2016-0418_Duke_App_E_Marshall_F

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EVALUATION OF WATER SUPPLY WELLS IN THE VICINITY OF DUKE
ENERGY COAL ASH BASINS IN NORTH CAROLINA
APPENDIX E - MARSHALL 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 E — Marshall
Table of Contents
Page
List of Tables
List of Figures
ii
List of Attachments
iv
List of Acronyms
v
E. Marshall
1
E.1 INTRODUCTION
1
E.1.1 Facility Location and Description
1
E.1.2 Current CAMA Status
3
E.1.3 Investigation Results
7
E.1.4 Selected Remedial Alternative and Recommended Interim Activities
8
E.1.5 Risk Classification Process
8
E.1.6 Purpose and Objectives
10
E.2 WATER SUPPLY WELL DATA EVALUATION
11
E.2.1 Data Sources
11
E.2.2 Screening Levels
11
E.2.3 Results
12
E.3 STATISTICAL EVALUATION OF BACKGROUND
13
E.3.1 Initial Data Evaluation
13
E.3.2 Raw Data Evaluation
14
E.3.3 Testing of Statistical Assumptions
16
E.3.4 BTV Estimates
17
E.3.5 Comparison of Water Supply Well Data to the Regional BTVs
18
E.4 GROUNDWATER FLOW EVALUATION
18
E.4.1 Introduction
18
E.4.2 Site Geology
19
E.4.3 Site Hydrogeology
20
E.4.4 Water Supply Well Capture Zone Analysis
25
E.4.5 Summary and Conclusions
27
E.5 GROUNDWATER CHARACTERISTICS EVALUATION
28
E.5.1 Evaluation Approach
29
E.5.2 CCR -Related Constituents Screening for Signature Development
29
E.5.3 Data Analysis Methods
30
E.5.4 Evaluation Results
32
E.5.5 Conclusions
37
E.6 SUMMARY
39
E.7 REFERENCES
40
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List of Tables
Table No.
Title
E2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
E2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
E2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
E2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
E2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
2L Screening Levels
E2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
MCL Screening Levels
E2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
DHHS Screening Levels
E2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to
RSL Screening Levels
E2-9
Do Not Drink Letter Summary
E3-1
NCDEQ and Duke Energy Background Water Supply Well Data
E3-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
E3-3
Statistical Evaluation of Background Data
E3-4
Comparison of NCDEQ Water Supply Well Sampling Data to Regional
Background Threshold Values
E3-5
Comparison of NCDEQ Water Supply Well Sampling Data to Facility Specific
Background Threshold Values
E4-1
Hydrostratigraphic Layer Properties — Horizontal Hydraulic Conductivity
E4-2
Estimated Groundwater Seepage Velocities
E5-1
Site -Specific Distribution Coefficient (Kd)
E5-2
Coal Ash Indicator Concentrations Observed in the Water Supply Wells of Low
Oxygen and High Detected Boron Concentrations
List of Figures
Figure No. Title
E1-1 Location Map
E1-2 Key Features
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E1-3
Location of Water Supply Wells and Facility Groundwater Conditions
E3-1
Facility Background Wells
E4-1
Two -Medium Groundwater System
E4-2
Slope -Aquifer System
E4-3
Regolith as Primary Groundwater Storage
E4-4
Transition Zone as Primary Transmitter of Impacted Groundwater
E4-5
Water Table Surface — Shallow Wells — Groundwater Measurement Dates 7/22 -
7/24, 2015
E4-6
Potentiometric Surface — Deep Wells — Groundwater Measurement Dates 7/22 -
7/24, 2015
E4-7
Potentiometric Surface — Bedrock Wells — Groundwater Measurement Dates
7/22 - 7/24, 2015
E4-8
Water Table Surface — Shallow Wells — Groundwater Measurement Date
9/28/2015
E4-9
Potentiometric Surface— Deep Wells — Groundwater Measurement Date
9/28/2015
E4-10
Potentiometric Surface— Bedrock Wells — Groundwater Measurement Date
9/28/2015
E4-11
Horizontal Hydraulic Conductivity Measurements
E4-12
Site Conceptual Model — Plan View Map —Area of Boron Exceedances of
2L Standards
E4-13
Cross -Section Conceptual Site Model
E4-14
Mounding Effect
E4-15
Groundwater Affected by Pumping
E4-16
Water Supply Well Capture Zones
E5-1
Pourbaix Diagrams for Iron and Manganese with Measured Eh and pH from Site
Monitoring Wells
E5-2
Example Box Plot and Piper Plot
E5-3
Box Plot Comparison for Major Coal Ash Constituents
E5-4
Box Plot Comparison for Barium and Cobalt
E5-5
Box Plot Comparison for Dissolved Oxygen, Iron, and Manganese
E5-6
Bedrock Groundwater Wells and Direction of Groundwater Flow
E5-7
Correlation Plot for Boron and Sulfate
E5-8
Correlation Plot for Boron and Dissolved Oxygen
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E5-9
Sampled Water Supply Wells
E5-9
Correlation Plot for Boron and Sulfate
E5-10
Piper Plot Evaluation - Ash Basin Porewater and Facility Downgradient Bedrock
Wells
E5-11
Piper Plot Evaluation - Water Supply, Regional Background, and Facility Bedrock
Wells
E5-12
Piper Plot Evaluation - Water Supply, Regional Background, Facility Bedrock, and
Ash Basin Porewater Wells
List of Attachments
Attachment Title
E-1 Histograms and Probability Plots for Selected Constituents
E-2 Results of Statistical Computations
E-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
DWR Division of Water Resources
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
µg/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
PV Photovoltaic
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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E. Marshall
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 Marshall Steam
Station (Marshall 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 Marshall ash basin under the CAMA requirements. A
technical weight of evidence approach has been used to evaluate the available data for the Marshall
site, and the evaluation demonstrates that groundwater utilized by local water supply wells near the
Marshall coal ash impoundment is not impacted by coal ash sources. These results indicate that a Low
classification for the Marshall Steam Station under the CAMA is warranted.
E.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 (HDR, Inc. [HDR], 2015a);
• Corrective Action Plan Part 1 (HDR, 2015b); and
• Corrective Action Plan Part 2 (HDR, 2016).
A review of the risk classification process and the status of that process are also provided.
This report provides technical evaluations in four important assessment areas: 1) an evaluation of the
private and public water supply well data collected by the NCDEQ with respect to groundwater
standards and screening levels; 2) additional statistical analysis of regional background groundwater
data, and facility -specific background groundwater data; 3) a more comprehensive evaluation of
groundwater flow with respect to local water supply wells, including a water supply well capture zone
analysis; and 4) a detailed comparison of facility -specific coal ash groundwater chemistry, background
groundwater chemistry (both regional and facility -specific), and water supply well chemistry.
E.1.1 Facility Location and Description
Duke Energy owns and operates Marshall which is located in Catawba County near the town of Terrell,
North Carolina (Figure E1-1).
E.1.1.1 Facility Setting
Marshall occupies 1,446 acres of land and is located on the shore of Lake Norman as shown on
Figure E1-2. The area surrounding Marshall generally consists of residential properties, undeveloped
land, and Lake Norman. Properties located within a 0.5 -mile radius of the Marshall ash basin
compliance boundary generally consist of undeveloped land and Lake Norman to the east; undeveloped
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land and residential properties located to the north and west; portions of the Marshall site (outside the
compliance boundary, see below), undeveloped land, and residences to the south; and commercial
properties to the southeast along North Carolina Highway 150.
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.
Four public water supply wells and 83 private water supply wells are in use, along with six assumed
private water supply wells, located within a 0.5 -mile radius of the ash basin compliance boundary
(Figure E1-3). No wellhead protection areas were identified within a 0.5 -mile radius of the ash basin
compliance boundary. Several surface water bodies that flow from the topographic divide along
Sherrills Ford Road toward Lake Norman were identified within a 0.5 -mile radius of the ash basin
compliance boundary. No water supply wells were identified between the source areas and Lake
Norman.
E.1.1.2 Past and Present Operations
Marshall began operations in 1965 as a coal-fired electrical generating station and currently operates
four coal-fired units. Units 1 and 2 began operation in 1965 and 1966, and Units 3 and 4 began
operation in 1969 and 1970. Improvements to the plant since 1970 have increased the electric
generating capacity to 2,078 megawatts.
The major ash -related structures at Marshall include the ash basin, the Phase I dry ash landfill, the
Phase II dry ash landfill, the photovoltaic (PV) structural fill area, the lined Industrial Landfill No. 1, the
subgrade fill area beneath Industrial Landfill No. 1, and the lined Flue Gas Desulfurization (FGD) residue
landfill. These key features are shown on Figure E1-2.
The ash basin system at Marshall consists of a single cell impounded by an earthen dike located on the
southeast end of the ash basin. The ash basin system was constructed in 1965 and is located north of
the power plant. Inflows from the station to the ash basin are discharged into the southwest portion of
the ash basin. The ash basin is operated as an integral part of the station's wastewater treatment
system, which receives permitted and variable discharges from the ash removal system, coal pile runoff,
landfill leachate, FGD wastewater, the station yard drain sump, and site stormwater.
During operations of the coal-fired units, the sluice lines discharge the water/slurry and other permitted
flows to the southwest portion of the ash basin. Inflows to the ash basin are highly variable due to
station operations and weather. The dry ash landfill consists of two units, which are located adjacent to
the east (Phase 1) and northeast (Phase II) portions of the ash basin. Phase I was constructed in
September 1984 and closed in March 1986. Placement of ash in the Phase II unit began around
March 1986 and was completed in 1999. The dry ash landfill units were constructed prior to the
requirement for lining industrial landfills and were closed with a soil and vegetative cover system.
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The PV structural fill was constructed of fly ash under the structural fill rules found in 15A NCAC
1313.1700 et seq. and is located adjacent to and partially on top of the northwest portion of the ash
basin. Placement of dry ash in the PV structural fill area began in October 2000 and the unit closed with
a soil and vegetative cover system in February 2013.
The Industrial Landfill No. 1, which is located over portions of the northernmost extent of the ash basin,
was constructed with a leachate collection and removal system and a three -component liner system.
The subgrade for portions of the Industrial Landfill No. 1 were constructed of fly ash under the structural
fill rules found in 15A NCAC 1313.1700 et seq. Fly ash and FGD residue, also known as gypsum, is also
disposed in the FGD residue landfill.
Duke Energy discharges managed and treated wastewater from Marshall in accordance with Permit
NC0004987. The permitted receiving body is the Catawba River. The permit is authorized by the NCDEQ
Division of Water Resources (DWR) under the National Pollutant Discharge Elimination System (NPDES).
E.1.1.3 Facility Geological/Hydrogeological Setting
Marshall 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 Marshall generally slopes from the northwest to southeast, ranging from an approximate
high elevation of 900 feet elevation near the western (Sherrills Ford Road) and northern (Island Point
Road) boundaries of the site, to an approximate low elevation of 760 feet at the shoreline of Lake
Norman. Thus the land elevation slopes down from the areas where water supply wells are located
towards Lake Norman. Ground surface elevation varies approximately 120 to 140 feet over an
approximate distance of 1.5 miles. Surface water drainage generally follows site topography and flows
from the northwest to the southeast across the site except where drainage patterns have been modified
by the ash basins or other construction.
Based on the site investigation, the groundwater system in the natural materials (alluvium, soil,
soil/weathered bedrock, and bedrock) at Marshall is a fractured bedrock system and is an unconfined,
connected system of flow layers. The Marshall 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 from northwest and north to the southeast
toward Lake Norman.
More detail on the site hydrogeology is provided in Section E.4.
E.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 December 31, 2015, prioritize for the purpose of closure and remediation
coal combustion residuals (CCR) surface impoundments, including active and retired sites, based on
these sites' risks to public health, safety, and welfare, the environment, and natural resources.
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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.
E.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 Marshall ash basin compliance boundary. Supplemental
receptor survey information was obtained from responses to water supply well survey questionnaires
mailed to property owners within the required distance requesting information on the presence of
water supply wells, well details, and well usage. Figure E1-3 shows the water supply wells within this
0.5 -mile radius.
E. 1. 2.2 Comprehensive Site Assessment, Round 1 Sampling Event, March — September 2015
The purpose of the Marshall 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 (HDR, 2015a):
• Installation of 83 groundwater monitoring wells and 13 soil borings to facilitate collection and
analysis of chemical, physical, and hydrogeological parameters of subsurface materials
encountered within and beyond the waste and Compliance Boundary.
• Collection of groundwater sampled from 83 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).
• Completion of a screening -level human health and ecological risk assessment.
E.1.2.3 Round 2 Sampling Event, September through October 2015
A total of 62 groundwater monitoring wells were sampled during the Round 2 event, including
12 compliance monitoring wells installed in 2011, 7 voluntary monitoring wells, and 1 FGD residue
landfill monitoring well. Samples were analyzed for total and dissolved CCR constituents.
E.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 Marshall 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 were modeled into the future over
a 250 -year period; the effect of capping the CCR source areas to reduce rainfall infiltration was modeled
over a 100 -year timeframe; and the effect of excavating CCR materials was modeled over a 100 -year
timeframe.
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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; and continued collection and statistical evaluation of data from background monitoring wells.
E.1.2.5 Round 3 (November 2015) and Round 4 (December 2015) Background Well Sampling
In response to an 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 E.3 for a statistical evaluation of background concentrations.
E. 1. 2.6 Corrective Action Plan — Part Z 3 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 (IMAC) and
North Carolina Department of Health and Human Services (NCDHHS) health screening levels
(HSL);
• Present Round 3 and Round 4 of background sampling results;
• A refined SCM;
• Refined groundwater flow and fate and transport model results;
• Refined groundwater to surface water model results;
• Site geochemical model results;
• Findings of the human health and ecological risk assessment;
• Evaluation of methods for achieving groundwater quality restoration;
• Conceptual plan(s) for recommended proposed corrective action(s);
• A schedule for implementation of the proposed corrective action(s); and
• A plan for monitoring and reporting of the effectiveness of the proposed corrective action(s).
Groundwater data collected during the four sampling rounds were compared to the following standards:
• North Carolina Groundwater Quality Standards as specified in Title 15A NCAC.0202L
(21- Standards);
• IMACs;
• NCDHHS HSL (hexavalent chromium only); and/or
• Site-specific PPBCs for groundwater at Marshall.
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E.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 Marshall are depicted in Figure E1-3 and are described as follows:
• Impacts from CCR -constituents in groundwater are spatially limited to areas beneath the ash
basin, beneath the dry ash landfill (Phase 11), downgradient and east of the ash basin and dry ash
landfill (Phase 1), and downgradient and southeast of the ash basin within the ash basin
compliance boundary.
• Groundwater impacts are present in the shallow soil/alluvium and deep soil/weathered
bedrock, and bedrock flow layers at the site.
• Surface water impacts were identified in the unnamed tributary that flows to Lake Norman
located downgradient of the Phase I dry ash landfill; however, the groundwater to surface water
mixing model shows no exceedances of surface water quality standards in Lake Norman.
• Constituents exceeding groundwater standards were higher beneath the dry ash landfill
(Phase 11) and downgradient and east of the ash basin and dry ash landfill (Phase 1) compared to
beneath the ash basin.
• Groundwater flow direction is generally in a southeasterly direction towards Lake Norman and
the unnamed tributary that flows to Lake Norman.
Constituents identified to exceed the applicable state and federal regulatory standards are listed by
location below:
• Ash samples collected from the ash basin, dry ash landfill (Phase II), and PV structural fill:
antimony, arsenic, barium, boron, cobalt, iron, manganese, selenium, and vanadium.
• Ash pore water samples: antimony, arsenic, barium, beryllium, boron, cadmium, chloride,
chromium, cobalt, iron, lead, manganese, nickel, selenium, sulfate, thallium, total dissolved
solids (TDS), and vanadium.
• Ash basin surface water: arsenic, beryllium, boron, cadmium, chloride, cobalt, copper, lead,
manganese, nickel, selenium, sulfate, thallium, TDS, vanadium, and zinc.
• Groundwater: antimony, arsenic, barium, beryllium, boron, chromium III, cobalt, iron,
manganese, selenium, sulfate, thallium, total dissolved solids, and vanadium.
Note that antimony, barium, chromium, cobalt, hexavalent chromium, iron, manganese,
thallium, and vanadium were also detected above their groundwater quality standard or criteria
in site background groundwater. Further sampling and analyses are necessary to determine if
constituent exceedances are the result of source -related impacts or naturally occurring
conditions (as discussed in CSA).
Finally, 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
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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.
E.1.4 Selected Remedial Alternative and Recommended Interim Activities
The recommended remedial alternative selected for Marshall is the combination of two remediation
technologies: 1) capping the ash basin, and 2) monitored natural attenuation (MNA). Groundwater
modeling showed that the construction of an engineered cap to reduce infiltration would also reduce
the movement of groundwater from the ash basin. A recommendation for further evaluation of the
effectiveness of a groundwater cut off wall for preventing discharges to the unnamed tributary to Lake
Norman 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.
E.1.5 Risk Classification Process
Duke is required by the CAMA to close the Marshall 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. According to
the NCDEQ document "Coal Combustion Residual Impoundment Risk Classifications, January 2016"
(NCDEQ, 2016), the Marshall ash basin is ranked "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 Marshall ash basin. NCDEQ will release the final risk
classifications after review of public comments.
Upon further review, the NCDEQ will issue either a final Low classification or a final Intermediate
classification for the Marshall ash basin. The following are the classification factors for Marshall as
provided in the NCDEQ (2016) document:
Groundwater Key Factor:
If either it is determined that no receptor is impacted by the coal ash impoundments or
alternate water is made available to all residents whose wells are being impacted by coal
ash impoundments, the overall groundwater risk would be low. Based on the information
received to date, there appears to be no downgradient receptors located 1,500 feet
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downgradient of the impoundment compliance boundary. The following data gaps related
to groundwater uncertainty include:
- Incomplete capture zone modeling in fractured bedrock for up -gradient and side -
gradient supply wells in the immediate vicinity of the impoundments.
- Incomplete geochemical modeling.
- Incomplete background concentration determination.
Based on the data provided in CSA Report and results of the groundwater modeling results
presented in the CAP Report, the number of down -gradient receptors (well users) 1,500 feet
from the compliance boundary that are potentially or currently known to be exposed to
impacted groundwater from source(s) or migration pathways related to the CCR
impoundments:
- Ash Basin. LOW RISK. There are no reported supply wells within 1,500 feet
downgradient of the impoundment compliance boundary.
Groundwater Supporting Factors and Other Considerations:
• Exceedance of 2L Standard or IMAC at or Beyond the Established CCR Impoundment
Compliance Boundary:
- Ash Basin. HIGH RISK. Several constituents were detected at or beyond the
compliance boundary above the 2L Standard or IMAC including antimony, boron,
chromium, cobalt, and vanadium.
• Population Served by Water Supply Wells Within 1,500 feet Up -Gradient or Side -Gradient of
the Established CCR Impoundment Compliance Boundary:
- Ash Basin. HIGH RISK. Duke identified approximately 42 water supply wells within
1,500 feet of the impoundment compliance boundary. Assuming 2.5 users per well,
there are at least 105 persons using water supply wells within 1,500 feet of the
impoundment compliance boundary.
• Population Served by Water Supply Wells within 1,500 Feet Downgradient of the Established
CCR Impoundment Compliance Boundary:
- 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:
- Ash Basin. HIGH RISK. There are several exceedances of the 2L Standard or IMAC
within 500 feet of a water supply well.
Groundwater Emanating from the Impoundment that Exceeds 2L Standard or IMAC and that
Discharges into a Surface Water Body:
- Ash Basin. HIGH RISK. Several constituents were detected above the 2L Standard or
IMAC in seeps potentially associated with the Ash Basin, including arsenic, boron,
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chromium, cobalt, lead, selenium, thallium and vanadium that are potentially
discharging to a surface water body. Several constituents were detected above the
2L Standard or IMAC or the NC 2B Surface Water Criteria in a surface water tributary
adjacent to the unlined Phase 1 ash landfill which was constructed over the ash
basin and included boron, cobalt, and vanadium. Several constituents were detected
above the 2L Standard or IMAC in groundwater samples collected downgradient of
the ash basin and adjacent to surface waters. These constituents included arsenic,
boron, cobalt, thallium, and vanadium.
• Data Gaps and Uncertainty Related to Transport of Contaminants to Potential Receptors:
— Ash Basin. INTERMEDIATE RISK. There is a moderate degree of uncertainty with the
data presented in the CSA Report, CAP Report, and subsequent characterization by
Duke Energy related to the impoundment. The horizontal extent of contamination
remains unclear until adequate background information can be determined and
whether there is any potential current or historical on -or off-site hydraulic influence
on observed contaminant distribution.
E.1.6 Purpose and Objectives
The purpose of this document is to provide additional detailed evaluation of Marshall -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 Marshall may be affected by CCR constituents, and provide a better understanding of
whether those metals and other constituents present in water supply wells are naturally occurring or
whether they are present due to migration from the groundwater in the vicinity of the ash basins.
This document is divided into four sections:
• Section E.2 provides an evaluation of the water supply well data with respect to regulatory
standards and health -risk-based screening levels.
• Section E.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 Marshall operations.
• Section E.4 provides the hydrogeologic findings of additional groundwater modeling and an
additional evaluation of groundwater flow patterns in the vicinity of Marshall with respect to
the locations of the water supply wells.
• Section E.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
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areas that show the potential presence of CCR constituents within and outside of the
compliance boundary for Marshall.
Section E.6 provides a summary of conclusions and a discussion of their potential impact on the
risk classification for this site.
E.2 WATER SUPPLY WELL DATA EVALUATION
The purpose of this section is to evaluate data for water supply wells in the vicinity of Marshall with
respect to applicable screening levels.
E.2.1 Data Sources
As noted above, 4 public water supply wells and 83 private water supply wells are in use, along with
6 assumed private water supply wells, located within a 0.5 -mile radius of the Marshall ash basin
compliance boundary (Figure E1-3). This section presents an evaluation of the water supply well data
from the following three sources:
• A total of 39 samples collected by the NCDEQ from 38 wells within a 1,500 -foot radius of the
Marshall ash basin compliance boundary;
• A total of 10 samples collected by the NCDEQ from 10 reconnaissance or background water
supply wells in the vicinity of Marshall, but well outside the ash basin compliance boundary; and
• A total of 29 samples collected by Duke Energy from background water supply wells located
within a 2- to 10 -mile radius from the Marshall 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.
E.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 that these values include IMACs; IMACs are included when referring to 2L Standards in this
report;
• Federal Safe Drinking Water Act (SDWA) 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).
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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.
E.2.3 Results
Tables E2-1 through E2-4 present the comparison of the NCDEQ data for the water supply wells located
within a 1,500 -foot radius of the Marshall ash basin compliance boundary to 2L standards, USEPA MCLS,
NCDHHS screening levels, and USEPA RSLs, respectively.
Tables E2-5 through E2-8 present the comparison of the NCDEQ and Duke Energy data for the
background water supply wells to 2L standards, USEPA MCLS, NCDHHS screening levels, and USEPA RSLs,
respectively.
The concentration of boron and the other potential coal ash indicators (discussed in Section 3 of the
main report) were low and not above screening levels in the water supply wells sampled by NCDEQ.
Boron was detected infrequently (4 of 39 samples) in the NCDEQ sampled water supply wells, as well as
in the NCDEQ and Duke Energy background wells (5 of 39 samples). 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 (Briel, 1997) showing that
groundwater pH in the state is commonly below the MCL range of 6.5 to 8.5. Lead was above the
drinking water standard in 2 of the 39 NCDEQ-sampled water supply wells.
None of the NCDEQ-sampled water supply well results were above Federal primary drinking water
standards (MCLs), with the exception of the pH and lead results noted above. Eight iron results were
above the SMCL, as were 3 of the results for manganese and two results for aluminum; however, the
SMCLs are based on aesthetics, and all results are below the USEPA risk-based RSLs.
The concentration of cobalt in one well was above the 2L Standard and NCDHHS screening level;
however, cobalt concentrations are within the range detected in the background wells. The
concentration of lead in two wells was above the screening level.
"Do Not Drink" Letters were issued by NCDHHS for 38 water supply wells at Marshall, with hexavalent
chromium and vanadium being the primary constituents listed in the letters (see Table E2-9). The letters
issued were based on the now -outdated screening levels, and those "Do Not Drink" warnings have been
lifted for these two constituents. Letters were issued for constituents other than hexavalent chromium
and vanadium, primarily for iron (9 wells), lead (1 well), manganese (3 wells), and sodium (1 well).
A detailed statistical evaluation of background and comparison to the water supply well data is provided
in the next section.
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E.3 STATISTICAL EVALUATION OF BACKGROUND
The purpose of the background evaluation is to develop a site-specific or facility -specific descriptor of
background for constituents of interest (i.e., a background threshold value [BTV]). If a sample result is
below the BTV, there is reasonable confidence that the constituent concentration is consistent with
background. However, a sample result above a BTV does not mean that it is not consistent with
background, only which statistically it cannot be determined based on the available background dataset.
Three datasets are available to describe background groundwater conditions in the vicinity of Marshall:
• The NCDEQ-sampled background water supply well dataset;
• The Duke Energy background water supply well dataset; and
• The Marshall facility background monitoring well dataset.
The water supply well data were summarized as indicated in Section E.2.1 to address wells where
resampling occurred.
The NCDEQ and the Duke Energy background water supply well datasets are referred to here as regional
background, and the Marshall background monitoring well dataset is referred to as facility -specific
background. Nine constituents were selected for the background evaluation studies at Marshall. 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 E.S. The BTV values were estimated for the nine constituents at Marshall by using a stepwise
approach outlined below.
1) Initial evaluation of background input data sources.
2) Raw data evaluation by descriptive statistics, histograms, outlier tests, and trend tests.
3) Testing of statistical assumptions of the input data by checking for independent, identically
distributed (IID) measurements and goodness -of -fit (GOF) distribution tests.
4) Selection of an appropriate parametric or non -parametric analysis method to estimate
constituents BTVs.
5) Summarizing the statistical analysis results and drawing conclusions.
The statistical methodology and the conclusions for the background evaluation are presented in the
following sections.
E.3.1 Initial Data Evaluation
The initial statistical evaluation was performed to check the homogeneity of variance assumption for
multiple groups of wells included in the regional background water supply well dataset, and separately
for the Marshall facility -specific background monitoring well dataset, before combining each into a
single dataset. In this step, data from discrete data sources for each background dataset were tested for
statistical variations using Levine's test. The test examines if the differences in sample variances occur
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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.
E.3.1.1 Regional Background Water Supply Well Data
Vanadium and hexavalent chromium were used in the statistical computations to determine if the two
background datasets (NCDEQ and Duke Energy) could be combined. The results of the Levine's test are
presented in Attachment E-1.
Statistical computations revealed that there are no significant difference in the variances between the
background regional water supply well data provided by NCDEQ and Duke Energy for both vanadium
and hexavalent chromium data. Therefore, further evaluation was performed on the combined dataset.
Table E3-1 presents the combined regional background water supply well dataset for Marshall.
E. 3.1.2 Facility Background Monitoring Well Data
Water supply wells in this region of North Carolina are predominantly bedrock wells. Section E.4
discusses this in more detail.
Background wells sampled at Marshall for the CSA included MW -4, MW -4D, MS -10, BG -1S, BG -1D, BG -
2S, BG-2BR, BG -3S AND BG -3D. The initial facility -specific background evaluation for Marshall was
performed on three background deep (transition zone) wells and one background bedrock monitoring
well (BG -1D, BG-2BR, BG -3D, and MW -4D) (see Figure E3-1). 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 Marshall is presented in Table E3-2. 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
datasets 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 E3-2 and
Figure E3-1 were combined for the facility BTV estimates.
E.3.2 Raw Data Evaluation
In the raw data evaluation for Marshall, the descriptive statistics for nine constituents for both the
regional and facility -specific datasets were computed and tabulated in Table E3-3. 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 Detect (Column 12). Critical information such as the requirement for a
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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 nine constituents for both regional and facility -specific datasets are
presented in Table E3-3. Attachment E-2 presents the histograms, probability plots and outlier tests for
the nine constituents.
E.3.2.1 Regional Background Water Supply Well Data
The descriptive statistics indicated the presence of a high percentage of non -detects (NDs) for most of
the constituents except barium; <— 5 samples out of 39 total samples had detections of cobalt, boron,
and nickel. 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 E3-3 (Columns 13-14), an analysis using
visual plots and the Dixon's Outlier Test indicated the presence of outliers in the data set. However,
outliers are inevitable in most environmental data and the decisions to exclude them need to be made
based on existing knowledge about the facility and the regional groundwater conditions. In this
instance, based on existing knowledge that these are data from background locations not adjacent to
the facility, no outliers were removed from the regional water supply dataset.
E.3.2.2 Facility Background Monitoring Well Data
The descriptive statistics performed on facility -specific background data indicated that greater than
40 percent of samples had NDs for boron, chromium, and lead. Boron had only 2 detects out of
32 samples, chromium had 18 detects, and lead had 11 detects. Statistical computations indicated the
presence of outliers in the data set, specifically with regard to monitoring well BG-2BR. Sampling results
from BG-2BR for the July 2015 event showed significant concentration variation from the remaining
sample results for this well and, therefore, the July 2015 results for this well were removed from further
analysis, and descriptive statistics were recalculated.
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E.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 E.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 nine constituents for both regional and facility -
specific datasets are presented in Table E3-3. Attachment E-2 presents the GOF tests statistics.
E. 3.3.1 Regional Background Water Supply Well Data
The test statistics revealed that most of the constituents follow a parametric distribution except iron
and cobalt; hence, parametric methods were used to compute BTVs for all constituents except iron and
cobalt. Non -parametric test methods were used to compute the BTV for iron. No further evaluation
was performed for cobalt due to the presence of only one detect out of 39 samples.
E.3.3.2 Facility Background Monitoring Well Data
The test statistics revealed that chromium, hexavalent chromium, and cobalt follow a parametric
distribution; hence, parametric methods were used to compute BTVs. The remaining constituents did
not follow a specific distribution; hence non -parametric methods were used to compute the BTVs. No
further evaluation was performed on boron due to the presence of only two detected results.
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E.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]). The
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.
A tolerance limit is a confidence limit on a percentile of the population rather than a confidence limit on
the mean. A UTL95-95 represents that statistic such that 95% of the observations (current and future)
from the target population will be less than or equal to the UTL95-95 with a CC of 0.95. Stated
differently, the UTL95-95 represents a 95% UCL of the 95th percentile of the data distribution. A
UTL95-95 is designed to simultaneously provide coverage for 95% of all potential observations (current
and future) from the background population with a CC of 0.95. A UTL95-95 can be used when many
(unknown) current or future on-site observations need to be compared with a BTV. For moderately to
highly skewed data sets (high percentage of NDs), upper limits using KM estimates in gamma UCL and
UTL equations provide better results, if the detected observations in the left -censored data set follow a
gamma distribution.
The nonparametric upper limits (e.g., UTLs, UPLs) are computed by the higher order statistics such as
the largest, the second largest, the third largest, and so on of the background data. The order of the
statistic used to compute a nonparametric upper limit depends on the sample size, coverage probability,
and the desired CC. In practice, non -parametric upper limits do not provide the desired coverage to the
population parameter (upper threshold) unless the sample size is large.
Table E3-3 presents the estimated BTV values (Column 16) and applicable methods (Column 17) used in
estimating the upper threshold values. Attachment E-3 presents the ProUCL output of the BTV
computations.
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E.3.5 Comparison of Water Supply Well Data to the Regional BTVs
The data for the water supply wells located within the 0.5 -mile radius from the ash basin compliance
boundary were compared to the regional background BTVs presented in Table E3-3. Comparison to the
regional background BTVs are provided in Table E3-4, and comparison to the facility -specific BTVs are
presented in Table E3-5.
All water supply well results for chromium, hexavalent chromium, iron, and vanadium are below their
respective regional BTVs, and all water supply well results for barium, chromium, hexavalent chromium,
iron, and vanadium are below their respective facility -specific BTV.
Of the 39 water supply well results there is one location where barium, cobalt, and nickel are above the
regional BTV.
Of the 39 water supply well results, there is one location where boron is above the regional BTV of 67.25
micrograms per liter (µg/L) (77 µg/L at MR2-0), but well below the 2L standard and DHHS screening
level of 700 µg/L, and well below the USEPA screening level of 4,000 pg/L. There are two locations
where boron is above the facility -specific BTV of 29 ug/L, but well below the 2L standard, DHHS
screening level, and USEPA screening level.
Of the 39 water supply well results, there are 29 locations where lead is above the facility -specific BTV of
0.28 ug/L, but at only 5 of these locations is lead above the regional BTV of 4 µg/L (MR20, MR2-0, MR2-
P, MR32, and MR9). Only two results are above the 2L standard of 15 µg/L (32 µg/L at MR2-0, and 22
µg/L at MR9).
Of the 39 water supply well results, there are 4 locations where iron is present above the facility -specific
BTV of 1,000 µg/L (MR20, MR2-P, MR32, and MR4, ranging from 1,100 to 3,700 µg/L). While these
concentrations are also above the 2L standard of 300 µg/L, this value is the federal SMCL for iron which
is based on aesthetics (iron staining). Two results are above the NCDHHS screening level for iron of
2,500 µg/L, but all results are well below the USEPA risk-based screening level for iron in tap water of
14,000 µg/L.
Of the 39 water supply wells, there are 4 locations where nickel is above the facility -specific BTV of 9
ug/L (MR12, MR4, MR20, MR2-0). None of these results are above screening levels.
Further discussion of boron and iron and groundwater chemistry is provided in Section E5
E.4 GROUNDWATER FLOW EVALUATION
[The evaluation in Section E.4, including figures and tables, was provided by HDR, Inc.]
E.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 Marshall to demonstrate that ash impacted
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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 83 groundwater monitoring wells to complement the existing 37 monitoring wells and
subsequent sampling of the 120 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 E.4.2, the regional groundwater
system and the hydrogeological SCM are presented in Section E. 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 E.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 E.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 E.4.4.
E.4.2 Site Geology
The Marshall site is located in the Piedmont Province of North Carolina. In-situ materials (in addition to
ash and fill) encountered at Marshall during the CSA include:
• Alluvium (S) — Alluvium is unconsolidated sediment that has been eroded by and redeposited by
streams. Alluvium is present near Lake Norman with thickness ranging from 0 to 32 feet.
• Residuum (Regolith -Residual Soils; M1) — Residuum is weathered soil that was derived from the
in-place weathering of bedrock. It varied in thickness but was relatively thin in comparison to
the saprolite thickness. The range of residuum thickness observed at the Marshall site was 0 to
20 feet.
• Saprolite/Weathered Rock (Regolith; M2) — Saprolite is soil developed by the in-place
weathering of bedrock and retains remnant bedrock structure. The range of
Saprolite/Weathered rock observed at the Marshall site was 24 to 117 feet.
• Partially Weathered/Fractured Rock (TZ) — This material consists of partially weathered and/or
highly fractured bedrock that occurs below Saprolite/Weathered Rock and above bedrock. The
thickness ranges from 0 to 16 feet.
• Bedrock (BR) — Bedrock is hard rock that is unweathered to slightly weathered and relatively
unfractured. The maximum depth that borings extended into bedrock was 54 feet. The bedrock
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at Marshall consist of medium- to coarse-grained biotite gneiss with some schistose texture,
biotite schist, a fine- to medium -grained biotite gneiss, granite, meta -quartz diorite, and quartz -
sericite schist.
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, 201Sa).
E.4.3 Site Hydrogeology
E. 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 E4-1) 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 E4-2). 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 impacted 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 E4-1) (Heath, 1980;
Harned and Daniel, 1992). The residual soil grades into saprolite, a coarser grained material that retains
the structure of the parent bedrock. Beneath the saprolite, partially weathered/fractured bedrock
occurs with depth until sound bedrock is encountered. This mantle of residual soil and saprolite
(regolith) is a hydrogeologic unit that covers and crosses various types of rock (LeGrand, 1988). These
layers serve as the principal groundwater storage reservoir and provide an intergranular medium
through which the recharge and discharge of water from the underlying fractured rock occurs (Daniel
and Harned, 1998) (Figure E4-3). 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
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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 transition zone may serve as a conduit of rapid horizontal flow
and transmission of impacted water (Figure E4-4). 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 Marshall Steam Station Ash
Basin 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 Marshall is consistent with the slope-
aquifer/regolith-fractured rock groundwater model and is an unconfined, connected aquifer system.
The hydrostratigraphic layers (layers of material that have different hydraulic parameters) at the site
consist of in-situ units, Alluvium (S), Residuum (Regolith -Residual Soil; M1), Saprolite/Weathered Rock
(Regolith; M2), Partially Weathered/Fractured Rock (TZ — Transition Zone), Bedrock (BR), and
anthropogenic units, ash (A) and fill (F), as described in Section E.4.2. These units are used in the
groundwater model of the site discussed in Section E.4.4.
Additional information concerning the development of the hydrostratigraphic layers is presented in
Section 11.1 of the CSA report (HDR, 2015a).
E.4.3.2 Groundwater Flow Direction
The Marshall 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 southern, western, and northern extent of the
Marshall property to the southeast toward Lake Norman and slightly east toward an unnamed tributary
that empties into Lake Norman.
Water level potentiometric surfaces and directions for the three flow layers are shown on Figures E4-5
(57)1, E4-6 (34), and E4-7 (10) for water levels recorded between 22 and 27 July 2015 and on
Figures E4-8 (39), E4-9 (34), and E4-10 (10) 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 -aquifer system and show that groundwater flow is away from off-site water
supply wells and toward the discharge feature, Lake Norman.
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 south, west, and north of
1 Numbers shown in parentheses represent the number of measurements used to prepare the groundwater flow
maps.
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the ash basin system serves as a groundwater recharge area and that Lake Norman and the unnamed
tributary serves as the discharge feature for groundwater flow at Marshall.
E.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 E4-11; Table E4-1) obtained during field tests, the average effective porosity obtained from
laboratory testing or from technical literature (CSA report Table 11-8, and CSA Supplement #1 Table 11-
11), and measured horizontal hydraulic gradients between a number of well pairs in the same flow
layer(s) (CSA report Section 6.2.2, Table 6-9). The estimated groundwater seepage velocities are shown
in Table E4-2. 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 E4-4) at Marshall.
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).
E.4.3.4 Constituents Associated with CCR
The data evaluation in the previous sections of this report determined that there is greater horizontal
flow than there is vertical downward flow at the site, particularly in the TZ flow layer. This section builds
upon that knowledge to evaluate the presence of constituents in groundwater associated with a release
from the ash basins. Evaluation of constituent presence or absence in each flow layer, and the
magnitude of the concentrations provide an independent means of assessing the horizontal and vertical
flow of groundwater, and the ability of groundwater to migrate vertically between the flow layers.
Certain constituents present in coal ash can serve as indicators of a release from a coal ash management
area to groundwater; these have been used by USEPA to design the groundwater monitoring program
under the final CCR Rule (USEPA, 2015a). The USEPA defined a phased approach to groundwater
monitoring. The first phase is detection monitoring where groundwater is monitored to detect the
presence of specific constituents that are considered to be indicators of a release from a coal ash
management area (e.g., metals) and other monitoring parameters (e.g., pH, TDS). These data are used
to determine if there has been a release from a coal ash management area. Detection monitoring is
performed for the following list of "indicator" constituents identified in Appendix III of the CCR Rule:
• Boron;
• Calcium;
• Chloride;
• Fluoride (this constituent was not analyzed for in the CSA);
• pH
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• 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.
E.4.3.5 Extent of Boron Exceedances in Groundwater
Groundwater at Marshall 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 Marshall, boron exceedances of the 2L Standards reported in groundwater during the 2015 Round 2
sampling event are shown in plan view (Figure E4-12) and in cross-section view (Figure E4-13) 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 western and northeastern portions of the ash
basin. Groundwater flow direction from these locations is to the southeast to Lake Norman. The
location of the boron exceedances in groundwater in the western portion of the ash basin are
approximately 1,500 feet from the nearest the water supply well, and groundwater flow from this area
is to the southeast, away from the water supply wells.
E.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
(deep), and bedrock. These monitoring wells are located in areas of suspected impacts, in presumed
background areas, and in areas between the ash basin system and off-site water supply wells.
Water supply wells constructed in the Piedmont province are typically drilled to greater depths than
monitoring wells installed for evaluation of inorganic constituents (i.e., constituents with specific gravity
similar to groundwater such as those found in coal ash). As described above, the groundwater levels
and groundwater seepage velocities in the TZ indicate that lateral flow predominates over downward
flow and that coal ash constituent concentrations decrease with depth.
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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 return 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 E4-3).
As noted above, bedrock flow is toward Lake Norman, the discharge feature, and not toward the water
supply wells. The data collection and analysis of flow in all three groundwater flow layers at the site was
conducted while the off-site water supply wells were under normal operations. The effect of pumping
of off-site water supply wells on the direction of groundwater flow at the site is reflected in the water
levels measured in the existing network of monitoring wells. Thus, the measurements of groundwater
flow velocity and direction, and the potentiometric flow maps, reflect groundwater conditions under
normal use of the off-site water supply wells. The effect of pumping water supply wells on groundwater
flow and direction is discussed in more detail in Section E.4.4.
E.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 E4-14). 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.
A review of topographic and monitoring well groundwater data at Marshall found no evidence of
mounding (Figures E4-5 and E4-8).
E.4.3.8 Summary
The hydrogeologic SCM presented in the CSA report (HDR, 2015a) and refined in the CAP -2 report
(HDR,2016) describes groundwater flow in the shallow, transition zone (deep),and bedrock groundwater
zones as predominantly horizontal with flow to the east and southeast toward Lake Norman. 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
0.017, 0.016, and 0.010 feet/foot in the shallow, transition zone (deep), and bedrock groundwater
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zones, respectively. Lake Norman serves as the hydrologic discharge boundary for groundwater at the
site. There are no water supply wells located between the ash basin system and Lake Norman.
E.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 Marshall. A well
capture zone is the area of an aquifer (all three flow layers) in which the water is removed by pumping
wells within a specified time period (Grubb, 1993) (see Figure E4-15). 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 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 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 E.4.3, in an unconfined aquifer system, such as at Marshall,
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
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 E4-15 and E4-16). 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 E.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, Marshall ash sluicing began in
1965 and coal ash sources include the ash basin, Phase I and II dry ash landfills, and PV farm structural
fill. Reverse particle tracking was performed to delineate well capture zones using MODPATH (Pollock,
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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 consistency with the calibrated CAP -2 model, the effective porosity values used for transport model
calibration were also used for reverse particle tracking: 15 percent in ash/fill, 15 percent in soil and
saprolite (M1/M2 zones), 1 percent in the transition zone, and 0.5 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 6.6 inches/year, including inactive areas of the ash basin,
Phase I dry ash landfill, and PV structural fill. The recharge rates applied at the Phase II dry ash landfill
and active ash basin are 4.0 inches/year and 12.3 inches/year, respectively. The head pressure is based
on the amount of water within the ash basin. Recharge was set to zero for the Industrial Landfill No. 1
and FGD residue landfill as they were constructed with liner systems that impede groundwater
recharge.
E. 4.4.1 Methodology
The steady-state groundwater flow and contaminant transport model developed for the Marshall CAP -2
report (HDR, 2016) was utilized for this study. The CAP -2 model was calibrated to match water levels
measured in June 2015 for shallow, deep (TZ), and bedrock 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 Marshall 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. During reverse particle tracking, MODPATH reverses the sign of the velocity term to
calculate 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.
The capture zone for each well was created by connecting the particle track termination points to create
a polygon (Figure E4-16). 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 50 years (corresponding to the
length of time that ash has been stored at the Marshall site, beginning in 1965). 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 E4-16).
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E.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 are consistent with the slope -aquifer system and show that groundwater flow is away from
off-site water supply wells and toward the ash basin and main discharge feature, Lake Norman. Note
that certain limitations and assumptions were made while developing the model. The limitations and
assumptions (listed on Figure E4-16) produce conservative results and do not affect the findings as
presented above. Results are considered conservative because water supply wells were conservatively
assumed to pump continuously at 400 gallons/day, which is the average household usage rate.
E.4.5 Summary and Conclusions
The major findings from the evaluation of groundwater flow at the Marshall Steam Station are as
follows:
The groundwater system at Marshall is consistent with the conceptual model of groundwater
within an unconfined, two -medium system (regolith consisting of soil and saprolite overlying
bedrock) separated by a transition zone of higher hydraulic conductivity (permeability) within a
slope -aquifer system. Within the basin footprint ash, fill, and alluvium are additional layers that
overlie the two -medium system. Three primary flow layers (as defined by the regolith, the
transition zone, and bedrock) are present in the unconfined groundwater system at the site;
shallow (S - water table), deep (D - TZ), and bedrock (BR).
• Site-specific water level measurements confirm that groundwater flow is to the southeast
toward Lake Norman from the topographic divides south, west, and north of the ash basin
system away from the water supply wells, and also confirm the flow model predictions.
• The transition zone that separates the regolith above from the bedrock below serves as the
primary transmitter of impacted groundwater with the regolith as the principal reservoir of
groundwater. Water level data and the groundwater modeling indicate horizontal flow
predominates over downward vertical flow. In essence, it is easier for groundwater to flow
horizontally within the transition zone than vertically down through the bedrock.
• Groundwater flow is laterally away from the water supply wells within the transition zone and
overlying saprolite and soil limiting the impact of coal ash related constituents in bedrock as
shown by analytical data and supported by groundwater modeling.
• A review of topographic and monitoring well groundwater data at Marshall found no evidence
of mounding associated with the ash basin system.
• 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.
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Based on this evidence, groundwater utilized by water supply wells near the coal ash
impoundments is not impacted by the coal ash sources.
E.5 GROUNDWATER CHARACTERISTICS EVALUATION
The results from the local water supply well sampling conducted by the NCDEQ in the vicinity of the
Marshall 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 sampled
local water supply wells, and the conditions in groundwater at the facility where CCR -impacts have been
demonstrated. A detailed statistical evaluation of background groundwater data compared to the local
water supply well data, and to the facility -specific background monitoring well data was presented in
Section E.3. As indicated in Section E.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 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
local water supply wells.
The evaluation consists of the following two key steps:
• Identify site-specific CCR -related signature constituents that can effectively serve as indicators
to evaluate the extent of the CCR -impacted groundwater.
• Compare the absolute and relative abundance of major common constituents and signature
constituents among various well groups to determine whether CCR -impacted groundwater at
the site has resulted in the water quality exceedances found in the local water supply wells.
Based on the results of this evaluation, there is no relationship between the CCR -impacted groundwater
and the water quality exceedances reported in the local water supply wells.
More details regarding the evaluation approach, data analysis methods, results, and conclusions are
presented below.
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E.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 concentrations 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 NCDEQ and from Duke Energy).
Note that the wells in a major group may be further divided into multiple subgroups in order to
evaluate the spatial trends of the groundwater data; for example, the facility bedrock wells may
be further divided into two subgroups based on the groundwater flow direction in the bedrock
unit: (a) facility bedrock wells that are likely to be within the area of CCR -impacted groundwater,
and (b) facility bedrock wells that are likely to be outside of this area.
• Identify useful redox sensitive 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.
• 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 E.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.
E.5.2 CCR -Related Constituents Screening for Signature Development
The first step for determining the CCR -impacted signature constituents is to identify the constituents
that have the following characteristics:
• They are recalcitrant to degradation and transformation under site-specific conditions.
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They are very soluble and subject to little sorption. The site-specific sorption coefficients for
various CCR -related constituents are shown in Table E5-1.
• 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 E5-1), and can be associated with CCR impacts to
groundwater (USEPA, 2015a). These two trace metals are also selected as candidate
constituents. Total barium and cobalt concentrations were used in this evaluation.
Dissolved oxygen, dissolved iron, and dissolved manganese: Groundwater in the ash basin 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 E5-1) (HDR, 2016). It is noted that, because
groundwater samples collected from the regional background wells and local water supply wells
only analyzed for total iron, total iron concentrations were used to conservatively represent the
iron concentrations in these groundwater samples. Because the concentrations of dissolved
iron and manganese are sensitive to the presence of dissolved oxygen, the iron and manganese
data used in this evaluation will help identify and compare the redox conditions of the different
well groups.
E.5.3 Data Analysis Methods
E. 5.3.1 Data Sources
The groundwater analytical data for Marshall used in this evaluation are from the following sources:
• Facility groundwater monitoring well data;
• Local water supply well data from NCDEQ;
• NCDEQ reconnaissance or background water supply well data; and
• Duke Energy background water supply well data.
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E.5.3.2 Data Aggregation
The general rules for data aggregation are described here. When multiple sampling events occur for a
well, the following rules were used to find a representative concentration value for the box plot and
correlation plot evaluations:
For boron, calcium, chloride, sulfate, TDS, barium, and cobalt, the representative value is
defined as the maximum of the detected values if the analytical results are not all NDs. If the
analytical results are all NDs, the lowest reporting limit is defined as the representative value.
Using the maximum concentrations will help not underestimate the CCR impacts to the local
water supply wells and facility monitoring wells.
• For dissolved oxygen, total and dissolved iron, and total and dissolved manganese, the average
concentration is used as the representative value for the general conditions observed in a well.
• For piper plots, the average concentration is used as the representative value for the general
conditions observed in a well.
The reporting limits are used to represent the ND results.
E.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 E5-2
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 75th percentile or the maximum value; the location of
the lower whisker is the greater of 1.5 times the IQR below the 25th percentile or the minimum value.
This analysis includes both detected and non-detected values.
E.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
correlation plot, different data groups can be plotted using different symbols with the concentrations of
one constituent on the x-axis and the concentrations of the other constituent on the y-axis. The
clustering patterns or trends will illustrate the correlations among data groups.
E.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.
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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 E5-2, 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).
E.5.4 Evaluation Results
E.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 E5-3. 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 E5-4, which shows trends similar to
those observed for other major CCR constituents in Figure E5-3. The barium and cobalt concentration
differences between the ash basin porewater and the groundwater in local water supply wells are also
not as significant as boron and sulfate. Because boron and sulfate are very mobile, subject to little
sorption onto mineral surfaces, and not susceptible to degradation or transformation, and because they
show the most elevated concentrations (relative to the concentrations found in the local water supply
wells), they are thus considered to be effective signature constituents.
The box plot comparison of dissolved oxygen, iron, and manganese is shown in Figure E5-5. The trend of
dissolved oxygen concentrations shows that the groundwater in the local water supply wells is generally
significantly 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).
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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 site groundwater generally favors the presence of reduced iron
and manganese (Figure E5-1), 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 a useful signature constituent.
E.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 wells, facility bedrock wells, local water supply wells, 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;
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• Regional background wells; and
• Facility bedrock wells, which are further divided into three subgroups:
— Subgroup 1 (Downgradient): The bedrock 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 -113R, AL -213R, AB -SBR, AB -613R, AB -913R, and
AB-15BR belong to this subgroup.
— Subgroup 2 (Side Gradient): The wells are 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. These wells are not expected to be influenced by the ash
basin. The wells, BG-2BR, MW-14BR, and GWA-1BR belong to this group. It is noted
that the groundwater flow field near GWA-1BR is uncertain; it may be assigned as a side
gradient or a downgradient well. It is tentatively assigned as a side gradient well here
primarily because the concentrations of dissolved oxygen, iron, and manganese
generally do not resemble the characteristics of the ash basin porewater.
— Subgroup 3 (Upgradient): Groundwater flowing through the bedrock wells in this
subgroup is expected to flow beneath the ash basin at some point in the future. Only
GWA-9BR is in this well group.
The data obtained from the facility bedrock wells may help identify the potential groundwater chemistry
characteristics of a CCR -impacted bedrock well and help illustrate the spatial pattern of CCR -impacted
facility bedrock wells. Understanding the chemistry and special patterns of CCR -impacted groundwater
will be useful in assessing the potential impacts to the local water supply wells. It should be noted that
the subgroups were formed to facilitate the evaluation presented below. The final well group
assignment will be based on the evaluation results, as shown in Figure E5-6.
Based on Figure E5-3, boron and sulfate concentration are useful indicators for CCR -impacted
groundwater. A correlation plot of boron and sulfate concentrations is shown in Figure E5-7. Panel (a)
shows the correlation plot for the ash basin porewater wells and the facility downgradient bedrock
wells. These results are distinguished by elevated boron concentrations and relatively high 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 are distinguished by relatively low boron and sulfate
concentrations in comparison to the ash basin porewater wells in Panel (a) except that GWA-1BR has an
elevated sulfate concentration more similar to the ash basin porewater wells. Panel (c) shows the
overlay of the data from the regional background wells and local water supply wells on the data in
Panel (b). Panel (c) shows that the ash basin porewater data are clustered in Area 1 and the local water
supply well data are clustered in Area 2. Note that the sulfate concentrations have much greater
variability in the regional background wells, and thus two regional background well data points fall
outside of Area 2. The facility downgradient bedrock wells are either in Area 1 or exhibit a significantly
higher sulfate concentration than those of the local water supply wells. All upgradient and side gradient
bedrock wells, except GWA-113R, show similar lower boron and sulfate concentrations to those observed
in the local water supply wells. As described earlier, it is somewhat difficult to classify a well to be a side
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gradient or a downgradient well. Based on this correlation plot, GWA-1BR may be somewhat influenced
by the CCR -impacted groundwater.
Based on Figures E5-3 and Figure E5-5, boron and dissolved oxygen concentration may also be useful
indicators for CCR -impacted groundwater. The correlation plot for boron and oxygen is shown in
Figure E5-8. Panel (a) shows the correlation plot for the ash basin porewater wells and the facility
downgradient bedrock wells. These results are distinguished by elevated boron concentrations and
relatively low dissolved oxygen concentrations. 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 are distinguished
by relatively low boron concentrations and dissolved oxygen concentrations that are higher than the ash
basin porewater wells in Panel (a). Panel (c) shows the overlay of the data from the regional background
wells and local water supply wells on the data in Panel (b). These added wells are distinguished by very
low to non -detect levels of boron, and a range of dissolved oxygen concentrations. The Panel (c) plot
shows that the data are clustered in two distinct areas. Area 1 contains the data from the ash basin
porewater wells. Area 2 contains the data from the local water supply wells and regional background
wells.
The data pairs for the facility bedrock wells that are classified as the downgradient group are generally
clustered toward the ash basin porewater data pairs (Area 1). In contrast, the data pairs of the side
gradient and upgradient wells are generally clustered toward the water supply and regional background
wells (Area 2). It is noted that dissolved oxygen concentrations in some regional background and local
water supply wells are already very low (<1,000 pg/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 pg/L for these wells. The dissolved oxygen concentration observed in
facility bedrock well, GWA-9BR, is approximately 6,000 pg/L, indicating the background dissolved oxygen
can be naturally high in the vicinity of the site. 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 pg/L dissolved oxygen.
The correlation plot result shows that the low oxygen and elevated boron concentrations serve as an
effective signature pair to help identify the CCR -impacted groundwater. The fact that many local water
supply wells are significantly more oxygenic suggests that these water supply wells do not obtain
groundwater from the ash basin because no effective mass transfer mechanism can replenish oxygen
during the groundwater transport from the ash basin to a local water supply well.
The groundwater data for a subset of the local water supply wells exhibit low dissolved oxygen
concentrations (lower than 4,000 pg/L) and detected boron concentrations higher than 20 pg/L. These
conditions could be suggestive of a potential impact of CCR -impacted groundwater. Therefore, these
locations were further evaluated for the concentrations of other CCR indicator constituents. The
locations of these water supply wells are shown in Figure E5-9. Table E5-2 shows the comparison
between the observed boron, sulfate, and barium concentrations in these wells and the site-specific
regional background threshold values for these constituents. The results show that the boron and
barium concentrations observed in these wells are below the BTVs derived in Section E.3 with the
exception of the boron concentration (77 pg/L) in the MR -2 (office) well, which is slightly higher than the
boron BTV (67.25 pg/L). The sulfate concentrations in these water supply wells are all below the sulfate
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BTV based on the regional background well data. The concentrations observed in these water supply
wells are within or close to the range of the background.
Based on Figures E5-7 and E5-8, CCR -impacted groundwater has been found in the facility bedrock wells
that are within or downgradient of the ash basin footprint. However, the groundwater in the facility
upgradient and side gradient bedrock wells is generally much more oxygenic and low in boron and
sulfate concentrations, thus the water quality of these upgradient and side gradient 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 high 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.
E.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 E5-10.
Panel (a) shows the data for the ash basin porewater wells; the cation subplot shows that calcium or
magnesium is the dominant cation in the porewater, the diamond subplot shows that the relative
abundance of calcium and magnesium in the porewater is larger than 60 percent, and the anion subplot
shows that the relative abundance of chloride is generally less than 20 percent. The results also show
that these wells have a wide range of sulfate abundance.
Panel (b) shows the data for both the ash basin porewater wells and the facility downgradient bedrock
wells. The data for the facility downgradient bedrock wells are generally clustered with those of the ash
basin porewater wells, suggesting that the CCR -impacted groundwater is present in the downgradient
bedrock wells. It is noted that some facility bedrock well data points (AB-1BR and AB -613R) deviate from
the general data distribution pattern. These deviations show the variability of bedrock groundwater
quality under the ash basin footprint. The impacts of the ash basin porewater on the facility
downgradient bedrock wells are generally consistent with the understanding of the groundwater flow
direction in the bedrock unit.
The piper plots for the water supply, regional background, upgradient, and side gradient bedrock wells
are provided in Figure E5-11. Panel (a) of Figure E5-11 shows the data for the local water supply and
regional background wells. As can be seen, these well data are grouped fairly tightly together in each of
the sections of the piper diagram except for an outlier in each subplot (see the data in blue circles). This
indicates that they have similar major ion characteristics, and the grouping is very distinctive from the
ash basin related wells in Figure E5-10. Panel (b) of Figure E5-11 shows the data for two subgroups of
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the facility bedrock wells (upgradient and side gradient) on top of the data of the water supply and
regional background wells in Panel (a) of Figure E5-11. When viewed this way, it is clear that the
upgradient facility bedrock well (GWA-9BR) and the two side gradient bedrock wells (BG-2BR and MW-
14BR) have characteristics very similar to and indistinguishable from the local water supply wells. It is
also clear that GWA-1BR data are not consistent with the other bedrock wells. This well is located in the
southwest corner of the facility and is more likely partially downgradient from the ash basin. This is
consistent with the findings from the correlation plot of boron and sulfate (Figure E5-7). Based on the
correlation and piper plot results, GWA-9BR is thus considered to be a downgradient well, as shown in
Figure E5-6.
Figure E5-12 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 line in Panel (b) encloses almost all the local water supply well data,
but excludes most of the ash basin related data in Panel (a).
The piper plot indicates that the groundwater at this location has a significantly higher relative
abundance of sulfate in comparison to that in the local water supply wells. For the other three
upgradient or side gradient facility bedrock wells, their data are within the variability of the local water
supply well data.
The data for the downgradient facility bedrock wells are generally within the variability of the ash basin
porewater well data. These piper plot results are consistent with the results of the correlation plots;
both show a similarity between the CCR -impacted facility bedrock wells and the ash basin porewater
wells. In the piper plots, the local water supply well data show a different cluster pattern in comparison
with the data of the ash basin porewater wells and the impacted facility bedrock wells, indicating that
the source water for the supply wells is not CCR -impacted groundwater.
E.5.5 Conclusions
Based on this groundwater chemistry evaluation, the following key conclusions can be drawn:
The boron and sulfate concentrations in the ash basin groundwater are considerably higher than
the maximum sampled boron concentration found in the local water supply wells. Because
boron and sulfate exhibit little sorption to mineral surfaces and are not expected to precipitate
or be transformed under the site geochemical conditions, they are considered to be the most
effective signature constituents among the coal ash related constituents for evaluating the
groundwater impacts from the ash basin.
• The boron and sulfate concentrations detected in the local water supply wells are within the
range of the boron and sulfate concentrations found in the 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 boron and sulfate correlation plot shows a very distinct data separation pattern between
the ash basin and facility downgradient bedrock wells and the water supply and regional
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background wells, indicating that the local water supply wells are not affected by CCR -impacted
groundwater.
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 the local water supply wells are generally more oxygenic. The lack of
dissolved oxygen can be considered to be a useful signature of CCR -impacted groundwater. This
suggests that many of the local water supply wells are not likely to 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 local water supply wells.
• The CCR -impacted facility bedrock wells identified using the correlation and piper plots are
consistent with the knowledge of the groundwater flow field in the vicinity of the facility, as
described in Section E.4. The local water supply wells are generally upgradient or side gradient
of the ash basin.
• The correlation and piper plots show very different clustering patterns 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 operational
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 E.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.
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E.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 0.5 -mile radius of the
Marshall ash basin compliance boundary could be impacted by CCR releases from the ash basin. The
conclusion from the detailed weight of evidence demonstrates that water supply wells in the vicinity of
the Marshall facility are not impacted by CCR releases from the ash basin.
The evaluation of the private and public water supply well data collected by NCDEQ and the detailed
statistical analysis of regional background groundwater data indicate that constituent concentrations in
the water supply wells are generally consistent with background. Of the 39 sample results, there are
2 values for lead that are above the BTV and above the screening level, 4 values for iron above the
lowest screening level and above the BTV, but all are below the USEPA health risk-based screening level,
and 1 value for boron was above the BTV but well below all screening levels.
The comprehensive evaluation of groundwater flow with respect to local water supply wells
demonstrates that groundwater flow is to the southeast toward Lake Norman from the topographic
divides south, west, and north of the ash basin system away from where the water supply wells are
located. 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.
This conclusion is confirmed by the detailed characterization of groundwater chemistry including
evaluation of CCR indicators, redox conditions, and correlation evaluations. The results of the chemical
correlation analyses indicate that, based on the different constituent clustering patterns from the ash
basin porewater wells and the water supply wells, the source water for the water supply wells is not
CCR -impacted groundwater.
Based on this combined weight of evidence, groundwater utilized by water supply wells near the coal
ash impoundments is not impacted by the coal ash sources.
These results indicate that a Low classification for the Marshall Steam Station under the CAMA is
warranted.
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E.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. 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.
3. CAMA. 2014. North Carolina Coal Ash Management Act. Senate Bill S729v7. Available at:
http://www.ncleg.net/Sessions/2013/Bills/Senate/PDF/S729v7.PDF
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 (Water -Resources
Investigations Report 97-4140, 65p.). U.S. Geological Survey.
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.
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13. Haley & Aldrich. 2015. Evaluation of NC DEQ 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. Marshall 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. Marshall Steam Station - Ash Basin Supplement to Drinking Water Supply Well
and Receptor Survey. HDR, Inc. [Online] URL: http://porta1.ncdenr.org/web/wq/drinking-
water-receptorsurveys
18. HDR. 2014c. Marshall Steam Station Ash Basin, Proposed Groundwater Assessment Work Plan
(Rev. 1), NPDES Permit NC0004987. HDR, Inc. December 30, 2014.
19. HDR. 2015a. Comprehensive Site Assessment Report, Duke Energy Marshall Steam Station,
September. HDR, Inc.
20. HDR. 2015b. Corrective Action Plan Part 1, Duke Energy Marshall Steam Station Ash Basin,
December. HDR, Inc.
21. HDR. 2016. Corrective Action Plan Part 2, Duke Energy Marshall Steam Station Ash Basin,
March. HDR, Inc.
22. Heath, R.C. 1980. Basic elements of groundwater hydrology with reference to conditions in
North Carolina: U.S. Geological Survey Open -File Report 80-44, 86p.
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, 693p.
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 E — Marshall
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. North Carolina 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. North Carolina State University. 1995. The North Carolina Wellhead Protection Guidebook,
published by NCSU for NCDENR, Division of Environmental Management, Groundwater Section.
32. 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
33. Rumbaugh J. and Rumbaugh, D. 2011. Groundwater Vistas Version 6.84 Build 6, Environmental
Simulation, Incorporated.
34. USEPA. 1980. Effects of Coal -ash Leachate on Ground Water Quality. U.S. Environmental
Protection Agency. EPA -600/7-80-066. March.
35. 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. October.
36. 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.
APRIL 2016 42 %UICH

