Superfund Record of Decision Otis Air National Guard (USAF) OU 5 5 Falmouth MA


                                    EPA/ROD/R01-98/133
                                    1998
EPA Superfund
     Record of Decision:
     OTIS AIR NATIONAL GUARD BASE/CAMP EDWARDS
     EPA ID: MA2570024487
     OU05
     FALMOUTH, MA
     09/30/1998

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EPA 541-R98-133


                           RECORD OF DECISION
             AREAS OF CONTAMINATION FTA-2/LF-2, PFSA/FS-10/FS-ll,
         SD-2/FS-6/FS-8, SD-3/FTA-3/CY-4, SD-4, and SD-5/FS-5 SOURCE AREAS

                   MASSACHUSETTS MILITARY RESERVATION
                        CAPE COD, MASSACHUSETTS

                           SEPTEMBER 1998

                          TABLE OF CONTENTS

    Section                      Title                                                   Page No.

    DECLARATION FOR THE RECORD OF DECISION                                               D-l
    1.0 SITE NAME, LOCATION, AND DESCRIPTION                                             1-1
    2.0 MMR SITE HISTORY AND ENFORCEMENT ACTIVITIES                                      2-1
    2.1 LAND USE AND RESPONSE HISTORY                                                    2-1
      2.2 ENFORCEMENT HISTORY                                                            2-1
    3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION                                            3-1
    4.0 EVALUATION OF SITE RISKS                                                         4-1
    5.0 SOIL TARGET CLEAN-UP LEVELS                                                      5-1
    6.0 DEVELOPMENT AND EVALUATION OF ALTERNATIVES                                       6-1
      6.1 STATUTORY REQUIREMENTS AND RESPONSE OBJECTIVES                                 6-1
      6.2 TECHNOLOGY AND ALTERNATIVE DEVELOPMENT AND SCREENING                           6-1
      6.3 ALTERNATIVE EVALUATION CRITERIA                                                6-2
    7.0 DECISION SUMMARY                                                                 7-1
      7.1 DECISION SUMMARY FOR AOC FTA-2/LF-2                                            7-1
       7.1.1 Scope and Role of Response Action at AOC FTA-2/LF-2                         7-1
       7.1.2 History of Land Use at AOC FTA-2/LF-2                                       7-2
       7.1.3 Summary of Site Characteristics at AOC FTA-2/LF-2                           7-2
       7.1.4 Summary of Risks at AOC FTA-2/LF-2                                          7-4
       7.1.5 Description of Evaluated Alternatives for AOC FTA-2/LF-2                    7-6
       7.1.6 Summary of Comparative Analysis of Alternatives for AOC FTA-LF-2            7-7
       7.1.7 Description of the Selected Remedy for AOC FTA-2/LF-2                       7-10
       7.1.8 Statutory Determinations for AOC FTA-2/LF-2                                 7-13
       7.1.9 Documentation of No Significant Changes for AOC FTA-2/LF-2                  7-15

    7.2 DECISION SUMMARY FOR AOC PFSA/FS-10/FS-ll                                        7-15
      7.2.1 Scope and Role of Response Action at AOC PFSA/FS-10/FS-ll                    7-15
      7.2.2 History of Land Use at AOC PFSA/FS-10/FS-ll                                  7-15
      7.2.3 Summary of Site Characteristics at AOC PFSA/FS-10/FS-ll                      7-16
      7.2.4 Summary of Risks at AOC PFSA/FS-10/FS-ll                                     7-19
      7.2.5 Description of Evaluated Alternatives for AOC PFSA/FS-10/FS-ll               7-20
      7.2.6 Summary of Comparative Analysis of Alternatives for AOC PFSA/FS-10/FS-ll     7-22
      7.2.7 Description of the Selected Remedy for AOC PFSA/FS-10/FS-ll                  7-24
      7.2.8 Statutory Determinations for AOC PFSA/FS-10/FS-ll                            7-28
      7.2.9 Documentation of No Significant Changes for AOC PFSA/FS-10/FS-ll             7-29

    7.3 DECISION SUMMARY FOR AOC SD-2/FS-6/FS-8                                          7-30
      7.3.1 Scope and Role of Response Action at AOC SD-2/FS-6/FS-8                      7-30
      7.3.2 History of Land Use at AOC SD-2/FS-6/FS-8                                    7-30
      7.3.3 Summary of Site Characteristics at AOC SD-2/FS-6/FS-8                        7-31
      7.3.4 Summary of Risks at AOC SD-2/FS-6/FS-8                                       7-32
      7.3.5 Description of Evaluated Alternatives for AOC SD-2/FS-6/FS-8                 7-34
      7.3.6 Summary of Comparative Analysis of Alternatives for AOC SD-2/FS-6/FS-8       7-35
      7.3.7 Description of the Selected Remedy for AOC SD-2/FS-6/FS-8                    7-38
      7.3.8 Statutory Determinations for AOC SD-2/FS-6/FS-8.                             7-40
      7.3.9 Documentation of No Significant Changes AOC SD-2/FS-6/FS-8                   7-42

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                                      TABLE OF CONTENTS
                                        (continued)

  7.4 DECISION SUMMARY FOR AOC SD-3/FTA-3/CY-4                                         7-42
     7.4.1 Scope and Role of Response Action at AOC  SD-3/FTA-3/CY-4                     7-42
     7.4.2 History of Land Use at AOC SD-3/FTA-3/CY-4                                  7-43
     7.4.3 Summary of Site Characteristics at AOC SD-3/FTA-3/CY-4                      7-43
     7.4.4 Summary of Risks at AOC SD-3/FTA-3/CY-4                                     7-46
     7.4.5 Description of Evaluated Alternatives for AOC SD-3/FTA-3/CY-4               7-47
     7.4.6 Summary of Comparative Analysis of Alternatives for AOC SD-3/FTA-3/CY-4     7-48
     7.4.7 Description of the Selected Remedy for AOC SD-3/FTA-3/CY-4                  7-50
     7.4.8 Statutory Determinations for AOC SD-3/FTA-3/CY-4                            7-53
     7.4.9 Documentation of No Significant Changes for AOC SD-3/FTA-3/CY-4             7-55

  7.5 DECISION SUMMARY FOR AOC SD-4                                                    7-56
     7.5.1 Scope and Role of Response Action at AOC  SD-4                               7-56
     7.5.2 History of Land Use at AOC SD-4                                             7-57
     7.5.3 Summary of Site Characteristics at AOC SD-4                                 7-57
     7.5.4 Summary of Site Risks at AOC SD-4                                           7-59
     7.5.5 Description of Evaluated Alternatives for AOC SD-4                          7-62
     7.5.6 Summary of Comparative Analysis of Alternatives for AOC SD-4                7-65
     7.5.7 Description of the Selected Remedy for AOC SD-4                             7-67
     7.5.8 Statutory Determinations for AOC SD-4                                       7-71
     7.5.9 Documentation of No Significant Changes for AOC SD-4                        7-72

  7.6 DECISION SUMMARY FOR AOC SD-5/FS-5                                               7-73
     7.6.1 Scope and Role of Response Action at AOC  SD-5/FS                            7-73
     7.6.2 History of Land Use at AOC SD-5/FS-5                                        7-73
     7.6.3 Summary of Site Characteristics at AOC SD-5/FS-5                            7-74
     7.6.4 Summary of Risks at AOC SD-5/FS-5                                           7-77
     7.6.5 Description of Evaluated Alternatives for AOC SD-5/FS-5                     7-79
     7.6.6 Summary of Comparative Analysis of Alternatives for AOC SD-5/FS-5            7-81
     7.6.7 Description of the Selected Remedy for AOC SD-5/FS-5                        7-83
     7.6.8 Statutory Determinations for AOC SD-5/FS-5                                  7-86
     7.6.9 Documentation of No Significant Changes for AOC SD-5/FS-5                   7-88

  7.7 SUMMARY OF SELECTED REMEDIES                                                     7-89

8.0 STATE ROLE                                                                         8-1

 GLOSSARY OF ACRONYMS AND ABBREVIATIONS

 APPENDICES
 APPENDIX A       FIGURES
 APPENDIX B       TABLES
 APPENDIX C       RESPONSIVENESS SUMMARY
   Attachment A   Public Comments Received During Public Comment Period
   Attachment B   Letter from USAF 102nd Fighter Wing
   Attachment C   Soil Recycling Facility Summary Levels
 APPENDIX D       TRANSCRIPT OF PUBLIC HEARING
 APPENDIX E       MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION LETTER OF CONCURRENCE

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 Figure

 1-1
 1-2
 7-1
 7-2
 7-3
 7-4
 7-5
 7-6
 7-7
 7-8
 7-9
 7-10
 7-11

Table
                       LIST OF FIGURES

                            Title

Site Location Map
Location of AOCs
Site Features at AOC FTA-2/ALF-2
Conceptual Layout for Biosparging at AOC FTA-2/LF-2
Site Features at AOC PFSA/FS-10/FS-ll
Conceptual Layout for Biosparging at AOC PFSA/FS-10/FS-ll
Site Features at AOC SD-2/FS-6/FS-8
Conceptual Layout for Excavation Areas at AOC SD-2/FS-6/FS-
Site Features at AOC SD-3/FTA-3/CY-4
Site Features at AOC SD-4
Conceptual Layout for Excavation Areas at AOC SD-4
Site Features at AOC SD-5/FS-5
Conceptual Layout for Excavation Areas at AOC SD-5/FS-5

                        Title
 6-1
 7-1

 7-2
 7-3
 7-4

 7-5
 7-6

 7-7
 7-8
 7-9

 7-10
 7-11
 7-12

 7-13

 7-14

 7-15
 7-16
 7-17

 7-18
 7-19

 7-20
 7-21

 7-22

 7-23
 7-24
 7-25

 7-26
 7-27
 7-28
 7-29
AOC Specific Response Objectives
Surface and Subsurface Soil Contaminants of Potential Concern for AOC
FTA-2/LF-2 Ecological and Human-Health Evaluation
Summary of Human-Health Risks at AOC FTA-2/LF-2
Summary of Ecological Risk Estimates at AOC FTA-2/LF-2
Estimation of Phytotoxicity Risks in Zero to 2 feet bgs Surface Soil at
AOC FTA-2/LF-2
ARARs, Criteria, Advisories, and Guidance Biosparging at AOC FTA-2/LF-2
Surface Soil Contaminants of Potential Concern for AOC
PFSA/FS-10/FS-ll Ecological and Human Health Evaluation
Summary of Human-Health Risks at AOC PFSA/FS-10/FS-ll
ARARs, Criteria, Advisories, and Guidance Biosparging at AOC PFSA/FS-10/FS-ll
Surface Soil Contaminants of Potential Concern for AOC SD-2/FS-6/FS-8
Ecological and Human Health Evaluation
Summary of Human Health Risks at AOC SD-2/FS-6/FS-8
Summary of Ecological Risk Estimates at AOC SD-2/FS-6/FS-8
Estimation of Phytotoxicity Risks in Zero to 2 feet bgs Surface Soil at
AOC SD-2/FS-6/FS-8
ARARs, Criteria, Advisories, and Guidance Excavation/Asphalt-Batching
at AOC SD-2/FS-6/FS-8
Surface Soil Contaminants of Potential Concern for AOC
SD-3/FTA-3/CY-4 Ecological and Human Health Evaluation
Summary of Human Health Mks at AOC SD-3/FTA-3/CY-4
Summary of Ecological Risk Estimates at AOC SD-3/FTA-3/CY-4
Estimation of Phytotoxicity Risks in Zero to 2 feet bgs Surface Soil at
AOC SD-3/FTA-3/CY-4
ARARs, Criteria, Advisories, and Guidance Limited Action at AOC SD-3/FTA-3/CY-4
Contaminants of Potential Concern for AOC SD-4 Pond Sediment
Ecological and Human Health Evaluation
Summary of Human Health Risks at AOC SD-4
Terrestrial Vegetation Risk Characterization Maximum Surface Soil
Concentrations AOC SD-4 RI Study Area
Terrestrial Vegetation Risk Characterization Mean Surface Soil
Concentrations AOC SD-4 RI Study Area
Summary of Ecological Risk Estimates at AOC SD-4
ARARs, Criteria, Advisories, and Guidance Excavation/Asphalt-Batching at AOC SD-4
Surface and Subsurface Soil Contaminants of Potential Concern for AOC
SD-5/FS-5 Ecological and Human Health Evaluation
Summary of Human Health Risks at AOC SD-5/FS-5
Summary of Ecological Risk Estimates at AOC SD-5/FS-5
Estimation of Phytotoxicity Risks in Zero to 2 feet bgs Surface Soil at AOC SD-5/FS-5
ARARs, Criteria, Advisories, and Guidance Excavation/Asphalt-Batching at AOC SD-5/FS-5

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DECLARATION FOR THE RECORD OF DECISION

1.0 SITE NAME AND LOCATION

Areas of Contamination
FTA-2/LF-2, PFSA/FS-10/FS-ll, SD-2/FS-6/FS-8,
SD-3/FTA-3/CY-4, SD-4,and SD-5/FS-5 Source Areas
Massachusetts Military Reservation
Cape Cod, Massachusetts

2.0 STATEMENT OF PURPOSE AND BASIS

This decision document presents the Air Force Center for Environmental Excellence (AFCEE) selected
remedial action decisions for contaminant source areas at the following Areas of Contamination (AOCs) at
the Massachusetts Military Reservation (MMR) in Barnstable County on Cape Cod, Massachusetts:

Fire Training Area No. 2 and Landfill No. 2 (FTA-2/LF-2)
Petroleum Fuels Storage Area, Fuel Spill No. 10, and Fuel Spill No.11
(PFSA/FS-10/FS-ll)
Storm Drainage Ditch No. 2, Fuel Spill No. 6, and Fuel Spill No. 8 (SD-2/FS-6/FS-8)
• Storm Drainage Ditch No. 3, Fire Training Area No. 3, and Coal Storage Yard No. 4
(SD-3/FTA-3)/CY-4)
Storm Drainage Ditch No. 4 (SD-4),and
Storm Drainage Ditch No. 5 and Fuel Spill No. 5 (SD-5/FS-5)

It was developed in accordance with the Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA) as amended, 42 U.S. Code °° 9601 et seg, and the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP) as amended, 40 Code of Federal Regulations Part 300, to the
extent practicable. The Director of AFCEE and the Director of the Office of Site Remediation and
Restoration, U.S. Environmental Protection Agency (USEPA) New England have been delegated the authority
to approve this Record of Decision.

This Record of Decision is based on the Administrative Record that has been developed in accordance with
Section 113(k) of CERCLA. The Administrative Record is available for public review at the AFCEE
Installation Restoration Program Office at MMR and the Falmouth Public Library, Falmouth, Massachusetts.

The Commonwealth of Massachusetts concurs with the selected remedies for AOC FTA-2/LF-2,
PFSA/FS-10/FS-ll, SD-2/FS-6/FS-8, SD-3/FTA-3/CY-4, SD-4 and SD-5/FS-5 Source Areas. Appendix E of this
Record of Decision contains a copy of the letter of concurrence.

3.0 DECISION BASIS

This section summarizes the basis for AFCEE's selection of a remedial action for the AOC FTA-2/LF-2,
PFSA/FS-10/FS-ll, SD-2/FS-6/FS-8, SD-3/FTA-3/CY-4, SD-4, and SD-5/FS-5 Source Areas.

3.1 AOC FTA-2/LF-2

The following subsections summarize AFCEE's assessment of the need for remedial action at the AOC
FTA-2/LF-2 source area, provide a brief description of the selected remedy, and present the statutory
determinations necessary to select a remedy.

3.1.1 Assessment of AOC FTA-2/ALF-2

Actual or potential releases of hazardous substances from the AOC FTA-2/LF-2 source area, not addressed
by implementing the response action selected in this Record of Decision, may present an imminent and
substantial endangerment to the public health, welfare, or the environment.

3.1.2 Description of the Selected Remedy for AOC FTA-2/LF-2

The selected remedy for AOC FTA-2/LF-2 is Biosparging with Ambient Air Monitoring. This remedial action
is a source control action that addresses leaching of organic compounds to groundwater, the principal
known threat at AOC FTA-2/LF-2. It consists of designing, constructing, and operating a biosparging
treatment system, maintaining institutional controls, and five-year reviews of remedy protectiveness. The
remedy reduces the release of contaminants from subsurface soils by treating subsurface soils to meet
protective cleanup levels. The major components of the selected remedy include:

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       •      mobilization and site preparation
       •      performing baseline ambient air monitoring
       •      collecting confirmation soil samples to refine the horizontal and vertical delineation of
              the target contaminants ethylbenzene and total xylenes at the proposed cleanup location
       •      performing a pilot-scale test of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system
       •      collecting ambient air samples to assess compliance with Applicable or Relevant and
              Appropriate Reguirements (ARARs)
       •      conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen, and the target compounds of ethylbenzene and total xylenes
       •      operating and maintaining the biosparging system until cleanup criteria are met
       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      filing a Record Notice of Landfill Operation with the Registry of Deeds to document the
              location of the landfill
       •      performing five-year site reviews

3.1.3 Statutory Determinations for AOC FTA-2/LF-2

The selected remedy is consistent with CERCLA, and to the extent practicable, the NCP, is protective of
human health and the environment, complies with federal and Commonwealth of Massachusetts reguirements
that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The remedy utilizes permanent solutions and alternative treatment technologies to the maximum extent
practicable. In addition, the remedy satisfies the statutory preference for treatment that reduces
toxicity, mobility, or volume as a principal element.

Because the risk assessment at AOC FTA-2/LF-2 was premised on restricted future site use, hazardous
substances may remain on site at concentrations greater than those consistent with unrestricted site use.
Therefore, a review will be conducted within five years after commencement of remedial action to ensure
that the remedy continues to provide adeguate protection of human health and the environment and at
five-year intervals thereafter.

3.2 AOC PFSA/FS-10/FS-ll

The following subsections summarize AFCEE's assessment of the need for remedial action at the AOC
PFSA/FS-10/FS-ll source area, provide a brief description of the selected remedy, and present the
statutory determinations necessary to select a remedy.

3.2.1 Assessment of AOC PFSA/FS-10/FS-ll

Actual or potential releases of hazardous substances from the AOC PFSA/FS-10/FS-ll source area, if not
addressed by implementing the response action selected in this Record of Decision, may present an
imminent and substantial endangerment to the public health, welfare, or the environment.

3.2.2 Description of the Selected Remedy for AOC PFSA/FS-10/FS-ll

The selected remedy for AOC PFSA/FS-10/FS-ll is Biosparging with Off-gas Collection and Treatment. This
remedial action is a source control action that addresses leaching of organic compounds to groundwater,
the principal known threat at AOC PFSA/FS-10/FS-ll. It consists of designing, constructing, and operating
biosparging and bioventing treatment systems, maintaining institutional controls, and performing
five-year reviews of remedy protectiveness. The remedy reduces the release of contaminants from
subsurface soils by treating subsurface soils to meet protective cleanup levels. The major components of
the selected remedy include:

       •      mobilization and site preparation
       •      performing baseline ambient air monitoring
       •      collecting confirmation soil samples at all five proposed cleanup locations to refine the
              horizontal and vertical delineation of the target contaminants ethylbenzene and total
              xylenes
       •      performing a pilot-scale test of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system with off-gas collection
              and treatment for the two proposed cleanup locations at this AOC with capillary-fringe
              contamination

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       •      designing and installing a bioventing system for the remaining three locations identified
              for cleanup at this AOC with shallow vadose zone contamination
       •      collecting ambient air samples to assess compliance with ARARs
       •      conducting quarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen,  and the target compounds of ethylbenzene and total xylenes
       •      operating and maintaining the biosparging and bioventing systems until cleanup criteria are
              met
       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      performing five-year site reviews

3.2.3 Statutory Determinations for AOC PFSA/FS-10/FS-ll

The selected remedy is consistent with CERCLA, and to the extent practicable, the NCP, is protective of
human health and the environment, complies with federal and Commonwealth of Massachusetts requirements
that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The remedy utilizes permanent solutions and alternative treatment technologies to the maximum extent
practicable. In addition, the remedy satisfies the statutory preference for treatment as a principal
element.

Because the risk assessment at AOC PFSA/FS-10/FS-ll was premised on restricted future site use, hazardous
substances may remain on site at concentrations greater than those consistent with unrestricted site use.
Therefore, a review will be conducted within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of human health and the environment and at
five-year intervals thereafter.

3.3 AOC SD-2/FS-6/FS-8

The following subsections summarize AFCEE's assessment of the need for remedial action at the AOC
SD-2/FS-6/FS-8 source area, provide a brief description of the selected remedy, and present the statutory
determinations necessary to select a remedy.

3.3.1 Assessment of AOC SD-2/FS-6/FS-8

Actual or potential releases of hazardous substances from the AOC SD-2/FS-6/FS-8 source area, if not
addressed by implementing the response action selected in this Record of Decision, may present an
imminent and substantial endangerment to the public health,  welfare, or the environment.

3.3.2 Description of the Selected Remedy for AOC SD-2/FS-6/FS-8

The selected remedy for AOC SD-2/FS-6/FS-8 is Excavation and Asphalt-batching. This remedial action is a
source control action that addresses human and ecological receptor exposure to surface soil contaminated
with inorganics, the principal known threat at AOC SD-2/FS-6/FS-8. It consists of excavating surface
soils exceeding protective cleanup levels, treating the excavated soils at an onsite asphalt-batching
facility, and using the treated material as a paving subbase at MMR. The major components of the selected
remedy include:

       •      mobilization and site preparation
       •      excavating sediment/surface sod exceeding cleanup criteria at historical sample locations
              SD-1 and SD-6
       •      collecting post-excavation confirmation samples from the excavation perimeter for
              analysis for chromium,  lead, and zinc
       •      transporting excavated soil to an onsite asphalt-batching facility for testing and
              treatment
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR

3.3.3 Statutory Determinations for AOC SD-2/FS-6/FS-8

The selected remedy is consistent with CERCLA, and to the extent practicable, the NCP, is protective of
human health and the environment, complies with federal and Commonwealth of Massachusetts requirements
that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The remedy utilizes permanent solutions and alternative treatment technologies to the maximum extent
practicable. In addition, the remedy satisfies the statutory preference for treatment that reduces
toxicity, mobility, or volume as a principal element.

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Because this remedy will not leave hazardous substances on site above health-based levels for
unrestricted use, the requirement for five-year site reviews will not apply to this action.

3.4 AOC SD-3/FTA-3/CY-4

The following subsections summarize AFCEE's assessment of the need for remedial action at the AOC
SD-3/FTA-3/CY-4 source area, provide a brief description of the selected remedy, and present the
statutory determinations necessary to select a remedy.

3.4.1 Assessment of AOC SD-3/FTA-3/CY-4

Actual or potential releases of hazardous substances from the AOC SD-3/FTA-3/CY-4 source area, if not
addressed by implementing the response action selected in this Record of Decision, may present an
imminent and substantial endangerment to the public health, welfare, or the environment.

3.4.2 Description of the Selected Remedy for AOC SD-3/FTA-3/CY-4

The selected remedy for AOC SD-3/FTA-3/CY-4 is Confirmation Sampling with Contingency of Excavation and
Asphalt-batching. This remedial action is a source control action that addresses the potential that
previous removal actions may not have removed all surface soil exceeding cleanup levels for semivolatile
organic compounds (SVOCs) and inorganics at AOC SD-3/FTA-3/CY-4. The remedy consists of confirmation
sampling with the contingency action of excavation and asphalt-batching, maintaining institutional
controls, and five-year reviews of remedy protectiveness.  The remedy reduces potential human and
ecological direct contact exposure to surface soil. The major components of the selected remedy include:

       •      preparing a brief sampling and analysis work plan
       •      mobilization and site preparation
       •      collecting surface soil samples from the area of coal ash disposal outside of the 1994
              removal area and analyzing the samples for SVOCs and inorganics
       •      comparing analytical data to  Soil Target Cleanup Levels (STCLs)  for SVOCs and inorganics
       •      if comparison shows contamination above STCLs,  implementing the  contingency action of
              excavating surface soil for asphalt-batching
       •      collecting post-excavation confirmation samples from the excavation perimeter for analysis
              for inorganics and SVOCs
       •      transporting excavated soil to an onsite asphalt-batching facility for testing and
              treatment
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at NWR
       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      performing five-year site reviews

3.4.3 Statutory Determinations for AOC SD-3/FTA-3/CY-4

The selected remedy is consistent with CERCLA, and to the extent practicable,  the NCP, is protective of
human health and the environment, complies with federal and Commonwealth of Massachusetts requirements
that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The contingency action utilizes permanent solutions and alternative treatment technologies to the maximum
extent practicable. In addition, the contingency action satisfies the statutory preference for treatment
that reduces toxicity, mobility, or volume as a principal element.

Because the risk assessment at AOC SD-3/FTA-3/CY-4 was premised on restricted future site use, hazardous
substances may remain on site at concentrations greater than those consistent with unrestricted site use.
Therefore, a review will be conducted within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of human health and the environment and at
five-year intervals thereafter.

3.5 AOC SD-4

The following subsections summarize AFCEE's assessment of the need for remedial action at the AOC SD-4
source area, provide a brief description of the selected remedy, and present the statutory determinations
necessary to select a remedy.

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3.5.1 Assessment of AOC SD-4

Actual or potential releases of hazardous substances from the AOC SD-4 source area, if not addressed by
implementing the response action selected in this Record of Decision, may present an imminent and
substantial endangerment to the public health, welfare, or the environment.

3.5.2 Description of the Selected Remedy for AOC SD-4

The selected remedy for AOC SD-4 is Excavation and Asphalt-batching. This remedial action is a source
control action that addresses ecological receptor exposure to total petroleum hydrocarbons (TPH)  in the
drainage ditch north of Reilly Road and inorganics in the sediments of the upgradient pond south of
Reilly Road, the principal known threats at AOC SD-4. It consists of excavating sediments exceeding
protective cleanup levels, treating the excavated soil/sediment at an onsite asphalt-batching facility,
and using the treated material as a paving subbase at MMR. The major components of the selected remedy
include:

       •       performing pre-excavation studies
       •       mobilization and site preparation
       •       performing a wetland delineation prior to excavation of pond sediment
       •       identifying areas for remedial  action at the upgradient pond based on the results of
              pre-excavation studies
       •       preparing a Wetland Restoration Specification (only if disturbance of pond/wetland is
              planned)
       •       performing pre-excavation confirmation soil sampling in the drainage ditch north of Reilly
              Road to assess the horizontal and vertical distribution of contamination exceeding the TPH
              STCL and to identify areas for  excavation
       •       excavating soil and sediment to achieve cleanup criteria
       •       collecting post-excavation confirmation sediment samples from the excavation perimeter at
              the upgradient pond for analysis for inorganics and/or acid volatile sulfides and
              simultaneously extracted metals
       •       collecting post-excavation confirmation soil samples from the excavation perimeter in the
              drainage ditch north of Reilly  Road for analysis for TPH
       •       transporting excavated soil and sediment to an onsite asphalt-batching facility for
              testing and treatment
       •       removing temporary roads,  backfilling excavations,  and restoring wetland areas
       •       using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •       performing five-year site reviews

3.5.3 Statutory Determinations for AOC SD-4

The selected remedy is consistent with CERCLA, and to the extent practicable, the NCP, is protective of
human health and the environment, complies with federal and Commonwealth of Massachusetts requirements
that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The remedy utilizes permanent solutions and alternative treatment technologies to the maximum extent
practicable. In addition, the remedy satisfies the statutory preference for treatment that reduces
toxicity, mobility, or volume as a principal element.

Because this remedy will leave TPH at concentrations above health-based levels for unrestricted use north
of Reilly Road, the requirement for five-year site reviews will apply to actions taken north of Reilly
Road. Actions proposed for south of Reilly Road are based on unrestricted site use and will not be
subject to live-year site reviews.

3.6 AOC SD-5/FS-5

The following subsections summarize AFCEE's assessment of the need for remedial action at the AOC
SD-5/FS-5 source area, provide a brief description of the selected remedy, and present the statutory
determinations necessary to select a remedy.

3.6.1 Assessment of AOC SD-5/FS-5

Actual or potential releases of hazardous substances from the AOC SD-5/FS-5 source area, if not addressed
by implementing the response action selected in this Record of Decision, may present an imminent and
substantial endangerment to the public health, welfare, or the environment.

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3.6.2 Description of the Selected Remedy for AOC SD-5/FS-5

The selected remedy for AOC SD-5/FS-5 is Excavation and Asphalt-batching. This remedial action is a
source control action that addresses human and ecological receptor exposure to surface soils contaminated
with volatile organic compounds (VOCs),  TPH, and inorganics and leaching of organic compounds to
groundwater, the principal known threats at AOC SD-5/FS-5. It consists of excavating sediments exceeding
protective cleanup levels, treating the excavated soil/sediment at an onsite asphalt-batching facility,
and using the treated material as a paving subbase at MMR maintaining institutional controls, and
five-year reviews of remedy protectiveness.  The major components of the selected remedy include:

       •       mobilization and site preparation
       •       performing pre-excavation  confirmation soil sampling to confirm the horizontal and
              vertical distribution of  contamination exceeding TPH and inorganic STCLs at six locations
              and VOC,  TWL and inorganic STCLs at the remaining two locations
       •       excavating soil  exceeding  cleanup criteria
       •       transporting excavated soil to an onsite asphalt-batching facility for testing and
              treatment
       •       collecting post-excavation confirmation samples from the excavation perimeters for
              analysis for TPH and inorganics at six of the proposed cleanup locations and for VOCs,
              TPH and inorganics at the  remaining two locations
       •       backfilling and  restoring  excavations  with clean borrow material
       •       using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MVR
       •       maintaining institutional  controls that restrict site access and limit potential human
              exposure to contaminants
       •       performing five-year site  reviews

3.6.3 Statutory Determinations for AOC SD-5/FS-5

The selected remedy is consistent with CERCLA, and to the extent practicable, the NCP, is protective of
human health and the environment,  complies with federal and Commonwealth of Massachusetts requirements
that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The remedy utilizes permanent solutions and alternative treatment technologies to the maximum extent
practicable. In addition, the remedy satisfies the statutory preference for treatment that reduces
toxicity, mobility, or volume as a principal element.

Because the risk assessment at AOC SD-5/FS-5 was premised on restricted future site use, hazardous
substances may remain on site at concentrations greater than those consistent with unrestricted site use.
Therefore, a review will be conducted within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of human health and the environment and at
five-year intervals thereafter.

4.0 DECLARATION

The foregoing represents the decision for remedial action at the AOCs FTA-2/LF-2, PFSA/FS-10/FS-ll,
SD-2/FS-6/FS-8, SD-3/FTA-3/CY-4, SD-4,  and SD-5/FS-5 Source Areas by AFCEE and the U.S. Environmental
Protection Agency, with the concurrence of the Commonwealth of Massachusetts Department of Environmental
Protection.

Concur and recommend for immediate implementation:

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                                 1.0 SITE NAME, LOCATION, AND DESCRIPTION

This Record of Decision addresses past releases of contaminants to soil and sediment at the following  six
Areas of Contamination  (AOCs) at the Massachusetts Military Reservation  (MMR) on Cape Cod, Massachusetts:

              Fire Training Area No.  2  and Landfill No. 2 (FTA-2/LF-2)
              Petroleum Fuels Storage Area,  Fuel Spill No. 10,  and Fuel Spill No.11 (PFSA/FS-10/FS- 11)
              Storm Drainage Ditch No.  2,  Fuel Spill No. 6,  and Fuel Spill No. 8 (SD-2/FS-6/FS-8)
       •      Storm Drainage Ditch No.  3,  Fire Training Area No. 3,  and Coal Storage Yard No.  4
              (SD-3/FTA-3/CY-4)
              Storm Drainage Ditch No.  4 (SD4),  and
              Storm Drainage Ditch No.  5 and Fuel Spill No.  5 (SD-5/FS-5)

Groundwater contamination associated with these AOCs is being addressed as part of  separate studies and
response actions, such as the Plume Response Plan. Actions implemented as a result  of this Record  of
Decision will support future groundwater remedial actions by minimizing future groundwater contamination.

MMR is located on western Cape Cod in Barnstable County, Massachusetts, approximately 60 miles south of
Boston and immediately southeast of the Cape Cod Canal. It occupies approximately 22,000 acres within  the
towns of Bourne, Falmouth, Mashpee, and Sandwich  (Figure 1-1 in Appendix A). The six AOCs addressed by
this Record of Decision are all located within an approximate 800 acre area at the  extreme southeast edge
of MMR  (Figure 1-2 in Appendix A).

MMR is a National Priorities List  (NPL) site under the Comprehensive Environmental  Response,
Compensation, and Liability Act of 1980 (CERCLA). Private sector sites placed on the NPL are eligible  to
receive funding for clean up from the nation's environmental trust fund  (i.e., Superfund). Federal
military facilities such as MMR receive funding from the Department of Defense. These six AOCs are
considered subsites to the entire installation.

A more complete description of MMR and these six AOCs can be found in the Phase I Records Search prepared
by E.G. Jordan Co. in 1986 and in the following Remedial Investigation  (RI) reports:

              Final Remedial Investigation Report Fire Training Area No. 2 (FTA-2)  and Landfill No.2
              (LF-2)(ABB Environmental  Services,  Inc.  [ABB-ES],  1996a)

       •      Final Remedial Investigation Report Petroleum Fuels Storage Area (Including AOCs Fuel Spill
              No.  10 [FS-10]  and Fuel Spill No.  11 [FS-11) (ABB-ES,  1996b)

       •      Final Remedial Investigation Runway/Aircraft Maintenance Storm Drainage Ditch No. 2
              (AOCs SD-2/FS6/FS-8)(ABB-ES,  1996c)

       •      Final Remedial Investigation Report Stormwater Drainage Ditch No.  3 (SD-3),  Former Fire
              Training Area No.  3 (FTA-3),  and Coal Yard No.  4   (CY-4)(ABB-ES,  1996d)

       •      Remedial Investigation Report for Area of Contamination SD-4(COM Federal Programs
              Corporation [COM],  1996).

       •      Final Remedial Investigation Stormwater Drainage  Disposal Site No.  5  (SD-5)  Including
              Fuel Spill No.  5 (FS-5)(ABB-ES,  1996e)

These reports are available for review at the main libraries in the towns of Bourne, Falmouth, Mashpee,
and Sandwich; at the U.S. Coast Guard library at MMR.

                              2.0 MMR SITE HISTORY AND ENFORCEMENT ACTIVITIES

This section provides a summary of land use and CERCLA enforcement history at MMR.

2.1 LAND USE AND RESPONSE HISTORY

Although military activity began at MMR as early as 1911, most  operations occurred  after 1935 and
consisted of two general types:  (1) mechanized army training and maneuvers; and  (2) military aircraft
operations, maintenance, and support. Intensive army activity occurred with the onset of World War II,
and continued through demobilization following the war  (1940-1946). Major aircraft  operations were
associated with surveillance and air defense aircraft and occurred from 1955 to 1970. Although aircraft
operations continue today, the greatest potential for release of contaminants to the environment was
between 1940 and 1970. Tenants at MMR include, or have included, the U.S. Coast Guard, Army National

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Guard  (Camp Edwards), U.S. Air Force, Air National Guard  (Otis Air National Guard Base), Veterans
Administration National Cemetery, U.S. Marine Corps, U.S. Department of Agriculture, and the Commonwealth
of Massachusetts. The U.S. Air Force managed MMR until 1973, when base management was transferred to the
Air National Guard.

MMR activities that had the potential to contaminate the environment included the storage, handling, and
disposal of solvents and petroleum fuels, as well as the leakage of these materials into stormwater
drainage systems and the sanitary sewer system. Landfill operations, firefighter training, coal and ash
storage, and numerous chemical and fuel spins also resulted in environmental contamination.

2.2 ENFORCEMENT HISTORY

On November 21, 1989, the U.S. Environmental Protection Agency (USEPA) placed MMR on the NPL under
CERCLA, as amended by the Superfund Amendments and Reauthorization Act of 1986  (SARA),  to evaluate and
implement response actions to clean up past releases of hazardous substances, pollutants, and
contaminants. A Federal Facility Agreement between the Department of Defense, National Guard Bureau
(NGB),  U.S. Coast Guard, and USEPA, was signed in 1991 and updated in 1997. The Federal Facility
Agreement established a procedural framework for ensuring that appropriate response actions are
implemented and reguired the Air National Guard to take the lead in cleanup activities at MMR, including
these six AOCs which are considered subsites to the entire installation. The Air Force Center for
Environmental Excellence  (AFCEE)  is the current Administrator of the Federal Facility Agreement at MMR.

In response to environmental contamination at MMR, the Department of Defense implemented its multiphase
Installation Restoration Program (IRP) at MMR to identify and evaluate problems associated with past
releases of hazardous substances. The IRP parallels the USEPA CERCLA investigation and cleanup process.
The Air National Guard, and subseguently AFCEE, followed USEPA guidelines for most IRP investigations
performed between 1986 and 1989,  and for all investigations performed since 1989.

In 1986, an extensive records search and review of available soil and groundwater data identified 73
areas at MMR as having potential for contamination. Four additional areas were later identified through
anonymous sources and unrelated base construction projects, bringing the total to 77. The investigative
history of the six AOCs addressed in this Record of Decision is presented in the individual RI reports
fisted in Section 1.0 and summarized for each AOC in Section 7.0.

AFCEE's Proposed Plan for remedial action for contaminant source areas at each of the six AOCs was issued
in November 1997 for public comment. Technical comments presented during the public comment period are
included in the Administrative Record. The Responsiveness Summary, Appendix C to this Record of Decision,
contains a summary of these comments and AFCEE's responses, and describes how these comments affected the
remedial action decision for each AOC.

                                 3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION

The NGB and AFCEE have held regular informational meetings, issued fact sheets, and held public meetings
to keep the community and other interested parties informed of activities at the six AOCs covered in this
Record of Decision.

Throughout MMR's history, community concern and involvement have been high. The NGB, AFCEE, USEPA, and
Massachusetts Department of Environmental Protection (MADEP) have kept the community and other interested
parties apprised of site activities through informational meetings, fact sheets, news releases, public
hearings, and Technical Environmental Affairs Committee  (TEAC) meetings. The TEAC was organized in 1986
by the NGB to provide a forum for public input on the MMR response activities. Membership on the TEAC
comprises USEPA, MADEP, and representatives from local, regional, and state groups. Beginning with the
October 7, 1992, TEAC meeting, members of the public could attend these bimonthly meetings.

During May 1991, an MMR community relations plan was released that outlined a program to address
community concerns and keep citizens informed and involved in the remediation process at MMR. In July
1994, and again in December 1996, an updated draft community relations plan was issued to incorporate
concerns and feedback provided by the community, and to document changes in AFCEE policy.

In October 1993, a Senior Management Board was created to advise AFCEE on IRP activities. A select person
from each of the four towns surrounding MMR is among the Board members, along with representatives of
USEPA,  MADEP, and the Adjunct General's office of the Commonwealth of Massachusetts. Process Action Teams
(PATs)  were also created to address specific issues at MMR, including plume containment, long-range water
supplies, innovative technologies,  and public information. The PATs have representation from the
community, local business, regulatory agencies, and AFCEE.

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AFCEE published a notice and brief analysis of the Proposed Plan in the "Falmouth and Mashpee
Enterprises" on October 31, 1997, the "Cape Cod Times" on November 3, 1997, and the "Bourne and Sandwich
Enterprises" on November 7, 1997. On November 13, 1997, AFCEE made the RI reports, the Feasibility Study,
and the Proposed Plan available for public review at the U.S. Coast Guard library at MMR and the main
public libraries in Bourne, Falmouth, Mashpee, and Sandwich, Massachusetts. The Proposed Plan has also
been made part the administrative record available for public review at the AFCEE IRP office at MMR and
the Falmouth Public Library.

From November 13, 1997, to January 15, 1998, AFCEE held a 60-day public comment period to accept public
comments on the remedial action alternatives presented for the six AOCs in the Proposed Plan, On November
13, 1997, AFCEE held a public meeting at the Administration Building at the Barnstable County Fairgrounds
in Barnstable, Massachusetts, to present and discuss the Proposed Plan. On December 2, 1997, AFCEE held a
public hearing to accept verbal comments on the Proposed Plan. Several residents and local officials
attended the hearing and provided verbal comments. AFCEE's responses to the comments received at the
hearing and during the public comment period are included in Appendix C. A transcript of the December 2,
1997, public hearing is included in Appendix D.

                                       4.0 EVALUATION OF SITE RISKS

Each of the RI reports for the six AOCs included a Preliminary Risk Assessment (PRA) ,  performed in
accordance with the MMR Risk Assessment Handbook  (Automated Sciences Group, Inc.[ASG], 1994). The PRAs
evaluated the probability and magnitude of potential human-health and environmental effects associated
with exposure to contaminated media at the subject AOC. The human-health risk assessment followed a
four-step process: (1) contaminant identification, which identified those hazardous substances that,
given the specifics of the site, were of significant concern; (2) exposure assessment, which identified
actual or potential exposure pathways, characterized the potentially exposed populations, and determined
the extent of possible exposure; (3)  toxicity assessment,  which considered the types and magnitude of
adverse health effects associated with exposure to hazardous substances; and  (4)  risk characterization,
which integrated the three earlier steps to summarize the potential and actual risks posed by hazardous
substances at the site, including carcinogenic and noncarcinogenic risks. A detailed discussion of the
human-health risk assessment approach is presented in the MMR Risk Assessment Handbook (ASG, 1994) and in
the individual RI reports. PRA results are presented in the individual RI reports listed in Section 1.0,
summarized in the Feasibility Study report, and discussed in Section 7.0 of this Record of Decision.

Potential human-health effects associated with exposure to the contaminants of potential concern were
estimated guantitatively or qualitatively through the development of several hypothetical exposure
pathways. The MMR Risk Assessment Handbook developed exposure pathways to reflect the potential for
exposure to hazardous substances based on the present uses, potential future uses, and location of the
AOC at MMR. Consistent with the MMR Risk Assessment Handbook, the potential for human exposure to
contaminated media was considered to be less for locations within the flightline than for locations
outside the flightline. This is because access to areas within the flightline area is controlled with
fences and guard posts, and activities not related to aircraft operations are limited and strictly
controlled. The MMR Risk Assessment Handbook indicates that a current and future utility worker exposure
scenario is appropriate for areas within the flightline, while current older child trespasser and future
residential scenarios are appropriate for areas outside the flightline. The evaluated pathways for each
AOC are listed in the risk assessment summaries presented in Section 7.0 of this Record of Decision.

Excess lifetime cancer risks were determined for each exposure pathway by multiplying the exposure level
by the chemical-specific cancer slope factor. Cancer slope factors have been developed by USEPA from
epidemiological or animal studies to reflect a conservative "upper bound" of the risk posed by
potentially carcinogenic chemicals. That is, the true risk is unlikely to be greater than the risk
predicted. The resulting risk estimates are expressed in scientific notation as a probability (e.g., 10
-6 for 1/1,000,000) and indicate (using this example), that an average individual is not likely to have
greater than a one in a million chance of developing cancer over 70 years as a result of site-related
exposure to the chemical at the stated concentration. Current USEPA practice considers carcinogenic risks
to be additive when assessing exposure to a mixture of hazardous substances.

The hazard index  (HI) was also calculated for each pathway as a measure of the potential for
noncarcinogenic health effects. The HI is the sum of hazard quotients  (HQs) for individual chemicals with
similar exposure pathways and toxic endpoints. An HQ is calculated by dividing the exposure level by the
reference dose (RfD)  or other suitable benchmark for noncarcinogenic health effects for an individual
chemical. RfDs have been developed by USEPA to protect sensitive individuals over the course of a
lifetime. They reflect a daily exposure level that is likely to be without an appreciable risk of an
adverse health effect. RfDs are derived from epidemiological or animal studies and incorporate
uncertainty factors to help ensure that adverse health effects will not occur. The HQ is often expressed
as a single value  (e.g., 0.3) indicating the ratio of the stated exposure to the RfD value  (in this

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example, the exposure as characterized is approximately one-third of an acceptable exposure level for the
given chemical).  The HQ is only considered additive for chemicals that have the same or similar toxic
endpoint; for example: the HQ for a chemical known to produce liver damage should not be added to a
second whose toxic endpoint is kidney damage.

Ecological PRAs were performed for all of the AOCs except AOC PFSA/FS-10/FS-ll.  A gualitative evaluation
concluded that potential ecological receptors are unlikely to be exposed to fuel-contaminated soil at AOC
PFSA/FS-10/FS-ll because of a lack of suitable habitat. Therefore, because the exposure pathway is not
complete, a quantitative ecological risk assessment was not conducted.

The ecological PRAs were also performed in accordance with the MMR Risk Assessment Handbook (ASG, 1994).
His were calculated for model species to evaluate potential risks from exposure to surface soils and
sediments. The PRAs did not identify ecological receptors for groundwater exposure, and this pathway was
not evaluated.

A detailed discussion of the ecological risk assessment approach and results is presented in the risk
assessment sections of the individual RI reports, summarized in the Feasibility Study report,  and
discussed in Section 7.0 of this Record of Decision.

                                      5.0 SOIL TARGET CLEANUP LEVELS

Soil Target Cleanup Levels (STCLs) (Hazardous Waste Remedial Actions Program [HAZWRAP],  1996)  developed
for the Drainage Structure Removal Program (DSRP) at MMR were used as target cleanup levels for the six
AOCs. The STCLs were developed to be protective of human health and the environment, and they are
considered applicable to the six AOCs addressed in this Record of Decision. Separate listings are
provided for organics with a water organic-carbon partition coefficient (K oc)  of less than 1,000 (i.e.,
those considered to have potential to leach to groundwater); organics with a K oc greater than 1,000; and
inorganics. The STCLs for protection of human health differentiate between locations inside and outside
the flightline, based on the reduced potential for human exposure within the flightline area,  and on
contaminant depth  (zero to 2 feet below ground surface [bgs] and zero to 15 feet bgs),  based on reduced
potential for exposure at greater depths. The STCLs for protection of ecological receptors are based only
on exposure to soil with a depth of zero to 2 feet bgs.

The STCLs for inorganics were, in general, set egual to the lowest of the following four risk-based
concentration values:

       •      for human health,  concentrations back-calculated to represent a 1x10 -6 cancer risk under
              the MMR Risk Assessment Handbook Tier I  exposure assumptions
       •      for human health,  concentrations back-calculated to represent a noncancer  HQ of  0.2 under
              the MMR Risk Assessment Handbook Tier I  exposure assumptions
       •      for ecological  receptors (mammals),  the  lowest of the hazard equivalent concentrations
              calculated for  each of  four indicator species (mouse,  vole,  shrew,  and fox)  under the   MMR
              Risk Assessment Handbook Tier I and II exposure assumptions
       •      for ecological  receptors (birds),  the lowest of the hazard equivalent concentrations
              calculated for  each of  five indicator species (sandpiper,  sparrow,  harrier,  owl,  and
              cardinal)  under the MMR Risk Assessment  Handbook Tier I  and  II  exposure assumptions

The exceptions to this were lead, for which the Massachusetts Contingency Plan (MCP) S-l/GW-1 soil
standard  (i.e., the standard for soil with the greatest potential for exposure and associated with
current or potential drinking water source areas) was used in one of five instances, and zinc,  for which
a Massachusetts upper confidence limit was used in three of five instances. STCLs were set at background
concentrations if risk-based concentrations were less than background.

The STCLs for organics were,  in general, also set equal to the lowest of the four listed risk-based
concentration values, if available. In addition, for organics with K oc of less than 1,000, STCLs were
based on federal Maximum Contaminant Levels  (MCLs) for drinking water if that approach yielded more
stringent results. In instances when risk-based values were not available and in a limited number of
other circumstances, the MCP S-l/GW-1 and S-3/GW-1 standards and Massachusetts upper confidence limits
were also considered.

Based on the foregoing approach, the use of the DSRP STCLs as target cleanup concentrations is considered
protective of human health and the environment at MMR. The following procedure,  based on the DSRP STCL
document, was used to identify soil cleanup levels for the six AOCs.

If the PRA did not identify human-health or ecological soil exposure risk greater than USEPA
risk-management guidelines, detected organics with a K oc of less than 1,000 were compared to

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leaching-based STCLs.  Because leaching may occur at any depth, all AOC soil data were considered in this
comparison regardless of sample depth. In addition, no differentiation was made between sites within or
outside the flightline. Total petroleum hydrocarbon (TPH)  data were compared to a STCL of 1,200 parts per
million (ppm)  for locations inside the flightline and 500 ppm for locations outside the flightline.

If the PRA identified human-health or ecological soil exposure risk, detected organics with a K oc of
less than 1,000 were compared to leaching-based STCLs, as described for the no-identified-risk example.
For other organics and inorganics, available data were compared to the appropriate STCL based on depth,
location (i.e., inside or outside the flightline), and whether the PRA identified potential human-health
or ecological risk. TPH data were compared to STCLs of 1,200 and 500 ppm for locations inside and outside
the flightline, respectively.

For both the no-identified-risk and identified-risk examples, if the data comparison showed that a
contaminant concentration exceeded the STCL, then the STCL was selected as the soil cleanup level for the
contaminant and was included in the remedial action objective. If no STCL exceedances were noted, soil
was no longer considered a medium of concern and a corresponding remedial action objective was not
developed.

                              6.0 DEVELOPMENT AND EVALUATION OF ALTERNATIVES

This section summarizes the statutory reguirements pertinent to making a remedial action decision and
lists the criteria used to evaluate the candidate remedial action alternatives.

6.1 STATUTORY REQUIREMENTS AND RESPONSE OBJECTIVES

Under its legal authorities, AFCEE's primary responsibility at Superfund sites is to undertake remedial
actions that are protective of human health and the environment. In addition, Section 121 of CERCLA
establishes several other statutory reguirements and preferences, including: a reguirement that the
remedial action, when complete,  must comply with all federal and more stringent state environmental
standards,  reguirements, criteria, or limitations, unless a waiver is invoked; a reguirement that a
remedial action be cost-effective and use permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable; and a preference for remedies in which
treatment permanently and significantly reduces the toxicity, mobility, or volume of hazardous substances
as a principal element. Response alternatives were developed to be consistent with these mandates.

Based on preliminary information relating to types of contaminants, environmental media of concern, and
potential exposure pathways, remedial response objectives were developed to aid in the development and
screening of remedial action alternatives. These remedial response objectives were developed to mitigate
existing and future potential threats to human health and the environment. Table 6-1 in Appendix B lists
response objectives developed for each AOC.

6.2 TECHNOLOGY AND ALTERNATIVE DEVELOPMENT AND SCREENING

CERCLA and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) set forth the
process by which remedial actions are evaluated and selected. In accordance with these reguirements,
Section 5.0 of the Feasibility Study identified, assessed, and screened technologies and process options
based on implementability and effectiveness. In Section 6.0 of the Feasibility Study, technologies and
process options remaining after screening were combined into the five candidate remedial alternatives
listed below.

       •      Alternative 1:  No  Action
       •      Alternative 2:  Limited Action
       •      Alternative 3:  Biosparging
       •      Alternative 4:  Excavation and Asphalt-batching
       •      Alternative 5:  Excavation and Offsite Treatment and Disposal

Each alternative was then evaluated and screened based on implementability and effectiveness, as
described in Section 300.430 (e)  (4) of the NCP, to assess whether any should be eliminated prior to
detailed analysis. All five remedial alternatives were retained for detailed analysis; however, as
pointed out in the Feasibility Study, all five were not evaluated in detail for each AOC. For example,
because biosparging does not treat inorganics, it was not evaluated in detail for AOCs where response
objectives included control of inorganics.

The NCP reaffirms CERCLA's preference for permanent solutions that use treatment technologies to reduce
the toxicity,  mobility, or volume of hazardous substances to the maximum extent practical. With respect
to this preference, the Feasibility Study included an alternative that uses treatment in its evaluation

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for each AOC.

6.3 ALTERNATIVE EVALUATION CRITERIA

Section 121(b)(1) of CERCLA presents several factors that, at a minimum, AFCEE is required to consider in
its assessment of remedial action alternatives. Building upon these specific statutory mandates, the NCP
articulates nine evaluation criteria to be used in assessing the individual remedial alternatives. The
nine criteria are used to select a remedy that meets the goals of protecting human health and the
environment, maintaining protection over time, and minimizing untreated waste.

