ALTERNATIVES FOR MANAGING
THE NATION’S COMPLEX
CONTAMINATED GROUNDWATER SITES
Committee on Future Options for Management in the
Nation’s Subsurface Remediation Effort
Water Science and Technology Board
Division on Earth and Life Studies
NATIONAL RESEARCH COUNCIL
OF THE NATIONAL ACADEMIES
THE NATIONAL ACADEMIES PRESS
Washington, D.C.
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001
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 panel responsible for the report were chosen for their special competences and with regard for appropriate balance.
This study was supported by Contract Number W911SR-09-1-0004 between the National Academy of Sciences and the U.S. Department of the Army. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.
International Standard Book Number-13: 978-0-309-27874-4
International Standard Book Number-10: 978-0-309-27874-0
Library of Congress Catalog Card Number 2012955130
Cover: The plume maps represent the distribution of TCE in one groundwater zone at the MEW Superfund site in California, before and after 17 years of applying pump and treat technology.
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THE NATIONAL ACADEMIES
Advisers to the Nation on Science, Engineering, and Medicine
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Charles M. Vest is president of the National Academy of Engineering.
The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the Institute of Medicine.
The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. Charles M. Vest are chair and vice chair, respectively, of the National Research Council.
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COMMITTEE ON FUTURE OPTIONS FOR MANAGEMENT IN THE NATION’S SUBSURFACE REMEDIATION EFFORT*
MICHAEL C. KAVANAUGH, Chair, Geosyntec, Oakland, California
WILLIAM A. ARNOLD, University of Minnesota, Minneapolis
BARBARA D. BECK, Gradient, Cambridge, Massachusetts
YU-PING CHIN, The Ohio State University, Columbus
ZAID CHOWDHURY, Malcolm Pirnie, Phoenix, Arizona
DAVID E. ELLIS, DuPont Engineering, Newark, Delaware
TISSA H. ILLANGASEKARE, Colorado School of Mines, Golden
PAUL C. JOHNSON, Arizona State University, Tempe
MOHSEN MEHRAN, Rubicon Engineering, Irvine, California
JAMES W. MERCER, Tetra Tech GEO, Sterling, Virginia
KURT D. PENNELL, Tufts University, Medford, Massachusetts
ALAN J. RABIDEAU, State University of New York, Buffalo
ALLEN M. SHAPIRO, U.S. Geological Survey, Reston, Virginia
LEONARD M. SIEGEL, Center for Public Environmental Oversight, Mountain View, California
WILLIAM J. WALSH, Pepper Hamilton LLP, Washington, DC
NRC Staff
LAURA J. EHLERS, Study Director
STEPHANIE E. JOHNSON, Senior Staff Officer
KERI SCHAFFER, Research Associate
JEANNE AQUILINO, Senior Administrative Associate
ELLEN DEGUZMAN, Research Associate, through June 2011
ANITA HALL, Senior Program Associate
______________________
*Kevin J. Boyle, Virginia Polytechnic Institute and State University, Blacksburg, was a member of the Committee from February 2010 to June 2012.
WATER SCIENCE AND TECHNOLOGY BOARD
DONALD I. SIEGEL, Chair, Syracuse University, Syracuse, New York
LISA ALVAREZ-COHEN, University of California, Berkeley
EDWARD J. BOUWER, Johns Hopkins University
YU-PING CHIN, The Ohio State University, Columbus
M. SIOBHAN FENNESSY, Kenyon College, Gambier, Ohio
BEN GRUMBLES, Clean Water America Alliance, Washington, DC
GEORGE R. HALLBERG, The Cadmus Group, Inc., Watertown, Massachusetts
KENNETH R. HERD, Southwest Florida Water Management District, Brooksville
GEORGE M. HORNBERGER, Vanderbilt University, Nashville, Tennessee
CATHERINE L. KLING, Iowa State University, Ames
DEBRA S. KNOPMAN, The Rand Corporation, Washington, DC
LARRY LARSON, Association of State Floodplain Managers, Madison, Wisconsin
RITA P. MAGUIRE, Maguire & Pearce PLLC, Phoenix, Arizona
DAVID H. MOREAU, University of North Carolina, Chapel Hill
ROBERT SIMONDS, The Robert Simonds Company, Culver City, California
FRANK H. STILLINGER, Princeton University, Princeton, New Jersey
MARYLYNN V. YATES, University of California, Riverside
JAMES W. ZIGLAR, SR., Van Ness Feldman, Washington, DC
NRC Staff
JEFFREY JACOBS, Director
LAURA J. EHLERS, Senior Staff Officer
LAURA J. HELSABECK, Senior Staff Officer
STEPHANIE JOHNSON, Senior Staff Officer
JEANNE AQUILINO, Financial and Administrative Associate
ANITA HALL, Senior Program Associate
MICHAEL STOEVER, Research Associate
SARAH BRENNAN, Senior Program Assistant
Preface
Despite nearly 40 years of intensive efforts in the United States as well as in other industrialized countries worldwide, restoration of groundwater contaminated by releases of anthropogenic chemicals to a condition allowing for unlimited use and unrestricted exposure remains a significant technical and institutional challenge. Recent (2004) estimates by the U.S. Environmental Protection Agency (EPA) indicate that expenditures for soil and groundwater cleanup at over 300,000 sites through 2033 may exceed $200 billion (not adjusted for inflation), and many of these sites have experienced groundwater impacts.
