United States Solid Waste and EPA542-R-01-010
Environmental Protection Emergency Response July 2001
Agency (5102G) www.eoa.aov/tio
www.cluin.org
EPA The State-of-the Practice of
Characterization and
Remediation of
Contaminated Ground Water
at Fractured Rock Sites
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An analysis of the information provided during a -workshop
at Providence, RI, on November 8-9, 2000 and
the Fractured Rock 2001 International Conference
at Toronto on March 26-28, 2001
In cooperation with:
Ontario Ministry of the Environment
West Central Region
U.S. Department of Energy
Office of Science & Technology
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U.S. Environmental
Protection Agency
Technology Innovation
Office
Ontario Ministry of the
Environment
West Central Region
U.S. Department of Energy
Office of Science &
Technology
Dear Colleague:
This letter transmits a report on the state of the practice, application, and research needs
concerning the characterization and remediation of contaminated ground water in fractured
bedrock. On November 8 and 9, 2000, we sponsored a workshop in Providence, RI at which
approximately 130 federal and state regulators, private consultants, and site owners explained
their field experiences including successes, problems, issues and barriers. The workshop was
planned and implemented with the help of a planning group representing Federal and state
regulators, private industry project managers, including the National Ground Water Association,
the Department of Energy, the U.S. Geological Survey, the Environmental Protection Agency,
Queens University, and the Ontario Smithville Phase IV Bedrock Remediation Program. On
October 5, 2000, we informed you of this workshop and our plans to send you the summary
report.
The workshop focused on the efforts of state, federal and private project managers who are
studying, testing or even applying innovative technologies to improve the efficacy of
remediating ground water in fractured bedrock. Although the total number of these sites in
North America has not been counted, we estimate that at least a third of the total sites in New
England are in fractured bedrock. Similar proportions are expected in the Northeast and the
northern Midwest sections of the US and most of Canada.
On March 26-28, 2001, the international conference, Fractured Rock 2001, was held in
Toronto. Over 55 papers and 80 poster sessions were presented by international researchers,
practitioners and regulators. The scope of this conference was beyond the workshop and
included a review of research laboratory studies, numerical modeling approaches and policy
issues. An analyses of these presentations and the discussions at the workshop is the basis of the
enclosed report.
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The hydrogeological complexities inherent .to fractured rock sites present extreme technical
challenges to both characterization and remediation. While recent research and application
developments include exciting progress, improved practices will require large resource
investments. Considerable uncertainty with regard to site conditions, interpretations, and the
prognosis for remediation will remain until technology improves. We believe the enclosed
report suggests an important agenda of research and technical transfer needs. We hope you find
it useful.
Sincerely,
TJeraldG.Boyd/
Acting Deputy Assistant Secretary,
Office of Science and Technology
U.S. Department of Energy
Walter W. Kovalick, Jr., Ph.D.
Director,
Technology Innovation Office
U.S. Environmental Protection
Agency
Kal Haniff
Regional Director,
West Central Region
Ontario Ministry of the
Environment
POCs
Skip Chamberlain
U. S. DOE/EM-53
19901 Germantown Rd.
Germantown, MD 20874
301-903-7248
grover.chamberlainlSi.em.doe.gov
Rich Steimle
U.S. EPA, Technology Innovation Office
Ariel Rios Building, 5102G
1200 Pennsylvania Avenue, NW
Washington DC, 20460
703-603-7195
(fax) 703-603-9135
steimle.richard(5),epa.gov
Ted O'Neill
Smithville Bedrock Remediation Program
2769 Thompson Avenue
Smithville, Ontario, Canada LOR 2AO
905-957-4077
(fax) 905-957-4079
toneill@niagara.com
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The United States Environmental Protection Agency, the Department of Energy, and the Ontario
Ministry of Environment, through the Smithville Phase IV Bedrock Remediation Program,
sponsored a workshop of invited experts in Providence, Rhode Island, on November 8-9, 2000 to
discuss the application of characterization and remediation technologies at fractured bedrock
sites. These agencies also sponsored the international conference; "Fractured Rock 2001" in
Toronto, on March 26-28,2001. This summary is partially based on a draft report written by
Bernadette Conant, Ontario, Canada, and substantial comments provided by Kathy Davies, EPA
Region 3; Dick Willey, EPA Region 1; Al Shapiro, USGS; Susan Solyanis, Mitretek Systems
and Carolyn Lepage, Lepage Environmental Services, Inc.; for EPA's Technology Innovation
Office (TIO). Comments were also provided by members of the Fractured Bedrock Workshop
Planning Group (Appendix 1).
