NC0004979_R. Hennet - Final Allen Expert Report_20160630

Expert Report of
Remy J.-C. Hennet
Allen Steam Station
Belmont, North Carolina
S.S. PAPADOPULOS & ASSOCIATES, INC.
Environmental & Water -Resource Consultants
June 30, 2016
7944 Wisconsin Avenue, Bethesda, Maryland 20814-3620 9 [phone]

Expert Report of
Remy J.-C. Hennet
Allen Steam Station
Belmont, North Carolina
Prepared for:
Duke Energy Carolinas, LLC
Prepared by:
Remy J.-C. Hennet, PhD
S.S. PAPADOPULOS & ASSOCIATES, INC.
Environmental & Water -Resource Consultants
June 30, 2016
7944 Wisconsin Avenue, Bethesda, Maryland 20814-3620 9 [phone]

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
Table of Contents
Page
Listof Appendices.......................................................................................................................... ii
Section1
Introduction................................................................................................................
1
Section2
Background................................................................................................................
2
Section 3
Geochemistry of the Ash Basins................................................................................
4
Section 4
Natural Attenuation in Groundwater.........................................................................
7
Section 5
Cap -in -Place Remedy................................................................................................
8
Section 6
Excavation and Removal...........................................................................................
9
Section7
Opinions...................................................................................................................
10
Opinion1..................................................................................................................
10
Opinion2..................................................................................................................
10
Opinion3..................................................................................................................
10
Section 8
Bases for Opinions...................................................................................................
11
Opinion1..................................................................................................................
11
Opinion2..................................................................................................................
15
Opinion3..................................................................................................................
18
Appendices
1

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
4M
List of Appendices
Appendix A Curriculum Vitae of Remy J.-C. Hennet
Appendix B Documents Considered and/or Relied Upon
Appendix C Background Concentration Ranges — USGS, Site Data, and Private Wells
Appendix D Natural Attenuation — Ash Basins to Compliance Boundary
Appendix E Boron and Nitrate — Well AB-14D
ii

REPORT

2-2- bVbVDObnrO2 9� V22OCIV1E2' JWC'
Section 1
Introduction
This expert report was prepared by Remy J-C. Hennet. I am a Principal at S.S. Papadopulos
& Associates (SSP&A). I hold a Ph.D. degree in geochemistry and a Master's degree in geology
from Princeton University, and university degrees in hydrogeology and geology from the
University of Neuchatel, Switzerland. My expertise includes the application of geochemistry,
hydrogeology and geology to evaluate the origins, fate, and transport of chemicals in the
environment and the remediation of environmental problems. I have more than 25 years of research
and professional experience. My Curriculum Vitae and list of depositions and trial appearances
are provided as Appendix A. The hourly rate charged by SSP&A for my services is $272.
I was retained by Duke Energy Carolinas, LLC (Duke Energy) to evaluate the geochemical
data that has been collected to characterize the nature and extent of any groundwater contamination
from the operation of coal ash basins at the Allen Steam Station, Belmont, North Carolina (the
Site), and to evaluate whether impacts have occurred to surface waters and private wells. I was
also tasked to analyze and evaluate certain allegations made by Plaintiffs' experts Bedient, Cosler,
and Parette with regards to the appropriateness of the remedy that is proposed for the Site, cap -in -
place with monitored natural attenuation, and their contention that complete excavation of the ash
is the only acceptable remedy.
To conduct this evaluation and render my opinions, I relied on my education, research, and
professional experience. I reviewed the Comprehensive Site Assessment Report and the
Corrective Action Plan Part 1 and Part 2 reports for the Site. I also relied on the peer -reviewed
literature and various professional reports cited herein that describe coal ash materials. I retrieved
data from publically accessible internet sites (USEPA, USGS, and State web sites). The data,
documents and information that I considered are of the type that can be reasonably relied upon to
support my opinions. I visited the Site on September 21, 2015. The information that I considered
for this report is listed as Appendix B.
The opinions presented in this report were reached by applying accepted methodologies in
the fields of geochemistry, hydrology, geology, and environmental remediation. The opinions
expressed in the report are my own and are based on the data and facts available to me at the time
of writing. Should additional relevant information become available, I reserve the right to
supplement the discussion and findings presented in this report.

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Section 2
Background
As required by the Coal Ash Management Act of 2014 (CAMA), Duke Energy conducted
a series of investigations and studies to characterize the potential for environmental impact from
operation of its ash basin system. Duke Energy submitted a Comprehensive Site Assessment
Report and Corrective Action Plan Part 1 and Part 2 reports to North Carolina Department of
Environment and Natural Resources (NCDENR).
The potential source of contamination at the Site is the ash basin system, which consists of
the inactive and active ash basins. Ash was disposed of in historical drainage features that were
dammed for impoundment. The drainage features were local tributaries to the Catawba River. Site
operations started in 1957 and the active basin started operating in 1973. A dike structure separates
the active and inactive ash basins. The ash basin system is an integral part of the Site wastewater
treatment system. The ash basin system receives discharges from the ash removal system, coal pile
runoff, landfill leachate, flue gas desulfurization wastewater, the station yard drain sump, and site
storm water.
Environmental impacts for groundwater occur when a party causes concentration to exceed
the North Carolina Groundwater Quality Standards, as specified in 15A NCAC 2L.0202 (2L
Standards). Concentration exceedances to the Interim Maximum Allowable Concentration
(IMAC) established by NCDENR pursuant to 15A NCAC 2L.0202(c) are also considered, even
though these standards have not been finalized. Surface water impacts are defined by concentration
exceedances to the North Carolina Surface Water Quality (213) standards (213 Standards). The 2B
Standards depend upon classification of a surface water body.
For groundwater, the constituents of interest identified at the Site are: antimony, arsenic,
barium, boron, chromium, hexavalent chromium, cobalt, iron, manganese, pH, sulfate, total
dissolved solids (TDS), and vanadium. The constituents of interest were identified based on
concentrations in groundwater that exceed the 2L Standards and/or IMAC.
The available data for the Site includes results from chemical analysis of soil, sediment,
rock, ash basin solids, ash basin pore water, groundwater, seepages and surface water samples.
Leaching data were collected for samples of ash materials from the basins. The data include
information on mineralogical composition of geologic and ash materials, and general physical
characteristics for these materials in place (i.e., grain size, porosity, permeability). Site background
conditions were characterized through analysis of background soil, rock, and water samples.
Additional data and information on coal ash chemistry are available from peer -reviewed literature
and specialized professional reports.
The extent of groundwater contamination is described in the Comprehensive Site
Assessment Report and Corrective Action Plan reports for the Site. The Comprehensive Site
Assessment Report concluded that there is no identified imminent hazard to human health or the
environment as a result of soil or groundwater contamination at the Site. Additional work is on-
going at the Site to further delineate the extent of groundwater contamination where data gaps have
been identified.
2

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
The Corrective Action Plan reports further evaluated the hydrology of the Site and the fate
and transport of contaminants in the groundwater environment. The reports examined the need for
remediation and the feasibility and adequacy of potential remedial measures for Site closure.
Based on its evaluation of the available data and information, Duke Energy selected a Cap-
in -place remedy for the ash basins, with additional source control measures being considered on
an as needed basis. The remedy consists of an engineered cap system over the ash basins and the
collection and treatment of storm water, runoff water, and seep water for permitted discharge. The
additional source control measures could include hydraulic containment, drains, amendments, and
other measures, as necessary to comply with future regulations and to address uncertainties and
unforeseen conditions. For the restoration of groundwater, Duke Energy has proposed to rely on
monitored natural attenuation. Monitoring after implementation of cap -in -place will provide the
basis for assessing the need for additional source control measures for groundwater restoration.
Plaintiffs' experts Bedient, Cosler, and Parette have submitted expert reports and opined
that a cap -in -place remedy with monitored natural attenuation is inappropriate for the Site. These
experts opined that excavation and removal of the ash basins should be the remedy for the Site.

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Section 3
Geochemistry of the Ash Basins
Coal ash is a by-product from the combustion of coal. Under atmospheric conditions, some
of the minerals in coal ash are metastable and undergo transformations that lead to the formation
of secondary mineral phases that range from amorphous to crystalline (i.e., hydrous
aluminosilicates, mullite, calcite, etc.). Over time, the rate of chemical leaching decreases and the
formation of amorphous clays and other secondary minerals results in a decrease in coal ash
permeability (Jones and Lewis, 1956; Warren and Dudas, 1988; Zevenberg et al., 1999a and
1999b; Bolanz et al., 2012; Fruchter, 1990; Ghuman et al., 1999; Mudd et al., 2004; EPRI, 2009).
Depending on their properties, chemicals that are released or leached to pore water during
mineral alteration can remain in the pore water and/or can be sequestered in the secondary mineral
phases which are immobile. Sequestration in or immobilization onto the mineral phases can be
through absorption, adsorption, ion exchange, and secondary mineral precipitation and co -
precipitation.
The organic carbon content of coal ash, typically measured at the low percent level by
weight, provides a substrate for microbial activity. This activity depletes oxygen, making coal ash
pore water generally reducing or anaerobic. As for pH conditions, fresh coal ash pore water at the
Site is typically alkaline, whereas aged or weathered ash pore water tends to be neutral (reflecting
the mineral alterations and prolonged contact with carbon dioxide from the atmosphere). Ash and
coal materials that are exposed to atmospheric oxygen can become acidified as a side effect of the
oxidation of their sulfidic mineral content.
In the ash basins, the water (i.e., sluiced ash water, rain, storm water) that percolates
through the ash to groundwater has a distinctive chemical fingerprint. The chemical fingerprint
reflects the interaction between water and coal ash materials. Ash pore water is a sodium -calcium -
sulfate aqueous solution, meaning that these compounds dominate the dissolved concentrations.
Boron, chloride, strontium, magnesium, iron, manganese, and potassium are typically present at
part per million level. Aluminum, barium, and arsenic are typically present at the low part per
million or less level. Traces, at the part per billion level, are also typical for antimony, cobalt,
vanadium and molybdenum.
All of the constituents of interest occur in soils, rock, surface water, and groundwater under
background conditions. The background range concentrations can be lower, similar, or higher than
in the ash basins, depending on the compound considered. This is why it is necessary to account
for the background range for evaluating the environmental impacts of the ash basins. For
groundwater background concentrations, data is available from the United States Geological
Survey, the State of North Carolina, and from the samples collected for Site characterization. The
Site is located over metamorphosed bedrock consisting of quartz diorite and tonalite, with meta
quartz diorite, metadiabase, metagranite, and pegmatite.' Together, and in context, these data
' Geologic Map of the Charlotte P x 2° Quadrangle, North Carolina and South Carolina, 1988, R. Goldsmith, D. J.
Milton, and J. W. Horton, Jr., USGS.
P

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
�S
define the background range for the constituents of interest. Background data information for
groundwater is illustrated in Appendix C.
The water that percolates from coal ash basins into subsurface soil and rock materials is
put in contact with different mineral phases that represent the geological materials onto which the
coal ash lies. Water -mineral interactions in the geological materials and mixing with groundwater
result in changes in chemical composition. Boron, because of its properties, remains in the water
phase and tends to transport conservatively (little or no retardation) with groundwater. Other
chemicals that include the constituents of interest, such as iron, manganese, arsenic and other trace
compounds in ash pore water, are not conservative and partition between the mineral and aqueous
(water) phases. Those reactive chemicals are attenuated in the subsurface environment by
immobilization and sequestration through mineral precipitation or co -precipitation and by
retardation through sorption and ion exchange processes. Iron is most important for attenuation in
the subsurface environment, as it is present at relatively high concentrations in ash and geological
materials. Iron minerals and mineral coatings are effective at attenuating (sequestering,
immobilizing, and retarding) other chemicals in groundwater (Dixit and Hering, 2003; Dzombak
and Morel, 1990; Stumm and Morgan, 1996).
Dissolved chemicals are present in groundwater as chemical species. The speciation of a
chemical is primarily controlled by the redox and pH conditions in the subsurface and by
interactions between chemicals in solution. The different chemical species of a given constituent
have different properties. It is therefore important to consider chemical speciation in the evaluation
of transport in the groundwater environment. For the compounds that are elevated in the ash pore
water and the impacted groundwater beneath and downgradient of the ash basins, the chemical
speciation can be derived from the Eh -pH diagrams (Atlas of Eh -pH Diagrams, 2005). Chemical
speciation informs whether a chemical can be reduced or oxidized and if its aqueous solubility is
controlled by mineral phases and/or other attenuating processes (e.g., sorption and ion exchange).
As part of the Site assessment work and studies that were conducted with Site materials,
solid -water partition coefficients (KD) were determined for 10 chemicals (arsenic, boron,
cadmium, chromium, iron, manganese, molybdenum, selenium, thallium, and vanadium). The
chemicals were dissolved in water and interacted with soil materials from the Site. The results
were obtained under controlled laboratory conditions and are not directly applicable to the Site
groundwater conditions; however, the results demonstrate that with the exception of boron, the
chemicals that were tested interact with the Site soil materials. The results demonstrate that
chemical attenuation is an active process at the Site for the tested compounds. Natural attenuation
for boron is dominated by physical attenuation and takes place principally through the
immobilization of the ash pore water and other physical processes that include dilution, diffusion,
and dispersion. Groundwater samples from wells screened within the ash contained elevated
concentrations of constituents of interest, confirming that attenuation is active with concentration
diminishing in the soil and rock materials beneath and downgradient of the ash basins (Appendix
D). These observations of concentrations attenuating away from the ash basins support Duke
Energy's decision to propose using monitored natural attenuation for the restoration of
groundwater as a supplement to the cap -in -place control measures.
The limited chemical interaction between boron and soil materials explains why boron is a
valid tracer for delineating the extent of the ash basin impacts; boron is typically present at low
5

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
�S
concentration in background groundwater (<50 ug/L range) and its presence at high concentration
(-1000 ug/L range) in the ash pore water makes it a simple conservative tracer that can be used to
delineate the extent of groundwater affected by the ash basins and evaluate the effectiveness of
physical attenuation processes that would affect all mobile COI's equally. The results for the other
chemicals tested for chemical interactions support the conclusion that natural attenuation, both
physically and chemically, is active under Site conditions and that natural attenuation can be
considered as a restoration remedy for groundwater after the cap -in -place remedy has been
implemented.
2

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
Section 4
Natural Attenuation in Groundwater
Natural attenuation results from physical, chemical, and biological processes that act alone
or in combination to reduce or decrease the volume of impacted groundwater and compound mass,
concentration, toxicity, and/or mobility in groundwater. The major processes that attenuate mass
or concentrations in groundwater are dilution, dispersion, absorption, adsorption, ion exchange,
precipitation, co -precipitation, complexation to organic substrate, and biomass accumulation. For
conservative compounds such as boron in groundwater, dilution and dispersion dominate
attenuation. For reactive compounds such as iron, manganese, or arsenic, adsorption, precipitation
and co -precipitation processes also attenuate concentrations in addition to dilution and dispersion.
USEPA provides guidance for the implementation of natural attenuation as a remedial
measure for groundwater contamination by inorganic compounds (EPA, Directive 9283.1-36,
August 2015; EPA 600-R-07-139, 2007a; EPA 600-R-07-140, 2007b; EPA 600-R-10-093, 2010;
EPA, Directive 9200.4-17P, April 21, 1999). The USEPA guidance provides objectives for the
performance of monitored natural attenuation:
1) Demonstrate that natural attenuation is occurring according to expectations;
2) Detect changes in environmental conditions (e.g., hydrogeologic, geochemical,
microbiological, or other changes) that may reduce the efficacy of any of the natural
attenuation processes;
3) Identify any potentially toxic and/or mobile transformation products;
4) Verify that the plume(s) is not expanding downgradient, laterally or vertically;
5) Verify no unacceptable impact to downgradient receptors;
6) Detect new releases of contaminants to the environment that could impact the
effectiveness of the natural attenuation remedy;
7) Demonstrate the efficacy of institutional controls that were put in place to protect
potential receptors; and
8) Verify attainment of remediation objectives.
As discussed in Section 8 of this report, the Site data indicate that natural attenuation is
occurring in the groundwater environment. The cap -in -place remedy will decrease the flux of
constituents of concern to groundwater and result in a decrease of the extent of the groundwater
impact. Monitored natural attenuation is therefore a valid remedial option for the restoration of
groundwater for this Site.
Progress toward the restoration of groundwater through natural attenuation will be
monitored once the cap -in -place remedy and additional source control measures, if any are
necessary, have been implemented. The monitoring data and information will be the basis for
selection of the final groundwater remedy for the Site.
7

