Final Remedial Investigation/Feasibility Study for Operable Unit B-1 On Adak Island,
July 13, 2001, Contract No. N62742-99-D-1800, CTO 002

EXECUTIVE SUMMARY

Under CERCLA 120 and Executive Order 12580, the U.S. Navy (Navy) is the lead agency responsible for the cleanup effort. The U.S. Environmental Protection Agency (EPA) Region 10, Alaska Department of Environmental Conservation (ADEC), and U.S. Fish and Wildlife Service (USFWS) provided oversight. This oversight included participation in the OU B Project Team. This team was made up of representatives from the Navy, ADEC, EPA, stakeholders such as the Aleutian/Pribilof Island Association (A/PIA), and consultants for the various members. The Project Team was formed in order to facilitate the development of a site-specific CERCLA process for assessment and remediation of ordnance on Adak and to resolve issues raised by EPA and ADEC under the dispute provisions of the Adak FFA. It has provided and continues to provide a forum for data input, discussion, and issue resolution. The Project Team was instrumental in the creation,

In order to meet the objectives of this agreement, the Navy recommended prioritizing remedial action decisions for specific sites within OU B. The emphasis is on sites where the RI work was completed during the 2000 field season, with a secondary focus on identifying sites which will allow the delineation of a contiguous parcel for transfer. Based upon the objectives of the land transfer agreement and discussions among the OU B Project Team members, a group of sites have been identified for potential transfer at the end of the 2001 field season. This group of sites is collectively known as OU B 1 and includes all identified areas of concern (AOCs) within the military reservation, lying outside of the Mt. Moffett/Andrew Lake area (Figure 1-1). This group of sites also includes many potential AOCs meeting the criteria for no further action during the preliminary assessment conducted in 1999 and 2000, and several land areas that have never been associated with any ordnance- related land use in the historical record. The results of the RI at OU B 1 sites are presented in this report. Sites not included in this group (OU B 2 sites) will undergo any remaining RI work during the 2001 field season, and the results of the investigation in those areas will be reported in a separate document.

INTRODUCTION

1.1 PURPOSE AND SCOPE

The purpose of the Remedial Investigation/Feasibility Study (RI/FS) was to collect and analyze data at sites potentially contaminated with unexploded ordnance (Munitions) at Operable Unit (OU) B at the former Naval Air Facility (NAF) on Adak, Alaska. The data collected during this and previous investigations are used to provide input to the hazard assessment methodology. The data have been evaluated during the preparation of this report and, through the feasibility study, areas have been selected for remedial action. RI/FS data collection began during the 2000 field season; however, due to the large volume of work scoped for the RI, it was not possible to complete the investigation in a single field season. Because the ultimate goal of the U.S. Navy (Navy) is to transfer the military reservation property to the U.S. Fish and Wildlife Service (USFWS) as soon as possible, so that USFWS may convey portions of the Island to The Aleut Corporation (TAC) for private sector reuse, it is the desire of the Navy to expedite the RI/FS process. The land transfer agreement for Adak was signed by all parties in September 2000. The objective of this agreement was to transfer 47,000 acres of real estate to USFWS.

In order to meet the objectives of this agreement in a timely manner, the Navy has recommended prioritizing remedial action decisions for specific sites within OU B. The emphasis will be on sites where the RI work was completed during the 2000 field season, with a secondary focus on identifying sites which will allow the delineation of a contiguous parcel for transfer. Based upon the objectives of the land transfer agreement and discussions among the OU B Project Team members, a group of sites have been identified for potential transfer at the end of the 2001 field season. It is anticipated that any necessary remediation at these sites will be accomplished during the 2001 season. The group of sites is collectively known as OU B 1 and it includes all identified areas of conern (AOCs) within the military reservation, lying outside of the Mt. Moffett/Andrew Lake area. This group of sites also includes many potential AOCs meeting the criteria for no further action during the preliminary assessment (PA) conducted in 1999/2000 and several land areas that have never been associated with any ordnance-related land use in the historical record. The OU B 1 sites are depicted on Figure 1-1. The results of the RI at OU B 1 sites are presented in this report. Sites not included in this group (OU B 2 sites) will undergo any remaining RI work during the 2001 field season and the results of investigation in those areas will be reported in a separate document. These sites are also depicted on Figure 1-1.