Section 7.0 of the Feasibility Study report provides a detailed analysis of the alternatives using the
first seven of the nine evaluation criteria. Definitions of the nine criteria are provided below:

Threshold Criteria

The two threshold criteria described below must be met in order for an alternative to be eligible for
selection in accordance with the NCP.

Overall Protection of Human Health and the Environment This criterion assesses whether a remedy will
protect human health and the environment. This includes an assessment of how human-health and
environmental risks posed through each pathway are eliminated, reduced, or controlled through treatment,
engineering controls, or institutional controls.

Compliance with Applicable or Relevant and Appropriate Requirements (ARARs) This criterion assesses
whether a remedy complies with all federal and state environmental and facility-siting laws and
requirements that apply or are relevant and appropriate to the conditions and cleanup options at a
specific site. If an alternative can not meet an ARAR, the analysis of the alternative must provide the
rationale for invoking a statutory waiver.

Primary Balancing Criteria

The following five criteria are used to compare and evaluate the elements of alternatives that meet the
threshold criteria.

Long-Term Effectiveness and Permanence This criterion assesses the effectiveness of the alternative in
protecting human health and the environment after response objectives have been met. In addition, it
includes consideration of the magnitude of residual risks and the adequacy and reliability of controls.

Reduction of Toxicitv, Mobility, or Volume Through Treatment This criterion evaluates the effectiveness
of treatment processes used to reduce toxicity, mobility, or volume of hazardous substances. It also
considers the degree to which treatment is irreversible, and the type and quantity of residuals remaining
after treatment. SARA emphasizes that, whenever possible, a remedy should be selected that uses treatment
to permanently reduce the toxicity of contaminants at the site, the spread of contaminants away from the
source of contamination, and the volume or amount of contamination at the site.

Short-Term Effectiveness This criterion evaluates the effectiveness of the alternative in protecting
human health and the environment during the construction and implementation of a remedy until response
objectives have been met. It considers the protection of the community, workers, and the environment
during implementation of remedial actions.

Implementability This criterion assesses the technical and administrative feasibility of an alternative
and availability of required goods and services. Technical feasibility considers the ability to construct
and operate a technology and its reliability, the ease of undertaking, additional remedial actions, and
the ability to monitor the effectiveness of a remedy. Administrative feasibility considers the ability to
obtain approvals from other parties or agencies and extent of required coordination with other parties or
agencies.

Cost This criterion evaluates the capital and operation and maintenance costs of each alternative.

Modifying Criteria

The modifying criteria are used in the final evaluation of remedial alternatives, generally after AFCEE
has received public comments on the Feasibility Study and Proposed Plan.

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State Acceptance This criterion considers the state's preferences among or concerns about the
alternatives, including comments on ARARs or the proposed use of waivers.

Community Acceptance This criterion considers the community's preferences among or concerns about the
alternatives.

Following the detailed analysis of each individual alternative, AFCEE performed a comparative analysis,
focusing on the relative performance of each alternative with respect to the nine evaluation criteria.
The purpose of the comparative analysis was to identify the advantages and disadvantages of the
alternatives relative to one another and to aid in the eventual selection of a remedial alternative for
soil at each AOC. Subsection 8.1 of the Feasibility Study report presents the approach of the comparative
analysis and Subsection 8.2 of the Feasibility Study report presents the comparison of the alternatives
for each AOC. Section 7.0 of this Record of Decision summarizes the comparative analysis of alternatives
for each AOC.

7.0 DECISION SUMMARY

The following subsections present decision summaries for each AOC. Each decision summary contains
AOC-specific information concerning the topics listed below:

• Scope and Role of Response Action
• History of Land Use
• Summary of Site Characteristics
• Summary of Risks
• Description of Evaluated Alternatives
• Summary of Comparative Analysis of Alternatives
• Description of the Selected Remedy
• Statutory Determinations
• Documentation of No Significant Changes

7.1 DECISION SUMMARY FOR AOC FTA-2/LF-2

The following subsections summarize information considered during the selection of a source area remedial
action for AOC FTA-2/LF-2. A more detailed description of AOC FTA-2/LF-2 site history, contamination, and
potential site risks can be found in the Final Remedial Investigation Report Fire Training Area No. 2
(FTA-2) and Landfill No. 2 (LF-2) prepared by ABB-ES in 1996. Additional discussion concerning candidate
remedial actions to reduce site risks is contained in the final Six Areas of Contamination Source Area
Feasibility Study prepared by ABB-ES in 1997. These reports are available for review at the main
libraries in the towns of Bourne, Falmouth, Mashpee, and Sandwich; and at the U.S. Coast Guard library at
MMR.

7.1.1 Scope and Role of Response Action at AOC FTA-2/LF-2

This response action addresses source-area soil contamination at the capillary-fringe beneath and
downgradient of the location of FTA-2. By using in-situ treatment to reduce the concentration of organic
and fuel-related chemicals, the selected action will prevent those chemicals from being a source of
groundwater contamination. The response action also includes institutional controls in the form of site
access restrictions to limit potential human-health risks and five-year site reviews to assess whether
the remedy remains protective of human health and the environment. Groundwater contamination beneath and
downgradient of this AOC will be addressed as part of the Plume Response Plan.

7.1.2 History of Land Use at AOC FTA-2/LF-2

This AOC, located west of the southern end of Runway No. 5 (Figure 7-1 in Appendix A), occupies
approximately 11 acres and includes a firefighter-training area developed on top of a buried municipal
landfill. The following items summarize the history of AOC FTA-2/LF-2.

• 1940 to 1944. The landfill received domestic refuse that was burned and buried.
• 1948 to 1956. Firefighter-training exercises were conducted at FTA-2. Materials that may
have been burned include waste oils, aviation gasoline (AVGAS), jet fuel, and waste
petroleum distillate solvents.
• 1988. A Site Investigation (SI) was performed to assess the presence of contamination.
• 1989. An RI was performed to assess the nature and distribution of contamination and
evaluate potential site risks.
• 1993. A supplemental RI was performed to further characterize the nature and
distribution of contamination and evaluate potential site risks.

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• 1997. A Feasibility Study was performed to evaluate approaches to control potential site
risks.

7.1.3 Summary of Site Characteristics at AOC FTA-2/LF-2

Prior to landfilling, the topography of the AOC consisted of a prominent north-south swale connected to
the current Study Area SD-1 drainage ditch on the southern side of South Outer Road. As a result of
landfilling, the AOC no longer has a surface drainage channel and the ground surface is level to gently
sloping; incident precipitation largely infiltrates and recharges groundwater. The ground surface is
vegetated with grass and scattered trees. Two 72-inch-diameter pipes, installed in the landfill at AOC
FTA-2/LF-2 in approximately 1962, carry runoff south from AOC SD-5/FS-5 through AOC FTA-2/LF-2, and
discharge the runoff to Study Area SD-1. AOC FTA-2/LF-2 is located within the flightline security area.
Access to areas within the flightline area is controlled with fences and guard posts, and activities not
related to aircraft operations are limited and strictly controlled. Fences around the flightline areas
are inspected daily by base security. These site access restrictions are expected to remain in place
through the duration of the current lease (expiration date of 2026) and the planned 25-year renewal.

7.1.3.1 Soil Contamination Assessment.

Investigations at AOC FTA-2/LF-2 detected fuel and non-fuel-related semivolatile organic compounds
(SVOCs) and inorganics in surface and subsurface soils. Fuel-related volatile organic compounds (VOCs)
and pesticides were also identified in subsurface soils. Section 5.0 of the RI report discusses AOC
FTA-2/LF-2 soil contamination in detail (ABB-ES, 1996a).

The Task 2-3B SI soil gas survey detected trace concentrations of chlorinated solvents including
trichloroethylene (TCE), tetrachloroethylene (PCE), and/or trichloroethane in seven samples.
Dichloroethylene (DCE) was also detected in the suspected vicinity of FTA-2. Test pits completed during
the SI identified areas of burned refuse and stained soil. Soil samples from the test pits identified
lead at concentrations (e.g., 62 milligrams per kilogram [mg/kg]) significantly greater than MMR
background concentrations. Split-spoon samples collected during the SI yielded no detections for Target
Compound List (TCL) SVOCs and identified inorganics at concentrations only slightly above background.

During the Task 2-5B RI, three surface soil samples identified seven inorganics above background
concentrations. The SVOC bis(2-ethylhexyl)phthalate (BEHP), dieldrin, and TPH were identified in a single
surface sample; several SVOC tentatively identified compounds (TICs) were also detected. Subsurface soils
at AOC FTA-2/LF-2 were found to contain many of the same inorganics as the surface soils, the SVOCs
naphthalene and 2-methylnaphthalene, and the pesticide beta-benzenehexachloride.

The Task 2-5C supplemental RI provided additional information on contaminant concentrations in subsurface
soils associated with the firefighter training site (ABB-ES, 1996a). Fourteen samples from test pits and
soil borings were submitted for laboratory analyses. TCL VOCs, including ethylbenzene (up to 2,900
micrograms per kilogram [Ig/kg]) and xylenes (up to 13,000 Ig/kg) were detected in AOC FTA-2/LF-2
subsurface soils. SVOCs, primarily polynuclear aromatic hydrocarbons (PAHs), were detected in each
sample, as were various combinations of 16 Target Analyte List (TAL) inorganics. Pesticides were detected
at moderate concentrations in one sample associated with the firefighter-training site. VOC and SVOC
TICs, generally indicative of residual fuel contamination, were consistent with the TPH found in
subsurface soils.

Additionally, 14 subsurface soil samples associated with the landfill were collected during the Task 2-5C
supplemental RI. VOCs were not detected above Contract Reguired Quantitation Limits (CRQLs) in the
samples collected for analysis. SVOCs were detected in all samples except two, with the highest
concentration of PAHs detected in the southernmost sampling location. Pesticides were identified in only
two AOC FTA-2/LF-2 subsurface soil samples. Combinations of 16 TAL inorganics were detected above
background concentrations in subsurface soils, similar to the detections for surface soils. VOC and SVOC
TICs indicative of residual fuel contamination were also detected.

In summary, available data indicate that the primary soil contaminants at AOC FTA-2/LF-2 are fuel-related
VOCs and fuel and non-fuel-related SVOCs. Inorganics are secondary contaminants at the site. The highest
concentrations of VOCs and SVOCs were observed at the FTA-2 burn pit which is interpreted to be the
primary AOC-related source.

7.1.3.2 Groundwater Contamination Assessment.

Results of the AOC FTA-2/LF-2 investigations identified three potential sources of VOC and SVOC
contamination in groundwater at the AOC: FTA-2, LF-2, and the upgradient Western Aguafarm at AOC
SD-5/FS-5 (see Subsection 7.6 of this Record of Decision). Of these, AOC SD-5/FS-5 is considered the most
significant source of currently observed contamination. Groundwater sampling from the Task 2-3B SI and

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the Tasks 2-5B and 2-5C RIs identified the highest concentrations of TCL VOCs and SVOCs, and SVOC TICs
upgradient of AOC FTA-2/LF-2 (E.G. Jordan Co., 1990a, ABB-ES, 1996a). The only VOCs detected in
crossgradient or downgradient monitoring well were toluene and xylenes at concentrations below CRQLs. The
SVOCs BEHP and 4-methylphenol and fuel-related SVOC TICs were also detected at concentrations less than
those found upgradient of the AOC. However, based on an evaluation of the fate and transport of detected
contaminants, fuel-related contaminants in deep subsurface soil associated with FTA-2 have potential to
affect groundwater guality. The inorganics cadmium, chromium, arsenic, and lead were present in
groundwater samples collected downgradient of AOC FTA-2/LF-2 and are commonly derived from landfilled
materials. Cadmium (up to 10.6 micrograms per liter [Ig/L]) and lead (up to 16.8 Ig/L) were detected at
concentrations greater than their respective MCLs of 5 and 15 Ig/L in monitoring wells downgradient of
AOC FTA-2/LF-2. The RI report concluded, however, that these inorganics may have been released by
reducing conditions in the aquifer, rather than by leaching from landfill materials at LF-2.

Separation of the effects on groundwater of former firefighter-training activities, the burning of
landfill wastes, and Western Aguafarm operations is difficult because of the proximity and similarity of
the contaminant sources. Groundwater contamination at AOC FTA-2/LF-2 is discussed in detail in the
Southeast Region Groundwater Operable Unit (SERGOU) RI report(ABB-ES, 1994).

7.1.4 Summary of Risks at AOC FTA-2/LF-2

The RI report for AOC FTA-2/LF-2 included a human-health PRA to evaluate potential human-health risks
associated with exposure to contaminated surface and subsurface soil under current and future site
conditions and an ecological PRA to evaluate potential ecological risks associated with exposure to
contaminated surface soil (zero to 2 feet bgs). The following subsections summarize the human-health and
ecological PRAs. A detailed discussion of the risk assessment approach and results is presented in the
MMR Risk Assessment Handbook (ASG, 1994) and in the RI report (ABB-ES, 1996a) .

7.1.4.1 Human Health Risk Assessment Summary.

The human-health PRA was based on samples collected during the RI Data from soil samples collected from
zero to 10 feet bgs were used for the human-health PRA. Table 7-1 in Appendix B provides summary
statistics on human-health contaminants of potential concern in soil.

The human-health PRA assessed potential risks associated with the following exposure scenarios based on
the guidance of the MMR Risk Assessment Handbook and the location of AOC FTA-2/LF-2 within the
flightline:

• Current Land Use Conditions: potential utility worker exposure to surface and subsurface
soils (zero to 10 feet bgs) at maximum and exposure point mean concentrations for a
six-week period

• Future Land Use Conditions: potential utility worker exposure to surface and subsurface
soils (zero to 10 feet bgs) at maximum and exposure point mean concentrations for a
six-month period

The human-health PRA indicated that cancer and noncancer risks do not exceed regulatory risk-management
guidelines associated with shallow soil exposure for a utility worker. TPH was not quantitatively
evaluated; however, the exposure point mean concentration was less than the MCP S-2 soil standard of
2,500 mg/kg for TPH. Lead also was not quantitatively evaluated; the exposure point mean concentration
was less than the USEPA soil-screening level of 400 mg/kg and the MCP S-l soil standard of 300 mg/kg for
lead. Table 7-2 in Appendix B summarizes results of the human-health PRA.

7.1.4.2 Ecological Risk Assessment Summary.

The ecological PRA evaluated potential effects on the following receptor species: white-footed mouse,
upland sandpiper, and red fox (see Table 7-1 in Appendix B).

Mean exposure scenario His for the white-footed mouse and upland sandpiper are 2 and 10, respectively.
Maximum exposure scenario His for the white-footed mouse and upland sandpiper are 4 and 20, respectively.
His for the red fox were below 1 for both mean and maximum exposure scenarios. The major
risk-contributing contaminants of concern (COCs) include chromium and zinc for the white-footed mouse and
dieldrin, lead, and zinc for the upland sandpiper. Ecological risks were also estimated for plants based
on surface soil data. His of 10 and 5 for plants at maximum and mean exposure concentrations,
respectively, at AOC FTA-2/LF-2 exceed the designated threshold of 1. Mercury was identified as the major
risk-contributing COG to plants from surface soil exposure at AOC FTA-2/LF-2.

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Because the ecological PRA calculations involve numerous conservative assumptions, risks may be
overestimated by up to one to two orders of magnitude (ASG, 1994).  Although His at AOC  FTA-2/LF-2 exceed
the threshold of 1, consideration of the uncertainties identified in the ecological PRA suggests that the
likelihood of adverse ecological effects from exposures to surface soil contaminants at the AOC is low.
Additionally, risks from naturally occurring concentrations of inorganics were not differentiated from
those attributed to site-related contaminants. Table 7-3 in Appendix B summarizes results of the
ecological PRA, and Table 7-4 in Appendix B summarizes phytotoxicity risks.

The PRA noted that contamination at depths as shallow as 4 feet bgs warrants caution in future remedial
activities. The PRA went on to recommend that any remedial alternative resulting in significant
excavation of subsurface soil be conducted such that remnant soils from these excavations do not remain
near the surface where they could pose a risk to ecological receptors.

7.1.4.3 Comparison to Leaching-based STCLs.

To assess the potential for site soils to contaminate groundwater at concentrations of concern, AOC data
for compounds with a K oc less than 1,000 were compared to leaching-based STCLs. This comparison
indicated that ethylbenzene and total xylenes exceed leaching-based STCLs in soil downgradient of the
firefighter-training site. These exceedances help form the basis for remedial action at AOC FTA-2/LF-2.

7.1.5 Description of Evaluated Alternatives for AOC FTA-2/LF-2

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria while controlling migration of contaminants from deep soils to groundwater at AOC FTA-2/LF-2:

       •      No Action
       •      Limited Action
       •      Biosparging with Ambient Air Monitoring

7.1.5.1 No Action.

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions (security fencing and
military guard posts) that currently limit potential human    exposure to site contaminants.

        Estimated Time for Design and Construction:       not applicable
        Estimated Time for Cleanup:                       not applicable
        Estimated Capital Cost:                           $0
        Estimated Operation and Maintenance Cost          $0
        Estimated Total Cost                              $0

7.1.5.2 Limited Action.

The Limited Action alternative at AOC FTA-2/LF-2 includes the following key components:

       •      maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •      filing a Record Notice of Landfill Operation with the Registry of Deeds to document the
              location of the landfill
       •      performing five-year site reviews

        Estimated Time for Design and Construction:                not applicable
        Estimated Time for Cleanup:                                not applicable
        Estimated Capital Cost:                                    $14,000
        Estimated Operation and Maintenance Cost (Present Worth*):  $25,000
        Estimated Total Cost                                       $39,000

         *Present worth based on 7 percent discount rate for 30 years.

7.1.5.3 Biosparging with Ambient Air Monitoring.

The biosparging alternative at AOC FTA-2/LF-2 includes the following key components:

       •      mobilization and site preparation
       •      performing baseline ambient air monitoring

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       •      collecting confirmation soil samples to refine the horizontal and vertical delineation of
              the target contaminants ethylbenzene and total xylenes at the proposed cleanup location
       •      performing a pilot-scale test of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system
       •      collecting ambient air samples to assess compliance with ARARs
       •      conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen, and the target compounds of ethylbenzene and total xylenes
       •      operating and maintaining the biosparging system until cleanup criteria are met
       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      filing a Record Notice of Landfill Operation with the Registry of Deeds to document the
              location of the landfill
       •      performing five-year site reviews

        Estimated Time for Design and Construction:                     18 months
        Estimated Time for Cleanup:                                     42 months
        Estimated Capital Cost:                                         $1,512,000
        Estimated Operation and Maintenance Cost  (Present Worth*):      $442,000
        Estimated Total Cost                                            $1,954,000

               *Present worth based  on 7 percent discount rate, biosparging for 5
               years, and institutional controls and five-year reviews for 30 years

7.1.6 Summary of Comparative Analysis of Alternatives for AOC FTA-2/LF-2

The following subsections summarize  the Comparative Analysis of Alternatives performed in the Feasibility
Study for AOC FTA-2/LF-2.

7.1.6.1 Overall Protection of Human Health and the Environment.

Although the PRA did not identify potential human-health risks exceeding regulatory risk-management
guidelines, it assumed the presence  of site access restrictions that would not be maintained under the No
Action alternative. Therefore, the No Action alternative is not considered protective of human health. In
addition, it does not include measures to protect groundwater guality. Unlike the No Action alternative,
the Limited Action alternative would provide institutional controls to limit potential future exposure.
It does not, however, include measures to protect groundwater guality. In comparison, the Biosparging
alternative includes both institutional controls to limit potential future exposure and treatment
measures to protect groundwater guality. Conseguently, it would be protective under both current and
future conditions.

7.1.6.2 Compliance with Applicable or Relevant and Appropriate Reguirements.

The No Action and Limited Action alternatives do not include remedial actions that would trigger ARARs.
The Biosparging alternative would be designed, built, and operated to comply with all ARARs. Therefore,
no waivers would be reguired.

7.1.6.3 Long-term Effectiveness and  Permanence.

Because the No Action alternative does not include institutional controls to limit potential future
exposure or treatment measures to protect groundwater guality, it does not offer long-term effectiveness
at protecting human health or the environment. The Limited Action alternative includes institutional
controls, but does not include treatment measures to protect groundwater guality, and, therefore, does
not offer long-term effectiveness at protecting human health or the environment. Because the Biosparging
alternative includes institutional controls to limit potential future exposure and treatment measures
that will permanently reduce the concentration of soil contaminants, thereby protecting  groundwater
guality, it offers both long-term effectiveness and permanence at protecting human health and the
environment.

7.1.6.4 Reduction of Toxicity, Mobility, or Volume Through Treatment.

Neither the No Action nor Limited Action alternative provides treatment to reduce the toxicity, mobility,
or volume of contaminants. The Biosparging alternative provides treatment that will permanently reduce
the concentration of contaminants.

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7.1.6.5 Short-term Effectiveness.

Neither the No Action nor Limited Action alternative includes actions that would result in adverse
short-term effects to human health or the environment. Construction activities and subsequent operation
and maintenance activities associated with the Biosparging alternative would offer minimal short-term
risks. The development of and adherence to a site-specific Health and Safety Plan would minimize
potential risks to workers. Because there is no current exposure to contamination, there is no
corresponding short-term risk. In summary, all three alternatives offer good short-term effectiveness.

7.1.6.6 Implementability.

The technical and administrative feasibility of all three alternatives is considered high. Neither the No
Action nor Limited Action alternative includes actions that require substantial technical or
administrative resources. Biosparging is a relatively new technology; however, it has been proven at
other sites, and availability of equipment and expertise is increasing.

7.1.6.7 Cost.

Operation and maintenance costs were estimated on an annual basis, and are lowest for the No Action
alternative, which does not provide any long-term maintenance or monitoring. Estimated operation and
maintenance costs are greatest for the Biosparging alternative.

The following table compares capital, operation and maintenance, and present worth costs for each
alternative evaluated, in detail for AOC FTA-2/LF-2.

Total Total O&M Total Costs
Alternative Capital Cost (Present Worth*) (Present Worth)

No Action $0 $0 $0
Limited Action $14,000 $25,000 $39,000
Biosparging $ 1,512,000 $442,000 $1,954,000

*Present worth based on 7 percent discount rate.

7.1.6.8 State Acceptance.

The Commonwealth of Massachusetts has reviewed the RI and Feasibility Study reports and the Proposed Plan
and concurs with AFCEE's selected remedy.

7.1.6.9 Community Acceptance.

During the public comment period on the Proposed Plan, AFCEE received several comments concerning the
effectiveness of biosparging. AFCEE's responses to these comments are contained in the Responsiveness
Summary which is included in Appendix C to this Record of Decision. Based on the number and content of
the comments, AFCEE believes that there is general acceptance of biosparging as a treatment alternative
for AOC FTA-2/LF-2.

7.1.7 Description of the Selected Remedy for AOC FTA-2/LF-2

The selected remedy for AOC FTA-2/LF-2 is Biosparging with Ambient Air Monitoring. This alternative
provides institutional and engineering controls to limit exposure to site-related contaminants and to
reduce source-area contaminant concentrations to protective levels. The remedy does not include a
management of migration component. Groundwater contamination beneath and downgradient of the AOC will be
addressed as part of the Plume Response Plan. Figure 7-2 in Appendix A shows the location for remedial
action at AOC FTA-2/LF-2.

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7.1.7.1 Soil Cleanup Levels.

Based upon data developed in the RI and the PRA and summarized in the Feasibility Study, remedial actions
to address risk associated with possible exposure to source-area soils at AOC FTA-2/LF-2 are not
warranted because present and future human-health risks are within or below USEPA's acceptable
carcinogenic risk range or for noncarcinogens, generally below an HI of 1. Further, although His in the
ecological PRA exceed 1, consideration of the identified uncertainties suggests that the likelihood of
adverse ecological effects is low.

Available data suggest that source-area soils may be a source of release of VOCs to groundwater. Such a
release could result in an unacceptable risk to those who drink groundwater at or downgradient of the
source area. Therefore, the STCLs established for the DSRP at MMR were used to estimate residual soil
levels that will be protective of future groundwater guality (see Section 5.0 of this Record of
Decision). The following table summarizes the STCLs reguired to protect human health and groundwater
guality for the groundwater contaminants of concern at this AOC.

        Contaminants           STCL            Basis for Selection

       Ethylbenzene        700 Ig/kg           Leaching-based
       Total Xylenes       10,000 Ig/kg        Leaching-based

The STCLs are consistent with ARARs for groundwater, attain USEPA's risk-management goal for remedial
actions, and have been determined by AFCEE, USEPA, and MADEP to be protective. These cleanup levels must
be met at the completion of the remedial action at the limits of STCL excellence established during
predesign confirmation soil sampling.

7.1.7.2 Description of Remedial Components.

The selected remedy for AOC FTA-2/LF-2 is Biosparging with Ambient Air Monitoring. Collection and
treatment of biosparging off-gas is not anticipated as part of this alternative; however,  ambient air
monitoring will be performed to confirm compliance with ARARs.  Key components of this alternative
include:

       •      mobilization and site preparation
       •      performing baseline ambient air monitoring
       •      collecting confirmation soil samples to refine the horizontal and vertical delineation of
              the target contaminants ethylbenzene and total xylenes at the proposed cleanup location
       •      performing a pilot-scale test of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system
       •      collecting ambient air samples to assess compliance with ARARs
       •      conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen,  and the target compounds  of ethylbenzene and total xylenes
       •      operating and maintaining the biosparging system until cleanup criteria are  met
       •      maintaining institutional controls that restrict  site access and limit potential human
              exposure to contaminants
              filing a Record Notice of Landfill Operation with the Registry of Deeds to document the
              location of the landfill
       •      performing five-year site reviews

Each of these components is described in the following paragraphs.

Mobilization and site preparation. Mobilization and site preparation will include procuring  necessary
subcontractors, purchasing eguipment, making arrangements for performing work adjacent to the runway,
identifying underground utilities, clearing brush and trees, and constructing temporary access roads.

Performing baseline ambient air monitoring. Pre-construction ambient air monitoring will be necessary to
provide baseline air guality data at AOC FTA-2/LF-2 to enable subseguent assessment of contaminant
emissions during biosparging pilot testing and full-scale operation.

Collecting confirmation soil samples to refine the horizontal and vertical delineation of the target
contaminants ethylbenzene and total xylenes at the proposed cleanup location. Based on available data,
biosparging is proposed for an approximate 140 by 200 feet area, just downgradient of the former
firefighter-training area to clean up ethylbenzene and total xylenes contamination exceeding STCLs. The
data also indicate this contamination is limited to an approximate two feet thick layer at or just below
the water table while the vadose zone above the capillary fringe is relatively clean. Collection of
confirmation soil samples is needed to refine the horizontal and vertical distribution of STCL

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exceedances for the target contaminants ethylbenzene and total xylenes at the proposed cleanup location.
This sampling will focus on the capillary fringe and the zone just below the water table. The details of
the sampling will be presented in the Remedial Action Work Plan (RAWP) which will be submitted to USEPA
and MADEP for review and approval prior to implementation.

Performing a pilot-scale test of biosparging to obtain site-specific data for use during full scale
design. Following the completion of confirmation soil sampling, pilot-scale testing will be performed to
obtain site-specific data for use during full-scale design. Data to be gathered includes information
useful for estimating the radius of influence of individual sparge wells, the optimal depth for placement
of sparge screens, the reguired air pressure, and for confirming that off-gas collection and treatment is
not reguired. Off-gas collection and treatment will not be reguired if estimated VOC emissions are within
the 25 ton per year VOC emission threshold of 310 Code of Massachusetts Regulations (CMR) 7.18(17). The
duration of the pilot test is anticipated to be approximately 2 weeks.

Designing and installing a full-scale biosparging treatment system. This component involves preparing
plans and specifications for full-scale design. The design plans and specifications will be submitted to
USEPA and MADEP for review and approval prior to implementation.

Collecting ambient air samples to assess compliance with ARARs. Ambient air monitoring will be performed
guarterly to assess whether operation of the biosparging system is within the 25 ton per year VOC
emission threshold of 310 CMR 7.18(17). If ambient air monitoring indicates exceedance of this threshold,
operation will be modified or off-gas collection and treatment installed to attain compliance.

Conducting guarterly performance monitoring in the form of soil sampling and analysis for carbon dioxide,
oxygen, and the target compounds of ethylbenzene and total xylenes. Quarterly performance monitoring will
be performed to assess progress toward achieving cleanup goals. This monitoring will include collection
of soil samples from the treatment zone for analysis for ethylbenzene and total xylenes. Soil gas will be
analyzed for carbon dioxide and oxygen.

Operating and maintaining the biosparging system until cleanup criteria are met. The biosparging system
will be operated and maintained until STCLs are met for ethylbenzene and total xylenes.

Maintaining institutional controls that restrict site access and limit potential human exposure to
contaminants. To limit potential human exposure to site-related contaminants, AFCEE will maintain site
access restrictions at AOC FTA-2A/F-2 that are consistent with current flightline security measures.
Institutional controls such as fences will be inspected and maintained/repaired not less than annually.
Overall protectiveness will be assessed during five-year site reviews. Alternately, if AFCEE can
demonstrate based on currently available or newly acguired data, that site access restrictions can be
relaxed or removed while protection of human health is maintained, AFCEE may petition USEPA for such a
relaxation or removal of restrictions.

Filing a Record Notice of Landfill Operation with the Registry of Deeds to document the location of the
landfill. AFCEE will file a Record Notice of Landfill Operation with the Registry of Deeds to document
the location of LF-2.

Performing five-year site review. Because the assumptions of the risk assessment at AOC FTA-2/LF-2 do not
allow unrestricted site use, and to provide an opportunity for review of the performance of the selected
remedy, AFCEE will perform five-year site reviews for AOC FTA-2/LF-2. During the five-year review, AFCEE
will review monitoring data, biosparging system operational data, and other pertinent data to assess
whether the selected remedy remains protective of human health and the environment and whether additional
remedial action is appropriate. The five-year site reviews will be performed in accordance with
applicable USEPA guidance.

7.1.8 Statutory Determinations for AOC FTA-2/LF-2

The selected remedy for AOC FTA-2/LF-2 is consistent with CERCLA and, to the extent practicable, the NCP.
The selected remedy is protective of human health and the environment, attains ARARs, and is
cost-effective. The statutory preference for treatment which permanently and significantly reduces the
toxicity, mobility, or volume of hazardous substances as a principal element is satisfied.
Additionally, the selected remedy utilizes alternative treatment technologies to the maximum extent
practicable for this site.

7.1.8.1 The Selected Remedy is Protective of Human Health and the Environment.

The selected remedy for AOC FTA-2/LF-2 will permanently reduce the risks to human health and environment
by eliminating, reducing, or controlling exposures to human and environmental receptors through
engineering and institutional controls. The principal threat at AOC FTA-2/LF-2 is leaching of organic

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chemicals from subsurface soil to groundwater. Engineering controls included in this alternative will
reduce the concentration of subsurface soil contaminants, and institutional controls will restrict site
access, resulting in reduced potential for human exposure to contaminated media.

The effectiveness of the selected alternative will be evaluated by comparing soil sampling data to STCLs
tabulated in the following table.

        Contaminants              STCL      Basis for Selection

       Ethylbenzene             700 Ig/kg     Leaching based
       Total Xylenes         10,000 Ig/kg     Leaching-based

7.1.8.2 The Selected Remedy Attains Applicable or Relevant and Appropriate Reguirements.

The selected remedy will attain all applicable or relevant and appropriate federal and state
reguirements.  No waivers are reguired. ARARs for AOC FTA-2/LF-2 were identified and discussed in the
Feasibility Study (Sections 3.0 and 7.0).  Table 7-5 in Appendix B summarizes the ARARs for the selected
remedy, including the regulatory citation, a brief summary of the reguirement,  and how it will be
attained.

7.1.8.3 The Selected Remedy is Cost-Effective.

In AFCEE's judgment, the selected remedy is cost-effective (i.e., the remedy affords overall
effectiveness proportional to its costs).  In selecting this remedy, after AFCEE identified alternatives
that are protective of human health and the environment and attain, or, as appropriate, waive ARARs,
AFCEE evaluated the overall effectiveness of each alternative according to the relevant three criteria:
long-term effectiveness and permanence; reduction in toxicity, mobility, or volume through treatment; and
short-term effectiveness, in combination.  The relationship of the overall effectiveness of this remedial
alternative was determined to be proportional to its costs.

    The costs of this remedial alternative are:

        Estimated Capital Cost                                                 $1,512,000
        Estimated Operation and Maintenance Cost (Present Worth*)                $442,000
        Estimated Total Cost                                                   $1,954,000

               *Present worth based on 7 percent discount rate, biosparging for 5
               year and institutional controls and five-year reviews for 30 years.

7.1.8.4 The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment or Resource Recovery
         to the Maximum Extent Practicable.

After AFCEE identified those alternatives that attain or, as appropriate, waive ARARs and that are
protective of human health and the environment, AFCEE determined which alternative made use of permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable. This determination was made by deciding which one of the identified alternatives provides
the best balance of tradeoffs among alternatives in terms of;  (1) long-term effectiveness and permanence;
(2) reduction of toxicity, mobility or volume through treatment;  (3) short-term effectiveness; (4)
implementability; and (5) cost. The balancing test emphasized long-term effectiveness and permanence and
the reduction of toxicity, mobility, or volume through treatment and considered the preference for
treatment as a principal element, the bias against offsite land disposal of untreated waste, and
community and state acceptance. AFCEE believes the selected remedy provides the best balance of tradeoffs
among the alternatives that are protective and attain ARARs.

7.1.8.5 The Selected Remedy Satisfies the Preference for Treatment Which Permanently and Significantly
        Reduces the Toxicity, Mobility, or Volume of Hazardous Substances as a Principle Element.

The principal element of the selected remedy is biosparging.  This element addresses the principal threat
at the AOC, contamination of subsurface soils with organic compounds that have potential to leach to
groundwater. The selected remedy satisfies the statutory preference for treatment as a principal element
by providing treatment to biologically degrade the organic compounds to concentrations at or below
cleanup goals.

7.1.9 Documentation of No Significant Changes for AOC FTA-2/LF-2

AFCEE presented a Proposed Plan  (preferred alternative) for remedial action at AOC FTA-2/LF-2 source
areas at a public information meeting held at the Barnstable County Fairgrounds in Falmouth,

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Massachusetts, on November 13, 1997, and at a public hearing held at Mashpee High School in Mashpee,
Massachusetts, on December 2, 1997. There have been no significant changes made to the Biosparging with
Ambient Air Monitoring preferred alternative presented in the Proposed Plan.

7.2 DECISION SUMMARY FOR AOC PFSA/FS-10/FS-ll

The following subsections summarize information considered during the selection of source-area remedial
action for AOC PFSA/FS-10/FS-ll. A more detailed description of AOC PFSA/FS-10/FS-ll site history,
contamination, and potential site risks can be found in the Final Remedial Investigation Report Petroleum
Fuels Storage Area (Including AOCs Fuel Spill No. 10 [FS-10] and Fuel Spill No. 11 [FS-11] ) prepared by
ABB-ES in 1996. Additional discussion concerning candidate remedial actions to reduce site risks is
contained in the final Six Areas of Contamination Source Area Feasibility Study prepared by ABB-ES in
1997. These reports are available for review at the main libraries in the towns of Bourne, Falmouth,
Mashpee, and Sandwich; and at the U.S. Coast Guard library at MMR.

7.2.1 Scope and Role of Response Action at AOC PFSA/FS-10/FS-ll

This response action addresses source-area soil contamination in the vadose zone and at the capillary
fringe beneath and downgradient of the location of the PFSA. By using in-situ treatment to reduce the
concentration of organic and fuel-related compounds, the selected action will prevent those compounds
from being a source of groundwater contamination. The response action also includes institutional
controls in the form of site access restrictions to limit potential human-health risks and five-year site
reviews to assess whether the remedy remains protective of human health and the environment. Groundwater
contamination beneath and downgradient of this AOC will be addressed as part of the Plume Response Plan.

7.2.2 History of Land Use at AOC PFSA/FS-10/FS-ll

The PFSA, located on the north side of South Outer Road (Figure 7-3 in Appendix A), has been the main
fuel delivery and distribution area for the flightline since the early 1950s. The following items
summarize the history of AOC PFSA/FS-10/FS-ll.

• Early 1950s to Present. The PFSA operated as the main fuel delivery and distribution area
for the flightline.
1960s. FS-10 and FS-11 occurred at the PFSA. FS-10 was a 2,000-gallon jet fuel spill in
one of the pumphouses. FS-11 was an approximate 2,000-gallon fuel spill from overfilling
one of the tanks.
• 1985 and 1986. Field investigations assessed the presence of soil and groundwater
contamination at PFSA and evaluated site risks.
• 1989. An RI was performed to characterize the nature and distribution of sediment, deep
soil, and groundwater contamination.
• 1993. The fuel distribution lines at the PFSA were upgraded from below ground to an
aboveground system. Approximately 11 cubic yards (cy) of fuel-contaminated soil was
excavated from around the below-ground fuel lines during construction activities.
• 1994. A supplemental RI was performed to further characterize groundwater contamination and
evaluate potential site risks.
• 1994. Four 50,000-gallon underground storage tanks were removed from the PFSA.
• June 1996. Heavy rain and a pump failure at the PFSA caused 6,000 gallons of
fuel-contaminated water to spill from a fuel pumphouse (Building 172). Of the 6,000
gallons, about 300 gallons was diesel and/or jet fuel. Because of high stormwater flows,
some fuel discharged to SD-2 south of the PFSA. In response to the spill, 480 cy of
fuel-contaminated soil was removed from the PFSA, and 120 cy of fuel-contaminated soil was
excavated from the SD-2 drainage ditch as part of an Immediate Response Action performed
under the MCP. The excavated soils were transported off site to Bardon Trimount of
Stoughton, Massachusetts for asphalt-batching. A soil vapor extraction system has been
installed as part of the Immediate Response Action to remove additional contamination
associated with the spill.
• 1997. A Feasibility Study was performed to evaluate approaches to control potential site
risks.

7.2.3 Summary of Site Characteristics at AOC PFSA/FS-10/FS-ll

The PFSA is an active fuel storage facility that has operated since the early 1950s (E.G. Jordan Co.,
1986). The facility consists of three aboveground storage tanks, aboveground fuel distribution lines,
pumphouses, and truck fill stands (see Figure 7-3 in Appendix A). The tanks vary in capacity from 0.5 to
1.2 million gallons. Each aboveground tank is surrounded by a containment berm made of native sand coated
with asphalt. The ground within the berms consists of native sand and gravel. The area outside the berms

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is a combination of paved roadways and grassy areas. The PFSA serves or has served as the primary storage
and distribution center for JP-4 jet fuel, AVGAS, motor gasoline (MOGAS), and No. 2 fuel oil for MMR.

The PFSA is located on the northern side of South Outer Road inside the flightline security area. Access
to areas within the flightline area is controlled with fences and guard posts, and activities not related
to aircraft operations are limited and strictly controlled. Fences around the flightline areas are
inspected daily by base security. These site access restrictions are expected to remain in place through
the duration of the current lease (expiration date of 2026) and the planned 25-year renewal. Most of the
AOC, PFSA is surrounded by a second, inner, 7-foot-high chainlink security fence, further restricting
access. The PFSA is adjacent to the southern end of the aircraft maintenance ramp, and occupies
approximately 5 acres of relatively flat terrain at the head of the SD-2 drainage swale. Runoff from the
PFSA is collected by a storm sewer system that discharges to SD-2, located immediately southeast of the
PFSA across South Outer Road. Floodplains, wetlands, and endangered species are not known to be present
at AOC PFSA/FS-10/FS-ll.

7.2.3.1 Soil Contamination Assessment.

The RI report estimated the total volume of near-surface fuel-contaminated soil at Tanks 23 and 24 to be
no more than 1,700 cy. This estimate was based on observations of soil discoloration and fuel odors.
Maximum detected concentrations of near-surface (zero to 10 feet bgs) soil contaminants include 6.4 mg/kg
of naphthalene, 1.3 mg/kg of 2-methylnaphthalene, 11.0 mg/kg of chromium, 11.6 mg/kg of lead, and 18
mg/kg of zinc. Fuel-related contamination was not detected in surface soils at Tank 21 during the RI;
however, fuel contamination may exist at the former location of the Tank 21 valve box.

Based on observations of soil discoloration and odor, the RI report estimated that a substantially larger
volume (approximately 69,000 cy) of fuel-contaminated soil exists within the capillary-fringe/shallow
groundwater beneath AOC PFSA/FS-10/FS-ll. This contaminated zone is estimated at 4 to 5 acres in extent,
with an average thickness of approximately 10 feet. Downgradient of the aboveground storage tanks,
maximum concentrations of the primary contaminants in capillary-fringe soils are 7.8 mg/kg of
ethylbenzene, 67 mg/kg of total xylenes, 2.5 mg/kg of naphthalene, and 6.6 mg/kg of 2-methylnaphthalene.
Maximum concentrations in the capillary fringe immediately downgradient of the pumphouses are 8.7 mg/kg
of ethylbenzene, 47 mg/kg of total xylenes, 0.9 mg/kg of 2-methylnaphthalene, 7.3 mg/kg of chromium, and
17.2 mg/kg of vanadium.

An estimated 1/8-inch of floating fuel free product was reported at the water table in monitoring well
MW-316 in August 1995 (Aker, 1995). This thickness is at the lower limit of field instrument accuracy,
and the true thickness of free product may be less. Free product was not measured at 11 other nearby
monitoring wells. The NGB initiated a program to monitor free product at AOC PFSA/FS-10/FS-ll; however,
additional data had not been collected as of July 1998.

7.2.3.2 Groundwater Contamination Assessment.

Groundwater beneath and downgradient of AOC PFSA/FS-10/FS-ll was contaminated by fuel-related compounds
leaching from contaminated surface soils and sediments associated with French drains and the storm sewer
catch basin. The primary source of groundwater contamination appears to be dissolution of entrained,
residual fuel-related VOCs and SVOCs within the capillary fringe at the water table, nearly 50 feet bgs.
Annual water table fluctuations of 2 to 5 feet likely exacerbate this process.

The most prominent hydrocarbons in soils are also present in groundwater beneath or immediately
downgradient of the AOC. Maximum detected concentrations of these compounds in groundwater are
naphthalene at 98 Ig/L and 2-methylnaphthalene at 180 Ig/L. Ethylbenzene and total xylenes were reported
at estimated concentrations of 380 Ig/L and 3,000 Ig/L, respectively. Each maximum concentration is less
than the respective MCL. Benzene (up to 56 Ig/L) was detected above the MCL of 5 Ig/L in groundwater
samples from monitoring wells downgradient of AOC PFSA/FS-10/FS-ll in 1988, but not in 1990 (ABB-ES,
1996b). Numerous fuel-related TICs were also detected.

Dissolved inorganics were detected above drinking water MCLs and action levels in groundwater samples
collected in 1989, 1990, and 1993 beneath AOC PFSA/FS-10/FS-ll and in areas immediately downgradient from
monitoring wells MW-306, MW-307, MW-308, MW-311, and MW-316. These inorganic constituents included the
following:

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Inorganic Max Concentration (Ig/L) MCL (Ig/L)

Arsenic 67.2 50
Beryllium 6.9 4
Cadmium 7.2 5
Chromium 252 J 100
Lead 44.7 15*
Nickel 138 100

j = estimated value

* = Action level at the tap
Source: ABB-ES, 1994

In 1993, analysis of groundwater samples from AOC PFSA/FS-10/FS-ll for total inorganics showed
concentrations below MCLs for the elements listed here with the exception of cadmium (up to 7.9 Ig/L).

The SERGOU RI report concluded that biodegradation of the plume is evident. Groundwater sampling results
strongly indicate that the plume attenuates to less than detection limits prior to reaching Johns Pond
(ABB-ES, 1994). Pondwater samples and pondbed samples did not detect AOC PFSA/FS-10/FS-ll contaminants.
This investigation indicated that the eastern edge of the AOC SD-5/FS-5 chlorinated solvent plume
underlies the western part of the AOC PFSA/FS-10/FS-ll plume.

7.2.3.3 Sediment Contamination Assessment.

In the eastern part of AOC PFSA/FS-10/FS-ll, near-surface soils associated with French drains and
sediments associated with the catch basin of the storm sewer system contain potentially significant
concentrations of TPH and metals, respectively. The major contaminants at the French drains are
ethylbenzene (up to 26 mg/kg), total xylenes (up to 92 mg/kg), and naphthalene (up to 5.2 mg/kg).
Additionally, the maximum concentration of TPH is (5.8 mg/kg. Sediments in the catch basin were removed
as part of the DSRP. The French drains were removed as part of the Fuel Systems Upgrade and DSRP.

Major contaminants in the catch basin sample are chromium (10.2 mg/kg), lead (37.3 mg/kg), and zinc
(45.1 mg/kg).

7.2.4 Summary of Risks at AOC PFSA/FS-10/FS-ll

The RI report for AOC PFSA/FS-10/FS-ll included a human-health PRA to evaluate potential human-health
risks associated with exposure to contaminated surface soil under current and future site conditions. The
following subsections summarize the human-health and ecological PRAs. A detailed discussion of the risk
assessment approach and results is presented in the MMR Risk Assessment Handbook (ASG, 1994) and in the
RI report (ABB-ES, 1996b).

7.2.4.1 Human-health Risk Assessment Summary.

The PRA was based on samples collected during the SI and RI for samples from zero to 10 feet bgs. Because
the French drains and storm sewer catch basin source areas were addressed under the Fuel Systems Upgrade
and the DSRP, data for soil/sediment samples from these areas were not evaluated in the PRA. Table 7-6 in
Appendix B provides summary statistics on human-health contaminants of potential concern in soil.

• Current Land Use Conditions: potential utility worker exposure to surface soils (zero to 2
feet bgs) at maximum and exposure point mean concentrations for a six-week period

• Future Land Use Conditions: potential utility worker exposure to surface soils (zero to 2
feet bgs) at maximum and exposure point mean concentrations for a six-month period

The human-health PRA estimated that cancer and noncancer risks do not exceed regulatory
risk-management guidelines associated with shallow soil exposure for a utility worker. TPH and lead were
not quantitatively evaluated; however, of the two samples analyzed for TPK only one had a detectable
concentration, and that concentration was well below the MCP S-l soil standard. Lead was detected in all
five samples considered in the PRA. The maximum concentration was, however, well below the USEPA soil
screening level and the MCP S-l Soil Standard. Table 7-7 in Appendix B summarizes results of the
human-health PRA.

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7.2.4.2 Ecological Risk Assessment Summary.

A qualitative evaluation concluded that potential ecological receptors are unlikely to be exposed to
fuel-contaminated soil at AOC PFSA/FS-10/FS-ll because of a lack of suitable habitat. Therefore,  because
the exposure pathway is not complete, a quantitative ecological risk assessment was not conducted.

7.2.4.3 Comparison to Leaching-based STCLs.

To assess the potential for site soils to contaminate groundwater at concentrations of concern,  AOC data
for compounds with a K oc of less than 1,000 were compared to leaching-based STCLs. This comparison
indicated that ethylbenzene and total xylenes exceed leaching-based STCLs in vadose zone soil at Tanks 21
and 23, and in capillary-fringe soil south of Tank 23 and south of Buildings 170,  172, and 173.  These
exceedances are the basis for remedial action at AOC PFSA/FS-10/FS-ll.

7.2.5 Description of Evaluated Alternatives for AOC PFSA/FS-10/FS-ll

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria while controlling migration of contaminants from deep soils to groundwater at AOC
PFSA/FS-10/FS-ll:

       •      No Action
       •      Limited Action
       •      Biosparging with Off-gas Collection and Treatment

7.2.5.1 No Action.

The No Action alternative was evaluated as a baseline with which to compare other alternatives.  No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions (security fencing and
military guard posts) that currently limit potential human    exposure to site contaminants.

          Estimated Time for Design and Construction:            not applicable
          Estimated Time for Cleanup:                            not applicable
          Estimated Capital Cost:                                $0
          Estimated Operation and Maintenance Cost:              $0
          Estimated Total Cost:                                  $0

7.2.5.2 Limited Action.

The Limited Action alternative at AOC PFSA/FS-10/FS-ll includes the following key components:

       •      maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •      performing five-year site reviews

           Estimated Time for Design and Construction:                 not applicable
           Estimated Time for Cleanup:                                 not applicable
           Estimated Capital Cost:                                                 $0
           Estimated Operation and Maintenance Cost  (Present Worth*):         $25,000
           Estimated Total Cost                                               $25,000

            *Present worth based on 7 percent discount rate for 30 years.

7.2.5.3 Biosparging with Off-gas Collection and Treatment.

Capillary-fringe contamination has been identified at two of five locations at AOC PFSA/FS-10/FS-ll and
this alternative includes biosparging with a bioventing component to address that contamination.  At the
remaining three locations only shallow vadose zone contamination has been identified and only bioventing
is proposed for them. If confirmation soil sampling indicates that inclusion of a biosparging component
is appropriate, the final design will be modified to include biosparging.

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The biosparging alternative at AOC PFSA/FS-10/FS-ll includes the following key components:

       •      mobilization and site preparation
       •      performing baseline ambient air monitoring
       •      collecting confirmation soil samples at all five proposed cleanup locations to refine the
              horizontal and vertical delineation of the target contaminants  ethylbenzene and total
              xylenes
       •      performing a pilot-scale test of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system with off-gas collection
              and treatment for the two proposed cleanup locations at this AOC with capillary-fringe
              contamination
       •      designing and installing a bioventing system for the remaining  three locations identified
              for cleanup at this AOC with shallow vadose zone contamination
       •      collecting ambient air samples to assess compliance with ARARs
       •      conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen, and the target compounds of ethylbenzene and total xylenes
       •      operating and maintaining the biosparging and bioventing systems until cleanup criteria are
              met
       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      performing five-year site reviews

         Estimated Time for Design and Construction:                        18 months
         Estimated Time for Cleanup:                                        42 months
         Estimated Capital Cost:                                           $2,460,000
         Estimated Operation and Maintenance Cost  (Present Worth*):        $1,179,000
         Estimated Total Cost:                                             $3,639,000

                *Present worth based on 7 percent discount rate, biosparging for 5
                years, and institutional controls and five-year reviews for 30 years.

7.2.6 Summary of Comparative Analysis of Alternatives for AOC PFSA/FS-10/FS-ll

The following subsections summarize the Comparative Analysis of Alternatives performed in the Feasibility
Study for AOC PFSA/FS-10/FS-ll.

7.2.6.1 Overall Protection of Human Health and the Environment.

Although the PRA did not identify potential human-health risks exceeding regulatory risk-management
guidelines, it assumed the presence of site access restrictions that would not be maintained under the No
Action alternative. Therefore, the No Action alternative is not considered protective of human health. In
addition, it does not include measures to protect groundwater guality. Unlike the No Action alternative,
the Limited Action alternative would provide institutional controls to limit potential future exposure.
It does not, however, include measures to protect groundwater guality. In comparison, the Biosparging
alternative includes both institutional controls to limit potential future exposure and treatment
measures to protect groundwater guality. Conseguently, it would be protective under both current and
future exposure conditions.

7.2.6.2 Compliance with Applicable or Relevant and Appropriate Reguirements.

The No Action and Limited Action alternatives do not include remedial actions that would trigger ARARs.
The Biosparging alternative would be designed, built, and operated to comply with all ARARs. Therefore,
no waivers would be reguired.

7.2.6.3 Long-term Effectiveness and Permanence.

Because the No Action alternative does not include institutional controls to limit potential future
exposure or treatment measures to protect groundwater guality, it does not offer long-term effectiveness
at protecting human health or the environment. The Limited Action alternative includes institutional
controls, but does not include treatment measures to protect groundwater guality, and, therefore, does
not offer long-term effectiveness at protecting human health or the environment. Because the Biosparging
alternative includes both institutional controls to limit potential future exposure and treatment
measures that will permanently reduce the concentration of soil contaminants, thereby protecting
groundwater guality, it offers both long-term effectiveness and permanence at protecting human health and
the environment.

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7.2.6.4 Reduction of Toxicity, Mobility, or Volume Through Treatment.

Neither the No Action nor Limited Action alternative provides treatment to reduce the toxicity, mobility,
or volume of contaminants. The Biosparging alternative provides treatment that will permanently reduce
the concentration of contaminants.

