F10AK029804_04.09_0500_a.pdf

F I N A L ( R E V I S I O N 2 )

FEASIBILITY STUDY OF

OB/OD AREA

FORMER FORT GLENN,

UMNAK ISLAND, ALASKA

FUDS #F10AK029804

January 2014

Prepared for:

U. S. Army Engineering and Support Center Huntsville, Alabama and

U. S. Army Corps of Engineers, Alaska District Elmendorf AFB, Alaska

Contract No. W912DY-09-D-0061 Task Order 0002

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Table of Contents

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Table of Contents Section 1 Executive Summary ....................................................................................................... 1-1

1.1 Remedial Investigation ............................................................................ 1-1

1.2 Feasibility Study Results Summary ......................................................... 1-2

1.2.1 Alternative 1 – No Action ............................................................ 1-3

1.2.2 Alternative 2 – Land Use Controls .............................................. 1-3

1.2.3 Alternative 3 – Focused Surface Removal and LUCs ................. 1-3

1.2.4 Alternative 4 – Surface Removal and LUCs................................ 1-3

1.2.5 Alternative 5 – Surface Removal, Focused Subsurface

Removal, and LUCs ..................................................................... 1-4

1.2.6 Alternative 6 – Surface Removal, Subsurface Removal, and

LUCs ............................................................................................ 1-4

1.2.7 Alternative 7 – Surface Removal, Focused Soil Cover, and

LUCs ............................................................................................ 1-4

1.2.8 Alternative 8 – Focused Surface Removal, Focused

Subsurface Removal, and LUCs .................................................. 1-4

Section 2 Introduction ..................................................................................................................... 2-1

2.1 Purpose ..................................................................................................... 2-1

2.2 Summary of Remedial Investigation Results ........................................... 2-2

2.2.1 OB/OD Area Location and Description ....................................... 2-2

2.2.2 RI Findings................................................................................... 2-2

2.2.3 RI Conclusions and Recommendations ....................................... 2-4

2.3 Applicable, Relevant, and Appropriate Requirements ............................ 2-4

Section 3 Identification and Screening of Technologies ............................................................. 3-1

3.1 Remedial Action Objectives .................................................................... 3-1

3.2 General Response Actions ....................................................................... 3-1

3.3 Identification and Screening of Remedial Technologies ......................... 3-1

3.3.1 Identification and Screening of Technologies ............................. 3-1

3.3.2 Evaluation of Technologies ......................................................... 3-1

Section 4 Development and Screening of Remedial Action Alternatives ................................... 4-1

4.1 Development of Alternatives ................................................................... 4-1

4.1.1 Development of MEC Alternatives ............................................. 4-1

4.1.1.1 Alternative 1 – No Action ............................................. 4-2

4.1.1.2 Alternative 2 – LUCs .................................................... 4-2

4.1.1.3 Alternative 3 – Focused Surface Removal and

LUCs ............................................................................. 4-3

4.1.1.4 Alternative 4 – Surface Removal and LUCs................. 4-4

4.1.1.5 Alternative 5 – Surface Removal, Focused

Subsurface Removal, and LUCs ................................... 4-5

4.1.1.6 Alternative 6 – Surface Removal, Subsurface

Removal, and LUCs ...................................................... 4-6

4.1.1.7 Alternative 7 – Surface Removal, Focused Soil

Cover, and LUCs .......................................................... 4-8

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4.1.1.8 Alternative 8 – Focused Surface Removal, Focused Subsurface Removal, and LUCs .................... 4-9

4.2 Screening of Individual Alternatives ..................................................... 4-11

Section 5 Detailed Analysis of Alternatives .................................................................................. 5-1

5.1 Introduction .............................................................................................. 5-1

5.1.1 Threshold Criteria ........................................................................ 5-1

5.1.2 Primary Balancing Criteria .......................................................... 5-1

5.1.3 Modifying Criteria ....................................................................... 5-2

5.2 Individual Analysis of Alternatives ......................................................... 5-2

5.2.1 Alternative 1 – No Action ............................................................ 5-2

5.2.1.1 Description .................................................................... 5-2

5.2.1.2 Assessment .................................................................... 5-3

5.2.2 Alternative 2 – LUCs ................................................................... 5-3

5.2.2.1 Description .................................................................... 5-3

5.2.2.2 Assessment .................................................................... 5-3

5.2.3 Alternative 3 – Focused Surface Removal and LUCs ................. 5-4

5.2.3.1 Description .................................................................... 5-4

5.2.3.2 Assessment .................................................................... 5-5

5.2.4 Alternative 4 – Surface Removal and LUCs................................ 5-6

5.2.4.1 Description .................................................................... 5-6

5.2.4.2 Assessment .................................................................... 5-6

5.2.5 Alternative 5 – Surface Removal, Focused Subsurface

Removal, and LUCs ..................................................................... 5-7

5.2.5.1 Description .................................................................... 5-7

5.2.5.2 Assessment .................................................................... 5-7

5.2.6 Alternative 6 – Surface Removal, Subsurface Removal, and LUCs ............................................................................................ 5-9

