United States
Environmental Protection
Agency
Office of Research and
Development
Washington, DC 20460
EPA/600/9-90/042
September 1990
A
ORD Ground Water
Research Plan: Strategy for
1991 and Beyond
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Foreword
Ground water is a vital natural resource in the United States. Its quality is of
foremost concern for the future of human health and the environment. The
importance of ground water for consumption and other uses, as well as the
interaction of ground water with the rest of the hydrologic cycle and other aspects
of the environment has become increasingly apparent in a number of EPA
programs. The Agency has therefore established standards and undertaken various
activities to protect and remediate this resource. To underscore the importance of
these activities, the Deputy Administrator convened an EPA-wide Ground Water
Task Force to coordinate and direct future efforts.
There are three essential andinter-relatedrequirementsforEPA's ground water
efforts: legislative authority, administrative framework, and scientific and techno-
logical know-how. This document addresses the third requirement, particularly the
role of research in building a scientific understanding of how to prevent, predict, and
remediate ground water contamination. This Plan presents the Office of Research
and Development's strategy for conducting subsurface and related research in
support of EPA's programs.
Erich Bretthauer
Assistant Administrator for Research and Development
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Preface
This document describes a ground water research plan for EPA's Office of
Research and Development (ORD). The ground water research program is carried
out by ORD's Office of Environmental Processes and Effects Research (OEPER),
the Office of Modeling, Monitoring Systems, and Quality Assurance (OMMSQA),
theOfficeofEnvironmentalEngineeringandTechnology Demonstration (OEEDT),
and the Office of Exploratory Research (OER). Four ORD laboratories have lead
responsibilities in ground water research: OEPER's Environmental Research
Laboratories in Ada, OK and in Athens, GA, OMMSQA's Environmental Moni-
toring Systems Laboratory in Las Vegas, NV, and OEEDT's Risk Reduction
Engineering Laboratory in Cincinnati, OH. ORD's Center for Environmental
Research Information (CERI) conducts educational seminars and prints and dis-
seminates publications in support of the ground water research program. The
overall program is coordinated by the ORD Matrix Manager for Ground Water
Research, Peter W. Preuss, Director of ORD's Office of Technology Transfer and
Regulatory Support. This Plan was prepared by Peter W. Preuss and Amy L. Mills
for the Assistant Administrator for Research and Development. The Plan reflects
the review and contributions of the ORD Ground Water Matrix Management Work
Group and the Deputy Administrator's Ground Water Task Force.
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Abstract
Ground water research at EPA encompasses several different ORD programs
which are contributing to the body of knowledge in this emerging science. Efforts
are focused on serving EPA programs which are requiring an increasingly sophis-
ticated knowledge base and greater technical assistance in order to develop and
implement environmental programs. Two major themes or objectives for future
research are prevention and remediation of ground water contamination. These
objectives can continue to be met through focused research products for EPA
program clients, supported by basic research on subsurface processes, monitoring
and remediation methods, while evaluating and refining research results based on
field experience. Of primary importance are coordination with other research
agencies and organizations, and dissemination of research expertise through
technology transfer and technical assistance. Several ground water research
initiatives are highlighted in this Plan which would serve these goals. Two
significant research initiatives proposed for consideration concern improving the
performance of remedial technologies, and basic process research on the behavior
and effects of agricultural chemicals in ground water and surface water. Enhanced
funding for ground water research should be considered in order to sustain its ability
to serve the Agency's needs.
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Contents
Foreword j
Preface \\
Abstract \\\
I. Introduction •)
II. Background -\
A. Subsurface Monitoring 1
B. Transport and Transformation 2
C. In Situ Subsurface Remediation 2
D. Underground Source Control 3
E. Technical Assistance and Technology Transfer 3
III. General Approaches for Future Ground Water Research 3
A. Staying at the Forefront of an Emerging Scientific Field 3
B. Preserving Continuity 3
C. Meeting Users' Needs 3
D. External Coordination 4
E. Dissemination of Research Results ~.4
F. Science Advisory Board Recommendations 4
G. Ground Water Research Legislation 5
IV. Growth Themes for ORD Ground Water Research 5
A. Prevention 5
B. Remediation 5
V. Emerging Research Topics 6
A. Monitoring 5
B. Transport and Transformation 6
C. Subsurface Remediation 7
VI. Future Needs and Support of Ground Water Research 7
VII. New and Proposed Research Q
A. New Research for FY 1990 and 1991 8
1. Wellhead Protection 8
2. Prevention of Ground Water Contamination from Pesticides:
Information Systems for State Use 8
3. Subsurface Cleanup and Mobilization Processes (SCAMP) 8
B. Proposed Initiatives for FY 1992 and Beyond 9
1. Improving Performance of Remedial Technologies (IMPORT) , 9
2. Mid-West Agrichemical Subsurface/Surface Transport and
Effects Research (MASTER) 9
° 3. Other Initiatives to Consider for the 1990s 10
C. Future Funding for ORD Ground Water Research 1 o
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ORD Ground Water Research Plan:
Strategy for FY1991 and Beyond
I. Introduction
The Science Advisory Board's, "Review of the EPA
Ground Water Research Program" (July, 1985) concluded,
among other things, that ORD should establish centralized
direction and management for its ground water research pro-
gram through a Ground Water Research Manager. They
recommended that this Manager develop an integrated, com-
prehensive ground water research plan. The plan would address
research needs and activities spanning the various EPAprograms
having ground water components.
ORD has responded to these recommendations by ap-
pointing a Ground Water Matrix Manager, who coordinates
with other ORD Offices to analyze ground water needs and
promote new initiatives. This Ground Water Research Plan
summarizes the status of ground water research at EPA, and
proposes areas for growth for fiscal year 1991 and beyond.
n. Background
ORD supports an active, diverse ground water research
program dedicated to provide the scientific basis for protecting
current and potential drinking water aquifers, and intercon-
nected surface water resources, from contamination. The
interrelated scientific fields of hydrogeology, hydrology, geo-
chemistry, geophysics, biochemistry, microbiology, statistics,
soil science, and physical chemistry are components of ground
water research. Each field provides a perspective on what can
collectively be called ground water science. Research areas
span source control, detection, monitoring, prediction, and
remediationof ground watercontamination. FiveEPAprograms
and their statutory missions are served: CERCLA, RCRA,
CWA, SDWA, and FIFRA.
