NC0038377_Powell Expert Report - Mayo_20160630

Expert Report of
Robert L. Powell Ph.D., P.E.
Mayo Steam Electric Plant
Roxboro, NC
In the matter of
State of North Carolina ex. rel. North
Carolina Department of
Environmental Quality vs.
Duke Energy Progress, LLC.
Prepared for:
Hunton & Williams, LLP
Charlotte, NC
Prepared by:
Ramboll Environ US Corporation
Tampa, Florida
Date:
June 30, 2016
Project Number:
25-39485A
ENVIRON

Contents
Page
1 Introduction and Summary of Opinions 1
2 Qualifications and Experience
3 Materials Considered
4 Explanation and Basis for Opinions
4.1 Opinion 1
4.2 Opinion 2
4.3 Opinion 3
4.4 Opinion 4
4.5 Opinion 5
3
4
5
5
5
7
8
9
5 Signature 12
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1 Introduction and Summary of Opinions
I have been retained by Hunton & Williams, LLP on behalf of its client, Duke Energy Progress,
LLC ("Duke Energy") to conduct an independent evaluation and provide certain expert opinions
in response to a lawsuit filed by the state of North Carolina in the matter of State of North
Carolina ex. rel. North Carolina Department of Environmental Quality and Roanoke River Basin
Association (plaintiffs) vs. Duke Energy Progress, LLC. The opinions I have formed and offer
herein are related to hydrologic/hydrogeologic conditions at Duke Energy's Mayo Steam Electric
Station in Roxboro, North Carolina (the "Mayo Station" or "Site") and the appropriateness of
measures to manage and a close an ash management facility on the property in compliance
with the requirements of the state Coal Ash Management Act of 2014 (CAMA), and to remedy
alleged violations of state laws related to discharges to ground water and surface water
systems.
In order to comply in part with the requirements of the CAMA, Duke Energy completed and filed
a Comprehensive Site Assessment Report (CSA) with the North Carolina Department of
Environment and Natural Resources (NCDENR) on September 2, 2015 (SynTerra; 2015a). This
CSA reported on the findings of an assessment of environmental conditions on the Mayo
Station property, focusing specifically on the impacts, if any, from the past and current onsite
management of coal ash on underlying soil, ground water and surface water resources.' The
scope of this CSA included extensive subsurface investigations of soil and ground water
conditions and water quality testing of ground water and surface waters on and adjoining the
Mayo Station property.
Subsequently Duke Energy also prepared and filed a Corrective Action Plan, Part 1 with the NC
Department of Environmental Quality2 dated December 1, 2015 (SynTerra; 2015b) and a
Corrective Action Plan, Part 2 dated February 29, 2016 (SynTerra; 2016) in which it reported on
its evaluation of potential remedial alternatives to address releases of constituents of coal ash to
underlying ground water systems as found and reported in the CSA. The remedial measures
evaluated in the CAP reports ranged from No- Action (essentially leaving current ash
management units in place under their then -current condition) to in -place capping, and/or
removal of the current ash management units, with reburial of the ash in a new lined landfill. The
CSA report, and subsequent Corrective Action Plan reports and monitoring data, form the
primary body of information that describes onsite environmental conditions and the performance
of remedial alternatives for the Mayo Station property that I have considered.
Based on my review of documents and related information in this case I have reached the
following general opinions:
Opinion 1: The environmental investigations performed by Duke Energy at the Mayo Station
pursuant to the CAMA and the prior compliance monitoring programs conducted pursuant to its
state operating permits provide a sufficient volume of scientific knowledge to define the general
nature of the hydrogeologic systems that underlie the Mayo Station property, the impacts of
' Coal ash is a waste byproduct from Duke Energy's onsite combustion of coal to generate electrical power.
2 Prior to September 18, 2015, the NCDEQ was referred to as the North Carolina Department of Environment and
Natural Resources (NCDENR).
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seepage from the onsite ash management unit on ground water and surface water quality, and
to support the closure planning of the onsite ash management unit.
Opinion 2: Ground water beneath the Mayo Station property originates primarily from the local,
onsite infiltration of rain water into native soil and process water that infiltrates through the
current ash management unit. Ground water beneath the site ultimately migrates into a surface
channel (Crutchfield Branch) that originates on the property and flows to the north, or to the east
as a broad area of seepage along the boundary with the Mayo Reservoir, which borders the
property.
Opinion 3: Seepage of water from the onsite ash management unit has caused the release of
certain Constituents of Interest (COls) to the shallow ground water at concentrations that
exceed the NCDEQ 2L water quality standards in localized areas beneath and immediately
downgradient of the ash management unit. Certain of these COls have migrated downgradient,
generally to the north towards Crutchfield Branch. Seepage from toe drains and other surface
seeps at the base of the dam that forms the ash management unit also flow into Crutchfield
Branch. Such discharges have not and should not cause any exceedance of applicable surface
water standards in Crutchfield Branch or other downstream surface waters.
Opinion 4: The presence of COls in ground water beneath the Mayo Station property poses no
risk to the use of ground water pumped from residential supply wells on neighboring private
properties for drinking water supply or to the quality of water in Mayo Reservoir.
Opinion 5: A substantial level of control of seepage from the ash management unit can be
achieved by the use of appropriate and conventional engineering controls, including the
placement of multi -media caps over closed portions of the ash management unit and the
collection and treatment of seepage that has been found to be discharging from the toe drains
at the base of the earthen dams that form the unit, or otherwise from natural, discrete seeps that
have formed in low areas along the base of the dam or bordering Crutchfield Branch. Such
controls should substantially reduce the overall release of COls into ground water and ultimately
into Crutchfield Branch over the long term, providing additional assurance of continued
achievement of surface water quality standards.
My qualifications as an expert in this case are provided in Section 2 of this report. The materials
I have relied on in formulating my opinions are identified in Section 3. The bases for and
detailed explanation of my opinions are presented in Section 4.
I am compensated by my employer, Ramboll-Environ US Corporation (Ramboll-ENVIRON), for
my services and expenses on this matter at my normal hourly compensation rate. Ramboll-
ENVIRON bills Duke Energy at a rate of $300/hour for these services.
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2 Qualifications and Experience
I am a Principal of Ramboll-Environ US Corporation ("Ramboll-Environ") in Tampa, Florida.
Ramboll-Environ (formerly ENVIRON International Corporation ("ENVIRON")) is an international
consulting firm that provides scientific, engineering and strategic risk management services to
clients in the public and private sectors. ENVIRON was formed in 1982, and in December 2014,
merged with Ramboll. The combined, Ramboll-Environ has nearly 300 offices and over 12,000
employees worldwide.
I am a practicing professional engineer, 3 hydrologist and hydrogeologist. I received a Ph.D. in
Civil Engineering (Groundwater Hydrology) in 1983. 1 received an M.S. in Civil Engineering
(Water Resources) in 1977. 1 received a B.S. in Civil Engineering (Environmental Engineering)
in 1973. All degrees were received from the University of Maryland, College Park.
I have approximately 40 years of experience as a practicing consultant in the fields of
environmental engineering, surface and ground water hydrology, hazardous waste
management, contaminated site investigation/remediation, risk assessment, and environmental
risk management. This experience includes professional consulting services at many of the
largest solid waste management facilities throughout the United States that are regulated under
federal and state environmental statutes. My recent work as an expert included consulting
services at two large coal ash management facilities in the state of Maryland, focusing on issues
of the impacts to underlying and adjoining ground water/surface water systems and the efficacy
of closure alternatives that had been implemented at the sites. I have also conducted
environmental investigation, and evaluated corrective action requirements at numerous
industrial and commercial facilities that generate solid/hazardous wastes and other regulated
materials for federal, state and private clients. These have included facilities that have
undergone closure under RCRA, TSCA, CERCLA, and related state regulatory programs. I
have previously been qualified as an expert and testified in United States federal and state
courts in the fields of ground water hydrology, environmental investigations and remediation
planning, environmental risk management, and cost allocation/National Contingency Plan (NCP)
consistency under CERCLA regulations.
