R. Hennet - Rebuttal Report

Rebuttal Report of
Remy J.-C. Hennet
Allen Steam Station
Buck Steam Station
Belews Creek Steam Station
Cliffside Steam Station
Marshall Steam Station
Mayo Steam Station
Roxboro Steam Electric Plant
S.S. PAPADOPULOS & ASSOCIATES, INC.
Environmental & Water -Resource Consultants
September 30, 2016
7944 Wisconsin Avenue, Bethesda, Maryland 20814-3620 9 [phone]

Rebuttal Report of
Remy J.-C. Hennet
Allen Steam Station
Buck Steam Station
Belews Creek Steam Station
Cliffside Steam Station
Marshall Steam Station
Mayo Steam Station
Roxboro Steam Electric Plant
Prepared for.
Duke Energy Carolinas, LLC
Prepared by:
Remy J.-C. Hennet, PhD
S.S. PAPADOPULOS & ASSOCIATES, INC.
Environmental & Water -Resource Consultants
September 30, 2016
7944 Wisconsin Avenue, Bethesda, Maryland 20814-3620 9 [phone]

2.2- bV6VD06nr02 8F b220CIVIE2' INC'
Table of Contents
Page
Listof Appendices.......................................................................................................................... ii
Section1 Introduction................................................................................................................ 1
Section 2 Decreasing Arsenic Trends in South Carolina Ash Basins ........................................ 2
Section 3 Response to Comments and Issues Raised by Plaintiffs' Experts ............................. 4
Dilution of Plume Concentrations in Drinking Water Wells ..................................... 4
Dissolved Oxygen in Groundwater............................................................................ 4
Boronas a Tracer....................................................................................................... 4
ContaminantFlux....................................................................................................... 5
Monitored Natural Attenuation.................................................................................. 5
Trivalent and Hexavalent Chromium......................................................................... 6
Decreasing Concentration Trends at the Roxboro Site .............................................. 6
Appendices
I

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
List of Appendices
Appendix A Additional Documents Considered and/or Relied Upon

REPORT

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
Section I
Introduction
I was retained by Duke Energy Progress, LLC and Duke Energy Carolinas, LLC ("Duke
Energy") to evaluate the geochemical data that has been collected to characterize the nature and
extent of any groundwater contamination from the operation of coal ash basins in North Carolina.
My tasks included the evaluation of whether impacts have occurred to surface waters and water
supply wells and to analyze and evaluate certain allegations made by Plaintiffs' experts with
regards to the appropriateness of the proposed remedial actions for the basins. I previously
submitted reports on my evaluations for seven Duke Energy sites: Allen Steam Station, Belmont;
Buck Steam Station, Salisbury; Belews Creek Steam Station, Belews Creek; Cliffside Steam
Station, Mooresboro; Marshall Steam Station, Terrell; Mayo Steam Station, Roxboro; and
Roxboro Steam Station, Roxboro. These reports are referenced in Appendix A.
This report is a supplement to my previously submitted reports. This report addresses
recent comments and additional issues raised by Plaintiffs' experts in supplemental reports, report
addenda, and deposition statements. In particular, this supplemental report addresses statements
and issues raised by Plaintiffs' experts Cosler, Hutson, Parette, and Campbell and Spruill.
My previous reports included my opinions, bases for opinions, Curriculum Vitae, and
compensation. There is no change to any of those statements. The additional information not
included in my previous reports, considered for this supplemental report, is referenced in Appendix
A.
1