EPA's role is some what unique in the Federal ground
water research community, due to our regulatory missions and
timetables. For example, EPA's need to monitor ground water
quality and remediate contamination to drinking water con-
centrations has generated research into areas sometimes untested
by other organizations. Technology transfer and technical
assistance to those implementing environmental programs de-
pends upon a strong in-house knowledge base, responsive re-
search agenda, and assertive outreach program. EPA's research
effort in support of environmental programs is therefore dis-
tinctive in purpose, direction, and timing. Other agencies
cannot be expected to fulfill this role. Our challenge in working
with other agencies and organizations is to identify areas of
common and separate interest, so that research is complemen-
tary but not duplicative or lacking.
To carry out its functions in supporting ground water
activities at EPA, ORD conducts research in five broad areas.
These areas, and some of ORD's significant contributions, are
summarized below:
A. Subsurface Monitoring
The goal of this research program is to produce techniques
and methodologies for detecting and quantifying changes in
hydrogeology, and in subsurface water quality. Both direct
sampling and remote sensing approaches are generated. This
program includes research on locating and installing monitor-
ing wells; sample collection andpreservation; quality assurance
and quality control; geophysical and geochemical detection and
mapping of shallow contaminant plumes with both surface and
downhole methods; mapping deeply buried plumes associated
with injection wells, determining chemical indicators of ground
water contamination; developing monitoring methodologies
for the unsaturated zone; advanced monitoring techniques such
as real-time, in situ monitoring of ground water with fiber optic
sensor and fluorescence spectroscopy; and external leak detec-
tion devices for underground storage tanks.
Most of ORD's subsurface monitoring research has been
undertaken in response to the needs of the CERCLA andRCRA
hazardous waste programs, where immediateneeds to accurately
sample and analyze ground water have challenged the state of
the science to develop appropriate laboratory and field tech-
niques. ORD's monitoring research and development has
advanced EPA's ability to meet environmental needs and
statutory requirements.
in:
Some of ORD's most significant contributions have been
fiber opticandx-ray fluorescence remote sensing;
unsaturated zone monitoring for hazardous waste
facilities and underground storage tanks;
well construction techniques to minimize sample
contamination;
identification of indicator parameters for ground
water contaminants;
methodsfor collection of uncontaminatedaquifer
core material;
quality assurance of field investigations;
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• application of standard geophysical techniques to
hazardous waste site investigations;
• development of geographical information systems
(CIS); and
• methods for statistical comparisons of ground
water monitoring data.
As these methods and technologies are developed, they are
transferred to EPA Regions, States, and the public through
guidance manuals, training, reports, and professional journals.
Casc-by-case technical support to program offices in these
areas is also a major effort.
B. Transport and Transformation
In order to predict the movement of contaminants in the
subsurface, and thereby predict potential human and ecological
exposure, ORD maintains a research program in transport and
transformation of contaminants. Predicting contaminant be-
havior in the subsurface requires understanding the mecha-
nisms and rates of transport, and chemical, physical, and
biological transformations of contaminants. Transport is often
assumed to occur in the dissolved, aqueous phase, but may also
occur in separate, dissolved phases such as in immiscible oils,
or sorbcd to fine, colloidal particles. The subsurface environ-
ment affects the oxidation state, and the rates and types of
chemical transformations. These transformations in turn affect
the solubility and mobility of the contaminants. Transforma-
tion and transport are therefore intimately related processes.
ORD's research studies theseprocesses for various contaminants
in differentsettings, and develops models for predicting time of
travel and exposure concentrations.
Recent developments in transport and transformation re-
search include advances in understanding the processes that
control these phenomena, and integrating these processes into
mathematical models for describing and predicting the behav-
ior of contaminants in the subsurface.
At the process level, there have been recent advances in:
• understanding the kinetics of the partitioning of
contaminants between ground water and aquifer
solids;
• thebehaviorof multiphase fluid systems of water,
oil, and air;
• themovementofmetalionsinresponsetochemical
conditions;
• abiotic transformation pathways and rates;
• vapor phase transport phenomena important in
the vadose zone;
• facilitated transport resulting from the presence
of colloidal materials, or cosolvents such as
alcohols;
* the movement of contaminants through fractured
rocks;
• aerobic and anaerobic biotransformation;
• re-examination of the capacity of pollution-
degrading bacteria to move through soils and
geological material, which has improved our
understanding of the partitioning of organic
compounds between ground water and residual
oily material,
• understanding higher order transformation
• reactions;
• ' understanding hydrodynamic dispersion in
relation to heterogeneity in the hydrodynamic
domain;
• amoredefinitivedescription of the metals sorption
processes;
mathematical descriptions of the reduction of
organic pollutants in ground water.
Recent advances in integrating process level information
into predictive tools include:
• the development and dissemination of the metal
speciation model MINTEQA2;
• the pesticide soils leaching model PRZM;
• the pesticide ground water leaching model
RUSTIC;
• the screening model for vulnerable soils DB APE,
and development of databases for access through
DBAPE;
• development of "the multimedia model
MULTIMED for predicting the exposure from
landfilled solid and hazardous wastes;
development and application of the CEEPES
comprehensive environmental management
model to agricultural chemicals.
Most of the transport and transformation research in ORD
is performed in support of the hazardous waste programs, and
their needs in predicting the off-site effects of ground water
contamination from waste disposal sites. Some is also done to
support the Office of Pesticide Programs to predict the leaching
behavior of agricultural chemicals. A new effort is underway
to support the Office of Water in determining the sorptive
properties of soils as a factor in protecting wellheads from
contaminant migration.
C. In situ Subsurface Remediation
ORD's ground water research in the area of subsurface
remediation is developing effective, reliable methods for re-
storing contaminated soils and ground water as close as possible
to their original quality. This includes methods for recovering
contaminants from aquifers for further treatment, reducing the
volume or toxicity of contaminants in situ, monitoring and
modelingremediationprojects.andexaminingpastremediation
and source control efforts to identify subsurface factors contrib-
uting to their success or failure.
Significant research advances have included the initiation
of applied bioremediation to the subsurface, the development of
design tools for remediation (i.e., the BIOPLUME model), and
methods for performance evaluation of pump-and-treat tech-
nology. Other areas of investigation include steam stripping
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and soil vacuum extraction of contaminants, with an emphasis
on understanding the subsurface processes governing the re-
sults of remedial measures.
ORD's research in the subsurface remediation area has
been performed insupportofEPA'sdrinkingwaterandhazardous
waste programs.