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
Section 5
Cap -in -Place Remedy
The engineered cap -in -place remedy that Duke Energy plans to construct to cover the ash
basins will have the effect of greatly reducing the infiltration of water and wastewater through the
coal ash. The amount of ash pore water that will recharge to groundwater will be greatly
diminished and the flux of chemicals entrained with infiltration water will also decrease.
The ash materials have a high water retention capacity, meaning that absent recharge by
infiltration water, as under a cap -in -place remedy, the ash pore water is mostly immobile, further
decreasing the flux of constituents of interest from the ash materials to groundwater (Tiruta-Barna
et al. 2006).
Secondary mineral phases will continue to form in the coal ash and in the soil and rock
materials beneath the coal ash basin. The permeability of coal ash materials under the cap is
expected to continue to decrease over time because of accumulation of secondary minerals in the
pore spaces. Groundwater -ash interactions will also decrease because of the lowering of the water
table, exposing less of the ash materials to groundwater. If monitoring of the cap -in -place remedy
indicates that restoration of groundwater is not taking place, additional source control measures
(i.e., drains, pumping, slurry walls) could be implemented to intercept the impacted groundwater
and/or to further depress the water table to further isolate the ash materials.
The geochemical conditions in the capped coal ash will remain generally reducing and
anaerobic from the continuous degradation of the organic substrate in the ash by micro-organisms,
with a pH condition near neutral to alkaline, depending on the age and degree of weathering of the
ash materials.
Under an uncapped condition, atmospheric oxygen is introduced into the ash materials with
infiltration water that contains dissolved oxygen. The atmospheric oxygen is consumed for the
oxidation of the organic substrate that is present in the ash materials. Consumption of oxygen takes
place primarily in the upper portion of the ash materials, as infiltration water progresses toward
the water table, and the effect of atmospheric oxygen is typically limited to the shallow ash. Under
a cap -in -place condition, the upper portion of the ash might possibly become more reducing. If
there was a reduction in atmospheric oxygen because of capping, it would result in more reducing
conditions in the pore water at depth in the ash materials. The geochemical result of more reducing
conditions would be for some increased sulfide activity from the reduction of sulfate to sulfide.
The presence of dissolved sulfide would result in the precipitation of sulfidic or pyritic minerals.
Under such reducing conditions, iron, manganese, and other metals dissolved in the pore water
would be precipitated or co -precipitated out of the pore water and become immobilized in the solid
matrix within the coal ash and beneath. Mineral precipitation and co -precipitation would remove
these constituents of interest from the aqueous phase, reduce their flux to groundwater, and
contribute to the restoration of groundwater.

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Section 6
Excavation and Removal
The excavation and removal of the ash in the ash basins and a portion of the soil materials
beneath the basins was considered by Duke Energy, but determined not to be the preferred remedy
for the Site based on environmental, engineering, social, and economic considerations.
Excavation is typically conducted using specialized machinery to removed materials that
are transported for disposal elsewhere. Excavation of the ash basins would expose subsurface soil
and rock materials to geochemical conditions that are different from the conditions with the ash in
place. A change in geochemical conditions would result in a rearrangement of the mineralogy in
the aquifer, with dissolution and precipitation of secondary mineralogy affecting groundwater
chemistry and redistributing the constituents of interest in the subsurface. The geochemical
disturbance will induce transient changes in the chemistry of groundwater that would only
gradually attenuate, long after the implementation of excavation.
The presence of sulfidic minerals in the soil and rock materials beneath the ash basins
would become oxidized by contact with infiltration water and atmospheric oxygen. Oxidation of
sulfidic minerals (i.e., pyrite) generates acidity, dissolved sulfate, and dissolved metals and
metalloids that are trace compounds of the minerals and are put into solution in the process. The
acidity released to groundwater would dissolve additional metals and metalloids from the soil and
aquifer matrices. The release of acidity to groundwater would decrease natural attenuation in the
aquifer and increase the leaching of natural occurring constituents of interest from native materials.
Excavation would not remove the impacted groundwater beneath and downgradient of the
excavation. The impacted groundwater that is left behind would serve as a long term sources that
could sustain the groundwater impacts after excavation.
Excavation of the large quantities of materials in the ash basins would take time to
implement (i.e., years or decades). During that period of open excavation, precipitation, storm
water, and runoff water would enter the excavation in great quantities and infiltrate to groundwater.
This added infiltration would introduce additional contamination and force impacted groundwater
farther into the aquifer system, therefore increasing the extent of the existing groundwater impacts.
Geochemical processes that control aquifer restoration are typically slow and take time to
effectively achieve restoration goals. This would be true under both the excavation and cap -in -
place remedies.
There are anticipated negative effects with regards to groundwater for the excavation and
removal remedy advocated by Plaintiffs' experts. These effects have to be considered for a
comparative evaluation of the cap -in -place and excavation options.
0

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Section 7
Opinions
Based on my education and experience, and a detailed review of the available data and
information, I have reached the following opinions:
Opinion 1.
The constituents of interest at the Site are naturally occurring upgradient from the Site at
concentrations that are within the background range. Certain constituents of interest are present
under background conditions at concentrations that exceed the 2L Standards, IMAC, or 2B
Standards.
Opinion 2.
The cap -in -place remedy will decrease the flux of constituents of interest from the ash
basins to groundwater. Natural attenuation is and will continue to be active in the groundwater
environment, resulting in a future decrease in the mass and concentration of the constituents of
interest that are dissolved in groundwater. The cap -in -place remedy, supplemented by source
control measures if necessary, and monitored natural attenuation are a reasonable and adequate
remedy for the Site.
Opinion 3.
Excavation of the ash basins is not necessary for Site groundwater restoration.. Excavation
alone cannot achieve the complete removal of the constituents of interest from the subsurface and
provides no substantial benefit over a cap -in -place remedy to restore groundwater.
I hold these opinions with a reasonable degree of scientific certainty. I reserve the right to
modify and supplement these opinions should additional information become available.
10

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Section 8
Bases for Opinions
Opinion 1.
The constituents of interest at the Site are naturally occurring upgradient from the
Site at concentrations that are within the background range. Certain constituents of interest
are present under background conditions at concentrations that exceed the 2L Standards,
IMAC, or 2B Standards.
The constituents of interest identified in the Comprehensive Site Assessment Report for
groundwater are: antimony, arsenic, barium, boron, chromium, hexavalent chromium, cobalt, iron,
manganese, pH, sulfate, total dissolved solids, and vanadium. These compounds and parameters
are naturally occurring in natural soil and rock materials, surface water, and groundwater.
I reviewed the publically accessible USGS data (http://nwis.waterdata.usgs.gov/nwis
wdata) for the occurrence of constituents of interest in groundwater across North Carolina and
compared that information with the data presented in the Comprehensive Site Assessment Report
for the Site. Results are illustrated in Appendix C. The data sets compared include:
• Site background wells;
• Private water wells in the vicinity of the Site; and
• Site monitoring wells.
I also evaluated natural attenuation in groundwater using the available Site data. Results
are illustrated in Appendices D and E.
From this evaluation of the available data I conclude that for the Site:
• Boron is present at high concentration (— 1,000 ug/L) in the ash pore water and impacted
groundwater and at low concentration in groundwater under background condition (i.e.,
not detected or < 50 ug/L). Under the redox and pH conditions encountered in the
groundwater environment, boron is soluble in water and does not appreciably interact with
the solid matrix 2. Boron therefore transports with groundwater with little or no retardation.
Under Site conditions in the groundwater environment, boron can be considered a
conservative tracer for environmental fate and transport at the Site. Boron is attenuated in
groundwater primarily by dilution and dispersion (see Appendix D).
• Sulfate is present over a wide range of concentrations in the ash pore water and
groundwater beneath and downgradient of the ash basins. Sulfate concentration in
background groundwater can vary greatly, but is typically lower than in the impacted
groundwater. Sulfate is redox reactive and its concentration in groundwater can be
controlled by several processes that include mineral precipitation (i.e., barite, pyrite).
Sulfate is attenuated in groundwater primarily by dilution and dispersion. Additional
2 Boron is often detected in septic system effluents, as borates in detergents, soaps, and personal care products can
contribute to the presence of boron in groundwater (EPA, 2008).
11

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
attenuation is provided by processes that can include mineral precipitation (i.e., barite) and
reduction of sulfate to sulfides under strongly reducing conditions.
Iron, manganese, and arsenic are reactive in the groundwater environment and do not
behave conservatively in groundwater, as boron does. Iron, manganese, and arsenic can
occur within a wide range of concentrations in background groundwater (see Appendix Q.
The compounds are present in background soil and rock materials. These compounds are
sensitive to attenuation processes in the groundwater environment. Iron, manganese and
arsenic attenuate in the groundwater environment (see Appendix D). This demonstrates
that these compounds can occur naturally at concentrations that can exceed the standards
and are attenuated at the Site.
• Trivalent chromium and hexavalent chromium form a redox pair, and both chemical
species are present in groundwater under background conditions. When not specified,
chromium refers to the sum of all chromium species in a sample. Hexavalent chromium
can form from trivalent chromium through oxidation under background conditions (Oze,
2007). The reducing conditions that prevail in the ash and impacted groundwater
environments at the Site are not amenable to the formation of hexavalent chromium, and
the amount of hexavalent chromium relative to trivalent chromium is small. Chromium and
hexavalent chromium are present in background groundwater, soil, and rock materials.
Chromium is also present in grout (Hewlett, 1988). There is no groundwater impact for
chromium from the ash basins as the reported detections of chromium are within the
background range.
Antimony, cobalt, and vanadium are present at trace levels that are typically within the
groundwater background range. These compounds are present in soil and rock materials as
well as in ash materials. There is no impact for antimony or vanadium from the ash basins
and the reported trace detections are within the background range. Cobalt concentrations
are discussed further in the well by well discussion below.
The identified constituents of interest at the Site include pH and total dissolved solids. I
reviewed the pH and total dissolved solids data in the context of the available chemical data and
mineralogical information. I conclude that:
The elevated pH occurrences (i.e. pH > 8.5) in monitoring wells that do not have detectable
boron concentrations is most likely a side effect of well construction. For the wells that
show elevated pH values with no detectable boron,' the leakage of grout into the wells'
sand packs is the simplest and most likely explanation for the elevated pH values, since
grout is strongly alkaline (Hewlett, 1988). For the monitoring wells that have detectable
concentration of boron, the occurrence of elevated pH can be explained by either grout
'For example, wells with elevated pH and no detectable boron: GWA-113R, AB-20D, AB-34D, AB-36D, GWA-2D,
AB-2113R, AB-211), AB-3513R, AB-35D, BG-lD, GWA-113, BG-213R, AB-23BRU, AB-24D, AB-2513R, AB-
25BRU, AB-28D, BG-4D, GWA-14D, GWA-21D, GWA-23D, GWA-2413R, GWA-26D, GWA-26S, GWA-61),
GWA-6DA, and AB-14BR
12

2-2- bVbVDObnrO2 9� V22OCIV1E2' JWC'
�S
leakage and/or by the presence of coal ash leachate impacting groundwater.4 Additional
work by Duke Energy is on -going to address well construction issues at the Site.
• There are a wells that report acidic pH values (i.e., pH< 5). These wells have no detectable
boron (<50 ug/L).5 Low pH values can occur under background conditions (see Appendix
D). Acidic values that could be related to Site operations would be associated with runoff
from the coal pile. The presence of pyritic materials in coal can be oxidized by contact with
rain water and generate an acidic leachate (Stumm and Morgan, 1996). For example, the
low pH value at monitoring well GWA-6S, located outside of the ash basins, is likely
related to the adjacent coal pile. This is confirmed by the presence of elevated sulfate and
other constituents of interest in this well. GWA-7S also reported a low pH value, but boron
was not detected in this well. The cause of the low pH value reported for this well is not
yet determined with reasonable certainty, and additional characterization is on -going.
• Both low and high pH values are reported at GWA-14D. The reason behind these large
changes in pH values is unclear, and could reflect well construction or field data quality
issues. The absence of detectable boron in that well indicates that groundwater is not
impacted by the ash basins in that area.
• Total dissolved solids represent the sum of all chemicals that are dissolved in a water
sample. This parameter does not inform as to chemical composition, but can be used to
appreciate the overall dissolved content in water samples. Total dissolved solids can vary
over a large range in background groundwater and exceed the 2L Standard. Total dissolved
solids values are elevated in ash pore water and in the impacted groundwater beneath and
downgradient of the ash basins.
Boron is periodically reported above the background range, but below the 2L Standard, in
monitoring well AB-14D. This occurrence is indicative of a moderate water quality impact from
the ash basins in that area. The presence of boron in this well is likely related to the localized
mounding of the water table near the ash basins. Slight changes in mounding geometry result in
the observed boron concentration fluctuations over time. The fluctuation is indicative of relative
changes in recharge rates between the nearby ash basin area and the uplands outside of the ash
basin. For example, boron concentrations would be expected to increase when the infiltration in
the ash basins is higher relative to the uplands recharge. Conversely, boron concentrations would
decrease when recharge in the uplands is higher relative to the ash basin area. Concentrations of
the constituents of interest other than boron are not distinguishable from the background range and
there is no indication of an impact for these compounds. The cap -in -place remedy will result in
much less infiltration in the ash basin. The periodic detection of boron concentrations in that area
4 For example, wells with elevated pH and detectable boron: AB-21SL, AB-25SL, AB-24SL, AB-235, AB-29SL,
GWA-5BR, GWA-513, AB-2913, GWA-313, AB-26D, GWA-3BR, AB-3113, GWA-5BR, GWA-513, AB-2913,
GWA-313, AB-2613, GWA-3BR, and AB-31D
5 For example, wells with acidic pH and no detectable boron: AB-2, AB-125, AB-14D, and GWA-7S. Boron detection
limit for well GWA-6S ranged between 500 and 2,500 ug/L, and the level of boron in this well is uncertain. There
was no boron data reported for well GWA-14D, in the information reviewed.
13