Evaluation of Water Supply Wells
in the Vicinity of Duke Energy Coal Ash Basins
Appendix E — Marshall
37. 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
38. 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
39. 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
40. USEPA. 2015b. USEPA Regional Screening Levels (RSLs). November 2015. U.S. Environmental
Protection Agency. Available at: http://www.epa.gov/reg3hwmd/risl</human/rb-
concentration table/Generic Tables/index.htm
41. Winograd, I.J. and Robertson, F.N. 1982. Deep oxygenated ground water: anomaly or common
occurrence?. Science, 216(4551), pp.1227-1230.
42. 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 E2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 1 of 3
15A NCAC 0ard(a):
Groundwater Standard (a)
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
1
NS
20
0.2
Federal MCL/SMCL(b):
(• denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
"500
6
30
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Appendix III
App
endix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Marshall
MR1
<500
5200
7.2
6.4
11
58
0.29
<1
13
<1
0.84
<10
<1
0.089
<0.2
0.11
<1
<1
Marshall
MR10
<5
5130
2.4
6
<2
65
<0.5
<0.5
38.8
<0.2
<0.08
0.99
<0.5
0.7
<0.2
<0.5
<0.5
<0.1
Marshall
MR11
<5
12900
1.3
6.5
2
71
<0.5
<0.5
48.5
<0.2
<0.08
0.87
<0.5
0.43
<0.2
<0.5
<0.5
<0.1
Marshall
MR12
<130
6500
2.3
6.75
<1
93
<1
2.9
34
<2
<0.1
<25
<25
2.4
0.042
0.088
<5
<0.5
Marshall
MR13
<5
17100
1.9
7.36
8.4
85
<0.5
<0.5
32.1
<0.2
<0.08
0.56
<0.5
<0.1
<0.2
4.7
<0.5
<0.1
Marshall
MR14
<5
9680
2.3
6.7
0.49
67
<0.5
<0.5
49.5
0.078
<0.08
0.82
0.16
0.2
0.043
0.067
<0.5
<0.1
Marshall
MR16
<5
21600
10.2
7.3
18.7
140
<0.5
<0.08
94
<0.11
<0.06
1.9
<0.03
<0.1
<0.01
<0.11
<0.16
<0.06
Marshall
MR17
<5
9600
1.4
7.13
0.74
46
<0.5
<0.5
12
<0.2
<0.08
<0.5
0.23
0.49
0.041
0.067
<0.5
<0.1
Marshall
MR18
<5
12000
3.5
7.18
2.8
88
<0.5
3
21
<0.2
<0.08
<0.5
0.22
0.42
0.038
<0.5
3.4
<0.1
Marshall
MR20
<5
28000
3.3
7.81
2.2
107
0.13
3.2
14
<0.2
<0.08
0.96
0.31
12
0.04
2.2
1.4
<0.1
Marshall
MR21
5
2700
4.1
6.11
0.55
49
<0.1
2.6
82
0.23
<0.08
<0.5
0.88
0.28
0.036
0.52
1.7
<0.1
Marshall
MR22
<5
3790
2.3
5.7
<2
55
<0.5
<0.5
79.3
<0.2
<0.08
0.91
<0.5
2.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR23
<5
23000
27.6
6.5
2.7
1 194
<0.5
<0.5
130
<0.2
<0.08
1.5
<0.5
0.48
<0.2
<0.5
<0.5
<0.1
Marshall
MR25
62
10000
7.8
6.1
3.1
150
0.049
1 <0.5
53.8
<0.2
<0.08
1.1
<0.5
0.97
<0.2
0.12
<0.5
<0.1
Marshall
MR26
<5
8100
3.4
6.5
2
80
<0.5
<0.5
57
<0.2
<0.08
1.4
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Marshall
MR28
<5
12600
14.3
6.2
2.4
105
<0.5
<0.5
44.5
<0.2
<0.08
1
<0.5
1.2
<0.2
<0.5
<0.5
<0.1
Marshall
MR29
<5
3200
1.5
6.3
<2
59
<0.5
<0.5
37
<0.2
<0.08
2.9
<0.5
0.28
<0.2
<0.5
<0.5
<0.1
Marshall
MR2-0
77
15200
1.2
6.3
3.4
92
0.058
<0.5
90.2
<0.2
0.086
4.5
<0.5
32
<0.2
2.1
<0.5
<0.1
Marshall
MR2-P
<500
22000
0.92
7
4
130
0.22
0.31
130
<1
<1
2.1
0.15
4.1
<0.2
1.9
<1
<1
Marshall
MR30
<20
13000
1
6.36
5
68
<0.4
0.39
30.5
<0.11
<0.06
3.22
<0.03
0.41
<0.01
0.67
0.43
<0.06
Marshall
MR31
<5
3820
1.6
6.5
<2
68
<0.5
<0.5
23.3
<0.2
<0.08
1.5
<0.5
0.37
<0.2
<0.5
<0.5
<0.1
Marshall
MR32
<5
15000
5.72
6.4
<1
106
<0.5
<0.5
130
<0.2
<0.08
2
2
8
<0.2
<0.5
<0.5
0.1
Marshall
MR33
<5
4510
2.9
6.2
<2
57
<0.5
<0.5
26.7
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR35
<5
14800
1.4
7.3
5
96
<0.5
<0.5
18
<0.2
<0.08
<0.5
<0.5
1.4
<0.2
1.3
<0.5
<0.1
Marshall
MR36
< 5
< 40
2.7
8.7
11.7
75
< 0.5
< 0.5
< 0.3
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Marshall
MR37
<5
2760
5.3
6.1
<2
2040
<0.5
<0.5
32.3
<0.2
<0.08
2.8
<0.5
0.24
<0.2
<0.5
<0.5
<0.1
Marshall
MR38
<5
3090
1.5
5.8
<2
224
<0.5
<0.5
91.7
0.21
<0.08
1.7
<0.5
0.54
<0.2
<0.5
<0.5
<0.1
Marshall
MR4
< 25
41000
55
7.09
< 1
200
< 1
0.66
370
0.19
0.12
< 5
0.36
0.13
0.041
< 10
0.3
< 0.5
Marshall
MR40
<5
21800
2.8
6.4
<2
97
<0.5
<0.5
17.4
<0.2
0.09
0.56
1 <0.5
0.86
<0.2
<0.5
<0.5
<0.1
Marshall
MR42
<5
3690
4.1
5.9
<2
47
<0.5
<0.5
35
<0.2
<0.08
0.96
<0.5
0.88
<0.2
<0.5
<0.5
<0.1
Marshall
MR43
<5
5010
1.6
6.1
<2
90
<0.5
<0.5
43
<0.2
<0.08
4.8
<0.5
1
<0.2
<0.5
<0.5
<0.1
Marshall
MR44
5.1
9060
1.6
6.2
<2
93
<0.5
<0.5
33
<0.2
<0.08
1.2
<0.5
0.33
<0.2
<0.5
<0.5
<0.1
Marshall
MR45
<5
3530
6.2
5.6
<2
65
<0.5
<0.5
127
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR46
<5
11600
1.6
6.5
2.3
55
<0.5
<0.5
38.7
<0.2
<0.08
0.97
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR47
<5
2870
1.1
6.1
<2
50
<0.5
<0.5
83.5
<0.2
<0.08
1.6
<0.5
0.18
<0.2
<0.5
<0.5
<0.1
Marshall
MR48
<5
7550
2.5
6.2
<2
49
<0.5
<0.5
58.4
<0.2
<0.08
1.4
<0.5
0.38
<0.2
<0.5
<0.5
<0.1
Marshall
MR6
<5
10200
4.7
6.2
<2
119
<0.5
0.1
52.9
<0.2
<0.08
1.74
<0.5
0.65
<0.2
<0.5
<0.5
<0.1
Marshall
MR8
<5
8400
3.3
6.4
2.6
98
<0.4
0.16
14
<0.11
<0.06
1 1.11
<0.03
0.82
<0.01
2.8
0.32
<0.06
Marshall
MR9
<5
7300
1.3
6.73
<1
88
<0.5
0.39
18
<0.2
<0.08
0.92
0.05
22
0.027
<0.5
<0.5
<0.1
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Table E2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
ISA NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(* denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Marshall
MR1
<5
7.6
0.0013
28
<10
1400
0.68
<2
1300
10000
28
0.34
17
17
<5
<3.1
Marshall
MR10
1.5
24.6
0.0033
260
0.43
804
1.7
<0.5
1560
5430
59
<0.005
20.5
20.5
<5
<2.5
Marshall
MR11
1
<10
0.0135
<50
0.52
584
0.72
<0.5
2430
3470
78.2
0.0069
35.8
35.8
<5
<2.5
Marshall
MR12
12
<200
0.36
330
<20
1500
53
10
2200
10000
99
0.06
34
34
<10
0.4
Marshall
MR13
2.8
<10
0.00953
<50
0.18
3080
0.79
<0.5
2700
7760
353
<0.005
40.9
40.9
<1
<2.5
Marshall
MR14
1.1
2.2
0.02
210
0.65
2300
1.5
0.89
1940
6400
85.3
0.016
37
37
<5
<1
Marshall
MR16
0.36
<10
0.00029
980
<0.03
4600
131
0.48
2900
5400
103
0.0063
53
52
<1
<2.5
Marshall
MR17
2.6
15
0.0107
240
0.25
2500
0.89
1
1900
5000
189
0.0104
38.5
38.5
<5
<1
Marshall
MR18
9.9
<10
0.161
500
0.037
3000
15
2
2700
13000
240
0.015
43
43
<5
<1
Marshall
MR20
14
<10
0.13
1100
0.43
5400
13
3.4
3000
14000
170
0.036
71
70
<5
<1
Marshall
MR21
9.8
25.1
0.013
190
0.15
1500
34
0.66
1700
2500
9.7
0.028
6
6
<5
<1
Marshall
MR22
<1
<10
0.0336
<50
0.56
1200
3.8
0.55
2430
4370
34.1
0.025
16.2
16.2
<5
<2.5
Marshall
MR23
3
<10
0.515
<50
1.1
6200
1.2
<0.5
3800
19000
280
0.112
54
54
<0
<1
Marshall
MR25
2
<10
0.0034
<50
0.96
3000
1.2
0.24
2300
12000
110
0.106
53
53
<5
<2.5
Marshall
MR26
3
<10
0.0132
<50
1.2
3000
<0.5
<0.5
2400
7100
170
0.007
38
38
<0
<1
Marshall
MR28
1.9
<10
0.0363
114
0.064
2500
4.4
1.1
2260
8060
162
0.151
35.5
35.5
<5
<2.5
Marshall
MR29
2.9
<10
0.0119
<50
1.5
915
3.2
0.69
1300
4080
106
0.0348
16.7
16.7
<5
<5
Marshall
MR2-O
5.5
11.1
0.0959
109
<0.03
3980
17.2
3.2
3550
6650
378
1.06
58.1
58.1
<5
2.9
Marshall
MR2-P
1.6
91
0.0051
3700
<10
3800
50
1.1
3400
7800
260
0.2
87
87
<5
1.1
Marshall
MR30
2.24
25.9
0.0058
27
2.74
2230
<2
0.61
1740
9260
163
0.0501
49
<2.5
Marshall
MR31
4.7
<10
0.0116
<50
1.4
900
0.81
<0.5
1450
6380
46
0.0284
19.2
19.2
<5
<2.5
Marshall
MR32
8
318
0.043
3100
0.41
1800
130
<0.5
3500
5830
110
0.138
32.3
32.3
<0
105
Marshall
MR33
1.7
<10
0.0113
<50
0.9
831
<0.5
<0.5
1280
5080
46.7
<0.005
16.7
16.7
<5
<2.5
Marshall
MR35
2
21.1
0.0064
65.4
<0.03
3270
23.5
<0.5
2020
7180
95
<0.005
54.5
54.5
<5
<2.5
Marshall
MR36
<1
<10
<0.001
105
<0.03
<10
0.54
<0.5
155
33500
<0.5
<0.005
46.6
46.6
<5
<2.5
Marshall
MR37
<1
<10
0.0065
<50
2.7
791
4.1
<0.5
1320
3230
21.9
0.0179
8.3
8.3
<5
<2.5
Marshall
MR38
<1
<10
0.0169
<50
1.3
1060
5.3
0.51
2310
3970
36
0.0393
13.9
13.9
<5
<2.5
Marshall
MR4
<5
33
0.00088
1200
<20
12000
30
3.5
5000
19000
580
0.0099
86
86
<10
4.7
Marshall
MR40
1.5
<10
0.0172
<50
0.5
1900
5.1
<0.5
1700
8040
100
0.0592
46.6
46.6
<5
<2.5
Marshall
MR42
<1
<10
0.0171
<50
0.63
542
<0.5
<0.5
1740
7110
60.3
0.0061
15.3
15.3
<5
<2.5
Marshall
MR43
3.9
<10
0.0149
190
2.4
2270
1.9
1.2
2500
5720
76.3
0.0055
29.2
29.2
<5
<2.5
Marshall
MR44
5.1
<10
0.0085
327
0.54
2130
0.96
<0.5
1780
8340
196
0.0159
39.4
39.4
<5
<2.6
Marshall
MR45
<1
21.5
0.0337
<50
0.73
1020
12
0.97
2360
4600
37.4
0.0422
9.2
9.2
<5
<2.5
Marshall
MR46
1.2
<10
0.0217
<50
0.6
422
10.2
<0.5
2530
2940
45.7
0.173
26.9
26.9
<5
<2.5
Marshall
MR47
1.7
<10
0.0073
<50
1.3
372
0.86
0.72
2340
4210
129
0.0096
13.9
13.9
<5
<2.5
Marshall
MR48
1.1
< 10
0.0121
< 50
0.98
524
5.4
0.52
1860
1730
55.8
0.02
19.9
19.9
< 5
< 2.5
Marshall
MR6
1.5
<30
0.098
20
0.83
2480
0.92
0.39
2330
9440
309
0.0336
38
37.5
<S
<2.5
Marshall
MR8
2.65
15.7
0.014619.8
0.56
1900
1.8
0.3
1700
7900
50
0.0211
36
35
<1
<2.5
Marshall
MR9
6.4
< 10
0.051
180
0.68
1300
0.71
2.4
802
6950
1 83.5
0.15
29
29
<5
< 1
Page 2 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Table E2-1
Comparison of NCDEQ Water Supply Well Data to 2L Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
ISA NCAC 02L.0202
Groundwater Standard (a):
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
NS
NS
NS
NS
DHHS Screening Level (c):
NS
NS
NS
NS
NS
RSL 2015(d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Marshall
MR1
0.24
7.4
63
13
684
Marshall
MR10
<1
16.5
64.2
7.6
170.7
Marshall
MR11
<1
17.6
86.9
7.7
402.5
Marshall
MR12
<1
12
83
9.81
130
Marshall
MR13
<1
19.4
116.5
2.8
117.2
Marshall
MR14
<1
17.5
89.6
8.35
300.1
Marshall
MR16
5.7
22
196
4.77
<
Marshall
MR17
<1
17.7
86.4
8.68
219
Marshall
MR18
<1
18.8
116
7.77
256.3
Marshall
MR20
<1
19.3
177
8.27
160
Marshall
MR21
<1
16.7
44
8.92
356.4
Marshall
MR22
<1
16.2
62.4
8.2
287.7
Marshall
MR23
<1
18.8
270.3
5.6
240
Marshall
MR25
0.21
22.6
132.7
7.7
149
Marshall
MR26
<1
17.2
100
7.1
236
Marshall
MR28
<1
16.6
130.4
6.6
184.8
Marshall
MR29
<1
16.4
45.7
7.6
382.1
Marshall
MR2-O
0.5
22.6
150.1
6.9
139
Marshall
MR2-P
3.9
15.6
149
5.5
1
Marshall
MR30
<1
15.6
191
5.41
Marshall
MR31
<1
18.8
57.4
7.9
118.5
Marshall
MR32
28
20
117.5
8.1
215
Marshall
MR33
<1
18.1
61.7
7.9
354.8
Marshall
MR35
<1
16.5
143.3
1.8
259.2
Marshall
MR36
1.2
16.2
136.3
0.01
<
Marshall
MR37
<1
17.9
44.8
8.7
329.5
Marshall
MR38
<1
16.3
48.8
6.8
304.9
Marshall
MR4
2.5
14.1
387
4.82
54
Marshall
MR40
<1
17.3
107.9
7.5
110.9
Marshall
MR42
<1
19
56
6.8
124.2
Marshall
MR43
1.2
16.9
79.1
7.3
428.9
Marshall
MR44
3.2
16.9
103.4
6.6
182.5
Marshall
MR45
<1
17
61.3
7
282.9
Marshall
MR46
<1
20.2
82
6.1
109.2
Marshall
MR47
<1
18.3
41.1
8
112.9
Marshall
MR48
<1
16.8
55.1
7.1
203.8
Marshall
MR6
2.9
17.9
135
8.39
216
Marshall
MR8
<1
17.7
106
7.98
206.8
Marshall
MR9
<1
14.4
76
8.76
110
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx 2L April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/8/2016

