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Fall 2005 Vol. 5 No. 3

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Mining for Answers

1938 photo of forests along the Coeur d’Alene River, devastated as a result of mining pollution, ©K.D. Swan/Corbis

Report Weighs EPA's Decisions on a Controversial Cleanup

For over a century, the steep hills of the Coeur d'Alene region of Idaho were home to some of the richest metal mines in the United States, producing huge amounts of silver, zinc, and lead. But for the region itself, mining was a mixed blessing. It provided a living -- albeit a difficult and dangerous one -- to many residents and made a few of them wealthy, but it also left a less welcome inheritance: widespread and lingering pollution.

Unhampered by environmental laws for much of the 20th century, these mining operations emitted large quantities of sulfur dioxide and lead into the air and dumped mining and milling waste into the Coeur d'Alene River and its tributaries. Metals were washed throughout the river basin, poisoning fish and waterfowl, settling in the soil of residential yards, and eventually turning up in the bloodstreams of local children.

High levels of lead in children's blood and in the environment prompted the U.S. Environmental Protection Agency in 1983 to designate a 21-square-mile area around the Bunker Hill Mining and Metallurgical Complex for cleanup under the federal Superfund law. EPA later broadened the Superfund project to include all polluted areas within the 1,500-square-mile Coeur d'Alene River Basin, and in 2002 proposed a $359 million plan to clean up much of the contamination over 30 years.

The expansion was unpopular with many of the basin's residents, who were skeptical that the massive effort was necessary and worried that the Superfund label would frighten businesses and tourists away, further hurting an economy already devastated by the loss of mining jobs. Other residents, including the Coeur d'Alene Tribe, demanded that the pollution be addressed. The National Research Council stepped into this contentious mix after being asked by Congress to evaluate whether EPA's assessment of the basin's problems and its cleanup plan were scientifically sound.

The study committee's report says that EPA was correct in concluding that lead in the environment poses a health risk to some residents in the wider basin. And the agency's main solution for countering this risk -- replacing polluted soil in residential yards with clean soil -- also was warranted. But given the high levels of lead in the soils of many communities, the committee said that the rate of blood testing has been less than optimal. All children ages 1-4 throughout the basin should be screened annually for blood lead.

Though EPA's decisions about human health risks were generally sound, the committee found some serious blind spots in the agency's plan for cleaning up the environment and protecting fish and wildlife. For example, the plan doesn't adequately consider the basin's frequent floods, which could recontaminate areas that have been cleaned. And groundwater has not been targeted, 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. EPA should identify specific places where zinc is leaching into groundwater and set priorities for removing or stabilizing these materials.

The Coeur d'Alene River Basin is not the only region in the nation that is struggling to cope with pollution left over from mining. Scores of other mining areas are on the Superfund cleanup list as well, including some as large as the Coeur d'Alene site. In dealing with these complex mining "megasites," the committee said, rigid long-term cleanup plans won't work. Instead, plans should be implemented in phases and adjusted after the results of each step are evaluated. And institutions are needed that can sustain the cleanup over the long haul, since sites such as Coeur d'Alene will be dealing with their unwanted legacy for the foreseeable future.   -- Sara Frueh

Superfund and Mining Megasites: Lessons from the Coeur d'Alene River Basin. Committee on Superfund Site Assessment and Remediation in the Coeur d'Alene River Basin, Board on Environmental Studies and Toxicology, Division on Earth and Life Studies (2005, approx. 382 pp.; ISBN 0-309-09714-2; available from the National Academies Press, tel. 1-800-624-6242; $55.00 plus $4.50 shipping for single copies).

The committee was chaired by David J. Tollerud, professor of public health, medicine, and pharmacology/toxicology, and chair, department of environmental and occupational health sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, Ky. The study was funded by the U.S. Environmental Protection Agency.

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Copyright 2005 by the National Academy of Sciences