Data Appear Gamma Distributed
Data Appear Gamma Distributed
Data Appear Gamma Distributed
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.982 0.983 0.965 0.988
Lead - ug/L - T
Conclusion with Alpha(0.05)
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 1 26 5 21 80.77%
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 9 of 15
4/8/2016
Test value
Crit. (0.05)
Shapiro -Wilk (Detects Only)
0.963
0.914
Lilliefors (Detects Only)
0.112
0.185
Shapiro -Wilk (NDs = DL)
0.965
0.923
Lilliefors (NDs = DL)
0.0996
0.171
Shapiro -Wilk (NDs = DL/2)
0.933
0.923
Lilliefors (NDs = DL/2)
0.121
0.171
Shapiro -Wilk (Lognormal ROS Estimates)
0.972
0.923
Lilliefors (Lognormal ROS Estimates)
0.11
0.171
Note: Substitution methods such as DL or DU2 are not recommended.
Lead - ug/L - T
Conclusion with Alpha(0.05)
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 1 26 5 21 80.77%
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 9 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number Minimum Maximum Mean Median SD
21 0.1 1 0.657 1 0.448
5 0.051 0.23 0.0958 0.07 0.0756
26 0.051 1 0.549 0.615 0.461
26 0.05 0.5 0.284 0.365 0.223
26 -0.0185 0.23 0.0792 0.0715 0.0565
26 0.01 0.23 0.0782 0.0699 0.0517
26 0.0304 0.23 0.0781 0.0696 0.0432
K hat K Star Theta hat Log Mean Log Stdv Log CV
2.949 1.313 0.0325 -2.525 0.609 -0.241
0.974 0.887 0.564 -1.194 1.244 -1.042
1.149 1.042 0.247 -1.754 1.121 -0.639
2.366 2.118 0.0331
-2.665 0.473 -0.177
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.804 0.83 0.832 0.788
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.665
0.762
Data Not Normal
0.419
0.396
Data Not Normal
0.665
0.92
Data Not Normal
0.336
0.174
Data Not Normal
0.668
0.92
Data Not Normal
0.334
0.174
Data Not Normal
0.972
0.92
Data Appear Normal
0.106
0.174
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.917 0.719 0.733 0.997
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.79
0.683
0.398
0.359
Data Not Gamma Distributed
3.655
0.775
0.337
0.177
Data Not Gamma Distributed
3.888
0.77
0.334
0.176
Data Not Gamma Distributed
0.122
0.755
0.0728
0.173
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.869 0.867 0.842 0.989
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 10 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.77
0.762
Data Appear Lognormal
Lilliefors (Detects Only)
0.361
0.396
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.729
0.92
Data Not Lognormal
Lilliefors (NDs = DL)
0.331
0.174
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.684
0.92
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.328
0.174
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.98
0.92
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0751
0.174
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
3.1
Manganese - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 0 27 10 17 62.96%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
17
5
5
5
5
0
10
2.34
9.1
3.794
3.1
2.011
27
2.34
9.1
4.553
5
1.324
27
2.34
9.1
2.979
2.5
1.344
27
0.805
9.1
3.401
3.1
1.563
27
1.278
9.1
3.361
3.1
1.51
27
1.812
9.1
3.384
3.1
1.389
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
5.991
4.261
0.633
1.248
0.397
0.318
12.54
11.17
0.363
1.475
0.294
0.199
9.659
8.611
0.308
1.039
0.285
0.274
6.514
5.815
0.516
1.162
0.323
0.278
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.799 0.836 0.632 0.817
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.662
0.842
Data Not Normal
0.338
0.28
Data Not Normal
0.725
0.923
Data Not Normal
0.336
0.171
Data Not Normal
0.429
0.923
Data Not Normal
0.324
0.171
Data Not Normal
0.87
0.923
Data Not Normal
0.144
0.171
Data Appear Normal
Gamma GOF Test Results
Page 11 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.882 0.837 0.72 0.944
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
1.082
0.729
0.267
0.296
0.267
Data Not Gamma Distributed
3.382
0.744
Data Not Lognormal
0.37
0.168
Data Not Gamma Distributed
5.193
0.744
0.542
0.33
0.168
Data Not Gamma Distributed
0.387
0.746
Data Not Lognormal
0.109
0.168
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.885 0.869 0.719 0.958
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.8
0.842
Data Not Lognormal
Lilliefors (Detects Only)
0.267
0.28
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.77
0.923
Data Not Lognormal
Lilliefors (NDs = DL)
0.38
0.171
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.542
0.923
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.333
0.171
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.934
0.923
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.105
0.171
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are
not recommended.
Nickel - ug/L - D
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 13 14 9 5 35.71%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number Minimum Maximum Mean Median SD
5 0.5 5 1.4 0.5 2.012
9 0.23 1.8 0.543 0.39 0.499
14 0.23 5 0.849 0.5 1.257
14 0.23 2.5 0.599 0.27 0.686
14 0.0409 1.8 0.476 0.4 0.42
14 0.0714 1.8 0.459 0.369 0.42
14 0.192 1.8 0.467 0.366 0.41
K hat K Star Theta hat Log Mean Log Stdv Log CV
2.208 1.546 0.246 -0.853 0.669 -0.784
1.207 0.996 0.703 -0.632 0.835 -1.322
1.507 1.232 0.398 -0.879 0.777 -0.883
2.076 1.679 0.221
-0.959 0.576 -0.601
Page 12 of 15
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx 4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.804 0.687 0.765 0.936
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.928 0.875 0.922 0.911
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value Crit. (0.05)
0.726
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.667
0.829
Data Not Normal
Lilliefors (Detects Only)
0.272
0.295
Data Appear Normal
Shapiro -Wilk (NDs = DL)
0.501
0.874
Data Not Normal
Lilliefors (NDs = DL)
0.395
0.237
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.597
0.874
Data Not Normal
Lilliefors (NDs = DL/2)
0.323
0.237
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.7
0.874
Data Not Normal
Lilliefors (Normal ROS Estimates)
0.251
0.237
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.928 0.875 0.922 0.911
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value Crit. (0.05)
0.726
0.729
0.234
0.282
1.733
0.756
0.337
0.234
1.865
0.751
0.277
0.233
0.617
0.746
0.184
0.232
Conclusion with Alpha(0.05)
Detected Data Appear Gamma Distributed
Data Not Gamma Distributed
Data Not Gamma Distributed
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.929 0.893 0.867 0.929
Zinc - ug/L - T
Conclusion with Alpha(0.05)
Data Appear Lognormal
Data Appear Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Appear Lognormal
Data Appear Lognormal
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 1 26 11 15 57.69%
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 13 of 15
4/8/2016
Test value
Crit. (0.05)
Shapiro -Wilk (Detects Only)
0.866
0.829
Lilliefors (Detects Only)
0.19
0.295
Shapiro -Wilk (NDs = DL)
0.81
0.874
Lilliefors (NDs = DL)
0.27
0.237
Shapiro -Wilk (NDs = DL/2)
0.75
0.874
Lilliefors (NDs = DL/2)
0.249
0.237
Shapiro -Wilk (Lognormal ROS Estimates)
0.876
0.874
Lilliefors (Lognormal ROS Estimates)
0.168
0.237
Note: Substitution methods such as DL or DU2 are not recommended.