2-2- bVbVDObnr02 9� V220CIV1E2' IWC'
Section 2
Decreasing Arsenic Trends in South Carolina Ash Basins
Plaintiffs' counsel provided experts Campbell, Spruill, and Hutson with groundwater
analytical data for arsenic in groundwater at two facilities in South Carolina. Plaintiffs' experts
concluded that these data provide a clear example of the beneficial impact that ash removal can
have on groundwater quality. Plaintiffs' experts provided little information on operations at these
sites that could be used to support their conclusion. Only two facilities were identified in Plaintiffs'
expert reports, namely the Grainger and Wateree power plants. Plaintiffs' experts based their
conclusion on concentration trends for arsenic at three monitoring wells at the Grainger power
plant and two monitoring wells at the Wateree power plant.
Plaintiffs' experts did not evaluate trends for compounds other than arsenic. Nor did they
attempt to consider site specific activities, other than excavation, that could have contributed to
the reported trends.
To better understand the conditions that led to the data trend cited, I visited the Wateree
power plant on September 27, 2016, and discussed the geology and hydrogeology of the site area,
and the details of site operations, with knowledgeable plant employees. What I discovered through
this inquiry is that several relevant changes in site operations have taken place during the period
of decreasing arsenic concentrations. These relevant changes and information obtained from this
inquiry include:
• The geology of the site materials consists of alternating sandy and clayey layers. Bedrock
is encountered at a depth of approximately 560 feet below ground surface. The ash basin
was put in operation in 1970/71. The basin is unlined and was previously a sand and gravel
quarry.
The removal of ash from the ash basin started in the 1990s and continued afterwards
(Wateree Station Semi -Annual Status report, July -December 2013; Table 1). The removal
of ash is for re -use by the cement industry.
A cut-off wall was constructed along the eastern berm of the ash basin in 2011/12. The cut-
off wall was anchored into native materials beneath the ash. The cut-off wall includes an
impermeable liner. The cut-off wall was constructed to mitigate seepage that discharged to
the Wateree River. The length of the cut-off wall is approximately 700 ft. Monitoring well
MW-11, one of the two wells with a decreasing arsenic trend at the site, is located on the
other side of the cut-off wall, away from the ash basin. The cut-off wall has apparently
achieved its purpose for mitigation of seepage.
• The removal of ash from the basin for transfer to an on -site landfill started in 2012. The
excavation has been gradual and continues to be so. To date, approximately half of the ash
has been removed from the basin. The native material in contact with the ash has not been
removed in any section of the basin.
Dewatering of the ash basin started in 2012. Sluicing of ash to the basin decreased in
frequency starting in 1998. Sluicing of bottom ash ceased in 2013. All sluicing of ash
ceased entirely in 2016.
2

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
�S
There are two wells relied upon by Plaintiffs' experts to support their opinion that the
decrease in arsenic concentration is due to the excavation of the ash. One well, MW-3, is located
on the north berm of the polishing pond. The polishing pond remains full of water, and the
excavation of the ash from the ash basin is unlikely to control arsenic concentration in that well.
The second well, MW-11, is located between the river and the ash basin, in the area of seepage
that discharged to the river prior to the construction of the cut-off wall.
Plaintiffs' experts failed to consider the site specific information in their interpretation of
the arsenic trends in the two Wateree wells. In particular, they failed to consider the dewatering of
the ash basin that started in 2012, and the construction of the cut-off wall in 2011/12 to mitigate
seepage.
The decreasing trend for arsenic concentration at MW-3 (the well located on the north berm
of the polishing pond, not the ash basin) is unlikely to be related to ash excavation. The location
of the well is not downgradient from the ash basin that is being excavated.
The decreasing trend for arsenic concentration at MW-I I must be interpreted in the context
of site operations. The construction of the cut-off wall that mitigated seepage undoubtedly played
a role in the arsenic trend. MW-11 is located between the ash basin and the seepage/river area, and
is separated from the ash basin by the impermeable cut-off wall. The trend is also a result of the
dewatering of the ash basin. Although the on -going excavation of the ash from the basin may have
played a role in the arsenic trend, it is not the primary cause of that trend.
In my opinion, the construction of the cut-off wall and the dewatering of the ash basin are
the primary causes of the decrease in arsenic concentrations at MW-11. A cap -in -place remedy
would similarly involve dewatering of the ash basin. The cut-off wall is a hydraulic control
measure that could be implemented as an addition to a cap -in -place remedy, if necessary.
The arsenic concentration trends at MW-3 or NW-11 at the Wateree Power Plant are not
evidence of the effectiveness of excavation as a remedy for groundwater contamination. Similar
trends can be expected to result from the implementation of a cap -in -place remedy, natural
attenuation, and/or hydraulic control measures.
3

