Federal Remediation
Technologies Roundtable
Meeting Summary

Federal
Remediation
Technologies
Roundtable
November 9,2010
Arlington, VA

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Table of Contents
ACTION ITEMS	1
WELCOME/INTRODUCTION	1
FRTR ANNOUNCEMENTS AND MEETING OBJECTIVES	1
Agency Announcements (Projects/Initiatives) & FRTR Subgroup Reports	1
Meeting Objectives	3
CHARACTERIZATION OF CONTAMINATION IN FRACTURED MEDIA	3
Addressing the Complexities of Contamination and Remediation in Fractured
Rock Aquifers	3
Tools for Characterization and Monitoring of Contaminated Fractured Rock	4
Demonstration and Validation of the Fracture Rock Passive Flux Meter	6
Fractured Bedrock Characterization and Effective Remedy Selection in
Region 4	7
Autopsy of a Small UST site in Bedrock: Implications for
Remedial Effectiveness	8
TREATMENT OF FRACTURED ROCK SITES	10
In Situ Bioremediation at FracRock Sites	10
Successful DNAPL Remediation Using Radio Frequency Heating and Return
to Thermal Equilibrium	12
Source Removal of VOC Contaminants in Bedrock, Letterkenny Army Depot,
Chambersburg, Pennsylvania	13
The Application of In Situ Chemical Oxidation (ISCO) in Fractured Bedrock
Using Geophysical Aided Design	15
Subsurface Characterization, Modeling, Monitoring, and Remediation of
Fractured Porous Rocks	16
MEETING WRAP-UP/NEXT MEETING AGENDA	 17
ATTACHMENTS	 18

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ACTION ITEMS
~ Information suitable for the development of new cost and performance case studies of
innovative technologies should be sent to Jim Cummings or Marti Otto.
WELCOME/INTRODUCTION
Arnold Layne, Director of the Technology Innovation and Field Services Division (TIFSD) in
the U.S. Environmental Protection Agency's (EPA) Office of Superfund Remediation and
Technology Innovation (OSRTI), welcomed the attendees to the 41st meeting of the Federal
Remediation Technologies Roundtable (FRTR). He thanked the members and presenters
responsible for developing the meeting's agenda on the topic of fractured rock characterization
and remediation. Noting the retirement from EPA of FRTR icon John Kingscott, formerly Chief
of the TIFSD Technology Assessment Branch, he introduced the current Acting Chief, Jim
Cummings. Layne reminded the attendees that as a public meeting, the FRTR proceedings would
be conducted using a Web conference tool to permit remote participants to watch the
presentations live on line.
Following self introductions, the attendees were given the opportunity to announce any events or
activities relevant to FRTR interests.
FRTR ANNOUNCEMENTS AND MEETING OBJECTIVES
Agency Announcements (Projects/Initiatives) & FRTR Subgroup Reports
Jim Cummings reported that John Quander (EPA/TIFSD) is working with the University of
Massachusetts at Amherst to organize an international conference—Sustainable Remediation
2011: State of the Practice (www.umass.edu/tei/conferences/SustainableRemediation/)—to be
held June 1-3, 2011. He reminded participants of the ongoing effort to collaborate in the
development of cost and performance case studies of cleanups using innovative technologies to
add to the FRTR database and urged them to send any new information to him or Marti Otto
(EPA/TIFSD). Additionally, he welcomed hearing about any cleanups where the source zone
will be addressed and the site has a small, shallow plume suitable for monitoring at reasonable
cost over the next 5-10 years. Data gathered from these sites will inform future discussions of the
impact of source reduction on plume longevity.
Carol Dona, U.S. Army Corps of Engineers (USACE), said that the federal partners in the Green
and Sustainable Remediation (GSR) Subgroup are working on a framework and metrics to define
the effort based on EPA's determination of how green remediation fits within the nine criteria
defined under CERCLA. Three frameworks are in development by other organizations: the
Interstate Technology Regulatory Council (ITRC), the Sustainable Remediation Forum (SuRF),
and ASTM International. The Army currently has five of 12 planned study projects under way to
evaluate GSR alternatives and identify options, determine the cost impacts, and document the
results. The objective is to determine which GSR alternatives have the greatest impact and when
and where implementing each alternative makes it most effective. The Navy recently led a joint
proposal to the Environmental Security Technology Certification Program (ESTCP) to compare
two publicly available GSR tools for consistency and reliability: the Sustainable Remediation
Tool (SRT) developed by the Air Force Center for Engineering and the Environment (AFCEE),
and the SiteWise™ Sustainable Environmental Remediation Tool developed jointly by the Navy,
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USACE, and Battelle. Full lifecycle analysis of both tools will identify improvements that can be
made to increase user confidence in the results they provide. Both tools are available on line
(www.ert2.org/t2gsrportal/tool s. aspx). The second version of SiteWise™ should be issued in
March 2011 with several improvements: technology mapping to show the activities involved and
a cost package to cost-out alternatives and calculate energy costs.
Beth Moore, U.S. Department of Energy (DOE), said that DOE's Office of Energy Efficiency
and Renewable Energy is co-sponsoring with EPA and other organizations the 2011 Brownfields
Conference (www.brownfields2011 .org), to be held April 3-5 in Philadelphia, PA. A large part
of the conference focus is on green remediation topics, including metrics and green jobs.
Dan Powell (EPA/TIFSD) noted that EPA released the final Superfund Green Remediation
Strategy (www, epa. gov/ superfund/ green remediation/) in September. The strategy outlines 40
specific action items aligned with 9 key actions designed to encourage examination of cleanup
alternatives that decrease the environmental footprint of remediation. In the coming year, the
cross-agency project to update the software tools listed in the FRTR Decision Support Tools
matrix (www.frtr.gov/decisionsupport/) for characterization, remediation, and project
visualization will incorporate green remediation tools. Several of the new tools will be evaluated
and compared at the Grants Chlorinated Solvents Plume site located in Grants, New Mexico, and
a report will be prepared. He also mentioned a new program initiative proposed by Kathy Yager
that builds upon EPA experience in the optimization of long-term monitoring for groundwater
treatment systems to encompass holistic cleanup optimization for remediation sites.