7.2.6.5 Short-term Effectiveness.

Neither the No Action nor Limited Action alternative includes actions that would result in adverse
short-term effects to human health or the environment. Construction activities and subseguent operation
and maintenance activities associated with the Biosparging alternative would offer minimal short-term
risks. The development of and adherence to a site-specific Health and Safety Plan would minimize
potential risks to workers. Because there is no current exposure to contamination, there is no
corresponding short-term risk. In summary, all three alternatives offer good short-term effectiveness.

7.2.6.6 Implementability.

The technical and administrative feasibility of all three alternatives is considered high. Neither the No
Action nor Limited Action alternative includes actions that reguire substantial technical or
administrative resources. Biosparging is a relatively new technology; however, it has been proven at
other sites, and availability of eguipment and expertise is increasing.

7.2.6.7 Cost.

Cost includes the capital (up-front) cost of implementing an alternative and the long-term cost of
operating and maintaining the alternative. Capital and operation and maintenance costs for each
alternative were calculated with an estimated accuracy of 30 percent to +50 percent. The alternatives
with the lowest capital costs are those that include the least amount of construction, such as the No
Action and Limited Action alternatives. The Biosparging alternative, which involves construction, has the
greatest capital cost. Operation and maintenance costs were estimated on an annual basis, and are lowest
for the No Action alternative, which does not provide any long-term maintenance or monitoring. Estimated
operation and maintenance costs are greatest for the Biosparging alternative.

To enable comparison of costs which will occur over different time periods, the present worth of capital
and operation and maintenance costs was also calculated. The No Action alternative has the lowest present
worthwhile the Biosparging alternative has the greatest present worth.

The following table compares capital, operation and maintenance, and present worth costs for each
alternative evaluated in detail for AOC PFSA/FS-10/FS-ll.

Total Total O&M Total Costs
Alternative Capital Cost (Present Worth*) (Present Worth)
No Action $ 0 $ 0 $ 0
Limited Action $ 0 $ 25,000 $ 25,000
Biosparging $ 2,460,000 $ 1,179,000 $ 3,639,000

*Present worth based on 7 percent discount rate.

7.2.6.8 State Acceptance.

The Commonwealth of Massachusetts has reviewed the RI and Feasibility Study reports and the Proposed Plan
and concurs with AFCEE's selected remedy.

7.2.6.9 Community Acceptance.

7.2.7 Description of the Selected Remedy for AOC PFSA/FS-10/FS-ll

The selected remedy for AOC PFSA/FS-10/FS-ll is Biosparging with Off-gas Collection and Treatment. This
alternative provides institutional and engineering controls to limit exposure to site-related
contaminants and to reduce source-area contaminant concentrations to protective levels. The remedy does
not include a management of migration component. Groundwater contamination beneath and downgradient of

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the AOC will be addressed as part of the Plume Response Plan.

The Feasibility Study identified five distinct locations for cleanup at AOC PFSA/FS-10/FS-ll (Figure 7-4
in Appendix A) .  Two of the five proposed cleanup locations described in Subsection 4.3.3 of the
Feasibility Study are associated with capillary-fringe soils; the selected remedy provides biosparging
with a bioventing component for those areas. The other three locations contain shallow vadose-zone
contamination; this alternative provides only a bioventing component for them. Prior to cleanup
activities, confirmation sampling will be conducted at all five areas to assess the horizontal
delineation of the cleanup locations.

7.2.7.1 Soil Cleanup Levels.

Based upon data developed in the RI and the PRA and summarized in the Feasibility Study, remedial actions
to address risk associated with possible exposure to source-area soils at AOC PFSA/FS-10/FS-ll are not
warranted because present and future risks are within or below USEPA's acceptable carcinogenic risk range
or for noncarcinogens, generally below an HI of 1. However, available data suggest that source-area soils
may be a source of release of VOCs to groundwater. Such a release could result in an unacceptable risk to
those who drink groundwater at or downgradient of the source area. Therefore, the STCLs established for
the DSRP at MMR were used to estimate residual soil levels that will be protective of future groundwater
guality (see Section 5.0 of this Record of Decision). The following table summarizes the STCLs reguired
to protect human health and groundwater guality for the groundwater contaminants of concern at this AOC.

        Contaminants                      STCL                        Basis for Selection

       Ethylbenzene                   700 Ig/kg                         Leaching-based
       Total Xylenes                  10,000 Ig/kg                      Leaching-based

The STCLs are consistent with ARARs for groundwater, attain USEPA's risk-management goal for remedial
actions, and have been determined by AFCEE,  USEPA, and MADEP to be protective. These cleanup levels must
be met at the completion of the remedial action at the locations of STCL exceedance established during
predesign confirmation soil sampling.

7.2.7.2 Description of Remedial Components.

The selected remedy for AOC PFSA/FS-10/FS-ll is Biosparging with Off-gas Collection and Treatment. Key
components of this alternative include:

       •      mobilization and site preparation
       •      performing baseline ambient air monitoring
       •      collecting confirmation soil samples at all five proposed cleanup locations  to refine the
              horizontal and vertical delineation of the target contaminants  ethylbenzene  and total
              xylenes
       •      performing a pilot-scale test  of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system with off-gas collection
              and treatment for the two proposed cleanup locations at this AOC with capillary-fringe
              contamination
       •      designing and installing a bioventing system for the remaining  three locations identified
              for cleanup at this AOC with shallow vadose zone contamination
       •      collecting ambient air samples to assess compliance with ARARs
       •      conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen,  and the target compounds of ethylbenzene and total xylenes
       •      operating and maintaining the  biosparging and bioventing systems until cleanup criteria are
              met
       •      Maintaining institutional controls that restrict site access and limit potential  human
              exposure to contaminants
       •      performing five-year site reviews

Each of these components is described in the following paragraphs.

Mobilization and site preparation. Mobilization and site preparation will include procuring necessary
subcontractors,  purchasing eguipment, identifying underground utilities, clearing brush and trees, and
constructing temporary access roads.

Performing baseline ambient air monitoring.  Preconstruction ambient air monitoring will be necessary to
provide baseline air guality data at AOC PFSA/FS-10/FS-ll to enable subseguent assessment  of contaminant
emissions during biosparging pilot testing and full-scale operation.

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Collecting confirmation soil samples to refine the horizontal and vertical delineation of the target
contaminants ethylbenzene and total xylenes at the proposed cleanup location. Based on available data,
five distinct locations are proposed for cleanup at AOC PFSA/FS-10/FS-ll (see Figure 7-4 in Appendix A).
Two of the five proposed cleanup locations described in Subsection 4.3.3 of the Feasibility Study are
associated with capillary-fringe soils located approximately 45 feet bgs; the selected remedy provides
biosparging with a bioventing component for those areas. The other three locations contain shallow
vadose-zone contamination; this alternative provides only a bioventing component for them. Prior to
cleanup activities, confirmation sampling should be conducted at all five areas to confirm the horizontal
delineation of the cleanup locations. Collection of confirmation soil samples is needed to refine the
horizontal and vertical distribution of STCL exceedances for the target contaminants ethylbenzene and
total xylenes at the proposed cleanup location. The details of the sampling will be presented in the RAWP
which will be submitted to USEPA and MADEP for review and approval prior to implementation.

Performing a pilot-scale test of biosparging to obtain site-specific data for use during full-scale
design. Following the completion of confirmation soil sampling, pilot-scale testing will be performed to
obtain site-specific data for use during full-scale design. Data to be gathered includes information
useful for estimating the radius of influence of individual sparge and soil venting wells, the optimal
depth for placement of sparge screens, the reguired air pressure, and for designing off-gas collection
and treatment systems. The duration of the pilot test is anticipated to be approximately 2 weeks.

Designing and installing a full-scale biosparging treatment system with off-gas collection and treatment
for two of the proposed cleanup locations at this AOC. This component involves preparing plans and
specifications for full-scale design of biosparging systems with off-gas collection and treatment at two
subareas at AOC PFSA/FS-10/FS-ll. The biosparging design will consider potential interactions with the
extraction, treatment, and reinjection system installed as part of the SD-5 North Plume remedial action.
The design plans and specifications will be submitted to USEPA and MADEP for review and approval prior to
implementation.

Designing and installing a bioventing system for the remaining three locations identified for cleanup at
this AOC. This component involves preparing plans and specifications for full-scale design of bioventing
systems at three remaining subareas at AOC PFSA/FS-10/FS-ll. The bioventing design will consider
potential interactions with the soil vapor extraction system installed at the PFSA in response to the
1996 spill. The design plans and specifications will be submitted to USEPA and MADEP for review and
approval prior to implementation.

Collecting ambient air samples to assess compliance with ARARs. Ambient air monitoring will be performed
guarterly to assess whether operation of the biosparging and bioventing systems is within the 25 ton per
year VOC emission threshold of 310 CMR 7.18(17). If ambient air monitoring indicates exceedance of this
threshold, biosparging/bioventing and/or off-gas collection and treatment operation will be modified to
attain compliance.

Conducting guarterly performance monitoring in the form of soil sampling and analysis for carbon dioxide,
oxygen, and target compounds of ethylbenzene and total xylenes. Quarterly performance monitoring will be
performed to assess progress toward achieving cleanup goals. This monitoring will include collection of
soil samples from the treatment zone for analysis for ethylbenzene and total xylenes. Soil gas will be
analyzed for carbon dioxide and oxygen. Operating-and-maintaining the biosparging and bioventing systems
until cleanup criteria are met. The biosparging and bioventing systems will be operated and maintained
until STCLs are met for ethylbenzene and total xylenes.

Maintaining institutional controls that restrict site access and limit potential human exposure to
contaminants. To limit potential human exposure to site-related contaminants, AFCEE will maintain site
access restrictions at AOC PFSA/FS-10/FS-ll that are consistent with current flightline security
measures. Institutional controls such as fences will be inspected and maintained/repaired not less than
annually. Overall protectiveness will be assessed during five-year site reviews. Alternately, if AFCEE
can demonstrate based on currently available or newly acguired data, that site access restrictions can be
relaxed or removed while protection of human health is maintained, AFCEE may petition USEPA for such a
relaxation or removal of restrictions.

Performing five-year site reviews. Because the assumptions of the risk assessment at AOC PFSA/FS-10/FS-ll
do not allow unrestricted site use, and to provide an opportunity for review of the performance of the
selected remedy, AFCEE will perform five-year site reviews for AOC PFSA/FS-10/FS-ll. During the five-year
reviews, AFCEE will review monitoring data, biosparging and bioventing systems operational data, and
other pertinent data to assess whether the selected remedy remains protective of human health and the
environment and whether additional remedial action is appropriate. The five-year site reviews will be
performed in accordance with applicable USEPA guidance.

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7.2.8 Statutory Determinations for AOC PFSA/FS-10/FS-ll

The selected remedy for AOC PFSA/FS-10/FS-ll is consistent with CERCLA and, to the extent practicable,
the NCP. The selected remedy is protective of human health and the environment, attains ARARs, and is
cost-effective. The statutory preference for treatment which permanently and significantly reduces the
toxicity, mobility, or volume of hazardous substances as a principal element is satisfied. Additionally
the selected remedy utilizes alternative treatment technologies and resource recovery technologies to the
maximum extent practicable for this site.

7.2.8.1 The Selected Remedy is Protective of Human Health and the Environment.

The selected remedy for AOC PFSA/FS-10/FS-ll will permanently reduce the risks to human health and the
environment by eliminating, reducing, or controlling exposures to human and environmental receptors
through engineering and institutional controls. The principal threat at AOC PFSA/FS-10/FS-ll is leaching
of organic chemicals from subsurface soil to groundwater. Engineering controls included in this
alternative will reduce the concentration of subsurface soil contaminants, and institutional controls
will restrict site access, resulting in reduced potential for human exposure to contaminated media. The
effectiveness of the selected alternative will be evaluated by comparing soil sampling data to STCLs in
the following table.

Contaminants STCL Basis for Selection

Ethylbenzene 700 Ig/kg Leaching-based
Total Xylenes 10,000 Ig/kg Leaching-based

7.2.8.2 The Selected Remedy Attains Applicable or Relevant and Appropriate Reguirements.

The selected remedy will attain all applicable or relevant and appropriate federal and state
reguirements. No waivers are reguired. ARARs for AOC PFSA/FS-10/FS-ll were identified and discussed in
the Feasibility Study (Sections 3.0 and 7.0). Table 7-8 in Appendix B summarizes the ARARs for the
selected remedy, including the regulatory citation, a brief summary of the reguirement, and how it will
be attained.

7.2.8.3 The Selected Remedy is Cost-effective.

In AFCEE's judgment, the selected remedy is cost-effective (i.e., the remedy affords overall
effectiveness proportional to its costs). In selecting this remedy, after AFCEE identified alternatives
that are protective of human health and the environment and attain, or, as appropriate, waive ARARs,
AFCEE evaluated the overall effectiveness of each alternative according to the relevant three criteria:
long-term effectiveness and permanence; reduction in toxicity, mobility, or volume through treatment, and
short-term effectiveness, in combination. The relationship of the overall effectiveness of this remedial
alternative was determined to be proportional to its costs.

The costs of this remedial alternative are:

Estimated Capital Cost $2,460,000
Estimated Operation and Maintenance Cost (Present Worth*) $1,179,000
Estimated Total Cost $3,639,000

*Present worth based on 7 percent discount rate, biosparging for 5
years, and institutional controls and five-year reviews for 30 years.

7.2.8.4 The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment or Resource Recovery
to the Maximum Extent Practicable.

After AFCEE identified those alternatives that attain or, as appropriate, waive ARARs and that are
protective of human health and the environment, AFCEE determined which alternative made use of permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable. This determination was made by deciding which one of the identified alternatives provides
the best balance of tradeoffs among alternatives in terms of (1) long-term effectiveness and permanence;
(2) reduction of toxicity, mobility, or volume through treatment; (3) short-term effectiveness; (4)
implementability; and (5) cost. The balancing test emphasized long-term effectiveness and permanence and
the reduction of toxicity, mobility, or volume through treatment, and considered the preference for
treatment as a principal element, the bias against offsite land disposal of untreated waste, and
community and state acceptance. AFCEE believes the selected remedy provides the best balance of tradeoffs
among the alternatives that are protective and attain RARs.

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7.2.8.5 The Selected Remedy Satisfies the Preference for Treatment Which Permanently and Significantly
Reduces the Toxicity, Mobility, or Volume of Hazardous Substances as a Principle Element.

The principal element of the selected remedy is biosparging. This element addresses the principal threat
at the AOC, contamination of subsurface soils with organic compounds that have potential to leach to
groundwater. The selected remedy satisfies the statutory preference for treatment as a principal element
by providing treatment to biologically degrade the organic compounds to concentrations at or below
cleanup goals.

7.2.9 Documentation of No Significant Changes for AOC PFSA/FS-10/FS-ll

AFCEE presented a Proposed Plan (preferred alternative) for remedial action at AOC PFSA/FS-10/FS-ll
source areas at a public information meeting held at the Barnstable County Fairgrounds in Falmouth,
Massachusetts, on November 13, 1997, and at a public hearing held at Mashpee High School in Mashpee,
Massachusetts, on December 2, 1997. There have been no significant changes made to the Biosparging with
Off-gas Collection and Treatment preferred alternative presented in the Proposed Plan.

7.3 DECISION SUMMARY FOR AOC SD-2/FS-6/FS-8

The following subsections summarize information considered during the selection of source-area remedial
action for AOC SD-2/FS-6/FS-8. A more detailed description of AOC SD-2/FS-6/FS-8 site history,
contamination, and potential site risks can be found in the Final Remedial Investigation Runway/
Aircraft Maintenance Storm Drainage Ditch No. 2 (AOCs SD-2/FS-6/FS-8) prepared by ABB-ES in 1996.
Additional discussion concerning candidate remedial actions to reduce site risks is contained in the
final Six Areas of Contamination Source Area Feasibility Study prepared by ABB-ES in 1997. These reports
are available for review at the main libraries in the towns of Bourne, Falmouth, Mashpee, and Sandwich;
and at the U.S. Coast Guard library at MMR.

7.3.1 Scope and Role of Response Action at AOC SD-2/FS-6/FS-8

This response action addresses source-area surface soil and sediment contamination at this AOC. By
excavating and treating soil and sediment exceeding cleanup criteria, the selected action will protect
human and ecological receptors from exposure to concentrations of inorganics exceeding protective cleanup
criteria. The selected action will also prevent those compounds from being a source of groundwater
contamination and from migrating further downstream towards Ashumet Pond. Non-site-related groundwater
contamination beneath and downgradient of this AOC will be addressed as part of the Plume Response Plan.

7.3.2 History of Land Use at AOC SD-2/FS-6/FS-8

AOC SD-2/FS-6/FS-8 extends from the base boundary approximately 2,500 feet south to Ashumet Pond (Figure
7-5 in Appendix A). SD-2 receives runoff water from the PFSA, an aircraft maintenance ramp, and hangars.
The following items summarize the history of AOC SD-2/FS-6/FS-8.

• 1950s. SD-2 began receiving stormwater runoff from the PFSA, aircraft maintenance ramp,
hangar nosedocks, and other support buildings.
• Early 1960s. Two fuel spills, FS-6 and FS-8, occurred on the aircraft maintenance ramp,
resulting in the release of approximately 23,000 gallons of fuel. Both FS-6 and FS-8 were
reportedly washed into the storm sewer that discharges to SD-2.
• 1968. An oil/water separator was constructed at SD-2, south of South Outer Road.
• 1986. Field investigations evaluated surface water and sediment contamination.
• 1988. An SI was performed to assess the presence of surface water, sediment, and
groundwater contamination.
• 1989. An RI was performed to characterize the nature and distribution of sediment and
groundwater contamination.
• 1993. A supplemental RI was performed to further characterize sediment contamination and
evaluate potential site risks.
• 1996. Heavy rain and a pump failure at the PFSA caused 6,000 gallons of fuel-contaminated
water to spill from a fuel pumphouse. Of the 6,000 gallons, about 300 gallons was diesel
and/or jet fuel. Because of high stormwater flows, some fuel discharged to SD-2 south of the
PFSA. In response to the spill, 480 cy of fuel-contaminated soil was removed from the PFSA,
and 120 cy of fuel-contaminated soil was excavated from the SD-2 drainage ditch as part of
an Immediate Response Action performed under the MCP
• 1997. A Feasibility Study was performed to evaluate approaches to control potential site
risks.

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7.3.3 Summary of Site (Characteristics at AOC SD-2/FS-6/FS-8

AOC SD-2/FS-6/FS-8 consists of a storm drainage ditch (i.e., SD-2) that extends from the southern
boundary of MAR at South Outer Road, south-southwest toward Ashumet Pond (see Figure 7-5 in Appendix A).
Two 42-inch-diameter storm drains and an oil/water separator discharge to the upstream end of SD-2. The
storm sewer system collects stormwater from approximately 80 acres of concrete and asphalt-paved
surfaces, hangar nosedocks, and support buildings. AOC SD-2/FS-6/FS-8 lies primarily outside the
flightline security area.

7.3.3.1 Soil/Sediment (Contamination Assessment.

Investigations at AOC SD-2/FS-6/FS-8 detected site-related TCL SVOCs, pesticides, polychlorinated
biphenyls (PCBs) , and TAL inorganics in sediments (surface soils) . Subsurface soil and groundwater
sampling and analysis did not indicate site-related TCL VOC, SVOC, pesticide, PCB, or TAL inorganic
contamination.

Collection of 18 sediment samples between 1986 and 1993 provided the following information relative to
sediment contamination. TCL SVOC analysis detected 19 SVOCs in sediment samples collected from the upper
three-guarters of the drainage ditch. SVOC concentrations were generally below the CRQL, with the
exception of sample SD-6, which was collected from an oily layer not observed at the other sampling
locations. Five pesticides were detected in the lower 200 feet of the drainage ditch, within the alluvial
fan adjacent to Ashumet Pond. The source of these pesticides is likely the former cranberry bog, where
earlier sampling detected one of the same compounds, and which discharges to the same area as AOC
SD-2/FS-6/FS-8. Pesticides were not detected in the upper portions of the drainage ditch. PCBs were
detected at low concentrations in three of the 18 samples collected from the drainage ditch. The
distribution of these samples suggests that low concentrations of PCB contamination exist over the length
of the AOC.

Ten TAL inorganics; were detected in sediments at concentrations above the MR background concentrations
for surface soils (ASG, 1994). Of these inorganics, lead (up to 56 times background) and zinc (up to
eight times background) were detected at the highest concentrations relative to background
concentrations. With the exception of lead and chromium, inorganic detections above background were
within the upper three-guarters of the drainage ditch, in a pattern similar to the observed SVOC
contamination.

Subsurface soil contamination was not detected above the water table in soil borings at AOC
SD-2/FS-6/FS-8. Because contamination was not detected above the water table, it was concluded that
traces of fuel-related VOCs and SVOCs detected below the water table did not result from infiltration of
surface runoff at the AOC.

Because the SVOC, pesticide, PCB, and inorganic contaminants detected at AOC SD-2/FS-6/FS-8 are of low
solubility and volatility, migration of contaminants is expected to be primarily by erosion and
redeposition of contaminated sediments.

7.3.3.2 Groundwater Contamination Assessment.

Groundwater at AOC SD-2/FS-6/FS-8 was sampled during three separate events: the Task 5 Mashpee
groundwater study, the Task 2-3B SI, and the Task 2-5 RI, Samples collected during each event were
analyzed for VOCs, SVOCs, TPH, and TAL inorganics. Groundwater sample analysis did not detect TCL VOCs or
SVOCs above CRQLs or TAL inorganics above the Contract Reguired Detection Limits. Fuel-related VOC and
SVOC TICs were detected in groundwater samples at estimated concentrations up to 11 Ig/L. The groundwater
contamination is attributed to the presence of contaminant sources upgradient of AOC SD-2/FS-6/FS-8,
namely AOC PFSA/FS-10/FS-ll, and is addressed in the SERGOU RI report (ABB-ES, 1994).

7.3.4 Summary of Risks at AOC SD-2/FS-6/FS-8

The RI report for AOC SD-2/FS-6/FS-8 included a human-health PRA to evaluate potential human-health risks
associated with exposure to contaminated surface soil and sediment under current and future site
conditions and an ecological PRA to evaluate potential ecological risks associated with exposure to
contaminated surface soil and sediment (zero to 2 feet bgs). The following subsections summarize the
human-health and ecological PRAs. A detailed discussion of the risk assessment approach and results is
presented in the NMM Risk Assessment Handbook (ASG, 1994) and in the RI report (ABB-ES, 1996c).

7.3.4.1 Human-health Risk Assessment Summary.

The PRA was based on samples collected during the SI, RI, and supplemental RI. Data from ditch sediment
and soil samples were combined and evaluated as surface soil in the PRA because the sediment samples are

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not beneath flowing or standing water for an appreciable time during the year and, therefore, are more
appropriately evaluated as soil. Table 7-9 in Appendix B provides summary statistics on human-health
contaminants of potential concern in soil.

The human-health PRA assessed potential risks associated with the following exposure scenarios based on
the guidance of the MMR Risk Assessment Handbook and the location of AOC SD-2/FS-6/FS-8:

• Current Land Use Conditions: potential child trespasser exposure to surface soils (zero to 2
feet bgs) at maximum and exposure point mean concentrations

• Future Land Use Conditions: potential child trespasser exposure to surface soils (zero to 2
feet bgs) at maximum and exposure point mean concentrations and potential residential
exposure to surface soils (zero to 2 feet bgs) at maximum and exposure point mean
concentrations

The human-health PRA indicated that cancer risks for current and future older child trespassers at
average soil contaminant concentrations do not exceed the USEPA target risk threshold of 10 -6 or the
MADEP target cancer risk of 1x10 -5 . Cancer risks for the future resident at mean concentrations were
within the USEPA target risk range of 10 -4 to 10 -6 and at the MADEP target risk value. For the future,
resident, maximum concentrations produce cancer risks within the USEPA range, but above the MADEP target
value; however, this may be an overestimate of risk because of the conservative assumptions used in the
PRA. SVOCs contributed approximately 65 percent of the potential risk for this future residential
scenario, while the inorganics beryllium and arsenic contributed approximately 20 percent. PCBs
contributed approximately 16 percent of the calculated risk. The cancer risk contributed by arsenic
concentrations is consistent with background. The noncancer HI values for modeled receptors were less
than 1. This indicates that noncancer health risks are below regulatory risk-management guidelines for
these scenarios. Lead and TPH could-not be guantitatively evaluated in the PRA. However, samples from all
locations except SD-6 had lead concentrations that are less than the USEPA soil screening level of 400
mg/kg and the MCP S-l soil standard of 300 mg/kg. In addition, TPH concentrations are below the MCP S-l
soil standard. Table 7-10 in Appendix B summarizes results of the human-health PRA.

7.3.4.2 Ecological Risk Assessment Summary.

Similar to the human-health PRA, the ecological PRA combined data from ditch sediment and soil samples
and evaluated them as surface soil in the PRA because the sediment samples are not beneath flowing or
standing water for an appreciable time during the year (see Table 7-9 in Appendix B).

Model receptor species identified for use in the risk guantification include the white-footed mouse,
cardinal, and red fox. The ecological PRA predicted potential risks to the white-footed mouse from food
chain exposure to chromium and zinc, and potential risks to the cardinal from food chain exposure to lead
and zinc. Calculated His, using exposure point mean concentrations for the mouse and cardinal, were 3 and
2, respectively above the target HI of 1. Mean concentrations represent a more realistic exposure
scenario for ecological receptors than maximum concentrations. His for the red fox were below 1 for both
mean and maximum exposure scenarios. Potential risks to plants, based on the most conservative of the
available phytotoxicity values, were also predicted to occur at maximum and mean exposure concentrations
of lead and zinc. Based on median phytotoxicity values, potential risks to plants would not be expected.
Maximum concentrations of chromium and lead were detected at sample location SD-6; the maximum
concentration of zinc was detected at sample location SD-1, where chromium was also detected at an
elevated concentration. If elevated soil concentrations from these two locations were removed from the
data set, both the maximum and average His would be significantly reduced. Table 7-11 in Appendix B
summarizes results of the ecological PRA, and Table 7-12 in Appendix B summarizes phytotoxicity risks.

7.3.5 Description of Evaluated Alternatives for AOC SD-2/FS-6/FS-8

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria while controlling potential adverse human-health and ecological effects from exposure to surface
soil and sediment at AOC SD-2/FS-6/FS-8:

• No Action
• Excavation Asphalt-batching
• Excavation and Offsite Treatment and Disposal.

Because this site is located almost wholly outside the MMR boundary, MMR has little ability to control
site access; therefore, the Limited Action alternative was not evaluated in detail.

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7.3.5.1 No Action.

The No Action alternative was evaluated as a baseline with which to compare other alternatives.  No
remedial action,  monitoring,  further investigation,  or five-year site reviews would be performed as part
of this alternative.

          Estimated Time for Design and Construction:                             not applicable
          Estimated Time for Cleanup:                                             not applicable
          Estimated Capital Cost:                                                             $0
          Estimated Operation and Maintenance Cost:                                            $0
          Estimated Total Cost                                                                $0

7.3.5.2 Excavation and Asphalt-batching.

The Excavation and Asphalt-batching alternative at AOC SD-2/FS-6/FS-8 includes the following key
components:

       •      mobilization and site preparation
       •      excavating sediment/surface  soil  exceeding cleanup criteria  at  historical  sample
              locations  SD-1 and SD-6
       •      collecting post-excavation confirmation samples  from the  excavation perimeter  for
              analysis for chromium,  lead,  and  zinc
       •      transporting excavated soil  to an onsite asphalt-batching facility for testing and
              treatment
       •      backfilling and restoring excavations  with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade  material at selected
              locations at MMR

          Estimated Time for Design and Construction:                              9 months
          Estimated Time for Cleanup:                                               2 weeks
          Estimated Capital Cost:                                                   $92,000
          Estimated Operation and Maintenance Cost:                                       $0
          Estimated Total Cost                                                      $92,000

7.3.5.3 Excavation and Offsite Treatment and Disposal.

The Excavation and Offsite Treatment and Disposal alternative  at AOC SD-2/FS-6/FS-8 includes the
following key components:

       •      mobilization and site preparation
       •      excavating sediment/surface  soil  exceeding cleanup criteria  at  historical  sample locations
              SD-1 and SD-6
       •      collecting post-excavation confirmation samples  from the  excavation perimeter  for
              analysis for chromium,  lead,  and  zinc
       •      transporting excavated soil  to a  permitted offsite treatment, storage,  and disposal
              facility for treatment and/or disposal
       •      backfilling and restoring excavations  with clean borrow material

         Estimated Time for Design and Construction:                                 9 months
         Estimated Time for Cleanup:                                                  2 weeks
         Estimated Capital Cost:                                                      $86,000
         Estimated Operation and Maintenance Cost:                                         $0
         Estimated Total Cost                                                         $86,000

7.3.6 Summary of Comparative Analysis of Alternatives for AOC  SD-2/FS-6/FS-8

The following subsections summarize the Comparative Analysis  of Alternatives  performed in the Feasibility
Study for AOC SD-2/FS-6/FS-8.

7.3.6.1 Overall Protection of Human Health and the Environment.

The No Action alternative would be protective of human health  under the current direct exposure  scenario
and under the future direct exposure scenario at average exposure concentrations. Under CERCLA and the
NCP,  the No Action alternative would be protective of human health under the  future direct exposure
scenario at maximum concentrations. It would not be protective of ecological  receptors.

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The Excavation and Asphalt-batching and the Excavation with Offsite Treatment and Disposal alternatives
offer equal protection to human health and the environment. Both will provide protection under current
and future exposure scenarios.

7.3.6.2 Compliance with Applicable or Relevant and Appropriate Requirements.

The No Action alternative does not include remedial actions that would triqqer ARARs. The two excavation
alternatives would be designed and implemented to comply with all ARARs. Therefore, no waivers would be
required.

7.3.6.3 Long-term Effectiveness and Permanence.

Because the No Action alternative does not include actions to reduce potential human-health or ecological
exposure risks or measures to protect groundwater quality, it does not offer long-term effectiveness at
protecting human health or the environment.

Both excavation alternatives will reduce potential exposure risks by removing sods which pose the
greatest risks. Therefore, both are considered to offer long-term effectiveness and permanence at
protecting human health and the environment.

7.3.6.4 Reduction of Toxicity, Mobility, or Volume Through Treatment.

The No Action alternative does not provide treatment to reduce the toxicity, mobility, or volume of
contaminants. The Excavation and Asphalt-batching alternative provides treatment that will reduce the
mobility of contaminants. Because the treatment/disposal approach that would be followed at an offsite
disposal facility is not known, it can not be said that the Excavation and Offsite Treatment and Disposal
alternative will provide reductions in toxicity, mobility, or volume through treatment.

7.3.6.5 Short-term Effectiveness.

The No Action alternative does not include actions that would result in adverse short-term effects to
human health or the environment. The PRA did not identify unacceptable current risks to human health.
Construction activities associated with the two excavation alternatives would present minimal short-term
risks to construction workers; however, the development of and adherence to a site-specific Health and
Safety Plan would minimize potential risks to workers. Clearing brush and trees to reach excavation
locations may cause minor disruption to habitat.

7.3.6.6 Implementability.

The technical and administrative feasibility of all three alternatives is considered high. None of the
three alternatives include actions that require substantial technical or administrative resources.

7.3.6.7 Cost.

Cost includes the capital (up-front) cost of implementing an alternative and the long-term cost of
operating and maintaining the alternative. Capital and operation and maintenance costs for each
alternative were calculated with an estimated accuracy of 30 percent to +50 percent. The alternative with
the lowest capital costs is No Action which does not include construction. The costs of the other two
alternatives, Excavation and Asphalt-batching and Excavation and Offsite Treatment and Disposal, are
separated by $6,000 or approximately seven percent. However, performing asphalt-batching of AOC
SD-2/FS-6/FS-8 soil concurrent with asphalt-batching of soils from other AOCs has the potential to reduce
overall costs and narrow or reverse the cost differential. Cost is not a good differentiator between
these two alternatives.

Operation and maintenance costs for the three alternatives were all estimated to be equal.

To enable comparison of costs which will occur over different time periods, the present worth of capital
and operation and maintenance costs was also calculated. The present worths closely reflect capital costs
and are not good dfferentiators between the two excavation alternatives. The following table compares
capital, operation and maintenance, and present worth costs for each alternative evaluated in detail for
AOC SD-2/FS-6/FS-8.

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Alternative

No Action
Excavation and
Asphalt-batching
Excavation and Offsite
Treatment and
Disposal
Total
Capital Cost

$ 0
$92,000

$86,000
Total O&M
(Present Worth*)

$ 0
$ 0

$ 0
Total Costs
(Present Worth)

$ 0
$92,000

$86,000
*Present worth based on 7 percent discount rate for 30 years.
7.3.6.8 State Acceptance.

The Commonwealth of Massachusetts has reviewed the RI and Feasibility Study reports and the Proposed Plan
and concurs with AFCEE's selected remedy.

7.3.6.9 Community Acceptance.

During the public comment period on the Proposed Plan, AFCEE received seven comments guestioning the
appropriateness and effectiveness of asphalt-batching. AFCEE's responses to these comments are contained
in the Responsiveness Summary which is included in Appendix C to this Record of Decision. AFCEE has taken
into consideration the public concerns regarding the use of on-site asphalt-batching and will work with
the regulatory agencies in developing a work plan which addresses these concerns.

One commentor suggested that constructing a temporary access road at the end of Wheeler Road in Mashpee,
as presented in the Proposed Plan, to reach excavation location SD-6 would have a negative effect on the
neighborhood and the environment and that a less disruptive approach should be used. In response to this
comment, AFCEE will investigate alternate routes to reach the subject sample location.

7.3.7 Description of the Selected Remedy for AOC SD-2/FS-6/FS-8

The selected remedy for AOC SD-2/FS-6/FS-8 is Excavation and Asphalt-batching. This alternative provides
engineering controls to limit exposure to site-related contaminants and to reduce source-area contaminant
concentrations to protective levels. This AOC is not known to be a source of groundwater contamination,
and the remedy does not include a management of migration component. Non-site-related groundwater
contamination beneath and downgradient of the AOC will be addressed as part of the Plume Response Plan.

7.3.7.1 Soil Cleanup levels.

Based upon data developed in the RI and the PRA and summarized in the Feasibility Study, remedial actions
are warranted at AOC SD-2/FS-6/FS-8 to address potential risks associated with direct contact exposure to
source-area soils at historical sample locations SD-1 and SD-6 (Figure 7-6 in Appendix A). Remedial
actions are also warranted to protect ecological receptors from maximum concentrations of site
contaminants observed at historical sample locations SD-1 and SD-6.

The STCLs established for the DSRP at MMR were used to estimate residual soil levels that will be
protective of potential direct contact receptors and future groundwater guality (see Section 5.0 of this
Record of Decision). Concentrations of organics in soils were found to be below STCLs. The following
table summarizes the STCLs reguired to protect human health and the environment at this AOC.
Contaminants
STCL
Basis for Selection
Chromium
Lead
Zinc
6.8 mg/kg
15.8 mg/kg
16 mg/kg
Outside the Flightline
Outside the Flightline
Outside the Flightline
The STCLs are consistent with ARARs for groundwater, attain USEPA's risk-management goal for remedial
actions, and have been determined by AFCEE, USEPA, and MADEP to be protective. These cleanup levels must
be met at the completion of the remedial action at the limits of STCL exceedance established during
predesign confirmation soil sampling.

7.3.7.2 Description of Remedial Components.

The selected remedy for AOC SD-2/FS-6/FS-8 is Excavation and Asphalt-batching. Key components of this
alternative include:

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• mobilization and site preparation
• excavating sediment/surface soil exceeding cleanup criteria at historical sample
locations SD-1 and SD-6
• collecting post-excavation confirmation samples from the excavation perimeter for
analysis for chromium, lead, and zinc
• transporting excavated soil to an onsite asphalt-batching facility for testing and
treatment
• backfilling and restoring excavations with clean borrow material
• using the asphalt-emulsion-coated product as a paving subgrade material at selected
locations at MMR

Each of these components is described in the following paragraphs.

Mobilization and site preparation. Mobilization and site preparation will include procuring necessary
subcontractors, purchasing equipment, identifying underground utilities, clearing brush and trees, and
constructing temporary access roads. AFCEE will evaluate reaching removal location SD-6 without building
a temporary access road from Wheeler Road in Mashpee.

Excavating sediment/surface soil exceeding cleanup criteria at historical sample locations SD-1 and SD-6.
AFCEE will excavate contaminated soil/sediment at historical sampling locations SD-1 and SD-6 with a
backhoe and dump truck or other appropriate equipment. Based on available data and the results of the
PRA, excavation volumes are expected to be 14 cy or less of surface soil (zero to 2 feet bgs).
Pre-excavation sampling may or may not be done. Details of proposed sampling and analysis, excavation,
and backfill/restoration activities will be presented in a RAWP and/or in design plans to be reviewed and
approved by regulatory agencies prior to implementation.

Collecting post-excavation confirmation samples from the excavation perimeter for analysis for chromium,
lead, and zinc. Confirmation samples will be collected from the perimeter of the excavation (post
excavation) and analyzed for chromium, lead, and zinc to confirm that all surface soil exceeding STCLs
for these chemicals have been removed.

Transporting excavated soil to an onsite asphalt-batching facility for testing and treatment. Samples of
the excavated soil will be collected and analyzed to assess whether the soil must be treated/disposed of
as a hazardous substance. Toxicity Characteristic Leaching Procedure (TCLP) testing will be performed
when total concentrations in soil are above theoretical concentrations at which TCLP criteria may be met
or exceeded. Soils considered hazardous will be disposed of off site at a permitted treatment, storage,
and disposal facility. Nonhazardous soils and those meeting threshold criteria will be transported to an
onsite facility for asphalt-batching. One TCLP sample will be collected per 100 cy of excavated material
or as directed by the asphalt-batching subcontractor. In addition, analytical data will be compared to
threshold concentrations for soil recycling facilities contained in the Massachusetts "Interim
Remediation Waste Management Policy for Petroleum Contaminated Soils" to assess acceptability for
cold-mix asphalt-batching. Details of the asphalt-batching treatment process and associated testing will
be presented in a RAWP and/or design plans and specifications to be reviewed and approved by USEPA and
MADEP prior to implementation.

Backfilling and restoring excavations with clean borrow material. Following completion of excavation
activities, the excavations will be backfilled and restored to original grade with clean fill material.
Temporary roads will be removed and the ground surface restored to original grade.

Using the asphalt-emulsion-coated Product as a paving subgrade material at MMR. Asphalt-batched material
will be used as paving subgrade material at selected locations at MMR. A minimum IE-inch wear coat will
be placed over the asphalt-batched material.

7.3.8 Statutory Determinations for AOC SD-2/FS-6/FS-8

The selected remedy for AOC SD-2/FS-6/FS-8 is consistent with CERCLA and, to the extent practicable, the
NCP. The selected remedy is protective of human health and the environment, attains ARARs, and is
cost-effective. The statutory preference for treatment which permanently and significantly reduces the
toxicity, mobility, or volume of hazardous substances as a principal element is satisfied. Additionally
the selected remedy utilizes alternative treatment technologies and resource recovery technologies to the
maximum extent practicable for this site.

7.3.8.1 The Selected Remedy is Protective of Human Health and the Environment.

The selected remedy for AOC SD-2/FS-6/FS-8 will permanently reduce the risks to human health and the
environment by eliminating, reducing, or controlling exposures to human and environmental receptors
through engineering controls. The principal threat at AOC SD-2/FS-6/FS-8 is surface soil that is

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contaminated with inorganics that may pose direct contact risk to human and ecological receptors.

The effectiveness of the selected alternative will be evaluated by comparing soil sampling data to STCLs
in the following table.

Contaminants STCL Basis for Selection
Chromium 6.8 mg/kg Outside the Flightline
Lead 15.8 mg/kg Outside the Flightline
Zinc 16 mg/kg Outside the Flightline

7.3.8.2 The Selected Remedy Attains Applicable or Relevant and Appropriate Reguirements.

The selected remedy will attain all applicable or relevant and appropriate federal and state
reguirements. No waivers are reguired. ARARs for AOC SD-2/FS-6/FS-8 were identified and discussed in the
Feasibility Study (Sections 3.0 and 7.0). Table 7-13 in Appendix B summarizes the ARARs for the selected
remedy, including the regulatory citation, a brief summary of the reguirement, and how it will be
attained.

7.3.8.3 The Selected Remedy is Cost-effective.

The estimated costs of Excavation and Asphalt-batching was $6,000 or approximately seven percent greater
than Excavation and Offsite Treatment and Disposal. However, performing asphalt-batching of AOC
SD-2/FS-6/FS-8 soil concurrent with asphalt-batching of soils from other AOCs has the potential to reduce
overall costs and narrow or reverse the cost differential. Because of this, cost is not considered a good
differentiator between these two alternatives. In addition, excavation and asphalt-batching addresses the
bias against offsite disposal and satisfies the statutory preference for treatment better than excavation
and offsite disposal.

In AFCEE's judgment, the selected remedy is cost-effective (i.e., the remedy affords overall
effectiveness proportional to its costs) . In selecting this remedy, after AFCEE identified alternatives
that are protective of human health and the environment and attain, or, as appropriate, waive ARARs,
AFCEE evaluated the overall effectiveness of each alternative according to the relevant three criteria:
long-term effectiveness and permanence; reduction in toxicity, mobility, or volume through treatment; and
short-term effectiveness, in combination. The relationship of the overall effectiveness of this remedial
alternative was determined to be proportional to its costs.

The costs of this remedial alternative are:

Estimated Capital Cost $92,000
Estimated Operation and Maintenance Cost $0
Estimated Total Cost $92,000

7.3.8.4 The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment or Resource Recovery
to the Maximum Extent Practicable.

After AFCEE identified those alternatives that attain or, as appropriate, waive ARARs and that are
protective of human health and the environment, AFCEE determined which alternative made use of permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable. This determination was made by deciding which one of the identified alternatives provides
the best balance of tradeoffs among alternatives in terms of: (1) long-term effectiveness and permanence;
(2) reduction of toxicity, mobility, or volume through treatment; (3) short-term effectiveness; (4)
implementability; and (5) cost. The balancing test emphasized long-term effectiveness and permanence and
the reduction of toxicity, mobility, or volume through treatment and considered the preference for
treatment as a principal element, the bias against offsite land disposal of untreated waste, and
community and state acceptance. AFCEE believes the selected remedy provides the best balance of tradeoffs
among the alternatives that are protective and attain ARARs.

7.3.8.5 The Selected Remedy Satisfies the Preference for Treatment Which Permanently and Significantly
Reduces the Toxicity, Mobility, or Volume of Hazardous Substances as a Principle Element.

The principal element of the selected remedy is excavation and asphalt-batching. This element addresses
the principal threat at the AOC, contamination of surface soil with inorganics, by removing soils that
exceed cleanup levels and treating them with asphalt-batching to reduce contaminant mobility. The
selected remedy satisfies the statutory preference for treatment as a principal element.

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7.3.9 Documentation of No Significant Changes for AOC SD-2/FS-6/FS-8

AFCEE presented a Proposed Plan (preferred alternative) for remedial action at AOC SD-2/FS-6/FS-8 source
areas at a public information meeting held at the Barnstable County Fairgrounds in Falmouth,
Massachusetts, on November 13, 1997, and at a public hearing held at Mashpee High School in Mashpee,
Massachusetts, on December 2, 1997. Comments received during the public comment period have caused AFCEE
to modify the Excavation and Asphalt-batching preferred alternative slightly. In the Proposed Plan, AFCEE
indicated its intention to reach one of the excavation locations at AOC SD-2/FS-6/FS-8 by constructing an
access road from Wheeler Road in Mashpee. As a result of public comments, AFCEE will evaluate the
possibility of reaching both excavation locations from the north, thereby potentially eliminating the
need to gain access road from Wheeler Road. There have been no significant changes to other components of
the preferred alternative.

7.4 DECISION SUMMARY FOR AOC SD-3/FTA-3/CY-4

The following subsections summarize information considered during the selection of source-area remedial
action for AOC SD-3/FTA-3/CY-4. A more detailed description of AOC SD-3/FTA-3/CY4 site history,
contamination, and potential site risks can be found in the Final Remedial Investigation Report
Stormwater Drainage Ditch No. 3[SD-3], Former Fire Training Area No. 3 [FTA-3] , and Coal Yard No. 4
[CY-4} prepared by ABB-ES in 1996. Additional discussion concerning candidate remedial actions to reduce
site risks is contained in the final Six Areas of Contamination Source Area Feasibility Study prepared by
ABB-ES in 1997. These reports are available for review at the main libraries in the towns of Bourne,
Falmouth, Mashpee, and Sandwich; and at the U.S. Coast Guard library at MMR.

7.4.1 Scope and Role of Response Action at AOC SD-3/FTA-3/CY-4

This response action consists of surface soil sampling to document soil contamination that may remain at
this AOC and to assess the adeguacy of the removal action completed in 1994. If sampling shows
contamination above STCLs, the contingency action of additional source-area soil removal followed by
asphalt-batching would be implemented. By performing surface soil sampling and, if necessary, excavating
and treating soil and sediment exceeding cleanup criteria, the selected action will protect human and
ecological receptors from exposure to concentrations of inorganics and SVOCs exceeding protective cleanup
criteria. The selected action will also prevent those compounds from being a source of groundwater
contamination. If contaminant concentrations are below cleanup criteria, no further cleanup action would
be reguired. The response action includes institutional controls in the form of site access restrictions
to limit potential human-health, risks and five-year site reviews to assess whether the remedy remains
protective of human health and the environment. The risk assessment did not identify the need to clean up
groundwater at this AOC.

7.4.2 History of Land Use at AOC SD-3/FTA-3/CY-4

This AOC is near the southeastern, boundary of MMR and east of the runways in an industrialized area
(Figure 7-7 in Appendix A). The following items summarize the history of AOC SD-3/FTA-3/CY4.

• 1950s. The SD-3 drainage ditch was constructed to receive the discharge from storm drains
serving aircraft hangars and several streets west of Granville Avenue and the discharge from
the Central Heating Plant.
• 1955 to 1978. Coal was stockpiled directly on the ground prior to installation of a
concrete storage pad.
• 1955 to 1992. The coal ash disposal area received coal ash and fly ash from the Central
Heating Plant.
• 1956 to 1958. FTA-3 was used for firefighter-training exercises. Subseguent to
firefighter-training activities, the site was backfilled with construction debris, fill, and
coal ash.
• 1987. An SI was performed to assess the presence of contamination in surface water,
sediment, soil, and, groundwater at this AOC.
• 1989. An RI was performed to characterize the nature and distribution of sediment, soil,
and groundwater contamination and evaluate site risks.
• 1993. A supplemental RI was performed to further characterize sediment contamination and
evaluate potential site risks.
• 1994. 42,000 cy of material, representing the majority of coal and coal ash at CY-4, were
excavated and used as fill below the main base landfill (LF-1) cover system.
• 1997. A Feasibility Study was performed to evaluate approaches to control potential site
risks.

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7.4.3 Summary of Site (Characteristics at AOC SD-3/FTA-3/CY-4

AOC SD-3/FTA-3/CY-4 is located near the southeastern border of MMR in a moderately industrialized area on
the eastern side of the runways, covering approximately 30 acres. The majority of the AOC is bordered by
Granville Avenue on the west and the Air National Guard Ammunition Storage Area on the east (see Figure
7-7 in Appendix A). A small portion of SD-3 is located east of the ammunition storage area. The SD-3
stormwater drainage ditch receives runoff from this area and the eastern edge of the aircraft maintenance
ramp, the former Central Heating Plant, and associated stockpiles of coal and surficial coal ash. FTA-3
was located in an area where construction debris and coal ash were disposed of after construction of the
Central Heating Plant in 1955. AOC SD-3/FTA-3/CY4 is located within the fenced flightline security area.
Access to areas within the flightline area is controlled with fences and guard posts, and activities not
related to aircraft operations are limited and strictly controlled. Fences around the flightline areas
are inspected daily by base security. These site access restrictions are expected to remain in place
through the duration of the current lease (expiration date of 2026) and the planned 25-year renewal.

Between February and April of 1994, the NGB, with concurrence of USEPA and MADEP, excavated coal, coal
ash, and potentially contaminated soils from CY-4 and FTA-3 for use as subgrade fill during final capping
of the main base landfill (LF1). A total of 42,000 cy of material, representing the majority of coal and
coal ash at CY-4, was excavated to depths of up to 15 feet. Additionally, soils at the FTA-3 location
were also removed. This excavation was then backfilled with clean fill and covered with wood chips,
restoring the land surface to approximately the original grade.

7.4.3.1 Soil Contamination Assessment.

Investigations at AOC SD-3/FTA-3/CY-4 detected fuel and coal-related contamination in surface and
subsurface soils, including VOCs (subsurface soils only) and several SVOCs, primarily PAHs. Low
concentrations of pesticides and inorganics were also identified at the AOC. Sections 2.0, 5.0, and 6.0
of the RI report discuss soil contamination at AOC SD-3/FTA-3/CY-4 in detail. However, most of the soils
represented by samples discussed in the RI were excavated and placed in the main base landfill in 1994.

Test-pit excavation performed during the SI identified areas of black to dark gray coal soot and fly ash
in subsurface soils. Samples collected from soil borings and test-pitting showed VOCs present in deep
subsurface soils (29 to 56 feet bgs) in three borings, including chloroethane and toluene at low
concentrations. The pesticide 4,4'-dichlorodiphenyltrichloroethane (4,4'-DDT) was also detected in
subsurface soils. Detections of SVOCs and inorganics above background were primarily limited to samples
collected from between zero and 2 feet bgs.

Two composite coal-ash samples were collected from CY-4 during the RI program. Analysis of the samples
identified several SVOCs indicative of residual fuel oils or coal components. Several inorganic
contaminants were also detected above the established MMR background concentrations for surface soil,
including arsenic, barium, beryllium, calcium, chromium, cobalt, copper, iron, lead, mercury, nickel,
potassium, selenium, silver, thallium, vanadium, and zinc.

7.4.3.2 Groundwater Contamination Assessment.

Groundwater samples collected during the Mashpee Groundwater Study, the SI, and the RI indicated that
groundwater beneath and downgradient of the AOC was affected by chlorinated solvent contamination,
including TCE, PCE, toluene, and 1, 1, 1 -trichloroethane. Data from the SERGOU RI and the "Johns Pond
Groundwater Underflow Study" indicate that AOC SD-3/FTA-3/CY-4 is most likely not a source of this
contamination (ABB-ES, 1994; and E.G. Jordan Co., 1991) . Data from multilevel monitoring well clusters
downgradient of the AOC show that groundwater at the water table does not contain chlorinated solvents;
they are only present lower in the aquifer. In addition, subsurface soil samples did not contain the
compounds identified in groundwater. This information suggests that the Central Heating Plant leaching
wells, spills from shops and hangars along the aircraft maintenance ramp, or possibly the solvent storage
facilities were the source of these compounds. The SERGOU RI report discusses groundwater contamination
at AOC SD-3/FTA-3/CY-4 in detail (ABB-ES, 1994).

7.4.3.3 Sediment Contamination Assessment.

Investigations at AOC SD-3/FTA-3/CY-4 detected fuel and coal-related contamination in sediments,
including SVOCs and inorganics. Low concentrations of pesticides and PCBs were also detected. Sections
2.0, 5.0, and 6.0 of the RI report discuss ditch sediment contamination in detail (ABB-ES, 1996d).

During SI activities, one sediment sample was collected approximately 8 feet from the 36-inch-diameter
outsell located east of the Air National Guard Ammunition Storage Area. Analysis of the sample identified
several fuel and coal-related SVOCs, primarily PAHs. Ten inorganics were also detected above NWR
background concentrations. The PCB Aroclor-1260 was detected at 420 Ig/kg.

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During the RI, four sediment samples were collected from the SD-3 drainage ditch: three from the
ditch west of the ammunition storage area and the fourth near the location of the SI sample. Results of
analysis indicated the presence of 24 SVOCs, which suggests contamination from fuel spills and coal.
Several inorganics were identified above MMR background concentrations. The PCB Aroclor-1260 was also
detected at concentrations ranging from 460 to 10,000 Ig/kg. TPH was detected in each sample where it was
a target analyte. VOCs were not detected in any of the samples.