2-2- bVbVDObnrO2 9� V22OCIV1E2' IMC'
�S J
should decrease in concentration to background concentration. Planned monitoring under the Cap-
in -place remedy will determine whether additional measures will be required for remediation.
Under an excavation remedy, the boron concentration and extent of impact could increase in that
area during the period of excavation, as additional infiltration to groundwater would take place in
the ash basin area. It should also be noted that when boron concentrations decrease, nitrate
concentrations increase at AB-141) (Appendix E). The reverse correlation indicates that nitrate and
elevated boron have different sources. The presence of nitrate or nitrogen compounds and low
levels of boron is consistent with residential fertilizer and septic system use in this area. This
observation supports the conclusion that groundwater at AB-14D reflects the variable influence of
both residential and ash basin waters on the transient composition of groundwater. The cap -in -
place remedy will reduce the recharge from the ash basins and under this condition nitrogen
concentrations will increase whereas boron concentration will decrease. Elevated nitrogen
concentrations (>1,000 ug/L) are reported in several wells in the area (GWA-15S/D, GWA-145,
AB-13S/D, AB-4S, AB-37D, GWA-91), AB-2OD, AB-12D). Boron is not detected (<50 ug/L) in
the monitoring wells. The absence of detectable boron combined with nitrogen from a source that
is not the ash basins is consistent with the conclusion that groundwater flow direction is from west
to east (from the residential area toward the ash basins and the river), and not the reverse.
Groundwater mounding from the ash basins has a limited influence on groundwater quality and
this influence does not extend to the private water supply wells since boron is not detected in those
wells. The cap -in -place remedy will suppress the mounding effect and there is no threat to the
public water supply wells at the Site under this remedy.
Plaintiffs' expert Cosler stated that in his opinion, background wells AB-1R, BG-IS, BG-
1D, BG-2S, BG-2D, and BG-2BR are or might be located downgradient from the ash basins, and
that therefore these wells are not representative of background groundwater quality. Cosler opined
that the inclusion of these wells in the determination of background exaggerates the background
levels. Groundwater in these wells contains no detectable boron, and the chemical fingerprints are
not indicative of an ash basin impact. The chemical fingerprints in these wells are consistent with
background range conditions. There is no geochemical basis to conclude that these wells are
impacted by the ash basins.
Cosler used a one-dimensional analytical chemical transport model to support his opinion
that the constituents of interest will transport with groundwater past the compliance boundary
(located under the Catawba River). Cosler did not provide sufficient documentation and
description of his calculations to allow for an evaluation of his model results. Cosler provided no
information that would demonstrate that his model was calibrated to Site data. Based on the limited
information provided, it appears that Cosler applied his model to boron. Cosler used boron
concentrations for well MW-I IS and well GWA-27D. For both wells, Cosler calculated boron
concentrations at the downgradient compliance boundary that are above the 2L Standard. There
are no groundwater data downgradient from well GWA-27D, and the Cosler results cannot be
verified. For the MW-I IS area, the downgradient compliance boundary is at the river shore line
or close to the shore line. There are four wells (MW-2OD, MW-2ODR, GWA-225, and GWA-
6 Septic system use in the area of AB-14D could contribute boron to groundwater. The detection of boron at low
concentrations in private wells where septic systems are in use, together with elevated nitrate concentrations, are
typically indicative of septic system contributions (EPA, 2008).
14

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
22BRU) located downgradient from the ash basin at the compliance boundary in that area. Boron
never exceeded the 2L Standard in those wells (the available data span the period April 2011 to
April 2016). This fact alone indicates that Cosler's model results are unreliable and invalid.
Cosler provided only an illustration of his model results in the form of a figure for boron
and cobalt and a table that contain his calculated model results. The figure provided gives a false
impression that the model results support Cosler's opinion. First, Cosler calibrated his model using
the results from the Corrective Action Plan transport model which he vehemently criticizes as
being wrong and faulty. If the Corrective Action Plan results and model are wrong and faulty, as
he claims, he should not have used those to calibrate his own model. This calls into questions the
reliability of the conclusions reached by Cosler based on these calculations. Second, for the results
on which he provided some details (boron and cobalt based on data for two wells), Cosler failed
to consider the fact that cobalt concentration is within the background range in the well (GWA-
4S) he used to support his conclusion for groundwater transport. Third, Cosler failed to consider
the fact that boron is not elevated in the well (GWA-5S) he uses to support his opinion on cobalt
transport. Fourth, in order to possibly reach the compliance boundary beneath the river,
groundwater would have to be deep enough in the aquifer next to the river, otherwise shallow
groundwater would discharge to the river since the water table inland is higher than the river stage.
Cosler used chemical data from water table wells located next to the river (GWA-4S and GWA-
5S) for his modeling. The chemistry in those wells is not appropriate since the wells do not
represent the deeper groundwater that could potentially reach the compliance boundary. If Cosler
had used the available chemistry for the deeper wells (i.e., AB-31D, GWA-4D, AB-32D, GWA-
5BR, and GWA-5D), his model calculation would show no exceedances to the standards. Finally,
Cosler's model calculations are not validated by any data. Similar flaws likely render unreliable
Cosler's model results for all constituents that he calculated transport predictions for. Cosler's
model results are therefore not valid, and his opinion that constituents of interest will transport
with groundwater past the compliance boundary under the Catawba River is not supported.
Concentrations in groundwater that exceed a criterion (2L Standard or IMAC), but that are
within the background range, are not indicative of a coal ash impact to groundwater. At the Site, a
coal ash impact to groundwater is indicated by the presence of a geochemical fingerprint that
includes boron, alone or together with other constituents of interest, at concentrations that are
higher than the upper bound of the background range.
Opinion 2.
The cap -in -place remedy will decrease the flux of constituents of interest from the ash
basins to groundwater. Natural attenuation is and will continue to be active in the
groundwater environment, resulting in a future decrease in the mass and concentration of
the constituents of interest that are dissolved in groundwater. The cap -in -place remedy,
supplemented by source control measures if necessary, and monitored natural attenuation
are a reasonable and adequate remedy for the Site.
The cap -in -place remedy proposed by Duke Energy and additional source control measures
that will be implemented, if necessary, will decrease the flux of the constituents of interest from
the ash basins to groundwater. This will be beneficial to Site remediation and groundwater
restoration. The decrease in flux will be accompanied by a reduction of the extent of the
groundwater plume and will allow natural attenuation to proceed at an accelerated rate toward
15

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
�S
restoration. The cap -in -place remedy will therefore represent a net improvement for groundwater
quality beneath and downgradient of the ash basins.
There is no human exposure to the impacted groundwater, and no imminent need for
aggressive remediation beyond the actions that Duke Energy is planning for the Site. The addition
of monitored natural attenuation to the source control measures will provide the means to follow
the progress of groundwater restoration.
The remediation planned by Duke Energy has flexibility built in to address unforeseen
events or to implement additional remediation at the local scale, should such measures be
necessary. For example, the interception of impacted groundwater (i.e., via pump and treat or some
form of hydraulic controls) could be implemented in some portions of the ash basins, to
complement the cap -in -place remedy if the restoration of groundwater does not occur as
anticipated.
The constituents of interest attenuate in the groundwater environment. Boron attenuates
primarily by dilution and dispersion, and other constituents attenuate by dilution and dispersion
and through other processes that include sorption, mineral precipitation, and ion exchange. This is
illustrated in Appendix D.
Plaintiffs' expert Parette has opined that monitored natural attenuation is not an appropriate
remedy for constituents of interest at the Site. Parette apparently based this on statements in the
Comprehensive Site Assessment Report and Corrective Action Plan Part 1 and Part 2 reports that
he took out of context. Duke Energy's proposed remedy for the Site is to implement a cap -in -place
remedy supplemented by source control measures, if necessary, with monitored natural attenuation
for groundwater restoration. The performance of the remedy will be evaluated through monitoring,
and a final groundwater remedy will be selected based on that information. Furthermore, as
discussed in Sections 4 and 5 above, natural attenuation for the constituents of interest is active at
the Site, and will remain active upon implementation of the cap -in -place remedy.
Parette has opined that the utilization of monitored natural attenuation in combination with
a cap -in -place remedy is problematic, as he believes conditions would be less favorable for natural
attenuation following capping. First, less favorable conditions do not imply that natural attenuation
is not taking place or cannot restore groundwater; and less favorable conditions do not negate the
merits of natural attenuation. Second, one main reason given by Parette for this opinion is that
capping of the ash basins would lead to more anoxic conditions in the Site groundwater. The coal
ash pore water and the impacted groundwater are already depleted of dissolved oxygen
(anaerobic). Water that contains atmospheric oxygen and infiltrates into the ash, is readily depleted
of its oxygen which is utilized to oxidize the organic content of the ash materials (the organic
carbon content is reported to be at the percent level, providing an ample supply of organic substrate
to sustain microbial activity in the ash materials). A cap would not change the situation, with the
exception of a shallow zone of ash materials where oxygen from infiltration water is utilized to
degrade the organic substrate in the ash in the absence of a cap. In the impacted groundwater
environment, the conditions are typically reducing and anaerobic, and oxygen does not reach
groundwater by infiltration through the ash. Third, some dissolved oxygen is present in the shallow
groundwater upgradient from the ash basins; that condition will remain after capping. Furthermore,
the available data demonstrate that natural attenuation is active at the Site (see Appendices D and
E), and in the portion of the aquifer that has been impacted by the ash basins, the ratio of upgradient
16

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
�S
groundwater to the water that percolates through the ash will increase under the cap -in -place
remedy. This will increase, not decrease the rate of natural attenuation.
Parette opined that the partition coefficients (KD) obtained from the testing of Site materials
in the laboratory are biased high because the synthetic groundwater used for the tests did not
contain all the chemical species present in Site groundwater. Because of this, Parette appears to
imply that because of this alleged bias, monitored natural attenuation is not appropriate for the
restoration of groundwater. Even if all chemical species present in Site groundwater had been
incorporated in the synthetic groundwater for testing, the main conclusion from the testing would
remain valid. The main conclusion from the testing is that the constituents of interest in
groundwater do interact with the solid matrix, demonstrating the occurrence of attenuation.
Running the tests with all chemical species incorporated in the synthetic groundwater might have
decreased somewhat the experimental KD values; however, this effect would not be a basis to
negate the conclusion that the dissolved constituents of interest interact with the Site solid matrices
that were tested. Boron is the exception, for which the testing showed that attenuation by
interaction with the solid matrix does not contribute substantially to attenuation in the groundwater
environment. Attenuation for boron in groundwater is primary through dilution and dispersion, as
discussed under Section 3 above.
Parette opined that vanadium is not attenuated in Site groundwater and that monitored
natural attenuation is not adequate. Parette remarked that the experimental data reported a decrease
in dissolved vanadium with increasing vanadium concentrations in the solid materials tested.
Based on that, Parette opined that vanadium does not attenuate in groundwater at the Site. The
apparent trend underlined by Parette can only be scientifically evaluated by considering the details
of the experimental procedures. Vanadium, like all constituents of interest, including boron, is
attenuated in groundwater by dilution and dispersion (see Appendix D). Some additional
attenuation by sorption and ion exchange can be expected for vanadium, but is not quantified for
the Site. Vanadium is present in soil, and rock materials at the Site under background conditions,
reflecting the vanadium content of the geological materials (USGS, 2013b).
Parette has opined that natural attenuation is impaired because of the presence of silica,
phosphate, bicarbonate, and dissolved organic carbon, and by the formation of complexes between
chemical species in groundwater. Competition between chemicals and complex formation in
groundwater does not mean that natural attenuation is not active for the constituents of interest at
the Site. The fact that the available data demonstrate that natural attenuation is active at the Site,
as discussed above, indicates that these impairments are not important and do not negate natural
attenuation. Parette's opinion is therefore not a basis to reject the monitored natural attenuation
aspect of the planned remedy for the Site. Parette also opined that the partition coefficients (KD)
obtained from the testing of Site materials in the laboratory are biased high because the synthetic
groundwater used for the tests did not contain all the chemical species present in Site groundwater.
Because of this, Parette appears to imply that monitored natural attenuation is not appropriate for
the restoration of groundwater. Even if all chemical species present in Site groundwater had been
incorporated in the synthetic groundwater for testing, the main conclusion from the testing would
remain valid. The main conclusion from the testing is that the constituents of interest in
groundwater do interact with the solid matrix, demonstrating the occurrence of attenuation. Boron
is the exception, for which testing showed that attenuation by interaction with the solid matrix does
17

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
not contribute substantially to attenuation. Attenuation for boron is primary through dilution and
dispersion, as discussed under Section 3 above.
Parette opined that monitored natural attenuation should not be selected to remedy arsenic
at the Site and that the cap -in -place remedy would likely increase the mobility of arsenic in
groundwater. There are several reasons why the cap -in -place remedy does not negate the use of
natural attenuation for the restoration of groundwater at the Site. Arsenic is amenable to natural
attenuation in the groundwater environment, as discussed above. The reduction of the infiltration
flux through the ash materials relative to the flux of groundwater from upgradient is expected to
increase arsenic attenuation in groundwater, not the reverse. In addition, more reducing conditions
in the ash materials would result in increased sulfide activity leading to the precipitation or co -
precipitation of arsenic with sulfide minerals. This sequestration of arsenic in the ash materials
would further decrease the arsenic flux from the ash to groundwater.
Parette opined that monitored natural attenuation should not be selected to remedy
antimony, boron, chromium, hexavalent chromium, cobalt, and vanadium at the Site. Antimony,
chromium, hexavalent chromium, cobalt and vanadium are within the groundwater background
range and do not require active remediation at the Site. Parette's opinions on these constituents are
therefore irrelevant. The exception is for cobalt in the area of the coal pile, and this occurrence
would not be addressed by either the cap -in -place or excavation remedies.
As for boron in groundwater, the elevated concentrations will decrease under the planned
source control measures because of a reduction in the flux of boron from the capped ash basins
and through attenuation (primarily dilution and dispersion). There is no risk of exposure to unsafe
level of boron at the Site and its vicinity, now, or in the future.
Opinion 3.
Excavation of the ash basins is not necessary for Site groundwater restoration.
Excavation alone cannot achieve the complete removal of the constituents of interest from
the subsurface and provides no substantial benefit over a cap -in -place remedy to restore
groundwater.
The excavation and removal of the ash in the ash basins and a portion of the soil materials
beneath the basins was evaluated by Duke Energy and determined not to be the best remedy for
the Site. Cap -in -place control measures with monitored natural attenuation combined with
additional control measures, if necessary, was selected as a better remedy for the Site. The
determination is based on a technical evaluation of the merits and limitations of these two options.
Excavation and complete removal of ash and shallow soil materials from the ash basins is
the remedy that Plaintiffs' experts advocate for the Site. I disagree with that conclusion for the
following major reasons (see also Sections 5 and 6 above):
• The engineered cap -in -place control measures that Duke Energy plans to construct to cover
the ash basins will have the effect of greatly reducing the infiltration of water and
wastewater through the coal ash. The amount of ash pore water that will recharge to
groundwater will be greatly diminished and the flux of chemicals entrained with infiltration
water will decrease.