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Section 3
Response to Comments and Issues Raised by Plaintiffs'
Experts
Plaintiffs' experts Cosler, Hutson, Parette, Campbell and Spruill supplemented their
original reports for some or all of the Duke Energy sites at issue. My response to certain of those
comments are as follows:
Dilution of Plume Concentrations in Drinking Water Wells
Cosler claims that drinking water supply -well concentrations likely underestimate coal -ash
contaminant concentrations in the surrounding bedrock aquifer by a factor on the order of 50 to
100.
Cosler relied on calculations but provided no geochemical data that would support his
contention. Cosler's calculations are based on assumptions that do not represent reality. For a
drinking water well to be impacted by an ash basin, the well would have to be located downgradient
from the basin, and the impact would have to be evidenced by the presence of boron and other
chemicals that are characteristic of the ash basin, at concentrations that are above the background
range. Absent these conditions, there is no evidence of an impact. The attempt by Cosler to apply
a concentration multiplier to the drinking water wells data is simply speculative and unreliable.
Dissolved Oxygen in Groundwater
Cosler states that dissolved oxygen moves at the same speed as groundwater in the
subsurface. Cosler also states that the dissolved oxygen plume migrates at a much faster rate (e.g.,
10 to 100 times faster) than dissolved coal ash constituents. These statements and migration rate
are not supported by data or relevant calculations, and ignore the fact that dissolved oxygen is
reactive in the subsurface (dissolved oxygen is readily consumed by microbial activity and other
processes). Dissolved oxygen is not conservative in the groundwater environment and its migration
rate cannot be simply equaled to the groundwater migration rate.
Boron as a Tracer
Cosler states that boron is not a conservative tracer. To support his statement, Cosler cites
to laboratory data from certain literature and from the Corrective Action Plan reports. Cosler
apparently misses the point and context as to the use of boron as a tracer for ash basin impacts on
groundwater. First, boron has the lowest Kd and retardation factor among the parameters that were
tested in the laboratory column and batch studies with site materials, as reported in the Corrective
Action Plan.' This indicates that boron is typically the most mobile compound tested on site
materials. Second, boron concentration in the ash basin water is much higher (e.g., 2 or 3 orders
of magnitude) than in background groundwater. Third, boron in groundwater is typically present
' For material from the Cliffside site, Kd value for molybdenum was reported to be lower than for boron (all other
compounds tested showed higher values). Molybdenum, however, is not relevant because it is not a constituent of
interest at the Cliffside site.
2

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
as an uncharged chemical species (boric acid). In this form, boron interacts only weakly with the
aquifer matrix. These facts make boron an excellent tracer to delineate the ash basin impacts to
groundwater. Although at some sites sulfate may have retardation factors lower than boron, sulfate
is ubiquitous and variable in background groundwater. This renders sulfate less reliable than boron
for tracing the ash basin impacts.
My opinion is that boron is an excellent tracer for the ash basin impacts because of its low
retardation factor, low background concentration in groundwater, and high concentration in the
ash basins. I reached this conclusion after evaluating all compounds for which data has been
provided for the sites, including sulfate.
Contaminant Flux
Plaintiffs' expert Parette dismisses the reduction of flux from the ash materials under a Cap-
in -place remedy as largely irrelevant. In so doing, he relies on the fact that the North Carolina 2L
standards are expressed in terms of concentration and not flux units.
Parette misses the importance of flux for the evaluation of environmental impacts. First,
for groundwater impact on surface water, it is the flux of contaminant from groundwater that
determines surface water concentration. Flux is therefore highly relevant in that context: a
decrease in groundwater flux results in a decreased concentration in surface water. Second, the
decrease in contaminant flux from the ash material to groundwater under a cap -in -place remedy
would result, because much less water would be contacting the ash material, and consequently
much less potential for contaminant leaching. The effect of this decrease would be a decrease in
the size of the groundwater plume delineated at a given concentration. Decreasing the extent of
the plume is one goal of remediation.
Monitored Natural Attenuation
Parette criticizes my opinion that a cap -in -place and monitored natural attenuation remedy
is reasonable and adequate for the sites. One criticism is that I did not consider downgradient
lateral migration of the COI plumes at each of these sites under a cap -in -place scenario. My opinion
remains that under a cap -in -place remedy, the vertical and horizontal (this includes the lateral
dimension) extent of the contaminants plumes will decrease in response to the remedy. The
primary actions that will drive the decrease in plume extent are the dewatering of the ash basins
and the reduction of infiltration through the ash from capping. Natural attenuation will further
reduce the extent of the contamination plume.
Parette opines that monitored natural attenuation is not an appropriate remedy for the ash
basins, because boron, sulfate, and cobalt are mobile in groundwater. Parette cites to a statement
from an EPA guidance document to support his opinion: "EPA generally expects that MNA will
only be appropriate for sites that have a low potential for contaminant migration" (USEPA 2015).
Parette fails to consider that Duke Energy is not proposing monitored natural attenuation as the
remedy for the sites, but only as a supplemental measure to the cap -in -place remedy. The remedy
proposed by Duke Energy includes the implementation of additional measures to cap -in -place and
monitored natural attenuation, as necessary, to achieve closure of the sites.
5