Three additional sediment samples were collected during the supplemental RI. One sample (SD-8) , collected
near the outfall of the two 24-inch-diameter drainage pipes, was analyzed for VOCs only; however, no VOCs
were detected in this sample. The two remaining samples contained contamination similar to previous
samples collected at the AOC: fuel and coal-related SVOCs and inorganics. In addition, the samples
contained the VOC chloroform at low concentrations and pesticides. The pesticides are thought to have
been transported with surface water runoff and sediments from around buildings at the southern end of
Granville Avenue, where pesticides were used for insect control.

Results of the sediment sampling suggest that coal particulates are components of drainage-ditch
sediments and that transport of these particulates from the source occurs during overland flow. PAHs and
phthalates generally decrease in concentration and prevalence with distance from the two 24-inch-diameter
storm sewer outfalls. The same distribution pattern was observed for inorganics and PCBs.

7.4.3.4 Surface Water Contamination Assessment.

One surface water sample was collected from the SD-3 drainage ditch immediately downstream of the two
24-inch-diameter outfalls during the SI. Detected VOCs included low concentrations of
bromodichloromethane, bromoform, chloroform, and dibromochloromethane. One SVOC was detected, as was
lead. A second surface water sample was collected by MMR personnel and analyzed for VOCs during RI
sediment sampling. Results of the sampling correlated well with SI sampling (ABB-ES, 1996d).

7.4.4 Summary of Risks at AOC SD-3/FTA-3/CY-4

The RI report for AOC SD-3/PTA-3/CY-4 included a human-health PRA to evaluate potential human-health
risks associated with exposure to contaminated surface soil and sediments under current and future site
conditions and an ecological PRA to evaluate potential ecological risks associated with exposure to
contaminated surface soil and sediment (zero to 2 feet bgs). The following subsections summarize the
human-health and ecological PRAs. A detailed discussion of the risk assessment approach and results is
presented in the MMR Risk Assessment Handbook (ASG, 1994) and in the RI report (ABB-ES, 1996d).

7.4.4.1 Human-health Risk Assessment Summary.

The PRA was based on samples collected during the SI, RI, and supplemental RI from locations that were
not disturbed during the 1994 excavation of coal and ash at FTA-3 and CY4. Data from ditch sediment and
soil samples were combined and evaluated as surface soil in the PRA because the sediment samples are not
beneath following or standing water for any appreciable time during the year. Table 7-14 in Appendix B
provides summary statistics on human-health contaminants of potential concern in soil.

• Current Land Use Conditions: potential child trespasser exposure to surface soils (zero to 2
feet bgs) at maximum and exposure point mean concentrations; and potential utility worker
exposure to surface soils (zero to 10 feet bgs) at maximum and exposure point mean
concentrations for a six-week period

• Future Land Use Conditions: potential child trespasser exposure to surface soils (zero to 2
feet bgs) at maximum and exposure point mean concentrations; and potential utility worker
exposure to surface soils (zero to 10 feet bgs) at maximum and exposure point mean
concentrations for a six-month period

The human-health PRA indicated that cancer and noncancer risks do not exceed regulatory risk-management
guidelines associated with soil and sediment exposure for a utility worker or older child trespasser.
Lead was detected in sample SD-2 at a concentration of 553 mg/kg, exceeding the USEPA soil-screening
level of 400 mg/kg and the MCP S-l soil standard of 300 mg/kg. TPH concentrations did not exceed the MCP
S-l standard of 500 mg/kg. Table 7-15 in Appendix B summarizes results of the human-health PRA.

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7.4.4.2 Ecological Risk Assessment Summary.

Data from ditch sediment and soil samples were combined and evaluated as surface soil in the PRA because
the sediment samples are not beneath flowing or standing water for an appreciable time during the year
(see Table 7-14 in Appendix B).

Model receptor species identified for use in the risk guantification include the white-footed mouse,
cardinal, and red fox. His for exposure point mean concentrations indicate that adverse effects are
possible for the white-footed mouse and cardinal. His for the red fox were below 1 for both mean and
maximum exposure scenarios. Potential risks to plants, based on the most conservative of the available
phytotoxicity values, were also predicted. Major risk-contributing compounds are 2,4-dinitrotoluene
(detected only once), chromium,  copper, and zinc; maximum concentrations were from sample SD-2, located
at the upstream end of the drainage ditch. If median phytotoxicity values were used,  potential risks to
plants from inorganics would be significantly lower. The PRA calculations involved numerous conservative
assumptions that may have overestimated risk by as much as a factor of 100. Table 7-16 in Appendix B
summarizes results of the ecological PRA, and Table 7-17 in Appendix B summarizes phytotoxicity risks.

7.4.5 Description of Evaluated Alternatives for AOC SD-3/FTA-3/CY-4

The Feasibility Study assessed how well the following two alternatives would meet the evaluation criteria
while controlling potential adverse human-health and ecological effects from exposure to surface soil at
AOC SD-3/FTA-3/CY-4:

       •      No Action
       •      The modified limited action alternative of Confirmation Sampling with Contingency of
              Excavation and Asphalt-batching

7.4.5.1  No Action.

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions (security fencing and
military guard posts) that currently limit potential human    exposure to site contaminants.

          Estimated Time for Design and Construction:        not applicable
          Estimated Time for Cleanup:                        not applicable
          Estimated Capital Cost:                            $0
          Estimated Operation and Maintenance Cost:          $0
          Estimated Total Cost:                               $0

7.4.5.2 Confirmation Sampling with Contingency of Excavation and Asphalt-batching.

The Confirmation Sampling with Contingency of Excavation and Asphalt-batching alternative at AOC
SD-3/FTA-3/CY-4 includes the following key components:

       •      preparing a brief  sampling and analysis work plan
       •      mobilization and  site preparation
       •      collecting surface soil samples from the area of coal ash disposal outside of the 1994
              removal area and  analyzing the samples for inorganics and SVOCs
       •      comparing analytical data to STCLs for SVOCs and inorganics
       •      if comparison shows contamination above STCLs,  implementing the contingency action of
              excavating surface soil for asphalt-batching
       •      collecting post-excavation confirmation samples from the excavation perimeter for analysis
              for inorganics and SVOCs
       •      transporting excavated soil to an onsite asphalt-batching facility for  testing and treatment
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •      maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •      performing five-year site reviews

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Estimated Time for Design and Construction: 9 months
Estimated Time for Cleanup: 3 months
Estimated Capital Cost: $22,000
Estimated Operation and Maintenance Cost (Present Worth*): $25,000
Estimated Total Cost $47,000

*Present worth based on 7 percent discount rate for 30 years.
Costs are for confirmation sampling only.

7.4.6 Summary of Comparative Analysis of Alternatives for AOC SD-3/FTA-3/CY-4

The following subsections summarize the Comparative Analysis of Alternatives performed in the Feasibility
Study for AOC SD-3/FTA-3/CY-4.

7.4.6.1 Overall Protection of Human Health and the Environment.

Because of uncertainty concerning the adeguacy of previous removal actions at AOC SD-3/FTA-3/CY-4, it can
not be said that the No Action alternative will be protective of human health and the environment.
Further, although the PRA did not identify potential human-health risks exceeding regulatory
risk-management guidelines, it assumed the presence of site access restrictions that would not be
maintained under the No Action alternative. Therefore, the No Action alternative is not considered
protective of human health. Confirmation Sampling with Contingency of Excavation and Asphalt-batching
alternative will be protective of human health and the environment because any remaining surface soils
with contaminant concentrations exceeding cleanup criteria will be removed and because institutional
controls will be maintained to limit potential human exposure.

7.4.6.2 Compliance with Applicable or Relevant and Appropriate Reguirements.

The No Action alternative does not include remedial actions that would trigger ARARs. The Confirmation
Sampling with Contingency of Excavation and Asphalt-batching alternative will be designed and implemented
to comply with all ARARs. No waivers would be reguired.

7.4.6.3 Long-term Effectiveness and Permanence.

Because of uncertainty concerning the adeguacy of previous removal actions at AOC SD-3/FTA-3/CY-4, it can
not be said that the No Action alternative offers long-term effectiveness at protection of human health
and the environment. Further, the No Action alternative does not include maintenance of institutional
controls to limit exposure to site contaminants. The Confirmation Sampling with Contingency of Excavation
and Asphalt-batching alternative offers long-term effectiveness by including sampling, and if necessary,
removal activities to ensure that protective cleanup criteria are met. Institutional controls are
included to limit human exposure to site contaminants.

7.4.6.4 Reduction of Toxicity, Mobility, or Volume Through Treatment.

The No Action alternative does not provide reduction of contaminant toxicity, mobility, or volume through
treatment. The Confirmation Sampling with Contingency of Excavation and Asphalt-batching alternative
provides for the reduction of contaminant mobility through treatment.

7.4.6.5 Short-term Effectiveness.

The No Action alternative does not include actions that would result in adverse short-term effects to
human health or the environment. The Confirmation Sampling with Contingency of Excavation and
Asphalt-batching alternative includes measures to identify these risks and address them if necessary.
Construction activities associated with the contingency action would present minimal short-term risks to
construction workers. The development of and adherence to a site-specific Health and Safety Plan would
minimize potential risks to workers. The clearing of brush and trees to implement the contingency remedy
may disrupt some habitat, but significant, adverse short-term environmental effects are not expected.

7.4.6.6 Implementability.

The technical and administrative feasibility of both alternatives is considered high. Neither alternative
includes actions that reguire substantial technical or administrative resources.

7.4.6.7 Cost.

Cost includes the capital (up-front) cost of implementing an alternative and the long-term cost of
operating and maintaining the alternative. Capital and operation and maintenance costs for each

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alternative were calculated with an estimated accuracy of 30 percent to +50 percent. The No Action
alternative has the lower capital costs, and Confirmation Sampling with Contingency of Excavation and
Asphalt-batching has the greater capital cost.

Operation and maintenance costs were estimated on an annual basis, and are lowest for the No Action
alternative, which does not provide any long-term maintenance or monitoring.

The following table compares capital, operation and maintenance, and present worth costs for each
alternative evaluated in detail for AOC SD-3/FTA-3/CY-4.
Alternative

No Action

Confirmation Sampling

Contingency Soil
Removal
Total
Capital Cost

$22,000

$1,441,000
Total O&M
(Present Worth*)

$25,000

$0
Total Costs
(Present Worth)

$47,000

$1,441,000
Combined
Confirmation
Sampling/Contingency
Sod Removal
$1,463,000
$25,000
$1,488,000
*Present worth based on 7 percent discount rate for 30 years.

7.4.6.8 State Acceptance.

The Commonwealth of Massachusetts has reviewed the RI and Feasibility Study reports and the Proposed Plan
and concurs with AFCEE's selected remedy.

7.4.6.9 Community Acceptance.

During the public comment period on the Proposed Plan, AFCEE received several comments guestioning the
appropriateness and effectiveness of asphalt-batching. AFCEE's responses to these comments are contained
in the Responsiveness Summary which is included in Appendix C to this Record of Decision. AFCEE has taken
into consideration the public concerns regarding the use of on-site asphalt-batching and will work with
the regulatory agencies in developing a work plan which addresses these concerns.

7.4.7 Description of the Selected Remedy for AOC SD-3/FTA-3/CY-4
The selected remedy for AOC SD-3/FTA-3/CY-4 is Confirmation Sampling with Contingency of Excavation and
Asphalt-batching. This alternative provides institutional and engineering controls to assess the adeguacy
of previous removal actions, limit exposure to site-related contaminants, and, if necessary, remove
source-area soils exceeding cleanup criteria and treat the soils to reduce contaminant mobility. The risk
assessment did not identify the need to clean up groundwater at this AOC; conseguently, the remedy does
not include a management of migration component.

7.4.7.1 Soil Cleanup Levels.

Based upon data developed in the RI and the PRA and summarized in the Feasibility Study, remedial actions
to address risks associated with possible direct contact exposure to source-area soils are not warranted
at AOC SD-3/FTA-3/CY-4. Estimated risks do not exceed USEPA and MADEP target risk criteria for
carcinogenic and noncarcinogenic endpoints. Adverse effects on ecological receptors are also considered
unlikely. However, additional surface sod sampling should be conducted at the site to assess the adeguacy
of previous removal actions.

The new data will be compared to the STCLs established for the DSRP at MMR (HAZWRAP, 1996). The STCLs
represent residual soils levels that will be protective of direct contact receptors and future
groundwater guality (see Section 5.0 of this Record of Decision).

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The STCLs are consistent with ARARs for groundwater, attain USEPA's risk-management goal for remedial
actions, and have been determined by AFCEE, USEPA, and MADEP to be protective. These cleanup levels must
be met at the completion of the remedial action at the limits of STCL exceedance established during
confirmation soil sampling.

7.4.7.2 Description Of Remedial Components.

The selected remedy for AOC SD-3/FTA-3/CY-4 is Confirmation Sampling with Contingency of Excavation and
Asphalt-batching. Key components of this alternative include:

• preparing a brief sampling and analysis work plan

• mobilization and site preparation

• collecting surface soil samples from the area of coal ash disposal outside of the 1994
removal area and analyzing the samples for inorganics and SVOCs

• comparing analytical data to STCLs for SVOCs and inorganics

• if comparison shows contamination above STCLs, implementing the contingency action of
excavating surface soil for asphalt-batching

• collecting post-excavation confirmation samples from the excavation perimeter for analysis
for inorganics and SVOCs

• transporting excavated soil to an onsite asphalt-batching facility for testing and
treatment

• backfilling and restoring excavations with clean borrow material

• using the asphalt-emulsion-coated product as a paving subgrade material at selected
locations at MMR

• maintaining institutional controls that restrict site access and limit potential human
exposure to contaminants

• performing five-year site reviews

Each of these components is described in the following paragraphs.

Preparing a brief sampling and Analysis work plan. AFCEE will prepare a brief sampling and analysis work
plan for collection, analysis, and evaluation of surface soil samples from the area of ash disposal at
AOC SD-3/FTA-3/CY-4 outside of the 1994 ash removal area (see Figure 7-7 in Appendix A). The work plan
will be submitted for USEPA and MADEP review and comment.

Collecting surface soil samples from the area of coal ash disposal outside of the 1994 removal area and
analyzing them for inorganics and SVOCs. Surface soil samples will be collected from the area of ash
disposal outside of the 1994 ash removal area. Target analytes will consist of TCL SVOCs and TAL
inorganics.

Comparing analytical data to STCLs for SVQCs and inorganic. Analytical data will be compared to STCLs for
SVOCs and inorganics. If comparison shows contamination exceeding STCLs, the contingency action of
Excavation and Asphalt-batching would be implemented to remove surface soil exceeding STCLs. If
comparison does not show contamination exceeding STCLs, no excavation will occur under the selected
remedy.

Collecting post-excavation confirmation samples from the excavation perimeter for analysis for inorganics
and SVOCs. Confirmation samples will be collected from the excavation perimeter to confirm the all
surface soil exceeding STCLs is complete.

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be disposed of offsite at a permitted treatment, storage, and disposal facility. Nonhazardous soils and
those meeting threshold criteria will be transported to an onsite facility for asphalt-batching. One TCLP
sample will be collected per 100 cy of excavated material or as directed by the asphalt-batching
subcontractor. In addition, analytical data will be compared to threshold concentrations for soil
recycling facilities contained in the Massachusetts "Interim Remediation Waste Management Policy for
Petroleum Contaminated Soils" to assess acceptability for cold-mix asphalt-batching. Based on available
data, excavation volumes could be as great as 6,500 cy of surface soil (zero to 6 inches). Details of the
asphalt-batching treatment process and associated testing will be presented in a RAWP and/or design plans
and specifications to be reviewed and approved by USEPA and MADEP prior to implementation.

Using the asphalt-emulsion-coated product as a paving subgrade material at MMR. Asphalt-batched material
will be used as paving subgrade material at selected locations at MMR. A minimum 1-inch wear coat will be
placed over the asphalt-batched material.

Maintaining institutional controls that restrict site access and limit potential human exposure to
contaminants. To limit potential human exposure to site-related contaminants, AFCEE will maintain site
access restrictions at AOC SD-3/FTA-3/CY-4 that are consistent with current flightline security measures.
Institutional controls such as fences will be inspected and maintained/repaired not less than annually.
Overall protectiveness will be assessed during five-year site reviews. Alternately, if AFCEE can
demonstrate based on currently available or newly acquired data, that site access restrictions can be
relaxed or removed while protection of human health is maintained, AFCEE may petition USEPA for such a
relaxation or removal of restrictions.

Performing five-year site reviews. Because the assumptions of the risk assessment at AOC SD-3/FTA-3/CY-4
do not allow unrestricted site use, and to provide an opportunity for review of the performance of the
selected remedy, AFCEE will perform five-year site reviews for AOC SD-3/FTA-3/CY-4. During the five-year
reviews, AFCEE will review analytical data from site sampling, asphalt-batching treatment data, and other
pertinent data to assess whether the selected remedy remains protective of human health and the
environment and whether additional remedial action is appropriate.

7.4.8 Statutory Determinations for AOC SD-3/FTA-3/CY-4

The selected remedy for AOC SD-3/FTA-3/CY-4 is consistent with CERCLA and, to the extent practicable, the
NCP. The selected remedy is protective of human health and the environment, attains ARARs, and is
cost-effective. The statutory preference for treatment which permanently and significantly reduces the
toxicity, mobility, or volume of hazardous substances as a principal element is satisfied. Additionally
the selected remedy utilizes alternative treatment technologies and resource recovery technologies to the
maximum extent practicable for this site.

7.4.8.1 The Selected Remedy is Protective of Human Health and the Environment.

The selected remedy for AOC SD-3/FTA-3/CY-4, Confirmation Sampling with Contingency of Excavation and
Asphalt-batching, will permanently reduce the risks to human health and the environment by assessing the
adequacy of previous removal actions and, if necessary, implementing additional actions to eliminate,
reduce, or control exposures to human and environmental receptors through engineering and institutional
controls. The principal threat at AOC SD-3/FTA-3/CY-4 is the potential contamination of surface soil with
inorganics. Institutional controls included in this alternative would limit potential human exposure to
surface soil.

7.4.8.2 The Selected Remedy Attains Applicable or Relevant and Appropriate Requirements.

The selected remedy will attain all applicable or relevant and appropriate federal and state
requirements. No waivers are required. ARARs for AOC SD-3/FTA-3/CY-4 were identified and discussed in the
Feasibility Study (Sections 3.0 and 7.0). Table 7-18 in Appendix B summarizes the ARARs for the selected
remedy, including the regulatory citation, a brief summary of the requirement, and how it will be
attained.

7.4.8.3 The Selected Remedy is Cost-effective.

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long-term effectiveness and permanence; reduction in toxicity, mobility, or volume through treatment; and
short-term effectiveness, in combination. The relationship of the overall effectiveness of this remedial
alternative was determined to be proportional to its costs.

The costs of this remedial alternative exclusive of the contingency action are:

       Estimated Capital Cost                                       $22,000
       Estimated Operation and Maintenance Cost  (Present Worth*)    $25,000
       Estimated Total Cost                                         $47,000

            *Present worth based on 7 percent discount rate, for 30 years.

    The costs including the contingency action are:

       Estimated Capital Cost                                     $1,463,000
       Estimated Operation and Maintenance Cost  (Present Worth*)     $25,000
       Estimated Total Cost                                       $1,488,000

            *Present worth based on 7 percent discount rate, for 30 years.

7.4.8.4  The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment or Resource Recovery
         to the Maximum Extent Practicable.

After AFCEE identified those alternatives that attain or, as appropriate, waive ARARs and that are
protective of human health and the environment, AFCEE determined which alternative made use of permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable. This determination was made by deciding which one of the identified alternatives provides
the best balance of tradeoffs among alternatives in terms of: (1) long-term effectiveness and permanence;
(2) reduction of toxicity, mobility, or volume through treatment; (3)  short-term effectiveness; (4)
implementability; and  (5) cost. The balancing test emphasized long-term effectiveness and permanence and
the reduction of toxicity, mobility, or volume through treatment, and considered the preference for
treatment as a principal element, the bias against offsite land disposal of untreated waste, and
community and state acceptance. AFCEE believes the selected remedy provides the best balance of tradeoffs
among the alternatives that are protective and attain ARARs.

7.4.8.5  The Selected Remedy Satisfies the Preference for Treatment Which Permanently and Significantly
         Reduces the Toxicity, Mobility, or Volume of Hazardous Substances as a Principle Element.

If Confirmation sampling indicates the additional soil removal is needed to meet cleanup goals, the
principal element of the contingency remedy is excavation and asphalt-batching. This element addresses
the principal potential threat at the AOC, contamination of surface soil with SVOCs and inorganics,  by
removing soils that exceed cleanup levels and treating them with asphalt-batching to reduce contaminant
mobility. The selected remedy satisfies the statutory preference for treatment as a principal element.

7.4.9 Documentation of No Significant Changes for AOC SD-3/FTA-3/CY-4

AFCEE presented a Proposed Plan  (preferred alternative) for remedial action at AOC SD-3/FTA-3/CY-4 source
areas at a public information meeting held at the Barnstable County Fairgrounds in Falmouth,
Massachusetts, on November 13, 1997, and at a public hearing held at Mashpee High School in Mashpee,
Massachusetts, on December 2, 1997. There have been no significant changes made to the Confirmation
Sampling with Contingency of Excavation and Asphalt-batching preferred alternative presented in the
Proposed Plan.

7.5 DECISION SUMMARY FOR AOC SD-4

The following subsections summarize information considered during the selection of source-area remedial
action for AOC SD-4. A more detailed description of AOC SD-4 site history, contamination, and potential
site risks can be found in the Remedial Investigation Report for Area of Contamination SD-4 prepared by
COM Federal Programs Corporation in 1996. Additional discussion concerning candidate remedial actions to
reduce site risks is contained in the final Six Areas of Contamination Source Area Feasibility Study
prepared by ABB-ES in 1997. These reports are available for review at the main libraries in the towns of
Bourne, Falmouth, Mashpee, and Sandwich; and at the U.S. Coast Guard library at MMR.

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7.5.1 Scope and Role of Response Action at AOC SD-4

This response action addresses source-area soil contamination in the SD-4 drainage ditch north of Reilly
Road and sediment contamination at a small pond (the "upgradient pond") located along the SD-4 drainage
way south of Reilly Road. Remedial actions north of Reilly Road will focus on TPH while remedial actions
south of Reilly Road will focus on inorganics.

To limit the adverse effects of excavation on the AOC SD-4 pond and wetland areas south of Reilly Road,
remedial activities there will focus on the pond where high concentrations of inorganics (especially
lead) and potential contaminant bioavailability have the greatest potential to cause adverse
environmental effects. Potential exceedances of AWQC in pond surface water are also a concern.
Pre-excavation studies at the pond will focus on surface water guality on the bioavailability of
inorganic contaminants, and on evaluation of pond/wetland structure and productivity to assess whether
adverse effects are actually occurring and whether sediment remediation is justified. The results of the
pre-excavation studies will be used to identify areas for remediation.

By excavating and treating sediments that contribute to unacceptable surface water contamination or that
contain inorganic contaminants with high potential bioavailability, the selected action will prevent
those sediments from contributing to adverse ecological effects. Because contaminated sediments are the
interpreted source of surface water contamination, AFCEE, by taking action to address contaminated
sediments, will not have to take separate action to clean up surface water. The risk assessment did not
identify the need to clean up subsurface soil or groundwater at this AOC.

7.5.2 History of Land Use at AOC SD-4

AOC SD-4 is a drainage way which lies on both sides of Reilly Road (Figure 7-8 in Appendix A). The
drainage way received overflow from storm sewers at the hangars, the runway/ramps, and a former
pumphouse. Operations at these buildings spilled or disposed liguids into the storm sewer. The following
items summarize the history of AOC SD-4.

• 1950s. SD-4 began receiving stormwater runoff from the runway, aircraft maintenance ramp,
aircraft hangars, support buildings, and a fuel pumphouse.

• 1968. An oil/water separator was constructed at SD-4, south of Reilly Road.

• 1989 to 1991. A two-phase SI was performed to assess the presence of sediment, soil, and
groundwater contamination.

• 1993 to 1994. An RI was performed to characterize the nature and distribution of soil,
sediment, surface water, and groundwater contamination and to evaluate potential site risks.

• 1997. A Feasibility Study was performed to evaluate approaches to control potential site
risks.

7.5.3 Summary of Site Characteristics at AOC SD-4

AOC SD-4 is a mostly wooded drainage basin located in the southeastern section of MMR, beginning within
the flightline security area immediately east of Hangar 124 and extending approximately 3,500 feet south
to Johns Pond (see Figure 7-8 in Appendix A). The head of the drainage way, located north of Reilly Road,
is within the flightline security area, approximately 300 feet in length, and is relatively flat, grassy,
and at the approximate elevation of the flightline area. Access to areas within the flightline area is
controlled with fences and guard posts, and activities not related to aircraft operations are limited and
strictly controlled. Fences around the flightline areas are inspected daily by base security. These site
access restrictions are expected to remain in place through the duration of the current lease (expiration
date of 2026) and the planned 25-year renewal. The remainder of the drainage way, located south of Reilly
Road, is outside of the flightline security area. The geomorphology of AOC SD-4 south of Reilly Road
suggests a relic glacial meltwater drainage way located within hilly terrain. Because of the size of the
AOC, it was divided into upgradient and downgradient areas. The upgradient area extends from the area
east of Hangar 124 to approximately 300 feet southwest of the MMR boundary near groundwater monitoring
well MW-515A and includes a low wetlands area and small pond. The downgradient area includes the drainage
swale from MW-515A south to a former cranberry bog adjacent to Johns Pond.

7.5.3.1 Surface Soil and Sediment Contamination Assessment.

Field observations and analytical results show that contamination of surface soils is limited primarily
to the presence of low concentrations of SVOCs, pesticides, PCBs, inorganics, and TPH in the wetlands
south of the unnamed upgradient pond at the confluence of the AOC SD-3/FTA-3/CY-4 and AOC SD-4 drainage

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ways. TPH appears to correlate positively with the detection of organic fuel constituents and
carcinogenic PAHs. The only other sample location with significant soil contamination was SI sample SD-3,
located at the head of the drainage way north of Reilly Road, in which TPH exceeded 1,200 mg/kg. The RI
report estimated the volume of TPH-contaminated soil/sediment as 1,442 cy, based on an assumed thickness
of 1 foot and an approximate surface area of 38,750 sguare feet. This volume also included surface soil
samples containing high concentrations of carcinogenic PAHs, as well as an area of visibly stained soils
located south of the upgradient pond and wetlands.

Dieldrin, a breakdown product of the pesticide aldrin, appears to be ubiguitous in surface soils; it was
also detected in surface water and sediment samples throughout the AOC SD-4 area. Dieldrin also appears
at other AOCs at MMR (ABB-ES, 1993) . The detection of this very persistent pesticide is attributed to
past pest control practices at MMR. Similarly, 4,4-DDT and its breakdown products are also found
throughout AOC SD-4.

Detection of the PCB Aroclor-1260 was limited to surface soil, sediment, and surface water samples,
suggesting that contamination is associated with surface water runoff, sediment transport, and deposition
within the AOC SD-4 drainage way.

7.5.3.2 Subsurface Soil Contamination Assessment.

Although detectable concentrations of VOCs, SVOCs, pesticides, and TPH were present, significant
contamination of subsurface soils was not identified. Chromium and iron were the only inorganics detected
above MMR background concentrations. The fine-grained nature and organic content of the alluvial
sediments and wetlands soils in the bottom of the drainage way may have sorbed contaminants, thereby
mitigating large-scale vertical migration of contaminants from the surface to the deeper overburden.

7.5.3.3 Groundwater Contamination Assessment.

Groundwater sampling conducted at AOC SD-4 showed minimal contamination. Concentrations of analytes were
below MCLs, with the following exceptions: (1) total lead was detected at 17.4 Ig/L (total) in MW-1
(located in the drainage ditch north of Reilly Road), which exceeds the federal action level and state
MCL of 15 Ig/L; and (2) dissolved antimony was detected at 6.4 Ig/L in the duplicate sample from W-6
(located downgradient of former Building 123), which exceeded the state and federal MCL of 6 Ig/L.

7.5.3.4 Surface Water Contamination Assessment.

The following compounds exceeded federal Ambient Water Quality Criteria (AWQC) in surface water samples
collected from the unnamed upgradient pond and the drainage way north of Johns Pond: the VOC PCE; and the
SVOCs benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene,
indeno(1,2,3-c,d)pyrene, dibenzo(a,h)anthracene, and benzo(g,h.i)perylene; the pesticides dieldrin and
4,4'-DDT; and the PCB Aroclor-1260. These compounds were detected at concentrations of 8 Ig/L or less.
PCE and phenanthrene exceeded the human-health AWQC, the presence of PCE in surface water at the
downgradient former cranberry bog may be the result of discharge of contaminated groundwater.

The remaining seven PAB's were detected in surface water samples from the upgradient pond at
concentrations exceeding the chronic freshwater AWQC. The pesticides dieldrin and 4,4'-DDT exceeded the
AWQC for human and aguatic receptors in samples also obtained from the upgradient pond. The PCB
Aroclor-1260 was detected in a sample obtained from the upgradient pond at a concentration exceeding AWQC
for human and aguatic receptors. These contaminants were possibly entrained in the samples as a result of
stirring up contaminant-sorbed sediments. AWQC were also exceeded for aluminum, arsenic, cadmium, copper,
iron, lead, mercury, thallium, zinc, and cyanide in samples obtained from the small upgradient pond.

7.5.4 Summary of Site Risks at AOC SD-4

The RI report for AOC SD-4 included a human-health PRA to evaluate potential human-health risks
associated with exposure to contaminated surface soil, groundwater, pond sediment, pond surface water,
and wetlands surface water under current and future site conditions and an ecological PRA (COM 1996). The
following subsections summarize the human-health and ecological PRAs. A detailed discussion of the risk
assessment approach and results is presented in the MMR Risk Assessment Handbook (ASG, 1994) and in the
RI report (COM 1996).

7.5.4.1 Human-health Risk Assessment Summary.

The human-health PRA was based on samples collected during the RI. Table 7-19 in Appendix B lists
human-health contaminants of potential concern in pond sediment at AOC SD-4.

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The human-health PRA assessed potential risks associated with the following exposure scenarios based on
the guidance of the MMR Risk Assessment Handbook and the location of AOC SD-4:

• Current Land Use Conditions: potential older child trespasser exposure to surface soils
(zero to 2 feet bgs) at maximum and exposure point mean concentrations; and potential
utility worker exposure to surface soils (zero to 10 feet bgs) at maximum and exposure
point mean concentrations for a six-week period

• Future Land Use Conditions: potential young child resident exposure to surface soils (zero
to 2 feet bgs) at maximum and exposure point mean concentrations; potential utility worker
exposure to surface soils (zero to 2 feet bgs) at maximum and exposure point mean
concentrations for a six-month period; and potential adult resident exposure to surface
soils (zero to 10 feet bgs), groundwater, pond surface water, pond sediment, and wetlands
surface water at maximum and exposure point mean concentrations

The human-health PRA indicates that cancer risks for current utility workers and older child trespassers
exposed to surface soil fall within or below the USEPA target risk range of 10 -4 to 10 -6 and below the
MADEP target cancer risk of 1x10 -5. Potential noncancer effects are not likely because His for both
current and potential receptors are less than 1.

For the future utility worker, cancer risks are within the USEPA target risk range and below the MADEP
target risk. Noncancer His were calculated to be less than 1. Cancer risks for the future child resident
are within the USEPA target risk range and above the MADEP target risk. Noncancer His were calculated to
be less than 1.

Adult resident medium-specific cancer risks range from 1x10 -5 to 3x10 -4 for mean concentrations and
5x10 -5 to 5x10 -4 for maximum concentrations. Total lifetime cancer risks (child and adult) exceed both
the USEPA target risk range and the MADEP target risk. The principal risk drivers are carcinogenic PAHs
and Aroclor-1260 in surface soils (SS-8, SS-9, and SS-11) ; 1,1 dichloroethane, total arsenic, and
beryllium in groundwater (MW-3); and carcinogenic PAHs in pond surface water (SW-5). The maximum
groundwater concentration of arsenic is above the MMR background level, whereas beryllium is egual to the
MMR background level. Concentrations of both arsenic and beryllium in groundwater are below the MCL.

Potential noncancer effects may be likely for the adult resident exposed to groundwater based on His
greater than 1 for both maximum and mean concentrations. These exceedances are attributed to
1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and manganese in groundwater. The maximum concentration
of manganese exceeded the MMR background concentration. MCLs are not available for manganese,
1,2,4-trimethylbenzene, or 1,3, 5-trimethylbenzene.

Based on the lead Integrated Exposure Uptake Biokinetic model, projected blood levels for greater than 98
percent of the children are expected to be below the benchmark value of 10 micrograms per deciliter based
on mean concentrations only. Table 7-20 in Appendix B summarizes results of the human-health PRA.

7.5.4.2 Ecological Risk Assessment Summary.

The AOC SD-4 PRA report evaluated potential ecological risks associated with exposure to contaminated
surface soil (zero to 2 feet bgs), sediment, and surface water at AOC SD-4 (COM 1996) . Separate
evaluations were made for exposure of various receptors to the following media at AOC SD-4: surface soil
and pond surface water; pond sediment and pond surface water; and wetlands sediment and wetlands surface
water (see Table 7-19 in Appendix B).

Results of the ecological PRA show potential adverse effects to all receptors of each of the three media
groups because His were all at or above 1. Major contributors to risk for the terrestrial birds and
mammals exposed to surface soil and pond surface water are inorganic COCs, benzo(b)fluoranthene,
benzo(k)fluoranthene, and Aroclor-1260. For terrestrial birds and mammals exposed to pond sediment and
surface water, the majority of risk is attributable to inorganic COCS.

Semi-aguatic receptors of pond sediment and surface water had His up to seven orders of magnitude greater
than 1. Nearly all COCs were risk drivers for these receptors. Although semi-aguatic receptors have
access to the pond, it is not known if the pond supports an abundance of fish that are consumed by
semi-aguatic receptors such as the osprey. Risk to terrestrial and semi-aguatic receptors from wetlands
sediment and surface water is caused primarily by inorganics.

Risks to aguatic organisms from pond surface water were evaluated by comparing surface water
concentrations with aguatic benchmark values. Aroclor-1260, dieldrin, 4,4'-DDT, and inorganics exceeded
benchmark values. Risk to benthic invertebrates were evaluated by comparing porewater concentrations to
benchmark values. Pesticides and Aroclor-1260 exceeded benchmark values.

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An assessment of risks to terrestrial vegetation resulted in an HI of 26 at maximum surface soil
concentrations and an HI of 8 at mean surface soil concentrations. At maximum concentrations, the HQs for
benzo(b)fluoranthene, benzo(k)fluoranthene, fluoranthene, lead, zinc, copper, and mercury exceeded 1. At
mean concentrations, only the HQ for lead exceeded 1. Tables 7-21 and 7-22 in Appendix B summarize
terrestrial vegetation risk. Table 7-23 in Appendix B summarizes the ecological PRA.

7.5.4.3 Risk Assessment Uncertainties and Interpretation.

The human-health PRA at AOC SD-4 concluded that potential risks associated with exposure to soils under
current land use conditions do not exceed USEPA or MADEP target risk levels for carcinogenic or
noncarcinogenic endpoints. For the future land use scenarios and maximum exposure concentrations, the PRA
concluded that potential cancer risks to child and adult residents and potential noncancer risk to adult
residents were at or above USEPA and MADEP target values. Principal contributors to potential cancer risk
were arsenic, beryllium, and 1,1-dichloroethane in groundwater, PAHs in pond surface water, and PAHs and
Aroclor-1260 in surface soils. Noncancer risks in groundwater were largely attributable to
1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and manganese. Potential risks at mean exposure point
concentrations were lower, showing slight exceedances of target risk values. Because arsenic and
beryllium in groundwater were below MCLs, and MCLs are not available for 1,2,4-trimethylbenzene and
1,3,5-trimethylbenzene, the PRA did not recommend cleanup of site groundwater. The possibility that
suspended sediments may have contributed to detections of contaminants in surface water lent considerable
uncertainty to the calculation of potential risk from exposure to surface water.

For ecological receptors, calculated His exceeded 1 for exposure to surface soil, surface water, and
sediment. Major contributors to risk for terrestrial birds and mammals exposed to surface soil and pond
surface water were inorganics, SVOCs, and Aroclor-1260. For terrestrial birds and mammals exposed to pond
sediment and surface water, the majority of risk was contributed by inorganics. However, because of the
conservative nature of the ecological PRA and guestions as to whether evaluated receptors actually make
extensive use of the AOC, the PRA likely overestimated potential ecological risk for terrestrial
receptors exposed to wetlands sediment and surface water. Similarly, risks to terrestrial receptors from
surface soil and pond surface water may have been overestimated; the PRA concluded that adverse effects
might be only local and limited in nature. Wetland sediment and surface water presented His to the meadow
vole, northern harrier, mallard duck, muskrat, and black duck that exceeded 1, but that were less than
10, suggesting that population effects are unlikely and that individual effects are uncertain. Although
His for the black-crowned night heron and osprey were 3 to 6 orders of magnitude greater than 1, field
observations during the RI suggest that the area would not be used extensively by either the
black-crowned night heron on the osprey. For these reasons, response objectives were not identified for
wetland sediment and surface water.

Evaluation of semi-aguatic and aguatic receptor exposure to pond sediment and pond surface water resulted
in calculated His up to several orders of magnitude greater than 1, suggesting possible adverse effects.
Major contributors to His were SVOCs, pesticides, Aroclor-1260, and inorganics. The possibility that
suspended sediments may have contributed to detection of contaminants in surface water, and the lack of
data concerning porewater concentrations and bioavailability of sediment contaminants, lent uncertainty
to the PRA.

Because of the relatively low water-solubility of most SVOCs, pesticides, and PCBs and their tendency to
sorb to soil and sediment, pond surface water is likely acting not as a source but rather as a transport
mechanism for these compounds. Cleanup of sediment, the likely source of the observed surface water
contamination, should result in the concomitant cleanup of surface water. Therefore, remedial action
objectives were not established for surface water.

7.5.5 Description of Evaluated Alternatives for AOC SD-4

• No Action
• Excavation and Asphalt-batching
• Excavation and Offsite Treatment and Disposal

Because potential ecological risk is a major concern at this site, the Limited Action alternative was not
evaluated in detail; the institutional controls of the Limited Action alternative have little ability to
control ecological exposure and risk.

To limit the potential adverse effects of excavation on the pond and wetland areas of SD-4, remedial
activities south of Reilly Road will focus on the pond where high concentrations of inorganics

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(especially lead)  and potential contaminant bioavailability have the greatest potential to cause adverse
environmental effects.

7.5.5.1 No Action.

The No Action alternative was evaluated as a baseline with which to compare other alternatives.  No
remedial action,  monitoring,  further investigation,  or five-year site reviews would be performed as part
of this alternative.

          Estimated Time for Design and Construction:                            not applicable
          Estimated Time for Cleanup:                                            not applicable
          Estimated Capital Cost:                                                             $0
          Estimated Operation and Maintenance Cost:                                           $0
          Estimated Total Cost                                                               $0

7.5.5.2 Excavation and Asphalt-batching.

The Excavation and Asphalt-batching alternative at AOC SD-4 includes the following key components:

       •      performing pre-excavation studies
       •      mobilization and site preparation
       •      performing a wetland delineation prior  to excavation of pond  sediment
       •      identifying areas for remedial  action at the upgradient pond  based  on the results  of
              pre-excavation  studies
       •      preparing a Wetland  Restoration Specification (only if disturbance  of pond/wetland is
              planned)
       •      performing pre-excavation confirmation  soil  sampling in the drainage ditch north of Reilly
              Road to assess  the horizontal and vertical distribution of contamination exceeding the  TPH
              STCL and to identify areas  for  excavation
       •      excavating soil and  sediment to achieve cleanup  criteria
       •      collecting post-excavation  confirmation sediment samples from the excavation perimeter  at
              the  upgradient  pond  for analysis for inorganics  and/or acid volatile sulfides and
              simultaneously  extracted metals
       •      collecting post-excavation  confirmation soil samples from the excavation perimeter in the
              drainage ditch  north of Reilly  Road for analysis for TPH
       •      transporting excavated soil and sediment to  an onsite asphalt-batching facility for testing
              and  treatment
       •      removing temporary roads, backfilling excavations,  and restoring wetland areas
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •      performing five-year site reviews

         Estimated Time for Design and Construction:                         9 months
         Estimated Time for Cleanup:                                        3 months
         Estimated Capital Cost:                                          $1,428,000
         Estimated Operation and Maintenance Cost:                                $0
         Estimated Total Cost                                             $1,428,000

7.5.5.3 Excavation and Offsite Treatment and Disposal.

The Excavation and Offsite Treatment and Disposal alternative  at AOC SD-4  includes the following key
components:

       •      performing pre-excavation studies
       •      mobilization and site preparation
       •      performing a wetland delineation prior  to excavation of pond  sediment
       •      identifying areas for remedial  action at the upgradient pond  based  on the results  of
              pre-excavation  studies
       •      preparing a Wetland  Restoration Specification (only if disturbance  of pond/wetland is
              planned)
       •      performing pre-excavation confirmation  soil  sampling in the drainage ditch north of Reilly
              Road to assess  the horizontal and vertical distribution of contamination exceeding the  TPH
              STCL and to identify areas  for  excavation
       •      excavating soil and  sediment to achieve cleanup  criteria
       •      collecting post-excavation  confirmation sediment samples from the excavation perimeter  at
              the  upgradient  pond  for analysis for inorganics  and/or acid volatile sulfides and
              simultaneously  extracted metals

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• collecting post-excavation confirmation soil samples from the excavation perimeter in the
drainage ditch north of Reilly Road for analysis for TPH
• transporting excavated sediment to an onsite location for testing and dewatering
• transporting soil and dewatered sediments to a permitted offsite treatment, storage, and
disposal facility for treatment and/or disposal
• removing temporary roads, backfilling excavations, and restoring wetland areas
• performing five-year site reviews

Estimated Time for Design and Construction: 9 months
Estimated Time for Cleanup: 3 months
Estimated Capital Cost: $1,375,000
Estimated Operation and Maintenance Cost: $0
Estimated Total Cost $1,375,000

7.5.6 Summary of Comparative Analysis of Alternatives for AOC SD-4

The following subsections; summarize the Comparative Analysis of Alternatives performed in the
Feasibility Study for AOC SD-4.

7.5.6.1 Overall Protection of Human Health and the Environment.

The No Action alternative would be protective of human health under current conditions, but would not
protect ecological receptors. It would not provide overall protection of human health and the
environment.

The two excavation alternatives offer similar levels of protection. Both would be protective of human
health under current conditions and would also provide protection of the environment, especially in the
small pond near the upper end of the drainage way.

7.5.6.2 Compliance with Applicable or Relevant and Appropriate Reguirements.

The No Action alternative does not include remedial actions that would trigger ARARs. Both excavation
alternatives would be designed and implemented to comply with all ARARs. No waivers would be reguired.

7.5.6.3 Long-term Effectiveness and Permanence.

Because the No Action alternative does not assess the bioavailability of contaminants in pond sediments
or further assess ecological effects, it does not provide a long-term or permanent solution to protect
human health and the environment. Both excavation alternatives include assessment of contaminant
bioavailability and biocommunity effects and include removal activities, if reguired. Both are considered
protective of human health and the environment.

7.5.6.4 Reduction of Toxicity, Mobility, or Volume Through Treatment.

The No Action alternative does not provide treatment to reduce the toxicity, mobility, or volume of
contaminants. The Excavation and Asphalt-batching alternative provides treatment that will reduce the
mobility of contaminants. The likely off-site treatment approach of asphalt-batching would reduce
contaminant mobility to the same extent as the on-site asphalt-batching alternative.

7.5.6.5 Short-term Effectiveness.

The No Action alternative does not include actions that would result in adverse short-term effects to
human health or the environment; however, by failing to assess contaminant bioavailability and
biocommunity effects, potential ecological risks may be ignored. Both excavation alternatives include
measures to assess contaminant bioavailability and to remove sediments where potential bioavailability
and community effects indicate that removal action is warranted. Construction activities associated with
the two excavation alternatives would likely result in significant short-term adverse effects on pond and
wetland habitat. Restoration measures would be reguired to mitigate these adverse effects. Construction
activities would present minimal short-term risks to construction workers, and those risks would be
minimized through the development of and adherence to a site-specific Health and Safety Plan.

7.5.6.6 Implementability.

The technical and administrative feasibility of all three alternatives is considered high. None of the
alternatives include actions that reguire substantial technical or administrative resources.

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7.5.6.7 Cost.

Cost includes the capital (up-front) cost of implementing an alternative and the long-term cost of
operating and maintaining the alternative. Capital and operation and maintenance costs for each
alternative were calculated with an estimated accuracy of 30 percent to +50 percent. The alternative with
the lowest capital costs is the No Action alternative which does not include construction. The estimated
costs for the other two alternatives are separated by approximately 4 percent and are approximately
egual. The difference in cost between the two excavation alternatives would likely be reduced if the
Excavation and Asphalt-batching alternative were implemented concurrently with asphalt-batching at other
AOCs. Cost is not a good differentiator between the two excavation alternatives.

Operation and maintenance costs do not differentiate among the alternatives.

To enable comparison of costs which will occur over different time periods, the present worth of capital
and operation and maintenance costs was also calculated. The present worths for the two excavation
alternatives are separated by approximately 4 percent and are approximately egual. Present worth is not a
differentiator between these two.

The following table compares capital, operation and maintenance, and present worth costs for each
alternative evaluated in detail for AOC SD-4.

Total Total O&M Total Costs
Alternative Capital Cost (Present Worth*) (Present Worth)

No Action $0 $0 $0

Excavation and $1,428,000 $0 $1,428,000
Asphalt-batching

Excavation and Offsite $1,375,000 $0 $1,375,000
Treatment and
Disposal

*Present worth based on 7 percent discount rate for 30 years.

7.5.6.8 State Acceptance.

The Commonwealth of Massachusetts has reviewed the RI and Feasibility Study reports and the Proposed Plan
and concurs with AFCEE's selected remedy.

7.5.6.9 Community Acceptance.

AFCEE also received a comment from the Mashpee Conservation Commission which stated the Commission's
desire to maintain the guality habitat of the SD-4 pond and wetland and to work with AFCEE on any
restoration activities following remedial activities. AFCEE believes that the proposed bioavailability
study and biocommunity survey will afford ecological protection and minimize pond/wetland disruption.
AFCEE will involve the Mashpee Conservation Commission in the development of detailed wetland restoration
plans.

7.5.7 Description of the Selected Remedy for AOC SD-4

The selected remedy for ALOC SD-4 is Excavation and Asphalt-batching. This alternative provides
institutional and engineering controls for areas north of Reilly Road to limit exposure to site-related
contaminants in soil and to reduce source-area soil contaminant concentrations to protective levels. For
areas south of Reilly Road, this alternative provides sampling and engineering controls to assess the
contribution of sediment contaminants to surface water contamination, the potential bioavailability and
toxicity of pond sediments, and, if necessary, removal of source-area sediments exceeding cleanup
criteria and treatment of excavated material to reduce contaminant mobility. The risk assessment did not
identify the need to clean up groundwater at this AOC; conseguently, the remedy does not include a
management of migration component.

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7.5.7.1 Soil and Sediment Cleanup Levels.

Based upon data developed in the RI and the PRA and summarized in the Feasibility Study, remedial actions
are warranted in the AOC SD-4 drainage ditch north of Reilly Road to address potential risks associated
with possible human direct contact and ecological receptor exposure to source-area soils contaminated
with TPH.

The TPH STCL established for the DSRP at MMR was used to estimate residual soil levels that will be
protective of direct contact and ecological receptors and future groundwater guality  (see Section 5.0 of
this Record of Decision).  Based on the inside-the-flightline status of the area north of Reilly Road,
1200 mg/kg TPH was selected as a protective clean-up level. This STCL is consistent with ARARs for
groundwater, attains USEPA's risk-management goal for remedial actions,  and has been determined by AFCEE,
USEPA, MADEP to be protective. This clean-up level must be met at the completion of the remedial action
at the limits of STCL exceedance established during predesign confirmation soil sampling.

For the small pond south of Reilly Road, if the results of the pre-excavation surface water quality
bioavailabilty, and biocommunity studies indicate the need for sediment cleanup, a second phase of study
may be required to develop appropriate cleanup criteria. The STCLs used north of Reilly Road and at other
AOCs at MMR were not developed with the intent of sediment remediation and may not be appropriate as a
basis for cleanup at AOC SD-4. If the pre-excavation studies indicate the need for sediment remediation
at AOC SD-4, AFCEE will develop a plan, to be reviewed and approved by USEPA and MADEP, to develop AOC
SD-4 site-specific sediment cleanup levels.

7.5.7.2 Description of Remedial Components.

The selected remedy for AOC SD-4 is Excavation and Asphalt-batching. Key components of this alternative
include:

       •       performing pre-excavation studies
       •       mobilization and site preparation
       •       performing a wetland delineation prior to excavation of pond sediment
       •       identifying  areas for remedial action at the upgradient pond based on the results of
              pre-excavation studies
       •       preparing a  Wetland Restoration Specification (only if disturbance of pond/wetland is
              planned)
       •       performing pre-excavation confirmation soil sampling in the drainage ditch north of Reilly
              Road to assess the horizontal and vertical distribution of contamination exceeding TPH STCL
              and to identify areas for excavation
       •       excavating soil and sediment exceeding cleanup criteria
       •       collecting post-excavation confirmation sediment samples from the excavation perimeter at
              the upgradient pond for analysis for inorganics and/or acid volatile sulfides and
              simultaneously extracted metals
       •       collecting post-excavation confirmation soil samples from the excavation perimeter in the
              drainage ditch north of Reilly Road for analysis for TPH
       •       transporting excavated soil and sediment to an onsite asphalt-batching facility for testing
              and treatment
       •       removing temporary roads,  backfilling excavations,  and restoring wetland areas
       •       using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •       performing five-year site reviews

Each of these components is described in the following paragraphs.

Performing pre-excavation studies. Prior to any excavation activities, AFCEE will carry out
pre-excavation studies to assess surface water quality in the upgradient pond and the bioavailability of
inorganics  (especially lead) in pond sediments. The assessment of surface water quality will include
collection of surface water samples from the upgradient pond for analysis for SVOCs, PCBs, total
dissolved metals, hardness, pH and total suspended solids. The analytical results will be compared to
AWQC as part of the assessment of whether excavation of pond sediments is warranted. Details will be
presented in the RAWP.

The assessment of bioavailability will include analysis for acid volatile sulfides and simultaneously
extracted metals and total organic carbon. In addition, AFCEE will evaluate pond/wetland structure and
productivity to assess whether adverse effects relating to pond sediment are evident, and whether any
potential benefits of sediment remediation justify disruption of the pond/wetland area. Details of
proposed sampling and analysis, excavation, and backfill/restoration activities will be presented in a
RAWP and in a Wetland Restoration Specification to be reviewed and approved by regulatory agencies prior

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to implementation. Figure 7-9 in Appendix A shows the area proposed for evaluation/cleanup at AOC SD-4.

Performing a wetland delineation. AFCEE will perform a wetland delineation south of Reilly Road prior to
any excavation activities in that area. Delineation of wetlands will be necessary to assess the extent of
potential wetland restoration activities.

Identifying areas for remedial action at the upgradient pond. Areas at the upgradient pond requiring
remediation will be identified based on the pre-excavation surface water, bioavailability, and
biocommunity studies, and on any subsequent studies required to develop sediment cleanup criteria.

Preparing a Wetland Restoration Specification (only if disturbance of pond/wetland is planned). Prior to
performing excavation activities in a delineated wetland, AFCEE will prepare a Wetland Restoration
Specification in accordance with identified ARARs for review and comment by USEPA, MADEP, and the Mashpee
Conservation Commission.

Performing pre-excavation confirmation soil sampling. AFCEE will perform pre-excavation soil sampling in
the drainage ditch north of Reilly Road to assess the horizontal and vertical distribution of
contamination exceeding the TPH STCL and to identify areas for excavation.