The intent of this report is to provide; 1) a base line of the state-of-the-practice to help measure
trends and directions, 2) a comprehensive view of remediation efforts to local, state and regional
practitioners, and 3) suggestions of high priority needs of characterization and remediation to
research and development laboratories. Suggestions or comments should be directed to Rich
Steimle, EPA at 703-603-7195 or steimle.richard@.er>a.gov .
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The State-of-the-Practice of Characterization and Remediation of
Contaminated Ground Water at Fractured Rock Sites
Over the past two decades, there has been increasing recognition that geologic complexities pose
some of the greatest challenges to site characterization and ground-water restoration. Fractured
rock sites are among the most complex because of their considerable geologic heterogeneity and
the nature of fluid flow and contaminant transport through fractured media. Relative to most
unconsolidated deposits, characterization of contaminant migration in fractured rock usually
requires more information to provide a similar level of understanding. The complexity of
contaminant source conditions also make remediation more difficult. Therefore, there is a need to
improve and augment current technologies applicable to these sites.
Professionals tasked with choosing technologies for contaminated ground-water in fractured rock
need access to information from research and practical experience from the field. However, few
forums exist for the sharing of this information. In addition, the development of a baseline of
national experiences would be very useful in identifying future research planning needs.
Consequently, U. S. Federal Agencies and the Ontario Ministry of the Environment through its
Smithville Phase IV Bedrock Remediation Program, have initiated several efforts to help define
the state-of-the-practice of remediation and characterization technologies in fractured bedrock
sites. These efforts include a web site established in 1999, a workshop held on November 8-9,
2000 and an international conference held on March 26-28,2001. The web site, http://clu-
in.org/fracrock. contains literature references, workshop presentations, over 30 site profiles, and
links to other web sites which contain fractured rock information.
The following sources of information were reviewed in the development of this summary:
• Summaries of fractured rock applications that others have placed on EPA's CLU-IN
fractured rock web site (www.CLU-IN.org/fracrock).
• Poster abstracts that consultants, manufacturers, and others developed for presentation at
an EPA-sponsored workshop in Providence, Rhode Island, November 8-9,2000 (which
are located on EPA's CLU-IN org/fracrock web site.
• Responses to questionnaires that attendees completed at the above-mentioned workshop
(hard copies were reviewed but questionnaire summaries are contained in the Fractured
Rock web site.
• Presentations at the Fractured Rock workshop (also contained on the web site).
• Reviews of oral and poster presentations at Fractured Rock 2001 an international
conference held in Toronto, Canada, March 26-28, 2001.
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The Emerging State-of-the-Practice in Fractured Rock
Until the last few years, the state-of-the-practice for fractured rock has been essentially the same as
that for all contaminated sites; it had not been differentiated from that for unconsolidated-deposits
sites. Recently, new strategies to deal with fractured rock sites have been emerging, but there is a
time lag in the widespread communication of new research and applications to both the practicing
community and decision-makers.
Research, development, and more rigorous technology evaluations have previously focused
predominantly on unconsolidated materials; particularly settings with relatively simple geology and
shallow contamination. In addition, most contaminated sites distributed on a national scale are in
unconsolidated-deposits; although, in some physiographic provinces the majority of the sites are in
fractured rock. However, most practitionershave more familiarity with investigation and remediation
of unconsolidated settings. The result is an industry that has been addressing fractured rock sites
primarily drawing on experience, methodologies, and conceptual approaches developed in
unconsolidated deposits, though at considerably greater expense and with generally less confidence
about the results. Technology evaluations more specific to fractured rock sites are now emerging.
