Hazardous Materials in
the Hydrologic
Environment: The Role
of Research by the U.S.
Geological Survey
Committee on U.S. Geological Survey Water Resources Research
Water Science and Technology Board
Commission on Geosciences, Environment, and Resources
National Academy Press
Washington, D.C. 1996
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the
National Research Council, whose members are drawn from the councils of the National Academy
of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of
the committee responsible for the report were chosen for their special competencies and with regard
for appropriate balance.
This report has been reviewed by a group other than the authors according to procedures
approved by a Report Review Committee consisting of members of the National Academy of Sci-
ences, the National Academy of Engineering, and the Institute of Medicine.
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distin-
guished scholars engaged in scientific and engineering research, dedicated to the furtherance of

Printed in the United States of America
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COMMITTEE ON U.S. GEOLOGICAL SURVEY WATER
RESOURCES RESEARCH
GEORGE M. HORNBERGER, Chairman, University of Virginia, Charlottesville
LISA ALVAREZ-COHEN, University of California, Berkeley
KENNETH R. BRADBURY, Wisconsin Geological and Natural History
Survey, Madison
CONSTANCE HUNT, World Wildlife Fund, Washington, D.C.
DAWN S. KABACK, Colorado Center for Environmental Management, Denver
DAVID H. MOREAU, North Carolina State University, Raleigh
FREDERICK G. POHLAND, University of Pittsburgh, Pittsburgh, Pennsylvania
FRANK W. SCHWARTZ, The Ohio State University, Columbus
LEONARD SHABMAN, Virginia Polytechnic Institute and State University,
Blacksburg
MITCHELL J. SMALL, Carnegie Mellon University, Pittsburgh, Pennsylvania
ALAN T. STONE, The Johns Hopkins University, Baltimore, Maryland
DAVID A. WOOLHISER, Colorado State University, Fort Collins
National Research Council Staff
STEPHEN D. PARKER, Project Director
ANITA A. HALL, Project Assistant

Staff
STEPHEN D. PARKER, Director
SHEILA D. DAVID, Senior Staff Officer
CHRIS ELFRING, Senior Staff Officer
GARY D. KRAUSS Staff Officer
JACQUELINE MACDONALD Senior Staff Officer
JEANNE AQUILINO Administrative Associate
ETAN GUMERMAN Research Associate
ANGELA F. BRUBAKER Research Assistant
ANITA A. HALL Administrative Assistant
MARY BETH MORRIS Senior Project Assistant
ELLEN DEGUZMAN Senior Project Assistant
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COMMISSION ON GEOSCIENCES, ENVIRONMENT,
AND RESOURCES
M. GORDON WOLMAN, Chair, The Johns Hopkins University, Baltimore,
Maryland
PATRICK R. ATKINS, Aluminum Company of America, Pittsburgh,
Pennsylvania
JAMES P. BRUCE, Canadian Climate Program Board, Ottawa, Canada
WILLIAM L. FISHER, University of Texas, Austin

vi
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Preface
This report is a product of the Committee on USGS Water Resources
Research, which provides consensus advice to the Water Resources Division
(WRD) of the U.S. Geological Survey (USGS) on scientific, research, and
programmatic issues. The committee is one of the groups that works under the
auspices of the Water Science and Technology Board (WSTB) of the National
Research Council. The committee considers a variety of topics that are
important scientifically and programmatically to the USGS and the nation and
issues reports when appropriate.
This report concerns the WRD science and technology that is relevant to
hazardous materials in the soil and water environment, including the subsurface,
stream and lake sediments, and surface waters. Within the USGS, this work is
dispersed in a number of WRD program areas, including basic research,
regional and site assessments, and data collection activities.
In the United States, a massive effort is in progress to remediate sites at
which hazardous materials threaten the environment. For perspective, it has
been estimated that there may be as many as 300,000 sites where soil and/or
ground water may require remediation to reverse the negative impacts of past
industrial, military, agricultural, and commercial activity. Estimates of the costs
of this effort over the next several decades approach a trillion dollars. The