One dominant attribute of the nation’s efforts on subsurface remediation efforts has been lengthy delays between discovery of the problem and its resolution. Reasons for these extended timeframes are now well known: ineffective subsurface investigations, difficulties in characterizing the nature and extent of the problem in highly heterogeneous subsurface environments, remedial technologies that have not been capable of achieving restoration in many of these geologic settings, continued improvements in analytical detection limits leading to discovery of additional chemicals of concern, evolution of more stringent drinking water standards, and the realization that other exposure pathways, such as vapor intrusion, pose unacceptable health risks. A variety of administrative and policy factors also result in extensive delays, including, but not limited to, high regulatory personnel turnover, the difficulty in determining cost-effective remedies to meet cleanup goals, and allocation of responsibility at multiparty sites.
Over the past decade, however, remedial technologies have shown in-
creased effectiveness in removing contaminants from groundwater, and the use of more precise characterization tools and other diagnostic technologies have improved our ability to achieve site-specific remedial action objectives within a reasonable time frame at an increasing number of sites. For example, of the over 1,700 National Priority List sites, the EPA has deleted over 360 (as of March 2012), including some that have reported achieving restoration goals for groundwater, usually defined as drinking water standards. Other regulatory programs at both the federal and state level report closures of many sites with contaminated groundwater, although “closure” is often defined by site-specific conditions, such as the need for long-term institutional controls. Such trends and financial pressures have prompted the Department of Defense (DoD) to set very aggressive goals for significantly reducing the expenditures for the Installation Restoration Program (IRP) within the next few years.
There is general agreement among practicing remediation professionals, however, that there is a substantial population of sites, where, due to inherent geologic complexities, restoration within the next 50 to 100 years is likely not achievable. Reaching agreement on which sites should be included in this category, and what should be done with such sites, however, has proven to be difficult. EPA recently summarized the agency’s recommended decision guidance (July 2011) for these more complex sites, presenting a Road Map for groundwater restoration that targets both Superfund and Resource Conservation and Recovery Act Corrective Action sites. A key decision in that Road Map is determining whether or not restoration of groundwater is “likely.” If not, alternative strategies must be evaluated to achieve the remedial action objectives, including possible modification of these objectives or the points of compliance. The National Research Council (NRC) has also addressed the issue of complex and difficult sites. Since 1987, there have been at least six NRC studies to evaluate barriers to achieving the goal of groundwater restoration. These reports addressed both technical and institutional barriers to restoration, but in general, the reports have concluded that some fraction of sites will require containment and long-term management and the number of such sites could be in the thousands. Other organizations have also undertaken in-depth assessments of barriers to restoration at more complex sites including the Interstate Technology and Regulatory Council.
