EPA  Superfund
       Record of Decision:
                                 PB96-964410
                                 EPA/ROD/R08-96/122
                                 October 1996
       Ellsworth Air Force Base,
       Operable Unit 5, Rapid City, SD
       6/7/1996

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                Final
         Record of Decision for
  Remedial Action at Operable Unit 5
Ellsworth Air Force Base, South Dakota
          United States Air Force
          Air Combat Command
         Ellsworth Air Force Base

               June 1996
                                  Project No.: FXBM947002

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                                                     Final Record of Decision Operable Unit 5
                                                      Ellsworth Air- Force Base, Souti; Dakota
                              TABLE OF CONTENTS
 Chapter                '                                                     Page

 1.0 DECLARATION FOR THE RECORD OF DECISION 	1-1
     1.1 SITE NAME AND LOCATION 	1-1
     1.2 STATEMENT OF BASIS AND PURPOSE 	1-1
     1.3 ASSESSMENT OF THE SITE  	1-1
     1.4 DESCRIPTION OF SELECTED REMEDY	1-1
     1.5 STATUTORY DETERMINATION 	1-1
     1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY 	1-2

 2.0 DECISION SUMMARY	2-1
    2.1 SITE NAME AND LOCATION 	2-1
    2.2 OPERABLE UNIT 5 (OU-5) DESCRIPTION/HISTORY AND REGULATORY OVERSIGHT
        ACTIVITIES  	2-1
        2.2.1     Description/History 	2-1
        2.2.2     Regulatory Oversight Activities	2-2
    2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION  	2-3
    2.4 SCOPE AND ROLE OF RESPONSE ACTION	2-3
    2.5 SITE CHARACTERISTICS 	2-4
        2.5.1     Soils  	2-5
        2.5.2     Ground Water	2-6
        2.5.3     Surface Water/Sediment .	2-6
    2.6 SITE RISK SUMMARY	2-7
        2.6.1     Human Health Risk 	2-7
        2.6.2     Ecological Risks	2-9
    2.7 DESCRIPTION OF ALTERNATIVES	2-9
    2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 	2-10
        2.8.1     Overall Protection of Human Health and the Environment	2-11
        2.8.2     Compliance with ARARs	2-11
        2.8.3     Long-Term Effectiveness and Permanence  	2-13
        2.8.4     Reduction of Toxicitv. Mobility, and Volume Through Treatment  	2-13
        2.8.5     Short-Term Effectiveness	2-13
        2.8.6     Implementability  	2-14
        2.8.7     Cost	2-14
        2.8.8     State Acceptance	2-15
        2.8.9     Community Acceptance	2-16
    2.9 SELECTED ALTERNATIVE	2-16
    2.10    STATUTORY DETERMINATIONS  	2-18
        2.10.1    Protection of Human Health and the Environment 	2-1 "5
        2.10.2    Compliance with ARARs	2-19
        2.10.3    Cost Effectiveness	2-19
        2.10.4    Utilization of Permanent Solutions and Alternative Treatment Technologies to the Extent
                Possible  	2-19
        2.10.5    Preference for Treatment as a Principal Element	2-20
    2.11    DOCUMENTATION OF SIGNIFICANT CHANGES	2-20
3.0  LIST OF ACRONYMS AND ABBREVIATIONS  	3-1
F:\PROJ<6037886\FS\OUi.ROD.FI\AL\OU5ROD.F.\'i         1                                MTV 7. 7996

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                                                        Final Record of Decision Operable Unit 5
                                                          Ellsworth A ir Force Base. South Dakota
                                     APPENDICES
 Appendix A     Figures
 Appendix B     Responsiveness Summary
                                   LIST OF FIGURES
 Figure 2-1       Area Location Map
 Figure 2-2       Site Map
 Figure 2-3       Operable Unit 5
F:\PROM037886\FS\OU5.ROD\FIKAL\OU5ROD.FSL         11                                  Mm 7, 1996

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                                                     Final Record of Decision Operable Unit 5
                                                      Ellsworth Air Force Base, South Dakota
                1.0 DECLARATION FOR THE RECORD OF DECISION

 1.1  SITE NAME AND LOCATION

     •   Operable Unit 5 (OU-5), Landfill No. 4 Area, Ellsworth Air Force Base (EAFB),
        National Priority List Site.
     •   Meade and Pennington Counties, South Dakota

 1.2  STATEMENT OF BASIS AND PURPOSE

 This decision document describes EAFB's selected remedial action for Operable Unit 5 (OU-5),
 in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act
 of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986
 (SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).

 This decision is based on the contents of the Administrative Record for OU-5, EAFB. The US
 Environmental Protection Agency (EPA) and the South Dakota Department of Environment and
 Natural Resources (SDDENR) concur with the selected remedial action.

 1.3 ASSESSMENT OF THE SITE

 Actual or threatened releases of hazardous substances from OU-5, if not addressed by
 implementing the response action selected in this Record of Decision (ROD), may present an
 imminent and substantial endangerment to public health, welfare, or the environment.

 1.4 DESCRIPTION OF SELECTED REMEDY

 Twelve potentially contaminated areas, or operable units, have been identified at EAFB. This
 ROD is for a remedial action at OU-5.

 The selected alternative, Covering, includes the following major components:

    •   Placing a soil cover capable of sustaining perennial vegetation over the landfill
        area;

    •   Institutional controls for the landfill area;

    •   Long-term ground-water monitoring; and, long-term maintenance  of soil cover.

 1.5 STATUTORY DETERMINATION

The selected remedy is protective of human health and the environment, complies with Federal
 and the State of South Dakota requirements that are legally applicable or relevant and appropriate
to the remedial action and is cost-effective. This remedy utilizes permanent solutions and
alternative treatment (or resource recovery) technologies, to the maximum extent practicable for
OU-5. However, because treatment of the principal threats of the OU was not practicable, this

F:\PROJ\6037886\FS\OU5.ROD\FINAL\OU5RODJWL        1-1                              June 10, 1996

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                                                      Final Record of Decision Operable Unit 5
                                                       Ellsworth Air Force Base, South Dakota
 remedy does not satisfy the statutory preference for treatment as a principal element. The size of
 the landfill and the fact that there are no apparent onsite hot spots that represent major sources of
 contamination precludes a remedy in which contaminants could be excavated and treated
 effectively.

 Because this remedy will result in low levels of hazardous substances remaining onsite beneath the
 landfill cover area, 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.

 1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
                                                       /?
 BRETT M. DULA                                      Date
 Lieutenant General, USAF
 Vice Commander
JACK W. MCGRAW                                   Date
Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary                          Date
Department of Environment and Natural Resources
State of South Dakota
F:\PROJ\603788S^S\OUSJtOD\Fl\AL\OU5RODJ:NL         1-2                              June 10, 1996

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                                                     Final Record of Decision Operable Unit 5
                                                      Ellsworth Air Force Base, South Dakota
               1.0 DECLARATION FOR THE RECORD OF DECISION

 1.1  SITE NAME AND LOCATION

     •   Operable Unit 5 (OU-5), Landfill No. 4 Area, Ellsworth Air Force Base (EAFB),
        National Priorities List Site.
     •   Meade and Pennington Counties, South Dakota

 1.2  STATEMENT OF BASIS AND PURPOSE

 This decision document describes EAFB's selected remedial action for Operable Unit 5 (OU-5),
 in accordance with the Comprehensive Environmental Response, Compensation, and Liability
 Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of
 1986 (SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan
 (NCP).

 This decision is based on the contents of the Administrative Record for OU-5, EAFB. The US
 Environmental Protection Agency (EPA) and the South Dakota Department of Environment and
 Natural Resources (SDDENR) concur with the selected remedial action.

 1.3 ASSESSMENT OF THE SITE

 Actual or threatened releases of hazardous substances from OU-5, if not addressed by
 implementing the response action selected in this Record of Decision (ROD), may present an
 imminent and substantial endangerment to public health,  welfare, or the environment.

 1.4 DESCRIPTION OF SELECTED REMEDY

 Twelve potentially contaminated areas, or operable units, have been identified at EAFB. This
 ROD is for a remedial action at OU-5.

 The selected alternative, Covering, includes the following major components:

    •   Placing a soil cover capable of sustaining perennial vegetation over the landfill
        area;

    •   Institutional controls for the landfill area;

    •   Long-term ground-water monitoring; and, long-term maintenance of soil cover.