Zinc - ug/L - T
Conclusion with Alpha(0.05)
Data Appear Lognormal
Data Appear Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Appear Lognormal
Data Appear Lognormal
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 27 1 26 11 15 57.69%
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Page 13 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
15
5
10
6
5
2.07
11
2.8
26
6.973
4.8
6.439
26
2.8
26
6.412
5
4.384
26
2.5
26
4.681
3.55
4.603
26
-1.626
26
5.181
4.7
4.835
26
0.01
26
4.926
4.4
4.746
26
2.244
26
5.399
4.55
4.394
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
2.654
1.991
2.627
1.742
0.567
0.325
4.6
4.095
1.394
1.745
0.418
0.239
2.682
2.398
1.745
1.346
0.543
0.403
1.266
1.146
3.89
1.547
0.457
0.295
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.705 0.686 0.658 0.686
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.531
0.85
Data Not Normal
0.389
0.267
Data Not Normal
0.504
0.92
Data Not Normal
0.34
0.174
Data Not Normal
0.464
0.92
Data Not Normal
0.318
0.174
Data Not Normal
0.667
0.92
Data Not Normal
0.265
0.174
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.832 0.791 0.79 0.868
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
1.459
0.735
0.299
0.258
Data Not Gamma Distributed
3.426
0.747
0.339
0.172
Data Not Gamma Distributed
2.482
0.753
0.237
0.173
Data Not Gamma Distributed
1.422
0.767
0.184
0.175
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Page 14 of 15
4/8/2016

Attachment C-2: Buck Facility Background Monitoring Well Data GOF Statistics
Correlation Coefficient R 0.862 0.841
Test value Crit. (0.05)
Shapiro -Wilk (Detects Only)
0.777
0.85
Lilliefors (Detects Only)
0.241
0.267
Shapiro -Wilk (NDs = DL)
0.737
0.92
Lilliefors (NDs = DL)
0.322
0.174
Shapiro -Wilk (NDs = DL/2)
0.756
0.92
Lilliefors (NDs = DL/2)
0.247
0.174
Shapiro -Wilk (Lognormal ROS Estimates)
0.838
0.92
Lilliefors (Lognormal ROS Estimates)
0.161
0.174
Note: Substitution methods such as DL or DL/2 are
not recommended.
0.863 0.9
Conclusion with Alpha(0.05)
Data Not Lognormal
Data Appear Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Appear Lognormal
Page 15 of 15
Haley & Aldrich, Inc.
GOF test stats after removing outliers.xlsx 4/8/2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
ATTACHMENT C-3
Method Computation Details
APRIL 2016 U'CH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -1: Buck Regional Background Water Supply Well Data BTVs Statistics
APRIL 2016 U'CH

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Background Statistics for Data Sets with Non -Detects
User Selected Options
A -D Test Statistic
Date/Time of Computation
4/2/2016 6:10:49 PM
From File
WorkSheet.xls
Full Precision
OFF
Confidence Coefficient
95%
Coverage
95%
Different or Future K Observations
1
Number of Bootstrap Operations
2000
Barium (ug/L)
Total Number of Observations
Number of Distinct Observations
Number of Detects
Number of Distinct Detects
Minimum Detect
Maximum Detect
Variance Detected
Mean Detected
Mean of Detected Logged Data
General Statistics
24
21
21
20
0.89
74
405.1
18.65
2.247
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309
Number of Missing Observations
Number of Non -Detects
Number of Distinct Non -Detects
Minimum Non -Detect
Maximum Non -Detect
Percent Non -Detects
SD Detected
SD of Detected Logged Data
d2max (for USL)
Page 1 of 10
0
3
1
5
5
12.5%
20.13
1.321
2.644
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.362 Anderson -Darling GOF Test
5% A -D Critical Value
0.777 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.134 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.196 Detected data appear Gamma Distributed at 5% Significance Level
Detected data appear Gamma Distributed at 5% Significance Level
Gamma Statistics on Detected Data Only
k hat (MLE)
0.865 k star (bias corrected MLE) 0.773
Theta hat (MLE)
21.55 Theta star (bias corrected MLE) 24.11
nu hat (MLE)
36.34 nu star (bias corrected) 32.48
MLE Mean (bias corrected)
18.65
MLE Sd (bias corrected)
21.2 95% Percentile of Chisquare (2k) 5.079
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.01 Mean 16.46
Maximum 74 Median 7.15
SD 19.69 CV 1.196
k hat (MLE) 0.594 k star (bias corrected MLE) 0.547
Theta hat (MLE) 27.72 Theta star (bias corrected MLE) 30.07
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Page 2 of 10
nu hat (MLE) 28.5 nu star (bias corrected) 26.27
MLE Mean (bias corrected) 16.46 MLE Sd (bias corrected) 22.25
95% Percentile of Chisquare (2k) 4.071 90% Percentile 43.68
95% Percentile 61.21 99% Percentile 104
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH HW
95% Approx. Gamma UTL with 95% Coverage 93.91 112.5 95% Approx. Gamma UPL 61.93 68.99
95% Gamma USL 117.5 146.9
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM)
0.756
nu hat (KM)
36.27
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 82.54
91.51
95% Approx. Gamma UPL 56.09
58.98
95% Gamma USL 101.8
116.5
Hexavalent Chromium (ug/L)
General Statistics
Total Number of Observations
24
Number of Missing Observations
0
Number of Distinct Observations
19
Number of Detects
21
Number of Non -Detects
3
Number of Distinct Detects
17
Number of Distinct Non -Detects
2
Minimum Detect
0.063
Minimum Non -Detect
0.03
Maximum Detect
2.9
Maximum Non -Detect
0.6
Variance Detected
0.798
Percent Non -Detects
12.5%
Mean Detected
0.831
SD Detected
0.893
Mean of Detected Logged Data
-0.896
SD of Detected Logged Data
1.311
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.309
d2max (for USL)
2.644
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.92
Anderson -Darling GOF Test
5% A -D Critical Value
0.779
Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.223
Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.196
