2016-0418_Duke_App_B_Belews_F

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www.haleyaldrich.com
EVALUATION OF WATER SUPPLY WELLS IN THE VICINITY OF DUKE
ENERGY COAL ASH BASINS IN NORTH CAROLINA
APPENDIX B - BELEWS CREEK 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 B — Belews Creek
Table of Contents
Page
List of Tables
List of Figures iii
List of Attachments v
List of Acronyms
vi
B. Belews Creek
1
B.1 INTRODUCTION
1
B.1.1
Facility Location and Description
1
B.1.2
Current CAMA Status
3
B.1.3
Investigation Results
7
B.1.4
Selected Remedial Alternative and Recommended Interim Activities
8
B.1.5
Risk Classification Process
8
B.1.6
Purpose and Objectives
10
B.2 WATER SUPPLY WELL DATA EVALUATION
11
B.2.1
Data Sources
11
B.2.2
Screening Levels
12
B.2.3
Results
12
B.3 STATISTICAL
EVALUATION OF BACKGROUND
13
B.3.1
Initial Data Evaluation
14
B.3.1.1 Regional Background Water Supply Well Data
14
B.3.1.2 Facility Background Monitoring Well Data
14
B.3.2
Raw Data Evaluation
15
8.3.2.1 Regional Background Water Supply Well Data
15
B.3.2.2 Facility Background Monitoring Well Data
16
B.3.3
Testing of Statistical Assumptions
16
B.3.3.1 Regional Background Water Supply Well Data
16
B.3.3.2 Facility Background Monitoring Well Data
17
B.3.4
BTV Estimates
17
B.3.5
Comparison of Water Supply Well Data to the Regional BTVs
18
B.4 GROUNDWATER FLOW EVALUATION
19
B.4.1
Introduction
19
B.4.2
Site Geology
19
B.4.3
Site Hydrogeology
20
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Appendix B — Belews Creek
B.4.3.1 Site Conceptual Model
8.4.3.2 Groundwater Flow Direction
B.4.3.3 Groundwater Seepage Velocities
B.4.3.4 Constituents Associated with CCR
8.4.3.5 Extent of Boron Exceedances in Groundwater
8.4.3.6 Bedrock Flow and Depth of Water Supply Wells
B.4.3.7 Groundwater Mounding
B.4.3.8 Summary
B.4.4 Water Supply Well Capture Zone Analysis
B.4.4.1 Methodology
B.4.4.2 Results
B.4.5 Summary and Conclusions
GROUNDWATER CHARACTERISTICS EVALUATION
B.5.1 Evaluation Approach
B.5.2 CCR -Related Constituents Screening for Signature Development
B.5.3 Data Analysis Methods
B.5.3.1 Data Sources
B.5.3.2 Data Aggregation
B.5.3.3 Box Plot
B.5.3.4 Correlation Plot
8.5.3.5 Piper Plot
B.5.4 Evaluation Results
B.5.4.1 Box Plot Comparison
B.5.4.2 Correlation Plot Evaluation
B.5.4.3 Piper Plot
B.5.5 Conclusions
SUMMARY
REFERENCES
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List of Tables
Table No.
Title
62-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
132-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
132-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
132-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
132-5
Comparison of Duke Energy Background Well Data to 2L Screening Levels
132-6
Comparison of Duke Energy Background Well Data to MCL Screening Levels
132-7
Comparison of Duke Energy Background Well Data to DHHS Screening Levels
132-8
Comparison of Duke Energy Background Well Data to RSL Screening Levels
132-9
Do Not Drink Letter Summary
133-1
Duke Energy Background Water Supply Well Data
133-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
133-3
Background Data Statistical Evaluation
133-4
Comparison of NCDEQ Water Supply Well Sampling Data to Background
Threshold Values
63-5
Comparison of NCDEQ Water Supply Well Sampling Data to Facility Specific
Background Threshold Values
64-1
Hydrostratigraphic Layer Properties — Horizontal Hydraulic Conductivity
134-2
Estimated Groundwater Seepage Velocities
65-1
Site -Specific Distribution Coefficient (Kd)
65-2
Coal Ash Indicator Concentrations Observed in the Water Supply Wells of Low
Oxygen and High Detected Boron Concentrations
List of Figures
Figure No. Title
61-1 Location Map
131-2 Key Features
131-3 Location of Water Supply Wells and Facility Groundwater Conditions
133-1 Facility Background Wells
64-1 Two -Medium Groundwater System
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64-2
Slope -Aquifer System
64-3
Regolith as Primary Groundwater Storage
134-4
Transition Zone as Primary Transmitter of Impacted Groundwater
64-5
Water Table Surface — Shallow Wells — Groundwater Measurement Date
7/7/2015
64-6
Potentiometric Surface — Deep Wells — Groundwater Measurement Date
7/7/2015
134-7
Potentiometric Surface — Bedrock Wells — Groundwater Measurement Date
7/7/2015
64-8
Water Table Surface — Shallow Wells — Groundwater Measurement Date
9/28/2015
64-9
Potentiometric Surface— Deep Wells — Groundwater Measurement Date
9/28/2015
64-10
Potentiometric Surface— Bedrock Wells — Groundwater Measurement Date
9/28/2015
64-11
Horizontal Hydraulic Conductivity Measurements
64-12
Site Conceptual Model — Plan View Map — Area of Boron Exceedances of
2L Standards
134-13
Cross -Section Conceptual Site Model
134-14
Mounding Effect
64-15
Groundwater Affected by Pumping
134-16
Water Supply Well Capture Zones
135-1
Pourbaix Diagrams for Iron and Manganese with Measured Eh and pH from Site
Monitoring Wells
135-2
Example Box Plot and Piper Plot
135-3
Box Plot Comparison for Major Coal Ash Constituents
135-4
Box Plot Comparison for Barium and Cobalt
135-5
Box Plot Comparison for Dissolved Oxygen, Iron, and Manganese
135-6
Bedrock Groundwater Wells and Direction of Groundwater Flow
65-7
Correlation Plot for Boron and Sulfate
135-8
Correlation Plot for Boron and Dissolved Oxygen
65-9
Sampled Water Supply Wells
65-10
Piper Plot Evaluation - Ash Basin Porewater and Facility Downgradient Bedrock
Wells
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B5-11 Piper Plot Evaluation - Water Supply Wells and Facility Bedrock Wells
135-12 Piper Plot Evaluation - Water Supply, Facility Bedrock, and Ash Basin Porewater
Wells
List of Attachments
Attachment Title
B-1 Histograms and Probability Plots for Selected Constituents
B-2 Results of Statistical Computations
B-3 Method Computation Details
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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
DWM Division of Waste Management
EPRI Electric Power Research Institute
FGD Flue Gas Desulfurization
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
SDWA Safe Drinking Water Act
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
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B. Belews Creek
The contents of this document supplements previous work completed by Duke Energy to meet the
requirements of the North Carolina Coal Ash Management Act of 2014 (CAMA) for the Belews Creek
Steam Station (Belews Creek, 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 Belews Creek ash basin under the CAMA
requirements. A technical weight of evidence approach has been used to evaluate the available data for
the site, and the evaluation demonstrates that groundwater utilized by local water supply wells near the
Belews Creek coal ash impoundment is not impacted by coal ash sources. These results indicate that a
Low classification for the Belews Creek under the CAMA is warranted.
13.1 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, a summary of the on-
site and background data evaluation findings and recommendations of the following reports:
• Comprehensive Site Assessment (CSA; HDR, Inc. [HDR], 2015a);
• Corrective Action Plan Part 1 (CAP -1; HDR, 2015b); and
• Corrective Action Plan Part 2 (CAP -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.
13.1.1 Facility Location and Description
Duke Energy owns and operates Belews Creek which is located in Stokes County, North Carolina
(Figure 131-1).
8.1.1.1 Facility Setting
Belews Creek occupies approximately 700 acres of land and is located on the west/southwest side of
Belews Lake as shown on Figure 131-2. The area surrounding Belews Creek generally consists of
residential properties, farm land, undeveloped land, and Belews Lake. Properties located within a 0.5 -
mile radius of the Belews Creek ash basin compliance boundary generally consist of residential
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properties located to the southwest, and residential farm land northeast, north, and west. Duke Energy
property is located to the north, northwest, south, and east with Belews Lake beyond to the south and
east.
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.
One public water supply well and 45 private water supply wells were identified, along with 5 assumed
private water supply wells, within a 1,500 -foot radius of the ash basin compliance boundary (Figure
B1-3). No wellhead protection areas were identified within a 1,500 -foot radius of the ash basin
compliance boundary. Several surface water bodies that flow from the topographic divide along
Middleton Loop Road toward the Dan River were identified within a 1,500 -foot radius of the ash basin
compliance boundary. No water supply wells were identified between the source areas and Dan River.
8.1.1.2 Past and Present Operations
Belews Creek began operations in 1974 as a coal-fired electrical generating station and currently
operates two coal-fired units. Unit 1 began operation in 1974 followed by Unit 2 in 1975. The electric
generating capacity of Belews Creek is 2,240 megawatts.
The major ash -related structures at Belews Creek include the ash basin, the closed Pine Hall Road Ash
Landfill, and structural fill area. These key features are shown on Figure 131-2.
The Belews Creek ash basin consists of a single cell impounded by an earthen dike located on the north
end of the ash basin. The ash basin system was constructed from 1970 to 1972 and is located
approximately 3,200 feet northwest of the station. The area contained within the ash basin waste
boundary is approximately 283 acres. The ash basin is operated as an integral part of the station's
wastewater treatment system, which receives permitted flows from the ash removal system, Belews
Creek powerhouse and yard holding sumps, chemical holding pond, coal yard sumps, stormwater,
landfill leachate, and treated flue gas desulfurization (FGD) wastewater.
The coal combustion residuals (CCR) and liquid discharges from Belews Creek's coal combustion process
have been disposed in the station's ash basin since its construction. In 1983, Belews Creek converted to
dry handling of fly ash with disposal in on-site landfills; bottom ash is sluiced to the ash basin and fly ash
is sluiced to the ash basin on start-up and in emergency situations. Discharge from the ash basin is
permitted by the NCDEQ Division of Water Resources under the National Pollutant Discharge
Elimination System (NPDES) Permit NC0024406.
There is one permitted closed ash landfill located adjacent to and southwest of the ash basin. The Pine
Hall Road Ash Landfill is permitted by the NCDEQ Division of Waste Management (DWM) under
Permit No. 85-03. The landfill is located upgradient of the ash basin and is just north of the Pine Hall
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Road topographic divide. The ash landfill was constructed prior to the requirement for lining industrial
landfills, and was closed with a hybrid cover system. The larger area of fill has an engineered closure
system consisting of a geomembrane cover system capped with soil and vegetation, whereas the flat
lower areas were closed with a soil and vegetation cover system.
An ash structural fill comprised of compacted fly ash was constructed southeast of the ash basin under
the structural fill rules found in 15A NCAC 136.1700. After completion, an engineered cover system
consisting of a geomembrane cover system capped with soil and vegetation was installed over the ash
structural fill. The ash structural fill is located south of the Pine Hall Road topographic divide and,
therefore, groundwater flow beneath the fill should be predominantly away from the ash basin. There
are no groundwater monitoring requirements or compliance boundary associated with the ash
structural fill.
8.1.1.3 Facility Geological/Hydrogeologica/ Setting
Belews Creek 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. The
natural topography at Belews Creek ranges from an approximate high elevation of 878 feet southeast of
the ash basin near the intersection of Pine Hall Road and Middleton Loop Road to an approximate low
elevation of 646 feet at the base of the dam located at the north end of the ash basin. Under natural
conditions, the general direction of groundwater flow can be approximated from the surface
topography. Topographic divides are located to the south and east of the ash basin approximately along
Pine Hall Road. A topographic divide exists to the west of the ash basin along Middleton Loop Road.
Another topographic divide exists north of the ash basin along a ridgeline that extends from the east
dike abutment toward the northeast. These topographic divides generally function as groundwater
divides although groundwater flow across topographic divides may be possible based on driving head
conditions from the ash basin and the existence of preferential flow paths within the shallow and/or
deep flow layers. Land elevation generally slopes downward toward the Dan River.
Based on the site investigation, the groundwater system in the natural materials (alluvium, soil,
soil/weathered bedrock, and bedrock) at Belews Creek is a fractured bedrock system and is an
unconfined, connected system of flow layers. The Belews Creek groundwater system is divided into
three layers referred to in this report as the shallow, deep transition zone (D or TZ), and bedrock flow
layers to distinguish the flow layers within the connected aquifer system. In general, groundwater
within the shallow and deep layers (S and D wells) and bedrock layer (BR wells) flows north and
northwest toward the Dan River.
More detail on the site hydrogeology is provided in Section B.4.
B.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
of CCR surface impoundments, including active and retired sites, based on these sites' risks to public
health, safety, and welfare, the environment, and natural resources.
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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-
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 the Receptor Survey, CSA, CAP -1, CAP -2, and
multiple sampling rounds is provided below.
8.1.2.1 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 Belews Creek ash basin compliance boundary (HDR, 2014a,
2014b). 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. Figure 61-3 shows the water supply
wells within this 0.5 -mile radius.
8.1.2.2 Comprehensive Site Assessment, Round 1 Sampling Event, March —September 2015
The purpose of the Belews Creek 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
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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:
• Installation of 64 groundwater monitoring wells, 10 geotechnical borings, and 1 soil boring;
• Collection of groundwater sampled from 75 newly installed, compliance, and voluntary
groundwater monitoring wells;
• Collection of seep, surface water, and sediment samples;
• 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); and
• Completion of a screening -level human health and ecological risk assessment.
8.1.2.3 Round 2 Sampling Event, September through October 2015
A total of 75 groundwater and ash porewater monitoring wells were sampled during the Round 2 event,
including 60 groundwater assessment wells and 15 voluntary and compliance wells. Samples were
analyzed for total and dissolved CCR constituents.
8.1.2.4 Corrective Action Plan —Part 1, 8 December 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 Belews Creek 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;
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• Additional surface water and sediment sampling should be conducted in the Dan River and in
the drainage channel between the ash basin and the Dan River;
• Refinement of the groundwater model; and
• Continued collection and statistical evaluation of data from proposed additional assessment
wells, background monitoring wells and data gap wells.
B.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 (HDR, 2014c). Groundwater sample collection and
analysis were conducted using procedures described in the CSA Report.
See Section 13.3 for a statistical evaluation of background concentrations.
B.1.2.6 Corrective Action Plan —Part 2, 4 March 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 (IMACs) and
North Carolina Department of Health and Human Services (NCDHHS) health screening level
(HSL; hexavalent chromium only);
• Refined SCM;
• Refined groundwater flow and contaminant fate and transport model results;
• Refined groundwater to surface water model results;
• Site geochemical model results;
• Findings of the 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 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 (21-
Standards);
2LStandards);
• I MACS;
• NCDHHS HSL (hexavalent chromium only); and/or
• Site-specific PPBCs for groundwater at Belews Creek.
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B.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 Belews Creek are depicted in Figure 131-3 and are described as follows:
• Impacts from CCR -constituents in groundwater are spatially limited to areas beneath the ash
basin, beneath the Pine Hall Road Ash Landfill, beneath the chemical pond, downgradient and
southeast of the ash basin, and northeast of the Pine Hall Road ash landfill both within and
outside of the compliance boundary.
• Groundwater impacts are present in the shallow and deep flow layers, and to a lesser extent, in
the bedrock flow layer; vertical migration of CCR constituents appears to be somewhat inhibited
by the underlying bedrock.
• Constituent concentrations in a limited number of bedrock wells exceeded regulatory standards
or criteria; these are arsenic, hexavalent chromium, and/or manganese; further investigation of
the bedrock flow layer will be conducted through installation of additional monitoring wells.
• Surface water impacts were identified in Belews Lake and Dan River samples; however, the
groundwater to surface water mixing model for Dan River shows no exceedances of surface
water quality standards, except for thallium at the edge of the mixing zone. Thallium
concentrations did exceed both the water supply standard and the water quality standard;
however, the thallium background concentration used for modeling also exceed the applicable
groundwater standard. This indicates that it is likely that thallium is naturally occurring in this
area at concentrations that exceed the background threshold value.
Groundwater flow direction in the vicinity of the ash basin is generally to the north towards the
Dan River, with a northwest component of flow west of the ash basin dam, away from the
nearest public or private water supply wells.
Constituents identified to exceed the applicable state and federal regulatory standards are listed by
location below:
• Ash samples collected from the ash basin: arsenic, boron, chromium, cobalt, iron, manganese,
selenium, and vanadium.
• Ash basin surface water: antimony, arsenic, boron, chloride, hexavalent chromium, cobalt, iron,
manganese, pH, thallium, total dissolved solids (TDS), and vanadium.
• Ash pore water samples: antimony, arsenic, beryllium, boron, cadmium, chloride, cobalt, iron,
manganese, nickel, pH, selenium, sulfate, thallium, TDS, and vanadium.
• Areas of wetness (AOWs): arsenic, beryllium, boron, chloride, chromium, cobalt, iron,
manganese, pH, sulfate, thallium, TDS, and vanadium.
• Groundwater: antimony, arsenic, beryllium, boron, cadmium, chloride, chromium, cobalt,
hexavalent chromium, iron, manganese, nickel, pH, selenium, sulfate, thallium, TDS, and
vanadium. Note that antimony, cobalt, chromium, hexavalent chromium, iron, manganese, pH
and vanadium were also detected above their groundwater quality standard or criteria in site
background groundwater. Further sampling and analysis are necessary to determine if
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constituent exceedances are the result of source -related impacts or naturally occurring
conditions (as discussed in the CSA).
• Soil: arsenic, barium, chromium, cobalt, iron, manganese, selenium, and vanadium.
• Surface water: aluminum, arsenic, cadmium, chloride, cobalt, copper, dissolved oxygen, iron,
manganese, lead, TDS, thallium, and turbidity.
Boron, chloride, sulfate, and TDS, all of which exceeded their 2L Standards and PPCBs either beneath or
downgradient of the source areas, 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.
B.1.4 Selected Remedial Alternative and Recommended Interim Activities
The recommended remedial alternative selected for Belews Creek is the combination of two
remediation technologies: 1) capping the ash basin, and 2) monitored natural attenuation (MNA). A
recommendation for further evaluation of active remedies to treat the groundwater beneath the
2.23 -acre parcel west of the ash basin dam not owned by Duke Energy was also included in the CAP -2
Report.
Geochemical modeling demonstrated that CCR constituents 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.
Additional groundwater monitoring well installation and a Tier III MNA evaluation (USEPA, 2007) was
recommended for implementation 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.
13.1.5 Risk Classification Process
Duke Energy is required by CAMA to close the Belews Creek ash basin system no later than
1 August 2029 or as otherwise dictated by the 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 Belews Creek 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 Belews Creek ash
basin. NCDEQ will release the final risk classifications after review of public comments.
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Appendix B — Belews Creek
According to the NCDEQ document "Coal Combustion Residual Impoundment Risk
Classifications, January 2016," (NCDEQ, 2016) the ash basin at the Belews Creek is ranked "low to
intermediate." The following are the classification factors as provided in the NCDEQ 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 infractured bedrock for up -gradient and side -
gradient supply wells in the immediate vicinity of the impoundments.
- Incomplete geochemical modeling.
- Incomplete background concentration determination.
- Horizontal and vertical extent of contamination downgradient not well defined.
- Potential contamination resulting from the on-site landfill and structural fill not
addressed.
- Groundwater flow in bedrock not well defined.
• 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:
- Active Ash Basin. 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:
- Active Ash Basin. HIGH RISK. There are several water supply wells within 500 feet of
the compliance boundary, including three water supply wells containing vanadium
or other constituents exceeding the 2L Standard or IMAC.
• Population Served by Water Supply Wells Within 1,500 feet Up -Gradient or Side -Gradient of
the Established CCR Impoundment Compliance Boundary:
- Active Ash Basin. INTERMEDIATE/HIGH RISK. Duke identified 24 drinking water
supply wells within 1,500 of the compliance boundary. Comparing to the shallow
and intermediate groundwater flow directions, no water supply well is exactly in
downgradient. However, most of water supply wells are in bedrock, but the
groundwater flow in bedrock has not been properly determined at the site. Based on
the topographic map and the location of the water supply wells identified in the CSA
Report, a total of five wells are (or potentially) side-downgradient of the Pine Hall
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Appendix B — Belews Creek
Road Landfill or the CCR impoundment. With the assumption of 2.5 users per well,
there would potentially be 13 users.
• Population Served by Water Supply Wells within 1,500 Feet Downgradient of the Established
CCR Impoundment Compliance Boundary:
— Active Ash Basin. 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:
— Active Ash Basin. HIGH RISK. There are several water supply wells within 500 feet of
the compliance boundary, including three water supply wells containing vanadium
or other constituents exceeding the 2L Standard or IMAC.
Groundwater Emanating from the Impoundment that Exceeds 2L Standard or IMAC and that
Discharges into a Surface Water Body:
— Active Ash Basin. HIGH RISK. Elevated chloride and thallium exceeding 2B standards
were detected in the Dan River. In addition, several constituents were detected at or
beyond the compliance boundary above the 2L Standard or IMAC, including
beryllium, cobalt, chromium, vanadium, TDS, and thallium, which may potentially
discharge to the Dan River.
• 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 flow paths have not been
adequately characterized. The horizontal and vertical extent beneath and
downgradient of the impoundment have not been adequately delineated. In
addition, both the closed Pine Hall Road Landfill and the on-site structural fill may
contribute to groundwater contamination, which have not been adequately
assessed. Groundwater flow direction in bedrock has not been well determined.
B.1.6 Purpose and Objectives
The purpose of this document is to provide additional detailed evaluation of Belews Creek 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 Belews Creek 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 of groundwater in the vicinity of the ash basin.
This document is divided into four sections:
• Section 13.2 provides an evaluation of the water supply well data with respect to regulatory
standards and health -risk-based screening levels.
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Appendix B — Belews Creek
Section 13.3 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 Belews Creek operations.
Section 13.4 provides the hydrogeologic findings of addition groundwater modeling and an
additional evaluation of groundwater flow patterns in the vicinity of Belews Creek with respect
to the locations of the water supply wells.
• Section 13.5 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 groundwater, water supply wells, and regional background
groundwater, 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 Belews Creek.
• Section 13.6 provides a summary of conclusions and a discussion of their potential impact on the
risk classification for this site.
13.2 WATER SUPPLY WELL DATA EVALUATION
The purpose of this section is to evaluate data for water supply wells in the vicinity of Belews Creek with
respect to applicable screening levels.
13.2.1 Data Sources
One public water supply well and 45 private water supply wells were identified, along with 5 assumed
private water supply wells, within a 0.5 -mile radius of the ash basin compliance boundary (Figure 132-1).
This section presents an evaluation of the water supply well data from the following two sources:
• A total of 34 samples collected by the NCDEQ from 34 wells within a 0.5 -mile radius of the
Belews Creek ash basin compliance boundary; and
• A total of 11 samples collected by Duke Energy from background water supply wells located
within a 2- to 10 -mile radius from the Belews Creek 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.
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Appendix B — Belews Creek
B.2.2 Screening Levels
Analytical data from the NCDEQ-sampled 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 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.
B.2.3 Results
Tables 132-1 through 132-4 present the comparison of the NCDEQ data for the water supply wells located
within a 0.5 -mile radius of the Belews Creek ash basin compliance boundary to 2L standards, USEPA
MCLS, NCDHHS screening levels, and USEPA RSLs, respectively.
Tables 132-5 through 132-8 present the comparison of the 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 3 out the 35 NCDEQ-sampled water supply wells; boron was not detected in the
11 Duke Energy background wells. Arsenic was below the drinking water standard in 27 of the 34
NCDEQ-sampled water supply wells. pH was below the drinking water standard range in 20 of the
34 NCDEQ-sampled water supply wells. In general, pH in these wells (both near the facility and in the
background wells) was below the state and federal standard range. These results are not unexpected,
based on a study published by the United States Geological Survey (USGS) (Chapman, et al., 2013) and
additional North Carolina specific studies (Brief, 1997) showing that groundwater pH in the state is
commonly below the MCL range of 6.5 to 8.5.
None of the NCDEQ-sampled water supply well results were above Federal primary drinking water
standards (MCLs), with the exception of the few pH and arsenic results noted above. Six of the iron and
manganese results were above the SMCL, as was one result for aluminum; however, the SMCLs are
based on aesthetics, and all results are below the USEPA risk-based RSLs.
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Appendix B — Belews Creek
The concentration of cobalt and chromium in one well was above the 2L Standard and NCDHHS
screening level; however, cobalt and chromium concentrations are below the MCL and USEPA RSL
screening levels.
"Do Not Drink" Letters were issued by NCDHHS for 3 water supply wells at Belews Creek (see
Table 132-9). Two letters were issued for vanadium, though these were based on the now -outdated
screening level, and those "Do Not Drink" warnings have been lifted for vanadium. One letter was
issued for iron (1 well).
A detailed statistical evaluation of background and comparison to the water supply well data is provided
in the next section.
B.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. 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.
Two datasets are available to describe background groundwater conditions in the vicinity of Belews
Creek:
• The Duke Energy background water supply well dataset; and
• The Belews Creek facility background monitoring well dataset.
The Duke Energy background water supply well dataset are referred to here as regional background
dataset, and the Belews Creek background monitoring wells are referred to as facility -specific
background dataset. Eight constituents were selected for the background evaluation studies at Belews
Creek. 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 B.S. The BTV values were estimated for the eight constituents at Belews Creek 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.
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Appendix B — Belews Creek
The statistical methodology and the conclusions for the background evaluation are presented in the
following sections.
B.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 Belews Creek facility -specific background monitoring well
dataset, before combining 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.
B.3.1.1 Regional Background Water Supply Well Data
The regional background dataset for Belews Creek were provided by a single source, Duke Energy.
Therefore, test for homogeneity was not performed for the regional dataset. Table 133-1 presents the
regional background water supply well dataset for Belews Creek.
B.3.1.2 Facility Background Monitoring Well Data
Water supply wells in this region of North Carolina are predominantly bedrock wells. Section B.4
discusses this in more detail.
Background wells sampled at Belews Creek for the CSA included BG -1D, BG-2BR, BG -2D, BG -3D, MW-
202BR, BG -3S, MW -202S, and MW -202D. The initial facility specific background evaluation for Belews
Creek was performed on four background deep (transition zone) wells and two bedrock background
monitoring wells (BG -1D, BG-2BR, BG -2D, BG -3D, MW-202BR, and MW -202D) (see Figure 133-1).
Background wells screened in the shallow formation were excluded from the analysis to limit the data
used to the 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 Belews Creek is
presented in Table 63-2. 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 63-2 and Figure 63-1 were combined for the facility
BTV estimates. The results of the Levine's test are presented in Attachment B-1.
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Appendix B — Belews Creek
13.3.2 Raw Data Evaluation
In the raw data evaluation for Belews Creek, the descriptive statistics for eight constituents for both the
regional and facility -specific datasets were computed and tabulated in Table 133-3. 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 eight constituents for both regional and facility -specific datasets are
presented in Table 133-3. Attachment B-1 presents the histograms, probability plots and outlier tests for
the eight constituents.
B. 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, and nickel; boron had no detects, cobalt had one detect, and nickel had two detects out of
11 samples. Due to the presence of high percentage of NDs in the dataset, the outlier test statistics
were computed using the detected data alone. As presented in Table 133-3 (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 are
made based on existing knowledge about the facility and 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.
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Appendix B - Belews Creek
B.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 non -detects for boron, cobalt, and lead. Boron had 3 detects and lead had
22 detects out of 59 samples; cobalt had 11 detects out of 27 samples. Statistical computations
indicated the presence of outliers in the dataset, specifically with regard to monitoring well MW -202D.
Sampling results from MW -202D for the January 2011 event showed significant concentration variation
from the remaining sample results for this well and, therefore, the January 2011 results for this well
were removed from further analysis and descriptive statistics were recalculated.
B.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 B.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
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 eight constituents for both regional and facility -
specific datasets are presented in Table 133-3. Attachment B-2 presents the GOF tests statistics.
B. 3.3.1 Regional Background Water Supply Well Data
The test statistics revealed that barium, hexavalent chromium, iron, lead, and vanadium follow a
parametric distribution; hence, parametric methods were used to compute BTVs. No further evaluation
was performed on boron, cobalt, or nickel due to the presence of <— two detects.
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Appendix B — Belews Creek
B.3.3.2 Facility Background Monitoring Well Data
The test statistics revealed that barium, cobalt, hexavalent chromium, iron, and nickel follow a
parametric distribution; hence, parametric methods were used to compute BTVs. Non -parametric test
methods were used to compute the BTV for lead and vanadium. No further evaluation was performed
on boron due to the presence of three detects.
6.3.4 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 -collected new/future
observation from the population will exhibit a concentration less than or equal to the UPL95 with a CC of
0.95. It is noted that the use of a UPL95 to compare many observations may result in a higher number
of false positives; that is the incorrect rejection of a true null hypothesis.
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,
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Appendix B — Belews Creek
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 133-3 presents the estimated BTV values (Column 16) and applicable methods (Column 17) used in
estimating the upper threshold values. Attachment B-3 presents the proUCL output of the BTVs
computations.
6.3.5 Comparison of Water Supply Well Data to the Regional BTVs
The data for the water supply wells located within the 0.5 -mile radius of the ash basin compliance
boundary were compared to the regional background BTVs and facility -specific BTVs presented in Table
133-3. Comparison to the regional background BTVs are presented in Table 133-4, and comparison to the
facility -specific BTVs are presented in Table 133-5
Very few of the results were above either the regional BTVs or the facility -specific BTVs.
All water supply well results for barium, boron, hexavalent chromium, and lead are below their
respective regional BTVs.
Three of the 34 results for barium in the NCDEQ-sampled water supply wells were above the facility -
specific BTV; however, all are well below the USEPA RSL for tap water (USEPA, 2015b).
Cobalt was detected in only 1 of 11 background water supply wells, and the regional BTV was assigned
as the single detected level. Cobalt was detected in only 4 of 35 NCDEQ-sampled water supply wells;
two of these concentrations are above the assigned regional BTV and one concentration is above the
facility -specific BTV, and of these one is above the 2L Standard, although all are below the USEPA RSL for
tap water (USEPA, 2015b).
One of the 34 results for hexavalent chromium in the NCDEQ-sampled water supply wells was above the
facility -specific BTV.
Four of the 34 results for iron in the NCDEQ-sampled water supply wells were above the regional BTV
and facility -specific BTV; however, all are well below the USEPA RSL for tap water (USEPA, 2015b).
Nine of the 34 results for lead in the NCDEQ-sampled water supply wells were above the facility specific
BTV; however, all are well below the USEPA RSL for tap water (USEPA, 2015b).
Only one result for nickel in the NCDEQ-sampled water supply wells was above the regional BTV and
facility -specific BTV, and all concentrations are below all of the screening levels.
Only two of the 34 results for vanadium in the NCDEQ-sampled water supply wells were above the
regional BTV, and only one result in the NCDEQ-sampled water supply wells was above the facility -
specific BTV, and all concentrations are well below the USEPA RSL for tap water (USEPA, 2015b).
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Appendix B — Belews Creek
13.4 GROUNDWATER FLOW EVALUATION
[The evaluation in Section B.4, including figures and tables, was provided by HDR, Inc.]
13.4.1 Introduction
The objective of this report is to expand upon site-specific groundwater flow and water quality data that
were presented in the CSA report (HDR, 2015a) for Belews Creek 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 17 monitoring wells and
subsequent sampling of the 81 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 13.4.2, the regional groundwater
system and the hydrogeological SCM are presented in Section 13.4.3.1, and the location of water supply
wells in the vicinity of the facility and hydrogeology of the site is presented in Section 6.4.3.2. Detailed
data were collected to evaluate groundwater flow direction, horizontal and vertical gradients, and the
velocity of groundwater flow as described in Section 13.4.3. 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 13.4.4.
13.4.2 Site Geology
The Belews Creek site is located in the Piedmont Province of North Carolina. In-situ materials (in
addition to ash and fill) encountered at Belews Creek during the CSA include:
• Residuum (Regolith -Residual Soils; M1) — Residuum is weathered soil that was derived from the
in-place weathering of bedrock. The thickness observed ranges from 5 to 68 feet.
Saprolite/Weathered Rock (Regolith; M2) — Saprolite is soil developed by the in-place
weathering of bedrock and retains remnant bedrock structure. The thickness observed ranges
from 0 to 49 feet.
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Appendix B — Belews Creek
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 observed ranges from 0 to 15 feet.
• Bedrock (BR) — Bedrock is hard rock that is unweathered to slightly weathered and relatively
unfractured. The maximum depth that borings extended into bedrock at the Belews Creek site
was 62.5 feet. The bedrock is an interlayered mica schist, schistose mica gneiss, augen gneiss,
flaser gneiss, quartz -feldspar gneiss, biotite gneiss, and hornblende schist and gneiss.
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).
13.4.3 Site Hydrogeology
8.4.3.1 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 134-1) 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 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 134-2). 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).
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 134-1) (Heath,
1980; Harried 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
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Evaluation of Water Supply Wells
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Appendix B — Belews Creek
through which the recharge and discharge of water from the underlying fractured rock occurs (Daniel
and Harned, 1998); (see Figure B4-3). Within the fractured crystalline bedrock layer, the fractures
control both the hydraulic conductivity and storage capacity of the bedrock. A transition zone (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 134-4). Additional details of the SCM are presented in
Sections 5.2 and 6.2.4 of the CSA report (HDR, 2015a) and Section 3.0 of the Belews Creek Corrective
Action Plan Part 1 (CAP -1) (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 Belews Creek 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, Residuum (Regolith -Residual Soil; M1), Saprolite/Weathered Rock (Regolith; M2),
Partially Weathered/Fractured Rock (TZ—Transition Zone), Bedrock (BR), and anthropogenic units, ash
(A) and fill (F), as described in Section B.4.2. These units are used in the groundwater model of the site