For hydrogeological studies in fractured rock, it is the discrete fracture pathways, rather than the total
fracture network, which are important. To be of hydraulic significance, fractures must be both
conductive and sufficiently interconnected to serve as part of a pathway. Only some subsets of open
fractures will have active groundwater flow, and a small number of transmissive fractures may
dominate. The challenge in application of characterization technologies is to locate the significant
fractures and apply technologies in a way such that measurements properly reflect in-situ conditions.
Stakeholders must understand the importance of developing an accurate, conceptual model of the
site. The complexity of the site will determine the necessary types of tools and testing. The results
can be applied to a initial model so that the subsurface conditions become understood well enough
to apply remediation. Understanding the site and the results of remediation efforts will be an
iterative and inclusive process.
The distribution of contaminant mass in the subsurface, and the perceived need for short- or long-
term controls, will determine the most appropriate remedial technologies and targets. Therefore,
conceptual models must reflect the most likely distribution of contaminants as well as the transport
processes controlling that distribution. This makes it possible to consider both current and future
contaminant impacts under different remediation scenarios, and to identify the mass that is most
likely to be limiting to cleanup. For example, dissolved contamination migrating with advecting
ground-water in fractures typically represents the fastest pathway and primary transport pathway of
concern. However, it may comprise only a very small portion of the total mass. Contamination may
be sequestered within the rock matrix, on fracture coatings, in NAPL zones, or within poorly-
connected fractures. Over the long term, such "sources" control ground-water contaminant
conditions and the need for ongoing remediation.
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Over the past 10 or 20 years, some technologies associated with definition and remediation of
contamination hi unconsolidated deposits have matured. A similar trend is now occurring in
fractured rock settings, with increased recognition of the importance of discrete fracture pathways
and matrix diffusion for contaminant fate and transport. Also, lessons learned in other disciplines
such as petroleum and civil engineering, and from the evaluation of potential radioactive-waste
disposal sites, are being increasingly re-evaluated to address questions of scale lithologies, structural
features and geochemistry unique to environmental contamination problems. The state-of-the-
practice for fractured rock as a distinct subclass of contaminated sites is being developed, although
experience with characterization technologies is generally more advanced than that for many
remediation technologies.
Site Characterization Technologies
Geological Characterization
Geological characterization at fractured rock sites includes use of conventional techniques such as
outcrop mapping, fracture trace analysis, drilling, coring, and, more recently, increased use of
borehole geophysics. Drilling boreholes remains the principal means of geological characterization
and, because it is generally slow and expensive, contributes significantly to characterization costs.
The majority of holes are vertical; inclined drilling is also used, albeit less frequently, to intersect
and sample vertical or near-vertical features. In addition, there is concern that drilling activities may
create a conduit for cross-contamination by drilling through previously isolated fractures and, at
DNAPL sites, may risk mobilization.
Cores are collected to provide information on site geology and physical samples for laboratory
testing. When core recovery is sufficient, fracture characteristics can be determined directly.
However, it is very expensive to collect oriented cores to determine the dip and strike of the fracture
features; it may also be very difficult to ascertain that the fractures are not caused by the drilling
itself. The presence or absence of fracture oxidation and weathering, and fracture fill or coatings,
can provide direct indications of likelihood of ground-water flow. However, fracture zones, which
are of most interest to investigators, are poorly recovered from core samples. Zones of potential
importance for ground-water flow frequently correspond to rubble zones or lost sections of core.
Therefore, drilling and coring are often followed by use of geophysical borehole logging to provide
more information on fracture zones.
Workshop discussions reflected a current debate over the cost-effectiveness of obtaining core during
drilling. In response to the workshop questionnaire, almost all (94%) of respondents indicated they
had used coring in characterization of fractured rock sites. The survey did not indicate how important
they rated core analysis for characterization, the percentage of holes that were cored, or whether their
reliance on it had changed over time. Other attendees indicated a preference for coring as the
primary means of geological characterization and correlation, and to provide desired borehole
conditions for subsequent hydraulic testing. Geophysical techniques were also recommended by
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those advocating the value of core, but as a supplementary, rather than primary, tool in support of
fracture characterization.
