NC0004774_R. Hennet - Final Buck Expert Report_20160630

Expert Report of
Remy J.-C. Hennet
Buck Steam Station
Salisbury, 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
Buck Steam Station
Salisbury, 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]

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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..................................................................................................................
13
Opinion3..................................................................................................................
16
Appendices
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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
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REPORT

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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 surface water and
groundwater contamination from the operation of coal ash basins at the Buck Steam Station, near
Salisbury, Rowan County, 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 Campbell and Spruill, 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, 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 August 13, 2014 and September 22, 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.
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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).
Operations at the Site started in 1926, and the last coal-fired unit ceased operation in 2013.
The ash basin system consists of Cell 1, Cell 2, and Cell 3 as per the Site reports. The ash basin
system is distributed between the three cells. The original ash basin system at the Site was
constructed in 1957 and modified by raising the dam in 1977 in the Cell 2 and 3 area. Cell 1 was
constructed in 1982. A pile of dewatered ash was constructed in the eastern portion of Cell 1 in
2009. The ash basin system is an integral part of the Site wastewater treatment system. The ash
basin system received 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 when a party causes concentrations 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 (2B) standards (2B Standards). The 2B
Standards depend upon classification of a surface water body.
For groundwater, the compounds of interest identified at the Site are: antimony, arsenic,
barium, beryllium, boron, cadmium, total chromium, hexavalent chromium, cobalt, iron,
manganese, nickel, selenium, sulfate, thallium, total dissolved solids (TDS), vanadium, and zinc.
The compounds of interest were identified based on concentrations in groundwater that exceed the
2L Standards and IMAC.
The available data for the Site includes results from chemical analysis of soil, sediment,
rock, ash basin solids, ash basin pore water, groundwater, 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 groundwater migration from the ash basin or ash storage areas.
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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 Campbell, Spruill, 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.

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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 metavolcanic rocks consisting of felsic metavolcanic, intermediate
metavolcanic, and mafic metavolcanic (Goldsmith et al. 1988). Together, and in context, these
data 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
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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 natural
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
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
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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.
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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, 2007; 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.
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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.