 1.5 STATUTORY DETERMINATION

The selected remedy is protective of human health and the environment, complies with Federal
and the State of South Dakota requirements that are legally applicable or relevant and appropriate
to the remedial action and is cost-effective. This remedy  utilizes permanent solutions and
alternative treatment (or resource recovery) technologies, to the maximum extent practicable for


F:\PROJ\6037886\FS\OU5.ROD\FINAL\OU5ROD.FNL       1-1                               May 7, 1996

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                                                      Final Record of Decision Operable Unit 5
                                                       Ellsworth Air Force Base. South Dakota
 O'  '. However, because treatment of the principal threats of the OU was not practicable, this
 R    y does  i satisfy the statutory preference for treatment as a principal element. The size of
 ti    ;dfill ai..: the fact that there are no apparent onsite hot spots that represent major sources of
 cor, . rnination precludes a remedy in which contaminants could be excavated and treated
 effectively.

 Because this remedy will result in low levels of hazardous substances remaining onsite beneath
 the landfill cover area, 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.

 1.6  SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
BRETT M. DULA                                      Date
Lieutenant General, USAF
Vice Commander
                                                       C
JACK W. MCGRAW                                  Dale
Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary                           Date
Department of Environment and Natural Resources
State of South Dakota
F:\PROJ\6037886\FS\OU5.RO' 'HN4L\OV5ROD.FNL        1-2                                May 7, 1996

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                                                     Final Record of Decision Operable Unit 5
                                                      Ellsworth Air Force Base. South Dakota
               1.0 DECLARATION FOR THE RECORD OF DECISION

 1.1  SITE NAME AND LOCATION

     •   Operable Unit 5 (OU-5), Landfill No. 4 Area, Ellsworth Air Force Base (EAFB),
        National Priorities List Site.
     •   Meade and Pennington Counties, South Dakota

 1.2  STATEMENT OF BASIS AND PURPOSE

 This decision document describes EAFB's selected remedial action for Operable Unit 5 (OU-5),
 in accordance with the Comprehensive Environmental Response, Compensation, and Liability
 Act  of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of
 1986 (SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan
 (NCP).

 This decision is based on the contents of the Administrative Record for OU-5, EAFB. The US
 Environmental Protection Agency (EPA) and the South Dakota Department of Environment and
 Natural Resources (SDDENR) concur with the selected remedial action.

 1.3  ASSESSMENT OF THE SITE

 Actual or threatened releases of hazardous substances from OU-5, if not addressed by
 implementing the response action selected in this Record of Decision (ROD), may present an
 imminent and substantial endangerment to public health, welfare, or the environment.

 1.4 DESCRIPTION OF SELECTED REMEDY

 Twelve potentially contaminated  areas, or operable units, have been identified at EAFB. This
 ROD is for a remedial action at OU-5.

 The  selected alternative, Covering, includes the following major components:

    •   Placing a soil cover capable of sustaining perennial vegetation over the landfill
        area;

    •   Institutional controls for the landfill area;

    •   Long-term ground-water monitoring; and, long-term maintenance of soil cover.

 1.5 STATUTORY DETERMINATION

The selected remedy is protective of human health and the environment, complies with Federal
and the State of South Dakota requirements that are legally applicable or relevant and appropriate
to the remedial action and is cost-effective. This remedy utilizes permanent solutions and
alternative treatment (or resource  recovery) technologies, to the maximum extent practicable for


F:\PROJ\6017886\FS\OU5ROD\F1SAL\OU5ROD.FNL       1-1                               May 7. 1996

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                                                      Final Record of Decision Operable Unit 5
                                                        Ellsworth Air Force Base, South Dakota
 OU-5. However, because treatment of the principal threats of the OU was no-  racticable, this
 remedy does not satisfy the statute;  preference for ireatment as a principal e;  'nent. The size of
 the landfill and the fact that there are no apparent onsite hot spots that represen. major sources of
 contamination precludes a remedy in which contaminants could be excavated and treated
 effectively.

 Because this remedy will result in low levels of hazardous substances remaining onsite beneath
 the landfill cover area, 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.

 1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
BRETT M. DULA
Lieutenant General, USAF
Vice Commander
Date
JACKW. MCGRAW
Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
Date
NETTIE H. MYERS^Secretary
Department of Environment and Natural Resources
State of South
Date
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                                         1-2
                     May 7, 1996

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                                                        Final Record of Decision Operable Unit 5
                                                         Ellsworth Air Force Base, South Dakota
                              2.0 DECISION SUMMARY

 2.1 SITE NAME AND LOCATION

 EAFB is a U.S. Air Force Air Combat Command (ACC) installation located 12 miles east of
 Rapid City, South Dakota, and adjacent to the small community of Box Elder (Figure 2-1).

 EAFB covers approximately 4,858 acres within Meade and Pennington counties and includes
 runways and airfield operations, industrial areas, and housing and recreational facilities
 (Figure 2-2). Open land, containing a few private residences, lies adjacent to EAFB on the north,
 south, and west, while residential and commercial areas lie to the east of the Base.

 2.2 OPERABLE UNIT 5 (OU-5) DESCRIPTION/HISTORY AND REGULATORY
     OVERSIGHT ACTIVITIES

 2.2.1    Description/History

 Ellsworth Air Force Base (EAFB) was officially activated in July 1942 as the Rapid City Army
 Air Base, a training facility for B-17 bomber crews. It became a permanent facility in 1948 with
 the 28th Strategic Reconnaissance Wing as its host unit. Historically, EAFB has been the
 headquarters of operations for a variety of aircraft, as well as the Titan I Intercontinental Ballistic
 Missile, and the Minuteman I and Minuteman II missile systems. The  Air Force has provided
 support, training, maintenance, and/or testing facilities.  Presently, the 28th Bombardment Wing
 (B-1B bombers) is the host unit of EAFB.

 Operable Unit 5 (OU-5) is the current designation for the area surrounding and including Landfill
 No. 4, a 10-acre site located near the northern perimeter of EAFB (Figure 2-3). From the 1940s
 through 1990, Landfill No. 4 was used primarily for the disposal of construction demolition and
 hardfill materials; however, reports and visual observations from previous installation restoration
 program (IRP) studies noted that this site was also used for general refuse and drum disposal.
 Numerous empty unlabeled drums as well as empty historic investigation derived waste (IDW)
 drums were observed at the landfill during the 1993/95 remedial investigation (RI). The Base
 commander terminated waste disposal activities at this landfill after 1990.

 Topographically, the northern portion of Landfill No. 4 dips steeply to the north-northwest. The
 eastern portion of the OU dips less steeply to the south and southeast. Several incised valleys
 exist to the north and east of Landfill No. 4.  These valleys carry storm-water runoff off-Base,
 north and northeast of OU-5 into several unnamed ephemeral tributaries of Elk Creek, which is
 north of the Base boundary.  The southern portion of the landfill slopes slightly to the south,
 while southwest of the landfill the topography is fairly level with a slight rise associated with a
 Base perimeter service road.  While part of the landfill has an existing soil cover that is
 vegetated, portions of the former disposal  area contain exposed landfill materials.

The uppermost geologic deposits at OU-5  are predominantly silt and clay, underlain in places by
coarse sand and gravel.  These deposits are typically thicker on terraces and drainage slopes (25
to 35 feet) and thinner in drainage bottoms (2 to 5 feet). Where present, gravels are usually
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                                                        Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
 deposited directly on the Pierre Shale and range in thickness from less than 2 feet to more than 20
 feet. Depth to shallow ground water at OU-5 ranges from approximately 12 to 36 ft.

 The shallow aquifer at EAFB is considered a potential drinking water source and possibly
 discharges to the surface. The ground water is classified as having a beneficial use as a drinking
 water supply suitable for human consumption (ARSD Chapter 74:03:15, Groundwater Quality
 Standards).

 Deeper bedrock aquifers also exist beneath EAFB. These deeper aquifers are separated from the
 shallow aquifer by 800 feet of impermeable clays and silts. In the past, EAFB utilized these deeper
 aquifers for its water supply. Presently, EAFB obtains its potable water from the Rapid City
 Municipal Distribution System.

 2.2.2    Regulatory Oversight Activities

 Environmental investigation activities at EAFB were initiated by the Air Force in 1985 through an
 IRP Phase I Installation Assessment/Records Search and Phase II, Confirmation/ Quantification.
 The Phase I study, dated September 1985, identified a total of 17 locations at EAFB where
 releases involving hazardous substances potentially occurred.