2-2- bVbVDObnr02 9� V220CIV1E2' JWC'
1SU
Trivalent and Hexavalent Chromium
Parette questions my opinion that trivalent chromium is prevalent over hexavalent
chromium in groundwater at the sites. There is ample literature on the subject that conclude that
trivalent chromium is the main chromium species in coal ash (Shah et al. 2007, Goodarzi and
Huggin, 2001). Table 3 from Shah et al. 2007, illustrates this point.
Table 3
Speciation of chromILIM (in mg/kg)
Total
Cr`'
Cry' by difference
Cry `/Cr6 + 'y
Coal 10.1
0.065
10.035
99.4 0.6
Bottom ash 26.3
ND
—26.3
100 -
Fly ash 31.3
0.857
30.443
97.3 2.7
As recognized by Parette, thermodynamics also support the prevalence of trivalent
chromium over the hexavalent form in typical groundwater and reduced groundwater such as
occurs beneath and downgradient of the coal ash basins. Hexavalent chromium is often present in
grout material used to construct wells (see for example Hewlett 1988 as referenced in my previous
reports). When interpreting chromium data, it is important to account for the possibility that
hexavalent chromium in a well could result from the leaching of such materials.
Parette opines that trivalent chromium from coal ash migrates in groundwater to areas of
greater dissolved oxygen and becomes oxidized to hexavalent chromium. This statement is not
supported by site data or quantified in any way that would show any relevance for the sites at issue.
Decreasing Concentration Trends at the Roxboro Site
As discussed in my August 1, 2016 report on the Roxboro site, iron and manganese
concentrations decreased markedly over time, after the installation of an impermeable liner on top
of a portion of an ash basin in 2004. I consider the construction of the liner as a major operational
change. There were no other operational changes during the trend period (2002-2015) in the area
that could explain the decreasing concentration trends. In my opinion, the observed concentration
decreases in the monitoring wells reflect the decommissioning and partial lining of the ash basin.
Parette criticizes my interpretation of the trends as being indicative of decreased
concentrations that resulted from the partial capping of the ash basin. Parette argues that my
interpretation is unreliable because the wells monitor only a single depth at the three well locations.
I disagree. My opinion remains that the partial capping of the ash basin at Roxboro had
beneficial effects on groundwater quality. First, the three wells are located down gradient of the
portion of the ash basin that was capped with an impermeable liner. Second, Parette failed to realize
that the three wells are monitoring different depth intervals in the groundwater environment
(GMW-6 is screened between 433 to 448 ft MSL and monitors the transition zone, GMW-10 is
2

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
�S
screened between 446 to 461 ft MSL and monitors bedrock, and GWM-11 is screened between
448 to 463 ft MSL and monitors bedrock). Third, the screened interval in each well is 15 feet,
providing a wide depth interval to monitor the groundwater down gradient of the capped portion
of the ash basin. Fourth, the concentration decreases occur at all depth intervals. These data and
facts strongly support my opinion that the decrease in concentrations observed after the lining of
the ash basin had a beneficial effect on groundwater quality. The observation of the beneficial
effect of capping a portion of an ash basin is relevant and supports the implementation of the Cap-
in -place remedy proposed by Duke Energy for the sites at issue.
7

