Upper Clark Fork Superfund Site

Upper Clark Fork Superfund Site
Name	Upper Clark Fork Superfund Site
Location	Butte, Anaconda-Pintler Range, Deer Lodge County, Granite County, Powell County, Montana
Coordinates	46°00′N 112°35′W
Area	~1200 square miles
Added	1983
Governing body	United States Environmental Protection Agency; Montana Department of Environmental Quality

Upper Clark Fork Superfund Site The Upper Clark Fork Superfund Site encompasses a large contaminated corridor of the Clark Fork River basin in western Montana. The area includes former operations and communities associated with Anaconda Copper Mining Company and the Butte mining district, and was listed on the CERCLA National Priorities List in the 1980s. The site connects to regional features such as Warm Springs Creek, Silver Bow Creek, and the Missouri River headwaters.

History and Background

Mining and smelting activities beginning in the mid-19th century around Butte and Anaconda were driven by companies like Anaconda Copper Mining Company and entrepreneurs associated with the Marcus Daly and William A. Clark enterprises. The Copper Kings era, along with infrastructure projects such as the Milwaukee Road and the Northern Pacific Railway, supported extensive ore extraction, ore processing, and smelting facilities. Waste practices produced large tailings dumps and smelter slags that accumulated along floodplains near Silver Bow Creek, Blacktail Mountain, and downstream reaches near Deer Lodge County. The historical operations intersect with events such as the Pony Express-era regional expansion and later New Deal-era economic programs in Montana.

Contamination and Sources

Primary contamination originated from tailings produced by underground and open-pit mines, smelter emissions from facilities in Anaconda and Butte, and mine drainage from properties like the Butte Mine Flooding areas. Contaminants include heavy metals such as lead, arsenic, cadmium, and copper, as well as residual processing chemicals associated with historical practices tied to corporations including Anaconda Company and contractors who operated rail transfer facilities connected to the Great Northern Railway. Geologic contributors include naturally mineralized zones in the Boulder Batholith and the Rocky Mountains, which amplified metal mobilization during floods linked to the 1908 Flood of Glendo-era regional hydrology.

Environmental and Health Impacts

Metal-laden sediments and airborne particulates affected aquatic ecosystems such as populations of Westslope cutthroat trout and bull trout, with bioaccumulation affecting birds of prey including bald eagle and peregrine falcon that use the Clark Fork River corridor. Contaminants impacted riparian habitats near Deer Lodge Valley and recreational areas like Kerr Dam reservoir reaches. Human health concerns were raised in communities including Anaconda and Rock Creek over exposure pathways documented by agencies including the Agency for Toxic Substances and Disease Registry and studies linked to the Environmental Protection Agency. Epidemiological attention paralleled litigation involving entities such as Atlantic Richfield Company (ARCO) and federal actions under CERCLA and the Clean Water Act.

Cleanup and Remediation Efforts

Remediation strategies encompassed removal, capping, and consolidation of tailings into repositories engineered under oversight from the United States Environmental Protection Agency and the Montana Department of Environmental Quality. Large-scale projects included dredging and streambank stabilization on tributaries like Silver Bow Creek and soil removal in residential areas of Anaconda. Engineering solutions referenced work by consulting firms and contractors experienced with former mining sites similar to Bingham Canyon Mine reclamation projects. Funding and technical planning involved negotiated settlement mechanisms with parties such as Atlantic Richfield Company and federal trustees, and used methodologies influenced by National Research Council guidance on mine-waste remediation.

Regulatory Response and Legal Actions

The site’s listing under CERCLA mobilized federal enforcement, consent decrees, and natural resource damage assessments coordinated with agencies including United States Fish and Wildlife Service and the National Park Service where applicable to upstream watershed protections. Major legal actions involved Atlantic Richfield Company as a responsible party and resulted in settlements allocating funds for cleanup and community restoration. State-level regulatory mechanisms used statutes administered by the Montana Department of Environmental Quality, while federal litigation referenced precedent-setting suits involving mining liabilities and Superfund cost recovery decisions adjudicated in United States Court of Appeals proceedings.

Current Status and Monitoring

Ongoing monitoring programs evaluate surface water in reaches of the Clark Fork River, groundwater wells in the Deer Lodge Valley, and ecological recovery of species such as cutthroat trout. Long-term stewardship combines institutional controls, periodic repository inspections, and adaptive remedial measures guided by the United States Environmental Protection Agency remedial project managers and state officials. Community involvement includes local stakeholders from Anaconda-Deer Lodge County and regional conservation groups collaborating with scientific partners like university research centers in Missoula and Butte. Remaining tasks focus on source control, habitat restoration, and addressing legacy contamination consistent with precedents from other complex sites like Tar Creek Superfund Site and recovery efforts following the Gold King Mine spill.

Category:Superfund sites in Montana Category:History of mining in Montana