Excavating soil and sediment exceeding cleanup criteria. Areas identified for remediation will be
excavated using backhoes, excavators, dredges, or other appropriate construction equipment.

Collecting post-excavation confirmation sediment samples from the excavation perimeter at the upgradient
pond. Confirmation sediment samples will be collected from the perimeter of the excavation (post
excavation) at the upgradient pond to confirm that clean-up goals have been achieved.

Collecting post-excavation confirmation soil samples from the excavation-perimeter for TPH. Confirmation
soil samples will be collected from the perimeter of the excavation in the drainage ditch north of Reilly
Road and analyzed for TPH to assess whether the TPH clean-up goal has been achieved.

Transporting excavated soil and sediment to an onsite asphalt-batching facility for testing and
treatment. Samples of the excavated soil and sediment will be collected and analyzed to assess whether
the material must be treated/disposed of as a hazardous substance. TCLP testing will be performed when
total concentrations in soil/sediment are above theoretical concentrations at which TCLP criteria may be
met or exceeded. Materials considered hazardous will be disposed of offsite at a permitted treatment,
storage, and disposal facility. Nonhazardous soils/sediments and those meeting threshold criteria will be
transported to an onsite facility, mixed with drying agents and aggregate brought in from offsite, and
passed through the asphalt-batching system. One TCLP sample will be collected per 100 cy of excavated
material or as directed by the asphalt-batching subcontractor. In addition, analytical data will be
compared to threshold concentrations for soil recycling facilities contained in the Massachusetts
"Interim Remediation Waste Management Policy for Petroleum Contaminated Soils" to assess acceptability
for cold-mix asphalt-batching.

It is anticipated that sediments will be dewatered using a drainage pad. Supernatant will be collected
and treated in a clarifier or other suitable treatment unit to meet pretreatment requirements for
indirect discharge or to prevent exceedances of Ambient Water Quality" Criteria in the receiving water if
discharged directly. Details of the asphalt-batching treatment process and associated testing will be
presented in a RAWP and/or design plans and specifications to be reviewed and approved by USEPA and MADEP
prior to implementation.

Removing temporary roads, backfilling excavations, and restoring wetland areas. Following removal
activities excavations will be backfilled with clean fill material, temporary roads and workpads will be
removed, and the disturbed wetland areas restored in accordance with the Wetland Restoration
Specification.

Using the asphalt-emulsion-coated product as a paving subgrade material at Asphalt-batched material will
be used as paving subgrade material at selected locations at MMR. A minimum IE-inch wear coat will be
placed over the asphalt-batched material.

Performing five-year site review . Because this remedy will leave TPH at concentrations above
health-based levels for unrestricted use north of Reilly Road, the requirement for five-year site reviews
will apply to actions taken north of Reilly Road. Actions proposed for south of Reilly Road, are based on
unrestricted site use and will not be subject to five-year site reviews.

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7.5.8 Statutory Determinations for AOC SD-4

The selected remedy for AOC SD-4, is consistent with CERCLA and, to the extent practicable, the NCP. The
selected remedy is protective of human health and the environment, attains ARARs, and is cost-effective.
The statutory preference for treatment which permanently and significantly reduces the toxicity,
mobility, or volume of hazardous substances as a principal element is satisfied. Additionally the
selected remedy utilizes alternative treatment technologies and resource recovery technologies to the
maximum extent practicable for this site.

7.5.8.1 The Selected Remedy is Protective of Human Health and the Environment.

The selected remedy for AOC SD-4 will permanently reduce the risks to human health and the environment by
eliminating, reducing, or controlling exposures to human and environmental receptors through engineering
controls. The principal threats at AOC SD-4 are inorganics in pond sediments and TPH in the drainage
ditch north of Reilly Road.

The effectiveness of the selected alternative north of Reilly Road win be evaluated by comparing soil
sampling data for TPH to the clean-up goal of 1200 ppm. The effectiveness at the small pond south of
Reilly Road will be evaluated by performing sampling to assess contaminant bioavailability and evaluating
biocommunity structure and productivity to assess potential adverse effects.

7.5.8.2 The Selected Remedy Attains Applicable or Relevant and Appropriate Reguirements.

The selected remedy will attain all applicable or relevant and appropriate federal and state
reguirements. No waivers are reguired. ARARs for AOC SD-4 were identified and discussed in the
Feasibility Study (Sections 3.0 and 7.0). Table 7-24 in Appendix B summarizes the ARARs for the selected
remedy, including the regulatory citation, a brief summary of the reguirement, and how it will be
attained.

7.5.8.3 The Selected Remedy is Cost-effective.

In AFCEE's judgment, the selected remedy is cost-effective (i.e., the remedy affords overall
effectiveness proportional to its costs). In selecting this remedy, after AFCEE identified alternatives
that are protective of human health and the environment and attain, or, as appropriate, waive ARARs,
AFCEE evaluated the overall effectiveness of each alternative according to the relevant three criteria:
long-term effectiveness and permanence; reduction in toxicity, mobility, or volume through treatment; and
short-term effectiveness, in combination. The relationship of the overall effectiveness of this remedial
alternative was determined to be proportional to its costs.

The costs of this remedial alternative are:

Estimated Capital Cost $1,428,000
Estimated Operation and Maintenance Cost $0
Estimated Total Cost $1,428,000

7.5.8.4 The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment or Resource Recovery
to the Maximum Extent Practicable.

After AFCEE identified those alternatives that attain or, as appropriate, waive ARARs and that are
protective of human health and the environment, AFCEE determined which alternative made use of permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable. This determination was made by deciding which one of the identified alternatives provides
the best balance of tradeoffs among alternatives in terms of: (1) long-term effectiveness and
permanence; (2) reduction of toxicity, mobility, or volume through treatment; (3) short-term
effectiveness; (4) implementability; and (5) cost. The balancing test emphasized long-term effectiveness
and permanence and the reduction of toxicity, mobility, or volume through treatment and considered the
preference for treatment as a principal element, the bias against offsite land disposal of untreated
waste, and community and state acceptance. AFCEE believes the selected remedy provides the best balance
of tradeoffs among the alternatives that are protective and attain ARARs.

7.5.8.5 The Selected Remedy Satisfies the Preference for Treatment Which Permanently and Significantly
Reduces the Toxicity, Mobility, or Volume of Hazardous Substances as a Principle Element.

The principal element of the selected remedy is excavation and asphalt-batching. This element addresses
the principal threats at the AOC, soil north of Reilly Road contaminated with TPH and pond sediments
contaminated with inorganics, by removing soils/sediments that exceed cleanup levels and treating them
with asphalt-batching to reduce contaminant mobility. The selected remedy satisfies the statutory

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preference for treatment as a principal element.

7.5.9 Documentation of No Significant Changes for AOC SD-4

AFCEE presented a Proposed Plan (preferred alternative) for remedial action at AOC SD-4 source areas at a
public information meeting held at the Barnstable County Fairgrounds in Falmouth, Massachusetts, on
November 13, 1997, and at a public hearing held at Mashpee High School in Mashpee, Massachusetts, on
December 2, 1997. In response to concerns raised by USEPA and MADEP during their review of the draft
Record of Decision, AFCEE has included excavation of soils exceeding the TPH clean-up goal of 1,200 ppm
in the SD-4 drainage ditch north of Reilly Road in the selected remedy. Although excavation of soil in
this area was not included in the Proposed Plan, it is consistent with the evaluations performed in the
Feasibility Study and does not reguire supplemental notice and comment.

7.6 DECISION SUMMARY FOR AOC SD-5/FS-5

The following subsections summarize information considered during the selection of source-area remedial
action for AOC SD-5/FS-5. A more detailed description of AOC SD-5/FS-5 site history, contamination, and
potential site risks can be found in the Final Remedial Investigation Report Stormwater Drainage Disposal
Site No. 5 (SD-5) Including Fuel Spill No. 5 (FS-5) prepared by ABB-ES in 1996. Additional discussion
concerning candidate remedial actions to reduce site risks is contained in the final Six Areas of
Contamination Source Area Feasibility Study prepared by ABB-ES in 1997. These reports are available for
review at the main libraries in the towns of Bourne, Falmouth, Mashpee, and Sandwich; and at the U.S.
Coast Guard library at MMR.

7.6.1 Scope and Role of Response Action at AOC SD-5/FS-5

This response action addresses surface soil contamination at AOC SD-5/FS-5. By excavating and treating
soil exceeding cleanup criteria, the selected action will protect human and ecological receptors from
exposure to concentrations of inorganics and TPH exceeding protective cleanup criteria. The selected
action will also prevent organic compounds from being a source of groundwater contamination. The response
action includes institutional controls in the form of site access restrictions to limit potential
human-health risks and five-year site reviews to assess whether the remedy remains protective of human
health and the environment. Groundwater contamination attributed to AOC SD-5/FS-5 is being addressed by
the SD-5 North Groundwater Plume Extraction, Treatment, and Reinjection System and the SD-5 South
Recirculating Well System.

7.6.2 History of Land Use at AOC SD-5/FS-5

AOC SD-5/FS-5 includes a storm drainage swale and several buildings on the western side of Runway No. 5
(Figure 7-10 in Appendix A). Possible contamination sources near SD-5/FS-5 include the aircraft
maintenance ramp, two underground fuel storage/transfer systems (Aguafarms), the Nondestructive
Inspection Laboratory (NDIL), and the Corrosion Control Shop. The following items summarize the history
of AOC SD-5/FS-5.

• 1950s. SD-5 began receiving stormwater runoff from a number of sources including the
Eastern and Western Aguafarms, the former NDIL, the Corrosion Control Shop, and the
Permanent Field Training Site hangar.
• Early 1960s. Three refueling aircraft were destroyed in a fire, resulting in the FS-5 fuel
spill of up to 15,000 gallons of AVGAS. The spill was washed into the storm drain leading to
SD-2.
• 1985. Field investigations evaluated liguid and sludge in the NDEL leaching well and nearby
soil.
• 1988. An SI was performed to assess the presence of soil and groundwater contamination.
• 1989. An RI was performed to characterize the nature and distribution of sediment, soil,
and groundwater contamination.
• 1993. A supplemental RI was performed to further characterize contamination and evaluate
site risks.
• 1994. The NDEL and Corrosion Control Shop were demolished and removed.
• 1994. Two 12,000-gallon underground storage tanks were removed from the AVLUBE area as part
of the Fuel System Upgrade Program.
• 1994-1995. A total of 17 underground storage tanks, including all six 25,000-gallon tanks at
the Western Aguafarm, all four 25,000-gallon tanks at the Eastern Aguafarm, and seven
550-gallon tanks associated with water separator control pits were removed.
• 1996. The NDEL leaching well and surrounding soil were removed as part of the DSRP.
• 1997. A Feasibility Study was performed to evaluate approaches to control potential site
risks.

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7.6.3 Summary of Site Characteristics at AOC SD-5/FS-5

AOC SD-5/FS-5 is located in the central part of the MMR cantonment area between North Inner Road and
Lingley Avenue on the north and south, respectively, and Base Runway No. 5 on the east, approximately
3,000 feet from the southern MMR boundary (ABB-ES, 1996e). The AOC occupies approximately 40 acres at the
northern end of a natural drainage Swale that formerly extended southward for more than 10,000 feet
toward Ashumet Pond. AOC SD-5/FS-5 extends approximately 2,000 feet along an unfilled portion of the
drainage swale and varies in width from approximately 750 to 1,200 feet. AOC SD-5/FS-5 is within the
flightline security area. Access to areas within the flightline area is controlled with fences and guard
posts, and activities not related to aircraft operations are limited and strictly controlled. Fences
around the flightline areas are inspected daily by base security. These site access restrictions are
expected to remain in place through the duration of the current lease (expiration date of 2026) and the
planned 25-year renewal. The SD-5/FS-5 drainage swale along the western side of the AOC has become
overgrown with trees with small grassy areas interspersed. Floodplains and wetlands are not known to
exist at AOC SD-5/FS-5, and endangered species are not known to reside there. The drainage swale is up to
25 feet below the grade of the flightline area.

The central drainage swale at AOC SD-5/FS-5 receives stormwater runoff from approximately 100 acres of
paved runways and ramps through an extensive stormwater drainage system. The swale is unlined and water
that does not evaporate or infiltrate, flows south to an unlined 1-acre stomwater infiltration basin (see
Figure 7- 10 in Appendix A). During extensive storm or runoff events, the Stormwater Infiltration Basin
overflows into two buried 72-inch-diameter pipelines, flows southward beneath AOC FTA-2/LF-2, and
discharges to Study Area SD-1.

AOC SD-5/FS-5 is divided into the following three source-area operable units (OUs):

SD-5A: the NDIL and the Corrosion Control Shop
SD-5B: the Western Aquafarm, AVLUBE Barrel Storage Area, and Refueler Truck Park Area
SD-5C: the Eastern Aquafarm, Permanent Field Training Site, Fuel Spill No. 5, and Central
Drainage Swale

A fourth OU, SD-5D, was identified for groundwater and is discussed in the Southeast Region Groundwater
Operable Unit (SERGOU) Remedial Investigation (RI) Report (Including Region III) (ABB-ES, 1994). The
SERGOU RI report discusses groundwater contamination as it relates to several sources in the southeastern
portion of MMR, including AOC SD-5/FS-5. Groundwater contamination attributed to AOC SD-5/FS-5 is being
addressed by the SD-5 North Groundwater Plume Extraction, Treatment, and Reinjection System and the SD-5
South Recirculating Well System.

7.6.3.1 Soil Contamination Assessment.

This subsection discusses soil contamination at the three source-area OUs at AOC SD-5.

SD-5A Operable Unit. Contamination within the SD-5A OU is present in surface and subsurface soils. Fuel
odors and discolored soil were observed in the capillary-fringe zone near the NDIL leaching well.

Some of the highest concentrations of inorganics contributing to ecological risk at AOC SD-5/FS-5 were
measured in surface soil samples (SS-1, SS-2, SS-3, and TP-8) collected between the Corrosion Control
Shop (Building 3117) and the adjacent Central Drainage Swale (Figure 7-11 in Appendix A). Chromium,
copper, cyanide, lead, and zinc were the primary contaminants from zero to 2 feet bgs. Elevated TPH
concentrations were also measured at SS-1 (23,466 mg/kg) and SS-3 (124,000 mg/kg).

Subsurface soil contamination is present in the form of VOCs that have potential to leach to groundwater.
TCE was reported at concentrations up to 73 Ig/kg at test pits TP-10 (8 feet bgs) and TP-12 (2 feet bgs)
near the Corrosion Control Shop. TCE is also present in the capillary-fringe zone at MW-4, which is near
the NDEL leaching well and downgradient of TP-10 and TP-12 (see Figure 7-11 in Appendix A). The presence
of TCE and 1,2-DCE in groundwater at concentrations above MCLs in monitoring wells and downgradient of
the Corrosion Control Shop and NDIL leaching well areas indicates those areas as a source of groundwater
contamination.

SD-5B Operable Unit. Contamination within the SD-5B OU is present in surface and capillary-fringe zone
soils. Inorganics and VOCs are the primary contaminants.

Inorganics contributing to potential ecological risks include chromium (up to 59.2 mg/kg) and zinc (up to
83.3 mg/kg). Chromium and zinc were detected above MMR background concentrations in samples at the AVLUBE
Barrel Storage and AVLUBE Underground Storage Tank (SS-8 and SS-9) areas. Chromium was detected above MMR
background at three test pits (TP-17, TP-18, and TP-19) in the Refueler Truck Park Area. Zinc was also
present at concentrations above background at soil sample locations SS-6 and SS-7. Elevated TPH

-------
concentrations were also measured at SS-7 (113,000 mg/kg) and MW-104 at zero to 2 feet bgs (134,000
mg/kg) , which were completed within the Refueler Truck Park Area.

Fuel odors and discolored soil were observed in the capillary-fringe zone in the Western Aguafarm.
Although no petroleum-related TCL VOCs were detected in the capillary-fringe zone in offsite laboratory
analyses, field gas chromatography results show benzene, toluene, ethylbenzene, and xylenes in several
samples from the soil, boring for MW-103, which is immediately downgradient of the underground storage
tanks (ABB-ES, 1996e). The VOC TCE (170 Ig/kg) was also detected in capillary-fringe soil at MW-103 (57
feet bgs).

Traces of TCE and petroleum-related TCL VOCs were detected at concentrations below MCLs in the area of
the Western Aguafarm. In a downgradient monitoring well at AOC FTA-2/LF-2 (MW-2), the presence of
ethylbenzene (910 Ig/L) detected in the 1993 sampling event for the SERGOU RI is attributed to releases
at the Western Aguafarm (ABB-ES, 1994).

SD-5C Operable Unit. Contamination within the SD-5C OU is present in surface and subsurface soils. The
surface soil contamination is primarily inorganics at concentrations above MMR background concentrations.
In isolated areas, subsurface soil contamination is also present in the form of VOCs with the potential
to leach to groundwater.

Within the Central Drainage Swale, chromium, copper, lead, and zinc are present in surface soil at most
of the sampled test-pit locations at concentrations above background. Metals do not appear to be
uniformly distributed across the drainage ditch, but instead are concentrated at outfalls.

For subsurface soil, the VOCs TCE (33 Ig/kg) and benzene (59 Ig/kg) were detected at TP-9 and TP-32,
respectively. TP-9 is at the outfall for the former NDEL leaching well; TP-32 is located within the
Stormwater Infiltration Basin. Based on analytical results from nearby test pits and observations at all
the test pits, the vertical distribution of these VOCs is interpreted to be less than 6 feet in depth.
The aerial distribution of the VOCs is also limited because they were not detected in nearby subsurface
soil.

7.6.3.2 Groundwater Contamination Assessment.

Groundwater beneath AOC SD-5/FS-5 is contaminated by solvent-related compounds that likely leached from
the NDIL drainage structure. In addition, fuel-related contamination in groundwater is likely to have
occurred as a result of leaks or spills from the Western Aguafarm. Maximum concentrations of TCE (270
Ig/L) were detected above the MCL (5 Ig/L) in the area of the NDIL drainage structure. PCE (5 Ig/L) and
1,2-DCE (110 Ig/L) were also detected at or above respective MCLs of 5 and 70 Ig/L in the area of the
NDIL drainage structure. At the Western Aguafarm, one total lead concentration of 31.4 Ig/L was measured
above the MCL of 15 Ig/L. In addition, BEHP (up to 25 Ig/L) and ethylbenzene (910 Ig/L) were detected in
monitoring wells downgradient of the Western Aguafarm above MCLs of 6 and 700 Ig/L, respectively.

7.6.4 Summary of Risks at AOC SD-5/FS-5

The RI report for AOC SD-5/FS-5 included a human-health PRA to evaluate potential human-health risks
associated with exposure to contaminated surface and subsurface soil under current and future site
conditions for the entire AOC; risks were not evaluated separately for each OU. An ecological PRA
evaluated potential risks associated with exposure to surface soil. The following subsections summarize
the human-health and ecological PRAs. A detailed discussion of the risk assessment approach and results
is presented in the MMR Risk Assessment Handbook (ASG, 1994) and in the RI report (ABB-ES, 1996e).

7.6.4.1 Human-health Risk Assessment Summary.

The human-health PRA was based on samples collected during the Tasks 2-5B and 2-5C Rls. Data from soil
samples collected from zero to 10 feet bgs were used for the human-health PRA. Table 7-25 in Appendix B
provides summary statistics on human-health contaminants of potential concern in soil.

• Current Land Use Conditions: potential utility worker exposure to surface and subsurface
soils (zero to 10 feet bgs) at maximum and exposure point mean concentrations for a six-week
period

-------
• Future Land Use Conditions: potential utility worker exposure to surface and subsurface
soils (zero to 10 feet bgs) at maximum and exposure point mean concentrations for a
six-month period

The human-health PRA indicates that cancer risks for current and future land use conditions fall within
or below the USEPA target risk range of 10 -4 to 10 -6 and below the MADEP target cancer risk of 1x10 -5.
The noncancer HI values for the current and future utility worker for mean concentrations, and for the
current utility worker for maximum concentrations, are less than 1. This indicates that noncancer health
risks are below regulatory risk-management guidelines. The HI for the future utility worker, based on
maximum concentrations, is 4. However, this may be an overestimate of risk because a number of
conservative assumptions are used in the PRA and because the HQs for the individual risk contributors may
be segregated based on target organ affected. Iron is the primary contributor to the elevated HI, along
with mercury and Aroclors.

TPH and lead could not be guantitatively evaluated in the PRA; however, maximum concentrations of TPH
(134,000 mg/kg) and lead (4,950 mg/kg) substantially exceed the MCP S-l soil standard for TPH of 500
mg/kg and the USEPA soil screening level for lead of 400 mg/kg. In addition, the mean concentration for
TPH in soil exceeds all MADEP standards for TPH, but is skewed high by five high concentration subsurface
soil samples from the NDIL/Corrosion Control Shop and Western Aguafarm areas. The mean TPH value,
excluding those five samples, is below the MCP S-l soil standard for TPH. The mean lead concentration
(188 mg/kg) was less than the USEPA screening level (400 mg/kg) and the MCP S-l soil standard (300
mg/kg) . Four individual samples, all in the NDIL/Corrosion Control Shop and Western Aguafarm areas of the
AOC, exceed the MCP S-2 soil standard of 600 mg/kg for lead. Table 7-26 in Appendix B summarizes results
of the human-health PRA. Appendix

7.6.4.2 Ecological Risk Assessment Summary

The PRA for AOC SD-5/FS-5 evaluated potential ecological risks associated with exposure to contaminated
surface soil (zero to 2 feet bgs) for the entire AOC (ABB-ES, 1996e). Model receptor species identified
for use in the risk guantification include the white-footed mouse, cardinal, and red fox (see Table 7-25
in Appendix B).

Mean exposure scenario His for exposures to surface soil for the white-footed mouse and cardinal were
both 40. Maximum exposure scenario His for the white-footed mouse and cardinal were 500 and 600,
respectively. His for the red fox were below 1 for both mean and maximum exposure scenarios. The major
risk-contributing COCs include chromium and zinc for the white-footed mouse, and copper, cyanide, and
zinc for the cardinal. Ecological risks were also estimated for plants based on surface soil data. His of
500 and 30 for plants at maximum and mean exposure concentrations, respectively, exceeded the designated
threshold of 1. Mercury and zinc were the major risk-contributing COCs to plants from surface soil
exposure.

Because the ecological PRA calculations involve numerous conservative assumptions, risks may be
overestimated by up to one to two orders of magnitude (ASG, 1994). Additionally, risks attributable to
naturally occurring concentrations of inorganics, were not differentiated from those attributed to
site-related contaminants. Table 7-27 in Appendix B summarizes results of the ecological PRA, and Table
7-28 in Appendix B summarizes phytotoxicity risks.

Based on the PRA, elevated surface sod concentrations of inorganic chemicals and TPH detected in two
specific areas within the AOC, near the NDIL/Corrosion Control Shop and at the Western Aguafarm, may pose
risk to ecological receptors at AOC SD-5/FS-5. Ecological risks are not expected in the remainder of the
AOC, including the main drainage swale.

7.6.4.3 Comparison to Leaching-based STCLs.

To assess the potential for site soils to contaminate groundwater at concentrations of concern, AOC data
for compounds with a K of less than 1,000 were compared to leaching-based STCLs. This comparison
indicated that trichloroethene exceeds leaching-based STCLs in soil near the NDIL sump and Corrosion
Control Shop and trichloroethene and benzene exceed STCLs in soil at the northern edge of the Stormwater
Infiltration Basin. These exceedances help form the basis for remedial action at AOC SD-5/FS-5.

7.6.5 Description of Evaluated Alternatives for AOC SD-5/FS-5.

The Feasibility Study assessed how well the following four alternatives would meet the evaluation
criteria while controlling potential adverse human-health and ecological effects from exposure to surface
soil and sediment at AOC SD-5/FS-5:

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       •       No Action
       •       Limited Action
       •       Excavation and Asphalt-batching
       •       Excavation and Offsite Treatment and Disposal

7.6.5.1 No Action.

The No Action alternative was evaluated as a baseline with which to compare other alternatives.  No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions (security fencing and
military guard posts) that currently limit potential human exposure to site contaminants.

       Estimated Time for Design and Construction:                             not applicable
       Estimated Time for Cleanup:                                             not applicable
       Estimated Capital Cost:                                                             $0
       Estimated Operation and Maintenance Cost:                                           $0
       Estimated Total Cost                                                                $0

7.6.5.2 Limited Action.

The Limited Action alternative at AOC SD-5/FS-5 includes the following key components:

       •       maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •       performing five-year site reviews

       Estimated Time for Design and Construction:                             not applicable
       Estimated Time for Cleanup:                                             not applicable
       Estimated Capital Cost:                                                             $0
       Estimated Operation and Maintenance Cost (Present Worth*):                     $25,000
       Estimated Total Cost                                                           $25,000

        *Present worth based on 7 percent discount rate for 30 years.

7.6.5.3 Excavation and Asphalt-batching.

The Excavation and Asphalt-batching alternative at AOC SD-5/FS-5 addresses soil contamination at eight
locations at AOC SD-5/FS-5 and includes the following key components:

       •       mobilization and site preparation
       •       performing pre-excavation confirmation soil sampling to confirm the horizontal  and
              vertical distribution of  contamination exceeding TPH and inorganic STCLs at six locations
              and VOCs,  TPH,  and inorganics at the remaining two locations
       •       excavating soil exceeding cleanup criteria
       •       transporting excavated soil to an onsite asphalt-batching facility for  testing  and
              treatment
       •       collecting post-excavation confirmation samples from the excavation perimeters  for analysis
              for TPH and inorganics at six of the proposed cleanup locations and for VOCs, TPH  and
              inorganics at the remaining two locations
       •       backfilling and restoring excavations with clean borrow material
       •       using the asphalt-emulsion-coated product as a paving subgrade  material at selected
              locations at MMR
       •       maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •       performing five-year site reviews

       Estimated Time for Design and Construction:                              9 months
       Estimated Time for Cleanup:                                              3 months
       Estimated Capital Cost:                                                $2,265,000
       Estimated Operation and Maintenance Cost (Present Worth*):                $25,000
       Estimated Total Cost                                                   $2,290,000
        *Present worth based on 7 percent discount rate for 30 years.

7.6.5.4 Excavation and Offsite Treatment and Disposal.

The Excavation and Offsite Treatment and Disposal alternative at AOC SD-5/FS-5 includes the following key
components:

-------
       •       mobilization and site preparation
       •       performing pre-excavation confirmation soil  sampling to confirm the horizontal  and vertical
              distribution of contamination exceeding TPH  and inorganic STCLs at six locations  and VOCs,
              TPH and inorganics at the remaining two locations
       •       excavating soil exceeding cleanup criteria
       •       collecting post-excavation confirmation samples from the excavation perimeters  for analysis
              for TPH and inorganics at six of the proposed cleanup locations and for VOCs, TPH,  and
              inorganics at the remaining two locations
       •       transporting excavated soil to a permitted offsite treatment,  storage,  and disposal
              facility for treatment and/or disposal
       •       backfilling and restoring excavations with clean borrow material
       •       maintaining institutional controls that restrict site access  and limit potential  human
              exposure to contaminants
       •       performing five-year site reviews

       Estimated Time for Design and Construction:                              9 months
       Estimated Time for Cleanup:                                              3 months
       Estimated Capital Cost:                                                $4,261,000
       Estimated Operation and Maintenance Cost  (Present Worth*):                $25,000
       Estimated Total Cost                                                   $4,286,000

        *Present worth based on 7 percent discount rate for 30 years.

7.6.6 Summary of Comparative Analysis of Alternatives for  AOC SD-5/FS-5

The following subsections summarize the Comparative Analysis of  Alternatives performed in the Feasibility
Study for AOC SD-5/FS-5.

7.6.6.1 Overall Protection of Human Health and the Environment.

The No Action alternative would be protective of human health under current conditions. It does not,
however,  include measures to protect groundwater guality or institutional controls to limit potential
future human exposure. Similar to the No Action alternative, the Limited Action alternative would be
protective under current conditions and it provides institutional controls to limit potential future
exposure. It does not, however, include measures to protect groundwater guality. Neither the No Action
nor the Limited Action alternative includes actions to protect ecological receptors. In comparison, the
excavation alternatives include institutional controls to  limit  potential future human exposure and
remedial actions that will protect ecological receptors and groundwater guality. Both excavation
alternatives would provide overall protection of human health and the environment.

7.6.6.2 Compliance with Applicable or Relevant and Appropriate Reguirements.

The No Action and Limited Action alternatives do not include remedial actions that would trigger ARARs.
Both excavation alternatives would be designed, built, and operated to comply with all ARARs. Therefore,
no waivers would be reguired.

7.6.6.3 Long-term Effectiveness and Permanence.

Because the No Action alternative does not include institutional controls to limit potential future
exposure or remedial actions to protect ecological receptors and groundwater guality, it does not offer
long-term effectiveness at protecting human health or the  environment. The Limited Action alternative
includes institutional controls, but does not include remedial actions to protect ecological receptors
and groundwater guality, and, therefore, does not offer long-term effectiveness at protecting human
health or the environment. Because both excavation alternatives  add remedial actions that will remove
soils exceeding STCLs established to be protective of human health and the environment, they offer both
long-term effectiveness and permanence.

7.6.6.4 Reduction of Toxicity, Mobility, or Volume Through Treatment.

Neither the No Action nor Limited Action alternative provides treatment to reduce the toxicity, mobility,
or volume of contaminants. The Excavation and Asphalt-batching alternative provides treatment that will
reduce the mobility of contaminants. Because the treatment/disposal approach that would be followed at an
offsite disposal facility is not known, it can not be said that  the Excavation and Offsite Treatment and
Disposal alternative will provide reductions in toxicity,  mobility, or volume through treatment.

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7.6.6.5 Short-term Effectiveness.

The No Action and Limited Action alternatives do not include actions that would result in adverse
short-term effects to human health or the environment. Construction activities associated with the two
excavation alternatives would present minimal short-term risks to construction workers, but those risks
would be minimized through the development of and adherence to a site-specific Health and Safety Plan.
Clearing brush and trees and other construction activities would likely result in habitat disruption;
however, severe adverse effects are not expected. No wetland habitats would be disturbed.

7.6.6.6 Implementability.

The technical and administrative feasibility of all four alternatives is considered high. Neither the No
Action nor Limited Action alternative includes actions that reguire substantial technical or
administrative resources. Construction eguipment and workers to perform the excavation alternatives are
anticipated to be readily available. Asphalt-batching and offsite disposal are not known to present
technical or administrative barriers.

7.6.6.7 Cost.

Cost includes the capital (up-front) cost of implementing an alternative and the long-term cost of
operating and maintaining the alternative. Capital and operation and maintenance costs for each
alternative were calculated with an estimated accuracy of 30 percent to +50 percent. The alternatives
with the lowest capital costs are the No Action and Limited Action alternatives which do not involve
extensive construction. The cost of the Excavation and Asphalt-batching alternative, although several
times greater than the cost of Limited Action, is approximately half the cost of Excavation and Offsite
Treatment and Disposal.

Operation and maintenance costs were estimated on an annual basis, and are lowest for the No Action
alternative, which does not provide any long-term maintenance or monitoring, and egual for the other
alternatives.

To enable comparison of costs which will occur over different time periods, the present worth of capital
and operation and maintenance costs was also calculated. Present worth costs closely reflect capital
costs.

The following table compares capital, operation and maintenance, and present worth costs for each
alternative evaluated in detail for AOC SD-5/FS-5.

Total Total O&M Total Costs
Alternative Capital Cost (Present Worth*) (Present Worth)

No Action $0 $0 $0
Limited Action $0 $25,000 $25,000
Excavation and $2,265,000 $25,000 $2,290,000
Asphalt-batching
Excavation and $4,261,000 $25,000 $4,286,000
Offsite Treatment and
Disposal

*Present worth based on 7 percent discount rate for 30 years.

7.6.6.8 State Acceptance.

The Commonwealth of Massachusetts has reviewed the RI and Feasibility Study reports and the Proposed Plan
and concurs with AFCEE's selected remedy.

7.6.6.9 Community Acceptance.

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7.6.7 Description of the Selected Remedy for AOC SD-5/FS-5
The selected remedy for AOC SD-5/FS-5 is Excavation and Asphalt-batching. This alternative provides
institutional and engineering controls to limit exposure to site-related contaminants and to reduce
source-area contaminant concentrations to protective levels. The remedy does not include a management of
migration component. Groundwater contamination attributed to AOC SD-5/FS-5 is being addressed by the SD-5
North Groundwater Plume Extraction, Treatment, and Reinjection System and the SD-5 South Recirculating
Well System.

7.6.7.1 Soil Cleanup Levels.

Based upon data developed in the RI and the PRA and summarized in the Feasibility Study, remedial actions
are warranted at AOC SD-5/FS-5 to address risks associated with possible direct contact exposure to lead
and TPH contaminated source-area soils. Remedial actions are also warranted to protect ecological
receptors from maximum concentrations of site contaminants.

In addition, available data suggest that source-area soils may be a source of release of VOCs to
groundwater. Such a release could result in an unacceptable risk to those who drink groundwater at or
downgradient of the source area. Therefore, the STCLs established for the DSRP at MMR were used to
estimate residual soil levels that will be protective of future groundwater quality (see Section 5.0 of
this Record of Decision).  The following table summarizes the STCLs required to protect human health and
groundwater quality for the groundwater contaminants of concern at this AOC.
      C ont aminant s
                              STCL
                    Basis for Selection
    Chromium
    Copper
    Cyanide
    Lead
    Mercury
    TPH
    Zinc
    Benzene
    Trichloroethene
6.8 mg/kg
19.3 mg/kg
1 mg/kg
15.8 mg/kg
1.48 mg/kg
1,200 ppm
16 mg/kg
10 Ig/kg
10 Ig/kg
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Leaching-based
Leaching-based
The STCLs are consistent with ARARs for groundwater, attain USEPA's risk-management goal for remedial
actions, and have been determined by AFCEE, USEPA, and MADEP to be protective. These cleanup levels must
be met at the completion of the remedial action at the limits of STCL exceedance established during
predesign confirmation soil sampling.

7.6.7.2 Description of Remedial Components.

The selected remedy for AOC SD-5/FS-5 is Excavation and Asphalt-batching. Key components of this
alternative include:
       •      mobilization and site preparation
       •      performing pre-excavation confirmation soft sampling to confirm the horizontal  and vertical
              distribution of contamination exceeding TPH and inorganic STCLs at six locations  and VOCs,
              TPH and inorganics at the remaining two locations
       •      excavating soil exceeding cleanup criteria
       •      transporting excavated soil to an onsite asphalt-batching facility for testing  and
              treatment
       •      collecting post-excavation confirmation samples from the excavation perimeters  for analysis
              for TPH and inorganics at six of the proposed cleanup locations and for VOCs, TPH,  and
              inorganics at the remaining two locations
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •      maintaining institutional controls that restrict site access and limit potential  human
              exposure to contaminants
       •      performing five-year site reviews

Each of these components is described in the following paragraphs.

Mobilization and site preparation. Mobilization and site preparation will include procuring necessary
subcontractors, purchasing equipment, identifying underground utilities, clearing brush and trees, and
constructing temporary access roads.

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Performing pre-excavation confirmation soil sampling. AFCEE will perform pre-excavation sampling to
confirm the horizontal and vertical distribution of contamination exceeding TPH and inorganic STCLs at
six locations and VOCs, TPH, and inorganics at the remaining two locations.

Excavating sediment/surface soil exceeding cleanup criteria. AFCEE will excavate areas identified for
remediation using backhoes, excavators, dredges, or other appropriate construction equipment. Based on
available data and the PRA, up to 9,400 cy of material may need to be excavated. Details of proposed
sampling and analysis, excavation, and backfill/restoration activities will be presented in a RAWP and/or
in design plans to be reviewed and approved by regulatory agencies prior to implementation.

Transporting excavated soil to an onsite asphalt-batching facility for testing and treatment. Samples of
the excavated soil will be collected and analyzed to assess whether the soil must be treated/disposed of
as a hazardous substance. One TCLP sample will be collected per 100 cy of excavated material or as
directed by the asphalt-batching subcontractor. In lieu of TCLP analysis, total concentrations in soil
may be used when total concentrations are less than the theoretical concentration at which TCLP criteria
would be exceeded. Soils considered hazardous will be disposed of offsite at a permitted treatment,
storage, and disposal facility. Nonhazardous soils and those meeting threshold criteria will be
transported to an onsite facility for asphalt-batching. In addition, analytical data will be compared to
threshold concentrations for soil recycling facilities contained in the Massachusetts "Interim
Remediation Waste Management Policy for Petroleum Contaminated Soil" to assess acceptability for cold-mix
asphalt-batching. Details of the asphalt-batching treatment process and associated testing will be
presented in a RAWP and/or design plans and specifications to be reviewed and approved by USEPA and MADEP
prior to implementation.

Collecting post-excavation confirmation samples from the excavation perimeter for analysis for chromium,
lead, and zinc. Confirmation samples will be collected from the perimeter of the excavations (post
excavation) and analyzed for the organics and inorganics listed in Subsection 7.6.7.1 to confirm that all
surface soil exceeding STCLs for these chemicals have been removed.

Using the asphalt-emulsion-coated product as a paving subgrade material at MMR. Asphalt-batched material
will be used as paving subgrade material at selected locations at MMR. A minimum IE-inch wear coat will
be placed over the asphalt-batched material.

Maintaining institutional controls that restrict site access and limit potential human exposure to
contaminants. To limit potential human exposure to site-related contaminants, AFCEE will maintain site
access restrictions at AOC SD-5/FS-5 that are consistent with current flightline security measures.
Institutional controls such as fences will be inspected and maintained/repaired not less than annually.
Overall protectiveness will be assessed during five-year site reviews. Alternately, if AFCEE can
demonstrate based on currently available or newly acquired data, that site access restrictions can be
relaxed or removed while protection of human health is maintained, AFCEE may petition USEPA for such a
relaxation or removal of restrictions.

Performing five-year site reviews. Because the assumptions of the risk assessment at AOC SD-5/FS-5 do not
allow unrestricted site use, and to provide an opportunity for review of the performance of the selected
remedy, AFCEE will perform five-year site reviews for AOC SD-5/FS-5. During the five-year review, AFCEE
will review monitoring and other pertinent data to assess whether the selected remedy remains protective
of human health and the environment and whether additional remedial action is appropriate.

7.6.8 Statutory Determinations for AOC SD-5/FS-5

The selected remedy for AOC SD-5/FS-5, is consistent with CERCLA and, to the extent practicable, the NCP.
The selected remedy is protective of human health and the environment, attains ARARs, and is
cost-effective. The statutory preference for treatment which permanently and significantly reduces the
toxicity, mobility, or volume of hazardous substances as a principal element is satisfied. Additionally
the selected remedy utilizes alternative treatment technologies and resource recovery technologies to the
maximum extent practicable for this site.

7.6.8.1 The Selected Remedy is Protective of Human Health and the Environment.

The selected remedy for AOC SD-5/FS-5. Excavation and Asphalt-batching, will permanently reduce the risks
to human health and the environment by eliminating, reducing, or controlling exposures to human and
environmental receptors through engineering and institutional controls. The principal threat at AOC
SD-5/FS-5 is surface soil that is contaminated with organics and inorganics and that may pose direct
contact risk to human and ecological receptors and leaching risks to groundwater.

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The effectiveness of the selected alternative will be evaluated by comparing soil sampling data to STCLs
in the following table.
     Contaminants
                             STCL
                   Basis for Selection
    Chromium
    Copper
    Cyanide
    Lead
    Mercury
    TPH
    Zinc
    Benzene
    Trichloroethene
6.8 mg/kg
19.3 mg/kg
1 mg/kg
15.8 mg/kg
1.48 mg/kg
1,200 ppm
16 mg/kg
10 Ig/kg
10 Ig/kg
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Inside the Flightline
Leaching-based
Leaching-based
7.6.8.2 The Selected Remedy Attains Applicable or Relevant and Appropriate Reguirements.

The selected remedy will attain all applicable or relevant and appropriate federal and state
reguirements.  No waivers are reguired. ARARs for AOC SD-3/FTA-3/CY-4, were identified and discussed in
the Feasibility Study  (Sections 3.0 and 7.0). Table 7-29 in Appendix B summarizes the ARARs for the
selected remedy, including the regulatory citation, a brief summary of the reguirement, and how it will
be attained.

7.6.8.3 The Selected Remedy is Cost-effective. In AFCEE's judgment, the selected remedy is cost-effective
(i.e., the remedy affords overall effectiveness proportional to its costs). In selecting this remedy,
once AFCEE identified alternatives that are protective of human health and the environment and attain,
or, as appropriate, waive ARARs, AFCEE evaluated the overall effectiveness of each alternative according
to the relevant three criteria: long-term effectiveness and permanence; reduction in toxicity, mobility,
or volume through treatment; and short-term effectiveness, in combination. The relationship of the
overall effectiveness of this remedial alternative was determined to be proportional to its costs.
The costs of this remedial alternative are:

    Estimated Capital Cost:
    Estimated Operation and Maintenance Cost (Present Worth*):
    Estimated Total Cost

     *Present worth based on 7 percent discount rate for 30 years.
                                                $2,265,000
                                                   $25,000
                                                $2,290,000
7.6.8.4 The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment or Resource Recovery
        to the Maximum Extent Practicable.
After AFCEE identified those alternatives that attain or, as appropriate, waive ARARs and that are
protective of human health and the environment, AFCEE determined which alternative made use of permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable. This determination was made by deciding which one of the identified alternatives provides
the best balance of tradeoffs among alternatives in terms of: (1) long-term effectiveness and permanence;
(2) reduction of toxicity, mobility, or volume through treatment; (3) short-term effectiveness; (4)
implementabibty; and  (5)  cost. The balancing test emphasized long-term effectiveness and permanence and
the reduction of toxicity, mobility, or volume through treatment and considered the preference for
treatment as a principal element, the bias against offsite land disposal of untreated waste, and
community and state acceptance. AFCEE believes the selected remedy provides the best balance of tradeoffs
among the alternatives that are protective and attain ARARs.

7.6.8.5 The Selected Remedy Satisfies the Preference for Treatment Which Permanently and Significantly
        Reduces the Toxicity, Mobility, or Volume of Hazardous Substances as a Principle Element.

The principal element of the selected remedy is excavation and asphalt-batching. This element addresses
the principal threat at the AOC, contamination of surface soil with organics and inorganics, by removing
soils that exceed cleanup levels and treating them with asphalt-batching to reduce contaminant mobility.
The selected remedy satisfies the statutory preference for treatment as a principal element.

7.6.9 Documentation of No Significant Changes for AOC SD-5/FS-5

AFCEE presented a Proposed Plan  (preferred alternative)  for remedial action at AOC SD-5/FS-5 source areas
at a public information meeting held at the Barnstable County Fairgrounds in Falmouth, Massachusetts, on
November 13, 1997, and at a public hearing held at Mashpee High School in Mashpee, Massachusetts,  on

-------
December 2, 1997. There have been no significant changes made to the Excavation and Asphalt-batching
preferred alternative presented in the Proposed Plan.

7 . 7 SUMMARY OF SEIiECTED REMEDIES

The following table lists the selected remedies for the six AOC source areas addressed in this Record of
Decision.

     AOC                            Selected Remedy                   Cost

     AOC FTA-2/LF-2             Biosparging with Ambient           $1,954,000
                                Air Monitoring
     AOC PFSA/FS-10/FS-10       Biosparging with Off-gas           $3,639,000
                                Collection and Treatment
     AOC SD-2/FS-6/FS-8         Excavation and                        $92,000
                                Asphalt-batching
     AOC SD-3/FTA-3/CY-4         Confirmation Sampling              $1,488,000
                                with Contingency of
                                Excavation and
                                Asphalt-batching
     AOC SD-4                   Excavation and                     $1,428,000
                                Asphalt-batching
     AOC SD-5/FS-5              Excavation and                     $2,290,000
                                Asphalt-batching

                                              8.0 STATE ROIiE

The Commonwealth of Massachusetts has reviewed the SI, RI, and Feasibility Study reports, and Proposed
Plan and concurs with the proposed remedial action decisions. The Commonwealth has also reviewed these
documents to determine if the decision complies with applicable or relevant and appropriate laws and
regulations of the Commonwealth. A copy of the letter of concurrence from the Commonwealth of
Massachusetts is attached as Appendix E of this Record of Decision.

-------
                         GLOSSARY  OF ACRONYMS  AND ABBREVIATIONS

ABB-ES               ABB Environmental  Services,  Inc.
AFCEE                Air Force  Center for Environmental Excellence
AOC                  area  of  contamination
ARAR                 Applicable or  Relevant  and Appropriate Requirement
ASG                  Automate Sciences  Group,  Inc.
AWQC                 Ambient  Water  Quality Criteria
AVGAS                aviation gasoline
BEHP                 bis(2-ethylhexyl)phthalate
bgs                  below ground surface
CDM                  CDM Federal Programs Corporation
CERCLA               Comprehensive  Environmental  Response,  Compensation, and Liability Act of  1980
CFR                  Code  of  Federal  Regulations
CMR                  Code  of  Massachusetts Regulations
COC                  contaminant of concern
CRQL                 Contract Required  Quantitation Limit
cy                   cubic yard
CY#                  Coal  Storage Yard  No.#
DCE                  dichloroethylene
DDT                  dichlorodiphenyltrichloroethane
DSRP                 Drainage Structure Removal Program
FFA                  Federal  Facility Agreement
FS#                  Fuel  Spill No.#
FTA#                 Fire  Training  Area No.#
HAZWRAP              Hazardous  Waste  Remedial  Actions  Program
HI                   hazard index
HQ                   hazard quotient
IRP                  Installation Restoration  Program
K oc                 water organic  carbon partition coefficient
LF#                  Landfill No.#
MADEP                Massachusetts  Department  of  Environmental Protection
MCL                  Maximum  Contaminant Level
MCP                  Massachusetts  Contingency Plan
mg/kg                milligrams per kilogram
MMR                  Massachusetts  Military  Reservation
MOGAS                motor gasoline
NCP                  National Oil and Hazardous Substances  Pollution Contingency Plan
NDIL                 Nondestructive Inspection Laboratory
NGB                  National Guard Bureau
NPL                  National Priorities List
OU                   operable unit
PAH                  polynuclear aromatic hydrocarbons
PAT                  Process  Action Team
PCB                  polychlorinated  biphenyl
PCE                  tetrachloroethylene
PFSA                 Petroleum  Fuels  Storage Area
ppm                  part  per million
PRA                  preliminary risk assessment
RAWP                 remedial action  work plan
RCRA                 Resource Conservation and Recovery Act
RfD                  reference  dose
RI                   remedial investigation
SARA                 Superfund  Amendments and  Reauthorization Act of 1986
SD#                  Storm Drainage Ditch No.#
SERGOU               Southeast  Region Groundwater Operable  Unit
SI                   site  investigation
STCL                 Soil  Target Cleanup Level
SVOC                 semivolatile organic compound
TAL                  Target Analyte List
TCE                  trichloroethylene
TCL                  Target Compound  List
TCLP                 Toxicity Characteristic Leaching  Procedure
TEAC                 Technical  Environmental Affairs Committee
TIC                  tentatively identified  compound
TPH                  total petroleum  hydrocarbons
Ig/kg                microgram  per  kilogram
Ig/L                 microgram  per  liter
                     U.S.  Environmental Protection Agency
                     volatile organic compound

-------
REFERENCES

ABB Environmental Services, Inc.  (ABB-ES), 1993. "Priority 2 and 3 Study Areas Site Investigation";
       Installation Restoration Program; Massachusetts Military Reservation; prepared for HAZWRAP;
       Portland, Maine; October 1993.

ABB Environmental Services, Inc.  (ABB-ES), 1994. "Southeast Region Groundwater Operable Unit Remedial
       Investigation Report (Including Region III)"; Installation Restoration  Program; Massachusetts
       Military Reservation; prepared for HAZWRAP; Portland,  Maine; August 1994.

ABB Environmental Services, Inc.  (ABB-ES), 1996a. "Final Remedial Investigation Report Fire Training Area
       No. 2 (FTA-2) and Landfill No. 2  (LF-2)"; Installation Restoration Program; Massachusetts Military
       Reservation; prepared for HAZWRAP; Portland,  Maine; September 1996.

ABB Environmental Services, Inc.  (ABB-ES) , 1996b. "Final Remedial Investigation Report Petroleum Fuels
       Storage Area (Including AOCs Fuel Spill No. 10[FS-10]  and Fuel Spill No. 11[FS-10])"; Installation
       Restoration Program, Massachusetts Military Reservation; prepared for HAZWRAP; Portland, Maine;
       December 1996.

ABB Environmental Services, Inc.  (ABB-ES), 1996c. "Final Remedial Investigation Runway/Aircraft
       Maintenance Storm Drainage Ditch No. 2 (AOCs SD-2/FS-6/FS-8)"; Installation Restoration Program;
       Massachusetts Military Reservation; prepared for HAZWRAP; Portland, Maine; December 1996.

ABB Environmental Services, Inc.  (ABB-ES) , 1996d. "Final Remedial Investigation Report Stormwater
       Drainage Ditch No. 3 (SD-3), Former Fire Training Area No. 3  (FTA-3), and Coal Yard No. 4  (CY-4)";
       Installation Restoration Program; Massachusetts Military Reservation; prepared for HAZWRAP;
       Portland, Maine; November 1996.

ABB Environmental Services, Inc.  (ABB-ES), 1996e. "Final Remedial Investigation Stormwater Drainage
       Disposal Site No. 5  (SD-5) Including Fuel Spill No. 5 (FS-5)"; Installation Restoration Program;
       Massachusetts Military Reservation; prepared for HAZWRAP; Portland, Maine; December 1996.

ABB Environmental Services, Inc,  (ABB-ES), 1997. "Final Six Areas of Contamination Source Area
       Feasibility Study", Installation Restoration Program;  Massachusetts Military Reservation; prepared
       for HAZWRAP; Portland,  Maine; November 1997.

Automated Sciences Group, Inc.  (ASG) , 1994. "Risk Assessment Handbook. Volumes I & II. Comprehensive
       Plan, Appendix C"; Installation Restoration Program; prepared for HAZWRAP Support Contractor
       Office;  September 1994.

Aker, M. 1995.  Memorandum of personal communication titled "PFSA Free Product Sampling -August 7, 1995"
       between M. Aker, Environmental Division,  Installation Restoration Program Office, Otis ANG Base,
       Massachusetts,  and M. Gunderson, HAZWRAP, Oak Ridge, Tennessee, December 4, 1995.

COM Federal Programs Corporation  (COM),  1996. "Remedial Investigation Report for Area of Contamination
       SD-4"; Installation Restoration Program;  Massachusetts Military Reservation; prepared for HAZWRAP;
       Boston,  Massachusetts;  April 1996.

E.G. Jordan Co., 1986.  "U.S. Air Force Installation Restoration Program, Phase I: Records Search, Air
       National Guard, Camp Edwards, U.S. Air Force, and Veterans Administration Facilities at
       Massachusetts Military Reservation, Task 6";  prepared for Oak Ridge National Laboratory; Portland,
       Maine; December 11, 1986.

E.G. Jordan Co., 1990 "Task 2-313 Site Inspection, Field Investigation, Work Conducted Spring Summer
       1988"; Installation Restoration Program;  Massachusetts Military Reservation; Prepared for HAZWRAP;
       Portland, Maine; February, 1990.

E.G. Jordan Co., 1991.  "Technical Memorandum, Johns Pond Groundwater Underflow Study, Interim Report";
       Installation Restoration Program; Massachusetts Military Reservation; prepared for HAZWRAP;
       Portland, Maine; January 1991.

Hazardous Waste Remedial Actions Program (HAZWRAP),  1996. "Soil Target Cleanup Levels, DSRP";
       Installation Restoration Program; Massachusetts Military Reservation; Oak Ridge, Tennessee;
       January 1996.

-------
                                  APPENDIX A FIGURES

-------
                               APPENDIX B TABIiES

                                      TABIiE 6-1
                          AOC-SPECIFIC RESPONSE OBJECTIVES

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION

Response Objective at AOC FTA-2/LF-2

•      Prevent organic compounds in soils associated with FTA-2 from being a source of groundwater
       contamination.

Response Objective at AOC PFSA/FS-10/FS-ll

•      Prevent organic compounds in soils from being a source of groundwater contamination.

