U.S. Air Force Former North River Radio Relay Site
From 1958 to 1978, the U.S. Air Force operated the North River Radio Relay Station (RRS) in the Unalakleet area. When military activities in the surrounding area ended, buildings, debris and thousands of 55-gallon drums were left in the area.
Unalakleet, population 800, is located on the Norton Sound at the mouth of the Unalakleet River 148 miles southeast of Nome and 395 miles northwest of Anchorage.
The Radio Relay Station was once one of 31 installations in the Alaska-wide "White Alice Communications System" used for defense and civilian communications. A combined tropospheric scatter/TD-2 microwave station, North River RRS relayed radio information to and from other such stations at Granite Mountain, Anvil Mountain, and Kotzebue. Its four dish antennas were situated on a hilltop, approximately 8 miles east of the village of Unalakleet, overlooking the Norton Sound. Support facilities located around and just below the dish antennas included a composite building, barracks, petroleum storage and distribution facilities, an equipment maintenance building, a water tower and a temporary garage. Radio Corporation of America/Alascom operated the site remotely from the early 1960s until 1978. The station was abandoned in 1978, and all structures at the site were demolished and removed by 1996.
The land around the former RRS is used for hunting, berry picking and recreation. A local resident owns a cabin and Native allotment about one-half mile from the hilltop site where the antennas were located, and about 700 feet from the main road leading to the site. Soil contaminated by polychlorinated biphenyls (PCBs - see our glossary) was discovered on July 10, 2003 near the beginning of the trail to this cabin.
Previous investigations at the North River RRS site include:
In 1986 the U.S. Army Corps of Engineers investigated the site and published three sampling reports in 1989.
In 1993 and 1995, two Army Corps contractors demolished buildings at North River RRS and buried all debris in an on-site landfill. These projects, however, did not include disposal of all the fuel drums and miscellaneous drums and debris scattered in the vicinity of Unalakleet.
In 2002 an Army Corps contractor removed approximately 3,300 drums scattered across a 10-square mile area, including several Native allotments. In June 2002, the Army Corps identified a different location with three drums possibly containing contaminants of concern and reported these to the U.S. Air Force. This is now called " area B" (see map, above) and is part of the Air Force's current remediation at North River RRS.
On July 9, 2003, the Air Force was notified by a Native allotment owner that she suspected there was contaminated soil in the middle of the access road to her property ( "Area C"). Air Force personnel were already in the area removing abandoned military drums and conducting soil sampling near the former RRS. On July 10, the Air Force personnel confirmed high levels of PCBs in the soil and vegetation. The actual spillage likely occurred many years ago and was related to drums stored or disposed of in the area. Results from sampling of soil on the trail showed PCB concentrations as high as 26,500 milligrams per kilogram (mg/kg) in an approximate 12 by 20-foot source area. The State cleanup level for PCBs in soil is 1 mg/kg. Contamination was spread across the trail by vehicle and foot traffic. Sampling completed in September 2003 confirmed that PCBs had been tracked to the nearby cabin.
Also in July of 2003, based on information from residents, Air Force personnel investigated the site of old barrels and possibly contaminated soil across the road from the demolition debris landfill ( "Area A"). Investigation showed the soil was contaminated with PCBs and petroleum.
Public Health and Environmental Concerns
Air Force employee samples for the presence of PCBs in the cabin. (Air Force photo, Summer 2003)
Warning signs have been posted on fences at Area A (shown above) and the road to the cabin to keep people out of areas with remaining contamination. (ADEC photo, 9/04)
The presence of PCBs is of significant environmental concern. Potential pathways of exposure include direct contact with contaminated soil, and exposure through hunting and subsistence food gathering. The Air Force visited the school in 2003 to let children know to stay away from the site. Local residents who thought they might have been exposed were referred to Health & Social Services Office of Epidemiology.