APPENDIX A

Appendix A
Additional Documents Considered
and/or Relied Upon

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
MSU
Additional Documents Considered and/or Relied Upon
Campbell, S.K., and R.K. Spruill. 2016a. Expert Report Addendum #1, Buck Steam Station, 1555
Dukeville Road, Salisbury, NC 28146. (Federal Case). August 30.
Campbell, S.K., and R.K. Spruill. 2016b. Expert Report Addendum #2, Buck Steam Station, 1555
Dukeville Road, Salisbury, NC 28146. (State Case). August 30.
Catawba Riverkeeper. 2016. SCE&G and Catawba Riverkeeper Reach Settlement on Coal Ash
Storage. http://www.catawbariverkeeper.org/issues/coal-ash-1/sce-g-and-catawba-
riverkeeper-reach-settlement-on-coal-ash-storage. September 18.
Cosler, D.J. 2016. Supplemental Expert Report of Douglas J. Cosler, Ph.D., P.E. Allen, Cliffside,
and Marshall Steam Station Ash Basins North Carolina. August 30.
General Engineering LLC. 1998. Wells MW-10 and MW-11. Hydrogeologic Assessment Report
Wateree Station South Carolina Electric and Gas Company. Eastover, South Carolina.
February 10 and April 23.
General Engineering LLC. 2015. Wateree Station: GW-12. March 12.
Geosyntec Consultants. 2014a. Amended Closure Plan. Wastewater Ash Ponds. Grainger
Generating Station. Conway, South Carolina. January.
Geosyntec Consultants. 2014b. Revised - Amended Closure Plan. Wastewater Ash Ponds.
Grainger Generating Station. Conway, South Carolina. August.
Goodarzi, F., and F.E. Huggins. 2001. Monitoring the Species of Arsenic, Chromium and Nickel
in Milled Coal, Bottom Ash and Fly Ash from a Pulverized Coal -Fired Power Plant in
Western Canada: Journal of Environmental Monitoring 3: 1-6.
HDR Engineering Inc of the Carolinas. 2016a. Comprehensive Site Assessment Supplement 2.
Allen Steam Station Ash Basin. August 2.
HDR Engineering Inc of the Carolinas. 2016b. Comprehensive Site Assessment Supplement 2.
Belews Creek Steam Station Ash Basin. August 11.
HDR Engineering Inc of the Carolinas. 2016c. Comprehensive Site Assessment Supplement 2.
Buck Steam Station Ash Basin. August 2.
HDR Engineering Inc of the Carolinas. 2016d. Comprehensive Site Assessment Supplement 2.
Cliffside Steam Station Ash Basin. August 8.
HDR Engineering Inc of the Carolinas. 2016e. Comprehensive Site Assessment Supplement 2.
Marshall Steam Station Ash Basin. August 4.
Hennet, R.J.-C. 2016a. Expert Report of Remy J.-C. Hennet. Allen Steam Station. Belmont, North
Carolina. June 30.
Hennet, R.J.-C. 2016b. Expert Report of Remy J.-C. Hennet. Belews Creek Steam Station. Belews
Creek, North Carolina. August 1.
Hennet, R.J.-C. 2016c. Expert Report of Remy J.-C. Hennet. Buck Steam Station. Salisbury, North
Carolina. June 30.
1

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Hennet, R.J.-C. 2016d. Expert Report of Remy J.-C. Hennet. Cliffside Steam Station. Mooresboro,
North Carolina. June 30.
Hennet, R.J.-C. 2016e. Expert Report of Remy J.-C. Hennet. Marshall Steam Station. Terrell,
North Carolina. August 1.
Hennet, R.J.-C. 2016f. Expert Report of Remy J.-C. Hennet. Mayo Steam Station. Roxboro, North
Carolina. June 30.
Hennet, R.J.-C. 2016g. Expert Report of Remy J.-C. Hennet. Roxboro Steam Station. Semora,
North Carolina. August 1.
Hennet, R.J.-C. 2016h. Photos and Notes from Wateree Site Visit. September 27.
Hutson, M.A. 2016a. Supplemental Expert Report of Mark A. Hutson, PG. Belews Creek Steam
Station Ash Basin Belews Creek, NC. August.
Hutson, M.A. 2016b. Videotaped Deposition of Mark A. Hutson, PG. State of North Carolina, ex
rel. North Carolina Department of Environmental Quality, and Roanoke River Basin
Association, Sierra Club, Waterkeeper Alliance, Cape Fear River Watch, Inc., Sound
Rivers, Inc. and Winyah Rivers Foundation vs. Duke Energy Progress, LLC. and State of
North Carolina, ex rel. North Carolina Department of Environmental Quality, and Catawba
Riverkeeper Foundation, Inc., Waterkeeper Alliance Mountaintrue, Appalachian Voices,
Yadkin Riverkeeper, Inc., Dan River Basin Association, and Southern Alliance for Clean
Energy v. Duke Energy Carolinas, LLC. 13-CVS-11032 and 13-CVS-14461. State of
North Carolina, County of Wake and State of North Carolina, County of Mecklenburg,
248.
Kleen Sites Geoservices. 1994. Wateree Well Logs: MW1, MW7, MW8, and MW-9. July.
LeBlanc, D.R. 1984. Sewage Plume in a Sand and Gravel Aquifer, Cape Cod, Massachusetts.
Water -Supply Paper 2218. U.S. Geological Survey.
Mixon, A.C., and GEI Consultants Inc. 2016. 2015 Annual Landfill Inspection Report for the
Wateree Station Class III Landfill in Eastover, SC. January 15.
Neupane, G., and R.J. Donahoe. 2013. Leachability of Elements in Alkaline and Acidic Coal Fly
Ash Samples during Batch and Column Leaching Tests: Fuel 104: 758-770.
Parette, R. 2016a. Supplemental Opinions on the Appropriateness of Monitored Natural
Attenuation in Conjunction with Cap -in -Place at the Allen, Belews Creek, Buck, Cliffside,
Marshall, Mayo, and Roxboro Steam Stations. August 30.
Parette, R. 2016b. Supplemental Opinions on the Appropriateness of Monitored Natural
Attenuation in Conjunction with Cap -in -Place at the Allen, Belews Creek, Buck, Cliffside,
Marshall, Mayo, and Roxboro Steam Stations. (Federal Case). August 30.
Parette, R. 2016c. Videotaped Deposition of Robert Parette, Ph.D., P.E. State of North Carolina,
ex rel. North Carolina Department of Environmental Quality vs. Catawba Riverkeeper
Foundation, et al. vs. Duke Energy Carolinas, LLC. 13-CVS-14661. State of North
Carolina in the General Court of Justice County of Mecklenburg Superior Court Division.
2