D. Underground Source Control
EPA's Underground Injection Control program regulates
the injection of hazardous wastes into the subsurface. ORD has
a research effort to develop protocols for injection well prac-
tices, injection well integrity testing methods, and to under-
stand the interaction of injected material with subsurface ma-
terials.
E. Technical Assistance and Technology Transfer
Technical assistance generally refers to one-on-one assis-
tance by ORD on site-specific or problem-specific Regional,
State, or National regulatory matters. Technology transfer
generally refers to printed documents, software packages, and
focused training that are initiated and budgeted by ORD. Both
are carried out by ORD laboratories primarily for Superfund
staff in the Regional Offices. This effort is largely funded by
OSWER through the Superfund Technical Support Project,
which provides support on ground water as well as other aspects
of Superfund site investigations and remedies. -
For example, the RSKERL provides assistance on subsur-
face remediation problems through the Subsurface Remediation
Technology Support Core Team, operates an information
clearinghouse on this subject, and transfers technology from the
National Center for Ground Water Research, a consortium of
Rice, Oklahoma, and Oklahoma; State Universities. Areas of
expertise include hydrogeological aspects of pump-and-treat
aquifer remediation, in situ bioremediation of soils and ground
water, geochemistry, fluid and contaminant transport, transfor-
mation, and mathematical modeling.
EMSL-LV provides assistance in detecting, monitoring,
site characterization, data interpretation, and geophysical
techniques. This includes saturated and unsaturated zone
monitoring, remote sensing, mapping, geostatistics, analytical
methods and quality assurance, borehole and surface geophysics,
and x-ray fluorescence field survey methods. A hotline and on-
site field training facility are important features of the technology
support program at EMSL-LV.
At ERL-Athens, the emphasis is on multimedia (i.e.,
ground water, surface water, and soil) exposure and risk assess-
ment modeling of remedial action alternatives. Through the
Agency's Center for Exposure Assessment Modeling (CE AM),
support is provided on applying models to assist in risk-based
decisions. This includes information on models and databases
that link ground water transport and transformation to human
and ecological exposure scenarios. Workshopsandanelectronic
bulletin board serve to enhance technology transfer and assis-
tance.
RREL operates the largest of the technical support centers
in ORD. Support is provided on engineering problems related
to but not specific to ground water, such as soil and above-
ground water treatment alternatives, remedial construction
processes and materials, source control, and geotechnical
methods.
Technical assistance and technical support continue to be
a highly important part of the ground water research program.
In the future, the services described above could be further
expanded to others in need of scientific and engineering
expertise for technical decision-making.
HI. General Approaches for Future Ground
Water Research
A. Staying at the Forefront of an Emerging Scientific
Field
Hydrogeology and contaminant behavior is an emerging
field, and EPA's scientific research is at the forefront. EPA's
contribution to the state of knowledge is evidenced by our
contributions to the literature, our sponsorship of cutting-edge
research by universities such as Stanford, Yale, Louisiana
State, Carnegie-Mellon, and the consortium of Rice, Okla-
homa, and Oklahoma State Universities, and our participation
in international conferences (such as the International Geological
Congress, andothers). Implementation of EPA's environmental
programs need the best available technologies and methods.
These needs demand that supporting research be innovative,
state-of-the-science, and timely. It is essential therefore that
ground water research be supported so that it may remain at the
forefront.
B. Preserving Continuity
Another essential aspect of the research program is conti-
nuity. Research projects studying flow, sorption, transforma-
tion, or model development of ten require years of steady effort.
Field studies in particular require multiple years of observation.
A successful ground water research program must maintain
stability over time in order to generate useful, tested products.
Ground water research should therefore be part of the Agency's
long-term research agenda. Two examples of on-going re-
search areas related to ground water which have successfully
adopted 5-year plans are the Biosystems Technology Devel-
opmentProgramandtheWellheadProtectionResearchProgram.
C. Meeting Users' Needs
There are several categories of users of EPA's ground
water research. A primary user of research is EPA Headquar-
ters program offices, that develop regulations, guidance, and
strategies for national implementation. The scientific under-
pinnings of these documents are based on ground water re-
search. For instance, the Office of Solid Waste, the major
supporting office for ground water research funding, uses
research results from fate and transport modeling to formulate
hazardous waste characteristic criteria.
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A second primary category of users is the Regional, State,
local government staff, and consulting community who imple-
ment environmental regulations, guidance, and strategies.
Technical field manuals and technical assistance activities are
generally geared to this group. They represent the largest
segment of the user community, and are increasingly receiving
more of the research focus through technology transfer, tech-
nical assistance, and training. Some examples are technical
assistance on developing remediation plans at Superfund sites,
or providing training on sampling procedures. This user group
is also a valuable source of information on the application of
ground watermethodsandtechniques.andcanprovideessential
feedback to research.
Third.basicresearchprojectsfeedintoother.moreadvanced
research projects which can eventually lead to products or
predictions. For instance, basic research in methods develop-
ment is necessary in order to conduct quantitative field or
laboratory studies. Research to develop scientific principles of
sorption, transformation, and migration provides the basis for
much of the research on technological controls for specific
sources of ground water contamination. Therefore, one of the
primary users of research is researchers, who work through
iterative, experimental processes to develop products of use to
environmental programs.
Fourth, EPA contributes to extramural knowledge and
applications in ground water science. Through interagency
agreements, publications, participation in conferences, and
membership in professional organizations, EPA ground water
research is shared among users in the scientific community for
Uicbettermentof all. Clearly, theresearchplarfshould emphasize
environmental program support, while seeking the best balance
among the various user groups.
The future trend will be toward greater and more innova-
tive technology transfer and technical assistance to Regions and
their contractors, as well as delegated States because these
groups are increasingly responsible for carrying out environ-
mental programs and are in need of technical knowledge. This
effort cannot occur in the absence of continued basic research
and development. Basic research to maintain and build our
knowledge base must be sustained so that there will continue to
be technology to transfer.