Hydraulic Characterization
Hydraulic testing and measurements of hydraulic heads from monitoring wells are the most basic
and mostfrequentlyused tools for characterization of ground-water flow in fractured rock. Hydraulic
testing (injection tests, pumping tests) and vertical head profiling (packer isolation, cluster wells,
sampling ports) have been used by 90% of respondents to the workshop questionnaire. In the EPA
CLU-IN site profiles, hydraulic testing methods were not listed separately, but vertical chemical
profiling (presumably conducted in conjunction with hydraulic head measurements) was the most
frequently listed characterization technique.
Mapping of hydraulic heads (under both ambient and pumping conditions) is the most common
method of inferring ground-water flow directions and fracture connectivity. Extrapolating hydraulic
gradients between individual fracture zones or different monitoring wells requires a determination
of whether monitoring reflects conditions in connected fracture pathways. Cross-hole pumping tests
are also used to determine bedrock aquifer properties and fracture interconnection. Pumping test
results are particularly applicable at sites where remedial response involves installation of pumping
systems for hydraulic control. Workshop attendees reported the use of pumping tests in site
investigations as part of standard practice.
Chemical Characterization
Collection and analysis of ground-water samples from monitoring wells is the most common method
of characterizing the extent of contamination at fractured rock sites. Like hydraulic testing, chemical
characterization of fracture pathways involves collecting samples from specific vertical intervals of
the borehole. These intervals may be isolated using packer assemblies in open boreholes, completion
of monitoring wells over specific intervals in well clusters, or installation of multi-level monitoring
assemblies. Multi-level monitoring assemblies designed for dedicated use in boreholes are
commercially available. Non-permanent (re-usable) systems with inflatable packers or continuous
borehole liner/sampling systems are among the most recent developments and are in the early stages
of real-site application. The use of such techniques as temporary monitoring assemblies, or chemical
profiling during drilling, may help to optimize sampling location and monitoring well design and
significantly reduce the capital costs of sample collection.
Geophysical Methods
Geophysical characterization represents an area where there has been considerable technology
development and an increased application at fractured rock sites over the past decade. Conventional
surface geophysics and borehole logging (wireline) methods have been applied in fractured bedrock
environments for years (e.g. oil industry, water supply research). However, recent refinements for
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use in environmental investigations have been in response to different requirements of scale and
resolution: from regional and site-level definition of fracture networks at 10's to 100's of meters,
down to the level of individual fractures or fracture zones.
Surface Geophysical Methods
Surface geophysical methods (DC resistivity, electromagnetics, ground-penetrating radar, seismic)
are typically used in conjunction with other remote methods early in the site investigation process
to assist in locating and defining the geologic contacts, structural features, and location and
orientation of fracture sets. Because they are non-intrusive, they avoid some of the risks of drilling,
such as cross-contamination and DNAPL remobilization. However, they may be limited to fairly
large-scale resolution. Also, their application can be hampered by cultural interferences, such as
utilities, pipes, overhead wires, buildings and pavement. This provides a limitation which makes
them inappropriate for some sites in urban areas and where active facilities are situated. In addition,
their use can also be limited by the presence of significant unconsolidated deposits overlying
bedrock.
Borehole Geophysical Methods
Conventional wireline logging methods, such as caliper, fluid logs (temperature, conductivity), EM
conductivity, and gamma logs, are the most commonly used geophysical tools. They are used in
combination with core logging or optical and acoustic imaging methods to assist in mapping of
geology and fracture zones, and to extend geologic correlation between boreholes. Recently,
borehole applications have expanded to include improved methods of imaging the borehole and
identifying which fracture zones have active flow. More recent techniques are television/televiewer
methods (acoustic and televiewer), of which over half of the respondents reported using, and flow
meters (heat-pulse and EM).
