Draft Final Preliminary Assessment Report September 29, 2000, Contract No. N44255-93-D-4050, RAC I/Delivery Order No. 0083
EXECUTIVE SUMMARY
In 1995, the former Naval Air Station (NAS) Adak was identified for closure under the Base Realignment and Closure Act and was placed on caretaker status. Since that time, the U.S. Navy (Navy) has been trying to facilitate civilian reuse of the island to take advantage of the modern infrastructure in place. Part of this reuse effort is to effectively mitigate the to future residents of the island due to ordnance or ordnance waste related to historical military operations on the island.
In 1997, the Navy began a comprehensive program to investigate all sites known or suspected to be contaminated with ordnance. During the first 2 years of the program, the "downtown" area of Adak was investigated, including all facilities with a high priority for reuse by future civilian residents. In 1999, the Navy began an investigation of the "outback" areas of the military reservation known or suspected to be contaminated with ordnance. These areas are more remote and are judged to have less reuse value than the downtown area.
During the 1999 investigation, many long standing points of disagreement between the Department of Defense (DoD) and the U.S. Environmental Protection Agency (EPA) with respect to ordnance investigation and remediation came to light. At the heart of the dispute is the fact that no Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process is available for the investigation and remediation of ordnance contamination. This type of contamination is unique and does not fit within the CERCLA framework developed for chemical contamination. The issues between these agencies were so complex, it was believed that arbitration was the only means of resolving the issues. However, in August 1999, the Navy, EPA, and the Alaska Department of Environmental Conservation (ADEC) agreed to work together diligently with future stakeholders on Adak to resolve the issues and develop a CERCLA-like process for investigation and remediation of ordnance-contaminated sites on Adak.
The Level I Screen described in this document is the first step in the site-specific, CERCLA-like process developed for the investigation and remediation of ordnance contaminated sites on Adak. The screen is a framework intended to facilitate somewhat objective evaluation of very subjective issues and information. All available data for each ordnance site on Adak were applied to the Level I Screen. The screen considers the ordnance characteristics of the site (i.e., type of ordnance and density) along with physical characteristics of the site (i.e., terrain and vegetation) to determine the qualitative risk associated and the general category of future action that may be needed at the site to minimize that risk (i.e., additional investigation, remedial action, or no action). The screen also incorporates evaluation of the strength of evidence upon which screening decisions are made to ensure that there is reasonable supporting data for the choices made at this stage of the process.
One hundred eighty-four (184) areas of potential concern (AOPCs) were screened using the framework developed by the agencies and stakeholders. The screening process was used to eliminate seventy-eight (78) sites that pose no significant threat to future residents of Adak. Twenty-five (25) sites were identified for inspection prior to completion of the screening process and seventy-seven 77 sites were advanced for Remedial Investigation (RI). Two sites were sent directly to the Feasibility Study (FS). Those sites advanced to RI will be considered for additional field work, referral to the FS for evaluation of remedial alternatives, or no further action as determined based upon the amount of data available for risk analysis and the qualitative risk posed by each site.
Following the Level I screening process, the outcome for some areas was modified to reflect decisions made during the OU B Project Team meeting, including the decisions to:
- forward all combat ranges (excluding AOPC cut out of these areas based on different anticipated use) to RI using an approved field methodology (see Exhibit A)
- forward several sites selected for RI directly to FS based upon the ample field data for this site, the confirmed presence of ordnance, and the anticipation that the site will warrant future remedial action, this AOPC has been forwarded directly to FS for analysis of remedial alternatives
- forward several sites selected for inspection directly to RI
The modification of the Level I Screen outcomes resulted in the elimination of seventy-eight (78) sites that pose no significant threat to future residents of Adak. Sixty-three (63) sites moved forward for consideration of RI, twenty-five (25) sites moving forward to inspection, and sixteen (16) sites moving forward to FS. Two sites were not screened due to lack of an exposure pathway for explosive danger. Six sites were screened, but were not moved forward to RI based upon the fact that these areas are outside the military reservation on Adak and are the responsibility of the ACOE under the Defense Environmental Reuse Program (DERP)-Formerly Used Defense Sites (FUDS) program.