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
Santee Cooper. 2014. Letter from Susan W. Jackson to Chris Forrest, SCDHEC Bureau of Water
and Gary Stewart, SCDHEC Bureau of Land and Waste Management, Regarding: South
Carolina Public Service Authority. Santee Cooper Grainger Generating Station, Horry
County, NPDES Permit# SC0001104; Site ID# 00367, NPDES Groundwater Semi-annual
and Compliance Report for 2014. May 28.
Santee Cooper. 2016a. Grainger Generating Station Stacks Fall. www.santeecooper.com/about-
santee-cooper/news-releases/news-items/grainger-generating-station-stacks-fall. aspx.
February 7.
Santee Cooper. 2016b. Letter from Susan W. Jackson to S.C. Department of Health and
Environmental Control, Regarding: Santee Cooper Grainger Station - NPDES Permit#
SC0001104, NPDES Groundwater and Surface Water Semi-annual Report for 2016. May
26.
Shah, P., V. Strezov, K. Prince, and P.F. Nelson. 2008. Speciation of As, Cr, Se and Hg Under
Coal Fired Power Station Conditions: Fuel 87: 1859-1869.
South Carolina Department of Health and Environmental Control. 2010. Wateree Well Logs: GW-
lA. February.
South Carolina Electric & Gas. 2013a. Wateree Station Semi -Annual Status Report July -
December 2012. January.
South Carolina Electric & Gas. 2013b. Wateree Station Semi -Annual Status Report January - June
2013. July.
South Carolina Electric & Gas. 2014a. Wateree Station Semi -Annual Status Report July -
December 2013. January.
South Carolina Electric & Gas. 2014b. Wateree Station Semi -Annual Status Report January - June
2014. July.
South Carolina Electric & Gas. 2015a. Wateree Station Semi -Annual Status Report January - June
2015. July.
South Carolina Electric & Gas. 2016a. Wateree Station Semi -Annual Status Report July -
December 2015. January.
South Carolina Electric & Gas. 2016b. Wateree Station Semi -Annual Status Report January - June
2016. July.
Southern Environmental Law Center. 2016. South Carolina Coal Ash Removal Ahead of Schedule
While North Carolina Stalls. www.southemenvironment.org/news-and-press/news-
feed/south-carolina-coal-ash-removal-ahead-of-schedule-while-north-carolina-stal.
January 25.
SynTerra. 2016a. Comprehensive Site Assessment Supplement 1. Mayo Steam Electric Plant. July
7.
SynTerra. 2016b. Comprehensive Site Assessment Supplement 1. Roxboro Steam Electric Plant.
August 1.
3

2-2- bVbVDObnr02 9� V220CIV1E2' IMC'
U.S. Environmental Protection Agency (USEPA). 1994. Natural Attenuation of Hexavalew
Chromium in Groundwater and Soils. EPA Ground Water Issue. EPA/540/5-94/505.
October.