Linda Fiedler (EPA/TIFSD) announced that EPA is compiling resources to develop a new Focus
Area on fractured rock for the CLU-IN website, as well as updating the Fractured Bedrock
Project Profiles with new material. The new Focus Area will provide overviews and links to a
variety of reports and papers on fractured bedrock topics. The project profiles will be expanded
to describe about 150 sites where treatment has been selected or implemented. The new
resources should be available at the end of December 2010 or in early January 2011.
Paul Beam (DOE) suggested adding landfills to the ballot of potential topics for the spring 2011
FRTR meeting. He is interested in landfills that contain low-level radioactive waste with respect
to long-term monitoring, geomembrane lifespan, contaminant transport within the landfill,
settling/shifting of landfill content and the effect on the cover system, and interaction of co-
disposed contaminants. If there is sufficient interest in this topic, a subgroup could be formed to
gather and develop additional information.
Kim Parker Brown, Naval Facilities Engineering Command (NAVFAC), reported that the Navy
plans to update its remedy optimization policy with GSR guidance. Efforts are ongoing to
develop GSR metrics and capture them in the NORM database, the internal database of
contamination problems at Navy installations.
Karla Harre (Naval Facilities Engineering Service Center) greeted the assembly as a new
member replacing long-time member Chuck Reeter. She added to Carol Dona's description of
the joint Navy/Army/Air Force project to compare SRT and SiteWise™ software by identifying
SimaPro® as the lifecycle assessment software to be used in the study. The software tools will be
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applied to two sites during remedial system evaluation optimizations. A report discussing the
ease and appropriateness of each tool, as well as comparing the results and identifying areas for
improvement, will be published.
David Carrillo (U.S. Air Force) reported that the Air Force is placing increasing emphasis on
performance-based contracting for environmental cleanup.
Mark Schoppet (NASA Remediation Program Manager) said that several meetings have been
held by NASA's new green remediation team. The group is still working to identify benchmarks
and tools that will help NASA develop GSR guidance.
Meeting Objectives
The meeting had the following overall objectives:
1.	Improve communication and common understanding of characterization and remediation
issues with fractured bedrock.
2.	Share experience and lessons learned in advancing best practices.
3.	Outline key issues and develop shared strategies to address them.
Jim Cummings went over the ballot of potential topics for the spring 2011 FRTR meeting and
asked that a representative from each member agency present cast a ballot and return it after the
lunch break, with the results to be announced at the end of the meeting. He then introduced Allen
Shapiro of the U.S. Geological Survey (USGS) as the first presenter and moderator of the initial
portion of the technical program.
CHARACTERIZATION OF CONTAMINATION IN FRACTURED MEDIA
Addressing the Complexities of Contamination and Remediation in Fractured Rock Aquifers
Allen Shapiro gave an overview of some of the complexities involved in dealing with
contaminants in fractured rock (Attachment A). Fractured rock and carbonate aquifers offer a
degree of geologic complexity that far exceeds that of near surface, unconsolidated, porous
media aquifers. The complex distribution and connectivity of fractures, joints, conduits, vugs,
and other discontinuities in the rock, coupled with the large range in their hydraulic properties,
results in highly convoluted flow paths over distances from meters to kilometers. Fractured rock
and carbonate aquifers are also characterized by void space associated with the initial formation
of the rock. The rock matrix is not significant in characterizing groundwater flow; however, it
does play a significant role in the long-term retention of contaminants and the design,
implementation, and success of remediation strategies.
Recent advances in understanding physical and chemical processes and characterizing
groundwater flow and chemical transport in fractured rock aquifers are leading to defensible site
conceptual models that can minimize the number of monitoring locations to achieve long-term
monitoring objectives. At the former Naval Air Warfare Center (NAWC), West Trenton, New
Jersey (http://ni.usgs.gov/nawc/). the presence of chlorinated solvents in fractured sedimentary
bedrock has provided opportunities for studies of subsurface processes and new characterization
and monitoring technologies. Innovative methods of monitoring in situ changes in
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biogeochemical conditions point to further reductions in long-term costs at geologically complex
sites of groundwater contamination.
Existing remediation technologies may be insufficient to achieve management objectives in the
complex geology of most fractured rock aquifers. Significant quantities of contaminant mass will
continue to be present in the groundwater, even after aggressive remediation technologies have
been applied. Efforts need to be directed at minimizing costs and streamlining protocols that
recognize the long-term stewardship that will be warranted at these geologically complex sites.
Given the prospect of long-term stewardship of fractured bedrock sites, Shapiro made several
management recommendations:
•	Look for methods of reducing long-term operational monitoring costs,
•	Manage the site with a financially prudent approach, and
•	Elucidate the basis for implementing any aggressive remediation technology.
In the area of ongoing research, he cited the following needs:
•	Methods of making monitoring more cost effective,
•	Enhanced characterization that allows installation of fewer monitoring locations to reach
project objectives,
•	A better understanding of in situ physical, chemical, thermal, and biogeochemical
processes that affect contaminant fate and transport,
•	Synthesis of lessons learned from different geologic settings at different scales, and
•	Development of innovative methods for monitoring in situ processes.
Question: Do you think in situ thermal treatment can reach DNAPL in fractured bedrock?
Response: The technology is promising, but its effectiveness depends on the hydrogeology
of the area. A tight area with little water intrusion might be a candidate, but if a
lot of fluid is coming in, energy costs will increase. In a tight area, however,
DNAPL movement would be small and might not be a problem.
Question: Your example sites are skewed toward rocks in the Midwest. Why are there not
more studies in eastern sites?
Response: It is a matter of opportunity. If anyone has glaciated crystalline rock sites in the
Northeast for long-term study, please let me know.