D. External Coordination
Coordination plays a major role in prevention and
remediation research. ORD coordinates with other federal
agencies as well as State governments and private and public
institutions to promote information exchange and produce
belter research products. Some examples are: current coordi-
nation on the preparation of an interagency research plan with
the USGS and USDA on agricultural chemicals and their
effects on water resources; ongoing coordination with these
agencies at field test sites for validating pesticide leaching
models and performing site investigations; participation in the
EPA/USGS Coordinating Committee; recently co-sponsoring
a conference on hazardous waste ground water research with
the Electric Power Research Institute; and participation in the
Federal Coordinating Council for Science, Engineering and
Technology (FCCSET), which has recently published a
synopsis of all ground water research supported by Federal
agencies. These types of alliances, and coordinated research
plans and projects will continue to be fostered in the future-
Particular attention should be paid to the special expertise
and perspective various organizations can bring to a research
problem. EPA's needs and expertise are somewhat unique in
the research community due to our regulatory missions and
timetables. Subsurface processes that attenuate, transport, or
transform synthetic chemicals and metals, and sampling strat-
egies for point and non-point sources, are examples of areas
where EPA specializes. Our Agency's mandates to protect and
remediate ground water quality have generated research into
some areas other organizations have not explored. We must
continue to work with other agencies to identify areas of
common and separate interest, so that important research is
conducted but not duplicated.
E. Dissemination of Research Results
Technology 'transfer and technical assistance are impor-
tant applications of ground water research. This mechanism
provides a direct link between the researchers' expertise and
EPA's program implementation at the Headquarters, Regional,
and State levels. Various efforts are underway, including
seminars and publications disseminated from ORD's Center
for Environmental Research Information (CERI). These
efforts also support EPA's Ground Water Protection Strategy
(1984), which calls for strengthening State ground water pro-
grams through technical assistance and a strong research pro-
gram.
ORD's major technical assistance activities in ground
water are supported by and directed at Superfund programs.
However, other programs such as RCRA are equally in need of
hazardous waste remediation expertise, and an institutional
mechanism for accessing all appropriate laboratories for short-
term, intensive, site-specific project support should be consid-
ered.
F. Science Advisory Board Recommendations
The Science Advisory Board's "Review of theEPA Ground
Water Research Program" (1985) identifiedanumberof needed
refinements, including the need for increased resources and the
need for increased technology transfer and training. They
indicated 16 specific recommendations for filling research
gaps among monitoring, source control, fate and transport,
and remediation. Some of those recommendations have been
partially implemented, such as CERCLA funding for ground
water research, increased funding for monitoring, source con-
trol, source minimization research, and technology transfer.
Many, however, have not been fully implemented due to
resource limitations and competing priorities for research
funding. This includes research on contaminant sources not
addressed by specific Congressional mandates, field validation
of predictive techniques, assessment of field applications of
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containment techniques (caps, liners, walls, hydrodynamic
controls), remedial actions in fractured formations and in karst
topography.
The SAB also emphasized the general need for sustained,
long-term research and emphasis on environmental protection
at EPA in "Future Risk: Research Strategies for the 1990's"
(1988). The SAB's "Resolution on Use of Mathematical
Models for EPA for Regulatory Assessment and Decision-
Making" (1989) recommended, among other things, that EPA
increase its model validation program. To the extent practi-
cable, EPA should incorporate these recommendations into
plans for future research.
G. Ground Water Research Legislation
Several bills have been introduced in Congress over the
past several years calling for additional ground water research
and related activities in the Federal government. This legislation
would give EPA specific authority and direction to perform
ground water research. Currently, EPA derives this authority
from a number of different statutes, such as the Safe Drinking
Water Act.
Major provisions of these bills that affect EPA include a
new interagency research oversight committee and an educa-
tion committee, a research demonstration program, environ-
mental profiles and research on significant ground water con-
taminants, technical assistance, training, and technology transfer,
establishment of a ground water information clearinghouse,
establishment of research institutes, and grants to States to
develop and implement ground water strategies. Most of these
provisions are consistent with parts of the existing program,
however the research demonstrations, environmental profiles,
and clearinghouse would entail significant added emphasis in
EPA's research program.
The attention that Congress has given to new legislation in
this area underscores the importance of existing work at EPA,
and reinforces the need for additional research to serve the
needs of the Nation.
IV. Growth Themes for ORD Ground Water
Research
Subject areas where ground water research should seek to
expand can be broadly characterized by two themes: preven-
tion and remediation.
A. Prevention
Prevention encompasses the identification of threats to
ground water from point and non-point sources, and mitigating
these threats through a combination of source control, manage-
ment practices, land use changes, and institutional measures.
Prevention requires an understanding of fate and transport
processes, use of predictive techniques, and monitoring to
delineate the threats to ground water.
One aspect of prevention is wellhead protection, which
involves focused land and source management practices aimed
at preventing contamination of aquifers which supply drinking
5
water wells. By characterizing the vulnerability of aquifer
systems, local sources of contamination, and likely pathways
and rates of transport and transformation to such wells, State
and local governments can develop plans for protecting their
drinking water supplies. Wellhead protection research includes
methods for delineating wellhead protection areas, and man-
aging point-source/non-point source contamination threats.
Other aspects of the prevention theme are predictive tools,
such as models for flow, fate and transport. Predictive models
can be used to support management decisions to prevent the
introduction of contaminants to the subsurface or to prevent
exposure above a health-based concentration at a specified
location. The correct use of these models depends upon the
underlying field and contaminant data and assumptions that are
incorporated in the models. Research into rate constants and
physical properties such as hydraulic conductivity and effec-
tive porosity can therefore all be looked upon as part of the
prevention goal.
Monitoring the subsurface for early detection of leaks from
underground storage tanks or waste impoundments, or seepage
from pesticide applications, can also be considered an integral
part of prevention. By employing various sampling and remote
sensing methodologies near the source of contamination, ac-
tions can be taken to prevent the spread of contamination to
ground water.
B. Remediation
The success of ground water remediation efforts depends
largely upon understanding subsurface processes in order to
design effective remedies. For example, the success of
remediation may be governed by mutiphase behavior of con-
taminants, partitioning among solid and fluid media, biotic and
abiotic transformations, and transport in fractured media. In
order to remediate ground water at a waste site, knowledge of
these processes and how they are likely to operate under given
site-specific environmental conditions is essential.
Predictive tools such as models are also part of designing
and tracking remedial actions. For example, the BIOPLUME
model predicts contaminant migration affected by oxygen-
limited biodegradation, and can be used to help plan a
bioremediation project. Monitoring is also integral to remedial
.actions, both for detecting contaminants and monitoring the
progress of ground water cleanup. For example, assessing
whether health-based concentrations have been reached at a
site depends heavily on the monitoring techniques and strategy
utilized.
