Mining began in the Coeur d'Alene River Basin in the late 1880s; lead smelting started in the area known as the Bunker Hill Mining and Metallurgical Complex in Kellogg in 1917 and continued until 1981. The area produced a significant portion of the nation's silver, lead, and zinc, and pumped a substantial amount of money into the area's economy. Mines in the basin have yielded 1.2 billion ounces of silver, 8 million tons of lead, and 3.2 million tons of zinc, worth about $4.5 billion in total.

Unfortunately, knowledge of the health and environmental impacts of commercial mining, milling, and smelting was limited during this time. Little was known about pollution control equipment, and smelter operations spewed emissions into the air. It was common for mine owners to store large waste piles on site and to dispose of mine wastes directly into the Coeur d'Alene River. An estimated 62 million tons of mine wastes were dumped directly into the river and its tributaries between 1884 and 1968, when the practice was finally halted. Smelter and mine wastes were redistributed throughout the floodplain as river, wind, and human activities reworked the soils. Fine particle residues known as tailings were frequently used as fill for residential and commercial construction projects as well. Today, federal and state laws regulate the release of mine tailings and emissions.

A century of discharges and emissions left surface water, ground water, soil, and sediment in the basin and surrounding area contaminated with heavy metals - estimated at more than 100 million tons in all. The most significant contaminants are lead, zinc, cadmium, and arsenic. The natural aging process of Coeur d'Alene Lake has been accelerated by higher than natural amounts of nutrients and sediments entering water bodies that feed into the lake. Accelerated eutrophication has led to increased algae and aquatic weed growth, less aquatic life, and reduced water quality. In addition, surrounding hillsides throughout the basin have been gradually denuded of vegetation by deposition of airborne metals, acidification by sulfur compounds, and logging.

Metals contamination can harm humans and wildlife. Lead is especially harmful to humans and can cause such adverse health effects as brain and nervous system damage in children, birth defects, and chronic kidney damage. Over time, blood lead levels of children in the area reached concentrations well above those considered toxic. Zinc is harmful to fish and other aquatic organisms, and animals ingesting heavy metals can die or harm the health of people who eat them.

Efforts to clean up the Bunker Hill Mining and Metallurgical Complex began in earnest in 1983 when the area was designated a Superfund site on the U.S. Environmental Protection Agency's (EPA's) National Priorities List (NPL) of properties seriously contaminated by hazardous substances. The site includes mining-contaminated areas in the Coeur d'Alene River corridor, adjacent floodplains, downstream water bodies, tributaries and fill areas, as well as the 21-square-mile Bunker Hill "Box" located in the area surrounding the historic smelting operations.

The cleanup project is divided into the following three areas:

• Operable Unit 1 encompasses work in the populated areas of the Bunker Hill "Box."
• Operable Unit 2 encompasses work in the nonpopulated, nonresidential areas of the "box."
• Operable Unit 3 includes areas of mining-related contamination outside the "box."

After the Bunker Hill Site was listed on the NPL in 1983, EPA initiated remedial investigations and feasibility studies focused initially on Operable Unit 1 of the Bunker Hill "Box," home to about 7,000 people in the communities of Pinehurst, Page, Smelterville, Kellogg, and Warner, Idaho. This area was selected first because it posed the greatest and most immediate threat both to people and the environment due to their close proximity to the lead smelter.

The primary goal of the cleanup effort was to reduce children's intake of lead from soil and dust sources. It was determined that the primary way young children are exposed to lead is through contact with contaminated soil outside their homes and household dust. In 1986, EPA began removing and replacing contaminated soils in public areas such as parks, playgrounds, and roadsides that tested above 1,000 parts per million lead. The next step was to remove and replace soil in residential yards with high lead content. A Record of Decision (ROD) for residential soils in the populated areas was completed in 1991, and EPA began replacing contaminated soils in home yards of pregnant women and young children (age six and under) at highest risk of lead poisoning.

Much progress has been achieved under the direction of Upper Mining Group (UMG) during the past 14 years, and the environment in the Bunker Hill communities in Operable Unit 1 has improved considerably. Although some work remains to be done, more than 2,700 residential yards have been excavated and replaced to date and more than 400 commercial properties and rights-of-way have been cleaned up. Children's blood lead levels have been greatly reduced; the percentage of children with elevated blood lead levels has dropped from over 40% to 3%. The 3% level is about the same as the national average. House dust lead levels are declining as well.

A ROD encompassing the nonpopulated, nonresidential areas of the "box" was signed in 1992 and has been updated twice (1996, 1998). These nonpopulated areas are primarily the abandoned Bunker Hill Mine and Metallurgical Industrial Complex in Kellogg and associated areas on the valley floor south of the South Fork of the Coeur d'Alene River, the former Bunker Hill mine and acid mine drainage, and the hillsides and gulches surrounding the populated areas.