Data Not Gamma Distributed at 5% Significance Level
Data Not Gamma Distributed at 5% Significance
Level
Gamma Statistics on Detected
Data Only
k hat (MLE)
0.831
k star (bias corrected MLE)
0.744
Theta hat (MLE)
1
Theta star (bias corrected MLE)
1.117
nu hat (MLE)
34.89
nu star (bias corrected)
31.23
MLE Mean (bias corrected)
0.831
MILE Sd (bias corrected)
0.964
95% Percentile of Chisquare (2k)
4.953
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Page 3 of 10
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.01 Mean
0.742
Maximum 2.9 Median
0.245
SD 0.868 CV
1.17
k hat (MLE) 0.699 k star (bias corrected MLE)
0.639
Theta hat (MLE) 1.062 Theta star (bias corrected MLE)
1.161
nu hat (MLE) 33.53 nu star (bias corrected)
30.67
MLE Mean (bias corrected) 0.742 MLE Sd (bias corrected)
0.928
95% Percentile of Chisquare (2k) 4.496 90% Percentile
1.902
95% Percentile 2.61 99% Percentile
4.312
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 4.029 4.578 95% Approx. Gamma UPL 2.685
2.871
95% Gamma USL 5.014 5.909
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 0.763 nu hat (KM)
36.62
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 3.789 4.206 95% Approx. Gamma UPL 2.554
2.683
95% Gamma USL 4.69 5.383
Iron (ug/L)
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309
Number of Missing Observations 0
Number of Non -Detects
General Statistics
Total Number of Observations
24
Number of Distinct Observations
9
Number of Detects
8
Number of Distinct Detects
7
Minimum Detect
14
Maximum Detect
1510
Variance Detected 255208
Mean Detected
279.5
Mean of Detected Logged Data
4.502
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309
Number of Missing Observations 0
Number of Non -Detects
16
Number of Distinct Non -Detects
2
Minimum Non -Detect
10
Maximum Non -Detect
50
Percent Non -Detects
66.67%
SD Detected
505.2
SD of Detected Logged Data
1.611
d2max (for USL) 2.644
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.508 Anderson -Darling GOF Test
5% A -D Critical Value 0.759 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.235 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.308 Detected data appear Gamma Distributed at 5% Significance Level
Detected data appear Gamma Distributed at 5% Significance Level
Gamma Statistics on Detected Data Only
k hat (MLE) 0.553
Theta hat (MLE) 505.4
k star (bias corrected MLE) 0.429
Theta star (bias corrected MLE) 651.6
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Page 4 of 10
nu hat (MLE) 8.849 nu star (bias corrected) 6.864
MLE Mean (bias corrected) 279.5
MLE Sd (bias corrected) 426.8 95% Percentile of Chisquare (2k)
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.01 Mean
Maximum 1510 Median
SD 308.9 CV
k hat (MLE) 0.135 k star (bias corrected MLE)
Theta hat (MILE) 708.3 Theta star (bias corrected MLE)
nu hat (MLE) 6.492 nu star (bias corrected)
MLE Mean (bias corrected) 95.8 MLE Sd (bias corrected)
95% Percentile of Chisquare (2k) 1.617 90% Percentile
95% Percentile 529.9 99% Percentile
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
95% Approx. Gamma UTL with 95% Coverage 651.4 758.4 95% Approx. Gamma UPL 350.9
95% Gamma USL 894.5 1134
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 0.118
WH HW
95% Approx. Gamma UTL with 95% Coverage 531.2 510.5 95% Approx. Gamma UPL
95% Gamma USL 679.9 674.2
Lead (ug/L)
3.479
95.8
0.01
3.225
0.146
655.6
7.014
250.6
283
1250
HW
348.3
nu hat (KM) 5.668
WH HW
334 305.6
General Statistics
Total Number of Observations
24
Number of Missing Observations
0
Number of Distinct Observations
16
Number of Detects
16
Number of Non -Detects
8
Number of Distinct Detects
14
Number of Distinct Non -Detects
2
Minimum Detect
0.12
Minimum Non -Detect
0.1
Maximum Detect
3.9
Maximum Non -Detect
1
Variance Detected
1.164
Percent Non -Detects
33.33%
Mean Detected
1.109
SD Detected
1.079
Mean of Detected Logged Data
-0.346
SD of Detected Logged Data
1.04
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.309
d2max (for USL)
2.644
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.238 Anderson
-Darling GOF Test
5% A -D Critical Value
0.759 Detected data appear Gamma
Distributed at 5% Significance
Level
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx
4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Page 5 of 10
K -S Test Statistic 0.108 Kolmogrov-Smirnoff GOF
0.73
5% K -S Critical Value 0.22 Detected data appear Gamma Distributed at 5% Significance Level
Detected data appear Gamma Distributed at 5% Significance Level
WH
Gamma Statistics on Detected Data Only
WH
k hat (MLE) 1.253 k star (bias corrected MLE)
1.06
Theta hat (MLE) 0.885 Theta star (bias corrected MLE)
1.046
nu hat (MLE) 40.09 nu star (bias corrected)
33.91
MLE Mean (bias corrected) 1.109
MLE Sd (bias corrected) 1.077 95% Percentile of Chisquare (2k)
6.22
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
Total Number of Observations
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Number of Missing Observations
Minimum 0.01 Mean
0.784
Maximum 3.9 Median
0.445
SD 0.999 CV
1.274
k hat (MLE) 0.525 k star (bias corrected MLE)
0.487
Theta hat (MLE) 1.495 Theta star (bias corrected MLE)
1.611
nu hat (MILE) 25.18 nu star (bias corrected)
23.37
MLE Mean (bias corrected) 0.784 MLE Sd (bias corrected)
1.124
95% Percentile of Chisquare (2k) 3.776 90% Percentile
2.133
95% Percentile 3.041 99% Percentile
5.28
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Maximum Non -Detect
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
Variance Detected
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 4.805 5.883 95% Approx. Gamma UPL 3.108
3.509
95% Gamma USL 6.067 7.783
SD Detected
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM)
