Milltown Reservoir Sediments/Clark Fork River
In 1981, Missoula County health officials discovered arsenic contamination in drinking water wells in Milltown, Montana. The wells were located near the Milltown dam and reservoir. To protect public health, EPA provided an alternative water supply to affected area residents and in 1982, proposed listing the site on the National Priorities List for cleanup under Superfund. The site was made final on the NPL in 1983.
EPA divided the Milltown Reservoir Sediments/Clark Fork River Superfund Site into three parts called Operable Units (OUs):