Table E2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
15at NCAC 0 . ():
Groundwater Standar.rd aa
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):
seconds standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015 (d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
35
5.7
100
100
0.2
Appendix III
Appendix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Marshall
MR1
<500
5200
7.2
6.4
11
58
0.29
<1
13
<1
0.84
<10
<1
0.089
c0.2
0.11
<1
<1
Marshall
MR10
<5
5130
2.4
6
<2
65
<0.5
<0.5
38.8
<0.2
<0.08
0.99
<0.5
0.7
<0.2
<0.5
<0.5
<0.1
Marshall
MR11
<5
12900
1.3
6.5
2
71
<0.5
<0.5
48.5
<0.2
<0.08
0.87
<0.5
0.43
<0.2
<0.5
<0.5
<0.1
Marshall
MR12
<130
6500
2.3
6.75
<1
93
<1
2.9
34
<2
<0.1
<25
<25
2.4
0.042
0.088
<5
<0.5
Marshall
MR13
<5
17100
1.9
7.36
8.4
85
<0.5
<0.5
32.1
<0.2
<0.08
0.56
<0.5
<0.1
<0.2
4.7
<0.5
<0.1
Marshall
MR14
<5
9680
2.3
6.7
0.49
67
<0.5
<0.5
49.5
0.078
<0.08
0.82
0.16
0.2
0.043
0.067
<0.5
<0.1
Marshall
MR16
<5
21600
10.2
7.3
18.7
140
<0.5
<0.08
94
<0.11
<0.06
1.9
<0.03
<0.1
<0.01
<0.11
<0.16
<0.06
Marshall
MR17
<5
9600
1.4
7.13
0.74
46
<0.5
<0.5
12
<0.2
<0.08
<0.5
0.23
0.49
0.041
0.067
<0.5
<0.1
Marshall
MR18
<5
12000
3.5
7.18
2.8
88
<0.5
3
21
<0.2
<0.08
<0.5
0.22
0.42
0.038
<0.5
3.4
<0.1
Marshall
MR20
<5
28000
3.3
7.81
2.2
107
0.13
3.2
14
<0.2
<0.08
0.96
0.31
12
0.04
2.2
1.4
<0.1
Marshall
MR21
5
2700
4.1
6.11
0.55
49
<0.1
2.6
82
0.23
<0.08
<0.5
0.88
0.28
0.036
0.52
1.7
<0.1
Marshall
MR22
<5
3790
2.3
5.7
<2
55
<0.5
<0.5
79.3
<0.2
<0.08
0.91
<0.5
2.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR23
<5
23000
27.6
6.5
2.7
194
<0.5
<0.5
130
<0.2
<0.08
1.5
<0.5
0.48
<0.2
<0.5
<0.5
<0.1
Marshall
MR25
62
10000
7.8
6.1
3.1
150
0.049
<0.5
53.8
<0.2
<0.08
1.1
<0.5
0.97
<0.2
0.12
<0.5
<0.1
Marshall
MR26
<5
8100
3.4
6.5
2
80
<0.5
<0.5
57
<0.2
<0.08
1.4
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Marshall
MR28
<5
12600
14.3
6.2
2.4
105
<0.5
<0.5
44.5
<0.2
<0.08
1
<0.5
1.2
<0.2
<0.5
<0.5
<0.1
Marshall
MR29
<5
3200
1.5
6.3
<2
59
<0.5
<0.5
37
<0.2
<0.08
2.9
<0.5
0.28
<0.2
<0.5
<0.5
<0.1
Marshall
MR2-0
77
15200
1.2
6.3
3.4
92
0.058
<0.5
90.2
<0.2
0.086
4.5
<0.5
32
<0.2
2.1
<0.5
<0.1
Marshall
MR2-P
<500
22000
0.92
7
4
130
0.22
0.31
130
<1
<1
2.1
0.15
4.1
<0.2
1.9
<1
<1
Marshall
MR30
<20
13000
1
6.36
5
68
<0.4
0.39
30.5
<0.11
<0.06
3.22
<0.03
0.41
<0.01
0.67
0.43
<0.06
Marshall
MR31
<5
3820
1.6
6.5
<2
68
<0.5
<0.5
23.3
<0.2
<0.08
1.5
<0.5
0.37
<0.2
<0.5
<0.5
<0.1
Marshall
MR32
<5
15000
5.72
6.4
<1
106
<0.5
<0.5
130
<0.2
<0.08
2
2
8
<0.2
<0.5
<0.5
0.1
Marshall
MR33
<5
4510
2.9
6.2
<2
57
<0.5
<0.5
26.7
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR35
<5
14800
1.4
7.3
5
96
<0.5
<0.5
18
<0.2
<0.08
<0.5
<0.5
1.4
<0.2
1.3
<0.5
<0.1
Marshall
MR36
<5
<40
2.7
8.7
11.7
75
<0.5
<0.5
<0.3
<0.2
<0.08
<0.5
<0.5
<0.1
<0.2
<0.5
<0.5
<0.1
Marshall
MR37
<5
2760
5.3
6.1
<2
2040
<0.5
<0.5
32.3
<0.2
<0.08
2.8
<0.5
0.24
<0.2
<0.5
<0.5
<0.1
Marshall
MR38
<5
3090
1.5
5.8
<2
224
<0.5
<0.5
91.7
0.21
<0.08
1.7
<0.5
0.54
<0.2
<0.5
<0.5
<0.1
Marshall
MR4
<25
41000
55
7.09
<1
200
<1
0.66
370
0.19
0.12
<5
0.36
0.13
0.041
<10
0.3
<0.5
Marshall
MR40
<5
21800
2.8
6.4
<2
97
<0.5
<0.5
17.4
<0.2
0.09
0.56
<0.5
0.86
<0.2
<0.5
<0.5
<0.1
Marshall
MR42
<5
3690
4.1
5.9
<2
47
<0.5
<0.5
35
<0.2
<0.08
0.96
<0.5
0.88
<0.2
<0.5
<0.5
<0.1
Marshall
MR43
<5
5010
1.6
6.1
<2
90
<0.5
<0.5
43
<0.2
<0.08
4.8
<0.5
1
<0.2
<0.5
<0.5
<0.1
Marshall
MR44
5.1
9060
1.6
6.2
<2
93
<0.5
<0.5
33
<0.2
<0.08
1.2
<0.5
0.33
<0.2
<0.5
<0.5
<0.1
Marshall
MR45
<5
3530
6.2
5.6
<2
65
<0.5
<0.5
127
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR46
<5
11600
1.6
6.5
2.3
55
<0.5
<0.5
38.7
<0.2
<0.08
0.97
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR47
<5
2870
1.1
6.1
<2
50
<0.5
<0.5
83.5
<0.2
<0.08
1.6
<0.5
0.18
<0.2
<0.5
<0.5
<0.1
Marshall
MR48
<5
7550
2.5
6.2
<2
49
<0.5
<0.5
58.4
<0.2
<0.08
1.4
<0.5
0.38
<0.2
<0.5
<0.5
<0.1
Marshall
MR6
<5
10200
4.7
6.2
<2
119
<0.5
0.1
52.9
<0.2
<0.08
1.74
<0.5
0.65
<0.2
<0.5
<0.5
<0.1
Marshall
MR8
<5
8400
3.3
6.4
2.6
98
<0.4
0.16
14
<0.11
<0.06
1.11
<0.03
0.82
<0.01
2.8
0.32
<0.06
Marshall
MRS)
<5
7300
1.3
6.73
<1
88
<0.5
0.39
18
<0.2
<0.08
0.92
0.05
22
0.027
<0.5
<0.5
<0.1
Page 1 of 2
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Table E2-2
Comparison of NCDEQ Water Supply Well Data to MCL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Page 2 of 2
15A N AC . ()
Standa
Groundwater.".ndard aa
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
N5
•denotes
M ry starsdard L (b):
Feseconds 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
m L
m L
m L
m L
NTU
'C
umhos cm
m L
mV
Marshall
MR1
<5
7.6
0.0013
28
<10
1400
0.68
<2
1300
10000
28
0.34
17
17
<5
<3.1
0.24
7.4
63
13
684
Marshall
MR10
1.5
24.6
0.0033
260
0.43
804
1.7
<0.5
1560
5430
59
<0.005
20.5
20.5
<5
<2.5
<1
16.5
64.2
7.6
170.7
Marshall
MR11
1
<10
0.0135
<50
0.52
584
0.72
<0.5
2430
3470
78.2
0.0069
35.8
35.8
<5
<2.5
<1
17.6
86.9
7.7
402.5
Marshall
MR12
12
<200
0.36
330
<20
1500
53
30
2200
10000
99
0.06
34
34
<10
0.4
<1
12
83
9.81
130
Marshall
MR13
2.8
<10
0.00953
<50
0.18
3080
0.79
<0.5
2700
7760
353
<0.005
40.9
40.9
<1
<2.5
<1
19.4 1
116.5
2.8
117.2
Marshall
MR14
1.1
2.2
0.02
210
0.65
2300
1.5
0.89
1940
6400
85.3
0.016
37
37
<5
<1
<1
17.5
89.6
8.35
300.1
Marshall
MR16
0.36
<10
0.00029
980
<0.03
4600
131
0.48
2900
5400
103
0.0063
53
52
<1
<2.5
5.7
22
196
4.77
<
Marshall
MR17
2.6
15
0.0107
240
0.25
2500
0.89
1
1900
5000
189
0.0104
38.5
38.5
<5
<1
<1
17.7
86.4
8.68
219
Marshall
MR18
9.9
<10
0.161
500
0.037
3000
15
2
2700
13000
240
0.015
43
43
<5
<1
<1
18.8
116
7.77
256.3
Marshall
MR20
14
<10
0.13
1100
0.43
5400
13
3.4
3000
14000
170
0.036
71
70
<5
<1
<1
19.3
177
8.27
160
Marshall
MR21
9.8
25.1
0.013
190
0.15
1500
34
0.66
1700
2500
9.7
0.028
6
6
<5
<1
<1
16.7
44
8.92
356.4
Marshall
MR22
<1
<30
0.0336
<50
0.56
1200
3.8
0.55
2430
4370
34.1
0.025
16.2
16.2
<5
<2.5
<1
16.2
62.4
8.2
287.7
Marshall
MR23
3
<10
0.515
<50
1.1
6200
1.2
<0.5
3800
19000
280
0.112
54
54
<0
<1
<1
18.8
270.3
5.6
240
Marshall
MR25
2
<10
0.0034
<50
0.96
3000
1.2
0.24
2300
12000
110
0.106
53
53
<5
<2.5
0.21
22.6
132.7
7.7
149
Marshall
MR26
3
<10
0.0132
<50
1.2
3000
<0.5
<0.5
2400
7100
170
0.007
38
38
<0
<1
<1
17.2
100
7.1
236
Marshall
MR28
1.9
<10
0.0363
114
0.064
2500
4.4
1.1
2260
8060
162
0.151
35.5
35.5
<5
<2.5
<1
16.6
130.4
6.6
184.8
Marshall
MR29
2.9
<10
0.0119
<50
1.5
915
3.2
0.69
1300
4080
106
0.0348
16.7
16.7
<5
<5
<1
16.4
45.7
7.6
382.1
Marshall
MR2-O
5.5
11.1
0.0959
109
<0.03
3980
17.2
3.2
3550
6650
378
1.06
58.1
58.1
<5
2.9
0.5
22.6
150.1
6.9
139
Marshall
MR2-P
1.6
91
0.0051
3700
<10
3800
5o
1.1
3400
7800
260
0.2
87
87
<5
1.1
3.9
15.6
149
5.5
1
Marshall
MR30
2.24
25.9
0.0058
27
2.74
2230
<2
0.61
1740
9260
163
0.0501
49
<2.5
<1
15.6
191
5.41
Marshall
MR31
4.7
<10
0.0116
<50
1.4
900
0.81
<0.5
1450
6380
46
0.0284
19.2
19.2
<5
<2.5
<1
18.8
57.4
7.9
118.5
Marshall
MR32
8
318
0.043
3100
0.41
1800
130
<0.5
3500
5830
110
0.138
32.3
32.3
<0
105
28
20
117.5
8.1
215
Marshall
MR33
1.7
<10
0.0113
<50
0.9
831
<0.5
<0.5
1280
5080
46.7
<0.005
16.7
16.7
<5
<2.5
<1
18.1
61.7
7.9
354.8
Marshall
MR35
2
21.1
0.0064
65.4
<0.03
3270
23.5
<0.5
2020
7180
95
<0.005
54.5
54.5
<5
<2.5
<1
16.5
143.3
1.8
259.2
Marshall
MR36
<1
<10
<0.001
105
<0.03
<10
0.54
<0.5
155
33500
<0.5
<0.005
46.6
46.6
<5
<2.5
1.2
16.2
136.3
0.01
<
Marshall
MR37
<1
<10
0.0065
<50
2.7
791
4.1
<0.5
1320
3230
21.9
0.0179
8.3
8.3
<5
<2.5
<1
17.9
44.8
8.7
329.5
Marshall
MR38
<1
<10
0.0169
<50
1.3
1060
5.3
0.51
2310
3970
36
0.0393
13.9
13.9
<5
<2.5
<1
16.3
48.8
6.8
304.9
Marshall
MR4
<5
33
0.00088
1200
<20
12000
30
3.5
5000
19000
580
0.0099
86
86
<10
4.7
2.5
14.1
387
4.82
54
Marshall
MR40
1.5
<10
0.0172
<50
0.5
1900
5.1
<0.5
1700
8040
100
0.0592
46.6
46.6
<5
<2.5
<1
17.3
107.9
7.5
110.9
Marshall
MR42
<1
<10
0.0171
<50
0.63
542
<0.5
<0.5
1740
7110
60.3
0.0061
15.3
15.3
<5
<2.5
<1
19
56
6.8
124.2
Marshall
MR43
3.9
<10
0.0149
190
2.4
2270
1.9
1.2
2500
5720
76.3
0.0055
29.2
29.2
<5
<2.5
1.2
16.9
79.1
7.3
428.9
Marshall
MR44
5.1
<10
0.0085
327
0.54
2130
0.96
<0.5
1780
8340
196
0.0159
39.4
39.4
<5
<2.6
3.2
16.9
103.4
6.6
182.5
Marshall
MR45
<1
21.5
0.0337
<50
0.73
1020
12
0.97
2360
4600
37.4
0.0422
9.2
9.2
<5
<2.5
<1
17
61.3
7
282.9
Marshall
MR46
1.2
<10
0.0217
<50
0.6
422
10.2
<0.5
2530
2940
45.7
0.173
26.9
26.9
<5
<2.5
<1
20.2
82
6.1
109.2
Marshall
MR47
1.7
<10
0.0073
<50
1.3
372
0.86
0.72
2340
4210
129
0.0096
13.9
13.9
<5
<2.5
<1
18.3
41.1
8
112.9
Marshall
MR48
1.1
<10
0.0121
<50
0.98
524
5.4
0.52
1860
1730
55.8
0.02
19.9
19.9
<5
<2.5
<1
16.8
55.1
7.1
203.8
Marshall
MRS
1.5
<10
0.098
20
0.83
2480
0.92
0.39
2330
9440
309
0.0336
38
37.5
<5
<2.5
2.9
17.9
135
8.39
216
Marshall
MR8
2.65
15.7
0.0146
19.8
0.56
1900
1.8
0.3
1700
7900
50
0.0211
36
35
<1
<2.5
<1
17.7
106
7.98
206.8
Marshall
MR9
6.4
<10
0.051
180
0.68
1300
0.71
2.4
802
6950
83.5
0.15
29
29
<5
<1
<1
14.4
76
8.76
110
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx MCL April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
Reporting limit is above the screening level.
Haley & Aldrich, Inc.
NCDEQ Data Water Supply Well Screen_2016-04.xlsx 4/8/2016

Table E2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Marshall 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
Federal MCL/SMCL(b):
(• denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
"500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
30
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Appendix III
App
endix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Marshall
MR1
<500
5200
7.2
6.4
11
58
0.29
<1
13
<1
0.84
<10
<1
0.089
<0.2
0.11
<1
<1
Marshall
MR10
<5
5130
2.4
6
<2
65
<0.5
<0.5
38.8
<0.2
<0.08
0.99
<0.5
0.7
<0.2
<0.5
<0.5
<0.1
Marshall
MR11
<5
12900
1.3
6.5
2
71
<0.5
<0.5
48.5
<0.2
<0.08
0.87
<0.5
0.43
<0.2
<0.5
<0.5
<0.1
Marshall
MR12
<130
6500
2.3
6.75
<1
93
<1
2.9
34
<2
<0.1
<25
<25
2.4
0.042
0.088
<5
<0.5
Marshall
MR13
<5
17100
1.9
7.36
8.4
85
<0.5
<0.5
32.1
<0.2
<0.08
0.56
<0.5
<0.1
<0.2
4.7
<0.5
<0.1
Marshall
MR14
<5
9680
2.3
6.7
0.49
67
<0.5
<0.5
49.5
0.078
<0.08
0.82
0.16
0.2
0.043
0.067
<0.5
<0.1
Marshall
MR16
<5
21600
10.2
7.3
18.7
140
<0.5
<0.08
94
<0.11
<0.06
1.9
<0.03
<0.1
<0.01
<0.11
<0.16
<0.06
Marshall
MR17
<5
9600
1.4
7.13
0.74
46
<0.5
<0.5
12
<0.2
<0.08
<0.5
0.23
0.49
0.041
0.067
<0.5
<0.1
Marshall
MR18
<5
12000
3.5
7.18
2.8
88
<0.5
3
21
<0.2
<0.08
<0.5
0.22
0.42
0.038
<0.5
3.4
<0.1
Marshall
MR20
<5
28000
3.3
7.81
2.2
107
0.13
3.2
14
<0.2
<0.08
0.96
0.31
12
0.04
2.2
1.4
<0.1
Marshall
MR21
5
2700
4.1
6.11
0.55
49
<0.1
2.6
82
0.23
<0.08
<0.5
0.88
0.28
0.036
0.52
1.7
<0.1
Marshall
MR22
<5
3790
2.3
5.7
<2
55
<0.5
<0.5
79.3
<0.2
<0.08
0.91
<0.5
2.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR23
<5
23000
27.6
6.5
2.7
1 194
<0.5
<0.5
130
<0.2
<0.08
1.5
<0.5
0.48
<0.2
<0.5
<0.5
<0.1
Marshall
MR25
62
10000
7.8
6.1
3.1
150
0.049
1 <0.5
53.8
<0.2
<0.08
1.1
<0.5
0.97
<0.2
0.12
<0.5
<0.1
Marshall
MR26
<5
8100
3.4
6.5
2
80
<0.5
<0.5
57
<0.2
<0.08
1.4
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Marshall
MR28
<5
12600
14.3
6.2
2.4
105
<0.5
<0.5
44.5
<0.2
<0.08
1
<0.5
1.2
<0.2
<0.5
<0.5
<0.1
Marshall
MR29
<5
3200
1.5
6.3
<2
59
<0.5
<0.5
37
<0.2
<0.08
2.9
<0.5
0.28
<0.2
<0.5
<0.5
<0.1
Marshall
MR2-0
77
15200
1.2
6.3
3.4
92
0.058
<0.5
90.2
<0.2
0.086
4.5
<0.5
32
<0.2
2.1
<0.5
<0.1
Marshall
MR2-P
<500
22000
0.92
7
4
130
0.22
0.31
130
<1
<1
2.1
0.15
4.1
<0.2
1.9
<1
<1
Marshall
MR30
<20
13000
1
6.36
5
68
<0.4
0.39
30.5
<0.11
<0.06
3.22
<0.03
0.41
<0.01
0.67
0.43
<0.06
Marshall
MR31
<5
3820
1.6
6.5
<2
68
<0.5
<0.5
23.3
<0.2
<0.08
1.5
<0.5
0.37
<0.2
<0.5
<0.5
<0.1
Marshall
MR32
<5
15000
5.72
6.4
<1
106
<0.5
<0.5
130
<0.2
<0.08
2
2
8
<0.2
<0.5
<0.5
0.1
Marshall
MR33
<5
4510
2.9
6.2
<2
57
<0.5
<0.5
26.7
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR35
<5
14800
1.4
7.3
5
96
<0.5
<0.5
18
<0.2
<0.08
<0.5
<0.5
1.4
<0.2
1.3
<0.5
<0.1
Marshall
MR36
< 5
< 40
2.7
8.7
11.7
75
< 0.5
< 0.5
< 0.3
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Marshall
MR37
<5
2760
5.3
6.1
<2
2040
<0.5
<0.5
32.3
<0.2
<0.08
2.8
<0.5
0.24
<0.2
<0.5
<0.5
<0.1
Marshall
MR38
<5
3090
1.5
5.8
<2
224
<0.5
<0.5
91.7
0.21
<0.08
1.7
<0.5
0.54
<0.2
<0.5
<0.5
<0.1
Marshall
MR4
< 25
41000
55
7.09
< 1
200
< 1
0.66
370
0.19
0.12
< 5
0.36
0.13
0.041
< 10
0.3
< 0.5
Marshall
MR40
<5
21800
2.8
6.4
<2
97
<0.5
<0.5
17.4
<0.2
0.09
0.56
1 <0.5
0.86
<0.2
<0.5
<0.5
<0.1
Marshall
MR42
<5
3690
4.1
5.9
<2
47
<0.5
<0.5
35
<0.2
<0.08
0.96
<0.5
0.88
<0.2
<0.5
<0.5
<0.1
Marshall
MR43
<5
5010
1.6
6.1
<2
90
<0.5
<0.5
43
<0.2
<0.08
4.8
<0.5
1
<0.2
<0.5
<0.5
<0.1
Marshall
MR44
5.1
9060
1.6
6.2
<2
93
<0.5
<0.5
33
<0.2
<0.08
1.2
<0.5
0.33
<0.2
<0.5
<0.5
<0.1
Marshall
MR45
<5
3530
6.2
5.6
<2
65
<0.5
<0.5
127
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR46
<5
11600
1.6
6.5
2.3
55
<0.5
<0.5
38.7
<0.2
<0.08
0.97
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR47
<5
2870
1.1
6.1
<2
50
<0.5
<0.5
83.5
<0.2
<0.08
1.6
<0.5
0.18
<0.2
<0.5
<0.5
<0.1
Marshall
MR48
<5
7550
2.5
6.2
<2
49
<0.5
<0.5
58.4
<0.2
<0.08
1.4
<0.5
0.38
<0.2
<0.5
<0.5
<0.1
Marshall
MR6
<5
10200
4.7
6.2
<2
119
<0.5
0.1
52.9
<0.2
<0.08
1.74
<0.5
0.65
<0.2
<0.5
<0.5
<0.1
Marshall
MR8
<5
8400
3.3
6.4
2.6
98
<0.4
0.16
14
<0.11
<0.06
1.11
<0.03
0.82
<0.01
2.8
0.32
<0.06
Marshall
MR9
<5
7300
1.3
6.73
<1
88
<0.5
0.39
18
<0.2
<0.08
0.92
0.05
22
0.027
<0.5
<0.5
<0.1
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table E2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
ISA NCAC 02L.0202
Groundwater Standard (a):
0.3
NS
1
300
NS
NS
50
100
NS
NS
NS
1
NS
NS
NS
NS
Federal MCL/SMCL (b):
(• denotes secondary standard)
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
NS
*5
NS
NS
NS
NS
DHHS Screening Level (c):
0.3
3500
1
2500
0.07
NS
200
100
NS
20000
2100
1
NS
NS
NS
NS
RSL 2015(d):
86
20000
0.8
14000
44(e)
NS
430
390
NS
NS
12000
6
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Vanadium
Aluminum
Copper
Iron
Hexavalent
Chromium
Magnesium
Manganese
Nickel
Potassium
Sodium
Strontium
Zinc
Alkalinity
Bicarbonate
Carbonate
Total
Suspended
Solids
Plant
Well Owner ID
u L
u L
m L
u L
u L
u L
u L
u L
u L
u L
u L
m L
m L
m L
m L
m L
Marshall
MR1
<5
7.6
0.0013
28
<10
1400
0.68
<2
1300
10000
28
0.34
17
17
<5
<3.1
Marshall
MR10
1.5
24.6
0.0033
260
0.43
804
1.7
<0.5
1560
5430
59
<0.005
20.5
20.5
<5
<2.5
Marshall
MR11
1
<10
0.0135
<50
0.52
584
0.72
<0.5
2430
3470
78.2
0.0069
35.8
35.8
<5
<2.5
Marshall
MR12
12
<200
0.36
330
<20
1500
53
10
2200
10000
99
0.06
34
34
<10
0.4
Marshall
MR13
2.8
<10
0.00953
<50
0.18
3080
0.79
<0.5
2700
7760
353
<0.005
40.9
40.9
<1
<2.5
Marshall
MR14
1.1
2.2
0.02
210
0.65
2300
1.5
0.89
1940
6400
85.3
0.016
37
37
<5
<1
Marshall
MR16
0.36
<10
0.00029
980
<0.03
4600
131
0.48
2900
5400
103
0.0063
53
52
<1
<2.5
Marshall
MR17
2.6
15
0.0107
240
0.25
2500
0.89
1
1900
5000
189
0.0104
38.5
38.5
<5
<1
Marshall
MR18
9.9
<10
0.161
500
0.037
3000
15
2
2700
13000
240
0.015
43
43
<5
<1
Marshall
MR20
14
<10
0.13
1100
0.43
5400
13
3.4
3000
14000
170
0.036
71
70
<5
<1
Marshall
MR21
9.8
25.1
0.013
190
0.15
1500
34
0.66
1700
2500
9.7
0.028
6
6
<5
<1
Marshall
MR22
<1
<10
0.0336
<50
0.56
1200
3.8
0.55
2430
4370
34.1
0.025
16.2
16.2
<5
<2.5
Marshall
MR23
3
<10
0.515
<50
1.1
6200
1.2
<0.5
3800
19000
280
0.112
54
54
<0
<1
Marshall
MR25
2
<10
0.0034
<50
0.96
3000
1.2
0.24
2300
12000
110
0.106
53
53
<5
<2.5
Marshall
MR26
3
<10
0.0132
<50
1.2
3000
<0.5
<0.5
2400
7100
170
0.007
38
38
<0
<1
Marshall
MR28
1.9
<10
0.0363
114
0.064
2500
4.4
1.1
2260
8060
162
0.151
35.5
35.5
<5
<2.5
Marshall
MR29
2.9
<10
0.0119
<50
1.5
915
3.2
0.69
1300
4080
106
0.0348
16.7
16.7
<5
<5
Marshall
MR2-O
5.5
11.1
0.0959
109
<0.03
3980
17.2
3.2
3550
6650
378
1.06
58.1
58.1
<5
2.9
Marshall
MR2-P
1.6
91
0.0051
3700
<10
3800
50
1.1
3400
7800
260
0.2
87
87
<5
1.1
Marshall
MR30
2.24
25.9
0.0058
27
2.74
2230
<2
0.61
1740
9260
163
0.0501
49
<2.5
Marshall
MR31
4.7
<10
0.0116
<50
1.4
900
0.81
<0.5
1450
6380
46
0.0284
19.2
19.2
<5
<2.5
Marshall
MR32
8
318
0.043
3100
0.41
1800
130
<0.5
3500
5830
110
0.138
32.3
32.3
<0
105
Marshall
MR33
1.7
<10
0.0113
<50
0.9
831
<0.5
<0.5
1280
5080
46.7
<0.005
16.7
16.7
<5
<2.5
Marshall
MR35
2
21.1
0.0064
65.4
<0.03
3270
23.5
<0.5
2020
7180
95
<0.005
54.5
54.5
<5
<2.5
Marshall
MR36
<1
<10
<0.001
105
<0.03
<10
0.54
<0.5
155
33500
<0.5
<0.005
46.6
46.6
<5
<2.5
Marshall
MR37
<1
<10
0.0065
<50
2.7
791
4.1
<0.5
1320
3230
21.9
0.0179
8.3
8.3
<5
<2.5
Marshall
MR38
<1
<10
0.0169
<50
1.3
1060
5.3
0.51
2310
3970
36
0.0393
13.9
13.9
<5
<2.5
Marshall
MR4
<5
33
0.00088
1200
<20
12000
30
3.5
5000
19000
580
0.0099
86
86
<10
4.7
Marshall
MR40
1.5
<10
0.0172
<50
0.5
1900
5.1
<0.5
1700
8040
100
0.0592
46.6
46.6
<5
<2.5
Marshall
MR42
<1
<10
0.0171
<50
0.63
542
<0.5
<0.5
1740
7110
60.3
0.0061
15.3
15.3
<5
<2.5
Marshall
MR43
3.9
<10
0.0149
190
2.4
2270
1.9
1.2
2500
5720
76.3
0.0055
29.2
29.2
<5
<2.5
Marshall
MR44
5.1
<10
0.0085
327
0.54
2130
0.96
<0.5
1780
8340
196
0.0159
39.4
39.4
<5
<2.6
Marshall
MR45
<1
21.5
0.0337
<50
0.73
1020
12
0.97
2360
4600
37.4
0.0422
9.2
9.2
<5
<2.5
Marshall
MR46
1.2
<10
0.0217
<50
0.6
422
10.2
<0.5
2530
2940
45.7
0.173
26.9
26.9
<5
<2.5
Marshall
MR47
1.7
<10
0.0073
<50
1.3
372
0.86
0.72
2340
4210
129
0.0096
13.9
13.9
<5
<2.5
Marshall
MR48
1.1
< 10
0.0121
< 50
0.98
S24
5.4
0.52
1860
1730
55.8
0.02
19.9
19.9
< 5
< 2.5
Marshall
MR6
1.5
<30
0.098
20
0.83
2480
0.92
0.39
2330
9440
309
0.0336
38
37.5
<5
<2.5
Marshall
MR8
2.65
15.7
0.014619.8
0.56
1900
1.8
0.3
1700
7900
50
0.0211
36
35
<1
<2.5
Marshall
MR9
6.4
< 10
0.051
180
0.68
1300
0.71
2.4
802
6950
1 83.5
0.15
29
29
<5
< 1
Page 2 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Table E2-3
Comparison of NCDEQ Water Supply Well Data to DHHS Screening Levels
Marshall 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
Marshall
MR1
0.24
7.4
63
13
684
Marshall
MR10
<1
16.5
64.2
7.6
170.7
Marshall
MR11
<1
17.6
86.9
7.7
402.5
Marshall
MR12
<1
12
83
9.81
130
Marshall
MR13
<1
19.4
116.5
2.8
117.2
Marshall
MR14
<1
17.5
89.6
8.35
300.1
Marshall
MR16
5.7
22
196
4.77
<
Marshall
MR17
<1
17.7
86.4
8.68
219
Marshall
MR18
<1
18.8
116
7.77
256.3
Marshall
MR20
<1
19.3
177
8.27
160
Marshall
MR21
<1
16.7
44
8.92
356.4
Marshall
MR22
<1
16.2
62.4
8.2
287.7
Marshall
MR23
<1
18.8
270.3
5.6
240
Marshall
MR25
0.21
22.6
132.7
7.7
149
Marshall
MR26
<1
17.2
100
7.1
236
Marshall
MR28
<1
16.6
130.4
6.6
184.8
Marshall
MR29
<1
16.4
45.7
7.6
382.1
Marshall
MR2-O
0.5
22.6
150.1
6.9
139
Marshall
MR2-P
3.9
15.6
149
5.5
1
Marshall
MR30
<1
15.6
191
5.41
Marshall
MR31
<1
18.8
57.4
7.9
118.5
Marshall
MR32
28
20
117.5
8.1
215
Marshall
MR33
<1
18.1
61.7
7.9
354.8
Marshall
MR35
<1
16.5
143.3
1.8
259.2
Marshall
MR36
1.2
16.2
136.3
0.01
<
Marshall
MR37
<1
17.9
44.8
8.7
329.5
Marshall
MR38
<1
16.3
48.8
6.8
304.9
Marshall
MR4
2.5
14.1
387
4.82
54
Marshall
MR40
<1
17.3
107.9
7.5
110.9
Marshall
MR42
<1
19
56
6.8
124.2
Marshall
MR43
1.2
16.9
79.1
7.3
428.9
Marshall
MR44
3.2
16.9
103.4
6.6
182.5
Marshall
MR45
<1
17
61.3
7
282.9
Marshall
MR46
<1
20.2
82
6.1
109.2
Marshall
MR47
<1
18.3
41.1
8
112.9
Marshall
MR48
<1
16.8
55.1
7.1
203.8
Marshall
M R6
2.9
17.9
135
8.39
216
Marshall
MR8
<1
17.7
106
7.98
206.8
Marshall
MR9
<1
14.4
76
8.76
110
10
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx DHHS April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the sreening level.
Reporting limit is above the screening level.
Haley & Aldrich, Inc.
NCDEQ Data Water Supply Well Screen_2016-04.xlsx
11
4/8/2016

Table E2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Marshall 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
Federal M L(b):
(• denotes secondary standard)
NS
NS
*250
6.5-8.5
*250
*500
6
10
2000
4
5
100
NS
15
2
NS
50
2
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
1 L
18
20
0.2
RSL 2015(d):
4000
NS
NS
NS
NS
NS
7.8
0.052
3800
25
9.2
22000
6
15
5.7
100
100
0.2
Append x III f
Appendix IV
Boron
Calcium
Chloride
pH
Sulfate
Total
Dissolved
Solids
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
Mercury
Molybdenum
Selenium
Thallium
Plant
Well Owner ID
u L
u L
m L
su
m L
m L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
u L
Marshall
MR1
<500
5200
7.2
6.4
11
58
0.29
<1
13
<1
0.84
<10
<1
0.089
<0.2
0.11
<1
<1
Marshall
MR10
<5
5130
2.4
6
<2
65
<0.5
<0.5
38.8
<0.2
<0.08
0.99
<0.5
0.7
<0.2
<0.5
<0.5
<0.1
Marshall
MR11
<5
12900
1.3
6.5
2
71
<0.5
<0.5
48.5
<0.2
<0.08
0.87
<0.5
0.43
<0.2
<0.5
<0.5
<0.1
Marshall
MR12
<130
6500
2.3
6.75
<1
93
<1 1
2.9
34
1 <2
<0.1
<25
<25 1
2.4
0.042
1 0.088
<5
<0.5
Marshall
MR13
<5
17100 1
1.9
7.36 1
8.4
85
<0.5
<0.5
32.1
<0.2
<0.08
0.56
<0.5
<0.1
<0.2
4.7
<0.5
<0.1
Marshall
MR14
<5
9680
2.3
6.7
0.49
67
<0.5
<0.5
49.5
0.078
<0.08
0.82
0.16
0.2
0.043
0.067
<0.5
<0.1
Marshall
MR16
<5
21600
10.2
7.3
18.7
140
<0.5
<0.08
94
<0.11
<0.06
1.9
<0.03
<0.1
<0.01
<0.11
<0.16
<0.06
Marshall
MR17
<S
9600
1.4
7.13
0.74
46
<0.5
<0.5
12
<0.2
<0.08
<0.5
0.23
0.49
0.041
0.067
<0.5
<0.1
Marshall
MR18
<5
12000
3.5
7.18
2.8
88
<0.5
3
21
<0.2
<0.08
<0.5
0.22
0.42
0.038
<0.5
3.4
<0.1
Marshall
MR20
<5
28000
3.3
7.81
2.2
107
0.13
3.2
14
<0.2
<0.08
0.96
0.31
12
0.04
2.2
1.4
<0.1
Marshall
MR21
5
2700
4.1
6.11
0.55
49
<0.1
2.6
82
0.23
<0.08
<0.5
0.88
0.28
0.036
0.52
1.7
<0.1
Marshall
MR22
<S
3790
2.3
5.7
<2
55
<0.5
<0.5
79.3
<0.2
<0.08
0.91
<0.5
2.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR23
<5
23000
27.6
6.5
2.7
194
<0.5
<0.5
130
<0.2
<0.08
1.5
<0.5
0.48
<0.2
<0.5
<0.5
<0.1
Marshall
MR25
62
10000
7.8
6.1 1
3.1
150
0.049
<0.5
53.8
<0.2
<0.08
1.1
<0.5
0.97
<0.2
0.12
<0.5
<0.1
Marshall
MR26
<5
8100
3.4
6.5
2
80
<0.5
<0.5
57
<0.2
<0.08
1.4
<0.5
0.81
<0.2
<0.5
<0.5
<0.1
Marshall
MR28
<5
12600
14.3
6.2
2.4
105
<0.5
<0.5
44.5
<0.2
<0.08
1
<0.5
1.2
<0.2
<0.5
<0.5
<0.1
Marshall
MR29
<5
3200
1.5
6.3
<2
59
<0.5
<0.5
37
<0.2
<0.08
2.9
<0.5
0.28
<0.2
<0.5
<0.5
<0.1
Marshall
MR2-0
77
15200
1.2
6.3
3.4
92
0.058
<0.5
90.2
<0.2
0.086
4.5
<0.5
32
<0.2
2.1
<0.5
<0.1
Marshall
MR2-P
< 500
22000
0.92
7
4
130
0.22
0.31
130
< 1
< 1
2.1
0.15
4.1
< 0.2
1.9
< 1
< 1
Marshall
MR30
<20
13000
1
6.36
5
68
<0.4
0.39
30.5
<0.11
<0.06
3.22
<0.03
0.41
<0.01
0.67
0.43
<0.06
Marshall
MR31
<5
3820
1.6
6.5
<2
68
<0.5
<0.5
23.3
<0.2
<0.08
1.5
<0.5
0.37
<0.2
<0.5
<0.5
<0.1
Marshall
MR32
<5
15000
5.72
6.4
<1
106
<0.5
<0.5
130
<0.2
<0.08
2
2
8
<0.2
<0.5
<0.5
0.1
Marshall
MR33
<5
4510
2.9
6.2
<2
57
<0.5
<0.5
26.7
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0.1
Marshall
MR35
<5
14800
1.4
7.3
5
96
<0.5
<0.5
18
<0.2
<0.08
<0.5
<0.5
1.4
<0.2
1.3
<0.5
<0.1
Marshall
MR36
< 5
< 40
2.7
8.7
11.7
75
< 0.5
< 0.5
< 0.3
< 0.2
< 0.08
< 0.5
< 0.5
< 0.1
< 0.2
< 0.5
< 0.5
< 0.1
Marshall
MR37
<5
2760
5.3
6.1
<2
2040
<0.5
<0.5
32.3
<0.2
<0.08
2.8
<0.5
0.24
<0.2
<0.5
<0.5
<0.1
Marshall
MR38
<5
3090
1.5
5.8
<2
224
<0.5
<0.5
91.7
0.21
<0.08
1.7
<0.5
0.54
<0.2
<0.5
<0.5
<0.1
Marshall
MR4
<25
41000
55
7.09
<1
200
<1
0.66
370
0.19
0.12
<5
0.36
0.13
0.041
<10
0.3
<0.5
Marshall
MR40
<5
21800
2.8
6.4
<2
97
<0.5
<0.5
17.4
<0.2
0.09
0.56
<0.5
0.86
<0.2
<0.5
<0.5
<0.1
Marshall
MR42
<5
3690
4.1
5.9
<2
47
<0.5
<0.5
35
<0.2
<0.08
0.96
<0.5
0.88
<0.2
<0.5
<0.5
<0.1
Marshall
MR43
<S
5010
1.6
6.1
<2
90
<0.5
<0.5
43
<0.2
<0.08
4.8
<0.5
1
<0.2
<0.5
<0.5
<0.1
Marshall
MR44
5.1
9060
1.6
6.2
<2
93
<0.5
<0.5
33
<0.2
<0.08
1.2
<0.5
0.33
<0.2
<0.5
<0.5
<0.1
Marshall
MR45
<S
3530
6.2
5.6
<2
65
<0.5
<0.5
127
<0.2
<0.08
1
<0.5
0.44
<0.2
<0.5
<0.5
<0A
Marshall
MR46
<5
11600
1.6
6.5
2.3
55
<0.5
<0.5
38.7
<0.2
<0.08
0.97
<0.5
1.4
<0.2
<0.5
<0.5
<0.1
Marshall
MR47
<5
2870
1.1
6.1
<2
50
<0.5
<0.5
83.5
<0.2
<0.08
1.6
<0.5
0.18
<0.2
<0.5
<0.5
<0.1
Marshall
MR48
<5
7550
2.5
6.2
<2
49
<0.5
<0.5
58.4
<0.2
<0.08
1.4
<0.5
0.38
<0.2
<0.5
<0.5
<0.1
Marshall
MR6
<5
10200
4.7
6.2
<2
119
<0.5
0.1
52.9
<0.2
<0.08
1.74
<0.5
0.65
<0.2
<0.5
<0.5
<0.1
Marshall
MR8
<5
8400
3.3
6.4
2.6
98
<0.4
0.16
14
<0.11
<0.06
1.11
<0.03
0.82
<0.01
2.8
0.32
<0.06
Marshall
MR9
<S
7300
1.3
6.73
<1
88
<0.5
0.39
18
<0.2
<0.08
0.92
0.05
22
0.027
<0.5
<0.5
<0.1
12
Page 1 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table E2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Marshall 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
Marshall
MR1
<5
7.6
0.0013
28
<10
1400
0.68
<2
1300
10000
28
0.34
17
17
<5
<3.1
Marshall
MR10
1.5
24.6
0.0033
260
0.43
804
1.7
<0.5
1560
5430
59
<0.005
20.5
20.5
<5
<2.5
Marshall
MR11
1
<10
0.0135
<50
0.52
584
0.72
<0.5
2430
3470
78.2
0.0069
35.8
35.8
<5
<2.5
Marshall
I MR12
12
<200
0.36
330
<20
1500
53
10
2200
10000
99
0.06
34
34
<10
0.4
Marshall
MR13
2.8
<10
0.00953
<50
0.18
3080
0.79
<0.5
2700
7760
353
<0.005
40.9
40.9
<1
<2.5
Marshall
MR14
1.1
2.2
0.02
210
0.65
2300
1.5
0.89
1940
6400
85.3
0.016
37
37
<5
<1
Marshall
MR16
0.36
<10
0.00029
980
<0.03
4600
131
0.48
2900
5400
103
0.0063
53
52
<1
<2.5
Marshall
MR17
2.6
15
0.0107
240
0.25
2500
0.89
1
1900
5000
189
0.0104
38.5
38.5
<5
<1
Marshall
MR18
9.9
< 10
0.161
500
0.037
3000
15
2
2700
13000
240
0.015
43
43
<5
< 1
Marshall
MR20
14
<10
0.13
1100
0.43
5400
13
3.4
3000
14000
170
0.036
71
70
<5
<1
Marshall
MR21
9.8
25.1
0.013
190
0.15
1500
34
0.66
1700
2500
9.7
0.028
6
6
<5
<1
Marshall
MR22
<1
<10
0.0336
<50
0.56
1200
3.8
0.55
2430
4370
34.1
0.025
16.2
16.2
<5
<2.5
Marshall
MR23
3
<10
0.515
<50
1.1
6200
1.2
<0.5
3800
19000
280
0.112
54
54
<0
<1
Marshall
MR25
2
<10
0.0034
<50
0.96
3000
1.2
0.24
2300
12000
110
0.106
53
53
<5
<2.5
Marshall
MR26
3
<10
0.0132
<50
1.2
3000
<0.5
<0.5
2400
7100
170
0.007
38
38
<0
<1
Marshall
MR28
1.9
<10
0.0363
114
0.064
2500
4.4
1.1
2260
8060
162
0.151
35.5
35.5
<5
<2.5
Marshall
MR29
2.9
<10
0.0119
<50
1.5
915
3.2
0.69
1300
4080
106
0.0348
16.7
16.7
<5
<5
Marshall
MR2-O
5.5
11.1
0.0959
109
<0.03
3980
17.2
3.2
3550
6650
378
1.06
58.1
58.1
<5
2.9
Marshall
MR2-P
1.6
91
0.0051
3700
<10
3800
50
1.1
3400
7800
260
0.2
87
87
<S
1.1
Marshall
MR30
2.24
25.9
0.0058
27
2.74
2230
<2
0.61
1740
9260
163
0.0501
49
<2.5
Marshall
MR31
4.7
<10
0.0116
<50
1.4
900
0.81
<0.5
1450
6380
46
0.0284
19.2
19.2
<5
<2.5
Marshall
MR32
8
318
0.043
3100
0.41
1800
130
<0.5
3500
5830
110
0.138
32.3
32.3
<0
105
Marshall
MR33
1.7
<10
0.0113
<50
0.9
831
<0.5
<0.5
1280
5080
46.7
<0.005
16.7
16.7
<5
<2.5
Marshall
MR35
2
21.1
0.0064
65.4
<0.03
3270
23.5
<0.5
2020
7180
95
<0.005
54.5
54.5
<5
<2.5
Marshall
MR36
<1
<10
<0.001
105
<0.03
<10
0.54
<0.5
155
33500
<0.5
<0.005
46.6
46.6
<5
<2.5
Marshall
MR37
<1
<10
0.0065
<50
2.7
791
4.1
<0.5
1320
3230
21.9
0.0179
8.3
8.3
<5
<2.5
Marshall
MR38
<1
<10
0.0169
<50
1.3
1060
5.3
0.51
2310
3970
36
0.0393
13.9
13.9
<5
<2.5
Marshall
MR4
<5
33
0.00088
1200
<20
12000
30
3.5
5000
19000
580
0.0099
86
86
<10
4.7
Marshall
MR40
1.5
<10
0.0172
<50
0.5
1900
5.1
<0.5
1700
8040
100
0.0592
46.6
46.6
<5
<2.5
Marshall
MR42
<1
<10
0.0171
<50
0.63
542
<0.5
<0.5
1740
7110
60.3
0.0061
15.3
15.3
<5
<2.5
Marshall
MR43
3.9
<10
0.0149
190
2.4
2270
1.9
1.2
2500
5720
76.3
0.0055
29.2
29.2
<5
<2.5
Marshall
MR44
5.1
<10
0.0085
327
0.54
2130
0.96
<0.5
1780
8340
196
0.0159
39.4
39.4
<5
<2.6
Marshall
MR45
<1
21.5
0.0337
<50
0.73
1020
12
0.97
2360
4600
37.4
0.0422
9.2
9.2
<5
<2.5
Marshall
MR46
1.2
<10
0.0217
<50
0.6
422
10.2
<0.5
2530
2940
45.7
0.173
26.9
26.9
<5
<2.5
Marshall
MR47
1.7
<10
0.0073
<50
1.3
372
0.86
0.72
2340
4210
129
0.0096
13.9
13.9
<5
<2.5
Marshall
MR48
1.1
<10
0.0121
<50
0.98
524
5.4
0.52
1860
1730
55.8
0.02
19.9
19.9
<5
<2.5
Marshall
MR6
1.5
<10
0.098
20
0.83
2480
0.92
0.39
2330
9440
309
0.0336
38
37.5
<5
<2.5
Marshall
MR8
2.65
15.7
0.0146
19.8
0.56
1900
1.8
0.3
1700
7900
50
0.0211
36
135<1
<2.5
Marshall
MR9
6.4
< 10
0.051
180
0.68
1300
0.71
2.4
802
6950
83.5
0.15
29
29
<5
< 1
13
Page 2 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Table E2-4
Comparison of NCDEQ Water Supply Well Data to RSL Screening Levels
Marshall 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 201S (d):
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos cm
Dissolved
Oxygen
m L
Oxidation
Reduction
Potential
my
Marshall
MR1
0.24
7.4
63
13
684
Marshall
MR10
<1
16.5
64.2
7.6
170.7
Marshall
MR11
< 1
17.6
86.9
7.7
402.5
Marshall
MR12
<1
12
83
9.81
130
Marshall
MR13
<1
19.4
116.5
2.8
117.2
Marshall
MR14
<1
17.5
89.6
8.35
300.1
Marshall
MR16
5.7
22
196
4.77
<
Marshall
MR17
<1
17.7
86.4
1 8.68
219
Marshall
MR18
<1
18.8
116
7.77
256.3
Marshall
MR20
<1
19.3
177
8.27
160
Marshall
MR21
<1
16.7
44
8.92
356.4
Marshall
MR22
<1
16.2
62.4
8.2
287.7
Marshall
MR23
<1
18.8
270.3
5.6
240
Marshall
MR25
0.21
22.6
132.7
7.7
149
Marshall
MR26
<1
17.2
100
7.1
236
Marshall
MR28
<1
16.6
130.4
6.6
184.8
Marshall
MR29
<1
16.4
45.7
1 7.6
382.1
Marshall
MR2-O
0.5
22.6
150.1
6.9
139
Marshall
MR2-P
3.9
15.6
149
5.5
1
Marshall
MR30
<1
15.6
191
5.41
Marshall
MR31
<1
18.8
57.4
7.9
118.5
Marshall
MR32
28
20
117.5
8.1
215
Marshall
MR33
<1
18.1
61.7
7.9
354.8
Marshall
MR35
<1
16.5
143.3
1.8
259.2
Marshall
MR36
1.2
16.2
136.3
0.01
<
Marshall
MR37
<1
17.9
44.8
1 8.7
329.5
Marshall
MR38
<1
16.3
48.8
6.8
304.9
Marshall
MR4
2.5
14.1
387
4.82
54
Marshall
MR40
<1
17.3
107.9
7.5
110.9
Marshall
MR42
<1
19
56
6.8
124.2
Marshall
MR43
1.2
16.9
79.1
7.3
428.9
Marshall
MR44
3.2
16.9
103.4
6.6
182.5
Marshall
MR45
<1
17
61.3
7
282.9
Marshall
MR46
<1
20.2
82
6.1
109.2
Marshall
MR47
<1
18.3 1
41.1
1 8
112.9
Marshall
MR48
<1
16.8
55.1
7.1
203.8
Marshall
MR6
2.9
17.9
135
8.39
216
Marshall
MR8
<1
17.7
106
7.98
206.8
Marshall
MR9
<1
14.4
76
8.76
110
14
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -1-E2-4 NCDEQ Data Water Supply Well Screen_2016-04.xlsx RSL April 2016