0.73
nu hat (KM)
35.03
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 3.781
4.102
95% Approx. Gamma UPL 2.617
2.712
95% Gamma USL 4.62
5.155
Manganese (ug/L)
General Statistics
Total Number of Observations
24
Number of Missing Observations
0
Number of Distinct Observations
15
Number of Detects
13
Number of Non -Detects
11
Number of Distinct Detects
13
Number of Distinct Non -Detects
2
Minimum Detect
0.56
Minimum Non -Detect
0.5
Maximum Detect
66.4
Maximum Non -Detect
5
Variance Detected
447.2
Percent Non -Detects
45.83%
Mean Detected
11.46
SD Detected
21.15
Mean of Detected Logged Data
1.087
SD of Detected Logged Data
1.618
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Nickel (ug/L)
Page 6 of 10
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309 d2max (for USL) 2.644
Nonparametric Distribution Free Background Statistics
Data appear to follow a Discernible Distribution at 5% Significance Level
Nonparametric Upper Limits for BTVs(no distinction made between detects and nondetects)
Order of Statistic, r 24 95% UTL with95% Coverage 66.4
Approximate f 1.263 Confidence Coefficient (CC) achieved by UTL 0.708
95% UPL 62.05 95% USL 66.4
95% KM Chebyshev UPL 77.23
Note: The use of USL to estimate a BTV is recommended only when the data set represents a background
data set free of outliers and consists of observations collected from clean unimpacted locations.
The use of USL tends to provide a balance between false positives and false negatives provided the data
represents a background data set and when many onsite observations need to be compared with the BTV.
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309 d2max (for USL)
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.769 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.748 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.371 Lilliefors GOF Test
5% Lilliefors Critical Value 0.443 Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
2.644
Mean
General Statistics
SD
0.828
Total Number of Observations
24
Number of Missing Observations
0
Number of Distinct Observations
6
95% KM Percentile (z)
2.128
Number of Detects
4
Number of Non -Detects
20
Number of Distinct Detects
4
Number of Distinct Non -Detects
2
Minimum Detect
0.59
Minimum Non -Detect
0.5
Maximum Detect
4.1
Maximum Non -Detect
5
Variance Detected
2.627
Percent Non -Detects
83.33%
Mean Detected
1.698
SD Detected
1.621
Mean of Detected Logged Data
0.24
SD of Detected Logged Data
0.833
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309 d2max (for USL)
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.769 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.748 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.371 Lilliefors GOF Test
5% Lilliefors Critical Value 0.443 Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
2.644
Mean
0.766
SD
0.828
95% UTL95% Coverage
2.678
95% KM UPL (t)
2.215
90% KM Percentile (z)
1.827
95% KM Percentile (z)
2.128
99% KM Percentile (z)
2.693
95% KM USL
2.956
DL/2 Substitution Background Statistics Assuming Normal Distribution
Mean
1.054
SD
1.163
95% UTL95% Coverage
3.74
95% UPL (t)
3.089
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Sodium (ug/L)
General Statistics
Sulfate (mg/L)
General Statistics
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx
Page 7 of 10
90% Percentile (z) 2.545 95% Percentile (z) 2.967
99% Percentile (z) 3.76 95% USL 4.13
DU2 is not a recommended method. DU2 provided for comparisons and historical reasons
Total Number of Observations
24
Minimum
4380
Second Largest
20400
Maximum
23000
Mean
8703
Coefficient of Variation
0.537
Mean of logged Data
8.967
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309
Number of Distinct Observations
22
First Quartile
5745
Median
7340
Third Quartile
9985
SD
4671
Skewness
1.974
SD of logged Data
0.441
d2max (for USL) 2.644
Lognormal GOF Test
Shapiro Wilk Test Statistic 0.924 Shapiro Wilk Lognormal GOF Test
5% Shapiro Wilk Critical Value 0.916 Data appear Lognormal at 5% Significance Level
Lilliefors Test Statistic 0.145 Lilliefors Lognormal GOF Test
5% Lilliefors Critical Value 0.181 Data appear Lognormal at 5% Significance Level
Data appear Lognormal at 5% Significance Level
Background Statistics assuming Lognormal Distribution
95% UTL with 95% Coverage 21695
95% UPL (t) 16952
95% USL 25145
Nonparametric Distribution Free Background Statistics
Data appear Lognormal at 5% Significance Level
Total Number of Observations 9
Minimum
0.26
Second Largest
27.7
Maximum
31.5
Mean
10.5
Coefficient of Variation
1.115
Mean of logged Data
1.498
90% Percentile (z) 13795
95% Percentile (z) 16190
99% Percentile (z) 21862
Number of Distinct Observations 9
Number of Missing Observations 15
First Quartile
2.8
Median
5.4
Third Quartile
15
SD
11.71
Skewness
1.15
SD of logged Data
1.674
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 3.031 d2max (for USL) 2.11
Normal GOF Test
Shapiro Wilk Test Statistic 0.813 Shapiro Wilk GOF Test
4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Vanadium (ug/L)
5% Shapiro Wilk Critical Value 0.829 Data Not Normal at 5% Significance Level
Lilliefors Test Statistic 0.287 Lilliefors GOF Test
5% Lilliefors Critical Value 0.295 Data appear Normal at 5% Significance Level
Data appear Approximate Normal at 5% Significance Level
Background Statistics Assuming Normal Distribution
95% UTL with 95% Coverage 46
95% UPL (t) 33.46
95% USL 35.21
Total Number of Observations
Number of Distinct Observations
Number of Detects
Number of Distinct Detects
Minimum Detect
Maximum Detect
Variance Detected
Mean Detected
Mean of Detected Logged Data
General Statistics
24
20
21
19
1.19
16.4
23.64
6.876
1.659