This project is being conducted to meet Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) 120; CERCLA 120(h); and Department of Defense (DoD) 6055.9-STD site characterization requirements for federal land transfer. The project is being conducted under the Base Realignment and Closure (BRAC) program. The principal regulatory driver for this project is CERCLA 120. This is because NAF Adak was placed on the CERCLA National Priorities List (NPL) in May 1994, prior to identification of the base for closure under the BRAC program. The Adak Federal Facilities Agreement (FFA) of 1993 specified the scope of work for this CERCLA site, and under DoD guidance on CERCLA 120(h) compliance, existing cleanup authorities and programs must be used in evaluating the need for remedial action. Therefore, the federal land transfer process under CERCLA 120(h) does not create an additional or overriding procedure for evaluating the need for remedial action.

Under CERCLA 120 and Executive Order 12580, the Navy is the lead agency responsible for the cleanup effort. The U.S. Environmental Protection Agency (EPA) Region 10, Alaska Department of Environmental Conservation (ADEC), and USFWS provide oversight. This oversight includes participation in the OU B Project Team. This team is made up of representatives from the Navy, ADEC, EPA, stakeholders such as the Aleutian/Pribilof Islands Association (A/PIA), TAC, and community representatives and consultants for the various members. The project team was formed in order to facilitate the development of a site-specific CERCLA process for assessment and remediation of ordnance on Adak. It provides a forum for data input, discussion, and issue resolution.

1.2 PROJECT BACKGROUND

In 1995, NAF Adak was listed for closure under BRAC. Since that time, the Navy has been facilitating private-party economic reuse on Adak. An integral part of this reuse plan is a land exchange agreement that would transfer a portion of the current military reservation from the federal government to TAC.

In 1997 and 1998, a geophysical and intrusive ordnance investigation was performed in the "downtown" area of Adak Island, which is the focus of private sector reuse. In 1998, the Navy investigated 23 areas identified as potential minefields and completed clearance of ordnance and explosives (OE)/Munitions at Clam Lagoon, a site confirmed to contain mines along with other OE/Munitions items. Further investigation activities were performed in 1999 and 2000 in areas outside of downtown, or remote areas of the military reservation. The military reservation is the northern half of Adak Island. Data collected in 1999 (Draft Site Investigation [SI] Report, Foster Wheeler Environmental, 2000a), along with previously collected data and archival information were used to prepare a Draft Final Preliminary Assessment Report (Foster Wheeler Environmental, 2000b). The PA identified areas of potential concern (AOPCs), which were screened against criteria developed by the OU B project team which includes members from EPA, ADEC, Navy, A/PIA, USFWS, TAC, and consulting members. The screening criteria were used to evaluate the likelihood and density of contamination with an analysis of the strength of supporting evidence. The results of the screening provided recommendations for moving AOPCs to No Further Action (NOFA) status and recommendations for moving sites, now labeled AOCs, forward to the RI/FS.

A framework for the 2000 RI/FS field season was assembled by the OU B project team through a series of meetings, telephone conferences, and electronic correspondence. This framework includes the specific methodology for geophysical survey of the AOCs and Explosive Safety Hazard Assessment (ESHA) methodology. Stringent requirements were specified and documented in the Draft Final RI/FS Work Plan (Foster Wheeler Environmental 2000g). These requirements included all aspects of data collection including transect spacing, equipment validation protocols, and data collection documentation. The specificity of the requirements allowed objective documentation that agreed-to data quality objectives (DQOs) were met.

The 2000 field work concluded in November and data compilation and analysis was performed in December 2000 and January 2001. This document is the result of the data analysis and application of the ESHA methodology to derive possible decision outcomes for the OU B 1 sites. The decision outcomes include NOFA or evaluation in the FS.

1.3 REPORT ORGANIZATION

This Draft RI/FS Report includes a number of components that have been developed to guide the performance of the RI and subsequent FS. The main body of the report contains all of the general information relating to the RI/FS, including:

A summary of pre-RI/FS ordnance investigations (Section 2)
A preliminary conceptual site model (CSM) (Section 2)
A summary of the Preliminary Site Assessment screening conducted to identify sites for RI/FS (Section 2)
A detailed description of the physical setting and resources on Adak (Sections 2.1 and 5)
A description of the regulatory history of the island and the current status of activities initiated in response to regulatory actions (Section 3)
A description of the community relations program in place on Adak (Section 4)
A detailed site history (Section 5)
A discussion of the RI/FS methodology; search and characterization techniques for various types of historical ordnance use areas such as impact areas and munitions storage areas; and the DQOs for this work (Section 6)
Hazard Assessment Methodology and ESHA Analysis Criteria (Section 7)
A description of the FS methodology (Section 8)
Screening Analysis and Analysis of Remedial Alternatives and evaluation of nine CERCLA criteria (Section 8)
References (Section 9)

Final Remedial Investigation/Feasibility Study for Operable Unit B-1 On Adak Island, July 13, 2001, Contract No. N62742-99-D-1800, CTO 002