In this context, the U.S. Army Environmental Command (AEC) agreed to support an NRC study to address the technical and management issues arising from barriers to restoration of contaminated groundwater at these complex sites. In particular, the AEC was concerned that delays in decision making on the final remedies at many of their more complex sites could diminish their ability to achieve DoD goals for the IRP. For the Army, one significant goal is achieving the remedy-in-place or response-complete
milestones for 100 percent of their IRP sites at active installations by 2014. This study was established under the Water Science and Technology Board (WSTB) of the NRC with the title “Future Options for Management in the Nation’s Subsurface Remediation Effort.” The Committee included fifteen individuals representing expertise in all areas relevant to the statement of task, including various scientific and technical disciplines, resource economics, environmental policy, risk assessment, and public stakeholder issues. Seven meetings were held over the past two years, with presentations from a wide range of interested parties. I would like to thank the following individuals for giving presentations to the committee during one or more of its meetings: Laurie Haines-Eklund, Army Environmental Command; Jim Cummings, EPA Superfund Office; Adam Klinger, EPA Underground Storage Tank Office; Jeff Marquesee and Andrea Leeson, Strategic Environmental Research and Development Program; Brian Looney, Department of Energy Environmental Management; John Gillespie, Air Force Center for Environmental Excellence; Anna Willett, Interstate Technology and Regulatory Council; Alan Robeson, American Water Works Association; Jill Van Dyke, National Groundwater Association; Ira May, May Geoenvironmental Services; Roy Herndon, Orange County Water District; Milad Taghavi, Los Angeles Department of Water and Power; Carol Williams, San Gabriel Water Supply; Gil Borboa, City of Santa Monica; David Lazerwitz, Farella Braun + Martel, LLP; James Giannopoulos, California State Water Quality Control Board; Herb Levine, EPA Region 9; Alec Naugle, California Region 2 Water Board; David Sweeney, New Jersey Department of Environmental Protection; Rula Deeb, Malcolm Pirnie; Amy Edwards, Holland & Knight LLP; Brian Lynch, Marsh Environmental Practice; Richard Davies, Chartis; Henry Schuver and Helen Dawson, EPA; Tushar Talele, Arcadis; Anura Jayasumana, Colorado School of Mines; Deborah Morefield, Office of the Deputy Undersecretary of Defense; Alana Lee, EPA Region 9; Betsy Southerland and Matt Charsky, EPA; Mike Truex, Pacific National Lab; and Jim Gillie, Versar/Joint Base Lewis McChord.
I wish to acknowledge the herculean efforts of Laura Ehlers and her colleagues at the WSTB for organizing our meetings, managing multiple tasks, and finally completing the editing of contributions from committee members, a task that requires both editing and substantial technical expertise and diplomacy in helping a diverse committee reach consensus. I am indebted to Laura for her efforts on completing this report. I also want to send special thanks to all the Committee members who so diligently participated in long sessions at our meetings, produced comprehensive summaries of the state of the science in subsurface remediation, and who wrestled with the complexities of addressing the challenges of better decision making. The contributions of those who worked on the final chapter are especially appreciated, and particularly those individuals who joined the committee
later in deliberations to fill in for vacancies caused by unanticipated changes in the committee roster.
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report: Lisa Alvarez-Cohen, University of California, Berkeley; Linda Lee, Purdue University; Jacqueline MacDonald Gibson, University of North Carolina, Chapel Hill; David Nakles, Carnegie Mellon University; Stavros Papadopulos, S.S. Papadopulos & Associates, Inc.; Tom Sale, Colorado State University; Rosalind Schoof, Environ International Corporation; Hans Stroo, HydroGeoLogic, Inc.; and Marcia E. Williams, Gnarus Advisors, LLC.
Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release. The review of this report was overseen by Susan L. Brantley, Pennsylvania State University, and Mitchell Small, Carnegie Mellon University. Appointed by the National Research Council, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.
Michael C. Kavanaugh, Chair
Committee on Future Options for Management
in the Nation’s Subsurface Remediation Efforts
Contents
Regulatory Response to Groundwater Contamination
The Life Cycle of a Contaminated Site
Statement of Task and Report Roadmap
Number of U.S. Hazardous Waste Sites
Impacts to Drinking Water Supplies
Conclusions and Recommendations
3 REMEDIAL OBJECTIVES, REMEDY SELECTION, AND SITE CLOSURE
The Cleanup Process and Associated Objectives
The Future of Cleanup Objectives
4 CURRENT CAPABILITIES TO REMOVE OR CONTAIN CONTAMINATION
Chemical Transformation Processes
Conclusions and Recommendations
5 IMPLICATIONS OF CONTAMINATION REMAINING IN PLACE
Potential for Failure of Remedies and Engineered Controls
Implications of the Long-Term Need for Institutional Controls
Emergence of Unregulated and Unanticipated Contaminants
Consequences for Water Utilities
Conclusions and Recommendations
6 TECHNOLOGY DEVELOPMENT TO SUPPORT LONG-TERM MANAGEMENT OF COMPLEX SITES
Modeling for Long-Term Management
Emerging Remediation Technologies
Conclusions and Recommendations
7 BETTER DECISION MAKING DURING THE LONG-TERM MANAGEMENT OF COMPLEX GROUNDWATER CONTAMINATION SITES
An Alternative Decision Process for Contaminated Groundwater