discussed in Section B.4.4.
Additional information concerning the development of the hydrostratigraphic layers is presented in
Section 11.1 of the CSA report (HDR, 2015a).
8.4.3.2 Groundwater Flow Direction
The Belews Creek 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 western, southern, and eastern extent of the
Belews Creek ash basin to the north and northwest toward the Dan River.
Water level potentiometric surfaces and directions for the three flow layers are shown on Figures 134-5
(34)1, B4-6 (26), and B4-7 (9) for water levels recorded on 7 July 2015, and on Figures B4-8 (33), B4-9
(31), and 134-10 (7) for water levels recorded on 28 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 -
1 Numbers shown in parentheses represent the number of measurements used to prepare the groundwater flow
maps.
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Evaluation of Water Supply Wells
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Appendix B — Belews Creek
aquifer system and show that groundwater flow is away from off-site water supply wells and toward the
discharge feature, the Dan 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 west, south, and east of
the ash basin serves as a groundwater recharge area and that Dan River serves as the discharge feature
for groundwater flow at Belews Creek.
8.4.3.3 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 134-11; Table 134-1) 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-
12), 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 64-2. 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 Harned 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 64-4) at Belews Creek.
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).
8.4.3.4 Constituents Associated with CCR
The data evaluation in the previous sections of this report determined that there is greater ability of
groundwater to flow horizontally than vertically 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 recent regulation. On 17 April 2015, the USEPA published its final rule "Disposal of Coal
Combustion Residuals from Electric Utilities" (Final CCR Rule) to regulate the disposal of CCR as solid
waste under subtitle D of the Resource Conservation and Recovery Act (USEPA, 2015a). The USEPA
defined a phased approach to groundwater monitoring. The first phase is detection monitoring where
groundwater is monitored to detect the 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, total dissolved solids). 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;
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Evaluation of Water Supply Wells
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Appendix B — Belews Creek
• Ccalcium;
• 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.
B.4.3.5 Extent of Boron Exceedances in Groundwater
Groundwater at Belews Creek 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 Belews Creek, boron exceedances of the 2L Standards reported in groundwater during the 2015
Round 2 sampling event are shown in plan view (Figure 134-12) and in cross-section view (Figure 134-13)
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 is not naturally occurring in detectable
concentrations in Piedmont groundwater. As can be seen from these figures, the boron exceedances of
the 2L Standards in groundwater are located beneath the Pine Hall Road Landfill and the northern end
of the active ash basin. Groundwater flow direction from the Pine Hall Road Landfill is to the north
toward the ash basin, and groundwater flow from the ash basin is to the north toward tributaries of the
Dan River. Groundwater flow from boron exceedances in groundwater away from the water supply
wells.
B.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 offsite water supply wells.
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Evaluation of Water Supply Wells
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Appendix B — Belews Creek
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 134-3).
As noted above, bedrock flow is away from the off-site water supply wells and towards the ash basin
and Dan River. 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 B.4.4.
8.4.3.7 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 134-14). Topographical and monitoring well groundwater data
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.
Although not mounding, but due to a narrow ash basin rim, there is evidence of groundwater flow
northwesterly across the topographic divide of Middleton Loop Road near the west abutment of the Ash
Basin Dam (Figures 64-5 and B4-8). The net effect of this localized gradient is reflected in the current
data set and occurs locally within the larger slope -aquifer system, and as such, the larger system still
controls the overall site gradient. There are no water supply wells down gradient of this area.
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Appendix B — Belews Creek
8.4.3.8 Summary
The hydrogeologic SCM presented in the CSA report and refined in the CAP -2 report describes
groundwater flow in the shallow (S — water table), deep (TZ — transition zone) and bedrock (13R)
groundwater zones as predominantly horizontal with flow to the north and northeast toward the Dan
River. A groundwater divide coincident with Pine Hall Road exists, and north of Pine Hall Road the
groundwater flow direction is toward the ash basin and Dan River. South of the road, the flow direction
is to the south toward Belews Lake. Groundwater flows to the south and southwest towards Belews
Lake in the northeast corner of the model domain. The basis for this conclusion is the analysis of
monitoring well water elevation data during the sampling events. The eastern flow direction is away
from the water supply wells with average horizontal gradients of 0.019 and 0.019 feet/foot in the
shallow (S — water table) and deep (TZ — transition zone) groundwater zones, respectively. There were
insufficient data to calculate a horizontal gradient for the bedrock groundwater zone. The Dan River and
Belews Lake 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 Dan River or Belews Lake.
13.4.4 Water Supply Well Capture Zone Analysis
A well capture zone analysis was performed, using reverse particle tracking, to delineate well capture
zones for the active water supply wells near the Duke Energy property boundary at Belews Creek. A well
capture zone is the area of an aquifer (all three flow layers) in which water is removed by pumping wells
within a specified time period (Grubb, 1993) (see Figure 134-15). Groundwater pumping produces a low
pressure area in the groundwater flow field that induces groundwater flow towards the well. The
pressure front does 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 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 miscible and mobile constituents in groundwater, if present, within the capture zone
are removed by pumping.
In the capture zone analysis, the previously developed groundwater flow model during CAP -2 (CAP -2
model) is used to simulate the normal pumping of the water supply wells. The capture zones generated
by the model are compared to the footprints of the ash basin waste boundary. This comparison can be
used to identify potential impacts to the recharge areas used by the water supply wells. The capture
zone analysis was performed for a simulated period of time extending back in time to when the ash
basin system was first placed into service. The capture zone analysis accounts for the potential effect of
adjacent water supply wells pumping at the same time, and considers the effects of local groundwater
flow and other relevant conditions, such as the location and water level elevations of the ash basin
system.
As previously discussed in Section 13.4.3, in an unconfined aquifer system, such as at Belews Creek,
groundwater flow normally follows the surface topography flowing from areas of higher elevation
(higher water levels) to areas of lower elevation (lower water levels) due to gravity (Freeze and Cherry,
1979). Typically, aquifer recharge occurs at higher elevations where vertical downward flow is
predominant. Aquifer discharge areas (e.g., a groundwater seepline near a stream) are found at lower
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Appendix B — Belews Creek
elevations. The well capture zone will extend further upgradient than downgradient, as that is the
predominant source of water recharge to the well (see Figures 64-15 and 134-16). As explained
previously, the shape of the capture zone is a result of the well position with respect to the groundwater
flow field and natural hydraulic gradients.
The limited number of questionnaires returned during the Receptor Survey (HDR, 2014a, 2014b)
indicates that surrounding water supply wells are installed into bedrock. As discussed in Section B.4.3.1,
although the water supply wells may be drilled into bedrock, the storage characteristics of the overlying
saprolite and transition zone exert control over the sustained quantity of water available to the well
(Harned, 1989). As discussed above, the regolith (soil/saprolite) provides the majority of water in the
water supply wells, not bedrock fractures.
As shown in Figure 2-1 of CAP -2, and included within the CAP -2 model, Belews Creek began sluicing ash
in 1974 and coal ash source includes the single cell ash basin. Reverse particle tracking was performed
to delineate well capture zones using MODPATH (Pollock, 1994). The program computes particle flow
paths or tracks, from the water supply wells, using the groundwater flow results from the CAP -2 model
(Niswonger et al., 2011). The reverse particle tracking was performed to extend the delineation of the
modeled capture zone for each water supply well back in time for 41 years, which corresponds to the
date when the Belews Creek coal ash sources were first used. The advective flow pathlines for
groundwater particles from the pumped well to their point of origin for this period of time are shown.
For consistency with the calibrated CAP -2 model, the effective porosity values used for transport model
calibration were also used for reverse particle tracking: 20 percent in ash/fill, 20 percent in soil and
saprolite (M1/M2 zones), 1 percent in the transition zone, and 1 percent in bedrock. The mean annual
recharge from precipitation in the Piedmont ranges from 4.0 to 9.7 inches/year (Daniel, 2001). The
recharge rate in the calibrated flow model is 3.0 to 9.0 inches/year, except for the ash basin where the
recharge is 15.0 inches/year. Recharge was set to zero for the Pine Hall Road Landfill as it contains an
engineered cap that impeded recharge to the groundwater system.
B. 4.4.1 Methodology
The steady-state groundwater flow and contaminant transport model developed for the Belews Creek
CAP -2 report (HDR, 2016) was utilized for this study. The CAP -2 model was calibrated to match water
levels measured in July 2015 for shallow (S — water table), deep (TZ — transition zone), and bedrock (BR)
wells. Active water supply wells within the model domain were included and actively pumped within
the model during water level calibration. The model uses a conservative assumption that each water
supply well is pumping continuously at 400 gallons/day, which is the average household usage rate
(USEPA, 2008). A detailed presentation of model calibration was provided in Appendix B of the CAP -2
report.
The flow solution for the Belews Creek CAP -2 "existing conditions" model scenario was used by
MODPATH to compute the particle path. A particle's path is computed from one model cell to the next
until it reaches the model boundary, an internal sink that removes water such as a wetland or seep, or
satisfies a time requirement (in this case the operational time period of 41 years for the original ash
basin). During reverse particle tracking, MODPATH reverses the sign of the velocity term to calculate
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Evaluation of Water Supply Wells
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Appendix B — Belews Creek
the time required for a discrete "particle of water" placed at a well to travel upstream to where that
particle originated. Groundwater Vistas is the graphical -user interface program that was used to set-up
and process the MODPATH simulations (Rumbaugh and Rumbaugh, 2011).
For the reverse particle tracking, a 30 -foot diameter ring consisting of 10 particles was inserted in the
upper bedrock layer of the model around each water supply well. Next, MODPATH was run in reverse to
determine the travel time from the water supply well and origin of each particle. The capture zone for
each well was created by connecting the particle track termination points to create a polygon
(Figure 134-16). The capture zone for each well represents an area of the aquifer where the water will be
removed by pumping continuously at 400 gallons/day for 41 years (corresponding to the length of time
that ash has been stored at the Belews Creek site beginning in 1974). Finally, the capture zones were
compared to the ash basin waste boundary to determine if water pumped by the well originates within
the ash basin waste boundary (Figure 134-16).
8.4.4.2 Results
The analysis found that the source of groundwater for the water supply wells is upgradient of the ash
basin, and supplied by recharge falling on areas not impacted by coal ash. The groundwater flow
directions for the water supply wells are consistent with the slope -aquifer system and show that
groundwater flow is away from off-site water supply wells and toward Belews Lake and the ash basin. A
groundwater divide coincident with Pine Hall Road exists and the groundwater flow direction across
most of the site is north toward the Dan River. South of the road, the flow direction is to the south
toward Belews Lake. Note that certain limitations and assumptions were made while developing the
model. The limitations and assumptions (listed on Figure 134-16) produce conservative results and do
not affect the findings as presented above. Results are considered conservative because particle
tracking has been assessed for the greatest amount of time since the ash basin system began operating,
and water supply wells were conservatively assumed to pump continuously at 400 gallons/day, which is
the average household usage rate.
B.4.5 Summary and Conclusions
Major findings from the evaluation of groundwater flow at the Belews Creek Steam Station are as
follows:
The groundwater system at Belews Creek 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 - transition zone), and bedrock (BR).
• Site-specific water level measurements confirm that groundwater flow is to the north and
northeast toward the Dan River from the topographic divides west, south, and east of the ash
basin away from the water supply wells, and also confirm the flow model predictions.
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Appendix B — Belews Creek
• 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 lateral flow
predominates over downward 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.
• Although not mounding, but due to the narrow ash basin rim, there is evidence of groundwater
flow northwesterly across the topographic divide of Middleton Loop Road near the west
abutment of the Ash Basin Dam. There are no water supply wells down gradient of this area.
• The water supply well capture zone analysis shows that the water supply wells are supplied with
water from precipitation recharge to the regolith (soil/saprolite) surrounding the pumping
well(s) and the capture zones do not intersect or originate in the coal ash sources. This analysis
considered the potential combined effects of adjacent pumping wells. Site-specific water level
measurements and groundwater modeling confirm that the combined pumping effect of the
water supply wells is not affecting the overall site groundwater flow direction.
Based on this evidence, groundwater utilized by water supply wells near the coal ash
impoundments is not impacted by the coal ash sources.
B.5 GROUNDWATER CHARACTERISTICS EVALUATION
The results from the local water supply well testing conducted by the NCDEQ in the vicinity of the
Belews Creek 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 water
supply well data was presented in Section B.3. As indicated in Section B.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 groundwater in the regolith. Based on the groundwater transport
modeling results in Section E.4.4.2, the source of groundwater for the local water supply wells is
upgradient of the ash basin, and supplied by recharge falling on areas not impacted by coal ash.
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 found in the nearby local water supply wells.
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Evaluation of Water Supply Wells
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Appendix B — Belews Creek
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.
B.5.1 Evaluation Approach
A multiple -lines -of -evidence approach, as summarized below, was used to facilitate the development of
chemical signatures of the CCR -impacted groundwater. The approach consists of the following key
components:
• Screen the geochemical and transport behaviors of typical CCR -related constituents to establish
candidate constituents for further evaluation.
• Assess the presence and magnitude or range in concentration of candidate constituents in the
groundwater beneath the site as a result of a release from the ash basin 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 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.
Identify useful sensitive 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 from background
conditions to serve as signature constituents to assess the potential relationship between the
facility CCR -impacted groundwater and the local water supply wells.
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Appendix B — Belews Creek
• 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 B.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.
B.5.2 CCR -Related Constituents Screening for Signature Development
The first step for determining 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 135-1.
• 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 135-1), 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 oxveen. dissolved iron. and dissolved maneanese: Groundwater in the ash basin area
generally contains very low concentrations of dissolved oxygen, but high concentrations of
dissolved iron and manganese concentrations (HDR, 2015a). The site-specific geochemical
analysis indicates that the reduction -oxidation (redox) state of groundwater in the ash basin
area is generally iron or manganese reducing (Figure 65-1) (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
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Appendix B — Belews Creek
dissolved iron and manganese are sensitive to the presence of dissolved oxygen, including the
iron and manganese data used in this evaluation will help identify and compare the redox
conditions among different well groups.
13.5.3 Data Analysis Methods
B. 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; and
• Duke Energy background water supply well data.
8.5.3.2 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, 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 value for the general
conditions observed in a well.
• The reporting limits are used to represent the ND results.
8.5.3.3 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 135-2
defines the various components of the box plot. The location of the upper whisker is the lesser of
1.5 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.
8.5.3.4 Correlation Plot
The constituents found to be signature indicators of the CCR -impacted groundwater can be used to
generate correlation plots to further evaluate the relationships among various data groups. To create a
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Appendix B — Belews Creek
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 illustrate correlations among data groups.
8.5.3.5 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 and groundwater in other groups of facility monitoring wells. An example figure is shown in
Figure 135-2, 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 -21S
shows about 20 percent of the total cation charges from sodium and potassium, approximately
25 percent from calcium, and about 55 percent from magnesium. In the anion subplot, the data point of
MW -14B shows about 18 percent of the total anion charges from sulfate, approximately 20 percent
from chloride and nitrate related anions (NO2_ and NO3-), and 62 percent from carbonate (CO32-)plus
bicarbonate (HCO3-) anions. In the diamond subplot, the data point of AB -17S shows about 47 percent
of the total anion charges from chloride, nitrate related anions, and sulfate, and approximately
80 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 USGS
(Winston, 2000).
B.5.4 Evaluation Results
8.5.4.1 Box Plot Comparison
The box plot comparison of boron, calcium, chloride, sulfate, and TDS concentrations among various
well groups is shown in Figure 135-3. 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 135-4, which shows trends similar to
those observed for other major CCR constituents in Figure 135-3. The difference in barium concentration
between the ash basin porewater and the groundwater in local water supply wells is also not as
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Appendix B — Belews Creek
significant as boron and sulfate. Because boron and sulfate are generally mobile, subject to little
sorption onto mineral surfaces, 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 135-5. 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 basin. 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 similar geologic
environments (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).
The iron and manganese concentration trends are opposite to that of dissolved oxygen. Based on the
site-specific geochemical evaluation, the ash basin porewater generally favors the presence of reduced
iron and manganese (Figure 65-1), 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, 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 an effective signature constituent in comparison to iron and manganese.
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Appendix B — Belews Creek
8.5.4.2 Correlation Plot Evaluation
Boron, sulfate, and dissolved oxygen were identified to be the effective signature constituents to assess
the extent of the CCR -impacted groundwater. The spatial patterns of boron and sulfate concentrations
observed in the facility bedrock wells were first evaluated using the boron and sulfate concentrations
observed in the ash basin monitoring, facility bedrock, local water supply, and the regional background
wells through a correlation plot.
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 (Figure 65-6), which are further divided into three subgroups:
— Subgroup 1 (Downgradient): These wells are located beneath or hydraulically
downgradient of the ash basin or ash landfill, or groundwater flowing through these
wells is likely originated from the ash basin. 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). The wells AB-4BR, AB-9BR, GWA-5BR2, and MW-200BR
belong to this subgroup. It is noted that the groundwater flow field near GWA-5BR2 is
uncertain; it may be assigned as either an upgradient or downgradient well due to its
proximity to a groundwater divide. Based on its geochemical signature and the flow
field in the deep overburden this well is given a preliminary classification as a
downgradient facility bedrock well.
— Subgroup 2 (Side Gradient): Only BG-2BR is in this well group. This well is located cross
gradient of the ash basin or groundwater flowing through these wells is not likely to
subsequently flow beneath the footprint of the ash basin. This well is not expected to
be influenced by the ash basin groundwater.
— Subgroup 3 (Upgradient): These wells are located in a different flow basin and on the
opposite side of the groundwater divide along Pine Hill Road (as noted in Section B.4.5),
and thus are not expected to be influenced by the ash basin groundwater. The wells
GWA-12BR, MW-202BR, and MW-203BR belong to this group.
The correlation plot of boron and sulfate concentrations is shown in Figure 65-7. Panel (a) shows the
correlation plot for the ash basin porewater wells and the facility downgradient bedrock wells. The ash
basin porewater results are distinguished by elevated boron concentrations and generally high sulfate
concentrations (> 100,000 micrograms per liter [µg/L]). The facility downgradient bedrock wells exhibit
relatively low boron and sulfate concentrations. Panel (b) shows the data from the facility side gradient
and upgradient bedrock wells in addition to the data in Panel (a). These added wells exhibit a similar
pattern to the downgradient bedrock wells and are distinguished from the ash basin porewater wells by
relatively low boron and sulfate concentrations. Panel (c) shows the overlay of the data from the local
water supply and regional background wells on the data in Panel (b). These added wells are
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Appendix B — Belews Creek
distinguished by very low to non -detect levels of boron, and a similar range of the sulfate concentrations
to the facility bedrock wells.
Panel (c) shows that the ash basin porewater data are clustered in Area 1 and the local water supply and
regional well data are clustered in Area 2. Wells in Area 1 exhibit high boron and high sulfate
concentrations while wells in Area 2 exhibit low boron and low sulfate concentrations. Two ash basin
porewater wells, AB -6S and AB-6SL, show lower sulfate concentrations than the others and so fall
outside of the clustering in Area 1.
Based on Figure B5-5, dissolved oxygen concentration is also a useful indicator for CCR -impacted
groundwater. The boron and dissolved oxygen correlation plot is shown in Figure 135-8. 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 in the ash basin porewater wells and
relatively low dissolved oxygen concentrations in both sets of wells. Panel (b) shows the data from the
facility side gradient and upgradient bedrock wells in addition to the data in Panel (a). These added
wells exhibit a similar pattern to the downgradient bedrock wells and are distinguished from the ash
basin porewater wells by relatively low boron concentrations and a range of dissolved oxygen
concentrations. Panel (c) shows the overlay of the data from the 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 wider
range of dissolved oxygen concentrations. The Panel (c) plot shows that the data are clustered in two
distinct areas. The variability of the dissolved oxygen concentrations for the local water supply wells are
within the range found in the Piedmont Province (Briel, 1997). Area 1 contains the data from the ash
basin porewater wells. Area 2 contains the data from the local water supply wells and facility bedrock
wells.
Although the facility bedrock wells show slightly higher boron concentrations than the local water
supply wells, there is a clear distinction between the ash basin porewater wells (Area 1) and all other
wells (Area 2). Note that 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. The correlation plot result shows that the low oxygen and elevated boron
concentrations serve as a useful signature pair to help identify the CCR -impacted groundwater. The fact
that most of the water supply wells are significantly more oxygenic suggests that the local water supply
wells do not obtain groundwater primarily from the ash basin because no effective mass transfer
mechanism can replenish oxygen during the groundwater transport from the ash basin to a water supply
well.
It is noted that dissolved oxygen concentrations in some local water supply wells are 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 groundwater data for a subset of the local water supply wells that exhibit either a detected boron
concentration higher than 5 µg/L or lower dissolved oxygen concentrations (below 4,000 pg/L) with a
non-detected boron concentration at a reporting limit higher than 5 µg/L were further evaluated. These
conditions could be suggestive of a potential impact of CCR -impacted groundwater. Therefore, these
locations were further evaluated for the boron and sulfate concentrations. The locations of these local
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Appendix B — Belews Creek
water supply wells are shown in Figure 135-9. Table 135-2 shows the comparison between the observed
boron and sulfate concentrations in these wells and the site-specific regional background threshold
values for these constituents. The results show that the boron concentrations observed in these wells
are below the facility -specific boron BTV (37 µg/L) derived in Section B.3. A sulfate BTV was not derived
in Section B.3. The maximum sulfate concentration detected in facility background bedrock wells
(24,500 µg/L) is used instead. The maximum detected sulfate concentration occurs in BG-2BR; as no
boron was detected in this well and the dissolved oxygen concentration is greater than 1,000 pg/L
(greater than the range of dissolved oxygen in ash basin porewater wells), this sulfate concentration is
representative of background conditions. It is noted that this value is also very similar to the maximum
sulfate concentration (20,500 µg/L) in the subset of the local water supply wells with boron
concentrations lower than 5 pg/L. The results of Table 135-2 indicate CCR impacts were not found in the
local water supply wells.
Based on Figures 65-7 and 135-8, no sign of CCR -impacted groundwater has been found in any facility
bedrock wells. The groundwater in the facility bedrock wells is generally much more oxygenic and lower
in boron and sulfate concentrations than the ash basin porewater wells, thus the water quality of the
facility bedrock wells is more similar to the local water supply wells than the wells within the ash basin
footprint. The correlation plots and the conceptual groundwater flow directions consistently support
the conceptual groundwater transport process that the background groundwater of higher dissolved
oxygen and low boron and sulfate concentrations is upgradient of the ash basin and the groundwater
becomes enriched with boron and/or sulfate and/or deprived of oxygen as it flows through the ash
basin area.
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.
8.5.4.3 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 135-10.
Panel (a) shows the data for the ash basin porewater wells; the cation subplot shows that calcium is the
dominant cation in the porewater; the diamond subplot shows that the relative abundance of calcium
and magnesium in the porewater is greater than 80 percent. The anion plot shows that the wells have a
wide range of sulfate and chloride abundances. As in the correlation plot for boron and sulfate
(Figure 135-9), two ash basin porewater wells, AB -6S and AB-6SL, have lower sulfate and chloride
concentrations which cause them to fall outside the clustering exhibited by the other ash basin
porewater wells.
Panel (b) shows the data for both the ash basin porewater wells and the facility downgradient bedrock
wells. While the downgradient facility bedrock wells are similarly enriched in calcium, they are low in
both sulfate and chloride. On the diamond plot the downgradient facility bedrock wells thus plot
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Appendix B — Belews Creek
outside of the ash basin porewater cluster, indicating that the groundwater in these bedrock wells is not
impacted by CCR.
The piper plots for the local water supply, side gradient and upgradient facility bedrock wells are
provided in Figure B5-11. Panel (a) of Figure 135-11 shows the data for the local water supply wells.
Although they show a range of calcium and magnesium abundances, these well data are grouped fairly
tightly together in each of the sections of the piper diagram. This indicates that they have similar major
ion characteristics, and the grouping is distinctive from the ash basin related wells in Figure 135-10.
Panel (b) of Figure 135-11 shows the data for the upgradient facility bedrock wells on top of the data of
the local water supply wells in Panel (a) of Figure B5-11. When viewed this way, it is clear that the
upgradient facility bedrock wells have characteristics similar to and indistinguishable from the local
water supply wells.
Figure 135-12 shows a side-by-side comparison of the ash basin related well data in Panel (a), and the
local water supply well related 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 dotted lines in Panel (b) encloses all the local water supply well data, but
excludes most of the ash basin porewater data in Panel (a).
In summary, in the piper plots, the local water supply well data show a different cluster pattern in
comparison to the data of the ash basin porewater wells, indicating that the source water for the local
supply wells is not CCR -impacted groundwater.
B.5.5 Conclusions
Based on this evaluation, the following key conclusions can be drawn:
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 are not readily sorbed 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 the boron and sulfate concentrations found in the facility background conditions;
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, and high iron and manganese concentrations. The redox
conditions found in many of the local water supply wells are generally more oxygenic. The lack
of dissolved oxygen is considered to be a useful signature of CCR -impacted groundwater. This
suggests that the local water supply wells of significantly higher dissolved oxygen concentrations
do not obtain groundwater primarily from the ash basin because no effective mass transfer
mechanism can replenish oxygen during the groundwater transport from the ash basin to the
local water supply wells.
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Appendix B — Belews Creek
• 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 13.4. The local water supply wells are upgradient or side gradient of the ash
basin.
• The correlation and piper plots show very different clustering patterns from the ash basin
porewater wells and the local water supply wells. 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 plots and piper 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 CCR -impacted groundwater.
• The evaluation provided here is an independent review of the available data from a
groundwater chemistry standpoint. Available information on groundwater levels and
groundwater chemistry for the facility has been used to conduct the evaluation and develop
conclusions. These conclusions need to be considered in the context of the long operation
history of the site and complexity of groundwater flow in the fractured bedrock system. There
may be changing patterns of groundwater flow over time, which makes the classification of
certain on-site bedrock wells into a particular subgroup (e.g., side -gradient or downgradient,
upgradient or side -gradient) challenging when considering both the hydraulic and chemical
data. While there may be some uncertainty in these specific classifications, that uncertainty
does not change the more important conclusions about the major directions of groundwater
flow and the impact on groundwater chemistry. From the results of the evaluation, it is clear
what areas are upgradient and what areas are downgradient. And the groundwater in the local
water supply wells is clearly aligned chemically with the upgradient facility monitoring well.
• This evaluation has provided additional lines of evidence, using (1) the presence of CCR
signature constituents and (2) general major ion chemistry, to support the groundwater flow
and transport results presented in Section 13.4.4.2.
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.
13.6 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
Belews Creek 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 Belews Creek facility are not impacted by CCR releases from the ash basin.
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Appendix B — Belews Creek
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 concentration 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 10 of 35 results for pH and 8 of 35 results for
arsenic. 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 (Brief, 1997; Chapman, et al., 2013).
The comprehensive evaluation of groundwater flow with respect to local water supply wells
demonstrates that groundwater flow is north and northeast toward the Dan River from the topographic
divides west, south, and east of the ash basin away from the water supply wells. The water supply well
capture zone analysis indicates that groundwater utilized by water supply wells near the coal ash
impoundments is not impacted by the coal ash sources. 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, bedrock 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 Belews Creek Steam Station under the CAMA is
warranted.
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Appendix B - Belews Creek
B.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. 2001. Estimating ground -water recharge in the North Carolina Piedmont for
land use planning [abs.], in 2001 Abstracts with Programs, 50th Annual Meeting, Southeastern
Section, April 5-6, 2001: Raleigh, N.C., The Geological Society of America, v. 33, no. 2, p. A-80.
7. 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.
8. Domenico, P.A. and Schwartz, F.W. 1998. Physical and chemical hydrogeology (Vol. 44). New
York: Wiley.
9. 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.
10. EPRI. 2005. Chemical Constituents in Coal Combustion Product Leachate: Boron. Electric Power
Research Institute Report 1005258. March 2005.
11. Freeze, R.A. and Cherry, J.A. 1979. Groundwater, Englewood Cliffs, NJ, Prentice -Hall.
12. 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.
APRIL 2016 40 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix B - Belews Creek
13. Haley & Aldrich. 2015. Evaluation of NCDEQ Private Well Data. December 2015.
14. 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.
15. 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.
16. HDR. 2014a. Belews Creek 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
17. HDR. 2014b. Belews Creek 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
18. HDR. 2014c. Belews Creek Steam Station Ash Basin, Proposed Groundwater Assessment Work
Plan (Rev. 1), NPDES Permit NC0024406. HDR, Inc. December 30, 2014.
19. HDR. 2015a. Comprehensive Site Assessment Report, Duke Energy Belews Creek Steam Station,
September. HDR, Inc.
20. HDR. 2015b. Corrective Action Plan Part 1, Duke Energy Belews Creek Steam Station Ash Basin,
December. HDR, Inc.
21. HDR. 2016. Corrective Action Plan Part 2, Duke Energy Belews Creek Steam Station Ash Basin,
March. HDR, Inc.
22. 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.
23. Heath, R.C. 1984. Ground -Water Regions of the United States (Water -Supply Paper 2242, 78p.).
U.S. Geological Survey.
24. 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.
25. 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.
APRIL 2016 41 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix B — Belews Creek
26. 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.
27. Niswonger, R.G., Panday, S., and Ibaraki, M. 2011. MODFLOW-NWT, A Newton formulation for
MODFLOW-2005 (Techniques and Methods 6-A37, 44p.). U.S. Geological Survey.
28. 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&groupld=38364
29. 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%20lmDoundment%20CIassifications.Ddf
30. 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
31. Pollock, D.W. 1994. User's guide for MODPATH/MODPATH-PLOT: A particle -tracking post-
processing package for MODFLOW, the U.S. Geological Survey finite -difference ground -water
flow model (Open -File Report 94-464, 249p.). U.S. Geological Survey
32. Rumbaugh J. and Rumbaugh, D. 2011. Groundwater Vistas Version 6.84 Build 6, Environmental
Simulation, Incorporated.
33. USEPA. 1980. Effects of Coal -ash Leachate on Ground Water Quality. U.S. Environmental
Protection Agency. EPA -600/7-80-066. March.
34. 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.
35. USEPA. 2008. Indoor Water Use in the United States. EPA Water Sense., U.S. Environmental
Protection Agency. [Online] URL: https://www3.epa.gov/watersense/docs/ws indoor508.pdf.
36. USEPA. 2012. 2012 Edition of the Drinking Water Standards and Health Advisories. Spring
2012. U.S. Environmental Protection Agency. Available at:
http://water.epa.gov/drink/contaminants/index.cfm
APRIL 2016 42 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix B — Belews Creek
37. 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
38. 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/fdsys/pl<g/FR-2015-04-17/PDF/2015-00257. PDF
39. 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
40. Winograd, I.J. and Robertson, F.N. 1982. Deep oxygenated ground water: anomaly or common
occurrence? Science, 216(4551), pp.1227-1230.
41. 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 43 %UICH