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309
Page 8 of 10
90% Percentile (z)
25.51
95% Percentile (z)
29.76
99% Percentile (z)
37.75
Number of Missing Observations
0
Number of Non -Detects
Number of Distinct Non -Detects
Minimum Non -Detect
Maximum Non -Detect
Percent Non -Detects
SD Detected
SD of Detected Logged Data
d2max (for USL)
3
1
1
1
12.5%
4.862
0.784
2.644
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.441 Anderson -Darling GOF Test
5% A -D Critical Value
0.754 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.126 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.192 Detected data appear Gamma Distributed at 5% Significance Level
Detected data appear Gamma Distributed at 5% Significance Level
Gamma Statistics on Detected Data Only
k hat (MLE)
2.013 k star (bias corrected MLE) 1.757
Theta hat (MLE)
3.416 Theta star (bias corrected MLE) 3.913
nu hat (MLE)
84.54 nu star (bias corrected) 73.79
MLE Mean (bias corrected)
6.876
MLE Sd (bias corrected)
5.187 95% Percentile of Chisquare (2k) 8.688
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.01 Mean 6.022
Maximum 16.4 Median 4.65
SD 5.087 CV 0.845
k hat (MLE) 0.735 k star (bias corrected MLE) 0.671
Theta hat (MLE) 8.19 Theta star (bias corrected MLE) 8.973
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Page 9 of 10
nu hat (MLE) 35.29 nu star (bias corrected) 32.21
MLE Mean (bias corrected) 6.022 MLE Sd (bias corrected) 7.351
95% Percentile of Chisquare (2k) 4.639 90% Percentile 15.27
95% Percentile 20.81 99% Percentile 34.09
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH HW
95% Approx. Gamma UTL with 95% Coverage 30.85 38.92 95% Approx. Gamma UPL 21.16 24.8
95% Gamma USL 37.86 49.84
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM)
1.606
nu hat (KM)
77.11
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 22.82
24.49
95% Approx. Gamma UPL 16.77
17.41
95% Gamma USL 27.05
29.65
Detected data follow Appr.
Gamma Distribution at 5% Significance Level
Zinc (mg/L)
Gamma Statistics on Detected Data Only
k hat (MLE)
0.605 k star (bias corrected MLE)
General Statistics
Theta hat (MLE)
0.281 Theta star (bias corrected MLE)
Total Number of Observations
24
Number of Missing Observations
0
Number of Distinct Observations
18
MILE Sd (bias corrected)
Number of Detects
18
Number of Non -Detects
6
Number of Distinct Detects
17
Number of Distinct Non -Detects
1
Minimum Detect
0.0079
Minimum Non -Detect
0.005
Maximum Detect
0.645
Maximum Non -Detect
0.005
Variance Detected
0.0462
Percent Non -Detects
25%
Mean Detected
0.17
SD Detected
0.215
Mean of Detected Logged Data
-2.793
SD of Detected Logged Data
1.596
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.309 d2max (for USL) 2.644
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.851 Anderson -Darling GOF Test
5% A -D Critical Value
0.791 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.175 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.214 Detected data appear Gamma Distributed at 5% Significance
Level
Detected data follow Appr.
Gamma Distribution at 5% Significance Level
Gamma Statistics on Detected Data Only
k hat (MLE)
0.605 k star (bias corrected MLE)
0.541
Theta hat (MLE)
0.281 Theta star (bias corrected MLE)
0.314
nu hat (MLE)
21.78 nu star (bias corrected)
19.49
MLE Mean (bias corrected)
0.17
MILE Sd (bias corrected)
0.231 95% Percentile of Chisquare (2k)
4.042
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment C-3: Buck Regional Background Water Supply Well Data BTVs Statistics
Page 10 of 10
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.0079 Mean
0.13
Maximum 0.645 Median
0.0169
SD 0.198 CV
1.523
k hat (MLE) 0.524 k star (bias corrected MLE)
0.486
Theta hat (MLE) 0.248 Theta star (bias corrected MLE)
0.267
nu hat (MLE) 25.13 nu star (bias corrected)
23.32
MLE Mean (bias corrected) 0.13 MLE Sd (bias corrected)
0.186
95% Percentile of Chisquare (2k) 3.771 90% Percentile
0.353
95% Percentile 0.504 99% Percentile
0.875
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 0.78 0.86 95% Approx. Gamma UPL 0.497
0.513
95% Gamma USL 0.991 1.139
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 0.437 nu hat (KM)
21
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 0.778 0.87 95% Approx. Gamma UPL 0.491
0.511
95% Gamma USL 0.994 1.161
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix C — Buck
Part -2: Buck Facility Background Monitoring Well Data BTVs Statistics
APRIL 2016 U'CH

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Background Statistics for Data Sets with Non -Detects
User Selected Options
26
Date/Time of Computation
4/4/2016 11:49:21 AM
From File
WorkSheet a.xls
Full Precision
OFF
Confidence Coefficient
95%
Coverage
95%
Different or Future K Observations
1
Number of Bootstrap Operations
2000
Barium - ug/L - T
General Statistics
Page 1 of 10
Total Number of Observations
26
Number of Distinct Observations
23
Approximate f
1.368
Number of Missing Observations
1
Minimum
6.1
First Quartile
18
Second Largest
86
Median
63.5
Maximum
87
Third Quartile
76.75
Mean
49.77
SD
31.58
Coefficient of Variation
0.634
Skewness
-0.3
Mean of logged Data
3.554
SD of logged Data
1.003
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.275
d2max (for USL)
2.681
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Nonparametric Upper Limits for Background Threshold Values
Order of Statistic, r
26
95% UTL with 95% Coverage
87
Approximate f
1.368
Confidence Coefficient (CC) achieved by UTL
0.736
95% Percentile Bootstrap UTL with 95% Coverage
87
95% BCA Bootstrap UTL with 95% Coverage
86.75
95% UPL
86.65
90% Percentile
85
90% Chebyshev UPL
146.3
95% Percentile
86
95% Chebyshev UPL
190
99% Percentile
86.75
95% USL
87