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
�S
• Natural attenuation will provide for a gradual restoration of the impacted groundwater
under either the cap -in -place and excavation scenarios. Geochemical processes that control
aquifer restoration will be slow and gradual and will require a long period of time (i.e.,
years or decades) under both the excavation and cap -in -place remedies.
• Excavation would not remove all the ash materials. It is simplistic to assume that
excavation at the scale promoted by Plaintiffs' experts would be able to remove the totality
of the ash at the Site. Ash materials were placed on bare soils for several decades, and some
ash most likely penetrated deeper in the subsurface than can be reached by the excavation
promoted by Plaintiffs' experts.
• Excavation would not remove the impacted groundwater beneath and downgradient of the
excavation. The residual mass of ash materials and the impacted groundwater would serve
as long term sources and sustain the groundwater impacts.
• Excavation will disturb large volumes of coal ash and expose chemically reduced materials
to atmospheric oxygen and water. A change in geochemical conditions would result in a
rearrangement of the mineralogy of the aquifer, with dissolution and precipitation of
secondary mineralogy affecting groundwater chemistry and redistributing the constituents
of interest in the subsurface. The geochemical disturbance would induce transient changes
in the chemistry of groundwater that would only gradually and slowly attenuate long after
the implementation of excavation.
• Excavation of the large quantities of materials in the ash basins would take time to
implement (i.e., years or decades). During that period of open excavation, precipitation,
storm water, and runoff water would enter the excavation in great quantities and infiltrate
to groundwater. This added infiltration would introduce additional contamination and force
impacted groundwater farther into the aquifer system, thereby increasing the extent of the
existing groundwater impacts.
Plaintiffs' expert Bedient advocates excavation and removal, coupled with additional
measures such as hydraulic groundwater containment, to prevent coal ash contaminants from
migrating across the compliance boundary and into the Catawba River for the foreseeable future.
If hydraulic control is necessary to control the migration of contaminants, as argued by Bedient, it
could be implemented without excavation and removal, for example under a cap -in -place source
control. Duke Energy's proposed cap -in -place source control remedy for the Site has the flexibility
to implement additional measures to control contaminant transport, if necessary.
Bedient wrongly assumes that the source of contamination would be entirely removed by
the excavation remedy. The excavation would not remove the impacted groundwater. The
excavation would not remove the mass of contaminants that is stored by sorption and mineral
coatings in the soil, rock and aquifer materials that could not be excavated. The excavation would
also not remove the naturally occurring compounds of concern that are components of the native
soil and rock materials. Furthermore, the excavation would not remove residual ash materials that
could have penetrated into the subsurface beyond the extent of the excavation.
Cosler and Parette advocate excavation and removal because they believe it would result
in a reduction of the clean-up time for groundwater by a factor 2.5 to 5 relative to the cap -in -place
source control remedy. The uncertainty on estimating clean-up rates for groundwater is very large,
19

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
�S
and predictions based on such estimates are highly uncertain and unreliable. The time factor
improvement claimed by Cosler and Parette for clean-up under the excavation scenario fails to
account for the time it would take to excavate the ash basins. Several years would be required to
excavate the ash basins and accounting for this would delay the onset of the groundwater cleanup.
The time factor improvement claimed by Cosler and Parette for clean-up under the excavation
scenario would provide little benefit since there is no imminent risk of exposure to unsafe
contaminant levels at the Site. In addition, the flux of contaminants from the ash basins will
decrease under the cap -in -place remedy (and the additional source control measures that will be
implemented, if necessary), and the extent of contamination will be reduced. Natural attenuation
will provide for gradual groundwater restoration, further reducing the need for aggressive
excavation and removal of the ash basins.
20

APPENDICES

Appendix A
Curriculum Vitae of Remy J.-C Hennet

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist
AREAS OF EXPERTISE
■ Geochemistry, Hydrogeology, Geology
■ Origin, Fate, and Transport of Chemicals
in the Environment
SUMMARY OF QUALIFICATIONS
A geochemist with 25 years of research and professional
experience, Dr. Hennet specializes in evaluating the origin,
fate, and transport of organic and inorganic chemicals in
the environment. Dr. Hennet is often retained as an expert
witness for litigation in providing services to industry, law
firms, and the U.S. Department of Justice. His areas of
expertise include the analysis of geochemical fingerprints,
the evaluation of the timing of chemical releases, allocation
of responsibilities, geochemical modeling, and the
evaluation and application of novel on -site technologies to
solve environmental problems. He is a member of the
American Academy of Forensic Sciences, the American
Chemical Society, and the Association of Groundwater
Scientists and Engineers. He was awarded the Woods
Hole Oceanographic Institution's Postdoctoral Scholarship
in 1987 and has numerous publications in the fields of
inorganic and organic geochemistry.
REPRESENTATIVE EXPERIENCE
S.S. Papadopulos & Associates, Inc., Bethesda,
Maryland
■ Environmental Forensics
■ Litigation Support
U.S. Department of Justice — Served as an expert
witness for several environmental litigation cases.
Examples of this work include: the quantification of the
history of benzene flux from the subsurface to ambient
air following the release of military jet fuel; the
evaluation of multi -source petroleum hydrocarbon
releases and their individual extent; the evaluation of
the impact of bleaching agent when released in a
desert environment; the impact and duration of large
herbicides, and other products); and the origin, fate,
chlorinated solvents at several military bases.
YEARS OF EXPERIENCE: 25+
EDUCATION
PhD - Geochemistry, Princeton
University, 1987
MA -Geology, Princeton University,
1983
Diplome - 3eme Cycle, Hydrogeologie,
Universite de Neuchatel, 1981
Diplome - Geologie, Sciences Exactes,
Universite de Neuchatel, 1980
REGISTRATIONS
Certified Professional Geological
Scientist: No. 10572, American
Institute of Professional Geologists
Licensed Professional Geoscientist:
Texas No. 425
PROFESSIONAL HISTORY
S.S. Papadopulos & Associates, Inc.:
Principal, 1989 to present
Woods Hole Oceanographic
Institution: Postdoctoral Scholar,
1987-1989
Princeton University: Research
Assistant, 1983-1987; Teaching
Assistant, 1982-1985
Universite de Neuchatel: Research
Assistant, 1980-1981
scale pesticide applications (fumigants,
transport, and timing of the release of
Atlantic Richfield Company, Montana —Provided technical support for natural resource damage
litigation and testified as an expert witness. For the Anaconda tailings ponds site, collected data for
a modeling simulation of the fate and transport of dissolved arsenic and cadmium in the alluvium
beneath and down -gradient of the ponds. For the Butte mining district, evaluated the background
condition for metals, arsenic, and sulfur chemical species. For the Montana Pole wood treatment
site, evaluated the mobility of arsenic and pentachlorophenol (PCP) in the groundwater
environment. For the Milltown Reservoir on the Clark Fork River; evaluated the background
conditions and the mobility of metals and arsenic chemical species in sediments accumulated
behind the reservoir.
■ Allocation of Responsibility and Costs (Confidential Clients), Nationwide — Reviewed and
interpreted large volumes of information to support multi -party allocation models.

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 2
• Atlantic Richfield/BP, California, Nevada — Provided a detailed evaluation of the design and
performance of abatement measures at closed sulfur and copper mines. Applied geochemical
fingerprints and performed modeling to evaluate the origin fate and transport of contamination.
■ Rhone Poulenc Corporation, Pennsylvania, California, and New Jersey — Studied arsenic
fixation in soil material by various physicochemical treatments as part of a collaborative effort with
Pennsylvania State University, with a focus on understanding the processes that control the fixation
of arsenic in soils. Advised on the interpretation of data to characterize the mobility of arsenic
chemical species at the Bay Road Site in the San Francisco Bay area, and at the Factory Lane Site
in New Jersey.
■ Panhandle Eastern Pipeline Company — Evaluated and characterized the fate, transport, and
distribution of polychlorinated biphenyls (PCBs) in the subsurface at several sites along a major
pipeline system. Pipeline liquid condensate was discharged to unlined pits located at pumping
stations spread along the system. The condensate contained PCBs from the operational bleeding
of oil from gas pressurization turbines. The disposal of condensate resulted in surface and
subsurface contamination by PCBs and light hydrocarbon compounds. Provided guidance in site
characterization, site remediation, and to the site closure process.
• Envirosafe Services Landfill, Toledo, Ohio —Reviewed detailed organic, inorganic, and isotope
data to evaluate the integrity of a large active landfill complex located in an area characterized by
historical waste disposal activity.
■ Lone Pine Superfund Site, Freehold, New Jersey —Performed data collection and interpretation
to predict chemical composition for the design of a treatment facility.
■ Heleva Superfund Site, Allentown, Pennsylvania —Conducted specialized sampling to assess
trace amount of chlorinated hydrocarbons in acetone -rich groundwater. Acquired isotope and
nutrient data to characterize subsurface conditions for natural attenuation and design of the
treatment plant.
• Love Canal, Niagara Falls, New York, and Stringfellow, Glen Avon, California, Superfund Sites
— Performed detailed data interpretations to assess the validity of expert witness' testimonies
related to the fate, behavior, and migration of toxic chemicals in the subsurface.
■ Tyson Superfund Site, Pennsylvania — Conducted a detailed technical investigation of the
performance of a large vacuum -extraction system consisting of more than 250 individual extraction
wells. The extraction of volatile organic compounds was impeded by subsurface heterogeneities
and the presence of residual non -aqueous phase liquids in the subsurface.
■ Little Mississinewa River Superfund Site, Union City, Indiana, — Several miles of river
sediments were contaminated with waste oil containing elevated PCBs, and PCTs, PAHs, and
metals. The main sources of contamination consisted of two major industrial outflows that
discharged to the river over a period of several decades. Using chromatograms and raw electronic
instrument response data from the analysis of about 200 samples, characterized the chemical
fingerprints of both sources and quantified relative contributions.
■ Coronet Company, Florida —Provided a detailed evaluation of the fate and transport of arsenic,
boron, radium, polonium, and other chemicals in soil, ponds sediment, and groundwater at a former
phosphate mining and fertilizer processing plant. Conducted geochemical modeling.
• White Pine Sash Superfund Site, Missoula, Montana —The release of wood treatment product
containing pentachlorophenol (PCP) in diesel resulted in contamination of the vadose zone above
a major water supply aquifer. Chlorinated-dioxins/furans were also detected in soil samples.
Concurrently with the PCP product release(s), diesel/fuel oil No 2 had been released from
underground storage tanks in the area. Evaluated and delineated the extent of impact of the
diesel/fuel oil No 2 release independently of the PCP -diesel release(s).

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 3
• CSX Transportation, Florida — Evaluated the origin(s) fate and transport of arsenic in the
environment.
• Titan Tire Corporation, Iowa — Evaluated the origin of PCB contamination and conducted a
detailed review of laboratory data packages.
■ Uranium Mine Tailings, New Mexico —Evaluated tailings piles (from the processing of uranium
ore) for water balance, dewatering, contaminant flux to groundwater, the progress of groundwater
plume development, and the effects of remedial measures. Recommended dose reconstruction in
water wells.
■ Citizens about Rushton Rezoning, Inc., South Lyon, Michigan — Analyzed the potential
environmental and hydrogeological impacts of water -treatment lagoons and infiltration spraying
fields. Calculated the fate and transport of nitrogen and phosphorous in the soil and groundwater.
[The lagoons and spraying fields were selected as a wastewater treatment for a large residential
development. The spraying fields were located on sloped glacial till that has limited permeability
and capacity. Regulated surface -water bodies were located adjacent to the spraying fields and
lagoons.]
Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
Studied the organic and inorganic chemistry of the Guaymas Basin hydrothermal system.
Performed detailed trace analyses of metals and petroleum hydrocarbons. The research included
the use of the research submarine Alvin for in -situ parameter measurements and sampling.
Researched and studied the formation of natural petroleum and the effects of organic molecules
degradation and migration on the formation of geopressured zones.
Princeton University, Princeton, New Jersey
As Research Assistant, studied metal -organic interaction in natural settings, and served as Senior
Thesis Advisor for an experimental study of lead -organic complexing and for an experimental study
of trichloroethane in groundwater. Served as Teaching Assistant in Historical Geology and
Geomorphology.
Universite de Neuchatel, Centre d'Hydrologie, Switzerland
Studied tritium in groundwater and performed related laboratory work. Conducted geochemical
fingerprinting in carbonate terrains as applied to the development of water resources.
PROFESSIONAL SOCIETIES
American Academy of Forensic Sciences
American Chemical Society
American Institute of Professional Geologists
Geological Society of America
National Ground Water Association — Association of Ground Water Scientists and Engineers
HONORS & AWARDS
Postdoctoral Scholar, Woods Hole Oceanographic Institution, 1987-1989
Princeton University Fellowship, 1982-1987
Swiss National Science Foundation Fellowship at Princeton University, 1981-1982
Mention Bien, Geologie, Universite de Neuchatel, 1980

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 4
APPOINTMENTS
2002-2005: Geological Sciences Advisory Board, University of Alabama.
1996-2001: Member of Governing Board, Association of Princeton Graduate Alumni.
2000: Convenor, THEIS 2000 Conference: Iron in Groundwater, National Ground Water
Association.
1993-1999: Technical Advisory Board, Xetex Corporation.
1989-1992: Member of Steering Committee, Working Group 91, Scientific Commission for
Oceanic Research.
PUBLICATIONS
Soderberg, K., D.P. McCarthy, and R. J.-C. Hennet, 2015. Volatilization of Polychlorinated Biphenyls:
Implication for their Distribution, Forensics and Toxicity in Urban Environments. Presentation at
the Geological Society of America Annual Meeting, November 1-4, 2015, Baltimore, MD.
Soderberg, K. and R.J.-C. Hennet, 2014. Detection of Pharmaceuticals in the Environment: History
of Use as a Forensic Tool. in Goldstein, W. ed. Pharmaceutical Accumulation the Environment:
Prevention, Control, Health Effects and Economic Impact. CRC Press: Boca Raton, FL. 262 p.
Hennet, R.J.-C, 2010. PCBs in the Interstate Natural Gas Transmission System — Status and
Trends. White Paper prepared for the Interstate Natural Gas Association of America.
Hennet, R.J.-C, 2010. Working with Lawyers: The Expert Witness Perspective. United States
Attorneys' Bulletin, v. 58, no. 1, pp. 14-17.
Soderberg, K., and R.J.-C. Hennet, 2007. Uncertainty and Trend Analysis -- Radium in
Groundwater and Drinking Water. Ground Water Monitoring and Remediation, v. 27, no. 4, pp.
122-127.
Soderberg, K., R. Hennet, and C. Muffels, 2005. Uncertainty and Trend Analysis for Radium in
Groundwater and Drinking Water (abstract). Presentation at the 2005 National Ground Water
Association Conference on Naturally Occurring Contaminants: Arsenic, Radium, Radon, and
Uranium, February 24-25, 2005, Charleston, SC. in Abstract Book, pp. 30-44.
Hennet, R.J.-C, 2002. The Application of Stable Isotope Ratios in Environmental Forensics. in
American Academy of Forensic Sciences Proceedings, pp. 103-104.
Hennet, R.J.-C, 2002. Life is Simply a Particular State of Organized Instability. in Fundamentals of
Life, G. Palyi et al., eds. Paris, France: Elsevier, pp. 109-110.
Hennet, R.J.-C., and L. Chapp, 2001. Using the Chemical Fingerprint of Pharmaceutical
Compounds to Evaluate the Timing and Origin of Releases to the Environment. in Proceedings
of the American Academy of Forensic Sciences, v.4, no. 1, p. 101.
Vlassopoulos, D., C. Andrews, R. Hennet, and S. Macko, 1999. Natural Immobilization of Arsenic in
the Shallow Groundwater of a Tidal Marsh, San Francisco Bay. Presentation at the American
Geophysical Union Spring Meeting, Boston, MA, May 31-June 4, 1999.
Hennet, R.J.-C, D. Carleton, S. Macko, and C. Andrews, 1997. Environmental Applications of
Carbon, Nitrogen, and Sulfur Stable Isotope Data: Case Studies (abstract). Invited speaker at
the Geological Society of America Annual Meeting, Salt Lake City, UT, November.
Jiao, J., C. Zheng, and R. Hennet, 1997. Analysis of Under -pressured Reservoirs for Waste
Disposal. Hydrogeology Journal, v.5, no. 3, pp. 19-31.