INTRODUCTION
In 1995, Naval Air Facility (NAF) Adak on Adak Island, Alaska was listed for closure under the Base Realignment and Closure (BRAC) Act. Since that time, the U.S. Navy (Navy) has been facilitating private-party economic reuse on Adak. An integral part of this reuse is a land exchange agreement that would transfer a portion of the current military reservation from the federal government to the Aleut Corporation (TAC). Completion of the land exchange will require the Navy to meet requirements established by the Department of Defense Explosive Safety Board (DDESB) for transfer of real estate potentially contaminated with ordnance and explosives (OE). In addition, under the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Navy must perform all remedial actions necessary to protect human health and the environment prior to the signing of the Record of Decision (ROD) for the site. The ROD must also be signed by the U.S. Environmental Protection Agency (EPA) and the Alaska Department of Environmental Conservation (ADEC) prior to land exchange.
Potential remedial actions for Adak will deal with two specific categories of hazards-those hazards associated with chemical contamination and those hazards associated with ordnance contamination. Because the approach to the study and remediation of these two types of hazards are very different, two separate operable units have been created for the CERCLA process. Operable Unit A (OU A) encompasses the entire military reservation with respect to chemical contamination, while Operable Unit B (OU B) encompasses the entire military reservation with respect to ordnance contamination. In 1998, the Navy completed a Remedial Investigation/Feasibility Study (RI/FS) for OU A. The results of this study are presented in the RI/FS report prepared by URS-Greiner Woodward-Clyde (formerly URS Greiner, formerly URS [URS]) (URS 1998). The Navy is in the process of preparing an RI/FS Work Plan for OU B, which will define the overall approach to site investigation and remediation of ordnance-related materials. The Navy has already completed preliminary ordnance investigations in many areas of Adak, which will facilitate proper scoping of the RI/FS and focus inspection/investigation efforts on the areas of greatest concern with respect to ordnance contamination.
PURPOSE AND SCOPE
The purpose of the Preliminary Assessment (PA) described in this document was to facilitate delineation of appropriate areas of concern (AOCs) with respect to historical ordnance use, and to prioritize those areas for future RI/FS activities such as accelerated removal actions, inspection, characterization, or no further action (NOFA) based upon the relative hazard presented by each area. The PA, which is referred to hereafter in this document as the Level I Screen, was initiated with a list of areas of potential concern (AOPCs) known or suspected to be contaminated with ordnance. The Level I Screening process utilized all available data from previous environmental investigations conducted on Adak and archival research, along with a site-specific set of evaluation criteria to qualitatively evaluate the relative risk/hazard associated with each AOPC and identify those areas with the greatest need for further action in the form of investigation or remediation. The evaluation considered not only the content of historical and physical data sets, but also the relative strength of the data based upon the quantity, specificity, and consistency. The physical site features which might have limited access to troops undergoing wartime training on Adak, also played a role in the evaluation, as did professional knowledge of military operations and ordnance characteristics. Sites determined to require some level of inspection, investigation, or remediation based upon the criteria applied in the Level I Screen were designated as AOCs. These areas were advanced to a Level II Screen to determine what type of actions might be appropriate for each AOC and what quantity of data should be collected for risk assessment at indicated sites.
The Level I Screening process was limited to the development and prioritization of AOCs. No efforts were made during this process to determine the scope or exact nature of future site activities. Study methodologies and investigation technologies for RI were also considered separately.
The Level I Screening methodology was inclusive and made use of all available data relating to ordnance use on Adak, including historical records, field data, anecdotal evidence, and professional knowledge and experience.
REPORT ORGANIZATION
This report presents the methodology and decision criteria used for the Level I Screen and the results of that screening process. Section 2.0 contains a brief background for the project and a description of the physical attributes of Adak Island. Section 3.0 summarizes the existing data available for consideration in the Level I Screen, including both historical archive data and physical data from previous preliminary investigations. Section 4.0 presents the Level I Screening methodology in detail and discusses how it was applied to the individual AOPCs. This section also presents the results of the screen for each AOPC. Section 5.0 summarizes the results of the Level I Screen. Section 6.0 presents references for the report.