Table B2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 1 of 3
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
(* denotes
Federal MCL/SMCL(b):
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
Belews Creek
BC1
<5
32500
7
7.67
12.2
95
<0.5
1.3
2.4
<0.2
<0.08
1.4
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC10
<5
2840
3
8.07
<2
42
<0.5
<0.5
18.6
<0.2
<0.08
1.6
<0.5
0.53
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC13
22.5
41200
14.9
7.48
8.5
180
<0.5
6.8
1.9
<0.2
<0.08
<0.5
<O.S
0.35
<0.2
2.4
0.58
<0.1
Belews Creek
BC14
< 5
2190
1.8
6.02
3.2
50
< 0.5
< 0.5
5.6
< 0.2
0.083
< 0.5
< 0.5
4.5
< 0.2
< 0.5
< 0.5
< 0.1
Belews Creek
BC15
<5
14300
5.7
6.15
3.6
91
<0.5
0.83
3.4
<0.2
<0.08
0.96
<0.5
0.81
<0.2
4.8
<0.5
<0.1
Belews Creek
BC17
<5
28300
4
2.57
7.2
150
<0.5
14.1
7.8
<0.2
<0.08
<0.5
<0.5
0.15
<0.2
3.5
<0.5
<0.1
Belews Creek
BC18
<5
10400
1.6
6.25
2
88
<0.5
2
2.3
<0.2
<0.08
0.79
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC19
< 5
19100
1.8
6.6
5.9
117
< 0.5
6.1
3.9
< 0.2
0.11
< 0.5
< 0.5
0.4
< 0.2
1.2
< 0.5
< 0.1
Belews Creek
BC20
<5
29000
2.2
7.12
8.1
136
<0.5
10.8
3
<0.2
<0.08
<0.5
<0.5
0.83
<0.2
20.2
<0.5
<0.1
Belews Creek
BC21
<25
3500
4.3
5.79
<2
64
<0.5
<0.1
9.5
<0.1
<0.08
0.89
<0.1
1.2
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-1
<5
11000
1.39
7.1
9.92
105
<0.5
<0.5
12
<0.2
<0.08
<0.5
<0.5
2
<0.2
2
<0.5
<0.1
Belews Creek
BC22
<0.5
43800
14.1
2.13
16.8
223
<0.5
0.69
1
<0.2
<0.08
<0.5
<0.5
0.16
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-2
<5
12000
1.48
6.9
9.07
111
<0.5
<0.5
9.4
<0.2
<0.08
<0.5
0.79
0.12
<0.2
1.9
<0.5
<0.1
Belews Creek
BC23
<5
29600
14.6
6.87
20.2
169
<0.5
1.5
7.2
0.3
<0.08
<0.5
4.3
0.99
<0.2
1.4
<0.5
<0.1
Belews Creek
BC2-3
<5
10000
<1
6.67
12
80
<0.5
<0.5
1.4
<0.2
<0.08
<0.5
<0.5
0.34
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC24
<5
15400
3.7
6.32
4.2
111
<0.5
12.1
12
<0.2
0.098
<0.5
<0.5
0.67
<0.2
1.9
<0.5
<0.1
Belews Creek
BC25
<5
4670
3.1
6.47
3.5
76
<0.5
<0.5
0.46
<0.2
<0.08
<0.5
<0.5
0.62
<0.2
0.68
<0.5
<0.1
Belews Creek
BC26
<5
16900
4
5.9
8.2
112
<0.5
1.9
0.5
<0.2
0.18
<0.5
<0.5
1.2
<0.2
4
<0.5
<0.1
Belews Creek
BC27
<5
22400
18.6
6.54
3.5
166
<0.5
1.6
8.3
<0.2
<0.08
2.5
<O.S
0.54
<0.2
1.1
<0.5
<0.1
Belews Creek
BC28
12.2
12800
<1
3.61
18.3
99
<0.5
2.8
<0.3
<0.2
<0.08
<0.5
<0.5
0.69
<0.2
3.4
<0.5
<0.1
Belews Creek
BC29
<5
6560
3.4
6.18
<2
66
<0.5
<0.5
10.3
<0.2
<0.08
<0.5
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC30
< 5
37100
7.5
7.14
8.7
152
< 0.5
108
2.2
< 0.2
< 0.08
< 0.5
< 0.5
0.14
< 0.2
10.5
1.8
< 0.1
Belews Creek
BC31
<5
36700
2.4
7.43
8.6
152
<0.5
0.93
12.7
<0.2
<0.08
<0.5
<0.5
0.24
<0.2
1.3
<0.5
<0.1
Belews Creek
BC32
<5
31700
4.1
7.95
9.2
127
<0.5
22.5
3.1
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
6.8
<0.5
<0.1
Belews Creek
BC33
<5
34000
2.8
7.29
9.1
148
<0.5
1.9
7.7
<0.2
<0.08
19.3
<0.5
0.13
<0.2
1.9
<0.5
<0.1
Belews Creek
BC34
<5
36200
8.3
6.5
6.1
156
<0.5
40.3
37.7
<0.2
<0.8
0.52
<0.5
0.54
<0.2
4.5
<0.5
<0.1
Belews Creek
BC35
<5
33400
7.2
7.09
14.2
143
<0.5
15.7
3.9
<0.2
<0.08
1.6
<0.5
3.8
<0.2
2.1
<0.5
<0.1
Belews Creek
BC4A
<5
17000
1.6
7.3
5
112
<0.5
0.17
6.88
<0.2
<0.08
0.99
0.03
1.4
<0.2
4.1
0.35
<0.1
Belews Creek
BC4B
<50
9950
<0.1
6.85
14
80
<0.5
<2
1.42
<0.5
<0.15
1.61
<1
0.1
<0.2
0.58
<2
<0.5
Belews Creek
BC5
< 5
1340
2.7
5.3
< 2
< 25
< 0.5
< 0.5
19
< 0.2
< 0.08
< 0.5
< 0.5
0.41
< 0.2
< 0.5
< 0.5
< 0.1
Belews Creek
BC6
<100
12000
11.3
6.1
9.25
101
<1
<5
<10
<1
<0.1
<1
<1
<2
<0.2
<5
<5
<0.1
Belews Creek
BC7
< 25
30000
2.1
8
9.3
127
< 1
<25
< 1.5
< 1
< 0.1
< 1
< 1
< 0.5
< 0.2
< 2.5
< 2.5
< 0.1
Belews Creek
BC8
22
4950
13.7
6.25
3.1
71
0.76
0.77
6.6
<0.11
<O.06
0.91
0.11
1.1
<0.2
1.14
0.22
<0.06
Belews Creek
BC9
<5
18000
6.3
7.16
9.8
119
<0.5
1.8
0.74
<0.2
<0.08
<0.5
<0.5
2.28
<0.2
<0.5
<-
<0.1
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Table B2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
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
Belews Creek
BC1
< 1
66.2
0.0073
261
0.093
2980
173
2.1
1180
7490
165
0.0211
81.1
81.1
<5
6.2
Belews Creek
BC10
< 1
< 10
0.0233
56.8
0.057
1090
4
0.85
1300
5030
33.6
0.0067
18.8
18.8
< 5
< 2.5
Belews Creek
BC13
4.8
<10
0.0075
<50
<0.03 H1
8060
1.4
<0.5
1240
10200
87.6
0.0069
120
120
<5
<2.5
Belews Creek
BC14
<1
<10
0.107
<50
<0.03
1770
2.7
<0.5
1370
5910
21.6
0.0787
18
18
<5
<2.5
Belews Creek
BC15
<1
<10
0.0167
<50
0.41
1430
9
1.6
1 2020
6370
63.1
1 0.0669
37.2
37.2
<5
<2.5
Belews Creek
BC17
<1
<10
0.0072
<50
<0.03
5560
0.83
<0.5
501
11900
200
0.0132
95.7
95.7
<5
<2.5
Belews Creek
BC18
1
<10
0.0193
<50
0.59
3880
1.3
<0.5
1430
6230
44.8
0.152
49.5
49.5
<5
<6.8
Belews Creek
BC19
< 1
< 10
0.0155
< 50
< 0.03
4070
4.6
< 0.5
1020
8090
87.9
0.126
66.9
66.9
< 5
< 2.5
Belews Creek
BC20
< 1
< 10
0.0128
< 50
< 0.3
4040
3.6
< 0.5
955
9260
94.2
0.0342
94.9
94.9
<5
<5
Belews Creek
BC21
< 0.5
< 10
0.0222
< 50
0.58
3040
0.58
0.55
1700
7470
18.3
0.0251
22.8
22.8
< 5
< 2.5
Belews Creek
BC2-1
0.4
<10
0.058
8500
<0.03
4180
29.8
<0.5
2140
7400
55
0.048
46.1
46.1
<0
5.2
Belews Creek
BC22
< 1
< 10
0.0026
< 50
< 0.03
6420
148
< 0.5
2170
9820
122
0.0183
123
123
< 5
< 2.5
Belews Creek
BC2-2
<0.3
<10
0.0032
1700
<0.03
1 3900
30
1.7
2040
7760
1 52.9
0.019
48.2
48.2
1 <0
<1
Belews Creek
BC23
<1
<10
0.0279
155
<0.03
5450
144
15
2800
8590
102
0.065
81
81
<5
<2.5
Belews Creek
BC2-3
<1
<10
<0.001
2310
<0,03
2230
11.7
<0.5
1850
6200
36.1
<0.005
30.4
30.4
<5
<2.5
Belews Creek
BC24
< 1
< 10
0.0384
< 50
< 0.03
4000
20.8
< 0.5
1510
7660
55.1
0.266
54.2
54.2
<5
< 2.5
Belews Creek
BC25
< 1
< 10
0.0188
< 50
0.037
2800
1.4
< 0.5
1060
6070
23.3
0.138
23.2
23.2
<5
< 2.5
Belews Creek
BC26
<1
<10
0.0049
<50
<0.03
4590
2.1
<0.5
771
8970
56.4
0.116
66.1
66.1
<5
<2.5
Belews Creek
BC27
1.7
<10
0.0157
<50
2.1
6820
0.62
<0.5
3110
7080
87.7
0.0088
48.3
48.3
<5
<2.5
Belews Creek
BC28
<1
11.8
0.0041
<50
<0.03
1100
2.2
<0.5
96.1
23700
161
0.0075
65.4
65.4
<5
<2.5
Belews Creek
BC29
< 1
< 30
0.014
< 50
0.16
3250
< 0.5
< 0.5
1630
6440
21.7
0.0087
36.9
36.9
<5
<5
Belews Creek
BC30
< 1
12.9
0.0068
< 50
< 0.03
5530
0.7
< 0.5
906
7940
64.6
0.0275
110
110
< 5
< 2.5
Belews Creek
BC31
<1
<10
0.0042
110
<0.03
4830
102
<0.5
1930
8840
79.2
0.0127
109
109
<5
<2.5
Belews Creek
BC32
<1
<10
<0.001
<50
<0.03
3310
23.8
<0.5
228
9370
210
<0.005
97.1
97.1
<5
<2.5
Belews Creek
BC33
< 1
< 10
< 0.001
269
< 0.03
5270
67.6
2.2
1810
8150
85.2
0.0449
98.4
98.4
<5
< 2.5
Belews Creek
BC34
< 1
< 10
0.0104
< 50
< 0.03
4620
0.8
< 0.5
2180
8640
94.4
0.0248
98.1
98.1
<5
<5
Belews Creek
BC35
< 1
49.1
0.008
365
0.18
6240
253
1.3
2340
6500
44.7
0.0627
92.4
92.4
<5
4.1
Belews Creek
BC4A
2.4
<10
0.0136
<25
0.085
5730
<0.5
0.29
1530
8550
44.8
0.0266
71.2
71.2
<5
<2.5
Belews Creek
B 4
0.58
< 50
0.00019
1890
<5
2050
10.6
0.34
1540
5600
37
0.00315
37
< 2.5
Belews Creek
B
<1
14.9
0.0323
<50
<0.03
1080
1.8
<0.5
1420
2360
16.9
0.0208
8.9
8.9
<5
<2.5
Belews Creek
BC6
< 0.3
< 50
< 0.005
290
< 30
2400
40
<5
2000
9700
69
0.009
32.8
32.8
<0
< 1
Belews Creek
BC7
< 0.3
< 50
< 0.005
< 50
< 0.03
2760
10.8
< 2.5
808
6500
99
< 0.005
84
84
<0
<1-
1Belews
Belews Creek
BC8
23.5
< 10
0.0228
15.2
0.06
1890
1.8
0.38
1190
8430
53.8
0.0147
28
26.9
<5
3
Belews Creek
BC9
<1.
<10
0.00915
322
<0.03
4600
32.8
0.76
1880
7720
74.5
0.0949
58
58
<1
<2.5
Page 2 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Table B2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
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
Belews Creek
BC1
1
16.2
220.2
0.17
76
Belews Creek
BC10
<1
19
139
1.5
112.9
Belews Creek
BC13
<1
18.2
155.5
0.65
79.9
Belews Creek
BC14
<1
23.3
29.8
3.14
244.3
Belews Creek
BC15
<1
19.2
116.1
6.73
232.2
Belews Creek
BC17
<1
20
215.3
0.55
194.5
Belews Creek
BC18
<1
17
104.9
7.33
242.8
Belews Creek
BC19
<1
24
148
3.78
221.5
Belews Creek
BC20
<1
25.5
208.7
2.87
106.7
Belews Creek
BC21
<1
12.9
80.7
6.41
262.9
Belews Creek
BC2-1
35
20.8
107.3
7
122
Belews Creek
BC22
<1
18.2
319.6
0.5
158.9
Belews Creek
BC2-2
4.9
20.1
111
0.14
<
Belews Creek
BC23
<1
23.5
230
2.46
229.6
Belews Creek
BC2-3
14.1
17.6
94.3
2.02
<
Belews Creek
BC24
<1
24.9
136
4
235.8
Belews Creek
BC25
<1
21.9
4.56
4.56
235.1
Belews Creek
BC26
<1
17.6
50.3
7.93
199.5
Belews Creek
BC27
<1
21.6
214.6
7.58
255.1
Belews Creek
BC28
<1
15.9
200.2
0.05
<
Belews Creek
BC29
< 1
17.3
97.5
4.62
197.9
Belews Creek
BC30
<1
16.9
268.5
1.52
163
Belews Creek
BC31
<1
16
242.2
1.15
168.8
Belews Creek
BC32
<1
16.9
230.4
0.1
78.9
Belews Creek
BC33
1.7
15.6
229.1
2.01
<
Belews Creek
BC34
<1
14.8
265.1
4.6
202.3
Belews Creek
BC35
2.1
13.7
244.7
2.58
151.1
Belews Creek
BC4A
<1
24.4
146.3
7.45
142.9
Belews Creek
BC413
19.3
13.3
123
4.92
Belews Creek
BC5
< 1
15.7
35.6
8.18
272.4
Belews Creek
BC6
3.6
19.2
125
5.4
255
Belews Creek
BC7
<1
19.8
198.5
0.1
89.6
Belews Creek
BC8
<1
20.1
90
7.31
216.5
Belews Creek
BC9
2.96
22.1
186
4.03
116.5
Page 3 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - 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
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-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.orni.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 abovethe screening level.
Haley & Aldrich, Inc.
Tables B2 -1-B2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/14/2016

Table 62-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
35A NCAC 02 r 0201700
Groundwater an a:
NS
250
6.5-8 5
250
800
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal MCL/SMCL (b):
denote, seconds standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
SO
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
mill
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
Belews Creek
BC1
<5
32500
7
7.67
12.2
95
<0.5
1.3
2.4
<0.2
<0.08
1.4
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC10
<5
2840
3
8.07
<2
42
<0.5
<0.5
18.6
<0.2
<0.08
1.6
<0.5
0.53
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC13
22.5
41200
14.9
7.48
8.5
180
<0.5
6.8
1.9
<0.2
<0.08
<0.5
<0.5
0.35
<0.2
2.4
0.58
<0.1
Belews Creek
BC14
<5
2190
1.8
6.02
3.2
50
<0.5
<0.5
5.6
<0.2
0.083
<0.5
<0.5
4.5
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC15
<5
14300
5.7
6.15
3.6
91
<0.5
0.83
3.4
<0.2
<0.08
0.96
<0.5
0.81
<0.2
4.8
<0.5
<0.1
Belews Creek
BC17
<5
28300
4
2.57
7.2
150
<0.5
14.1
7.8
<0.2
<0.08
<0.5
<0.5
0.15
<0.2
3.5
<0.5
<0.1
Belews Creek
BC18
<5
10400
1.6
6.25
2
88
<0.5
2
2.3
<0.2
<0.08
0.79
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC19
<5
19100
1.8
6.6
5.9
117
<0.5
6.1
3.9
<0.2
0.11
<0.5
<0.5
0.4
<0.2
1.2
<0.5
<0.1
Belews Creek
BC20
<5
29000
2.2
7.12
8.1
136
<0.5
10.8
3
<0.2
<0.08
<0.5
<0.5
0.83
<0.2
20.2
<0.5
<0.1
Belews Creek
BC21
<25
3500
4.3
5.79
<2
64
<0.5
<0.1
9.5
<0.1
<0.08
0.89
<0.1
1.2
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-1
<5
11000
1.39
7.1
9.92
105
<0.5
<0.5
12
<0.2
<0.08
<0.5
<0.5
2
<0.2
2
<0.5
<0.1
Belews Creek
BC22
<0.5
43800
14.1
2.13
16.8
223
<0.5
0.69
1
<0.2
<0.08
<0.5
<0.5
0.16
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-2
<5
12000
1.48
6.9
9.07
111
<0.5
<0.5
9.4
<0.2
<0.08
<0.5
0.79
0.12
<0.2
1.9
<0.5
<0.1
Belews Creek
BC23
<5
29600
14.6
6.87
20.2
169
<0.5
1.5
7.2
0.3
<0.08
<0.5
4.3
0.99
<0.2
1.4
<0.5
<0.1
Belews Creek
BC2-3
<5
10000
<1
6.67
12
80
<0.5
<0.5
1.4
<0.2
<0.08
<0.5
<0.5
0.34
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC24
<5
15400
3.7
6.32
4.2
111
<0.5
12.1
12
<0.2
0.098
<0.5
<0.5
0.67
<0.2
1.9
<0.5
<0.1
Belews Creek
BC25
<5
4670
3.1
6.47
3.5
76
<0.5
<0.5
0.46
<0.2
<0.08
<0.5
<0.5
0.62
<0.2
0.68
<0.5
<0.1
Belews Creek
BC26
<5
16900
4
5.9
8.2
112
<0.5
1.9
0.5
<0.2
0.18
<0.5
<0.5
1.2
<0.2
4
<0.5
<0.1
Belews Creek
BC27
<5
22400
18.6
6.54
3.5
166
<0.5
1.6
8.3
<0.2
<0.08
2.5
<0.5
0.54
<0.2
1.1
<0.5
<0.1
Belews Creek
BC28
12.2
12800
<1
3.61
18.3
99
<0.5
2.8
<0.3
<0.2
<0.08
<0.5
<0.5
0.69
<0.2
3.4
<0.5
<0.1
Belews Creek
BC29
<5
6560
3.4
6.18
<2
66
<0.5
<0.5
10.3
<0.2
<0.08
<0.5
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC30
<5
37100
7.5
7.14
8.7
152
<0.5
108
2.2
<0.2
<0.08
<0.5
<0.5
0.14
<0.2
10.5
1.8
<0.1
Belews Creek
BC31
<5
36700
2.4
7.43
8.6
152
<0.5
0.93
12.7
<0.2
<0.08
<0.5
<0.5
0.24
<0.2
1.3
<0.5
<0.1
Belews Creek
BC32
<5
31700
4.1
7.95
9.2
127
<0.5
22.5
3.1
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
6.8
<0.5
<0.1
Belews Creek
BC33
<5
34000
2.8
7.29
9.1
148
<0.5
1.9
7.7
<0.2
<0.08
19.3
<0.5
0.13
<0.2
1.9
<0.5
<0.1
Belews Creek
BC34
<5
36200
8.3
6.5
6.1
156
<0.5
40.3
37.7
<0.2
<0.8
0.52
<0.5
0.54
<0.2
4.5
<0.5
<0.1
Belews Creek
BC35
<5
33400
7.2
7.09
14.2
143
<0.5
15.7
3.9
<0.2
<0.08
1.6
<0.5
3.8
<0.2
2.1
<0.5
<0.1
Belews Creek
BC4A
<5
17000
1.6
7.3
5
112
<0.5
0.17
6.88
<0.2
<0.08
0.99
0.03
1.4
<0.2
4.1
0.35
<0.1
Belews Creek
BC4B
<50
9950
<0.1
6.85
14
80
<0.5
<2
1.42
<0.5
<0.15
1.61
<1
0.1
<0.2
0.58
<2
<0.5
Belews Creek
BC5
<5
1340
2.7
5.3
<2
<25
<0.5
<0.5
19
<0.2
<0.08
<0.5
<0.5
0.41
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC6<100
12000
11.3
6.1
9.25
101
<1
<5
<10
<1
<0.1
<1
<1
<2
<0.2
<5
<5
<0.1
Belews Creek
BC7
<25
30000
2.1
8
9.3
127
<1
<2.5
<1.5
<1
<0.1
<1
<1
<0.5
<0.2
<2.5
<2.5
<0.1
Belews Creek
BCS
22
4950
13.7
6.25
3.1
71
0.76
0.77
6.6
<0.11
<0.06
0.91
0.11
1.1
<0.2
1.14
0.22
<0.06
Belews Creek
BC9
<5
18000
6.3
7.16
9.8
119
<0.5
1.8
0.74
<0.2
<0.08
<0.5
<0.5
2.28
<0.2
<0.5
<0.5
<0.1
Page 1 of 2
Haley & Aldrich, Inc.
Tables 62-1-62-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Table 62-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 2 of 2
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):
• denotes 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
Belews Creek
BC1
<1
66.2
0.0073
261
0.093
2980
173
2.1
1180
7490
165
0.0211
81.1
81.1
<5
6.2
1
16.2
220.2
0.17
76
Belews Creek
BC10
<1
<10
0.0233
56.8
0.057
1090
4
0.85
1300
5030
33.6
0.0067
18.8
18.8
<5
<2.5
<1
19
139
1.5
112.9
Belews Creek
BC13
4.8
<10
0.0075
<50
<0.03 H1
8060
1.4
<0.5
1240
10200
87.6
0.0069
120
120
<5
<2.5
<1
18.2
155.5
0.65
79.9
Belews Creek
BC14
<1
<10
0.107
<50
<0.03
1770
2.7
<0.5
1370
5910
21.6
0.0787
18
18
<5
<2.5
<1
23.3
29.8
3.14
244.3
Belews Creek
BC15
<1
<10
0.0167
<50
0.41
1430
9
1.6
2020
6370
63.1
0.0669
37.2
37.2
<5
<2.5
<1
19.2
116.1
6.73
232.2
Belews Creek
BC17
<1
<10
0.0072
<50
<0.03
5560
0.83
<0.5
501
11900
200
0.0132
95.7
95.7
<5
<2.5
<1
20
215.3
0.55
194.5
Belews Creek
BC18
1
<10
0.0193
<50
0.59
3880
1.3
<0.5
1430
6230
44.8
0.152
49.5
49.5
<5
<6.8
<1
17
104.9
7.33
242.8
Belews Creek
BC19
<1
<10
0.0155
<50
<0.03
4070
4.6
<0.5
1020
8090
87.9
0.126
66.9
66.9
<5
<2.5
<1
24
148
3.78
221.5
Belews Creek
BC20
<1
<10
0.0128
<50
<0.3
4040
3.6
<0.5
955
9260
94.2
0.0342
94.9
94.9
<5
<5
<1
25.5
208.7
2.87
106.7
Belews Creek
BC21
< 0.5
<10
0.0222
< 50
0.58
3040
0.58
0.55
1700
7470
18.3
0.0251
22.8
22.8
<5
< 2.5
<1
12.9
80.7
6.41
262.9
Belews Creek
BC2-1
0.4
<10
0.058
8500
<0.03
4180
29.8
<0.5
2140
7400
55
0.048
46.1
46.1
<0
5.2
35
20.8
107.3
7
122
Belews Creek
BC22
<1
< 10
0.0026
<50
< 0.03
6420
148
< 0.5
2170
9820
122
0.0183
123
123
<5
< 2.5
<1
18.2
319.6
0.5
158.9
Belews Creek
BC2-2
<0.3
<10
0.0032
1700
<0.03
3900
30
1.7
2040
7760
52.9
0.019
48.2
48.2
<0
<1
4.9
20.1
111
0.14
<
Belews Creek
BC23
<1
<10
0.0279
155
<0.03
5450
144
15
2800
8590
102
0.065
81
81
<5
<2.5
<1
23.5
230
2.46
229.6
Belews Creek
BC2-3
<1
<10
<0.001
2310
<0.03
2230
11.7
<0.5
1850
6200
36.1
<0.005
30.4
30.4
<5
<2.5
14.1
17.6
94.3
2.02
<
Belews Creek
BC24
<1
< 10
0.0384
<50
-0.03
4000
20.8
< 0.5
1510
7660
55.1
0.266
54.2
54.2
'S
< 2.5
<1
24.9
136
4
235.8
Belews Creek
BC25
<1
<10
0.0188
<50
0.037
2800
1.4
<0.5
1060
6070
23.3
0.138
23.2
23.2
<5
<2.5
<1
21.9
4.56
4.56
235.1
Belews Creek
BC26
<1
<10
0.0049
<50
<0.03
4590
2.1
<0.5
771
8970
56.4
0.116
66.1
66.1
<5
<2.5
<1
17.6
50.3
7.93
199.5
Belews Creek
BC27
1.7
<10
0.0157
<50
2.1
6820
0.62
<0.5
3110
7080
87.7
0.0088
48.3
48.3
<5
<2.5
<1
21.6
214.6
7.58
255.1
Belews Creek
BC28
<1
11.8
0.0041
<50
< 0.03
1100
2.2
< 0.5
96.1
23700
161
0.0075
65.4
65.4
.5
< 2.5
<1
15.9
200.2
0.05
<
Belews Creek
BC29
<1
<10
0.014
<50
0.16
3250
<0.5
<0.5
1630
6440
21.7
0.0087
36.9
36.9
<5
<5
<1
17.3
97.5
4.62
197.9
Belews Creek
BC30
<1
12.9
0.0068
<50
<0.03
5530
0.7
<0.5
906
7940
64.6
0.0275
110
110
<5
<2.5
<1
16.9
268.5
1.52
163
Belews Creek
BC31
<1
<10
0.0042
110
<0.03
4830
102
<0.5
1930
8840
79.2
0.0127
109
109
<5
<2.5
<1
16
242.2
1.15
168.8
Belews Creek
BC32
<1
<10
<0,001
<50
<0.03
3310
23.8
<0.5
228
9370
210
<0.005
97.1
97.1
<5
<2.5
<1
16.9
230.4
0.1
78.9
Belews Creek
BC33
<1
<10
< 0.001
269
< 0.03
5270
67.6
2.2
1810
8150
85.2
0.0449
98.4
98.4
<5
< 2.5
1.7
15.6
229.1
2.01
<
Belews Creek
BC34
<1
<10
0.0104
<50
<0.03
4620
0.8
<0.5
2180
8640
94.4
0.0248
98.1
98.1
<5
<5
<1
14.8
265.1
4.6
202.3
Belews Creek
BC35
<1
49.1
0.008
365
0.18
6240
253
1.3
2340
6500
44.7
0.0627
92.4
92.4
<5
4.1
2.1
13.7
244.7
2.58
151.1
Belews Creek
BC4A
2.4
< 10
0.0136
< 25
0.085
5730
< 0.5
0.29
1530
8550
44.8
0.0266
71.2
71.2
<5
< 2.5
<1
24.4
146.3
7.45
142.9
Belews Creek
BUB
0.58
<50
0.00019
1890
<5
2050
10.6
0.34
1540
5600
37
0.00315
37
<2.5
19.3
13.3
123
4.92
Belews Creek
BC5
<1
14.9
0.0323
<50
<0.03
1080
1.8
<0.5
1420
2360
16.9
0.0208
8.9
8.9
<5
<2.5
<1
15.7
35.6
8.18
272.4
Belews Creek
BC6
<0.3
<50
<0.005
290
<10
2400
40
<5
2000
9700
69
0.009
32.8
32.8
<0
<1
3.6
19.2
125
5.4
255
Belews Creek
BC7
<0.3
<50
<0.005
<50
<0.03
2760
10.8
<2.5
808
6500
99
<0.005
84
84
<0
<1
<1
19.8
198.5
0.1
89.6
Belews Creek
BC8
23.5
<10
0.0228
15.2
0.06
1890
1.8
0.38
1190
8430
53.8
0.0147
28
26.9
<5
3
<1
20.1
90
7.31
216.5
Belews Creek
BC9
<1
<10
0.00915
322
< 0.03
4600
32.8
0.76
1880
7720
74.5
0.0949
58
58
< 1
< 2.5
2.96
22.1
186
4.03
116.5
Haley & Aldrich, Inc.
Tables 62-1-62-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - 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
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-screeni ng-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.orni.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 sreeni ng level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables B2 -1-B2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/14/2016

