OSWER/OSRTI Washington, DC 20460



## N ATIONAL 

## P RIORITIES 

## L IST 

## (NPL)

***Proposed Site*** March 2015


### ANACONDA ALUMINUM CO COL UMBIA Columbia Falls, Montana

F

AL LS RED UCTION PL AN T Flathead County

 **Site Location :** 
The Anaconda Aluminum Co Col umbia F al ls Red uction Pl an t (also called Columbia Falls Aluminum) is a primary

aluminum smelting facility located in northwest Montana approximately two miles northeast of Columbia Falls, in Flathead County.

 **Site History:**
The Anaconda Copper Mining Company built the aluminum r eduction f acility and began aluminum production in 1955. The Atlantic Richfield Company (ARCO) purchased the plant in 1978 and operated it until 1985 when it was sold to the

Montana Aluminum Investor’s Corporation and began operations under CFAC. In 1999, Glencore acquired the company and operated until 2009 when production stopped due to poor economic conditions for aluminum production. The property boundary currently includes approximately 3,200 acres with an operational area of approximately 950 acres. The plant is currently not in use.

 **Site Contamination/Contaminants:**
A byproduct of the aluminum reduction process is spent potliner which is known to contain cyanide and flouride compounds that can leach into ground water. Spent potliner material was landfilled on site from approximately 1955 to approximately 1985. Other landfills located at the site received various wastes throughout the lifespan of the plant, including air scrubber sludge, likely containing fluoride compounds.

The ground w ater and percolation ponds at the site are contaminated with cyanide and fluoride, as well as oth er metals.

 **Potential Impacts on Surrounding Community/Environment :**  Contaminants have been released into ground w ater beneath the site, as well as the Flathead River and Cedar Creek (both located directly adjacent to the site). Cyanide has contaminated two nearby residential wells . O ther homes within the same neighborhood have domest ic wells for their water source wh ich may potentially be contaminated

. Cyanide and metals, including fluoride and manganese are contaminating the Flathead River. The Flathead River is a fisher y that supports a variety of fish, including the federally

- designated threatened bull trout, the federally

- designated sens itive westslope cutthroat trout and other species that are harvested for human consumption.

 **Response Activities (to date):**
There have been no response activities to date.

 **Need for NPL Listing:**
The site needs to be placed on t he NPL to clean up surface water, sediment and ground water contamination

. Other federal and state clean up programs were evaluated bu t are not viable at this time . The EPA received a letter of support for placing

this site on the NPL from the state.

[The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may change as additional information is gathered on the sources and extent of contamination. See 56 FR 5600, February 11, 1991, or subsequent FR notices.]

For more information about the hazardous substances identified in this narrative summary, including general information regar ding the effects of exposu re to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs ca n be found on the Internet

at http://www.atsdr.cdc.gov/toxfa qs/index.asp or by telephone at 1

- 888

- 42

- ATSDR or 1

- 888

- 422

- 8737.