 In Phase II of the IRP investigation, field activities included soil vapor surveys, geophysical
 surveys, surface and subsurface  soil sampling, ground-water sampling, ground-water hydrologic
 testing, and ecological investigations.

 On August 30, 1990 (55 Federal Register 35509), EAFB was listed on the U.S. EPA's National
 Priority List (NPL). A Federal Facility Agreement (FFA) was signed in January 1992 by the Air
 Force, EPA, and the State of South Dakota (State) and went into effect on April  1, 1992.  The
 FFA establishes a procedural framework and schedule for developing, implementing, and
 monitoring appropriate response actions for EAFB in accordance with the Comprehensive
 Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by
 the Super-fund Amendments and Reauthorization Act of 1986 (SARA), and the National Oil and
 Hazardous  Substances Pollution Contingency Plan (NCP). It also states the oversight procedures
 for EPA and the State to ensure Air Force compliance with the specific requirements. The FFA
 identified 11 site-specific operable units (OUs) and a Basewide ground-water OU. The Basewide
 ground-water OU is primarily used to address contaminated ground water that was not addressed
 during an investigation of a site-specific operable unit.

 Listing on the NPL and execution of the FFA required the Air Force to perform a remedial
 investigation/feasibility study (RI/FS) to investigate the 12 OUs. In 1993 and 1994, an extensive
RI field program was conducted to characterize conditions at OU-5. The program included
 drilling and sampling of boreholes, installation of monitoring wells, ground-water sampling,
 geotechnical analysis of soil samples, ecological evaluation, assessment of human health risks, and
 review and compilation of previous IRP investigations. Collection and laboratory analysis of soil,
ground water, surface water, and sediment samples were included in the RI field program.
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                                                       Final Record of Decision Operable Unit 5
                                                        Ells-worth Air Force Base. South Dakota
 2.3  HIGHLIGHTS OF COMMUNITY PARTICIPATION

 Community relations activities that have taken place at EAFB to date include:

         FFA process. After preparation of the FFA by the USAF, EPA, and SDDENR, the
         document was published for comment. The FFA became effective April 1, 1992.

     •    Administrative Record. An Administrative Record for information was established in
         Building 8203 at EAFB. The Administrative Record contains information used to
         support USAF decision-making. All the documents in the Administrative Record are
         available to the public.

     •    Information repositories. An Administrative Record outline is located at the Rapid
         City Library (public repository).

     •    Community Relations Plan (CRP). The CRP was prepared and has been accepted by
         EPA and the State of South Dakota and is currently being carried out. An update to this
         plan will be prepared in 1996.

     •    Restoration Advisory Board (RAB). The RAB has been formed to facilitate public
         input in the cleanup and meets quarterly. In addition to USAF, EPA, and South Dakota
         oversight personnel, the RAB includes community leaders and local representatives
         from the surrounding area.

     •    Mailing list. A mailing list of all interested parties in the community is maintained by
         EAFB and updated regularly.

     •    Fact sheet. A fact sheet describing the status of the IRP at EAFB was distributed to the
         mailing list addressees in 1992.

     •   Open house. An informational meeting on the status of the IRP and other
        environmental efforts at EAFB was held on May 6,  1993. An open house was held
        November 16, 1995 in conjunction with the Restoration Advisory Board meeting.
        Information on the status of environmental efforts at EAFB was provided at the open
        house.

   _•   Newspaper articles. Articles have been written for the Base newspaper regarding IRP
        activity.

    •   Proposed Plan. The proposed plan on this action was distributed to the mailing list
        addressees for their comments.

A public comment period was held from December 28, 1995 to January 26,  1996. and a public
meeting was held on January 11, 1996.  At this meeting, representatives from EAFB answered
questions about the remedial action. A response to the comments received during this period is
included in the Responsiveness Summary, which is part of this Record of Decision (ROD).


F PROJ.60rsS6\FS\OL: ROD\F1\'AL\OU5RODF\'L        2-3                                Mm 7. 1996

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                                                       Final Record of Decision Operable Unit 5
                                                        Ellsworth Air Force Base, South Dakota
 "  -is ROD is based on the contents of the Administrative Record for OU-5, in accordance with
 •   ^CLA, as amended by SARA, am  ne NCP. The RI/FS reports and the Proposed Plan for
 Ul>5 provide inforjnation about OU-  and the selected remedy. These documents are available
 at the Information Repositories at EAi;B and the Rapid City Public Library.

 2.4 SCOPE AND ROLE OF RESPONSE ACTION

 The FFA identified 11 potential source area operable units (OUs) as well as a Base-wide
 ground-water operable unit. The  12 operable units are identified as follows:

        OU-1       Fire Protection Training Area
        OU-2       Landfills Nos. 1 and 6
        OU-3       Landfill No. 2
        OU-4       Landfill No. 3
        OU-5       Landfill No. 4
        OU-6       Landfill No. 5
        OU-7       Weapons Storage Area
        OU-8       Explosive  Ordnance Disposal Area (Pramitol Spill)
        OU-9       Old Auto Hobby Shop Area
        OU-10      North Hangar Complex
        OU-11      Base-wide Ground Water
        OU-12      HardfillNo. 1

 This ROD is to document the  selected remedy for the preferred remedial action (RA) at OU-5.
 The remedial action objectives (RAOs) are to reduce the potential risks posed by contaminants in
 surface soils and to reduce the mobility of potential contaminants in the landfill through
 containment.

 The development of alternatives for the landfill was conducted under the EPA's Presumptive
 Remedies Approach [Presumptive Remedies: Policy and Procedures (OSWER Directive
 9355.0-47FS). Presumptive Remedy for CERCLA Municipal Landfill Sites (OSWER Directive
 9355.0-49FS)y.  By using this approach, selecting an alternative for remediation is streamlined
 by using preferred technologies based on historical patterns of remedy selection and the EPA's
 scientific and engineering evaluation of performance data on technology implementation.

 The presumptive remedy stipulates containment as the appropriate remedy for landfills. The
 response action, containment by covering, would remove risk associated with the ingestion,
 dermal contact, and inhalation exposure pathways.  The area over which remediation goals will
 be achieved pfter remediation  is complete is defined as the  area of attainment, and is bac=id on the
 RAOs  For   "-5, the area of attainment consists of the identified boundarie7 of LandfiL No. 4.
 This include    e areas of the landfill not meeting appropriate State of South: »akota closure
 standards.  i\   sures to address leachate or gas collection were not considered since identified
wastes placed .n the landfill are not likely to produce significant amounts of gas, nor does the
waste typify that which would normally be associated with leachate production.
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                                                       Final Record of Decision Operable Unit 5
                                                         Ellsworth Air Force Base, South Dakota
 2.5 SITE CHARACTERISTICS

 This section describes the presence and distribution of contaminants at OU-5 as a result of past
 activities.

 2.5.1    Soils

     Soil Vapor

 A total of 150 soil vapor samples were collected within the landfill boundary and analyzed
 during the field investigation at OU-5. From these samples, three volatile organic compounds
 (VOCs), 1,1,1,-tetrachloroethane (TCA), methylene chloride, and cis-l,2-dicholoroethene, were
 each detected once, trichloroethylene (TCE) was detected twice, and perchloroethylene (PCE)
 was detected in six samples.

     Volatile Organic Compounds (VOCs)

 Eight soil samples were analyzed for VOCs during the RI. These samples were collected out of
 the fill and downgradient from the landfill. There were no VOCs reported from surface or
 capillary fringe (subsurface) samples collected at OU-5.

     Semivolatile Organic Compounds (SVOCs)

 Nine separate SVOCs were  reported from the eight soil samples from OU-5.  Surface soil
 samples had reported concentrations of eight different polycyclic aromatic hydrocarbons (PAHs)
 at estimated values (48 micrograms per kilogram [//g/kg] to 250 /zg/kg), which are below the
 sample quantitation limit. No PAHs were .reported in capillary fringe soil samples. The source
 of the reported PAHs is considered a result of disposal of fill over the north edge of the landfill
 area.

     Total Petroleum Hydrocarbons (TPH) as Jet Fuel

 Eight soil samples were analyzed for TPH as jet fuel (JP-4). Jet fuel was reported in one surface
 soil sample at a concentration of 190 milligrams per kilogram (mg/kg).

     Pesticides

 Two pesticides (endrin and heptachlor epoxide) were reported from the eight samples analyzed.
 The pesticides were detected from a single surface soil sample at levels below quantitation limits.
No pesticides were reported in the capillary fringe soil samples.