3 My currently active PE license is in the state of Florida (No. 64379) where I currently reside and work.
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3 Materials Considered
The opinions set forth in this report are based on my approximately 40 years of experience in
consulting engineering as well as my formal academic training as an environmental engineer
and hydrologist/hydrogeologist. In forming my opinions, I considered observations I made during
my visit to the Site on June 7, 2016 and information concurrently provided by Duke personnel,
along with information from certain documents that describe the conditions of the Mayo Station
property, as identified below, which documents were provided to me at my request by counsel. I
also reviewed and considered the reports and opinions of the opposing experts in this matter
(Mr. Mark Hutson and Dr. Robert Parette). Specifically, I reviewed and considered the following
Site and case related documents:
Comprehensive Site Assessment Report, Mayo Electric Steam Plant; SynTerra; September 2,
2015[a].
Corrective Action Plan, Part 1, Mayo Electric Steam Plant; SynTerra; December 1, 2015[b].
Corrective Action Plan, Part 2, Mayo Electric Steam Plant; SynTerra; February 29, 2016.
Expert Report of Mark Hutson, PG; Mayo Electric Steam Plant, Roxboro, NC; February 2016.
Expert Report of Mark Hutson, PG; Mayo Electric Steam Plant, Roxboro, NC, Addendum No. 1;
May 2016.
Opinions on the Appropriateness of Monitored Natural Attenuation in Conjunction with Cap -In -
Place at the Mayo Steam Station, Roxboro, NC; Robert Parette, PhD, P.E.; May 13, 2016.
NPDES Permit No. NC0038377 (Exhibit 12 to the Complaint)
Emergency Action Plan (EAP), Duke Energy Mayo Plant, Mayo Lake Dam, May 16, 2016
Notice of Deficiency Re: Mayo Lake Ash Dam; NCDENR; August 11, 2014.
Water quality data for seeps and surface water, Mayo site.
I reserve the right to amend or supplement my opinions if additional information becomes
available.
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4 Explanation and Basis for Opinions
4.1 Opinion 1
The environmental investigations performed by Duke Energy at the Mayo Station pursuant to
the CAMA and the prior compliance monitoring programs conducted pursuant to its state
operating permits provide a sufficient volume of scientific knowledge to define the general
nature of the hydrogeologic systems that underlie the Mayo Station property, the impacts of
seepage from the onsite ash management unit on ground water and surface water quality, and
to support the closure planning of the onsite ash management unit.
During the 2015 CSA investigation, extensive numbers of soil borings and monitoring wells were
drilled and/or constructed on the Mayo Station property to investigate subsurface hydrogeologic
conditions. Samples of soil cutting were collected for physical/chemical examination, ground
water and surface water samples were collected and chemically tested, aquifer hydraulic tests
were performed on multiple wells from each of the identified ground water zones (i.e. the
saprolite, transition and the bedrock units), and water level and water quality measurements
were performed in onsite wells. Collectively this body of field investigations has provided a
comprehensive database that describes the natural geology and hydrology of the Mayo Station
property and from which a Conceptual Site Model of the underlying ground water system, and
its interaction with overlying surface waters, can be formed. The level of investigation in this
instance is on par, in my nearly 40 years of experience, with comparable investigations I have
performed at some of the most complex waste sites under federal and state environmental
regulations (e.g. CERCLA or RCRA). The resulting knowledge that has been gained is sufficient
to perform the initial screening and evaluation of options for future management of the ash
management unit on the Mayo Station property pursuant to CAMA. To the extent that additional
data needs are identified in the course of the ongoing remedial evaluations, focused data
collection programs are likely to occur as these analyses progress to remedial design. This is a
normal course for such evaluations and does not diminish the comprehensive nature of the work
already performed under such a short time -frame.
4.2 Opinion 2
Ground water beneath the Mayo Station property originates primarily from the local, onsite
infiltration of rain water into native soil and process water that infiltrates through the current ash
management unit. Ground water beneath the site ultimately discharges into a natural surface
channel (Crutchfield Branch) that originates on the property and flows north, or as a broad area
of seepage along the boundary with the Mayo Reservoir, which borders the property to the east
(see Figure ES-1 of the CSA report; SynTerra, 2015a).
The extensive geologic and hydrologic data that has been derived from the onsite drilling
program and documented in the CSA report demonstrates that the Mayo Station property is
underlain by the typical saprolitic soils and fractured bedrock that are characteristic of the mid -
Atlantic Piedmont region. Shallow soils are formed by the in -place weathering of native rocks
into a relatively fine grained matrix of clayey soil with varying amounts of intermixed silts, sand
and rock fragments. Beneath this soil is a transitional zone of less weathered but typically highly
fractured rock at the base level of the saprolite zone, with varying amounts of infilled soils in the
5 Ramboll Environ

fractures. Deeper still is native fractured bedrock, 4 where the degree of fracturing typically
diminishes with greater depth.
In this type of geology, and on the Mayo Station property, subsurface water principally derives
from the local infiltration of rainwater at the ground surface and the subsequent percolation of
this infiltration into successive deeper soil and rock layers. The amount of natural recharge in
unpaved areas of the Site is in the range of 6-8 inches/year. As water percolates through the
subsurface, it generally follows a downward pathway through the soil and rock fractures towards
lower elevations. Ground water has also historically been added to the Site in the form of
infiltration and seepage from the ash management unit, where ash has been historically
deposited as a wet slurry and storm water that accumulated inside the ash management unit.
The ash management unit was originally formed by construction of an earthen dam across the
valley that formed Crutchfield Branch, a natural drainage channel system that originates on the
Mayo Station property. The dam created an impoundment into which a wet ash slurry was
pumped. This valley was and is a natural collection area for surface water runoff and shallow
ground water on the Site. As the ash management unit became increasing filled, ground water
continued to flow through subsurface layers beneath the ash and ultimately to the north into the
natural open channel of Crutchfield Branch downstream of the dam. Based on my observations
during my site visit on June 7, 2016, the water discharging from the ash management unit dam
into Crutchfield Branch amounts to 3-5 gpm from each of two toe-drain/seepage areas. The vast
majority of the water otherwise entering the ash management unit is released as surface water
that flows through a polishing pond and then a NPDES permitted outfall into a surface channel
leading to Mayo Reservoir.
As ground water and infiltration flows deeper into the ground, there is a tendency to flow
laterally down slope along bedding planes in the soil, or fractures in the transition zone or
bedrock, towards surface drainage features. Most prominent in this regard is Crutchfield Branch,
which crosses the Mayo Station property from the south to north, more or less bifurcating the
property. The emergence of ground water by drainage into this natural drainage may be in the
form of discrete seeps (or springs), or as a much broader and diffuse inflow as base -flow along
the streambed. This flow of water is apparent in the ground water level data collected during the
CSA (see Figures 6-9 and 6-10 of the CSA report; SynTerra, 2015a) and also in seeps that
observed have formed along the open channel north of the dam along with the steady flow of
seepage from the toe drains at its base.
As ground water flows into the topographically low area to the north of the dam, higher
pressures found in deeper wells in the transition and bedrock zones will force water to the
surface, causing it to discharge through the creek -bed and thus become part of the surface
base -flow in Crutchfield Branch. Ground water level data reported in the CSA are consistent
with this generalized interpretation of the ground water flow system.
