The Bunker Hill Mining and Metallurgical Complex stretches across 1,500 square miles of northern Idaho and eastern Washington. Mining began there in 1883, and decades of operations left soil, sediment, groundwater, and surface water contaminated with heavy metals. The site was added to the National Priorities List in 1983 and remains on it today. Construction cleanup is not complete, and the site is not yet ready for its anticipated future use.
Lead is the primary concern, though the site also contains arsenic, cadmium, zinc, antimony, copper, mercury, PCBs (polychlorinated biphenyls), and more than a dozen other hazardous substances. Contamination affects populated and non-populated land, the broader Coeur d'Alene Basin, and multiple environmental media including soil, groundwater, surface water, sediment, and buildings. Lead poses the greatest risk to young children and pregnant women, causing learning disabilities, behavioral problems, and slower growth. Adults can experience memory loss, high blood pressure, and muscle or joint pain. Human exposure is not yet under control at the site.
Cleanup is organized into four operable units covering populated areas, non-populated areas, and the wider Coeur d'Alene Basin. Work has included removing and replacing contaminated soil at more than 7,000 yards and public spaces, installing engineered barriers to block contaminant movement, upgrading treatment plants, and converting farmland into wetland habitat. A settlement with Hecla Mining Company put about 180 million dollars into an EPA account for the site. Over 435 million dollars from the Asarco bankruptcy was placed in the Coeur d'Alene Work Trust for Basin cleanup. These funds support ongoing work, which includes property cleanups, pilot studies in the Lower Coeur d'Alene River Basin, and groundwater collection and treatment. Current projects extend through 2027 and 2028, and a full cleanup will take decades.
Children's blood lead levels have dropped more than 50 percent since cleanup began in the 1980s, falling below the CDC reference level of 5 micrograms per deciliter. More than 1,800 acres of remediated land have been transferred to Idaho for economic development. Redevelopment successes include the Trail of the Coeur d'Alenes recreational trail, Silver Mountain Resort, and Galena Ridge Golf Course. As of December 2024, 239 businesses at the site employ 2,490 people and generate an estimated 261 million dollars in annual sales.
Community members can stay involved through quarterly meetings of the Basin Environmental Improvement Project Commission and its Citizen Coordinating Council. The EPA publishes the Basin Bulletin newsletter three times per year. Free blood lead testing for children is available year-round through the Panhandle Health District at 208-783-0707. Yard soil testing information is available from the Idaho Department of Environmental Quality at 208-783-5781. Documents are available at five public libraries and the EPA Region 10 Superfund Records Center in Seattle.