    Inorganic Contaminants

Four samples from OU-5 were sampled for inorganics. Manganese, potassium, and silver were
reported at values greater than the background range. The risk assessment indicated that no
unacceptable risk exists for these inorganic compounds.
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                                         2-5
May 7, 7995

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                                                       Final Record of Decision Operable Unit 5
                                                        Ellsworth Air Force Base, South Dakota
 2.5.2    Ground Water

     Volatile Organic Compounds (VOCs)

 Six monitoring wells were sampled for VOCs at OU-5. Four VOCs were detected in the
 ground-water samples.  Three of the four detected VOCs were from a sample from a single well
 from which samples were deemed to be non-reportable according to the Final Sampling and
 Analysis Plan, Volume II: Quality Assurance Project Plan (QAPP). The fourth VOC was
 reported at an estimated value below the sample quantitation limit.  There were no exceedances of
 federal MCLs or state ground water quality standards.

     Semivolatile Organic Compounds (SVOCs)

 The most frequently detected SVOC, bis(2-ethylhexyl) phthalate, was detected twice at a
 maximum concentration of 6.0 micrograms per liter (ug/L), however,  bis (2-ethylhexyl) phthalate
 was also reported in the associated laboratory blank at a concentration above EPA usability
 criteria values identified in the QAPP and is therefore not considered reportable.

     TPH (Jet Fuel)

 Jet fuel was reported in one sample at a concentration of 100 ng/L.

     Pesticides/Polychlorinated Biphenyls (PCBs)

 No pesticides or PCBs were reported from the five locations sampled at OU-5.

    Inorganic Contaminants

 Four wells were sampled for inorganic contaminants at OU-5. Thirteen inorganics were reported
 at concentrations exceeding the background range. The risk assessment indicated that no
 unacceptable risk exists for these inorganic compounds.


    2.5.3   Surface Water/Sediment

 One surface water sample was analyzed for VOCs, SVOCs, pesticides/PCBs, and inorganics.
 One VOC and one tentatively identified SVOC were reported from this sample. No pesticides or
 PCBs were reported.  Eleven inorganics were reported.

 One sediment sample  was also analyzed for VOCs, SVOCs, pesticides/PCBs, and inorganics.
 One VOC and two SVOCs were reported from this sample. No pesticides or PCBs were
 reported. Twenty inorganics were reported.

 As there was only a single sample collected for surface water and sediment, a site mean and upper
 confidence limit could not be calculated.  The source of the reported inorganics is considered a
 result of both landfill activity and naturally-occurring geologic deposits.

F:\PROJ\60378a&FS\OUS.ROD\FINAL\OU5RODJ:NL        2-6                              June 5, 1996

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                                                         Final Record of Decision Operable Unit 5
                                                           Ellsworth A ir Force Base. South Dakota
 2.6  SITE RISK SUMMARY
 2.6.1    Human Health Risks
                                 Risk Assessment Process
 The assessment of human health risks for this OU considered the following topics:

     (1)  Contaminants of concern (COCs) in ground-water, surface water, sediment, and soil
         samples taken at OU-5;

     (2)  Current and future land-use conditions;

     (3)  Potential environmental pathways by which populations might be exposed;

     (4)  Estimated exposure point concentrations of COCs;

     (5)  Estimated intake levels of the COCs;

     (6)  ToxicityoftheCOCs;and

     (7)  Uncertainties in the assessments of exposure, toxicity, and general risks.

Noncarcinogenic and carcinogenic risks were calculated for the following four potential exposure
groups:

     (1)  Current adult trespasser who  ingests surface soil;

     (2)  The future child/adult living onsite who ingests surface soil;

     (3)  The future adult living onsite who ingests and showers with shallow ground water;

     (4)  Future adult construction workers who excavate onsite for building residences.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment,
and air. The risk assessment evaluated potential effects on human health posed by exposure to
contaminants within OU-5. Carcinogenic risks were estimated as the incremental probability of
an individual developing cancer over a lifetime as a result of exposure to a potential cancer
causing chemical. The acceptable risk range expressed as a  probability is one cancer incident in
ten thousand people to one cancer incident in a million people. This level of risk is also denoted
by 1  x 10"4 to 1 x 10'6. Risks within the acceptable risk range may or may not warrant remedial
action depending upon site-specific circumstances. Risks below this range cannot be
differentiated from the background occurrence of cancer in  human populations. Risks calculated
in a risk assessment are potential risks and are excess (i.e., over background) cancer risks due to
exposure from contaminants at the OU.
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                                                         Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
 Noncarcinogenic health risks are evaluated using a hazard index. If the hazard index is less than
 or equal to one, the contaminant concentration is considered an acceptable level and generally
 assumes that the human population may be exposed to it during a 30-year period without adverse
 health effects.

                                 Risk Assessment Results

 The risk assessment for OU-5 indicated that the carcinogenic risk was within the acceptable risk
 range of 1 x 10~4 to 1 x 10"6.  Part of the site risk present at OU-5 includes risk from exposure to
 surface soil contaminants from within the landfill.  Due to the heterogeneity of the landfill
 contents, uncertainty is associated with the calculated risk values for the surface soil.

 The risk assessment for OU-5 indicated that there were no noncarcinogenic risks resulting in an
 HI above 1.0.       •

 Results of the risk assessment indicated shallow ground water and surface water were not media
 of current concern. Therefore, remedial action is  not warranted for the ground water and surface
 water at this time.  The ground water at OU-5 will still be retained as part of the Base-wide
 ground water evaluation for OU-11.

                                     Risk Summary

 Remedial action is warranted for the landfill based on the  potential risk to human health from
 future releases of unidentified hazardous substances in the landfill. Contaminants in the landfill
 may leach downward to contaminate the underlying ground water. Off-Base residents may then
 ingest or come in contact with the contaminated ground water. Also, the surface of the landfills
 may erode, thus exposing off-Base residents to contaminants in both surface  water and air. Due
 to the potential  heterogeneity of the waste materials present within the landfill, uncertainty is
 associated with the calculated risk values for surface soil.

 Rather than attempting to gain more certainty in the risk assessment for the landfill contents, the
 Air Force utilized guidance developed by EPA titled Presumptive Remedy for CERCLA
 Municipal Landfill Sites (OSWER Directive 9355.0-49FS).  The presumptive remedy for
 landfills is onsite containment of landfill contents. Using  the presumptive remedy strategy, a
 quantitative risk assessment is not necessary to evaluate whether the containment remedy
 addresses all exposure pathways and contaminants potentially associated with a landfill. Rather,
 all potential exposure pathways can be  identified using the conceptual site model and compared
 with the pathways  addressed by the presumptive remedy.  Containment of the landfill contents
 addresses exposure pathways and risks  normally associated with landfills. The contaminant
 exposure pathways for the potential risks at OU-5 include  (1) direct physical contact with the
 landfill  contents, and (2) consumption or contact  with ground water that is or may become
 contaminated.

 Actual or threatened releases of hazardous substances from OU-5, if not addressed by
 implementing the response action selected in this Record of Decision (ROD), may present an
 imminent and substantial endangerment to public health, welfare, and the environment.
F \PROA603-SS6tfS\OC: ROD F!\Al\OL5ROD.F,\'L        2-8                                 Mav21,1996

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                                                         Final Record of Decision Operable Unit 5
                                                          Ellsworth A ir Force Base. South Dakota
 2.6.2    Ecological Risks

 An ecological risk evaluation of OU-5 was based on a combination of data and literature reviews,
 field and laboratory analyses, analyte evaluation and screening, and preliminary risk screening.
 The pertinent findings are summarized below.

 A variety of animal species may live, forage, or nest in OU-5 habitats. These species include
 various types of invertebrates, amphibians, birds, and mammals. Terrestrial vegetation and soil
 faunal communities do not reveal characteristics that indicate chemical-related impacts. This
 finding is consistent with the relatively low levels of contaminants in the soil.

 Because of the altered natural environment at OU-5, rare, threatened, or endangered species, are
 unlikely to utilize the  area for more than a brief, periodic habitat.  Due to the low levels of
 contaminant concentrations, the contaminants do not pose an unacceptable risk to these species.
 In addition, the limited contact these species would have with the OU-5 area ensures
 unacceptable risk to a single individual will not occur. Chapter 6 of the OU-5 RI gives a detailed
 evaluation of the ecological risk assessment and lists the potential ecological receptors.