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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 source 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.
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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.
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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 compounds of interest identified in the Comprehensive Site Assessment Report for
groundwater are: antimony, arsenic, barium, boron, total chromium, hexavalent chromium, cobalt,
iron, manganese, pH, sulfate, total dissolved solids, thallium, 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. 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
attenuation is provided by processes that can include mineral precipitation (i.e., barite) and
reduction of sulfate to sulfides under strongly reducing conditions.
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• 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.
• Vanadium concentrations in soil and rock materials at the Site are naturally enriched
reflecting the composition of the bedrock, decomposed bedrock, and soils (USGS, 2013b).
Vanadium is a background condition at the Site.
• Antimony, barium, and cobalt 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 groundwater impact above the background range
outside of the ash basins area for antimony, barium, and cobalt. Cobalt concentrations
reported for wells GWA-9S and GWA-I IS are in the upper end of the background range.
Boron is elevated at GWA-9S, but below the 2L Standard. The presence of boron indicates
an impact from the ash basins at GWA-9S. The well is located downgradientfrom the ash
basins. Boron is not detected in GWA- I I S, and this well is not impacted by the ash basins.
• Thallium in groundwater samples is most often reported below detection) and only
occasionally at concentrations that exceed the IMAC in groundwater samples from beneath
the ash basins. Thallium is present at trace concentration in groundwater, soil and rock
materials under background conditions and in ash materials and ash pore water. Thallium
was not detected in groundwater samples taken outside of the ash basin area.
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 detection limit is 0.1 ug/l; less than 5% of analyzed samples for the Site and vicinity contained a detectable
concentration.
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• 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
leakage and/or by the presence of coal ash leachate impacting groundwater3. 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). Acidic pH is best explained by
mineral reactions (i.e., sulfide oxidation) that takes place when materials that contain
pyritic minerals are exposed to atmospheric oxygen and water. For the acidic wells4 that
have no detectable boron (<50 ug/L) and low pH values within the background range (see
Appendix D), the low values are most likely background related. The acidic wells that
contain detectable boron are influenced by Site operations and the acidity in these wells
could result from either the natural background or the ash materials.
• Total dissolved solids represent the sum of all chemicals that are dissolved in a water
sample. This parameter does not inform on 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. Total dissolved solids values are elevated
in ash pore water and in the impacted groundwater beneath and downgradient of the ash
basins.
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 compounds 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.
2 For example, wells with elevated pH and no detectable boron: GWA-113, GWA-313RU, AB-313, GWA-713, AS-313,
GWA-213R, BG-ID, GWA-13D, GWA-14D, GWA-19D, and BG-1BR.
s For example, wells with elevated pH and detectable boron: AB-4SL, AB-8S, AB-7SL, GWA-413, AS-213, AS-113,
AB-213R, AB-913, AB-7BRU, AB-413R, GWA-IOD, AB-913R, GWA-1813, and GWA-913R.
4 For example, wells with acidic pH values and no boron: BG 18, GWA-11 S, and MW-6S.
5 For example, wells with acidic pH values and detectable boron: AS- IS, and GWA-9S.
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�S J
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
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.
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
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Appendices D and E), and in the portion of the aquifer that has been impacted by the ash basins,
the ratio of upgradient 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. 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
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 well GWA-9S. The well groundwater shows
acidic condition with cobalt above the background range and IMAC. This well is located along the
groundwater pathway from the ash basins to the river. The cap -in -place remedy and monitored
natural attenuation are adequate for the restoration of groundwater in that area, as capping of the
ash basins will reduced the available oxygen that contributes to acidity and pH can be expected to
increase toward neutral as a result. At less acidic pH, cobalt will attenuate through sorption and
mineral precipitation and co -precipitation.' 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.
Plaintiffs' experts Spruill and Campbell jointly opined that background water quality data
are insufficient for the Site, and that Duke Energy has not performed the evaluation required to
establish any natural background concentration for any of the compounds of interest, at or near the
Buck property. Spruill and Campbell ignore the data available from the United States Geological
Survey and the State of North Carolina, and the fact that Duke Energy did consider that
information. Combining that information with the Site characterization data allows for a
reasonable evaluation of the background range for the Site (see Appendix C).
6 The excavation remedy advocated by Plaintiffs' experts would not remove the impacted groundwater in that area.
Excavation would promote the introduction of additional atmospheric oxygen into the subsurface, which can have
the detrimental effect of further acidifying groundwater, resulting in increased metal concentrations in groundwater.
15

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�S
Spruill and Campbell jointly opined that four background wells? for the Site are not proven
to be located hydraulically upgradient of the coal ash basins. Spruill and Campbell only considered
the hydraulic uncertainty and failed to consider the available chemical data. There is no detectable
boron reported in these four wells indicating that the wells have not been impacted by the ash
basins. The chemical data indicate that the wells are upgradient from the ash basins.
Spruill and Campbell jointly opined that hexavalent chromium in well BG-lBR is not
representative of background. I concur. The available data for this well is not reliable and the
reported hexavalent chromium concentration (78 ug/1) is anomalous and outside of the background
range. Further measurements at that well, which is described as a dry well, is required to verify the
anomalous hexavalent chromium reading. The evaluation of this well is on -going. Well BG-1BR
is upgradient from the ash basins and the chemical fingerprint of the well water is not indicative
of an ash basin impact. The well reported a high pH condition which is indicative of grout
contamination during well construction. Data for well BG-lBR is not usable for background
evaluation.
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.
• 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
7 MW-6S; MW-6D; BG-3S; and BG-3D.
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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 exposed 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' experts Spruill and Campbell jointly opined that the most protective remediation
option for coal ash at the Buck property is complete excavation and transfer to an engineered,
encapsulating, water -free, properly -maintained and monitored repository. Spruill and Campbell
wrongly assume that the source of contamination could 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 would 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.
Spruill and Campbell opined that coal ash -derived contamination impacting groundwater
and surface water will require additional assessment after the coal ash is removed, and that the
contamination will require remediation using methods protective of human health and the
environment, in particular the potable groundwater resources used by many hundreds of people
living near the Buck site. These additional measures and assessments will be implemented by
Duke Energy under the planned cap -in -place, if necessary. The opinion of Spruill and Campbell
that these measures will be required under the excavation remedy effectively negates most if not
all of the alleged advantages of excavation.
Plaintiffs' expert Parette advocates excavation and removal because he believes it would
result in 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, and predictions based on such estimates are highly uncertain and
unreliable. The time factor improvement claimed by Parette for clean-up under the excavation
scenario fails to account for the time it would take to excavate the ash basins. It would take
several years to excavate the ash basins, and accounting for this would delay the onset of the
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�S
groundwater cleanup. The time factor improvement claimed by 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.
MV

APPENDICES

Appendix A
Curriculum Vitae of Remy J.-C. Hennet

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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.