Knowledge of subsurface conditions also interfaces with
the design of engineering methods and technologies for
remediation. For example, ground water pumping systems and
practices must be compatible with the local hydrogeology and
contaminant properties. Because subsurface remediation is
relatively new and much remains unknown about the subsur-
face precesses and long-term results of various remedies, de-
velopment and evaluation of remedies must continue to be a
focus for research.
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V. Emerging Research Topics
Within the prevention and remediation themes, ORD has
identified a number of emerging topics and research needs in
ground water.
A. Monitoring
Advanced monitoring techniques that rely upon non-in-
trusive, in situ, or microelectronic techniques hold promise for
tiiefuturc,andmaysupplementorpossiblyreplaceconventional
laboratory "wet chemistry" for ground water monitoring. De-
velopment of fiber optics and x-ray fluorescence (XRF) have
been successful for in-situ, real time monitoring of some
organics and metal compounds, respectively. For example, in
XRF, an x-ray is directed at a sample, and in response the
sample emits induced fluorescence in the x-ray spectrum. A
detector analyzes the fluorescence for both type and concentra-
tion of inorganics. With further refinement, it may be possible
to do at least preliminary screenings for a range of specific
contaminants at waste sites or USTs with these methods. The
advantages in time and cost savings, holding times, chain of
custody, and laboratory requirements are significant.
Other emerging topics include monitoring strategies for
non-point sources of contamination, long-term monitoring
strategiesforclosed hazardous wastesites.problems monitoring
in wet environments, remote sensing methods for fracture
characterization, unsaturated zone processes and monitoring
techniques, monitoring strategies for karst terrain, and new
applications for problem solving with GIS.
B. Transport and Transformation
The roles of organic carbon, redox potential (eH), pH, and
solubility in aqueous phase transport need better understanding
in order to develop and rely upon predictions of contaminant
transport. Facilitated transport, a phenomenon that refers to
various mechanisms whereby contaminants move through the
subsurface at velocities greater than expected by considering
solubility and primary permeability alone, merits greater un-
derstanding. For example.sorptionof contaminants on colloidal
particles, and flow through macropores facilitate transport, and
must be accounted for in our predictions of time of travel and
exposure. Although anecdotal evidence exists that this phe-
nomenon occurs, it is not fully understood and is not accounted
for in operational transport models.
Another research topic in the area of contaminant transport
is complex wastes, or wastes with several components, densi-
ties, or behavioral characteristics. The separation of leachates
into water-soluble and immiscible fractions can result in plume
stratification, with light non-aqueous phase liquids (LNAPLS)
floating above dense non-aqueous phase liquids (DNAPLS). A
portion of the former sometimes can be removed from the
subsurface, while the latter settle in residual masses which are
not currently amenable to conventional removal methods.
Another complexity to this situation is the chemical alterations
which takeplace in the subsurface, sometimes producingplumes
of degradation products more toxic than the original waste.
The kinetics of adsorption and desorption, collectively
referred to as sorption, must be better understood to predict
transport reliably and design remedies. This is particularly
applicable to understanding the slow desorption of residual
contaminants in the deep subsurface. Remedies that enhance
desorption may be necessary in some settings.
Most transport models assume homogeneous
hydrogeology, while in fact this is more the exception rather
than the rule. Accelerated flow through fractured media is one
important example of the effects of heterogeneity on transport.
This phenomenon needs to be better understood and integrated
into transport models.
Transport, transformation, and environmental fate of non-
point sources, particularly agricultural chemicals is of special
interest to EPA. For example, much remains to be learned in the
areas of nitrate and pesticide behavior in the subsurface in order
to predict fate and effects with confidence.
Abiotic transformation processes have been studied for
some time, but much remains to be done, given the large number
of organic pollutants. Recent discoveries, for example, show
that certain halogenated hydrocarbon solvents may be hydro-
lyzed or reduced over a period of days or months to other
compounds having different properties.
The mobility and bioavailability of toxic metals and met-
alloids depend on the species of the metal, which in turn is a
function of metal/metalloid chemical properties and the char-
acteristics of the subsurface. Improving our understanding in
these areas is providing a better basis for predicting exposures
to these toxic substances.
Little is known about the fate of pollutants disposed of in
underground injection wells. The conditions of temperature
and pressure in this environment may greatly accelerate the
transformation and transport of pollutants.
Ground Water Modeling
The National Research Council, Water Science and Tech-
nology Board, Committee on Ground Water Modeling
Assessment's report "Ground Water Models: Scientific and
Regulatory Applications" (September, 1989) contained anumber
of recommendations applicable to EPA ground water research.
In summary, the report recommends: (1) continued validation
and refinement of ground water models, particularly those for
flow through the unsaturated zone, fractured rock, multiphase
flow, and codes Unking mass transport and chemical reactions;
(2) the role of bacteria in transport andremoval of contaminants;
(3) improving the presentation of uncertainty in model pre-
dictions, and improving our ability to estimate the reliability of
model results; (5) continued efforts at characterizing subsurface
processes through field and laboratory studies; and (6) devel-
oping approaches for parameter estimation and measurement
techniques.
The Science Advisory Board gave similar recommenda-
tions in their July, 1985 report, "Review of the EPA Ground
-------
Water Research Program" and their January, 1989 report,
"Resolution on Use of Mathematical Models for EPA for
Regulatory Assessment and Decision-Making", particularly
points (1) and (3) above. Clearly, future research in transport
and transformation should address improvements in the devel-
opment, application, and validation (i.e., laboratory or field
evaluation) of predictive models that EPA uses.
C. Subsurface Remediation
Identification of information requirements for remedy
selection, and methods for subsurface remediation continue to
be crucial areas for research. Low and variable permeability
influence the transport of contaminants, as well as the disper-
sion of surfactants used in clean up, and pumping rates in pump-
and-treat operations. Other important relationships between
subsurface conditions and application of remedial technology
must continue to be explored, in order to maximize the success
of costly and time-consuming remedial efforts.
Enhanced in situ methods for biotic and abiotic contami-
nant degradation is an active research area that merits greater
attention. The permanent solutions possible through this ap-
proach (as opposed to moving contaminants to treatment sys-
tems, concentrating them, and moving the residuals to still other
locations), and the important alternatives these methods pro-
vide to unproven extraction methods, render in situ methods
one of the most important growth areas for research. Processes
for transforming contaminants in the subsurface to simpler, less
toxic compounds are being explored for application to
remediation of hazardous waste sites and pesticide use.