Boron - ug/L - T
General Statistics
Total Number of Observations
26
Number of Missing Observations
1
Number of Distinct Observations
6
Number of Detects
5
Number of Non -Detects
21
Number of Distinct Detects
5
Number of Distinct Non -Detects
1
Minimum Detect
25
Minimum Non -Detect
50
Maximum Detect
49
Maximum Non -Detect
50
Variance Detected
98.7
Percent Non -Detects
80.77%
Mean Detected
33.8
SD Detected
9.935
Mean of Detected Logged Data
3.488
SD of Detected Logged Data
0.28
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Cobalt - ug/L - T
Page 2 of 10
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.275 d2max (for USL) 2.681
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.9 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.762 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.211 Lilliefors GOF Test
5% Lilliefors Critical Value 0.396 Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
Mean
33.8
SD
8.886
95% UTL95% Coverage
54.02
95% KM UPL (t)
49.27
90% KM Percentile (z)
45.19
95% KM Percentile (z)
48.42
99% KM Percentile (z)
54.47
95% KM USL
57.62
DU2 Substitution Background Statistics Assuming Normal Distribution
0.205
Mean of Detected Logged Data
Mean
26.69
SD
5.32
95% UTL95% Coverage
38.8
95% UPL (t)
35.95
90% Percentile (z)
33.51
95% Percentile (z)
35.44
99% Percentile (z)
39.07
95% USL
40.95
DU2 is not a recommended method. DU2 provided for comparisons and historical reasons
Number of Missing Observations 14
Number of Non -Detects
Number of Distinct Non -Detects
Minimum Non -Detect
Maximum Non -Detect
Percent Non -Detects
SD Detected
SD of Detected Logged Data
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.671 d2max (for USL)
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.926 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.748 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.248 Lilliefors GOF Test
5% Lilliefors Critical Value 0.443 Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
9
1
0.5
0.5
69.23%
0.0823
0.398
paled
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
Mean 0.205 SD 0.0712
95% UTL95% Coverage 0.395 95% KM UPL (t) 0.337
90% KM Percentile (z) 0.296 95% KM Percentile (z) 0.322
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016
General Statistics
Total Number of Observations
13
Number of Distinct Observations
5
Number of Detects
4
Number of Distinct Detects
4
Minimum Detect
0.13
Maximum Detect
0.31
Variance Detected
0.00677
Mean Detected
0.205
Mean of Detected Logged Data
-1.645
Number of Missing Observations 14
Number of Non -Detects
Number of Distinct Non -Detects
Minimum Non -Detect
Maximum Non -Detect
Percent Non -Detects
SD Detected
SD of Detected Logged Data
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.671 d2max (for USL)
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.926 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.748 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.248 Lilliefors GOF Test
5% Lilliefors Critical Value 0.443 Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
9
1
0.5
0.5
69.23%
0.0823
0.398
paled
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
Mean 0.205 SD 0.0712
95% UTL95% Coverage 0.395 95% KM UPL (t) 0.337
90% KM Percentile (z) 0.296 95% KM Percentile (z) 0.322
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Chromium (VI) - ug/L - T
General Statistics
Iron - ug/L - T
99% KM Percentile (z) 0.371
Page 3 of 10
95% KM USL 0.371
DU2 Substitution Background Statistics Assuming Normal Distribution
Mean 0.236 SD 0.0465
95% UTL95% Coverage 0.36 95% UPL (t) 0.322
90% Percentile (z) 0.296 95% Percentile (z) 0.313
99% Percentile (z) 0.344 95% USL 0.344
DU2 is not a recommended method. DU2 provided for comparisons and historical reasons
Total Number of Observations 7
Minimum
0.074
Second Largest
0.52
Maximum
0.58
Mean
0.386
Coefficient of Variation
0.467
Mean of logged Data
-1.114
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 3.399
Number of Distinct Observations 7
Number of Missing Observations 19
First Quartile
0.28
Median
0.47
Third Quartile
0.51
SD
0.181
Skewness
-0.84
SD of logged Data
0.72
d2max (for USL) 1.938
Normal GOF Test
Shapiro Wilk Test Statistic 0.904 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.803 Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.25 Lilliefors GOF Test
5% Lilliefors Critical Value 0.335 Data appear Normal at 5% Significance Level
Data appear Normal at 5% Significance Level
Background Statistics Assuming Normal Distribution
95% UTL with 95% Coverage 1
95% UPL (t) 0.761
95% USL 0.736
Critical Values for Background Threshold Values (BTVs)
90% Percentile (z) 0.618
95% Percentile (z) 0.683
99% Percentile (z) 0.806
Number of Missing Observations 0
Number of Non -Detects
General Statistics
Total Number of Observations
27
Number of Distinct Observations
22
Number of Detects
23
Number of Distinct Detects
20
Minimum Detect
18
Maximum Detect
306
Variance Detected
3968
Mean Detected
84.09
Mean of Detected Logged Data
4.194
Critical Values for Background Threshold Values (BTVs)
90% Percentile (z) 0.618
95% Percentile (z) 0.683
99% Percentile (z) 0.806
Number of Missing Observations 0
Number of Non -Detects
4
Number of Distinct Non -Detects
2
Minimum Non -Detect
10
Maximum Non -Detect
50
Percent Non -Detects
14.81%
SD Detected
62.99
SD of Detected Logged Data
0.716
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Tolerance Factor K (For UTL) 2.26
Page 4 of 10
d2max (for USL) 2.698
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.373 Anderson -Darling GOF Test
5% A -D Critical Value 0.754 Detected data appear Gamma Distributed at 5% Significance
Level