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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).

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• 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

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REMY J.-C. RENNET
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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.

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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,
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7

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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:
• BG-1BR
• BG-3BRU
• BG-1D
• BG-3D
• BG-1S
• BG-3S
• BG-2D
• MW-6D
• BG-2S
• MW-6S
All non -detects samples in the site background and private wells datasets were set to one half their
detection limit.
The USGS dataset sample values were averaged by well after setting values to one half their detection
limit, in an effort to try to avoid unnecessary spatial bias in sites sampled more frequently. Sites where
' 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'
all the values in the average calculation were non -detects were 1AIMM.Mred 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 Buck - Boron (Unfiltered)
Site Background Wells Boron pg/L n = 79
Private Wells Boron pg/L n = 79
Site Background Wells Non -detect
Private Wells Non -detect
NC 2L Standard, 700 fag/L
10
Concentration pg/L
100
1000

Site Background Wells/USGS Wells/Private Wells for Buck - Sulfate (Unfiltered)
• Site Background Wells Sulfate mg/L n = 79
• USGS Wells Sulfate, Averaged by Location mg/L n =60
Private Wells Sulfate mg/L n = 80
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
100%
90 %
80 %
70 %
60%
a�
40%
30
20%
f�
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%
c
50%
L
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - Arsenic (Unfiltered)
Site Background Wells Arsenic pg/L n = 79
USGS Wells Arsenic, Averaged by Location pg/L n =122
Private Wells Arsenic fag/L n = 78
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
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 Buck - Iron (Unfiltered)
Site Background Wells Iron pg/L n = 79
USGS Wells Iron, Averaged by Location pg/L n =2221
Private Wells Iron fag/L n = 83
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
INU zL z:)tanaara, ,5uu
4p
0.1 1.0 10.0 100.0 1000.0 10000.0
Concentration pg/L
• *0
100000.0 1000000.0

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - Manganese (Unfiltered)
• Site Background Wells Manganese fag/L n = 79
• USGS Wells Manganese, Averaged by Location pg/L n =813
Private Wells Manganese pg/L n = 72
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
INU ZL bianaara, aU Pgiu
0.01 0.10 1.00 10.00 100.00
Concentration pg/L
1000.00 10000.00 100000.00

100%
90 %
80 %
70 %
60%
a�
40%
30
20%
10%
0%-4
1
Site Background Wells/USGS Wells/Private Wells for Buck - Barium (Unfiltered)
• Site Background Wells Barium fag/L n = 79
• USGS Wells Barium, Averaged by Location pg/L n =77
Private Wells Barium pg/L n = 80
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�
50%
a
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - Chromium (Unfiltered)
• Site Background Wells Chromium pg/L n = 79
• USGS Wells Chromium, Averaged by Location pg/L n =124
Private Wells Chromium pg/L n = 83
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%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - Antimony (Unfiltered)
• Site Background Wells Antimony pg/L n = 63
• USGS Wells Antimony, Averaged by Location pg/L n =61
Private Wells Antimony pg/L n = 78
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NC IMAC Standard, 1 /L
•i •
_ • i
•
0
•
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.01 0.10 1.00 10.00
Concentration pg/L
100.00 1000.00

Site Background Wells/Private Wells for Buck - Vanadium (Unfiltered)
100%
90 %
80 %
70 %
60%
a�
40%
•
30
20%
10%
0%
0.1
• Site Background Wells Vanadium pg/L n = 37
Private Wells Vanadium pg/L n = 74
Site Background Wells Non -detect
Private Wells Non -detect
NC IMAC Standard, 0.3 pg/L
1.0
Concentration pg/L
10.0
100.0