Table B2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 1 of 3
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
(* denotes
Federal MCL/SMCL(b):
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
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
Belews Creek
BC1
<5
32500
7
7.67
12.2
95
<0.5
1.3
2.4
<0.2
<0.08
1.4
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC10
<5
2840
3
8.07
<2
42
<0.5
<0.5
18.6
<0.2
<0.08
1.6
<0.5
0.53
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC13
22.5
41200
14.9
7.48
8.5
180
<0.5
6.8
1.9
<0.2
<0.08
<0.5
<0.S
0.35
<0.2
2.4
0.58
<0.1
Belews Creek
BC14
< 5
2190
1.8
6.02
3.2
50
< 0.5
< 0.5
5.6
< 0.2
0.083
< 0.5
< 0.5
4.5
< 0.2
< 0.5
< 0.5
< 0.1
Belews Creek
BC15
<5
14300
5.7
6.15
3.6
91
<0.5
0.83
3.4
<0.2
<0.08
0.96
<0.5
0.81
<0.2
4.8
<0.5
<0.1
Belews Creek
BC17
<5
28300
4
2.57
7.2
150
<0.5
14.1
7.8
<0.2
<0.08
<0.5
<0.5
0.15
<0.2
3.5
<0.5
<0.1
Belews Creek
BC18
<5
10400
1.6
6.25
2
88
<0.5
2
2.3
<0.2
<0.08
0.79
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC19
< 5
19100
1.8
6.6
5.9
117
< 0.5
6.1
3.9
< 0.2
0.11
< 0.5
< 0.5
0.4
< 0.2
1.2
< 0.5
< 0.1
Belews Creek
BC20
<5
29000
2.2
7.12
8.1
136
<0.5
10.8
3
<0.2
<0.08
<0.5
<0.5
0.83
<0.2
20.2
<0.5
<0.1
Belews Creek
BC21
<25
3500
4.3
5.79
<2
64
<0.5
<0.1
9.5
<0.1
<0.08
0.89
<0.1
1.2
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-1
<5
11000
1.39
7.1
9.92
105
<0.5
<0.5
12
<0.2
<0.08
<0.5
<0.5
2
<0.2
2
<0.5
<0.1
Belews Creek
BC22
<0.5
43800
14.1
2.13
16.8
223
<0.5
0.69
1
<0.2
<0.08
<0.5
<0.5
0.16
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-2
<5
12000
1.48
6.9
9.07
111
<0.5
<0.5
9.4
<0.2
<0.08
<0.5
0.79
0.12
<0.2
1.9
<0.5
<0.1
Belews Creek
BC23
<5
29600
14.6
6.87
20.2
169
<0.5
1.5
7.2
0.3
<0.08
<0.5
4.3
0.99
<0.2
1.4
<0.5
<0.1
Belews Creek
BC2-3
<5
10000
<1
6.67
12
80
<0.5
<0.5
1.4
<0.2
<0.08
<0.5
<0.5
0.34
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC24
<5
15400
3.7
6.32
4.2
111
<0.5
12.1
12
<0.2
0.098
<0.5
<0.5
0.67
<0.2
1.9
<0.5
<0.1
Belews Creek
BC25
<5
4670
3.1
6.47
3.5
76
<0.5
<0.5
0.46
<0.2
<0.08
<0.5
<0.5
0.62
<0.2
0.68
<0.5
<0.1
Belews Creek
BC26
<5
16900
4
5.9
8.2
112
<0.5
1.9
0.5
<0.2
0.18
<0.5
<0.5
1.2
<0.2
4
<0.5
<0.1
Belews Creek
BC27
<5
22400
18.6
6.54
3.5
166
<0.5
1.6
8.3
<0.2
<0.08
2.5
<0.S
0.54
<0.2
1.1
<0.5
<0.1
Belews Creek
BC28
12.2
12800
<1
3.61
18.3
99
<0.5
2.8
<0.3
<0.2
<0.08
<0.5
<0.5
0.69
<0.2
3.4
<0.5
<0.1
Belews Creek
BC29
<5
6560
3.4
6.18
<2
66
<0.5
<0.5
10.3
<0.2
<0.08
<0.5
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC30
< 5
37100
7.5
7.14
8.7
152
< 0.5
108
2.2
< 0.2
< 0.08
< 0.5
< 0.5
0.14
< 0.2
10.5
1.8
< 0.1
Belews Creek
BC31
<5
36700
2.4
7.43
8.6
152
<0.5
0.93
12.7
<0.2
<0.08
<0.5
<0.5
0.24
<0.2
1.3
<0.5
<0.1
Belews Creek
BC32
<5
31700
4.1
7.95
9.2
127
<0.5
22.5
3.1
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
6.8
<0.5
<0.1
Belews Creek
BC33
<5
34000
2.8
7.29
9.1
148
<0.5
1.9
7.7
<0.2
<0.08
19.3
<0.5
0.13
<0.2
1.9
<0.5
<0.1
Belews Creek
BC34
<5
36200
8.3
6.5
6.1
156
<0.5
40.3
37.7
<0.2
<0.8
0.52
<0.5
0.54
<0.2
4.5
<0.5
<0.1
Belews Creek
BC35
<5
33400
7.2
7.09
14.2
143
<0.5
15.7
3.9
<0.2
<0.08
1.6
<0.5
3.8
<0.2
2.1
<0.5
<0.1
Belews Creek
BC4A
<5
17000
1.6
7.3
5
112
<0.5
0.17
6.88
<0.2
<0.08
0.99
0.03
1.4
<0.2
4.1
0.35
<0.1
Belews Creek
BC4B
<50
9950
<0.1
6.85
14
80
<0.5
<2
1.42
<0.5
<0.15
1.61
<1
0.1
<0.2
0.58
<2
<0.5
Belews Creek
BC5
< 5
1340
2.7
5.3
< 2
< 25
< 0.5
< 0.5
19
< 0.2
< 0.08
< 0.5
< 0.5
0.41
< 0.2
< 0.5
< 0.5
< 0.1
Belews Creek
BC6
<100
12000
11.3
6.1
9.25
101
<1
<5
<10
<1
<0.1
<1
<1
<2
<0.2
<5
<5
<0.1
Belews Creek
BC7
< 25
30000
2.1
8
9.3
127
< 1
<25
< 1.5
< 1
< 0.1
< 1
< 1
< 0.5
< 0.2
< 2.5
< 2.5
< 0.1
Belews Creek
BC8
22
4950
13.7
6.25
3.1
71
0.76
0.77
6.6
<0.11
<0.06
0.91
0.11
1.1
<0.2
1.14
0.22
<0.06
Belews Creek
BC9
<5
18000
6.3
7.16
9.8
119
<0.5
1.8
0.74
<0.2
<0.08
<0.5
<0.5
2.28
<0.2
<0.5
<-
<0.1
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table B2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
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
Belews Creek
BC1
< 1
66.2
0.0073
261
0.093
2980
173
2.1
1180
7490
165
0.0211
81.1
81.1
<5
6.2
Belews Creek
BC10
< 1
< 10
0.0233
56.8
0.057
1090
4
0.85
1300
5030
33.6
0.0067
18.8
18.8
< 5
< 2.5
Belews Creek
BC13
4.8
<10
0.0075
<50
<0.03 H1
8060
1.4
<0.5
1240
10200
87.6
0.0069
120
120
<5
<2.5
Belews Creek
BC14
<1
<10
0.107
<50
<0.03
1770
2.7
<0.5
1370
5910
21.6
0.0787
18
18
<5
<2.5
Belews Creek
BC15
<1
<10
0.0167
<50
0.41
1430
9
1.6
1 2020
6370
63.1
1 0.0669
37.2
37.2
<5
<2.5
Belews Creek
BC17
<1
<10
0.0072
<50
<0.03
5560
0.83
<0.5
501
11900
200
0.0132
95.7
95.7
<5
<2.5
Belews Creek
BC18
1
<10
0.0193
<50
0.59
3880
1.3
<0.5
1430
6230
44.8
0.152
49.5
49.5
<5
<6.8
Belews Creek
BC19
< 1
< 10
0.0155
< 50
< 0.03
4070
4.6
< 0.5
1020
8090
87.9
0.126
66.9
66.9
< 5
< 2.5
Belews Creek
BC20
< 1
< 10
0.0128
< 50
< 0.3
4040
3.6
< 0.5
955
9260
94.2
0.0342
94.9
94.9
<5
<5
Belews Creek
BC21
< 0.5
< 10
0.0222
< 50
0.58
3040
0.58
0.55
1700
7470
18.3
0.0251
22.8
22.8
< 5
< 2.5
Belews Creek
BC2-1
0.4
<10
0.058
8500
<0.03
4180
29.8
<0.5
2140
7400
55
0.048
46.1
46.1
<0
5.2
Belews Creek
BC22
< 1
< 10
0.0026
< 50
< 0.03
6420
148
< 0.5
2170
9820
122
0.0183
123
123
< 5
< 2.5
Belews Creek
BC2-2
<0.3
<10
0.0032
1700
<0.03
1 3900
30
1.7
2040
7760
1 52.9
0.019
48.2
48.2
1 <0
<1
Belews Creek
BC23
<1
<10
0.0279
155
<0.03
5450
144
15
2800
8590
102
0.065
81
81
<5
<2.5
Belews Creek
BC2-3
<1
<10
<0.001
2310
<0,03
2230
11.7
<0.5
1850
6200
36.1
<0.005
30.4
30.4
<5
<2.5
Belews Creek
BC24
< 1
< 10
0.0384
< 50
< 0.03
4000
20.8
< 0.5
1510
7660
55.1
0.266
54.2
54.2
<5
< 2.5
Belews Creek
BC25
<1
<10
0.0188
<50
0.037
2800
1.4
<0.5
1060
6070
23.3
0.138
23.2
23.2
<5
<2.5
Belews Creek
BC26
< 1
< 10
0.0049
< 50
< 0.03
4590
2.1
< 0.5
771
8970
56.4
0.116
66.1
66.1
< 5
< 2.5
Belews Creek
BC27
1.7
<10
0.0157
<50
2.1
6820
0.62
<0.5
3110
7080
87.7
0.0088
48.3
48.3
<5
<2.5
Belews Creek
BC28
<1
11.8
0.0041
<50
<0.03
1100
2.2
<0.5
96.1
23700
161
0.0075
65.4
65.4
<5
<2.5
Belews Creek
BC29
< 1
< 30
0.014
< 50
0.16
3250
< 0.5
< 0.5
1630
6440
21.7
0.0087
36.9
36.9
<5
< 5
Belews Creek
BC30
< 1
12.9
0.0068
< 50
< 0.03
5530
0.7
< 0.5
906
7940
64.6
0.0275
110
110
< 5
< 2.5
Belews Creek
BC31
< 1
< 10
0.0042
110
< 0.03
4830
102
< 0.5
1930
8840
79.2
0.0127
109
109
<5
< 2.5
Belews Creek
BC32
<1
<10
<0.001
<50
<0.03
3310
23.8
<0.5
228
9370
210
<0.005
97.1
97.1
<5
<2.5
Belews Creek
BC33
< 1
< 10
< 0.001
269
< 0.03
5270
67.6
2.2
1810
8150
85.2
0.0449
98.4
98.4
<5
< 2.5
Belews Creek
BC34
< 1
< 10
0.0104
< 50
< 0.03
4620
0.8
< 0.5
2180
8640
94.4
0.0248
98.1
98.1
<5
<5
Belews Creek
BC35
< 1
49.1
0.008
365
0.18
6240
253
1.3
2340
6500
44.7
0.0627
92.4
92.4
<5
4.1
Belews Creek
BC4A
2.4
<10
0.0136
<25
0.085
5730
<0.5
0.29
1530
8550
44.8
0.0266
71.2
71.2
<5
<2.5
Belews Creek
B 4
0.58
< 50
0.00019
1890
<5
2050
10.6
0.34
1540
5600
37
0.00315
37
< 2.5
Belews Creek
B
< 1
14.9
0.0323
< 50
< 0.03
1080
1.8
< 0.5
1420
1 2360
16.9
0.0208
8.9
8.9
<5
< 2.5
Belews Creek
BC6
< 0.3
< 50
< 0.005
290
< 10
2400
40
<5
2000
9700
69
0.009
32.8
32.8
<0
< 1
Belews Creek
BC7
< 0.3
< 50
< 0.005
< 50
< 0.03
2760
10.8
< 2.5
808
6500
99
< 0.005
84
84
<0
< 1
Belews Creek
BC8
23.5
< 10
0.0228
15.2
0.06
1890
1.8
0.38
1190
8430
53.8
0.0147
28
26.9
<5
3
Belews Creek
BC9
<1.
<10
0.00915
322
<0.03
4600
32.8
0.76
1880
7720
74.5
0.0949
58
58
<1
<2.5
Page 2 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table B2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
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
Belews Creek
BC1
1
16.2
220.2
0.17
76
Belews Creek
BC10
<1
19
139
1.5
112.9
Belews Creek
BC13
<1
18.2
155.5
0.65
79.9
Belews Creek
BC14
<1
23.3
29.8
3.14
244.3
Belews Creek
BC15
<1
19.2
116.1
6.73
232.2
Belews Creek
BC17
<1
20
215.3
0.55
194.5
Belews Creek
BC18
<1
17
104.9
7.33
242.8
Belews Creek
BC19
<1
24
148
3.78
221.5
Belews Creek
BC20
<1
25.5
208.7
2.87
106.7
Belews Creek
BC21
<1
12.9
80.7
6.41
262.9
Belews Creek
BC2-1
35
20.8
107.3
7
122
Belews Creek
BC22
<1
18.2
319.6
0.5
158.9
Belews Creek
BC2-2
4.9
20.1
111
0.14
<
Belews Creek
BC23
<1
23.5
230
2.46
229.6
Belews Creek
BC2-3
14.1
17.6
94.3
2.02
<
Belews Creek
BC24
<1
24.9
136
4
235.8
Belews Creek
BC25
<1
21.9
4.56
4.56
235.1
Belews Creek
BC26
<1
17.6
50.3
7.93
199.5
Belews Creek
BC27
<1
21.6
214.6
7.58
255.1
Belews Creek
BC28
<1
15.9
200.2
0.05
<
Belews Creek
BC29
< 1
17.3
97.5
4.62
197.9
Belews Creek
BC30
<1
16.9
268.5
1.52
163
Belews Creek
BC31
<1
16
242.2
1.15
168.8
Belews Creek
BC32
<1
16.9
230.4
0.1
78.9
Belews Creek
BC33
1.7
15.6
229.1
2.01
<
Belews Creek
BC34
<1
14.8
265.1
4.6
202.3
Belews Creek
BC35
2.1
13.7
244.7
2.58
151.1
Belews Creek
BC4A
<1
24.4
146.3
7.45
142.9
Belews Creek
BC413
19.3
13.3
123
4.92
Belews Creek
BC5
< 1
15.7
35.6
8.18
272.4
Belews Creek
BC6
3.6
19.2
125
5.4
255
Belews Creek
BC7
<1
19.8
198.5
0.1
89.6
Belews Creek
BC8
<1
20.1
90
7.31
216.5
Belews Creek
BC9
2.96
22.1
186
4.03
116.5
10
Page 3 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - 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
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-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.orni.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.
Reporti ng limit is a bone the screening level.
Haley & Aldrich, Inc.
Tables B2 -1-B2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
11
4/14/2016

Table B2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
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
(*denotes
Federal M ry standard) L (b):
secondary stan
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
Belews Creek
BC1
<5
32500
7
7.67
12.2
95
<0.5
1.3
2.4
<0.2
<0.08
1.4
<0.5
2.8
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC10
<5
2840
3
8.07
<2
42
<0.5
<0.5
18.6
<0.2
<0.08
1.6
<0.5
0.53
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC13
22.5
41200
14.9
7.48
8.5
180
<0.5
6.8
1.9
<0.2
<0.08
<0.5
<0.5
0.35
<0.2
2.4
0.58
<0.1
Belews Creek
BC14
<5
2190
1.8
6.02
3.2
50
<0.5
<0.5
5.6
<0.2
0.083
<0.5
<0.5
4.5
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC15
<5
14300
5.7
6.15 1
3.6
91
<0.5
0.83
3.4
<0.2
<0.08
0.96
<0.5
0.81
<0.2
4.8
<0.5
<0.1
Belews Creek
BC17
<5
28300
4
2.57
7.2
150
<0.5
14.1
7.8
<0.2
<0.08
<0.5
<0.5
0.15
<0.2
3.5
<0.5
<0.1
Belews Creek
BC18
<5
10400
1.6
6.25
2
88
<0.5
2
2.3
<0.2
<0.08
0.79
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC19
< 5
19100
1.8
6.6
5.9
117
< 0.5
6.1
3.9
< 0.2
0.11
< 0.5
< 0.5
0.4
< 0.2
1.2
< 0.5
< 0.1
Belews Creek
BC20
<5
29000
2.2
7.12
8.1
136
<0.5
10.8
3
<0.2
<0.08
<0.5
<0.5
0.83
<0.2
20.2
<0.5
<0.1
Belews Creek
BC21
< 25
3500
4.3
5.79
< 2
64
< 0.5
< 0.1
9.5
< 0.1
< 0.08
0.89
< 0.1
1.2
< 0.2
< 0.5
< 0.5
< 0.1
Belews Creek
BC2-1
<5
11000
1.39
7.1
9.92
105
<0.5
<0.5
12
<0.2
<0.08
<0.5
<0.5
2
<0.2
2
<0.5
<0.1
Belews Creek
BC22
<0.5
43800
14.1
2.13
16.8
223
<0.5
0.69
1
<0.2
<0.08
<0.5
<0.5
0.16
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC2-2
<5
12000
1.48
6.9
9.07
111
<0.5
<0.5
9.4
<0.2
<0.08
<0.5
0.79
0.12
<0.2
1.9
<0.5
<0.1
Belews Creek
BC23
<5
29600
14.6
6.87
20.2
169
<0.5
1.5
7.2
0.3
<0.08
<0.5
4.3
0.99
<0.2
1.4
<0.5
<0.1
Belews Creek
BC2-3
<5
10000
<1
6.67
12
80
<0.5
<0.5
1.4
<0.2
<0.08
<0.5
<0.5
0.34
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC24
<5
15400
3.7
6.32
4.2
111
<0.5
12.1
12
<0.2
0.098
<0.5
<0.5
0.67
<0.2
1.9
<0.5
<0.1
Belews Creek
BC25
<5
4670
3.1
6.47
3.5
76
<0.5
<0.5
0.46
<0.2
<0.08
<0.5
<0.5
0.62
<0.2
0.68
<0.5
<0.1
Belews Creek
BC26
<5
16900
4
5.9
8.2
112
<0.5
1.9
0.5
<0.2
0.18
<0.5
<0.5
1.2
<0.2
4
<0.5
<0.1
Belews Creek
BC27
<5
22400
18.6
6.54
3.5
166
<0.5
1.6
8.3
<0.2
<0.08
2.5
<0.5
0.54
<0.2
1.1
<0.5
<0.1
Belews Creek
BC28
12.2
12800
<1
3.61
18.3
99
<0.5
2.8
<0.3
<0.2
<0.08
<0.5
<0.5
0.69
<0.2
3.4
<0.5
<0.1
Belews Creek
BC29
<5
6560
3.4
6.18
<2
66
<0.5
<0.5
10.3
<0.2
<0.08
<0.5
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC30
<5
37100
7.5
7.14
8.7
152
<0.5
108
2.2
<0.2
<0.08
<0.5
<0.5
0.14
<0.2
10.5
1.8
<0.1
Belews Creek
BC31
<5
36700
2.4
7.43
8.6
152
<0.5
0.93
12.7
<0.2
<0.08
<0.5
<0.5
0.24
<0.2
1.3
<0.5
<0.1
Belews Creek
BC32
<5
31700
4.1
7.95
9.2
127
<0.5
22.5
3.1
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
6.8
<0.5
<0.1
Belews Creek
BC33
<5
34000
2.8
7.29
9.1
148
<0.5
1.9
7.7
<0.2
<0.08
19.3
<0.5
0.13
<0.2
1.9
<0.5
<0.1
Belews Creek
BC34
<5
36200
8.3
6.5
6.1
156
<0.5
40.3
37.7
<0.2
<0.8
0.52
<0.5
0.54
<0.2
4.5
<0.5
<0.1
Belews Creek
BC35
<5
33400
7.2
7.09
14.2
143
<0.5
15.7
3.9
<0.2
<0.08
1.6
<0.5
3.8
<0.2
2.1
<0.5
<0.1
Belews Creek
BC4A
<5
17000
1.6
7.3
5
112
<0.5
0.17
6.88
<0.2
<0.08
0.99
0.03
1.4
<0.2
4.1
0.35
<0.1
Belews Creek
B 4
<50
9950
<0.1
6.85
14
80 1
<0.5
<2
1.42
<0.5
<0.15
1.61
<1
0.1
<0.2
0.58
<2
<0.5
Belews Creek
BCS
<5
1340
2.7
5.3
<2
<25
<0.5
<0.5
19
<0.2
<0.08
<0.5
<0.5
0.41
<0.2
<0.5
<0.5
<0.1
Belews Creek
BC6
<100
12000
11.3
6.1
9.25
101
<1
<5
<10
<1
<0.1
<1
<1
<2
<0.2
<5
<5
<0.1
Belews Creek
BC7
< 25
30000
2.1
8
9.3
127
< 1
< 2.5
< 1.5
< 1
< 0.1
< 1
< 1
< 0.5
< 0.2
< 2.5
< 2.5
< 0.1
Belews Creek
BC8
22
4950
13.7
6.25
3.1
71
0.76
0.77
6.6
<0.11
<0.06
0.91
0.11
1.1
<0.2
1.14
0.22
<0.06
Belews Creek
BC9
<5
18000
6.3
7.16
9.8
119
<0.5
1.8
0.74
<0.2
<0.08
<0.5
<0.5
2.28
<0.2
<0.5
<0.5
<0.1
12
Page 1 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table B2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
N5
NS
N5
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
Belews Creek
BC1
< 1
66.2
0.0073
261
0.093
2980
173
2.1
1180
7490
165
0.0211
81.1
81.1
<5
6.2
Belews Creek
BC10
< 1
< 10
0.0233
56.8
0.057
1090
4
0.85
1300
5030
33.6
0.0067
18.8
18.8
< 5
< 2.5
Belews Creek
BC13
4.8
<10
0.0075
<50
<0.03 H1
8060
1.4
<0.5
1240
10200
87.6
0.0069
120
120
<5
<2.5
Belews Creek
I BC14
< 1
< 10
0.107
< 50
< 0.03
1770
2.7
< 0.5
1370
5910
21.6
0.0787
18
18
<5
< 2.5
Belews Creek
BC15
< 1
< 10
0.0167
< 50
0.41
1430
9
1.6
2020
6370
63.1
0.0669
37.2
37.2
<5
< 2.5
Belews Creek
BC17
<1
<10
0.0072
<50
<0.03
5560
0.83
<0.5
501
11900
200
0.0132
95.7
95.7
<5
<2.5
Belews Creek
BC18
1
<10
0.0193
<50
0.59
3880
1.3
<0.5
1430
6230
44.8
0.152
49.5
49.5
<5
<6.8
Belews Creek
BC19
< 1
< 10
0.0155
< 50
< 0.03
4070
4.6
< 0.5
1020
8090
87.9
0.126
66.9
66.9
< 5
< 2.5
Belews Creek
BC20
< 1
< 10
0.0128
< 50
< 0.3
4040
3.6
< 0.5
955
9260
94.2
0.0342
94.9
94.9
<5
<5
Belews Creek
BC21
<0.5
<10
0.0222
<50
0.58
3040
0.58
0.55
1700
7470
18.3
0.0251
22.8
22.8
<5
<2.5
Belews Creek
BC2-1
0.4
<10
0.058
8500
<0.03
4180
29.8
<0.5
2140
7400
55
0.048
46.1
46.1
<0
5.2
Belews Creek
BC22
<1
<10
0.0026
<50
<0.03
6420
148
<0.5
2170
9820
122
0.0183
123
123
<5
<2.5
Belews Creek
BC2-2
<0.3
<10
0.0032
1700
<0.03
3900
30
1.7
2040
7760
52.9
0.019
48.2
48.2
<0
<1
Belews Creek
BC23
<1
<10
0.0279
155
<0.03
5450
144
15
2800
8590
102
0.065
81
81
<5
<2S
Belews Creek
BC2-3
<1
<10
<0.001
2310
<0.03
2230
11.7
<0.5
1850
6200
36.1
<0.005
30.4
30.4
<5
<2.5
Belews Creek
BC24
< 1
< 10
0.0384
< 50
< 0.03
4000
20.8
< 0.5
1510
7660
55.1
0.266
54.2
54.2
< 5
< 2.5
Belews Creek
BC25
< 1
< 10
0.0188
< 50
0.037
2800
1.4
< 0.5
1060
6070
23.3
0.138
23.2
23.2
<5
< 2.5
Belews Creek
BC26
< 1
< 10
0.0049
<50
< 0.03
4590
2.1
< 0.5
771
8970
56.4
0.116
66.1
66.1
< 5
< 2.5
Belews Creek
BC27
1.7
< 10
0.0157
< 50
2.1
6820
0.62
< 0.5
3110
7080
87.7
0.0088
48.3
48.3
<5
< 2.5
Belews Creek
BC28
< 1
11.8
0.0041
< 50
< 0.03
1100
2.2
< 0.5
96.1
23700
161
0.0075
65.4
65.4
<5
< 2.5
Belews Creek
BC29
< 1
< 10
0.014
< 50
0.16
3250
< 0.5
< 0.5
1630
6440
21.7
0.0087
36.9
36.9
<5
<5
Belews Creek
BC30
<1
12.9
0.0068
<50
<0.03
5530
0.7
<0.5
906
7940
64.6
0.0275
110
110
<5
<2.5
Belews Creek
BC31
<1
<10
0.0042
110
<0.03
4830
102
<0.5
1930
8840
79.2
0.0127
109
109
<5
<2.5
Belews Creek
BC32
<1
<10
<0.001
<50
<0.03
3310
23.8
<0.5
228
9370
210
<0.005
97.1
97.1
<5
<2.5
Belews Creek
BC33
<1
<10
<0.001
269
<0.03
5270
67.6
2.2
1810
8150
85.2
0.0449
98.4
98.4
<5
<2.5
Belews Creek
BC34
< 1
< 10
0.0104
< 50
< 0.03
4620
0.8
< 0.5
2180
8640
94.4
0.0248
98.1
98.1
<5
<5
Belews Creek
BC35
< 1
49.1
0.008
365
0.18
6240
253
1.3
2340
6500
44.7
0.0627
92.4
92.4
<5
4.1
Belews Creek
BC4A
2.4
<10
0.0136
<25
0.085
5730
<0.5
0.29
1530
8550
44.8
0.0266
71.2
71.2
<5
<2.5
Belews Creek
BC48
0.58
<50
0.00019
1890
<5
2050
10.6
0.34
1540
5600
37
0.00315
37
<2.5
Belews Creek
BCS
< 1
14.9
0.0323
< 50
< 0.03
1080
1.8
< 0.5
1420
2360
16.9
0.0208
8.9
8.9
< 5
< 25
Belews Creek
BC6
<0.3
<50
<0.005
290
<10
2400
40
<5
2000
9700
69
0.009
32.8
32.8
<0
<1
Belews Creek
BC7
< 0.3
< 50
< 0.005
< 50
< 0.03
2760
10.8
<25
808
6500
99
< 0.005
84
84
<0
< 1
Belews Creek
BC8
23.5
< 10
0.0228
15.2
0.06
1890
1.8
0.38
1190
843053.8
0.0147
28
26.9
<5.
3
Belews Creek
BC9
< 1
< 10
0.00915
322
< 0.03
4600
32.8
0.76
1880
7720
74.5
0.0949
58
58
< 1
< 2.5
13
Page 2 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table B2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
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
Belews Creek
BC1
1
16.2
220.2
0.17
76
Belews Creek
BC10
<1
19
139
1.5
112.9
Belews Creek
BC13
< 1
18.2
155.5
0.65
79.9
Belews Creek
BC14
<1
23.3
29.8
3.14
244.3
Belews Creek
BC15
<1
19.2
116.1
6.73
232.2
Belews Creek
BC17
<1
20
215.3
0.55
194.5
Belews Creek
BC18
< 1
17
104.9
7.33
242.8
Belews Creek
BC19
< 1
24
148
3.78
221.5
Belews Creek
BC20
<1
25.5
208.7
2.87
106.7
Belews Creek
BC21
<1
12.9
80.7
6.41
262.9
Belews Creek
BC2-1
35
20.8
107.3
7
122
Belews Creek
BC22
<1
18.2
319.6
0.5
158.9
Belews Creek
BC2-2
4.9
20.1
111
0.14
<
Belews Creek
BC23
<1
23.5
230
2.46
229.6
Belews Creek
BC2-3
14.1
17.6
94.3
2.02
<
Belews Creek
BC24
<1
24.9
136
4
235.8
Belews Creek
BC25
< 1
21.9
4.56
4.56
235.1
Belews Creek
BC26
< 1
17.6
50.3
7.93
199.5
Belews Creek
BC27
< 1
21.6
214.6
7.58
255.1
Belews Creek
BC28
<1
15.9
200.2
0.05
<
Belews Creek
BC29
<1
17.3
97.5
4.62
197.9
Belews Creek
BC30
<1
16.9
268.5
1.52
163
Belews Creek
BC31
<1
16
242.2
1.15
168.8
Belews Creek
BC32
< 1
16.9
230.4
0.1
78.9
Belews Creek
BC33
1.7
15.6
229.1
2.01
<
Belews Creek
BC34
< 1
14.8
265.1
4.6
202.3
Belews Creek
BC35
2.1
13.7
244.7
2.58
151.1
Belews Creek
BC4A
<1
24.4
146.3
7.45
142.9
Belews Creek
BC48
19.3
13.3
123
4.92
Belews Creek
BCS
<1
15.7
35.6
8.18
272.4
Belews Creek
BC6
3.6
19.2
125
5.4
255
Belews Creek
BC7
<1
19.8
198.5
0.1
89.6
Belews Creek
BC8
< 1
20.1
90
7.31
216.5
Belews Creek
BC9
2.96
22.1
186
4.03
116.5
14
Page 3 of 3
Haley & Aldrich, Inc.
Tables 132-1-82-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - 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
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-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.orni.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 a be ve the screening level.
Haley & Aldrich, Inc.
Tables B2 -1-B2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx
15
4/14/2016

16
Table 82-5 Page 1 of 3
Comparison of Duke Energy Background Well Data to 21. Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke 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
1
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
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
11.
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
5.7
Appendix III (f)
Appendix IV (g)
Station
Well ID
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
SI Units
Sulfate
mg/L
Total
Dissolved
Solids
mg/L
Antimony
Arsenic
Barium
Beryllium
Cadmium Chromium
Cobalt
Lead
Mercury
ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
<50
17100
<1
<1
11
<1
<1
<5
<1
73.2
<0.05
Belews Creek
DBKG-BC2
< 50
5500
< 1
< 1
77
< 1
< 1
< 5
< 1
4.98
< 0.05
Belews Creek
DBKG-BC3
<50
12000
<1
<1
6
<1
<1
<5
<1
<1
<0.05
Belews Creek
DBKG-BC4
<50
8310
<1
<1
<5
<1
<1 I
<5
<1
<1
<0.0S
Belews Creek
DBKG-BCS
< 50
13600
< 1
< 1
13
< 1
< 1
< 5
< 1
1.56
< 0.05
Belews Creek
DBKG-BC6
<5
28000
<0.5
<0.5
3.S
<0.2
<0.08
<0.5
0.6
<0.1
<0.2
Belews Creek
DBKG-BC7
<5
10800
11
6.9
8.S
150
0.63
1.7
2.4
<0.2
<0.08
3.5
<0.S
0.6
<0.2
Belews Creek
DBKG-BC8
< 5
38300
2.2
8.05
1.4
170
0.S
< 0.5
119
< 0.2
< 0.08
< 0.5
< 0.5
0.2
< 0.2
Belews Creek
DBKG-BC9
<5
26600
2.S
7.64
6.2
150
0.58
<0.S
33.4
<0.2
<0.08
<0.S
<0.S
0.17
<0.2
Belews Creek
DBKG-BC10
< 50
6920
11
6.24
6.4
1.13
< 1
80
< 1
< 1
< 5
< 1
1.82
< 0.05
Belews Creek
DBKG-BC11
<50
8140
1.4
7.01
4
1.12
<1
<5
<1
<1
<5
<1
<1
<0.05
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx 2L April 2016

17
Table BZ -5 Page 2 of 3
Comparison of Duke Energy Background Well Data to 21. Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L
Groundwater Staandad(a):
Standard a:
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1,000
Federal MCL/SMCL (b):
* denotes secondary standard
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5000
DHHS Screening Level (c):
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
2,100
1,000
RSL 2015 (d):
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
12,000
6,000
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Station
Well ID
Molybdenum Selenium
ug/L ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
4.05
1.1
<0.2
1.94
55
0.69
790
1450
12
<5
177
36800
620
645
Belews Creek
DBKG-BC2
< 1
< 1
< 0.2
0.653
< 5
0.126
< 10
1670
< S
< 5
1440
6730
90
69
Belews Creek
DBKG-BC3
1.18
< 1
< 0.2
< 0.3
< 5
< 0.005
145
3470
18
< 5
1150
5890
51
6
Belews Creek
DBKG-BC4
< 1
< 1
< 0.2
1.OS
< 5
0.08
10
1710
< S
< S
421
9780
143
78
Belews Creek
DBKG-BC5
3.23
< 1
< 0.2
4.89
< S
0.035
< 10
3990
< S
< S
3370
5290
279
11
Belews Creek
DBKG-BC6
10.8
0.59
< 0.1
< 1
< 10
0.0011
389
< 0.03
4480
96.5
3
2200
14000
60.9
138
Belews Creek
DBKG-BC7
<0.5
<0.5
<0.1
1.8
12.4
0.0133
<SO
3
5680
31.8
1.4
847
16200
54.6
16.5
Belews Creek
DBKG-BC8
< 0.5
< 0.5
< 0.1
1.1
< 10
0.0035
< SO
0.038
6530
< 0.5
< 0.5
749
8990
332
5.4
Belews Creek
DBKG-BC9
0.75
< 0.5
< 0.1
< 1
< 10
0.0028
326
0.043
5700
195
< 0.5
3330
10900
131
6.2
Belews Creek
DBKG-BC10
< 1
< 1
< 0.2
0.688
11
0.094
55
0.14
2180
< S
< 5
1350
10700
113
29
Belews Creek
DBKG-BC11
1.62
<1
<0.2
0.734
<5
0.037
14
0.15
2470
<S
<5
1740
4530
38
7
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx 2L April 2016