Comparison of NCDEQ Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
A - Denotes [MAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL - Maximum Contaminant Level.
MDL - Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA - Not available.
NS - No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL - Risk Based Screening Level.
SMCL - Secondary Maximum Contaminant Level.
su - standard units.
USEPA - United States Environmental Protection Agency.
ug/L - micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
B Detected in method blank (MB).
1 Estimated result between PQL and MDL.
12 Spike recovery outside quality assurance limits @ 135%.
Zb Sample was clear but contained sand -like particles.
Zc Well depth was 635 feet per well tag.
18 Temperature of the sample was exceeded during storage.
BH Method Blank (MB) greater than one half of the Reporting Level (RL), but the sample concentrations are greater than 10x the MB.
** Alkalinity = carbonate + bicarbonate.
S1 Matrix spike and / or matrix spike duplicate sample recovery was not within control limits due to matrix interference. Laboratory Control Sample (LCS) was within control limits.
Z Sample was re -digested and re -analyzed with similar sample and spike results.
M1 Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
D6 The relative percent difference (RPD) between the sample and sample duplicate exceeded laboratory control limits.
< Measurement limited by threshold (cannot detect measureable amount below this number). Actual detectable amount below threshold is unknown.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards2012.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www.epa.gov/risk/risk-based-screening-ta ble-generic-tables
(e) - Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) - The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) -The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is a Bove the sreeni ng level.
Reporting limit is above the screeni ng level.
Haley & Aldrich, Inc.
NCDEQ Data Water Supply Well Screen_2016-04.xlsx
15
4/8/2016

Table E2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to 21. Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
16
Page 1 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016
Groundwater
15A NCAC 02L.0202
Standard a:
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL(b):
* denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID
Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedAntimony
Solids
mg/L
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<5
16000
4.5
6.93
13.3
105
<0.5
<0.5
13.8
<0.2
<0.08
<0.5
<0.5
0.16
Marshall
MRBKG-8
NCDEQ
9.1
74200
4.6
7.12
186
373
<0.5
0.84
24.6
<0.2
<0.08
0.51
<0.5
0.29
Marshall
MRBKG-11
NCDEQ
<5
18600
1.7
7.39
10.8
112
<0.5
<0.5
58.5
<0.2
<0.08
0.76
<0.5
0.36
Marshall
MRBKG-14
NCDEQ
12.7
1680
3.5
5.15
<2.0
<25.0
<0.5
<0.5
24.9
<0.2
<0.08
0.85
<0.5
0.46
Marshall
MRBKG-15
NCDEQ
<5
9520
1.7
6.25
<2
90
<0.5
<0.5
24.2
<0.2
<0.08
1.9
<0.5
0.96
Marshall
MRBKG-16
NCDEQ
<5
10400
2.1
6.04
<2
83
<0.5
<0.5
19.7
<0.2
<0.08
0.89
<0.5
0.61
Marshall
MRBKG-18
NCDEQ
<5
7510
2
6.15
<2.0
51
<0.5
<0.5
44
<0.2
<0.08
1.9
<0.5
0.18
Marshall
MRBKG-27
NCDEQ
<5
25600
4.2
6.3
9.9
139
<0.5
<0.5
26.7
<0.2
<0.08
<0.5
<0.5
0.28
Marshall
MRBKG-31
NCDEQ
135
8850
9.4
5.64
2.1
100
<0.5
<0.5
59.2
<0.2
<0.08
2.3
<0.5
1.3
Marshall
MRBKG-39
NCDEQ
<5
7960
1.6
6.03
<2
79
<0.5
<0.5
57.2
<0.2
<0.08
1.4
<0.5
0.57
Marshall
DBKG-MRI
Duke
<50
10900
<1
<1
33
<1
<1
<S
<1
1.13
Marshall
DBKG-MR2
Duke
<50
55800
<1
<1
486
<1
<1
7
<0
1.83
Marshall
DBKG-MR3
Duke
<50
8960
<1
<1
7
<1
<1
<5
<0
<1
Marshall
DBKG-MR4
Duke
<50
44900
<1
<1
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR5
Duke
<50
1550
<1
<1
34
<1
<1
<5
<0
1.37
Marshall
DBKG-MR6
Duke
<SO
3340
<1
<1
19
<1
<1
<5
<0
5.4
Marshall
DBKG-MR7
Duke
<50
33200
<1
<1
6
<1
<1
<5
<0
<1
Marshall
DBKG-MR8
Duke
<50
3300
<1
<1
11
<1
<1
<5
<0
<1
Marshall
DBKG-MR9
Duke
107
84900
<1
2.58
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR10
Duke
<50
3650
<1
<1
155
<1
<1
<5
<0
<1
Marshall
DBKG-MR11
Duke
<50
43500
<1
<1
40
<1
<1
<5
<0
<1
Marshall
DBKG-MR12
Duke
<50
21400
<1
<1
<5
<1
<1
<5
<0
<1
Marshall
DBKG-MR13
Duke
<50
13100
<1
<1
16
<1
<1
<S
<1
<1
Marshall
DBKG-MR14
Duke
<50
43400
<1
6.81
83
<1
<1
<5
<1
<1
Marshall
DBKG-MR15
Duke
<50
23600
<1
<1
15
<1
<1
<5
<1
1.84
Marshall
DBKG-MR16
Duke
<50
13800
1.2
<0.5
23
<0.2
<0.08
<5
<0.5
0.21
Marshall
DBKG-MR17
Duke
<50
24400
1.2
<0.5
6
<0.2
<0.08
9
<0.5
0.26
Marshall
DBKG-MR18
Duke
<50
23100
1.1
<0.5
19
<0.2
<0.08
<5
<0.5
0.19
Marshall
DBKG-MR19
Duke
<50
35700
1.19
<1
150
<1
0.01
<S
<1
2.45
Marshall
DBKG-MR20
Duke
<50
8070
<1
<1
64
<1
<1
<5
<1
<1
Marshall
DBKG-MR21
Duke
<50
8540
<1
<1
65
<1
<1
<S
<1
<1
Marshall
DBKG-MR22
Duke
< 50
44000
1.46
< 1
104
< 1
< 1
< 5
< 1
< 1
Marshall
DBKG-MR23
Duke
<SO
11000
<1
<1
67
<1
<1
<5
<1
<1
Marshall
DBKG-MR24
Duke
<SO
9810
1.24
<1
75
<1
<1
<5
<1
5.16
Marshall
DBKG-MR25
Duke
17
86800
0.64
4.7
27.8
<0.2
<0.08
<0.5
<0.5
0.2
Marshall
DBKG-MR26
Duke
<5
35800
1
<0.5
10.3
<0.2
<0.08
6.9
<0.5
6.3
Marshall
DBKG-MR27
Duke
<5
2010
0.8
05159
<0.2
<0.08
<0.5
<0.5
0.36
Marshall
DBKG-MR28
Duke
<50
81800
4.1
8.06
170
370
<1
5.339
<1
<1
<5
1.33
1.8
Marshall
DBKG-MR29
Duke
<50
15400
19
7.31
0.36
140
<1
<1
56
<1
<1
<S
<1
<1
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016

Table E2-5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to 21. Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
17
Page 2 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016
15A NCAC 02L.0202
Groundwater Standard a:
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
1L
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Magnesium
Hexavalent
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<0.2
2.9
0.72
<0.1
1
<10
0.0019
57.5
<0.6
5890
43.3
<0.5
3360
7180
Marshall
MRBKG-8
NCDEQ
<0.2
3.7
<0.5
<0.1
<1
<10
0.0028
<50
<0.6
4120
14.1
<0.5
1900
29900
Marshall
MRBKG-11
NCDEQ
<0.2
4.9
<0.5
<0.1
1.2
<10
0.0049
<50
<0.6
5070
26.1
0.9
3450
9510
Marshall
MRBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1.0
<10
0.0032
<50
<0.6
808
10.7
<0.5
1110
6620
Marshall
MRBKG-15
NCDEQ
<0.2
0.58
<0.5
<0.1
4.6
<10
0.0088
<50
1.1
3480
2.7
<0.5
2390
7410
Marshall
MRBKG-16
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
<10
0.0128
<50
<0.6
2870
0.69
<0.5
2020
6240
Marshall
MRBKG-18
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.8
<10
0.0019
<50
1.7
2430
<0.50
<0.5
1940
6440
Marshall
MRBKG-27
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0066
1340
<0.03
4190
271
1.1
3290
8420
Marshall
MRBKG-31
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
68.8 M1
0.0161
179
0.56
2820
3.2
1.8
1930
8750
Marshall
MRBKG-39
NCDEQ
<0.2
<0.5
<0.5
<0.1
3
<10
0.0096
<50
0.82
1810
0.57
<0.5
2360
6790
Marshall
DBKG-MR1
Duke
<0.05
<1
<1
<0.2
0.326
15
0.024
19
1470
10
<5
1970
1750
Marshall
DBKG-MR2
Duke
<0.05
<1
<1
<0.2
0.554
6
0.011
42
11700
13
7
4190
151000
Marshall
DBKG-MR3
Duke
<0.05
<1
1.37
<0.2
2.25
<S
<0.005
14
2400
<S
<S
1150
6570
Marshall
DBKG-MR4
Duke
<0.05
<1
<1
<0.2
1.95
<5
<0.005
75
3110
10
<S
2110
11700
Marshall
DBKG-MRS
Duke
<0.05
<1
<1
<0.2
0.807
6
0.011
<10
539
<5
<5
2070
5370
Marshall
DBKG-MR6
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.076
11
448
15
<S
1340
983
Marshall
DBKG-MR7
Duke
<0.05
<1
<1
<0.2
<0.3
<5
<0.005
989
4310
270
<5
3240
7100
Marshall
DBKG-MR8
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.006
<10
340
7
<S
1140
2850
Marshall
DBKG-MR9
Duke
<0.05
<1
<1
<0.2
<0.3
9
<0.005
47
6270
19
<5
918
29300
Marshall
DBKG-MR10
Duke
0.27
<1
<1
<0.2
<0.3
90
0.043
50
1290
23
<S
2240
5950
Marshall
DBKG-MR11
Duke
<0.05
<1
<1
<0.2
22.9
<5
<0.005
<10
3820
6
<5
3870
7260
Marshall
DBKG-MR12
Duke
<0.05
3.63
<1
<0.2
<0.3
<S
<0.005
613
4220
64
<S
2360
9320
Marshall
DBKG-MR13
Duke
<0.05
<1
<1
<0.2
7.41
<5
<0.005
<10
2340
<5
<5
1930
5770
Marshall
DBKG-MR14
Duke
<0.05
7.63
<1
<0.2
0.446
9
<0.005
18
5230
17
<5
4230
10300
Marshall
DBKG-MR15
Duke
<0.05
<1
<1
<0.2
0.739
19
0.011
16
<0.03
5890
6
<5
3530
9680
Marshall
DBKG-MR16
Duke
<0.05
<0.5
<0.5
<0.1
7.6
<5
<0.005
<10
1.8
4280
<5
<5
1890
9270
Marshall
DBKG-MR17
Duke
<0.05
1.6
0.68
<0.1
<1
<S
0.006
254
0.039
2870
10
<S
2800
6860
Marshall
DBKG-MR18
Duke
<0.05
1.2
1.7
<0.1
4.7
8
<0.005
12
3.7
5990
<S
<S
3060
9090
Marshall
DBKG-MR19
Duke
<0.05
1.73
<1
<0.2
12.7
55
0.011
66
0.61
15400
<5
<5
3900
17600
Marshall
DBKG-MR20
Duke
<0.05
<1
<1
<0.2
5.32
<S
0.017
<10
0.36
2460
<S
<S
1440
6790
Marshall
DBKG-MR21
Duke
<0.05
<1
<1
<0.2
3.14
23
<0.005
32
0.17
2660
<5
<5
2270
6650
Marshall
DBKG-MR22
Duke
<0.05
1.94
1.27
<0.2
2.65
5
<0.005
<10
0.13
4730
<S
<S
2700
7490
Marshall
DBKG-MR23
Duke
<0.05
<1
<1
<0.2
4.5
13
0.006
13
0.15
5720
<5
<5
2850
8180
Marshall
DBKG-MR24
Duke
<0.05
<1
<1
<0.2
13.1
10
0.028
1480
0.11
3980
8
<S
2310
7670
Marshall
DBKG-MR25
Duke
<0.2
2.1
<0.5
<0.1
<1
22.6
<0.001
<50
<0.03
1740
9.2
<0.5
2080
25000
Marshall
DBKG-MR26
Duke
<0.2
0.7
<0.5
<0.1
<1
119
0.0274
3920
4150
988
3.3
3140
6710
Marshall
DBKG-MR27
Duke
<0.2
<0.5
<0.5
<0.1
<1
11
0.0023
<50
392
14.4
<0.5
1240
936
Marshall
DBKG-MR28
Duke
<0.05
2.34
<1
<0.29.44
2150
<0.005
3720
3590
74
<5
2610
23000
Marshall
DBKG-MR29
Duke
<0.05
<1
<1
0.354
6.83
<5
<0.005
<10
5660
<5
<5
2220
8160
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016

Table EZ -5
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to 21. Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
18
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016
ISA NCAC 02L.0202
Groundwater Standard a:
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
*S
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015 (d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
'C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
mV
Marshall
MRBKG-2 NCDEQ
89.6
0.0169
55.8
55.8
<S
<2.5
<1
16.68
0.168
0.32
28
Marshall
MRBKG-8 NCDEQ
1150
0.006
61.6
61.6
<5
<2.5
<1
17.68
0.537
1.17
106
Marshall
MRBKG-11 NCDEQ
207
0.0082
76.8
76.8
<S
5.1
<1
16.74
0.9
0.52
112
Marshall
MRBKG-14 NCDEQ
12.2
0.01
7.4
7.4
<5.0
<2.5
<1
16.81
0.053
2.4
241
Marshall
MRBKG-15 NCDEQ
63.1
0.0102
49.6
49.6
<S
<2.5
<1
16.18
0.113
1.68
167
Marshall
MRBKG-16 NCDEQ
75.3
0.0291
44.9
44.9
<S
<2.5
<1
15.25
0.094
3.14
173
Marshall
MRBKG-18 NCDEQ
119
<0.005
33.5
33.5
<5.0
<2.5
<1
16.52
0.09
2.68
201
Marshall
MRBKG-27 NCDEQ
232
0.0136
80
80
<5
<2.5
<1
16.86
0.19
3.22
88
Marshall
MRBKG-31 NCDEQ
120
0.0061
21.4
21.4
<S
20.6
2.9
17.14
0.114
7.32
205
Marshall
MRBKG-39 NCDEQ
201
0.0055
35.8
35.8
<5
<2.5
10.6
16.86
0.085
4.18
192
Marshall
DBKG-MR1 Duke
44
0.029
Marshall
DBKG-MR2 Duke
9S9
0.041
Marshall
DBKG-MR3 Duke
40
<0.005
Marshall
DBKG-MR4 Duke
844
0.029
Marshall
DBKG-MRS Duke
11
0.012
Marshall
DBKG-MR6 Duke
15
0.08
Marshall
DBKG-MR7 Duke
166
0.009
Marshall
DBKG-MR8 Duke
9
0.009
Marshall
DBKG-MR9 Duke
1060
<0.005
Marshall
DBKG-MR10 Duke
33
0.104
Marshall
DBKG-MR11 Duke
146
<0.005
Marshall
DBKG-MR12 Duke
259
0.007
Marshall
DBKG-MR13 Duke
106
0.262
Marshall
DBKG-MR14 Duke
215
<0.005
Marshall
DBKG-MR15 Duke
109
0.254
Marshall
DBKG-MR16 Duke
219
0.012
Marshall
DBKG-MR17 Duke
223
<0.005
Marshall
DBKG-MR18 Duke
401
0.009
Marshall
DBKG-MR19 Duke
334
0.012
Marshall
DBKG-MR20 Duke
100
0.25
Marshall
DBKG-MR21 Duke
208
0.009
Marshall
DBKG-MR22 Duke
524
<0.005
Marshall
DBKG-MR23 Duke
187
0.007
Marshall
DBKG-MR24 Duke
122
0.078
Marshall
DBKG-MR25 Duke
2210
<0.005
<2.6
Marshall
DBKG-MR26 Duke
161
0.0249
Marshall
DBKG-MR27 Duke
10.3
0.006
Marshall
DBKG-MR28 Duke
0101016
74
Marshall
DBKG-MR29 Duke
148
<0.005
<5
18
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx 2L April 2016

19
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated 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 E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table E2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to MCL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
20
Page 1 of 3
Haley Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016
Groundwater
ISA NCAC 02L.0202
Standard a
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL(b):
* denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID
Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedAntimony
Solids
mg/L
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<5
16000
4.5
6.93
13.3
10S
<0.5
<0.5
13.8
<0.2
<0.08
<0.5
<0.5
0.16
Marshall
MRBKG-8
NCDEQ
9.1
74200
4.6
7.12
186
373
<0.5
0.84
24.6
<0.2
<0.08
0.51
<0.5
0.29
Marshall
MRBKG-11
NCDEQ
<5
18600
1.7
7.39
10.8
112
<0.5
<0.5
58.5
<0.2
<0.08
0.76
<0.5
0.36
Marshall
MRBKG-14
NCDEQ
12.7
1680
3.5 1
5.15
<2.0
<25.0
<0.5
<0.5
24.9
<0.2
<0.08
0.85
<0.5
0.46
Marshall
MRBKG-15
NCDEQ
<5
9520
1.7
6.25
<2
90
<0.5
<0.5
24.2
<0.2
<0.08
1.9
<0.5
0.96
Marshall
MRBKG-16
NCDEQ
<5
10400
2.1
6.04
<2
83
<0.5
<0.5
19.7
<0.2
<0.08
0.89
<0.5
0.61
Marshall
MRBKG-18
NCDEQ
<5
7510
2
6.15
<2.0
51
<0.5
<0.5
44
<0.2
<0.08
1.9
<0.5
0.18
Marshall
MRBKG-27
NCDEQ
<5
25600
4.2
6.3
9.9
139
<0.5
<0.5
26.7
<0.2
<0.08
<0.5
<0.5
0.28
Marshall
MRBKG-31
NCDEQ
135
8850
9.4
5.64
2.1
100
<0.5
<0.5
59.2
<0.2
<0.08
2.3
<0.5
1.3
Marshall
MRBKG-39
NCDEQ
<5
7960
1.6
6.03
<2
79
<0.5
<0.5
57.2
<0.2
<0.08
1.4
<0.5
0.57
Marshall
DBKG-MRI
Duke
<SO
10900
<1
<1
33
<1
<1
<S
<1
1.13
Marshall
DBKG-MR2
Duke
<50
S5800
<1
<1
486
<1
<1
7
<0
1.83
Marshall
DBKG-MR3
Duke
<50
8960
<1
<1
7
<1
<1
<5
<0
<1
Marshall
DBKG-MR4
Duke
<50
44900
<1
<1
15
<1
<1
<5
<0
<1
Marshall
DBKG-MRS
Duke
<50
1550
<1
<1
34
<1
<1
<5
<0
1.37
Marshall
DBKG-MR6
Duke
<50
3340
<1
<1
19
<1
<1
<5
<0
5.4
Marshall
DBKG-MR7
Duke
<50
33200
<1
<1
6
<1
<1
<5
<0
<1
Marshall
DBKG-MR8
Duke
<50
3300
<1
<1
11
<1
<1
<5
<0
<1
Marshall
DBKG-MR9
Duke
107
84900
<1
2.58
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR10
Duke
<50
3650
<1
<1
15S
<1
<1
<5
<0
<1
Marshall
DBKG-MR11
Duke
<50
43500
<1
<1
40
<1
<1
<5
<0
<1
Marshall
DBKG-MR12
Duke
<50
21400
<1
<1
<5
<1
<1
<5
<0
<1
Marshall
DBKG-MR13
Duke
<SO
13100
<1
<1
16
<1
<1
<S
<1
<1
Marshall
DBKG-MR14
Duke
<50
43400
<1
6.81
83
<1
<1
<5
<1
<1
Marshall
DBKG-MR15
Duke
<50
23600
<1
<1
15
<1
<1
<5
<1
1.84
Marshall
DBKG-MR16
Duke
<50
13800
1.2
<0.5
23
<0.2
<0.08
<5
<0.5
0.21
Marshall
DBKG-MR17
Duke
<SO
24400
1.2
<0.5
6
<0.2
<0.08
9
<0.5
0.26
Marshall
DBKG-MR18
Duke
<SO
23100
1.1
<0.5
19
<0.2
<0.08
<5
<0.5
0.19
Marshall
DBKG-MR19
Duke
<SO
35700
1.19
<1
150
<1
0.01
<S
<1
2.45
Marshall
DBKG-MR20
Duke
<50
8070
<1
<1
64
<1
<1
<5
<1
<1
Marshall
DBKG-MR21
Duke
<50
8540
<1
<1
65
<1
<1
<S
<1
<1
Marshall
DBKG-MR22
Duke
<SO
44000
1.46
<1
104
<1
<1
<5
<1
<1
Marshall
DBKG-MR23
Duke
<SO
11000
<1
<1
67
<1
<1
<5
<1
<1
Marshall
DBKG-MR24
Duke
<50
9810
1.24
<1
75
<1
<1
<5
<1
5.16
Marshall
DBKG-MR25
Duke
17
86800
0.64
4.7
27.8
<0.2
<0.08
<0.5
<0.5
0.2
Marshall
DBKG-MR26
Duke
<5
35800
1
<0.5
10.3
<0.2
<0.08
6.9
<0.5
6.3
Marshall
DBKG-MR27
Duke
<5
2010
0.8
<0.5
15.9
<0.2
<0.08
<0.5
<0.5
0.36
Marshall
DBKG-MR28
Duke
<50
81800
4.1
8.06
170
370
<1
5.3
39
<1
<1
<5
1.33
1.8
Marshall
DBKG-MR29
Duke
<50
15400
19
7.31
0.36
140
<1
<1
56
<1
<1
<5
<1
<1
Haley Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016

Table E2-6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to MCL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
21
Page 2 of 3
Haley Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016
Groundwater
ISA NCAC 02L.0202
Standard a
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
11.
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Magnesium
Hexavalent
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<0.2
2.9
0.72
<0.1
1
<10
0.0019
57.5
<0.6
5890
43.3
<0.5
3360
7180
Marshall
MRBKG-8
NCDEQ
<0.2
3.7
<0.5
<0.1
<1
<10
0.0028
<50
<0.6
4120
14.1
<0.5
1900
29900
Marshall
MRBKG-11
NCDEQ
<0.2
4.9
<0.5
<0.1
1.2
<10
0.0049
<50
<0.6
5070
26.1
0.9
3450
9510
Marshall
MRBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1.0
<10
0.0032
<50
<0.6
808
10.7
<0.5
1110
6620
Marshall
MRBKG-15
NCDEQ
<0.2
0.58
<0.5
<0.1
4.6
<10
0.0088
<50
1.1
3480
2.7
<0.5
2390
7410
Marshall
MRBKG-16
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
<10
0.0128
<50
<0.6
2870
0.69
<0.5
2020
6240
Marshall
MRBKG-18
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.8
<10
0.0019
<50
1.7
2430
<0.50
<0.5
1940
6440
Marshall
MRBKG-27
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0066
1340
<0.03
4190
271
1.1
3290
8420
Marshall
MRBKG-31
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
68.8 M1
0.0161
179
0.56
2820
3.2
1.8
1930
8750
Marshall
MRBKG-39
NCDEQ
<0.2
<0.5
<0.5
<0.1
3
<10
0.0096
<50
0.82
1810
0.57
<0.5
2360
6790
Marshall
DBKG-MRI
Duke
<0.05
<1
<1
<0.2
0.326
15
0.024
19
1470
10
<5
1970
1750
Marshall
DBKG-MR2
Duke
<0.05
<1
<1
<0.2
0.554
6
0.011
42
11700
13
7
4190
151000
Marshall
DBKG-MR3
Duke
<0.05
<1
1.37
<0.2
2.25
<S
<0.005
14
2400
<S
<S
1150
6570
Marshall
DBKG-MR4
Duke
<0.05
<1
<1
<0.2
1.95
<5
<0.005
75
3110
10
<S
2110
11700
Marshall
DBKG-MRS
Duke
<0.05
<1
<1
<0.2
0.807
6
0.011
<10
539
<5
<5
2070
5370
Marshall
DBKG-MR6
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.076
11
448
15
<S
1340
983
Marshall
DBKG-MR7
Duke
<0.05
<1
<1
<0.2
<0.3
<5
<0.005
989
4310
270
<5
3240
7100
Marshall
DBKG-MR8
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.006
<10
340
7
<S
1140
2850
Marshall
DBKG-MR9
Duke
<0.05
<1
<1
<0.2
<0.3
9
<0.005
47
6270
19
<5
918
29300
Marshall
DBKG-MR10
Duke
0.27
<1
<1
<0.2
<0.3
90
0.043
50
1290
23
<S
2240
5950
Marshall
DBKG-MR11
Duke
<0.05
<1
<1
<0.2
22.9
<5
<0.005
<10
3820
6
<5
3870
7260
Marshall
DBKG-MR12
Duke
<0.05
3.63
<1
<0.2
<0.3
<S
<0.005
613
4220
64
<S
2360
9320
Marshall
DBKG-MR13
Duke
<0.05
<1
<1
<0.2
7.41
<5
<0.005
<10
2340
<5
<5
1930
5770
Marshall
DBKG-MR14
Duke
<0.05
7.63
<1
<0.2
0.446
9
<0.005
18
5230
17
<5
4230
10300
Marshall
DBKG-MR15
Duke
<0.05
<1
<1
<0.2
0.739
19
0.011
16
<0.03
5890
6
<5
3530
9680
Marshall
DBKG-MR16
Duke
<0.05
<0.5
<0.5
<0.1
7.6
<5
<0.005
<10
1.8
4280
<5
<5
1890
9270
Marshall
DBKG-MR17
Duke
<0.05
1.6
0.68
<0.1
<1
<S
0.006
254
0.039
2870
10
<S
2800
6860
Marshall
DBKG-MR18
Duke
<0.05
1.2
1.7
<0.1
4.7
8
<0.005
12
3.7
5990
<S
<S
3060
9090
Marshall
DBKG-MR19
Duke
<0.05
1.73
<1
<0.2
12.7
55
0.011
66
0.61
15400
<5
<5
3900
17600
Marshall
DBKG-MR20
Duke
<0.05
<1
<1
<0.2
5.32
<S
0.017
<10
0.36
2460
<S
<S
1440
6790
Marshall
DBKG-MR21
Duke
<0.05
<1
<1
<0.2
3.14
23
<0.005
32
0.17
2660
<5
<5
2270
6650
Marshall
DBKG-MR22
Duke
<0.05
1.94
1.27
<0.2
2.65
5
<0.005
<10
0.13
4730
<S
<S
2700
7490
Marshall
DBKG-MR23
Duke
<0.05
<1
<1
<0.2
4.5
13
0.006
13
0.15
5720
<5
<5
2850
8180
Marshall
DBKG-MR24
Duke
<0.05
<1
<1
<0.2
13.1
10
0.028
1480
0.11
3980
8
<S
2310
7670
Marshall
DBKG-MR25
Duke
<0.2
2.1
<0.5
<0.1
<1
22.6
<0.001
<50
<0.03
1740
9.2
<0.5
2080
25000
Marshall
DBKG-MR26
Duke
<0.2
0.7
<0.5
<0.1
<1
119
0.0274
3920
4150
988
3.3
3140
6710
Marshall
DBKG-MR27
Duke
<0.2
<0.5
<0.5
<0.1
<1
11
0.0023
<50
392
14.4
<0.5
1240
936
Marshall
DBKG-MR28
Duke
<0.05
2.34
<1
<0.2
9.44
2150
<0.005
3720
3590
74
<5
2610
23000
Marshall
DBKG-MR29
Duke
<0.05
<1
<1
0.354
6.83
<5
<0.005
<10
5660
<5
<5
2220
8160
Haley Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016

Table EZ -6
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to MCL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
22
Page 3 of 3
Haley Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016
15A NCAC 02L.0202
Groundwater Standard a
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MCL/SMCL (b):
* denotes secondary standard
NS
*5
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015 (d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the
CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
'C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
my
Marshall
MRBKG-2 NCDEQ
89.6
0.0169
55.8
55.8
<S
<2.5
<1
16.68
0.168
0.32
28
Marshall
MRBKG-8 NCDEQ
1150
0.006
61.6
61.6
<5
<2.5
<1
17.68
0.537
1.17
106
Marshall
MRBKG-11 NCDEQ
207
0.0082
76.8
76.8
<S
5.1
<1
16.74
0.9
0.52
112
Marshall
MRBKG-14 NCDEQ
12.2
0.01
7.4
7.4
<5.0
<2.5
<1
16.81
0.053
2.4
241
Marshall
MRBKG-15 NCDEQ
63.1
0.0102
49.6
49.6
<S
<2.5
<1
16.18
0.113
1.68
167
Marshall
MRBKG-16 NCDEQ
75.3
0.0291
44.9
44.9
<S
<2.5
<1
15.25
0.094
3.14
173
Marshall
MRBKG-18 NCDEQ
119
<0.005
33.5
33.5
<5.0
<2.5
<1
16.52
0.09
2.68
201
Marshall
MRBKG-27 NCDEQ
232
0.0136
80
80
<5
<2.5
<1
16.86
0.19
3.22
88
Marshall
MRBKG-31 NCDEQ
120
0.0061
21.4
21.4
<S
20.6
2.9
17.14
0.114
7.32
205
Marshall
MRBKG-39 NCDEQ
201
0.0055
35.8
35.8
<5
<2.5
10.6
16.86
0.085
4.18
192
Marshall
DBKG-MRI Duke
44
0.029
Marshall
DBKG-MR2 Duke
9S9
0.041
Marshall
DBKG-MR3 Duke
40
<0.005
Marshall
DBKG-MR4 Duke
844
0.029
Marshall
DBKG-MRS Duke
11
0.012
Marshall
DBKG-MR6 Duke
15
0.08
Marshall
DBKG-MR7 Duke
166
0.009
Marshall
DBKG-MR8 Duke
9
0.009
Marshall
DBKG-MR9 Duke
1060
<0.005
Marshall
DBKG-MR10 Duke
33
0.104
Marshall
DBKG-MR11 Duke
146
<0.005
Marshall
DBKG-MR12 Duke
259
0.007
Marshall
DBKG-MR13 Duke
106
0.262
Marshall
DBKG-MR14 Duke
215
<0.005
Marshall
DBKG-MR15 Duke
109
0.254
Marshall
DBKG-MR16 Duke
219
0.012
Marshall
DBKG-MR17 Duke
223
<0.005
Marshall
DBKG-MR18 Duke
401
0.009
Marshall
DBKG-MR19 Duke
334
0.012
Marshall
DBKG-MR20 Duke
100
0.25
Marshall
DBKG-MR21 Duke
208
0.009
Marshall
DBKG-MR22 Duke
524
<0.005
Marshall
DBKG-MR23 Duke
187
0.007
Marshall
DBKG-MR24 Duke
122
0.078
Marshall
DBKG-MR25 Duke
2210
<0.005
<2.6
Marshall
DBKG-MR26 Duke
161
0.0249
Marshall
DBKG-MR27 Duke
10.3
0.006
Marshall
DBKG-MR28 Duke
2010
0.016
74
Marshall
DBKG-MR29 Duke
148
<0.005
<5
22
Page 3 of 3
Haley Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx MCL April 2016

23
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated 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 E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table E2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to DHHS Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
24
Page 1 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL (b):
` denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015 (d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID
Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
pH
su
Sulfate
mg/L
Total DissolvedSolids
mg/L
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<5
16000
4.5
6.93
13.3
105
<0.5
<0.5
13.8
<0.2
<0.08
<0.5
<0.5
0.16
Marshall
MRBKG-8
NCDEQ
9.1
74200
4.6
7.12
186
373
<0.5
0.84
24.6
<0.2
<0.08
0.51
<0.5
0.29
Marshall
MRBKG-11
NCDEQ
<5
18600
1.7
7.39
10.8
112
<0.5
<0.5
58.5
<0.2
<0.08
0.76
<0.5
0.36
Marshall
MRBKG-14
NCDEQ
12.7
1680
3.5
5.15
<2.0
<25.0
<0.5
<0.5
24.9
<0.2
<0.08
0.85
<0.5
0.46
Marshall
MRBKG-15
NCDEQ
<5
9520
1.7
6.25
<2
90
<0.5
<0.5
24.2
<0.2
<0.08
1.9
<0.5
0.96
Marshall
MRBKG-16
NCDEQ
<5
10400
2.1
6.04
<2
83
<0.5
<0.5
19.7
<0.2
<0.08
0.89
<0.5
0.61
Marshall
MRBKG-18
NCDEQ
<5
7510
2
6.15
<2.0
51
<0.5
<0.5
44
<0.2
<0.08
1.9
<0.5
0.18
Marshall
MRBKG-27
NCDEQ
<5
25600
4.2
6.3
9.9
139
<0.5
<0.5
26.7
<0.2
<0.08
<0.5
<0.5
0.28
Marshall
MRBKG-31
NCDEQ
135
8850
9.4
5.64
2.1
100
<0.5
<0.5
59.2
<0.2
<0.08
2.3
<0.5
1.3
Marshall
MRBKG-39
NCDEQ
<5
7960
1.6
6.03
<2
79
<0.5
<0.5
57.2
<0.2
<0.08
1.4
<0.5
0.57
Marshall
DBKG-MR1
Duke
<50
10900
<1
<1
33
<1
<1
<5
<1
1.13
Marshall
DBKG-MR2
Duke
<50
55800
<1
<1
486
<1
<1
7
<0
1.83
Marshall
DBKG-MR3
Duke
<50
8960
<1
<1
7
<1
<1
<5
<0
<1
Marshall
DBKG-MR4
Duke
<50
44900
<1
<1
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR5
Duke
<50
1550
<1
<1
34
<1
<1
<5
<0
1.37
Marshall
DBKG-MR6
Duke
< 50
3340
< 1
< 1
19
< 1
< 1
<5
<0
5.4
Marshall
DBKG-MR7
Duke
<50
33200
<1
<1
6
<1
<1
<5
<0
<1
Marshall
DBKG-MR8
Duke
<50
3300
<1
<1
11
<1
<1
<5
<0
<1
Marshall
DBKG-MR9
Duke
107
84900
<1
2.58
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR10
Duke
<50
3650
<1
<1
155
<1
<1
<5
<0
<1
Marshall
DBKG-MR11
Duke
<50
43500
<1
<1
40
<1
<1
<5
<0
<1
Marshall
DBKG-MR12
Duke
<50
21400
<1
<1
<5
<1
<1
<5
<0
<1
Marshall
DBKG-MR13
Duke
<50
13100
<1
<1
16
<1
<1
<5
<1
<1
Marshall
DBKG-MR14
Duke
<50
43400
<1
6.81
83
<1
<1
<5
<1
<1
Marshall
DBKG-MR15
Duke
<50
23600
<1
<1
15
<1
<1
<5
<1
1.84
Marshall
DBKG-MR16
Duke
<50
13800
1.2
<0.5
23
<0.2
<0.08
<5
<0.5
0.21
Marshall
DBKG-MR17
Duke
<50
24400
1.2
<0.5
6
<0.2
<0.08
9
<0.5
0.26
Marshall
DBKG-MR18
Duke
<50
23100
1.1
<0.5
19
<0.2
<0.08
<5
<0.5
0.19
Marshall
DBKG-MR19
Duke
<50
35700
1.19
<1
150
<1
0.01
<5
<1
2.45
Marshall
DBKG-MR20
Duke
<50
8070
<1
<1
64
<1
<1
<5
<1
<1
Marshall
DBKG-MR21
Duke
<50
8540
<1
<1
65
<1
<1
<5
<1
<1
Marshall
DBKG-MR22
Duke
<50
44000
1.46
<1
104
<1
<1
<5
<1
<1
Marshall
DBKG-MR23
Duke
<50
11000
<1
<1
67
<1
<1
<5
<1
<1
Marshall
DBKG-MR24
Duke
<50
9810
1.24
<1
75
<1
<1
<5
<1
5.16
Marshall
DBKG-MR25
Duke
17
86800
0.64
4.7
27.8
<0.2
<0.08
<0.5
<0.5
0.2
Marshall
DBKG-MR26
Duke
<5
35800
1
<0.5
10.3
<0.2
<0.08
6.9
<0.5
6.3
Marshall
DBKG-MR27
Duke
<5
2010
0.8
<0.5
15.9
<0.2
<0.08
<0.5
<0.5
0.36
Marshall
DBKG-MR28
Duke
<50
81800
4.1
8.06
170
370
<1
5.3
39
<1
<1
<5
1.33
1.8
Marshall
DBKG-MR29
Duke
<50
15400
19
7.31
0.36
140
<1
<1
56
<1
<1
<5
<1
<1
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016