this report. It is hoped that by maintaining a broad, forward-looking perspective,
this assessment will prove useful.
As the committee deliberated and became more cognizant of USGS
activities, productive discussions occurred between the members and USGS
personnel. This interaction was critical to success of this project. The committee
is particularly grateful to Dr. Robert M. Hirsch, Chief Hydrologist, Dr. Gail E.
Mallard, Acting Assistant Chief Hydrologist for Research and External
Coordination, and their colleagues for all the information and cooperation they
provided.
It is hoped that this report will help promote the understanding of natural
processes relevant to hazardous materials science and technology, and that in
turn, this improved understanding will lead to advances in public policy and
environmental management. The work of the USGS in this area is key to
making progress on one of the most crucial natural resources science policy
issues of our time.
George M. Hornberger
Chair, Committee on USGS
Water Resources Research
PREFACE viii
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Contents
EXECUTIVE SUMMARY 1

State-of-the-Art in the Field 38
Critical Areas for Research 44
Opportunities for the USGS 45
5 MATHEMATICAL MODELS AND DECISION SUPPORT 48
Predictive Flow and Transport Models 49
Decision Support Systems 61
Optimization and Decision Analysis 64
Decision Support in the USGS Hazardous Materials Science Pro-
gram
67
Opportunities for the USGS in Modeling 68
6 CONCLUSIONS 70
Overall Program Framework 70
USGS Collaboration With Other Agencies 71
Some Critical Issues 72
Educational Opportunities 73
Issues in Planning and Implementation 73
REFERENCES 75
APPENDIXES
A U.S. Geological Survey Water Resources Division Plan for Haz-
ardous Materials Science
90
B Biographical Sketches of Committee Members 106
CONTENTS x
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for solving problems become available. This will require application of a risk-
based approach for setting research priorities to assure that resources are
directed to activities with the greatest potential benefits to public health and the
environment. As part of this risk-based approach, priorities for research and the
evaluation of research results must involve input from cooperating agencies and
peer review of planning strategies and research results.
Although relevant activities in the hazardous materials science and
technology program are dispersed throughout the WRD, this study revealed no
cause for significant reorganization. Nevertheless, the importance of both
internal and external coordination and cooperation will likely increase in the
future in response to strong pressure from Congress to increase productivity
through interagency cooperation. In many cases this cooperation and proactive
outreach will mean maintaining a keen sensitivity to the needs of those entities
who are effectively consumers of research and information generated by USGS
scientists.
The characterization of processes relevant to the transport and fate of
hazardous materials in soils and waters is a significant strength of the USGS.
Long-term, field-based studies, for example, have been one of the agency's
greatest strengths. This type of research should continue and be expanded to
integrate methods to evaluate the effectiveness of remediation efforts. Such an
approach will require continued dedication to research, together with the
development and implementation of new modeling capabilities and decision-

urgency (e.g., sewage discharges, waste storage, urban runoff, etc.). From the
mid-1950's to the early 1970's, the research program of the USGS WRD
burgeoned (Langbein, 1981). In that era, federal programs within the USGS
grew as did the work done for other federal agencies. Subsequent to the 1970s,
WRD programs in hazardous materials science and technology have diversified
and come into their own as the “bread and butter” of the USGS. The Toxic
Substances Hydrology Program was established in 1983, the Nuclear Waste
Hydrology Program was established as a separate program in 1985 (although
the WRD has had a significant effort in this area since the early
INTRODUCTION 3
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1960s), and the National Water Quality Assessment (NAWQA) Program was
established as a pilot program in 1986 and as a full-scale program in 1991.
Langbein (1981) pointed out the increasingly important niche that was
being occupied by studies related to water quality within research programs of
the WRD:
Over the years there has been a considerable change in the subject matter of
research due mainly to corresponding changes in the nation's water problems,
especially water quality. Fortunately, the division began to broaden its research
in the 1960's with research into water chemistry as such, and soon expanded
the scope to include geochemical relations. During the 1950's nuclear bomb
testing and the resulting radioactive fallout, and the environmental movement