Response Objective at AOC SD-2/FS-6/FS-8

•      Protect potential human and ecological receptors from exposure to unacceptable concentrations of
       inorganics and SVOCs in surface soils at SD-1 and SD-6.

Response Objectives at AOC SD-3/FTA-3/CY-4

•       Response objectives were not identified for AOC SD-3/FTA-3/CY-4; however, additional soil
       sampling should be conducted to confirm the adeguacy of previous removal actions.

Response Objectives at AOC SD-4

•      Prevent unacceptable human-health risk from exposure to pond sediment and surface water.

•      Prevent unacceptable aguatic and semi-aguatic receptor risk from exposure to pond surface water
       and sediment.

•      Prevent exposure to sediments contaminated with unacceptable concentrations of TPH in the drainage
       ditch north of Reilly Road and soil and sediment contaminated with unacceptable concentrations of
       inorganics in the area of the upgradient pond.

Response Objectives at AOC SD-5/FS-5

•      Protect potential human receptors from exposure to unacceptable concentrations of TPH and lead in
       surface soils.

•      Protect ecological receptors from unacceptable risk resulting from exposure to surface soils.

•      Prevent organic compounds in soils from being a source of groundwater contamination.

Notes:

AOC     =     area of contamination
SVOC    =     semivolatile organic compound
TPH     =     total petroleum hydrocarbon

-------
                                      TABIiE 7-2
                    SUMMARY OF HUMAN-HEALTH RISKS AT AOC FTA-2/LF-2

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
                                MEAN CONCENTRATIONS
                                                        MAXIMUM CONCENTRATIONS
RECEPTOR/MEDIA
     Notes:

     AOC
                                 TOTAL
                                HAZARD
                                 INDEX
Current Land Use

     Short-term Utility       0.04
     Worker
     Exposure to Surface
     Soil

Future Land Use

     Long-term Utility        0.2
     Worker
     Exposure to Surface
     Soil
                         TOTAL
                        CANCER
                         RISK
                        1E-07
                        5E-07
 TOTAL
HAZARD
 INDEX
                                        0.2
                                        0.7
 TOTAL
CANCER
 RISK
                                                    3E-07
                                                    2E-06
area of contamination
                                   TABLE 7-3
             SUMMARY OF ECOLOGICAL RISK ESTIMATES AT AOC FTA-2/LF-2

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
                      RECEPTOR
                                                          TOTAL HAZARD  INDEX

                                                            EXPOSURE  POINT
                                                            CONCENTRATION
                                                         MEAN
                                                                     MAXIMUM
             White-footed Mouse

             Upland Sandpiper

             Red Fox
                                        2            4

                                        10           20

                                      0.003        0.006
               Notes:

               AOC
          area of contamination

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                                       TABLE 7-4
    ESTIMATION OF  PHYTOTOXICITY RISKS IN ZERO TO 2-FEET BGS  SURFACE SOIL AT AOC FTA-2/LF-2
                              FREQUENCY
                                 OF
                              DETECTION
CHEMICAL  [a]
TCL SVOCs
Bis(2-ethylhexyl)phthalate      1/4
                  MAXIMUM
                  HAZARD
                 QUOTIENT  [d]
  MEAN
 HAZARD
QUOTIENT  [d]
100
TCL PESTICIDES/PCBs
Dieldrin
TAL INORGANICS
Arsenic
Chromium
Lead
Mercury
Zinc
                         1E-01
                         2E-01
                         9E-01
                         8E+00
                         6E-01
        9E-02
        1E-01
        3E-01
        4E + 00
        3E-01
                                                                                                             1E+01
Notes:
[a] Chemicals are  COCs.
[b] Lesser of maximum detected concentration and mean concentration.
[c] Phytotoxicity  Critical  Soil Concentration  (see RAH  [ASG,  1994]  Appendix 0,  Tables 0-3 and 0-4, lower  end of range for inorganics)
[d] Hazard Quotient  = concentration divided by benchmark.
[e] Hazard Index = sum  of  HQs.
Shaded value indicated  an  HQ greater than or equal to 1.
-                                = not applicable
AOC                              = area of contamination
BGS                              = below ground surface
COC                              = contaminant of concern
HQ                               = Hazard Quotient
mg/kg                            = milligram per kilogram
NA                               = no phytotoxicity data available
PCB                              = polychlorinated biphenyl
RAH                              = Risk Assessment Handbook
SVOC                             = semivolatile organic compound
TAL                              = Target Analyte List
TCL                              = Target Compound List
TPH                              = total petroleum hydrocarbons

-------
                                             TABLE  7-5
                         ARARs,  CRITERIA,  ADVISORIES,  AND GUIDANCE
                               BIOSPARGING AT AOC FTA-2/LF-2

                          SIX AOCs SOURCE  AREA RECORD  OF DECISION
                             MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

CHEMICAL-SPECIFIC REQUIREMENTS
                                                                                                                               ACTION  TO  BE  TAKEN TO ATTAIN REQUIREMENT
Federal Guidance and Criteria To Be
Considered
                                                              RfDs are considered the levels unlikely  to  cause  signi fleant
                                                              adverse health effects associated with a threshold mechanism
                                                              of action in human exposure  for  a li fetime.
USEPA Carcinogen Assessment Group,
Cancer Slope Factors  (CSFs)
                                                                                     USEPA CSFs were  used  to  compute  the  cancer  risk-based
                                                                                     STCLs for certain  chemicals.
LOCATION-SPECIFIC REQUIREMENTS
Massachusetts Endangered Wildlife and
Wild Plants  (321 CMR 8.00)
Applicable
  The Commonwealth of Massachusetts has authority to             Biosparging activities will be performed so as to minimi ze
  research,  list, and protect any species deemed endangered,     adverse effects to state endangered or threatened species.
  threatened,  or of special concern.  These species are listed as
  either endangered, threatened, or species of special concern
  in the regulations. The Massachusetts lists may di ffer from
  the federal  lists of endangered species.
Massachusetts Air Pollution Control
Regulations  (310 CMR 7.00)
Applicable
  Three state-listed species (grasshopper sparrow, upland
  sandpiper, northern harrier)  are known to inhabit the
  grassland areas of MMR.

  Actions must be conducted in a manner that minimi zes the
  effect on Massachusetts-listed endangered species and
  species listed by the Massachusetts Natural Heritage
  Program.

These regulations set emission limits necessary to attain
ambient air quality standards.
 Construction activities will be managed to meet the
 standards for visible emissions (310 CMR 7.06), dust,  odor,
and demolition (310 CMR 7.09), and noise (310 CMR 7.10).
        =  area of contamination
        =  Applicable or Relevant and Appropriate Requirement
        =  Code of Massachusetts Regulations
        =  cancer slope factor
        =  Massachusetts Military Reservation
                                                RfD     =  reference dose
                                                STCL    =  Soil Target Clean-up Level
                                                USEPA   =  United States Environmental Protection Agency

-------
                                      TABIiE 7-7
                SUMMARY OF HUMAN-HEALTH RISKS AT AOC PFSA/FS-10/FS-ll

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
                                MEAN CONCENTRATIONS
                                                        MAXIMUM  CONCENTRATIONS
RECEPTOR/MEDIA
Current Land Use
        Short-term Utility
        Worker
        Exposure to Surface
        Soil

Future Land Use
        Long-term Utility
        Worker
        Exposure to Surface
        Soil
                                 TOTAL
                                HAZARD
                                 INDEX
0.005
0.02
           TOTAL
          CANCER
           RISK
          6E-C
 TOTAL
HAZARD
 INDEX
                         0.009
 TOTAL
CANCER
 RISK
                                     9E-08
          3E-07
                          0.04
                                     4E-07
        Notes:

        AOC     =  area of contamination

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                                       TABLE 7-8
                     ARARs,  CRITERIA,  ADVISORIES, AND GUIDANCE
                           BIOSPARGING AT AOC PFSA/FS-10/FS-ll

                       SIX AOCs  SOURCE  AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

CHEMICAL-SPECIFIC REQUIREMENTS
                                                               REQUIREMENT SYNOPSIS
                                                                                                                                 ACTION  TO  BE  TAKEN  TO ATTAIN REQUIREMENT
LOCATION-SPECIFIC REQUIREMENTS
Massachusetts Endangered Wildlife
and Wild Plants  (321 CMR 8.00)
                                         Applicable
The Commonwealth of Massachusetts  has  authority to
research, list, and protect  any  species  deemed endangered,
threatened, or of special  concern.  These species are listed as
either endangered, threatened, or  species of special concern in
the regulations. The Massachusetts  lists may differ from the
federal lists of endangered  species.

-------
                                       TABLE 7-8
                     ARARs,  CRITERIA,  ADVISORIES, AND GUIDANCE
                           BIOSPARGING AT AOC PFSA/FS-10/FS-ll

                       SIX AOCs  SOURCE  AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

ACTION-SPECIFIC REQUIREMENTS
                                                               REQUIREMENT SYNOPSIS
                                                                                                                                 ACTION  TO  BE  TAKEN TO ATTAIN REQUIREMENT
RCRA Air Emissions Standards  for
Equipment Leaks  (40  CFR  Part  264,
Subpart BE)
                                      Relevant and
                                      Appropriate
AOC     =  area of contamination
ARAR    =  Applicable  or  Relevant  and Appropriated Requirement
CFR     =  Code of Federal  Requlations
CMR     =  Code of Massachusetts  Requlations
CSF     =  cancer slope  factor
MMR     =  Massachusetts  Military  Reservation
ppmw    =  parts per million  by weiqht
RCRA    =  Resource Conservation  and Recovery Act
RfD     =  Reference dose
STCL    =  Soil Tarqet Clean-up Level
USEPA   =  United States  Environmental Protection Aqency
                                                                                                                                  If threshold  conditions are met at this location, biosparqinq
                                                                                                                                  will  include  collection and treatment of biosparqinq  off-qas.
                                                                                                                                  Off-qas would be  treated to meet standards for volatile
                                                                                                                                  orqanic compounds at 310 CMR 7.18. In addition,
                                                                                                                                  construction  of the biosparqinq and ventinq systems will be
                                                                                                                                  conducted  to  meet the standards for visible emissions  (310
                                                                                                                                  CMR 7.06);  dust,  odor,  construction,  and demolition  (310
                                                                                                                                  CMR 7.09);  and noise (310 CMR 7.10).

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                                     TABIiE 7-10
                  SUMMARY OF HUMAN-HEALTH RISKS AT AOC SD-2/FS-6/FS-8

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
                                MEAN CONCENTRATIONS
                                                        MAXIMUM CONCENTRATIONS
RECEPTOR/MEDIA
                                 TOTAL
                                HAZARD
                                 INDEX
               TOTAL
              CANCER
               RISK
 TOTAL
HAZARD
 INDEX
 TOTAL
CANCER
 RISK
Current Land Use
        Child Trespasser
        Exposure to Surface
        Soil
Future Land Use
       Child Trespasser
       Exposure to Surface
       Soil

       Residential Exposure
       to Surface Soil
   0.003
   0.003
    0.04
               2E-07
               2E-07
               IE-OS
                             0.01
                             0.01
                             0.1
                                         1E-06
                                         1E-06
                                         4E-05
       Notes:

       AOC     =  area of contamination
                                      TABLE 7-11
             SUMMARY OF ECOLOGICAL RISK ESTIMATES AT AOC SD-2/FS-6/FS-8

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
                      RECEPTOR
                                                          TOTAL HAZARD  INDEX

                                                    EXPOSURE POINT  CONCENTRATION

                                                         MEAN        MAXIMUM
             White-footed Mouse

             Cardinal

             Red Fox
                              3

                              2

                           0.0003
               10

               6

             0.002
               Notes:

               AOC
area of contamination

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                                      TABIiE 7-12
    ESTIMATION OF PHYTOTOXICITY RISKS IN ZERO TO 2-FEET BGS  SURFACE  SOIL AT AOC  SD-2/FS-6/FS-8

                        SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
CHEMICAL  [a]
TAL INORGANICS
Cadmium
Chromium
Lead
Zinc

TPH
                             FREQUENCY
                                OF
                             DETECTION
 2/8
 7/8
11/11
 7/8

 2/4
              MAXIMUM
               CONG.

              (mg/kg)
2.40
 103
 677
 118

 194
EXPOSURE
POINT
MEANfb]
(mg/kg)
0.806
18.4
PHYTOTOXICITY
BENCHMARK
VALUE [c]
(mg/kg)
3
75
44.2
                                                                   83.7
100
 70

 NA
                                                   MAXIMUM
                                                   HAZARD
                                                  QUOTIENT  [d]
                                        8E-01
                                        1E+00
                                        7E+00
                                        2E+00
                                                    MEAN
                                                   HAZARD
                                                  QUOTIENT  [d]
3E-01
2E-01
1E+00
6E-01
                                                     HAZARD  INDEX  [e]
                                                                                                           1E+01
                                                                                                                             2E+00
Notes:
[a] Chemicals are COCs.
[b] Lesser of maximum detected concentration and mean  concentration.
[c] Phytotoxicity Critical Soil Concentration  (see RAH [ASG,  1994] Appendix  0,  Tables  0-3  and 0-4,  lower end of range for inorganics)
[d] Hazard Quotient = concentration divided by benchmark.
[e] Hazard Index = sum of HQs.
Shaded value indicated an HQ greater than or egual to  1.
                                = not applicable
AOC                             = area of contamination
BGS                             = below ground surface
COG                             = contaminant of concern
HQ                              = Hazard Quotient
mg/kg                           = milligram per kilogram
NA                              = no phytotoxicity data available
RAH                             = Risk Assessment Handbook
TAL                             = Target Analyte List
TPH                             = total petroleum hydrocarbons

-------
                                      TABIiE 7-13
                     ARARs, CRITERIA, ADVISORIES, AND GUIDANCE
                 EXCAVATION/ASPHALT-BATCHING AT AOC SD-2/FS-6/FS-8

                      SIX AOCs SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

CHEMICAL-SPECIFIC REQUIREMENTS
                                        STATUS
                       REQUIREMENT SYNOPSIS
                                                                      ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
Federal Guidance and Criteria To Be
Considered
USEPA Risk Reference Doses  (RfDs)
To Be Considered
    RfDs are considered the levels unlikely to cause significant
    adverse health effects associated with a threshold mechanism
    of action in human exposure for a lifetime.
    USEPA RfDs were used to calculate risk-based STCLs for
    noncarcinogens in various media.
USEPA Carcinogen Assessment Group,
Cancer Slope Factors  (CSFs)

LOCATION-SPECIFIC REQUIREMENTS

State

Massachusetts Endangered Wildlife
and Wild Plants  (321 CMR 8.00)
To Be Considered
Applicable
    CSFs represent the most up-to-date information on cancer risk
    from USEPA's Carcinogen Assessment Group.
    USEPA CSFs were used to compute the cancer risk-based
    STCLs for certain chemicals.
The Commonwealth of Massachusetts has authority to
research, list, and protect any species deemed endangered,
threatened,  or of special concern. These species are listed as
either endangered,  threatened, or species of special concern in
the regulations. The Massachusetts lists may differ from the
federal lists of endangered species.

Three state-listed species (grasshopper sparrow, upland
sandpiper, northern harrier)  are known to inhabit the grassland
areas of MMR.
Excavation activities will be performed so as to minimize
adverse effects to state endangered or threatened species.
                                                         Actions must be conducted in a manner that minimizes the
                                                         effect on Massachusetts-listed endangered species and
                                                         species listed by the Massachusetts Natural Heritage Program.

-------
                                       TABLE 7-13
                     ARARs,  CRITERIA,  ADVISORIES, AND GUIDANCE
                 EXCAVATION/ASPHALT-BATCHING AT AOC SD-2/FS-6/FS-

                       SIX AOCs  SOURCE  AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

ACTION-SPECIFIC REQUIREMENTS
                                                               REQUIREMENT SYNOPSIS
                                                                                                                                     ACTION  TO  BE  TAKEN TO ATTAIN REQUIREMENT
                                         Relevant and
                                         Appropriate
These requirements identify the maximum concentrations of
contaminants for which the waste would  be  a RCRA-
characteristic hazardous wastes for  toxicity.  The analytical test
given in Appendix II is referred to  as  the TCLP.
                                         Applicable
                                                                                                                                      Excavation  activities will be conducted to meet the
                                                                                                                                      standards for  visible emissions (310 CMR 7.06) ; dust,  odor,
                                                                                                                                      construction,  and demolition (310 CMR 7.09); noise  (310
                                                                                                                                      CMR  7.10);  and volatile organic compounds  (310 CMR
                                                                                                                                      7.18).  If these standards are exceeded, emissions would be
                                                                                                                                      managed through engineering controls.
AOC     =  area of contamination
ARAR    =  Applicable  or  Relevant  and Appropriated Requirement
CFR     =  Code of Federal  Regulations
CMR     =  Code of Massachusetts  Regulations
CSF     =  cancer slope factor
MMR     =  Massachusetts  Military  Reservation
RCRA    =  Resource  Conservation  and Recovery Act
RfD     =  reference dose
STCL    =  Soil Target Clean-up Level
TCLP    =  Toxicity  Characteristic Leaching Procedure
TSD     =  treatment,  storage, disposal
USEPA   =  United States  Environmental Protection Agency

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                                    TABIiE 7-15
              SUMMARY OF HUMAN-HEALTH RISKS AT AOC SD-3/FTA-3/CY-4

                  SIX AOCs SOURCE AREA RECORD OF DECISION
                     MASSACHUSETTS MILITARY RESERVATION
        RECEPTOR/MEDIA
                           MEAN CONCENTRATIONS
                            TOTAL
                            HAZARD
                            INDEX
                     TOTAL
                     CANCER
                     RISK
                                                    MAXIMUM  CONCENTRATIONS
TOTAL
HAZARD
INDEX
TOTAL
CANCER
RISK
Current Land Use

       Child Trespasser      0.04      1E-06
       Exposure to Surface
       Soil

       Short-term Utility    0.06      3E-07
       Worker Exposure to
       Surface Soil

Future Land Use
       Child Trespasser      0.04      1E-06
       Exposure to Surface
       Soil

       Long-term Utility     0.3       1E-06
       Worker Exposure to
       Surface Soil
       Notes:

       AOC  =
                                     0.2
                                     0.3
                                     0.2
                                                 5E-06
                                                 1E-06
                                                 5E-06
                                                 6E-06
area of contamination
                                     TABLE 7-16
            SUMMARY OF ECOLOGICAL RISK ESTIMATES AT AOC  SD-3/FTA-3/CY-4

                     SIX AOCS SOURCE AREA RECORD OF DECISION
                       MASSACHUSETTS MILITARY RESERVATION
                  RECEPTOR



White-footed Mouse

Cardinal

Red Fox

   Notes:

   AOC    =    area of contamination
                               TOTAL HAZARD INDEX
                          EXPOSURE POINT CONCENTRATION
                           MEAN             MAXIMUM
                            10

                            50

                           0.001
          40

         100

        0.004

-------
                                             TABIiE 7-17
    ESTIMATION OF PHYTOTOXICITY RISKS IN ZERO TO 2-FEET BGS SURFACE SOIL AT AOC SD-3/FTA-3/CY-4

                             SIX AOCs SOURCE AREA RECORD OF DECISION
                                MASSACHUSETTS MILITARY RESERVATION



CHEMICALS [c]
TOL SVOCS
2, 4-Dinitrotoluene
TAL INORGANICS
Antimony
Cadmium
Chromium
Cobalt
Copper
Cyanide
Lead
Manganese
Mercury
Nickel
Selenium
Vanadium
Zinc
FREQUENCY
OF
DETECTION


1/9

2/9
1/9
8/9
5/9
8/9
1/9
9/9
9/9
3/9
7/9
4/9
9/9
9/9
MAXIMUM
CONG.

(mg/kg)

0.67

23
2.8
111
140
535
0.78
553
443
0.39
231
5.7
32.8
1,710
EXPOSURE-
POINT
MEAN [b]
(mg/kg)

0.351

9.0
0.73
23
23.9
110
0.78
114.6
101
0.120
34.2
1.39
14.9
254
PHYTOTOXICITY
BENCHMARK
VALUE [c]
(mg/kg)

0.49

5
3
75
25
60
NA
100
1,500
0.3
100
5
NA
70
MAXIMUM
HAZARD
QUOTIENT [d]


1E+00

5E+00
9E-01
1E+00
6E+00
9E+00
-
6E+00
3E-01
1E+00
2E+00
IE+00
-
2E+01
MEAN
HAZARD
QUOTIENT [d]


7E-01

2E+00
2E-01
3E-01
IE+00
2E+00
-
IE+00
7E-02
4E-01
3E-01
3E-01
-
4E+00
                                                                                 6E+01
                                                                                                 1E+01
TPH                  4/4             256            128           NA
                                         HAZARD INDEX  [e]
Notes:
(a] Chemicals are COCs.
(b) Lesser of maximum detected concentration and mean concentration.
[c] Phytotoxicity Critical Soil Concentration  (see RAH  [ASG, 1994] Appendix 0, Tables 0-3 and 0-4,  lower  end  of  range  for  inorganics)
[d] Hazard Quotient = concentration divided by benchmark.
[e] Hazard Index = sum of HQs.
Shaded value indicates an HQ greater than or egual to 1.
                             = not applicable
AOC
BGS
COG
HQ
mg/kg
NA
PCB
RAH
SVOC
TAL
TCL
TPH
                             = area of contamination
                             = below ground surface
                             = contaminant of concern
                             = Hazard Quotient
                             = milligram per kiloram
                             = no phytotoxicity data available
                             = polychlorinate biphenyl
                             = Risk Assessment Handbook
                             = semivolatile organic compound
                             = Target Analyte List
                             = Target Compound List
                             = total petroleum hydrocarbons

-------
REQUIREMENTS

CHEMICAL-SPECIFIC REQUIREMENTS

Federal Guidance and Criteria To Be
Considered
                                        STATUS
                     TABIiE 7-18
     ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
       LIMITED ACTION AT AOC SD-3/FTA-3/CY-4

      SIX AOCs SOURCE AREA RECORD OF DECISION
         MASSACHUSETTS MILITARY RESERVATION

      REQUIREMENT SYNOPSIS
      ACTIONS TO BE TAKEN TO ATTAIN REQUIREMENT
USEPA Risk Reference Doses  (RfDs)   To Be Considered
USEPA Carcinogen Assessment Group,  To Be Considered
Cancer Slope Factors  (CSFs)

LOCATION-SPECIFIC REQUIREMENTS

State

Massachusetts Endangered Wildlife   Applicable
and Wild Plants  (321 CMR 8.00)
FVDs are considered the levels unlikely to cause significant
adverse health effects associated with a threshold mechanism
of action In human exposure for a lifetime.

CSFs represent the most up-to-date information on cancer risk
from USEPA's Carcinogen Assessment Group.
USEPA RIM were used to calculate risk-based STCLs for
noncarcinogens in various media.
USEPA CSFs were used to compute the cancer risk-based
STCLs for certain chemicals.
The Commonwealth of Massachusetts has authority to
research, list, and protect any species deemed endangered,
threatened,  or of special concern. These species are listed as
either endangered,  threatened, or species of special concern in
the regulations. The Massachusetts lists may differ from the
federal lists of endangered species.

Three state-listed species (grasshopper sparrow, upland
sandpiper, northern harrier)  are known to inhabit the grassland
areas of MMR
Sampling activities will be performed to minimize adverse
effects to state endangered or threatened species.
                                                        Actions must be conducted in a manner that minimizes the
                                                        effect on Massachusetts-listed endangered species and
                                                        species listed by the Massachusetts Natural Heritage Program.

-------
                                                                    TABIiE 7-18
                                                     ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
                                                      LIMITED ACTION AT AOC SD-3/FTA-3/CY-4

                                                     SIX AOCS SOURCE AREA RECORD OF DECISION
                                                       MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

ACTION-SPECIFIG REQUIREMENTS

Federal
                                       STATUS
     REQUIREMENT SYNOPSIS
          ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
RCPA Identification and Listing of   Applicable
Hazardous Wastes, Toxicity
Characteristics  (40 CFR Part 261.24)
State

Hazardous Waste Regulations - Waste  Applicable
Piles  (310 CMR 30.640)
Massachusetts Air Pollution Control  Applicable
Regulations  (310 CMR 7.00)
These reguirements identify the maximum concentration of
contaminants for which the waste would be a RCRA-
characteristics hazardous waste for toxicity. The analytical
given in Appendix II is referred to as the TCLP.
The reguirements apply to owners and operators of facilities
that use waste piles to store or treat hazardous waste.
Then regulations set emission limits necessary to attain
ambient air guality standards.
       If the contingency remedy of excavation and asphalt
       batching is implemented,  source area soils will be analyzed
test   for TCLP.  If TCLP results exceed the standards in 261.24,
       the Material Will be disposed off-site in a RCRA permitted
       TSD facility.
       If the contingency remedy of excavation and asphalt
       batching is implemented,  accumulation of excavated soil
       will be Managed according to these reguirements.

       If the contingency remedy of excavation and asphalt
       batching is implemented,  excavation of soil and asphalt
       batching will be performed to meet the standards for visible
       emissions (310 CMR 7.06); dust,  odor, construction, and
       demolition (310 CMR 7.09); noise (310 CMR 7.10); and
       volatile organic compounds (310 CMR 7.18). If standards
       are exceeded, emissions will be managed through
       engineering controls.
AOC   = area of contamination
ARAR  = Applicable or Relevant and Appropriate Reguirement
CFR   = Code of Federal Regulations
CMR   = Code of Massachusetts Regulations
CSF   = cancer slope factor
MMR   = Massachusetts Military Reservation
RCRA  = Resource Conservation and Recovery Act
RfD   = reference dose
STCL  = Soil Target Clean-up Level
TCLP  = Toxicity Characteristic Leaching Procedure
TSD   = treatment, storage, disposal
USEPA = United States Environmental Protection Agency

-------
                                                TABIiE 7-20
                                 SUMMARY OF HUMAN HEALTH RISKS AT AOC SD-4
                                  Six AOCS SOURCE AREA RECORD OF DECISION
                                    MASSACHUSETTS MILITARY RESERVATION

                                                    MEAN CONCENTRATIONS
              RECEPTOR/MEDIA
                                                   TOTAL
                                                  HAZARD
                                                   INDEX
                                                                              MAXIMUM
                                                                           CONCENTRATIONS
              TOTAL
              CANCER
               RISK
 TOTAL
HAZARD
 INDEX
TOTAL
CANCER
 RISK
Current Land Use
        Child Trespasser Exposure to
        Surface Soil
   0.007
              9E-07
                         0.02
                                   3E-06
        Short-term Utility Worker Exposure
        to Surface Soil
    0.01
              3E-07
                         0.04
                                   1E-06
 Future Land Use
        Child Resident Exposure to Surface
        Soil
     0.2
              3E-05
                          0.6
                                   1E-04
        Long-term Utility Worker Exposure
        to Surface Soil
    0.06
              1E-06
                          0.2
                                   5E-06
        Adult Resident Exposure to Surface
        Soil
    0.02
              IE-OS
                         0.07
                                   5E-05
        Adult Resident Exposure to
        Groundwater
              1E-04
                          30
                                   3E-04
        Adult Resident Exposure to Pond
        Surface Water
    0.02
              3E-04
                         0.04
                                   5E-04
        Adult Resident Exposure to
        Wetlands Surface Water
   0.0003
                NC
                        0.0003
                                     NC
        Adult Resident Exposure to Pond
        Sediment
0.000000007
                NC
                     0.000000007
                                     NC
        Lifetime Resident (Adult & Child)
        Exposure to Soil, Groundwater,
        Surface Water, Sediment
     NA
              5E-04
                          NA
                                   9E-04
    Notes:
    AOC  =    area of contamination
    NA   =    Not applicable
    NC   =    Not calculated because no toxicity values are available for the contaminants of
              concern.

-------
                            TABIiE 7-22
            Terrestrial Vegetation Risk Characterization
                  Mean Surface Soil Concentrations

                      AOC SP-4 RI STUDY AREA
               MASSACHUSETTS MILITARY RESERVATION
Unit - ing/kg

Volatile Organics
2-Butanone
Benzene
Carbon Bisulfide
Chloroform
Ethyl Benzene
Tetrachloroethene
Toluene
Trichloroethene
Total Xylenes
Semi-volatile Organics
2-Methylnaphthalene
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(g,h,i)perylene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Bis (2-ethylhexyl)phthalate
Carbazole
Chrysene
Dibenz(a,h)anthracene
Dibenzofuran
Di-n-butylphthaiate
Fluoranthene
Fluorene
Indeno(1,2,3-cd)pyrene
Naphthalene
Phenanthrene
Pyrene
Pesticides/PBCs
4,4'-DDD
4,4' -DDE
Mean
Critical Soil
Concentration
mg/kg
0.
0.
0.
0.
0
0

0.
0.
.cs








:halate


le




;ne



0
0.
HQ
Concentration (a)
mg/kg
0081
0064
0069
0064
.007
.007
0.01
0072
0075
0.81
0.27
0.25
0.15
0.94
0.98
0.55
2.6
2.6
0.43
0.3
1.1
0.37
0.33
0.53
2.1
0.28
0.64
0.48
1.1
1.5
.004
0032
41144
43

73.
10
102
33
6
1.
8
2
5.
6.
7.
8.
8.
8.
8.
100

7.

6.
38
7.
6.
8.

4.
7.


.2
.7
NA
43
.2
.8
.6
.3
68
.6
.5
77
59
82
48
98
46
46
.0
NA
82
9
21
.7
26
26
98
10
16
08
50
50
2.0E-07
0.000147
NE
0.000087
0.000686
0.000068
0.000298
0.001152
0.004464
0.094186
0.108
0.043328
0.022762
0.120205
0.115566
0.061247
0.307329
0.307329
0.0043
NE
0.140665
0.041111
0.05314
0.013695
0.289256
0.044728
0.071269
0.048
0.264423
0.211864
0.00008
0.000064

-------
                                  TABIiE 7-22
                Terrestrial Vegetation Risk Characterization
                      Mean Surface Soil Concentrations

                           AOC SD-4 RI STUDY AREA
                     MASSACHUSETTS MILITARY RESERVATION

Unit - ing/ kg

4, 4 '-DDT
alpha-Chlordane
Dieldrin
Aroclor-1260
Herbicides
Dichloroprop
Inorganics
Aluminum
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Cyanide
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Vanadium
Zinc
Mean
Concentration
ing/ kg
0.0067
0.003
0.051
0.83

0.0094

6558
4.6
35
0.48
1.1
877
16
4.5
41
0.3
7989
169
887
206
0.15
8.4
465
0.94
0.67
22
57
Critical Soil
Concentration
ing/ kg
50
NA
1.39
10

NA

NA
20
NA
NA
3
NA
75
25
60
NA
NA
100
NA
1500
0.3
100
NA
5
NA
NA
70
HQ
(a)

0.000134
NE
0.036691
0.083

NE

NE
0.23
NE
NE
0.366667
NE
0.213333
0.18
0.683333
NE
NE
1.69
NE
0.137333
0.5
0.084
NE
0.188
NE
NE
0.814286
                                      HI
a)  values obtained from Tables 0-3 and 0-4

HI - Hazard Index
NA - Not Available
NE - Not Evaluated

-------
                    TABIiE 7-23
 SUMMARY OF ECOLOGICAL RISK ESTIMATES AT AOC SD-4

     SIX AOCS SOURCE AREA RECORD OF DECISION
        MASSACHUSETTS MILITARY RESERVATION
                      RECEPTOR
  TOTAL HAZARD INDEX

    EXPOSURE POINT
    CONCENTRATION
                                                 MEAN
                                                             MAXIMUM
Terrestrial Receptor Exposure to Surface Soil and
Pond Water
     White-footed Mouse
     Northern Short-tailed Shrew
     Short-eared Owl
     Cardinal
   12
   70
  369
   11
   77
  185
  4285
   40
Terrestrial and Semi-aquatic Receptor Exposure to
Pond Water and Sediment
     Muskrat
     Mallard Duck
     Osprey
     Meadow Vole
     Northern Harrier
     Black Duck
     Black-crowned Night Heron
   18
 216,628
  68,448
   16
    1
 89,084
19,100,89
    4
   50
 322,984
 106,174
   15
    5
 132,865
28,689,298
Terrestrial and Semi-aquatic Receptor Exposure to
Wetlands Surface Water and Sediment
     Meadow Vole
     Northern Harrier
     Mallard Duck
     Muskrat
     Osprey
     Black Duck
     Black-crowned Niqht Heron
    4
    3
    4
    2
  6, 695
    4
2,774,335
    7
    5
    6
    3
  6,833
    6
 2,788,472
    Notes:
    AOC
                area of contamination

-------
                                                                                   TABLE 7-24
                                                                     ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
                                                                      EXCAVATION/ASPHALT-BATCHING AT AOC SD-4

                                                                      SIX AOCS SOURCE AREA RECORD OF DECISION
                                                                        MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

CHEMICAL-SPECIFIC REQUIREMENTS

Federal

Federal AWQC  (33 USC 1251 et seq.;
                                        STATUS
                         REQUIREMENT SYNOPSIS
                                                                        ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
Relevant and
Appropriate
USEPA Risk Reference Doses  (RfDs)   To Be Considered



USEPA Carcinogen Assessment Group,  To Be Considered
Cancer Slope Factors (CSFs)

LOCATION-SPECIFIC REQUIREMENTS

WETLANDS

Federal

Protection of Wetlands - Executive   Applicable
Order  (EO) 11990  (40 CFR 6,
Appendix A)
Federal AWQC include  (1) criteria for protection of human
health from toxic properties of contaminants ingested through
drinking water and aguatic organisms, and  (2) criteria for
protection of aguatic life. Human-health criteria were
developed for 95 compounds. Remedial actions involving
contaminated surface water must consider the uses of the
water and the circumstances of the release or threatened
release; this determines whether AWQC are relevant and
appropriate.

RfDs are considered the levels unlikely to cause significant
adverse health effects associated with threshold mechanism
of action in human exposure for a lifetime.

CSFs represent the most up-to-date information on cancer
risk from USEPA's Carcinogen Assessment Group.
Excavation of sediment will be conducted to prevent long-
term AWQC exceedances in the wetland and in Johns Pond.
Excavation of wetland areas may cause short-term
exceedances of AWQC within the SD-4 wetlands. Surface
water guality in the wetland and water entering Johns Pond
will be monitored and the results will be compared to AWQC.
                                                                                     USEPA RfDs were used to calculate risk-based STCLs for
                                                                                     noncarcinogens in various media.
                                                                                     USEPA CSFs were used to compute the cancer risk-based
                                                                                     STCLs for certain chemicals.
                   Appendix A of 40 CFR 6 sets forth policy for carrying out
                   provisions of the Protection of Wetlands Executive Order.
                   Under this order, federal agencies are reguired to minimize
                   the degradation, loss, or destruction of wetlands, and to
                   preserve the natural and beneficial values of wetlands.
                   Appendix A reguires that no remedial alternatives adversely
                   affect a wetland if another practicable alternative is available.
                   If no alternative is available, effects from implementing the
                   chosen alternative must be mitigated.
                                                                  Excavation activities within the wetlands will be done in a
                                                                  manner to minimize effects. Altered areas will be repaired
                                                                  or restored.

-------
TABLE 7-24
ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
EXCAVATION/ASPHALT-BATCHING AT AOC SD-4

SIX AOCS SOURCE AREA RECORD OF DECISION
MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

State
STATUS
REQUIREMENT SYNOPSIS
ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
Massachusetts Wetlands Regulations Applicable
(310 CMR 10.00)
These regulations protect inland and coastal wetlands, as well
as a 100-foot buffer zone, from activities that may alter the
resource area. Some wetlands receive additional protection
as wildlife habitat. Status of wildlife habitat is determined by
the presence of particular plant communities and/or
hydrologic characteristics.

The regulations specifically prohibit the loss over 5,000 sguare
feet of bordering vegetated wetlands. The loss may be
permitted with replication of the lost area within two growing
seasons.
If remedial activities after more than 5,000 sguare feet of
protected area, the affected area will be restored within
two growing seasons.
Massachusetts Endangered Wildlife Applicable
and Wild Plants (321 CMR 8.00)
The Commonwealth of Massachusetts has authority to
research, list, and protect any species deemed endangered,
threatened, or of special concern. Then species are listed as
either endangered, threatened, or species of special concern
in the regulations. The Massachusetts lists may differ from
the federal lists of endangered species.

Three state-listed species (grasshopper, sparrow, upland
sandpiper, northern harrier) are known to inhabit the
grassland areas of MMR.

Actions must be conducted in a manner that minimizes the
effect on Massachusetts-listed endangered species and
species listed by the Massachusetts Natural Heritage
Program.
Excavation activities will be performed to minimize adverse
effects to state endangered or threatened species.

-------
                                                                                   TABLE 7-24
                                                                     ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
                                                                      EXCAVATION/ASPHALT-BATCHING AT AOC SD-4

                                                                      SIX AOCS SOURCE AREA RECORD OF DECISION
                                                                        MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

ACTION-SPECIFIG REQUIREMENTS

Federal
                                          STATUS
                       REQUIREMENT SYNOPSIS
                                                                            ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
RCRA Identification and Listing of
Hazardous Wastes; Toxicity
Characteristics  (40 CFR Part 261.24)
Rivers and Harbors Act of 1899  (33
USC 403)
Applicable     These requirements identify the maximum concentrations of
               contaminants for which the waste would be a RCRA-
               characteristic hazardous waste for toxicity. The analytical test
               given in Appendix II is referred to as the TCLP.

Relevant and   Section 10 of the Rivers and Harbors Act of 1899 requires
Appropriate    authorization from the Secretary of the Army, acting through
               the USAGE, for the construction of any structure in or over
               any "navigable Water of the U.S.," the excavation from or
               deposition of material in such waters, or any obstruction or
               alteration in such waters.
                                                                   Source area soils will be analyzed for TCLP. If TCLP results
                                                                   exceed to standards in 261.24, the material will be disposed
                                                                   off-site in a RCRA permitted TSD facility.
                                                                    Permits are not required for CERCLA on-site actions. The
                                                                    substantive requirements will be met.
Fish and Wildlife Coordination Act  (16 Relevant and
USC 661 et seq. )                        Appropriate
Clean Water Act, Dredge or Fill
Requirements Section 404  (33 CFR
Part 230; 40 CFR Part 230)
 Applicable
This act requires that any federal agency proposing to modify
a body of water must consult with the U.S. Fish and Wildlife
Service, National Marine Fisheries Services, and other related
state agencies to develop measures to prevent, mitigate or
compensate for project-related losses to fish and wildlife.

Section 404 of the Clean Water Act regulates the discharge of
dredged or fill materials to U.S. waters, including wetlands.
Filling of wetlands, or incidental redeposit of material during
excavation, would be considered a discharge of fill materials.
Procedures for complying with regulatory conditions are
contained in 33 CFR Part 323. Guidelines for Specification of
Disposal Sites for Dredged or Fill material at 40 CFR Part 230,
promulgated under Clean Water Act Section 404 (b) (1),
maintain that no discharge of dredged or fill material will be
permitted if there is a practical alternative that would have
less effect on the aquatic ecosystem. If adverse impacts are
unavoidable, action must be taken to restore, or create
alternative wetlands.
                                                                                   Actions will be taken to develop measures to prevent,
                                                                                   mitigate or compensate for project-related impacts to fish
                                                                                   and wildlife. Relevant agencies will be contacted to help
                                                                                   analyze impact of remedial actions on fish and wildlife.
Filling of wetlands and/or excavation of wetlands which
could result in incidental deposition of excavated materials
will be avoided if practical. If unavoidable, restoration
activities will be performed to minimize potential adverse
effects and meet the substantive requirements of these
regulations. The restoration of excavated wetlands will
likely require placement of fill materials in the SD-4
 wetland.

-------
                                                                                   TABLE 7-24
                                                                     ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
                                                                      EXCAVATION/ASPHALT-BATCHING AT AOC SD-4

                                                                      SIX AOCS SOURCE AREA RECORD OF DECISION
                                                                        MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT                               STATUS

Federal  (Continued)

Clean Water Act NPDES Program  (40     Applicable
CFR 122, 125)


State
        REQUIREMENT SYNOPSIS
The National Pollutant Discharge Elimination System  (NPDES)
permit program specifies the permissible concentration or
level of contaminants in the discharge from any point source,
including surface runoff, to waters of the United States.
          ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
Construction activities will be controlled to meet NPDES
discharge reguirements. Supernatant from the dewatering of
sediments will be treated to meet the substantive
reguirements of these regulations.
Hazardous Waste Regulations - Waste   Relevant and
Piles  (310 CMR 30.640)                Appropriate
Then reguirements apply to owners and operators of
facilities that use waste piles to store or treat hazardous
waste.
Accumulation of excavated soil will be managed according to
these reguirements.
Massachusetts Air Pollution Control   Applicable
Regulations  (310 CMR 7.00)
Then regulations set emission limits necessary to attain
ambient air guality standards.
Excavation activities will be conducted to most the standards
for visible emissions  (310 CMR 7.06); dust, odor,
construction, and demolition  (310 CMR 7.09); noise  (310
CMR 7.10); and volatile organic compounds  (310 CMR 7.18).
If standards are exceeded, emissions will be managed
through engineering controls.
                                                                 Notes:
AOC    =  area of contamination
ARAR   =  Applicable or Relevant and Appropriate Reguirement
AWQC   =  Ambient Water Quality Criteria
CERCLA =  Comprehensive Environmental Response Compensation and Liability Act
CFR    =  Code of Federal Regulations
CMR    =  Code of Massachusetts Regulations
CSF    =  cancer slope factor
EO     =  Executive Order
MMR    =  Massachusetts Military Reservation
                                NPDES   =  National Pollutant Discharge Elimination System
                                RCRA    =  Resource Conservation and Recovery Act
                                RFD     =  reference dose
                                STCL    =  Soil Target Clean-up Level
                                TCLP    =  Toxicity Characteristic Leaching Procedure
                                TSD     =  treatment storage, disposal
                                USAGE   =  United States Army Corps of Engineers
                                USC     =  United States Code
                                USEPA   =  United States Environmental Protection Agency

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RECEPTOR/MEDIA
                                     TABIiE 7-26
                    SUMMARY OF HUMAN-HEALTH RISKS AT AOC SD-5/FS-5

                      SIX AOCS SOURCE AREA RECORD OF DECISION
                         MASSACHUSETTS MILITARY RESERVATION
                                  MEAN CONCENTRATIONS
                                                             MAXIMUM CONCENTRATIONS
                                  TOTAL
                                  HAZARD
                                  INDEX
             TOTAL
             CANCER
             RISK
         TOTAL
         HAZARD
         INDEX
 TOTAL
CANCER
 RISK
Current Land Use
        Short-term Utility
        Worker
        Exposure to Surface
        Soil
0.05
             2E-07
                             0.9
                                         3E-06
Future Land Use
        Long-term Utility
        Worker
        Exposure to Surface
        Soil
0.2
             1E-06
                                         IE-OS
        Notes:

        AOC    =    area of contamination
        The above risk values do not include potential risks from exposure  to  lead  and  TPH,
         which were not evaluated quantitatively.

                                      TABLE 7-27
                 SUMMARY OF ECOLOGICAL RISK ESTIMATES AT AOC SD-5/FS-5

                       SIX AOCS SOURCE AREA RECORD OF DECISION
                          MASSACHUSETTS MILITARY RESERVATION
                           RECEPTOR
                                            TOTAL HAZARD INDEX
                                              EXPOSURE POINT
                                               CONCENTRATION
                     White-footed Mouse

                     Cardinal

                     Red Fox
          MEAN

           40

           40

          0.06
MAXIMUM

  500

  600

  0.8
                        Notes:

                        AOC
 area of contamination

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                                                                                   TAKLE 7-29
                                                                     ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
                                                                   EXCAVATION/ASPHALT-BATCHING AT AOC SD-5/FS-5

                                                                      SIX AOCS SOURCE AREA RECORD OF DECISION
                                                                        MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT
                                          STATUS
                     REQUIREMENT SYNOPSIS
                                                                  ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
CHEMICAL-SPECIFIC
REQUIREMENTS

Federal Guidance and Criteria To Be
Considered

USEPA Risk Reference Doses  (RfDs)
USEPA Carcinogen Assessment
Group, Cancer Slope Factors  (CSFs)

LOCATION-SPECIFIC
REQUIREMENTS

State

Massachusetts Endangered Wildlife
and wild plants  (321 CMR 8.00)
To Be Considered
To Be Considered
Applicable
RfDs are considered the levels unlikely to cause significant
adverse health effects associated with a threshold mechanism
of action in human exposure for a lifetime.

CSFs represent the most up-to-date information on cancer risk
from USEPA's Carcinogen Assessment Group.
The Commonwealth of Massachusetts has authority to
research, list, and protect any species deemed endangered,
threatened,  or of special concern. These species are listed as
either endangered,  threatened, or species of special concern
in the regulations. The Massachusetts lists may differ from the
federal lists of endangered species.

Three state-listed species (grasshopper sparrow, upland
sandpiper, norther harrier) are known to inhabit the grassland
areas of MMR.
USEPA RfDs were used to calculate risk-based
STCLs for noncarcinogens in various media.
                                                                                       USEPA CSFs were used to compute the cancer
                                                                                       risk-based STCLs for certain chemicals.
Excavation activities will be performed so as to
minimize adverse effects to state endangered or
threatened species.
                                                               Actions must be conducted in a manner that minimizes the
                                                               effect on Massachusetts-listed endangered species and
                                                               species listed by the Massachusetts Natural Heritage Program.

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                                                                                       TABIiE 7-29
                                                                        ARARS, CRITERIA, ADVISORIES, AND GUIDANCE
                                                                      EXCAVATION/ASPHALT-BATCHING AT AOC SD-5/FS-5

                                                                         SIX AOCS SOURCE AREA RECORD OF DECISION
                                                                           MASSACHUSETTS MILITARY RESERVATION
REQUIREMENT

ACTION-SPECIFIG REQUIREMENTS

Federal
                                          STATUS
                     REQUIREMENT SYNOPSIS
                                                                     ACTION TO BE TAKEN TO ATTAIN REQUIREMENT
RCRA Identification and Listing of
Hazardous Wastes; Toxicity
Characteristics  (40 CFR Part 261.24)
Applicable
These requirements identify the maximum concentrations of
contaminants for which the waste would be a RCRA-
characteristic hazardous waste for toxicity. The analytical test
given in Appendix II is referred to as the TCLP.
Source area soils will be analyzed for TCLP. If
TCLP results exceed the standards in 261.24, the
material will be disposed off-site in a RCRA
permitted TSD facility.
State
Hazardous Waste Regulations - Waste       Applicable
Piles  (310 CMR 30.640)

Massachusetts Air Pollution Control       Applicable
Regulations  (310 CMR 7.00)
                     These requirements apply to owners and operators of facilities
                     that use waste piles to store or treat hazardous waste.

                     These regulations set emission limits necessary to attain
                     ambient air quality standards.
                                                                  Accumulation of excavated soil will be managed
                                                                  according to these requirements.

                                                                  Excavation of soil and asphalt-batching will be
                                                                  performed to meet the standards for visible
                                                                  emissions (310 CMR 7.06); dust, odor, construction,
                                                                  and demolition (310 CMR 7.09); noise  (310 CMR
                                                                  7.10); and volatile organic compounds (310 CMR
                                                                  7.18). If standards are exceeded, emissions will be
                                                                  managed through engineering controls.
Notes:
AOC     =   area of contamination
ARAR    =   Applicable or Relevant and Appropriate Requirement
CFR     =   Code of Federal Regulations
CMR     =   Code of Massachusetts Regulations
CSF     =   cancer slope factor
MMR     =   Massachusetts Military Reservation
RCRA    =   Resource Conservation and Recovery Act
RfD     =   reference dose
STCL    =   Soil Target Clean-up Level
TCLP    =   Toxicity Characteristics Leaching Procedure
TSD     =   treatment, storage, disposal
USEPA   =   United States Environmental Protection Agency

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                     APPENDIX C RESPONSIVENESS SUMMARY
                          RESPONSIVENESS SUMMARY

                            RECORD OF DECISION
              AREAS OF CONTAMINATION FTA-2/LF-2, PFSA/FS-10/FS-ll,
          SD-2/FS-6/FS-8, SD-3/FTA-3/CY-4, SD-4, and SD-5/FS-5  SOURCE AREAS

                     MASSACHUSETTS MILITARY RESERVATION
                          CAPE COD, MASSACHUSETTS

                             SEPTEMBER 1998

                     MASSACHUSETTS MILITARY RESERVATION
                          CAPE COD, MASSACHUSETTS

                              TABLE OF CONTENTS

Section                         Title                                                    Page  No.


1.0 OVERVIEW OF REMEDIAL ALTERNATIVES CONSIDERED IN THE FEASIBILITY
    STUDY INCLUDING THE SELECTED REMEDY	1-1

 1.1 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC FTA-2/LF-2	1-1
   1.1.1 No Action 	1-1
   1.1.2 Limited Action 	1-1
   1.1.3 Biosparging with Ambient Air Monitoring 	1-1
   1.1.4 Selected Remedy 	1-2

 1. 2 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC PFSA/FS-10/FS-ll	1-2
   1.2.1 No Action 	1-3
   1.2.2 Limited Action 	1-3
   1.2.3 Biosparging with Off-gas Collection and Treatment  	1-3
   1.2.4 Selected Remedy 	1-4

 1.3 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-2/FS-6/FS-8	1-4
   1.3.1 No Action 	1-5
   1.3.2 Excavation and Asphalt-batching 	1-5
   1.3.3 Excavation and Off-site Treatment and Disposal 	1-5
   1.3.4 Selected Remedy 	1-6

 1.4 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-3/FTA-3/CY-4  	1-6
   1.4.1 No Action 	1-6
   1.4.2 Confirmation Sampling with Contingency of Excavation and Asphalt-batching 	1-4
   1.4.3 Selected Remedy 	1-7

 1.5 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-4 	1-7
   1.5.1 No Action 	1-8
   1.5.2 Excavation and Asphalt-batching 	1-8
   1.5.3 Excavation and Off-site Treatment and Disposal 	1-9
   1.5.4 Selected Remedy 	1-9
1.6 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-5/FS-5	1-10
  1.6.1 No Action 	1-10
  1.6.2 Limited Action 	1-10
  1.6.3 Excavation and Asphalt-batching 	1-10
  1.6.4 Excavation and Off-site Treatment and Disposal  	1-11
  1.6.5 Selected Remedy 	1-12

2.0 BACKGROUND ON COMMUNITY INVOLVEMENT 	2-1

3.0 SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT  PERIOD
    AND AFCEE RESPONSES 	3-1

ATTACHMENT A        PUBLIC COMMENTS
ATTACHMENT B        LETTER FROM USAF 102 ND FIGHTER WING
ATTACHMENT C        SOIL RECYCLING FACILITY SUMMARY LEVELS

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This Responsiveness Summary has been prepared to meet the requirements of Sections 113(k)(2)(B)(iv) and
117(b) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 as amended by
the Superfund Amendments and Reauthorization Act of 1986  (SARA), which requires response to "...
siqnificant comments, criticisms, and new data submitted in written or oral presentations" on a proposed
plan for remedial action. The purpose of this Responsiveness Summary is to document the Air Force Center
for Environmental Excellence (AFCEE) responses to questions and comments expressed, during the public
comment period by the public, potentially responsible parties, and governmental bodies in written and
oral comments regarding the Proposed Plan to Clean Up Six Source Areas of Contamination  (AOCs) at the
Massachusetts Military Reservation  (MMR).

AFCEE published a notice and brief analysis of the Proposed Plan in the "Falmouth and Mashpee
Enterprises" on October 31, 1997, the "Cape Cod Times" on November 3, 1997, and the "Bourne and
Sandwich Enterprises" on November 7, 1997. On November 13, 1997, AFCEE made the remedial investigation
(RI) reports, the Feasibility Study, and Proposed Plan available for public review at the U.S. Coast
Guard library at MMR; and the main public libraries in Bourne, Falmouth, Mashpee, and Sandwich,
Massachusetts. The Proposed Plan has also been made part of the administrative record available for
public review at the AFCEE Installation Restoration Program (IRP) office at MMR and the Falmouth Public
Library.