Use of brine testing and borehole flowmeters capitalize on the vertical flow caused by head
differences between fractures intersected by a single borehole. By measuring the direction and
magnitude of this flow under both ambient and stressed (pumping or injection) conditions, it is
possible to locate fractures or fracture zones where ground water is entering or exiting the borehole.
This can assist in identifying fractures of potential significance for sampling and testing, as well as
allowing estimates of hydraulic parameters. By helping identify the relative contribution of ground
water from different fractures to the borehole, flowmeters are also useful in helping to interpret
chemical sampling results. The main limitation of most flowmeters is their detection limits. Lower
detection limits (e.g., approx. 0.01 gpm for heat-pulse flow meters) are insufficient to detect some
low-flow fractures, which may be important for transport. Almost as sensitive as the heat pulse
flowmeter, but with a higher range, the EM flowmeter may be used. For higher flow systems, it may
be necessary to use spinner flow meters.
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New Approaches . • -
Newer technologies include digital borehole imaging methods which allow direct inspection of the
borehole surface and viewing fractures in-situ. Orientation of the features as they intersect the
borehole can also be determined. The possibilities of these methods are further enhanced by the
advancement of software that constructs oriented "virtual cores" from the televiewer data.
Interpretations using these methods are subject to the same limitations experienced by other borehole
based techniques.
Other imaging methods, which represent promising new research areas, but are not yet used in
common practice, are methods which allow extension of data collection beyond the constraints of
measurements in boreholes. They allow extrapolation and interpretation between them, including
borehole radar, seismic, and resistivity tomography. Two-and three-dimensional imaging methods
require ground-truthing with physical/geological sampling, but offer the possibility of better siting
sampling locations within complex fracture networks.
An interdisciplinary approach using multiple lines of evidence is recommended and is particularly
important for characterizing fractured rock. The need to use a combination of different
characterization tools was underscored by several workshop attendees. This approach has been
borne-out by experience with geophysical methods in particular. The non-uniqueness of geophysical
signatures and the need for parallel use of several methods has long been recognized. Side-by side
comparison of geophysical logs is standard. Greatly improved analysis and interpretation of site
conditions are possible; however, only if skilled, experienced geophysicists are conducting the
interpretation. The importance of appropriate QA/QC programs for those personnel using these
technologies were also stressed by the workshop.
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TABLE 1
State-of-the-Practice on the Use of Characterization Technologies
n=53 sites
Technology
Borehole Geophysics (total)
Single point resistance
Natural Gamma
Caliper
Borehole Televiewer (total)
Video Camera
Acoustic Televiewer
Fluid Loggings (total)
Temperature
Conductivity/Resistivity
Flow Meter (total)
Heat Pulse
Trace Brines
EM Flowmeter
Chemical Profiling (total)
Cluster Wells
Sampling Port Packer
Isolation
Surface Seismic Surveys (total)
Refraction
Reflection
Fracture Trace Analyses
Surface EM Conductivity
Surveys
Surface GPR Surveys
Number of Mentions in
Workshop
Questionnaires, CLU-
IN Profiles and
Conference
Proceedings
28
6
9
8
32
9
5
27
12
11
23
5
2
1
39
13
6
11
14
3
3
22
14
14
10
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Coring
Tracer Studies
Downhole Seismic Surveys
Measurement of Hydraulic
Head
Hydraulic Testing
Outcrop or Geologic
Testing
Borehole Radar Surveys
2D Resistivity Surveys
Modeling (water or solute
transport)
Time Series Sampling
FLUTe with NAPL Ribbon
•35
15
4
16
17
9
7
3
13
10
2
Remediation Technologies
Hydraulic Capture/Containment
Pumping and treating ground water is the most common technology (Table 2) for hydraulic
containment. To the degree that contamination is contained within accessible fractures., the existence
of discrete fracture pathways can be a positive factor for remediation. If the relevant fracture
pathways are sufficiently permeable and connected, contaminated ground water can be readily
extracted by pumping. Often without the need to apply large gradients or pump (and treat) huge
volumes of water thus, migration of the contaminated ground-water plume can thereby be controlled.