Ground water beneath the eastern -most portions of the property (generally from the rail -line
spur eastward) flows to the east and discharge as a broad seepage front into Mayo Reservoir.
4 Rock types reported in this bedrock zone are primarily metamorphic in origin with varying degrees of fracturing.
6 Ramboll Environ

This discharge is not expected to be a source of any COls to the reservoir that would be
regulated under the CAMA, as there are no ash management units in this area of the property.
4.3 Opinion 3
Seepage of water from the onsite ash management unit has caused the release of certain
Constituents of Interest (COls) to the shallow ground water at concentrations that exceed the
NCDEQ 2L water quality standards in localized areas beneath and immediately downgradient of
the ash management unit. Certain of these COls have migrated downgradient, generally to the
north towards Crutchfield Branch. Seepage from toe drains and other surface seeps at the base
of the dam that forms the ash management unit also flow into Crutchfield Branch. Such
discharges have not and should not cause any exceedance of applicable surface water
standards in Crutchfield Branch or other downstream surface waters.
The interpretation of the precise extent of COI migration from the ash management unit is
complicated by their natural occurrence in ground water and the relatively limited number of
tests of water samples from each well that could be performed under the tight project schedules
mandated by the CAMA regulations. COls currently identified in groundwater beneath the ash
management unit above NCDEQ 2L standards include antimony, arsenic, barium, boron, cobalt,
iron, manganese, pH, thallium, TDS, and vanadium. Boron is the most conservative and mobile
of these COIs, and best defines the subsurface extent of the migration of ash -derived
constituents to the north along the Crutchfield Branch drainage. Based on repeated testing of
water from investigative monitoring wells and surface water in the creek, boron migrating in
ground water ultimately fully discharges into Crutchfield Branch from toe -drain and seeps at the
base of the dam or otherwise as base -flow into the channel reach below the dam that extends
down to the vicinity of Mayo Lake Road (the facility property boundary and ground water
compliance boundary). This conclusion is supported by the absence of boron in wells further
downgradient (MW-16S, D, and BR) and the presence of boron in the surface flow of Crutchfield
Branch in this area (see Tables 9-3 and 10-1 of the CSA report; SynTerra 2015a). By the time
this ground water to surface inflow has reached the NC -VA state boundary (approximately 1000
feet to the north), boron concentrations measured below the dam have already been
substantially (more than 60%) diluted by the inflow/mixing of clean ground water further
downstream along the creek bed (see Table 9-3 of the CSA report; SynTerra, 2015a).
Because many of the other COls identified at the Site occur naturally in ground water and there
is only limited data to define the range of background concentrations, boron currently serves as
the most reliable, conservative "tracer" to interpret the presence of ash -derived COls in ground
water. Boron is a soluble and mobile constituent of the ash that has not been generally detected
5 in background monitoring wells located upgradient of the ash management units on the Mayo
Station property. Simply stated, if boron is not concurrently found in monitoring wells that
otherwise have reported COI exceedances of NCDEQ 2L standards, it is unlikely such
exceedances derive from seepage/migration from the ash management areas.
5 The typical detection limit for boron is 50 ug/L, which is sufficiently sensitive to serve as a reliable tracer for COI
migration from ash management areas.
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One of the other COls, manganese, was also found to be mobile in ground water and is
currently discharging into the Branch via seeps at the base of the dam or as diffuse seepage
through the streambed. Manganese has been found in background areas of the Site and is a
natural constituent of ground water in the area. Its presence in ground water, therefore, does not
derive solely from migration from the ash. The discharge of manganese into Crutchfield Branch
below the dam has not and should not cause any exceedance of applicable surface water
standards in Crutchfield Branch or the downstream Mayo Creek.
Other Cols (e.g. antimony, cobalt, iron, vanadium) have also been detected in areas upgradient
of the ash management unit at concentrations in excess of NCDEQ 2L standards (see Figures
10-2, 10-3, and 10-4 of the CSA report; SynTerra, 2015a). These COls are likely naturally
derived in ground water from the in -place weathering of native rocks. They are also found
beneath the ash management unit and are constituents of the ash, but have not been found in
downstream areas, beyond Mayo Lake Road, in the concurrent presence of boron. Because
they are also naturally occurring, the limited testing of ground water thus far for these types of
natural constituents presents a particular challenge when attempting to define the outer
boundary of ash -related impacts. Based on the limited spreading of these types of COls in
ground water downgradient of the dam, however, it is apparent that the natural geochemical
reactions (adsorption, precipitation, mineral complexing) in the soil and shallow ground water
zones underlying the ash management unit are significantly attenuating the migration of these
constituents as compared to boron.
Duke Energy is required to maintain a minimum surface release into the Mayo Creek channel
below Mayo Reservoir of 2 cubic feet per second (cfs), which flow will substantially dilute
(approximately 100 fold) any uncollected seepage that emerges from the toe drains or seeps
below the ash management unit dam into Crutchfield Branch, once these drainage channels
merge a short distance downstream. This dilution further adds to the factor of safety for
protection of surface water supplies in more -distant downstream areas.
It is clear from my review of the ground water and seep data that the more mobile COls have
migrated and will continue to migrate from the ash management unit at levels that are causing
exceedances of NCDEQ 2L standards in ground water immediately beneath and downgradient
of the dam, but only within the current compliance boundary. Most of the less mobile ash -related
COI show much less migration. The migration of COls from the ash is facilitated by a permanent
water table within the ash deposits that is caused by the pumping of process water to the unit,
the local infiltration of rainwater through the unit and to a lesser extent the lateral ground water
inflow from adjoining higher areas. These COls discharge into Crutchfield Branch on the Mayo
Station property and become part of its surface water base -flow. Surface water testing during
the CSA investigations demonstrate that migration of COls into Crutchfield Branch is not
causing any exceedances of NCDEQ 2B surface water standards.
4.4 Opinion 4
The presence of COls in ground water beneath the Mayo Station property and the migration of
COls in ground water to the north into Crutchfield Branch poses no risk to the local use of water
on neighboring private properties for drinking water supply.
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Information provided in Section 4.2 of the CSA report (SynTerra; 2015a) indicate there is no
onsite use of ground water for drinking water supply on the Mayo Station property. All potable
water used by onsite employees is supplied by the local municipality. There are some private
water supply wells located on adjoining or neighboring properties to the south which is far (more
than 0.5 miles) removed and upgradient from the ash management unit. Portions of this area
are also serviced by municipal water from the City of Roxboro. The onsite movement of
groundwater is to the north away from these private wells. COls found beneath the ash
management unit should pose no threat to these potable water systems. The property
immediately north of Mayo Lake Road along Crutchfield Branch is undeveloped and used for
agriculture. I understand there are no supply wells on this property.
I also understand that there is no use of surface water from Crutchfield Branch or nearby
downstream surface channels for drinking water supply.
4.5 Opinion 5
A substantial level of control of seepage from the ash management unit can be achieved by the
use of appropriate and conventional engineering controls, including the placement of a multi-
media cap over closed portions of the ash management unit and the collection and treatment of
seepage that has been found to be discharging from the toe drains at the base of the earthen
dams that forms the unit, or otherwise from natural, discrete seeps that have formed in low
areas along the base of the dam or bordering Crutchfield Branch. Such controls should
substantially reduce the overall release of COls into ground water and ultimately into Crutchfield
Branch over the long term, providing additional assurance of continued achievement of surface
water quality standards.