Table E2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to DHHS Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
25
Page 2 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MGL/SMCL (b):
* denotes secondary standard
2
NS
50
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
1L
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015(d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44(e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents
Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iran
Chromium,Hexavalent
Magnesium
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<0.2
2.9
0.72
<0.1
1
<10
0.0019
57.5
<0.6
5890
43.3
<0.5
3360
7180
Marshall
MRBKG-8
NCDEQ
<0.2
3.7
<0.5
<0.1
<1
<10
0.0028
<50
<0.6
4120
14.1
<0.5
1900
29900
Marshall
MRBKG-11
NCDEQ
<0.2
4.9
<0.5
<0.1
1.2
<10
0.0049
<50
<0.6
5070
26.1
0.9
3450
9510
Marshall
MRBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1.0
<10
0.0032
<50
<0.6
808
10.7
<0.5
1110
6620
Marshall
MRBKG-15
NCDEQ
<0.2
0.58
<0.5
<0.1
4.6
<10
0.0088
<50
1.1
3480
2.7
<0.5
2390
7410
Marshall
MRBKG-16
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
<10
0.0128
<50
<0.6
2870
0.69
<0.5
2020
6240
Marshall
MRBKG-18
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.8
<10
0.0019
<50
1.7
2430
<0.50
<0.5
1940
6440
Marshall
MRBKG-27
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0066
1340
<0.03
4190
271
1.1
3290
8420
Marshall
MRBKG-31
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
68.8 M1
0.0161
179
0.56
2820
3.2
1.8
1930
8750
Marshall
MRBKG-39
NCDEQ
<0.2
<0.5
<0.5
<0.1
3
<10
0.0096
<50
0.82
1810
0.57
<0.5
2360
6790
Marshall
DBKG-MR1
Duke
<0.05
<1
<1
<0.2
0.326
15
0.024
19
1470
10
<5
1970
1750
Marshall
DBKG-MR2
Duke
<0.05
<1
<1
<0.2
0.554
6
0.011
42
11700
13
7
4190
151000
Marshall
DBKG-MR3
Duke
<0.05
<1
1.37
<0.2
2.25
<5
<0.005
14
2400
<5
<5
1150
6570
Marshall
DBKG-MR4
Duke
<0.05
<1
<1
<0.2
1.95
<5
<0.005
75
3110
10
<5
2110
11700
Marshall
DBKG-MRS
Duke
<0.05
<1
<1
<0.2
0.807
6
0.011
<10
539
<5
<5
2070
5370
Marshall
DBKG-MR6
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.076
11
448
15
<5
1340
983
Marshall
DBKG-MR7
Duke
<0.05
<1
<1
<0.2
<0.3
<5
<0.005
989
4310
270
<5
3240
7100
Marshall
DBKG-MR8
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.006
<10
340
7
<5
1140
2850
Marshall
DBKG-MR9
Duke
<0.05
<1
<1
<0.2
<0.3
9
<0.005
47
6270
19
<5
918
29300
Marshall
DBKG-MR10
Duke
0.27
<1
<1
<0.2
<0.3
90
0.043
50
1290
23
<5
2240
5950
Marshall
DBKG-MR11
Duke
<0.05
<1
<1
<0.2
22.9
<5
<0.005
<10
3820
6
<5
3870
7260
Marshall
DBKG-MR12
Duke
<0.05
3.63
<1
<0.2
<0.3
<5
<0.005
613
4220
64
<5
2360
9320
Marshall
DBKG-MR13
Duke
<0.05
<1
<1
<0.2
7.41
<5
<0.005
<10
2340
<5
<5
1930
5770
Marshall
DBKG-MR14
Duke
<0.05
7.63
<1
<0.2
0.446
9
<0.005
18
5230
17
<5
4230
10300
Marshall
DBKG-MR15
Duke
<0.05
<1
<1
<0.2
0.739
19
0.011
16
<0.03
5890
6
<5
3530
9680
Marshall
DBKG-MR16
Duke
<0.05
<0.5
<0.5
<0.1
7.6
<5
<0.005
<10
1.8
4280
<5
<5
1890
9270
Marshall
DBKG-MR17
Duke
<0.05
1.6
0.68
<0.1
<1
<5
0.006
254
0.039
2870
10
<5
2800
6860
Marshall
DBKG-MR18
Duke
<0.05
1.2
1.7
<0.1
4.7
8
<0.005
12
3.7
5990
<5
<5
3060
9090
Marshall
DBKG-MR19
Duke
<0.05
1.73
<1
<0.2
12.7
55
0.011
66
0.61
15400
<5
<5
3900
17600
Marshall
DBKG-MR20
Duke
<0.05
<1
<1
<0.2
5.32
<5
0.017
<10
0.36
2460
<5
<5
1440
6790
Marshall
DBKG-MR21
Duke
<0.05
<1
<1
<0.2
3.14
23
<0.005
32
0.17
2660
<5
<5
2270
6650
Marshall
DBKG-MR22
Duke
<0.05
1.94
1.27
<0.2
2.65
5
<0.005
<10
0.13
4730
<5
<5
2700
7490
Marshall
DBKG-MR23
Duke
<0.05
<1
<1
<0.2
4.5
13
0.006
13
0.15
5720
<5
<5
2850
8180
Marshall
DBKG-MR24
Duke
<0.05
<1
<1
<0.2
13.1
10
0.028
1480
0.11
3980
8
<5
2310
7670
Marshall
DBKG-MR25
Duke
<0.2
2.1
<0.5
<0.1
<1
22.6
<0.001
<50
<0.03
1740
9.2
<0.5
2080
25000
Marshall
DBKG-MR26
Duke
<0.2
0.7
<0.5
<0.1
<1
119
0.0274
3920
4150
988
3.3
3140
6710
Marshall
DBKG-MR27
Duke
<0.2
<0.5
<0.5
<0.1
<1
11
0.0023
<50
392
14.4
<0.5
1240
936
Marshall
DBKG-MR28
Duke
<0.05
2.34
<1
<0.2
9.44
2150
<0.005
3720
3590
74
<5
2610
23000
Marshall
DBKG-MR29
Duke
<0.05
<1
<1
0.354
6.83
<5
<0.005
<10
5660
<5
<5
2220
8160
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016

Table E2-7
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to DHHS Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
26
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016
15A NCAC 02L.0202
Groundwater Standard a:
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MGL/SMCL (b):
* denotes secondary standard
NS
*5
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
my
Marshall
MRBKG-2 NCDEQ
89.6
0.0169
55.8
55.8
<5
<2.5
<1
16.68
0.168
0.32
28
Marshall
MRBKG-8 NCDEQ
1150
0.006
61.6
61.6
<5
<2.5
<1
17.68
0.537
1.17
106
Marshall
MRBKG-11 NCDEQ
207
0.0082
76.8
76.8
<5
5.1
<1
16.74
0.9
0.52
112
Marshall
MRBKG-14 NCDEQ
12.2
0.01
7.4
7.4
<5.0
<2.5
<1
16.81
0.053
2.4
241
Marshall
MRBKG-15 NCDEQ
63.1
0.0102
49.6
49.6
<5
<2.5
<1
16.18
0.113
1.68
167
Marshall
MRBKG-16 NCDEQ
75.3
0.0291
44.9
44.9
<5
<2.5
<1
15.25
0.094
3.14
173
Marshall
MRBKG-18 NCDEQ
119
<0.005
33.5
33.5
<5.0
<2.5
<1
16.52
0.09
2.68
201
Marshall
MRBKG-27 NCDEQ
232
0.0136
80
80
<5
<2.5
<1
16.86
0.19
3.22
88
Marshall
MRBKG-31 NCDEQ
120
0.0061
21.4
21.4
<5
20.6
2.9
17.14
0.114
7.32
205
Marshall
MRBKG-39 NCDEQ
201
0.0055
35.8
35.8
<5
<2.5
10.6
16.86
0.085
4.18
192
Marshall
DBKG-MR1 Duke
44
0.029
Marshall
DBKG-MR2 Duke
959
0.041
Marshall
DBKG-MR3 Duke
40
<0.005
Marshall
DBKG-MR4 Duke
844
0.029
Marshall
DBKG-MRS Duke
11
0.012
Marshall
DBKG-MR6 Duke
15
0.08
Marshall
DBKG-MR7 Duke
166
0.009
Marshall
DBKG-MR8 Duke
9
0.009
Marshall
DBKG-MR9 Duke
1060
<0.005
Marshall
DBKG-MR10 Duke
33
0.104
Marshall
DBKG-MR11 Duke
146
<0.005
Marshall
DBKG-MR12 Duke
259
0.007
Marshall
DBKG-MR13 Duke
106
0.262
Marshall
DBKG-MR14 Duke
215
<0.005
Marshall
DBKG-MR15 Duke
109
0.254
Marshall
DBKG-MR16 Duke
219
0.012
Marshall
DBKG-MR17 Duke
223
<0.005
Marshall
DBKG-MR18 Duke
401
0.009
Marshall
DBKG-MR19 Duke
334
0.012
Marshall
DBKG-MR20 Duke
100
0.25
Marshall
DBKG-MR21 Duke
208
0.009
Marshall
DBKG-MR22 Duke
524
<0.005
Marshall
DBKG-MR23 Duke
187
0.007
Marshall
DBKG-MR24 Duke
122
0.078
Marshall
DBKG-MR25 Duke
2210
<0.005
<2.6
Marshall
DBKG-MR26 Duke
161
0.0249
Marshall
DBKG-MR27 Duke
10.3
0.006
Marshall
DBKG-MR28 Duke
2010
0.016
74
Marshall
DBKG-MR29 Duke
148
<0.005
<5
26
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx DHHS April 2016

27
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated 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 E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table E2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to RSL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
28
Page 1 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
Groundwater Standard a:
700
NS
250
6.5-8.5
250
500
1
10
700
4
2
10
1
15
Federal MCL/SMCL (b):
` denotes secondary standard
NS
NS
*250
6.5-8.5
*250
*500
6
10
2,000
4
5
100
NS
15
DHHS Screening Level (c):
700
NS
250
NS
250
NS
1
10
700
4
2
10
1
15
RSL 2015(d):
4,000
NS
NS
NS
NS
NS
7.8
0.052
3,800
25
9.2
22,000
6
15
Appendix III (f)
Appendix IV (g)
Plant
Well Owner ID
Source
Boron
ug/L
Calcium
ug/L
Chloride
mg/L
PH
su
Sulfate
mg/L
Total Dissolved
Solids
mg/L
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Lead
ug/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<5
16000
4.5
6.93
13.3
105
<0.5
<0.5
13.8
<0.2
<0.08
<0.5
<0.5
0.16
Marshall
MRBKG-8
NCDEQ
9.1
74200
4.6
7.12
186
373
<0.5
0.84
24.6
<0.2
<0.08
0.51
<0.5
0.29
Marshall
MRBKG-11
NCDEQ
<5
18600
1.7
7.39
10.8
112
<0.5
<0.5
58.5
<0.2
<0.08
0.76
<0.5
0.36
Marshall
MRBKG-14
NCDEQ
12.7
1680
3.5
5.15
<2.0
<25.0
<0.5
<0.5
24.9
<0.2
<0.08
0.85
<0.5
0.46
Marshall
MRBKG-15
NCDEQ
<5
9520
1.7
6.25
<2
90
<0.5
<0.5
24.2
<0.2
<0.08
1.9
<0.5
0.96
Marshall
MRBKG-16
NCDEQ
<5
10400
2.1
6.04
<2
83
<0.5
<0.5
19.7
<0.2
<0.08
0.89
<0.5
0.61
Marshall
MRBKG-18
NCDEQ
<5
7510
2
6.15
<2.0
51
<0.5
<0.5
44
<0.2
<0.08
1.9
<0.5
0.18
Marshall
MRBKG-27
NCDEQ
<5
25600
4.2
6.3
9.9
139
<0.5
<0.5
26.7
<0.2
<0.08
<0.5
<0.5
0.28
Marshall
MRBKG-31
NCDEQ
135
8850
9.4
5.64
2.1
100
<0.5
<0.5
59.2
<0.2
<0.08
2.3
<0.5
1.3
Marshall
MRBKG-39
NCDEQ
<5
7960
1.6
6.03
<2
79
<0.5
<0.5
57.2
<0.2
<0.08
1.4
<0.5
0.57
Marshall
DBKG-MR1
Duke
<50
10900
<1
<1
33
<1
<1
<5
<1
1.13
Marshall
DBKG-MR2
Duke
<50
55800
<1
<1
486
<1
<1
7
<0
1.83
Marshall
DBKG-MR3
Duke
<50
8960
<1
<1
7
<1
<1
<5
<0
<1
Marshall
DBKG-MR4
Duke
<50
44900
<1
<1
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR5
Duke
<50
1550
<1
<1
34
<1
<1
<5
<0
1.37
Marshall
DBKG-MR6
Duke
< 50
3340
< 1
< 1
19
< 1
< 1
<5
<0
5.4
Marshall
DBKG-MR7
Duke
<50
33200
<1
<1
6
<1
<1
<5
<0
<1
Marshall
DBKG-MR8
Duke
<50
3300
<1
<1
11
<1
<1
<5
<0
<1
Marshall
DBKG-MR9
Duke
107
84900
<1
2.58
15
<1
<1
<5
<0
<1
Marshall
DBKG-MR10
Duke
<50
3650
<1
<1
155
<1
<1
<5
<0
<1
Marshall
DBKG-MR11
Duke
<50
43500
<1
<1
40
<1
<1
<5
<0
<1
Marshall
DBKG-MR12
Duke
<50
21400
<1
<1
<5
<1
<1
<5
<0
<1
Marshall
DBKG-MR13
Duke
<50
13100
<1
<1
16
<1
<1
<5
<1
<1
Marshall
DBKG-MR14
Duke
<50
43400
<1
6.81
83
<1
<1
<5
<1
<1
Marshall
DBKG-MR15
Duke
<50
23600
<1
<1
15
<1
<1
<5
<1
1.84
Marshall
DBKG-MR16
Duke
<50
13800
1.2
<0.5
23
<0.2
<0.08
<5
<0.5
0.21
Marshall
DBKG-MR17
Duke
<50
24400
1.2
<0.5
6
<0.2
<0.08
9
<0.5
0.26
Marshall
DBKG-MR18
Duke
<50
23100
1.1
<0.5
19
<0.2
<0.08
<5
<0.5
0.19
Marshall
DBKG-MR19
Duke
<50
35700
1.19
<1
150
<1
0.01
<5
<1
2.45
Marshall
DBKG-MR20
Duke
<50
8070
<1
<1
64
<1
<1
<5
<1
<1
Marshall
DBKG-MR21
Duke
<50
8540
<1
<1
65
<1
<1
<5
<1
<1
Marshall
DBKG-MR22
Duke
<50
44000
1.46
<1
104
<1
<1
<5
<1
<1
Marshall
DBKG-MR23
Duke
<50
11000
<1
<1
67
<1
<1
<5
<1
<1
Marshall
DBKG-MR24
Duke
<50
9810
1.24
<1
75
<1
<1
<5
<1
5.16
Marshall
DBKG-MR25
Duke
17
86800
0.64
4.7
27.8
<0.2
<0.08
<0.5
<0.5
0.2
Marshall
DBKG-MR26
Duke
<5
35800
1
<0.5
10.3
<0.2
<0.08
6.9
<0.5
6.3
Marshall
DBKG-MR27
Duke
<5
2010
0.8
<0.5
15.9
<0.2
<0.08
<0.5
<0.5
0.36
Marshall
DBKG-MR28
Duke
<50
81800
4.1
8.06
170
370
<1
5.3
39
<1
<1
<5
1.33
1.8
Marshall
DBKG-MR29
Duke
<50
15400
19
7.31
0.36
140 1
<1
<1
56
<1
<1
<5
<1
<1
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016

Table E2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to RSL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
29
Page 2 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
Groundwater Standard (a):
1
NS
20
0.2
0.3
NS
1
300
NS
NS
50
100
NS
NS
Federal MGL/SMCL (b):
* standard
denotes secondary
2
N5
SO
2
NS
*50 to 200
1.3
*300
NS
NS
*50
NS
NS
NS
DHHS Screening Level (c):
1L
18
20
0.2
0.3
3,500
1
2,500
0.07
NS
200
100
NS
20,000
RSL 2015 (d):
5.7
100
100
0.2
86
20,000
0.8
14,000
44 (e)
NS
430
390
NS
NS
Appendix IV (g)
Constituents Not Identified in the CCR
Rule
Plant
Well Owner ID
Source
Mercury
ug/L
Molybdenum
ug/L
Selenium
ug/L
Thallium
ug/L
Vanadium
Aluminum
Copper
Iron
Chromium,Hexavalent
Magnesium
Manganese
Nickel
Potassium
Sodium
ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L
ug/L
Marshall
MRBKG-2
NCDEQ
<0.2
2.9
0.72
<0.1
1
<10
0.0019
57.5
<0.6
5890
43.3
<0.5
3360
7180
Marshall
MRBKG-8
NCDEQ
<0.2
3.7
<0.5
<0.1
<1
<10
0.0028
<50
<0.6
4120
14.1
<0.5
1900
29900
Marshall
MRBKG-11
NCDEQ
<0.2
4.9
<0.5
<0.1
1.2
<10
0.0049
<50
<0.6
5070
26.1
0.9
3450
9510
Marshall
MRBKG-14
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1.0
<10
0.0032
<50
<0.6
808
10.7
<0.5
1110
6620
Marshall
MRBKG-15
NCDEQ
<0.2
0.58
<0.5
<0.1
4.6
<10
0.0088
<50
1.1
3480
2.7
<0.5
2390
7410
Marshall
MRBKG-16
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
<10
0.0128
<50
<0.6
2870
0.69
<0.5
2020
6240
Marshall
MRBKG-18
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.8
<10
0.0019
<50
1.7
2430
<0.50
<0.5
1940
6440
Marshall
MRBKG-27
NCDEQ
<0.2
<0.5
<0.5
<0.1
<1
<10
0.0066
1340
<0.03
4190
271
1.1
3290
8420
Marshall
MRBKG-31
NCDEQ
<0.2
<0.5
<0.5
<0.1
1.2
68.8 M1
0.0161
179
0.56
2820
3.2
1.8
1930
8750
Marshall
MRBKG-39
NCDEQ
<0.2
<0.5
<0.5
<0.1
3
<10
0.0096
<50
0.82
1810
0.57
<0.5
2360
6790
Marshall
DBKG-MR1
Duke
<0.05
<1
<1
<0.2
0.326
15
0.024
19
1470
10
<5
1970
1750
Marshall
DBKG-MR2
Duke
<0.05
<1
<1
<0.2
0.554
6
0.011
42
11700
13
7
4190
151000
Marshall
DBKG-MR3
Duke
<0.05
<1
1.37
<0.2
2.25
<5
<0.005
14
2400
<5
<5
1150
6570
Marshall
DBKG-MR4
Duke
<0.05
<1
<1
<0.2
1.95
<S
<0.005
75
3110
10
<5
2110
11700
Marshall
DBKG-MRS
Duke
<0.05
<1
<1
<0.2
0.807
6
0.011
<10
539
<5
<5
2070
5370
Marshall
DBKG-MR6
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.076
11
448
15
<S
1340
983
Marshall
DBKG-MR7
Duke
<0.05
<1
<1
<0.2
<0.3
<5
<0.005
989
4310
270
<5
3240
7100
Marshall
DBKG-MR8
Duke
<0.05
<1
<1
<0.2
<0.3
10
0.006
<10
340
7
<S
1140
2850
Marshall
DBKG-MR9
Duke
<0.05
<1
<1
<0.2
<0.3
9
<0.005
47
6270
19
<5
918
29300
Marshall
DBKG-MR10
Duke
0.27
<1
<1
<0.2
<0.3
90
0.043
50
1290
23
<5
2240
5950
Marshall
DBKG-MR11
Duke
<0.05
<1
<1
<0.2
22.9
<5
<0.005
<10
3820
6
<5
3870
7260
Marshall
DBKG-MR12
Duke
<0.05
3.63
<1
<0.2
<0.3
<5
<0.005
613
4220
64
<5
2360
9320
Marshall
DBKG-MR13
Duke
<0.05
<1
<1
<0.2
7.41
<5
<0.005
<10
2340
<5
<5
1930
5770
Marshall
DBKG-MR14
Duke
<0.05
7.63
<1
<0.2
0.446
9
<0.005
18
5230
17
<5
4230
10300
Marshall
DBKG-MR15
Duke
<0.05
<1
<1
<0.2
0.739
19
0.011
16
<0.03
5890
6
<S
3530
9680
Marshall
DBKG-MR16
Duke
<0.05
<0.5
<0.5
<0.1
7.6
<S
<0.005
<10
1.8
4280
<5
<5
1890
9270
Marshall
DBKG-MR17
Duke
<0.05
1.6
0.68
<0.1
<1
<5
0.006
254
0.039
2870
10
<5
2800
6860
Marshall
DBKG-MR18
Duke
<0.05
1.2
1.7
<0.1
4.7
8
<0.005
12
3.7
5990
<5
<5
3060
9090
Marshall
DBKG-MR19
Duke
<0.05
1.73
<1
<0.2
12.7
55
0.011
66
0.61
15400
<5
<5
3900
17600
Marshall
DBKG-MR20
Duke
<0.05
<1
<1
<0.2
5.32
<S
0.017
<10
0.36
2460
<S
<S
1440
6790
Marshall
DBKG-MR21
Duke
<0.05
<1
<1
<0.2
3.14
23
<0.005
32
0.17
2660
<5
<5
2270
6650
Marshall
DBKG-MR22
Duke
<0.05
1.94
1.27
<0.2
2.65
5
<0.005
<10
0.13
4730
<5
<5
2700
7490
Marshall
DBKG-MR23
Duke
<0.05
<1
<1
<0.2
4.5
13
0.006
13
0.15
5720
<5
<5
2850
8180
Marshall
DBKG-MR24
Duke
<0.05
<1
<1
<0.2
13.1
10
0.028
1480
0.11
3980
8
<5
2310
7670
Marshall
DBKG-MR25
Duke
<0.2
2.1
<0.5
<0.1
<1
22.6
<0.001
<50
<0.03
1740
9.2
<0.5
2080
25000
Marshall
DBKG-MR26
Duke
<0.2
0.7
<0.5
<0.1
<1
119
0.0274
3920
4150
988
3.3
3140
6710
Marshall
DBKG-MR27
Duke
<0.2
<0.5
<0.5
<0.1
<1
11
0.0023
<50
392
14.4
<0.5
1240
936
Marshall
DBKG-MR28
Duke
<0.05
2.34
<1
<0.2
9.44
2150
<O.00S
3720
3590
74
<S
2610
23000
Marshall
OBKG-MR29
Duke
<0.05
<1
<1
0.354
6.83
1 <5
<0.005
<10
5660
<5
<5
1 2220
8160
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016

Table E2-8
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to RSL Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
30
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016
15A NCAC 02L.0202
Groundwater Standard a:
NS
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
Federal MGL/SMCL (b):
* denotes secondary standard
NS
*5
NS
NS
NS
NS
NS
NS
NS
NS
NS
DHHS Screening Level (c):
2,100
1
NS
NS
NS
NS
NS
NS
NS
NS
NS
RSL 2015(d):
12,000
6
NS
NS
NS
NS
NS
NS
NS
NS
NS
Constituents Not Identified in the CCR Rule
Plant
Well Owner ID Source
Strontium
ug/L
Zinc
mg/L
Alkalinity
mg/L
Bicarbonate
mg/L
Carbonate
mg/L
Total
Suspended
Solids
mg/L
Turbidity
NTU
Temperature
°C
Specific
Conductance
umhos/cm
Dissolved
Oxygen
mg/L
Oxidation
Reduction
Potential
mV
Marshall
MRBKG-2 NCDEQ
89.6
0.0169
55.8
55.8
<5
<2.5
<1
16.68
0.168
0.32
28
Marshall
MRBKG-8 NCDEQ
1150
0.006
61.6
61.6
<5
<2.5
<1
17.68
0.537
1.17
106
Marshall
MRBKG-11 NCDEQ
207
0.0082
76.8
76.8
<5
5.1
<1
16.74
0.9
0.52
112
Marshall
MRBKG-14 NCDEQ
12.2
0.01
7.4
7.4
<5.0
<2.5
<1
16.81
0.053
2.4
241
Marshall
MRBKG-15 NCDEQ
63.1
0.0102
49.6
49.6
<5
<2.5
<1
16.18
0.113
1.68
167
Marshall
MRBKG-16 NCDEQ
75.3
0.0291
44.9
44.9
<5
<2.5
<1
15.25
0.094
3.14
173
Marshall
MRBKG-18 NCDEQ
119
<0.005
33.5
33.5
<5.0
<2.5
<1
16.52
0.09
2.68
201
Marshall
MRBKG-27 NCDEQ
232
0.0136
80
80
<5
<2.5
<1
16.86
0.19
3.22
88
Marshall
MRBKG-31 NCDEQ
120
0.0061
21.4
21.4
<5
20.6
2.9
17.14
0.114
7.32
205
Marshall
MRBKG-39 NCDEQ
201
0.0055
35.8
35.8
<5
<2.5
10.6
16.86
0.085
4.18
192
Marshall
DBKG-MR1 Duke
44
0.029
Marshall
DBKG-MR2 Duke
959
0.041
Marshall
DBKG-MR3 Duke
40
<0.005
Marshall
DBKG-MR4 Duke
844
0.029
Marshall
DBKG-MR5 Duke
11
0.012
Marshall
DBKG-MR6 Duke
15
0.08
Marshall
DBKG-MR7 Duke
166
0.009
Marshall
DBKG-MR8 Duke
9
0.009
Marshall
DBKG-MR9 Duke
1060
<0.005
Marshall
DBKG-MR10 Duke
33
0.104
Marshall
DBKG-MR11 Duke
146
<0.005
Marshall
DBKG-MR12 Duke
259
0.007
Marshall
DBKG-MR13 Duke
106
0.262
Marshall
DBKG-MR14 Duke
215
<0.005
Marshall
DBKG-MR15 Duke
109
0.254
Marshall
DBKG-MR16 Duke
219
0.012
Marshall
DBKG-MR17 Duke
223
<0.005
Marshall
DBKG-MR18 Duke
401
0.009
Marshall
DBKG-MR19 Duke
334
0.012
Marshall
DBKG-MR20 Duke
100
0.25
Marshall
DBKG-MR21 Duke
208
0.009
Marshall
DBKG-MR22 Duke
524
<0.005
Marshall
DBKG-MR23 Duke
187
0.007
Marshall
DBKG-MR24 Duke
122
0.078
Marshall
DBKG-MR25 Duke
2210
<0.005
<2.6
Marshall
DBKG-MR26 Duke
161
0.0249
Marshall
DBKG-MR27 Duke
10.3
0.006
Marshall
DBKG-MR28 Duke
2010
0.016
74
Marshall
DBKG-MR29 Duke
148
<0.005
<5
30
Page 3 of 3
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx RSL April 2016

31
Comparison of NCDEQ and Duke Energy Background Water Supply Well Data to Screening Levels
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
^ - Denotes IMAC value.
* - Denotes SMCL value.
°C - Degrees Celsius.
Blank data cells indicate no data available.
CCR - Coal Combustion Residual.
DEQ- Department of Environmental Quality.
DHHS - Department of Health and Human Services.
HI - Hazard Index.
IMAC- Interim Maximum Allowable Concentration.
MCL- Maximum Contaminant Level.
MDL- Method Detection Limit.
mg/L - milligrams/liter.
mV - millivolts.
NA- Not available.
NS- No Standard Available.
NTU - Nephelometric Turbidity Units.
PQL- Practical Quantitation Limit (h).
RSL- Risk Based Screening Level.
SMCL -Secondary Maximum Contaminant Level.
su - standard units.
USEPA- United States Environmental Protection Agency.
ug/L- micrograms/liter.
umhos/cm - micromhos/centimeter.
Data Qualifiers
< Not Detected below the laboratory reporting limit.
Ml Matrix spike recovery exceeded QC limits. Batch accepted based on laboratory control sample (LCS) recovery.
(a) - Classifications and Water Quality Standards Applicable to Groundwaters of North Carolina. North Carolina Administrative Code. April 1, 2013.
http://portal.ncdenr.org/web/wq/ps/csu/gwstandards
(b) - USEPA 2012 Edition of the Drinking Water Standards and Health Advisories. Spring 2012. http://www.epa.gov/sites/production/files/2015-09/documents/dwstandards20l2.pdf.
(c) - DHHS Screening Levels. Department of Health and Human Services, Division of Public Health, Epidemiology Section, Occupational and Environmental
Epidemiology Branch. http://portal.ncdenr.org/c/document_library/get_file?p_I_id=1169848&folderld=24814087&name=DLFE-112704.pdf
(d) - USEPA Risk Based Screening Levels (November 2015). Values for tapwater. HI = 1.
http://www. a pa.gov/risk/risk-based-screen i ng-ta bl e -generic -tables
(e) -Alternative screening level calculated for hexavalent chromium using RSL calculator (http://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search) and current dose -response data from the USEPA's
Integrated Risk Information System. Available at: http://www.epa.gov/IRIS/. The RSL for hexavalent chromium is not a drinking water standard, and the basis of the draft oral cancer toxicity value
used in the calculation of the RSL has been questioned by USEPA's Science Advisory Board; therefore, RSL for Chromium (IV) is based on the noncancer values developed by USEPA.
(f) -The CCR Rule lists these constituents as Constituents for Detection Monitoring (Appendix III).
http://www.gpo.gov/fdsys/pkg/FR-2015-04-17/pdf/2015-00257.pdf
(g) - The CCR Rule lists these constituents as Constituents for Assessment Monitoring (Appendix IV).
(h) - Each analytical procedure has a PQL, which is defined as "the lowest level achievable among laboratories within specified limits during routine laboratory operation". The PQL is about three to
five times the calculated MDL for the analytical procedure, and represents a practical and routinely achievable reporting limit with a relatively good certainty that any reported value is reliable.
Detected value is above the Breen i ng level.
_ Reporting limit is above the screening level.
Haley & Aldrich, Inc.
Tables E2 -5-E2-8 NCDEQ and Duke Energy Bkg Well Screen_2016-04.xlsx April 2016

Table E2-9
Do Not Drink Letter Summary
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Haley & Aldrich, Inc.
Table E2-9 Do Not Drink Summary.xlsx
Page 1 of 1
April 2016
32
Constituents Listed in Part 1 of Letter
Facility Well ID
Vanadium
Hex
Chromium
Chloride Chromium Cobalt Iron
Lead
Manganese Sodium Strontium Sulfate Thallium Zinc
Marshall MR -2 Office
X
X
Marshall MR -2 Plant
X
X
Marshall MR -6
X
Marshall MR -8
X
Marshall MR -9
X
Marshall MR -911
X
X
Marshall MR -10
X
X
Marshall MR -11
X
X
Marshall MR -12
X
X
X
Marshall MR -13
X
Marshall MR -14R
X
X
Marshall MR -16
X
X
X
Marshall MR -17
X
Marshall MR -17R
X
X
Marshall MR -17R
X
X
Marshall MR -18
X
X
Marshall MR -18R
X
Marshall MR -18R
X
Marshall MR -20
X
X
Marshall MR -21
X
Marshall MR -23
X
Marshall MR -25
X
Marshall MR -26
X
Marshall MR -28
X
Marshall MR -29
X
X
Marshall MR -32
X
X
X
Marshall MR -33
X
X
Marshall MR -35
X
Marshall MR -43
X
X
Marshall MR -44
X
X
X
Marshall MR -44
X
X
X
Marshall MR -44
X
X
X
Marshall MR -21R
X
Marshall MR -22
X
Marshall MR -36
X
Marshall MR -37
X
Marshall MR -38
X
Marshall MR -45
X
Total number of Constituent Letters
32
17
0 0 0 9
1
3 1 0 0 0 0
Total Number of "Do Not Drink" Letters
(Excluding Hexavalent Chromium and
Vanadium)
11
Total Number of "Do Not Drink" Letters
(Including Hexavalent Chromium and
Vanadium)
38
Total Number of "Do Not Drink" Letters
for Hexavalent Chromium
17
Total Number of "Do Not Drink" Letters
for Vanadium
32
Haley & Aldrich, Inc.
Table E2-9 Do Not Drink Summary.xlsx
Page 1 of 1
April 2016
32

33
Table E3-1 Page 1 of 2
NCDEQ and Duke Energy Background Water Supply Well Data
Marshall Steam Station
Water Supply well Evaluation
Duke Energy
April 2016
Notes:
<- Not detected, value is the reporting limit.
°C - Degrees Celsius.
DEQ - Department of Environmental Quality.
Ml - Matrix spike recovery exceeded QC limits.
Batch accepted based on laboratory control
sample (LCS) recovery.
mg/L - milligrams/liter.
mV - millivolts.
NC - North Carolina.
NTU - Nephelometric Turbidity Units.
s - standard units.
ug/L - micrograms/liter.
.mhos/cm - mlcromhos/centimeter.
Haley & Aldrich, Inc.
Table E3-1 NCDEQand Duke Energy Background Well Data_2016-04.xlsx April 2016

34
Table E3-1 Page 2 of 2
NCDEQ and Duke Energy Background Water Supply Well Data
Marshall Steam Station
Water Supply well Evaluation
Duke Energy
April 2016
MMMOMMMMMOMMMM
=mom
Notes:
<- Not detected, value is the reporting limit.
Y - Degrees Celsius.
DEQ- Department of Environmental Quality.
M3 - Matrix spike recovery exceeded QC limits.
Batch accepted based on laboratory control
sample (LCS) recovery.
mg/L - milligrams/liter.
my - millivolts.
NC - North Carolina.
NTU - Nephelometric Turbidity Units.
su-standard units.
ug/L - micrograms/liter.
.mhos/cm - micromhos/centimeter.
Haley & Aldrich, Inc.
Table E3-1 NCDEQand Duke Energy Background Well Data_2016-04.xlsx April 2016

35
Page 1 of 1
Table E3-2
Facility Specific Background Data for Bedrock and Deep Monitoring Wells
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Well ID
Sample ID
Date Sampled
Barium
(ug/L)
Boron
(ug/L)
Chromium
(ug/L)
Cobalt
(ug/L)
Hexavalent Chromium
(ug/L)
Iron
(ug/L)
Lead
(ug/L)
Nckel, Dissolved
(ug/L)
Vanadium
(ug/L)
BG -1D
BG-1D_WG_20150717
17 -Jul -15
68
<50
3.1
3.3
310
0.19
5.8
3.5
BG -1D
BG -113 Dup
17 -Jul -15
2.62
277
BG -11)
MA -BG -ID -NS -3Q15
29 -Sep -15
70
29
1.5
0.99
47
<0.1
7.7
3.4
BG -11)
MA -BG -ID -NS -4Q15-1
11 -Nov -15
89
< 50
2.3
1.2
1.3
350
0.11
7.2
3.1
BG -11)
MA -BG -ID -NS -4Q15-2
11 -Dec -15
98
<50
0.6
3.2
0.016
1000
<0.1
8.6
1.4
BG -11)
MA -BG -ID -FD -4Q15-2
11 -Dec -15
89
<50
0.49
2.7
0.045
630
<0.1
9
2.4
BG-2BR
BG-2BR_WG_20150718
18 -Jul -15
580
<50
80.4
11.9
18200
17.5
100
BG-2BR
MA-BG-2BR-NS-3Q15
29 -Sep -15
330
< 50
6.7
0.23
410
0.28
1.2
13.3
BG-2BR
MA-BG-2BR-FD-3Q15
29 -Sep -15
350
< 50
7.1
0.13
190
0.16
1.4
12.7
BG-2BR
MA-BG-2BR-NS-4Q15-1
11 -Nov -15
380
< 50
6.2
0.23
6
270
0.19
1
12.1
BG-2BR
MA-BG-2BR-NS-4Q15-2
11 -Dec -15
380
< 50
7.4
< 0.5
7.6
40
< 0.1
0.91
14.1
BG -31)
BG -3D WG 20150720
20 -Jul -15
760
26
6.6
1.8
250
0.26
7.3
21.9
BG -3D
MA -BG -3D -NS -3Q15
28 -Sep -15
820
< 50
4.4
0.47
40
0.051
7.1
22.1
BG -31)
MA -BG -3D -NS -4Q15-1
11 -Nov -15
880
<50
4.1
0.24
3.7
60
<0.1
6
21.9
BG -3D
MA -BG -3D -FD -4Q15-1
11 -Nov -15
890
< 50
3.8
0.24
4.1
58
0.051
6.1
20.8
BG -31)
MA -BG -3D -NS -4Q15-2
11 -Dec -15
820
< 50
2
0.24
1.9
< 50
< 0.1
6.4
23.8
MW -41)
MW-4D_WG_20110207
07 -Feb -11
43
<50
<5
268
<1
MW -41)
MW-4D_WG_20110601
01 -Jun -11
43
< 50
< 5
21
< 1
MW -4D
MW-4D_WG_20111005
05 -Oct -11
43
< 50
< 5
26
< 1
MW -41)
MW-4D_WG_20120208
08 -Feb -12
46
<50
<5
376
<1
MW -41)
MW -4D WG 20120606
06 -Jun -12
43
<50
<5
88
<1
MW -41)
MW-4D_WG_20121004
04 -Oct -12
41
< 50
< 5
41
< 1
MW -41)
MW-4D_WG_20130206
06 -Feb -13
41
<50
<5
17
<1
MW -41)
MW-4D_WG_20130605
05 -Jun -13
43
<50
<5
18
<1
<5
MW -41)
MW-4D_WG_20131001
01 -Oct -13
42
< 50
< 5
17
< 1
MW -41)
MW-4D_WG_20140206
06 -Feb -14
42
<50
<5
16
<1
MW -41)
MW-4D_WG_20140604
04 -Jun -14
42
<50
<5
25
<1
MW -41)
MW-4D_WG_20141008
08 -Oct -14
41
<50
<5
37
<1
MW -41)
MW-4D_WG_20150204
04 -Feb -15
42
<50
<5
<10
<1
MW -41)
MW-4D_WG_20150608
08 -Jun -15
42
<50
<5
<1
24
<1
MW -41)
MW-4D_WG_20150710
10 -Jul -15
40
<50
1.29
<0.5
77
0.078
0.42
2.8
MW -41)
MA -MW -4D -NS -3Q15
30 -Sep -15
41
<50
11.3
0.3
210
0.073
8.6
2.5
MW -4D
MA -MW -4D -4Q15-2
11 -Dec -15
42
<50
1.2
<0.5
0.8
88
0.065
1
2.9
Notes:
<- Not Detected, value is the reporting limit.
ug/L - Microgram per liter.
Haley & Aldrich, Inc.
Table E3.2 -Facility Bkg Data.xlsx April 2016

36
Page 1 of 1
Table E3-3
Statistical Evaluation of Background Data
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
1
2
3
4
5
6
1 7
8
1 9
1 10
11
12
13
1 14
15
16
17
Units
Frequency of
Detection
Percent
Non-
Detects Range of Non -Detects
KM Mean
KM
Variance
KM
Standard
Deviation
KM
Coefficient
of Variation
50th
Percentile
(Q2)
95th
Percentile
Regional Background
Evaluation
Outlier
Removed
Distribution
BTV
Method
Barium
ug/L
31
Variable
Units
Frequency of
Detection
Percent
Non- KM
Detects Range of Non -Detects KM Mean Variance
KM
Standard
Deviation
KM
Coefficient
of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Outlier
Presence*
Outlier
Removed
Distribution
BTV
Method
Barium
ug/L
38
/
39
3%
5
5
51.66
6208
78.79
1.525
26.7
150.5
486
Yes
No
Gamma
208.3
95%Approx. Gamma UTL WH and KM
Boron
ug/L
5
/
39
87%
5
50
12.83
656.2
25.62
1.997
50
55.7
135
Yes
No
Normal
67.25
95% KM UTL
Chromium
ug/L
11
/
39
72%
0.5
5
1.549
3.524
1.877
1.212
5
6.91
9
No
No
Gamma
5.253
95%Approx. Gamma UTL WH and KM
Cobalt
ug/L
1
/
39
97% 1
0
1
0.0341
0.0442
0.21
6.164
0.5
1
1.33
NA
No
NA
1.33
Maximum Detect
Hexavalent Chromium
ug/L
13
/
21
38%
0.03
0.6
0.295
0.495
0.703
2.381
0.03
1.71
3.7
Yes
No
Gamma
3.304
95%Approx. Gamma UTL WH and KM
Iron
ug/L
22
/
39
44%
10
50
338.4
774378
880
2.6
50
1704
3920
Yes
No
Distribution free
3920
Maximum Detect (95% UTL)
Lead
ug/L
24
/
39
38%
1
1
1.003
2.108
1.452
1.447
1
5.184
6.3
Yes
No
Gamma
4.022
95%Approx. Gamma UTL WH and KM
Nickel
ug/L
5
/
39
87%
0.5
5
1.049
1.535
1.239
1.181
5
5
7
No
No
Normal
3.681
95% KM UTL
Vanadium
ug/L
26
/
39
33%
0.3
1
3.234
21.45
4.632
1.432
1.2
12.74
22.9
Yes
No
Gamma
14.7
95%Approx. Gamma UTL WH and KM
Notes:
* - Tested at 5% significance level.
BTV - Background Threshold Value.
KM - Kaplan -Meier Method.
NA - Not Available.
RL - Reporting Limit.
ug/L- Microgram per liter.
UPLs - Upper Prediction Limits.
UTLs - Upper Tolerance Limits.
Var - Variance.
WH - Wilson Hilferty Transformation.
Haley & Aldrich, Inc.
Table E3.3_Background rta Mical a I.ation..k. April 2016
Facility Specific
Background Evaluation
Variable
Units
Frequency of
Detection
Percent
Non-
Detects Range of Non -Detects
KM Mean
KM
Variance
KM
Standard
Deviation
KM
Coefficient
of Variation
50th
Percentile
(Q2)
95th
Percentile
Maximum
Detect
Outlier
Presence*
Outlier
Removed
Distribution
BTV
Method
Barium
ug/L
31
/
31
0%
NA
NA
217.5
86950
294.9
1.356
43
850
890
Yes
Yes
Distribution free
890
Maximum Detect (95% UTL)
Boron
ug/L
2
/
31
94%
50
50
27.5
2.25
1.5
0.0545
50
50
29
Yes
Yes
NA
29
Maximum Detect
Chromium
ug/L
18
/
32
44%
5
5
3.271
6.118
2.473
0.756
5
7.235
11.3
Yes
Yes
Gamma
10.61
95%Approx. Gamma UTL WH and KM
Cobalt
ug/L
14
/
18
22% 1
0.5
1
0.909
1 1.121 1
1.059
1.164
0.5
3.215
3.3
Yes
Yes
Gamma
4.48
95%Approx. Gamma UTL WH and KM
Hexavalent Chromium
ug/L
9
/
9
0%
NA
NA
2.829
7.272
2.697
0.953
1.9
6.96
7.6
No
No
Normal
11
95%UTL
Iron
ug/L
30
/
32
6%
10
50
166.2
45206
212.6
1.279
59
509
1000
Yes
Yes
Distribution free
1000
Maximum Detect (95% UTL)
Lead
ug/L
11
/
31
65%
0.1
1
0.111
0.00539
0.0735
0.661
0.26
1
0.28
Yes
Yes
Distribution free
0.28
Maximum Detect (95% UTL)
Nickel
ug/L
17
/
18
6%
5
5
4.818
10.07
3.173
0.659
6.05
8.66
9
No
No
Distribution free
9
Maximum Detect (95% UTL)
Vanadium
ug/L
17
/
17
0%
NA
NA
10.86
74.19
8.613
0.193
12.1
22.44
23.8
Yes
Yes
Distribution free
23.8
Maximum Detect (95% UTL)
Notes:
* - Tested at 5% significance level.
BTV - Background Threshold Value.
KM - Kaplan -Meier Method.
NA - Not Available.
RL - Reporting Limit.
ug/L- Microgram per liter.
UPLs - Upper Prediction Limits.
UTLs - Upper Tolerance Limits.
Var - Variance.
WH - Wilson Hilferty Transformation.
Haley & Aldrich, Inc.
Table E3.3_Background rta Mical a I.ation..k. April 2016

