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Record of Decision System (RODS)



Address:  3 MI SE OF ANACONDA 
City & State:  ANACONDA  MT  59711
EPA ID:  MTD093291656
EPA Region:  08
NPL Status:  Currently on the Final NPL
ROD Type:  Record of Decision
ROD ID:  EPA/ROD/R08-96/127
ROD Date:  09/30/1996
Operable Unit(s):  16
Media:  Soils, railroad beds.
Contaminant:  Arsenic and lead.
Abstract:  Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.

The Anaconda Company Smelter site is located in the Deer Lodge Valley in southwestern Montana, in and around the city of Anaconda and about 25 miles northwest of the city of Butte. This Operable Unit (OU) covers the Community Soils area. This area of concern covers approximately 300 geographic areas that are 1 square mile each. The Community Soils area of concern is generally bounded on the east and south by the border of Deer Lodge and Silver Bow Counties, on the west by the Anaconda Wast Valley, and on the north by the border of Deer Lodge and Powell Counties. The majority of this land is classified as rural. The five communities included have a combined population of under 8,600.

Around 1884, the Anaconda Mining Company (AMC) and its predecessors commenced large copper concentrating and smelting operations at the area presently known as the Old Works. The Old Works was located west of Anaconda and operated until about 1901. In about 1902, ore processing and smelting operations began at the Washoe Reduction Works on Smelter Hill across from the Old Works. In 1977, Atlantic Richfield Company (ARCO) purchased AMC and assumed its liabilities. Operations at the Anaconda Smelter ceased in 1980, and the smelter facilities were dismantled soon thereafter.

Milling and smelting activities conducted at the Old Works and Washoe Reduction Works smelters for nearly 100 years have resulted in the contamination of various environmental media in the surrounding area, primarily through airborne emissions and disposal practices from smelting operations. Prior to closure of smelter operations in 1980, the Anaconda Smelter was a source of substantial air emissions at the site. Other sources of aerial contaminants related to the Anaconda milling and smelting operations have also contributed to community soils contamination.

The Anaconda Smelter was placed on the National Priorities List (NPL) in the fall of 1983. Studies conducted into the type and extent of contamination revealed that soils had elevated levels of arsenic. Permanent relocation of families in the area was completed in the fall of 1988. From 1988 until 1995, studies into the cleanup of the soils continued and progress monitored. The Community Soils OU addresses all remaining residential and commercial/industrial soils of the Anaconda Smelter site. This OU will also bring closure to previous cleanup actions conducted at residential properties within the site.
Remedy:  The selected remedies for this OU address contamination in the residential soils, the commercial/industrial soils, and the railroad beds. The selected remedies will achieve reduction of risk to human health through the following: reduction of surface soil arsenic concentrations in residential and commercial/industrial areas to acceptable levels; and/or prevention of direct human contact with waste materials exceeding acceptable levels.
The major components of the remedy for residential soils include: removal and replacement with clean soil and placement of a vegetative or other protective barrier; treatment or other measures in areas where removal is not implementable; clean up of all future residential soils at the time of development; and implementation of institutional controls.

The major components of the remedy for commercial/industrial soils include: cleanup of all current commercial or industrial areas through a combination of revegetative techniques and/or engineered covers; and cleanup of all future commercial or industrial areas at the time of development.

The major components of the remedy for the railroad beds include: constructing an engineered cover over all contaminated railroad bed material within the community of Anaconda; separating the railbed from residential and commercial/industrial areas with a barrier to restrict access to the railbed and to control surface runoff from the railbed through the use of retaining walls and/or curbing; and maintaining existing institutional controls to restrict access.
Text:  View full-text ROD [ 312K ]
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