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 5
Jiao, J., C. Zheng, and R. Hennet, 1995. Study of the Feasibility of Liquid Waste Disposal in
Underpressured Geological Formations. Proceedings of the American Geophysical Union Spring
Meeting, Baltimore, MD, May 30—June 2, 1995. in Eos Supplement, v. 76, no. 17, S137.
Vlassopoulos, D., P. Lichtner, W. Guo, and R. Hennet, 1995. Long -Term Controls on Attenuation of
Mine -Waste Related Contamination in Alluvial Aquifers: The Role of Aluminosilicate Clay
Minerals. Proceedings of the American Geophysical Union Spring Meeting, Baltimore, MD, May
30-June 2, 1995. in Eos Supplement, v. 76, no. 17, S150.
Feenstra, S., and R. Hennet, 1993. Assessment of Performance Limitations on Soil Vapor
Extraction (SVE) in Variable Soils. The Newsletter of the Association of Ground Water Scientists
and Engineers, v. 9, no. 3, pp. 112-113.
Hennet, R.J.-C., and S. Feenstra, 1993. Assessment of Performance Limitations on Soil Vapor
Extraction (SVE) in Variable Soils (abstract). Presentation at the Symposium on Chlorinated
Volatile Organic Compounds in Ground Water, National Ground Water Association 45th Annual
Convention, Kansas City, MO, October 17-20, 1993. in Ground Water, v. 31, no. 5, pp. 828-829.
Hennet, R.J.-C., and C. Andrews, 1993. PCB Congeners as Tracers for Colloid Transport in the
Subsurface —A Conceptual Approach. in Manipulation of Groundwater Colloids for
Environmental Restoration. Ann Arbor, MI: Lewis Publishers, pp. 241-246.
Hennet, R.J.-C, 1992. Abiotic Synthesis of Amino Acid Under Hydrothermal Conditions and the
Origin of Life: A Perpetual Phenomenon? Invited speaker at the Gordon Research Conference
on Organic Geochemistry, New Hampshire.
Hennet, R.J.-C, N. Holm, and M. Engel, 1992. Abiotic Synthesis of Amino Acid Under Hydrothermal
Conditions and the Origin of Life: A Perpetual Phenomenon? Naturwissenschaften, v. 79,
pp. 361-365.
Hennet, R.J.-C, and N. Holm, 1992. Hydrothermal Systems: Their Varieties, Dynamics, and
Suitability for Prebiotic Chemistry. in Origins of Life and Evolution of the Biosphere, Netherlands,
v. 22, pp. 15-31.
Holm, N., A. Cairns -Smith, R. Daniel, J. Ferris, R. Hennet, E. Shock, B. Simoneit, and H. Yanagawa,
1992. Future Research. in Origins of Life and Evolution of the Biosphere, v. 22, pp. 181-190.
Hunt, J.M., and R. Hennet, 1992. Modeling Petroleum Generation in Sedimentary Basins. in
Productivity, Accumulation, and Preservation of Organic Matter Recent and Ancient Sediments.
J. Whelan and J. Farrington, eds. New York: Columbia University Press, pp. 20-52.
Hunt, J.M., M. Lewan, and R. Hennet, 1991. Modeling Oil Generation with Time -Temperature Index
Graphs Based on the Arrhenius Equation. AAPG Bulletin, v. 75, no. 4, pp. 795-807.
Hennet, R.J.-C, D. Crerar, and J. Schwartz, 1988. The Effect of Carbon Dioxide Partial Pressure on
Metal Transport in Low -Temperature Hydrothermal Systems. Chemical Geology, v. 69, pp. 321-
330.
Hennet, R.J.-C, D. Crerar, and J. Schwartz, 1988. Organic Complexes in Hydrothermal Systems:
Economic Geology, v. 83, pp. 742-767.
Hennet, R.J.-C, and F. Sayles, 1988. Effect of Dissolved Organic Compounds on Trace Metal
Mobility in Low -Temperature Hydrothermal Systems (abstract). Presentation at the Joint
Oceanographic Assembly, Acapulco, Mexico, August 23-31, 1988. in Journal of Arboriculture,
v. 14, Mexico 88, p. 43.

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 6
Hennet, R.J.-C, and J.K. Whelan, 1988. In -Situ Chemical Sensors for Detecting and Exploring
Ocean Floor Hydrothermal Vents. Woods Hole Oceanographic Institution Technical Report
WHOI-88-53, p. 69.
Hennet, R.J.-C, 1987. The Effect of Organic Complexing and Carbon Dioxide Partial Pressure on
Metal Transport in Low -Temperature Hydrothermal Systems. Unpublished PhD thesis,
Department of Geochemistry, Princeton University. 308 p.
Hennet, R.J.-C, D. Crerar, E. Brown, and J. Schwartz, 1986. Transport of Base Metals in
Hydrothermal Brines by Organic and Possible Thiocarbonate Complexes: The Genesis of
Stratiform Sediment -Hosted Lead and Zinc Deposits. Conference Proceedings. in Geological
Science, Stanford University, v. 20, pp. 197-198.
Hennet, R.J.-C, 1985. Partial Pressure of Carbon Dioxide and Base Metal Solubility: A Model for
the Genesis of Hydrothermal Ore Deposits. Poster presentation at the Gordon Research
Conference on Inorganic Geochemistry of Hydrothermal Deposits, New Hampshire.
Hennet, R.J.-C, D. Crerar, and E. Brown, 1985. Base Metal Transport by Organic Complexing in
Ore -Forming Brines (abstract). in Proceedings of the Second International Symposium on
Hydrothermal Reactions. The Pennsylvania State University, p. 43.
Hennet, R.J.-C, D. Crerar, and J. Schwartz, 1985. Metal -Organic Complexes in Ore -Forming
Brines. Presentation at the1901h National Meeting of the American Chemical Society, Division of
Environmental Chemistry, Chicago, IL, September 9, 1985.
Hennet, R.J.-C, 1983. Formation Constants of Lead and Zinc Metal -Organic Complexes Using
Polarography (ASV, DPP), Specific Ion Electrodes (ISE), and Nuclear Magnetic Resonance
Spectroscopy (NMR). Unpublished MA thesis, Princeton University.
Hennet, R.J.-C, D. Crerar, J. Schwartz, and T. Giordano, 1983. New Ligand-Bond Mechanisms for
the Transport of Zinc in the Genesis of Mississippi Valley -Type Ore Deposits. Eos, v. 64, no. 45,
p. 885.
Flury, F.R., R. Hennet, and A. Matthys, 1981. Developpement des resources en eaux de la Ville de
Delemont (Jura, Suisse). Unpublished Diplome d'Hydrogeologie. Centre d'Hydrogeologie.
Universite de Neuchatel, Switzerland.
Hennet, R.J.-C, 1980. Cartographie de la Region Neuchatel-Valangin: Etude de la Mineralogie par
Diffraction-X, de la Stratigraphie et des Microfacies du Valanginien. Discussion de Stratotype de
Valangin. Unpublished Diplome de Geologie. University de Neuchatel, Switzerland.
DEPOSITION AND TESTIMONY EXPERIENCE
DEPOSITIONS
2016 Tri-Realty Company v. Ursinus College. The United States District Court for the Eastern
District of Pennsylvania. Civil Action No. 2:11-cv-05885-GP. April 20.
2015 Duke Energy Progress, Inc. v. N.0 Department of Environment Resources, et al. State of
North Carolina, Wake County in the Office of Administrative Hearings. Case No. 15 HER
02581. July 9.
2014 United States of America v. Richard Middleton, Circle Environmental, Inc., BSJR, LLC, and
WaterPollutionSolutions.com, Inc. The United States District Court for the Middle District of
Georgia Albany Division. Case No. 1:11-cv-00127-WLS. November 3.

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 7
2014 Santa Fe Pacific Gold Corporation vs. United Nuclear Corporation vs. The Travelers
Indemnity Company, et al, State of New Mexico, County of Cibola Eleventh Judicial District.
No. CV-97-13911. February 6.
2013 State of New Mexico ex rel. vs. Kerr-McGee Corporation et al. State of New Mexico, County
of Cibola Thirteenth Judicial District Court. No. CB-83-190-CV & CB-83-220-CV
(Consolidated). April24-26.
2012 Grant Neibaur and Sons Farms, et al vs. The United States of America. U.S. District Court
for the District of Idaho. No. CIV 4:11 -cv-001 59-BLW. September 19.
2012 State of New Mexico ex rel. vs. Kerr-McGee Corporation et al. State of New Mexico, County
of Cibola Thirteenth Judicial District Court. No. CB-83-190-CV & CB-83-220-CV
(Consolidated). September 11-14.
2012 Commissioner of the Department of Planning and Natural Resources, et al. vs Century
Aluminum Company, et al. District Court of the Virgin Islands Division of St. Croix. Civil No.
2005-0062. June 26.
2012 Commissioner of the Department of Planning and Natural Resources, et al. vs Century
Alumina Company, et al. District Court of the Virgin Islands Division of St. Croix. Civil No.
2005-0062. June 25.
2012 ExxonMobil Oil Corporation vs Nicoletti Oil, Inc., et al. U.S. District Court Eastern District of
California. No. 1:09-cv-01498-A WI-DLB. June 14.
2012 United States of America vs Dico Inc. and Titan Corporation. U.S. District Court Southern
District of Iowa. No. 4:10-cv-00503-RP-RAW. January 20.
2011 Joseph A. Pookatas, Donald L.Michel and the Confederated Tribes of the Colville
Reservation and the State of Washington (Plaintiff Intervenor) vs Teck Cominco Metals,
LTD. U.S. District Court Eastern District of Washington at Yakima. CB-04-0256-LRS.
June 10.
2010 United States Virgin Islands Department of Planning and Natural Resources vs. St. Croix
Renaissance Group, L.L.L.P., et al. District Court of the Virgin Islands Division of St. Croix.
Civil No. 2007/114. October 20.
2010 In the Matter of the Application for Water Rights of Leadville Water, JV., in Park County,
Colorado. District Court, Water Division No. 1, State of Colorado. 07CW251. September
22-23.
2009 Timm Adams et al. vs. United States of America et al. U.S. District Court, District of Idaho.
03-0049-E-BLW. January 15.
2008 Pennsauken Solid Waste Management Authority vs. Devoe et al. New Jersey Superior
Court, Camden County, Law Division. No. L-13345-91. October 15.
2007 Arbitration in the Issue of PCB Contamination in the Little Mississinewa River, Union City,
Indiana. Pittsburgh, Pennsylvania. August 22.
2007 San Diego Unified Port District vs. TDY Industries, Inc.; Ryan Aeronautical Company;
Teledyne Ryan Company; Teledyne Ryan Aeronautical Company; Teledyne Industries, Inc;
Allegheny Teledyne, Inc.; Allegheny Technologies, Inc. United States District Court,
Southern District of California. Case Number 03 CV 1146-B (POR). January 5.
2006 Sierra Club, Natural Resources Defense Council, and Natural Parks Conservation
Association vs. Robert B. Flowers, Chief of Engineers, United States Army Corps of

2.2- bV6VD06rlr'02 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 8
Engineers et al. U.S. District Court, Southern District of Florida. Case No. 03-23427-CIV-
Hoeveler. October 31 and November 17.
2003 Linda Akee et al. vs. The Dow Chemical Company et al., Dole Food Company, Inc., Third -
Party Plaintiffs vs. The United States of America, Third -Party Defendant. U.S. District Court
for the District of Hawaii. Civil Action No. CV00-00382 BMK. August 25.
2000 Chevy Chase Bank, FSB, Plaintiff/Counter-Defendant vs. Shell Oil Company and Motiva
Enterprises, LLC, Defendants/Counter-Plaintiffs. U.S. District Court for the District of
Maryland, Southern Division. December 14.
1999 Textron vs. Ashland, Inc. et al. Superior Court of New Jersey.
1999 McMahon vs. The United States of America. U.S. District Court, Southern District of Texas,
Laredo Division. Case No. L-99-009. December 1.
1998 Kay Bettis et al. vs. Ruetgers-Nease Corp. et al. U.S. District Court for the Northern District
of Ohio Eastern Division. Case No. 4:90 CV 0502.
1996 State of Montana vs. Atlantic Richfield Company. U.S. District Court, District of Montana,
Helena Division. Case No. CV-83-317-HLN-PGH.
1996 Kenneth Bowers vs. The United States and Tenco Services, Inc. U.S. District Court for the
District of South Carolina. Case No. 2:95-5568.
1995 Reichhold Chemicals, Inc. vs. Textron Inc. et al. U.S. District Court, Northern District of
Florida. Case No. 92-30393RV.
TESTIMONY
2015 United Nuclear Corporation vs. London Insurance Companies. Eleventh Judicial District
Court. County of McKinley, State of New Mexico. No. D-1 1 13-CV-9700139. January 21 and
22.
2013 United States of America vs Dico Inc. and Titan Corporation. U.S. District Court Southern
District of Iowa. No. 4:10-cv-00503-RP-RAW. December 4.
2009 Timm Adams et al. vs. United States of America and E.I. DuPont de Nemours and
Company, a Delaware corporation. U.S. District Court, District of Idaho. Case No. CIV-03-
0049-E-BLW. August 4, 5, 6.
2008 Attorney General of the State of Oklahoma and Oklahoma Secretary of the Environment vs.
Tyson Foods, Inc., et al. U.S. District Court for the Northern District of Oklahoma. 4:05-CV-
00329-TCK-SAJ. March 7.
2006 Sierra Club, Natural Resources Defense Council, and Natural Parks Conservation
Association vs. Robert B. Flowers, Chief of Engineers, United States Army Corps of
Engineers et al. U.S. District Court, Southern District of Florida. Case No. 03-23427-CIV-
Hoeveler. November 28 and 29.
2004-2005 Universal Waste, Inc. and Clearview Acres, Ltd. Regarding Delisting Petition for Site
Number 0633009. Adjudicatory Hearing by New York Department of Environmental
Conservation, Office of Hearings and Mediation. Site Number 0633009. October 27 and
February 3.
2004 Part 31, City of South Lyon and the Citizens About Rushton Rezoning, Inc., Permit No.: M
00994; and Permit No: GW186300602. State of Michigan, Department of Environmental
Quality, Office of Administrative Hearings, Lansing, MI. May 20, 21, and 27.

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
REMY J.-C. RENNET
Geochemist Page 9
2003 Robert McMahon vs. The United States of America. U.S. District Court, Southern District of
Texas. Case No. L-99-009. February.
2001 Bolinder et al. vs. United States. U.S. District Court, District of Utah. Case No.
2:97CV0912. May.
1998 State of Montana vs. Atlantic Richfield Company. U.S. District Court, District of Montana,
Helena Division. Case No. CV-83-317-HLN-PGH, Natural Resource Damage Claim.
January.
1997 In the matter of the claim of Missoula White Pine Sash Company, Missoula, Montana.
Administrative hearing before the Petroleum Tank Release Compensation Board vs.
Department of Environmental Quality, State of Montana. Claim No. 97-960307-P-00037.
October.
1996 Doria Tartsah Goombi et al. vs. U.S. Department of the Interior. U.S. Department of Interior,
Office of Hearings and Appeals, Hearings Division, Oklahoma City, Oklahoma. Case No.
D95-179 (1-41). August.