37
Page 1 of 1
Table E3-4
Comparison Of NCDEQ Water Supply Well Sampling Data To Regional Background Threshold Values
Marshall 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
38 / 39
12 - 370
60.63
19.8
38.8
80.65
86.18
130
208.3
1
Boron
ug/L
4 / 39
5 - 77
37.28
5
5
5
5.04
167
67.25
1
Chromium
ug/L
31 / 39
0.56 - 4.8
1.613
0.85
1.11
1.95
2.38
5.5
5.253
0
Cobalt
ug/L
9 / 39
0.05 - 2
0.484
0.278
0.5
0.5
0.5
1.1
1.33
1
Hexavalent Chromium
ug/L
31 / 39
0.037 - 2.74
0.878
0.222
0.65
1.3
1.44
11
3.304
0
Iron
ug/L
22 / 39
19.8 - 3,700
590.7
50
50
225
286.8
1390
3920
0
Lead
ug/L
36 / 39
0.089 - 32
2.77
0.264
0.49
1.1
1.4
13
4.022
5
Nickel
ug/L
23 / 39
0.24 - 10
1.584
0.5
0.51
1.05
1.14
3.41
3.681
1
Vanadium
I ug/L
1 31 / 39
1 0.36 - 14
1 3.827
1 1.06
1 2
1 4.85
1 5.04
1 10.11
1 14.7
0
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 E3-3.
Haley & Aldrich, Inc.
Table E3-4 NCDEQ Water Supply Well Data Compared to Regional BTVs.xlsx April 2016

38
Page 1 of 1
Table E3-5
Comparison Of NCDEQ Water Supply Well Sampling Data To Facility Specific Background Threshold Values
Marshall 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
38 / 39
12 - 370
60.63
19.8
38.8
80.65
86.18
130
890
0
Boron
ug/L
4 / 39
5 - 77
37.28
5
5
5
5.04
167
29
2
Chromium
ug/L
31 / 39
0.56 - 4.8
1.613
0.85
1.11
1.95
2.38
5.5
10.61
0
Cobalt
ug/L
9 / 39
0.05 - 2
0.484
0.278
0.5
0.5
0.5
1.1
4.48
0
Hexavalent Chromium
ug/L
31 / 39
0.037 - 2.74
0.878
0.222
0.65
1.3
1.44
11
11
0
Iron
ug/L
22 / 39
19.8 - 3,700
590.7
50
50
225
286.8
1390
1,000
4
Lead
ug/L
36 / 39
0.089 - 32
2.77
0.264
0.49
1.1
1.4
13
0.28
29
Nickel
ug/L
23 / 39
0.24 - 10
1.584
0.5
0.51
1.05
1.14
3.41
9
4
Vanadium
ug/L
31 / 39
0.36 - 14
3.827
1.06
2
4.85
5.04
10.11
23.8
0
Notes:
BTV - Background Threshold Value.
DEQ- Department of Environmental Quality.
NA - Not Available.
INC - North Carolina.
ug/L - micrograms/liter.
(a) - Frequency of Detection: number of detects / total number of results.
(b) - BTV values shown on Table E3-3.
Haley & Aldrich, Inc.
Table E3-5 NCDEQ Water Supply Well Data Compared to Facility Specific BTVs.xlsx April 2016

Table E4-1
Hydrostratigraphic Layer Properties - Horizontal Hydraulic Conductivity
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Hydrostratigraphic Unit
N
Geometric Mean
(cm/sec)
Geometric Mean +
1SD (cm/sec)
Geometric Mean -
1SD (cm/sec)
Geometric Median
(cm/sec)
Minimum (cm/sec)
Maximum (cm/sec)
Ash
17
2.9E-04
4.5E-03
1.9E-05
3.5E-04
2.5E-06
4.3E-02
Fill
14
4.8E-05
1.7E-04
1.3E-05
6.4E-05
5.4E-06
3.9E-04
Alluvium (S)
10
4.9E-04
5.2E-03
4.6E-05
1.0E-03
8.2E-06
2.6E-02
mi
31
7.8E-04
3.8E-03
1.6E-04
5.3E-04
1.0E-04
2.6E-02
M2
22
7.1 E-05
5.3E-04
9.5E-06
9.9E-05
1.5E-06
2.3E-03
Transition Zone (TZ)
12
5.2E-04
3.1E-03
8.5E-05
6.9E-04
3.4E-05
5.8E-03
Bedrock (BR)
54
2.4E-04
1.2E-03
5.0E-05
2.9E-04
7.6E-06
5.6E-03
Notes:
1. Hydraulic Conductivity, 'k,' values have an approximate lognormal distribution. Geometric mean, median, and standard deviation
estimated by taking the log of the values and running standard statistics on the log values, then converting those values back.
2. Dataset derived from CSA Investigation and historical reports. Refer to tables 11-4 and 11-6 for historic conductivity data.
3. Fill dataset derived from CSA Investigation Sites Allen (N=5), Cliffside (N=4), Dan River (N=2), and Riverbend (N= 3)
4. Alluvium dataset derived from Riverbend CSA investigation (N=3), Allen (N=2), Cliffside (N=3), and Dan River (N=2).
Page 1 of 1
39

Table E4-2
Estimated Groundwater Seepage Velocities
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Well Pair
Ash
Fill
Alluvium
M1
M2
TZ5%
TZIO
13112%
BR5%
Regolith (S wells); Seepage Velocity (ft/yr)
AB -3S / GWA-1S 53.1
10.3
71.5
93.9
6.5
-
AL -2S / AB -10S 16.5
3.2
22.2
29.1
2.0
AB -7S / AB -9S 24.8
4.8
33.5
43.9
3.0
AB -7S / AB -8S 54.4
10.6
73.4
96.3
6.7
GWA-4S / AB -13S 30.9
6.0
41.7
54.8
3.8
AB -1 S / MW -10S 1 53.2 1
10.3
71.8
94.2
6.5
-
-
Transition Zone (D Wells); Seepage Velocity (ft/yr)
AB -1 D / MW -1 OD
-
-
-
-
317.2
158.6
AB -31D / GWA-1 D
254.6
127.3
MW -12D / AB -14D
231.5
115.7
GWA-6D / AB -11 D
59.7
29.8
AB -16D / AB -12D
111.1
55.5
GWA-4D / AB -13D
151.8
1 75.9
AL -41D / AB -1 OD
132.8
66.4
Fractured Bedrock (BR Wells); Seepage Velocity (ft/yr)
AB-5BR / GWA-1 BR
172.2
68.9
AB-15BR / AB-9BR
66.9
26.8
GWA-9BR / AB-9BR
132.5
53.0
Notes:
1. Refer to Table 11-9 for horizontal hydraulic conductivity values.
2. Refer to Table 6-9 for horizontal hydraulic gradients.
3. Refer to Tables 11-8 and 11-11 for effective porosity/specific yield for upper and lower hydrostratigraphic units
4. TZ and BR subscripts indicate effective porosities used
Page 1 of 1
40

Table E5-1
Site -Specific Distribution Coefficient (Kd)
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Constituent
Mininum
(L/kg)
Mean
(L/kg)
Maximum
(L/kg)
Antimony
6.32E-06
5.52E-05
1.22E-04
Arsenic
2.01E+01
1.82E+02
8.09E+02
Boron
1.87E-02
5.54E-02
1.65E-01
Barium
2.78E-06
7.47E-06
1.03E-05
Beryllium
7.15E+03
1.72E+04
2.44E+04
Cobalt
3.25E-01
7.63E-01
1.67E+00
Chromium
3.98E+06
1.01E+07
1.53E+07
Iron
6.00E-02
1.65E-01
2.61E-01
Lead
1.22E+02
3.03E+02
6.01E+02
Nickel
1.11 E-01
3.34E-01
4.85E-01
Selenium
1.03E+00
2.12E+01
5.94E+01
Sulfate
2.27E-01
6.71E-01
1.99E+00
Thallium
NA
NA
NA
Vanadium
2.56E+00
2.16E+02
1.60E+03
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 E5-1 and E5-2.xlsx
Page 1 of 1
April 2016
41

Table E5-2
Coal Ash Indicator Concentrations Observed in the Water Supply Wells of Low Oxygen and High Detected Boron Concentrations
Marshall Steam Station
Water Supply Well Evaluation
Duke Energy
April 2016
Notes:
BTV - Background Threshold Value.
mg/L - Milligrams per liter.
µg/L - Micrograms per liter.
(a) - The water supply wells contain dissolved oxygen less than 3,500 ug/L or boron concentration higher
than 20 µg/L.
(b) - BTV = background threshold value in the unit of µg/l- determined from the regional background well data.
(c) - Sulfate threshold concentration is determined by the 90th percentile value of the sulfate concentrations of the
regional background wells.
Haley & Aldrich, Inc.
Tables E5-1 and E5-2.xlsx
Page 1 of 1
April 2016
42
Dissolved
Sulfate
Boron BTV
Barium
Barium BTV
Sulfate
Water Supply Well (a)
Oxygen
Boron (µg/L)
Threshold
[Vg/L) (b)
(µg/L)
(µg/L) (b)
[lag/L)
(µg/L)
(mg/L) (c)
MR -13
2,800
<5
32.1
8,400
MR -16
3,186
<5
94
18,700
MR -35
1,800
<5
18
5,000
67.25
208.3
154,330
MR -36
10
<5
0.3
11,700
MR -2 (office)
5,600
77
90.2
3,400
MR -25
5,500
62
53.8
3,100
Notes:
BTV - Background Threshold Value.
mg/L - Milligrams per liter.
µg/L - Micrograms per liter.
(a) - The water supply wells contain dissolved oxygen less than 3,500 ug/L or boron concentration higher
than 20 µg/L.
(b) - BTV = background threshold value in the unit of µg/l- determined from the regional background well data.
(c) - Sulfate threshold concentration is determined by the 90th percentile value of the sulfate concentrations of the
regional background wells.
Haley & Aldrich, Inc.
Tables E5-1 and E5-2.xlsx
Page 1 of 1
April 2016
42

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

/ IND STRIAL
D ILL #1
DEMOLITION
LANDFILL
ASBESTOS DRY ASH
LANDFILL
LANDFILL CHASE 1)
PVSTRUCTURAL
1 FILL
STEAM PLANT
DRY ASH
LANDFILL
(PHASE 1)
1?O
kk
gTER Cp S�pN
LAKENORMAN r
l
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A yo
1 STEAMSHALL STATION / / UICH
/ V
N N
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LEGEND
NOTES

O
0
0
--- -7
INDUSTRIAL Q
OO / DFILL #1 % O
DEMOLITION
LANDFILL
ASBESTOS ` DRY ASH
LANDFILL
LANDFILL fi CHASE 1)
PV STRUCTURAL
1 FILL
O `
O 1 BASIN
O
LAKE NORMANFGD
SIDUE
I FILL
W
1 C,,
MARSHALL�'^u
STEAM STATION / OO CH
DA
Z
r/<<NTER
LEGEND
1tl
r
A 2
O O
AO O
NOTES
FN Tal
ITA
ulky

� I
f 1
(/ INDUSTRIAL
#1
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DEMOLITION
LANDFILL
ASBESTOS DRY ASH
LANDFILL
LANDFILL CHASE 1)
PVSTRUCTURAL
1 FILL
STEAM PLANT
— BG1D
X Q�\
BG3D
BG2PBJR
i
DRY ASH
LANDFILL
(PHASE 1)
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A 2
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LEGEND
NOTES

F)l
DATE
TWO MEDIUM GROUNDWATER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-1
SOIL
Regolith
ONE'
ZONE'-
unsaturated
unsaturated
none
Water table
REGOLITH
Regolith
RESIDUUM
saturated
II
zone
JfFANSITION{
4 _
ZONE l
WEATHERED
J / BEDROCK
j�
UNWEATHERED
BEDROCK
r .�
r\
t
FRACTURED BEDROCK
SHEETJOINT
r
r��
1
�
I
BEDROCK
STRUCTURE
r
� 4 1
-
r
''
I11
I
�l FRACTURE
1
1
t
NOTES:
1. HARNED, D.A. AND DANIEL III, C.C.
1992. THE TRANSITION ZONE BETWEEN BEDROCK REGOLITH: CONDUIT FOR
CONTAMINATION?, P. 336-348, IN
DANIEL, C.C., III, WHITE,
R.K., AND STONE, P.A., EDS., GROUNDWATER IN
THE PIEDMONT: PROCEEDINGS OF A CONFERENCE ON GROUND WATER IN THE PIEDMONT OF THE EASTERN
UNITED STATES, OCTOBER 16-18,
1989, CLEMSON UNIVERSITY, 693P.
F)l
DATE
TWO MEDIUM GROUNDWATER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-1

F)l
�IffR
log A0
STEM A
Slope Aquifer Boundary and Topographic D1171de
Discharge Boundary
- - - - - - - Compartment (C) Boundary
.... 0........... Water Table
X�x> - Fractures
Groundwater Flow Direction
SOURCE: LEGRAND, 2004
DATE
SLOPE AQUIFER SYSTEM APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-2

WELL
--------- "+
RECDC]LITH RESlzRVOIR -----------
.
�P
`5 }
STORAGE
REDROCI{
- ERACTUR'ES BEDROCK
J F
t _ Y
1 1 Y
5 Y
m
0 r, Y
P
fTA 1 � Y
Y
1
Y
Source: Heath, 1984
DATE
REGOLITH AS PRIMARY APRIL 2016
GROUNDWATER STORAGE
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-3

J
J
J
LU
D W
W �
CL'
0 cc
03 a
REGOLITH B
z
Q
TRANSITION Cca
700E "A
BEDROCK
LAND FILL.
Arrows indicate direction
of ground -water flow
,LEACHATE4
W J
J
Q
W
0
Source: Harned and Daniel, 1992
DATE
FNTRANSITION ZONE AS PRIMARY TRANSMITTER APRIL 2016
OF IMPACTED GROUNDWATER
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-4

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
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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
0 500 1,000
SCALE (FEET)
FEZ
CATAWBA 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
EXISTING LANDFILL GROUNDWATER MONITORING
WELL (ASH LANDFILLS AND FGD RESIDUE
LANDFILL)
WATER TABLE CONTOUR LINE
E 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/STRUCTURAL FILL BOUNDARY
STREAM
1) W.E. INDICATES WATER ELEVATION
DATE
APRIL 2016
FIGURE
E4-5

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
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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
0 500 1,000
SCALE (FEET)
FEZ
CATAWBA 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
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/STRUCTURAL FILL BOUNDARY
STREAM
1) W.E. INDICATES WATER ELEVATION
DATE
APRIL 2016
FIGURE
E4-6

O
O'
O
O Opo
p O
O
NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE
2. WASTE BOUNDARY IS APPROXIMATE. 500 0 500 1,000
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 (FEET)
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
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
FEZ
CATAWBA COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
GROUNDWATER CONTOUR LINE
E 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/STRUCTURAL FILL BOUNDARY
STREAM
1) W.E. INDICATES WATER ELEVATION
DATE
APRIL 2016
FIGURE
E4-7
;
40�
s
NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE
2. WASTE BOUNDARY IS APPROXIMATE. 500 0 500 1,000
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 (FEET)
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
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BYAMEC FOSTER WHEELER, DATED MAY 29, 2015.
FEZ
CATAWBA COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE GROUNDWATER FLOW DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT GROUNDWATER
MONITORING WELL
GROUNDWATER CONTOUR LINE
E 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/STRUCTURAL FILL BOUNDARY
STREAM
1) W.E. INDICATES WATER ELEVATION
DATE
APRIL 2016
FIGURE
E4-7

00 -e
O M
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a9 0 .
'p��N
b;
00
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0.
000
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e o a
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a E
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4
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k#'
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O O
Ot d..I .e .. 411 ..
��' •,.'�k iii 4 � _ i ��G- F 1 �.
ti
Y
4
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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
500 0 500 1, 000
SCALE (FEET)
CATAWBA COUNTY, NORTH CAROLINA
LEGEND
NOTE:
ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
DATE
12[!111:19
APRIL 2016
I •
.P
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
EXISTING LANDFILL
GROUNDWATER MONITORING
WELL (ASH LANDFILLS AND FGD
RESIDUE LANDFILL)
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/STRUCTURAL FILL
BOUNDARY
STREAM
NOTE:
ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
DATE
12[!111:19
APRIL 2016
I •
.P

r
k �t.
y _ 7
pw
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s
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. 500 0 500 1, 000
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 (FEET)
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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
CATAWBA COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE
GROUNDWATER FLOW
O
DIRECTION
O
WATER SUPPLY WELLS
ASH BASIN ASSESSMENT
®
GROUNDWATER
MONITORING WELL
ASH BASIN COMPLIANCE
v,
MONITORING WELL
ASH BASIN VOLUNTARY
GROUNDWATER
MONITORING WELL
GROUNDWATER
CONTOUR LINE
ASH BASIN COMPLIANCE
BOUNDARY
ASH BASIN COMPLIANCE
BOUNDARY COINCIDENT
WITH DUKE ENERGY
PROPERTY BOUNDARY
r
ASH BASIN WASTE
-
BOUNDARY
DUKE ENERGY PROPERTY
QO
BOUNDARY
el�
LANDFILL COMPLIANCE
BOUNDARY
"14
O
FILL BOUNDARY
STREAM
NOTES:
1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE
2. WASTE BOUNDARY IS APPROXIMATE. 500 0 500 1, 000
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 (FEET)
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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
CATAWBA 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
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/STRUCTURAL
FILL BOUNDARY
STREAM
NOTE:
1) W.E. INDICATES WATER ELEVATION
2) ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
DATE
APRIL 2016
FIGURE
E4-9

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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
K
^
V ^
Y'¢ t
�1 .�
O 41
f�
0-
O
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.01 07 (a).
9. HYDROGRAPHY IS FROM THE PROVISIONAL JURISDICTIONAL WATERS MAP (USAGE APPROVAL PENDING), PROVIDED BY AMEC FOSTER WHEELER, DATED MAY 29, 2015.
K
^
V ^
Y'¢ t
�1 .�
O 41
f�
500 0 500 1, 000
SCALE (FEET)
CATAWBA COUNTY, NORTH CAROLINA
LEGEND
APPROXIMATE
GROUNDWATER FLOW
DIRECTION
O WATER SUPPLY WELLS
ASH BASIN ASSESSMENT
Q 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/STRUCTURAL
FILL BOUNDARY
STREAM
NOTE:
1 W.E. INDICATES WATER ELEVATION
2) ALL ELEVATIONS ARE REFERENCED TO NORTH AMERICAN
VERTICAL DATUM OF 1988 (NAVD88).
DATE
■2C0111:19
APRIL 2016
E4-10

DATE
NOTES: HORIZONTAL HYDRAULIC CONDUCTIVITY
1. ONLY SITE-SPECIFIC, IN-SITU MATERIAL REPRESENTED IN THIS FIGURE. MEASUREMENTS APRIL 2016
2. REFER TO TABLE E4-1 FOR ADDITIONAL INFORMATION.
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-11
Horizontal Hydraulic Conductivity for Native Hydrostratigraphic Layers NT= 219
1. DDE -01
1, DOE -02
U
41
—
U
Y
a 1.00E-03
--
c
1, DDE -04
,3
LS
7+
1.00E-05
O
N
x 1.0017-06
1.ODE-07
M1 [N=31) M2 (N=22) TZ (N=12) BR (N=54)
7.5E-04 7 1 E-05 5.2E-04 2.4E-04
DATE
NOTES: HORIZONTAL HYDRAULIC CONDUCTIVITY
1. ONLY SITE-SPECIFIC, IN-SITU MATERIAL REPRESENTED IN THIS FIGURE. MEASUREMENTS APRIL 2016
2. REFER TO TABLE E4-1 FOR ADDITIONAL INFORMATION.
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-11

G
Qp� oD _ rsz' 1
L ° OULL gPH&8C 0
�IND
r 4
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500 0 500 1, 000
MW8S
- f
l
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1J
■
y
sm
SITE CONCEPTUAL MODEL - PLAN VIEW MAP
AREA OF BORON EXCEEDANCES OF 2L STANDARDS
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
MARSHALL STEAM STATION ASH BASIN
LEGEND:
O
NOTES:
11
� ,?., • ". ` ,:. ;.; ; v. �'- �,. _ � ; ti 4v ,., ,y .�:. .��r Ate. , _
s �' �"� _...... ,: - ��� a ■.�. _
t aDLrlO
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- ?FF '_ `s' V ` f I •"�i . v � 4 f' '" •, � .r. � " { aC `\ D A �� oD ' - _
.44 \ _ I ,,■
y '
n
qA
AILAO, A
son
.. `"� ' ■
gad T
A I
W
500 0 500 1, 000
MW8S
- f
l
10,
1J
■
y
sm
SITE CONCEPTUAL MODEL - PLAN VIEW MAP
AREA OF BORON EXCEEDANCES OF 2L STANDARDS
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
MARSHALL STEAM STATION ASH BASIN
LEGEND:
O
NOTES:
11
10,
1J
■
y
sm
SITE CONCEPTUAL MODEL - PLAN VIEW MAP
AREA OF BORON EXCEEDANCES OF 2L STANDARDS
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
MARSHALL STEAM STATION ASH BASIN
LEGEND:
O
NOTES:
11

CROSS SECTION MARSHALL ASH BASIN
(LOOKING NORTHEAST)
NOTE:
LEGEND
ASH
REGOLITH
PARTIALLY WEATHERED ROCK/TRANSITION ZONE
(PWR/TZ)
BEDROCK
EI LL
1. TRANSECT AA'
FROM
FIGURE
82 IN THE CSA REPORT USED FOR CROSS—SECTION SHOWN ABOVE.
2. DRAWING NOT
TO SCALE
AND
IS INTENDED FOR ILLUSTRATION PURPOSES ONLY.
APPROXIMATE EXTENT of 2L STANDARD (700
3. APPROXIMATE
EXTENT
OF 2L
STANDARD EXCEEDANCES OF BORON IN GROUNDWATER BASED ON RESULTS
G9/L) ExcEEDANCEs of BORON IN
GROUNDWATER
FROM 2015 ROUND 2
SAMPLING
EVENT
4. THE CLOSEST
WATER
SUPPLY
WELL IS LOCATED —1,500 FT EAST OF TRANSECT A
APPROXIMATE GROUNDWATER—A'.
FLOW DIRECTION
F)l
CROSS-SECTION CONCEPTUAL SITE MODEL
WATER SUPPLY WELL EVALUATION
DUKE ENERGY CAROLINAS, LLC
MARSHALL STEAM STATION ASH BASIN
CATAWBA COUNTY, NORTH CAROLINA
DATE
APRIL 2016
FIGURE
E4 13

F)l
Pecharge
e w
(Plan \fiew) -41
L
Vertical Per olation
Ground level
Initlal wde.r level
Y
NOTE: F IGURE F ROM NORTH CAROLINAS TATE
UNIVERSITY (1995); MODIFIED FROM DRISCOLL (1986).
DATE
MOUNDING EFFECT APRIL 2016
WATER SUPPLY WELL EVALUATION FIGURE
DUKE ENERGY CAROLINAS, LLC E4-14

Ff�clvuge
fi �
yNy'N�
_I (/�t ML"ld•,
1
, N
I
ilYm Tdi;
�� �d /"�#fir s •s . -
♦ - S M Low o re weW,ty rpdk � � r ' ►.; � A'� f a w .
+8 L,qOS's siccr0dY
'��t94�-Afl1Rf
DwWs
w 4
1
I
s 6
N
0 TO w
70 N g0
V 1 Q 1 �Q 110 100
MEAD IFT3
bJ PLAN VIEW
LEGEND•
i1y,�ypr„ q, 1111 "t
&Z
oow4a wr al Wed,
— —
Ed%upoo l,st L,net
,4,
E *11 oAll'%u1+pn l4 1hs Mill
#.
Ground w#bir Dr. 6
W*t. T*W
F)l
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 E4-15

,a
EA
RASHNDFILL
'x"30, '#
`• ... , i' - r °�,; i � �I&F _ SE ; a•:�6 ri•{ r, '. '
PHA I
f .,- , :. , 4. dr�'1r` Jp- a Rf _ .. _. x ,_ v'I"ry��,. ,��yy : %aj, p�j �k• ,
�
, e
1�
.. - . .. - :.. , .� ...... - "; '• r. •.-esu'.:... ,: ,. {:- t
,
PV
I
,
STRUCTURAL_.
j
f
•ya y P -' .
yjI �
i'
p v
IW�5:... ;�, ��',_.-. : � =.: a. a .- .... d`5 ,, •te'"r .},; f. :t.� i�:..n� 5} .1r� ,�:
V�pp
. ,•,..4 ' r'. .... lr1'° -._.'r lair :'r!>S''�:' ,`�. 1: '.k- _
,. .,y,> - .. ,...,. : ;�✓. e, <; ..:_ :,_ -'. w: •: ,..=a .. ....,�:. tea_,-; � aii'�"
' .� .• _ • ' ;_ f :®ems � "
= W
r ti
rt
r,
,. •ti v
.. .d K. I... � v ��-_—.-._-- -+. ..r • .. �. 4 y Iry� h r#:: Via. �'
r
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: t ,
- 4
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:.�'.' -
R,. - ,
H
v.;
,.' . r {: , ;: ,..r. Pis'; - � 5' .�,:
DR
s= �: '�� - r4 Y -AS
yy Fk �j�,,.
S-. �° ff',•LLI e f A • .A'
a .�
:
a
a� ;
_
L
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r ,
yY4
' w
wr
li yp,,gd�r
:
-.
_
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d
�s
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e
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,
I a
iz
H
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_
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Pr
i
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_
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- : y
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 1, 000
SCALE (FEET)
Y
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
- - - 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 50 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
zones for 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
MARSHALL STEAM STATION ASH BASIN FIGURE
E4-16
CATAWBA COUNTY, NORTH CAROLINA

1.0
O.:
W
0.(
—0.5 'L
2
IRON
© FO(01H),(a)
° °
Fez+
° a
° ❑ ° � a 0
° ❑ o
C Ha(9) C
6 8
pH
NOTE
DIAGRAMS ADOPTED FROM APPENDIX E OF THE CAP -2
REPORT FOR THE MARSHALL STEAM STATION BY HDR.
1.0
0.5
u
W
0.0
-1&. 1 —0.5 L
10 12 2
MANGANESE
02(9) > 0.21 atm
° Pyrolusite(s)
° mr`+ !s it
0 EV
° °
,&*0A0,13,
Rhodoch rosRe(s}
�CH,(g>
° Shallow
CI Deena
;s) O Bedrock
O Upgradient
O Source
O Downgradient
4 6 8 10 12
pH

Panel (a): Example Box Plot
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
a
♦ Ash Basin Pw ater
m Ash Basin Water
ffi a4 ♦ AII'BR' Wells
d
c 0
a o
IOU 100
so -__ _ 8
1
eu m
44
s e
S It 10 $
cdlenwn chwkw ,U*"-, NO2 P1-6 Nw
CATIONS ANIONS
Possible Outlier
Upper Whiskers
751h (Percentile
aka 3fd Quartile
`
The "Notch"
55% Confidence Interval of . •.
: Interquartile (IOR)
the Median
i 150 Percent of Datal
Ik Wian +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
a
♦ Ash Basin Pw ater
m Ash Basin Water
ffi a4 ♦ AII'BR' Wells
d
c 0
a o
IOU 100
so -__ _ 8
1
eu m
44
s e
S It 10 $
cdlenwn chwkw ,U*"-, NO2 P1-6 Nw
CATIONS ANIONS

10000000
1000000
100000
J
Of
7
10000 w
C
O
C
v
C 1000
O
U
Boron
100
10
•
1
Calcium
MARSHALL
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

1000,0 Barium
100.0
as
c
0
L 10.0
m
c�
c
0
U
MARSHALL
Cobalt
A]
AB FM RBG WSW
NOTE
ACRONYMS:
AB =ASH BASIN POREWATER WELL
FM = OTHER FACILITY MONITORNG WELL
RBG = REGIONAL BACKGROUND WELL
WSW = WATER SUPPLY WELL
AB FM
RBG WSW

1000000.0
100000.0
Dissolved Oxygen
10000.0 -
J
CI —
7
1000.0
r
lC
L
d
v -
�❑ 100.0
U
10.0
1.0
0.1
DISSOLVED
MARSHALL
Iron
DISSOLVED
TOTAL
TOTAL
A *
Manganese
DISSOLVED
DISSOLVED
TOTAL
TOTAL
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 DISSOLVED OXYGEN CONCENTRATION DATA FOR
THE DUKE ENERGY REGIONAL BACKGROUND WELLS.

LEGEND
INDUSTRIAL
IDFILL#1 N
DEMOLITION
LANDFILL
BG26R
/���
ALANEDSFI L DRY
ASH
LANDFILL
GWA9BRI
(PHASE II)
[ J
AB15BR Q�
I
AL
NOTES
'
PV STRUCTURAL
1 FILL
`
MW14BR
�o STEA MaIgNT
RO
AB9BR
DRY ASH
�y
LANDFILL
(PHASE 1)
`
ASH BASIN
AB6BR
ACTIVE ASH BASIN
LAKE NORMAN
AB1BR
FGD
ESIDUE
L DFILL
AB5BR
/
'
I
I
W
o
GWA1 BR
C�-
1
MARSHALL
Q -o
STEAM STATION /
J
/+
DAIC „'
V
S r/44NTER
R yq�
Dp
N
A
/ N
2
O
AO
O
O

10,000,000
■Ash Basin Forewater Well Panel (a)
u*Facility Bedrock Well (Downgradient) A ■
S 1,000,000All
s •A
p A � r
100,000 A
P !L A
t n,ow A
1,000 1 r .
1 10 100 1,000 10,000 100,000
Boron Concentration (ug/Q
Panel (b)
■
A
■ ■
Y A
A
�A,
10,000,000
Ash Basin Forewater W01
*Facility Bedrock Well(Downgradient)
-.,r------_r_—�_.—___.�__.__..._-w
0 Facility Berock Well (Side gradient)
1,000,000
0 Facility Bedrock Well (U pgrad ient)
❑raciiityBerack Well (Side gradient) ' Area 1
I
100.000
GWA-1BR
•. a Facility Bedrock well(Upgradient) • A
• Water Supply WelI AL ■
10,000
00
Background Well 1 A
0
A !• ■
1000 _
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, MR1, MR2 (PLANT WELL),
AND MR12 WERE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED AT A
REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (20 ug/L OR 5 Ng/L). SULFATE FOR MR1, MR2 (PLANT WELL),
AND MR12 WAS DETECTED AND LOWER THAN 11,000 Ng/L.
3. AREA 1 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE ASH BASIN
POREWATER; AREA 2 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE
WATER SUPPLY AND REGIONAL BACKGROUND WELLS.
10,000 100,000
Panel (c)
10,000,000
-.,r------_r_—�_.—___.�__.__..._-w
■Ash Basin Porewater Well 1
0F3fility 6edrOfk Well (UOwngradicnt)11
1
,L Al
❑raciiityBerack Well (Side gradient) ' Area 1
I
i
1,000,000
•. a Facility Bedrock well(Upgradient) • A
• Water Supply WelI AL ■
1
ac,Re�onaI
Background Well 1 A
O A
�
C1. n(7,nnn
•.. 1
GWA-IBR 1 t if
r--------� 1� ■ A +rr
1
t n•o00
` ——
1
*�t1
♦ ♦ 4
1000
1 10 100 1,000 10,000
100,000
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, MR1, MR2 (PLANT WELL),
AND MR12 WERE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED AT A
REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (20 ug/L OR 5 Ng/L). SULFATE FOR MR1, MR2 (PLANT WELL),
AND MR12 WAS DETECTED AND LOWER THAN 11,000 Ng/L.
3. AREA 1 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE ASH BASIN
POREWATER; AREA 2 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE
WATER SUPPLY AND REGIONAL BACKGROUND WELLS.
10,000 100,000

10,000
8,000
b
5,000
v
c
4,000
0
m
1 2,000
0
01
1
Panel
AAsh Basin PuTewater Well
•Facility Bedrock Well [Downgradient]
01'acility Berock Well {Side Gradient]
O1 adlity Bedrock Well (Upgradienl)
O
6
0 `
= r t 4 �►� 4
10 100 1,000 10,000 10D,000
Boron Concentration [ug/L]
Panel (a)
Pane[ (c)
10,000 Ir
10,000
J
—
AAsil B35rn PoreWarer Wel'
8,000
46 Facility Bedrock Wcll (Downgradient)
b
c
8;000
6,000
o
c
_._Q 0 Facility Bedrock Well (Upgradient)
v
4,000
D
0
w
6,000
*
©Regional Background well
h
2,000
i
o
• A A
i—
T4,000
F©
/ A li------------ Y
°�
1
10 100 1,000 10,000 10D,000
2,000
Boron Concentration (ug/L)
10,000
8,000
b
5,000
v
c
4,000
0
m
1 2,000
0
01
1
Panel
AAsh Basin PuTewater Well
•Facility Bedrock Well [Downgradient]
01'acility Berock Well {Side Gradient]
O1 adlity Bedrock Well (Upgradienl)
O
6
0 `
= r t 4 �►� 4
10 100 1,000 10,000 10D,000
Boron Concentration [ug/L]
no] I*�
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS, MR1, MR2 (PLANT WELL),
AND MR12 WERE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED AT A
REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (20 pg/L OR 5 pg/L). THE DISSOLVED OXYGEN CONCENTRATIONS
FOR MR1, MR2 (PLANT WELL), AND MR12 WERE LARGER THAN 5,000 Ng/L.
3. AREA 1 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE ASH BASIN
POREWATER; AREA 2 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE
WATER SUPPLY AND REGIONAL BACKGROUND WELLS.
Pane[ (c)
10,000
--
—
♦ Ash Basin Porewater Well
0 Facility Bedrock Well (Downgradient)
c
8;000
0 ao ty Bere k Well (Side Gradient)
o
_._Q 0 Facility Bedrock Well (Upgradient)
m
1
1
Area i ♦ Water Supply Well
w
6,000
*
©Regional Background well
1
i
c
i—
T4,000
F©
/ A li------------ Y
°�
Area I
2,000
-
A ►
t
tS
1
1
1' ■
1 j A / A I
r ` r
4---fA_l�
0
____ IM
1
10 100 1,000 10, 000 100,000
Boron Concentration (ug/L)
no] I*�
1. ONLY WELLS SAMPLED FOR BOTH BORON AND DISSOLVED OXYGEN
ARE PLOTTED.
2. THE DATA PAIRS FOR THE WATER SUPPLY WELLS, MR1, MR2 (PLANT WELL),
AND MR12 WERE NOT PLOTTED BECAUSE BORON WAS NOT DETECTED AT A
REPORTING LIMIT SIGNIFICANTLY HIGHER THAN THOSE FOR THE OTHER
SUPPLY WELLS (20 pg/L OR 5 pg/L). THE DISSOLVED OXYGEN CONCENTRATIONS
FOR MR1, MR2 (PLANT WELL), AND MR12 WERE LARGER THAN 5,000 Ng/L.
3. AREA 1 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE ASH BASIN
POREWATER; AREA 2 IS DEFINED BY THE DATA CLUSTERING PATTERN OF THE
WATER SUPPLY AND REGIONAL BACKGROUND WELLS.

LEGEND
INDUSTRIAL
O� O / DFILL#1
DEMOLITION��
LANDFILL
1.6
DRY ASH
ASBESTOS LANDFILL
I LANDFILL (PHASE 11)
I NOTES
PV STRUCTURAL
1 FILL
` DRY ASH
�•y LANDFILL
MR35 O O ; (PHASE 1)
MR16 O MR13
OMR36 O 1 ASH BASIN
_ LAKENORMAN r
FGD
SIDUE
I FILL I �'
W
C,
MARSHALL�'^u
STEAM STATION / OO CH
DA
Z
r/<<NTER
r
A 2
O O
AO O
rN Tal
ITA
ulky

(a) Ash Basin Porewater Wells Only
100
EXPLANATION
A Ash Basin Porewater Well
0 100
(b) Ash Basin Porewater and Downgradient Facility Bedrock Wells
100
EXPLANATION
Ash Basin Porewater Well
A Facility Bedrock Well (Downgradient)
v� ♦ \\ /
x � v,x
Y Y
0 o
AB-6BR
loo 0 / \�� \♦i `\�/ \
A A
0 100
\♦ i / \\� ` GOM \\ i
♦ � \ / t; \ / ♦ / \ A,� \ / wry / ` LOM � ♦ / \ /
\A / \ / ♦ ♦\ \A / \ / ♦ i
-- y ---�` --- l00--�F---y ---j` -- -- — —y --- /---- l00 -- ---y �� --
/ \ / ♦ / \ / ♦ / \ / / \ / p / \ / \♦B 6&R \ / \ / \ / /
0 \ 100 100 / \ 0 0 / A \ 100 100 / \ / 0
100 0 0 100 100 0 0 100
Ca" C1- Ca' Cl
CATIONS ANIONS CATIONS ANIONS

(a) Water Supply and Regional Background Wells
EXPLANATION
Water Supply Well
O Regional Background Well
C~
O°
5
\
\
\
0
\,
/
100 0
100
\ Y Y
\ / \ / ♦ /
A
\p , 100�-V--- ���--
0 i 1 0 100�f ` \
100 7 0
Ca
21
CATIONS
0
(b) Water Supply and Regional Background Wells and Up- and Side Gradient
Facility Bedrock Wells
100
EXPLANATION
0 Water Supply Well
O Regional Background Well
0 Facility Bedrock Well (Upgradient)
❑ Facility Bedrock Well (Side Gradient)
0 100 100 0
NOTE
BLUE CIRCLES SHOW THE DATA THAT APPARENTLY DEVIATE
FROM THE GENERAL DATA CLUSTERING PATTERN.
Cl -
ANIONS
0
40 /O\ x
\`' GWA' 1 BR
A
0
A
\\
0, \\
W " ♦/
/`G W\PP
---,L---A/ --- ----\L---: ---
\ A�
100
100 100
Cal'
CATIONS
0 100
100 100
0 0
Cl -
ANIONS
—A0
100

(a) Ash Basin Porewater and Downgradient Facility Bedrock Wells
100
EXPLANATION
Ash Basin Porewater Well
D Facility Bedrock Well (Downgradient)40
v /
0
Y 1(
100 0 / `\; `\ / \,; \ 0 100
A A
04
100
v L
41 41, \ k , \ 0 T
D ` \
\
y y i
�F— ,� ---�� --- 100 -- �F---,----
A 100 100
0 0
Ca" Cl -
CATIONS ANIONS
NOTE
BLUE DIAMOND DEFINES THE GENERAL DATA CLUSTERING
PATTERN OF THE WATER SUPPLYAND REGIONAL
BACKGROUND WELLS.
(b) Water Supply and Regional Background Wells and
Up- and Side -Gradient Facility Bedrock Wells
100
EXPLANATION
0 Water Supply Well
0 Regional Background Well
E Facility Bedrock Well (Upgradient)
❑ Facility Bedrock Well (Side Gradient)
�O
—40 OL
100 100
Ca''
CATIONS
A
I \
\
100
0100 loop
0 0
G \
,\ h
0
1(0
Cl -
ANIONS
`\

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

MARSHALL REGIONAL BACKGROUND WATER SUPPLY WELL
DATA
Test for Equal Variances: Hexavalent Chromium (ug/L) versus Data Source
Method
Null hypothesis All variances are equal
Alternative hypothesis At least one variance is different
Significance level a = 0.05
95% Bonferroni Confidence Intervals for Standard Deviations
Data
Source N StDev
Duke 11 1.13557
NC DEQ 10 0.43314
CI
(0.325918, 4.96910)
(0.178274, 1.35639)
Individual confidence level = 97.50
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.273
0.82 0.378
Test for Equal Variances: Hexavalent Chromium (ug/L) vs Data Source
Test for Equal Variances: Hexavalent Chromium (ug/L) vs Data Source
Multiple comparison intervals for the standard deviation, a = 0.05
Multiple Comparisons
P -Value 0.273
Levene's Test
Duke- P -Value 0.378
N
v
7
O
N
c6
O
NC DEQ
T �
0.0 0.5 1.0 1.5 2.0 2.5 3.0
If intervals do not overlap, the corresponding stdevs are significantly different.

Test for Equal Variances: Vanadium (ug/L) versus Data Source
Method
Null hypothesis All variances are equal
Alternative hypothesis At least one variance is different
Significance level a = 0.05
95% Bonferroni Confidence Intervals for Standard Deviations
Data
Source N StDev
Duke 29 5.23350
NC DEQ 10 1.19350
CI
(2.80461, 10.5839)
(0.35492, 5.1729)
Individual confidence level = 97.5%
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.030
2.82 0.101
Test for Equal Variances: Vanadium (ug/L) vs Data Source
N
v
7
O
N
M
cv
Test for Equal Variances: Vanadium (ug/L) vs Data Source
Multiple comparison intervals for the standard deviation, a = 0.05
Multiple Comparisons
P -Value 0.030
Levene's Test
Duke I I P -Value 0.101
NC DEQ
—r-
0 1 2 3 4 5 6 7 8 9
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 E — Marshall
Part -2: Marshall Facility Background Monitoring Well
Data Test for Equal Variances
APRIL 2016 U'CH

MARSHALL FACILITY BACKGROUND MONITORING WELL DATA
Test for Equal Variances: Chromium (VI) - ug/L - T versus sys_loc_code —
Marshall Facility Specific
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 3 0.73309 (0.0096346, 276.129)
BG-2BR 2 1.13137 (
BG -3D 3 1.17189 (0.0154016, 441.411)
MW -4D 1 * (
Individual confidence level = 98.3333%
Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.762
0.19 0.834
* 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 Marshall
Facility Specific
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 5 0.8735 (0.24228, 6.293)
BG-2BR 5 38.8923 (6.69397, 451.517)
BG -3D 5 1.0794 (0.24163, 9.634)
MW -4D 2 0.2828 (
Individual confidence level = 98.75%

Tests
Method
Multiple comparisons
Levene
Test
Statistic P -Value
— 0.000
0.77 0.530
* NOTE * The graphical summary cannot be displayed because the multiple
comparison intervals cannot be calculated.