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - Cobalt (Unfiltered)
• Site Background Wells Cobalt pg/L n = 37
• USGS Wells Cobalt, Averaged by Location pg/L n =2
Private Wells Cobalt pg/L n = 77
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NC IMAC Standard, 1 /L
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
0.01 0.10 1.00
Concentration pg/L
10.00
100.00

100%
90%
80%
70%
60%
a�
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - pH
• Site Background Wells pH n = 80
• USGS Wells pH, Averaged by Location n =875
Private Wells pH n = 83
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%
c
50%
L
40%
30%
20%
10%
0%
Site Background Wells/USGS Wells/Private Wells for Buck - Total Dissolved Solids (Filtered)
Site Background Wells Total Dissolved Solids mg/L n = 79
USGS Wells Dissolved solids, Averaged by Location mg/L n =2014
Private Wells Total Dissolved Solids mg/L n = 83
Site Background Wells Non -detect
USGS Wells Non -detect
Private Wells Non -detect
NC 2L Standard, 500 m /L
y • c, 00=+000� •� •
••w
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.
Estimated values (J qualifier) were omitted from the analysis for the private well data. 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. 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 b22OCIb.LE2' INC'
Buck Box Plot Well Group List
All Wells
Wells with Boron > 50 ug/L
Background
Porewater
Inside Waste
Outside Waste
BG-1BR
AB-2S
AB-10D
GWA-10D
MW-1D
BG-1D
AB-2SL
AB-10S
GWA-10S
MW-1S
BG-1S
AB-3S
AB-11D
GWA-11D
MW-3D
BG-2D
AB-4S
AB-2BR
GWA-11S
MW-3S
BG-2S
AB-4SL
AB-21D
GWA-12BRU
MW-4D
BG-3BRU
AB-5S
AB-31D
GWA-12D
MW-4S
BG-3D
AB-5SL
AB-4BR
GWA-12S
MW-5D
BG-3S
AB-7S
AB-4BRU
GWA-11D
MW-5S
MW-61D
AB-7SL
AB-5BRU
GWA-1S
MW-71D
MW-6S
AB-8S
AB-6BRU
GWA-22D
MW-7S
AB-7BRU
AB-BBRU
AB-81D
AB-9BR
AB-9BRU
AB-91D
AB-9S
AS-11D
AS-1S
AS-21D
AS-31D
AS-3S
BC-18
GWA-2BR
MW-8D
GWA-213RU
MW-8S
GWA-3BR
MW-9D
GWA-3BRU
MW-9S
GWA-3S
GWA-13D
GWA-41D
GWA-13SR
GWA-4S
GWA-14D
GWA-513RU
GWA-14S
GWA-5S
GWA-15D
GWA-6BR
GWA-15S
GWA-6BRU
GWA-17S
GWA-6S
GWA-18D
GWA-71D
GWA-18S
GWA-7S
GWA-19D
GWA-81D
GWA-19S
GWA-9BR
GWA-20D
GWA-91D
GWA-20S
GWA-9S
GWA-2S
MW-10D
MW-6BR
MW-11D
MW-21D
MW-11S
MW-2S
MW-12D
MW-13D
MW-12S

Antimony (Unfiltered) - Buck
150 -
J
1
0 100 -
.6
50 -
•
0-
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=78 Groundwater
n=31 n=71 n=63 n=61
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
m
M
10.0
O
J
M
i
•
•
•
•
Milo b
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=78
n=31 n=71 n=63
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
USGS
Groundwater
n=61

Arsenic (Unfiltered) - Buck
r�1zni
C
CD
U
O 500 -
U
•
•
,
0-
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
USGS
n=30 Boundary Boundary Background n=78
Groundwater
n=31 n=139 n=79
n=122
100 =
C _
U -
Cn -
0) -
O
J -
c 1=
a> _
U -
C -
O -
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
0
•
•
•
' •
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=78 Groundwater
n=31 n=139 n=79 n=122
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)

Barium (Unfiltered) - Buck
illifilz
J
1
C •
O
O
C
0
U
C
(j 500 -
•
0-
Ash Porewater Inside Waste
Outside Waste
Site Groundwater Private Wells
USGS
n=30 Boundary
Boundary
Background n=80
Groundwater
n=31
n=139
n=79
n=77
Sample Location Type. Red Line:
NC 2L Standard (700 ug/L)
IIIH
10-
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=80 Groundwater
n=31 n=139 n=79 n=77
Sample Location Type. Red Line: NC 2L Standard (700 ug/L)