18
Table B2-5 Page 3 of 3
Comparison of Duke Energy Background Well Data to 21. Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.020
Groundwater Standard a:
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Station
Well ID
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
mg/L
Turbidity
Temperature
Specific
Conductance
Dissolved
Oxygen
Oxidation
Reduction
potential
Belews Creek
DBKG-BC1
Belews Creek
DBKG-BC2
Belews Creek
DBKG-BC3
Belews Creek
DBKG-BC4
Belews Creek
DBKG-BC5
Belews Creek
DBKG-BC6
Belews Creek
DBKG-BC7
<S
Belews Creek
DBKG-BC8
<5
Belews Creek
DBKG-BC9
<S
Belews Creek
DBKG-BC10
<5
Belews Creek
DBKG-BC11
< 5
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx 2L April 2016

Comparison of Duke Energy Background Well Data to Screening Levels
Belews Creek 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
< 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/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.epa.gov/risk/risk-based-screen ing-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http:Hepa-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 132-5-62-8 Duke Bkg Well Screen_2016-04.xlsx
19
Page 1 of 1
4/9/2016

20
Table 82-6 Page 1 of 3
Comparison of Duke Energy Background Well Data to MCL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke 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
1
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
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1L
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
5.7
Appendix III (f)
Appendix IV (g)
Station
Well ID
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
SI Units
Sulfate
mg/L
Total
Dissolved
Solids
mg/L
Antimony
Arsenic
Barium
Beryllium
Cadmium Chromium
Cobalt
Lead
Mercury
ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
<50
17100
<1
<1
11
<1
<1
<5
<1
73.2
<0.05
Belews Creek
DBKG-BC2
< 50
5500
< 1
< 1
77
< 1
< 1
< 5
< 1
4.98
< 0.05
Belews Creek
DBKG-BC3
<50
12000
<1
<1
6
<1
<1
<5
<1
<1
<0.05
Belews Creek
DBKG-BC4
<50
8310
<1
<1
<5
<1
<1 I
<5
<1
<1
<0.0S
Belews Creek
DBKG-BCS
< 50
13600
< 1
< 1
13
< 1
< 1
< 5
< 1
1.56
< 0.05
Belews Creek
DBKG-BC6
<5
28000
<0.5
<0.5
3.S
<0.2
<0.08
<0.5
0.6
<0.1
<0.2
Belews Creek
DBKG-BC7
<5
10800
11
6.9
8.S
150
0.63
1.7
2.4
<0.2
<0.08
3.5
<0.S
0.6
<0.2
Belews Creek
DBKG-BC8
< 5
38300
2.2
8.05
1.4
170
0.S
< 0.5
119
< 0.2
< 0.08
< 0.5
< 0.5
0.2
< 0.2
Belews Creek
DBKG-BC9
<5
26600
2.S
7.64
6.2
150
0.58
<0.S
33.4
<0.2
<0.08
<0.S
<0.S
0.17
<0.2
Belews Creek
DBKG-BC10
< 50
6920
11
6.24
6.4
1.13
< 1
80
< 1
< 1
< 5
< 1
1.82
< 0.05
Belews Creek
DBKG-BC11
<50
8140
1.4
7.01
4
1.12
<1
<5
<1
<1
<5
<1
<1
<0.05
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx MCL April 2016

21
Table BZ -6 Page 2 of 3
Comparison of Duke Energy Background Well Data to MCL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx MCL April 2016
15A NCA.0202
Groundwater Standard a
d(a)
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1,000
Federal MCL/SMCL (b):
* denotes secondary standard
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5000
DHHS Screening Level (c):
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
2,100
1,000
RSL 2015 (d):
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
12,000
6,000
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Station
Well ID
Molybdenum Selenium
ug/L ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
4.05
1.1
<0.2
1.94
55
0.69
790
1450
12
<5
177
36800
620
645
Belews Creek
DBKG-BC2
< 1
< 1
< 0.2
0.653
< 5
0.126
< 10
1670
< S
< S
1440
6730
90
69
Belews Creek
DBKG-BC3
1.18
< 1
< 0.2
< 0.3
< 5
< 0.005
145
3470
18
< 5
1150
5890
51
6
Belews Creek
DBKG-BC4
< 1
< 1
< 0.2
1.05
< 5
0.08
10
1710
< S I
< S
421
9780
143
78
Belews Creek
DBKG-BC5
3.23
< 1
< 0.2
4.89
< 5
0.035
< 10
3990
< S
< 5
3370
5290
279
11
Belews Creek
DBKG-BC6
10.8
0.59
< 0.1
< 1
< 10
0.0011
389
< 0.03
4480
96.5
3
2200
14000
60.9
138
Belews Creek
DBKG-BC7
<0.5
<0.5
<0.1
1.8
12.4
0.0133
<50
3
5680
31.8
1.4
847
16200
54.6
16.5
Belews Creek
DBKG-BC8
< 0.5
< 0.5
< 0.1
1.1
< 10
0.0035
< 50
0.038
6530
< 0.5
< 0.5
749
8990
332
5.4
Belews Creek
DBKG-BC9
0.75
< 0.5
< 0.1
< 1
< 10
0.0028
326
0.043
5700
195
< 0.5
3330
10900
131
6.2
Belews Creek
DBKG-BC10
< 1
< 1
< 0.2
0.688
11
0.094
55
0.14
2180
< S
< S
1350
10700
113
29
Belews Creek
DBKG-BC11
1.62<1
<0.2
0.734
<5
0.037
14
0.15
2470
<S
<5
1740
4530
38
7
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx MCL April 2016

22
Table B2-6 Page 3 of 3
Comparison of Duke Energy Background Well Data to MCL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx MCL April 2016
15A NCAC 02L.020
Groundwater Standard a
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Station
Well ID
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
mg/L
Turbidity
Temperature
Specific
Conductance
Dissolved
Oxygen
Oxidation
Reduction
potential
Belews Creek
DBKG-BC1
Belews Creek
DBKG-BC2
Belews Creek
DBKG-BC3
Belews Creek
DBKG-BC4
Belews Creek
DBKG-BC5
Belews Creek
DBKG-BC6
Belews Creek
DBKG-BC7
<S
Belews Creek
DBKG-BC8
<5
Belews Creek
DBKG-BC9
<S
Belews Creek
DBKG-BC10
<5
Belews Creek
DBKG-BC11
< 5
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx MCL April 2016

Comparison of Duke Energy Background Well Data to Screening Levels
Belews Creek 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
< 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/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.epa.gov/risk/risk-based-screen ing-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http:Hepa-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 132-5-62-8 Duke Bkg Well Screen_2016-04.xlsx
23
Page 1 of 1
4/9/2016

24
Table 82-7 Page 1 of 3
Comparison of Duke Energy Background Well Data to DHHS Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke 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
1
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
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1L
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
5.7
Appendix III (f)
Appendix IV (g)
Station
Well ID
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
SI Units
Sulfate
mg/L
Total
Dissolved
Solids
mg/L
Antimony
Arsenic
Barium
Beryllium
Cadmium Chromium
Cobalt
Lead
Mercury
ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
<50
17100
<1
<1
11
<1
<1
<5
<1
73.2
<0.05
Belews Creek
DBKG-BC2
< 50
5500
< 1
< 1
77
< 1
< 1
< 5
< 1
4.98
< 0.05
Belews Creek
DBKG-BC3
<50
12000
<1
<1
6
<1
<1
<5
<1
<1
<0.05
Belews Creek
DBKG-BC4
<50
8310
<1
<1
<5
<1
<1 I
<5
<1
<1
<0.0S
Belews Creek
DBKG-BCS
< 50
13600
< 1
< 1
13
< 1
< 1
< 5
< 1
1.56
< 0.05
Belews Creek
DBKG-BC6
<5
28000
<0.5
<0.5
3.S
<0.2
<0.08
<0.5
0.6
<0.1
<0.2
Belews Creek
DBKG-BC7
<5
10800
11
6.9
8.S
150
0.63
1.7
2.4
<0.2
<0.08
3.5
<0.S
0.6
<0.2
Belews Creek
DBKG-BC8
< 5
38300
2.2
8.05
1.4
170
0.S
< 0.5
119
< 0.2
< 0.08
< 0.5
< 0.5
0.2
< 0.2
Belews Creek
DBKG-BC9
<5
26600
2.S
7.64
6.2
150
0.58
<0.S
33.4
<0.2
<0.08
<0.S
<0.S
0.17
<0.2
Belews Creek
DBKG-BC10
< 50
6920
11
6.24
6.4
1.13
< 1
80
< 1
< 1
< 5
< 1
1.82
< 0.05
Belews Creek
DBKG-BC11
<50
8140
1.4
7.01
4
1.12
<1
<5
<1
<1
<5
<1
<1
<0.05
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx DHHS April 2016

25
Table BZ -7 Page 2 of 3
Comparison of Duke Energy Background Well Data to DHHS Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCA.0202
Groundwater Standard a
d(a):
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1,000
Federal MCL/SMCL (b):
* denotes secondary standard
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5000
DHHS Screening Level (c):
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
2,100
1,000
RSL 2015 (d):
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
12,000
6,000
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Station
Well ID
Molybdenum Selenium
ug/L ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
4.05
1.1
<0.2
1.94
S5
0.69
790
1450
12
<5
177
36800
620
64S
Belews Creek
DBKG-BC2
< 1
< 1
< 0.2
0.653
< 5
0.126
< 10
1670
< S
< 5
1440
6730
90
69
Belews Creek
DBKG-BC3
1.18
< 1
< 0.2
< 0.3
< 5
< 0.005
145
3470
18
< 5
1150
5890
51
6
Belews Creek
DBKG-BC4
< 1
< 1
< 0.2
1.05
< 5
0.08 1
10
1 1710
< S I
< 5
421 1
9780
143 1
78
Belews Creek
DBKG-BC5
3.23
< 1
< 0.2
4.89
< 5
0.035
< 10
3990
< 5
< 5
3370
5290
279
11
Belews Creek
DBKG-BC6
10.8
0.59
< 0.1
< 1
< 10
0.0011
389
< 0.03
4480
96.5
3
2200
14000
60.9
138
Belews Creek
DBKG-BC7
<0.5
<0.5
<0.1
1.8
12.4
0.0133
<50
3
5680
31.8
1.4
847
16200
54.6
16.5
Belews Creek
DBKG-BC8
< 0.5
< 0.5
< 0.1
1.1
< 10
0.0035
< 50
0.038
6530
< 0.5
< 0.5
749
8990
332
5.4
Belews Creek
DBKG-BC9
0.75
< 0.5
< 0.1
< 1
< 10
0.0028
326
0.043
5700
19S
< 0.5
3330
10900
131
6.2
Belews Creek
DBKG-BC10
< 1
< 1
< 0.2
0.688
11
0.094
55
0.14
2180
< S
< 5
1350
10700
113
29
Belews Creek
DBKG-BC11
1.62<1
<0.2
0.734
<5
0.037
14
0.15
2470
<5
<5
1740
4530
38
7
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx DHHS April 2016

26
Table B2-7 Page 3 of 3
Comparison of Duke Energy Background Well Data to DHHS Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.020
Groundwater Standard a:
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Station
Well ID
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
mg/L
Turbidity
Temperature
Specific
Conductance
Dissolved
Oxygen
Oxidation
Reduction
potential
Belews Creek
DBKG-BC1
Belews Creek
DBKG-BC2
Belews Creek
DBKG-BC3
Belews Creek
DBKG-BC4
Belews Creek
DBKG-BC5
Belews Creek
DBKG-BC6
Belews Creek
DBKG-BC7
<S
Belews Creek
DBKG-BC8
<S
Belews Creek
DBKG-BC9
<S
Belews Creek
DBKG-BC10
<S
Belews Creek
DBKG-BC11
< 5
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx DHHS April 2016

Comparison of Duke Energy Background Well Data to Screening Levels
Belews Creek 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
< 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/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.epa.gov/risk/risk-based-screen ing-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http:Hepa-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 isabove thesreening level.
_ Reporting limit is above the xreen i ng level.
Haley & Aldrich, Inc.
Tables 132-5-62-8 Duke Bkg Well Screen_2016-04.xlsx
27
Page 1 of 1
4/9/2016

28
Table B2-8 Page 1 of 3
Comparison of Duke Energy Background Well Data to RSL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-82-8 Duke 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
30
1
15
1
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
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1L
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
35
5.7
Appendix III (f)
Appendix IV (g)
Station
Well ID
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
SI Units
Sulfate
mg/L
Total
Dissolved
Solids
mg/L
Antimony
Arsenic
Barium
Beryllium
Cadmium Chromium
Cobalt
Lead
Mercury
ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
< 50
17100
< 1
< 1
11
< 1
< 1
< 5
< 1
73.2
< 0.05
Belews Creek
DBKG-BC2
< 50
5500
< 1
< 1
77
< 1
< 1
< 5
< 1
4.98
< 0.05
Belews Creek
DBKG-BC3
< 50
12000
< 1
< 1
6
< 1
< 1
< 5
< 1
< 1
< 0.05
Belews Creek
DBKG-BC4
<50
8310
<1
<1
<5
<1
<1
<5
<1
<1
<0.05
Belews Creek
DBKG-BC5
<50
13600
<1
<1
13
<1
<1
<5
<1
1.56
<0.05
Belews Creek
DBKG-BC6
<5
28000
<0.5
<0.5
3.5
<0.2
<0.08
<0.5
0.6
<0.1
<0.2
Belews Creek
DBKG-BC7
<5
10800
11
6.9
8.5
150
0.63
1.7
2.4
<0.2
<0.08
3.5
<0.5
0.6
<0.2
Belews Creek
DBKG-BC8
<5
38300
2.2
8.05
1.4
170
0.5
<0.5
119
<0.2
<0.08
<0.5
<0.5
0.2
<0.2
Belews Creek
DBKG-BC9
<5
26600
2.5
7.64
6.2
150
0.58
<0.5
33.4
<0.2
<0.08
<0.5
<0.5
0.17
<0.2
Belews Creek
DBKG-BC10
< 50
6920
11
6.24
6.4
1.13
< 1
80
< 1
< 1
< 5
< 1
1.82
< 0.05
Belews Creek
DBKG-BC11
<50
8140
1.4
7.01
4
-jr1.12
<1
<5
<1
<1
<5
<1 I
Haley & Aldrich, Inc.
Tables 82-5-82-8 Duke Bkg Well Screen_2016-04.xlsx RSL April 2016

29
Table B2-8 Page 2 of 3
Comparison of Duke Energy Background Well Data to RSL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCA.0202
Groundwater Standard a
d(a):
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1,000
Federal MCL/SMCL (b):
* denotes secondary standard
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5000
DHHS Screening Level (c):
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
2,100
1,000
RSL 2015 (d):
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
12,000
6,000
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Station
Well ID
Molybdenum Selenium
ug/L ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Belews Creek
DBKG-BC1
4.05
1.1
<0.2
1.94
S5
0.69
790
1450
12
<5
177
36800
620
64S
Belews Creek
DBKG-BC2
< 1
< 1
< 0.2
0.653
< 5
0.126
< 10
1670
< S
< 5
1440
6730
90
69
Belews Creek
DBKG-BC3
1.18
< 1
< 0.2
< 0.3
< 5
< 0.005
145
3470
18
< 5
1150
5890
51
6
Belews Creek
DBKG-BC4
< 1
< 1
< 0.2
1.05
< 5
0.08 1
10
1 1710
< S I
< 5
421 1
9780
143 1
78
Belews Creek
DBKG-BC5
3.23
< 1
< 0.2
4.89
< 5
0.035
< 10
3990
< 5
< 5
3370
5290
279
11
Belews Creek
DBKG-BC6
10.8
0.59
< 0.1
< 1
< 10
0.0011
389
< 0.03
4480
96.5
3
2200
14000
60.9
138
Belews Creek
DBKG-BC7
<0.5
<0.5
<0.1
1.8
12.4
0.0133
<50
3
5680
31.8
1.4
847
16200
54.6
16.5
Belews Creek
DBKG-BC8
< 0.5
< 0.5
< 0.1
1.1
< 10
0.0035
< 50
0.038
6530
< 0.5
< 0.5
749
8990
332
5.4
Belews Creek
DBKG-BC9
0.75
< 0.5
< 0.1
< 1
< 10
0.0028
326
0.043
5700
19S
< 0.5
3330
10900
131
6.2
Belews Creek
DBKG-BC10
< 1
< 1
< 0.2
0.688
11
0.094
55
0.14
2180
< S
< 5
1350
10700
113
29
Belews Creek
DBKG-BC11
1.62<1
<0.2
0.734
<5
0.037
14
0.15
2470
<5
<5
1740
4530
38
7
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx RSL April 2016

30
Table B2-8 Page 3 of 3
Comparison of Duke Energy Background Well Data to RSL Screening Levels
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.020
Groundwater Standard a:
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Station
Well ID
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
mg/L
Turbidity
Temperature
Specific
Conductance
Dissolved
Oxygen
Oxidation
Reduction
potential
Belews Creek
DBKG-BC1
Belews Creek
DBKG-BC2
Belews Creek
DBKG-BC3
Belews Creek
DBKG-BC4
Belews Creek
DBKG-BC5
Belews Creek
DBKG-BC6
Belews Creek
DBKG-BC7
<S
Belews Creek
DBKG-BC8
<S
Belews Creek
DBKG-BC9
<S
Belews Creek
DBKG-BC10
<S
Belews Creek
DBKG-BC11
<S
Haley & Aldrich, Inc.
Tables 82-5-62-8 Duke Bkg Well Screen_2016-04.xlsx RSL April 2016

Comparison of Duke Energy Background Well Data to Screening Levels
Belews Creek 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
< 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/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.epa.gov/risk/risk-based-screen ing-table-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http:Hepa-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 isabuve the sreeni ng level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables 132-5-62-8 Duke Bkg Well Screen_2016-04.xlsx
31
Page 1 of 1
4/9/2016

Page 1 of 1
32
Table 62-9
Do Not Drink Letter Summary
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Table 32-9 Do Not Drink Summary.xlsx 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
Belews Creek BC -4
X
Belews Creek BC -8
X
Belews Creek BC -2 Well 1 & 2
X
Total number of Constituent Letters
2
0
0
0
0
1
0
0
0
0
0
0
0
Total Number of "Do Not Drink" Letters
(Excluding Hexavalent Chromium and
1
Vanadium)
Total Number of "Do Not Drink" Letters
(Including Hexavalent Chromium and
3
Vanadium)
Total Number of "Do Not Drink" Letters
0
for Hexavalent Chromium
Total Number of "Do Not Drink" Letters
2
for Vanadium
Haley & Aldrich, Inc.
Table 32-9 Do Not Drink Summary.xlsx April 2016

33
Table 133-1 Page 1 of 2
Duke Energy Background Water Supply Well Data
Bel— Creek Steam Station
Water Supply well Evaluation
Duke Energy
April 2016
Notes:
<- Not detected, value is the reporting limit.
°C - Degrees Celsius.
mg/L- milligrams/liter.
mV - millivolts.
NTU - Nephelometric Turbidity Units.
su - standard units.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Haley & Aldrich, Inc.
Table B3-1 Duke Energy Background Well Data_2016-04.xlsx April 2016

34
Table 63-1 Page 2 of 2
Duke Energy Background Water Supply Well Data
Bel— Creek Steam Station
Water Supply well Evaluation
Duke Energy
April 2016
MMMOMMMMMOMMMM
=mom
Notes:
<- Not detected, value is the reporting limit.
°C - Degrees Celsius.
mg/L - milligrams/liter.
mV - millivolts.
NTU - Nephelometric Turbidity Units.
su - standard units.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Haley & Aldrich, Inc.
Table B3-1 Duke Energy Background Well Data_2016-04.xlsx April 2016

Table B3-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
Belews Creek 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)
Nckel, Dissolved
(ug/L)
Vanadium
(ug/L)
MW -202D
BL -MW -202D -NS 0.1-3Q15
02 -Oct -15
3.4
MW -202D
BL -MW -202D -NS -3Q15
02 -Oct -15
5.7
<50
<0.5
130
0.07
3.4
0.42
MW -202D
BL -MW -202D -NS -4Q15-2
16 -Dec -15
6.3
<50
<0.5
0.28
160
0.057
2.8
<1
MW -202D
MW -202D01062011
06 -Jan -11
78
<50
7280
7.52
MW -202D
MW -202D01062015
06 -Jan -15
6
<50
17
<1
MW -202D
MW -202D01082014
08 -Jan -14
7
<50
350
<1
MW -202D
MW -202D01092012
09 -Jan -12
11
<50
850
1.11
MW -202D
MW -202D01092013
09 -Jan -13
6
<50
114
<1
MW -202D
MW -202D_05042011
04 -May -11
8
<50
223
<1
MW -202D
MW -202D05052015
05 -May -15
6
< 50
< 1
35
< 1
MW -202D
MW -202D_05062014
06 -May -14
6
<50
43
<1
MW -202D
MW -202D_05082013
08 -May -13
5
< 50
76
< 1
< S
MW -202D
MW -202D_05092012
09 -May -12
6
<50
131
<1
MW -202D
MW -202D09052012
05 -Sep -12
7
<50
260
<1
MW -202D
MW -202D_09062011
06 -Sep -11
12
<50
707
1.15
MW -202D
MW -202D_09092013
09 -Sep -13
5
<50
113
<1
MW -202D
MW -202D_09092014
09 -Sep -14
9
<50
64
<1
MW -202D
MW -202D WG 20110106
06 -Jan -11
78
<0.05
7280
7.52
MW -202D
MW-202D_WG_20110504
04 -May -11
8
<0.05
223
<1
MW -202D
MW-202D_WG_20110906
06 -Sep -11
12
<50
707
1.15
MW -202D
MW -202D WG 20120109
09 -Jan -12
11
<50
850
1.11
MW -202D
MW-202D_WG_20120509
09 -May -12
6
<50
131
<1
MW -202D
MW-202D_WG_20120905
05 -Sep -12
7
<50
260
<1
MW -202D
MW-202D_WG_20130109
09 -Jan -13
6
<50
114
<1
MW -202D
MW-202D_WG_20130508
08 -May -13
5
< 50
76
< 1
< 5
MW -202D
MW -202D WG 20130909
09 -Sep -13
5
<50
113
<1
MW -202D
MW-202D_WG_20140108
08 -Jan -14
7
<50
350
<1
MW -202D
MW-202D_WG_20140506
06 -May -14
6
<50
43
<1
MW -202D
MW -202D WG 20140909
09 -Sep -14
9
<50
64
<1
MW -202D
MW-202D_WG_20150106
06 -Jan -15
6
<50
17
<1
MW -202D
MW-202D_WG_20150505
05 -May -15
6
< 50
< 1
35
< 1
MW -202D
MW-202D_WG_20150716
16 -Jul -15
5.3
<50
<0.5
72
0.067
1.2
<1
MW-202BR
BL-MW-202BR-FD-4Q15-1
12 -Nov -15
6.5
<50
0.35
0.21
450
0.17
2.6
0.74
MW-202BR
BL-MW-202BR-NS 0.1-3Q15
02 -Oct -15
0.88
MW-202BR
BL-MW-202BR-NS-3Q15
02 -Oct -15
6.2
<50
<0.5
51
0.053
0.8
0.82
MW-202BR
BL-MW-202BR-NS-4Q15-1
12 -Nov -15
5.9
<50
0.33
0.22
450
0.099
2.8
0.71
MW-202BR
BL-MW-202BR-NS-4Q15-2
16 -Dec -15
4.4
<50
0.14
0.18
130
0.052
2.9
0.59
MW -2026R
MW-202BRDUP
16 -Jul -15
9.4
30
<0.5
42
<0.1
0.45
1.6
Haley & Aldrich, Inc.
Table B3.2 -Facility Bkg Data.xlsx
Page 1 of 2
April 2016
35

36
Page 2 of 2
Table B3-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
Belews Creek 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)
Nckel, Dissolved
(ug/L)
Vanadium
(ug/L)
MW-202BR
MW-202BR_WG_20150716
16 -Jul -15
11
37
<0.5
78
0.068
0.68
2.3
BG -11)
BG-1D_WG_20150714
14 -Jul -15
4.1
<50
0.9
100
0.26
3.4
0.75
BG -11)
BL -BG -ID -NS -3Q15
29 -Sep -15
3.1
29
2
<0.02
38
0.05
4.3
<1
BG -11)
BL -BG -ID -NS -4Q15-1
12 -Nov -15
4
< 50
1.8
0.096
100
0.11
5.2
< 1
BG-iD
BL -BG -ID -NS -4Q15-2
16 -Dec -15
7.2
< 50
1.6
0.039
36
< 0.1
4
< 1
BG-2BR
BG-2BR_WG_20150709
09 -Jul -15
7.7
<50
<0.5
83
0.056
0.63
7.4
BG-2BR
BL-BG-2BR-NS-3Q15
29 -Sep -15
8.1
<50
<0.5
0.7
40
<0.1
0.43
9
BG-2BR
BL-BG-2BR-NS-4Q15-1
12 -Nov -15
9.4
< 50
0.2
0.4
550
0.17
1.2
7.8
BG-2BR
BL-BG-2BR-NS-4Q15-2
16 -Dec -15
13
<50
<0.5 1
0.6
120
<0.1
0.23
7.9
BG -21)
BG-21)_WG_20150709
09 -Jul -15
7.8
<50
0.28
72
0.097
0.66
1.4
BG -21)
BL -BG -2D -NS -3Q15
29 -Sep -15
6.8
<50
<0.5
0.12
27
<0.1
1
0.96
BG -21)
BL -BG -2D -NS -4Q15-1
12 -Nov -15
10
<50
0.19
0.12
75
<0.1
1.6
1
BG -21)
BL -BG -2D -NS -4Q15-2
16 -Dec -15
6.6
< 50
< 0.5
0.15
28
< 0.1
0.68
1
BG -2S
BG-2S_WG_20150709
09 -Jul -15
60
<50
0.19
650
<0.1
0.96
0.31
BG -2S
BL-BG-2S-NS-3QI5
29 -Sep -15
61
< 50
0.13
1.4
300
0.12
0.82
0.62
BG -2S
BL -BG -2S -NS -4Q15-1
12 -Nov -15
110
< 50
0.2
1.3
1600
0.24
1.3
0.87
BG -2S
BL -BG -2S -NS -4Q15-2
16 -Dec -15
110
< 50
< 0.5
1.3
120
< 0.1
1.4
0.47
BG -3D
BG-3D_WG_20150718
18 -Jul -15
51
<50
0.23
1900
1.5
0.24
0.94
BG -31)
BL -BG -3D -NS -3Q15
30 -Sep -15
9.1
<50
<0.5
0.047
44
0.14
0.25
0.47
BG -313
BL -BG -3D -NS -4Q15-1
12 -Nov -15 1
10
<50
<0.5
0.053
77
0.11
0.41
0.34
BG -31)
BL -BG -3D -NS -4Q15-2
16 -Dec -15 1
9.4
1 <50
<0.5
0.091
60
0.051
0.41
0.7
Notes:
<- Not Deteced, value is the reporting limit.
ug/L- Microgram per liter.
Haley & Aldrich, Inc.
Table B3.2_Facility Bkg Data.xlsx April 2016

37
Page 1 of 1
Table 63-3
Background Data Statistical Evaluation
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
1 2 3 4 5 6 1 7 8 9 10 11 1 12 1 13 1 14 15 16 17
Regional Background Evaluation
ug/L- Microgram per liter.
BTV - Background Threshold Value.
UPLs- Upper Prediction Limits.
KM - Kaplan -Meier Method.
UTLs - Upper Tolerance Limits.
NA - Not Available.
UTLs - Upper Tolerance Limits.
RL - Reporting Limit.
WH -Wilson Hilferty Transformation.
Variable
Units
Frequency of
Detection
Percent
Non-
Detects
Range of Non-
Detects
KM Mean
KM
Variance
KM Standard KM Coefficient
Deviation of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Outlier
Presence*
Outlier
Removed
Distribution
BTV
Method
Barium
ug/L
9 / 11
18%
5
5
31.93
1523
39.03
1.222
11
99.5
119
No
No
Gamma
126.8
95% Approx. Gamma UPL WH and KM
Boron
ug/L
0 / 11
100%
5
50
NA
NA
NA
NA
50
50
NA
NA
No
NA
50
Maximum RL
Cobalt
ug/L
1 / 11
91%
0.5
1
0.525
0.00188
0.0433
0.0825
1
1
0.6
NA
No
NA
0.6
Maximum Detect
Hexavalent Chromium
ug/L
5 / 6
17%
0.03
0.03
0.567
1.186
1.089
1.922
0.0915
2.288
3
Yes
No
Gamma
2.2
95% Gamma KM USL WH
Iron
ug/L
7 / 11
36%
10
SO
161
56487
237.1
1.476
50
589.5
790
Yes
No
Normal
610.9
95%KM UPL
Lead
ug/L
7 / 11
36%
0.1
1
7.585
432.4
20.79
2.742
1
39.09
73.2
Yes
No
Gamma
29.57
95%Approx. Gamma UPL WH and KM
Nickel
ug/L
2 / 11
1 82%
0.5
5
1.35
1 1.043
1.021
0.756
5
1 5
3
No
No
NA
3
1 Maximum Detect
Vanadium
ug/L
8 / 11
1 27% 1
0.3
1
1 1.304
1 1.529 1
1.237
0.948 1
1
1 3.415
4.89
Yes
I No I
Gamma
1 3.606
95% Approx. Gamma UPL WH and KM
Facility Specific Background Evaluation
ug/L- Microgram per liter.
BTV - Background Threshold Value.
UPLs- Upper Prediction Limits.
KM - Kaplan -Meier Method.
UTLs - Upper Tolerance Limits.
NA - Not Available.
UTLs - Upper Tolerance Limits.
RL - Reporting Limit.
WH -Wilson Hilferty Transformation.
Variable
Units
Frequency of
Detection
Percent
Non-
Detects
Range of Non-
Detects
KM
KM Mean Variance
KM Standard KM Coefficient
Deviation of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Outlier
Presence*
Outlier
Removed
Distribution
BTV
Method
Barium
ug/L
51
/ 51
0%
NA
8.157
42.53
6.522
0.8
6.8
12
51
Yes
Yes
Lognormal
16.98
95%UTL with 95% Coverage
Boron
ug/L
3
/ 51
94%
0.05
50
24.01
200.9
14.17
0.59
50
50
37
NA
No
NA
37
Maximum Detect
Cobalt
ug/L
11
/ 27
59%
0.5
1
0.445
0.253
0.503
1.132
0.5
1.74
2
Yes
No
Gamma
1.167
95% Approx. Gamma UPL WH and KM
Hexavalent Chromium
ug/L
15
/ 17
12%
0
0.02
0.194
0.038
0.195
1.002
0.12
0.62
0.7
No
No
Gamma
0.766
95% Approx. Gamma UPL WH and KM
Iron
ug/L
51
/ 51
01.
NA
213.3
103560
321.8
1.509
100
778.5
1900
Yes
Yes
Lognormal
1022
95%UTL with 95% Coverage
Lead
ug/L
22
/ 51
57%
0.1
1
0.198
0.114
0.338
1.705
1
1.13
1.5
Yes
Yes
Distribution free
1.15
95%UTL
Nickel
ug/L
27
/ 29
1 7% 1
5
5
1.715
1 2.096
1.448
0.844 1
1.2
1 5
5.2
No
No I
Gamma 1
4.838
95% Approx. Gamma UPL WH and KM
Vanadium
ug/L
20
/ 25
1 20% 1
1
1
2.009
1 7.114
2.667
1.328 1
1
1 7.88
9
No
No I
Distribution free 1
9
1 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.
UTLs - Upper Tolerance Limits.
RL - Reporting Limit.
WH -Wilson Hilferty Transformation.
BTV values and statistics were calculated using ProUCL v. 5.0.00
Haley & Aldrich, Inc.
Table B3-3_Background E.1l ion_B.1e Cre kA. April 2016