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

Histogram of Background Constituents- Marshall (Regional)
Barium (u L)2� Boron (u L) � Chromium (ug/y
20
20 �l
10 0 10
0 0 0 �
0 120 240 360 480 0 30 60 90 120 2 4 6 8
Cobah(uo/L) Hex valent Chromium u L Imn(ug(L)
T 16 8 30
V
7
s s u:
LL
0 0
O.o 0.3 0;6 0.9 L2 0.D 0.5 1.0 Ls 2.0 2.5 3.0 3.5 0 1000 2000 3000 4000
Lead u Nickel u L Vanadium u
20
20-
210- 0
10 10
0AL__�0
0.0 1.6 3.2 4.8 6.4 1.6 3.2 4.8 6.4 0 5 10 15 20
Histogram of Background Constituents- Marshall (Facility)
Barium - ug/L - T Boron-ug/L-T Chromium - ug/L - T
16 16
8 15 8
0 0 0
0 200 400 600 800 25 30 35 40 45 50 0 3 6 9 12
Cobalt - u L -T Chromium (VIj-ug/L-T Iron - u L -T
T
V
C
01 10
5.0
3
y z.s 1 s
-7-179LL
0.0 0El
- a
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0 2 4 6 8 0 200 400 600 800 1000
Lead-ug/L-T Nickel - u L -D Vanadium -u L -T
30 5.0
5 2 2.5
0 0 E LAW 0.0
0.2 0.4 0.6 0.8 1.0 0 2 4 6 8 0 4 8 12 16 20 24
Probability Plot of Background Constituents- Marshall Probability Plot of Background Constituents- Marshall
Normal - 95% CI (Regional) Normal - 95% CI (Facility)
Barium u L)�_ Bomn u Chromium (ug/L _
99•
90 90-
0 90
s0 50 s0 • �- .'�
30 10 30
1 � 1 1
0 250 500 0 80 160
99 Cobalt u L 99 Hexavalent Chromium u L 99 Iron u L
• •
! 90 90 90
V 50 50 50
O)
CL '0.10 10
•
I.
0 1 2 -20 0.5 3.0 -3000. 0 3000
99XNaIL)99 Nickel uL 99 Vanadium u L90.
90
so50 501010 30-
11 _ -. 1.. • . r .nm�
0 4 0 5 10 -5 5 15
99 Badum-u L -T
90
50
10
1
-800 0 800
99 Bomn u L -T
90
s0
30 •
1 •
30 45 fi0
" Chromium -u L -T
90
so
10
1
0 5 10
99 Cobalt - u L -T 99Chromium. 1 -u L -T 99 Iron -u L -T
90 90 90
s0 50 s0
C 30
10, • 10 Ase ,
1 1 - 1
-3 0 3 -8 0 8 0 60D .1200
PRIVLEGED & CONFIDENTIAL -ATTORNEY-CLIENT COMMUNICATION -ATTORNEY
WORK PRODUCT - DO NOT DISTRIBUTE WITHOUT APPROVAL OF COUNSEL
99
90
50
10
1- /
0 8 16

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

Attachment E-1: Marshall Regional Background Water Supply Well Data Outlier Test Statistics
Outlier Tests for Selected Uncensored Variables
User Selected Options
Date/Time of Computation 3/30/2016 6:40:13 PM
From File PROLICL input file for Marshall.xls
Full Precision OFF
Rosner's Outlier Test for Barium (ug/L)
Mean 51.66
Standard Deviation 79.82
Number of data 39
Number of suspected outliers 4
# Mean
sd
1 51.66
78.79
2 40.23
36.2
3 37.13
31.16
4 33.99
24.99
Potential
Obs.
outlier
Number
486
28
155
16
150
26
104
18
For 5% significance level, there are 3 Potential Outliers
Potential outliers are:
486, 155, 150
For 1 % Significance Level, there are 3 Potential Outliers
Potential outliers are:
486, 155, 150
Rosner's Outlier Test for Boron (ug/L)
Mean 40.41
Standard Deviation 27.75
Number of data 39
Number of suspected outliers 4
# Mean
sd
1 40.41
27.39
2 37.92
23.29
3 36.05
20.53
4 36.91
20.13
Potential
Obs.
outlier
Number
135
31
107
1
5
4
5
10
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 135
For 1 % Significance Level, there is 1 Potential Outlier
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_regional.xlsx
Test
Critical
Critical
value
value (5%)
value (1%)
5.513
3.03
3.37
3.171
3.01
3.36
3.622
3
3.34
2.801
2.99
3.33
Test
Critical
Critical
value
value (5%)
value (1%)
3.453
3.03
3.37
2.966
3.01
3.36
1.512
3
3.34
1.585
2.99
3.33
Page 1 of 5
4/8/2016

Attachment E-1: Marshall Regional Background Water Supply Well Data Outlier Test Statistics
Potential outliers is: 135
Rosner's Outlier Test for Chromium (ug/L)
Mean 3.985
Standard Deviation 2.153
Number of data 39
Number of suspected outliers 4
# Mean
sd
1 3.985
2.125
2 3.853
2.016
3 3.944
1.963
4 4.039
1.902
Potential
Obs.
outlier
Number
9
5
0.5
2
0.5
10
0.5
37
For 5% Significance Level, there is no Potential Outlier
For 1 % Significance Level, there is no Potential Outlier
Rosner's Outlier Test for Cobalt (ug/L)
Mean 0.521
Standard Deviation 0.403
Number of data 39
Number of suspected outliers 4
# Mean
sd
1 0.521
0.398
2 0.5
0.386
3 0.514
0.382
4 0.528
0.377
Potential
Obs.
outlier
Number
1.33
11
0
1
0
16
0
17
For 5% Significance Level, there is no Potential Outlier
For 1% Significance Level, there is no Potential Outlier
Dixon's Outlier Test for Hexavalent Chromium (ug/L)
Number of Observations = 21
10% critical value: 0.391
5% critical value: 0.44
1 % critical value: 0.524
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_regional.xlsx
Test
Critical
Critical
value
value (5%)
value (1%)
2.36
3.03
3.37
1.663
3.01
3.36
1.754
3
3.34
1.861
2.99
3.33
Test
Critical
Critical
value
value (5%)
value (1%)
2.033
3.03
3.37
1.297
3.01
3.36
1.346
3
3.34
1.4
2.99
3.33
Page 2 of 5
4/8/2016

Attachment E-1: Marshall Regional Background Water Supply Well Data Outlier Test Statistics
1. Observation Value 3.7 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.545
For 10% significance level, 3.7 is an outlier.
For 5% significance level, 3.7 is an outlier.
For 1 % significance level, 3.7 is an outlier.
2. Observation Value 0.03 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.000
For 10% significance level, 0.03 is not an outlier.
For 5% significance level, 0.03 is not an outlier.
For 1 % significance level, 0.03 is not an outlier.
Rosner's Outlier Test for Iron (ug/L)
Mean 346.1
Standard Deviation 888.8
Number of data 39
Number of suspected outliers 4
# Mean
sd
1 346.1
877.3
2 252
676
3 158.3
355.7
4 121.6
280.8
Potential
Obs.
outlier
Number
3920
4
3720
11
1480
14
1340
38
For 5% significance level, there are 4 Potential Outliers
Potential outliers are:
3920, 3720, 1480, 1340
For 1 % Significance Level, there are 4 Potential Outliers
Potential outliers are:
3920, 3720, 1480, 1340
Rosner's Outlier Test for Lead (ug/L)
Mean 1.248
Standard Deviation 1.387
Number of data 39
Number of suspected outliers 4
Test
Critical
Critical
value
value (5%)
value (1%)
4.074
3.03
3.37
5.13
3.01
3.36
3.716
3
3.34
4.339
2.99
3.33
Potential Obs. Test Critical Critical
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_regional.xlsx
Page 3 of 5
4/8/2016

Attachment E-1: Marshall Regional Background Water Supply Well Data Outlier Test Statistics
# Mean
sd
outlier
Number
value
value (5%)
value (1%)
1 1.248
1.369
6.3
4
3.691
3.03
3.37
2 1.115
1.125
5.4
23
3.808
3.01
3.36
3 0.999
0.882
5.16
14
4.718
3
3.34
4 0.884
0.54
2.45
26
2.9
2.99
3.33
For 5% significance level, there are 3 Potential Outliers
Potential outliers are:
6.3, 5.4, 5.16
For 1 % Significance Level, there are 3 Potential Outliers
Potential outliers are:
6.3, 5.4, 5.16
Rower's Outlier Test for Nickel (ug/L)
Mean 3.682
Standard Deviation 2.075
Number of data 39
Number of suspected outliers 4
# Mean
sd
1 3.682
2.048
2 3.595
2.029
3 3.678
1.99
4 3.767
1.943
Potential
Obs.
outlier
Number
7
28
0.5
2
0.5
10
0.5
30
For 5% Significance Level, there is no Potential Outlier
For 1 % Significance Level, there is no Potential Outlier
Rosner's Outlier Test for Sodium (ug/L)
Mean 12963
Standard Deviation 23652
Number of data 39
Number of suspected outliers 4
Test
Critical
Potential
Obs.
# Mean
sd
outlier
Number
1 12963
23347
151000
28
2 9331
6783
29900
32
3 8775
5934
29300
1
4 8205
4884
25000
2
Haley & Aldrich, Inc.
Outlier test stats for Marsha
ll_regional.xlsx
Test
Critical
Critical
value
value (5%)
value (1%)
1.62
3.03
3.37
1.525
3.01
3.36
1.597
3
3.34
1.681
2.99
3.33
Test
Critical
Critical
value
value (5%)
value (1%)
5.912
3.03
3.37
3.032
3.01
3.36
3.459
3
3.34
3.439
2.99
3.33
Page 4 of 5
4/8/2016

Attachment E-1: Marshall Regional Background Water Supply Well Data Outlier Test Statistics
For 5% significance level, there are 4 Potential Outliers
Potential outliers are:
151000, 29900, 29300, 25000
For 1 % Significance Level, there are 4 Potential Outliers
Potential outliers are:
151000, 29900, 29300, 25000
Rosner's Outlier Test for Vanadium (ug/L)
Mean 3.337
Standard Deviation 4.633
Number of data 39
Number of suspected outliers 4
For 5% significance level, there are 3 Potential Outliers
Potential outliers are:
22.9, 13.1, 12.7
For 1 % Significance Level, there are 3 Potential Outliers
Potential outliers are:
22.9, 13.1, 12.7
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_regional.xlsx
Page 5 of 5
4/8/2016
Potential
Obs.
Test
Critical
Critical
# Mean
sd
outlier
Number
value
value (5%)
value (1%)
1 3.337
4.574
22.9
19
4.277
3.03
3.37
2 2.823
3.381
13.1
14
3.039
3.01
3.36
3 2.545
2.956
12.7
26
3.436
3
3.34
4 2.263
2.441
9.44
11
2.94
2.99
3.33
For 5% significance level, there are 3 Potential Outliers
Potential outliers are:
22.9, 13.1, 12.7
For 1 % Significance Level, there are 3 Potential Outliers
Potential outliers are:
22.9, 13.1, 12.7
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_regional.xlsx
Page 5 of 5
4/8/2016

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

Attachment E-1: Marshall Facility Background Monitoring Well Data Outlier Test Statistics
Outlier Tests for Selected Uncensored Variables
User Selected Options
Date/Time of Computation 3/30/2016 6:25:38 PM
From File WorkSheet.xls
Full Precision OFF
Rosner's Outlier Test for Barium - ug/L - T
Mean 228.8
Standard Deviation 297.1
Number of data 32
Number of suspected outliers 4
# Mean
sd
1 228.8
292.4
2 207.5
276
3 185
250.3
4 163.1
223.6
Potential
Obs.
outlier
Number
890
12
880
14
820
13
820
15
For 5% significance level, there are 4 Potential Outliers
Potential outliers are:
890, 880, 820, 820
For 1 % Significance Level, there is no Potential Outlier
Test
Critical
Critical
value
value (5%)
value (1%)
2.261
2.94
3.27
2.437
2.92
3.25
2.537
2.91
3.24
2.938
2.89
3.22
Rosner's Outlier Test for Boron - ug/L - T
Mean 48.59
Standard Deviation 5.547
Number of data 32
Number of suspected outliers 4
# Mean
sd
1 48.59
5.459
2 49.32
3.772
3 50
0
4 50
0
Potential
Obs.
outlier
Number
26
11
29
3
50
1
50
2
For 5% significance level, there are 4 Potential Outliers
Potential outliers are:
26, 29, 50, 50
For 1 % Significance Level, there are 4 Potential Outliers
Potential outliers are:
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_facility.xlsx
Test
Critical
Critical
value
value (5%)
value (1%)
4.139
2.94
3.27
5.388
2.92
3.25
N/A
2.91
3.24
N/A
2.89
3.22
Page 1 of 5
4/8/2016

Attachment E-1: Marshall Facility Background Monitoring Well Data Outlier Test Statistics
26, 29, 50, 50
Rosner's Outlier Test for Chromium - ug/L - T
Mean 6.761
Standard Deviation 13.4
Number of data 33
Number of suspected outliers 4
For 5% significance level, there are 2 Potential Outliers
Potential outliers are:
80.4, 11.3
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 80.4
Dixon's Outlier Test for Cobalt - ug/L - T
Number of Observations = 19
10% critical value: 0.412
5% critical value: 0.462
1 % critical value: 0.547
1. Observation Value 11.9 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.746
For 10% significance level, 11.9 is an outlier.
For 5% significance level, 11.9 is an outlier.
For 1 % significance level, 11.9 is an outlier.
2. Observation Value 0.13 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.033
For 10% significance level, 0.13 is not an outlier.
For 5% significance level, 0.13 is not an outlier.
For 1 % significance level, 0.13 is not an outlier.
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Potential
Obs.
Test
Critical
Critical
# Mean
sd
outlier
Number
value
value (5%)
value (1%)
1 6.761
13.2
80.4
7
5.58
2.95
3.29
2 4.459
2.241
11.3
18
3.052
2.94
3.27
3 4.239
1.892
0.49
3
1.981
2.92
3.25
4 4.364
1.79
0.6
6
2.103
2.91
3.24
For 5% significance level, there are 2 Potential Outliers
Potential outliers are:
80.4, 11.3
For 1 % Significance Level, there is 1 Potential Outlier
Potential outliers is: 80.4
Dixon's Outlier Test for Cobalt - ug/L - T
Number of Observations = 19
10% critical value: 0.412
5% critical value: 0.462
1 % critical value: 0.547
1. Observation Value 11.9 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.746
For 10% significance level, 11.9 is an outlier.
For 5% significance level, 11.9 is an outlier.
For 1 % significance level, 11.9 is an outlier.
2. Observation Value 0.13 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.033
For 10% significance level, 0.13 is not an outlier.
For 5% significance level, 0.13 is not an outlier.
For 1 % significance level, 0.13 is not an outlier.
Haley & Aldrich, Inc.
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Attachment E-1: Marshall Facility Background Monitoring Well Data Outlier Test Statistics
Dixon's Outlier Test for Chromium (VI) - ug/L - T
Number of Observations = 9
10% critical value: 0.441
5% critical value: 0.512
1 % critical value: 0.635
1. Observation Value 7.6 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.212
For 10% significance level, 7.6 is not an outlier.
For 5% significance level, 7.6 is not an outlier.
For 1 % significance level, 7.6 is not an outlier.
2. Observation Value 0.016 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.005
For 10% significance level, 0.016 is not an outlier.
For 5% significance level, 0.016 is not an outlier.
For 1 % significance level, 0.016 is not an outlier.
Rosner's Outlier Test for Iron - ug/L - T
Mean 713.4
Standard Deviation 3146
Number of data 33
Number of suspected outliers 4
For 5% significance level, there are 3 Potential Outliers
Potential outliers are:
18200, 1000, 630
For 1 % Significance Level, there are 2 Potential Outliers
Potential outliers are:
18200, 1000
Rosner's Outlier Test for Lead - ug/L - T
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Potential
Obs.
Test
Critical
Critical
# Mean
sd
outlier
Number
value
value (5%)
value (1%)
1 713.4
3098
18200
7
5.644
2.95
3.29
2 166.9
215.6
1000
6
3.865
2.94
3.27
3 140
155.4
630
3
3.154
2.92
3.25
4 123.7
128.1
410
9
2.234
2.91
3.24
For 5% significance level, there are 3 Potential Outliers
Potential outliers are:
18200, 1000, 630
For 1 % Significance Level, there are 2 Potential Outliers
Potential outliers are:
18200, 1000
Rosner's Outlier Test for Lead - ug/L - T
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Attachment E-1: Marshall Facility Background Monitoring Well Data Outlier Test Statistics
Mean 1.05
Standard Deviation 3.034
Number of data 32
Number of suspected outliers 4
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 17.5
For 1% Significance Level, there is 1 Potential Outlier
Potential outliers is: 17.5
Dixon's Outlier Test for Nickel - ug/L - D
Number of Observations = 18
10% critical value: 0.424
5% critical value: 0.475
1 % critical value: 0.561
1. Observation Value 9 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.050
For 10% significance level, 9 is not an outlier.
For 5% significance level, 9 is not an outlier.
For 1 % significance level, 9 is not an outlier.
2. Observation Value 0.42 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.071
For 10% significance level, 0.42 is not an outlier.
For 5% significance level, 0.42 is not an outlier.
For 1 % significance level, 0.42 is not an outlier.
Dixon's Outlier Test for Vanadium - ug/L - T
Number of Observations = 18
10% critical value: 0.424
5% critical value: 0.475
1 % critical value: 0.561
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Potential
Obs.
Test
Critical
Critical
# Mean
sd
outlier
Number
value
value (5%)
value (1%)
1 1.05
2.986
17.5
6
5.509
2.94
3.27
2 0.52
0.446
1
18
1.077
2.92
3.25
3 0.504
0.444
1
19
1.117
2.91
3.24
4 0.486
0.442
1
20
1.161
2.89
3.22
For 5% Significance Level, there is 1 Potential Outlier
Potential outliers is: 17.5
For 1% Significance Level, there is 1 Potential Outlier
Potential outliers is: 17.5
Dixon's Outlier Test for Nickel - ug/L - D
Number of Observations = 18
10% critical value: 0.424
5% critical value: 0.475
1 % critical value: 0.561
1. Observation Value 9 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.050
For 10% significance level, 9 is not an outlier.
For 5% significance level, 9 is not an outlier.
For 1 % significance level, 9 is not an outlier.
2. Observation Value 0.42 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.071
For 10% significance level, 0.42 is not an outlier.
For 5% significance level, 0.42 is not an outlier.
For 1 % significance level, 0.42 is not an outlier.
Dixon's Outlier Test for Vanadium - ug/L - T
Number of Observations = 18
10% critical value: 0.424
5% critical value: 0.475
1 % critical value: 0.561
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_facility.xlsx
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Attachment E-1: Marshall Facility Background Monitoring Well Data Outlier Test Statistics
1. Observation Value 100 is a Potential Outlier (Upper Tail)?
Test Statistic: 0.799
For 10% significance level, 100 is an outlier.
For 5% significance level, 100 is an outlier.
For 1 % significance level, 100 is an outlier.
2. Observation Value 1.4 is a Potential Outlier (Lower Tail)?
Test Statistic: 0.053
For 10% significance level, 1.4 is not an outlier.
For 5% significance level, 1.4 is not an outlier.
For 1 % significance level, 1.4 is not an outlier.
Haley & Aldrich, Inc.
Outlier test stats for Marsha ll_facility.xlsx
Page 5 of 5
4/8/2016

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

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

Attachment E-2- Marshall 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 3/30/2016 4:40:48 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/2 Normal ROS
Correlation Coefficient R 0.688 0.688 0.69 0.691
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
39
0
39
38
1
2.56%
Data Not Normal
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Detects Only)
38
6
486
52.89
27.25
80.51
Statistics (All: NDs treated as DL value)
39
5
486
51.66
26.7
79.82
Statistics (All: NDs treated as DL/2 value)
39
2.5
486
51.6
26.7
79.86
Statistics (Normal ROS Imputed Data)
39
-90.76
486
49.21
26.7
82.71
Statistics (Gamma ROS Imputed Data)
39
0.01
486
51.53
26.7
79.9
Statistics (Lognormal ROS Imputed Data)
39
2.827
486
51.61
26.7
79.85
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
1.112
1.042
47.56
3.455
0.949
0.275
Statistics (NDs = DL)
1.068
1.003
48.39
3.408
0.982
0.288
Statistics (NDs = DL/2)
1.039
0.976
49.67
3.39
1.021
0.301
Statistics (Gamma ROS Estimates)
0.849
0.801
60.69
Statistics (Lognormal ROS Estimates)
3.393
1.013
0.298
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.688 0.688 0.69 0.691
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)
0.511
0.938
Data Not Normal
0.28
0.144
Data Not Normal
0.512
0.939
Data Not Normal
0.279
0.142
Data Not Normal
0.514
0.939
Data Not Normal
0.27
0.142
Data Not Normal
0.585
0.939
Data Not Normal
0.275
0.142
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.869 0.871 0.873 0.885
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Anderson -Darling (Detects Only) 1.188 0.775
Kolmogorov-Smirnov (Detects Only) 0.137 0.147 Detected Data appear Approximate Gamma Distri
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Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Anderson -Darling (NDs = DL)
1.112
0.776
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.134
0.145
Detected Data appear Approximate Gamma Distri
Anderson -Darling (NDs = DL/2)
1.019
0.777
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.129
0.145
Detected Data appear Approximate Gamma Distri
Anderson -Darling (Gamma ROS Estimates)
1.1
0.785
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.118
0.146
Detected Data appear Approximate Gamma Distri
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.985 0.988 0.989 0.99
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.972
0.938
Data Appear Lognormal
Lilliefors (Detects Only)
0.081
0.144
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.977
0.939
Data Appear Lognormal
Lilliefors (NDs = DL)
0.0722
0.142
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.989
0.939
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.0727
0.142
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.989
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0701
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Boron (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 39 0 39 5 34 87.18%
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
34 5 50 38.09 50 20.15
5 9.1 135 56.16 17 60.08
39 5 135 40.41 50 27.75
39 2.5 135 23.8 25 25.02
39 -260.4 135 -79.75 -81.56 92.21
39 0.01 135 9.757 0.01 28.1
39 0.0359 135 10.35 1.634 27.04
K hat K Star Theta hat Log Mean Log Stdv Log CV
0.972 0.522 57.79 3.432 1.261 0.367
1.461 1.365 27.66 3.319 1.045 0.315
1.239 1.161 19.21 2.715 1.081 0.398
0.151 0.157 64.56
0.53 1.968 3.712
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.898 0.844 0.711 0.361
Test value Crit. (0.05) Conclusion with Alpha(0.05)
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Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (Detects Only)
0.785
0.762
Data Appear Normal
Lilliefors (Detects Only)
0.343
0.396
Data Appear Normal
Shapiro -Wilk (NDs = DL)
0.724
0.939
Data Not Normal
Lilliefors (NDs = DL)
0.328
0.142
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.533
0.939
Data Not Normal
Lilliefors (NDs = DL/2)
0.43
0.142
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.986
0.939
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.0492
0.142
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma ROc
Correlation Coefficient R 0.921 0.835 0.817 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)
Conclusion with Alpha(0.05)
0.591
0.692
0.283
0.333
0.365
Detected Data Appear Gamma Distributed
5.67
0.767
Data Not Lognormal
0.398
0.144
Data Not Gamma Distributed
4.996
0.772
0.715
0.332
0.145
Data Not Gamma Distributed
8.429
0.956
Data Not Lognormal
0.484
0.159
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.929 0.841 0.848 0.997
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.837
0.762
Data Appear Lognormal
Lilliefors (Detects Only)
0.283
0.396
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.694
0.939
Data Not Lognormal
Lilliefors (NDs = DL)
0.407
0.142
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.715
0.939
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.372
0.142
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.985
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.037
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
3.049
Chromium (ug/L)
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Num Obs
Num Miss
Num Valid
Detects
NDs
% NDs
Raw Statistics
39
0
39
11
28
71.79%
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
28
0.5
5
4.357
5
1.604
Statistics (Detects Only)
11
0.51
9
3.037
1.9
3.049
Statistics (All: NDs treated as DL value)
39
0.5
9
3.985
5
2.153
Statistics (All: NDs treated as DL/2 value)
39
0.25
9
2.421
2.5
1.748
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Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Statistics (Normal ROS Imputed Data) 39
Statistics (Gamma ROS Imputed Data) 39
Statistics (Lognormal ROS Imputed Data) 39
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
-5.955 9 0.47 0.76 3.351
0.01 9 1.471 0.76 2.136
0.0919 9 1.505 0.846 1.985
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
1.259
0.976
2.413
0.664
0.985
1.484
1.962
1.828
2.031
1.107
0.901
0.815
1.967
1.833
1.231
0.609
0.857
1.408
0.365
0.354
4.033
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.978
0.939
Data Appear Normal
Lilliefors (Normal ROS Estimates)
-0.207
1.125
-5.426
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.879 0.884 0.806 0.638
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.95 0.811 0.863 0.984
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
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.764
0.85
Data Not Normal
Lilliefors (Detects Only)
0.323
0.267
Data Not Normal
Shapiro -Wilk (NDs = DL)
0.779
0.939
Data Not Normal
Lilliefors (NDs = DL)
0.374
0.142
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.67
0.939
Data Not Normal
Lilliefors (NDs = DL/2)
0.405
0.142
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.978
0.939
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.0847
0.142
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.95 0.811 0.863 0.984
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)
0.699
0.747
Data Appear Lognormal
0.224
0.261
Detected Data Appear Gamma Distributed
5.371
0.76
Data Not Lognormal
0.407
0.143
Data Not Gamma Distributed
4.468
0.76
0.311
0.143
Data Not Gamma Distributed
1.821
0.843
0.233
0.152
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.964 0.846 0.861 0.996
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only) 0.912
0.85
Data Appear Lognormal
Lilliefors (Detects Only) 0.174
0.267
Data Appear Lognormal
Shapiro -Wilk (NDs = DL) 0.704
0.939
Data Not Lognormal
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Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Lilliefors (NDs = DL)
0.404
0.142
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.745
0.939
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.332
0.142
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.981
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0483
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
0.6
Hexavalent Chromium (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 39 18 21 13 8 38.10%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
8
0.03
0.6
0.386
0.6
0.295
13
0.039
3.7
0.865
0.56
1.035
21
0.03
3.7
0.683
0.6
0.855
21
0.015
3.7
0.609
0.3
0.873
21
-1.755
3.7
0.284
0.17
1.201
21
0.01
3.7
0.562
0.15
0.898
21
0.0103
3.7
0.568
0.166
0.893
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.846
0.702
1.023
-0.841
1.327
-1.577
0.782
0.702
0.874
-1.143
1.433
-1.253
0.667
0.604
0.913
-1.407
1.563
-1.111
0.457
0.423
1.231
-1.669
1.638
-0.981
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.872 0.831 0.807 0.871
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)
0.771
0.866
Data Not Normal
0.213
0.246
Data Appear Normal
0.706
0.908
Data Not Normal
0.296
0.193
Data Not Normal
0.667
0.908
Data Not Normal
0.279
0.193
Data Not Normal
0.929
0.908
Data Appear Normal
0.155
0.193
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.991 0.972 0.98 0.992
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Anderson -Darling (Detects Only) 0.269 0.765
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 5 of 11
4/8/2016

Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Kolmogorov-Smirnov (Detects Only)
0.169
0.245
Detected Data Appear Gamma Distributed
Anderson -Darling (NDs = DL)
0.542
0.781
Data Appear Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.157
0.197
Data Appear Gamma Distributed
Anderson -Darling (NDs = DL/2)
0.416
0.79
Data Not Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.155
0.198
Data Appear Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
0.585
0.814
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.161
0.201
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.989 0.963 0.973 0.993
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.972
0.866
Data Appear Lognormal
Lilliefors (Detects Only)
0.143
0.246
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.917
0.908
Data Appear Lognormal
Lilliefors (NDs = DL)
0.224
0.193
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.94
0.908
Data Appear Lognormal
Lilliefors (NDs = DL/2)
0.171
0.193
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.979
0.908
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0965
0.193
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 39 0 39 22 17 43.59%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number
Minimum
Maximum
Mean
Median
SD
17
10
50
31.18
50
20.58
22
11
3920
589.4
53.75
1134
39
10
3920
346.1
50
888.8
39
5
3920
339.3
25
891.2
39
-2640
3920
-202.1
14
1344
39
0.01
3920
332.5
13
893.7
39
0.102
3920
335.5
16.12
892.6
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.374
0.354
1575
4.602
1.957
0.425
0.357
0.347
968.5
3.971
1.713
0.431
0.317
0.309
1071
3.669
1.887
0.514
0.148
0.153
2252
2.914
2.665
0.914
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.751 0.641 0.64 0.642
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 6 of 11
4/8/2016

Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.57
0.911
Data Not Normal
0.344
0.189
Data Not Normal
0.428
0.939
Data Not Normal
0.415
0.142
Data Not Normal
0.428
0.939
Data Not Normal
0.411
0.142
Data Not Normal
0.88
0.939
Data Not Normal
0.213
0.142
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.962 0.934 0.942 0.964
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
1.748
0.831
0.194
0.281
0.199
Data Not Gamma Distributed
5.172
0.845
Data Not Lognormal
0.354
0.152
Data Not Gamma Distributed
4.934
0.854
0.851
0.322
0.153
Data Not Gamma Distributed
2.461
0.959
Data Not Lognormal
0.262
0.159
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.949 0.914 0.93 0.991
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.885
0.911
Data Not Lognormal
Lilliefors (Detects Only)
0.194
0.189
Data Not Lognormal
Shapiro -Wilk (NDs = DL)
0.822
0.939
Data Not Lognormal
Lilliefors (NDs = DL)
0.232
0.142
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.851
0.939
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.21
0.142
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.969
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0941
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
1.764
Lead (ug/L)
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 7 of 11
4/8/2016
Num Obs
Num Miss
Num Valid
Detects
NDs
% NDs
Raw Statistics
39
0
39
24
15
38.46%
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
15
1
1
1
1
0
Statistics (Detects Only)
24
0.16
6.3
1.403
0.59
1.764
Statistics (All: NDs treated as DL value)
39
0.16
6.3
1.248
1
1.387
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 7 of 11
4/8/2016

Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Statistics (All: NDs treated as DL/2 value)
39
0.16
6.3
1.056
0.5
1.443
Statistics (Normal ROS Imputed Data)
39
-1.412
6.3
1.029
0.57
1.56
Statistics (Gamma ROS Imputed Data)
39
0.01
6.3
1.001
0.392
1.49
Statistics (Lognormal ROS Imputed Data)
39
0.0775
6.3
1.026
0.46
1.464
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.894
0.81
1.57
-0.316
1.159
-3.666
Statistics (NDs = DL)
1.344
1.258
0.929
-0.195
0.915
-4.703
Statistics (NDs = DL/2)
1.107
1.039
0.953
-0.461
0.921
-1.996
Statistics (Gamma ROS Estimates)
0.559
0.533
1.791
Statistics (Lognormal ROS Estimates)
-0.614
1.078
-1.756
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.838 0.79 0.752 0.901
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)
0.702
0.916
Data Not Normal
0.241
0.181
Data Not Normal
0.635
0.939
Data Not Normal
0.315
0.142
Data Not Normal
0.577
0.939
Data Not Normal
0.339
0.142
Data Not Normal
0.79
0.939
Data Not Normal
0.199
0.142
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/2aamma RO'
Correlation Coefficient R 0.966 0.921 0.924 0.97
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)
0.994
0.776
0.167
0.184
Detected Data appear Approximate Gamma Distri
1.889
0.77
0.225
0.144
Data Not Gamma Distributed
3.305
0.776
0.309
0.145
Data Not Gamma Distributed
0.56
0.807
0.092
0.149
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.97 0.96 0.942 0.982
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only) 0.924 0.916 Data Appear Lognormal
Lilliefors (Detects Only) 0.145 0.181 Data Appear Lognormal
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 8 of 11
4/8/2016

Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Shapiro -Wilk (NDs = DL)
0.914
0.939
Data Not Lognormal
Lilliefors (NDs = DL)
0.233
0.142
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.881
0.939
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.266
0.142
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.954
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.103
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Data Appear Normal
Nickel(ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 39 0 39 5 34 87.18%
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
34 0.5 5 3.809 5 2.015
5 0.9 7 2.82 1.8 2.519
39 0.5 7 3.682 5 2.075
39 0.25 7 2.022 2.5 1.283
39 -9.11 7 -1.988 -2.16 3.643
39 0.01 7 0.702 0.01 1.43
39 0.0415 7 0.872 0.408 1.284
K hat K Star Theta hat Log Mean Log Stdv Log CV
1.854 0.875 1.521 0.744 0.839 1.128
1.633 1.525 2.255 0.967 1.002 1.037
1.612 1.505 1.254 0.363 1.01 2.783
0.271 0.267 2.592
-0.839 1.2 -1.43
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.909 0.83 0.826 0.561
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)
0.828
0.762
Data Appear Normal
0.257
0.396
Data Appear Normal
0.677
0.939
Data Not Normal
0.404
0.142
Data Not Normal
0.705
0.939
Data Not Normal
0.338
0.142
Data Not Normal
0.99
0.939
Data Appear Normal
0.0469
0.142
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO:
Correlation Coefficient R 0.993 0.702 0.801 0.993
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 9 of 11
4/8/2016

Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Anderson -Darling (Detects Only)
0.324
0.685
Data Appear Lognormal
Kolmogorov-Smirnov (Detects Only)
0.223
0.361
Detected Data Appear Gamma Distributed
Anderson -Darling (NDs = DL)
6.837
0.764
Data Not Lognormal
Kolmogorov-Smirnov (NDs = DL)
0.415
0.144
Data Not Gamma Distributed
Anderson -Darling (NDs = DL/2)
6.256
0.764
Data Not Lognormal
Kolmogorov-Smirnov (NDs = DL/2)
0.398
0.144
Data Not Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
5.966
0.873
Data Appear Lognormal
Kolmogorov-Smirnov (Gamma ROS Est.)
0.421
0.154
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.977 0.81 0.818 0.998
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.942
0.762
Data Appear Lognormal
Lilliefors (Detects Only)
0.18
0.396
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.639
0.939
Data Not Lognormal
Lilliefors (NDs = DL)
0.406
0.142
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.661
0.939
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.401
0.142
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.989
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0398
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DL/2 are
not recommended.
1.2
Goodness -of -Fit Test Statistics for Uncensored Full Data Sets without Non -Detects
User Selected Options
Date/Time of Computation 3/30/2016 4:42:09 PM
From File WorkSheet.xls
Full Precision OFF
Confidence Coefficient 0.95
Vanadium (ug/L)
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 39 0 39 26 13 33.33%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Number
Minimum
Maximum
Mean
Median
SD
13
0.3
1
0.677
1
0.363
26
0.326
22.9
4.668
2.825
5.201
39
0.3
22.9
3.337
1.2
4.633
39
0.15
22.9
3.225
1.2
4.699
39
-11.71
22.9
1.12
1.2
6.857
39
0.01
22.9
3.115
1.2
4.769
39
0.0558
22.9
3.205
1.2
4.711
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GOF stats for Marshall_regional.xlsx
Page 10 of 11
4/8/2016
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
1.027
0.934
4.546
0.98
1.13
1.153
Statistics (NDs = DL)
0.805
0.76
4.147
0.468
1.226
2.617
Statistics (NDs = DL/2)
0.654
0.62
4.933
0.237
1.448
6.104
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 10 of 11
4/8/2016

Attachment E-2- Marshall Regional Background Water Supply Well Data GOF Statistics
Statistics (Gamma ROS Estimates)
0.336
0.327
9.284
Statistics (Lognormal ROS Estimates)
0.979
0.125
0.143 1.571 10.99
Normal GOF
Test Results
0.786
Data Appear Lognormal
No NDs
NDs = DL
NDs = DL/2Normal ROS
Correlation Coefficient R
0.872
0.812
0.817 0.825
0.148
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.771
0.92
Data Not Normal
Lilliefors (Detects Only)
0.202
0.174
Data Not Normal
Shapiro -Wilk (NDs = DL)
0.677
0.939
Data Not Normal
Lilliefors (NDs = DL)
0.256
0.142
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.683
0.939
Data Not Normal
Lilliefors (NDs = DL/2)
0.256
0.142
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.959
0.939
Data Appear Normal
Lilliefors (Normal ROS Estimates)
0.121
0.142
Data Appear Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.99 0.982 0.99 0.994
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)
0.33
0.773
0.979
0.125
0.176
Detected Data Appear Gamma Distributed
1.417
0.786
Data Appear Lognormal
0.215
0.147
Data Not Gamma Distributed
1.13
0.798
0.156
0.163
0.148
Data Not Gamma Distributed
1.426
0.85
Data Not Lognormal
0.22
0.153
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.994 0.975 0.979 0.993
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4/8/2016
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.979
0.92
Data Appear Lognormal
Lilliefors (Detects Only)
0.106
0.174
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.933
0.939
Data Not Lognormal
Lilliefors (NDs = DL)
0.156
0.142
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.939
0.939
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.126
0.142
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.971
0.939
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.0889
0.142
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are not recommended.
Haley & Aldrich, Inc.
GOF stats for Marshall_regional.xlsx
Page 11 of 11
4/8/2016