5.2.6.1 Description .................................................................... 5-9

5.2.6.2 Assessment .................................................................... 5-9

5.2.7 Alternative 7 – Surface Removal, Focused Soil Cover and LUCs .......................................................................................... 5-10

5.2.7.1 Description .................................................................. 5-10

5.2.7.2 Assessment .................................................................. 5-10

5.2.8 Alternative 8 – Focused Surface Removal, Focused

Subsurface Removal, and LUCs ................................................ 5-12

5.2.8.1 Description .................................................................. 5-12

5.2.8.2 Assessment .................................................................. 5-12

5.3 Comparative Analysis of Remedial Action Alternatives ....................... 5-13

5.3.1 Overall Protection of Human Health and the Environment ....... 5-13

5.3.2 Compliance with ARARs .......................................................... 5-14

5.3.3 Long-Term Effectiveness and Permanence ............................... 5-14

5.3.4 Reduction of TMV through Treatment ...................................... 5-15

5.3.5 Short-Term Effectiveness .......................................................... 5-16

5.3.6 Implementability ........................................................................ 5-16

5.3.7 Cost ............................................................................................ 5-16

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5.3.8 State Acceptance ........................................................................ 5-17

5.3.9 Community Acceptance ............................................................. 5-18

5.4 MEC Hazard Assessment ...................................................................... 5-18

Section 6 References ...................................................................................................................... 6-1

List of Appendices List of Appendices Appendix A Cost of Remedial Action Alternatives

Appendix B MEC Hazard Assessment

List of Tables List of Tables Table 3-1 Potentially Applicable Technologies and Process Options

Table 3-2 Detailed Screening of Technologies and Process Options

Table 4-1 Assembly of Remediation Alternatives

Table 5-1 Detailed Analysis of Remedial Action Alternatives

Table 5-2 Cost Summary of Remedial Action Alternatives

Table 5-3 MEC Hazard Assessment Summary

List of Figures List of Figures Figure 2-1 Former Fort Glenn Location Map

Figure 2-2 OB/OD Area Location and Boundary Map

Figure 2-3 OB/OD Area RI Visual Survey Results

Figure 2-4 OB/OD Area RI Results

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Acronyms and Abbreviations Acronyms and Abbreviations

ARAR Applicable or Relevant and Appropriate Requirements bgs Below Ground Surface

BIP Blown in Place

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CFR Code of Federal Regulations

COPC Chemical of Potential Concern

COPEC Chemical of Potential Ecological Concern

DDESB Department of Defense Explosives Safety Board

DGM Digital Geophysical Mapping

DQO Data Quality Objective

EM Engineering Manual

EMM Earth-Moving Machinery

ESS Explosives Safety Submission

FS Feasibility Study

FUDS Formerly Used Defense Site

GRA General Response Actions

HA Hazard Assessment

LTM Long-Term Monitoring

LUC Land Use Control

MC Munitions Constituents

MD Munitions Debris

MEC Munitions and Explosives of Concern mg/kg Milligrams Per Kilogram

MPPEH Material Potentially Presenting an Explosive Hazard

MRS Munitions Response Site

MRSPP Munitions Response Site Prioritization Protocol

NCP National Oil and Hazardous Substances Pollution Contingency Plan

O&M Operations and Maintenance

OB/OD Open Burn/Open Detonation

QC Quality Control

RAO Remedial Action Objective

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RI Remedial Investigation

RRD Range-Related Debris

SUXOS Senior Unexploded Ordnance Supervisor

TMV Toxicity, Mobility, and Volume

TNT Trinitrotoluene

TPP Technical Project Planning

URS URS Group, Inc.

USACE United States Army Corps of Engineers

USAESCH United States Army Engineering and Support Center, Huntsville

USEPA United States Environmental Protection Agency

UXO Unexploded Ordnance

UXOQCS Unexploded Ordnance Quality Control Specialist

UXOSO Unexploded Ordnance Safety Officer

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SECTIONONE Executive Summary

Final (Revision 2) FS Report of OB/OD Area 1-1 RI/FS, Former Fort Glenn, Umnak Island

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This Feasibility Study (FS) is for the Open Burn/Open Detonation (OB/OD) Area at former Fort Glenn, Umnak Island, Alaska. This report is being completed following the Remedial Investigation (RI) and RI Report (URS 2012).

1.1 REMEDIAL INVESTIGATION

1.1.1 The OB/OD Area was selected for an RI based on prior investigations including the Archive Search Report (CELMS 2001), Site Inspection (Parsons 2009), and Explosive Ordnance Disposal Incident Report (Ferris and Bivens 2002). The RI was designed to satisfy data quality objectives (DQOs) developed during the Technical Project Planning (TPP).

1.1.2 During the TPP, three data DQOs were established for the OB/OD Area and one DQO was established for the background study. The DQOs for the RI are as follows:

· Evaluate historical aerial photography of the OB/OD Area for evidence of potential demolition craters and then field verify their presence through visual reconnaissance. Also, collect global positioning system coordinates of the lahar flow(s), if present.