Water has historically entered the ash management unit from the discharge of water as a
carrying media for the slurried ash pumped into the unit for disposal; the natural accumulation of
rainfall onto, and local onsite runoff into, the unit; and to a lesser extent by the lateral subsurface
movement of shallow ground water from surrounding higher ground towards the topographically
lower valley that was impounded/filled. The slurried ash appears to be the largest source of
water currently reaching the unit,, followed by rainfall/surface runoff.' Water in the ash
management unit is treated by settling solids/particulates in the large pond on its north side and
then in a polishing pond before it is discharged through an NPDES permitted outfall into Mayo
Reservoir.
Based on my observations while visiting the Site, the majority of the current surface water base -
flow during dry (non -storm) conditions in Crutchfield Branch above Mayo Lake Road is derived
from seepage flowing from the toe drains and natural seeps into two discrete channels below
the dam which merge to form Crutchfield Branch. The combined flow from these drains/seeps is
approximately 5-10 gpm, and is caused by the current significant impoundment of water behind
the dam. 8 Testing of surface water chemistry below these seeps and at the state boundary a
I understand Duke Energy is planning to end this practice in the next few years and it will be replaced by a dry ash
management system.
' Annual rainfall amounts to about 47 inches/year (see CSA report, Section 2.7; Synterra, 2015a).
8 This rate of flow would diminish after the impoundment is drained and the ash management unit is covered to
prevent infiltration.
9 Ramboll Environ

short distance downstream as reported in the Table 9-3 of the CSA report (SynTerra, 2015a),
demonstrates that even with the current rate of seepage, the water quality in Crutchfield Branch
meets NCDEQ 2B standards, in compliance with the condition A(8) of the current NDPES
permit. Many of the COls found in ground water beneath the unit (e.g. arsenic) are attenuated
before this seepage reaches the stream, but the more conservative and mobile COls such as
boron are still present.
Capture/control of this seepage using standard engineered drainage equipment would
substantially eliminate the COls that are reaching the Crutchfield Branch drainage channel.
Based on my discussions with Duke Energy personnel during my Site visit on June 7, 2015,
Duke Energy is planning to install a collection box/french drain below each toe drain later this
year; the accumulated water will then be pumped back up into the ash management unit. Such
controls, along with the natural attenuation of COls by adsorption and co -precipitation in the
underling transition and bedrock zones, will substantially reduce the release of COls into the
Crutchfield Branch over the near term, thereby providing additional assurance of continued
achievement of surface water quality standards while the ash management unit remains open.
I understand Duke Energy intends to eventually close the ash management unit by draining the
unit, lowering the height of the earthen dam approximately by half, and regrading the ash in the
unit to provide for the natural flow of surface runoff towards the dam, where it will be conveyed
into downstream drainage channel by sheet and channelized flow. The regraded ash will then
be covered with a multi -media cap. Such a cap represents the current state of the art in
moisture control and would virtually eliminate infiltration as a source of future water entering the
closed ash management unit. In effect the ash basin will be converted from a wet pond into a
dry grass -covered pasture.
Modeling analyses in the CAP 1 and 2 reports (SynTerra 2015b and 2016) show that the net
effect of a cap would be to lower the water table in the ash, but some saturated ash would likely
remain in the deepest part of the unit due to the continued lateral inflow of shallow ground
water. Such inflow could prove difficult to completely control upstream of the unit given its size
and the surrounding topography, and additional measures to intercept/treat/recycle seepage
and toe drain discharge below the reconfigured dam may prove to be necessary if such
discharges are not otherwise permitted under the Site's NPDES permit.9 Such measures could
be readily deployed using standard engineered drainage equipment. Working in concert with the
capping system and the natural attenuation of COls in the underlying transition and bedrock
zones, this type of unit closure would substantially add to the level of protection of the
downstream surface water quality in Crutchfield Branch.
In his expert report, Dr. Parette opines that the placement of a cap over the ash management
unit would cause the underlying ground water to become anoxic, creating a reducing
9 1 understand Duke Energy has submitted a modified NPDES permit application to NCDEQ that incorporates the toe
drains and identified seeps below the ash management unit dam as explicitly authorized discharges under the
permit. As yet, no final decision on this permit application has been made by the NCDEQ. The current permit
(NC0038377) precludes "direct" discharges from the ash pond to Crutchfield Branch (I am unaware of any such
discharges at present), but seemingly anticipates that there could be, and does not preclude "any indirect
discharges from the ash pond" provided they do not cause a violation of water quality standards in Crutchfield
Branch [see Section A(8) of the permit].
10 Ramboll Environ

environment that would cause even greater amounts of COls to be released into ground water.
This conclusion is speculative and unsupported by the Site data. Following capping, shallow
ground water would continue to flow slowly beneath and through the ash beneath the cap, albeit
at a slower overall recharge rate than is currently the case. This water will infiltrate into the
ground in the areas along the immediate perimeter of the unit and would initially be enriched
with oxygen. The subsequent movement of this water beneath the cap would continue to supply
aerobic ground water to the shallowest ash layers. As the water seeps deeper through the ash
and hence into deeper ground water layers, this oxygen is consumed by biotic and abiotic
reactions such that a more reducing environment will then predominate in these deeper zone.
My review of the current ground water monitoring data for the Site from the CSA demonstrates
such reactions and conditions are already occurring and much of the deeper ground water
zones beneath the ash management unit already exhibit a reducing environment. The solubility
of COls in this ground water have adjusted accordingly. I am not aware of any evidence in this
case, and it is mere speculation Dr. Parette's part, that the placement of caps over the ash will
cause this condition to significantly deteriorate toward an even stronger reducing condition.
Even if this did turn out to be the case, it could in turn trigger the conversion of sulfate already
present in the water into sulfide compounds, which in turn would cause the precipitation of
insoluble minerals from many of the COls found in the ground water zone today. What is
indisputable, however, is that an impermeable cap will substantially reduce the volumes of water
that flow through the ash under current conditions, and thereby lessen the rate of release of
COls to ground water and ultimately Crutchfield Branch.
The other closure alternative considered by Duke Energy in the CAP1 and 2 reports (removal of
the ash management unit) was not adopted in part because the unit was inspected and found to
be structurally stable,10 and capping, seepage control and MNA is believed to be effective in
controlling migration of COls and at far less cost as compared to complete removal of the unit. I
concur with this conclusion. The engineering controls described above should be more than
adequate to protect surface water resources below the ash management unit dam, and there
are no serviceable ground water resources in the area that would be threatened by the
continued presence of the closed ash management unit with an effective cap and seepage
control system. In my nearly 40 years of experience working on projects to close land -based
solid waste management units under a range of federal and state environmental regulations
(e.g. CERCLA and RCRA), I have never seen an example whereby the complete removal of a
large, structurally stable solid waste unit was ordered by the supervising regulatory agency,
when effective containment measures can otherwise be readily deployed to protect the
environment, as is the case in this instance. The complete removal of the ash management unit
at the Mayo Station is unwarranted and unnecessary.
10 Some maintenance and repair issues with the spillway piping were noted in the NCDENR's August 2014 NOD
which Duke Energy is currently working with the state to correct.
11 Ramboll Environ

5 Signature
The opinions in this expert report are based on my education and training, my more than
40 years of experience in environmental consulting, and the materials listed in Section. I
may revise these opinions as additional information, documents, testimony, or discovery
responses become available.
Robert L. Powell, Ph.D., P.E.
June 30, 2016
12 Ramboll Environ

ENVIRON
Robert L. Powell, PhD, PE Principal
Tampa, Florida
[phone] [e-mail]
Dr. Robert Powell has over 40 years of experience in environmental engineering and hydrogeology, with special
emphasis on the investigation and management of risks related to the release of chemical contaminants into soil,
surface water and groundwater systems. Specific areas of expertise include the evaluation of fate and transport of
chemicals in the natural environment; investigation and remediation of chemical releases; and the development of
complex models of chemical migration in natural hydrologic systems. He has provided litigation support and acted as
an expert witness in state and federal courts on a range of matters related to property damage and personal injury
claims from chemical releases and migration into the natural environment, cost contribution and recovery under the
National Contingency Plan and environment -related bankruptcy claims and insurance recovery.