Topics include in situ bioremediation, where microbes are
stimulated to degrade organic contaminants in place. Use of
naturally occurring, indigenous species is showing promise for
some contaminants and settings, while engineered microbes are
being developed for others. It has been shown in the laboratory
and field that certain organic wastes can be converted into
biomass and harmless by-products of microbial metabolism.
This has begun to be demonstrated in the field for indigenous
species with hydrocarbon components of gasoline and for
chlorinated compounds such as vinyl chloride and DCE, which
can be cometabolized with methane. More highly chlorinated
compounds tend to be more recalcitrant to these methods, and
may require addition of microbes with special biodegradative
functions. White rot fungus has also shown to be effective on
a number of contaminants including DDT, PCBs, PAHs,
chlorinated phenols and chlorinated dioxins.
The major limiting factor in successful field application
of bioremediation, however, appears to be transporting oxygen
or other electron acceptor and nutrients to the microbial popu-
lations so that they may flourish and metabolize the contami-
nants rapidly. This transport factor is a function of the het-
erogeneity and hydraulic conductivity of the site's geologic
media and distance from the remedial application to the con-
taminant plume. In addition, in certain anaerobic conditions,
reductive dechlorination can be an effective bioremediation
method. In all circumstances, the importance of reliable site
investigations, monitoring systems, and predictive tools are
evident.
Ahead in bioremediation research is identification of
breakdown mechanisms for a range of contaminants, identifi-
cation of alternative electron acceptors (other than oxygen),
aerobic degradation of solvents, and the feasibility of adding
micro-organisms with special metabolic capabilities. Of equal
importance is overcoming hydrogeological obstacles to em-
ploying bioremediation in the field, and developing methods
for enhancing transport of nutrients to microbial populations.
This research must be built upon methods development and
controlled studies of biological transformation processes. Some
of this research is incorporated in ORD's Biosystems research
program.
In the future, EPA may be able to estimate and enhance the
rate and extent of natural degradation processes of many
contaminants of concern in soils and ground water. A major
emphasis should be to approximate the extent of contaminant
reduction that can be attained with bioremediation to determine
whether the technology can be used to meet EPA's regulatory
standards for remediation and closure.
Abiotic remediation is another topic that has an unexplored
potential. EPA investigators are in the process of isolating the
natural compounds responsible for the observed abiotic reduc-
tion of several classes of pollutants. These compounds may be
useful in enhancement of degradation processes.
VI. Future Needs and Support of ORD Ground
Water Research
While significant strides have been made in understanding
various aspects of ground water science and technology, ground
water research is still in its infancy in many respects. Unlike
surface water, ground water is very difficult to observe and
measure in the field, it moves slowly, and is strongly influenced
by the medium through which it flows. Further, contamination
results in different flow characteristics as well as a range of
chemical interactions and transformations, most of which cannot
be quantitatively predicted at this time.
The scope of research needs has been broadened by
greater concern for ground water quality, new legislation and
regulations, better problem identification, and a tendency for
investigations to uncover ever greater variability in the chem-
istry, physics, and biology of the subsurface. Research must
strive for but may never attain solutions to every contamination
problem in every hydrogeologic setting.
EPA programs require increasingly sophisticated knowl-
edge on whichtobasecomplex.costiycontaminationprevention
and remediation decisions. The importance of continued and
expanded supporting research is paramount. The value to EPA
programs in supporting ORD research has been demonstrated
by such advances as in ground water monitoring practices, site
characterizations, tools for risk assessments, remedy selections
-------
at hazardous waste sites, and pesticide leaching models. Con-
tinued sustenance of these and other program office activities
will depend in part on future research in the high priority areas
identified below.
VII. New and Proposed Research
A. New Research for FY1990 and 1991
Three research initiatives have been approved within the
last two fiscal years which will address some of the emerging
topics presented in this Plan.
I. Wellhead Protection
In September, 1988, ORD and EPA's Office of Water
en teredintoaS-yearresearchand technology transferagreement
tosupportStateWellheadProtection (WHP) Programs. States
are currently implementing WHP programs in accordance with
the 1986 Amendments to the SDWA. The purpose of the
research is to advance fundamental understanding and transfer
information regarding how to protect ground water supplies
which flow to drinking water wells in various physical and
institutional settings across the nation. ORD begins research
and development activities for WHP in FY 1990.
Four research priorities are envisioned. First, field testing
and verification for WHP area delineation methods will be
undertaken, including the refinement of current modeling ap-
proaches. Second, ORD willevaluatetheability of thesubsurface
to assimilate certain amounts of contamination without impact
to drinking water supplies, and apply this information to the
delineation of WHP areas. Third, ORD will evaluate and apply
knowledge of agricultural chemical behavior, including the use
ofpcsticideleaching models, for delineating WHP areas. Fourth,
ORD will develop WHP area ground water monitoring strate-
gies, including definition of optimal sampling and monitoring
designs.
The WHP research is consistent with the prevention theme
for ground waterresearch, as well as ORD's approaches to long-
term basicresearch.servicetoFJPAclientoffices.andtechnology
transfer to the States. It also will use results from several
emerging topics identified in this Plan, such as sorption, model
validation, transport of agricultural chemicals, and monitoring
strategies.
2. Preventing Ground Water Contamination from
Pesticides: Information Systems for State Use
The problem of pesticides in ground water is national in
scope, but locally variable, therefore accurate predictions of
pesticide transport and transformation requires specific infor-
mation at the local level. Evaluation of all likely combinations
of pesticides, environmental settings, and managementpractices
is virtually impossible using random, large-scale monitoring
studies or limited site-specific investigations. However, tools
are available to locate problem areas, and develop strategies for
regulation and use of pesticides on a local level. These tools
include models which have been developed to predict the
leaching of pesticides to ground water, data which has been
collected on soil properties and other relevant environmental
factors, and geographic information systems (GIS) for display-
ing and analyzing spatial information. To date, these types of
tools have not been systematically integrated into a workstation
framework for State and local risk management.
The main purpose of this initiative is to provide such a
framework for States upon which they can develop locally
meaningful pesticide management plans. The work will also
include field evaluation of monitoring and modeling schemes.
The project will be carefully coordinated with related research
on the effects of agricultural chemicals on water quality at the
USGS andUSDA, in order to ensure integration of information
and dissemination of results.