· Evaluate the presence and extent of surface and subsurface munitions and explosives of concern (MEC) in demolition craters and the kickout area.

· Characterize the nature and extent of potential munitions constituents (MC).

· Collect two background data sets, one comprising 12 discrete surface soil samples and another comprising nine incremental surface soil samples, for comparison with metals concentrations in site investigative samples.

1.1.3 The following is a brief summary of results from the RI completed during the summer of

2011 (URS 2011).

· Aerial photographic evidence, digital geophysical mapping (DGM) results, lahar boundary survey, visual reconnaissance survey results, and other investigations indicated that there were two clusters of demolition craters, one in the northwest and one in southeast of the OB/OD Area. Of the two clusters, the northwest cluster was impacted by a lahar flow resulting from volcanic activity in 2008. A total of 19 demolition craters were identified and investigated. In the northwest crater cluster, three visible demolition craters were identified on the surface partially filled with lahar. All three craters contained munitions debris (MD), MEC, multiple anomalies, and were partially filled by lahar. An additional five lahar filled demolition craters, not visible on the surface, were identified with DGM data. The southeast crater cluster was not impacted by lahar. The 16 associated demolition craters exhibited MD, MEC, and numerous magnetic anomalies.

· DGM data were collected on 9.04 acres of transect and grids. A total of 3,250 anomalies were identified.

· 456 anomalies were selected for intrusive investigation. However, only 293 selected target anomalies were intrusively investigated due to time constraints, difficult digging conditions with up to 4 feet of lahar present in some areas, and the fact that MEC had been discovered

1 Executive Summary

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· 222 selected target anomalies resulted in 425 MD items, eight anomalies resulted in 89 MEC items, and the other 63 target anomalies were classified as 14 quality control (QC) seeds, 3 range-related debris (RRD), 18 other debris, 16 hot rocks, and 12 no-finds.

· Surface soil was investigated using a combination incremental/discrete sampling approach.

Subsurface soil samples were collected at MEC discoveries, directly beneath the MEC item.

Two incremental soil samples were collected at each demolition crater. Small amounts of lead, copper, zinc, and trinitrotoluene (TNT) contamination were discovered and found to be chemicals of potential concern (COPCs) and/or chemicals of potential ecological concern (COPECs) at collocated MEC locations.

· Human health risks were evaluated for the site worker, recreational user, and future residential scenarios. COPCs included TNT, copper, and lead in soils. For the site worker and recreational user, carcinogenic risk did not exceed 1x10-6, noncarcinogenic hazard was less than 1.0, and lead concentrations were below levels of concern. For the future resident, potential carcinogenic risks of 3.3x10-5 were estimated based on a detection of TNT at a single sample location (OBOD-SB010-3.0). A noncarcinogenic hazard of 2.7 also was estimated based on the copper result at a single sample location (OBOD-SB009-3.0). Risk associated with incidental MC are considered to be low for future residential receptors and result from localized detections around discovered MEC items. Copper, lead, and zinc were identified as COPECs in surface soil samples in an ecological screening evaluation. A more refined ecological evaluation concluded it is unlikely that MC poses potential risks to ecological receptors.

· The 2,076-acre OB/OD Area was split into two munitions response sites (MRSs) based on the results of the RI. The OB/OD Area (MRS-04) (337 acres) was delineated based on MEC identified during the RI. The Remaining OB/OD Area (MRS-14) (1,739 acres) was identified as an area containing no MEC.

· The MEC Hazard Assessment (HA) level for the OB/OD Area (MRS-04) is 1. The Remaining OB/OD Area (MRS-14) was not given a MEC HA level because no MEC was identified.

· The Munitions Response Site Prioritization Protocol (MRSPP) level for the OB/OD Area (MRS-04) is 3. The MRSPP level for the Remaining OB/OD Area (MRS-14) is No Longer Required.

1.2 FEASIBILITY STUDY RESULTS SUMMARY

1.2.0.1 The following eight alternatives were selected for detailed analysis at the OB/OD Area

(MRS-04):

· Alternative 1 – No Action

· Alternative 2 – Land Use Controls (LUCs)

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· Alternative 3 – Focused Surface Removal and LUCs

· Alternative 4 – Surface Removal and LUCs

· Alternative 5 – Surface Removal, Focused Subsurface Removal, and LUCs

· Alternative 6 – Surface Removal, Subsurface Removal, and LUCs

· Alternative 7 – Surface Removal, Focused Soil Cover, and LUCs

· Alternative 8 – Focused Surface Removal, Focused Subsurface Removal, and LUCs

1.2.0.2 The following sections provide a brief summary of the results from the detailed analysis of each alternative.

1.2.1 Alternative 1 – No Action

This alternative assumes no further action would be taken regarding MEC contamination and is included as a baseline comparison.

1.2.2 Alternative 2 – Land Use Controls

This alternative consists of LUCs only. Administrative controls would include access restrictions, an educational awareness program, and an inspection and maintenance program, all of which would be documented in the Fort Glenn administrative record. Engineering controls would consist of signage only. The overall cost of this alternative is approximately $1.0 million.