The discovery of elevated PCB levels in soil near Unalakleet led to concerns regarding the possible exposure to PCBs among area residents and the public health implications of such exposures. The State of Alaska Section of Epidemiology (DHSS Division of Public Health) responded to these concerns by conducting an exposure investigation that is detailed in a report listed below (see Epidemiology Investigation...). A total of 26 people participated by providing a blood sample. Participants ranged in age from 18 - 81 years. Their report found that, "The PCB levels detected in Unalakleet participants are very low, and are below any levels that would be expected to cause ill health effects. PCB levels in tested Unalakleet residents are similar to those of people in other parts of Alaska and in other parts of the United States. All people are exposed to small amounts of PCBs through the foods they eat, and the PCB levels detected in Unalakleet participants are similar to these global background exposures. No additional medical exams or treatments are needed or recommended for any of the participants with regard to PCB exposure." (See page 3 of the report.)
Anyone concerned about health conditions may be related to this site may contact the Office of Epidemiology, Alaska Department of Health and Social Services, at 907-269-8000 or email@example.com.
Lt. Col. Mark S. Tissi, of the Air Force, discusses the cleanup efforts in June '04 outside the cabin with EPA representative Jacques Gusmano and former Air Force project manager Doug Wooten. (ADEC photo)
The areas around the cabin were scraped of contaminated soil and filled in with clean rock. (Air Force photo, 7/04)
DEC staff continues to work with the Air Force to minimize PCB exposure to people and animals until the site is completely cleaned up. Action to remedy contamination is taking place as a "Time-Critical Removal," a designation the military can give when the situation is urgent and when fewer than six months are available to plan a cleanup. The following sites have been designated for this type of response (shown in the map above):
Area A: This location contains two areas of PCB contamination in concentrations of about 500 mg/kg, over the cleanup level of 1 mg/kg. These areas were made ready for excavation in 2004 by removing vegetation and sampling, but excavation did not proceed due to time constraints. The contaminated soil had fencing put around it with signs warning about the contamination.
Area B: An old landfill where drums and debris were pushed off the hillside, this area has fairly limited petroleum contamination. It was exposed and sampled, but not excavated in 2004. The final disposition of this soil will be addressed at a later time. Other miscellaneous debris was noticeable around the surface-stained area.
Area C: When PCB contamination was verified along the trail to the cabin in the summer of 2003, DEC requested the Air Force to perform the cleanup as quickly as possible, and the Air Force responded. In late September of 2003, the Air Force completed its initial PCB assessment and removed the most heavily contaminated soil (an "interim remedial action"). Approximately 31,530 pounds (estimated then to be 90%) of the highly-contaminated PCB soil was excavated, placed in drums, and shipped to Elmendorf Air Force Base in Anchorage for disposal. Additional sampling identified lower levels of PCB (under 50 mg/kg) on the trail, vegetation, and adjoining road and Air Force land. Protective barriers, liners, and fencing were installed on and around these areas as temporary protective measures.
Sampling of soil, cabin surfaces, and vegetation was completed that fall to determine the extent of contamination and to help plan cleanup activities for the next summer. The Air Force also consulted the U.S. Environmental Protection Agency (EPA) on all aspects of the project. Heavy snow and Arctic weather conditions isolated the PCB-contaminated areas over winter.
On October first, 26 Unalakleet area residents were medically screened for PCB exposure. The laboratory results indicated that PCB levels in the participants were very low, similar to global background exposures resulting from trace PCBs in foods, and less than levels that would be expected to cause ill health effects. (View report below: "Epidemiology Investigation..." .) Biological sampling was conducted in January and February on resident birds consumed by subsistence hunters. These laboratory results were negative. On August 26th, an Air Force Toxicologist conducted a preliminary on-site risk assessment evaluation for potential pathways and receptors.
Fencing was erected around the entire trail to the cabin in late 2003. (ADEC photo)
In the summer of 2004, the cabin's trail and the areas around the cabin were scraped of contaminated soil and filled in with clean rock. As few trees as possible were cut. Only one contaminated area remains: the "hot spot"near the road, where the drums were found. (Air Force photo, 7/04)
The Air Force issued a report on the removal of the soil, and that report was approved by DEC and made final in March 2004 (see Final Report for work in 2003 below). A draft of the plan for work in the summer of 2004 was distributed to DEC, EPA, and community members for review on March 22 and made final in June. The work plan called for complete excavation and confirmation sampling of all PCB-contaminated soil above the standard 1 mg/kg cleanup level. Soil contaminated at 50 mg/kg and above would be put in drums, sealed, and airlifted to Elmendorf Air Force base for proper disposal. The contaminated soil with PCB concentrations between 1 and 50 mg/kg would be placed in double super-sacks, stored in Seavans, and barged to a disposal facility in the Lower 48 at the end of the summer 2004.