scientific and technical base if the mistakes of the past are to be avoided in the
future. The potential roles for the USGS in addressing these serious national
problems draw on the experience that the USGS has developed over many
decades (Figure 1-1).
Recognizing that problems related to hazardous materials research and
technology are both national and international in scope, and that the USGS is an
agency charged with providing information to resolve important water-related
problems of the nation, the Committee on USGS Water Resources Research
undertook a review of the research efforts and an assessment of the directions
the WRD should take in this area. In support of the USGS's general objective to
expand the body of scientific knowledge relevant to hazardous materials and
their behavior in the environment, this project sought to:
(1) help establish an overall framework for the USGS's research plan;
(2) identify critical research areas for the coming decade;
(3) advise on educational opportunities in the context of research;
(4) provide guidance on processes and measures for evaluating the
success of research in this area; and
(5) advise on improved approaches for involving “consumers” of the
science and technology in program planning and the
implementation of results.
The committee focused much of its attention on the first two items listed
above. With regard to educational opportunities, the general advice to the WRD
in Preparing for the Twenty-First Century: A Report to the USGS Water
Resource Division (National Research Council, 1991) holds in particular for the
hazardous materials programs. With regard to measures for evaluating research,
the use of peer review is highly recommended. By involving “consumers” of
research in the peer review, the process would also serve to address item 5.
Some of these items will be discussed more fully in the final chapter of this
report, although the bulk of the technical material in this report will concentrate
on a discussion of a framework for research and the identification of some

sites, the use of research results in the decision-making process, and methods to
assess the success of the various programs in reaching some of the goals within
the critical research areas.
INTRODUCTION 7
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2
Overview of the Federal Effort in
Hazardous Material Regulation and
Remediation
LEGISLATIVE BACKGROUND
Efforts of the federal government to regulate toxic and hazardous materials
during the past 40 years have revealed the lack of available knowledge
regarding the extent and severity of hazardous material impacts on human
health and the environment. It is difficult, for example, to state precisely how
many potentially toxic materials are in use, how many enterprises are involved
in hazardous waste management, the total volume of chemical wastes generated
in the United States each year, and the total number of sites used for hazardous
waste management. In addition, very little is known about the toxic effects or
environmental fate of many chemicals. Thus, there are abundant research
challenges in the area of hazardous materials.
The primary role of the USGS in reducing public risks associated with
hazardous materials is to provide scientific support, primarily to other agencies.

it has also resulted in disposal problems, for example, on farms where disposal
options are limited.
The Toxic Substances Control Act (TSCA), enacted in 1976, was also
designed to manage releases of hazardous substances into the environment.
TSCA gives EPA the authority to restrict the use of substances that are likely to
present an unreasonable risk of injury to human health or to the environment. In
the same year, Congress also authorized the first law regulating hazardous
wastes—the Resources Conservation and Recovery Act (RCRA). Although this
act was passed largely in response to the growing public awareness of serious
problems related to disposal, the RCRA actually regulates the generation and
transport of hazardous wastes.
The Clean Water Act of 1977 as a general pollution statute contains
multiple provisions, the most relevant of which pertains to defining EPA's
mission in the restoration of the physical, chemical, and biological integrity of
the nation's waters. The act prescribes a list of toxic water pollutants and
provides that they are subject to effluent limitations based on a “best available
technology” standard, with EPA having discretion to impose more stringent
limitations based on an “ample margin of safety” standard. This act, of course,
has its roots in the 1948 Federal Water Pollution Control Act, the initial federal
legislation regarding water quality control, which defined the federal role
concerning water quality monitoring and research.
Public concern over hazardous substances increased throughout the late
1970s and early 1980s as the Love Canal incident became national news and
policymakers began to confront the technical complexities of regulating these
substances (Barke, 1988). EPA has estimated that U.S. industries produced
approximately 290 million tons of hazardous wastes
OVERVIEW OF THE FEDERAL EFFORT IN HAZARDOUS MATERIAL REGULATION
AND REMEDIATION
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surface water, and from releases to the air. Estimated costs for remediation of
these sites exceed $100 billion (World Resources Institute, 1993).
The U.S. Environmental Protection Agency began to question the high
priority placed on remediation of hazardous waste sites in the late 1980s, as the
agency broadened its use of scientific risk assessment. In February 1987, the
EPA released a report on the relative risk of environmental problems in an
attempt to set priorities for its own activities (U.S. Environmental Protection
Agency, 1987). The report concluded that areas related to ground water
consistently ranked medium or low in terms of the relative risk they pose to
human health and the environment. The report found that active hazardous
waste sites ranked relatively high in cancer risks but relatively low in non-
cancer human health risks and ecological effects. These sites can also depress
property
OVERVIEW OF THE FEDERAL EFFORT IN HAZARDOUS MATERIAL REGULATION
AND REMEDIATION
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values. Overall, they were ranked medium in terms of risks to welfare. The
report further concluded that RCRA sites, Superfund sites, underground storage
tanks, and municipal non-hazardous waste sites were among areas of high EPA
effort but relatively medium or low risk (Environmental Protection Agency,
1990).