Appendix B
Documents Considered and/or Relied Upon

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
1SU
Documents Considered and/or Relied Upon
2015. Allen Instream Monitoring for 2014-2015.
2016. Duke AB Groundwater Data from MANAGES June 22, 2016 Request - All Wells. June 23.
2016. Duke NPDES DMR Data from MANAGES June 22, 2016 Request. June 22.
2016. Duke Seep-AOW Data from MANAGES June 22, 2016 Request. June 23.
Abernethy, R.F., M.J. Peterson, and F.H. Gibson. 1969. Spectrochemical Analyses of Coal Ash for
Trace Elements. Report of Investigations 7281. United States Department of the Interior.
Akinyemi, S.A., A. Akinlua, W.M. Gitari, N. Khuse, P. Eze, R.O. Akinyeye, and L.F. Petrik. 2012.
Natural Weathering in Dry Disposed Ash Dump: Insight from Chemical, Mineralogical
and Geochemical Analysis of Fresh and Unsaturated Drilled Cores: Journal of
Environmental Management 102: 96-107.
Amstaetter, K., T. Borch, P. Larese-Casanova, and A. Kappler. 2010. Redox Transformation of
Arsenic by Fe(II)-Activated Goethite (a-FeOOH): Environmental Science and Technology
44: 102-108.
Bedient, P.B. 2016. Amended Expert Opinion of Philip B. Bedient, Ph.D., P.E. Remediation of
Soil and Groundwater at the Allen Steam Station Operated by Duke Energy Carolinas,
LLC. April 13.
Bedient, P.B. 2016. Expert Opinion of Philip B. Bedient, Ph.D., P.E. Remediation of Soil and
Groundwater at the Allen Steam Station Operated by Duke Energy Carolinas, LLC.
February 29.
Bolanz, R.M., J. Majzlan, L. Jurkovic, and J. G6ttlicher. 2012. Mineralogy, Geochemistry, and
Arsenic Speciation in Coal Combustion Waste from Novaky, Slovakia: Fuel 94: 125-136.
Butler, J.R. 1953. The Geochemistry and Mineralogy of Rock Weathering (1) The Lizard Area,
Cornwall: Geochimica et Cosmochimica Acta 4: 157-178.
Butler, J.R., and D.T. Secor. 1991. Chapter 4 - The Central Piedmont. In The Geology of the
Carolinas: CGS 50th Anniversary Volume. (1st ed.): University of Tennessee Press.
Catalano, J.G., B.L. Huhmann, Y. Luo, E.H. Mitnick, A. Slavney, and D.E. Giammar. 2012. Metal
Release and Speciation Changes during Wet Aging of Coal Fly Ashes: Environmental
Science and Technology 46: 11804-11812.
Choi, S., P.A. O'Day, and J.G. Hering. 2009. Natural Attenuation of Arsenic by Sediment Sorption
and Oxidation: Environmental Science and Technology 43: 4253-4259.
Cosler, D.J. 2016. Amended Expert Opinion of Douglas J. Cosler, Ph.D., P.E. Allen Steam Station
Ash Basins. April 13.
Cosler, D.J. 2016. Expert Opinion of Douglas J. Cosler, Ph.D., P.E. Allen Steam Station Ash
Basins. February 29.
1

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Cosler, D.J. 2016. Videotaped Deposition of Douglas J. Cosler, Ph.D., P.E. State of North
Carolina ex rel. North Carolina Department of Environment and Natural Resources vs.
Catawba Riverkeeper Foundation Inc., Appalachian Voices, Yadkin Riverkeeper,
Mountaintrue, Dan River Basin Association, Roanoke River Basin Association, Southern
Alliance for Clean Energy, and Waterkeeper Alliance. June 1 and 2.
Daniels, J.L., and G.P. Das. 2014. Practical Leachability and Sorption Considerations for Ash
Management: Geo-Congress 2014 Technical Papers: Geo-Characterization and Modeling
for Sustainability: 15.
Delany, J.M., and S.R. Lundeen. 1990. The LLNL Thermochemical Database -- Revised Data and
File Format for the EQ316 Package. Lawrence Livermore National Laboratory. UCID-
21658. March.
Deutsch, W.J. 1997. Chapter 3 - Water/Rock Interactions. In Groundwater Geochemistry -
Fundamentals and Applications to Contamination: Lewis Publishers. 31.
Dicken, C.L., S.W. Nicholson, J.D. Horton, M.P. Foose, and J.A.L. Mueller. 2007. Preliminary
Integrated Geologic Map Databases for the United States - Alabama, Florida, Georgia,
Mississippi, North Carolina, and South Carolina, Version 1.1. Open -File Report 2005-
1323. U.S. Geological Survey. Available at: http://pubs.usgs.gov/of/2005/1323/.
Dixit, S., and J.G. Hering. 2003. Comparison of Arsenic(V) and Arsenic(III) Sorption onto Iron
Oxide Minerals: Implications for Arsenic Mobility: Environmental Science and
Technology 37: 4182-4189.
Duke Energy. Guiding Principles for Ash Basin Closure.
Duke Energy. 2016. Duke Energy Coal Plants and Ash Management. https://www.duke-
energy.com/pdfs/duke-energy-ash-metrics.pdf. June 2.
Duke Energy, M.A. Abney, J.E. Derwort, and J.R. Quinn. 2014. Assessment of Balanced and
Indigenous Populations in Lake Wylie near Allen Steam Station. NC0004979. October.
Dzombak, D.A., and F.M.M. Morel. 1990. Surface Complexation Modeling: Hydrous Ferric
Oxide. New York: John Wiley & Sons.
Electric Power Research Institute (EPRI). 2005. Chemical Constituents in Coal Combustion
Product Leachate: Boron. Technical Report. 1005258. March.
Electric Power Research Institute (EPRI). 2006. Groundwater Remediation of Inorganic
Constituents at Coal Combustion Product Management Sites. Overview of Technologies,
Focusing on Permeable Reactive Barriers. Technical Report. 1012584. October.
Electric Power Research Institute (EPRI). 2009. Coal Ash: Characteristics, Management and
Environmental Issues. Technical Update - Coal Combustion Products - Environmental
Issues. 1019022. September.
Electric Power Research Institute (EPRI). 2010. Comparison of Coal Combustion Products to
Other Common Materials. Chemical Characteristics. 1020556. September.
Fetter, C.W. 1999. Contaminant Hydrogeology (2nd ed.): Prentice Hall, Inc.
Freeze, R.A., and J.A. Cherry. 1979. Groundwater. Englewood Cliffs, NJ: Prentice -Hall, Inc.
2

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Fruchter, J.S., D. Ral, and J.M. Zachara. 1990. Identification of Solubility -Controlling Solid
Phases in a Large Fly Ash Field Lysimeter: Environmental Science and Technology 24:
1173-1179.
Ghuman, G.S., K.S. Sajwan, and M.E. Denham. 1999. Impact of Coal Pile Leachate and Fly Ash
on Soil and Groundwater. In Biogeochemistry of Trace Elements in Coal and Coal
Combustion Byproducts. Sajwan, K.S., Alva, A.K., and Keefer, R.F. eds. New York:
Kluwer Academic/Plenum Publishers. 235-246.
Haley & Aldrich. 2016. Report on Evaluation of Water Supply Wells in the Vicinity of Duke
Energy Coal Ash Basins in North Carolina. April.
Hall, G.E.M., J.E. Vaive, R. Beer, and M. Hoashi. 1996. Selective Leaches Revisited, with
Emphasis on the Amorphous Fe Oxyhydroxide Phase Extraction: Journal of Geochemical
Exploration 56: 59-78.
Harte, P.T., J.D. Ayotte, A. Hoffman, K.M. Revesz, M. Belaval, S. Lamb, and J.K. Bohlke. 2012.
Heterogeneous Redox Conditions, Arsenic Mobility, and Groundwater Flow in a
Fractured -Rock Aquifer near a Waste Repository Site in New Hampshire, USA:
Hydrogeology Journal 20: 1189-1201.
Hasany, S.M., and M.A. Qureshi. 1981. Adsorption Studies of Cobalt(II) on Manganese Dioxide
from Aqueous Solutions: International Journal of Applied Radiation and Isotopes 32: 747-
52.
HDR Engineering Inc of the Carolinas. 2015. Comprehensive Site Assessment Report. Allen
Steam Station Ash Basin. August 23.
HDR Engineering Inc of the Carolinas. 2015. Corrective Action Plan Part 1. Allen Steam Station
Ash Basin. November 20.
HDR Engineering Inc of the Carolinas. 2016. Corrective Action Plan Part 2. Allen Steam Station
Ash Basin. February 19.
He, Y.T., A.G. Fitzmaurice, A. Bilgin, S. Choi, P.A. O'Day, J. Horst, J. Harrington, H.J. Reisinger,
D.R. Burris, and J.G. Hering. 2010. Geochemical Processes Controlling Arsenic Mobility
in Groundwater: A Case Study of Arsenic Mobilization and Natural Attenuation: Applied
Geochemistry 25: 69-80.
Hewlett, P.C. 1988. Lea's Chemistry of Cement and Concrete (4th ed.): Elsevier Butterworth -
Heinemann.
Holm, T.R. 2002. Effects of C032-/bicarbonate, Si, and P043- on Arsenic Sorption to HFO:
American Water Works Association 94, no. 4: 174-181.
Horton, J.W., and V.A. Zullo. 1991. The Geology of the Carolinas: CGS 50th Anniversary Volume
(1st ed.): University of Tennessee Press.
Interstate Technology Regulatory Council (ITRC). 2010. Technical/Regulatory Guidance: A
Decision Framework for Applying Monitored Natural Attenuation Processes to Metals and
Radionuclides in Groundwater. December.
3

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Jones, G.W., and T. Pichler. 2007. Relationship between Pyrite Stability and Arsenic Mobility
during Aquifer Storage and Recovery in Southwest Central Florida: Environmental Science
and Technology 41: 723-730.
Jones, L.H., and A.V. Lewis. 1956. Weathering of Fly Ash: Nature 185, no. 4710: 404-405.
Karamalidis, A.K., and D.A. Dzombak. 2010. Surface Complexation Modeling: Gibbsite: John
Wiley & Sons, Inc.
Keon, N.E., C.H. Swartz, D.J. Brabander, C. Harvey, and H.F. Hemond. 2001. Validation of an
Arsenic Sequential Extraction Method for Evaluating Mobility in Sediments:
Environmental Science and Technology 35: 2778-2784.
Kim, K., S.-H. Kim, S.-M. Park, J. Kim, and M. Choi. 2010. Processes Controlling the Variations
of pH, Alkalinity, and CO2 Partial Pressure in the Porewater of Coal Ash Disposal Site:
Journal of Hazardous Materials 181: 74-81.
L.Tiruta-Barna, Z. Rakotoarisoa, and J. M6hu. 2006. Assessment of the Multi -Scale Leaching
Behaviour of Compacted Coal Fly Ash: Journal of Hazardous Materials B 137: 1466-1478.
Lee, S.-Z., H.E. Allen, C.P. Huang, D.L. Sparks, P.F. Sanders, and W.J.G.M. Peijnenburg. 1996.
Predicting Soil - Water Partition Coefficients for Cadmium: Environmental Science and
Technology 30: 3418-3424.
LeGrand, H.E. 1988. Region 21, Piedmont and Blue Ridge. In The Geology of North America.
Black, W.B., Rosenshein, J.S., and Seaber, P.R. eds. Vol. 0-2: Geological Society of
America. 201-207.
Lengke, M.F., C. Sanpawanitchakit, and R.N. Tempel. 2009. The Oxidation and Dissolution of
Arsenic -Bearing Sulfides: The Canadian Mineralogist 47: 593-613.
Lengke, M.F., and R.N. Tempel. 2003. Natural Realgar and Amorphous AsS Oxidation Kinetics:
Geochimica et Cosmochimica Acta 67, no. 5: 859-871.
Liu, G., H. Zhang, L. Gao, L. Zheng, and Z. Peng. 2004. Petrological and Mineralogical
Characterizations and Chemical Composition of Coal Ashes from Power Plants in Yanzhou
Mining District, China: Fuel Processing Technology 85: 1635-1646.
Masscheleyn, P.H., R.D. Delaune, and W.H. Patrick. 1991. Heavy Metals in the Environment.
Arsenic and Selenium Chemistry as Affected by Sediments Redox Potential and pH:
Journal of Environmental Quality 20: 522-527.
Meng, X., S. Bang, and G.P. Korfiatis. 2000. Effects of Silicate, Sulfate, and Carbonate on Arsenic
Removal by Ferric Chloride: Water Resources 34, no. 4: 1255-1261.
Meng, X., G.P. Korfiatis, S. Bang, and K.W. Bang. 2002. Combined Effects of Anions on Arsenic
Removal by Iron Hydroxides: Toxicology Letters 133: 103-111.
Miller, G.P. 2011. Monitored Natural Attenuation: A Remediation Strategy for Groundwater
Impacted by Coal Combustion Product Leachate. World of Coal Ash (WOCA)
Conference, Denver, CO, May 9-12. 14.
Mineralogical Society of America. 1983. Carbonates: Mineralogy and Chemistry. Reviews in
Mineralogy. Vol. 11.
E

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Mineralogical Society of America. 1990. Mineral -Water Interface Geochemistry. Reviews in
Mineralogy. Vol. 23.
Mudd, G.M., T.R. Weaver, and J. Kodikara. 2004. Environmental Geochemistry of Leachate from
Leached Brown Coal Ash: Journal of Environmental Engineering 130, no. 12: 1514-1526.
Mudd, G.M., T.R. Weaver, J. Kodikara, and T. McKinley. 1998. Groundwater Chemistry of the
Latrobe Valley Influences by Coal Ash Disposal - 1: Dissimilatory Sulphate Reduction and
Acid Buffering. International Association of Hydrogeologists Conference: Groundwater -
Sustainable Solutions, Melbourne, VIC, February. 12.
National Institute of Advanced Industrial Science and Technology. 2005. Atlas of Eh pH
Diagrams. Intercomparison of Thermodynamic Databases. Open File Report No. 419.
Geological Survey of Japan. May.
North Carolina Department of Environment and Natural Resources. 2013. North Carolina
Administrative Code. Title 15A. Subchapter 2L Section .0100, .0200, .0300.
Classifications and Water Quality Standards Applicable to the Groundwaters of North
Carolina. April 1.
North Carolina Department of Environmental Quality. 2016. Well Test Information for Residents
near Duke Energy Coal Ash Impoundments. Summary and Table.
https:Hdeq.nc.gov/about/divisions/water-resources/water-resources-hot-topics/dwr-coal-
ash-regulation/well-test-information-for-residents-near-duke-energy-coal-ash-
impoundments.
North Carolina Department of the Environmental and Natural Resources. 2013. 15A NCAC 02L
.0202 Groundwater Rules. Groundwater Standards Table. April 1.
North Carolina Department of the Environmental and Natural Resources. 2013. 15A NCAC 02L
.0202 Groundwater Rules. Interim Maximum Allowable Concentrations (IMACs) Table.
April 1.
North Carolina Department of the Environmental and Natural Resources. 2016. 15A NCAC 02B
Surface Water Standards and Protective Values & EPA Nationally Recommended Water
Quality Criteria. March.
North Carolina Department of the Environmental and Natural Resources. 2016. Coal Combustion
Residual Impoundment Risk Classifications. January.
North Carolina Department of the Environmental and Natural Resources. 2016. Environmental
Review Commission. Report on the Status of Assessment, Corrective Action, Prioritization,
and Closure for Each Coal Combustion Residuals Surface Impoundment as Required by
the Coal Ash Management Act. January 13.
North Carolina Department of the Environmental and Natural Resources. 2016. Proposed
Classification Chart. May 18.
North Carolina Department of the Environmental and Natural Resources. 2016. Proposed
Classifications. May 18.
Oze, C., D.K. Bird, and S. Fendori 2007. Genesis of Hexavalent Chromium from Natural Sources
in Soil and Groundwater: PNAS 104, no. 16: 6544-6549.
5