Tools for Characterization and Monitoring of Contaminated Fractured Rock
Dan Goode (USGS) acknowledged the work of many colleagues over decades in providing the
information he came to share (Attachment B). His presentation highlights a brochure prepared by
Linda Fiedler and Claire Tiedeman (USGS) that describes the types of technical assistance
available from EPA and USGS in the characterization and remediation of contaminated
fractured-rock sites.
He drew attention to a recent 2-volume report, Fractured Bedrock Field Methods and Analytical
Tools (www.sabcs.chem.uvic.ca/fracturedbedrock. html). written as guidance for contaminated
sites practitioners by Tom Doe of Golder Associates Inc. for the British Columbia Ministry of
Environment, Canada. A table from this publication provides a list of characterization
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recommendations, although it omits important tools such as modeling and synthesis. Many of the
approaches and methods used at porous rock sites are applicable at fractured rock sites.
An example of a crystalline rock site in a report entitled Influence of Geologic Setting on
Ground-Water Availability in the Lawrenceville Area, Gwinnett County, Georgia
(http://pubs.usgs.gov/sir/2005/5136/) was used to illustrate the importance of mapping the
surface geology locally. The large-scale geologic structure is correlated with permeable features
in the ground. Cross-sections show that the major water-bearing zones in the crystalline rock are
associated with contacts that are mappable at land surface.
In a discussion of the work conducted at the NAWC site in West Trenton, New Jersey, Goode
pointed out the cost-effectiveness of aquifer testing at a site where a pump-and-treat system is in
place. In a system with seven pumping wells, it is easy to switch a well off and run an aquifer
test for as long as desired, thereby gaining additional information through the remediation
system. Hydrogeologic characterization at the NAWC was critical to achieving effective
bioaugmentation of the rock fractures. The information was used in designing the strategy for
injection of bioaugmentation amendments, for determining importance of monitoring at
intermediate wells, and for interpreting bioaugmentation results, in which work is ongoing.
Investigators used rock coring to evaluate the effectiveness of a thermal conductive heating pilot
study at NAWC and found the method had removed nearly 70 percent of the trichloroethene
(TCE) from the saturated rock samples. As heating the ground required the installation of three
transformers at considerable cost, however, this use of technology likely would not be
considered green remediation.
Goode provided the following take-home message: Tools are available for characterization and
monitoring in fractured rock sites. Good site conceptual models are critical for selection of
methods and synthesis. Continuous characterization of fractured rock sites, even during the
remediation phase, is essential to achieve an iterative synthesis of multiple investigations.
Question: How do you use the hydrogeologic information to move to a modeling scenario
and to determining whether remediation is feasible?
Response: These data provide a broad range of results. One would be that if bioaugmentation
is done throughout the site, how can amendments be introduced to the
contaminated areas? If an existing well is contaminated, it may be possible to
bioaugment a different well connected in the subsurface to the contaminated one
with good assurance that both wells will be affected. Knowledge of the
connection allows use of the natural flow system to carry the amendments to
where they are needed. Knowledge of the connections also pinpoints the critical
monitoring locations. With the proper hydrogeologic framework and with the
models, it is possible to have a systematic, transparent way of identifying where
to pump and where to monitor.
Demonstration and Validation of the Fracture Rock Passive Flux Meter
Kirk Hatfield (University of Florida) pointed out that complex hydrogeologic conditions such as
fractured and karst bedrock settings pose substantial economic and technical challenges to both
the characterization and remediation of DNAPL source zones (Attachment C). The objective of
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his project is to demonstrate and validate the fractured rock passive flux meter (FRPFM) as a
new technology for measuring the magnitudes and directions of cumulative water and
contaminant fluxes in fractured rock aquifers. The sensor consists of an inflatable core that
compresses a reactive fabric against the wall of a borehole and to any water-filled fractures
intersected by a borehole. The reactive fabric is designed to intercept and retain target
groundwater contaminants (e.g., TCE). In addition, the fabric releases non-toxic tracers, some of
which visibly indicate active fracture location, aperture, orientation, and direction of fracture
flow along a borehole, while others quantify cumulative groundwater discharge within the
fractures.
Demonstration and validation studies are in progress to compare multiple competing
technologies, including fractured rock passive flux meters, hydrophysical logging, scanning
colloidal borescope, and borehole dilution tests. The technologies are being evaluated based
upon their ability to identify flowing fractures, determine flow direction, and quantify both water
and contaminant mass flux in flowing fractures. Recently completed laboratory studies test the
capabilities of each technology in two separate flow simulators: a planar single-fracture
simulator (performed multiple tests for varying duration; fracture aperture = 0.5 mm; specific
discharge range 25 to 2,500 cm/day) and a large-scale three-dimensional aquifer box with
layered high-contrast flow zones (physical flow domain 2 m length, 0.5 m width, and 1 m height;
alternating layers of low-permeability sand separated by high-permeability gravel; specific
discharge range 25 to 4,000 cm/day (per layer)).
Demonstration objectives include assessing the performance of the competing technologies
under controlled conditions and developing a standard operating procedure for using these
technologies to characterize both flow and contaminant flux accurately in fractured rock systems.
Field demonstration tests have started at a site in Guelph, Ontario, and also will be performed at
the NAWC site in West Trenton, New Jersey.
Question: Once the point measurements have been validated with the instrument, do you
plan to integrate any of the existing methods for calculating discharge from the
plumes that have been developed in past work for ESTCP?
Response: Yes. A major issue with site risk assessment is the estimation of water and
contaminant discharges and their uncertainties. Usually complex stochastic
simulations are required to generate these estimates. We plan to submit a paper
demonstrating simple techniques for estimating water and contaminant discharges
and discharge uncertainties using flux data from multi-well transects. Typical
statistical methods can't be used to make such calculations, because point
measurements of flux produce skewed distributions and are spatially correlated.
