Technical Documents

Proposed Plan For Cleanup Of Ordnance And Explosives And Unexploded Ordnance Within Operable Unit B-1 On Adak Island, May 2001

INTRODUCTION

This Proposed Plan describes the U.S. Navy's proposal for addressing safety risks posed by ordnance and explosives (OE) and unexploded ordnance (Munitions) on Adak Island, Alaska, within a portion of the former Navy facility. This portion is called Operable Unit B-1 (OU B-1). OU B-1 consists of 130 sites shown in this figure. Operable Unit B-2 is another portion of the former Navy facility and consists of 62 sites. A Proposed Plan for OU B-2 is anticipated for next year. Six sites initially evaluated are outside the Navy facility on the southern part of Adak and will be investigated by the U.S. Army Corps of Engineers under the Formerly Used Defense Sites (FUDS) program. This Proposed Plan, developed by the Navy in consultation with the Alaska Department of Conservation (ADEC) and the U.S. Environmental Protection Agency (EPA), describes the proposed decisions for the sites in OU B-1, including actions for 26 sites where the potential for OE or Munitions exists. These sites were identified using historical records, geophysical information, subsurface investigations, and/or knowledge of known former ordnance activities.

Risks associated with chemical and petroleum contamination (including possible chemical contamination from ordnance filler materials at several sites) on Adak Island were initially addressed under Operable Unit A (OU A). However additional archival information suggesting more widespread presence of ordnance on Adak was discovered. As a result, OU B was created to focus on these ordnance-related hazards. The Navy is proposing to sample and clean up soil that is found above cleanup levels for ordnance-related chemicals at 14 sites that were found during Ou B-1 investigations.

The Navy and the agencies invite you to comment on this Proposed Plan. Your comments will help determine what actions will be taken at the former Naval facility at Adak Island. Final decisions for OU B-1 OE/Munitions sites will be presented in Record of Decision (ROD) for OU B-1. This Proposed Plan fulfills the requirements of Section 117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund.

SCOPE AND ROLE OF OPERABLE UNIT B-1

A land transfer agreement was signed in September 2000. Under this agreement, the Navy is to return approximately 47,000 acres of the military reservation property on Adak Island to the U.S. Fish & Wildlife Service (USFWS). The Bureau of Land Management (BLM) will then convey these lands to the Aleut Corporation (TAC) for private sector reuse in exchange for other lands desired by USFWS. To complete this process as quickly as possible, the OU B Project Team divided OU B into OU B-1 and OU B-2. OU B-1 is the portion of the military reservation that contains the core of the proposed reuse area and will therefore be the initial focus for final clean up decisions.

OU B-1 includes all ordnance sites within the military reservation lying outside of the Mt. Moffett/Andrew Lake area (identified as OU B-2). OU B-1 includes 104 sites that met the criteria for No Further Action (NOFA) during the Preliminary Assessment (PA) and Remedial Investigation (RI). The Navy is proposing to undertake the cleanup actions described in this Proposed Plan for the 26 OE/Munitions sites and 14 chemical sites within OU B-1 during the 2001 field season. Some sites fall into both categories. Results from the OU B-2 site investigations (also conducted in 2001) will be reported in a separate document. That document will be in the OU B-2 Remedial Investigation (RI)/Feasibility Study (FS), expected to be available in early 2002.

KEY POINTS

1. Because of limitations of existing technologies, uncertainties associated with past land use, and the steep terrain and dense vegetative cover that exists in many areas on Adak, we cannot know if all areas on Adak are free of OE/Munitions. For this reason, the Navy is committed to maintain the existing Adak ordnance awareness and education program for visitors and residents. In addition, the Navy will provide a copy of the ROD to BLM to maintain as part of the permanent file of conveyance documentation that is available to future users. The Navy will also continue to respond to any future discoveries of OE/Munitions.
   
   
2. Starting in July 1999, the OU B Project Team of Adak Stakeholders -- consisting of the Navy, EPA, ADEC, TAC, Aleutian/Pribilof Islands Association (A/PIA), USFWS and community members -- began to develop a process to characterize and prioritize cleanup of ordnance materials on Adak. The results of this process, conducted under CERCLA, are summarized in this Proposed Plan.
   
   
3. The Project Team identified 130 ordnance sites. Table 1 summarizes the status of these sites.
   
   
4. Over 1,200 miles of geophysical investigation were performed within approximately 17,000 acres of the northern portion of Adak as part of the RI for OU B. Approximately 1,000 OE-related items such as metal fragments were collected; 60 of these were intact Munitions. Almost all of the OE/Munitions has been found at depths shallower than 2 feet and none greater than 4 feet.
   
   
5. The Project Team determined that 40 of the OU B-1 RI sites did not require additional action because of OE/Munitions removal during investigation, evaluation of target information, or lack of ordnance-related hazard, based on an Adak-specific hazard assessment approach.
   
   
6. Three sites
   • Combat Range 3, Site C#-01A, Ordnance Disposal Site;
   • Combat Range 6, Site C6-01A Mortar Impact Area; and
   • Mitt Lake Impact Area, Site ML-01A, Mortar Impact Area
   were evaluated for remedial action alternatives. In addition 23 sites were identified for additional field work and possible cleanup. These sites include:
   • Combat Range 3 Sites, C3-01B, -01C, -01D, 01-E, and C3-04A;
   • Combat Range 8 Sites, C8-01, -03, and -05A;
   • Lake Jean Site, LJ-01;
   • Mitt Lake Sites ML-01B, -02A, and -02B;
   • Lake DeMarie Site DM-06A;
   • Finger Bay Sites, FB-01 and -04;
   • Blind Cove Site BC-01;
   • Husky Pass Training Area;
   • the Shagak Bay Gun Emplacements, GUN-01, -02, and -03; and
   • the Ammo Pier sites, FBAP-02 and AP-02.
   The alternatives are summarized in later sections of the Proposed Plan and the details of the Selected Alternative will be described in the Record of Decision.

   
   

7. Current land use plans require clearance of OE/Munitions items to a depth of 2 feet below ground surface (bgs) to support the current and reasonably expected future land uses at sites requiring cleanup within OU B-1. However, the clearance process to be used for these sites results in an added measure of protection by achieving clearance of OE/Munitions items to a depth of 4 feet bgs.
   
   

Table 1 lists the number of sites in OU B-1 and the site status totals. The key below the table provides a description of the status categories.