Cleanup actions began in the summer of 2004, but logistical complications and a larger volume of contaminated soil than originally anticipated prevented the completion of activities approved in the 2004 Time Critical Removal Work Plan. The Air Force first worked from the lesser contaminated areas: along the road, around the cabin and along its trail, cleaning up the trail to 1 mg/kg. PCB concentrations remained high, above 50 mg/kg, up until a few hundred feet from the cabin, although the contamination was present only in the top few inches. Most of the trail to the cabin was scraped off and backfilled with new gravel. PCB contamination still remains at the source area near the beginning of the trail (Area C) and at Area A. The magnitude of the PCB contamination at Area C was greater than originally expected. Remaining contamination has been covered, fenced in, and warning signs posted.
Additional excavation took place in 2004: 808 drums and 600 "super sacks" of contaminated soil were shipped out. (Air Force photos, 7/04)
The quantity of contaminated soil proved too much for the level of effort funded in the summer of 2004, and the Air Force was unable to remove it all. The remaining contamination was fenced and covered until it can be removed. (Air Force photo 9/04)
Other investigation not included in the Time-Critical Removal:
Other site investigation work was conducted in June 2004 at the North River RRS, but not under the expedited schedule of the Time-Critical Removal. Air Force contractors conducted sampling around the locations of the former White Alice infrastructure, including surface and subsurface soil sampling for petroleum, PCBs, and other contaminants (Site Inspection Final Report 2005 below). The sampling results will be made available to DEC pending the completion of the report documenting this work.
The scope and goals of the Time-Critical Removal and Site Investigation at North River RRS in the future will be discussed by the Air Force, DEC, and the Native Village of Unalakleet to determine the best site remedy.
The PCB source area was excavated in 2004 to bedrock at 6 feet below the ground surface. More contamination than anticipated was discovered. Remaining contamination will be fenced, posted with warning signs, and scheduled for later removal. (ADEC photo, 9/04)
North River Radio Relay Station Site Inspection Final Report (abbreviated), March 2005, U.S. Air Force, (PDF 3.2MB) This is for the area of the former White Alice infrastructure, not including the "time-critical removal".
final report for the 2004 Site Investigation that was performed in the non-time critical areas by AF contractors
A Partial Copy of the 2004 Time-Critical Removal Report, North River (former) Radio Relay Site, April 2004, 611th U.S. Air Force, (PDF 1.9MB). Due to the large size of attachments, DEC will provide the remaining report contents upon request (Colin Craven, Project Manager - (907) 451-2181).
Final Report for work in 2003 : Time-Critical Removal for 2003, North River (former) Radio Relay Site, (dated March 2004),U.S. Air Force, (PDF 1.2MB)
Report tables (PDF 15K)
Epidemiology Investigation of Polychlorinated Biphenyl (PCB) Exposures in Unalakleet, Interim Report - November 3, 2003. Prepared By: Lori A. Verbrugge, Ph.D., Joe McLaughlin, MD, MPH, and Scott Arnold, Ph.D. (PDF 344K)
Map of Unalakleet area, showing proximity of North River site to Unalakleet (497K pdf file)
Diagram of the western portion of the North River former radio relay station ("White Alice") site, showing the Area A (drums for removal summer of 2004), Area B by the demolished building landfill, and Area C, by the trail to the cabin and the road to the hilltop, former site of the dishes. (99K pdf file)
Aerial photo of the hilltop portion of the North River White Alice site (475K jpg file) just northeast of the PCB removal site on the trail to the cabin.
Aerial photo with drawing of Air Force land, sampling area, and nearby cabin (132K pdf file)
Drawing, same scale as previous photo, showing general sample locations (118K pdf file)
Drawing, showing fencing and excavation around PCB area (93K pdf file)