AND REMEDIATION
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trates how research follows a well-defined pathway that leads from process
discovery to process description and finally to process application. Process
discovery is concerned with the original characterization of a process and often
its mathematical formulation. Such a discovery may derive from experiments,
field studies, or theoretical analyses. In most instances, contributions are
required from all areas.
A case in point is the study of dispersion in porous media. The original
studies on the process of dispersion occurred in the early 1950's with simple
column experiments and the development of the theoretical-mathematical
description of the component processes. The role of dispersion at field scales
remained poorly understood until the late 1970's when appropriate theoretical
studies combined with subsequent large-scale field experiments were advanced.
Thus, process discovery depends upon a complementary collection of research
techniques involving laboratory, field, and theoretical approaches.
After a process is discovered, the thrust of research shifts to process
description. This research expands the knowledge base about processes,
detailing how the process works, determining its relative importance to other
processes, and establishing values for characteristic parameters of the process.
The main investigative approaches involve carefully controlled field and

opportunities for the USGS in addressing critical needs in these areas.
The character of scientific research has changed with time. For instance,
from relatively humble beginnings in the 1920's, 1930's, and 1940's, hydrology
has developed into a complex science embodying elements of physics,
chemistry, mathematics, and biology. The research categorization methodology
developed in the previous section can be used as a measure of research progress
in the study of flow and mass transport processes. In general, as fundamental
problems are solved and experience is gained, the research emphasis logically
shifts to applications. For example, such is the case with ground water flow
through saturated media. After over 100 years of research, the continuing focus
in the area of saturated flow is mainly to develop flow codes (e.g., MODFLOW;
McDonald and Harbaugh, 1988), or computational enhancements to codes (e.g.,
Hill, 1990). The study of coupled flow processes (complex problems where, for
example, mass transport depends upon fluid flow and fluid flow depends upon
mass transport), however, remains at the process discovery stage and will
require extensive research to sort out a large array of complex effects.
The emphasis on research related to problems of hazardous waste will
almost certainly shift toward applications. What remains to be discussed is what
ultimately brings about this shift to applications, and when it is likely to occur
in the various process areas. Analysis of these questions should be useful in
planning future USGS research efforts on hazardous materials science and
technology.
OVERVIEW OF RELEVANT USGS PROGRAMS
The WRD of the USGS has a number of programs in which studies are
conducted to aid in resolving problems related to the contamination of surface
and ground waters by hazardous materials (see Appendix A). Funding for
projects related to hazardous materials in various programs within the USGS
has reflected priorities established both by the USGS and by Congress
(Figure 2.1).
OVERVIEW OF THE FEDERAL EFFORT IN HAZARDOUS MATERIAL REGULATION