Typical statistical methods assume data follow symmetric distributions and are
independent or uncorrected. However, we present a way in which spatial
correlation and skewness are considered and simple statistical tools yield valid
estimates of water and contaminant discharge and their uncertainties.
Question: Has the flux meter been used yet at the NAWC test site?
Response: Not yet, but possibly this winter. At this stage we are validating the technology,
and it is preferable to test it at sites that are well characterized.
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Comment: As previously discussed, one of the key issues here is that when dealing with
highly complex sites, as one starts to integrate over areas, one starts to reduce that
complexity. The uncertainty of concentration at a given point is huge, but by
integrating over an area, that uncertainty can be dramatically reduced.
Fractured Bedrock Characterization and Effective Remedy Selection in Region 4
Ben Bentkowski (EPA Region 4) provided a regional perspective on characterization of fractured
bedrock aquifers and how it has aided in effective remedy selection (Attachment D). Generally,
Appalachian tectonics caused a large region of fractured igneous and metamorphic aquifers in
the central portion of Region 4. This tectonic deformation also caused the Valley and Ridge
province to the west of the mountains resulting in fractured sedimentary aquifers.
Characterization of these fractures is the key to understanding the hydrogeology of each site. As
the characterization of each site needs its own approach formulated from a range of techniques,
the general approach is first to understand the groundwater flow system and then the contaminant
distribution. This base level of knowledge is necessary for effective remedy selection.
The Region 4 federal facilities with fractured bedrock generally are larger sites with multiple
release locations and often large release amounts. Non-federal sites usually are smaller with
smaller release amounts. The sites presented were evaluated as to the conceptual site model, type
and degree of characterization, and the possible or selected remedy. Details from the following
sites—most of them large, complex sites at federal facilities—illustrated the discussion:
•	Air Force Plant No. 6, Marietta, Georgia (Fractured Metamorphic Rock)
•	Alabama Army Ammunition Plant, Childersburg, Alabama (Fractured Sedimentary
Rock)
•	Redstone Arsenal, Huntsville, Alabama (Fractured Sedimentary Rock)
•	Oak Ridge Reservation, Oak Ridge, Tennessee (Fractured Sedimentary Rock)
•	Anniston Army Depot, Anniston, Alabama (Fractured Sedimentary Rock)
•	J.P. Stevens Facility, Upstate South Carolina (Fractured Metamorphic Rock)
•	Hitachai, Greenville, South Carolina (Fractured Metamorphic Rock)
Preliminary conclusions are presented as to which types of aquifer characterization aided in more
effective remedy selection. This work does not include evaluating the more purely karst regions
of Kentucky, Tennessee, Florida, and southern Georgia. Also, the evaluation focuses on
CERCLA sites rather than RCRA sites, with limited evaluation of state lead sites.
Question: Does in situ thermal treatment actually remediate down to remediation goals?
Where does it work, and under what circumstance does it not work?
Response: At the Hitachi site, in situ thermal desorption within the small treatment area met
the goal of 60 |ig/kg TCE in the vadose zone and saprolite, but not in the bedrock.
The areal extent of contaminated groundwater was much larger, and it would have
been very expensive to attempt to treat the entire plume.
Question: Did Air Force Plant No. 6 or any of your other large sites apply for a technical
impracticability (TI) waiver?
Response: Air Force Plant No. 6 is currently regulated under RCRA, and the plume lies
within the facility boundaries, so it has not applied for waiver. That cleanup is
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managed by the State of Georgia and the Air Force. Anniston Army Depot tried
for a front-end TI waiver, but it did not go forward. Region 4 has never granted a
TI waiver.
Question: At Air Force Plant No. 6, they were looking for flux reduction. How is it being
monitoring?
Response: The people who would know are Lester Williams from the USGS and staff in
CH2M Hill's Atlanta office, in addition to the Air Force staff involved.
Autopsy of a Small UST site in Bedrock: Implications for Remedial Effectiveness
Bill Brandon (EPA Region 1) described complications that beset monitoring the remedy for
releases from a 5,000-gallon underground storage tank, UST-13 (Attachment E). UST-13 was
used for collecting waste oils (mainly spent fuels and chlorinated solvents) at the former Defense
Reutilization and Marketing Office, Fort Devens, Massachusetts. The tank was removed in 1992
with a limited amount of contaminated soil, as the tank grave was partially excavated into
bedrock. From 1994 to 1997, a remedial investigation, feasibility study, and record of decision
were completed for the site. In 1998, the selected remedy implemented monitored natural
attenuation (MNA) with long-term monitoring (LTM) to evaluate groundwater cleanup
following the source actions.
An extensive cut-and-fill program, including significant bedrock blasting carried out to prepare
the site for construction of a large warehouse structure in 2000-2001, destroyed some key
monitoring wells and complicated the ongoing evaluation of MNA and source action
effectiveness. New monitoring wells were installed post-construction in 2001, and LTM efforts
were resumed, but the presence of the new building precluded replacement of many wells to the
original locations. Moreover, changes were observed in post-construction groundwater flow
patterns, and it was expected that additional work would be needed to verify the adequacy of the
monitoring network and to make adjustments to the well network or the remedy.
The presence of shallow bedrock beneath large portions of the site, as well as the setting of the
shallow water table locally within the bedrock, further complicate analysis of groundwater
cleanup. The former tank grave is located at or near a local groundwater divide, where the grave
of the former leaking UST-13 penetrated into the upper bedrock. The release of contaminants has
affected bedrock, and it appears likely that some residual source material exists in the bedrock
beneath the former tank grave. These matters support the ongoing need for additional evaluation
of bedrock.
Persistent lingering contamination in the source area supported additional efforts to address the
bedrock contamination more comprehensively. In 2007, EPA performed an analysis of bedrock
data collected during the 2000 blasting event. As fresh bedrock exposures were created, EPA
conducted geologic mapping and measured the three-dimensional (3-D) orientations of the rock
fabric and associated fractures identified in the sheared granite gneiss and meta-sedimentary
bedrock. A total of 156 joint orientation measurements were collected (66 stations) and 49
foliation measurements were recorded (49 stations). The data were used to create an updated
conceptual site model, particularly with respect to elements of the bedrock fracture network
relevant to groundwater flow at site scale. Stereo plots and 2-D mapping of these bedrock
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structural elements were integrated with updated maps of the bedrock surface morphology.