 Findings of the RI indicate that the contaminants at OU-5 are not altering the ecology to
 noticeable levels. A Base-wide ecological risk assessment will be conducted as part of OU-11,
 and OU-5 will be included in this Base-wide evaluation.

 2.7    DESCRIPTION OF ALTERNATIVES

 Presumptive Remedy for CERCLA Municipal Landfill Sites, (OSWER Directive 9355.3-1 IPS)
 was the basis for the abbreviated feasibility study (FS). The OSWER directive established
 containment of the contamination within the landfill and the collection and treatment of landfill
 gas and contaminated  ground water within the landfill boundary as the presumptive remedy for
 CERCLA municipal landfills.

 Although not specifically identified as a municipal landfill, OU-5 exhibits characteristics that
 make this presumptive remedy applicable. The landfill contents at OU-5 do not have the
 characteristics to produce any significant leachate or gases.  The risk assessment did not identify
 the ground water at OU-5 as a pathway of concern. Though the landfill contents were not
 identified as a source of unacceptable risk to human health, the heterogeneity of the landfill
 contents causes uncertainties in the risk assessment. Therefore, the  presumptive remedy focuses
on containment of the  landfill contents.

 Alternative I - No Action

       •     No Action.

       •     The no  action alternative represents the baseline condition at OU-5 and refers to
             taking no further action at OU-5. It is expected that'any  existing maintenance
             (e.g., grass mowing) would be continued.
F •PKOf.603'SS6\FS\OU5.RODFKAL\OL'SROD^FM        2-9                                 Mav ~, 1996

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                                                         Final Record of Decision Operable Unit 5
                                                          Ellsworth A ir Force Base, South Dakota
 The no action alternative does not meet remedial action objectives for OU-5.

 Alternative 2 - Institutional Controls

        •       Implementing access restrictions.
        •       Restricting future land and ground-water use.
        •       Developing long-term ground-water monitoring.
        •       Developing a long-term maintenance plan for the existing soil cover.
 This alternative does not meet the remedial action objectives for OU-5.

 Alternative  3 - Vegetative Soil Cover

       •       Placing a soil cover capable of sustaining perennial vegetation over the landfill
               area;

       •       Institutional controls for the landfill area;

       •      Long-term ground-water monitoring; and, long-term maintenance of soil cover.

 2.8    SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

 The analysis  of alternatives coupled with the use of the presumptive remedy combine for a
 narrower range of feasible approaches to address remedial activities at OU-5.

 The remedial action objectives for OU-5 are as follows:

       Landfill

       •      Provide protection against direct contact or ingestion of the landfill contents.
       •      Minimize infiltration through the landfill.
       •      Control surface water runoff and erosion of the landfill cover.

 The area of attainment is defined as the area that will achieve the remedial action objectives after
 remediation is completed. The area of attainment for OU-5 is the extent of Landfill No. 4 that is
 approximately 10 acres in size.

 Pursuant to Section 300.430(e)(9)(iii) of the EPA's revised National Contingency Plan, the
 remedial action to be implemented should be selected based upon consideration of nine
 evaluation critei.a. These criteria are as follows:

       1.      Overall protection of human health and environment.
       2.      Compliance with applicable  or relevant and appropriate requirements (ARARs).
       3.      Long-term effectiveness and permanence.
       4.      Reduction of toxicity, mobility, or volume of contamination.
       5.      Short-term effectiveness.


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                                                        Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
        6.     Implementability.
        7.     Cost.
        8.     State acceptance.
        9.     Community acceptance.

 The following sections provide a brief review and comparison of the remedial alternatives
 according the EPA's evaluation criteria.

 2.8.1   Overall Protection of Human Health and the Environment

 The assessment of this criterion considers how the alternatives achieve and maintain protection
 of human health and the environment.

 Alternative 1 (no action) does nothing to reduce risk at OU-5. Alternative 2 (Institutional
 Controls) provides for care of the OU through maintenance of erosional and/or non-vegetated
 areas. Access restrictions would reduce risk by reducing exposure. Alternative 3 (Covering)
 provides containment of the surface soil and the landfill contents. This would eliminate risk
 associated with exposure to soil and the future risk associated with potentially contaminated
 ground water.

 2.8.2   Compliance with ARARs

 Alternatives are assessed under this criterion in terms of compliance with ARARs. Applicable
 requirements include cleanup standards, standards of control and other substantive environmental
 protection requirements, criteria or limitations promulgated under Federal or state laws. These
 laws specifically address a hazardous substance, pollutant, contaminant, remedial action, location
 or other circumstances at a CERCLA site.

 ARARs are grouped into these three categories:

       •      Chemical-Specific ARARs are health or risk-based numerical values or
              methodologies that, when applied to site-specific conditions, result in
              establishment of the amount or concentration that may be found in, or discharged
              to, the environment.

       •      Location-Specific ARARs restrict the concentration of hazardous substances or
              the conduct of activities solely because they are in specific locations such as flood
              plains, wetlands, historic places, and sensitive ecosystems or habitats.

       •      Action-Specific ARARs are usually technology or activity-based requirements or
              limitations on actions taken with respect to hazardous wastes.

State of South Dakota guidelines for petroleum in soils are the only known chemical-specific
ARARs for soil at OU-5.  Detected levels of petroleum-related compounds do not exceed  State
ARARs at OU-5. Ground water at OU-5 is not contaminated above State or Federal MCLs.
Inorganics detected in the one surface water sample collected that were above Federal Ambient
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                                                        Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
 Water Quality Criteria were determined to be naturally occurring and are not considered for
 remediation. There are no State or Federally promulgated standards for chemicals in sediments.

 A summary evaluation of Federal and State ARARs pertinent to this remedial action is provided in
 Table 2-1 at the end of Section 2.0, and a narrative discussion of compliance with ARARs is
 provided below for the alternatives considered.

 Alternative 1 (No Action):

 The No Action alternative does not comply with State solid waste landfill closure requirements.
 The OU-5 RI concluded that ground water has not been adversely affected and has not been a
 potential transport pathway; therefore, ground water ARARs at the OU are met. No permits are
 required for this alternative. However, Alternative 1  does not meet the remedial action objectives
 for OU-5 because an action would not be taken to prevent human contact with surface-soil
 contaminants, and because potential contaminants within the landfill may leach to the ground
 water.

 Alternative 2 (Institutional Controls):

 Alternative 2 does not comply with State of South Dakota solid waste landfill closure
 requirements. The OU-5 RI concluded that ground water has not been adversely affected and has
 not been a potential transport pathway; therefore, ground-water ARARs at the OU are met. No
 Federal or State permits are required for this alternative. However, Alternative 2 does not meet
 the remedial action objectives for OU-5 because an action would not be taken to prevent human
 contact with surface-soil contaminants and because potential contaminants within the landfill may
 leach to the ground water.

 Alternative 3 (Covering):

 Alternative 3 would meet State of South Dakota Waste Management Regulations for the disposal
 of solid waste by providing a two-foot minimum earth cover capable of sustaining perennial
 vegetation; implementing institutional controls including maintaining access control; filling,
 grading, and contouring the site; maintenance of the cover and vegetation; and other
 requirements as set forth in ARSD  Chapter 74:27: 1 5. The State is Federally authorized for the
 Resource Conservation and Recovery Act (RCRA) Subtitle D Municipal Solid Waste Program
 (8 October 1993, 58 FR 52486).

 Long:term ground-water monitoring will  be used to verify continued compliance with Federal
 MCLs (National Primary Drinking Water Regulations, 40 CFR 141.1 1-12) and State  Ground
 Water Quality Standards beyond the boundary of the landfill. By following the presumptive
 remedy approach, the MCLs are not considered ARARs for the ground water within the
 boundaries of the landfill.

 Implementation of the presumptive remedy strategy for landfills has been shown by EPA to meet
 the remedial action objectives by preventing direct contact with landfill contents and ingestion of
 surface soils.
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                                                         Final Record of Decision Operable Unit 5
                                                           Ellsworth Air Force Base, South Dakota
 2.8.3   Long-Term Effectiveness and Permanence

 The assessment of this criterion included long-term effectiveness of alternatives in maintaining
 protection of human health and the environment after response action objectives have been met.

 Alternative 1 would not provide additional effectiveness or permanence in reducing the potential
 for direct contact or ingestion of the surface soil or sediments. No further controls for the OU
 would be developed under this alternative.