"�LLIWOL
1983 PhD, Civil Engineering (Groundwater Hydrology), University of Maryland
1977 MS, Civil Engineering (Water Resources), University of Maryland
1973 BS, Civil Engineering (Environmental), University of Maryland
EXPERIENCE
CERCLA Remedial Investigations and Remediation Planning
Dr. Powell has conducted numerous Remedial Investigations and Feasibility Studies and related remedial planning
projects for private and public -sector clients under the federal Superfund and related state programs for the
investigation and remediation of contaminants released into the natural environment. Representative projects
include:
— Completed an RI/FS of soil and groundwater conditions for a former refinery -waste disposal site in Fullerton,
California, that was regulated under CERCLA by the USEPA. This work focused on the investigation and control
of waste migration in shallow, perched groundwater zones and the mitigation of impacts on regional water
supply aquifers. Contaminants of concern at the site included hydrocarbons, aromatics, thiophenes and metals.
The RI/FS lead to the issuance of final ROD by the USEPA to close the site and restore the overlying property to
beneficial use as a community golf course. Groundwater impacts were addressed by a Monitored Natural
Attenuation remedy.
— Served as the principal technical advisor to the PRP steering committee, composed of a number of major
international oil companies, during a negotiation with the USEPA for the development of a Scope of Work to
implement the final remedy for closure of the OII NPL site near Los Angeles, California. This project focused on
the development of specific performance metrics and verification measures to evaluate the effectiveness of
identified remedial actions in meeting specific performance goals prescribed in the final ROD for the OII site,
the development of work plans for the implementation of additional investigations to facilitate remedial design,
and in the negotiation of a final scope of work with the USEPA to implement closure of the site.
— Directed the completion of a supplemental feasibility study for the California EPA for closure of the primary
disposal area at the Stringfellow NPL site in Glen Avon, California. This project also included conducting pilot
tests for the evaluation of technologies for removal of VOC and other contaminants through the use of high -
vacuum extraction, and a performance review of the remedial systems in the downstream areas to control the
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Rob L. Powell, PhD, PE
migration of contamination. Prior to this work, Rob served for nearly ten years as the technical advisor to the
Stringfellow Advisory Community, a group representing various community and local government interests.
- Prepared an analysis of the human health risks associated with emission of chemicals during the remediation of
the Royal Hardage hazardous waste disposal facility in Criner, Oklahoma. The facility had served as a
regional site for the disposal of hazardous liquids, sludge and solids in bulk and in drums. Waste management
unit that were constructed at the facility included a hazardous waste landfill, a waste lagoon (filled with sludge
and other bulk solids) and a large burial mound of liquid and solid waste in steel drums. This facility was
closed under the oversight of the USEPA under the Superfund program.
- Prepared an analysis of the human health risks associated with the excavation of wastes from the Hyde Park
Landfill NPL Site near Niagara Falls, New York. This landfill had been used for the disposal of a wide range of
hazardous liquids and sludge from the manufacturing of pesticides, solvents and other chemical intermediaries
into an open pit in fractured bedrock. The site was believed to be leaking DNAPLs and other liquids into
groundwater and the nearby Niagara River. The risk analysis was prepared for the USEPA and the US
Department of Justice to support the negotiation with the landfill owner for the closure of the site.
- Managed the completion of a major regional groundwater Remedial Investigation/Feasibility Study to address
VOC contamination over a 30 square mile multi -layer aquifer system in New Brighton, Minnesota associated
with releases from the Twin Cities Army Ammunition Plant. This project was completed for the Minnesota
Pollution Control Agency under a cooperative agreement with the USEPA under CERCLA.
- Provided regulatory support and expert reports to three major corporations in a series of negotiations with
USEPA regarding CERCLA liability for groundwater contamination in the Baldwin Park Operable Unit of the
San Gabriel Valley NPL site near Los Angeles.
- Prepared a remedial action plan and supported negotiation with the USEPA on behalf of a PRPs group for the
closure of Atlas Mine NPL site near Coalinga, California. This site was formerly an asbestos mine and ore
processing facility that was a major source of asbestos -contaminated sediments discharging into the Central
Valley of California.
- On behalf of a PRP group, prepared pilot treatment tests and a remedial action plan to address releases of
sulfuric acid and toxic metals in soil and groundwater, and supported negotiation with the SCDHEC, for the
closure of the Stoller Chemical site, a former fertilizer manufacturing facility near Charleston, Sout Carolina,
listed on the NPL.
- Provided consulting services to Fairfax County, Virginia to oversee the investigation and cleanup of a large
gasoline release from a ruptured pipeline into a new residential community. Services focused on the evaluation
of applicable remedial strategies and the quantification of potential pathways for exposure from gasoline that
accumulated on the underlying water table.
RCRA Facility Permitting, Compliance and Corrective Action
Dr. Powell maintains an active practice of permitting, compliance support, and corrective action services,
including RCRA facility investigations and remedial planning projects, to companies regulated under RCRA for the
treatment, storage and disposal of hazardous wastes and under the RCRA UST program. Representative projects
include:
- Directed the completion of a remedial investigation and remediation planning project in Culvert City, California
to evaluate alternatives for the cleanup of MTBE and other gasoline constituents from the Charnock Sub -basin
and to restore the use of municipal well field owned by the city of Santa Monica and the Southern California
Water Company to productive use. This project involved extensive field investigations to define the nature
/extent of contamination, development of regional groundwater and water quality databases, computer
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Rob L. Powell, PhD, PE
modeling of groundwater flow and contaminant transport, evaluation of technologies to treat groundwater for
gasoline, MTBE and tBA, and the development and evaluation of detailed remedial alternatives to restore
regional groundwater quality and the use of well fields for municipal supply. The project was completed under
the oversight of the USEPA under RCRA and the LARWQCB under the state water code.
- Completed detailed hydrogeologic studies and analyses, designed final groundwater monitoring systems, and
prepared a final groundwater monitoring program for the Laidlaw Environmental hazardous waste landfill in
Pinewood, South Carolina, as part of a RCRA Part B permit application. Also completed investigation of
shallow groundwater contamination and developed a control strategy to limit the migration of contamination in
accordance with applicable permit requirements. During the adjudicatory hearings for the Part B permit, served
as the primary expert witness for the permit applicant on hydrogeologic characterization, groundwater
monitoring and landfill integrity issues.
- Served as a member in an expert international (US and Canadian) panel to develop an environmental
management strategy and remediation plans for Laidlaw Environmental for the control of soil and groundwater
contamination at a former waste oil and solvent disposal site near Montreal, Canada. The site was used for the
disposal of a range of bulk organic liquids into a former gravel -mining pit. Liquid organic wastes migrated as a
DNAPL into underlying fractured bedrock zones and contaminated regional groundwater supplies. The site
closure was being conducted under the supervision of the Quebec Ministry of the Environment.
- Completed investigations of soil and groundwater contamination at the BKK landfill in West Covina,
California, as part of a program for closure of a former hazardous waste co -disposal landfill under a RCRA
Corrective Action program. The site was former used for the disposal of liquid hazardous wastes into an
unlined municipal landfill area. This project was performed under the oversight of the USEPA.