Conversely, the lack of fracture inter-connectivity is the major limiting factor to a successful pump-
and-treat system.
Fracturing
Approximately half of the respondents who were using pump and treat technology also fractured
the bedrock to improve well yield. Blast fracturing appears to be favored over pneumatic and
hydraulic methods. The possible reasons include the widespread use in construction projects
and broad knowledge base, greater number of service providers (local contractors experienced
with area geologic conditions), simplicity, robustness and economic feasibility.
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Vacuum Vapor Extraction
A significant number of respondents to the workshop survey (32%) indicated that they had used
vacuum vapor extraction. It was not clear whether vapor extraction is being used primarily in
unconsolidated deposits overlying 'fractured bedrock, in dewatered zones resulting from
implementation of remediation systems, or whether vapor extraction systems had actually been used
for removal of volatile contaminants from fractured bedrock vadose zones.
Other Remediation Technologies
Apart from pump-and-treat and its enhancements, there is very little experience with other
technologies. Many of the innovative technologies being applied in unconsolidated deposits are now
also under consideration and testing for application at fractured-rock sites. However, the primary
concern with implementing test studies of innovative technologies is the uncertainty in having a
sufficient monitoring network to adequately assess the success/failure of technologies implemented.
There is concern that contaminant flow may move into previously uncontaminated fractures which
are not being monitored or controlled. Confidence in the use of these technologies in unconsolidated
settings, along with confidence that the fractured rock site is well characterized may help alleviate
these concerns in the future.
Using monitorednatural attenuation and engineered biodegradation have appeal for the same reasons
as in unconsolidated deposits. Chemical oxidation and other abiotic strategies are of similar interest
in that they have the potential for destruction of the contaminant in situ, rather than removal for
above-ground treatment. There is current interest in further research to investigate the potential for
biodegradation or oxidation of high dissolved-phase contaminant concentrations in the vicinity of
NAPL sources to accelerate NAPL dissolution. Diffusive-delivery oxidation or biodegradation
systems, as well as thermal methods, are also currently of interest because of their potential to
address matrix contamination.
Engineered or enhanced bioremediation and chemical oxidation require the injection of nutrients or
reagents. Pumping for hydraulic control, recycling of reagents, or treatment of breakdown products
may also be required. Therefore, these strategies must address the same kinds of challenges
encountered in unconsolidated deposits. These challenges can be more significant in fractured rock
due to the level of heterogeneity. However, based on protocols already established for use in
unconsolidated deposits, acceptance of monitored natural attenuation will likely require
demonstration of a firm understanding of transport processes, pathways, and fate of contaminants.
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TABLE 2
State of the Practice on the use of Remediation Technologies
n=53 sites
Technology
Pump and treat w/
enhancements including
fracturing and flushing
Dual Phase Extraction,
Vacuum Vapor Extraction,
and Soil Vapor Extraction
In-situ oxidation
Natural attenuation
Fracturing plus installment
of permeable reactive barrier
Pump and treat plus in- well
stripping
Bioremediation
Frequency of Use*
51
20
10
4
2
1
1
Performance Experience
Two purposes - containment
of plume or removal of
contaminant. Results often
favor containment.
Coupled with fracturing and
pump and treat in one
instance. PCE concentrations
after one year of shutdown
were less than 200ug/l in one
vacuum, hot air injection and
vapor extraction system.
One system installed above
bedrock in Caldwell facility
for TCE treatment
An enhancement with sodium
lactate reduced
concentrations of TCE to
MCLs.
*More than one technology was used at most sites
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Research, Applied Research, and Technology Transfer Needs
1.) The factors and their relative significance affecting mass transfer of contamination from
fractures to the matrix and from the matrix to the fractures (i.e. matrix diffusion and counter-
diffusion) in fractured rock aquifers. Relevant factors could include, but not be limited to ranges
of concentration gradients and magnitudes of permeability, contrasts between fractures and
matrices for different rock types, short term changes from precipitation recharge, the impacts of
mineral coatings present on the fractures, impacts of fracture size and flow rate, etc. Provide
testing methodologies for identifying these factors. Provide an assessment of how these factors
will ultimately affect plume development and subsequent cleanup to low risk-based levels.