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Parette, R. 2016. Opinions on the Appropriateness of Monitored Natural Attenuation in
Conjunction with Cap -in -Place at the Allen Steam Station. May 13.
Poulton, S.W., and D.E. Canfield. 2005. Development of a Sequential Extraction Procedure for
Iron: Implications for Iron Partitioning in Continentally Derived Particulates: Chemical
Geology 214: 209-221.
Reisinger, H.J., D.R. Burris, and J.G. Hering. 2005. Remediating Subsurface Arsenic
Contamination with Monitored Natural Attenuation: Environmental Science and
Technology 39: 458A-464A.
Rightnour, T.A., and K.L. Hoover. 1998. The Springdale Project: Applying Constructed Wetland
Treatment to Coal Combustion By -Product Leachate. Electric Power Research Institute
(EPRI). TR-111473. November.
Schwartz, G.E., N. Rivera, S.-W. Lee, J.M. Harrington, J.C. Hower, K.E. Levine, A. Vengosh, and
H. Hsu -Kim. 2016. Leaching Potential and Redox Transformations of Arsenic and
Selenium in Sediment Microcosms with Fly Ash: Applied Geochemistry 67: 177-185.
Schwarzenbach, R.P., P.M. Gschwent, and D.M. Imboden. 1993. Environmental Organic
Chemistry: John Wiley & Sons, Inc.
Smedley, P.L., and D.G. Kinniburgh. 2002. A Review of the Source, Behaviour and Distribution
of Arsenic in Natural Waters: Applied Geochemistry 17: 517-568.
Stefaniak, S., E. Miszczak, J. Szczepanska-Plewa, and I. Twardowska. 2015. Effect of Weathering
Transformations of Coal Combustion Residuals on Trace Element Mobility in View of the
Environmental Safety and Sustainability of their Disposal and Use. I. Hydrogeochemical
Processes Controlling pH and Phase Stability: Journal of Environmental Management 156:
128-142.
Stumm, W. 1992. Chemistry of the Solid -Water Interface. Processes at the Mineral -Water and
Particle -Water Interface in Natural Systems. New York: John Wiley & Sons.
Stumm, W., and J.J. Morgan. 1996. Aquatic Chemistry, Chemical Equilibria and Rates in Natural
Waters (3rd ed.): John Wiley & Sons, Inc.
Swedlund, P.J., and J.G. Webster. 1999. Adsorption and Polymerisation of Silicic Acid on
Ferrihydrite, and its Effect on Arsenic Adsorption: Water Resources 33, no. 16: 3413-3422.
Taylor, H.F.W. 1997. Cement Chemistry (2nd ed.): Thomas Telford.
Tessier, A., P.G.C. Campbell, and M. Bisson. 1979. Sequential Extraction Procedure for the
Speciation of Particulate Trace Metals: Analytical Chemistry 51, no. 7: 844-851.
Thomas, M. 2007. Optimization the Use of Fly Ash in Concrete: 24.
U.S. Environmental Protection Agency (USEPA). 1989. Sampling Frequency for Ground -Water
Quality Monitoring. EPA 600-S4-89-032. September.
U.S. Environmental Protection Agency (USEPA). 1992. Technical Resource Document. Batch -
Type Procedures for Estimating Soil Adsorption of Chemicals. EPA 530-SW-87-006-F.
April.
2

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
U.S. Environmental Protection Agency (USEPA). 1994. Method 1312. Synthetic Precipitation
Leaching Procedure. EPA SW-846 (Ch. 6).
U.S. Environmental Protection Agency (USEPA). 1999a. Understanding Variation in Partition
Coefficient, Ka, Values. Volume I: The Kd Model, Methods of Measurement, and
Application of Chemical Reaction Codes. EPA 402-R-99-004A. August.
U.S. Environmental Protection Agency (USEPA). 1999b. Understanding Variation in Partition
Coefficient, Kd, Values. Volume II: Review of Geochemistry and Available Kd Values for
Cadmium, Cesium, Chromium, Lead, Plutonium, Radon, Strontium, Thorium, Tritium (H),
and Uranium. E 402-R-99-004B. August.
U.S. Environmental Protection Agency (USEPA). 2006. Design Manual Removal of Arsenic from
Drinking Water Supplies by Iron Removal Process. EPA 600-R-06-030. April.
U.S. Environmental Protection Agency (USEPA). 2007a. Monitored Natural Attenuation of
Inorganic Contaminants in Ground Water. Volume I - Technical Basis for Assessment.
EPA 600-R-07-139. Washington, D.C. October.
U.S. Environmental Protection Agency (USEPA). 2007b. Monitored Natural Attenuation of
Inorganic Contaminants in Ground Water. Volume II - Assessment for Non -Radionuclides
Including Arsenic, Cadmium, Chromium, Copper, Lead, Nickel, Nitrate, Perchlorate, and
Selenium. EPA 600-R-07-140. Washington, D.C. October.
U.S. Environmental Protection Agency (USEPA). 2008. Chapter 3: Boron. In Regulatory
Determinations Support Document for Selected Contaminants from the Second Drinking
Water Contaminant Candidate List (CCL 2). EPA Report 815-R-08-012.27.
U.S. Environmental Protection Agency (USEPA). 2009. Statistical Analysis of Groundwater
Monitoring Data at RCRA Facilities Unified Guidance. EPA 530-R-09-007. March.
U.S. Environmental Protection Agency (USEPA). 2010. Monitored Natural Attenuation of
Inorganic Contaminants in Ground Water. Volume III - Assessment for Radionuclides
Including Tritium, Radon, Strontium, Technetium, Uranium, Iodine, Radium, Thorium,
Cesium, and Plutonium -Americium. EPA 600-R-10-093. Washington, D.C. September.
U.S. Environmental Protection Agency (USEPA). 2012. A Citizen's Guide to Monitored Natural
Attenuation. EPA 542-F-12-014. Washington, D.C. September.
U.S. Environmental Protection Agency (USEPA). 2015. Hazardous and Solid Waste Management
Systems: Disposal of Coal Combustion Residuals from Electric Utilities. Federal Register.
Vol. 80 No. 74. April 17.
U.S. Environmental Protection Agency (USEPA). 2015. Use of Monitored Natural Attenuation
for Inorganic Contaminants in Groundwater at Superfund Sites. Directive 9283.1-36.
August.
U.S. Environmental Protection Agency (USEPA). 2016. Coal Ash Basics.
https://www.epa.gov/coalash/coal-ash-basics.
U.S. Geological Survey (USGS). 1963. Data of Geochemistry, Sixth Edition. Chapter F. Chemical
Composition of Subsurface Waters. Geological Survey Professional Paper 440-F.
7

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
U.S. Geological Survey (USGS). 1973. United States Mineral Resources. Geological Survey
Professional Paper 820.
U.S. Geological Survey (USGS). 1976. Numerical Simulation Analysis of the Interaction of Lakes
and Ground Water. Professional Paper 1001.
U.S. Geological Survey (USGS). 1980. Basic Elements of Ground -Water Hydrology With
Reference to Conditions in North Carolina. Water -Resources Investigations Open -File
Report. 80-44.
U.S. Geological Survey (USGS). 1988. Geologic Map of the Charlotte I degree x 2 degrees
Quadrangle, North Carolina and South Carolina. Miscellaneous Investigations Series.
MAP I-1251-E.
U.S. Geological Survey (USGS). 1992. Trace Elements and Radon in Groundwater Across the
United States, 1992-2003. Scientific Investigations Report 2011-5059.
U.S. Geological Survey (USGS). 1997. Ground Water Atlas of the United States, Segment 11 --
Delaware, Maryland, New Jersey, North Carolina, Pennsylvania, Virginia, West Virginia.
Hydrologic Investigations Atlas 730-L.
U.S. Geological Survey (USGS). 1997. Water Quality in the Appalachian Valley and Ridge, The
Blue Ridge, and the Piedmont Physiographic Provinces, Eastern United States. 1422-D.
U.S. Geological Survey (USGS). 2001. Geochemical Landscapes of the Conterminous United
States -- New Map Presentations for 22 Elements. Professional Paper. 1648.
U.S. Geological Survey (USGS). 2002. Preliminary Hydrogeologic Assessment and Study Plan
for a Regional Ground -Water Resource Investigation of the Blue Ridge and Piedmont
Provinces of North Carolina. Water -Resources Investigations Report 02-4105.
U.S. Geological Survey (USGS). 2009. Characterization of Groundwater Quality Based on
Regional Geologic Setting in the Piedmont and Blue Ridge Physiographic Provinces,
North Carolina. Scientific Investigations Report. 2009-5149.
U.S. Geological Survey (USGS). 2013a. Description of Input and Examples for PHREEQC
Version 3 - A Computer Program for Speciation, Batch -Reaction, One -Dimensional
Transport, and Inverse Geochemical Calculations. Techniques and Methods. 6-A43.
U.S. Geological Survey (USGS). 2013b. 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 2013-
5072.
U.S. Geological Survey (USGS). 2014. Geochemical and Mineralogical Maps for Soils of the
Conterminous United States. Open -File Report 2014-1082.
VanDerHoek, E.E., and R.N.J. Comans. 1996. Modeling Arsenic and Selenium Leaching from
Acidic Fly Ash by Sorption on Iron (Hydr) oxide in the Fly Ash Matrix: Environmental
Science and Technology 30: 517-523.
Wallis, I., H. Prommer, T. Pichler, V. Post, S.B. Norton, M.D. Annable, and C.T. Simmons. 2011.
Process -Based Reactive Transport Model to Quantify Arsenic Mobility during Aquifer

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Storage and Recovery of Potable Water: Environmental Science and Technology 45: 6924-
6931.
Wang, S., and C.N. Mulligan. 2006. Review: Natural Attenuation Processes for Remediation of
Arsenic Contaminated Soils and Groundwater: Journal of Hazardous Materials B138:
459-470.
Warren, C.J., and M.J. Dudas. 1988. Leaching Behaviour of Selected Trace Elements in
Chemically Weathered Alkaline Fly Ash: The Science of the Total Environment 76: 229-
246.
Wenzel, W.W., N. Kirchbaumer, T. Prohaska, G. Stingeder, E. Lombi, and D.C. Adriano. 2001.
Arsenic Fractionation in Soils Using an Improved Sequential Extraction Procedure:
Analytica Chimica Acta 436: 309-323.
Williamson, M.A., and J.D. Rimstidt. 1994. The Kinetics and Electrochemical Rate -Determining
Step of Aqueous Pyrite Oxidation: Geochimica et Cosmochimica Acta 58, no. 24: 5443-
5454.
Wright, M.T., and K. Belitz. 2010. Factors Controlling the Regional Distribution of Vanadium in
Groundwater: Ground Water 47, no. 4: 515-525.
Zevenbergen, C., J.P. Bradley, L.P. VanReeuwijk, and A.K. Shyam. 1999a. Clay Formation
During Weathering of Alkaline Coal Fly Ash: International Ash Utilization Symposium,
Center for Applied Energy Research, University of Kentucky Paper #14: 8.
Zevenbergen, C., J.P. Bradley, L.P. VanReeuwijk, A.K. Shyam, O. Hjelmar, and R.N.J. Comans.
1999b. Clay Formation and Metal Fixation during Weathering of Coal Fly Ash:
Environmental Science and Technology 33: 3405-3409.
Zevenbergen, C., L.P. VanReeuwijk, J.P. Bradley, P. Bloemen, and R.N.J. Comans. 1996.
Mechanism and Conditions of Clay Formation During Natural Weathering of MSWI
Bottom Ash: Clays and Clay Minerals 44, no. 4: 546-552.
0

Appendix C
Background Concentration Ranges - USGS,
Site Data, and Private Wells

2.2- bV6VD06nr oe 8F b220CIVIE2' INC'
Appendix C Explanation Sheet
Background concentration cumulative distribution plots were created for the following analytes:
• Boron
• Chromium
• Sulfate
• Antimony
• Arsenic
• Vanadium
• Iron
• Cobalt
• Manganese
• pH
• Barium
• Total Dissolved Solids
The cumulative distribution plots illustrate the differences in the range of concentrations sampled from
different locations. Locations (site background wells, private wells, and USGS wells) can be compared by
the relationships between their sample concentrations at different percentiles.
Data Sources
The site background data was obtained from the from the Duke Energy MANAGES environmental
database, queried on 6/23/2016 by Tim Hunsucker.
USGS well dataset was obtained from the USGS National Water Information System' (NWIS). The NWIS
was queried on 6/10/2016 for all groundwater data from North Carolina wells for the analytes listed
above. The NWIS query results did not contain data for total boron or total vanadium.
The private well data was obtained from the NC DEQ websitez from the document "Full Well Water
Testing Results For Posting 8.2031,. Estimated values (J qualifier) were omitted from the analysis for the
private well data.
Data Handling
The following site wells were considered background wells for the calculations:
• AB-111
•
BG-3S
• GWA-17S
• BG-1D
•
BG-4BR
• GWA-19D
• BG-1S
•
BG-4D
• GWA-19S
• BG-2BR
•
BG-4S
• GWA-21D
• BG-2D
•
GWA-16D
• GWA-21S
• BG-2S
•
GWA-16S
• BG-3D
•
GWA-17D
All non -detects samples in the site background and private wells datasets were set to one half their
detection limit.
1 http://nwis.waterdata.usgs.gov/nwis/qwdata
z https://deg.nc.gov
3 https://ncdenr.s3.amazonaws.com/s3fs-public/document-
Iibra ry/Full%20WeII%20Water%20Testing%20Results%20For%2OPosting%208.20.pdf

2.2- bV6VD06nr'o2 8F b220CIVIE2' INC'
The USGS dataset sample values were averaged by well after sAMlues to one half their detection
limit, in an effort to try to avoid unnecessary spatial bias in sites sampled more frequently. Sites where
all the values in the average calculation were non -detects were considered non -detects for plotting
purposes.
For percentile calculations and plotting, all non -detect values for a given analyte were set to the lowest
non -detect value in that dataset. This ensured non -detect samples would be the top (highest) ranks for
the percentile calculation. This was necessary because they cannot be assumed to be greater than any
detected value.