 Alternative 2 would be effective in reducing direct exposure to landfill contents by restricting
 access to the site (in addition to the general EAFB access restrictions).  This alternative would
 not reduce the potential impacts to ground water from percolation of rainwater through those
 areas of the landfill not adequately covered. Long-term maintenance of the existing cover and
 vegetation at Landfill No. 4 would somewhat reduce the potential for erosion of the existing
 cover. Permanency and reliability of these controls would be evaluated through long-term
 ground-water monitoring and maintenance of the existing landfill soil cover. Uncertainties  exist
 for the ability to provide long-term access restrictions.

 Alternative 3 would offer the highest level of long-term effectiveness in reducing risk due to
 exposure of contaminants in the landfill, and would significantly reduce the potential for landfill
 contents to impact ground-water quality. Access restrictions would deter unauthorized access to
 the site.  Installing an .earth cover would effectively contain the contents of the landfill and
 reduce the potential for exposure to contaminants. Providing positive drainage off the site would
 also reduce ponding on the landfill and further reduce the potential for infiltration. Erosion
 would be limited by the development and maintenance of vegetation. Permanency and
 reliability would be evaluated through  long-term ground-water monitoring and maintenance of
 the existing landfill cover and vegetation. Future land uses will be allowed for the landfill only if
 the integrity of the landfill cover is not compromised.

 2.8.4  Reduction of Toxiciry, Mobility-, and Volume Through Treatment

 The assessment of this criterion involves considering the anticipated performance of specific
 treatment technologies an alternative may employ.

 Alternative  1 would not provide for the reduction of toxicity, mobility, or volume of the
 chemicals of concern in the surface soil and sediment. Alternative 2 would reduce the mobility
 of contaminants in surface soils through long-term erosion maintenance of existing cover soils.
 Alternative 3 reduces infiltration and potential wind-blown contamination through containment;
 however, treatment of the contamination is not being proposed.

 2.8.5   Short-Term Effectiveness

The assessment of this criterion considers the effectiveness of alternatives in maintaining
protection of human health and the environment during the construction of a remedy until
 response action objectives have been met.
F PROJ603-S36FS\OL'5.ROD'F!\AL'
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                                                         Final Record of Decision Operable Unit 5
                                                           Ellsworth Air Force Base, South Dakota
 It is not anticipated that the_proposed alternatives vould significantly impact worker or
 community health and safety during the implemen   'on period.  Alternatives 2 and 3 may impact
 community and worker health and safety through c.  .t emissions during the initial construction
 phase.  The impact could be minimized through du^c mitigation.

 Alternatives 2 and 3 may create a short-term increase in risk during remedial activities due to the
 inhalation exposure pathway.  Disturbance of surface soil through earthwork and soil disturbance
 would result in exposure to workers.  Dust mitigation during these activities would minimize this
 potential impact. Alternative 3 would present the potential for temporarily increasing the
 opportunity for erosion of the disturbed soils, although erosion and sediment control measures
 will help to minimize this adverse impact.

 2.8.6   Implementability

 The assessment of this criterion considers the administrative and technical feasibility of
 implementing the alternatives and the availability of necessary goods and services for
 implementation of the response action.

 Alternative  1 would not be difficult to implement since, besides long-term monitoring using
 existing monitoring wells, no further action would be undertaken.

 Alternative 2 requires no special or unique activities and could be implemented using locally
 available materials and contractors. Long-term monitoring would indicate whether additional
 action would need to be implemented in the future.

 Alternative 3 could be implemented with standard construction equipment, materials, and
 methods.  The availability of an on- or off-Base supply of cover material will require further
 consideration during the Remedial Design Analysis.  Land use (or deed) restrictions can be
 implemented at EAFB by various administrative means.

 2.8.7  Cost

 The assessment of this criterion considers the capital and operation and maintenance (O&M)
 costs associated with each alternative.  Alternatives are evaluated for cost  in terms of both capital
 costs and long-term O&M costs necessary to ensure continued effectiveness of the alternatives.
 Capital costs include the sum of the direct capital costs (materials and labor) and indirect capital
 costs (engineering, licenses, permits).  Long-term O&M costs include labor, materials, energy,
 equipment replacement, disposal,  and sampling necessary to ensure the future effectiveness of
 the alternative.  The objective of the cost analysis is to eliminate those alternatives that do not
 provide measurably greater protection of human health and the environment for additional costs
 that may be incurred.  Cost estimates do nc>j T :lude yearly escalation adjustments. Final costs
 developed in the Remedial Design will be -:'.;uctured using the Remedial Action Work
 Breakdown structure. A summary of the costs for each alternative is as follows:
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                                                                Final Record of Decision Operable Unit 5
                                                                 Ellsworth Air Force Base, South Dakota
Alternative No. 1 (No Action) _
Total Capital Costs
Total Annual (Sampling/Analysis) Costs
30-Year Present Value for Annual Costs
Annual Cost = $13,500
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value*
SO
SO
so
so
Alternative No. 2 (Institutional Controls)
Total Capital Costs
Total Annual (Sampling/Analysis/O&M2) Costs - Years 1-5
Total Annual (Sampling/Analysis/O&M) Costs - Years 6 -30
30-Year Present Value for Annual Costs
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value*
545,198
570,552
536,752
S71 1,044
5756,242
Alternative No. 3 (Capping)
Total Capital Costs
Total Annual (Sampling/Analysis/O&M) Costs - Years 1-5
Total Annual (Sampling/Analysis/O&M) Costs - Years 6-30
30- Year Present Value for Annual Costs
Years = 30
Discount Rate = 5%
TO TAL30- Year Present Value1
51,063,133
570,552
536,752
5711,044
57,774,777
Notes

        1)      The Total 30 Year Present Value is the sum of the total capital costs and the 30-Year Present
               Value for annual costs.
        2)      Operations & Maintenance.

2.8.8   State Acceptance

The assessment of this criterion considered the State's preferences for or concerns about the
alternatives.
F.\PROf,603-386,FS\OU5.ROD\FI^'AL\OL'5ROD.F^•L
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                                                         Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
 The State concurs with the selected remedy. The State provided comments on the remedial
 investigation, feasibility study, Proposed Plan, and this ROD. After incorporating adequate
 responses to the comments into the respective documents, the State concurred with the remedy.

 2.8.9   Community Acceptance

 Comments offered by the public were used to assess the community acceptance of the proposed
 alternative.  The community expressed their concerns about the selected remedy during the public
 comment period. The questions and concerns of the community are discussed in detail in the
 Responsiveness Summary that is Appendix B of the ROD.

 2.9    SELECTED ALTERNATIVE

 Based on the requirements of CERCLA, comparative analysis of the nine criteria, public
 comments, and in consultation with EPA and the State, the Air Force has determined that the
 selected alternative is Alternative 3, Vegetative Soil Covering.  This alternative includes
 institutional controls in conjunction with physical modification of the OU to reduce potential risk.
 Five-year reviews of the remedy will be required because potential contaminants will remain at
 OU-5 following completion of remedial action.

 Major components of Alternative 3 are:

        •      Placing a soil cover capable of sustaining perennial vegetation over the landfill
              area;

        •      Institutional controls for the landfill  area;

        •      Long-term ground-water monitoring; and, long-term maintenance of soil cover.

 Each item is discussed below.

                                 Installation of Soil Cover

 A pre-design study will be conducted to verify the defined limits of the landfill and determine the
 type and extent of cover needed. It is anticipated that a single-layer earth cover, two feet thick
 will be placed over the area of attainment (approximately 10 acres). The cover will  meet State
 landfill closure requirements. The  cover material must be capable of sustaining vegetation.
 Borings drilled during the pre-design study would be used to determine the quantity of material
 required to construct a cover of the required thickness.  The pre-design study would also be used
 to determine the type of cover needed to reduce infiltration of precipitation through the landfill
 and ensure continued compliance with the Federal MCLs and State Ground Water Quality
 Standards.

 The area of attainment will be filled, graded, and contoured to maintain stability, eliminate
 slumping, settling, or ponding of water above previously active disposal areas, and to provide
 positive drainage off the landfill area. Vegetation will be established in areas of OU-5 that are

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                                                          Final Record of Decision Operable Unit 5
                                                           Ellsworth Air Force Base, South Dakota
 under-vegetated and areas disturbed by. new construction and.cover placement to enhance
 evapotranspiration and reduce infiltration and soil erosion.