38
Page 1 of 1
Table 63-4
Comparison of NCDEQ Water Supply Well Sampling Data to Regional Background Threshold Values
Belews Creek 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
31 / 34
0.46 - 37.7
7.19
0.818
1.975
4.75
9.475
12.49
126.8
0
Boron
ug/L
3 / 34
12.2 - 22.5
18.9
5
5
5
5
24.25
50
0
Cobalt
ug/L
4 / 34
0.03 - 4.3
1.308
0.5
0.5
0.5
0.5
0.937
0.6
2
Hexavalent Chromium
ug/L
11 / 34
0.037 - 2.1
0.396
0.03
0.03
0.03
0.143
0.587
2.2
0
Iron
ug/L
13 / 34
15.2 - 8500
1250
50
50
50
234.5
1300
610.9
4
Lead
ug/L
31 / 34
0.1 - 4.5
1.008
0.133
0.343
0.645
1.2
2.196
29.57
0
Nickel
ug/L
12 / 34
0.29 - 15
2.256
0.5
0.5
0.5
0.828
2.17
3
1
Vanadium
ug/L
7 / 34
0.4 - 23.5
4.911
0.43
1
1
1
1.49
3.606
2
Notes:
BTV - Background Threshold Value.
DEQ- Department of Environmental Quality.
NC - North Carolina.
ug/L - micrograms/liter.
(a) - Frequency of Detection: number of detects / total number of results.
(b) - BTV values shown on Table 63-3.
Haley & Aldrich, Inc.
Table 133-4 NCDEQ Water Supply Well Data Compared to Regional BTVs.xlsx April 2016

39
Page 1 of 1
Table 63-5
Comparison of NCDEQ Water Supply Well Sampling Data to Facility Specific Background Threshold Values
Belews Creek 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
31 / 34
0.46 - 37.7
7.19
0.818
1.975
4.75
9.475
12.49
16.98
3
Boron
ug/L
3 / 34
12.2 - 22.5
18.9
5
5
5
5
24.25
37
0
Cobalt
ug/L
4 / 34
0.03 - 4.3
1.308
0.5
0.5
0.5
0.5
0.937
1.167
1
Hexavalent Chromium
ug/L
11 / 34
0.037 - 2.1
0.396
0.03
0.03
0.03
0.143
0.587
0.766
1
Iron
ug/L
13 / 34
15.2 - 8500
1250
50
50
50
234.5
1300
1022
4
Lead
ug/L
31 / 34
0.1 - 4.5
1.008
0.133
0.343
0.645
1.2
2.196
1.15
9
Nickel
ug/L
12 / 34
0.29 - 15
2.256
0.5
0.5
0.5
0.828
2.17
4.838
1
Vanadium
ug/L
7 / 34
0.4 - 23.5
4.911
0.43
1
1
1
1.49
9
1
Notes:
BTV - Background Threshold Value.
DEQ- Department of Environmental Quality.
NA - Not Available.
NC - North Carolina.
ug/L - micrograms/liter.
(a) - Frequency of Detection: number of detects / total number of results.
(b) - BTV values shown on Table 63-3.
Haley & Aldrich, Inc.
Table 133-5 NCDEQ Water Supply Well Data Compared to Facility Specific BTVs.xlsx April 2016

Table B4-1
Hydrostratigraphic Layer Properties - Horizontal Hydraulic Conductivity
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Hydrostratigraphic Unit
N
Geometric Mean
(cm/sec)
Geometric Mean +
1SD (cm/sec)
Geometric Mean -
ISD (cm/sec)
Geometric Median
(cm/sec)
Minimum (cm/sec)
Maximum (cm/sec)
Ash
12
1.0E-03
2.5E-03
4.2E-04
7.6E-04
3.3E-04
4.2E-03
Fill
14
4.8E-05
1.7E-04
1.3E-05
6.4E-05
5.4E-06
3.9E-04
M1
28
1.9E-04
1.1 E-03
3.5E-05
2.1 E-04
4.7E-06
3.8E-03
M2
7
8.9E-05
2.5E-04
3.2E-05
9.7E-05
2.7E-05
6.2E-04
Transition Zone (TZ)
16
3.4E-04
4.8E-03
2.4E-05
1.5E-04
4.2E-06
4.8E-02
Bedrock (BR)
48
9.1 E-05
1.1E-03
7.8E-06
9.6E-05
5.2E-07
3.1 E-02
Notes:
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.
Dataset derived from CSA Investigation and historical reports. Refer to tables 11-3, 11-5 and 11-7 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)
Page 1 of 1
40

Table B4-2
Estimated Groundwater Seepage Velocities
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Well Pair
Ash
Fill
Alluvium
M1
M2
TZ5
TZ10
BR
Regolith (S wells); Seepage Velocity (ft/year)
GWA-8S / MW -200S 131.6
9.6
25.8
9.1
AB -7S / AB -5S 13.6
1.0
2.7
0.9
GWA-5S / MW -103S 113.4
8.3
22.3
7.9
GWA-9S / GWA-11S 27.2
2.0
5.3
1.9
GWA-5S / MW -200S 149.7
11.0
29.4
10.4
Transition Zone (D Wells); Seepage Velocity (ft/year)
GWA-81D / MW -200D
-
-
-
204.2
102.1
AB -91D / AB -51D
14.1
7.0
GWA-7D / AB -61D
98.6
49.3
GWA-91D / GWA-11 D
42.2
21.1
GWA-51D / MW -200D
225.3
112.6
BG -1 D / MW -200D
225.3
112.6
GWA-12D / MW -202D*
1196.8
598.4
Fractured Bedrock (BR Wells); Seepage Velocity (ft/year)
Not enough data to determine hydraulic gradient in Bedrock
Notes:
1. Refer to Table 11-10 for horizontal hydraulic conductivity values.
2. Refer to Table 6-9 for horizontal hydraulic gradients.
3. Refer to Tables 11-9 and 11-12 for effective porosity/specific yield for upper and lower hydrostratigraphic units, respectively.
4. Alluvium (S) was not encountered in any of the new boreholes or historic boreholes in the area of the BCSS ash basin
5. TZ subscripts indicate effective porosities used
Page 1 of 1
41

Table 65-1
Site -Specific Distribution Coeffiucient (Kd)
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Constituent
Minimum (L/kg)
Mean (L/kg)
Maximum (L/kg)
Antimony
2.24E-05
4.56E-04
2.91E-03
Arsenic
7.41E+02
1.37E+05
4.68E+06
Boron
4.06E-02
4.12E-01
8.07E+00
Barium
2.73E-06
1.43E-05
5.07E-05
Beryllium
5.99E+03
2.18E+04
6.88E+04
Cobalt
2.17E-01
1.70E+00
6.22E+00
Chromium
2.35E+06
1.08E+07
3.90E+07
Iron
3.16E-02
2.28E-01
1.02E+00
lead
1.62E+02
7.94E+02
2.70E+03
Manganese
1.26E-02
6.97E-02
2.51E-01
Nickel
9.88E-02
5.81E-01
2.31E+00
Selenium
1.16E+01
3.87E+02
5.70E+03
Sulfate
3.16E+00
1.17E+02
8.91E+04
Thallium
NA
NA
NA
Vanadium
I 3.84E+01
I 1.68E+04
I 3.50E+05
Notes:
L/kg - Liters per kilogram.
NA - Not Available.
Table adopted from Appendix E of the CAP -2 Report by HDR.
Haley & Aldrich, Inc.
Tables B5-1 and B5-2.xlsx
Page 1 of 1
April 2016
42

Table 65-2
Coal Ash Indicator Concentrations Observed in the Water Supply Wells of Low Oxygen and High Detected Boron Concentrations
Belews Creek Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
BTV - Background Threshold Value
µg/L = Micrograms per liter.
(a) - The water supply wells contain boron concentrations higher than 5 µg/l_ or dissolved oxygen less than 4,000 µg/l_ with
a boron non -detect at a reporting limit higher than pg/L.
(b) - BTV = background threshold value in the unit of pg/L determined from the facility background well data.
(c) - Sulfate threshold concentration is defined as the maximum sulfate concentration detected in a background monitoring well.
Haley & Aldrich, Inc.
Tables 65-1 and B5-2.xlsx
Page 1 of 1
April 2016
43
Dissolved
Sulfate
Water Supply Well (a)
Oxygen
Boron (µg/L)
Boron BTV
Sulfate
Threshold
(µg/L) (b)
(µg/L)
(µg/L)
(µg/L) (c)
BC2
< 100
< 100
9,070
BC7
< 100
< 25
9,190
BC8
7,310
22
37
8,400
24,500
BC13
650
22.5
18,700
BC28
50
12.2
5,000
Notes:
BTV - Background Threshold Value
µg/L = Micrograms per liter.
(a) - The water supply wells contain boron concentrations higher than 5 µg/l_ or dissolved oxygen less than 4,000 µg/l_ with
a boron non -detect at a reporting limit higher than pg/L.
(b) - BTV = background threshold value in the unit of pg/L determined from the facility background well data.
(c) - Sulfate threshold concentration is defined as the maximum sulfate concentration detected in a background monitoring well.
Haley & Aldrich, Inc.
Tables 65-1 and B5-2.xlsx
Page 1 of 1
April 2016
43

VIRGINIA
L i, I I III i
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i
1
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NOTES

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NOTES
BELEWS LAKE
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F)l
DATE
TWO MEDIUM GROUNDWATER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC 134-1
SOIL
Regolith
ONE'
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unsaturated
unsaturated
none
Water table
REGOLITH
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RESIDUUM
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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 134-1

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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 B4_2

WELL
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DATE
REGOLITH AS PRIMARY APRIL 2016
GROUNDWATER STORAGE
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC 34-3

J
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,LEACHATE4
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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 34-4

O
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• • •• A
• • •
•
•
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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 BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
r
FEZ
STOKES 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
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
- - - LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
NR - NO READING
DATE
APRIL 2016
FIGURE
B4-5

DUKE ENERGY rl �
e
iwl Inn 0 n K�ffg
Q�9 D
ENERGY
PROPERTY
e �
9�D.
X147.
7477a�3'
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O
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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.
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.
500 0 500 1,000
SCALE (FEET)
QELEM,% LAKE
Cif MalrIOa 729 F4
QAPPROO KOHME)
FEZ
STOKES 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
ASH BASIN COMPLIANCE BOUNDARY
_ ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
— — — LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
NR - NO READING
DATE
APRIL 2016
FIGURE
B4-6

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MW203BR
7mm
Al
• AB
75�
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N LOOP ROAD
•
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o °
HODDLEM9 LOOP ROAD °
0
r cs ^v
° l'" vs
DUKE
0 ENERGY
0 PROPERTY
RTY
G!��lr SIF
Y5-
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.
I
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.
•
��
DUKEENERGY
� 1
It
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
\�
PROPERTY
RTY r
DUKE
��
v
ENERGY
ROPE RTY
,�
MW203BR
7mm
Al
• AB
75�
• •
N LOOP ROAD
•
PINE HALL
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• N�K
• FGY GWA-12BR
• • 0 0 • • •• PROPERTY 771.35'
•
• •
O J °
o °
HODDLEM9 LOOP ROAD °
0
r cs ^v
° l'" vs
DUKE
0 ENERGY
0 PROPERTY
RTY
G!��lr SIF
Y5-
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.
SCALE
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007.
(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
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
QELE /MSLMC
ELEVXTIOO N 720 P4
QQPPGROO K(I[I T D
FEZ
STOKES COUNTY, NORTH CAROLINA
LEGEND
- APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
GROUNDWATER CONTOUR LINE
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
- - - DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
- - - LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
NR - NO READING
DATE
APRIL 2016
FIGURE
B4-7

.� m w, -. �� Y e. g I DC CHCGRC�r(
PROPERTY
tic
DUKE
EHE RGY
PROPERTY RTY a
' 1 1 AIN BANN
A.
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1
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o
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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.
SCALE
6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE, DATED 2007.
(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 BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
DOLES (LAME
GILEVA400H 726 P4
QAPP6ROAHMATE)
FEZ
.t�
STOKES 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
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
- - - LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
DATE
APRIL 2016
FIGURE
B4-8

DUKE ENERGY 11.
PROPERTY
PW v AMD D 7m o
°,
°
O
01 %7�lJx�J e
7J
O
MODLE70,H LOOP ROAD
0
o
0 00 0 00
o ibm" 0
DUKE ENERGY
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 �,���
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 BYAMEC FOSTER WHEELER, DATED MAY 29, 2015
FEZ
STOKES 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
ASH BASIN COMPLIANCE BOUNDARY
_ ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
- - - LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
NOTE:
ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
DATE
APRIL 2016
FIGURE
B4-9
DUKE -
ENERGY e
,;;:
1 /
AM
1 U al:JoV J
1 q 1
WA -1
o I D
M79
PW v AMD D 7m o
°,
°
O
01 %7�lJx�J e
7J
O
MODLE70,H LOOP ROAD
0
o
0 00 0 00
o ibm" 0
DUKE ENERGY
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 �,���
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 BYAMEC FOSTER WHEELER, DATED MAY 29, 2015
FEZ
STOKES 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
ASH BASIN COMPLIANCE BOUNDARY
_ ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
- - - LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
NOTE:
ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
DATE
APRIL 2016
FIGURE
B4-9

DUKE
`y
It
PROPERTY
RTY r
[roll 'v o e a
_Weu tpfS. nn nwfe \\ .. _ _
0
0 0
On,
0 0 00 0 HdDDDD[LE'TCDD LOOOOPO00 0O , 'GdOG°QD
0 00 0 0° 'bI—--PROPEG14S'l` J
O
O r, '
O
O f
o °
i
HODDLEM9 LOOP ROAD 0
0
0',
DUKE
IENERGY
o PROO PC PTY
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. 5OO 5OO �, ���
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.0107 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
FEZ
BELEMS LME
E LEVXTIOO H 720 P4
QQPPROO KOMT D
LEGEND
- APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
Groundwater Contour Line
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY COINCIDENT
WITH DUKE ENERGY PROPERTY BOUNDARY
ASH BASIN WASTE BOUNDARY
— — — DUKE ENERGY PROPERTY BOUNDARY
LANDFILL COMPLIANCE BOUNDARY
— — — LANDFILL FACILITY BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
STREAM
_ NOTE:
r, 1)ARTESIAN FLOW OBSERVED AT MW-200BRAND
TOP OF CASING USED AS AN APPROXIMATE WATER LEVEL.
if
Y s'_ 2) ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
41 $?
STOKES COUNTY, NORTH CAROLINA
DATE
APRIL 2016
FIGURE
B4-10

�
DATE
NOTES: HORIZONTAL HYDRAULIC CONDUCTIVITY
1. ONLY SITE-SPECIFIC, IN-SITU MATERIAL REPRESENTED IN THIS FIGURE. APRIL 2016
2. REFER TO TABLE B4-1 FOR ADDITIONAL INFORMATION. MEASUREMENTS
F)lWATER SUPPLY WELL EVALUATION FIGURE
�
x
f
Horizontal Hydraulic
Conductivity for Native
Hydrostratigraphic
Layers NT= 99
I
1.00E-01
f --
1 -DOE -02 .
V
x
1.00E-03
1AQE-04
V
.7
=
1.00E-05
O
x
1.00E-06
LACE
-07
M1 (N=28)
M2 (N= 7)
TZ (N=16)
BR (N=48
1.9E-04
8.9E-05
3.4E-04
9.1E-05
�
DATE
NOTES: HORIZONTAL HYDRAULIC CONDUCTIVITY
1. ONLY SITE-SPECIFIC, IN-SITU MATERIAL REPRESENTED IN THIS FIGURE. APRIL 2016
2. REFER TO TABLE B4-1 FOR ADDITIONAL INFORMATION. MEASUREMENTS
F)lWATER SUPPLY WELL EVALUATION FIGURE
�
x
f
I
X
f --
DUKE ENERGY CAROLINAS, LLC B4-11

00
00
►►00 ���' sem.
00 00 ►►�
�•� ►00wo
►►►
'r .
r �
W(Do L)
t
Lada
1
O 1 -
O 00 Of
0 0 0 0 1
° 0 0001fb1
0
3
.
O
CJ �
�µ .y'r
M . J
,W2
500 0 500 1, 000
I
rD 1
O i
.o
LEGEND:
O
L ---
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
COINCIDENT WITH DUKE ENERGY PROPERTY
BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
= LANDFILL COMPLIANCE BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
3
i
_ NOTES:
SITE CONCEPTUAL MODEL - PLAN VIEW MAP
AREA OF BORON EXCEEDANCES OF 2L STANDARDS
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
BELEWS STEAM STATION ASH BASIN
11
1
00
00
►►00 ���' sem.
00 00 ►►�
�•� ►00wo
►►►
'r .
r �
W(Do L)
t
Lada
1
O 1 -
O 00 Of
0 0 0 0 1
° 0 0001fb1
0
3
.
O
CJ �
�µ .y'r
M . J
,W2
500 0 500 1, 000
I
rD 1
O i
.o
LEGEND:
O
L ---
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
COINCIDENT WITH DUKE ENERGY PROPERTY
BOUNDARY
ASH BASIN WASTE BOUNDARY
DUKE ENERGY PROPERTY BOUNDARY
= LANDFILL COMPLIANCE BOUNDARY
STRUCTURAL FILL, ASH LANDFILL -EDGE OF
WASTE
3
i
_ NOTES:
SITE CONCEPTUAL MODEL - PLAN VIEW MAP
AREA OF BORON EXCEEDANCES OF 2L STANDARDS
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
BELEWS STEAM STATION ASH BASIN
11

Q Q NINE HALL ROAD
w
Jo
mz
v}
zm
��
QQ
00
o m
0
m z
�m
00
0m
GWA-12S
GWA-12D
GWA-12BR
_ GWA-8S
_- -7
GWA-8D
ASH BASIN DAM
PWR/TZ
AB -9D
APPROXIMATE EXTENT
AB -9S
OF 2L EXCEEDANCES
--
AB -98R AB -Bs
AB -SSL
A13 -8D
AB -5S OF BORON
AB -SSL
GTB
AND/OR TOTAL AB-2AB-2D
DISSOLVED SOLIDS
\
AB -5D
—�--
ACTIVE J,
ASH BASIN
EGOLITH
-
_ MW-1025
-------� _ - y M MW -102D
w_
MWD
O
MW -2006R
�
BEDROCK
A
CROSS SECTION
BELEWS CREEK ACTIVE ASH BASIN LEGEND
(LOOKING WEST)
ASH BASIN SURFACE
WATER
ASH
REGOLITH
PARTIALLY WEATHERED ROCK/TRANSITION
ZONE (PWR/TZ)
BEDROCK
I TOTE:
FILL
1. TRANSECT AA' FROM FIGURE 1 1 1 IN
THE CSA REPORT
USED FOR CROSS—SECTION SHOWN ABOVE.
APPROXIMATE EXTENT
OF 2L STANDARD
DRAWING NOT TO SCALE AND IS INTENDED
FOR LLUSTRATION
PURPOSES ONLY.
r (700 ,pg/L) EXCEEDANCES
of BORON
2. APPROXIMATE EXTENT OF 2L STANDARD
EXCEEDANCES OF
BORON IN GROUNDWATER
BASED ON RESULTS FROM IN GROUNDWATER
2015 ROUND 2 SAMPLING EVENT,
APPROXIMATE GROUNDWATER
3.. THE CLOSEST WATER SUPPLY WELL IS
LOCATED —1,200
NORTHEAST OF TRANSECT
AA'.
FLOW DIRECTION
CROSS-SECTION CONCEPTUAL SITE MODEL
DATE
WATER SUPPLY WELL EVALUATION
APRIL 2016
DUKE ENERGY CAROLINAS, LLC
DELEWS CREEK STEAM STATION ASH BASIN
FIGURE
STOKES COUNTY, NORTH TAROUN,-
B4 13

F)l
R chaff +G
Aject I W
(Ran e )
Tr
w
L
eit+cal Per olctlor)
�
Ground level
InItiol water level
DATE
MOUNDING EFFECT APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC B4-14

i # r
r
A 1M'im Ta1#"�-
11
1
'i iAI ik 'A -A
=t+� tiz.4MR0�ir�UYiORl�+st*,rlw{► . 7F*fJ°a.
ggromm
F)l
b! PLAN VIEW
LEGEND
0 Pumovew"t
--- ems' 1-orL Irwin
GFound waar' Di% a.
r!go* Lw*
r
l
70 go 90
HEAD If Th
w0
110 1a* 110 100
Z;, z 011 dor at we".
Zom of coalwoburron to 00 Mill
Worm- ToW
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 B4-15
4
M
�
�
w
i
A
o
w
r
Ar
�
a
4
F)l
b! PLAN VIEW
LEGEND
0 Pumovew"t
--- ems' 1-orL Irwin
GFound waar' Di% a.
r!go* Lw*
r
l
70 go 90
HEAD If Th
w0
110 1a* 110 100
Z;, z 011 dor at we".
Zom of coalwoburron to 00 Mill
Worm- ToW
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 B4-15

NOTES:
1. WASTE BOUNDARY IS APPROXIMATE.
2. AERIAL PHOTOGRAPHY WAS OBTAINED FROM NC ONE MAP CURRENT ORTHOGRAPHY.
3. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND
IN 15A NCAC 02L.01 07 (a).
4. DUKE ENERGY OWNS AND OPERATES THE CATAWBA-WATEREE PROJECT (FEDERAL
ENERGY REGULATORY COMMISSION (FERC) PROJECT NO. 2232). LAKE WYLIE RESERVOIR
IS PART OF THE CATAWBA-WATEREE PROJECT. ADJACENT TO THE ALLEN SITE, DUKE ENERGY
OWNS ALL OF THE PROPERTY WITHIN THE FERC PROJECT BOUNDARY WITH THE EXCEPTION
OF ONE PARCEL LOCATED EAST OF THE ASH BASIN. DUKE ENERGY HAS WATER RIGHTS FOR
THE PARCEL. THE LOCATION OF THE COMPLIANCE BOUNDARY AS DRAWN REFLECTS THE
DUKE ENERGY PROPERTY OWNERSHIP.
500 0 500
SCALE (FEET)
1, 000
L
T-7
11
LEGEND:
ZONE OF AQUIFER THAT CONTRIBUTED GROUNDWATER
TO THE PUMPED WELL DURING THE TIME PERIOD
MODELED
WELL CAPTURE ZONE UNAFFECTED BY MODEL
NO -FLOW BOUNDARY
WELL CAPTURE ZONE AFFECTED BY MODEL
NO -FLOW BOUNDARY
EXTENT OF MODEL GRID
APPROXIMATE GROUNDWATER FLOW
DIRECTION
0.5 MILE OFFSET FROM ASH BASIN
COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
COINCIDENT WITH DUKE ENERGY PROPERTY
BOUNDARY
ASH BASIN WASTE BOUNDARY
LANDFILL/STRUCTURAL FILL BOUNDARY
PINE HALL ROAD ASH LANDFILL COMPLIANCE
BOUNDARY
- - - DUKE ENERGY PROPERTY BOUNDARY
O WATER SUPPLY WELLS
NOTES:
Since water supply wells are located near the model grid boundary where cells are
naturally thin, MODPATH particles encountered cells that violate a minimum cell
thickness requirement. This produced early termination of particles prior to 41 years
The edge of the model grid is represented as a no -flow boundary, and as a result the
capture zones for water supply wells that are closest to the boundary are affected as
water does not flow across the boundary. The well capture zone for water supply well
#34 is not shown in the figure due to the model boundary effects. The well capture
zones for this well and other nearby water supply wells will be evaluated in the future
when the model grid is expanded to include the wells and the groundwater flow model
is updated.
The analysis presented is based on the CAP2 model that is calibrated to steady-state
flow conditions. Average constant pumping rates and average constant groundwater
recharge rates are assumed.
The particle tracks and travel time calculations are based on advective groundwater
flow and other transport processes such as adsorption are not included in the
calculations.
Based on receptor well survey responses and publically available technical literature
in the Piedmont of North Carolina, it is assumed that the water supply wells are
installed in bedrock.
WATER SUPPLY WELL CAPTURE ZONES DATE
WATER SUPPLY WELL EVALUATION APRIL 2016
DUKE ENERGY CAROLINAS, LLC FIGURE
BELEWS CREEK STEAM STATION ASH BASIN
B4-16
STOKES COUNTY, NORTH CAROLINA

1.0
D.
W
Q-
-a
IRON
F
FeCIH
0217 0 21 RTM
e(�Hl
� Fc({7H)3{aj
Fe o
Q 13 O ^i H
O
CH4(9) > 1 CIA)8(5
00O3
�2 4 6 8 10 12
pH
NOTE
DIAGRAMS ADOPTED FROM APPENDIX E OF THE CAP -2
REPORT FOR BELEWS CREEK STEAM STATION BY HDR.
1.0
0.5
W
0.0
MANGANESE
02)9) > 021 atrn
Ryrolusi�'�
MnL" t t,
v o
Q D
tl
R h o6x h rositc(3)
—0-51
0 G 11 1 I 1 :. I
2 4 6 8 10 12
pH
❑ S"hellaw
0 Deep
* Bedrock
i * Upgradiord
* Source
O Downgradi$nt

Panel (a): Example Box Plot
a Possible Outlier
NOTES
1. BOX PLOT EXPLANATION DIAGRAM ADOPTED FROM
HTTP://SITES.GOOGLE.COM/SITE/DAV I DSSTATISTICS/HOME/
NOTCHED -BOX -PLOTS.
2. PIPER PLOT ADOPTED FROM CSA REPORT FOR
MARSHALL STEAM STATION BY HDR.
Panel (b): Example Piper Plot
♦ Mh Bas[n Porewaler
Ash Banin Water
R2 ♦ A11'BR' Wells
2
ANIONS
Upper Whiskers
751h (Percentile
aka 3fd Quartile
.
The "Notch"
55% Confidence Interval of . •.
: Interquartile (IOR)
the Median
i 150 Percent of Datal
MWian +1- 157 x IORln0.5 .
25th Percentile
aka tst Quamle
Lower Whiskers
NOTES
1. BOX PLOT EXPLANATION DIAGRAM ADOPTED FROM
HTTP://SITES.GOOGLE.COM/SITE/DAV I DSSTATISTICS/HOME/
NOTCHED -BOX -PLOTS.
2. PIPER PLOT ADOPTED FROM CSA REPORT FOR
MARSHALL STEAM STATION BY HDR.
Panel (b): Example Piper Plot
♦ Mh Bas[n Porewaler
Ash Banin Water
R2 ♦ A11'BR' Wells
2
ANIONS

10000000.0
Boron Calcium
1000000.0
100000.0
� Z
J 10000.0
C1
7
C
0
1000.0
C
ao
V
C
O
V 100.0
10.0
1.0
0.1
BELEWS CREEK
Chloride
Sulfate
Total Dissolved Solids
AB FM RBG WSW AB FM RBG WSW AB FM RBG WSW AB FM RBG WSW AB FM RBG WSW
NOTE
ACRONYMS:
AB = ASH BASIN POREWATER WELL
FM = OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL

AI—AHTHnR (RANTRnWFN—nFFIfF PHX
BELEWS
CREEK
1000.00
Barium
Cobalt
100.00
J 10.00
rn
7
C
D
L
V
i
0
U 1.00
•
� •
0.10
=
0.01 AB FM
RBG
WSW
AB FM RBG WSW
NOTE
BELEWS CREEK STEAM STATION
m`
AN
WATER SUPPLY WELL EVALUATION
UICH
ABO ASH BASIN POREWATER WELL
DUKE ENERGY
FM = OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL
BOX PLOT COMPARISON FOR
BARIUM AND COBALT
APRIL 2016 FIGURE 135-4

10000.0 Dissolved Oxygen
1000.0
J 100.0
C1
7
C
O
L
V
C
O
U 10.0
1.0
0.1
BELEWS CREEK
Iron
DISSOLVED
TOTAL
TOTAL
DISSOLVED
Manganese
DISSOLVED DISSOLVED
TOTAL
TOTAL
w 1i
AB 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 REGIONAL BACKGROUND DATA FOR
DISSOLVED OXYGEN.

�o
QPEQ�
I \
I MW200BR
I � �
I ASH BIASIN
I �r
I --J/
♦ A84BR
MW203BR
r
/ AB9BR
/
1
/SBG BR
= PINE HALL ROAD
1 ASH LANDFILL ASH
o I STRUCTURAL
\Q FILL
ec n I
I�
O I MW202BR
R
?,4nTIN LUTHE9014G
L-1
L—_
BELEWS LAKE
BELEWS CREEK
STEAM STATION
LEGEND
NOTES

1,000 1
1 10 100 1,000
Boron Concentration(ug/L)
F3
AAL
■
10,000 100,000
Panel (a)
1,000,000
_____ _
_Ii
■Ash Basin Porewater Well
a
Q Facility Bedrock Well (Downgradient)
0 Facility Berock Well (Side Gradient) ■
c 10o,aoo
0
0 Facility Bedrock Well (Upgradient)
L
Q Regional Background Wells
d
0 ■
[1
10,000
+ ®
C
G+
N
■
1,000 1
1 10 100 1,000
Boron Concentration(ug/L)
F3
AAL
■
10,000 100,000
1,000
1 10 100 1,000
Boron Concentration(ug/L)
Panel (b)
1,000,000
_____ _
_Ii
■ Ash Basin Porewater Well
a
O Facility Bedrock Well (Down gradient)
0 Facility Berock Well (Side Gradient) ■
3.
0 Facility Bedrock Well (Upgradient)
c 100,000
0
Q Regional Background Wells
L
d
+ ®
C
�• ■
10,000
900
U
Q ■
1,000
1 10 100 1,000
Boron Concentration(ug/L)
NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND SULFATE ARE PLOTTED
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS BC2, BC4, BC6, BC7,
BC7R, BC9, AND BC21 ARE NOT PLOTTED BECAUSE BORON WAS NOT
DETECTED ATA REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE
FOR THE OTHER SUPPLY WELLS (5 pg/L). THE SULFATE CONCENTRATIONS
FOR THIS SUBSET OF WELLS RANGED FROM 2,000 TO 14,000 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, REGIONAL BACKGROUND, AND FACILITY BEDROCK WELLS.
■
A&L
A
10,000 100,000
Panel (c)
1,000,000
_____ _
_Ii
■ Ash Basin Porewater Well i
0 Facility Bedrock Well (Downgradient)
Area 1
a
4 Facility Berock Well (Side Gradient) ,w
■
O Facility Bedrock Well (Upgradient) ■ ,
100,000 -.
* Water Supply Well 1_________—:
°
Q Regional Background Wells
+ ®
C
�• ■
y 10,1100
�
1 1
Area 2
�o
1,000
•-----------
1
10 100 1,000 10,000 100,000
Boron Concentration (ug/I_)
NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND SULFATE ARE PLOTTED
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS BC2, BC4, BC6, BC7,
BC7R, BC9, AND BC21 ARE NOT PLOTTED BECAUSE BORON WAS NOT
DETECTED ATA REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE
FOR THE OTHER SUPPLY WELLS (5 pg/L). THE SULFATE CONCENTRATIONS
FOR THIS SUBSET OF WELLS RANGED FROM 2,000 TO 14,000 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, REGIONAL BACKGROUND, AND FACILITY BEDROCK WELLS.
■
A&L
A
10,000 100,000

NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS BC2, BC4, BC6, BC7, BC7R,
BC9, AND BC21 ARE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED
ATA REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (5 pg/L). THE DISSOLVED OXYGEN CONCENTRATIONS FOR THIS
SUBSET OF WELLS RANGED FROM 100 TO 6,400 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 FACILITY BEDROCK WELLS.
Panel (a)
Panel (c)
10,000
10,000
■ Ash Basin Porewater Well
`3m
0 Facility Bedrock Well (Downgradient)
5,000
a
U Facility Berock Well (Side Gradient)
© Facility Berock Well (Side Gradient)
0 Facility Bedrock Well (Upgradient)
c
0
6,000
0 Fad I ity Bed rock We I I (U pgrad i en t)
u
c
r
4,000
0
lC
0
4,000
c
2,000
0
2,000
•
15
(1110 ■ &A A
0
m
1
1 10 100 1,000 10,000 100,000
4,000
Boron Concentration(ug/L)
NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS BC2, BC4, BC6, BC7, BC7R,
BC9, AND BC21 ARE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED
ATA REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (5 pg/L). THE DISSOLVED OXYGEN CONCENTRATIONS FOR THIS
SUBSET OF WELLS RANGED FROM 100 TO 6,400 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 FACILITY BEDROCK WELLS.
Panel (b)
Panel (c)
10,a0o
10,000
■ Ash Basin Porewater Well
=
0 Facility Bedrock Well (Downgradient)
B4ODO
o
U Facility Berock Well (Side Gradient)
© Facility Berock Well (Side Gradient)
0 Facility Bedrock Well (Upgradient)
c
6,000
0 Fad I ity Bed rock We I I (U pgrad i en t)
a
V
0
4,000
a
0
2,000
a C8
15
(1110 ■ &A A
0
m
1
10 100 1,000 10,000 100,000
4,000
Boron Concentration (ug/L)
NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS BC2, BC4, BC6, BC7, BC7R,
BC9, AND BC21 ARE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED
ATA REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (5 pg/L). THE DISSOLVED OXYGEN CONCENTRATIONS FOR THIS
SUBSET OF WELLS RANGED FROM 100 TO 6,400 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 FACILITY BEDROCK WELLS.
Panel (c)
10,000
r Ash Basin Porewater Well
p Facility Bedrock Well (Downgradient)
8,000
© Facility Berock Well (Side Gradient)
0 Fad I ity Bed rock We I I (U pgrad i en t)
2f
• Water Supply Well
6,000
Area 2 r
k
m
4,000
p
i
i
Q13
2,000
---------_------,
Area 1
iA
0
- --- -- -------
1
10 100 1,000 10,000 100,000
Boron Concentration (ug/L)
NOTES
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS BC2, BC4, BC6, BC7, BC7R,
BC9, AND BC21 ARE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED
ATA REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (5 pg/L). THE DISSOLVED OXYGEN CONCENTRATIONS FOR THIS
SUBSET OF WELLS RANGED FROM 100 TO 6,400 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 FACILITY BEDROCK WELLS.