- Prepared hydrogeologic investigations, developed statistically based environmental sampling programs,
designed and constructed groundwater monitoring systems, conducted RCRA facility investigations, developed
statistically based closure plans for former hazardous waste lagoons, and provided regulatory support for
negotiation of federal, state, and local permits for two major RCRA hazardous waste landfills (near Bakersfield
and in the Imperial Valley) operated by Laidlaw Environmental in California. During later public and zoning
hearings for the operating permits, provided testimony on the site hydrogeology and environmental monitoring
programs. Also, provided turnkey groundwater compliance monitoring programs for a period of five years at
both facilities.
- Directed a RCRA facility investigation report and stabilization measures evaluation for soil/surface
water/sediment and groundwater contamination at a precious metals manufacturing facility in Massachusetts
under a consent agreement with USEPA (Region 1). This project has included extensive hydrogeologic and
aquatic investigations, environmental monitoring, risk assessment and environmental fate & transport modeling
to support the identification of site -related risks and developed focused stabilization measures for soil,
groundwater and storm water runoff. Contaminants of concern at the site that have been the focus of this work
include VOCs, metals, PCBs and radionuclides.
- Prepared a RCRA facility investigation, a corrective measures study and remedial plans and specifications for
the investigation of soil and groundwater contamination to support the closure of several unlined waste disposal
pits at an operating hazardous waste disposal facility in central Louisiana. The facility had been used for the
storage, treatment, and recovery of fuel products from waste oils and related organic liquids. Sludge from the
thermal treatment (distillation) units was disposed into two unlined pits. Contamination (oil and solvents)
migrated into underlying soils and groundwater. The facility was required to remove the wastes and install a
groundwater remediation system as part of the implementation of a new master plan to develop a regional
waste management facility. ENVIRON's services were provided to the facility owner, the largest commercial
hazardous waste management facility operator in North America.
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Rob L. Powell, PhD, PE
- Developed an environmental risk management program and statistical sampling design to evaluate waste
classification and direct the reuse/disposal strategies for certain combustion co -product materials (gypsum and
fly -ash) under federal and California state hazardous waste criteria in accordance with procedures prescribed
in CCR Title 22 and 40CFR Part 261.
- Completed an analysis of the performance of natural -clay liner for a wastewater storage lagoon near Barstow,
California on behalf of Southern California Edison Co. to demonstrate compliance with regulations under the
California Water Code. The project resulted in an agreement by the RWQCB that the pond liner systems meet
the functional requirements of the liner standards under CCR Title 26.
- Provided supervision and oversight of a RCRA facility assessment at a facility in Roebuck, South Carolina on
behalf of the owner.
Litigation/Mediation Services and Expert Testimony
Dr. Powell provides litigation/mediation consulting, negotiation, and expert testimony services in cases involving
the recovery of damages to property and personal injury from contaminants in the natural environment; the
consistency of remedial investigations and remedial/removal actions with the requirements of the NCP, insurance
cost recovery, and cost allocation. He has also testified in administrative and zoning hearings regarding
environmental permitting of commercial hazardous waste facilities. Representative projects include:
- Provided expert services and trial testimony in defense of Tampa Electric in a property damage/cost recovery
claim related to the alleged past disposal of MGP wastes on a property in N. Miami, FL.
- Provided expert services and testimony to a major oil company in defense of a NRDA claim filed by the state of
NJ related to the releases of gasoline from a service station in southern NJ.
- Provided expert services and testimony on behalf of a major utility in an insurance cost recovery claim related
to contaminantion at numerous former MGPs on Long Island, NY.
- Provided expert hydrologic services in defense of a Clean Water Act criminal investigation by the US Attorney
related to the discharge of storm water and solid wastes from an operating MSW landfill in Hawaii.
- Provided expert services and testimony to a major pipeline/terminal operator in defense of a claim filed by the
state of NJ related to alleged releases of gasoline and MTBE at an operating terminal in Cherry Hill, NJ.
- Provided expert services to a pipeline operator in defense of claims filed by a nearby landowner related to
historic releases of hydrocarbons from a pump station in Danielsville, GA.
- Provided expert services and testimony in a property damage case involving the release of gasoline/MTBE to
groundwater in Hartford County, Maryland.
- Provided expert services and testimony in an arbitration hearing related to indemnity claims for past and future
costs for investigation and remediation of soil and groundwater contamination at a petroleum refinery in
Louisiana.
- Provided an expert report and testimony in a property damage and personal injury claim related to the release
of gasoline/kerosene from a convenience store and gasoline station in northern Indiana. Subsequently
provided expert reports and testimony in a mediation of claims against a past owner for contribution to site
cleanup costs at five gasoline stations in northern Indiana. This work included an analysis of forensic data to
quantify the relative amounts of petroleum (principally gasoline) releases that occurred prior to the sale of the
properties to the current owner.
- Provided an expert report and testimony on a RCRA claim and enforcement action by the USEPA related to the
future closure of waste management units at a magnesium extraction facility in central Utah.
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Rob L. Powell, PhD, PE
- Provided expert testimony in a series of bankruptcy estimation hearings related to the value of CERCLA claims
by the USEPA against the estate of a large international mining and smelting/refining company.
- Provided expert testimony in an international arbitration case involving the recovery of environmental response
costs for soil and groundwater contamination, environmental compliance, and worker Health & Safety pursuant
to a contract indemnity. The principal environmental issues in the cases related to the release of chlorinated
solvents from degreasing operation at former and operating aircraft fastener manufacturing facilities in the US
and Europe.
- Provided expert testimony in Louisiana state court on behalf of Clean Harbors in a citizen's lawsuit related to
the closure of former waste management lagoons on a hazardous waste management facility near Baton
Rogue, LA. Testimony related to the nature of current contamination in the vicinity of the closed lagoons and the
potential for migration into groundwater and nearby surface waters.
- Provided expert and negotiation services to Lockheed -Martin in the settlement of claims by the city of San
Francisco to recovery the costs for the investigation and remediation of jet fuel releases discovered during the
redevelopment of the new international terminal at the San Francisco International Airport.
- Provided expert testimony services on behalf of a semiconductor client in support of settlement mediation
negotiations for claims related to the release of chlorinated solvents into shallow aquifers in Santa Clara
County, California. These claims were successfully mediated under the supervision of a federal District Court
judge in San Jose, California.
- Provided deposition and trial testimony in federal district court regarding the nature, extent and source of
contamination, the allocation of future remedial costs among PRPs, and the consistency of the RI/FS and past
removal actions with the National Contingency Plan at a former wood -treating plant in Charleston, South
Carolina.
- Prepared a cost allocation and NCP consistency analysis for a multiparty NPL site in Utica, NY involving a
former manufactured gas plant, tar recovery plant, gas oil refinery, petroleum storage terminals, chemical plant,
municipal harbor and dredge spoil areas. The allocation analysis formed the basis for opinions that were
presented in an expert report in a cost recovery lawsuit filed in federal District Court. Subsequently provided
deposition testimony in support of the allocation analysis.
- Prepared an analysis of the relative contribution by various PRP sectors (industrial, commercial, municipal, small
quantity generation) of hazardous substances to five municipal landfills in the New York City area as part of
litigation support to various PRPs in a Superfund cost recovery action. Also analyzed the associated
environmental impacts of leachate discharges from the landfills into adjoining tidal and marine estuaries.
Subsequently, Dr. Powell was retained by a special master to the federal district court in New York to provide
expert scientific services in support of the court's mediation of a lawsuit by private citizens against the city of
New York regarding the extent of engineering controls that should be installed to control the migration of
leachate into adjoining tidally controlled estuaries from a particular landfill.
- Provided litigation support to a South Carolina electric and gas company in a negotiation with the city of
Charleston related to the former operation of an MGP and the alleged damages to nearby properties owned
by the city. This project also included an analysis of the potential increase in construction costs for a new city
aquarium and marina, and a stormwater protection project, from manufactured gas plant -related contaminants
in shallow soil and groundwater.
