Congress asked the Research Council to assess EPA's decisions concerning a 1,500-square-mile area in the Coeur d'Alene River Basin of northern Idaho and eastern Washington that is designated for cleanup under Superfund legislation because of contamination from years of mining for silver, zinc, and lead. A 21-square-mile "box" around Idaho's Bunker Hill Mining and Metallurgical Complex was declared a Superfund site in 1983 after high blood levels of lead were detected in local children, and high levels of metals were measured in the environment.
EPA expanded its Superfund cleanup in 1998 to include contaminated areas throughout the Coeur d'Alene River Basin, and in 2002 outlined a plan to clean up parts of this pollution and lessen risks to human health and the environment. Three-quarters of the proposed $359 million expenditures are to finance the first steps toward protecting the environment, including fish and wildlife, over an approximate 30-year period. The committee's concerns pertain primarily to these remedies. The other quarter of the funds is intended to address human health risks, which EPA expects to accomplish well before the 30-year mark.
EPA correctly concludes that environmental lead poses health risks to some basin residents, the report says. The agency's finding that lead in the environment -- as opposed to lead in house paint -- is the main source of children's health risk from lead also was warranted, and EPA's emphasis on cleaning up residential yards by replacing polluted soil with clean soil is appropriate. But the committee called the current rate of blood testing in children suboptimal, given the high concentration of lead in the soils of many communities. All children ages 1-4 years throughout the basin should be screened annually for blood lead in conjunction with other routine health care screening tests, the report says.
Wider blood testing would also complement EPA's use of the so-called IEUBK model, which estimates residents' future levels of blood lead. The agency's choice to base its cleanup decisions on these estimates rather than on actual blood-lead levels created controversy at the site, but the committee concluded that use of this model was in accord with EPA's policy and was reasonable given the need to predict and lessen future risks to residents as well as current ones. Information on the bioavailability of lead from the site's soil – that is, the amount of lead in soil that is actually absorbed by the body – would improve the reliability of the model's predictions.
EPA's assessment of risks to the environment, including fish and wildlife, was generally in line with best scientific practices and was based on quality monitoring studies of metals in the environment, the committee said, but it expressed serious concern about the likely effectiveness of the agency's interim plan to mitigate those risks. For example, EPA has not targeted groundwater for cleanup even though the main source of dissolved metals in rivers and lakes – and the greatest threat to aquatic life in the basin – is zinc that seeps into surface water from groundwater. The agency should more thoroughly identify specific places where zinc is leaching into groundwater and set priorities for removing or stabilizing these materials, the committee said. Locating and removing the largest sources of lead-contaminated sediments in riverbeds – especially those likely to be carried downstream – should be a priority as well.
The agency's plan also does not adequately take into account the basin's frequent floods, which could recontaminate cleaned-up land with metal-polluted sediments, the report says. EPA should select strategies that are likely to withstand this danger and lessen the impact of these floods.
In addition, the committee pointed out that although the EPA's plan relies heavily on removing hazardous metals from the ground, there are no repositories in the area to hold these materials. Constructing new ones will be difficult and time-consuming given the basin's complex terrain and the controversy surrounding Superfund issues. Still, the report acknowledges, the only ultimate solution to the basin's pollution problems is to remove or stabilize contaminated materials.
The committee was asked to extract lessons from the Coeur d'Alene site that could be applied at other large, mining-related Superfund sites. Laying out detailed, long-range plans for cleaning up these complex "megasites" is unrealistic, the committee said. Instead, programs should emphasize adaptive management – a flexible approach that allows plans to be revised based on evaluations of each phase in the cleanup. EPA is currently using some of these principles at the Coeur d'Alene site, the report notes, but the agency's approach lacks some needed elements, such as specific benchmarks to indicate whether remedies are working.
The committee's findings and recommendations reflect a unanimous consensus, and the report was subjected to a rigorous peer-review process overseen by the National Academies. The study was sponsored by the U.S. Environmental Protection Agency. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows.
Copies of Superfund and Mining Megasites: Lessons From the Coeur d'Alene River Basin are available from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at http://www.nap.edu. Reporters may obtain a prepublication copy from the Office of News and Public Information (contacts listed above).
[ This news release and report are available at http://national-academies.org ] NATIONAL RESEARCH COUNCIL
Division on Earth and Life Studies
Board on Environmental Studies and Toxicology
Committee on the Superfund Site Assessment and Remediation in the Coeur d'Alene River Basin
David J. Tollerud (chair)
Chair
Department of Environmental and Occupational Health Sciences, and
Professor of Public Health, Medicine, and Pharmacology/Toxicology
School of Public Health and Information Sciences
University of Louisville
Louisville, Ky.
Herbert E. Allen
Director
Center for the Study of Metals in the Environment, and
Professor of Environmental Engineering
University of Delaware
Newark
Lawrence W. Barnthouse
President and Principal Scientist
LWB Environmental Services Inc.
Oak Ridge, Tenn.
Corale L. Brierley1
Consultant
Brierley Consultancy LLC
Highlands Ranch, Colo.
Edwin H. Clark II
President
Clean Sites Inc.
Alexandria, Va.
Thomas W. Clarkson2
J. Lowell Orbison Distinguished Alumni Professor of Environmental Medicine, and
Professor of Biochemistry and Biophysics, and of Pharmacology and Physiology
School of Medicine and Dentistry
University of Rochester
Rochester, N.Y.
Edmund A.C. Crouch
Senior Scientist
Cambridge Environmental Inc.
Cambridge, Mass.
Alison C. Cullen
Associate Professor
Daniel J. Evans School of Public Affairs
University of Washington
Seattle
Joseph H. Graziano
Professor of Environmental Health Sciences and Pharmacology, and
Associate Dean for Research
School of Public Health
Columbia University
New York City
David L. Johnson
Professor of Environmental Chemistry
College of Environmental Science and Forestry
State University of New York
Syracuse
Ronald J. Kendall
Founder and Director
Institute of Environmental and Human Health
Health Sciences Center, and
Founding Chair and Professor
Department of Environmental Toxicology
Texas Tech University
Lubbock
John C. Kissel
Director
Environmental Health Program, and
Associate Professor
Department of Environmental and Occupational Health Sciences
University of Washington
Seattle
Thomas W. La Point
Director
Institute of Applied Sciences, and
Professor
Department of Biological Sciences
University of North Texas
Denton
David W. Layton
Senior Environmental Scientist
Lawrence Livermore National Laboratory
Livermore, Calif.
C. Herb Ward
Foyt Family Chair of Engineering, and
Chair
Department of Civil and Environmental Engineering
Rice University
Houston
Spencer H. Wood
Professor
Department of Geosciences
Boise State University
Boise, Idaho
Robert O. Wright
Attending Pediatrician
Children's Hospital, and
Assistant Professor of Environmental Health
Harvard School of Public Health
Boston
RESEARCH COUNCIL STAFF
Karl E. Gustavson
Study Director
1 Member, National Academy of Engineering
2 Member, Institute of Medicine