K -S Test Statistic 0.103 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.184 Detected data appear Gamma Distributed at 5% Significance
Level
Detected data appear Gamma Distributed at 5% Significance Level
Gamma Statistics on Detected Data Only
k hat (MLE) 2.253 k star (bias corrected MLE)
1.988
Theta hat (MLE) 37.32 Theta star (bias corrected MLE)
42.3
nu hat (MLE) 103.6 nu star (bias corrected)
91.45
MLE Mean (bias corrected) 84.09
MLE Sd (bias corrected) 59.64 95% Percentile of Chisquare (2k)
9.449
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.01 Mean
73.13
Maximum 306 Median
57
SD 64.02 CV
0.875
k hat (MLE) 0.71 k star (bias corrected MLE)
0.656
Theta hat (MLE) 103 Theta star (bias corrected MLE)
111.5
nu hat (MLE) 38.33 nu star (bias corrected)
35.41
MLE Mean (bias corrected) 73.13 MLE Sd (bias corrected)
90.31
95% Percentile of Chisquare (2k) 4.57 90% Percentile
186.4
95% Percentile 254.9 99% Percentile
419.2
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 342.1 439.8 95% Approx. Gamma UPL 243.4
291.4
95% Gamma USL 442.9 602.7
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 1.456 nu hat (KM)
78.63
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 257.8 273.9 95% Approx. Gamma UPL 195
201.2
95% Gamma USL 319.9 348.5
Lead - ug/L - T
General Statistics
Total Number of Observations 26
Number of Distinct Observations 7
Number of Detects 5
Number of Distinct Detects 5
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx
Number of Missing Observations 1
Number of Non -Detects 21
Number of Distinct Non -Detects 2
4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Page 5 of 10
Minimum Detect 0.051 Minimum Non -Detect
0.1
Maximum Detect 0.23 Maximum Non -Detect
1
Variance Detected 0.00572 Percent Non -Detects
80.77%
Mean Detected 0.0958 SD Detected
0.0756
Mean of Detected Logged Data -2.525 SD of Detected Logged Data
0.609
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.275 d2max (for USL)
2.681
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.79 Anderson -Darling GOF Test
5% A -D Critical Value 0.683 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.398 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.359 Data Not Gamma Distributed at 5% Significance Level
Data Not Gamma Distributed at 5% Significance Level
Gamma Statistics on Detected Data Only
k hat (MLE) 2.949 k star (bias corrected MLE)
1.313
Theta hat (MLE) 0.0325 Theta star (bias corrected MLE)
0.073
nu hat (MLE) 29.49 nu star (bias corrected)
13.13
MLE Mean (bias corrected) 0.0958
MLE Sd (bias corrected) 0.0836 95% Percentile of Chisquare (2k)
7.155
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.01 Mean
0.0782
Maximum 0.23 Median
0.0699
SD 0.0517 CV
0.661
k hat (MLE) 2.366 k star (bias corrected MLE)
2.118
Theta hat (MLE) 0.0331 Theta star (bias corrected MLE)
0.0369
nu hat (MLE) 123 nu star (bias corrected)
110.2
MLE Mean (bias corrected) 0.0782 MLE Sd (bias corrected)
0.0538
95% Percentile of Chisquare (2k) 9.869 90% Percentile
0.15
95% Percentile 0.182 99% Percentile
0.253
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 0.24 0.254 95% Approx. Gamma UPL 0.187
0.193
95% Gamma USL 0.288 0.31
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 2.715 nu hat (KM)
141.2
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 0.167 0.166 95% Approx. Gamma UPL 0.139
0.137
95% Gamma USL 0.191 0.19
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx
4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Page 6 of 10
Manganese - ug/L - T
General Statistics
Total Number of Observations 27 Number of Missing Observations
0
Number of Distinct Observations 9
Number of Detects 10 Number of Non -Detects
17
Number of Distinct Detects 8 Number of Distinct Non -Detects
1
Minimum Detect 2.34 Minimum Non -Detect
5
Maximum Detect 9.1 Maximum Non -Detect
5
Variance Detected 4.046 Percent Non -Detects
62.96%
Mean Detected 3.794 SD Detected
2.011
Mean of Detected Logged Data 1.248 SD of Detected Logged Data
0.397
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.26 d2max (for USL)
2.698
Gamma Statistics on Detected Data Only
k hat (MLE) 5.991 k star (bias corrected MLE)
4.261
Theta hat (MLE) 0.633 Theta star (bias corrected MLE)
0.89
nu hat (MLE) 119.8 nu star (bias corrected)
85.21
MLE Mean (bias corrected) 3.794
MLE Sd (bias corrected) 1.838 95% Percentile of Chisquare (2k)
16.25
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 1.278 Mean
3.361
Maximum 9.1 Median
3.1
SD 1.51 CV
0.449
k hat (MLE) 6.514 k star (bias corrected MLE)
5.815
Theta hat (MLE) 0.516 Theta star (bias corrected MLE)
0.578
nu hat (MLE) 351.7 nu star (bias corrected)
314
MLE Mean (bias corrected) 3.361 MLE Sd (bias corrected)
1.394
95% Percentile of Chisquare (2k) 20.53 90% Percentile
5.224
95% Percentile 5.932 99% Percentile
7.417
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 7.09 7.183 95% Approx. Gamma UPL 5.999
6.028
95% Gamma USL 8.099 8.271
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 6.725 nu hat (KM)
363.2
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 5.799 5.765 95% Approx. Gamma UPL 5.096
5.056
95% Gamma USL 6.435 6.414
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx
4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Page 7 of 10
Nickel - ug/L - D
General Statistics
Total Number of Observations 14 Number of Missing Observations
13
Number of Distinct Observations 11
Number of Detects 9 Number of Non -Detects
5
Number of Distinct Detects 9 Number of Distinct Non -Detects
2
Minimum Detect 0.23 Minimum Non -Detect
0.5
Maximum Detect 1.8 Maximum Non -Detect
5
Variance Detected 0.249 Percent Non -Detects
35.71%
Mean Detected 0.543 SD Detected
0.499
Mean of Detected Logged Data -0.853 SD of Detected Logged Data
0.669