Most of the capital costs are associated with mobilization and logistics. Most of the long-term maintenance costs are associated with travel to and from the island. Alternative 2 will require five-year reviews.

1.2.3 Alternative 3 – Focused Surface Removal and LUCs

Alternative 3 builds on Alternative 2 by including a focused surface MEC removal in a 30-acre “focus area” that contains the majority of surface debris and the highest density of anomalies.

Although Alternative 3 reduces toxicity, mobility, and volume (TMV) through the removal of MEC in a focused area (Section 4.1.1.3), it does not address MEC outside of the focus area.

This alternative costs approximately $1.9 million to complete in one estimated field season (less than 1 month of field operations). Alternative 3 will require five-year reviews.

1.2.4 Alternative 4 – Surface Removal and LUCs

Alternative 4 is similar to Alternative 3 but includes a total removal of surface MEC. Alternative 4 reduces TMV of MEC on the surface throughout the entire MRS. This alternative does not address subsurface hazards or potential migration of MEC through erosion or frost heave.

Alternative 4 costs approximately $5.5 million to complete in one estimated field season (1 to 2 months of field operations). Alternative 4 will require five-year reviews.

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1.2.5 Alternative 5 – Surface Removal, Focused Subsurface Removal, and LUCs

Alternative 5 includes all aspects of Alternative 4 with the addition of a subsurface removal to the depth of detection in the focus area. Alternative 5 reduces TMV on the surface over the entire OB/OD Area (MRS-04) and the subsurface in the focus area only. There would still be potential MEC present in subsurface soils deeper than the depth of detection in the focus area and at all depths outside of the focus area. Alternative 5 costs approximately $9.5 million to complete in one estimated field season (4 months of field operations). Alternative 5 will require five-year reviews.

1.2.6 Alternative 6 – Surface Removal, Subsurface Removal, and LUCs

Alternative 6 includes all aspects of Alternative 4 with the addition of a subsurface removal to the depth of detection, which is estimated to be less than 3 feet below ground surface (bgs) outside of the focus area. Alternative 6 reduces TMV on the surface and subsurface. There would still be potential MEC present in subsurface soils deeper than the depth of detection.

Alternative 6 costs approximately $32.1 million to complete in three estimated field seasons (13 months of field operations). Alternative 6 will require five-year reviews.

1.2.7 Alternative 7 – Surface Removal, Focused Soil Cover, and LUCs

Alternative 7 includes all components of Alternative 4 with the addition of a soil cover over the focus area. Alternative 7 reduces TMV of MEC on the surface throughout the entire MRS.

Alternative 7 does not reduce TMV in the subsurface but addresses subsurface risk by adding a 2-foot-thick soil cover over the focus area. This alternative reduces potential migration of MEC in the focus area. Alternative 7 costs approximately $11.0 million to complete over two estimated field seasons (3 to 4 months of field operations). Two field seasons are required to allow time for the soil cover design between the first and second seasons. Alternative 7 will require five-year reviews.

1.2.8 Alternative 8 – Focused Surface Removal, Focused Subsurface Removal, and LUCs

Alternative 8 includes all aspects of Alternative 3 with the addition of a subsurface removal to the depth of detection in the focus area. Alternative 8 reduces TMV on the surface and the subsurface in the focus area only. There would still be potential MEC present in subsurface soils deeper than the depth of detection in the focus area; as well as on the surface and at all depths outside of the focus area. Alternative 8 costs approximately $8.1 million to complete in one estimated field season (3 months of field operations). Alternative 8 will require five-year reviews.

SECTIONTWO Introduction

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2.1 PURPOSE

2.1.0.1 The purpose of this FS is to identify and evaluate alternatives for remedial action for the OB/OD Area at former Fort Glenn, Umnak Island, Alaska. The FS is the basis for presenting to the public technically feasible and cost-effective remedial actions that are protective of human health and the environment. Fort Glenn is a Defense Environmental Restoration Program Formerly Used Defense Site (FUDS), FUDS #F10AK029805.

2.1.0.2 This FS is part of an RI/FS delivery order for five sites at the former Fort Glenn that is being completed by URS Group, Inc. (URS) for the United States Army Engineering and Support Center, Huntsville (USAESCH), under Contract Number W912DY-09-D-0061, Delivery Order 0002. USAESCH is completing this delivery order for the United States Corps of Engineers Pacific Ocean, Alaska. This FS report has been prepared in accordance with the August 6, 2010 Performance Work Statement Revision 1 and with Engineering Pamphlet 1110-1-18 (April 3, 2006). The goal of the delivery order is to complete the tasks necessary to gain acceptance of a Decision Document in accordance with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and Department of Defense, Department of the Army, and United States Army Corps of Engineers (USACE) guidance. An RI/FS is necessary to support the Decision Document.

2.1.0.3 This FS report is a companion document to the RI report (URS 2012) that was submitted under separate cover. The FS process consists of the following general steps:

· Establish remedial action objectives (RAOs) to address hazards and risks identified in the RI report.

· Develop general response actions (GRAs) that may be taken to satisfy the RAOs.

