Division of Spill Prevention and Response


Big Mountain Radio Relay Station

Database Name: Big Mountain Radio Relay Station

Status: Active

Location: Big Mountain, near Kokhanok and Iliamna

Latitude: 59 23 27.0

Longitude: -155 13 33.0


DEC Contaminated Sites contact: Jessica Morris, Project Manager, (907) 269-3077 (Anchorage)

U.S. Air Force contact: Lori Roy, Project Manager for Big Mountain RRS, Air Force Civil Engineer Center, 10471 20th St., Suite 302, JBER, AK  99506-2201, (907) 552-7697 (JBER stands for Joint Base Elmendorf-Richardson)


Contacts updated: July 23, 2014

Summary updated: November 2004

Click on photos or maps for larger versions.


Big Mountain RRS lies 220 miles southwest of Anchorage on the south shore of Iliamna Lake. The United States Air Force (Air Force) owns 440 acres, separated into three distinct land parcels connected by local gravel roads. The installation consists of a Lower Camp located alongside the airstrip, an Upper Camp located on the top of the 2,160-foot mountain (Big Mountain), and a Barge Landing site at Reindeer Bay. The University of Alaska owns the Barge Landing site and the State of Alaska owns the surrounding land in this area. There are no roads in the area connecting the Big Mountain installation to the surrounding communities, although there are a few cabins in the general area. Access to the installation area is by air, by barge landing on the lake during the summer months, and by snow machine over the frozen lake during the winter months. The surrounding communities on and near Iliamna Lake include: Kokhanok, Iliamna, New Halen, Pedro Bay, Nondalton and Igiugig.

Equipment and Power Building (SS10) and Antennas 1, 2, and 4 at Upper Camp. (DEC photo)

Equipment and Power Building (SS10) and Antennas 1, 2, and 4 at Upper Camp. (DEC photo)

The Big Mountain RRS was established by the Air Force as part of a defense communication network and aircraft warning system across Alaska. It was constructed in 1956 as part of the White Alice Communication System (WACS) and was operational as a tropospheric scatter station as part of the WACS from September 1957 to 1979. As communication and defense surveillance technology improved, progressively fewer personnel were needed to operate and support the installation mission on site, which resulted in the gradual downsizing of the operational facilities. In 1979 the installation was closed. Most of the original equipment, structures, and facility infrastructure were left in place at that time.

During installation activity, hazardous and potentially hazardous substances were used and stored there to support base activities. These substances included diesel fuel and gasoline, oils, antifreeze, solvents for servicing and cleaning equipment), lead-acid and nickel-cadmium batteries, asbestos (as construction insulation material), and electrical transformers containing PCBs.

Big Mountain RRS Upper Camp. (DEC photo)

Big Mountain RRS Upper Camp. (DEC photo)

The Air Force is the responsible party for cleaning up these sites following the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) standards for protecting people, animals, and the environment. DEC oversees the cleanup to assure it meets the State of Alaska standards. The Air Force and DEC work with community members through public meetings and newsletters. The Big Mountain installation is part of the Clean Sweep Program. The program removes facilities and structures at installations no longer required by the Air Force. The Clean Sweep Program is the initial step of environmental restoration to allow for the eventual transfer of the property to others.


Public Health and Environmental Concerns

Environmental concerns at Big Mountain RRS include: petroleum-contaminated soil and groundwater at the tank sites within Upper and Lower Camp, PCB- and metal-contaminated soil at Upper Camp, and potential landfill leachate in the groundwater and surrounding wetland at Lower Camp.


Current Status

An Interim Decision Document was signed by the Air Force and DEC in December 2002. The interim decision for 3 of the 4 sites [42,400-gallon fuel AST system (ST001), 1,000-gallon fuel AST (SS002), and dual AST fuel system (SS014)] is excavation and thermal treatment of the petroleum-contaminated soil. Groundwater monitoring wells will be installed to identify potential groundwater impacts at these three sites. Final groundwater remedies will be identified after the additional monitoring results have been evaluated. Since soil removal is expected to remove the source of any potential future groundwater contamination, monitored natural attenuation may be adequate to address potential groundwater impacts. The interim decision for the 4th site [Landfill (LF005)] is a limited landfill cap and additional assessment activities including groundwater monitoring well installation and sampling, an ecological risk assessment and sampling, and institutional controls. The interim remedies will be conducted in 2004 and 2005.

Dual 126,000-gallon AST System (SS014) at Upper Camp. (DEC photo)

Dual 126,000-gallon AST System (SS014) at Upper Camp. (DEC photo)

A Decision Document for Site Closure was also signed by the Air Force and DEC in December 2002. Antennae 2 and 4 (SS013) and Antennae 1 and 3 (SS015) have no contaminants present above cleanup levels, therefore, no cleanup action is necessary. During the Clean Sweep activities in 2003, an investigation to further defined the PCB- and metal-contaminated soil at Upper Camp was conducted. A Proposed Plan and Decision Document for the remaining 7 sites is scheduled for 2004, followed by cleanup action(s) in 2005.

Community involvement continues through fact sheets/newsletters, and public meetings with DEC, the Air Force, and the community.

More Information


Contaminated Sites Database reports - There are a number of individual "contaminated sites" on the air station, and reports on the status of each is available on DEC's database. We have a glossary available to help you with any acronyms used in the reports.