From November 13, 1997 to January 15, 1998, AFCEE held a 60-day public comment period to accept public
comments on the preferred alternatives presented for the six AOCs in the Proposed Plan. On November 13,
1997, AFCEE held a public meeting at the Administration Building at the Barnstable County Fairgrounds in
Barnstable, Massachusetts, to present and discuss the Proposed Plan. On December 2, 1997, AFCEE held a
public hearing at Mashpee High School, Mashpee, Massachusetts to accept verbal comments on the Proposed
Plan. Several residents and local officials attended the hearing and provided verbal comments. AFCEE's
responses to the comments received at the hearing and during the public comment period are included in
Section 3.0 of this Responsiveness Summary. A transcript of the December 2, 1997 public hearing is
included in Appendix D of this Record of Decision.

This Responsiveness Summary is organized into the following sections:

1.  Overview of Remedial Alternatives Considered in the Feasibility Study Including the Selected
    Remedy-This section briefly outlines the remedial alternatives evaluated in detail in the Feasibility
    Study and presented in the Proposed Plan, including AFCEE's selected remedy.

2.  Background on Community Involvement-This section provides a brief history of community involvement
    and AFCEE initiatives to inform the community of site activities.

3.  Summary of Comments Received During the Public Comment Period and AFCEE Responses-This section
    provides AFCEE responses to verbal and written comments received from the public and not formally
    responded to during the public comment period. Copies of the comment letters are included in
    Attachment A of this Responsiveness Summary. A transcript of the December 2, 1997 public hearing is
    included in Appendix D of this Record of Decision.

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                 1.0 OVERVIEW OF REMEDIAL ALTERNATIVES CONSIDERED IN THE
                     FEASIBILITY STUDY INCLUDING THE SELECTED REMEDY

1.1 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC FTA-2/LF-2

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria of the National Oil and Hazardous Substances Pollution Contingency Plan while controlling
migration of contaminants from deep soils to groundwater at AOC FTA-2/LF-2:

       •      No Action
       •      Limited Action
       •      Biosparging with Ambient Air Monitoring

1.1.1 No Action

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions  (security fencing and
military guard posts) that currently limit potential human exposure to site contaminants.

1.1.2 Limited Action

The Limited Action alternative at AOC FTA-2/LF-2 includes the following key components:

       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      filing a Record Notice of Landfill Operation with the Registry of Deeds to document the
              location of the landfill
       •      performing five-year site reviews

1.1.3 Biosparging with Ambient Air Monitoring

The biosparging alternative at AOC FTA-2/LF-2 includes the following key components:

       •      mobilization and site preparation
       •      performing baseline ambient air monitoring
       •      collecting confirmation soil samples to refine the horizontal and vertical delineation of
              the target contaminants ethylbenzene and total xylenes at the proposed clean-up location
       •      performing a pilot-scale test of biosparging to obtain site-specific data for use during
              full-scale design
       •      designing and installing a full-scale biosparging treatment system
       •      collecting ambient air samples to assess compliance with Applicable or Relevant and
              Appropriate Reguirements (ARARs)
       •      conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen,  and the target compounds of ethylbenzene and total xylenes,
       •      operating and maintaining the biosparging system until clean-up criteria are met
       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      filing a Record Notice of Landfill Operation with the Registry of Deeds to document the
              location of the landfill
       •      performing five-year site reviews

1.1.4 Selected Remedy

The selected remedy for AOC FTA-2/LF-2 is Biosparging with Ambient Air Monitoring. This
alternative provides institutional and engineering controls to limit exposure to site-related
contaminants and to reduce source-area contaminant concentrations to protective levels. The
remedy does not include a management of migration component. Groundwater contamination
beneath and downgradient of the AOC will be addressed as part of the Plume Response Plan.

1.2 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC PFSA/FS-10/FS-ll

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria while controlling migration of contaminants from deep soils to groundwater at AOC
PFSA/FS-10/FS-ll:

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       •       No Action
       •       Limited Action
       •       Biosparging with Off-gas  Collection and Treatment

1.2.1 No Action

The No Action alternative was evaluated as a baseline with which to compare other alternatives.
No remedial action, monitoring, further investigation, or five-year site reviews would be
performed as part of this alternative.  No action would be taken to maintain site access restrictions
(security fencing and military guard posts)  that currently limit potential human exposure to site
contaminants.

1.2.2 Limited Action

The Limited Action alternative at AOC PFSA/FS-10/FS-ll includes the following key components:

       •       maintaining institutional controls that restrict  site access and limit  potential human
              exposure to contaminants
       •       performing five-year site reviews

1.2.3 Biosparging with Off-gas Collection and Treatment

Capillary-fringe contamination has been identified at two of five locations at AOC PFSA/FS-10/FS-ll, and
this alternative includes biosparging with a bioventing component to address that contamination.  At the
remaining three clean-up locations only shallow vadose zone contamination has been identified and only
bioventing is proposed for them. If confirmation soil sampling indicates that inclusion of a biosparging
component is appropriate, the final design will be modified to include biosparging.

The biosparging alternative at AOC PFSA/FS-10/FS-ll includes the following key components:

       •       mobilization and site preparation
       •       performing baseline ambient air monitoring
       •       collecting confirmation soil samples at all five  proposed clean-up locations to refine the
              horizontal and vertical delineation of the target  contaminants ethylbenzene and total
              xylenes
       •       performing a pilot-scale  test  of biosparging to obtain site-specific data for use during
              full-scale design
       •       designing and installing  a full-scale biosparging treatment system with bioventing  for the
              two proposed clean-up locations at this AOC with  capillary-fringe contamination
       •       designing and installing  a bioventing system for  the remaining three locations identified
              for clean-up at this AOC  with  shallow vadose zone  contamination
       •       collecting ambient air samples to  assess compliance with ARARs
       •       conducting guarterly performance monitoring in the form of soil sampling and analysis for
              carbon dioxide,  oxygen,  and the target compounds  of ethylbenzene and total xylenes
       •       operating and maintaining the  biosparging and bioventing systems until  clean-up criteria
              are met
       •       maintaining institutional controls that restrict  site access and limit  potential human
              exposure to contaminants
       •       performing five-year site reviews

1.2.4 Selected Remedy

The selected remedy for AOC PFSA/FS-10/FS-ll is Biosparging with Off-gas Collection and Treatment.  This
alternative provides institutional and engineering controls to limit exposure to site-related
contaminants and to reduce source-area contaminant concentrations to protective levels. The remedy does
not include a management of migration component. Groundwater contamination beneath and downgradient of
the AOC will be addressed as part of the Plume Response Plan.

The Feasibility Study identified five distinct locations for clean-up at AOC PFSA/FS-10/FS-ll  (see Figure
7-4 in Appendix A of this Record of Decision). Two of the five proposed clean-up locations described in
Subsection 4.3.3 of the Feasibility Study are associated with capillary-fringe soils; the selected remedy
provides biosparging with a bioventing component for those areas. The other three locations contain
shallow vadose-zone contamination, this alternative provides only a bioventing component for them.  Prior
to clean-up activities, confirmation sampling should be conducted at all five areas  to assess  the
horizontal delineation of the clean-up locations.

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1.3 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-2/FS-6/FS-8

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria while controlling potential adverse human-health and ecological effects from exposure to surface
soil and sediment at AOC SD-2AFS-61FS-8:

       •      No Action
       •      Excavation and Asphalt-batching
       •      Excavation and Off-site Treatment and Disposal

Because this site is located almost wholly outside the MMR boundary, MMR has little ability to control
site access; therefore the Limited Action alternative was not evaluated in detail.

1.3.1 No Action

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative.

1.3.2 Excavation and Asphalt-batching

The Excavation and Asphalt-batching alternative at AOC SD-2/FS-6/FS-8 includes the following key
components:

       •      mobilization and site preparation
       •      excavating sediment/surface soil exceeding clean-up criteria at historical sample
              locations SD-1 and SD-6
       •      collecting post-excavation  confirmation samples from the excavation perimeter for analysis
              for chromium,  lead,  and zinc
       •      transporting excavated soil to an on-site asphalt-batching facility for testing and
              treatment
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR

1.3.3 Excavation and Off-site Treatment and Disposal

The Excavation and Off-site Treatment and Disposal alternative at AOC SD-2/FS-6/FS-8 includes the
following key components:

       •      mobilization and site preparation
       •      excavating sediment/surface soil exceeding clean-up criteria at historical sample
              locations SD-1 and SD-6
       •      collecting post-excavation  confirmation samples from the excavation perimeter for
              analysis for chromium,  lead,  and zinc
       •      transporting excavated soil to a permitted off-site treatment,  storage,  and disposal
              facility for treatment and/or disposal
       •      backfilling and restoring excavations with clean borrow material

1.3.4 Selected Remedy

The selected remedy for AOC SD-2/FS-6/FS-8 is Excavation and Asphalt-batching. This alternative provides
engineering controls to limit exposure to site-related contaminants and to reduce source-area contaminant
concentrations to protective levels. The  remedy does not include a management of migration component.
Groundwater contamination beneath and downgradient of the AOC will be addressed as part of the Plume
Response Plan.

1.4 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-3/FTA-3/CY-4

The Feasibility Study assessed how well the following two alternatives would meet the evaluation criteria
while controlling potential adverse human-health and ecological effects from exposure to surface soil at
AOC SD-3/FTA-3/CY-4:

       •      No Action
       •      The modified limited action alternative of Confirmation Sampling with Contingency of
              Excavation and Asphalt-batching

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1.4.1 No Action

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, nor five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions (security fencing and
military guard posts) that currently limit potential human exposure to site contaminants.

1.4.2 Confirmation Sampling with Contingency of Excavation and Asphalt-batching

The Confirmation Sampling with Contingency of Excavation and Asphalt-batching alternative at AOC
SD-3/FTA-3/CY-4 includes the following key components:

       •      preparing a brief sampling and analysis work plan
       •      mobilization and site preparation
       •      collecting surface soil samples from the area of coal ash disposal outside of the 1994
              removal area and analyzing the samples for inorganics and semivolatile  organic compounds
              (SVOCs)
       •      comparing analytical data to Soil Target Clean-up Levels (STCLs)  for SVOCs and inorganics
       •      if comparison shows contamination above STCLs,  implementing the contingency action of
              excavating surface soil for asphalt-batching
       •      collecting post-excavation confirmation samples from the excavation perimeter for analysis
              for inorganics and SVOCs
       •      transporting excavated soil to an on-site asphalt-batching facility for testing and
              treatment
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •      maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •      performing five-year site reviews

1.4.3 Selected Remedy

The selected remedy for AOC SD-3/FTA-3/CY-4 is Confirmation Sampling with Contingency of Excavation and
Asphalt-batching. This alternative provides institutional and engineering controls to assess the adequacy
of previous removal actions, limit exposure to site-related contaminants, and, if necessary, remove
source area soils exceeding clean-up criteria and treat the soils to reduce contaminant mobility. The
risk assessment did not identify the need to clean-up groundwater at this AOC; consequently, the remedy
does not include a management of migration component.

1.5 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-4

The Feasibility Study assessed how well the following three alternatives would meet the evaluation
criteria while controlling potential adverse human-health and ecological effects from exposure to surface
soil and sediment at AOC SD-4:

       •      No Action
       •      Excavation and Asphalt-batching
       •      Excavation and Off-site Treatment and Disposal

Because potential ecological risk is a major concern at this site, the Limited Action alternative was not
evaluated in detail; the institutional controls of the Limited Action alternative have little ability to
control ecological exposure and risk. Further, the presence of institutional controls was not assumed in
the risk assessment.

To limit the potential adverse effects of excavation on the pond and wetland areas of SD-4, remedial
activities south of Reilly Road will focus on pond sediments where high concentrations of inorganics
(especially lead) and potential contaminant bioavailability have the greatest potential to cause adverse
environmental effects.

1.5.1 No Action

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative.

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1.5.2 Excavation and Asphalt-batching

The Excavation and Asphalt-batching alternative at AOC SD-4 includes the following key components:

       •       performing pre-excavation studies
       •       mobilization and site preparation
       •       performing a wetland delineation prior to excavation of pond sediment
       •       identifying areas for remedial  action at the upgradient pond based on  the  results  of
              pre-excavation studies
       •       preparing a Wetland Restoration Specification (only if disturbance of  pond/wetland is
              planned)
       •       performing pre-excavation confirmation soil  sampling in the drainage ditch north of Reilly
              Road to assess the horizontal and vertical distribution of contamination exceeding the  TPH
              STCL and to identify areas for  excavation
       •       excavating soil and sediment exceeding clean-up  criteria
       •       collecting post-excavation confirmation sediment samples from the  excavation perimeter  at
              the upgradient pond for analysis for inorganics  and/or acid volatile sulfides and
              simultaneously extracted metals
       •       collecting post-excavation confirmation soil samples from the excavation perimeter in the
              drainage ditch north of Reilly  Road for analysis for TPH
       •       transporting excavated soil and sediment to  an on-site asphalt-batching facility for
              testing and treatment
       •       removing temporary roads,  backfilling excavations,  and restoring wetland areas
       •       using the asphalt-emulsion-coated product as a paving subgrade material at selected
              locations at MMR
       •       performing five-year site reviews

1.5.3 Excavation and Off-site Treatment and Disposal

The Excavation and Off-site Treatment and Disposal alternative at AOC SD-4 includes  the  following key
components:

       •       performing pre-excavation studies
       •       mobilization and site preparation
       •       performing a wetland delineation prior to excavation of pond sediment
       •       identifying areas for remedial  action at the upgradient pond based on  the  results  of
              pre-excavation studies
       •       preparing a Wetland Restoration Specification (only if disturbance of  pond/wetland is
              planned)
       •       performing pre-excavation confirmation soil  sampling in the drainage ditch north of Reilly
              Road to assess the horizontal and vertical distribution of contamination exceeding the  TPH
              STCL and to identify areas for  excavation
       •       excavating soil and sediment exceeding clean-up  criteria
       •       collecting post-excavation confirmation sediment samples from the  excavation perimeter  at
              the upgradient pond for analysis for inorganics  and/or acid volatile sulfides and
              simultaneously extracted metals
       •       collecting post-excavation confirmation soil samples from the excavation perimeter in the
              drainage ditch north of Reilly  Road for analysis for TPH
       •       transporting excavated sediment to an on-site location for testing and dewatering
       •       transporting soil and dewatered sediments to a permitted off-site  treatment,  storage, and
              disposal facility for treatment and/or disposal
       •       removing temporary roads,  backfilling excavations,  and restoring wetland areas
       •       performing five-year site reviews

1.5.4 Selected Remedy

The selected remedy for AOC SD-4 is Excavation and Asphalt-batching. This alternative provides
institutional and engineering controls for areas north of  Reilly Road to limit exposure  to site-related
contaminants in soil and to reduce source area soil contaminant concentrations to protective levels.  For
areas south of Reilly Road, this alternative provides sampling and engineering controls  to assess the
contribution of sediment contaminants to surface water contamination, the potential  bioavailability and
toxicity of pond sediments, and, if necessary, removal of  source area sediments  exceeding cleanup
criteria and treatment of excavated material to reduce contaminant mobility. The risk assessment did not
identify the need to clean up groundwater at this AOC; consequently, the remedy  does not include a
management of migration component.

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1.6 DESCRIPTION OF EVALUATED ALTERNATIVES FOR AOC SD-5/FS-5

The Feasibility Study assessed how well the following four alternatives would meet the evaluation
criteria while controlling potential adverse human-health and ecological effects from exposure to surface
soil and sediment at AOC SD-5/FS-5:

       •      No Action
       •      Limited Action
       •      Excavation and Asphalt-batching
       •      Excavation and Off-site Treatment and Disposal

1.6.1 No Action

The No Action alternative was evaluated as a baseline with which to compare other alternatives. No
remedial action, monitoring, further investigation, or five-year site reviews would be performed as part
of this alternative. No action would be taken to maintain site access restrictions (security fencing and
military guard posts) that currently limit potential human exposure to site contaminants.

1.6.2 Limited Action

The Limited Action alternative at AOC SD-5/FS-5 includes the following key components:

       •      maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •      performing five-year site reviews

1.6.3 Excavation and Asphalt-batching

The Excavation and Asphalt-batching alternative at AOC SD-5/FS-5 addresses soil contamination at eight
locations at AOC SD-5/FS-5 and includes the following key components:

       •      mobilization and site preparation
       •      performing pre-excavation confirmation soil sampling to confirm the horizontal and
              vertical distribution of contamination exceeding total petroleum hydrocarbon (TPH)  and
              inorganic STCLs at six locations and volatile organic compounds (VOCs),  TPH,  and inorganics
              at the remaining two locations
       •      excavating soil exceeding clean-up criteria
       •      transporting excavated soil to an on-site asphalt-batching facility for testing and
              treatment
       •      collecting post-excavation confirmation samples from the excavation perimeters for analysis
              for TPH and inorganics at six of the proposed clean-up locations and for VOCs,  TPH,  and
              inorganics at the remaining two locations
       •      backfilling and restoring excavations with clean borrow material
       •      using the asphalt-emulsion-coated product as a  paving subgrade  material at selected
              locations at MMR
       •      maintaining institutional controls that restrict site access and limit  potential human
              exposure to contaminants
       •      performing five-year site reviews

1.6.4 Excavation and Off-site Treatment and Disposal

The Excavation and Off-site Treatment and Disposal alternative at AOC SD-5/FS-5 includes the following
key components:

       •      mobilization and site preparation
       •      performing pre-excavation confirmation soil sampling to confirm the horizontal and
              vertical distribution of contamination exceeding TPH and inorganic STCLs at six locations
              and VOCs,  TPH,  and inorganics at the remaining  two locations
       •      excavating soil exceeding clean-up criteria
       •      collecting post-excavation confirmation samples from the excavation perimeters for
              analysis for TPH and inorganics,  at six of the  proposed clean-up locations and for VOCs,
              TPH,  and inorganics at the remaining two locations
       •      transporting excavated soil to a permitted off-site treatment,  storage,  and disposal
              facility for treatment and/or disposal
       •      backfilling and restoring excavations with clean borrow material

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       •      maintaining institutional controls that restrict site access and limit potential human
              exposure to contaminants
       •      performing five-year site reviews

1.6.5 Selected Remedy

The selected remedy for AOC SD-5/FS-5 is Excavation and Asphalt-batching. This alternative provides
institutional and engineering controls to limit exposure to site-related contaminants and to reduce
source area contaminant concentrations to protective levels. The remedy does not include a management of
migration component. Groundwater contamination attributed to AOC SD-5/FS-5 is being addressed by the SD-5
North Groundwater Plume Extraction, Treatment, and Reinjection System and the SD-5 South Recirculating
Well System.

                                  2.0 BACKGROUND ON COMMUNITY INVOLVEMENT

The National Guard Bureau  (NGB)  and AFCEE have held regular informational meetings, issued fact sheets,
and held public meetings to keep the community and other interested parties informed of activities at the
six AOCs covered in this Record of Decision. The NGB was responsible for the IRP at MMR until 1996 when
AFCEE assumed this responsibility.

Throughout MMR's history, community concern and involvement have been high. The NGB, AFCEE, USEPA, and
Massachusetts Department of Environmental Protection (MADEP) have kept the community and other interested
parties apprised of site activities through informational meetings, fact sheets, news releases, public
hearings, and Technical Environmental Affairs Committee  (TEAC) meetings. The TEAC was organized in 1986
by the NGB to provide a forum for public input on the MMR response activities. Membership on the TEAC
comprises USEPA, MADEP, and representatives from local, regional, and state groups. Beginning with the
October 7, 1992, TEAC meeting, members of the public could attend these bimonthly meetings.

During May 1991, an MMR community relations plan was released that outlined a program to address
community concerns and keep citizens informed and involved in the remediation process at MMR. In July
1994, and again in December 1996, an updated draft community relations plan was issued to incorporate
concerns and feedback provided by the community, and to document changes in AFCEE policy.

In October 1993, a Senior Management Board was created to advise AFCEE on IRP activities. A select person
from each of the four towns surrounding MMR is among the Board members, along with the regulatory
agencies and the Adjunct General's office of the Commonwealth of Massachusetts. Process Action Teams
(PATs) were also created to address specific issues at MMR, including plume containment, long-range water
supplies, innovative technologies, and public information. The PATs have representation from the
community, local business, regulatory agencies, and AFCEE.

AFCEE published a notice and brief analysis of the Proposed Plan in the "Falmouth and Mashpee
Enterprises" on October 31, 1997, the "Cape Cod Times" on November 3, 1997, and the "Bourne and Sandwich
Enterprises" on November 7, 1997. On November 13, 1997, AFCEE made the RI reports, the Feasibility Study,
and the Proposed Plan available for public review at the U.S. Coast Guard library at MMR; and the main
public libraries in Bourne, Falmouth, Mashpee, and Sandwich, Massachusetts. The Proposed Plan has also
been made part the administrative record available for public review at the AFCEE IRP MMR office and at
the Falmouth Public Library.

From November 13, 1997 to January 15, 1998, AFCEE held a 60-day public comment period to accept public
comments on the alternatives presented for the six AOCs in the Proposed Plan. On November 13, 1997, AFCEE
held a public meeting at the Administration Building at the Barnstable

County Fairgrounds in Barnstable, Massachusetts, to present and discuss the Proposed Plan. On December 2,
1997, AFCEE held a public hearing to accept verbal comments on the Proposed Plan. Several residents and
local officials attended the hearing and provided comments. AFCEE's responses to the comments received at
the hearing and during the public comment period are included in Section 3.0 of this Responsiveness
Summary. Copies of the comment letters are included in Attachment A of this Responsiveness Summary. A
transcript of the December 2, 1997, public hearing is included in Appendix D of this Record of Decision.

           3.0 SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT PERIOD AND AFCEE RESPONSES

AFCEE received verbal comments from two people during the public hearing on December 2, 1997, and nine
written comments during the public comment period  (see Attachment A to this Appendix). The following
paragraphs summarize the comments and provide AFCEE's responses.

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The commentors are listed below:

Provided comments at hearing

John Palmieri, Mashpee, Massachusetts
Greg Taylor, Mashpee, Massachusetts

Provided written comments

George D. Kaszuba, Mashpee, Massachusetts
Paul G. Bierlish, South Dennis Massachusetts
David Dow, East Falmouth, Massachusetts
Ray Bowman, Mashpee Environmental Coalition, Mashpee, Massachusetts
Robert L. Caldwell, Caldwell Environmental, Action, Massachusetts
Bob Sherman, Town of Mashpee Conservation Commission, Mashpee, Massachusetts
R. Greg Taylor, Town of Mashpee Department of Public Works, Mashpee, Massachusetts
Elias A. McQuaid, Mashpee Board of Health, Mashpee, Massachusetts
Robert L. Whritenour, Jr., Office of the Board of Selectmen, Town of Mashpee, Mashpee,
Massachusetts (comment prepared by Foothill Environmental Consultants, Inc.)

I_. Public Hearing Statement from John Palmieri Mashpee:

Comment: This letter expressed concern regarding the effectiveness of asphalt-batching in preventing
future contamination by polychlorinated biphenyls (PCBs) detected in the soil at some site. Asphalt
spreading should be localized, and a monitoring program should be developed and implemented for potential
leaching of contaminants from the asphalt.

Response: Asphalt-batching is an extensively-tested and proven remediation technology that reduces the
mobility of contaminants by binding them to soil particles with an asphalt emulsion. Contaminated
material is turned into an environmentally stable, structurally enhanced paving subgrade material. The
subgrade material is capped with an asphalt wear cover for durability and to limit the infiltration of
water. The technology has been applied to soils contaminated with organic and inorganic compounds,
including PCBs. An asphalt-batching system has been successfully operated at MMR for contaminated soils
removed under the Drainage Structure Removal Program (DSRP). The DSRP identified and removed over 17,000
tons of contaminated soil associated with drainage structures at MMR in 1996. The soil was treated at an
on-site asphalt-batching facility and used as subgrade material for approximately 4.5 miles of roadways
at MMR.

Asphalt-batching site soils will immobilize the contaminants, thus minimizing potential risks from soils.
Asphalt-batching has been accepted by the regulators as a technology that is successful at immobilizing
the types of contaminants detected at the AOCs addressed in the "Six AOC Proposed Plan" Pre- and
post-treatment samples will be collected and analyzed to confirm the effectiveness of the treatment
system. Leaching of contaminants from asphalt-batched soils has been evaluated at other sites (with
favorable results) by sampling groundwater wells near stockpiled treated soils and by performing
laboratory leaching test. Coupled with the formation of a relatively impermeable barrier, the chemical
and physical fixation of contaminants by asphalt-batching is considered to be protective of human health
and the environment, and effective in minimizing contaminant migration to the groundwater. The finished
product will be used locally as the subgrade material for selected roadways at MMR.

PCBs were detected in surface soil at the AOCs proposed for asphalt-batching. However, the low freguency
and concentration of detections do not present potential unacceptable risks to human health or the
environment. In addition, PCBs have low solubility in water, making them resistant to leaching. This
natural characteristic will be further augmented by asphalt-batching treatment.

Contaminant levels summarized in the Massachusetts "Interim Remediation Waste Management Policy for
Petroleum Contaminated Soils" will be used to assess acceptability of soils for asphalt-batching. If
contaminant concentrations exceed these criteria, summarized in the table at the end of this
Responsiveness Summary, the soils will be disposed off-site. For example based on the listed criteria,
soils exceeding the threshold level for PCBs (2 ppm) would be disposed off-site. Specific locations for
the use of this material will be determined with the input of the regulatory agencies.

Because of the proven capability of asphalt-batching to stabilize contamination, the relatively low
contaminant levels detected at the AOCs, and the use of threshold levels to evaluate soils for treatment
or disposal, post-installation monitoring is not deemed necessary.

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2_. Public Hearing Statement from Greg Taylor, Mashpee:

Comment: The "Six AOC Proposed Plan" does not present the specifics of the Remedial Investigations and
Preliminary Risk Assessments conducted at the AOCs. Although the plan is simplified for public
consumption, it does not present the necessary details in order to make informed decisions on the
proposed remedial actions.

Response: Consistent with Superfund reguirements, as reguested, additional site-specific information will
be presented in the Proposed Plans. The Proposed Plan is intended to be a brief, simplified presentation
of proposed remedial activities and factors considered during their evaluation, consistent with the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) process. However,
because of the need for readers to review more detailed information to make informed decisions, AFCEE
will include additional site-specific information in future Proposed Plans. Further details regarding
site characteristics and proposed remedial activities are presented in the "Six AOC Record of Decision"
(this document). Responses to site-specific comments on the six AOCs addressed in the Proposed Plan are
presented below.

Details of the site history of each AOC, contaminants detected, their concentrations, and assessments of
the potential risks that these contaminants may pose are presented in the Remedial Investigation reports,
summarized in the "Six AOC Feasibility Study", and are highlighted in the "Six AOC Record of Decision",
this document. The "Six AOC Feasibility Study" also presents estimates of volumes of contaminated soil
and the evaluation of remedial alternatives. Specifics on the design of final remedial activities will be
presented in future remediation work plans and design documents once remedial alternatives are selected.
Design documents are expected to be available by mid-1999.

Comment: In each of the six AOCs the ecological risk assessment has been dismissed because it was too
conservative. If the assessment was not done correctly the first time, then it should be done again.

Response: The Preliminary Risk Assessments are screening assessments, based on generalized receptors and
exposure scenarios for the six AOCs. These scenarios and conditions, although useful for screening
purposes, may not be representative of site-specific conditions. Because of the generalized nature of
these assessments, identification and discussion of uncertainties is an integral part of the risk
assessment process. These uncertainties are also considered during the Feasibility Study as part of the
development of remedial response objectives. Examples of uncertainties include the assumption that an
organism would be exposed to the maximum concentrations of contaminants throughout its life, and that
inorganics would be available to potential receptors. The risk assessments were performed in accordance
with the "MMR Risk Assessment Handbook", which sets forth a consistent, accepted methodology for
estimating and evaluating risks at MMR (ASG, 1996) . AFCEE, with regulatory concurrence, makes risk
management decisions based on potential risks estimated using the RAH methodology. The uncertainty and
potential conservative estimates are considered as part of the risk management decision process.

Comment: For AOC FTA-2.LF-2, identify the primary chemicals of concern for this site. Identify the
"several chemicals" with the potential to migrate to groundwater that were identified above threshold
concentrations, and provide their concentrations.

Identify the inorganic and fuel-related chemicals of concern (COCs) encountered in the groundwater.
Please provide the Southeast Region Groundwater Operable Unit (SERGOU) clean up plan and explain how the
contaminated groundwater associated with this site is addressed in that plan. What is the depth to
groundwater at this site?

What subsurface soils are contributing to the groundwater contamination above or below the groundwater
table of both? There's only discussion about in or above the groundwater table. Aren't these contaminants
underneath the groundwater also?

Response: COCs at AOC FTA-2/LF-2 were ethylbenzene and total xylenes because of their potential to
migrate to groundwater. By definition, COCs are those chemicals which have been detected through the risk
assessment process to have the potential to cause risks in exceedance of regulatory guidelines. A
complete listing of Contaminants of Potential Concern, contaminants with the potential to migrate to
groundwater, and contaminant concentrations are presented on Table 7-1 in the "Six AOC Record of
Decision," this document.

COCs detected in groundwater at AOC FTA-2/LF-2 were arsenic, beryllium, 1,1,2,2-Tetrachloroethane (PCA),
and bis(2-ethylhexyl)phthalate (BEHP). The depth to groundwater is approximately 40 feet below ground
surface. Further information on groundwater at this AOC is summarized in Subsection 7.1.3.2 of the "Six
AOC Record of Decision".

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Plumes in the Southeast Region Groundwater Operable Unit (SERGOU) are being addressed by the AFCEE Plume
Response Plan. The following AOCs and associated groundwater contamination were investigated in the
SERGOU Remedial Investigation: FTA-2/LF-2, SD-5/FS-5, PFSA/FS-10/FS-ll, and Southeast MMR (Eastern
Briarwood). Although chemicals associated with AOC FTA-2/LF-2 have been detected in groundwater, they
appear to be biodegrading naturally. A plume has not been detected migrating off-base or reaching any
receptors. Therefore, biosparging is proposed to reduce subsurface soil contaminants both above and below
the water table. The proposed biosparging system will reduce concentrations of contaminants with the
potential to migrate to groundwater.

Comment: Provide a conceptual layout of the biosparging that's proposed in this area. Define what AFCEE
intends to do to assure that "a prudent design" will minimize interactions in the two systems.

Response: Layout and design of remedial systems will be presented in the design documents following
alternative selection. These are expected to be available by mid-1999. Prudent design of a biosparging
system would minimize its interaction with other nearby systems. In the case of AOC PFSA/FS-10/FS-ll, the
proposed biosparging system will be designed to minimize capture of biosparging air bubbles by using the
existing SD-5 extraction, treatment, and reinjection system.

Comment: For AOC SD-2/FS-6/FS-8, provide a summary of the COCs and the range of concentrations in this
area. What is AFCEE's point in discussing "average" site concentrations versus maximum concentrations
along the drainage ditch? What are the COCs creating the unacceptable risk? How many sample locations are
there in the ditch? And over what total length? What are the COCs driving the adverse ecological risk in
the ditch? What are the ecological receptors?

Response: COCs at AOC SD-2/FS-6/FS-8 were chromium, lead and zinc. These are the chemicals with the
potential to exceed regulatory risk management guidelines for ecological receptors. Receptors evaluated
in the risk assessment included the white-footed mouse, cardinal and red fox. A complete listing of
Contaminants of Potential Concern that were evaluated in the PRA and their concentrations is presented in
Table 7-9 of the "Six AOC Record of Decision" (this report).

"Maximum" contaminant concentrations detected at only two sampling locations at AOC SD-2 resulted in
potential risks in excess of regulatory guidelines. The "average" contaminant concentrations, detected in
the remainder of soils at this AOC, do not represent potential risks in excess of regulatory guidelines.
The point of the comparison is to show that the proposed removal of soils from the two locations with the
"maximum" concentrations will reduce risks to within regulatory guidelines.

Sediment samples were collected and analyzed from 17 locations along the approximate 2000 foot length of
AOC SD-2/FS-6/FS-8.

Comment: What is meant by "non-site related groundwater" contamination beneath the AOC SD-2/FS-6/FS-8?
Explain how the preferred alternative addresses the concerns of contamination encountered and treats the
contaminants so that they will not pose a future risk.

Response: "Non site-related groundwater" is groundwater (including its contaminants) flowing beneath a
site which originates from an upgradient source. In the case of AOC SD-2/FS-6/FS-8, the non-site related
groundwater contamination is attributed to AOC PFSA/FS-10/FS-ll.

The preferred remedial action for AOC PFSA/FS-10/FS-ll includes biosparging and bioventing. These systems
will reduce the release of contaminants from subsurface soils, and thus reduce contamination to
groundwater, including the "non-site related groundwater" downgradient beneath AOC SD-2/FS-6/FS-8."

Comment: For AOC SD-3/FTA-3/CY-4, why doesn't the Department of Defense know that the earlier work on
this site removed all of the ash? Is there a post-excavation report documenting this? What leads us to
believe that additional work needs to be done here? Is there an ecological risk? How are we resolving
that with enough secondary testing to assure that we haven't missed something?

Response: During the removal action conducted at AOC SD-3/FTA-3/CY-4 in 1994, coal, coal ash and soil
were excavated and removed. However, the removal was not conducted under the MMR Installation Restoration
Program or the CERCLA process, and a post-excavation report is not available. Therefore, confirmation
sampling is proposed to assess the adeguacy of the removal action, whether or not the potential for
ecological risks still exists, and the need for further actions. The proposed confirmation sampling for
the site will be presented in a sampling and analysis plan following alternative selection. This is
expected to be available by mid-1999.

Comment: For AOC SD-4, what are the fuel-related inorganic and organic COCs and their concentrations in
this medium? The plan indicates that average contaminated concentrations did not result in adverse health
risk. Did the maximum concentrations exceed levels for human health risk? If so, what were the compounds

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and what were the concentrations? Is there an adverse ecological risk associated with this AOC? AFCEE
essentially dismisses the value of the ecological risk assessment because of "conservative assumptions"
during calculations. If this was not a reasonable ecological risk assessment then one should be done.

Response: COCs for AOC SD-4 pond sediment included several semivolatile compounds (SVOCs) and inorganics.
SVOC COCs were benzo(a)anthracene, benzo(a)pyrene, benzo(g,h,i)perylene, benzo(b)flournathene,
benzo(k)flouranthene, chrysene, indeno(1,2,3-c,d)pyrene, and phenanthrene. Inorganic COCs were aluminum,
cadmium, copper, cyanide, lead, vanadium, and zinc. Maximum detected concentrations of copper and lead
indicated potential risks to human health in excess of regulatory guidelines at this AOC, while average
concentrations did not. The comparison of risks at average and maximum concentrations is presented to
show the diminished risks at this AOC, using average chemical concentrations. The COCs listed above
resulted in an ecological risk which exceeded regulatory limits. Therefore, the potential exists for
environmental risks from contaminants detected at AOC SD-4. AFCEE does not dismiss the results of the
ecological assessment, but recognizes that the ecological risks may be overestimated by the use of
conservative assumptions to address the uncertainties in the risk assessment process, particularly the
establishment of appropriate receptors and exposure scenarios. Because of the potential for both human
health and ecological risks at AOC SD-4, AFCEE is proposing the removal of contaminated sediment to
reduce risks. A listing of Contaminants of Potential Concern evaluated in the risk assessment and
their concentrations is presented on Table 7-19 of the "Six AOC Record of Decision," this document.

Comment: For AOC SD-5/FS-5, explain the discussion of potential risks associated with exposure to
"average" versus "maximum" chemical concentrations.

Provide a site plan that shows in better detail the excavation that's being intended for AOC SD-5/FS-5.
Provide a more detailed plan of the locations and the depths in all that comprise the 9,400 cubic yards
of estimated contaminated soil that's being excavated from the site how the connection and the
relationship with the contaminated groundwater at this AOC and with the SD-5 plume and how that ties in
with the SD-5 north treatment system and.

Response: The assessment of risks to human health indicated that average contaminant concentrations do
not exceed regulatory guidelines, while maximum concentrations do exceed regulatory guidelines. COCs for
AOC SD-5/FS-5 included several inorganics and Total Petroleum Hydrocarbons. Inorganic COCs were chromium,
copper, cyanide, lead, mercury and zinc. The ecological risk assessment indicated that both average and
maximum contaminant concentrations exceed regulatory guidelines for wildlife and plants.

The areas at AOC SD-5/FS-5 proposed for excavation and treatment are shown on Figure 7-12 of the "Six AOC
Record of Decision," this document. The volumes of soil estimated for excavation are presented in the
"Six AOC Feasibility Study." Estimated depths of excavations ranged from two to 11 feet, based on
previous sampling results. Actual depths will be determined by soil analyses conducted during the
remedial action. Specifications for remedial actions will be presented in design documents prepared
following alternative selection (approximately mid-1999). The SD-5 plume response activities are designed
to remediate the existing groundwater contamination associated with AOC SD-5. The remedial actions
proposed in the "Six AOC Proposed Plan" and Record of Decision are designed to remediate the source areas
of the SD-5 groundwater plume.

3. 11/26/97 Letter from George D. Kaszuba:

Comment: Remedial solutions should give additional consideration to the safety and well being of the fish
and wildlife of Ashumet and Johns ponds.

Response: Recent collection and analyses of pond water and sediment samples from Johns Pond have not
detected contamination related to MMR source areas. Results of these sampling and analysis activities are
presented in the "Draft Baseline Ecological Study, 1997 Annual Report" (December 1997). The Ecological
Monitoring Program will include human health and ecological risk evaluations. Additional data on the
ponds has been collected as part of the "Johns Pond Underflow Study" (E.G. Jordan Co., 1991), USGS
investigations at Johns Pond, and the SERGOU Remedial Investigation (ABB-ES, 1994).

The "Six AOC Proposed Plan" proposes remedial solutions for selected source areas at MMR. The proposed
actions will reduce levels of contaminants at source areas with the potential to contaminate groundwater.
The AFCEE Plume Response Plan addresses groundwater remedial activities.

4. 11/30/97 Letter from Paul G. Bierlish:

Comment: Current technology and funding do not exist to remediate the groundwater plumes associated with
MMR. All these meetings on proposed remedial activities are only to calm the peoples concerns.

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Response: The "Six AOC Proposed Plan" proposes remedial solutions for selected source areas at MMR. The
proposed actions will reduce levels of contaminants at source areas with the potential to contaminate
groundwater. The AFCEE Plume Response Plan addresses groundwater remedial activities.

The purpose of the public meeting and public hearing on the "Six AOC Proposed Plan" is to is to listen to
the public's views and concerns so that AFCEE can take them into account in the decision making process.
Public comments are valuable and will be considered for this Record of Decision and future Proposed
Plans.

5.    12/7/97 Letter from David Dow, East Falmouth, MA:

General Comment: The "Six AOC Proposed Plan" does not present the specifics of the Remedial
Investigations and Preliminary Risk Assessments conducted at the AOCs. The information in the Proposed
Plan is inadeguate for allowing public review. The current "proposed plan" needs to be revised to include
further details on the six AOCs and the proposed remedial activities.

Response: The Proposed Plan is intended to be a brief, simplified presentation of proposed remedial
activities and factors considered during their evaluation, consistent with the CERCLA process. However,
because of the reguest by the Cape citizens to the review to review more detailed information to make
informed decisions, AFCEE will include additional site-specific information in future Proposed Plans.
Further details regarding site characteristics and proposed remedial activities are presented in the "Six
AOC Record of Decision"  (this document).  Responses to site-specific comments on the six AOCs addressed in
the Proposed Plan are presented below. Your comment points out a valid need to ensure close coordination.

Details of the site history of each AOC,  contaminants detected, their concentrations, and assessments of
the potential risks that these contaminants may pose are presented in the Remedial Investigation reports,
summarized in the "Six AOC Feasibility Study", and are highlighted in the "Six AOC Record of Decision".
The "Six AOC Feasibility Study" also presents estimates of volumes of contaminated soil and the
evaluation of remedial alternatives. Specifics on the design of final remedial activities will be
presented in future remediation work plans and design documents once remedial alternatives are selected.
Design documents are expected to be available by mid-1999.

Comment: The public comment period needs to be extended to allow review by the public and the MMR Process
Action Teams.

Response: AFCEE extended the end of public comment period, which began on November 13, 1997, from
December 15, 1997 to January 15, 1998, to allow for further public review and comment.

Comment: A linkage needs be established between the strategies proposed to treat the sources of
contamination (six AOCs) and the plumes associated with these sources of contamination. Despite the
decision by AFCEE, EPA, and the MADEP to operationally separate the plume containment process from the
treatment of the source areas because of budgetary/time constraints, there is a need to develop an
integrated approach to treat both the source areas and contain the plumes. It is not desirable to adopt a
piecemeal approach to develop options for plume containment to be reviewed by the Joint Process Action
Team  (JPAT) separate from the program to treat the source areas of this pollution which is being reviewed
by the Technical Environmental Affairs Committee (TEAC).

Response: The source area and plume remediation strategies are coordinated through AFCEE, the Process
Action Teams, public review process, and regulatory agencies. Remediation of the source areas of
contamination at MMR is an integral part of the base cleanup program.

Comment: There needs to be a listing of the chemicals of concern for each AOC, including the
concentrations of the chemicals that pose a threat to either human health or sensitive ecological
receptors.

Response: Chemicals of Concern  (COCs) are those chemicals which have been determined through the risk
assessment process to have the potential to cause risks in exceedance of regulatory guidelines. COCs,
Potential Contaminants of Concern evaluated in the risk assessment, and the range of detected
concentrations are presented in the tables in Appendix B of this document.

Comment: The volume of contaminated sediment, aerial coverage and depth of contamination should be listed
for each AOC.

Response: Volumes of sediment estimated for excavation are summarized as follows:

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SD-2/FS-6/FS-8: Area = 50 ft 2; Depth = 2 ft.; Volume = 14 yd 3
SD-4: Pond Area = 12,270 ft 2; Depth = 2 ft; Volume = 2,727 yd 3
SD-5/FS-5: Area = 162,600 ft 2; Depth = 2 to 11 ft.; Volume = 9,400 yd 3

Note: Estimated volumes for excavation include 2:1 slopes for side walls to prevent cave-in.

Comment: There needs to be a description of the testing methods for deciding which contaminated sediments
will be treated as hazardous wastes (thus entailing off site disposal), as opposed to those contaminated
sediments to be subjected to biosparging, limited action, or excavation and asphalt-batching. The risk
analysis procedure supporting this seguenced treatment process should be described (including
guantitative risk levels for both carcinogenic and chronic toxicity endpoints), so that the public will
be ensured that the mixture of heavy metals, organochlorine compounds, polynuclear aromatic hydrocarbons
(PAHs), volatile organic solvents or fuel products, etc. is adeguately addressed.

Response: A sampling and analysis plan for the remedial activities will be developed following
alternative selection. This document is expected to be available by mid-1999. This plan will present
methods and freguencies for the analysis of soil. Risk-based threshold limits have been developed for
soil recycling facilities by MADEP. These limits are summarized in the table at the end of this
Responsiveness Summary. These limits will be used to evaluate the results of soil analyses, and to assess
whether soils will be asphalt-batched or disposed off-site.

Comment: Currently biosparging is proposed as the treatment of choice for AOC FTA-2/LF-2 and AOC
PFSA/FS-10/FS-ll, while excavation and asphalt batching is proposed for AOCs SD-2/FS-6/FS-8,
SD-3/FTA-3/CY-4, SD-4, and SD-5/FS-5. Since the storm drains are likely to be continuing sources of
pollution to local water bodies (including Johns and Ashumet Ponds) after storm water drainage events,
the proposed plan should discuss the long term mitigation for these sources of pollution.

Response: The activities and practices which caused most of the past contamination to storm drainage
ditches have ceased, and oil/water separators now treat storm water prior to discharge to the ditches.
The MMR "Fuel Systems Upgrade" contract, conducted in 1995, implemented controls on the fuel delivery and
distribution system at the base.

The USAF 102nd Fighter Wing is responsible for MMR's storm water pollution prevention program. Activities
designed to minimize storm water discharge to Ashumet and Johns ponds are summarized in the letter from
the USAF included in Attachment B to this Responsiveness Summary. These include detention basins to allow
on-base infiltration of storm water.

Comment: What is the status of the Southeast Region Groundwater Operable Unit(SERGOU) plume containment
process (associated with AOCs FTA-2/LF-2, PFSA/FS-10/FS-ll, SD-2/FS-6/FS-8, and SD-3/FTA-3/CY-4)?

Response: Plumes in the SERGOU are being addressed by the AFCEE Plume Response Plan. There are currently
no plans for groundwater remedial activities AOCs SD-2/FS-6/FS-8 and SD-3/FTA-3/CY-4 because site-related
groundwater contamination has not been detected at these sites. Although groundwater contamination
associated with AOC FTA-2/LF-2 has been detected, a plume does not appear to exist. Contaminants at AOC
PFSA/FS-10/FS-ll have resulted in a plume of fuel-related contaminants migrating approximately 4000 feet
downgradient from the site. However, the contaminants appear to be biodegrading naturally, and have not
been detected off-base. Therefore, plume response activities are not currently proposed for AOCs
FTA-2/LF-2 and PFSA/FS-10/FS-ll. The biosparging systems proposed for AOCs FTA-2/LF-2 and
PFSA/FS-10/FS-ll are designed to reduce concentrations of contaminants with the potential to migrate to
groundwater.

Comment: For sites such as AOC SD-4 where heavy metals pose a threat to sensitive ecological receptors,
how will the bioavailability be evaluated (i.e. based upon methylated forms of these contaminants or the
inorganic moieties)? This is especially important given the wetland and pond habitats that are potential
sinks for this pollution.

Response: The bioavailability of inorganics in sediments will be assessed through the analysis of acid
volatile sulfides. Sulfide, a common constituent of organic pond sediment, forms very low solubility
precipitates with many inorganics. When combined with sulfide, these inorganics are not bioavailable. By
comparing sulfide and inorganic concentrations, the bioavailability of inorganics can be assessed. In
addition, a biocommunity survey will be conducted to assess biocommunity structure and productivity.

Comment: For AOCs in which biosparging is employed, AFCEE should conduct a pilot test to determine
whether the microbes responsible for the bioremediation can metabolize the VOCs to concentrations below
the threshold responsible for effects on sensitive ecological receptors; whether nutrients need to be
added to help accelerate this microbial degradation reaction; and to determine if organic substrates need
to be added complete this biological breakdown process (co-metabolism is involved).

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Response: Biosparging is proposed for two AOCs which do not have associated plumes migrating off-base to
receptors. The organic contamination at these sites is amenable to biodegradation, and biosparging has
been successfully used in other similar remediation efforts. Confirmation monitoring will be conducted to
evaluate the effectiveness of the biosparging systems, including reduction of contaminant levels to Soil
Target Cleanup Levels (STCLs). These risk-based levels have been developed to protect potential human and
ecological receptors. If these levels are not attained, revisions to the remedial action will be
evaluated.

Comment: For the human health risk assessments at sites where institutional controls will be utilized,
how much of the non-exceedance is due to limited access versus the actual toxicity posed by the levels of
chemical contaminants? How effective will these institutional controls be if the military departs the
MMR?

Response: Institutional controls at MMR involve ensuring that if flightline security measures that
currently limit site access are relaxed, additional measures will be taken to limit access to the AOCs.
These controls were not used to diminish the potential risks, but were used for the exposure scenario
used in the assessment of potential risks, in accordance with the MMR Risk Assessment Handbook (ASG,
1994). These controls are part of the proposed remediation, and will be enforceable through the Record of
Decision for the six AOCs. One of the major components of the proposed remedial actions for AOCs where
institutional controls are in place is a five-year site review. These reviews will be conducted at
five-year intervals to assure that the remedy continues to provide adeguate protection of human health
and the environment, including continuation of restricted site access.

Comment: What are the appropriate ARARs reguired by the state and Federal government that must be met as
a threshold reguirement for each chosen cleanup alternatives? Why is there no comparable assessment for
the threshold criteria?

Response: The Applicable or Relevant and Appropriate Reguirements (ARARs) for the proposed remedial
actions are listed and assessed for each AOC in Section 7.0 of the "Six AOC Record of Decision," this
document. The comparative analysis of alternatives for each AOC, using the threshold criteria, is also
presented in Section 7.0 of the Record of Decision under the "Summary of Comparative Analysis" subsection
for each alternative.

Comment: The regulatory agencies (USEPA and MADEP) do not appear to be part of the public participation
process for the "Six AOC Proposed Plan".

Response: The purpose of the "Six AOC Proposed Plan" and associated public meeting and public hearing is
to listen to the public's views and concerns so that AFCEE can take them into account in the decision
making process. Public comments are valuable and will be considered for this Record of Decision and
future Proposed Plans.

The regulatory agencies, USEPA and MADEP, have been integral participants in the CERCLA process at the
six AOCs. They provided guidance, review, and approval of all work plans, Remedial Investigations
Reports, Preliminary Risk Assessments, the Feasibility Study, the Proposed Plan, and associated public
review process for the six AOCs. Regulatory agency comments on documents are part of the Administrative
Record.

6_. 12/9/97 Letter from Ray Bowman, Mashpee Environmental Coalition:

Comment: The construction of an additional road at the northern end of Wheeler Road in Mashpee to provide
access to AOC SD-2/FS-6/FS-8 for the removal of contaminated soil could have a negative impact on the
neighborhood and environment. The existing roadway constructed last year at the SD-2 drainage ditch
should be utilized for access to the contaminated areas. A temporary metal surface material used on the
existing road, such as that used by the National Guard for temporary access, would seem to be less
destructive to the environment in the area, than constructing a new road. The material could be used on
the existing road to access the areas, and then removed after the soil has been removed.

Response: AFCEE will evaluate the existing roadway prior to excavation activities to determine if both
areas to be remediated at AOC SD-2/FS-6/FS-8 can be accessed from the existing roadway, AFCEE will work
with the Town of Mashpee to assure that adverse affects to the neighborhood and environment are
minimized.

Comment: The Proposed Plan should discuss the long term mitigation of both the storm drainage ditch
sediments and the storm water, itself, which the ditches still convey. The storm water presents a
continuing threat to Ashumet and Johns Pond, and should be eliminated as soon as possible.

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Response: The activities and practices which caused most of the past contamination to storm drainage
ditches have ceased, and oil/water separators now treat storm water prior to discharge to the ditches.

The USAF 102nd Fighter Wing is responsible for MMR's storm water pollution prevention program. Activities
designed to minimize storm water discharge to Ashumet and Johns ponds are summarized in the letter from
the USAF included in Attachment A to this Appendix. These include detention basins to allow on-base
infiltration of storm water.

!_. 12/9/97 Excerpted Comment from Robert Caldwell, Acton, MA:

Comment: This letter expressed concern regarding the proposed remedial technologies, asphalt-batching and
biosparging. Asphalt-batching does not remove contaminants from the environment. It was felt that
biosparging is costly, time-consuming, difficult to control, and tends to strip contaminants rather than
biologically augment the process.

Response: Both remedial technologies, asphalt-batching and biosparging, have been shown to be effective
means of remediating contaminants in soil.

Technology that reduces concentrations of volatile constituents adsorbed to soils through biological
degradation. The air injected into the subsurface through wells promotes biological degradation. Air
injection rates are controlled to minimize the transfer of hydrocarbons from a dissolved to a vapor
phase. The fuel-related organic contamination at these sites is amenable to biodegradation, and
biosparging has been successfully used in other similar remediation efforts, particularly in highly
permeable soils like those at MMR.

8_. 1/1/98 Letter from Bob Sherman, Maspee Conservation Commission:

General Comment: Though the sediments in the pond at AOC SD-4 are obviously contaminated, the wetland and
pond exhibit considerable wildlife habitat guality. The Mashpee Conservation Commission hopes to work
together with AFCEE/MMR to see that the wetland values of this system are restored.

Response: AFCEE shares the Town of Mashpee's concern for minimizing any adverse effects of remedial
activities on the pond and wetlands at AOC SD-4.

Comment: Are specific plans formulated for the proposed excavation activities at AOC SD-4, including the
replication of the pond and wetlands? What is the timetable for the work?

Response: Specific plans and a timetable for the proposed remediation and replication will be developed
following remedy selection. Remedial plans are expected to be available by mid-1999. They will be
developed during the design process, and will include local involvement.