Additionally, lateral hydraulic gradients, vertical hydraulic gradients, and long-term water level
trends were reevaluated for the bedrock and overburden groundwater systems, culminating in a
series of detailed hydrogeologic cross sections parallel and normal to groundwater gradients in
the area centered on former UST-13. The prevalence and consistency of the bedrock foliation
strongly suggest that this basic characteristic of the bedrock needs to be factored into any
remedial or monitoring scheme. Although joint orientations were much more variable, the most
prevalent joint orientations are generally also parallel to the foliation. These foliation-parallel
joints may play a significant role in contaminant migration, particularly in the immediate vicinity
of UST-13. The analysis suggests that the potential for down-dip migration of contaminants,
including residual NAPL, to the west/southwest and lateral migration of dissolved contaminants
of concern along strike to the south are possible, yet neither pathway is currently monitored.
To address these findings, new monitoring wells were recommended for the UST-13 source area
and in down-gradient directions, but the project team refocused available resources in 2009 to
address persistent residual fuel hydrocarbons and chlorobenzene compounds. An in situ chemical
oxidation (ISCO) injection effort, aimed at the hotspot area near well 32M-01-18XBR, was
conducted in February 2009. About 1,800 gallons of water/sodium persulfate solution with a
sodium hydroxide catalyst was injected through 4 new injection wells drilled into or on top of the
bedrock in the former UST-13 area. The 4 post-injection monitoring events conducted to date
point to significant decreases of many key contaminants of concern in well 32M-01-18XBR, but
hydraulic information collected during the injection events suggests considerable uncertainty still
exists with respect to the interconnectivity of the fracture system, and by extension, the
appropriateness of the current monitoring and injection wells.
Moving forward, evaluation of time-series contaminant trends will need to consider the role of
seasonal water-level changes in relation to oscillating contaminant values. If contaminants
persist, additional remedial action may be needed, and optimization of remedial systems and
associated monitoring likely will need more careful consideration of the bedrock fracture system
characteristics.
Question: Did you do any numerical modeling to try to understand how the site has
changed?
Response: No, those resources have not been applied because it is essentially considered a
"nuisance" site.
Question: Are there any fluctuations due to tidal influence?
Response: No, the site is 40 miles inland.
Question: Is your desire to re-inject under the building reinforced by subsequent data?
Response: It is a logical inference: the hydraulic head data show a pressure gradient in that
direction and the geologic data show a slope in that direction.
Question: Was this site labor intensive?
Response: The problem was more a matter of time than money. The 5-year review report for
the three UST sites at Ft. Devens shows that they are all still being monitored
because residual contamination remains in the top of the rock.
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Question: In the design of the persulfate injection, was the decision to inject into the
contaminant mass based on knowledge backed up by geochemical information?
Response: Essentially, they came up with a scheme to zap a small hot spot, expecting it to go
away.
TREATMENT OF FRACTURED ROCK SITES
In Situ Bioremediation at FracRock Sites
Mary deFlaun (Geosyntec Consultants Inc.) pointed out that retention of bacteria in fractured
bedrock can be a challenge for bioaugmentation (Attachment F). The relatively low surface area
in the aquifer compared to porous media sites may not retain a high enough density of bacteria
for effective remediation. Recirculation can be used to retain bacteria within the area of concern,
but the cost and infrastructure associated with this strategy can be prohibitive at some sites. Two
case studies illustrate the passive and semi-passive application of bioaugmentation in fractured
bedrock. The NAWC site in West Trenton, New Jersey, has high concentrations of TCE
indicating the presence of DNAPL in fractured mudstones. Similarly, a site in Tennessee had
DNAPL concentrations in both the clay overburden source area as well as further downgradient
in a karst aquifer.
Both sites were treated with a combination of emulsified oil substrate and KB-1® bacterial
consortium, which contains dechlorinating Dehalococcoides ethenogenes (DHC) bacteria. The
working hypothesis is that the hydrophobic oil partitions to coat the surface of the fractures and
helps to retain the hydrophobic bacteria at the surface of the fractures. Long-term monitoring
suggests that the oil/bacteria coating on the fractures prevents further diffusion of TCE into the
groundwater from the bedrock by degrading the TCE at the rock/water interface. The
combination of a long-term electron donor and a bacterial consortium that uses TCE as an
electron acceptor is a remedial approach that does not require an ex situ operating system.
Effective concentrations of the KB-1® bacterial consortium are expected to exist (and increase by
growth and replication) as long as adequate electron donor and electron acceptor persists. This
passive approach requires replenishment of the electron donor only on a periodic basis, but the
indications are that this replenishment is needed relatively infrequently, on the order of years.
Question: Did you need to characterize the local microbial community prior to treatment?
Response: No, aside from looking for DHC in the groundwater where chloroethenes are
involved. If DHC is present in sufficiently high concentrations, injections of EVO
alone will speed up the dechlorination process. If DHC is absent or found only at
low concentration, bioaugmentation is indicated.
Question: Has modeling been done to help estimate the optimum number of treatments?
Response: The problem is knowing how much contaminant is in the rock. It is difficult to
model around that major uncertainty.
Question: Was the spike in DHC in well 38BR at NAWC (see slide 21) attributed to
inoculation with KB-1® or to growth of the indigenous population?
Response: Well 38BR received only EVO, so the spike probably was attributable to down-
gradient movement of bacteria over the 3-year period following injection.
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Question: Did you examine any other substrates? Why choose emulsified oil over molasses?