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.614 d2max (for USL)
2.372
Gamma Statistics on Detected Data Only
k hat (MLE) 2.208 k star (bias corrected MLE)
1.546
Theta hat (MLE) 0.246 Theta star (bias corrected MLE)
0.351
nu hat (MLE) 39.75 nu star (bias corrected)
27.83
MLE Mean (bias corrected) 0.543
MLE Sd (bias corrected) 0.437 95% Percentile of Chisquare (2k)
7.975
Gamma ROS Statistics using Imputed Non -Detects
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
GROS may not be used when kstar of detected data is small such as < 0.1
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum 0.0714 Mean
0.459
Maximum 1.8 Median
0.369
SD 0.42 CV
0.915
k hat (MLE) 2.076 k star (bias corrected MLE)
1.679
Theta hat (MLE) 0.221 Theta star (bias corrected MLE)
0.273
nu hat (MLE) 58.14 nu star (bias corrected)
47.01
MLE Mean (bias corrected) 0.459 MLE Sd (bias corrected)
0.354
95% Percentile of Chisquare (2k) 8.427 90% Percentile
0.93
95% Percentile 1.151 99% Percentile
1.647
The following statistics are computed using Gamma ROS Statistics on Imputed Data
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 1.757 1.841 95% Approx. Gamma UPL 1.202
1.22
95% Gamma USL 1.57 1.628
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM) 1.313 nu hat (KM)
36.75
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 1.566 1.583 95% Approx. Gamma UPL 1.109
1.098
95% Gamma USL 1.413 1.418
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx
4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Sodium - ug/L - T
General Statistics
Total Number of Observations 21
Minimum 5630
Second Largest 75000
Maximum 80400
Mean 22526
Coefficient of Variation 1.101
Mean of logged Data 9.539
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.371
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Page 8 of 10
Number of Distinct Observations
21
Number of Missing Observations
6
First Quartile
6140
Median
9290
Third Quartile
23300
SD
24803
Skewness
1.52
SD of logged Data
0.959
d2max (for USL) 2.58
Nonparametric Upper Limits for Background Threshold Values
Order of Statistic, r 21 95% UTL with 95% Coverage 80400
Approximate f 1.105 Confidence Coefficient (CC) achieved by UTL 0.659
95% Percentile Bootstrap UTL with 95% Coverage 80400 95% BCA Bootstrap UTL with 95% Coverage 80400
95% UPL 79860 90% Percentile 64300
90% Chebyshev UPL 98685 95% Percentile 75000
95% Chebyshev UPL 133183 99% Percentile 79320
95% USL 80400
Sulfate - ug/L - N
General Statistics
Total Number of Observations 26
Minimum 170
Second Largest 91800
Maximum 105000
Mean 19399
Coefficient of Variation 1.621
Mean of logged Data 8.544
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.275
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Number of Distinct Observations 21
Number of Missing Observations 1
First Quartile 1425
Median 2000
Third Quartile 20475
SD 31454
Skewness 1.907
SD of logged Data 1.735
d2max (for USL) 2.681
Nonparametric Upper Limits for Background Threshold Values
Order of Statistic, r 26 95% UTL with 95% Coverage 105000
Approximate f 1.368 Confidence Coefficient (CC) achieved by UTL 0.736
95% Percentile Bootstrap UTL with 95% Coverage 105000 95% BCA Bootstrap UTL with 95% Coverage 101700
95% UPL 100380 90% Percentile 78800
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Vanadium - ug/L - T
General Statistics
90% Chebyshev UPL 115560
95% Chebyshev UPL 159117
95% USL 105000
Total Number of Observations 13
Minimum
7.3
Second Largest
157
Maximum
167
Mean
53.92
Coefficient of Variation
1.259
Mean of logged Data
3.136
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.671
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Page 9 of 10
95% Percentile 90850
99% Percentile 101700
Number of Distinct Observations
12
Number of Missing Observations
14
First Quartile
8.7
Median
10.3
Third Quartile
128
SD
67.87
Skewness
0.98
SD of logged Data
1.34
d2max (for USL) 2.331
Nonparametric Upper Limits for Background Threshold Values
General Statistics
Order of Statistic, r
13
95% UTL with 95% Coverage
167
Approximate f
0.684
Confidence Coefficient (CC) achieved by UTL
0.487
95% Percentile Bootstrap UTL with 95% Coverage
167
95% BCA Bootstrap UTL with 95% Coverage
167
95% UPL
167
90% Percentile
155.8
90% Chebyshev UPL
265.2
95% Percentile
161
95% Chebyshev UPL
360.9
99% Percentile
165.8
95% USL
167
Variance Detected
41.46
Zinc - ug/L - T
Nonparametric Distribution Free Background Statistics
Data appear to follow a Discernible Distribution at 5% Significance Level
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016
General Statistics
Total Number of Observations
26
Number of Missing Observations
1
Number of Distinct Observations
12
Number of Detects
11
Number of Non -Detects
15
Number of Distinct Detects
10
Number of Distinct Non -Detects
2
Minimum Detect
2.8
Minimum Non -Detect
5
Maximum Detect
26
Maximum Non -Detect
10
Variance Detected
41.46
Percent Non -Detects
57.69%
Mean Detected
6.973
SD Detected
6.439
Mean of Detected Logged Data
1.742
SD of Detected Logged Data
0.567
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.275
d2max (for USL)
2.681
Nonparametric Distribution Free Background Statistics
Data appear to follow a Discernible Distribution at 5% Significance Level
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016

Attachment C-3: Buck Facility Background Monitoring Well Data BTVs Statistics
Page 10 of 10
Nonparametric Upper Limits for BTVs(no distinction made between detects and nondetects)
Order of Statistic, r 26 95% UTL with95% Coverage 26
Approximate f 1.368 Confidence Coefficient (CC) achieved by UTL 0.736
95% UPL 20.4 95% USL 26
95% KM Chebyshev UPL 24.29
Haley & Aldrich, Inc.
BTV test stats after removing outliers.xlsx 4/8/2016