Comment: Does AFCEE/MMR intend to file a Notice of Intent with the Mashpee Conservation Commission for
the work? What Professional Wetland Scientist(s) will design/oversee the project? What criteria/
standards/guidelines will be used to design and carry out the replication of the pond and wetlands?

Response: Although the proposed actions are on-base and do not reguire federal, state, or local
permitting, the substantive reguirements of the Massachusetts Wetlands Regulations and other ARARs
identified in the Record of Decision must be complied with. AFCEE will cooperate with local authorities,
including filing a Notice of Intent with the Mashpee Conservation Commission, and the use of a wetlands
professional in the design and implementation of the project. The designs and potential wetlands
replication will be coordinated with the Mashpee Conservation Commission.

9_. 1/13/97 Letter from R. Gregory Taylor, Mashpee Department of Public Works:

Comment: The "encapsulation" of contaminants in cold mix asphalt-batching is a concern. Since there is
the possibility of a total 30,000 tons of final product, tight monitored control of the placement and
future leachate to ground water is reguested. All material with PCB's should be removed and disposed off
site. The intent to use the "encapsulated" material as needed anywhere around the base is unacceptable.
The use of asphalt-batched material should be allowed only in areas of closely monitored containment. All
hot mix asphalt cracks and eventually allows water to leach through. Continued monitoring is needed if
this disposal technigue is allowed. The 30,000 tons of material correlates to 6 inches of material over
820,000 s.f. (20 acres), representing a large undertaking.

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water. The technology has been applied to soils contaminated with organic and inorganic compounds,
including PCBs. An asphalt-batching system has been successfully operated at MMR for contaminated soils
removed under the Drainage Structure Removal Program (DSRP). The DSRP identified and removed over 17,000
tons of contaminated soil associated with drainage structures at MMR in 1996. The soil was treated at an
on-site asphalt-batching facility and used as subgrade material for approximately 4.5 miles of roadways
at MMR.

Asphalt-batching site soils will immobilize the contaminants, thus minimizing potential risks from soils.
Asphalt-batching has been accepted by the regulators as a technology that is successful at immobilizing
the types of contaminants detected at the AOCs addressed in the "Six AOC Proposed Plan". Pre- and
post-treatment samples will be collected and analyzed to confirm the effectiveness of the treatment
system. Leaching of contaminants from asphalt-batched soils has been evaluated at other sites (with
favorable results) by sampling groundwater wells near stockpiled treated soils and by performing
laboratory leaching tests. Coupled with the formation of a relatively impermeable barrier, the chemical
and physical fixation of contaminants by asphalt-batching is considered to be protective of human health
and the environment, and effective in minimizing contaminant migration to the groundwater.

The cold-mix asphalt-batching technology is performed at ambient temperatures and entails recycling
contaminated soil into a bituminous paving or road base product. Excavated soils may be processed through
a crusher or screen to produce a physically uniform soil material. The soil may then be blended with
other aggregate (if reguired due to existing soil conditions) and asphalt emulsion in a pugmill. Soil
gradation results and the pavement design will dictate soil preparation needs. The finished product will
be used as the base or subbase material for roadways at MMR. Potential cracks or leaks in the asphalt
wear cover is not expected to substantially increase the mobility of encapsulated contamination. The
roadways will be inspected annually by the base's public works department, and cracks and leaks repaired
if necessary.

Contaminant levels, developed by the Massachusetts Department of Environmental Protection (MADEP), will
be used to assess the acceptability of soils for asphalt-batching. If contaminant concentrations exceed
these criteria, summarized in the table at the end of this Responsiveness Summary, the soils will be
disposed off-site. For example based on the listed criteria, soils exceeding the threshold level for PCBs
(2 ppm) would be disposed off-site. Specific locations for the use of this material will be determined
with the input of the regulatory agencies.

The previous asphalt-batching remediation conducted at MMR during the Drainage Structure Removal Program,
resulted in successful use of over 17,000 tons of emulsion product to pave approximately 4.5 miles of
road.

10. 1/14/97 Memorandum from Elias A. McOuaid, Mashpee Board of Health:

Comment: Contaminated soils in the 6 Areas Of Contamination (AOC's) should be deposited in a lined
landfill on base which would then have to be capped and surrounded by monitoring wells or disposed of
off-base in a DEP approved site. The Mashpee Board of Health believes that the proposal to batch the
contaminated into an asphalt mixture to be used on base as needed is not environmentally sound.

Response: Asphalt-batching is an extensively-tested and proven remediation technology that reduces the
mobility of contaminants by binding them to soil particles with an asphalt emulsion. Contaminated
material is turned into an environmentally stable, structurally enhanced paving subgrade material. The
subgrade material is capped with an asphalt wear cover for durability and to limit the infiltration of
water. The technology has been applied to soils contaminated with inorganic and organic compounds,
including PCBs. An asphalt-batching system has been successfully operated at MMR for contaminated soils
removed under the Drainage Structure Removal Program (DSRP). The DSRP identified and removed over 17,000
tons of contaminated soil associated with drainage structures at MMR in 1996. The soil was treated at an
on-site asphalt-batching facility and used as subgrade material for approximately 4.5 miles of roadways
at MMR.

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the types of contaminants detected at the AOCs addressed in the "Six AOC Proposed Plan". Pre- and
post-treatment samples will be collected and analyzed to confirm the effectiveness of the treatment
system. Leaching of contaminants from asphalt-batched soils has been evaluated at other sites (with
favorable results) by sampling groundwater wells near stockpiled treated soils and by performing
laboratory leaching tests. Coupled with the formation of a relatively impermeable barrier, the chemical
and physical fixation of contaminants by asphalt-batching is considered to be protective of human health
and the environment, and effective in minimizing contaminant migration to the groundwater. The finished
product will be used locally as the base or subbase material for roadways at MMR.

Contaminant threshold levels, developed by the Massachusetts Department of Environmental Protection
(MADEP), will be used to assess the acceptability of soils for asphalt-batching. If contaminant
concentrations exceed these criteria, summarized in the table at the end of this Responsiveness Summary,
the soils will be disposed off-site. For example based on the listed criteria, soils exceeding the
threshold level for PCBs (2 ppm) would be disposed off-site. Specific locations for the use of this
material will be determined with the input of the regulatory agencies.

There are currently no sites available for another landfill at MMR which would be necessary to dispose of
the soil on site. Off-site disposal was evaluated and determined to be not as cost effective as on-site
asphalt-batching. Additionally, alternatives that involve off-site treatment and/or disposal do not meet
the CERCLA preference to conduct treatment and/or disposal on site.

11. 1/14/98 Letter from Robert L. Whritenour, Jr., Mashpee Office of Selectman transmitting 12/8/97
Memorandum from Jim Ouin, Foothill Engineering Consultants, Inc.:

Comment: Other bioremediation alternatives should have been considered as remedies for the six AOCs. This
type of remediation is ideal for more innovative and cost effective solutions.

Response: AFCEE recognizes the potential of bioremediation technologies to provide innovative and
cost-effective treatment of contaminated soils. AFCEE is selecting bioremediation in the form of
biosparging for two of the six AOCs.

Comment: The selected alternative for AOC FTA-2/LF-2 is reasonable. More details should be provided as to
the "institutional controls" proposed.

Response: Institutional controls at MMR involve ensuring that if flightline security measures that
currently limit site access are relaxed, additional measures will be taken to limit access to the AOCs.
These controls are part of the proposed remediation, and will be enforceable through the Record of
Decision for the six AOCs.

Comment: The selected alternative for AOC PFSA/FS-10/FS-ll is reasonable. However, this alternative
should include engineering and/or institutional controls on the fuel delivery and distribution system to
prevent this type of incident from occurring in the future.

Response: The activities and practices which caused most of the past contamination at AOC
PFSA/FS-10/FS-ll have ceased. The MMR "Fuel Systems Upgrade" contract, conducted in 1995, implemented
controls on the fuel delivery and distribution system at the base.

Comment: - Although the asphalt-batching treatment proposed for AOCs SD-2/FS-6/FS-8, SD-4 and SD-5/FS-5
is common, concern was expressed regarding the used of cold emulsified asphalt for long term
stabilization of contaminated soil in a wet environment.

Response: Asphalt-batching is an extensively-tested and proven remediation technology that reduces the
mobility of contaminants by binding them to soil particles with an asphalt emulsion. Contaminated
material is turned into an environmentally stable, structurally enhanced paving subgrade material. The
subgrade material is capped with 1.5 inches of asphalt wear cover for durability and to limit the
infiltration of water. The technology has been applied to soils contaminated with inorganic and organic
compounds, including PCBs. An asphalt-batching system has been successfully operated at MMR for
contaminated soils removed under the Drainage Structure Removal Program (DSRP). The DSRP identified and
removed over 17,000 tons of contaminated soil associated with drainage structures at MMR in 1996.

The soil was treated at an on-site asphalt-batching facility and used as subgrade material for
approximately 4.5 miles of roadways at MMR.

Asphalt-batching site soils will immobilize the contaminants and provide long-term stabilization, thus
minimizing potential risks from soils. Asphalt-batching has been accepted by the regulators as a
technology that is successful at immobilizing the types of contaminants detected at the AOCs addressed in
the "Six AOC Proposed Plan". Pre- and post-treatment samples will be collected and analyzed to confirm

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the effectiveness of the treatment system. Leaching of contaminants from asphalt-batched soils has been
evaluated at other sites (with favorable results) by sampling groundwater wells near stockpiled treated
soils and by performing laboratory leaching tests. Coupled with the formation of a relatively impermeable
barrier, the chemical and physical fixation of contaminants by asphalt-batching is considered to be
protective of human health and the environment, and effective in minimizing contaminant migration to the
groundwater. The finished product will be used locally as the base or subbase material for roadways at
MMR.

Contaminant threshold levels, developed by the Massachusetts Department of Environmental Protection
(MADEP) , will be used to assess the acceptability of soils for asphalt-batching. If contaminant
concentrations exceed these criteria, summarized in the table at the end of this Responsiveness Summary,
the soils will be disposed off-site. For example based on the listed criteria, soils exceeding the
threshold level for PCBs (2 ppm) would be disposed off-site. Specific locations for the use of this
material will be determined with the input of the regulatory agencies.

Comment: The alternative proposed for AOCs SD-2/FS-6/FS-8, SD-4, and SD-5/FS-5 should also include
engineering and/or institutional controls to prevent further contamination from reaching the storm
drainage ditches.

The USAF 102nd Fighter Wing is responsible for MMR's storm water pollution prevention program. Activities
designed to minimize storm water discharge to Ashumet and Johns ponds are summarized in the letter from
the USAF included in Attachment A to this Appendix. These include detention basins to allow on-base
infiltration of storm water.

Comment: The selected alternative for AOC SD-3/FTA-3/CY-4 is reasonable and appropriate.

Response: Comment noted.

Comment: Concern was expressed that the material excavated from the pond at AOC SD-4 may not be suitable
for asphalt-batching.

Response: Pond sediments excavated at AOC SD-4 will be dewatered and mixed with other aggregate material,
as appropriate, prior to asphalt-batching. The extracted water will be collected and treated to meet
pretreatment reguirements for indirect discharge or to prevent exceedances of Ambient Water Quality
Criteria in the receiving water for direct discharge. In accordance with CERCLA, AFCEE will comply with
the substantive reguirements of all ARARs for on-site actions, and will obtain all reguired permits for
off-site actions.

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                                ATTACHMENT A

                WRITTEN COMMENTS RECEIVED DURING PUBLIC COMMENT PERIOD

        To: 
      From: 
        Cc:
       Bcc:
   Subject: Public Comment on 6 Areas of Contamination
Attachment:
      Date: 11/26/97 8:13 AM

Mr Whitaker,

As a Mashpee home owner on John's Pond, my main concern after reading the proposed clean up solutions is
that additional consideration is given to ensure the solutions ensure as much as possible the safety and
well being of the wildlife and fish in and around the lake to ensure their survival.

I noticed when fishing Ashument and John's Pond this summer that the fish seemed "oxygen starved" for
some reason and almost lethargic at times, which usually indicates something is in the water causing them
to act sluggish and abnormal. Also, there seemed to be less wildlife (ducks, geese, frogs, etc.,) then
normal, which is usually and indication that something in the water is keeping them away.

Everything possible must be done to ensure that additional contamination into the lakes is eliminated, so
they can eventually recover. It will do no good to go through with these clean up solutions if the local
lakes and echo system is killed/dead anyway. Then, it is just a waste of money, because it will not have
stopped or prevented anything, and was done too late and after the fact. Like spending millions and
million of dollars to bring a dead animal back to life, which never could be done,  so all the work and
money spent would be a waste of tax dollars as well as a waste of time.

If the safety of the fish, wildlife,  and echo system cannot be assured from the plums and their
contamination seepage once the clean up is completed, then no clean up should take place, since it is
just throwing tax dollars away, since the inevitable will occur anyway.

The millions of dollars then, would be better spent on building a saltwater purification plant to ensure
unlimited clean water is available to Cape Cod. If such a plant ends up having to be built anyway, after
all the clean up efforts, it would be guite obvious the cleanup efforts were a waste of time and money
and did not work.

I hope the clean up efforts if completed however do work, and the fish, wildlife, and echo systems are
saved as a result.

G90RGE D. KASZUBA                                  
79 Pond Circle
Mashpee, MA 02649
Work:      (508) 968-7210
Home:      (508) 477-7981

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                                                        David Dow
                                                        18 Treetop Lane
                                                        East Falmouth, Ma.
                                                        December 7, 1997
HQ AFCEE/MMR
Attn.:  Six AOCs
322 East Inner Road
Otis ANG Base, Ma. 02542-5028

Dear Sir/Madam:
02536-4814
The proposed plan on the six areas of contamination  (AOCs) is not a plan at all, but merely a collection
of concepts with a few supporting figures. The information put out for public review is totally
inadeguate for allowing any citizen to be able to make a meaningful public review. The current "proposed
plan" needs to be revised with some meat put on the bones of the current loose agglomeration of general
concepts(masguerading as a plan).  The public comment period due to expire on December 15, 1997 needs to
be extended to such a time as a month will elapse after a revised plan is submitted for public review
(plus review by the JPAT, TRET, TEAC, and SMB),  with a new meeting scheduled to receive public comment.

The revised plan needs to address the following items:

•       Need to establish a linkage between the strategies proposed to treat the sources of contamination
       (6 AOCs)  and the plumes associated with these sources of contamination.  Despite the decision by
       AFCEE,  EPA,  and the Ma. DEP to operationally separate the plume containment process from the
       treatment of the source areas because of budgetary/time constraints,  there is a need to develop an
       integrated approach to treat both the source areas and contain the plumes. It is not desirable to
       adopt a piecemeal approach to develop options for plume containment (to be reviewed by the JPAT)
       separate from the program to treat the source areas of this pollution (which is being reviewed by
       the TEAC).  This divide and conguer strategy between the JPAT and TEAC is totally unacceptable.

•       There needs to be a listing of the chemicals of concern for each AOC,  including the concentrations
       of the chemicals that pose a threat to either human health or sensitive ecological receptors. Also
       the volume of contaminated sediments,  areal coverage and depth of contamination should be listed
       for each AOC. It is unrealistic to assume that citizens who work full time will have the time to
       go back and look up these details in the Remedial Investigation reports for each of the AOCs
       (especially considering the length of these reports and how widely dispersed actual information is
       in these reports).

•       There needs to be a description of the testing methods for deciding which contaminated sediments
       will be treated as hazardous wastes (thus entailing off site disposal),  as opposed to those
       contaminated sediments to be subjected to biosparging, limited action,  or excavation and
       asphalt-batching.  The risk analysis procedure supporting this seguenced treatment process should
       be described (including guantitative risk levels for both carcinogenic and chronic toxicity
       endpoints),  so that the public will be ensured that the mixture of heavy metals,  organochlorine
       compounds,  PAHs, volatile organic solvents or fuel products,  etc. is adeguately addressed.
       Currently biosparging is proposed as the treatment of choice for AOC FTA-2/LF-2 and AOC
       PFSA/FS-10/FS-ll,  while excavation and asphalt batching is proposed for AOCs SD-2/FS-6/FS-8,
       SD-3/FTA-3/CY-4, and SD-5/FS-5. Since the storm drains are likely to be continuing sources of
       pollution to local water bodies (including Johns and Ashumet Ponds)  after storm water drainage
       events, the proposed plan should discuss the long term mitigation for these sources of pollution
       (which in AFCEE's view is infiltration galleries on the base or in my view is source reduction or
       recycling to reduce pollution at its real source).

       What is the status of the SERGOU plume containment process (associated with AOCs FTA-2/LF-2,
       PFSA/FS-10/FS-ll,  SD-2/FS-6/FS-8, and SD-3/FTA-3/CY-4)?

•       For sites such as AOC SD-4  where heavy metals pose a threat to sensitive ecological receptors, how
       will the bioavailability be evaluated  (i.e. based upon methylated forms of these contaminants or
       the inorganic moieties)? This is especially important given the wetland and pond habitats that are
       potential sinks for this pollution.

•       For AOCs in which biosparging is employed, AFCEE should conduct a pilot test to determine whether
       the microbes responsible for the bioremediation can metabolize the VOCs to concentrations below
       the threshold responsible for effects on sensitive ecological receptors; whether nutrients need to
       be added to help accelerate this microbial degradation reaction; and to determine if organic
       substrates need to be added to complete this biological breakdown process  (co-metabolism is

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       involved).

       For the human health risk assessments at sites where institutional controls will be utilized,  how
       much of the non-exceedence is due to limited access versus the actual toxicity posed by the levels
       of chemical contaminants? How effective will these institutional controls be if the military
       departs the MMR?

       What are the appropriate ARARs required by the state and Federal government that must be met as a
       threshold requirement for each chosen cleanup alternatives? It is hard to comment on the two
       threshold requirements (protection of human health and the environment and compliance with the
       state and federal ARARs), when the ARARs are not listed and we are simply qiven qualitative
       assurance that the human health standards and environmental risks have been adequately addressed.
       At least the consumers quide chart qives some insiqht into the balancinq criteria assessments for
       each treatment alternative.  Why is there no comparable assessment for the threshold criteria?

       Meaninqful  public comment requires that adequate information be provided to the public in a timely
       fashion. The six AOCs "proposed plan" falls far short of on standard required to provide
       meaningful  public comment and harks back to the pre-AFCEE days when public involvement was of the
       pro forma variety. This is a step in the wrong direction. The recent trend of AFCEE choosing the
       least costly alternative in the plume containment proposed plans (natural attenuation)  has not
       inspired a  lot of confidence in the integrity of the public comment process (especially when the
       views of the JPAT appear to be summarily dismissed).  The regulatory agencies (EPA and Ma.  DEP)
       appear to be missing in action in this process,  especially when many local citizens count on them
       to protect  public health and be the stewards of the natural environment.

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December 9, 1997

Dear Sir,

The Board of Directors of the Mashpee Environmental Coalition (MEG) for the most part agree with the
preferred cleanup alternatives for the remediation of the Six AOCs. Our only objection is the
construction of an additional access road at the northern end of Wheeler Road in Mashpee to site
SD-2/FS-6/FS-8 for the removal of contaminated soil.

We feel the construction of a new access road will have a negative impact on the neighborhood and
environment. The existing road/way constructed last year at the SD-2 drainage ditch should be utilized
for access to the contaminated areas. A temporary metal surface material used on the existing road, such
as that used by the National Guard for temporary access, would seem to be less destructive to the
environment in the area, than constructing a new road. The material could be used on the existing road to
access the areas, and then removed after the soil has been removed.

We also would like to remind you again (see Letter of 24 September 1997) that we feel the current
Drainage Easements pose a threat to Ashumet and John's Ponds and should be eliminated as soon as
possible. They only serve as a continuous threat to the ponds and surrounding properties. The "Hundred
Year Storm" could be here tomorrow and contaminants from these drainage ditches would be here flushed
directly into our ponds. Please respond to this reguest for some type of action concerning these drainage
ditches.

Thank you for your consideration,

-------
Dear Sir,

     Enclosed please find our Pre Proposal Format sent to Mr. J. Plunkett of the Enviro Tech Center at
Otis for your information. The proposal is self explanatory. Additionally, we have proven Technology to
remove  (large Scale Project)  PCB and EDB from soils and water. The technology had been demonstrated
with/through our partnering companies in Ontario, Canada. The permitting process in the USA is so
draconian we are unable to economically meet the guide lines. Also, no agreement for process
confidentially could be obtained.

     Our position on both biosparging and Asphalt capping is luke warm to negative. Asphalt capping does
no remove the contaminate from the environment. Biosparging is both costly and time consuming and tends
to strip contaminates rather than biologically augment it. It is difficult to control the actual
mineralization rates of the various microbial family's one encounters in natural occurring bacteria.
("Kill more than you cure"!)  The remediation takes on a keystone cops atmosphere. Lots of initial
biological activity with little or no actual reduction of the target compounds to be biologically
remediated.

     We are a Massachusetts based Tech Corporation whom to date has been unable to gain a ear to allow us
a opportunity to succeed at an economical solution to the removal of contaminated soils and water plumes
located on the cape

Sincerely,
Robert L. Caldwell

cc:   Ken Burroughs
      Dd Zudkevitch Phd

-------


Date: 1/8/98

     It is my understanding that the comment period for the six AOC's has been extended to Jan 15, 1998.
My Commission would like to comment particularly on the remediation planned for SD-4. From what we have
learned, the remediation will involve dredging a pond and associated wetland, and that replication will
be undertaken. Please correct me if I am misinformed on any of the proceeding.  I have a series of
guestions:

     (1) Are specific plans formulated for the work, including the replication?
     (2) What is the timetable for the work?
     (3) Does AFCEE/MMR intend to file a Notice of Intent with the Mashpee Conservation Commission for
         the work?  (If not, please cite the legal rationale as to why AFCEE/MMR does not intend to file
         an application with us. If it is AFCEE/MMR's contention that they are not obligated to seek a
         permit through this Commission, to what extent will we be consulted as to the work and
         replication?)
     (4) What Professional Wetland Scientist(s) will design/oversee the project?
     (5) What criteria/standards/guidelines will be used to design and carry the replication?

     Some 5 years ago or so, I saw this pond/wetland complex at the invitation of MMR officials. Though
the sediments in the pond are obviously contaminated, I remember the wetland and pond to have exhibited
considerable wildlife habitat guality. The Commission has developed criteria for replication that would
seem to be appropriate for this project. I would hope that we would be able to work together with
AFCEE/MMR to see that the wetland values of this system are restored. Of course, if any details of the
work were immediately available, I would attempt to make comments before Jan 15.

     I would appreciate hearing from AFCEE/MMR as soon as possible regarding these matters.

cc: Executive Secretary, Robert Whritenour
Chairman of the Board of Selection, George Costa
Karen Wilson, Jacobs Engineering Group, Inc.

-------

Dear Mr. Whitaker:

The following comments are in support of previous discussions at the public hearing on December 2,
1997 and J-PAT meetings on December 3, 1997 and January 7, 1998.

1. The "encapsulation" of contaminants in cold mix asphalt batching is a concern. Since there is the
possibility of a total 30,000 tons of final product, tight monitored control of the placement and
future leachate to ground water is reguested.

2. All material with PCB's should be removed and disposed off site.

3. The intent to use the "encapsulated" material as needed anywhere around the base is unacceptable.
The thought of a "Johnny Appleseed " approach to using contaminant laced material in areas that
could be open to future reconstruction or zones of contribution to down gradient wells is
unacceptable. The regulating authorities need to reject this approach.

4. The use of asphalt batched material should be allowed only in areas of closely monitored
containment. An example would be at the LF-1 source area or within a portion of the paved airport
with pavement below and above.

All hot mix asphalt cracks and eventually allows water to leach through. Continued monitoring is
needed if this disposal technigue is allowed.

The 30,000 tons of material correlates to 6 inches of material over 820,000 s.f. (20 acres) . I do
not believe many people, including the program presenters, understand the magnitude of this
undertaking.

The FEC MMR Team has reviewed the alternatives to clean up the six Areas of Concern, as proposed by
AFCEE. In general FEC would have liked to see other bioremediation alternatives considered. This type of
remediation is ideal for more innovative and cost effective solutions. In response to the proposed
alternatives, FEC has to following comments.

AOC FTA-2/LF-2 - FEC feels the selected alternative for AOC FTA-2/LF-2 is reasonable. More details
should be provide as to the "institutional controls" proposed.

AOC PFSA/FS-10/FS-ll - FEC feels the selected alternative for AOC PFSA/FS-10/FS-ll is reasonable.
However, this alternative should include engineering and/or institutional controls on the fuel
delivery and distribution system to prevent this type of incident from occurring in the future.

AOC SD-2/FS-6/FS-8 - Although this type of treatment is common, FEC guestions the use of a cold
emulsified asphalt for long term stabilization of the contaminated soil in such a wet environment.

AOC SD-3/FTA-3/CY-4 - FEC feels the selected alternative for SD-3/FTA-3/CY-4 is reasonable and
appropriate.

AOC SD-4 - FEC is concerned that the material excavated from the pond may not be suitable for
asphalt batching. This alternative should also include engineering and/or institutional controls to
prevent further contamination from reaching SD-4.

AOC SD-5/FS-F - FEC guestions the use of an cold emulsified asphalt for long term stabilization of
the contaminated soil in such a wet environment. This alternative should also include engineering
and/or institutional controls to prevent further contamination from reaching SD-5.

-------
ATTACHMENT B

IiETTER FROM USAF 102nd FIGHTER WING

09 January 1998

MEMORANDUM FOR AFCEE (Mr. Jim Snyder)

FROM: 102FW/SPTG-CC
158 Reily Street, Box 09
Otis ANGB, MA 02542-5028

SUBJECT: Request for Information

1. Reference your 16 Dec 97 letter (Attachment 1) which requested input from the 102nd Fiqhter Winq for
a response which the IRP proqram is preparinq to send to the Mashpee Environmental Coalition in
response to its 09 Dec 97 letter (Attachment2).

2. Per your request, the followinq information is provided concerninq the storm water runoff issue.

a. The overall storm water runoff system which exists at Otis ANGB today was constructed by the
United State Air Force when it initially constructed the airfield runways, aircraft taxiways
and parkinq ramps, and aircraft operations areas.

b. The 102nd Fiqhter Winq has a storm water pollution prevention proqram developed in
accordance with the provisions of the U.S. Environmental Protection Aqency's requlations. In
addition to monitorinq our storm water runoff by visual observation on a quarterly basis as
required by EPA, we take quarterly samples of our storm water at our outfall locations and
have them analyzed by a private laboratory for numerous parameters.

c. We are aware of community concern reqardinq storm water runoff and have made efforts over the
past few years to reduce the amount of storm water which leaves the base. Followinq is a
summary of action we have taken.

1) We dammed what is called outfall location SD-1 at several locations to provide
holdinq areas to allow runoff to better infiltrate into the qround on base.

2) We hired an enqineerinq firm durinq the latter part of 1996 to conduct a
feasibility study of what is known as outfall location SD-2. This is the area
immediately adjacent to our duel storaqe area and is the storm water outfall for
which the 102FW and the community share the qreatest concern. Our qoal was to
ascertain if it was possible to reduce or eliminate storm water runoff throuqh this
outfall. Based on the initial report, we will be hirinq an enqineerinq firm this
year to desiqn a system which will divert storm water from the SD-2 outfall to the
SD-1 outfall, where it can better infiltrate into the qround on base. Based on the
eventual desiqn and projected costs from this desiqn effort, we'll be submittinq a
request to the Air National Guard Readiness Center at Andrews AFB, Maryland for
Project fundinq.

3) We constructed a retention area on base in the late 1996/early 1997 time frame to
better enable on-base recharqe of storm water to what we call the SD-4 storm Water
outfall.

3. The issue of eliminatinq the casements for storm water is one which is beyond the ability of the
102FW to answer. We will be forwardinq the Mashpee Environmental Coalition's letter to the Air
National Guard Readiness Center for its review.

4. We are aware of the community's concern about storm water runoff from Otis ANGB and hope that the
above information helps explain the efforts which we have taken and have underway to address these
mutual concerns.

-------
                                        ATTACHMENT C

                      SOIL RECYCLING FACILITY SUMMARY LEVELS

                     MASSACHUSETTS SOIL RECYCLING FACILITY SUMMARY LEVELS a
Contaminant

Total Arsenic  (As)
Total Cadmium  (Cd)
Total Chromium  (Cr)
Total Mercury  (Hg)
Total Lead  (Pb)
Total VOCs c
Total Petroleum
Hydrocarbons
Total PCBs
Total Halogenated
Volatile Organic
Compounds
Listed or
Characteristic
Hazardous Waste
(TCLP f)
    Hot Mix
Asphalt Plants
   mg/kg b

     30
     30
    500
     10
  1,000
     <2
      5
              30 to 1,800 d
            5,000 to 60,000 e
  Thermal
 Processing
Plant mg/kg

   30
   11
  500
    3
1,000
   <2
    5
  Cold Mix
Emulsion Plant
     mg/kg

       30
       30
      500
       10
    1,000
       <2
        5
SOURCE: Interim Remediation Waste Management Policy for Petroleum Contaminated Soils,
        MADEP Policy WSC-94-400.
NOTES:

     a   Contaminant levels presented in this table are a summary of soil recycling permits
         issued by the DEP's Division of Hazardous Waste as of April 1994. For a complete
         listing for a specific facility please consult the applicable facility permit.

     b   Concentrations for all three processes are in mg/kg, dry weight.

     c   As determined by EPA method 8240 or eguivalent, provided that the presence of
         such constituents does not cause the soil to be either a characteristic or listed
         hazardous waste pursuant to 310 CMR 30,000.

     d   The concentrations specified represent the lowest and highest VOC concentration
         permitted among all soil recycling facilities. However, each permitted VOC level is
         process-specific and LSPs and generators should consult the facility's individual soil
         recycling permit to ensure that the VOC concentration in the contaminated soil is
         consistent with that authorized in the facility permit.
         The concentrations specified represent the lowest and highest TPH concentration
         permitted among all soil recycling facilities. However, each permitted TPH level is
         process-specific and LSPs and generators should consult the facility's individual soil
         recycling permit to ensure that the TPH concentration in the contaminated soil is
         consistent with that authorized in the facility permit.

         TCLP testing should be performed for metals or organic compounds when the total
         concentrations in the soil are above the theoretical levels at which the TCLP criteria
         may be met or exceeded. For guidance parties should consult United States
         Environmental Protection Agency, memorandum #36, "Notes on RCRA Methods
         and QA Activities", pp. 19-21, Gail Hanson, January 12, 1993.

-------
                                         APPENDIX D
                                TRANSCRIPT OF PUBLIC HEARING
In Re:  Public Hearing for Six AOC's:
                                  Public Hearing for Six AOC's

                                  Mashpee High School

                                  Mashpee, MA 02649

                                  December 2, 1997
                      MARY E. PHILLIPS

                      Registered Professional Reporter
                      P.O. Box 160
                      Sagamore Beach, MA 02562-0160
                      (508)  888-6717

-------
 1





 2





 3  Jerry Whitaker





 4  Lee Perry




 5  Chuck Rossoll





 6  Stanley Reed





 7  Walter Zorn





 8  Jim Snyder




 9  Cathy Kiley





10  David Dow





11  Deena Despault





12  Paul Rossi




13  C.  Gray Wolf





14  Carol Keating





15  Philip Elia





16  Kathleen Elia





17  Sara Corner




18  Jon Luther





19  Diane Bryant





20  Greg Taylor





21  John Palmier!




22





23





24





25
                         ATTENDEES
AFCEE/MMR
Sierra Club
AFCEE/MMR











ABB-ES





ABE-ES





HAZWRAP





AFCEE/MMR





MADEP











713 Old Barnstable Road





713 Old Barnstable Road





P.O. Box 1547, Mashpee





EPA





49 Pond Circle, Mashpee





49 Pond Circle, Mashpee





OpTech





OpTech





OpTech





Mashpee DPW





Mashpee

-------
 1                                           PROCEEDINGS





 2                                    (December 2,  1997,  8:13 p.m.)





 3                    MR.  WHITAKER:  Okay.  I'm going to be





 4          starting off the formal  public hearing by reading a





 5          statement. It should take about four or five





 6          minutes.





 7                    After that I'll be asking you to come to





 8          the microphone, state your name and the town you're





 9          from and let us know what your concerns are.





10                    So with that I d like to start the public





11          hearing. Good evening. My name is Jerry Whitaker





12          and I'm a public affairs specialist for the





13          Installation Restoration Program at the Massachusetts





14          Military Reservation.





15                    I will be the  Hearing officer this





16          evening.





17                    The purpose of tonight's hearing is to





18          accept oral comments, oral testimony and written





19          comments on the Proposed Plan to clean up six areas





20          of contamination at the  Massachusetts Military





21          Reservation.





22                    The six areas  of contamination are





23          comprised of 13 separate sites that have been grouped





24          into six operable units. These sites are: Fire





25          fighter training Area 2  and Landfill 2.











                               MARY  E. PHILLIPS

-------
 1                    The petroleum fuel storage area,  which





 2          consists of fuel spills 10 and 11.





 3                    Storm drain 2 and fuel spills 6 and 8.





 4                    Storm drain 3,  fire fighter training area 3





 5          and coal yard 4.





 6                    Storm drain 4 and storm drain 5.  And fuel





 7          spill 5.





 8                    Earlier this evening you heard a synopsis





 9          of our plans to clean these sites.  On November 13th





10          we began a 30-day formal  public comments period to





11          solicit public input on the Proposed Plan to clean





12          these sites.





13                    This public comment period ends on





14          December 15th. Tonight the Air Force Center for





15          Environmental Excellence  is hosting a public hearing





16          which is being transcribed.





17                    All comments and testimony that are given





18          here tonight will be transcribed verbatim and become





19          part of the official record on this project.





20                    Each and every  comment will be responded to





21          in the form of a Responsiveness Summary. This





22          document categorizes and  summarizes all of the





23          comments we receive through the duration of the





24          public comment period.





25                    The Responsiveness Summary will be part of





                               MARY E. PHILLIPS

-------
 1          the Record of Decision,  or ROD as it's commonly





 2          called,  that will be issued at a later date.





 3                    The ROD specifies the actions to be taken





 4          to clean the sites and is signed by the parties to





 5          the Federal Facilities Agreement. These parties





 6          include the Air Force Center for Environmental





 7          Excellence and the U.S.  Environmental Protection





 8          Agency.





 9                    There are copies of the Proposed Plan





10          located outside in the hallway as well as up here on





11          the table.





12                    In addition, when the transcript of





13          tonight's meeting is finalized, it will be placed





14          into the main libraries of Falmouth,  Mashpee,





15          Sandwich, Bourne, and the on-base U.S. Coast Guard





16          library. The Proposed Plan is also on file in those





17          libraries.





18                    Tonight's hearing is different than the





19          informational meeting held earlier this evening.





20          Public meetings are interactive. A public meeting is





21          exclusively an opportunity for the Air Force Center





22          for Environmental Excellence, the U.S. Environmental





23          Protection Agency and the Massachusetts Department of





24          Environmental Protection to receive your oral





25          comments. We will not be responding to your comments














                               MARY E. PHILLIPS

-------
 1          during the hearing.





 2                    Everyone who wishes to submit oral comments





 3          must speak into the microphone.  Please state your





 4          first and last name and town of residence.





 5                    As I mentioned earlier,  the comments





 6          submitted tonight will be responded to in the





 7          Responsiveness Summary.





 8                    Written comments can be given to me any





 9          time tonight or through December 15th. If mailing





10          comments, please ensure that the envelope is





11          postmarked by December 15th and mailed to the proper





12          address.





13                    I've included a handout which is located in





14          the hallway with a property mailing address as well





15          as our fax number, my e-mail address and the





16          Massachusetts Military Reservation Installation





17          Restoration Program web site for those of you who





18          would like to submit comments through those





19          channels.





20                    It's now time to open the official record





21          for oral  comment on the Proposed Plan to clean up six





22          areas of  contamination at the Massachusetts Military





23          Reservation.





24                    Please keep your comments exclusively to





25          this Proposed Plan.














                               MARY E. PHILLIPS

-------
 1                    If you have questions about other issues,  I





 2          would ask that you approach me after the hearing is





 3          over or at a later date.





 4                    During any of the comments you make,  we may





 5          ask for clarification if we don't understand what the





 6          comment is.





 7                    That is the only interaction that we will





 8          have until the official record is closed.





 9                    With that said, the floor is open for oral





10          comments. If anyone has any comments, please step up





11          to the microphone, give us your name, the town you





12          reside and then your comments.





13                    MR.  PALMIERI: My name is John Palmieri,





14          town of Mashpee. I'd like to make a couple of





15          comments relative to excavation and asphalt batching





16          that's been proposed for this area.





17                    First of all, I'm concerned about the PCB's





18          that have been found in at least two locations in the





19          soil. As everything I understand about PCB's is that





20          it's a very stable compound and does not break down





21          easily.





22                    I'm concerned that by imbedding it in the





23          asphalt is not a complete solution. I believe in





24          time the asphalt may actually break down and the





25          PCB's may still remain and are subject to further














                               MARY E. PHILLIPS

-------
 1          leaching into the ground.





 2                    I'd recommend that you consider an





 3          alternate by gathering the PCB contaminations and





 4          removing it completely from the base and obviously





 5          away from the aguifer.





 6                    The second comment would be relative to





 7          where you're placing the asphalt batching.





 8                    I'd suggest you, consider a proposal to





 9          monitor the whole process, after, long after you put





10          it in the soil,  you never know if it might leach





11          again.





12                    Although you believe it is a consistent





13          process, I'd be concerned about batch-to-batch





14          day-to-day processing of this material.





15                    You might have break down and not even be





16          aware of it during your processing.





17                    And I'd suggest rather than putting it on





18          the roads which would spread it across the entire





19          base, you localize it in one spot,  and furthermore





20          you put monitors in the ground before you put this





21          material down and that these monitors then could be





22          used to monitor subseguent leaching five, 10, 20, 50





23          years down the road to see that the material is there





24          and is  not leaking into the aguifer. Thank you.





25                    MR. WHITAKER: Thank you,  John. Any other











                               MARY E. PHILLIPS

-------
 1          comments?





 2                    MR.  TAYLOR:   My name is Greg Taylor from








3           the town of Mashpee.





4                     First initial comments related to all six





5           areas is that it appears that in an effort to





6           simplify the plan for public consumption AFCEE has





7           stripped the document that they've provided us of the





8           necessary details in order to make an informed





9           decision on any of the actions that are going on.





10                    My guestions on each one will relate in





11          part to the information that isn't readily available





12          without somehow finding other documents to go





13          through.





14                    It's also disturbing to see that in each of





15          the six areas, AOC's,  that AFCEE has dismissed the





16          existing ecological assessment because it's too





17          conservative.  If the ERA was done correctly the





18          first time or wasn't done correctly the first time





19          then it should be done again.





20                    On the AOC FTA-2/LF-2, please identify the





21          primary chemicals of concern for this site. Please





22          identify the guote "several chemicals" with the





23          potential to migrate to groundwater where identified





24          were above threshold concentrations, and please





25          provide their concentrations.








                               MARY E. PHILLIPS

-------
 1                    Please identify the inorganic and fuel





 2          related COG's encountered in the groundwater.





 3                    Please provide the SERGOU clean up plan and





 4          explain how the contaminated groundwater associated





 5          with this site is addressed in that plan.





 6                    What is the depth to groundwater at this





 7          site?





 8                    What subsurface soils are contributing to





 9          the groundwater contamination above or below the





10          groundwater table of both? There's only discussion





11          about in or above the groundwater table. Aren't





12          these contaminants underneath the groundwater also?





13                    Please provide a conceptual layout of the





14          biosparging that's proposed in this area.





15                    Please define what AFCEE intends to do to





16          assure that guote "a prudent design" end guote will





17          minimize interactions in the two systems. The second





18          area SD-2, FS-6 and FS-8, please provide a summary of





19          the COC's and the range of concentrations in this





20          area.





21                    What is AFCEE's point in discussing average





22          quote "average" end guote site concentrations versus





23          maximum concentrations along the drainage ditch?





24                    What are the COC's creating the





25          unacceptable risk? How many sample locations are











                     MARY E. PHILLIPS

-------
 1          there in the ditch? And over what total length?





 2                    What are the COG's driving the adverse





 3          ecological risk in the ditch?





 4                    What are the receptors, the ecological





 5          receptors?





 6                    What does AFCEE mean by guote "non-site





 7          related groundwater" end guote contamination beneath





 8          the AOC?





 9                    And please explain the preferred





10          alternative, how it addresses the concerns of





11          contamination encountered and treats the contaminants





12          so that they will not pose a future risk.





13                    Third area AOC SD-3/FTA-3/CY-4.  We had





14          some information -- I'd like to once again ask why





15          doesn't the Department of Defense know that the





16          earlier work on this site removed all of the ash?





17                    Is there a post-excavation report





18          documenting this? What leads us to believe that





19          additional work needs to be done here?





20                    Is there an ecological risk here or not?





21          There's said to be a potential one still.  How are we





22          resolving that with enough secondary testing to





23          assure that we haven't missed something? It appears





24          that in the closure something was missed.  And now





25          how do we know we're not missing something again?











                     MARY E. PHILLIPS

-------
 1                    In the AOC SD-4 what are the fuel-related





 2          inorganic and inorganic COG's in this --





 3          concentrations in this medium?





 4                    Once again the plan indicates that average





 5          contaminated concentrations did not result in adverse





 6          health risk.





 7                    Did the maximum concentrations exceed





 8          levels for human health risk? If so,  what were the





 9          compounds and what were the concentrations? Is there





10          an adverse ecological risk associated with this AOC?





11                    Once again AFCEE essentially dismisses the





12          value of the ecological risk assessment because of





13          quote "conservative assumptions" end guote during





14          calculations, if this was not a reasonable





15          ecological risk assessment then one should be done.





16          Why hasn't one been done that's acceptable?





17                    There should be a site plan that shows in





18          better detail the excavation that's being intended in





19          this area. On the AOC SD-5 and FS-5,  once again the





20          discussion on human risk associated with this AOC is





21          confusing. In fact, it's misleading.





22                    The first sentence states that there is no





23          adverse risk for current and future scenarics using





24          quote "average" end quote exposure concentrations.





25                    The next scenario indicates in the same











                     MARY E. PHILLIPS

-------
 1          item says that,  in fact,  there are exceedances in





 2          both the federal and state guidelines. They do





 3          exist.





 4                    Finally, the last sentence says that the





 5          ecological risks exist and that chemical





 6          concentrations in the soil above the groundwater





 7          exceed threshold values.





 8                    once again, we should at least show the





 9          connection and the relationship with the contaminated





10          groundwater at this AOC and with the SD-5 plume and





11          how that ties in with the SD-5 north treatment system





12          and provide a more detailed plan of the locations and





13          the depths in all that comprise the 9,400 cubic yards





14          of estimated contaminated soil that's being excavated





15          from the site. Thank you.





16                    MR. WHITAKER: Thanks, Greg. Any other





17          comments or guestions that people would like to get





18          on the public record part of the Record of Decision?





19                        (No response.)





20                    MR. WHITAKER:  If there are not further oral





21          comments to be made, then I shall now close the





22          official record for oral testimony. The record is





23          now closed for oral testimony.





24                    Please note that you can still provide





25          written comments to us through December 15th. Thank











                     MARY E. PHILLIPS

-------
 1          you for coming this evening.





 2                    Once again,  I'd like to extend the offer if





 3          you have guestions we'll hang around and try to





 4          answer them.  Thank you.





 5                    (Whereupon the hearing concluded





 6          at 8:30 p.m.)





 7





 8





 9





10





12





13





14





15





16





17





18





19





20





21





22





23





24





25











                     MARY E.  PHILLIPS

-------
 1                                   CERTIFICATE





 2





 3                    I,  MARY E.  PHILLIPS,  Registered Professional





 4          Reporter,  do hereby certify that the foregoing transcript,





 5          pages 2 through 15 inclusive,  was taken by me





 6          stenographically and thereafter under my direction was





 7          reduced to typewriting and is  a true record of the testimony





 8          of the proceedings to the best of my ability.





 9





10                    Dated at Bourne, Massachusetts, this llth





11          day of December, 1997.





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                     MARY E. PHILLIPS

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 1          comments?





 2                    MR.  TAYLOR:   My name is Greg Taylor from





 3          the town of Mashpee.





 4                    First initial comments related to all six





 5          areas is that it appears that in an effort to





 6          simplify the plan for public consumption AFCEE has





 7          stripped the document that they've provided us of the





 8          necessary details in order to make an informed





 9          decision on any of the actions that are going on.





10                    My guestions on each one will relate in





11          part to the information that isn't readily available





12          without somehow finding other documents to go





13          through.





14                    It's also disturbing to see that in each of





15          the six areas, AOC's,  that AFCEE has dismissed the





16          existing ecological assessment because it's too





17          conservative.  If the ERA was done correctly the





18          first time or wasn't done correctly the first time





19          then it should be done again.





20                    On the AOC FTA-2/LF-2, please identify the





21          primary chemicals of concern for this site. Please





22          identify the guote "several chemicals" with the





23          potential to migrate to groundwater where identified





24          were above threshold concentrations, and please





25          provide their concentrations.











                     MARY E. PHILLIPS

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 1                    Please identify the inorganic and fuel





 2          related COG's encountered in the groundwater.





 3                    Please provide the SERGOU clean up plan and





 4          explain how the contaminated groundwater associated





 5          with this site is addressed in that plan.





 6                    What is the depth to groundwater at this





 7          site?





 8                    What subsurface soils are contributing to





 9          the groundwater contamination above or below the





10          groundwater table of both? There's only discussion





11          about in or above the groundwater table. Aren't





12          these contaminants underneath the groundwater also?





13                    Please provide a conceptual layout of the





14          biosparging that's proposed in this area.





15                    Please define what AFCEE intends to do to





16          assure that guote "a prudent design" end guote will





17          minimize interactions in the two systems. The second





18          area SD-2, FS-6 and FS-8, please provide a summary of





19          the COC's and the range of concentrations in this





20          area.





21                    What is AFCEE's point in discussing average





22          quote "average" end guote site concentrations versus





23          maximum concentrations along the drainage ditch?





24                    What are the COC's creating the





25          unacceptable risk? How many sample locations are











                     MARY E. PHILLIPS

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 1          there in the ditch? And over what total length?





 2                    What are the COG's driving the adverse





 3          ecological risk in the ditch?





 4                    What are the receptors, the ecological





 5          receptors?





 6                    What does AFCEE mean by guote "non-site





 7          related groundwater" end guote contamination beneath





 8          the AOC?





 9                    And please explain the preferred





10          alternative, how it addresses the concerns of





11          contamination encountered and treats the contaminants





12          so that they will not pose a future risk.





13                    Third area AOC SD-3/FTA-3/CY-4.  We had





14          some information -- I'd like to once again ask why





15          doesn't the Department of Defense know that the





16          earlier work on this site removed all of the ash?





17                    Is there a post-excavation report





18          documenting this? What leads us to believe that





19          additional work needs to be done here?





20                    Is there an ecological risk here or not?





21          There's said to be a potential one still.  How are we





22          resolving that with enough secondary testing to





23          assure that we haven't missed something? It appears





24          that in the closure something was missed.  And now





25          how do we know we're not missing something again?











                     MARY E. PHILLIPS

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 1                    In the AOC SD-4 what are the fuel-related





 2          inorganic and inorganic COG's in this --





 3          concentrations in this medium?





 4                    Once again the plan indicates that average





 5          contaminated concentrations did not result in adverse





 6          health risk.





 7                    Did the maximum concentrations exceed





 8          levels for human health risk? If so,  what were the





 9          compounds and what were the concentrations? Is there





10          an adverse ecological risk associated with this AOC?





11                    Once again AFCEE essentially dismisses the





12          value of the ecological risk assessment because or





13          quote "conservative assumptions" end guote during





14          calculations. If this was not a reasonable





15          ecological risk assessment then one should be done.





16          Why hasn't one been done that's acceptable?





17                    There should be a site plan that shows in





18          better detail the excavation that's being intended in





19          this area. On the AOC SD-5 and FS-5,  once again the





20          discussion on human risk associated with this AOC is





21          confusing. In fact, it's misleading.





22                    The first sentence states that there is no





23          adverse risk for current and future scenarics using





24          quote "average" end quote exposure concentrations.





25                    The next scenario indicates in the same











                     MARY E. PHILLIPS

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 1          item says that,  in fact,  there are exceedances in





 2          both the federal and state guidelines. They do





 3          exist.





 4                    Finally, the last sentence says that the





 5          ecological risks exist and that chemical





 6          concentrations in the soil above the groundwater





 7          exceed threshold values.





 8                    Once again, we should at least show the





 9          connection and the relationship with the contaminated





10          groundwater at this AOC and with the SD-5 plume and





11          how that ties in with the SD-5 north treatment system





12          and provide a more detailed plan of the locations and





13          the depths in all that comprise the 9,400 cubic yards





14          of estimated contaminated soil that's being excavated





15          from the site. Thank you.





16                    MR. WHITAKER: Thanks, Greg. Any other





17          comments or guestions that people would like to get





18          on the public record part of the Record of Decision?





19                                     (No response.)





20                    MR. WHITAKER:  If there are not further oral





21          comments to be made, then I shall now close the





22          official record for oral testimony. The record is





23          now closed for oral testimony.





24                    Please note that you can still provide





25          written comments to us through December 15th. Thank











                     MARY E. PHILLIPS

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 1          you for coming this evening.





 2                    once again,  I'd like to extend the offer if





 3          you have guestions we'll hang around and try to





 4          answer them.  Thank you.





 5                    (Whereupon the hearing concluded





 6          at 8:30 p.m.)





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                     MARY E.  PHILLIPS

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 1                                    CERTIFICATE





 2





 3                    I,  MARY E.  PHILLIPS,  Registered Professional





 4          Reporter,  do hereby certify that the foregoing transcript,





 5          pages 2 through 15 inclusive,  was taken by me





 6          stenographically and thereafter under my direction was





 7          reduced to typewriting and is  a true record of the testimony





 8          of the proceedings to the best of my ability.





 9





10                    Dated at Bourne, Massachusetts, this llth





11          day of December, 1997.





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                     MARY E. PHILLIPS

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                                            APPENDIX E


                     MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL PROTECTION



These 6 AOCs are located within an approximate 800 acre area at the extreme southeast portion of the MMR
and two of the AOCs extend south of the base boundary toward Ashumet and Johns Ponds. AFCEE plans to
conduct the following remedial actions at the AOCs:

       •      FTA-2/FL-2:  Biosparging with Ambient Air Monitoring;
              PFSA/FS-10/FS-ll:  Biosparging with Off-gas Collection;
              SD-2/FS-6FS-8:  Excavation and Asphalt-batching;
       •      SD-3/FTA-3/CY-4:  Confirmation Sampling with Contingency for Excavation and
              Asphalt-batching;
       •      SD-4:  Excavation and Asphalt-batching;  and
              SD-5/FS-5:  Excavation and Asphalt-batching.

It is the Department's understanding that groundwater contamination associated with those AOCs is being
addressed separately as part the Southeast Regional Groundwater Operable Unit and the Plume Response
Program.

       The Department concurs with the Record of Decision. The Department's concurrence is based upon
representations made to the Department by the AFCEE and assumes that all information provided is
substantially complete and accurate. Without limitation, if the Department determines that any material
omissions or misstatements exist, if new information becomes available, or if conditions at the Study
Area change, resulting in potential or actual human exposure or threats to the environment, the
Department reserves its authority under M.G.L. C.21E, and the Massachusetts Contingency Plan, 310 CMR
40.000 et seg. , and any other applicable law or regulation to reguire further response actions.

       Please incorporate this letter into the Administrative Record for the 6 AOCs. The Department looks
forward to working with you to expedite the cleanup at the MMR. If you have any guestions regarding these
comments, please contact Leonard Pinaud at  (508) 946-2871.



cc:   DEP-SERO
      ATTN: Millie Garcia-Surette, Deputy Regional Director
            Leonard J. Pinaud, Chief, Federal Facilities Remediation Section

      Distributions:    SERO
                        SMB
                        Plume Containment Team
                        Public Information Team
                        Long Range Water Supply PAT
                        Boards of Selectmen
                        Boards of Health

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