0
o�
0 00
BC28 Q O O O
O
O
?,4nTIN L UTHER 0146 JR
�o
QPEQ�
I \
I
I ASH BIASIN
I �r
BC2
1
o/
OBC13
LEGEND
BELEWS LAKE
BELEWS CREEK
STEAM STATION
NOTES

(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) �♦
G� ♦ v` �' v� �� ♦ �` ��
A/\ / k X
O `y
\ / ` AB,6S\
100 0 / `AB 0 100 100 0>\ �X; \ 0 100
0") \ i `\ i ' `\ ` O '� `\ i
x \, v ♦ \♦ x \ / �G ♦ \♦
--\/ \ /
♦\ , \ / / \ , \ / \ ♦ / ♦\ , \ / \ / \ , \ / \
------x----4-------'-----x----4- - ------- -F -- -
- - '-----
- --f-
\ — ,\ /\ —�\
0 A 100 100 0 0 V, 100 100 ` 0
100 0 0 100 100 0 0 100
Ca 21 Cr Ca'+ Cl-
CATIONS ANIONS CATIONS ANIONS

(a) Water Supply Wells (b) Water Supply Wells and Up- and Side Gradient Facility Bedrock Wells
EXPLANATION 100 100
0 Water Supply Well EXPLANATION
Water Supply Well
■ Facility Bedrock Well (Upgradient)
vv ❑ Facility Bedrock Well (Sidegradient) vv
v /
Y \ \/ /
0 /\�• i \\ // \ �\ 0 0 �`\ /`� \ 0
100 0A \� 0 100 1000 �� \Y 0 100
/ /\ /
vf
L \ A
— — — /A\ �/
h n
U�
--- \L--- A ___ 2,,-
100
\—/\—/4---� �� ---x---/4---� \ /x �\ 100 —/\ /x� -- �\
0 100 100 0 0 1.00 1.00 � 0
100 0 0 100 100 0 0 100
Ca 21 Cl- Call CI
CATIONS ANIONS CATIONS ANIONS

(a) Ash Basin Porewater and Downgradient Facility Bedrock Wells
EXPLANATION 100
♦ Ash Basin Porewater Well
Facility Bedrock Well (Downgradient) A
&1
x �� \v aux
C)
V
\ /\ /\ /
0
0 \\/ \\> / \\t / \\/
/\
100 0 / \�/ \X \� \ 0 100
\ / A �� \
If
\-- \`--Q��--���--- 100AL \4 \�i \\ \\ \\ i �A
0 100 100
100 0 0 100
Cat+
CATIONS
NOTE
BLUE DIAMOND DEFINES THE GENERAL DATA CLUSTERING
PATTERN OF THE WATER SUPPLYAND UPGRADIENTAND SIDE
GRADIENT FACILITY BEDROCK WELLS.
Cl -
ANIONS
(b) Water Supply Wells and Up- and Side -Gradient Facility Bedrock Wells
EXPLANATION 100
• Water Supply Well
■ Facility Bedrock Well (Upgradient)
❑ Facility Bedrock Well (Sidegradient) v /
\ I
&\ /
x
\� \/ Y
100 0� �v 0 100
---'� --- wk / \ x ---y --- Ifo
100
0 0 100 100 0
100 0 0 100
Cal' Cl -
CATIONS ANIONS

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

BELEWS CREEK 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_loe_code N StDev CI
BG -1D 3 0.039552 (0.0000087, 1482.81)
BG-2BR 3 0.152753 (0.0000338, 5726.78)
BG -2D 3 0.017321 (0.0000038, 649.36)
BG -3D 3 0.023861 (0.0000053, 894.55)
MW-202BR 3 0.020817 (0.0000046, 780.43)
MW -202D 1 0.197990 ( *, *)
Individual confidence level = 99.16670
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.000
3.52 0.038
* NOTE * The graphical summary cannot be displayed because the multiple comparison
intervals
cannot be calculated.
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 -1D
4
0.125000
(0.0084829,
5.4)
BG-2BR
4
0.684957
(0.0542639,
25.4)
BG -2D
4
0.207525
(0.0143089,
8.8)
BG -3D
4
0.264244
(0.0338475,
6.1)
MW-202BR
6
0.679107
(0.0682961,
12.1)
MW -202D
3
0.334863
(0.0000741,
12554.2)
Individual confidence level = 99.1667%
Tests
Test
Method Statistic P -Value

Multiple comparisons — 0.175
Levene 0.73 0.610
Test for Equal Variances: Vanadium - ug/L - T vs sys_loc_code
Multiple comparison intervals for the standard deviation, a = 0.05
BG -1D Multiple Comparisons
P -Value 0.175
Levene's Test
BG-2BR P -Value 0.610
v
p BG -2D
U
U
O
BG -3D
tA
MW-202BR
MW -202D
0 1 2 3 4 5 6 7 8
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 B — Belews Creek
Part 2: 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- Belews Creek (Regional)
Barium (u L) Be= (u L) Cobalt(ug/L)
4
5. 5.0
a 2. 23
0 0. 0.0-
0 20 40 60 80 100 120 30 ZO 30 40 50 0.5 Q6 0.7 0.8 0.9 1.0
H exava lent Chromium (uQ1Q Iron u ead lu L _
T 10
C 4
O1
7
2 2 5
LL
07 0
0.0 0.5 LO 15 A 2.5 3.0 0 Z00 400 600 800 0 10 20 30 40 50 60 70
Nickel u Vanadium u
5.05.0.
2.5 2
0.0 0.
1 2 3 4 5 0 1 2 3 4 5
C
Ol
i
a
Probability Plot of Background Constituents- Belews Creek
Normal - 95% CI (Regional)
99 Barium u 99 Boron u L 99 CobaB u
90 90 90
10 10 10-
1 1 1
-100 0 Im 0 60 120 do 0.8 16
99
90
50
10
1 vwlze�AAIvd4A
<�
-s-aao o o
so
99 Nickel u 99 Vanadium u
50 50
10 10
0 5 30 -4 0 4 xi
s
sao
so 0
-
Histogram of Background Constituents -Belews Creek (Facility)
Barium -u L -T Born -u L -T Cobalt - u L -T
30
40
1
15 20 5
0 0 0-
20 30 40 50 0 la 24 36 48 0.25 0.50 0.75 100 1.25 L50 1.75 2.00
Chromium I -u L -T IrrTJ
on - u L -T Lead - u L -T
T
v
� 4 20 .
OJ
7
y 2 10
LL
0 0 0
0.0 0.1 0.2 0.3 0.4 0.5 06 0.7 0 400 800 1200 16W 0.0 0.3 0.6 0.9 1.2 1.5
Nickel - ug/L - D Vanadium - ug/L-T
10 16
5 8
0:0 L2 a4 3.6 4.8 0 2 4 6 8
Probability Plot of Background Constituents -Belews Creek
Normal - 95% CI (Facility)
99 Barium - u L -T 99, Boron - u L -T 99 Cobah-u L -T
90 90 90
50 50 50 P°"' •P0"
10 10 10-
1
o zo 40 o 40 eaz.4
99Chromium I -u L -T 99 Iron -u L -T 99Lead-u L -T
C
� 90 90 90 P M .ate
>J 50 50 50
a�
to la 10
-
1 1 1 o-v.r .urm
-os 0.0 os o laao z000 o. 1 z
40 90
50 50
10 10
� .... .ate
1
0 4 8
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 B — Belews Creek
Part 3: Belews Regional Background Water Supply Well
Data Outlier Test Statistics
APRIL 2016 U'CH

Attachment B-1: Belews Creek 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 1:35:03 PM
From File WorkSheet.xls
Full Precision OFF
Dixon's Outlier Test for Barium (ug/L)
Number of Observations = 11
10% critical value: 0.517
5% critical value: 0.576
1 % critical value: 0.679
1. Observation Value 119 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.364
For 10% significance level, 119 is not an outlier.
For 5% significance level, 119 is not an outlier.
For 1 % significance level, 119 is not an outlier.
2. Observation Value 2.4 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.034
For 10% significance level, 2.4 is not an outlier.
For 5% significance level, 2.4 is not an outlier.
For 1 % significance level, 2.4 is not an outlier.
Dixon's Outlier Test for Hexavalent Chromium (ug/L)
Number of Observations = 6
10% critical value: 0.482
5% critical value: 0.56
1 % critical value: 0.698
1. Observation Value 3 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.960
For 10% significance level, 3 is an outlier.
For 5% significance level, 3 is an outlier.
For 1 % significance level, 3 is an outlier.
2. Observation Value 0.03 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.003
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 3
4/8/2016

Attachment B-1: Belews Creek 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 = 11
10% critical value: 0.517
5% critical value: 0.576
1 % critical value: 0.679
1. Observation Value 790 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.595
For 10% significance level, 790 is an outlier.
For 5% significance level, 790 is an outlier.
For 1 % significance level, 790 is not an outlier.
2. Observation Value 10 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
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 = 11
10% critical value: 0.517
5% critical value: 0.576
1 % critical value: 0.679
1. Observation Value 73.2 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.977
For 10% significance level, 73.2 is an outlier.
For 5% significance level, 73.2 is an outlier.
For 1 % significance level, 73.2 is an outlier.
2. Observation Value 0.1 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.020
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 Vanadium (ug/L)
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 2 of 3
4/8/2016

Attachment B-1: Belews Creek Regional Background Water Supply Well Data Outlier Test Statistics
Number of Observations = 11
10% critical value: 0.517
5% critical value: 0.576
1 % critical value: 0.679
1. Observation Value 4.89 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.729
For 10% significance level, 4.89 is an outlier.
For 5% significance level, 4.89 is an outlier.
For 1 % significance level, 4.89 is an outlier.
2. Observation Value 0.3 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.237
For 10% significance level, 0.3 is not an outlier.
For 5% significance level, 0.3 is not an outlier.
For 1 % significance level, 0.3 is not an outlier.
Haley & Aldrich, Inc.
Outlier test stats_regional.xlsx
Page 3 of 3
4/8/2016

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix B — Belews Creek
Part 4: Belews Facility Background Monitoring Well Data Outlier Test Statistics
APRIL 2016 U'CH

Attachment B-1: Belews Creek Facility Background Monitoring Well Data Outlier Test Statistics
Outlier Tests for Selected Uncensored Variables
User Selected Options
Date/Time of Computation 4/2/2016 3:27:54 PM
From File WorkSheet a.xls
Full Precision OFF
Rosner's Outlier Test for Barium - ug/L - T
Mean 10.79
Standard Deviation 14.88
Number of data 53
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 10.79 14.74 78 3 4.56 3.151 3.504
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 78
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 78
Rosner's Outlier Test for Cobalt - ug/L - T
Mean 0.63
Standard Deviation 0.474
Number of data 27
Number of suspected outliers 1
Potential Obs.
# Mean sd outlier Number
1 0.63 0.465 2 7
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 2
For 1% Significance Level, there is no Potential Outlier
Dixon's Outlier Test for Chromium (VI) - ug/L - T
Number of Observations = 17
10% critical value: 0.438
5% critical value: 0.49
1 % critical value: 0.577
1. Observation Value 0.7 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.454
Haley & Aldrich, Inc.
Outlier test before removing_facility.xlsx
Test Critical Critical
value value (5%) value (1%)
2.945 2.86 3.18
Page 1 of 3
4/8/2016

Attachment B-1: Belews Creek Facility Background Monitoring Well Data Outlier Test Statistics
Page 2 of 3
For 10% significance level, 0.7 is an outlier.
For 5% significance level, 0.7 is not an outlier.
For 1 % significance level, 0.7 is not an outlier.
2. Observation Value 0 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.098
For 10% significance level, 0 is not an outlier.
For 5% significance level, 0 is not an outlier.
For 1 % significance level, 0 is not an outlier.
Rosner's Outlier Test for Iron - ug/L - T
Mean 480
Standard Deviation 1396
Number of data 53
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 480 1382 7280 3 4.919 3.151 3.504
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 7280
For 1% Significance Level, there is 1 Potential Outlier
Potential outliers is: 7280
Rosner's Outlier Test for Lead - ug/L - T
Mean 0.857
Standard Deviation 1.413
Number of data 53
Number of suspected outliers 1
Potential Obs.
Test Critical Critical
# Mean sd outlier Number
value value (5%) value (1%)
1 0.857 1.399 7.52 3
4.761 3.151 3.504
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 7.52
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 7.52
Rosner's Outlier Test for Nickel - ug/L - D
Mean 1.95
Standard Deviation 1.661
Haley & Aldrich, Inc.
Outlier test before removing_facility.xlsx
4/8/2016

Attachment B-1: Belews Creek Facility Background Monitoring Well Data Outlier Test Statistics
Number of data 29
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 1.95 1.633 5.2 9 1.991 2.89 3.22
For 5% Significance Level, there is no Potential Outlier
For 1% Significance Level, there is no Potential Outlier
Rosner's Outlier Test for Vanadium - ug/L - T
Mean 2.074
Standard Deviation 2.691
Number of data 25
Number of suspected outliers 1
Potential Obs. Test Critical Critical
# Mean sd outlier Number value value (5%) value (1%)
1 2.074 2.636 9 13 2.627 2.82 3.14
For 5% Significance Level, there is no Potential Outlier
For 1 % Significance Level, there is no Potential Outlier
Haley & Aldrich, Inc.
Outlier test before removing_facility.xlsx
Page 3 of 3
4/8/2016

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

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

Attachment B-2: Belews Creek 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 12:54:44 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 0.911 0.87 0.872 0.881
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
11
0
11
9
2
18.18%
Data Not Normal
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
2
5
5
5
5
0
Statistics (Detects Only)
9
2.4
119
38.37
13
42.87
Statistics (All: NDs treated as DL value)
11
2.4
119
32.3
11
40.65
Statistics (All: NDs treated as DL/2 value)
11
2.4
119
31.85
11
41
Statistics (Normal ROS Imputed Data)
11
-25.47
119
28.74
11
44.19
Statistics (Gamma ROS Imputed Data)
11
0.01
119
31.39
11
41.36
Statistics (Lognormal ROS Imputed Data)
11
1.654
119
31.88
11
40.97
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.774
0.59
49.55
2.877
1.44
0.5
Statistics (NDs = DL)
0.726
0.589
44.49
2.647
1.386
0.524
Statistics (NDs = DL/2)
0.65
0.533
49.02
2.521
1.512
0.6
Statistics (Gamma ROS Estimates)
0.349
0.314
90.03
Statistics (Lognormal ROS Estimates)
2.519
1.525
0.605
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.911 0.87 0.872 0.881
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)
0.817
0.829
Data Not Normal
0.279
0.295
Data Appear Normal
0.752
0.85
Data Not Normal
0.319
0.267
Data Not Normal
0.754
0.85
Data Not Normal
0.313
0.267
Data Not Normal
0.869
0.85
Data Appear Normal
0.276
0.267
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO'
Correlation Coefficient R 0.96 0.967 0.966 0.946
Anderson -Darling (Detects Only)
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Test value Crit. (0.05) Conclusion with Alpha(0.05)
0.411 0.751
Page 1 of 7
4/8/2016

Attachment B-2: Belews Creek Regional Background Water Supply Well Data GOF Statistics
Kolmogorov-Smirnov (Detects Only)
0.212
0.289
Detected Data Appear Gamma Distributed
Anderson -Darling (NDs = DL)
0.718
0.764
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.239
0.265
Data Appear Gamma Distributed
Anderson -Darling (NDs = DL/2)
0.688
0.77
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.212
0.267
Data Appear Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
0.346
0.811
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.148
0.274
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.975 0.961 0.953 0.97
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.928
0.829
Data Appear Lognormal
Lilliefors (Detects Only)
0.179
0.295
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.904
0.85
Data Appear Lognormal
Lilliefors (NDs = DL)
0.186
0.267
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.88
0.85
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.163
0.267
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.919
0.85
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.157
0.267
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
14
Iron (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 11 0 11 7 4 36.36%
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
7
10
790
247
145
282.5
11
10
790
168.1
50
245
11
5
790
162.6
25
248.3
11
-524.3
790
36.43
14
376.6
11
0.01
790
157.2
14
251.8
11
0.763
790
158.6
14
250.9
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.683
0.485
361.8
4.621
1.692
0.366
0.588
0.488
285.8
4.071
1.6
0.393
0.499
0.424
325.8
3.819
1.793
0.47
0.195
0.202
806.5
3.286
2.344
0.713
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.922 0.837 0.834 0.835
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 2 of 7
4/8/2016

Attachment B-2: Belews Creek Regional Background Water Supply Well Data GOF Statistics
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.849
0.803
Data Appear Normal
Lilliefors (Detects Only)
0.212
0.335
Data Appear Normal
Shapiro -Wilk (NDs = DL)
0.71
0.85
Data Not Normal
Lilliefors (NDs = DL)
0.314
0.267
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.705
0.85
Data Not Normal
Lilliefors (NDs = DL/2)
0.304
0.267
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.968
0.85
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.118
0.267
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.987 0.991 0.992 0.977
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)
0.252
0.74
0.168
0.324
0.605
0.775
0.24
0.268
0.566
0.781
0.24
0.269
0.604
0.866
0.243
0.282
Conclusion with Alpha(0.05)
Detected Data Appear Gamma Distributed
Data Appear Gamma Distributed
Data Appear Gamma Distributed
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.971 0.959 0.973 0.979
Test value Crit. (0.05)
Shapiro -Wilk (Detects Only)
0.923
0.803
Lilliefors (Detects Only)
0.183
0.335
Shapiro -Wilk (NDs = DL)
0.896
0.85
Lilliefors (NDs = DL)
0.178
0.267
Shapiro -Wilk (NDs = DL/2)
0.925
0.85
Lilliefors (NDs = DL/2)
0.176
0.267
Shapiro -Wilk (Lognormal ROS Estimates)
0.941
0.85
Lilliefors (Lognormal ROS Estimates)
0.154
0.267
Note: Substitution methods such as DL or DU2 are
not recommended.
Lead (ug/L)
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
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 3 of 7
4/8/2016
Num Obs
Num Miss
Num Valid
Detects
NDs
% NDs
Raw Statistics
11
0
11
7
4
36.36%
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
4
0.1
1
0.775
1
0.45
Statistics (Detects Only)
7
0.17
73.2
11.79
1.56
27.13
Statistics (All: NDs treated as DL value)
11
0.1
73.2
7.785
1
21.74
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 3 of 7
4/8/2016

Attachment B-2: Belews Creek Regional Background Water Supply Well Data GOF Statistics
Statistics (All: NDs treated as DL/2 value)
11
0.05
73.2
7.644
0.5
21.79
Statistics (Normal ROS Imputed Data)
11
-32.64
73.2
1.546
0.2
26.55
Statistics (Gamma ROS Imputed Data)
11
0.01
73.2
7.506
0.2
21.84
Statistics (Lognormal ROS Imputed Data)
11
0.0106
73.2
7.556
0.41
21.82
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.334
0.286
35.34
0.436
2.091
4.799
Statistics (NDs = DL)
0.34
0.308
22.87
0.0679
1.811
26.66
Statistics (NDs = DL/2)
0.309
0.286
24.71
-0.184
1.939
-10.53
Statistics (Gamma ROS Estimates)
0.213
0.216
35.17
Statistics (Lognormal ROS Estimates)
-0.714
2.436
-3.414
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.689 0.6 0.6 0.602
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)
0.503
0.803
Data Not Normal
0.456
0.335
Data Not Normal
0.392
0.85
Data Not Normal
0.46
0.267
Data Not Normal
0.391
0.85
Data Not Normal
0.458
0.267
Data Not Normal
0.724
0.85
Data Not Normal
0.358
0.267
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO:
Correlation Coefficient R 0.953 0.901 0.909 0.934
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)
0.789
0.779
0.303
0.334
Detected Data appear Approximate Gamma Distri
1.509
0.812
0.354
0.274
Data Not Gamma Distributed
1.511
0.818
0.329
0.276
Data Not Gamma Distributed
0.973
0.856
0.242
0.281
Detected Data appear Approximate Gamma Distri
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.958 0.944 0.949 0.983
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only) 0.919 0.803 Data Appear Lognormal
Lilliefors (Detects Only) 0.183 0.335 Data Appear Lognormal
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 4 of 7
4/8/2016

Attachment B-2: Belews Creek Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (NDs = DL)
0.905
0.85
Data Appear Lognormal
Lilliefors (NDs = DL)
0.203
0.267
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.918
0.85
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.203
0.267
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.976
0.85
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.114
0.267
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are
not recommended.
4.89
Vanadium (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 11 0 11 8 3 27.27%
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
0.3
1
0.767
1
0.404
8
0.653
4.89
1.607
1.075
1.415
11
0.3
4.89
1.378
1
1.26
11
0.15
4.89
1.273
0.734
1.318
11
-1.287
4.89
1.064
0.734
1.557
11
0.01
4.89
1.211
0.734
1.369
11
0.252
4.89
1.292
0.734
1.304
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
2.234
1.479
0.719
0.234
0.686
2.931
2.077
1.571
0.663
0.0608
0.717
11.8
1.497
1.149
0.851
-0.128
0.901
-7.021
0.655
0.537
1.85
-0.0685
0.805
-11.75
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.831 0.813 0.829 0.837
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)
0.708
0.818
Data Not Normal
0.282
0.313
Data Appear Normal
0.688
0.85
Data Not Normal
0.314
0.267
Data Not Normal
0.712
0.85
Data Not Normal
0.28
0.267
Data Not Normal
0.875
0.85
Data Appear Normal
0.218
0.267
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.942 0.925 0.951 0.977
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 5 of 7
4/8/2016

Attachment B-2: Belews Creek Regional Background Water Supply Well Data GOF Statistics
Anderson -Darling (Detects Only)
0.597
0.723
Data Appear Lognormal
Kolmogorov-Smirnov (Detects Only)
0.244
0.297
Detected Data Appear Gamma Distributed
Anderson -Darling (NDs = DL)
0.614
0.738
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.257
0.258
Data Appear Gamma Distributed
Anderson -Darling (NDs = DL/2)
0.439
0.742
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.186
0.26
Data Appear Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
0.588
0.77
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.218
0.267
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.941 0.96 0.971 0.974
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.883
0.818
Data Appear Lognormal
Lilliefors (Detects Only)
0.205
0.313
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.944
0.85
Data Appear Lognormal
Lilliefors (NDs = DL)
0.208
0.267
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.963
0.85
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.174
0.267
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.961
0.85
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.163
0.267
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are
not recommended.
1.193
Goodness -of -Fit Test Statistics for Data Sets with Non -Detects
User Selected Options
Date/Time of Computation 4/2/2016 1:02:15 PM
From File WorkSheet.xls
Full Precision OFF
Confidence Coefficient 0.95
Hexavalent Chromium (ug/L)
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 6 of 7
4/8/2016
Num Obs
Num Miss
Num Valid
Detects
NDs
% NDs
Raw Statistics
11
5
6
5
1
16.67%
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Detects Only)
5
0.038
3
0.674
0.14
1.301
Statistics (All: NDs treated as DL value)
6
0.03
3
0.567
0.0915
1.193
Statistics (All: NDs treated as DL/2 value)
6
0.015
3
0.564
0.0915
1.195
Statistics (Normal ROS Imputed Data)
6
-1.985
3
0.231
0.0915
1.592
Statistics (Gamma ROS Imputed Data)
6
0.01
3
0.564
0.0915
1.195
Statistics (Lognormal ROS Imputed Data)
6
0.00224
3
0.562
0.0915
1.196
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.448
0.313
1.505
-1.836
1.761
-0.959
Statistics (NDs = DL)
0.422
0.322
1.344
-2.115
1.717
-0.812
Statistics (NDs = DL/2)
0.397
0.31
1.42
-2.23
1.847
-0.828
Statistics (Gamma ROS Estimates)
0.384
0.303
1.467
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 6 of 7
4/8/2016

Attachment B-2: Belews Creek Regional Background Water Supply Well Data GOF Statistics
Statistics (Lognormal ROS Estimates)
Crit. (0.05)
Conclusion with Alpha(0.05)
-2.547 2.348 -0.922
Normal GOF
Test Results
0.41
0.374
No NDs
NDs = DL
NDs = DL/2 Normal ROE
Correlation Coefficient R
0.753
0.713
0.716 0.713
0.821
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.587
0.762
Data Not Normal
Lilliefors (Detects Only)
0.456
0.396
Data Not Normal
Shapiro -Wilk (NDs = DL)
0.534
0.788
Data Not Normal
Lilliefors (NDs = DL)
0.47
0.362
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.538
0.788
Data Not Normal
Lilliefors (NDs = DL/2)
0.469
0.362
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.832
0.788
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.354
0.362
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO;
Correlation Coefficient R 0.968 0.952 0.955 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)
0.776
0.718
0.314
0.41
0.374
Data Not Gamma Distributed
0.968
0.748
Data Appear Lognormal
0.4
0.352
Data Not Gamma Distributed
0.821
0.752
0.89
0.385
0.353
Data Not Gamma Distributed
0.754
0.754
Data Appear Lognormal
0.377
0.353
Detected Data appear Approximate Gamma Distri
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.906 0.894 0.935 0.962
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.828
0.762
Data Appear Lognormal
Lilliefors (Detects Only)
0.314
0.396
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.808
0.788
Data Appear Lognormal
Lilliefors (NDs = DL)
0.283
0.362
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.89
0.788
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.262
0.362
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.951
0.788
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.224
0.362
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Haley & Aldrich, Inc.
GOF test stats_regional.xlsx
Page 7 of 7
4/8/2016

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

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Goodness -of -Fit Test Statistics for Uncensored Full Data Sets without Non -Detects
User Selected Options
0.623
Date/Time of Computation
4/2/2016 3:29:32 PM
From File
WorkSheet a.xls
Full Precision
OFF
Confidence Coefficient
0.95
Barium - ug/L - T
Raw Statistics
0.623
Number of Valid Observations
51
Number of Missing Observations
4
Number of Distinct Observations
28
Minimum
3.1
Maximum
51
Mean of Raw Data
8.157
Standard Deviation of Raw Data
6.522
Khat
4.369
Theta hat
1.867
Kstar
4.125
Theta star
1.977
Mean of Log Transformed Data
1.98
Standard Deviation of Log Transformed Data
0.415
Normal GOF Test Results
Correlation Coefficient R
0.623
Approximate Shapiro Wilk Test Statistic
0.437
Approximate Shapiro Wilk P Value
0
Lilliefors Test Statistic
0.253
Lilliefors Critical (0.05) Value
0.124
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.718
A -D Test Statistic 2.86
A -D Critical (0.05) Value 0.754
K -S Test Statistic 0.148
K -S Critical(0.05) Value 0.125
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.911
Approximate Shapiro Wilk Test Statistic
0.868
Approximate Shapiro Wilk P Value 6.5824E-6
Lilliefors Test Statistic
0.121
Lilliefors Critical (0.05) Value
0.124
Data appear Approximate—Lognormal at (0.05) Significance Level
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Page 1 of 9
4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Iron - ug/L - T
Raw Statistics
0.753
Number of Valid Observations
51
Number of Missing Observations
4
Number of Distinct Observations
34
Minimum
17
Maximum
1900
Mean of Raw Data
213.3
Standard Deviation of Raw Data
321.8
Khat
0.895
Theta hat
238.2
Kstar
0.856
Theta star
249.2
Mean of Log Transformed Data
4.709
Standard Deviation of Log Transformed Data
1.081
Normal GOF Test Results
Correlation Coefficient R
0.753
Approximate Shapiro Wilk Test Statistic
0.597
Approximate Shapiro Wilk P Value 2.220E-16
0.0728
Lilliefors Test Statistic
0.307
Lilliefors Critical (0.05) Value
0.124
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.945
A -D Test Statistic 2.387
A -D Critical (0.05) Value 0.785
K -S Test Statistic 0.23
K -S Critical(0.05) Value 0.128
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.98
Approximate Shapiro Wilk Test Statistic
0.953
Approximate Shapiro Wilk P Value
0.0728
Lilliefors Test Statistic
0.145
Lilliefors Critical (0.05) Value
0.124
Data appear Approximate—Lognormal at (0.05) Significance Level
Cobalt - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 55 28 27 11 16 59.26%
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Page 2 of 9
4/8/2016