Boron (Unfiltered) - Buck
7500 -
J
0)
1
5000 -
MO
2500 -
0- 1 M I•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=79
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (700 ug/L)
10000 —
100 —
Ash Porewater Inside Waste Outside Waste Site Groundwater
n=30 Boundary Boundary Background
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (700 ug/L)
•
Private Wells
n=79

Chromium (Unfiltered) - Buck
250 -
200 -
J
0 150- •
C
O
c
1100 -
0
U
.MN
•
i
•
0- •
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=83 Groundwater
n=31 n=139 n=79 n=124
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
100 —
N -
U
0)
O
J
J
1
C
O
A
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=83
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (10 ug/L)
•
USGS
Groundwater
n=124

Cobalt (Unfiltered) - Buck
911I1M
J
200
O
U
100 -
•
a
0
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=77 Groundwater
n=31 n=45 n=37 n=2
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
100 —
•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=77
n=31 n=45 n=37
Sample Location Type. Red Line: NC IMAC Standard (1 ug/L)
USGS
Groundwater
n=2

Iron (Unfiltered) - Buck
3e+05 -
2e+05 -
C
O
U
C
U 1 e+05 -
Oe+00
1e+05
N
U
O
J
' 1 e+03 -
J
1
C
O
U
C _
O
U 1e+01 —
•
s
A
H
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=83
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (300 ug/L)
•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=83
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (300 ug/L)
i
USGS
Groundwater
n=2221
i
•
USGS
Groundwater
n=2221

Manganese (Unfiltered) - Buck
0111101M
20000 -
J
1
C
O
a)
U
U)
0)
O
J
0
10000 —
100-
C
a>
U
C
O _
U
1—
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=72
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (50 ug/L)
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=72
n=31 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (50 ug/L)
i
uSGS
Groundwater
n=813
uSGS
Groundwater
n=813

pH (Unfiltered) - Buck
12-
O 9
c
N
U
C
O
i
[01
In
am
A
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=19 Boundary Boundary Background n=83 Groundwater
n=20 n=191 n=80 n=875
Sample Location Type. Red Line: NC 2L Standard (6.5 - 8.5)
•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=19 Boundary Boundary Background n=83 Groundwater
n=20 n=191 n=80 n=875
Sample Location Type. Red Line: NC 2L Standard (6.5 - 8.5)

Sulfate (Unfiltered) - Buck
C
N
U
C
O
U
200 -
m
100 —
a> -
M _
U _
U)
0)
O
J
J
E
C
O
M
L
C
v 1—
O
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=80 Groundwater
n=30 n=139 n=79 n=60
Sample Location Type. Red Line: NC 2L Standard (250 mg/L)
i
.
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells USGS
n=30 Boundary Boundary Background n=80 Groundwater
n=30 n=139 n=79 n=60
Sample Location Type. Red Line: NC 2L Standard (250 mg/L)

Total Dissolved Solids (Filtered) - Buck
25000 -
20000 -
J
15000 -
0
chi 10000 -
c
O
U
5000 -
Ole
10000
a>
M
U
U)
0)
O
J
E _
C
23O
L
100 =
am -
U -
C -
O —
U =
Ash Porewater Inside Waste
Outside Waste
Site Groundwater Private Wells
n=30 Boundary
Boundary
Background n=83
n=30
n=139
n=79
Sample Location Type. Red Line:
NC 2L Standard (500 mg/L)
•
•
•
•
•
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=83
n=30 n=139 n=79
Sample Location Type. Red Line: NC 2L Standard (500 mg/L)
USGS
Groundwater
n=2014
I
•
•
USGS
Groundwater
n=2014

Vanadium (Unfiltered) - Buck
300 -
J
o)200 -
C
O
M
U
100 -
0
i[eIl"
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=74
n=31 n=45 n=37
Sample Location Type. Red Line: NC IMAC Standard (0.3 ug/L)
Ash Porewater Inside Waste Outside Waste Site Groundwater Private Wells
n=30 Boundary Boundary Background n=74
n=31 n=45 n=37
Sample Location Type. Red Line: NC IMAC Standard (0.3 ug/L)