Response: Emulsified vegetable oil is available from a number of different vendors, and it is
easy to use it to reach the target area because it is completely soluble in water in
its emulsified state. The emulsion does not break down for several days, which
gives it time to move around. Substrates like molasses are consumed much more
rapidly than emulsified oil and require more frequent addition to maintain the
effect. Some of the vendors claim emulsified oil will remain effective up to five
years, although our experience has indicated effectiveness for one and one-half
years to two years. Substrate longevity is dependent on a variety of site-specific
factors, such as the types and amounts of contaminants present, the composition
of the indigenous microbial population, and the presence of other sinks for
organic carbon in the system.
Question: If rebound occurs in three to four years, what is the implication in terms of
treatment? Is it the result of back diffusion? Do you have to change the strategy?
Response: Monitoring results indicate when carbon levels decrease and contaminant levels
increase, which is a signal to add more substrate. Contaminants can travel from up
gradient as well as diffuse from the bedrock. They move out of the rock much
more slowly than they move into it, so treatment could continue for a very long
time.
Question: Has any mass balance analysis been done with electron donor and the amount of
TCE that has been reduced?
Response: Mass balance analysis is done initially to determine how much substrate to add,
but for treatment longevity, a greater amount of substrate than indicated is often
used. In these two projects, no follow-on mass balance analysis was performed in
the years after injection.
Question: Would it be better to wait until rebound occurs to add amendments rather than
injecting them on a regular basis?
Response: For the pilot test at NAWC, waiting for rebound was the preferred technical
course, but that was not an option due to factors of timing and funding.
Question: What was the concentration of EVO injected? How many gallons per well? Were
any problems observed with channeling due to recirculation? Any problems with
pH?
Response: The EVO injected was a 2-percent solution. The amount added varied from 100 to
several hundred gallons depending upon how long it took for the EVO to show up
in the extraction well. After EVO appeared, the inoculant was added. Some
channeling likely did occur with the second injection in BRP-1 as no EVO was
detected between wells BRP-1 and 41BR. No pH problems occurred.
Question: For future applications of this technology in fractured bedrock, would there be
any benefit to looking for substrate with a smaller droplet size, which might allow
it to penetrate farther into the formation?
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Response: Yes. Some of the products have a smaller droplet size than others and possibly
achieve greater penetration.
Successful DNAPL Remediation Using Radio Frequency Heating and Return to Thermal
Equilibrium
Alicia Kabir, Environmental Resources Management (ERM), described how radio frequency
(RF) heating technology works and how it is applied, and then presented a case study of the
technology's implementation at an active manufacturing facility in the New England area
(Attachment G). The facility's bedrock was affected by residual 1,1,1-trichloroethane (TCA)
DNAPL. Removal of up to 99.9% TCA was observed in the source area after three years of full-
scale RF system operation. Active treatment was suspended in November 2006. ERM is now
monitoring the bedrock aquifer as it returns to thermal equilibrium and is evaluating potential
rebound of the concentrations of volatile organic compounds (VOCs) in groundwater.
This was the first-ever in situ application of RF heating to treat TCA DNAPL in bedrock. The
implementation of in situ RF heating increased groundwater temperatures, accelerated DNAPL
dissolution, and transformed TCA into its daughter products through abiotic elimination and
hydrolysis.
In RF heating, electromagnetic radiation is directed toward a non-conducting material (e.g.,
bedrock). The advantage of the RF heating process is that the heat is generated from within the
material on the molecular level. Thus, RF heating does not necessarily require as detailed an
understanding of hydrogeologic conditions as other remedial technologies. RF heating targets a
volume of the aquifer, and its effectiveness is largely unrelated to subsurface stratigraphy and
homogeneity.
Groundwater temperatures have declined steadily since suspension of system operation. Unlike
other remedial technologies that target DNAPL, rebound of VOC concentrations is not expected
to occur with RF heating. Because RF heating is not a "contact" technology, no pockets of
DNAPL within the treatment zone that have not been affected by the RF system are expected to
occur. Additionally, the RF equipment can be decontaminated and reused.
Question: During the feasibility study, did the regulators ask for comparisons with other
thermal technologies for this site?
Response: Yes. Sampling indicated that such a large number of coils would be needed for
effective electric resistance heating of the rock that it would tremendously energy
intensive, expensive, and detrimental to the environment in terms of waste.
Thermal conductive heating depends on water to push the energy, and too little
water was available in the subsurface for this technology to be feasible.
Question: Has this technology been coupled with passive follow-on technologies, such as
MNA or bioremediation?
Response: There are synergies to be obtained. For example, the heat can be used to activate
persulfate for in situ oxidation. The temperatures achieved with RF heating can be
detrimental to microbial populations; although once the temperature subsides
bioremediation might be an option.
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Question: What diameter were the boreholes?
Response: The wells used in the case study were 6-inch CPVC wells.
Question: How did you re-use the boreholes as monitoring points?
Response: The wells were installed initially as monitoring points with 15 feet of riser and 50
feet of screen; the rest was open borehole. The RF heating antenna was installed
temporarily in the monitoring well.
Question: Did the heat not melt the PVC?
Response: We use CPVC or fiberglass as regular PVC wells will melt. If thermal heating
might be used at the site, it will save money to design the monitoring system with
that in mind.
Question: Are the heating wells the only ones used to verify treatment performance?
Response: The site had a network of about 50 monitoring wells, 15 in the source area and 30
in the immediate down gradient. The wells down gradient showed a 50-60 percent
mass reduction. Several sentinel wells placed at the drinking water source showed
no increase in concentrations.
Question: From a thermodynamic standpoint, does heating the water not eventually heat the
rock?
Response: The fractures in the rock contain water, and the rock does heat to some extent, but
not as much as it would using some of the other thermal technologies. Latent heat
remains in the subsurface; when the RF system was turned off at the case study
site, the subsurface took 18 months to regain thermal equilibrium.
Question: Are there parameters that are not conducive to RF heating, such as excessive
moisture?
Response: The presence of too much water and rapid subsurface flushing can dissipate the
heat too quickly. The site must be able to retain the heat to be suitable for RF
heating.