100%
90%
80%
70%
60%
c
50%
L
40%
30%
20%
10%
0%
Site Background Wells/Private Wells for Allen - Boron (Unfiltered)
Site Background Wells Boron pg/L n = 83
Private Wells Boron pg/L n = 105
Site Background Wells Non -detect
Private Wells Non -detect
NC 2L Standard, 700 fag/L
f
I=
10
Concentration pg/L
100
1000

Site Background Wells/USGS Wells/Private Wells for Allen - Sulfate (Unfiltered)
• Site Background Wells Sulfate mg/L n = 83
• USGS Wells Sulfate, Averaged by Location mg/L n =60
Private Wells Sulfate mg/L n = 121
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
100%
90%
80%
70%
60%
a�
50%
40%
30%
20%
10%
0%
0.01 0.10
NG 2L Standard, 25U
1.00
10.00
Concentration mg/L
•
100.00 1000.00

100%
90 %
80 %
70%
60%
a�
40%
30
20%
10%
0%
0.01
Site Background Wells/USGS Wells/Private Wells for Allen - Arsenic (Unfiltered)
• Site Background Wells Arsenic pg/L n = 83
• USGS Wells Arsenic, Averaged by Location pg/L n =122
Private Wells Arsenic pg/L n = 110
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
0.10
NG 1L Standard, 10
1.00
10.00
Concentration pg/L
100.00 1000.00

100%
90%
80%
70%
60%
a�
c
50%
^L♦
^W
I..L
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Allen - Iron (Unfiltered)
• Site Background Wells Iron pg/L n = 83
• USGS Wells Iron, Averaged by Location pg/L n =2221
Private Wells Iron pg/L n = 115
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NC 2L Standard, 300 p/L
® MM • ••
•• • •
0.1 1.0 10.0 100.0 1000.0
Concentration pg/L
10000.0 100000.0 1000000.0

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Allen - Manganese (Unfiltered)
• Site Background Wells Manganese fag/L n = 83
• USGS Wells Manganese, Averaged by Location pg/L n =813
Private Wells Manganese pg/L n = 100
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
INU « bianaara, au
F •i
0.01 0.10 1.00 10.00 100.00
Concentration pg/L
•• • •
_ _'dmo • 400046000010
'
1000.00 10000.00 100000.00

100%
90 %
80%
70 %
60%
a�
40%
30%
20%
10%
0%
1
Site Background Wells/USGS Wells/Private Wells for Allen - Barium (Unfiltered)
• Site Background Wells Barium fag/L n = 83
• USGS Wells Barium, Averaged by Location pg/L n =77
Private Wells Barium pg/L n = 125
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
10
NU 2L Standard, NU
100
Concentration pg/L
1000
10000

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Allen - Chromium (Unfiltered)
• Site Background Wells Chromium pg/L n = 83
• USGS Wells Chromium, Averaged by Location pg/L n =124
Private Wells Chromium pg/L n = 113
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NU 1L Standard, 10
0.01 0.10 1.00 10.00
Concentration pg/L
100.00 1000.00

100%
90%
80%
70%
60%
c
50%
L
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Allen - Antimony (Unfiltered)
Site Background Wells Antimony pg/L n = 83
USGS Wells Antimony, Averaged by Location fag/L n =61
Private Wells Antimony fag/L n = 100
Site Background Wells Non —detect
USGS Wells Non —detect
Private Wells Non —detect
iNU nwHU 5tanaara, -i
0.01 0.10 1.00 10.00 100.00
Concentration pg/L

100%
90%
80%
70%
60%
a�
50%
a
40%
30%
20%
10%
0%
0.1
Site Background Wells/Private Wells for Allen - Vanadium (Unfiltered)
• Site Background Wells Vanadium pg/L n = 70
Private Wells Vanadium pg/L n = 117
Site Background Wells Non -detect
Private Wells Non -detect
NC IMAC Standard, 0.3 pg/L
••
i
•
s®
= rr•
1.0
Concentration pg/L
10.0
100.0

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
0.01
Site Background Wells/USGS Wells/Private Wells for Allen - Cobalt (Unfiltered)
• Site Background Wells Cobalt pg/L n = 70
• USGS Wells Cobalt, Averaged by Location pg/L n =2
Private Wells Cobalt pg/L n = 102
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NC IMAC Standard, 1 /L
S
••
••
•_ •
0.10
Concentration pg/L
1.00
10.00

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Allen - pH
• Site Background Wells pH n = 42
• USGS Wells pH, Averaged by Location n =875
Private Wells pH n = 125
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
N[; 91 Stgndgrd R 5 - R 5
•
•
•
•
•
•
•
•
•
•
•
•
•
2 4
6
8
10
12
14
16
18
20
pH

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Allen - Total Dissolved Solids (Filtered)
• Site Background Wells Total Dissolved Solids mg/L n = 83
• USGS Wells Dissolved solids, Averaged by Location mg/L n =2014
Private Wells Total Dissolved Solids mg/L n = 126
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NC 2L Standard, 500 m /L
ago"* N •
•f
'' Q • • M
1 10 100 1000
Concentration mg/L
10000
100000

Appendix D
Natural Attenuation — Ash Basins to
Compliance Boundary

2.2- bV6VD06nr oe 8F b22OCIVIE2' INC'
Appendix D Explanation Sheet
Box plots were created for boron, sulfate, arsenic, iron, manganese, vanadium, barium, chromium,
antimony, cobalt, pH, and total dissolved solids (TDS) to illustrate concentration changes that occur from
the ash basins to the compliance boundary. Box plots were created for ash pore -water data, wells within
the waste boundary, and wells outside the waste boundary but within the compliance boundary. Any
sample event in which boron was not detected (>50 ug/L) was excluded from the analysis since it would
not be indicative of groundwater impacted by the ash basins.
For comparison purposes box plots of the Site background data, private drinking water supply well (<0.5
mile radius from site), and USGS data are included, even if boron was not detected during the sampling
event. The Site background and USGS data are included in the illustration for comparison and are
referenced in Appendix C. Ash porewater, inside waste boundary, and outside waste boundary groups
only included concentrations if boron was detected (>50 ug/L) at that well for the sample date. Groups
in which samples have been screened for boron detects are colored differently from groups which use
all sample results regardless if boron was detected. Estimated values (J qualifier) were omitted from the
analysis for the private well data. The box plots were constructed to show the median with the upper
and lower "hinges" corresponding to the first and third quartiles (25th and 75th percentiles). Values for
non -detects are set at half of the detection limit. All data analyzed for unfiltered samples to allow for
comparison to the 2L standards and IMAC. The exception is for TDS which requires filtration.
The box plots contain two categories of six groups, and are defined as follows:
Wells with boron detected > 50 ug/L in sample
Ash Porewater — Wells screened within the ash
Inside Waste Boundary— Wells screened below the ash, within the waste boundary
Outside Waste Boundary — Wells screened outside the waste boundary, downgradient from ash
All wells, regardless if boron was detected in sample
Site Background — Wells screened outside compliance boundary, up -gradient of ash basin
Private Water Supply — All private drinking wells samples within 0.5-mile radius of the Site'
USGS Groundwater— North Carolina USGS well data'
The following table is a list of all Site wells used for the box plot analysis and which group they were
sorted in. No wells were excluded from the private water supply data or USGS groundwater.
' https://ncdenr.s3.amazonaws.com/s3fs-public/document-
libra ry/Full%20WeII%20Water%20Testing%20Res ults%20For%20Posting%208.20.pdf
Z http://nwis.waterdata.usgs.gov/nwis/qwdata queried downloaded on 6/10/2016 and included all data from
North Carolina for the analytes listed above

2.2- bV6VD06nr oe 8F b22OCIVIE2' INC'
Allen Box Plot Well Group List
All Wells
Wells with Boron > 50 ug/L
Background
Porewater
Inside Waste
Outside Waste
AB-1R
AB-20S
AB-20D
AB-10D
GWA-51D
BG-1D
AB-21S
AB-21BR
AB-10S
GWA-5S
BG-1S
AB-21SL
AB-21D
AB-11D
GWA-6BR
BG-2BR
AB-23S
AB-22D
AB-12D
GWA-61D
BG-2D
AB-24S
AB-22S
AB-12S
GWA-6S
BG-2S
AB-24SL
AB-23BRU
AB-13D
GWA-71D
BG-3D
AB-25S
AB-24D
AB-13S
GWA-7S
BG-3S
AB-25SL
AB-25BR
AB-14D
GWA-81D
BG-4BR
AB-27S
AB-25BRU
AB-1R
GWA-8S
BG-4D
AB-28S
AB-26D
AB-2
GWA-91D
BG-4S
AB-29S
AB-26S
AB-21D
GWA-9S
GWA-16D
AB-29SL
AB-27D
AB-4S
AB-14BR
GWA-16S
AB-30S
AB-28D
AB-5
AB-4BR
GWA-17D
AB-35S
AB-29D
AB-6A
AB-41D
GWA-17S
AB-39S
AB-30D
AB-6R
CIF
GWA-19D
GWA-19S
GWA-21D
GWA-21S
AB-31D
AB-91D
GWA-18D
AB-31S
AB-9S
GWA-18S
AB-32D
GWA-14D
GWA-22D
AB-32S
GWA-14S
GWA-22S
AB-33D
GWA-15D
GWA-23D
AB-33S
GWA-15S
GWA-23S
AB-34D
GWA-1BR
GWA-24BR
AB-34S
GWA-11D
GWA-24D
AB-35BR
GWA-1S
GWA-26D
AB-35D
GWA-26S
GWA-61DA
AB-36D
GWA-2D
PH WELL
AB-36S
GWA-2S
AB-1
AB-37D
GWA-3BR
AB-8
AB-38D
GWA-31D
GWA-4S
AB-39D
GWA-3S
GWA-5BR
AB-23D
GWA-41D
AB-37S
AB-38S

Antimony (Unfiltered) - Allen
15-
J
1:1110-
•
•
s=
•
O
O
U
•
C
O
U
•
•
5-
_
•
•
•
•
•
0-
Ash Porewater
Inside Waste Outside Waste Site Groundwater Private Wells
USGS
n=55
Boundary Boundary Background n=100
Groundwater
n=52 n=61 n=83
n=61
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
10.0 —
• •
°�
i • i
Cn
• •
•
O
•
J
_
I
=
•
J
-
C
-
O
(6
C
0
0.1 —
c
=
O
_
U
-
Ash Porewater
Inside Waste Outside Waste Site Groundwater Private Wells
USGS
n=55
Boundary Boundary Background n=100
Groundwater
n=52 n=61 n=83
n=61
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)

Arsenic (Unfiltered) - Allen
9101ilz
m
100
O
J
M
U
•
•
•
0
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=110 Groundwater
n=52 n=73 n=83 n=122
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
•
•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=110
n=52 n=73 n=83
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
•
USGS
Groundwater
n=122

Barium (Unfiltered) - Allen
1500 -
J
•
•
0)
1000 -
•
s=
O
•
•
c
O
U
C
O
•
U
500 -
mom
0-
Ash Porewater
Inside Waste
Outside Waste
Site Groundwater
Private Wells
USGS
n=55
Boundary
Boundary
Background
n=125
Groundwater
n=52
n=73
n=83
n=77
Sample Location Type. Red
Line: NC 2L Standard
(700 ug/L)
1000 —
N
-
M
U
-
U)
0)
O
J
—
J
-
C
O
(6
C
v
10 —
c
=
O
_
U
I
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=125
n=52 n=73 n=83
Sample Location Type. Red Line: NC 2L Standard (700 ug/L)
USGS
Groundwater
n=77

Boron (Unfiltered) - Allen
6000 -
J
1
p 4000
c
CD
U
C
O
U
•
2000 -
M
10000 —
100 —
Ash Porewater Inside Waste
Outside Waste Site Groundwater
n=55 Boundary
Boundary Background
n=52
n=71 n=83
Sample Location Type.
Red Line: NC 2L Standard (700 ug/L)
1
Ash Porewater Inside Waste
Outside Waste Site Groundwater
n=55 Boundary
Boundary Background
n=52
n=71 n=83
Sample Location Type.
Red Line: NC 2L Standard (700 ug/L)
Private Wells
n=105
Private Wells
n=105

Chromium (Unfiltered) - Allen
250 -
200 - •
J
0 150-
C •
O
c •
1100 -
C •
0
U
50-
•
• i
•
� t
0-
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=113 Groundwater
n=52 n=73 n=83 n=124
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
100 —
U -
W
0)
O
J
J
1
C
O
U
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=113
n=52 n=73 n=83
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
•
USGS
Groundwater
n=124

Cobalt (Unfiltered) - Allen
600 -
400 -
J
1
C
O
C
O
U
C
O
U 200 -
•
0
100 —
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=102 Groundwater
n=52 n=35 n=70 n=2
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=102
n=52 n=35 n=70
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
USGS
Groundwater
n=2

Iron (Unfiltered) - Allen
3e+05 -
2e+05 -
C
O
U
C
U 1 e+05 -
i
Oe+00 •
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=115 Groundwater
n=52 n=73 n=83 n=2221
Sample Location Type. Red Line: NC 2L Standard (300 ug/L)
1e+05 —
N
U
O
J
;.1e+03-
J
1
C
O
U
C _
O
U 1e+01 —
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=115 Groundwater
n=52 n=73 n=83 n=2221
Sample Location Type. Red Line: NC 2L Standard (300 ug/L)

Manganese (Unfiltered) - Allen
30000 -
J
20000 -
C
O
U
10000 -
0
10000 —
C -
a> _
U -
C -
O _
U
I
i
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=100 Groundwater
n=52 n=73 n=83 n=813
Sample Location Type. Red Line: NC 2L Standard (50 ug/L)
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=100
n=52 n=73 n=83
Sample Location Type. Red Line: NC 2L Standard (50 ug/L)
USGS
Groundwater
n=813

pH (Unfiltered) - Allen
12.5 -
5.0 -
IN
am
A
•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=125
n=28 n=70 n=42
Sample Location Type. Red Line: NC 2L Standard (6.5 - 8.5)
t
t '
•
.
USGS
Groundwater
n=875
.
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=125 Groundwater
n=28 n=70 n=42 n=875
Sample Location Type. Red Line: NC 2L Standard (6.5 - 8.5)

Sulfate (Unfiltered) - Allen
400 -
ill
J
E
C
O
20 200 -
WA
GDOM
m
100 —
0) -
O
J
J
E
C
O
Ash Porewater
n=55
•
•
•
S
•
Inside Waste Outside Waste Site Groundwater Private Wells USGS
Boundary Boundary Background n=121 Groundwater
n=52 n=73 n=83 n=60
Sample Location Type. Red Line: NC 2L Standard (250 mg/L)
i
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=121
n=52 n=73 n=83
Sample Location Type. Red Line: NC 2L Standard (250 mg/L)
•
USGS
Groundwater
n=60

Total Dissolved Solids (Filtered) - Allen
25000 -
20000 -
8
1
J
15000 -
•
O
C
i
coi 10000 -
c
o
=
U
5000 -
•
•
0-
Ash Porewater
Inside Waste Outside Waste
Site Groundwater Private Wells
USGS
n=55
Boundary Boundary
Background n=126
Groundwater
n=52 n=73
n=83
n=2014
Sample Location Type. Red
Line: NC 2L Standard (500 mg/L)
10000 —
a> _
M
U _
C�
01
O
J
E - •
C MOMO -
23
L
100 =
o - •
U -
C -
O -
U _ ; •
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=55 Boundary Boundary Background n=126 Groundwater
n=52 n=73 n=83 n=2014
Sample Location Type. Red Line: NC 2L Standard (500 mg/L)

Vanadium (Unfiltered) - Allen
75 -
25
U
100 —
N
M
C
O
O =
U -
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=117
n=52 n=35 n=70
Sample Location Type. Red Line: NC IMAC Standard (0.3 ug/L)
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=55 Boundary Boundary Background n=117
n=52 n=35 n=70
Sample Location Type. Red Line: NC IMAC Standard (0.3 ug/L)

Appendix E
Boron and Nitrate — Well AB-14D

Appendix E: Historic Boron and Nitrate Concentrations Versus Time for AB-14D
140
120
100
60
40
Boron NO3
20
Jan-11
Jan-12
Jan-13
Date
Jan-14
Jan-15
4000
3500
3000
J
M
7
C
O
L
2500
U
C
O
U
N
(9
L
z
2000
1500
-1 1000
Jan-16