SWMU 21, White Alice Upper Quarry CERCLA Site
Background
This 3-acre site is an abandoned quarry along the access road to the former White Alice radar array facility, located about 2 miles west of downtown Adak. The site was evaluated under CERCLA because drums of PCB-containing oil were disposed of in the area and PCBs were identified in the soil at SWMU 21A. Although there are no formal records to confirm this, anecdotal information indicates that during demolition of the White Alice facility (1980 to 1982), drums containing transformer oil were disposed of at (or in the vicinity of) SWMU 21A. A removal action was conducted in 1992 to remove 780 cubic yards of PCB-affected soils. A 20-mil liner and soil cover were placed over areas of residual PCBs to minimize direct exposure to and possible migration of residual PCBs (US Navy 1995b). Removed soils were disposed of beneath the SWMU 67 cap.
The remedial action objectives are to maintain this area as an outdoor recreational area due to the presence of Aroclor 1260 at levels that result in an elevated residential ICR, and to maintain the protective cap. Excavation by non-Navy personnel is absolutely prohibited although recreational land uses, which add additional cover, may be permissible. Navy personnel will be allowed to excavate for the purposes of repairing caps, etc.
Identified Contaminants
Aroclor 1260 was identified in the OU-A ROD as the chemical of concern. It was detected at a maximum concentration 1.6 mg/kg which is above the ADEC residential soil cleanup level of 10.0 mg/kg. An estimated residential ICR of 1.4x10E-5 was calculated . The ICR for the current recreational use was 4x10E-7 and the industrial ICR was 2.5x10E-7.
CERCLA Institutional Controls
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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.
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