The objectives of the Operable Unit 2 ROD are to minimize direct human contact with contaminants, reduce erosion of the hillsides, minimize windblown dust from contaminated areas, reduce suspended sediment and contaminant loading in surface water runoff to the South Fork of the Coeur d'Alene River, minimize migration of contaminants to ground water, and consolidate contaminated material removed during remedial actions in on-site repositories and close those areas with engineered covers to reduce infiltration.

Priority cleanup actions focused on source removals, surface capping, reconstruction of creeks, demolition of abandoned milling and processing facilities, engineered closures for waste consolidated on-site, and revegetation efforts. The ROD also requires periodic monitoring of soil, water, and air to provide information about the changing nature and extent of contamination of various media.

Among the projects that have been completed in Operable Unit 2 are removal of approximately 1.5 million cubic yards of mine tailings from Smelterville Flats, demolition and in-place disposal of more than 200 buildings in the industrial complex, including the zinc plant and the lead smelter, removal of about 600,000 cubic yards of contaminated material from Magnet and Government Gulches, and re-establishment of the natural creek channels in these areas, removal of 300,000 cubic yards of contaminated materials from the Arizona mine dump in Deadwood Gulch, revegetation of about 1,000 acres of hillsides to combat erosion, consolidation of water into large impoundment areas, stabilization of Reed Landing, and construction of a surface water overflow channel as part of the Milo Creek flood control project to handle large floods and prevent contamination of clean areas.

As a result of the work completed to date, immediate threats to human health have been addressed by source removal efforts, capping activities, erosion control measures, ongoing treatment of mine water, and institutional controls. Theses efforts have reduced or eliminated the potential for humans to have direct contact with soil/source contaminants and have reduced opportunities for transport of contaminants by surface water and air. In addition, they are expected to provide surface and ground water quality improvements over time throughout the area.

In 2002, EPA issued an interim ROD to address mining contamination in the broader Coeur d'Alene Basin upstream and downstream of Coeur d'Alene Lake. The ROD is a 30-year cleanup plan focused on preventing people from coming into contact with unhealthy levels of metals contamination, improving water quality, minimizing downstream migration of metal contaminants, and improving conditions for fish and wildlife. It includes

• cleanup of residential yards in affected areas outside the "box" and expanded health education and intervention
• cleanup of commercial areas, rights-of-way, and common areas to prevent recontamination of residential areas
• cleanup of 31 recreational areas near the Coeur d'Alene River
• testing of drinking water wells east of Kingston to assure a safe source of drinking water
• outreach to advise anglers of potential risks of eating fish from areas of concern
• cleanup of lead in floodplains and surface waters of recreation areas
• stabilization of sediment sources
• removal of hot spots
• stabilization of banks and
• improvement of stream riparian zones.

Implementation of the Operable Unit 3 ROD is well underway and is expected to continue for the next three decades.

The state of Idaho has been actively involved in efforts to clean up the Coeur d'Alene Basin. The state has helped shape the scope of work for cleanup as well as the approach for implementation of the work to reflect Idaho's goals and priorities and to take into consideration local interests and concerns. State activities implemented by DEQ include

• conducted water, soil, and sediment sampling in water bodies in the Basin to determine the extent of metals contamination
• developed a comprehensive state plan to guide environmental improvement efforts in the basin, including remedial actions to address human health risks and water quality improvements
• developed a Human Health Risk Assessment, a baseline evaluation of potential threats to public health from contamination in the basin in the absence of any cleanup actions
• collaborated with EPA to develop the RODs for Operable Units 1, 2, and 3, assuring the state a major role in determining how cleanup work will be implemented in the basin in the 21st century
• sponsored multiple public meetings to solicit input from area citizens on cleanup issues and remediation plans
• guided implementation of a new state law establishing a Basin Environmental Improvement Project Commission to implement the ROD for Operable Unit 3
• negotiated an agreement, in cooperation with EPA, with mining companies outlining their responsibilities to perform Operable Unit 1 cleanup work in the "box"
• facilitated transfer of several remediated properties to local ownership, including 600 acres to Eagle Crest Inc. and an office building to the city of Kellogg
• developed the Consolidated Bunker Hill Infrastructure Revitalization Plan identifying infrastructure projects and potential sources of funding for those projects in communities within the basin
• conducted a residential yard remediation pilot project to reduce costs, increase property owner input and satisfaction, and assure local firms the opportunity to perform the work, and played a key role in overseeing ongoing residential yard cleanups in the basin
• worked with the Coeur d'Alene Tribe and local governments to develop a management plan to protect water quality in Coeur d'Alene Lake (ongoing).