Question: Will high concentrations of disseminated sulfides impact RF heating?
Response: No impact is expected as sulfides do not respond to heat. Their presence should
not alter the RF heating approach.
Source Removal of VOC Contaminants in Bedrock, Letterkenny Army Depot, Chambersburg,
Pennsylvania
Paul Stone (US ACE) reported on the use of three separate technologies for three separate
operable units in a four-mile continuous section of karst valley at Letterkenny Army Depot
(Attachment H). The highly folded and fractured karst bedrock underlying the Industrial Area
was the main source of VOCs contaminating the groundwater. Three different in situ
technologies were demonstrated successfully at this site: two ISCO pilot studies and one
enhanced biological treatment.
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Fenton's reagent was applied in the Disposal Area, the first application of hydrogen peroxide in a
karst bedrock aquifer. The well-developed epikarst allowed for the even spread/dosing of the
Fenton's into the underlying VOC bedrock source. Very high pressures were obtained that could
be controlled, directionally, by venting. The pilot study resulted in the first recorded change in
Disposal Area groundwater quality. The goal was to test whether this process would reduce the
mass of NAPL VOCs beneath a former waste disposal lagoon (the K-l Area) at the site. The
pilot was done to support a focused feasibility study (FFS) of this area.
In the winter of 2001 an ISCO pilot study was completed to determine the feasibility of
remediating VOCs in the groundwater at the Lagoon Area (SE OU 11) using pressurized ozone
(i.e., O3, peroxone). The pressurized O3 increased the concentration of oxidant at the bedrock
surface. Despite highly porous bedrock media, the injection zone pressure was maintained,
which allowed a larger than normal amount of ozone to be injected for enhanced destruction of
VOCs. This pilot study resulted in the first recorded change in Lagoon Area groundwater quality.
Active remediation (i.e., oxidant introduction) occurred over a period of about three years. The
oxidant distribution system is designed to place the oxidant solution specifically in the portions
of the aquifer where groundwater passing through comes in contact with the aquifer matrix. This
potential treatment alternative also was evaluated in the FFS
Enhanced biological treatment over a period of years remediated petroleum hydrocarbons and
chlorinated solvent constituents in the groundwater in the South East Industrial Area both on and
off post. A 6-month pilot indicated that the discharge of VOCs to the springs was nondetectable
within 1 month of injection sodium lactate. Biological indicator compounds, particularly
methane, also showed marked increases in concentration. In late 2000, the Army implemented
the enhanced bioremediation effort at full scale. The program involved the introduction of
sodium lactate, with a tracer dye, into a series of injection wells over a 30-day period every 6 to
8 months. Bi-monthly groundwater samples were collected from a series of on-site and off-site
locations for analysis of lactate, dye, VOCs, and dissolved gases to track cleanup progress. A
ROD selecting enhanced bioremediation as the remedy for the SE OU 10 groundwater was
signed in 2006.
Question: Was carbonate quenching a problem at this site?
Response: There is no primary porosity at this site as it is all secondary, very fine grained. A
bench study was performed to make sure carbonate quenching would not be an
issue.
Question: Typically when applying Fenton's reagent, a certain amount of off-gassing occurs.
Was the off-gas captured in this demonstration?
Response: The injectors had pressure gauges and pressure release valves. The system
responded so rapidly by slowing down when pressure was vented that it was
almost like cooking on a gas stove. Sometimes the system was used to push the
CO2 that formed over the area.
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The Application of In Situ Chemical Oxidation (ISCO) in Fractured Bedrock Using
Geophysical Aided Design
Susanne Borchert (CH2M HILL) discussed the application of ISCO to several fractured bedrock
sites and how the results of geophysical tests and hydraulic tests were used in the application
design to overcome the challenges presented by a bedrock matrix (Attachment I). Permanganate
is commonly used during ISCO applications for groundwater remediation. Experience gained
from most permanganate sites in the United States is from applications in unconsolidated
aquifers.
Examples of unique characterization tools for bedrock include hydraulic connectivity tests and
effective permeability tests to help predict and optimize distribution of the permanganate.
Another example is analysis of the fracture apertures (Paillet ranking method) to determine the
percentage of open fractures per linear foot. This analysis not only allows estimation of the
quantity and distribution of groundwater in the bedrock matrix, but also helps predict the amount
of contact the permanganate oxidant will have with contaminants in the estimated groundwater
volume and with the bedrock surface. These factors are important in calculating permanganate
dosing during remedial designs.
Open borehole field tests were conducted at several Defense sites prior to permanganate
injection. The tests included isolated vertical chlorinated solvent profiling with packers, fluid
temperature and resistivity, hydraulic testing for connectivity and permeability, and down-hole
geophysical logging. These and other data were used to develop the injection volumes, rates, and
pressures; the injection method; the permanganate mass requirements; the permanganate
concentrations per linear foot; and the amount of chase water per boring.
Lessons were learned over multiple applications:
1.	The characterization tests that prove most useful at any a given site are unpredictable and
need multiple lines of evidence to shape the conceptual site model for ISCO design and
delivery. The following tools were most useful at their respective sites:
•	Televiewer and hydraulic connectivity tests in Maryland
•	Caliper, televiewer, and heat pulse flow meter in Georgia
•	FLUTe™ liners, caliper, fluid temperature and conductivity in West Virginia
2.	To mitigate plume displacement by oxidant solution, use small injection volumes
(fraction of estimated pore volume). Do not underestimate the transport distance of a low
volume of injectant in fractures/lineaments—monitor potential surfacing.
3.	During ISCO injection in an open borehole extending beyond treatment zone, consider
placing the packer below the lowest impacted water-bearing fracture. This practice
enhances the use of oxidant to destroy contaminants in open fractures.
Question: Is ISCO effective enough for use on fractured bedrock sites? Is it worth it in terms
of the amount of chemical required?