· Identify volumes or areas of media to which GRAs may be applied.

· Identify and evaluate technology process options based on effectiveness, implementability, and relative cost to select a representative process option for each technology type.

· Assemble the selected representative technologies into alternatives representing a range of GRA combinations, as appropriate.

· Where numerous alternatives have been identified, screen the alternatives based on the criteria of effectiveness, implementability, and cost to reduce the number of alternatives to analyze in detail.

· For detailed analysis, evaluate retained alternatives based on nine criteria as specified by the United States Environmental Protection Agency (USEPA) (USEPA 1988) and 40 Code of Federal Regulations (CFR) 300.430.(e)(9)(iii):

— Overall Protection of Human Health and the Environment

— Compliance with applicable or relevant and appropriate requirements (ARARs)

— Long-Term Effectiveness and Permanence

2 Introduction

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— Reduction of TMV

— Short-Term Effectiveness

— Implementability

— Cost

— Support Agency Acceptance (to be evaluated after agency review)

— Community Acceptance (to be evaluated after public comment period)

2.2 SUMMARY OF REMEDIAL INVESTIGATION RESULTS

2.2.1 OB/OD Area Location and Description

2.2.1.1 The former Fort Glenn is located on the eastern end of Umnak Island in the Fox Islands of the Aleutian Island Chain of Alaska (Figure 2-1). Umnak Island lies approximately 50 miles southwest of Dutch Harbor and 850 miles southwest of Anchorage, Alaska. The Fort Glenn installation has been abandoned since it was excessed in 1955 and remnants of hundreds of structures are scattered over the 102,000-acre former installation. There is a system of cinder roads throughout the former installation, some of which are in reasonably good shape for vehicular traffic. Three cinder runways are also present, one of which was re-graded during the RI and is suitable for light aircraft. The only occupants at the former installation are employees of the Bering Pacific Ranches Limited, which has leased the property since 1993. Their ranch house and slaughtering facility is located in the middle of the former Fort Glenn installation.

Although Umnak Island is remote with no towns or cities on the eastern end of the island, public access is not restricted and is open in many areas. There is a landing beach on the east coastline at Otter Bight.

2.2.1.2 The OB/OD Area is located in the southeastern portion of the former Fort Glenn installation (Figure 2-2). The site property is currently owned by the Aleut Corporation, the St.

George Tanaq Corporation, the State of Alaska Department of Transportation and Public Facilities, and the United States Fish and Wildlife Service. The OB/OD Area consists of small gently rolling hills on the northeast and southwest sides with a small valley in the center. Two distinct clusters of suspected demolition craters were identified in historical aerial photographs.

The largest craters are located at approximately N 53° 22′ 56″ W 167° 56′ 51″, and the other craters are located approximately 0.5 mile to the southeast. A map showing the major site features observed during the RI visual survey is presented as Figure 2-3.

2.2.1.3 Land use is currently agricultural (free range cattle grazing) and recreational, with nearby residential. Future land use at Fort Glenn is expected to remain the same as its current use. Receptors evaluated in the RI included current and future site workers, current and future recreational users, potential future residents and ecological receptors.

2.2.2 RI Findings

The RI findings are shown on Figure 2-4 and summarized below:

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· Size: The OB/OD Area (2,076 acres) was recommended to be split into the OB/OD Area (MRS-04) (337 acres) and the Remaining OB/OD Area (MRS-14) (1,739 acres).

· Site Features: The site consisted of the remnants of old roads, 19 visible demolitions craters, a lahar flow that covered portions of the site including several demolition craters, a large cantonment area, and storage quonsets. There are gently rolling, grass covered hills on the northeast and southwest sides of the site and a small valley through the central portion of the site. Deep drainages with steep slopes are present along the north and in the southern portion of the site.

· Access: Unrestricted, but access is very limited based on difficulty of traveling to the island.

· Geophysical Investigation Results: 3,250 anomalies in a total of 9.04 acres of DGM transects and grids.

· Intrusive Investigation Results: A total of 293 selected target anomalies were intrusively investigated. Of these, 222 anomalies resulted in 425 MD items. Eight anomalies resulted in the recovery of 89 MEC items. Outside of the lahar impacted area most items were found between 0 and 1 foot bgs. Inside the lahar impacted area, items were found between 0 and 4 feet bgs. However, based on the size of the filled demolition craters, items could be deeper than 20 feet bgs. All but one QC seed was recovered.

· MEC/MD: A total of 102 MEC items were disposed within the OB/OD Area (MRS-04) during this RI. 89 MEC items were the source of eight selected target anomalies. An additional 13 MEC items were recovered from surface locations. No MEC was identified in the Remaining OB/OD Area (MRS-14).

· Incidental MC Sampling: Soil sampling was completed around damaged MEC items to determine if incidental MC had been released into the surrounding soil. Surface soil was investigated using a combination of incremental and discrete samples. Discrete subsurface soil samples were also collected adjacent to discovered MEC items. Three COPCs for human health risk assessment were identified (TNT, copper, and lead) and three COPECs for ecological risk assessment were identified (copper, lead, and zinc). All COPCs and COPECs were detected in discrete samples adjacent to discovered MEC.