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

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Goodness -of -Fit Test Statistics for Uncensored Full Data Sets without Non -Detects
User Selected Options
0.821
Date/Time of Computation 3/30/2016 6:02:41 PM
0.661
From File WorkSheet.xls
0.93
Full Precision OFF
Confidence Coefficient 0.95
0.358
Barium - ug/L - T
0.157
Raw Statistics
Number of Valid Observations
32
Number of Missing Observations
1
Number of Distinct Observations
17
Minimum
40
Maximum
890
Mean of Raw Data
228.8
Standard Deviation of Raw Data
297.1
Khat
0.773
Theta hat
296.1
Kstar
0.721
Theta star
317.3
Mean of Log Transformed Data
4.661
Standard Deviation of Log Transformed Data
1.205
Normal GOF Test Results
Correlation Coefficient R
0.821
Shapiro Wilk Test Statistic
0.661
Shapiro Wilk Critical (0.05) Value
0.93
Approximate Shapiro Wilk P Value 1.6439E-8
Lilliefors Test Statistic
0.358
Lilliefors Critical (0.05) Value
0.157
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.929
A -D Test Statistic 4.011
A -D Critical (0.05) Value 0.787
K -S Test Statistic 0.291
K -S Critical(0.05) Value 0.161
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R 0.869
Shapiro Wilk Test Statistic 0.733
Shapiro Wilk Critical (0.05) Value 0.93
Approximate Shapiro Wilk P Value 4.7101 E-7
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 1 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Lilliefors Test Statistic 0.286
Lilliefors Critical (0.05) Value 0.157
Data not Lognormal at (0.05) Significance Level
Chromium (VI) - ug/L - T
Raw Statistics
0.962
Number of Valid Observations
9
Number of Missing Observations
8
Number of Distinct Observations
9
Minimum
0.016
Maximum
7.6
Mean of Raw Data
2.829
Standard Deviation of Raw Data
2.697
Khat
0.594
Theta hat
4.762
Kstar
0.47
Theta star
6.018
Mean of Log Transformed Data
-0.00177
Standard Deviation of Log Transformed Data
2.187
Normal GOF Test Results
Correlation Coefficient R
0.962
Shapiro Wilk Test Statistic
0.91
Shapiro Wilk Critical (0.05) Value
0.829
Approximate Shapiro Wilk P Value
0.415
Lilliefors Test Statistic
0.19
Lilliefors Critical (0.05) Value
0.295
Data appear Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R
0.942
A -D Test Statistic
0.39
A -D Critical (0.05) Value
0.763
K -S Test Statistic
0.185
K -S Critical(0.05) Value
0.292
Data appear Gamma Distributed at (0.05) Significance Level
0.295
Lognormal GOF Test Results
Correlation Coefficient R
0.915
Shapiro Wilk Test Statistic
0.831
Shapiro Wilk Critical (0.05) Value
0.829
Approximate Shapiro Wilk P Value
0.0532
Lilliefors Test Statistic
0.237
Lilliefors Critical (0.05) Value
0.295
Data appear Lognormal at (0.05) Significance Level
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 2 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Vanadium - ug/L - T
Raw Statistics
0.739
Number of Valid Observations
18
Number of Missing Observations
15
Number of Distinct Observations
17
Minimum
1.4
Maximum
100
Mean of Raw Data
15.82
Standard Deviation of Raw Data
22.61
Khat
0.912
Theta hat
17.35
Kstar
0.797
Theta star
19.85
Mean of Log Transformed Data
2.121
Standard Deviation of Log Transformed Data
1.157
Normal GOF Test Results
Correlation Coefficient R
0.739
Shapiro Wilk Test Statistic
0.573
Shapiro Wilk Critical (0.05) Value
0.897
Approximate Shapiro Wilk P Value 5.4886E-7
0.0781
Lilliefors Test Statistic
0.306
Lilliefors Critical (0.05) Value
0.209
Data not Normal at (0.05) Significance Level
Gamma GOF Test Results
Correlation Coefficient R 0.899
A -D Test Statistic 0.937
A -D Critical (0.05) Value 0.771
K -S Test Statistic 0.226
K -S Critical(0.05) Value 0.21
Data not Gamma Distributed at (0.05) Significance Level
Lognormal GOF Test Results
Correlation Coefficient R
0.953
Shapiro Wilk Test Statistic
0.906
Shapiro Wilk Critical (0.05) Value
0.897
Approximate Shapiro Wilk P Value
0.0781
Lilliefors Test Statistic
0.218
Lilliefors Critical (0.05) Value
0.209
Data appear Approximate—Lognormal at (0.05) Significance Level
Goodness -of -Fit Test Statistics for Data Sets with Non -Detects
User Selected Options
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 3 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Date/Time of Computation 3/30/2016 6:05:05 PM
From File WorkSheet.xls
Full Precision OFF
Confidence Coefficient 0.95
Chromium - ug/L - T
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.594 0.52 0.511 0.463
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
33
0
33
19
14
42.42%
Data Not Normal
Number
Minimum
Maximum
Mean
Median
SD
Statistics (Non -Detects Only)
14
5
5
5
5
0
Statistics (Detects Only)
19
0.49
80.4
8.058
3.8
17.75
Statistics (All: NDs treated as DL value)
33
0.49
80.4
6.761
5
13.4
Statistics (All: NDs treated as DL/2 value)
33
0.49
80.4
5.7
2.5
13.6
Statistics (Normal ROS Imputed Data)
33
-10.31
80.4
5.546
3.447
14.26
Statistics (Gamma ROS Imputed Data)
33
0.01
80.4
5.368
2.3
13.8
Statistics (Lognormal ROS Imputed Data)
33
0.434
80.4
5.591
2.62
13.66
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
0.724
0.645
11.13
1.255
1.153
0.918
Statistics (NDs = DL)
1.127
1.044
6.001
1.406
0.883
0.628
Statistics (NDs = DL/2)
0.926
0.862
6.154
1.112
0.881
0.793
Statistics (Gamma ROS Estimates)
0.356
0.344
15.09
Statistics (Lognormal ROS Estimates)
0.97
1.041
1.074
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.594 0.52 0.511 0.463
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)
0.383
0.901
Data Not Normal
0.41
0.203
Data Not Normal
0.308
0.931
Data Not Normal
0.42
0.154
Data Not Normal
0.297
0.931
Data Not Normal
0.39
0.154
Data Not Normal
0.485
0.931
Data Not Normal
0.308
0.154
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.821 0.703 0.728 0.835
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Anderson -Darling (Detects Only) 1.419 0.781
Kolmogorov-Smirnov (Detects Only) 0.266 0.206 Data Not Gamma Distributed
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 4 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Anderson -Darling (NDs = DL)
3.413
0.773
Kolmogorov-Smirnov (NDs = DL)
0.28
0.157 Data Not Gamma Distributed
Anderson -Darling (NDs = DL/2)
4.061
0.779
Kolmogorov-Smirnov (NDs = DL/2)
0.283
0.158 Data Not Gamma Distributed
Anderson -Darling (Gamma ROS Estimates)
1.276
0.843
Kolmogorov-Smirnov (Gamma ROS Est.)
0.159
0.165 Detected Data appear Approximate Gamma Distri
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.964 0.902 0.903 0.968
Cobalt - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 33 14 19 15 4 21.05%
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
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.943
0.901
Data Appear Lognormal
Lilliefors (Detects Only)
0.153
0.203
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.844
0.931
Data Not Lognormal
Lilliefors (NDs = DL)
0.228
0.154
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.847
0.931
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.234
0.154
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.95
0.931
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.1
0.154
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are not recommended.
0.01
Cobalt - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 33 14 19 15 4 21.05%
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
0.5
1
0.625
0.5
0.25
15
0.13
11.9
1.811
0.47
3.013
19
0.13
11.9
1.562
0.5
2.705
19
0.13
11.9
1.496
0.3
2.731
19
-0.897
11.9
1.493
0.47
2.756
19
0.01
11.9
1.451
0.3
2.753
19
0.13
11.9
1.499
0.335
2.73
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.673
0.583
2.691
-0.309
1.348
-4.366
0.749
0.666
2.084
-0.353
1.201
-3.399
0.674
0.602
2.22
-0.499
1.256
-2.516
0.461
0.423
3.148
-0.499
1.267
-2.537
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.747 0.714 0.706 0.762
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 5 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Shapiro -Wilk (Detects Only)
0.583
0.881
Data Not Normal
Lilliefors (Detects Only)
0.288
0.229
Data Not Normal
Shapiro -Wilk (NDs = DL)
0.535
0.901
Data Not Normal
Lilliefors (NDs = DL)
0.298
0.203
Data Not Normal
Shapiro -Wilk (NDs = DL/2)
0.524
0.901
Data Not Normal
Lilliefors (NDs = DL/2)
0.308
0.203
Data Not Normal
Shapiro -Wilk (Normal ROS Estimates)
0.589
0.901
Data Not Normal
Lilliefors (Normal ROS Estimates)
0.269
0.203
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.945 0.921 0.927 0.95
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)
0.949
0.781
0.881
0.225
0.231
Detected Data appear Approximate Gamma Distri
1.158
0.779
0.901
0.241
0.206
Data Not Gamma Distributed
1.709
0.786
0.901
0.261
0.207
Data Not Gamma Distributed
0.64
0.811
0.901
0.183
0.211
Data Appear Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.952 0.962 0.926 0.947
User Selected Options
Date/Time of Computation
From File
Full Precision
Confidence Coefficient
Iron - ug/L - T
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Conclusion with Alpha(0.05)
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Goodness -of -Fit Test Statistics for Data Sets with Non -Detects
3/30/2016 6:06:16 PM
WorkSheet.xls
OFF
0.95
Page 6 of 10
4/8/2016
Test value
Crit. (0.05)
Shapiro -Wilk (Detects Only)
0.899
0.881
Lilliefors (Detects Only)
0.213
0.229
Shapiro -Wilk (NDs = DL)
0.924
0.901
Lilliefors (NDs = DL)
0.19
0.203
Shapiro -Wilk (NDs = DL/2)
0.856
0.901
Lilliefors (NDs = DL/2)
0.239
0.203
Shapiro -Wilk (Lognormal ROS Estimates)
0.892
0.901
Lilliefors (Lognormal ROS Estimates)
0.207
0.203
Note: Substitution methods such as DL or DL/2 are not recommended.
User Selected Options
Date/Time of Computation
From File
Full Precision
Confidence Coefficient
Iron - ug/L - T
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Conclusion with Alpha(0.05)
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Appear Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Data Not Lognormal
Goodness -of -Fit Test Statistics for Data Sets with Non -Detects
3/30/2016 6:06:16 PM
WorkSheet.xls
OFF
0.95
Page 6 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 33 0 33 31 2 6.06%
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
2
10
50
30
30
28.28
31
16
18200
757.5
77
3244
33
10
18200
713.4
60
3146
33
5
18200
712.5
60
3147
33
-2792
18200
609.5
60
3209
33
0.01
18200
711.5
60
3147
33
2.47
18200
712.4
60
3147
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
0.339
0.327
2236
4.634
1.556
0.336
0.334
0.324
2135
4.542
1.564
0.344
0.328
0.319
2169
4.5
1.612
0.358
0.28
0.275
2543
4.479
1.655
0.37
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.441 0.433 0.433 0.433
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)
0.227
0.929
Data Not Normal
0.451
0.159
Data Not Normal
0.221
0.931
Data Not Normal
0.45
0.154
Data Not Normal
0.221
0.931
Data Not Normal
0.45
0.154
Data Not Normal
0.286
0.931
Data Not Normal
0.437
0.154
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.765 0.759 0.761 0.777
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
4.187
0.846
0.3
0.17
Data Not Gamma Distributed
4.433
0.848
0.293
0.166
Data Not Gamma Distributed
4.304
0.849
0.29
0.166
Data Not Gamma Distributed
3.217
0.866
0.265
0.167
Data Not Gamma Distributed
Lognormal GOF Test Results
Page 7 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.941 0.948 0.954 0.958
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.893
0.929
Data Not Lognormal
Lilliefors (Detects Only)
0.121
0.159
Data Appear Lognormal
Shapiro -Wilk (NDs = DL)
0.908
0.931
Data Not Lognormal
Lilliefors (NDs = DL)
0.128
0.154
Data Appear Lognormal
Shapiro -Wilk (NDs = DL/2)
0.925
0.931
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.114
0.154
Data Appear Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.937
0.931
Data Appear Lognormal
Lilliefors (Lognormal ROS Estimates)
0.121
0.154
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Lead - ug/L - T
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 33 1 32 12 20 62.50%
Statistics (Non -Detects Only)
Statistics (Detects Only)
Statistics (All: NDs treated as DL value)
Statistics (All: NDs treated as DL/2 value)
Statistics (Normal ROS Imputed Data)
Statistics (Gamma ROS Imputed Data)
Statistics (Lognormal ROS Imputed Data)
Statistics (Detects Only)
Statistics (NDs = DL)
Statistics (NDs = DL/2)
Statistics (Gamma ROS Estimates)
Statistics (Lognormal ROS Estimates)
Number Minimum Maximum Mean Median SD
20 0.1 1 0.73 1 0.423
12 0.051 17.5 1.584 0.135 5.013
32 0.051 17.5 1.05 0.27 3.034
32 0.05 17.5 0.822 0.27 3.05
32 -4.077 17.5 0.479 0.0755 3.583
32 0.01 17.5 0.863 0.0305 3.168
32 0.0136 17.5 0.675 0.0871 3.073
K hat K Star Theta hat Log Mean Log Stdv Log CV
0.311 0.288 5.1 -1.748 1.574 -0.901
0.551 0.52 1.907 -1.087 1.367 -1.257
0.482 0.458 1.705 -1.52 1.277 -0.84
0.256 0.252 3.378
-2.246 1.295 -0.577
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2 Normal ROS
Correlation Coefficient R 0.556 0.497 0.441 0.615
Shapiro -Wilk (Detects Only)
Lilliefors (Detects Only)
Shapiro -Wilk (NDs = DL)
Lilliefors (NDs = DL)
Shapiro -Wilk (NDs = DL/2)
Lilliefors (NDs = DL/2)
Shapiro -Wilk (Normal ROS Estimates)
Lilliefors (Normal ROS Estimates)
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
0.341
0.859
Data Not Normal
0.519
0.256
Data Not Normal
0.282
0.93
Data Not Normal
0.475
0.157
Data Not Normal
0.228
0.93
Data Not Normal
0.511
0.157
Data Not Normal
0.644
0.93
Data Not Normal
0.257
0.157
Data Not Normal
Page 8 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.876 0.739 0.713 0.887
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)
2.82
0.822
0.298
0.469
0.265
Data Not Gamma Distributed
3.038
0.806
Data Not Lognormal
0.306
0.164
Data Not Gamma Distributed
4.392
0.814
0.801
0.399
0.165
Data Not Gamma Distributed
4.535
0.877
Data Not Lognormal
0.288
0.17
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.815 0.917 0.889 0.917
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.689
0.859
Data Not Lognormal
Lilliefors (Detects Only)
0.298
0.256
Data Not Lognormal
Shapiro -Wilk (NDs = DL)
0.844
0.93
Data Not Lognormal
Lilliefors (NDs = DL)
0.256
0.157
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.801
0.93
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.227
0.157
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.866
0.93
Data Not Lognormal
Lilliefors (Lognormal ROS Estimates)
0.13
0.157
Data Appear Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
6.05
Nickel - ug/L - D
Num Obs Num Miss Num Valid Detects NDs % NDs
Raw Statistics 33 15 18 17 1 5.56%
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)
Number
Minimum
Maximum
Mean
Median
SD
17
0.42
9
5.043
6.1
3.217
18
0.42
9
5.041
6.05
3.121
18
0.42
9
4.902
6.05
3.178
18
0.42
9
4.872
6.05
3.205
18
0.42
9
4.892
6.05
3.186
18
0.42
9
4.837
6.05
3.242
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 9 of 10
4/8/2016
K hat
K Star
Theta hat
Log Mean
Log Stdv
Log CV
Statistics (Detects Only)
1.5
1.275
3.361
1.249
1.041
0.833
Statistics (NDs = DL)
1.581
1.355
3.188
1.269
1.014
0.799
Statistics (NDs = DL/2)
1.538
1.319
3.186
1.231
1.013
0.823
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 9 of 10
4/8/2016

Attachment E-2- Marshall Facility Background Monitoring Well Data GOF Statistics
Statistics (Gamma ROS Estimates) 1.53 1.312 3.196
Statistics (Lognormal ROS Estimates) 1.196 1.035 0.866
Normal GOF Test Results
No NDs NDs = DL NDs = DL/2Normal ROS
Correlation Coefficient R 0.923 0.933 0.933 0.919
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)
0.83
0.892
Data Not Normal
0.24
0.215
Data Not Normal
0.849
0.897
Data Not Normal
0.212
0.209
Data Not Normal
0.848
0.897
Data Not Normal
0.222
0.209
Data Not Normal
0.841
0.897
Data Not Normal
0.225
0.209
Data Not Normal
Gamma GOF Test Results
No NDs NDs = DL NDs = DL/23amma RO;
Correlation Coefficient R 0.826 0.839 0.848 0.847
Anderson -Darling (Detects Only)
Kolmogorov-Smirnov (Detects Only)
Anderson -Darling (NDs = DL)
Kolmogorov-Smirnov (NDs = DL)
Anderson -Darling (NDs = DL/2)
Kolmogorov-Smirnov (NDs = DL/2)
Anderson -Darling (Gamma ROS Estimates)
Kolmogorov-Smirnov (Gamma ROS Est.)
Test value
Crit. (0.05)
Conclusion with Alpha(0.05)
1.711
0.756
0.335
0.32
0.213
Data Not Gamma Distributed
1.683
0.756
Data Not Lognormal
0.283
0.207
Data Not Gamma Distributed
1.484
0.756
0.813
0.296
0.207
Data Not Gamma Distributed
1.495
0.756
Data Not Lognormal
0.297
0.207
Data Not Gamma Distributed
Lognormal GOF Test Results
No NDs NDs = DL NDs = DL/2 Log ROS
Correlation Coefficient R 0.891 0.893 0.909 0.903
Test value Crit. (0.05) Conclusion with Alpha(0.05)
Shapiro -Wilk (Detects Only)
0.782
0.892
Data Not Lognormal
Lilliefors (Detects Only)
0.335
0.215
Data Not Lognormal
Shapiro -Wilk (NDs = DL)
0.787
0.897
Data Not Lognormal
Lilliefors (NDs = DL)
0.298
0.209
Data Not Lognormal
Shapiro -Wilk (NDs = DL/2)
0.813
0.897
Data Not Lognormal
Lilliefors (NDs = DL/2)
0.31
0.209
Data Not Lognormal
Shapiro -Wilk (Lognormal ROS Estimates)
0.801
0.897
Data Not Lognormal
Lilliefors (Lognormal ROS Estimates)
0.318
0.209
Data Not Lognormal
Note: Substitution methods such as DL or DU2 are
not recommended.
Haley & Aldrich, Inc.
GOF stats for Marshall_facility.xlsx
Page 10 of 10
4/8/2016

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

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

Attachment E-3- Marshall 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
3/30/2016 4:44:35 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) 2.124
Page 1 of 8
Number of Missing Observations 0
Number of Non -Detects
General Statistics
Total Number of Observations
39
Number of Distinct Observations
35
Number of Detects
38
Number of Distinct Detects
34
Minimum Detect
6
Maximum Detect
486
Variance Detected
6483
Mean Detected
52.89
Mean of Detected Logged Data
3.455
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124
Page 1 of 8
Number of Missing Observations 0
Number of Non -Detects
1
Number of Distinct Non -Detects
1
Minimum Non -Detect
5
Maximum Non -Detect
5
Percent Non -Detects
2.564%
SD Detected
80.51
SD of Detected Logged Data
0.949
d2max (for USL) 2.857
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 1.188 Anderson -Darling GOF Test
5% A -D Critical Value 0.775 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.137 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.147 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) 1.112 k star (bias corrected MLE)
1.042
Theta hat (MLE) 47.56 Theta star (bias corrected MLE)
50.76
nu hat (MLE) 84.52 nu star (bias corrected)
79.18
MLE Mean (bias corrected) 52.89
MLE Sd (bias corrected) 51.82 95% Percentile of Chisquare (2k)
6.153
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
51.53
Maximum 486 Median
26.7
SD 79.9 CV
1.55
k hat (MLE) 0.849 k star (bias corrected MLE)
0.801
Theta hat (MLE) 60.69 Theta star (bias corrected MLE)
64.34
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx
4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
0.43
nu hat (KM)
Page 2 of 8
nu hat (MLE) 66.24 nu star (bias corrected)
62.48
MLE Mean (bias corrected) 51.53 MLE Sd (bias corrected)
57.58
95% Percentile of Chisquare (2k) 5.194 90% Percentile
125.3
95% Percentile 167.1 99% Percentile
265.9
The following statistics are computed using Gamma ROS Statistics on Imputed Data
312.3
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
86.02
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 208.3 226.7 95% Approx. Gamma UPL 157.6
165.5
95% Gamma USL 321.5 373.3
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)
0.43
nu hat (KM)
33.54
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 192.7
196.8
95% Approx. Gamma UPL 147.8 147.5
54.97
95% Gamma USL 291.9
312.3
95% KM USL
86.02
Boron (ug/L)
Mean
23.8
General Statistics
25.02
95% UTL95% Coverage
Total Number of Observations
39
Number of Missing Observations
0
Number of Distinct Observations
7
64.96
Number of Detects
5
Number of Non -Detects
34
Number of Distinct Detects
5
Number of Distinct Non -Detects
2
Minimum Detect
9.1
Minimum Non -Detect
5
Maximum Detect
135
Maximum Non -Detect
50
Variance Detected
3609
Percent Non -Detects
87.18%
Mean Detected
56.16
SD Detected
60.08
Mean of Detected Logged Data
3.432
SD of Detected Logged Data
1.261
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.124
d2max (for USL)
2.857
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic
0.785
Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value
0.762
Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic
0.343
Lilliefors GOF Test
5% Lilliefors Critical Value
0.396
Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
Mean
12.83
SD
25.62
95% UTL95% Coverage
67.25
95% KM UPL (t)
56.57
90% KM Percentile (z)
45.66
95% KM Percentile (z)
54.97
99% KM Percentile (z)
72.42
95% KM USL
86.02
DL/2 Substitution Background Statistics Assuming Normal Distribution
Mean
23.8
SD
25.02
95% UTL95% Coverage
76.96
95% UPL (t)
66.53
90% Percentile (z)
55.87
95% Percentile (z)
64.96
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx 4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
Chromium (ug/L)
Page 3 of 8
99% Percentile (z) 82.01 95% USL 95.29
DL/2 is not a recommended method. DL/2 provided for comparisons and historical reasons
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124 d2max (for USL) 2.857
Gamma GOF Tests on Detected Observations Only
General Statistics
A -D Test Statistic 0.699 Anderson -Darling GOF Test
Total Number of Observations
39
Number of Missing Observations
0
Number of Distinct Observations
12
Gamma Statistics on Detected Data Only
Number of Detects
11
Number of Non -Detects
28
Number of Distinct Detects
10
Number of Distinct Non -Detects
2
Minimum Detect
0.51
Minimum Non -Detect
0.5
Maximum Detect
9
Maximum Non -Detect
5
Variance Detected
9.296
Percent Non -Detects
71.79%
Mean Detected
3.037
SD Detected
3.049
Mean of Detected Logged Data
0.664
SD of Detected Logged Data
0.985
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124 d2max (for USL) 2.857
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.699 Anderson -Darling GOF Test
5% A -D Critical Value 0.747 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.224 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.261 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) 1.259 k star (bias corrected MLE)
0.976
Theta hat (MLE) 2.413 Theta star (bias corrected MLE)
3.112
nu hat (MLE) 27.69 nu star (bias corrected)
21.47
MLE Mean (bias corrected) 3.037
MLE Sd (bias corrected) 3.075 95% Percentile of Chisquare (2k)
5.898
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
1.471
Maximum 9 Median
0.76
SD 2.136 CV
1.452
k hat (MLE) 0.365 k star (bias corrected MLE)
0.354
Theta hat (MLE) 4.033 Theta star (bias corrected MLE)
4.158
nu hat (MLE) 28.46 nu star (bias corrected)
27.6
MLE Mean (bias corrected) 1.471 MLE Sd (bias corrected)
2.474
95% Percentile of Chisquare (2k) 3.066 90% Percentile
4.242
95% Percentile 6.375 99% Percentile
11.81
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
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx
4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
Page 4 of 8
95% Approx. Gamma UTL with 95% Coverage 8.788
10.77 95% Approx. Gamma UPL 6.062
6.889
95% Gamma USL 15.36
21.31
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
k hat (KM)
0.681 nu hat (KM)
53.14
WH
HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 5.253
5.29 95% Approx. Gamma UPL 4.124
4.08
95% Gamma USL 7.704
8.043
Hexavalent Chromium (ug/L)
General Statistics
Total Number of Observations
21 Number of Missing Observations
18
Number of Distinct Observations
15
Number of Detects
13 Number of Non -Detects
8
Number of Distinct Detects
13 Number of Distinct Non -Detects
2
Minimum Detect
0.039 Minimum Non -Detect
0.03
Maximum Detect
3.7 Maximum Non -Detect
0.6
Variance Detected
1.072 Percent Non -Detects
38.1%
Mean Detected
0.865 SD Detected
1.035
Mean of Detected Logged Data
-0.841 SD of Detected Logged Data
1.327
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.371 d2max (for USL)
2.58
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic
0.269 Anderson -Darling GOF Test
5% A -D Critical Value
0.765 Detected data appear Gamma Distributed at 5% Significance
Level
K -S Test Statistic
0.169 Kolmogrov-Smirnoff GOF
5% K -S Critical Value
0.245 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)
0.846 k star (bias corrected MLE)
0.702
Theta hat (MLE)
1.023 Theta star (bias corrected MLE)
1.232
nu hat (MLE)
22 nu star (bias corrected)
18.26
MLE Mean (bias corrected)
0.865
MLE Sd (bias corrected)
1.033 95% Percentile of Chisquare (2k)
4.775
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 0.562
Maximum 3.7 Median 0.15
SD 0.898 CV 1.597
k hat (MLE) 0.457 k star (bias corrected MLE) 0.423
Theta hat (MLE) 1.231 Theta star (bias corrected MLE) 1.328
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx 4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
Page 5 of 8
nu hat (MLE) 19.18 nu star (bias corrected) 17.77
MLE Mean (bias corrected) 0.562 MLE Sd (bias corrected) 0.864
95% Percentile of Chisquare (2k) 3.448 90% Percentile 1.572
95% Percentile 2.291 99% Percentile 4.087
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 3.764 4.459 95% Approx. Gamma UPL 2.294 2.491
95% Gamma USL 4.389 5.355
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) 0.443 nu hat (KM) 18.61
WH HW WH HW
95% Approx. Gamma UTL with 95% Coverage 3.304 3.674 95% Approx. Gamma UPL 2.099 2.185
95% Gamma USL 3.808 4.333
Iron (ug/L)
Lead (ug/L)
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Number of Missing Observations 0
Number of Non -Detects
General Statistics
Total Number of Observations
39
Number of Distinct Observations
23
Number of Detects
22
Number of Distinct Detects
22
Minimum Detect
11
Maximum Detect
3920
Variance Detected
1286674
Mean Detected
589.4
Mean of Detected Logged Data
4.602
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Number of Missing Observations 0
Number of Non -Detects
17
Number of Distinct Non -Detects
2
Minimum Non -Detect
10
Maximum Non -Detect
50
Percent Non -Detects
43.59%
SD Detected
1134
SD of Detected Logged Data
1.957
d2max (for USL) 2.857
Nonparametric Upper Limits for BTVs(no distinction made between detects and nondetects)
Order of Statistic, r 39 95% UTL with95% Coverage 3920
Approximate f 2.053 Confidence Coefficient (CC) achieved by UTL 0.865
95% UPL 3720 95% USL 3920
95% KM Chebyshev UPL 4223
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 stats for Marshall_regional.xlsx 4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
Page 6 of 8
General Statistics
Total Number of Observations 39 Number of Missing Observations
0
Number of Distinct Observations 24
Number of Detects 24 Number of Non -Detects
15
Number of Distinct Detects 23 Number of Distinct Non -Detects
1
Minimum Detect 0.16 Minimum Non -Detect
1
Maximum Detect 6.3 Maximum Non -Detect
1
Variance Detected 3.111 Percent Non -Detects
38.46%
Mean Detected 1.403 SD Detected
1.764
Mean of Detected Logged Data -0.316 SD of Detected Logged Data
1.159
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124 d2max (for USL)
2.857
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.994 Anderson -Darling GOF Test
5% A -D Critical Value 0.776 Data Not Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.167 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.184 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) 0.894 k star (bias corrected MLE)
0.81
Theta hat (MLE) 1.57 Theta star (bias corrected MLE)
1.732
nu hat (MLE) 42.9 nu star (bias corrected)
38.87
MLE Mean (bias corrected) 1.403
MLE Sd (bias corrected) 1.559 95% Percentile of Chisquare (2k)
5.231
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
1.001
Maximum 6.3 Median
0.392
SD 1.49 CV
1.489
k hat (MLE) 0.559 k star (bias corrected MLE)
0.533
Theta hat (MLE) 1.791 Theta star (bias corrected MLE)
1.878
nu hat (MLE) 43.58 nu star (bias corrected)
41.56
MLE Mean (bias corrected) 1.001 MLE Sd (bias corrected)
1.371
95% Percentile of Chisquare (2k) 4.002 90% Percentile
2.671
95% Percentile 3.758 99% Percentile
6.414
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 5.015 5.716 95% Approx. Gamma UPL 3.613
3.905
95% Gamma USL 8.279 10.34
The following statistics are computed using gamma distribution and KM estimates
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx 4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
1.049
SD
1.239
95% UTL95% Coverage
3.681
Page 7 of 8
k hat (KM)
0.477
nu hat (KM)
37.23
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 4.022
4.104
95% Approx. Gamma UPL 3.032
3.012
95% Gamma USL 6.244
6.712
SD
1.283
Nickel (ug/L)
4.747
95% UPL (t)
4.212
90% Percentile (z)
General Statistics
95% Percentile (z)
4.132
Total Number of Observations
39
Number of Missing Observations
0
Number of Distinct Observations
7
Number of Detects
5
Number of Non -Detects
34
Number of Distinct Detects
5
Number of Distinct Non -Detects
2
Minimum Detect
0.9
Minimum Non -Detect
0.5
Maximum Detect
7
Maximum Non -Detect
5
Variance Detected
6.347
Percent Non -Detects
87.18%
Mean Detected
2.82
SD Detected
2.519
Mean of Detected Logged Data
0.744
SD of Detected Logged Data
0.839
Vanadium (ug/L)
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124 d2max (for USL) 2.857
Normal GOF Test on Detects Only
Shapiro Wilk Test Statistic 0.828 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.762 Detected Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.257 Lilliefors GOF Test
5% Lilliefors Critical Value 0.396 Detected Data appear Normal at 5% Significance Level
Detected Data appear Normal at 5% Significance Level
Kaplan Meier (KM) Background Statistics Assuming Normal Distribution
Mean
1.049
SD
1.239
95% UTL95% Coverage
3.681
95% KM UPL (t)
3.165
90% KM Percentile (z)
2.637
95% KM Percentile (z)
3.087
99% KM Percentile (z)
3.931
95% KM USL
4.589
DU2 Substitution Background Statistics Assuming Normal Distribution
0.3
22.9
Mean
2.022
SD
1.283
95% UTL95% Coverage
4.747
95% UPL (t)
4.212
90% Percentile (z)
3.666
95% Percentile (z)
4.132
99% Percentile (z)
5.006
95% USL
5.687
DU2 is not a recommended method. DU2 provided for comparisons and historical reasons
Total Number of Observations
Number of Distinct Observations
Number of Detects
Number of Distinct Detects
Minimum Detect
Maximum Detect
Haley & Aldrich, Inc.
BTV stats for Marsha ll_regional.xlsx
General Statistics
39
Number of Missing Observations
0
25
26
Number of Non -Detects
13
24
Number of Distinct Non -Detects
2
0.326
Minimum Non -Detect
0.3
22.9
Maximum Non -Detect
1
4/8/2016

Attachment E-3- Marshall Regional Background Water Supply Well Data BTVs Statistics
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx 4/8/2016
Page 8 of 8
Variance Detected 27.05 Percent Non -Detects
33.33%
Mean Detected 4.668 SD Detected
5.201
Mean of Detected Logged Data 0.98 SD of Detected Logged Data
1.13
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.124 d2max (for USL)
2.857
Gamma GOF Tests on Detected Observations Only
A -D Test Statistic 0.33 Anderson -Darling GOF Test
5% A -D Critical Value 0.773 Detected data appear Gamma Distributed at 5% Significance Level
K -S Test Statistic 0.125 Kolmogrov-Smirnoff GOF
5% K -S Critical Value 0.176 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) 1.027 k star (bias corrected MLE)
0.934
Theta hat (MLE) 4.546 Theta star (bias corrected MLE)
4.998
nu hat (MLE) 53.39 nu star (bias corrected)
48.57
MLE Mean (bias corrected) 4.668
MLE Sd (bias corrected) 4.83 95% Percentile of Chisquare (2k)
5.733
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
3.115
Maximum 22.9 Median
1.2
SD 4.769 CV
1.531
k hat (MLE) 0.336 k star (bias corrected MLE)
0.327
Theta hat (MLE) 9.284 Theta star (bias corrected MLE)
9.532
nu hat (MLE) 26.17 nu star (bias corrected)
25.49
MLE Mean (bias corrected) 3.115 MLE Sd (bias corrected)
5.449
95% Percentile of Chisquare (2k) 2.908 90% Percentile
9.086
95% Percentile 13.86 99% Percentile
26.13
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 18.86 23.44 95% Approx. Gamma UPL 12.94
14.84
95% Gamma USL 33.2 46.95
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) 0.488 nu hat (KM)
38.03
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 14.7 15.67 95% Approx. Gamma UPL 10.78
11.05
95% Gamma USL 23.69 27.12
Haley & Aldrich, Inc.
BTV stats for Marshall_regional.xlsx 4/8/2016

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

Attachment E-3- Marshall Facility Background Monitoring Well Data BTVs Statistics
Background Statistics for Data Sets with Non -Detects
User Selected Options
40
Date/Time of Computation
3/30/2016 6:37:14 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 - T
General Statistics
Total Number of Observations 31
Minimum
40
Second Largest
880
Maximum
890
Mean
217.5
Coefficient of Variation
1.356
Mean of logged Data
4.606
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.197
Page 1 of 6
Number of Distinct Observations
16
Number of Missing Observations
2
First Quartile
42
Median
43
Third Quartile
340
SD
294.9
Skewness
1.53
SD of logged Data
1.184
d2max (for USL) 2.76
Nonparametric Upper Limits for Background Threshold Values
General Statistics
Order of Statistic, r
31 95% UTL with
95% Coverage
890
Approximate f
1.632 Confidence Coefficient (CC) achieved by UTL
0.796
95% Percentile Bootstrap UTL with 95% Coverage
890 95% BCA Bootstrap UTL with
95% Coverage
885
95% UPL
884
90% Percentile
820
90% Chebyshev UPL
1116
95% Percentile
850
95% Chebyshev UPL
1523
99% Percentile
887
95% USL
890
Variance Detected
8.732
Chromium - ug/L - T
General Statistics
Total Number of Observations
32
Number of Missing Observations
1
Number of Distinct Observations
19
Number of Detects
18
Number of Non -Detects
14
Number of Distinct Detects
18
Number of Distinct Non -Detects
1
Minimum Detect
0.49
Minimum Non -Detect
5
Maximum Detect
11.3
Maximum Non -Detect
5
Variance Detected
8.732
Percent Non -Detects
43.75%
Mean Detected
4.039
SD Detected
2.955
Mean of Detected Logged Data
1.081
SD of Detected Logged Data
0.893
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.186
d2max (for USL)
2.773
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx
4/8/2016

Attachment E-3- Marshall Facility Background Monitoring Well Data BTVs Statistics
Page 2 of 6
Gamma Statistics on Detected Data Only
1.749
k hat (MLE) 1.738 k star (bias corrected MLE)
1.485
Theta hat (MLE) 2.324 Theta star (bias corrected MLE)
2.719
nu hat (MLE) 62.56 nu star (bias corrected)
53.47
MLE Mean (bias corrected) 4.039
11.23 95%
MLE Sd (bias corrected) 3.314 95% Percentile of Chisquare (2k)
7.764
Gamma ROS Statistics using Imputed Non -Detects
15.38
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
General Statistics
Minimum 0.283 Mean
3.271
Maximum 11.3 Median
2.615
SD 2.523 CV
0.771
k hat (MLE) 1.717 k star (bias corrected MILE)
1.577
Theta hat (MLE) 1.905 Theta star (bias corrected MLE)
2.074
nu hat (MLE) 109.9 nu star (bias corrected)
100.9
MLE Mean (bias corrected) 3.271 MLE Sd (bias corrected)
2.604
95% Percentile of Chisquare (2k) 8.08 90% Percentile
6.733
95% Percentile 8.378 99% Percentile
12.08
The following statistics are computed using Gamma ROS Statistics on Imputed Data
0.13
Upper Limits using Wilson Hilferty (WH) and Hawkins Wixley (HW) Methods
0.5
WH HW WH
HW
95% Approx. Gamma UTL with 95% Coverage 10.98 11.72 95% Approx. Gamma UPL 8.559
8.894
95% Gamma USL 14.65 16.19
1.387
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)
1.749
nu hat (KM)
111.9
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 10.61
11.23 95%
Approx. Gamma UPL 8.316
8.589
95% Gamma USL 14.06
15.38
Cobalt - ug/L - T
General Statistics
Total Number of Observations
18
Number of Missing Observations
15
Number of Distinct Observations
13
Number of Detects
14
Number of Non -Detects
4
Number of Distinct Detects
11
Number of Distinct Non -Detects
2
Minimum Detect
0.13
Minimum Non -Detect
0.5
Maximum Detect
3.3
Maximum Non -Detect
1
Variance Detected
1.387
Percent Non -Detects
22.22%
Mean Detected
1.091
SD Detected
1.178
Mean of Detected Logged Data
-0.508
SD of Detected Logged Data
1.148
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.453
d2max (for USL)
2.504
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx 4/8/2016

Attachment E-3- Marshall Facility Background Monitoring Well Data BTVs Statistics
Page 3 of 6
Gamma GOF Tests on Detected Observations Only
0.738
A -D Test Statistic 0.992 Anderson -Darling GOF Test
26.57
5% A -D Critical Value 0.761 Data Not Gamma Distributed at 5% Significance Level
HW
K -S Test Statistic 0.254 Kolmogrov-Smirnoff GOF
HW
5% K -S Critical Value 0.235 Data Not Gamma Distributed at 5% Significance Level
4.788
Data Not Gamma Distributed at 5% Significance Level
2.982
Gamma Statistics on Detected Data Only
4.954
k hat (MLE) 0.974 k star (bias corrected MLE)
0.813
Theta hat (MLE) 1.12 Theta star (bias corrected MLE)
1.342
nu hat (MLE) 27.26 nu star (bias corrected)
22.76
MLE Mean (bias corrected) 1.091
MLE Sd (bias corrected) 1.21 95% Percentile of Chisquare (2k)
5.243
Gamma ROS Statistics using Imputed Non -Detects
9
GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs
9
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
8
For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates
0.016
Minimum 0.01 Mean
0.911
Maximum 3.3 Median
0.297
SD 1.091 CV
1.198
k hat (MLE) 0.806 k star (bias corrected MLE)
0.709
Theta hat (MLE) 1.13 Theta star (bias corrected MLE)
1.285
nu hat (MLE) 29.03 nu star (bias corrected)
25.52
MLE Mean (bias corrected) 0.911 MLE Sd (bias corrected)
1.082
95% Percentile of Chisquare (2k) 4.804 90% Percentile
2.28
95% Percentile 3.086 99% Percentile
5.01
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 5.062 5.726 95% Approx. Gamma UPL 3.224
3.421
95% Gamma USL 5.226 5.941
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)
0.738
nu hat (KM)
26.57
WH
HW
WH
HW
95% Approx. Gamma UTL with 95% Coverage 4.48
4.788
95% Approx. Gamma UPL 2.928
2.982
95% Gamma USL 4.617
4.954
Chromium (VI) - ug/L - T
General Statistics
Total Number of Observations
9
Number of Distinct Observations
9
Number of Missing Observations
8
Minimum
0.016
First Quartile
0.8
Second Largest
6
Median
1.9
Maximum
7.6
Third Quartile
4.1
Mean
2.829
SD
2.697
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx 4/8/2016

Attachment E-3- Marshall Facility Background Monitoring Well Data BTVs Statistics
Iron - ug/L - T
Lead - ug/L - T
Page 4 of 6
Coefficient of Variation 0.953 Skewness 0.71
Mean of logged Data -0.00177 SD of logged Data 2.187
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 3.031 d2max (for USL) 2.11
Normal GOF Test
Shapiro Wilk Test Statistic 0.91 Shapiro Wilk GOF Test
5% Shapiro Wilk Critical Value 0.829 Data appear Normal at 5% Significance Level
Lilliefors Test Statistic 0.19 Lilliefors GOF Test
5% Lilliefors Critical Value 0.295 Data appear Normal at 5% Significance Level
Data appear Normal at 5% Significance Level
Background Statistics Assuming Normal Distribution
95% UTL with 95% Coverage 11
95% UPL (t) 8.115
95% USL 8.518
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.186
90% Percentile (z) 6.285
95% Percentile (z) 7.265
99% Percentile (z) 9.102
Number of Missing Observations 1
Number of Non -Detects
General Statistics
Total Number of Observations
32
Number of Distinct Observations
29
Number of Detects
30
Number of Distinct Detects
27
Minimum Detect
16
Maximum Detect
1000
Variance Detected
48269
Mean Detected
176
Mean of Detected Logged Data
4.462
Critical Values for Background Threshold Values (BTVs)
Tolerance Factor K (For UTL) 2.186
90% Percentile (z) 6.285
95% Percentile (z) 7.265
99% Percentile (z) 9.102
Number of Missing Observations 1
Number of Non -Detects
2
Number of Distinct Non -Detects
2
Minimum Non -Detect
10
Maximum Non -Detect
50
Percent Non -Detects
6.25%
SD Detected
219.7
SD of Detected Logged Data
1.245
d2max (for USL) 2.773
Nonparametric Upper Limits for BTVs(no distinction made between detects and nondetects)
Order of Statistic, r 32 95% UTL with95% Coverage 1000
Approximate f 1.684 Confidence Coefficient (CC) achieved by UTL 0.806
95% UPL 759.5 95% USL 1000
95% KM Chebyshev UPL 1107
Total Number of Observations
Number of Distinct Observations
Number of Detects
Number of Distinct Detects
Minimum Detect
Maximum Detect
General Statistics
31
Number of Missing Observations
2
11
11
Number of Non -Detects
20
9
Number of Distinct Non -Detects
2
0.051
Minimum Non -Detect
0.1
0.28
Maximum Non -Detect
1
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx 4/8/2016

Attachment E-3- Marshall Facility Background Monitoring Well Data BTVs Statistics
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 31 95% UTL with95% Coverage 1
Approximate f 1.632 Confidence Coefficient (CC) achieved by UTL 0.796
95% UPL 1 95% USL 1
95% KM Chebyshev UPL 0.436
Nickel - ug/L - D
General Statistics
Page 5 of 6
Variance Detected
0.007
Percent Non -Detects
64.52%
Mean Detected
0.137
SD Detected
0.0837
Mean of Detected Logged Data
-2.167
SD of Detected Logged Data
0.639
Critical Values for Background Threshold Values (BTVs)
15
Number of Distinct Non -Detects
Tolerance Factor K (For UTL)
2.197
d2max (for USL)
2.76
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 31 95% UTL with95% Coverage 1
Approximate f 1.632 Confidence Coefficient (CC) achieved by UTL 0.796
95% UPL 1 95% USL 1
95% KM Chebyshev UPL 0.436
Nickel - ug/L - D
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 18 95% UTL with95% Coverage 9
Approximate f 0.947 Confidence Coefficient (CC) achieved by UTL 0.603
95% UPL 9 95% USL 9
95% KM Chebyshev UPL 19.03
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.
Vanadium - ug/L - T
General Statistics
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx 4/8/2016
General Statistics
Total Number of Observations
18
Number of Missing Observations
15
Number of Distinct Observations
16
Number of Detects
17
Number of Non -Detects
1
Number of Distinct Detects
15
Number of Distinct Non -Detects
1
Minimum Detect
0.42
Minimum Non -Detect
5
Maximum Detect
9
Maximum Non -Detect
5
Variance Detected
10.35
Percent Non -Detects
5.556%
Mean Detected
5.043
SD Detected
3.217
Mean of Detected Logged Data
1.249
SD of Detected Logged Data
1.041
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.453
d2max (for USL)
2.504
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 18 95% UTL with95% Coverage 9
Approximate f 0.947 Confidence Coefficient (CC) achieved by UTL 0.603
95% UPL 9 95% USL 9
95% KM Chebyshev UPL 19.03
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.
Vanadium - ug/L - T
General Statistics
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx 4/8/2016

Attachment E-3- Marshall Facility Background Monitoring Well Data BTVs Statistics
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Nonparametric Upper Limits for Background Threshold Values
Page 6 of 6
Total Number of Observations
17
Number of Distinct Observations
16
0.895 Confidence Coefficient (CC) achieved by UTL
0.582
Number of Missing Observations
16
Minimum
1.4
First Quartile
2.9
Second Largest
22.1
Median
12.1
Maximum
23.8
Third Quartile
20.8
Mean
10.86
SD
8.613
Coefficient of Variation
0.793
Skewness
0.327
Mean of logged Data
1.975
SD of logged Data
1.007
Critical Values for
Background Threshold Values (BTVs)
Tolerance Factor K (For UTL)
2.486
d2max (for USL)
2.475
Nonparametric Distribution Free Background Statistics
Data do not follow a Discernible Distribution (0.05)
Nonparametric Upper Limits for Background Threshold Values
Order of Statistic, r
17 95% UTL with
95% Coverage
23.8
Approximate f
0.895 Confidence Coefficient (CC) achieved by UTL
0.582
95% Percentile Bootstrap UTL with 95% Coverage
23.8 95% BCA Bootstrap UTL with
95% Coverage
23.8
95% UPL
23.8
90% Percentile
21.98
90% Chebyshev UPL
37.45
95% Percentile
22.44
95% Chebyshev UPL
49.5
99% Percentile
23.53
95% USL
23.8
Haley & Aldrich, Inc.
BTV stats for Marshall facility after removing outlier.xlsx 4/8/2016