3. Subsurface Cleanup and Mobilization Processes
(SCAMP)
The potential effectiveness of "pump and treat" technology
to remediate contaminated ground water and soils is largely
unknown, but widely practiced. Further, the technology
sometimes fails to accomplish the mandates of the Superfund
Amendments and Reauthorization Act of 1986 (SARA) which
states that cost-effective technologies be utilized for the per-
manent remediation of contaminated sites. The successful
application of this technology in site remediation requires an
understandingofsitecharacterizationrnethods and the processes
controlling contaminant transport and mobilization in the
subsurface. Poor understanding of these processes and inad-
equate site characterization are the most common reasons that
pump and treat does not perform as a cost-effective, permanent
remedy. This does not mean that pump and treat should be
abandoned, but that a research program should be carried out to
significantly improve its efficacy, and current guidelines for the
implementation of this technology should be reexamined with
new recommendations for its use.
The overall objective of the research is to acquire process
and characterization information that will allow development
of a decision-making framework for predicting the appropriate-
ness and potential efficacy of "pump and treat" for site
remediation. This research will support the goals of the
Superfund and RCRA programs by providing information
necessary to improve remedial actions at hazardous waste sites.
The effort will consist of up to seven phases or activities:
1) consolidation of existing information, and development of a
5-year plan for research and development projects and outputs;
2) development of improved methods for site characterization;
3) research on immiscible fluid flow and residual saturation,
and their effects on pump and treat methods; 4) research on
mass transport in heterogeneous media, and its effect on pump
and treat methods; 5) research on contaminant sorption to
geologic materials, and its effect on pump and treat methods; 6)
research and developmentof accelerated remediation methods,
such as combination of pump and treat with use of surfactants
ormicro-organisms; and?) technical assistance and technology
transfer to Superfund personnel.
-------
The SCAMP research is a fundamental part of the ground
water remediation theme of this Plan, and several emerging
topics including site characterization, behavior of immiscible
substances, sorption, bioremediation, effects of heterogeneous
media, and model refinement. It also strongly supports the
CERCLA and RCRA programs in site remedy decisions, and
responds to several Regional research priorities expressed in a
recent survey of Regional Superfund offices. In addition, it
addresses several research activities recommended by the SAB,
as noted in Chapter 2 of this Plan.
B. Proposed Initiatives for FY 1992 and Beyond
Of the many remaining research needs in ground water,
two high-priority research areas have been identified for special
consideration in FY 1992 planning and beyond. With consid-
eration of limited funding availability, the following two initia-
tives address many, although not all, of the emerging topics
discussed earlier in this Plan.
1. Improving Performance of Remedial Technologies
(IMPORT)
The Superfund Research Plan for FY92 identified the
evaluation of contaminant fate and transport mechanisms as a
major Regional need. Without adequate information about the
subsurface behavior of contaminants, remedial goals for soils
cannot be set and the performance of remedial technologies for
soils and ground water cannot be predicted. Contaminated soils
frequently act as a source of pollutants to ground water, either
by direct contact with the water table or as recharge water
percolates through the vadose zone to the water table aquifer.
Soil cleanup goals for Superfund sites do not emerge from a
standardized methodology and frequently do not reflect risk
associated with alternative pathways, such as exposure to
contaminated water. Given the relationship between ground-
water quality and contaminated soil, it should be possible to
establish soil cleanup goals at Superfund sites that are quanti-
tatively related to drinking water standards. To accomplish
this, the Superfund program needs to understand subsurface
contaminant fate and transport. Basic research that focuses on
the physical and chemical parameters of subsurface contami-
nant transport will provide a firm technical basis for setting
remedial goals for soils at Superfund sites. In addition, such
research provides the basis for evaluating and predicting the
effectiveness of existing and potential in situ remedial tech-
nologies.
The purpose of IMPORT is two-fold: (1) to develop a
systematic approach to determining remedial goals at S uperfund
sites; and (2) to improve the knowledge base for selecting and
implementing in situ remedial technologies. This initiative
would complement the FY91 SCAMP initiative, which will
include some subsurface process studies as an integral part of
predicting the length of time required for pump-and-treat sys-
tems to remediate ground water. A joint ORD/OSWER five-
year research plan would be developed to coordinate IMPORT
.research on subsurface assessment, characterization, monitor-
ing, and prediction for remedial planning .
These integrated efforts would result in improved guid-
ance on site-specific remedial planning for Superfund sites in
the areas of cleanup goals for contaminated soils and the
selection of remedial technologies for contaminated soils and
ground water. A critical component of this initiative would be
an aggressive technology transfer andtechnicalsupportprogram
to synthesize information, transfer it to field personnel, and
assist in its application to ongoing remedial projects. The
necessary resources will be anticipated and reserved during
development of the comprehensive research plan to ensure the
rapid transfer of this information.
The IMPORT initiative would address the remediation
theme of this Plan, and the emerging topics of information for
remedy selection and post-closure monitoring strategies. This
research would also strongly support EPA and State CERCLA
and RCRA decisions on remedy selection, and was strongly
suggested by Regional Superfund offices in a recent survey of
research needs. It also addresses several recommendations
made by the SAB, as discussed in Chapter 2 of this Plan.
2. Mid-West Agrichemical Subsurface/Surface Transport
and Effects Research (MASTER)
EPA, USGS, and especially USDA have various research
projects in progress studying the effects of agriculture on the
quality of ground water and surface water. Although each
agency has its unique responsibilities and areas of expertise and
concentration, there is mutual concern about the fate of agri-
cultural chemicals as they move through the environment that
could best be addressed through a coordinated plan of study.
Such apian was drafted inFebruary, 1989, aridselected the mid-
continent soybean and corn-growing region to determine the
regional factors affecting the distribution of atrazine, an herbicide
of long-standing use, through the environment.
It is expected that methodologies developed through this
interagency research couldbeusedbytheagricultural community
and others to predict the effects of various soil, hydrogeological,
andclimatic factors and management practices on thedistribution
of agricultural chemicals on ground and surface waters in other
parts of the U.S. This interagency effort will, among other
things, generate basic and applied research into the transport
and transformation of agricultural chemicals in midwest
farmland. The information afforded from this research will
provide a better basis for predicting and con trolling the leaching
of agricultural chemicals into drinking water aquifers.
