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Case Summary: Atlantic Richfield to pay over $21 million for past costs at Anaconda Smelter Site

On September 11, 2013, the Montana District Court approved a past cost settlement with Atlantic Richfield to reimburse the EPA for over $21 million of its cleanup costs at the Anaconda Smelter Site and the Warm Springs Ponds Operable Units for work conducted between August 2002 and December 31, 2010.

EPA conducted the cleanup work at these sites as part of the ongoing remediation of copper mining wastes and smelting operations in the town of Anaconda and associated sites in Butte, the Clark Fork River,  and the Milltown Dam sites and operable units, which resulted from over a century of mining operations.

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Information about the Company

Atlantic Richfield Company (ARCO) purchased the former operator, Anaconda Minerals Company, and assumed its liabilities in 1977. ARCO’s history dates back to the 1866, when Atlantic Refining formed and was soon purchased by Standard Oil. Richfield Oil was formed in 1905.  In 1966 the two companies merged forming ARCO. ARCO joined the British Petroleum group in 2000.

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Information about the Anaconda Smelter Site

Anaconda Smelter Site, Warm Springs Pond Operable Units and Clark Fork River - The town of Anaconda is located about 25 miles from Butte, Mont. Smelter emissions dispersed contaminants, with elevated arsenic and metal levels, over more than 300 square miles. Large amounts of slag and tailings were also produced and the current estimate of that waste volume includes 230 million cubic yards of tailings, 30 million cubic yards of slag, and 0.5 million cubic yards of flue dust. Approximately 20,000 acres of soil were severely impacted by airborne emissions and millions of gallons of ground water were polluted. Cleanup efforts began with EPA overseeing the smelter's demolition and site stabilization at Anaconda in 1983.

The selected remedy calls for soil remediation, tailing removal and impoundment and institutional controls. The money from the settlement will be deposited in a special account for ongoing cleanup efforts and oversight. The Anaconda site is divided into five operable units (OU).

  • Mill Creek OU. This first cleanup action involved relocating residents from Mill Creek and other soil stabilization and removal efforts.
  • Flue Dust OU. The second cleanup action addressed flue dust on Smelter Hill through removal, treatment, and containment. At the same time, Atlantic Richfield removed the Arbiter and beryllium wastes and contaminated residential yard materials from portions of Anaconda.
  • Old Works/East Anaconda Development Area (OW/EADA) OU. The third cleanup action addressed waste sources adjacent to the community of Anaconda.
  • Community Soils OU. The fourth cleanup action provided for cleanup of remaining residential, commercial and industrial soils contaminated with arsenic in Anaconda.
  • ARWW&S OU. The fifth and final OU provides for cleanup of all remaining contamination at the site, including large volumes of wastes, slag, tailings, debris, and contaminated soil, groundwater, and surface water that are spread over 300 square miles of agricultural, pasture, rangeland, forests, and riparian and wetland areas.

The Clark Fork River and Milltown Dam were contaminated by mining wastes during a flood shortly after the dam was constructed in 1908.  The Milltown Dam site was remediated by breaching the dam and removing millions of tons of sediments and transporting them back to the Warms Springs Pond for containment and capping in a repository.  The Clark Fork Basin consists of 120 miles of river between the Butte sites and the Milltown Dam.  The selected remedy is tailings removal and stream bank stabilization.

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Contact Information

For additional information contact

Site Contact:
Henry Elsen
Attorney Advisor
Region 8
U.S. Environmental Protection Agency
10 W 15th Street
Helena, Montana 59626
(406) 457-5030

Headquarter Contact:
Jared Hautamaki
Attorney Advisor
U.S. Environmental Protection Agency
1200 Pennsylvania Ave. NW
Mailcode 2272A
Washington DC, 20004

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