2.) Determine the field studies needed to assess how any of the following concepts may be
applied: discrete fracture network; dual-porosity medium or equivalent porous medium. Provide
information on the extrapolation of fracture orientation, length and aperture measured on the
local scale to those on the field site scale (hundreds to thousands of feet). Provide information on
differentiating dual porosity behavior from nonlinear or convective flow near the borehole (e.g.
from pump test data interpretation).
3.) Develop appropriate methods for aquifer test analysis for fracture flow systems. Assess
the applicability of various methods used routinely in the evaluation of pump test data in
unconsolidated formations to pump test data collected in a variety of fractured rock terrains-.
4.) Assess the applicability of currently used models developed for porous media for
fractured systems, especially in which the geometric characteristics of the fractures are unknown.
Include an evaluation of the Various methods using field data from sites in varied rock terrains.
Evaluate the use of probabilistic methods in assessing the magnitude and extent of contamination
and progress towards cleanup. Develop a unified federal agency approach to R&D concerning
modeling.
The results of research in the above areas should be addressed by appropriate technology
transfer products including especially guidelines, protocols, issue papers, etc.
1.) Guidelines for applying porous media flow and transport models to fractured rock
settings. These guidelines should include the practical and appropriate limits of their application
(by fractured rock setting, scale, etc.)as well as, applicable modifications to existing models to
simulate unique fractured rock attributes.
2.) Documented case studies (including lessons learned) comparing whole well (no packers,
purging, low flow sampling) and individual zone sampling results (packers-in-place, diffusion
multi-level samplers or a FLUTe system) and their influence on the interpretation of the
magnitude and vertical extent of contamination. Include borehole measuring methods to
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characterize the vertical distribution of contaminants, while minimizing investigation induced
cross contamination and/or short circuiting in existing monitoring wells.
3.) Suggested studies (i.e., fracture trace, geophysics, structural) which should precede
monitoring or test well locating.
4.) Documented case studies on the use of geophysical techniques and vertical chemical
profiling. Selection of borehole geophysical tools by geologic terrain and contaminant type.
5.) Determination of the appropriate level of lateral and vertical detail needed to characterize
(delineate contamination, determine risk), remediate (design, construct, operate) and monitor
(remedial performance, compliance) contamination at fractured bedrock sites.
6.) Recommended borehole methods to characterize the vertical distribution of contaminants,
while minimizing cross contamination and/or short circuiting within the monitoring well.
7.) Guidelines for the use of tracers to evaluate flow and transport of field site dimensions.
Provide information on determining test set up (e.g. estimating length of test, location of
monitoring points both horizontally and vertically, the use of pumping wells, etc.) Discuss
uncertainties; present the merits/flaws of conducting the test under pumping conditions and
natural flow gradients; and assess the influences of scale, adsorption, matrix diffusion, dead end
fractures, flow velocity, etc., for various fractured rock terrains.
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Appendix 1
Fractured Bedrock Workshop Planning Group
November 8-9,2000
Skip Chamberlain, U.S. Department of Energy
Kathy Davies, U.S. Environmental Protection Agency, Region 3
Tom Early, Oak Ridge National Laboratory
Pete Haeni, U.S. Geological Survey
John Koutsandreas, U.S. Department of Energy (Alternate)
Bob Masters, National Ground Water Association
Ted O'Neill, Smithville Bedrock Remediation Program
Randall Ross, U.S. Environmental Protection Agency, Office of Research and Development
Damien Marie Savino, United Technologies Corporation
Rich Steimle, U.S. Environmental Protection Agency, Technology Innovation Office
John Vidumsky, Dupont Specialty Chemicals
Bill Wertz, New York Department of Environmental Conservation
Bernie Woody, United Technologies Corporation (Alternate)
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