Currently, ORD's role in the interagency effort is mainly as
an advisory body. However, EPA's concerns with environ-
mental impacts of pesticides, wellhead protection, and non-
point source pollution suggest that basic knowledge in this area
is of primary importance. The interagency initiative presents an
excellent opportunity to share and contribute, to an important
research effort. An interagency work group has met and agreed
on several proposed research areas for EPA, should funding
become available.
Of particular benefit to EPA would be the addition of
research components to this interagency effort for studying
-------
subsurface degradation processes of agricultural chemicals,
behavior of nitrates in surface and ground waters, macropore
flow in the subsurface, testing and improving EPA-developed
pesticide leaching models, real time monitoring methods, non-
point source monitoring strategies, interaction of pesticide
runoff with wetlands and potential recharge to ground water,
and ecosystem effects.
This initiative would address the prevention theme of this
Plan, and the emerging topics of monitoring strategies for non-
point sources, subsurface behavior of agricultural chemicals,
and model validation. MASTER is not entirely a ground water
initiative, however much of the investigation is within the scope
of this Plan. Several recommendations of the SAB would be
addressed by this research, as discussed in Chapter 2. The goals
of this initiative are also consistent with the President's Water
Quality Initiative, EPA's Agricultural Chemicals in Ground
Water Strategy, and the Agency's support for interagency
coordination in research.
3. Other Initiatives to Consider for the 1990s
Other research initiatives to consider for the future, in line
with the themes, emerging topics, and approaches discussed
earlier include:
• Further development of bioremediation methods,
including continuation of such essential efforts as
characterizing subsurface controls on
implementing bioremediation in situ for
contaminated ground water, and developing
methods for evaluating and augmenting
bioremediation processes in the subsurface.
• Enhancement of wellhead protection research,
such as assessing the relative impacts of multiple
sources of contamination to underground water
supplies, as well as identifying and preventing
"unaddressed" sources of contamination, e.g.,
from Class V injection wells.
RCRA Technical Support Centers. Expand the
existing infrastructure for Superfund technical
support at ORD laboratories to address similar
problems at RCRA sites.
• Enhancement of technology transfer to State and
local users. New and innovative means of
transmitting research results can be developed.
* Further development of in situ , real-time
monitoring devices, to provide faster, less costly
results for planning, regulatory compliance, and
remedial actions.
• Characterization of subsurface heterogeneity, and
quantifying the dispersion term in different
settings. This impacts the results of virtually all
of the transport models EPA uses.
• Abiotic transformations of contaminants. Non-
biological transformations in the subsurface are
not well understood for many compounds, and
have significant effects on mobility and toxicity.
• Methods for measuring redox potential in ground
water samples. This property is essential for
understanding certain reactions and modeling the
subsurface.yetcurrentmethods may be inadequate
for measuring it.
• • Develop chemical-specific reference documents,
or environmental profiles, containing physical/
chemical properties, environmental transport and
fateinformation, remedial methods and treatability
information for significant ground water
contaminants.
Analysis of water quality trends in ground water
usedfordrinkingwater supplies. There are various
approaches to analyzing the growing body of
information on ground water quality to better
understand national and regional trends.
Subsurface transportof pathogens. Muchremains
to be known about the public health risk of viruses
and bacteria transported via ground water to water
supplies.
Potential effects of alternative fuels use and storage
on ground water quality. While the use of certain
fuels may improve ambient air quality, potential
leakage of highly mobile fuel products from
storage tanks may endanger ground water quality.
• Effects of global warming on ground water. Global
warming may have significant impacts on ground
water quality and quantity, for example through
water tablelowering of major aquifers andchanges
in recharge patterns.
C. Future Funding of ORD Ground Water Research
At the current funding level of approximately $23 million/
year, ORD can respond to some but not all of the research needs
expressed by programs. To respond to a range of needs, both on
the generic and site-specific scale, on-going research and new
initiatives must be better supported.
An increase in the ground water research budget could
potentially support within five years a significant improvement
in the development and evaluation of databases, codes, and
field methodologies to respond to many of the outstanding
needs of EPA programs. For example, an increase of funds in
transport and transformation (currently funded at approxi-
mately $9M/yr.) could advance current research efforts to the
stage where we might understand and begin to predict with
some accuracy: a) the behavior of major classes of organic
compounds in major hydrogeologic settings, b) the transport of
contaminants in certain complex environments, such as fractured
rock, c) abiotic transformations of certain common compounds,
and d) biotransformation in the subsurface, particularly under
anaerobic conditions.
With an increase in the monitoring budget (currently at
approximately $7M/yr.) we could move forward in developing
advanced, low cost screening f,nd monitoring techniques for
major contaminants. In aquifer remediation (currently at ap-
10
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proximately 5M/yr.) we could be much farther along in devel-
oping, evaluating, and predicting the time and cost involved
with a number of subsurface remedies. In underground source
control (currently at approximately IM/yr.) we could signifi-
cantly advance our knowledge of the impact of injection wells
on the subsurface and consequent effects on ground water.
In technology transfer and technical assistance (currently
at approximately IM/yr.) we could provide much needed sup-
port for information clearinghouses, technology transfer to
States, and greater support for EPA enforcement cases and
other site-specific ground water activities. We could make
major progress toward improving data management systems
for storing and accessing the vast amount of information
available for site characterization.
A larger budget in general would also improve our ability
to provide seed money for promising external projects, and
leverage other agencies and organizations for cooperative re-
search efforts.
Congress has considered new legislation for ground water
research over the past several years, including authorization for
additional appropriations. The potential impact on current
research activities is not clear, however significant new funds
might be appropriated to carry out the legislative provisions,
such as research demonstrations, environmental profiles of
significant ground water contaminants, and grants to States.
The potential results of not advancing ground water re-
search through some mechanism (legislative or otherwise) are,
(1) early contaminant detection and ground water protection
limitedbyuntestedmonitoringapproaches, (2) uneven predict-
ability of contaminant transport and subsequent human and
ecological exposure, (3) poor source control planning where
based on crude predictions of contaminant fate and transport,
and (4) inefficient or ineffective remedial actions at hazardous
waste sites and other ground water corrective actions.
Aside from these impacts on implementation of EPA and
State programs, there are potential impacts of a lagging
knowledge base for future rulemaking and national policy
development. A strong, current knowledge base in ground
water has benefits for many aspects of environmental pro-
grams.
11
&U.S, GOVERNMENT PRINTING OFFICE: 1990 - 748-159/2M67
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