- Provided litigation support and deposition testimony on allocation and NCP consistency in a CERCLA cost
recovery case in Newark, California, related to the remediation of a facility undergoing redevelopment as a
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Rob L. Powell, PhD, PE
brownfield site, following over 100 years of operation of metals manufacturing. The case was won in summary
judgment in favor of ENVIRON's client on NCP consistency issues.
- Provided expert litigation support services to a major international oil company in a negotiation with the Port of
San Diego related to the allocation of costs for cleanup of hydrocarbon jgasoline and diesel fuel) and coal tar
releases completed by the Port as part of a Brownfields redevelopment project.
- Provided expert litigation support on issues of NCP consistency for the recovery of costs related to the closure of
waste lagoons at a facility manufacturing PCP -based wood treating chemicals in Newark, California.
- Prepared a cost allocation analysis of former owner/operators and generators of wastes disposed of in a
municipal landfill in central California. This analysis was used to provide information to the California EPA for
its consideration in preparing an NBAR for this state Superfund site.
- Provided litigation support to a PRP to examine cost allocation among former owner/operators of two wood -
treating plants in Missouri and Louisiana.
- Provided litigation support and deposition testimony on behalf of an industrial client, related to environmental
insurance claims for soil and groundwater contamination at multiple facilities throughout the US.
- Prepared an expert report and provided deposition testimony for an insurance claim related to environmental
releases from multiple aerospace test/manufacturing facilities in California.
- Prepared an expert report and provided deposition testimony on behalf of a major international oil company
for an insurance claim related to environmental releases from multiple petroleum refineries and tank farm
facilities throughout the US.
- Prepared an expert report and provided deposition testimony for an insurance claim related to environmental
releases from a former manufacturing facility in Wilmington, North Carolina. A central issue in the case was
the allocation of future remediation costs among potentially divisible sources of onsite DNAPL-VOC
contamination.
- Prepared an expert settlement report and participated in settlement negotiations for the recovery of insurance
related to environmental conditions at 45 MGP sites in the mid -western US on behalf of a major gas production
and transmission company.
- Prepared an expert report and provided deposition testimony in support of litigation by the Southern California
Gas Company for the recovery of insurance for environmental conditions at 29 former MGP sites in southern
California.
- Prepared an expert report and presented deposition testimony on behalf of DOW Chemical Company in a
case seeking recovery of past and future costs for environmental corrective action at DOW's chemical
manufacturing plants in Freeport, Texas.
- Prepared an expert report and provided deposition testimony on behalf of Union Pacific Corporation in an
insurance cost recovery case related to soil and groundwater contamination from its former operation of a
major locomotive and rail -car manufacturing facility in Sacramento, California.
- Provided deposition and trial testimony in federal District Court regarding the extent of contamination, costs to
remediate, and the potential for community exposure in a property damage case related to a gasoline release
in a residential area in Columbia, South Carolina.
- Provided expert consulting services in a cost recovery suit related to the rupture of a regional pipeline
transporting gasoline near Davis, California. Services focused on an evaluation of the reasonableness of
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Rob L. Powell, PhD, PE
response costs and the forensic reconstruction of the mechanisms/actions that contributed to the initial release
and subsequent spread of gasoline in nearby irrigation canals.
- Provided expert and deposition services to the owner of a large former "truck stop" near Sacramento, California
that was an ongoing Brownfields redevelopment project related to the recovery of costs from former
owner/operators for the remediation of soil and groundwater for gasoline and diesel -range hydrocarbons.
- Provided litigation consulting support and presented trial testimony in state court regarding the source and
extent of groundwater contamination and future remedial costs in a trespass/property damage case in
Greenville, South Carolina.
- Testified before the California State Water Resources Control Board regarding proposed regulations on vadose
zone monitoring at waste disposal sites.
- Provided expert testimony at administrative hearings on the environmental setting, groundwater conditions, and
monitoring programs for hazardous waste landfills in South Carolina and California.
- Provided deposition and trial testimony in state court for a public water utility in Florida regarding the source
and extent of groundwater contamination in a major county -owned well field near Tampa, Florida.
Other General Engineering and Hydrology Practice
Designed and supervised the installation and operation of a system to recover PCB- contaminated oil and VOCs
from a shallow water table at a chemical manufacturing facility in northern NewJersey for compliance with the
state ECRA statute.
Provided expert consulting support to Hillsboro County, Florida, for the permitting of a major waster disposal
landfill at a facility near Tampa. The waste disposal facility was proposed to be used for the disposal of acidic
gypsum wastes from the manufacturing of phosphate -based fertilizers by extraction with sulfuric acid.
Evaluated the hydrologic impacts of land application of wastewater effluent on water resources in Orange
County, Florida, to demonstrate compliance with operating state permits.
Conducted a flood protection analysis and developed a management strategy for the South Florida Water
Management District to control agricultural discharges of storm water into drainage canals in St. Lucie County,
Florida.
Evaluated the feasibility of groundwater and surface water supply development on behalf of a municipal water
utility in western Florida.
Prepared a real-time flood forecasting system to optimize flood protection and water supply objectives for a major
municipal reservoir in Manatee County, Florida.
Evaluated the hydrologic impact of major municipal well field pumping on lake levels and wetlands near Ft.
Lauderdale and Tampa, Florida.
Prepared numerous due diligence Phase I reviews for acquisition of industrial and hazardous waste treatment and
disposal facilities.
Conducted an in-depth due diligence review of environmental issues on behalf of an investor group as part of an
acquisition/reorganization of an airline, following their bankruptcy.
Managed multidisciplinary projects including flood hazard analysis, flood protection, sediment and erosion
control, dam and reservoir analysis and design, lake restoration, surface mining impact evaluations, combined
sewer overflow conveyance and storage systems, and solid waste disposal facilities in the mid -Atlantic and
southeast regions of the US.
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Rob L. Powell, PhD, PE
Designed remedial measures for surface drainage and leachate control; directed restoration and closure; and
performed water quality data analysis for a hazardous waste landfill, Glen Burnie, Maryland.
Prior to joining ENVIRON, Rob held the following positions:
Manager of Water Resources Engineering Services, Gulf Coast Area; Camp Dresser & McKee, Inc., Tampa,
Florida
Faculty Research Associate; University of Maryland, Department of Civil Engineering, College Park, Maryland
Department Head/Senior Engineer; Water Resources Division, Greenhorne & O'Mara, Inc, Riverdale, Maryland
Graduate Research Assistant; Department of Civil Engineering, University of Maryland, College Park, Maryland
Project Engineer; Water Resources Division, Greenhorne & O'Mara, Inc., Riverdale, Maryland
Design Engineer; Dewberry, Nealon & Davis, Fairfax, Virginia
CREDENTIALS
Registrations and Certifications
Registered Professional Engineer, State of Maryland, 1977
Registered Professional Engineer, State of Florida, 2006
Professional Activities
Member, American Society of Civil Engineers
SELECTED PUBLICATIONS & PRESENTATIONS
Calise, SJ., and R.L. Powell. 1984. Microcomputer based management of land disposal systems. Paper presented at
the ASCE Annual Meeting (Florida Section), September.
Powell, R.L., and Y.M. Sternberg. 1983. Deterministic models of uncertainty for regional contaminant transport systems.
Paper presented at the National Water Well Association -Eastern Regional Conference on Groundwater
Management, October.
Onasch, C., R.L. Powell, and R.M. Ragan. 1982. Near surface regional groundwater systems modeling and potential
applications for remote sensing. AGRISTARS Report CP-G2-04361. NASA-GSFC, October.