· Human Health Risk Assessment: Human health risks were evaluated for the site worker, recreational user, and future resident scenarios. COPCs included TNT, copper, and lead in soils. For the site worker and recreational user, carcinogenic risk did not exceed 1x10-6, and noncarcinogenic hazard was less than 1.0. For the future resident, potential carcinogenic risks of 3.3x10-5 were estimated based on detection of TNT at a single sample location (OBOD-SB010-3.0), a noncarcinogenic hazard of 2.7 also was estimated based on copper at a single sample location (OBOD-SB009-3.0), and lead slightly exceeded the residential soil cleanup level of 400 milligrams per kilogram (mg/kg) at a single location (OBOD-SS003- 2.0; 475 mg/kg). Since the TNT and copper results were deeper than 2.0 feet bgs, the risk is considered unlikely because the exposure is beyond the typical residential contact with surface soils (0 to 2 feet bgs). All three concentrations were measured at the source of MEC items (i.e., adjacent to or directly below the MEC item), any surrounding concentrations would be reduced via attenuating transport mechanisms. Sampling in conjunction with

Final (Revision 2) FS Report of OB/OD Area 2-4 RI/FS, Former Fort Glenn, Umnak Island

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Q:\1617\0581\FS Report\Final Rev2\Fort Glenn OBOD Area Final FS_rev2.doc\ isolated MEC items indicates a highly localized source, with the exposure concentration (maximum detected) biased high because the sample collected was in association with a small, single source item at depth. The actual exposure concentration can reasonably be expected to be substantially lower than the maximum concentration detected, and similarly, the associated risk or hazard would be substantially lower as well. As a result, because the exposure concentration is biased high, and would be much less if combined with surrounding samples consistent with a representative residential exposure, no further action for MC in soil is warranted. Exposure pathways to groundwater in the OB/OD Area are considered to be potentially complete but insignificant based on both the screening results from the groundwater seep and the low frequency/localized nature of detected soil contamination that could be the source of groundwater contamination. Therefore, groundwater is no longer considered a medium of concern.

· Ecological Risk Assessment: Ecological evaluation has concluded it is unlikely that incidental MC poses potential risks to ecological receptors.

· MEC HA Baseline Level: The OB/OD Area (MRS-04) has a MEC HA level of 1 (865 points). The Remaining OB/OD Area (MRS-14) was not scored because no MEC was identified.

· MRSPP Priority: The OB/OD Area (MRS-04) has an MRSPP Priority of 3. The Remaining OB/OD Area (MRS-14) has an MRSPP Priority of No Longer Required.

2.2.3 RI Conclusions and Recommendations

2.2.3.1 The OB/OD Area has been adequately characterized during the RI. Based on the RI results, there is a potential for exposure to MEC hazards by current or future agricultural, commercial, recreational, and residential receptors at the OB/OD Area (MRS-04). There is no incidental MC risk for the current or future agricultural, commercial, or recreational receptors.

Risk associated with incidental MC are considered to be low for future residential receptors and result from localized detections around discovered MEC items.

2.2.3.2 The results of the RI were used to provide the following recommendations:

· Proposed boundaries for the OB/OD Area (MRS-04) and the Remaining OB/OD Area (MRS-14) are presented on Figure 2-2.

· An FS for MEC/MD at the OB/OD Area (MRS-04).

· No Further Action for the Remaining OB/OD Area (MRS-14).

2.3 APPLICABLE, RELEVANT, AND APPROPRIATE REQUIREMENTS

Identification of, and compliance with, ARARs is mandated by CERCLA (as amended by the Superfund Amendments and Reauthorization Act) and by its implementing regulations contained in the NCP (40 CFR Part 300). Section 121(d) of CERCLA requires that remedial actions be evaluated to determine if they meet laws, standards, requirements, regulations, criteria, or

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Q:\1617\0581\FS Report\Final Rev2\Fort Glenn OBOD Area Final FS_rev2.doc\ limitations under federal environmental laws and regulations that are determined to be ARARs.

The NCP requires compliance with ARARs during and at completion of remedial actions. Under limited circumstances, ARARs for on-site remedial actions may be waived.

ARARs are identified on a site-specific basis using a two-part analysis: 1) a determination of whether or not a given requirement is applicable and 2) if a determination is made that it is not applicable, a determination of whether or not a requirement is relevant and appropriate. To determine whether a requirement is relevant and appropriate, characteristics of the remedial action, the hazardous substances present, and the physical characteristics of the site must be compared to those addressed in the statutory or regulatory requirement. In some cases, a requirement may be relevant but not appropriate. In other cases, only part of a requirement will be considered relevant and appropriate. When it is determined that a requirement is both relevant and appropriate, the requirement must be complied with to the same degree as if it were applicable.

Below are the NCP definitions of “applicable” and “relevant and appropriate” standards:

· “Applicable” standards are those cleanup standards, standards of control, and other substantive environmental protection requirements, criteria, or limitations promulgated under Federal or State laws that specifically address a hazardous substance, contaminant, remedial action, or locational circumstance.