                                   Institutional Controls

 Institutional controls will be implemented to prevent human exposure to contaminated soil and
 ground water. These controls will include: (1) issuing a continuing order to restrict onsite worker
 access to contaminated soil, and restrict or control temporary construction activities unless proper
 protective equipment is worn; (2) filing a notice with the State of South Dakota to recommend
 denial of water appropriations permit applications to install ground-water wells within the landfill
 boundary and the area of potential contamination; (3) annotating base records in the event of
 property transfer.

 A continuing order would be issued by the Installation Commander to restrict access to or
 disturbance of the landfills as long as Ellsworth AFB owns the property.  Specifically, it would:

           •  Restrict or place limitations on the installation of any new underground utilities or
              other construction activities in the area of the landfills, thus preventing accidental
              exposures to construction workers.

           •  Provide for the use of proper protective equipment, in the event that access
              through the landfill cover is required.

           •  Require that the integrity of the landfill covers are maintained.  Limit future land
              uses to non-intrusive activities only (or activities that will not effect the landfill
              cover).  Maintenance of the landfills will require development of standard '
              operating  procedures (SOPs) to provide for inspections and repairs. To assist with
              the institutional controls, a fence will be placed around the landfill and authorized
              personnel  would have access through a locked gate.  Access would only be
              allowed to perform landfill maintenance and monitoring activities. Warning signs
              will be posted  at the landfill to deter unauthorized access.

    The continuing order also will mandate that, if the landfill covers were ever removed or
    destroyed, the area of attainment will be reevaluated to determine the need for a replacement
    cover or other remedial action.

    Continuing order requirements will be in effect as long as the property is owned by Ellsworth
    AFB. In the case of the sale or transfer of property within OU-5 by the United States to any
    other person or entity, the Air Force will place covenants in the deed that will restrict access
    and prohibit disturbance of the landfill or the remedial action without approval of the United
    States.  These covenants will be in effect until removed upon agreement of the State of South
    Dakota, the U.S. Environmental Protection Agency, and the U.S. Air Force or their
    successors in interest. The Air Force will also include in the deed the covenants required by
    section 120(h)(3) of CERCLA, which include (1) a warranty that the United States will
    conduct any remedial action to be required by law after the date of the transfer; (2) a right of
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                                                         Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
    access in behalf of EPA and the Air Force or their successors in interest to the property to
    participate in any response or corrective action that might be required after the date of
    transfer. The right of access referenced in the preceding sentence shall include the State of
    South Dakota for purposes of conducting or participating in any response or corrective action
    that might be required after the date of transfer.

                          Long-Term Monitoring and Maintenance

    A long-term monitoring program will be developed and implemented during remedial action
    and is subject to approval of both EPA and SDDENR.  Contaminant concentrations in the
    ground water will be monitored to evaluate the effectiveness of the existing landfill cover and
    to determine if the ground-water is being further impacted by the contents of the landfill.

    A maintenance program will be implemented to ensure the long-term integrity on the existing
    landfill conditions that will be maintained.  The maintenance program will include
    development of SOPs to provide for inspections, repairs, and general maintenance of the
    landfills.

    This alternative will meet the remedial action objectives and reduce the potential risk for
    OU-5 by preventing future exposure to contaminants in the surface soils and by reducing the
    mobility of potential contaminants in the landfill.

    For Landfill No. 4, Alternative 3 will achieve significant risk reduction by limiting  exposure
    to landfill  materials and to contaminants present in surface soils and would reduce the
    potential for future movement of contaminants in the ground water beneath the landfill.  The
    selected alternative will be protective of human health and the environment and will comply
    with ARARs.

    2.10  STATUTORY DETERMINATIONS

    This selected remedy meets the statutory requirements of Section 121 of CERCLA  as
    amended by SARA. These requirements include protectiveness of human health and the
    environment, compliance with ARARs, cost effectiveness, and utilization of permanent
    solutions and alternative treatment technologies to the extent practicable.  The statutory
    preference for treatment is not satisfied; however, the selected alternative is the presumptive
    remedy for landfills.  Containment, by definition, does not attempt to reduce the toxicity or
    volume of potentially hazardous materials; rather, it reduces the likelihood of exposure to
    these materials by preventing the movement of materials beyond the boundaries of the
    landfill and preventing direct contact with landfill materials. The selected remedy represents
    the best balance of tradeoffs among th- alternatives considered, with respect to pertinent
    criteria, given the scope of the action.

    The manner in which the selected remedy meets each of these requirements is discussed in
    the sections below.
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                                                         Final Record of Decision Operable Unit 5
                                                       	EllsxioflbJLir Force Base.-South Dakoia-
    2.10.1 Protection of Human Health and the Environment

    Implementation of the presumptive remedy (containment by covering) strategy for landfills
    has been shown by EPA to meet the remedial action objectives and to protect human health
    and the environment by preventing (1) direct contact with landfill contents and (2) ingestion
    of surface soils. Specifically, the covering alternative:

           •       Eliminates exposure to landfill contents by installing an earth cover.

           •       Reduces the potential infiltration of rainwater and leaching of contaminants to
                  the ground water.

           •       Prevents unauthorized access to the area by installing a perimeter fence and
                  restricted access signs.

           •       Provides for long-term  monitoring of ground water to identify potential future
                  risks associated with OU-5.

    2.10.2 Compliance with  ARARs

    Alternative 3 will meet State landfill closure requirements by providing the required amount
    of cover over the landfill, site improvements, access/land and ground-water use restrictions,
    and long-term monitoring. The OU-5  RI concluded that ground water has not been adversely
    affected and has not been a potential transport pathway; therefore, ground water ARARs at
    OU-5 are met.  Additional information about ARAR compliance is contained in
    Section 2.8.2.

    2.10.3 Cost Effectiveness

    The selected remedy provides overall effectiveness in reducing human health risks relative to
    its costs. The presumptive remedy process ensures cost-effective remedies are chosen. The
    chosen landfill cover type  ensures containment of the landfill contents. Site specific
    conditions were used to determine the  type and extent of cover necessary for the landfill.
    Based on the information provided  during the remedial investigation and the predesign study,
    the most effective cover will be installed.

    2.10.4  Utilization of Permanent Solutions and Alternative Treatment Technologies to
           the Extent Possible

    EPA has established that installing  a proper cover has proven effective in containing landfill
    contents. This alternative provides long-term prevention of exposure to potential landfill
    material, prevents unauthorized access, and provides for long-term ground water monitoring
    to detect movement of chemicals from the area.  A five-year review of the selected remedy
    will be performed due to the uncertainty of characterizing landfill contents.  The review will
    be conducted no less than every five years after signing of the ROD to ensure the remedy
    continues to provide adequate protection of human health and the environment. Results of
F:\PROJ\6037886\FS\OL'5.ROD\n\Al\OU5ROD.FKL          2-19                               Mav "  1996

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                                                        Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base. South Dakota
    the review will be used to determine if modification of any or all parts of the selected remedy
    will be required.

    2.10.5 Preference for Treatment as a Principal Element

    Treatment of the landfill contents is not supported based on the findings of the remedial
    investigation for OU-5. No identifiable hot spots were detected that would warrant removal
    and/or separate treatment. The risks associated with OU-5 can be addressed by eliminating
    exposure to the landfill contents by installing a cover and restricting access.

    2.11    DOCUMENTATION OF SIGNIFICANT CHANGES

    The selected action is the same as the preferred alternative presented in the Proposed Plan for
    OU-5 remedial action. There have been no significant changes relative to the Proposed Plan.
F:\PROJ\603~886\F&OL'S.ROD':FI:\AL\Oi'.*ROD.F\L          2-20                               Mm 7, 1996

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TABLE 2-1  EVALUATION OF FEDERAL AND STATE ARARS THAT APPLY TO OU-5, ELLSWORTH AFB, SOUTH DAKOTA
 Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Safe Drinking Water Act
National Primary Drinking
Water Standards
National Secondary
Drinking Water Standards
Maximum Contaminant
Level Goals
Clean Water Act
Water Quality Criteria
Clean Air Act of 1983
National Primary and
Secondary Ambient Air
Quality Standard
Solid Waste Disposal Act as
amended by Resource
Conservation and Recovery Act of
1976
Solid Waste Disposal Facility
Criteria
Citations
42 DSC 300 f, g
40 CFR Part 141.11-12
40CFRPart 143.03
40CTRPart 141.50 & Public
Law No. 99-330, lOOStat. 642
(1986)
33 USC 1251-1376
40 CFR Part 131
42 USC 7401
40 CFR Part 50.1-6, 8,9,1 1,12,
and Appendices A, H, J, K
42 USC 6901
40 CFR Parts 257 and 258
Description

Establishes health-based standards for
public water systems (maximum
contaminant levels)
Establishes aesthetic-based standards for
public water systems (maximum
contaminant levels)
Establishes drinking water quality goals
set at concentrations of unknown or
anticipated adverse health effects with
an adequate margin of safety

Establishes criteria for water quality
based on toxicity to aquatic organisms
and human health

Establishes national primary and
secondary ambient air quality standards
to protect public health and welfare.