Response: Time is also a factor, and ISCO will destroy the contaminants faster than
bioremediation. It is a question of priorities. Is it important to destroy a large
fraction of the contaminant mass even if complete remediation is not achieved?
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Comment: Matrix diffusion analysis is very important for figuring out the mass of
contaminant to be treated. At a site in Region 3, the analysis indicated that most
of the contaminant mass was in the upper 20 feet of bedrock, with only small
lenses occurring below that depth. This information allowed better focus of the
treatment process, with far less waste.
Subsurface Characterization, Modeling, Monitoring, and Remediation of Fractured Porous
Rocks
Sammantha Magsino (National Academies) gave a quick overview of the history and
organization of the National Academy of Sciences and the National Research Council
(Attachment J). Within the National Academies, the Committee on Geological and Geotechnical
Engineering (COGGE) has the following charges:
•	To identify, investigate, and report on questions relating to geological and geotechnical
engineering to government, industry, academia, and the public;
•	To inform public policy on geological and geotechnical engineering issues;
•	To identify new technologies and potential applications; and
•	To promote the acquisition and dissemination of knowledge.
Geological and geotechnical characterizing, modeling, and monitoring of the subsurface are
integral to safe, economical, and environmentally responsible development, maintenance,
operation, remediation, and decommissioning of infrastructure related to energy, water, waste,
and transportation. Modeling and monitoring fluid travel paths and velocities through subsurface
fractures and pore space are among the most significant engineering challenges associated with
these tasks. Monitoring and modeling of subsurface fluid flow and transport are especially
important at sites where wastes or hazardous substances are produced, stored, or unintentionally
released.
Carlos Santamarina (Georgia Institute of Technology and member of the standing committee
(COGGE) presented evidence to illustrate the importance of coupled processes in fractured
porous rocks, and examples of potential emergent phenomena, including:
•	Flow localization. Spatial variability (linked to the earlier presentation by Allen Shapiro
on pore space, pore size, viability, and connectivity) leads to flow localization; this
phenomenon is exacerbated in spatially correlated fractured media.
•	Fines migration. The coupling between fluid migration and fines migration can lead to
clogging; in particular, a clogging ring may form at a characteristic distance from the
extraction well, significantly diminishing flow rate and altering the effective stress field.
•	Bioremediation. There is increasing recognition of the importance of pore size for
bioactivity. For a nominal bacteria size of 1 micron in diameter, larger sediment pores
and fracture openings are required to allow for bioactivity. Indeed, bioclogging studies
show highest impact in silts and fine sands.
•	Reactive fluid transport. Extreme pH conditions promote mineral dissolution. In
particular, acid fronts will dissolve grains and fracture walls facilitating fluid transport,
which further promotes further dissolution. This positive feedback mechanism can lead to
piping. Localized erosion or homogeneous dissolution is determined by the interplay
between advection, diffusion and reactivity.
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•	Hydro-chemo-mechanical coupling. Mineral dissolution can have important mechanical
implications. In particular, experimental and numerical results show that there is a
pronounced decrease in horizontal stresses during mineral dissolution under zero lateral
stress conditions, often reaching the Coulomb failure condition.
These examples show that hydro-chemo-bio-thermo-mechanical processes are inherently
coupled in fractured porous rocks (thermo not shown in this brief presentation), and can lead to
unanticipated phenomena.
In closing, Sammantha Magsino suggested that an ad hoc committee of the National Research
Council could conduct a study to address issues relevant to flow and transport in fractured
porous rocks, underlying coupled processes and potential emergent phenomena. Subsurface
characterization, modeling, monitoring, and remediation aspects applicable throughout the
lifecycle of engineered facilities that have potential to release contaminants would be considered.
The committee would plan and hold a workshop to examine the state of art and state of practice
in the following areas:
•	Subsurface fracture and matrix characterization, especially relevant geotechnical and
hydrological properties, and the development of conceptual models; detection of fluid
and contaminant pathways and travel times;
•	Coupled processes, governing parameters in various regimes, emergent phenomena and
implications;
•	Modeling of factors that affect change in geotechnical and hydrological properties over
time; modeling contaminant transport and remediation to aid decision making during
facility design, operation and monitoring, remediation, and decommissioning;
•	Early indicators (such as change in fracture properties; moisture levels) of system
failures resulting in unintentional release of fluids; and
•	Potential mitigation measures to eliminate or reduce adverse impacts of system failures
and related releases.
The committee would issue a final report that will include recommendations with respect to
where research and development could improve the current state of art in SCMMR, and where
incorporation of scientific and technical advances could enhance the state of practice in SCMMR
and inform federal regulations and implementing guidance. A meeting will be scheduled for the
near future to refine the statement of task for the study committee and to identify those willing to
partner with the Nuclear Regulatory Commission in supporting this activity.
MEETING WRAP-UP/NEXT MEETING AGENDA
Balloting for the next FRTR meeting topic indicated monitoring and characterization as the topic
of greatest interest to member agencies. The next meeting will be scheduled in May 2011. Jim
Cummings thanked everyone for attending, and the meeting was adjourned.
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ATTACHMENTS
A.	Addressing the Complexities of Contamination and Remediation in Fractured Rock
Aquifers
B.	Tools for Characterization and Monitoring of Contaminated Fractured Rock
C.	Demonstration and Validation of the Fracture Rock Passive Flux Meter
D.	Fractured Bedrock Characterization and Effective Remedy Selection in Region 4
E.	Autopsy of a Small UST site in Bedrock: Implications for Remedial Effectiveness
F.	In Situ Bioremediation at FracRock Sites
G.	Successful DNAPL Remediation Using Radio Frequency Heating and Return to Thermal
Equilibrium
H.	The Application of In Situ Chemical Oxidation (ISCO) in Fractured Bedrock Using
Geophysical Aided Design
I.	Source Removal of VOC Contaminants in Bedrock, Letterkenny Army Depot,
Chambersburg, Pennsylvania
J. Subsurface Characterization, Modeling, Monitoring, and Remediation of Fractured
Porous Rocks
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