Hawley, M.E., and R.L. Powell. 1982. Risk analysis in groundwater quality testing at hazardous waste landfills. Paper
presented at the 14th Mid -Atlantic Industrial Waste Conference, June.
Cook, D.E., R.H. McCuen, and R.L. Powell. 1980. Water quality projections: A preimpoundment case study. Water
Resource Bulletin 16(1).
Dew, F.W., R.H. McCuen, and R.L. Powell. 1978. A programming approach to planning for agricultural resource
allocation and irrigation system design. Journal of the Washington Academy of Science 68(4).
Fisher, G.T., R.H. McCuen, R.L. Powell, and WJ. Rawls. 1977. Flooding flow frequency for ungaged watersheds: A
literature evaluation. ARS-NE-86. Agriculture Research Service, USDA, November.
McCuen, R.H., R.L. Powell, and R.C. Sutherland. 1976. Relative importance of factors affecting pollutant loadings in
runoff from urban stream. In Utility of Urban Modeling. ASCE Technical Memorandum No. 31, July.
environcorp.com

TRIAL/DEPOSITION TESTIMONY SUMMARY
Robert L. Powell, Ph.D.
YEAR
CASE NAME
VENUE
CASE NO.
(Trial/De o)
1993
Johnson, et al. v. Hoechst Celanese and Daniel Construction
State of South Carolina, Court of Common Pleas
90-CP-23-2180
(D/T)
1994
The Alpine Forrest Partners v. Crown Central Petroleum Corporation
U.S. District Court of South Carolina, Columbia Division
3:90-2730-0
(T)
1994
Braswell Shipyard, Inc. v. Beazer East, Inc.
U.S. District Court, District of South Carolina, Charleston Division
2:89-455-8
(D/T)
1994
City of West Covina v. BKK Corporation
Superior Court of California, County of Los Angeles
KC 013713
(D)
BC 083729
1994
Snyder General v. Century Indemnity
U.S. District Court, Northern District of Texas,
3:93-CV-0832-D
(D)
Dallas Division
1995
Angelo K. Tsakopoulos v. Phillips Petroleum Company, et al.
Superior Court of California, County of Sacramento
526157
(D)
1995
James R. Thomason, Jr. v. Ortho Pharmaceutical Corporation
U.S. District Court, District of South Carolina, Greenville Division
6:94-2851-3
(D)
1996
Union Oil Company of California v. The Aetna Casualty & Surety
Superior Court of California, County of Los Angeles
BC 028271
(D)
Company
1996
Atlantic Richfield Company v. Aetna Casualty & Surety Company of
Superior Court of California, County of Los Angeles
BC 015575
(D)
America, et al.
1997
Employers Insurance of Wausau v. McGraw -Edison Company, et al.
Circuit Court of the 18th Judicial Circuit, Dupage County, Illinois
91 MR 0256
(D)
1997
AMOCO Chemical Company, et al. v. Certain Underwriters at Lloyd's
Circuit Court of Cook County, Illinois
93L8484
(D)
of London, et al.
1998
Southern Pacific, et al. v. Certain Underwriters at Lloyd's of London,
Superior Court of California, County of Los Angeles
BC 154722
(D)
et al.
1999
Niagara Mohawk Power Corporation v. Jones Chemical et. al.
U.S. District Court, Northern District of New York
95-CV-717
(D)
1999
A.O. Smith Corporation v. Rheem Manufacturing Corporation
U.S. District Court, Northern District of California.
C 94 03887 CW
(D)
1999
Olin Corporation v. Fisons Corporation, et al.
U.S. District Court for the District of Massachusetts
CA93-11166-WGY
(D)
2000
Raytheon Company v. Certain Underwriters at Lloyd's London, et al.
Superior Court of California, County of San Francisco
950755
(D)
2002
Associated Indemnity Corporation and The American Insurance
U.S. District Court, Eastern District of Michigan, Northern Division
No. 99 CV 10426
(D)
Company v. The Dow Chemical Company
The Dow Chemical Company v. Fireman's Fund Insurance Company,
No. 99 CV 10427
et al.
6/28/16

TRIAL/DEPOSITION TESTIMONY SUMMARY
Robert L. Powell, Ph.D.
YEAR CASE NAME VENUE CASE NO.
(Trial/Depo)
2005/2010
Merco Group at Aventura landings et.al. v. Tampa Electric Company,
Circuit Court for Miami -Dade County, Florida
04-22909
(D/T)
et.al.
2006
Terry Giauque et.al. v. Clean Harbors Plaquimine, LLC et al.
18' Judicial District Court, Parrish of Iberville, Louisiana
60195
(D/T)
2007
Keystone Consolidated Industries, Inc. and Valhi v. Employers Mutual
US District Court for the Central District of Illinois
03-1201
(D)
Liability Insurance Company of Wisconsin
2007
City of Rialto, et.al. v. US Department of Defense et al.
US District Court, Central District of California
ED CV 04-00079 PSG
(D)
2007-8
Official Committee of Unsecured Creditors v. ASARCO LLC
US Bankruptcy Court, Southern District of Texas
05-21207
(D/T)
2007
Larry Bowens et al. v. 7-Eleven, Inc. et al.
Elkhart (IN) Superior Court III
20D03-0209-CT-48
(D)
2007
United States vs. U. S. Magnesium Corporation
US District Court for the District of Utah, Central Division
2:01CV004013
(D)
2007
Occidental Petroleum Corporation and Oxy USA, Inc. v.
Private Arbitration
NA
(D/T)
CITGO Petroleum Corporation
2007
Kurt Petersen, et al. v. D.R. Horton, Inc.
Circuit Court for Montgomery County, Maryland
268778-V
(D/T)
2007
ALCOA v. Fairchild Industries
Private Arbitration
NA
(T)
2009-10
USF&G et al. v. SOCO West, Inc.
US District Court for the District of Montana
CV-04-29-BLG-RFC
(D/T)
CV-08-29-BLG-RFC
2010
State of Alabama et al v. Alabama Wood Treating Corporation, et al.
US District Court for the Southern District of Alabama
1:85 CV-0642-CG-C
(D)
2010-2015
BASF Catalyst v. Allstate Insurance Co. et al.
Superior Court of New Jersey
MID-L-2061-05
(D/T)
2010
St. Croix Renaissance Group v. St. Croix Alumina
District Court of the Virgin Islands, St. Croix Division
CV-04-067
(D/T)
2010
U.S. Virgin Islands, Department of Planning and Natural Resources v.
District Court of the Virgin Islands, St. Croix Division
CV 2007/01 14
(D)
St. Croix Renaissance Group, LLLP et al.
6/28/16

TRIAL/DEPOSITION TESTIMONY SUMMARY
Robert L. Powell, Ph.D.
2012
(D/T)
Lee E. Buchwald vs. The Renco Group, Inc.
U S Bankruptcy Court, Southern District of New York
Civil Action No: 2:012-
CV-0040B
2012
(D)
The Bank of NY Mellon Trust Co. vs. Morgan Stanley Mortgage
Capital
U S District Court, Southern District of New York
Case No: 11 CV 0505
(CM)(GWG)
2012
(D/T)
Angelo's Aggregate Materials LTD v. state of Florida DEP
FDEP hearing before FL Administrative Law Judge
Case No. 09-1543
2013
(D/T)
Long Island Lighting, Keyspan Corp. v. Alliance Underwriters
Insurance Co. et al.
Supreme Court, County of New York
Index No. 604715/97
2013
(D)
NJ Department of Environmental Protection vs. Atlantic Richfield et al.
US District Court, Southern District of New York
No. 08 CIV. 00312
2014
(D)
Richard Bennett v. Colonial Pipeline Company
Superior Court of Gwinnette County, Georgia
No.13A03746-3
6/28/16