SWMUs 52, 53 and 59, Former LORAN Station CERCLA Site

Background
The former Loran (long-range navigation) Station is located on a northwest-facing promontory along the Bering Sea coastline on the northwest flank of Mount Adagdak. The station, which consists of three buildings in varying stages of disrepair, occupies a bench on a promontory about 150 feet above MLLW. In addition to the buildings, there are two debris disposal areas, one along the western slope below the building bench and the other on the northern slope accessed by a higher road. There are no other developments within about a mile radius of the site. The station is about 6½ miles from downtown Adak, and roads to the site have not been maintained for several years. The site was constructed between 1948 and 1950 to support Naval and Coast Guard navigation, and the station was closed in 1979. It was proposed for investigation under CERCLA because debris, including radio equipment, was left in the buildings after closure and additional debris was disposed of on the western and northern slopes. Debris and unused hazardous material were removed from the site in 1990 and 1991 during the initial site investigations. In addition, two 10,000-gallon JP-5 tanks and one 10,000-gallon gasoline tank were removed from the site (US Navy 1996).

The remedial action objective is maintain this area as commercial and industrial land use due to the presence of benzo(a)pyrene and arsenic in soil that exceed the ADEC cumulative risk level of 1x10E-5 for residential soils.

Identified Contaminants
Two COC's were identified in the OU-A ROD for this site. The first, benzo(a)pyrene was detected in 1 of 36 soil samples at a concentration of 2.25 mg/kg which exceeds the ADEC residential soil cleanup level of 0.9 mg/kg. A residential ICR of 1x10E-5 was estimated for benzo(a)pyrene. The second COC is arsenic, which was detected in 32 of 35 samples at a maximum concentration of 99.7 mg/kg that exceeds the ADEC soil cleanup level of 4.5 mg/kg. A residential ICR of 2x10E-5 was estimated for arsenic at this site, while a recreational (current use) ICR of 1x10E-8 and an industrial ICR of 2x10E-6 were estimated.

Click here to display the data table.

CERCLA Institutional Controls

Equitable Servitude

Inspections and Reporting
The ICs identified in this plan will be inspected and reported on an annual basis, or as necessary. Annual site inspection reports will present the results of inspections. The annual reporting requirements will be included in CERCLA 5-year reviews.

Land Use Restrictions
Outdoor recreational and commercial and industrial land uses for the CERCLA Downtown Area sites are allowable under the OU A ROD. Examples of recreational land uses include hiking, bird watching, hunting, nature watching or any other short-term, non-intrusive activity on the land. Examples of commercial and industrial uses include manufacturing, industrial research and development, utilities, commercial warehouse operations, retail gas stations, auto service stations, equipment repair and service stations, professional offices, financial institutions, publicly owned office buildings, retail business where the principal activity is the sale of food or merchandise, personal service establishments (health clubs, barber/beauty salons, mortuaries, photographic studios, etc.), churches providing worship services (excluding daycare services), and motels/hotels (excluding those that allow residences). The planned land use at the Downtown Area CERCLA sites (except landfills) is consistent with these land use restrictions.

Soil Excavation Restrictions
Excavation Notifications are required for all the Downtown Area CERCLA sites as an IC. The excavation notifications will be required for all proposed excavations below 2 feet at each of the ICs sites. The notifications will be evaluated to determine whether a proposed project at an IC site is consistent with the land use restrictions. The notifications are an additional tool for the Navy to receive timely information (in the absence of local zoning requirements) to monitor land use restrictions. The primary purpose of the IC Excavation Notification is to apprise the Navy of any changes in land use. Information regarding the depth to contamination present is available in the information repository on the second floor of Bob Reeves High School. In the event of an emergency excavation for utility repairs, the requester shall notify the Navy within three working days after the emergency repair has been completed to provide the name, location, depth, and duration of the excavation.

CERCLA Engineering Controls

Engineering controls encompass a variety of engineered remedies to contain or reduce contamination, or physical barriers intended to limit access to property. Engineering controls, as they relate to Adak Island, include fences, signs, caps or barriers, and treatment systems including monitoring wells. The engineering controls identified in the OU A ROD, petroleum cleanup sites, and those that will apply as interim measures to OU B are described below.

Under the OU A ROD signed in 2000, fishing advisory signs were posted for subsistence fishers because of low levels of PCBs detected in bottom fish (rock sole) and shellfish (blue mussels) of Sweeper Cove and Kuluk Bay. The OU A ROD Amendment removes the requirement for fish advisory signs. Instead, the Navy will provide an information pamphlet to the residents of the City of Adak, because they are the most likely people to eat locally caught fish and shellfish as part of a subsistence diet. Fish information pamphlets will be updated as new information is collected and trends are analyzed. Copies of the updated pamphlets will be put in residence mail boxes, and copies will be placed at the City of Adak and U.S. Fish and Wildlife offices. The consumption of rock sole or blue mussels by recreational fishers poses no unacceptable health risks.

Ordnance hazard signs are in place on fencing around the part of the perimeter of the access restricted area adjacent to Lake Andrew. As of the end of the 2002 field season, remediation has been completed on all areas outside the access-restricted area adjacent to Lake Andrew. For this reason, with the exception of the signs at the perimeter of the Lake Andrew area, these signs are no longer required and were removed in 2003. Fences and gates at the access-restricted areas adjacent to Lake Andrew will be retained and maintained until the OU B-2 ROD is executed. Thereafter, ICs and ECs will be subject to the terms of the OU B-2 ROD.

Other Engineering Controls
Other engineering controls/remedies listed in the Comprehensive Monitoring Plan, Revision 1 are listed below.

Excavation and treatment by thermal desorption of contaminated sediments and soils and recycling of treated sediment and soils as cover material at Roberts Landfill;
Placement of a soil cover on one non-landfill site;
Recycling of treated soils from CERCLA sites as cover material at Roberts Landfill;
Monitoring groundwater at CERCLA sites for volatile compounds and semivolatile compounds;
Removal and treatment of petroleum-contaminated soils to meet State of Alaska cleanup requirements;
Monitored natural attenuation of petroleum chemicals in soil and groundwater;
Free-product recovery to the maximum extent practicable as an interim remedial measure, followed by final remediation to achieve cleanup levels under State of Alaska requirements for soils and groundwater; and
Maintenance of an Munitions Awareness educational program for on-island residents and visitors.

loran station survey