Attachment B-2: Belews Creek 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
16
0.5
1
0.563
0.5
0.171
11
0.14
2
0.729
0.33
0.723
27
0.14
2
0.63
0.5
0.474
27
0.14
2
0.464
0.25
0.505
27
-0.506
2
0.495
0.33
0.585
27
0.01
2
0.472
0.28
0.537
27
0.074
2
0.478
0.287
0.513
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
1.236
0.96
0.59
-0.772
0.991
-1.284
2.507
2.253
0.251
-0.674
0.646
-0.958
1.729
1.562
0.268
-1.085
0.693
-0.639
0.831
0.763
0.568
-1.119
0.831
-0.743
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.882 0.85 0.734 0.981
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)
0.76
0.85
Data Not Normal
0.336
0.267
Data Not Normal
0.727
0.923
Data Not Normal
0.386
0.171
Data Not Normal
0.547
0.923
Data Not Normal
0.367
0.171
Data Not Normal
0.908
0.923
Data Not Normal
0.154
0.171
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.94 0.933 0.883 0.979
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)
0.898
0.747
0.296
0.261
Data Not Gamma Distributed
1.87
0.754
0.332
0.17
Data Not Gamma Distributed
4.419
0.76
0.348
0.171
Data Not Gamma Distributed
0.334
0.78
0.0831
0.174
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.942 0.947 0.842 0.976
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Page 3 of 9
4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Chromium (VI) - 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 53 36 17 15 2 11.76%
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)
Number
Test value
Crit. (0.05)
Shapiro -Wilk (Detects Only)
0.865
0.85
Lilliefors (Detects Only)
0.247
0.267
Shapiro -Wilk (NDs = DL)
0.899
0.923
Lilliefors (NDs = DL)
0.29
0.171
Shapiro -Wilk (NDs = DL/2)
0.713
0.923
Lilliefors (NDs = DL/2)
0.335
0.171
Shapiro -Wilk (Lognormal ROS Estimates)
0.948
0.923
Lilliefors (Lognormal ROS Estimates)
0.115
0.171
Note: Substitution methods such as DL or DL/2 are not recommended.
Chromium (VI) - 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 53 36 17 15 2 11.76%
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)
Number
Minimum
Maximum
Mean
Median
SD
2
0
0.02
0.01
0.01
0.0141
15
0.039
0.7
0.22
0.15
0.2
17
0
0.7
0.196
0.12
0.2
17
0
0.7
0.195
0.12
0.2
17
-0.22
0.7
0.169
0.12
0.237
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.899 0.902 0.904 0.906
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R N/A N/A N/A N/A
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Test value Crit. (0.05)
0.33
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.808
0.881
Data Not Normal
Lilliefors (Detects Only)
0.234
0.229
Data Not Normal
Shapiro -Wilk (NDs = DL)
0.815
0.892
Data Not Normal
Lilliefors (NDs = DL)
0.216
0.215
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.818
0.892
Data Not Normal
Lilliefors (NDs = DL/2)
0.215
0.215
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.916
0.892
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.179
0.215
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R N/A N/A N/A N/A
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Test value Crit. (0.05)
0.33
0.753
0.128
0.225
N/A
N/A
N/A
N/A
N/A
N/A
Conclusion with Alpha(0.05)
Detected Data Appear Gamma Distributed
Page 4 of 9
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx 4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Kolmogorov-Smirnov (NDs = DL/2) N/A N/A
Anderson -Darling (Gamma ROS Estimates) N/A N/A
Kolmogorov-Smirnov (Gamma ROS Est.) N/A N/A
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R N/A N/A N/A N/A
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.97
0.881 Data Appear Lognormal
Lilliefors (Detects Only)
0.09
0.229 Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
N/A
N/A
Lilliefors (NDs = DL)
N/A
N/A
Shapiro -Wilk (NDs = DL/2)
N/A
N/A
Lilliefors (NDs = DL/2)
N/A
N/A
Shapiro -Wilk (Lognormal ROS Estimates)
N/A
N/A
Lilliefors (Lognormal ROS Estimates)
N/A
N/A
Note: Substitution methods such as DL or DU2 are
not recommended.
1.5
Lead - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 55 4 51 22 29 56.86%
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
29
0.1
1
0.783
1
0.392
22
0.05
1.5
0.35
0.105
0.482
51
0.05
1.5
0.596
1
0.48
51
0.05
1.5
0.374
0.5
0.346
51
-0.428
1.5
0.223
0.11
0.388
51
0.01
1.5
0.215
0.07
0.354
51
0.0164
1.5
0.213
0.097
0.341
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.749
0.677
0.467
-1.849
1.211
-0.655
0.971
0.927
0.614
-1.114
1.264
-1.135
1.092
1.041
0.342
-1.508
1.127
-0.747
0.574
0.553
0.375
-2.219
1.031
-0.465
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.799 0.866 0.883 0.949
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only) 0.635 0.911 Data Not Normal
Lilliefors (Detects Only) 0.373 0.189 Data Not Normal
Shapiro -Wilk (NDs = DL) N/A N/A
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Page 5 of 9
4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Lilliefors (NDs = DL)
0.329
0.124 Data Not Normal
Shapiro -Wilk (NDs = DL/2)
N/A
N/A
Lilliefors (NDs = DL/2)
0.259
0.124 Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
N/A
N/A
Lilliefors (Normal ROS Estimates)
0.186
0.124 Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.917 0.778 0.936 0.958
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)
2.557
0.783
0.802
0.288
0.193
Data Not Gamma Distributed
6.083
0.781
Data Not Lognormal
0.342
0.128
Data Not Gamma Distributed
3.493
0.778
0.34
0.267
0.128
Data Not Gamma Distributed
2.032
0.808
1.661
0.139
0.131
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.904 0.882 0.919 0.959
Nickel - ug/L - D
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 55 26 29 27 2 6.90%
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)
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Number
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.802
0.911
Data Not Lognormal
Lilliefors (Detects Only)
0.207
0.189
Data Not Lognormal
Shapiro -Wilk (NDs = DL)
N/A
N/A
1.724
Lilliefors (NDs = DL)
0.34
0.124
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
N/A
N/A
1.661
Lilliefors (NDs = DL/2)
0.295
0.124
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
N/A
N/A
0.23
Lilliefors (Lognormal ROS Estimates)
0.123
0.124
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are not recommended.
0.23
Nickel - ug/L - D
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 55 26 29 27 2 6.90%
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)
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Number
Minimum
Maximum
Mean
Median
SD
2
5
5
5
5
0
27
0.23
5.2
1.724
1
1.485
29
0.23
5.2
1.95
1.2
1.661
29
0.23
5.2
1.778
1.2
1.445
29
0.23
5.2
1.718
1.017
1.44
29
0.23
5.2
1.699
1
1.441
29
0.23
5.2
1.685
1
1.443
Page 6 of 9
4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
1.333
1.21
1.293
0.125
0.983
7.871
1.276
1.167
1.529
0.227
1.021
4.495
1.407
1.284
1.264
0.179
0.969
5.399
1.399
1.277
1.214
Not Lognormal
0.121
0.954
7.91
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.929 0.933 0.943 0.883
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)
0.852
0.923
Data Not Normal
0.231
0.171
Data Not Normal
0.851
0.926
Data Not Normal
0.226
0.165
Data Not Normal
0.876
0.926
Data Not Normal
0.207
0.165
Data Not Normal
0.863
0.926
Data Not Normal
0.227
0.165
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.963 0.947 0.964 0.971
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)
0.874
0.766
0.923
0.156
0.172
Detected Data appear Approximate Gamma Distri
0.927
0.768
Not Lognormal
0.15
0.166
Detected Data appear Approximate Gamma Distri
0.835
0.765
0.165
0.173
0.166
Data Not Gamma Distributed
0.776
0.765
Not Lognormal
0.14
0.166
Detected Data appear Approximate Gamma Distri
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.972 0.968 0.971 0.976
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.926
0.923
Data
Appear Lognormal
0.171
0.171
Data
Not Lognormal
0.915
0.926
Data
Not Lognormal
0.176
0.165
Data
Not Lognormal
0.923
0.926
Data
Not Lognormal
0.19
0.165
Data
Not Lognormal
Page 7 of 9
4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Shapiro -Wilk (Lognormal ROS Estimates) 0.934 0.926 Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates) 0.154 0.165 Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are not recommended.
Vanadium - ug/L - T
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.8 0.761 0.762 0.836
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
55
30
25
20
5
20.00%
Data Not Normal
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
5
1
1
1
1
0
Statistics (Detects Only)
20
0.34
9
2.342
0.95
2.961
Statistics (All: NDs treated as DL value)
25
0.34
9
2.074
1
2.691
Statistics (All: NDs treated as DL/2 value)
25
0.34
9
1.974
0.75
2.74
Statistics (Normal ROS Imputed Data)
25
-1.076
9
2.013
0.94
2.768
Statistics (Gamma ROS Imputed Data)
25
0.01
9
1.974
0.82
2.75
Statistics (Lognormal ROS Imputed Data)
25
0.317
9
2.019
0.924
2.719
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.975
0.862
2.403
0.257
1.033
4.017
Statistics (NDs = DL)
1.091
0.987
1.9
0.206
0.925
4.497
Statistics (NDs = DL/2)
0.948
0.861
2.082
0.067
0.997
14.88
Statistics (Gamma ROS Estimates)
0.684
0.628
2.886
Statistics (Lognormal ROS Estimates)
0.122
0.983
8.065
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.8 0.761 0.762 0.836
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)
0.635
0.905
Data Not Normal
0.349
0.198
Data Not Normal
0.58
0.918
Data Not Normal
0.375
0.177
Data Not Normal
0.58
0.918
Data Not Normal
0.359
0.177
Data Not Normal
0.677
0.918
Data Not Normal
0.319
0.177
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.915 0.9 0.909 0.923
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Test value
Crit. (0.05) Conclusion with Alpha(0.05)
2.116
0.769
0.297
0.2 Data Not Gamma Distributed
3.177
0.771
0.354
0.179 Data Not Gamma Distributed
Page 8 of 9
4/8/2016

Attachment B-2: Belews Creek Facility Background Monitoring Well Data GOF Statistics
Anderson -Darling (NDs = DL/2)
3.048
0.775
Kolmogorov-Smirnov (NDs = DL/2)
0.313
0.18 Data Not Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
1.511
0.79
Kolmogorov-Smirnov (Gamma ROS Est.)
0.213
0.182 Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.926 0.906 0.904 0.924
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.848
0.905
Data Not Lognormal
Lilliefors (Detects Only)
0.248
0.198
Data Not Lognormal
Shapiro -Wilk (NDs = DL)
0.816
0.918
Data Not Lognormal
Lilliefors (NDs = DL)
0.308
0.177
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.807
0.918
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.247
0.177
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.846
0.918
Data Not Lognormal
Lilliefors (Lognormal ROS Estimates)
0.229
0.177
Data Not Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Haley & Aldrich, Inc.
GOF test after removing_facility.xlsx
Page 9 of 9
4/8/2016

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

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

Attachment B-3: Belews Creek Regional Background Water Supply Well Data BTVs Statistics
Background Statistics for Data Sets with Non -Detects
User Selected Options
General Statistics
Date/Time of Computation
4/2/2016 1:04:25 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)
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815
Page 1 of 6
Number of Missing Observations
General Statistics
Total Number of Observations
11
Number of Distinct Observations
10
Number of Detects
9
Number of Distinct Detects
9
Minimum Detect
2.4
Maximum Detect
119
Variance Detected
1838
Mean Detected
38.37
Mean of Detected Logged Data
2.877
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815
Page 1 of 6
Number of Missing Observations
0
Number of Non -Detects
2
Number of Distinct Non -Detects
1
Minimum Non -Detect
5
Maximum Non -Detect
5
Percent Non -Detects
18.18%
SD Detected
42.87
SD of Detected Logged Data
1.44
d2max (for USL) 2.234
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.411 Anderson -Darling GOF Test
5% A -D Critical Value 0.751 Detected data appear Gamma Distributed at 5% Significance
Level
K -S Test Statistic 0.212 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.289 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) 0.774 k star (bias corrected MLE)
0.59
Theta hat (MLE) 49.55 Theta star (bias corrected MLE)
65
nu hat (MLE) 13.94 nu star (bias corrected)
10.62
MLE Mean (bias corrected) 38.37
MLE Sd (bias corrected) 49.94 95% Percentile of Chisquare (2k)
4.273
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
31.39
Maximum 119 Median
11
SD 41.36 CV
1.318
k hat (MLE) 0.349 k star (bias corrected MLE)
0.314
Theta hat (MLE) 90.03 Theta star (bias corrected MLE)
99.91
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx
4/8/2016

Attachment B-3: Belews Creek Regional Background Water Supply Well Data BTVs Statistics
0.669
nu hat (KM)
Page 2 of 6
nu hat (MLE) 7.671 nu star (bias corrected)
6.912
MLE Mean (bias corrected) 31.39 MLE Sd (bias corrected)
56.01
95% Percentile of Chisquare (2k) 2.832 90% Percentile
92.05
95% Percentile 141.5 99% Percentile
269.2
The following statistics are computed using Gamma ROS Statistics on Imputed Data
178.8
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 332.9 487.2 95% Approx. Gamma UPL 161.5
200
95% Gamma USL 215.5 284.6
General Statistics
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)
0.669
nu hat (KM)
14.72
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 237.8
278.1
95% Approx. Gamma UPL 126.8
134.6
95% Gamma USL 162.5
178.8
Hexavalent Chromium (ug/L)
General Statistics
Total Number of Observations
6
Number of Missing Observations
5
Number of Distinct Observations
6
Number of Detects
5
Number of Non -Detects
1
Number of Distinct Detects
5
Number of Distinct Non -Detects
1
Minimum Detect
0.038
Minimum Non -Detect
0.03
Maximum Detect
3
Maximum Non -Detect
0.03
Variance Detected
1.693
Percent Non -Detects
16.67%
Mean Detected
0.674
SD Detected
1.301
Mean of Detected Logged Data
-1.836
SD of Detected Logged Data
1.761
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
3.708
d2max (for USL)
1.822
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.776
Anderson -Darling GOF Test
5% A -D Critical Value
0.718
Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.41
Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.374
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)
0.448
k star (bias corrected MLE)
0.313
Theta hat (MLE)
1.505
Theta star (bias corrected MLE)
2.157
nu hat (MLE)
4.481
nu star (bias corrected)
3.126
MLE Mean (bias corrected)
0.674
MLE Sd (bias corrected)
1.206
95% Percentile of Chisquare (2k)
2.822
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 B-3: Belews Creek Regional Background Water Supply Well Data BTVs Statistics
General Statistics
Total Number of Observations
Page 3 of 6
For such situations, GROS method tends to yield inflated values of UCLs and BTVs
8
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
7
Minimum 0.01 Mean
0.564
Maximum 3 Median
0.0915
SD 1.195 CV
2.121
k hat (MLE) 0.384 k star (bias corrected MLE)
0.303
Theta hat (MLE) 1.467 Theta star (bias corrected MLE)
1.859
nu hat (MLE) 4.61 nu star (bias corrected)
3.638
MLE Mean (bias corrected) 0.564 MLE Sd (bias corrected)
1.023
95% Percentile of Chisquare (2k) 2.764 90% Percentile
1.66
95% Percentile 2.569 99% Percentile
4.929
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 10.92 14.43 95% Approx. Gamma UPL 3.624
3.876
95% Gamma USL 2.617 2.658
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) 0.271 nu hat (KM)
3.25
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 8.55 10.46 95% Approx. Gamma UPL 2.989
3.05
95% Gamma USL 2.2 2.152
Iron (ug/L)
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815
Number of Missing Observations 0
Number of Non -Detects
General Statistics
Total Number of Observations
11
Number of Distinct Observations
8
Number of Detects
7
Number of Distinct Detects
7
Minimum Detect
10
Maximum Detect
790
Variance Detected
79830
Mean Detected
247
Mean of Detected Logged Data
4.621
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815
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
36.36%
SD Detected
282.5
SD of Detected Logged Data
1.692
d2max (for USL) 2.234
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.849 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.803 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.212 Lilliefors GOF Test
5% Lilliefors Critical Value 0.335 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 161 SD 237.7
95% UTL95% Coverage 830 95% KM UPL (t) 610.9
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment B-3: Belews Creek Regional Background Water Supply Well Data BTVs Statistics
Lead (ug/L)
Page 4 of 6
90% KM Percentile (z) 465.6 95% KM Percentile (z) 551.9
99% KM Percentile (z) 713.9 95% KM USL 691.9
DU2 Substitution Background Statistics Assuming Normal Distribution
Mean 162.6 SD 248.3
95% UTL95% Coverage 861.5 95% UPL (t) 632.6
90% Percentile (z) 480.8 95% Percentile (z) 571
99% Percentile (z) 740.2 95% USL 717.3
DU2 is not a recommended method. DU2 provided for comparisons and historical reasons
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815 d2max (for USL) 2.234
Gamma GOF Tests on Detected Observations Only
General Statistics
A -D Test Statistic
0.789 Anderson -Darling GOF Test
Total Number of Observations
11
Number of Missing Observations
0
Number of Distinct Observations
9
5% K -S Critical Value
Number of Detects
7
Number of Non -Detects
4
Number of Distinct Detects
7
Number of Distinct Non -Detects
2
Minimum Detect
0.17
Minimum Non -Detect
0.1
Maximum Detect
73.2
Maximum Non -Detect
1
Variance Detected
736
Percent Non -Detects
36.36%
Mean Detected
11.79
SD Detected
27.13
Mean of Detected Logged Data
0.436
SD of Detected Logged Data
2.091
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815 d2max (for USL) 2.234
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.789 Anderson -Darling GOF Test
5% A -D Critical Value
0.779 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.303 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.334 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)
0.334 k star (bias corrected MLE)
0.286
Theta hat (MLE)
35.34 Theta star (bias corrected MLE)
41.24
nu hat (MLE)
4.67 nu star (bias corrected)
4.002
MLE Mean (bias corrected)
11.79
MLE Sd (bias corrected)
22.05 95% Percentile of Chisquare (2k)
2.656
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 7.506
Maximum 73.2 Median 0.2
SD 21.84 CV 2.909
k hat (MLE) 0.213 k star (bias corrected MLE) 0.216
Theta hat (MLE) 35.17 Theta star (bias corrected MLE) 34.78
Haley & Aldrich, Inc.
BTV test stats_regional.xlsx 4/8/2016

Attachment B-3: Belews Creek Regional Background Water Supply Well Data BTVs Statistics
Page 5 of 6
nu hat (MLE) 4.695 nu star (bias corrected) 4.748
MLE Mean (bias corrected) 7.506 MLE Sd (bias corrected) 16.16
95% Percentile of Chisquare (2k) 2.179 90% Percentile 22.69
95% Percentile 37.9 99% Percentile 79.27
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 78.9 93.8 95% Approx. Gamma UPL 33.24 32.91
95% Gamma USL 47.13 50.08
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)
0.133
nu hat (KM)
2.927
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 66.05
70.26
95% Approx. Gamma UPL 29.57
27.49
95% Gamma USL 40.83
39.92
0.719 Theta star (bias corrected MLE) 1.086
nu hat (MLE)
Vanadium (ug/L)
MLE Mean (bias corrected)
1.607
MLE Sd (bias corrected)
1.321 95% Percentile of Chisquare (2k) 7.743
General Statistics
Total Number of Observations
11
Number of Missing Observations
0
Number of Distinct Observations
10
Number of Detects
8
Number of Non -Detects
3
Number of Distinct Detects
8
Number of Distinct Non -Detects
2
Minimum Detect
0.653
Minimum Non -Detect
0.3
Maximum Detect
4.89
Maximum Non -Detect
1
Variance Detected
2.001
Percent Non -Detects
27.27%
Mean Detected
1.607
SD Detected
1.415
Mean of Detected Logged Data
0.234
SD of Detected Logged Data
0.686
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.815 d2max (for USL) 2.234
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.597 Anderson -Darling GOF Test
5% A -D Critical Value
0.723 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.244 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.297 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)
2.234 k star (bias corrected MLE) 1.479
Theta hat (MLE)
0.719 Theta star (bias corrected MLE) 1.086
nu hat (MLE)
35.74 nu star (bias corrected) 23.67
MLE Mean (bias corrected)
1.607
MLE Sd (bias corrected)
1.321 95% Percentile of Chisquare (2k) 7.743
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 B-3: Belews Creek Regional Background Water Supply Well Data BTVs Statistics
Page 6 of 6
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
1.211
Maximum 4.89 Median
0.734
SD 1.369 CV
1.13
k hat (MLE) 0.655 k star (bias corrected MLE)
0.537
Theta hat (MLE) 1.85 Theta star (bias corrected MLE)
2.256
nu hat (MLE) 14.4 nu star (bias corrected)
11.81
MLE Mean (bias corrected) 1.211 MLE Sd (bias corrected)
1.653
95% Percentile of Chisquare (2k) 4.02 90% Percentile
3.227
95% Percentile 4.535 99% Percentile
7.731
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 9.562 12.78 95% Approx. Gamma UPL 5.149
6.083
95% Gamma USL 6.572 8.135
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) 1.112 nu hat (KM)
24.46
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 5.686 5.992 95% Approx. Gamma UPL 3.606
3.647
95% Gamma USL 4.303 4.414
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 B — Belews Creek
Part -2: Belews Facility Background Monitoring Well Data BTVs Statistics
APRIL 2016 U'CH

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
Background Statistics for Data Sets with Non -Detects
User Selected Options
51
Date/Time of Computation
4/2/2016 3:35:10 PM
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
Cobalt - ug/L - T
Page 1 of 7
Total Number of Observations
51
Number of Distinct Observations
28
Minimum Non -Detect
0.5
Number of Missing Observations
4
Minimum
3.1
First Quartile
6
Second Largest
13
Median
6.8
Maximum
51
Third Quartile
9.05
Mean
8.157
SD
6.522
Coefficient of Variation
0.8
Skewness
5.878
Mean of logged Data
1.98
SD of logged Data
0.415
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.054 d2max (for USL) 2.965
Lognormal GOF Test
Shapiro Wilk Test Statistic 0.868 Shapiro Wilk Lognormal GOF Test
5% Shapiro Wilk P Value 6.5824E-6 Data Not Lognormal at 5% Significance Level
Lilliefors Test Statistic 0.121 Lilliefors Lognormal GOF Test
5% Lilliefors Critical Value 0.124 Data appear Lognormal at 5% Significance Level
Data appear Approximate Lognormal at 5% Significance Level
Background Statistics assuming Lognormal Distribution
95% UTL with 95% Coverage 16.98
95% UPL (t) 14.61
95% USL 24.78
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
27
13
11
11
0.14
2
0.522
0.729
-0.772
90% Percentile (z) 12.33
95% Percentile (z) 14.33
99% Percentile (z) 19.01
Number of Missing Observations 28
Number of Non -Detects
16
Number of Distinct Non -Detects
2
Minimum Non -Detect
0.5
Maximum Non -Detect
1
Percent Non -Detects
59.26%
SD Detected
0.723
SD of Detected Logged Data
0.991
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx 4/8/2016

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
Page 2 of 7
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.26 d2max (for USL)
2.698
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.898 Anderson -Darling GOF Test
5% A -D Critical Value 0.747 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.296 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.261 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) 1.236 k star (bias corrected MLE)
0.96
Theta hat (MLE) 0.59 Theta star (bias corrected MLE)
0.76
nu hat (MLE) 27.2 nu star (bias corrected)
21.12
MLE Mean (bias corrected) 0.729
MLE Sd (bias corrected) 0.744 95% Percentile of Chisquare (2k)
5.835
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
0.472
Maximum 2 Median
0.28
SD 0.537 CV
1.137
k hat (MLE) 0.831 k star (bias corrected MLE)
0.763
Theta hat (MLE) 0.568 Theta star (bias corrected MLE)
0.619
nu hat (MLE) 44.87 nu star (bias corrected)
41.22
MLE Mean (bias corrected) 0.472 MLE Sd (bias corrected)
0.541
95% Percentile of Chisquare (2k) 5.037 90% Percentile
1.162
95% Percentile 1.558 99% Percentile
2.499
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 2.261 2.567 95% Approx. Gamma UPL 1.584
1.706
95% Gamma USL 2.957 3.51
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) 0.781 nu hat (KM)
42.18
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 1.556 1.563 95% Approx. Gamma UPL 1.167
1.149
95% Gamma USL 1.942 1.988
Chromium (VI) - ug/L - T
General Statistics
Total Number of Observations 17
Number of Distinct Observations 16
Number of Detects 15
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx
Number of Missing Observations 36
Number of Non -Detects 2
4/8/2016

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
Page 3 of 7
Number of Distinct Detects
14 Number of Distinct Non -Detects
2
Minimum Detect
0.039 Minimum Non -Detect
0
Maximum Detect
0.7 Maximum Non -Detect
0.02
Variance Detected
0.04 Percent Non -Detects
11.76%
Mean Detected
0.22 SD Detected
0.2
Critical Values for
Background Threshold Values (BTVs)
95% UTL95% Coverage
Tolerance Factor K (For UTL)
2.486 d2max (for USL)
2.475
Normal
GOF Test on Detects Only
99% Percentile (z)
Shapiro Wilk Test Statistic
0.808 Shapiro Wilk GOF Test
DL/2 is not a recommended method.
5% Shapiro Wilk Critical Value
0.881 Data Not Normal at 5% Significance Level
Gamma GOF Tests on Detected Observations Only
Lilliefors Test Statistic
0.234 Lilliefors GOF Test
0.33 Anderson -Darling GOF Test
5% Lilliefors Critical Value
0.229 Data Not Normal at 5% Significance Level
0.753 Detected data appear Gamma Distributed at 5% Significance Level
Data Not Normal at 5% Significance Level
0.128 Kolmogrov-Smirnoff GOF
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
Mean
0.194 SD
0.195
95% UTL95% Coverage
0.679 95% KM UPL (t)
0.545
90% KM Percentile (z)
0.444 95% KM Percentile (z)
0.515
99% KM Percentile (z)
0.648 95% KM USL
0.677
DL/2 Substitution Background Statistics Assuming Normal Distribution
Mean
0.195 SD
0.2
95% UTL95% Coverage
0.693 95% UPL (t)
0.555
90% Percentile (z)
0.452 95% Percentile (z)
0.525
99% Percentile (z)
0.661 95% USL
0.691
DL/2 is not a recommended method.
DL/2 provided for comparisons and historical reasons
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.33 Anderson -Darling GOF Test
5% A -D Critical Value
0.753 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.128 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.225 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)
1.567
Theta hat (MLE)
0.141
nu hat (MLE)
47
MLE Mean (bias corrected)
0.22
MLE Sd (bias corrected)
0.193
k star (bias corrected MLE) 1.298
Theta star (bias corrected MLE) 0.17
nu star (bias corrected) 38.93
95% Percentile of Chisquare (2k) 7.101
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) 0.996
WH HW
95% Approx. Gamma UTL with 95% Coverage 1.25 1.888 95% Approx. Gamma UPL
95% Gamma USL 1.24 1.871
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx
nu hat (KM) 33.85
WH HW
0.766 1.017
4/8/2016

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
Iron - ug/L - T
General Statistics
Lead - ug/L - T
Page 4 of 7
Background Lognormal ROS Statistics Assuming Lognormal Distribution Using Imputed Non -Detects
Data not Log Transformable!
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 17 95% UTL with95% Coverage 0.7
Approximate f 0.895 Confidence Coefficient (CC) achieved by UTL 0.582
95% UPL 0.7 95% USL 0.7
95% KM Chebyshev UPL 1.069
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.
Total Number of Observations 51
Minimum
17
Second Largest
850
Maximum
1900
Mean
213.3
Coefficient of Variation
1.509
Mean of logged Data
4.709
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.054
Number of Distinct Observations 34
Number of Missing Observations 4
First Quartile
47.5
Median
100
Third Quartile
223
SD
321.8
Skewness
3.438
SD of logged Data
1.081
d2max (for USL) 2.965
Lognormal GOF Test
Shapiro Wilk Test Statistic 0.953 Shapiro Wilk Lognormal GOF Test
5% Shapiro Wilk P Value 0.0728 Data appear Lognormal at 5% Significance Level
Lilliefors Test Statistic 0.145 Lilliefors Lognormal GOF Test
5% Lilliefors Critical Value 0.124 Data Not Lognormal at 5% Significance Level
Data appear Approximate Lognormal at 5% Significance Level
Background Statistics assuming Lognormal Distribution
95% UTL with 95% Coverage 1022
95% UPL (t) 691.4
95% USL 2736
General Statistics
Total Number of Observations 51
Number of Distinct Observations 20
Number of Detects 22
90% Percentile (z) 443.5
95% Percentile (z) 656.9
99% Percentile (z) 1372
Number of Missing Observations 4
Number of Non -Detects 29
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx 4/8/2016

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
Nickel - ug/L - D
Page 5 of 7
Number of Distinct Detects
18
Number of Distinct Non -Detects
2
Minimum Detect
0.05
Minimum Non -Detect
0.1
Maximum Detect
1.5
Maximum Non -Detect
1
Variance Detected
0.233
Percent Non -Detects
56.86%
Mean Detected
0.35
SD Detected
0.482
Mean of Detected Logged Data
-1.849
SD of Detected Logged Data
1.211
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.054 d2max (for USL) 2.965
Nonparametric Upper Limits for BTVs(no distinction made between detects and nondetects)
Order of Statistic, r 50 95% UTL with95% Coverage 1.15
Approximate f 1.316 Confidence Coefficient (CC) achieved by UTL 0.731
95% UPL 1.15 95% USL 1.5
95% KM Chebyshev UPL 1.687
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.232 d2max (for USL) 2.73
Gamma GOF Tests on Detected Observations Only
General Statistics
A -D Test Statistic
0.874 Anderson -Darling GOF Test
Total Number of Observations
29
Number of Missing Observations
26
Number of Distinct Observations
22
5% K -S Critical Value
Number of Detects
27
Number of Non -Detects
2
Number of Distinct Detects
21
Number of Distinct Non -Detects
1
Minimum Detect
0.23
Minimum Non -Detect
5
Maximum Detect
5.2
Maximum Non -Detect
5
Variance Detected
2.204
Percent Non -Detects
6.897%
Mean Detected
1.724
SD Detected
1.485
Mean of Detected Logged Data
0.125
SD of Detected Logged Data
0.983
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.232 d2max (for USL) 2.73
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.874 Anderson -Darling GOF Test
5% A -D Critical Value
0.766 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic
0.156 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.172 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)
1.333 k star (bias corrected MLE)
1.21
Theta hat (MLE)
1.293 Theta star (bias corrected MLE)
1.425
nu hat (MLE)
71.98 nu star (bias corrected)
65.31
MLE Mean (bias corrected)
1.724
MLE Sd (bias corrected)
1.568 95% Percentile of Chisquare (2k)
6.78
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
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx 4/8/2016

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
Page 6 of 7
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
Minimum
0.23
Mean
1.699
Maximum
5.2
Median
1
SD
1.441
CV
0.848
k hat (MLE)
1.399
k star (bias corrected MLE)
1.277
Theta hat (MLE)
1.214
Theta star (bias corrected MLE)
1.33
nu hat (MLE)
81.16
nu star (bias corrected)
74.09
MLE Mean (bias corrected)
1.699
MLE Sd (bias corrected)
1.503
95% Percentile of Chisquare (2k)
7.028
90% Percentile
3.683
95% Percentile
4.673
99% Percentile
6.934
The following statistics are computed using Gamma ROS Statistics on Imputed Data
19
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
1
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 6.424
6.885
95% Approx. Gamma UPL 4.805
4.988
95% Gamma USL 8.354
9.259
Percent Non -Detects
20%
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)
1.403
nu hat (KM)
81.37
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 6.479
6.945 95%
Approx. Gamma UPL 4.838
5.02
95% Gamma USL 8.438
9.357
Vanadium - ug/L - T
General Statistics
Total Number of Observations
25
Number of Missing Observations
30
Number of Distinct Observations
19
Number of Detects
20
Number of Non -Detects
5
Number of Distinct Detects
19
Number of Distinct Non -Detects
1
Minimum Detect
0.34
Minimum Non -Detect
1
Maximum Detect
9
Maximum Non -Detect
1
Variance Detected
8.767
Percent Non -Detects
20%
Mean Detected
2.342
SD Detected
2.961
Mean of Detected Logged Data
0.257
SD of Detected Logged Data
1.033
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.292
d2max (for USL)
2.663
Normal GOF Test on Detects Only
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Nonparametric Upper Limits for BTVs(no distinction made between detects and nondetects)
Order of Statistic, r 25 95% UTL with95% Coverage 9
Approximate f 1.316 Confidence Coefficient (CC) achieved by UTL 0.723
95% UPL 8.67 95% USL 9
95% KM Chebyshev UPL 13.87
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx 4/8/2016

Attachment B-3: Belews Creek Facility Background Monitoring Well Data BTVs Statistics
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.
Haley & Aldrich, Inc.
BTV test after removing_facility.xlsx
Page 7 of 7
4/8/2016