· “Relevant and appropriate” standards are those that apply to circumstances sufficiently similar to those encountered at a CERCLA site that, although otherwise not legally required, their application is appropriate at that specific site. If a requirement is found to be relevant and appropriate under the NCP, it will be treated in the same way as an applicable requirement (40 CFR 300.5).

· Per 40 CFR 300.400 (g)(4), “Only those state standards that are promulgated, are identified by the state in a timely manner, and are more stringent than federal requirements may be applicable or relevant and appropriate.”

For identification purposes, ARARs are categorized as chemical-specific, action-specific or location-specific:

· Chemical-specific ARARs are based on health- or risk-based concentration limits or discharge limitations in environmental media (i.e., air, soil, or water) for specific hazardous chemicals. The requirements may be used to set cleanup levels for the chemicals of concern in the designated media, or to set a safe level of discharge (e.g., air emission or wastewater discharge) where a discharge occurs as a part of the remedial action.

· Action-specific ARARs generally set performance, design, or other similar operational controls or restrictions on particular activities related to management of hazardous substances or pollutants. These requirements address specific activities that are used to accomplish a remedy. Action-specific requirements do not in themselves determine the remedial action;

rather, they indicate how a selected remedial action alternative must be designed, operated, or managed.

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· Location-specific ARARs are restrictions placed on the types of activities that may occur in particular locations. The location of a site may be an important characteristic in determining its impact on human health and the environment. Location-specific ARARs include federal requirements for wetlands protection and floodplain restrictions on management of hazardous waste.

No standards were identified as being applicable or relevant and appropriate for the MEC removal actions stated in this FS.

Anchorage

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16170581 Figure 2-1

Former Fort Glenn Location Map RI/FS at Former Fort Glenn

Umnak Island, Alaska

0 200 400100 Miles ¹

Note:

1. NAD83 State Plane Alaska Zone 10, US Survey Feet.

Alaska

Canada Russia

B e r i n g S e a

No r th P ac i f i c Ocean

Fort Glenn

Dutch Harbor

Umnak Island _̂

A l e u t i a n I s l a n d s

Fort Glenn

Umnak P ass

Inanudak Bay

Nikolski U m n a k I s l a n d

Okmok Caldera

Mount Vsevidof

B e r i n g S e a

No r th P ac i f i c Ocean

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Z:

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Explosives Storage Area

Survey Control Point

Landing Beach

Notes:

1. NAD83 Alaska State Plane Zone 10, US Survey Feet

2. Aerial photo source: 1988, TEC

¹ 0 3,000 6,0001,500 Feet¹

Bering Sea

Inanudak Bay

Umnak P ass

U m n a k I s l a n d

Legend Former Fort Glenn

OB/OD Area (MRS-04) (337 acres)

Remaining OB/OD Area (MRS-14) (1,739 acres)

Focus Area (30 acres)

RI Field Camp Feature

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OB/OD Area Location and Boundary Map

RI/FS at Former Fort Glenn Umnak Island, Alaska

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Southeast cluster of craters, 16 craters visible

Northwest cluster of craters, 3 craters visible

Area of deep ravines with steep side slopes

Notes:

1. NAD83 Alaska State Plane Zone 10, US Survey Feet

2. Aerial photo source: GeoEye-1, captured 8/2/2011

3. Cantonment area consists of dilapidated buildings, revetments, quonsets, and covered magazines.

No evidence of OB/OD activities or burial pits were were discovered in this area, but DMM and buried RRD trash pits were discovered.

4. RRD trash pile consisted of M106 Fuze containers in a drainage features.

Umnak P ass

0 1,000 2,000500 Feet¹

Bering Sea

Inanudak Bay

Umnak P ass

U m n a k I s l a n d

Legend Former Fort Glenn

OB/OD Area (MRS-04) (337 acres)

Focus Area (30 acres)

Visual Reconnaissance Track

GF Crater

E Crater Filled with Lahar

GF MEC

"D) Fuze Container

!( Site Feature

Cantonment Area

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OB/OD Area RI Visual Survey Results RI/FS at Former Fort Glenn

Umnak Island, Alaska

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OB/OD Area RI Results RI/FS at Former Fort Glenn

Umnak Island, Alaska

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2. Aerial photo source: GeoEye-1, captured 8/2/2011

0 600 1,200300 Feet¹

Bering Sea

Inanudak Bay

Umnak P ass

U m n a k I s l a n d

Legend Former Fort Glenn

OB/OD Area (MRS-04) (337 acres)

Focus Area (30 acres)

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!. MD

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GF Crater

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DGM Transect Path

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!( DGM Target Selected for Intrusive Investigation

SECTIONTHREE Identification and Screening of Technologies

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3.1 REMEDIAL ACTION OBJECTIVES

RAOs are site-specific cleanup objectives that were established during the RI process based on the nature and extent of contamination, potential for human and environmental exposure, and ARARs. The development of RAOs for a MEC FS focuses on addressing the physical hazards to human and ecological receptors due to the presence of MEC. The following RAOs were proposed for the OB/OD Area (MRS-04) in the RI report:

· Reduce the potential for direct contact of MEC by human receptors, considering the current agricultural and recreational land use and potential future residential land use.

