The site is located at the southern end of the Deer Lodge Valley, at and near the location of the former Anaconda Minerals Company (AMC) ore processing facilities. These facilities were developed to remove copper from ore mined in Butte from about 1884 through 1980, when the smelter closed. Arco purchased AMC in 1977 and is the Potentially Responsible Party (PRP) at the site.
More than 65,000 acres at the southern end of Deer Lodge Valley have been affected by operations at the Anaconda Company Smelter. One hundred years of milling and smelting operations, including discharges into the air and stream, have scattered wastes that are high in arsenic and metals over a wide area.
Milling and smelting produced wastes with high concentrations of arsenic, as well as copper, cadmium, lead and zinc. These contaminants pose potential risks to human health, to life in nearby streams, and to plants and animals in adjacent lands. In addition to the millions of cubic yards of tailings, furnace slag, flue dust, and square miles of soil contaminated by airborne wastes, millions of gallons of ground water have been polluted from wastes and soils.
Estimated waste volumes at the site include about 230 million cubic yards of concentrated mine tailings, 30 million cubic yards of furnace slags, 500,000 cubic yards of flue dust and 300 square miles of contaminated soils.
In 1980, Atlantic Richfield Company (Arco) closed the smelter and thousands of people lost their jobs. In September 1983, the Environmental Protection Agency (EPA) placed the area surrounding the smelter on its Superfund National Priorities List (NPL), and EPA, the State of Montana and Arco began investigations into the extent of contamination.
Because of the size of the facilities, the hundred year operation, the large volume of wastes and the wide area contaminated, the site has been divided into smaller, more manageable Operable Units, including the BP-ARCO repository where Milltown, Silver Bow Creek and Clark Fork River sediments will be shipped.
For more information on the site, visit the EPA's Anaconda Smelter webpage.
View these articles about the Anaconda Smelter site.