3.2 GENERAL RESPONSE ACTIONS

GRAs are medium-specific response categories that will satisfy the RAO. Response actions that are potentially applicable for addressing contamination at the OB/OD Area (MRS-04) are listed below and summarized in Table 3-1.

· No Action

· LUCs

· MEC Removal

· Containment

· Disposal of MEC by Demolition

3.3 IDENTIFICATION AND SCREENING OF REMEDIAL TECHNOLOGIES

Remedial technologies are the methods by which a GRA may be undertaken. Process options are the specific processes within a remedial technology type by which the technology may be implemented.

3.3.1 Identification and Screening of Technologies

As an initial screening, remedial technologies and process options were evaluated based on their technical implementability and general applicability to the conditions at the OB/OD Area (MRS-04). All of the MEC remedial technologies and process options identified in Table 3-1 are technically feasible and applicable to the OB/OD Area (MRS-04), and were retained for further evaluation.

3.3.2 Evaluation of Technologies

3.3.2.1 Using the Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA (USEPA 1988), the process options were further evaluated with respect to three evaluation criteria: effectiveness, implementability, and cost. These evaluation criteria are used as an initial screen of technology types and process options to eliminate those that are ineffective

3 Identification and Screening of Technologies

SECTIONTHREE Identification and Screening of Technologies

Final (Revision 2) FS Report of OB/OD Area 3-2 RI/FS, Former Fort Glenn, Umnak Island

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Q:\1617\0581\FS Report\Final Rev2\Fort Glenn OBOD Area Final FS_rev2.doc\ or unworkable at a site. Detailed screening of technologies and process options are summarized in Table 3-2. For each evaluation criterion, the process options were rated as low, medium, high, or between two ratings (e.g., low-medium). The following rationale was used as a guideline:

· Effectiveness: Based on demonstrated ability of component technologies to achieve remediation goals, potential impacts to human health and the environment during implementation, and reliability of technology/process option with respect to addressing conditions at the site. The effectiveness analysis is based on engineering judgment and each process option is evaluated as to whether effectiveness is low, medium, or high relative to other process options in the same technology.

· Implementability: Based on factors such as safety; constructability; regulatory and public support; compatibility with reasonably anticipated future land use; and availability of material, equipment, technical expertise, or off-site treatment and disposal facilities. The implementability analysis is based on engineering judgment and each process option is evaluated as to whether implementability is low, medium, or high relative to other process options in the same technology.

· Cost: Based on overall cost, including capital costs and long-term monitoring (LTM) costs.

Capital costs are based on the amount of equipment that is needed and costs necessary to perform the process option. LTM costs are based on the relative cost required after initial implementation of the process option. The cost analysis is based on engineering judgment and each process option is evaluated as to whether costs are low, medium, or high relative to other process options in the same technology. A comprehensive discussion of costing procedures during the FS is contained in A Guide to Developing and Documenting Cost Estimates During the Feasibility Study (USEPA 2000).

3.3.2.2 The process options with favorable effectiveness, implementability, and cost were retained as the representative process option. Identifying only one or two representative process options for each technology was not intended to limit the process options that could potentially be employed in remedial design, but instead to provide a basis for evaluation of a manageable number of alternatives. The choice of a specific process option should be evaluated more completely during the remedial design process.

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TABLE 3-1

POTENTIALLY APPLICABLE TECHNOLOGIES AND PROCESS OPTIONS

General Response

Action Technology Process Option Description No Action None None No remedial action would be taken to address the MEC hazards.

Land Use Controls

Institutional

Educational Awareness Program

Provide educational awareness of explosive hazards through meetings and fact sheets, with a target audience to include local ranchers, village of Nikolski, Unalaska, and other potential visitors. Goal is to raise the public's understanding and awareness of the hazards associated with MEC in affected areas.

Health and Safety Program Require implementation of a health and safety program for protection of site workers.

Inspection and Maintenance

Periodic reviews of the performance of any remedial actions, including periodic site inspections and maintenance of engineered controls.

Engineering Fencing Install fencing to prevent unauthorized access.

Signage Place signs warning potential agricultural and commercial workers, nearby residents and visitors of dangers and restrictions related to property.

MEC

Removal

Detection Technology

DGM

Support a subsurface MEC removal action by developing a map of subsurface anomalies (metallic items that might be MEC) using a digital geophysical instrument that is pulled or pushed across the ground surface. The instrument induces an electrical current that generates a secondary magnetic field in both ferrous and nonferrous items, which in turn is measured and used to detect the item. During the RI, the Geonics EM61-MK2 was used and found to be successful for detection of subsurface metal at this site.

Innovative Technology

Support a subsurface MEC removal action by developing a more detailed map of subsurface anomalies using innovative technologies, such as Metal Mapper. This technology provides multiple illumination directions, from a single survey location, through the use of orthogonal high power transmitter coils and triaxial receiver cubes.