Sets forth revised minimum federal
criteria for Municipal Solid Waste
Landfills (MSWLFs) for existing and
new units
ARAR
Type

Chemical
Chemical
Chemical

Chemical

Action


Action
Applicability

Relevant and appropriate for federal
Class II aquifers.
Relevant and appropriate. ' ;
Relevant and appropriate. (
i
i
i
\
I
Relevant and appropriate. Aquifer
may be a federal Class II A '
(discharge to surface water). [
1
i
Applicable [•
E
5
i
i
i
Relevant and appropriate for
addressing landfill closure
performance standards. i

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TABLE 2-1 (Continued)
  Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Land Disposal Restrictions
Guideline.,,. ;;;L Land
Disposal of Solid Waste
Resource Conservation and
Recovery Act of 1976
Hazardous Waste
Management System:
Geneia!
Identification and Listing
of Hazardous Wastes
Standards Applicable to
Generators of Hazardous
Wastes
Standards Applicable to
Transporters of
Hazardous Wastes
Standards for Owners
and Operators of
Hazardous Waste
TSDF's
Citations
40 C? R Part 268
40 CFR Part 24 1.1 00-2 13

40 CFR Part 260
40 CFR Part 261
40 CFR Part 262
40 CFR Part 263
40 CFR Part 264
Description
Identifies hazardous wastes that are
restricted from land disposal and
defines those limited circumstances
under which a prohibited waste may
continue to be land disposed
Establishes requirements and
procedures for the disposal of solid
waste.

Establishes definitions as well as
procedures and criteria for
modification or revocation of any
provision in 40 CFR Parts 260-265
Defines those solid wastes which
are subject to regulations as
hazardous wastes under 40 CFR
Parts 262-265
Establishes standards for generators
of hazardous waste
Establishes standards which apply
to persons transporting hazardous
waste within the U.S. if the
transportation requires a manifest
under 40 CFR Part 262
Establishes standards for acceptable
hazardous waste management.
ARAR
Type
Action
Action

Action
Action
Action
Action
Action
Applicability
Relevant and Appropriate.
Alternatives may include the
disposal of residual waste due to
treatment.
Relevant and appropriate for
meeting landfill closure '
performance guidelines.

Applicable for identifying
hazardous waste during soil
placement at OU-2.
Applicable for identifying
hazardous waste during soil
placement at OU-2.
Applicable to alternatives relating
to removal or offsite transport of
a hazardous material.
Applicable for any transport of
hazardous materials offsite.
Relevant and Appropriate for
performance guidelines for
landfill closure.

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TABLE 2-1  (Continued)
  Applicable or Relevantand Appropriate Federal Standards, Requirements, Criteria and Limitations
  Standard, Requirement, Crkeria or,
  Limitation
          Citations
             Description
    ARAR
     Type
           Applicability
           Standards for Owners and
           Operators of Hazardous
           Waste TSDF's with Interim
           Status
       40 CFR Part 265
Establishes standards for acceptable
hazardous waste management during
interim status.
    Action
Relevant and Appropriate for
performance guidelines for landfill
closure.
  Criteria and Standards for the
  National Pollutant Discharge
  Elimination System
       40 CFR Part 125
Establishes criteria and standards for
technology-based requirements in
permits under the Clean Water Act
   Chemical
Relevant and appropriate.
  Toxic Substances Control Act
      40 CFR Part 761.1
Substances regulated include, but are
not limited to, soils and other materials
contaminated as a result of spills
    Action
Applicable.
  Executive Order No. 11988 on
  Floodplains Management
         42 USC 7401
40 CFR 6.302 (b) & Appendix A
Requires federal agencies to evaluate
the potential effects of actions they may
take in a floodplain to avoid, to the
extent possible, the adverse impacts
associated with direct and indirect
development of a floodplain.
   Location
Applicable.
   Executive Order on Protection of
   Wetlands
       E.G. No. 11,990
40 CFR 6.302(a) & Appendix A
Requires federal agencies to avoid, to
the extent possible, the adverse impacts
associated with the destruction or loss of
wetlands and to avoid support of new
construction in wetlands if a practicable
alternative exists
Action/Location
Applicable.

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TABLE 2-1 (Continued)
  Applicable or Relevant and Appropriate State Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
So n (li Dnkoln Wnstc Management
Regulations
South Dakota Waste Management
Regulations
South Dakota Waste Management
Regulations
South Dakota \\astc Management
Regulations
South Dakota Water Quality
Standards
South Dakota Gi ..uud Water
Standards
South Dakota Surface Water
Quality Standards
South Dakota Remediation Criteria
for Petroleum-Contaminated Soils
Citations
74:26:03:04
74:27:03:11
74:27:09:06
74:27:15
74:03:04:02, 10
74:03:15
74:03:02
74:03:32,33
Description
Establishes requirements for disposal of
hazardous wastes in sanitary landfills
Defines requirements for closure of solid waste
disposal facilities
Defines criteria for permit applications for other
solid waste TSD facilities
Establishes standards for landfill closure and
post-closure monitoring
Defines use of Box Elder Creek and certain
tributaries
Defines ground water classifications by
beneficial use and sets chemical standards
Establishes surface water quality standards.
Establishes requirements for the remediation of
soil contaminated with petroleum products.
ARAR Type
Action
Action
Action
Action
Action
Chemical
Chemical
Chemical
Applicability
Relevant and appropriate.
Relevant and appropriate. '
Relevant and appropriate. '
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.

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                                                      Final Record of Decision Operable Unit 5
                                                       Ellsworth Air Force Base, South Dakota
                  3.0 LIST OF ACRONYMS AND ABBREVIATIONS

 ACC:        Air Combat Command
 AFB:        Air Force Base
 ARARs:      Applicable or Relevant and Appropriate Requirements
 CERCLA:    Comprehensive Environmental Response, Compensation and Liability Act
 COC:        Contaminant of Concern
 CRP:         Community Relations Plan
 EAFB:       Ellsworth Air Force Base
 EPA:         Environmental Protection Agency
 FFA:         Federal Facilities Agreement
 IRP:          Installation Restoration Program
 JP-4:         Jet Propulsion Fuel Number Four; contains both kerosene and gasoline fractions.
 Mg/L:         Micrograms per liter
 Mg/kg:        Micrograms per kilogram
 mg/kg:       Milligrams per kilogram
 NCP:         National Oil and Hazardous Substances Contingency Plan
 NPL:         National Priorities List
 O&M:        Operation and Maintenance
 OU:          Operable Unit
 PAH:         Polynuclear Aromatic Hydrocarbon
 PCB:         Polychlorinated Biphenyl; liquids used as a dielectrics in electrical equipment
 PCE:          Perchloroethylene; liquids used in degreasing or paint removal.
 RAB:         Restoration Advisory Board
 RAO:         Remedial Action Objective
 RI/FS:       Remedial Investigation/Feasibility Study
 ROD:        Record of Decision
 SARA:      Superfund Amendments and Reauthorization Act
 SDDENR:    South Dakota Department of Environment and Natural Resources
 SVOC:      Semivolatile Organic Compound
 TCA:         1, 1,1,-tetrachloroethane
 TCE:         Trichloroethylene
 TPH:         Total Petroleum Hydrocarbon
TSD:         Treatment, storage or disposal sites/methods
 USAF:       United States Air Force
 VOC:        Volatile Organic Compound
F: \PROJ\603 7886\FS\OU5. ROD\F1NAL \OU5ROD. FNL
                                         3-1
May 7, 1996

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                                                             Final Record of Decision Operable Unit 5
                                                              Ellsworth Air Force Base, South Dakota
                                          APPENDIX A


                                            FIGURES
F:\PROJ\60378S6\FS\OU5.ROD\FINAL\OU5ROD.FNL                                               May 7. 1996

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        N
                                                                            MMNtSOTA
                   NORTH DAKOTA
                   	:	'

                  SOUTH  DAKOTA
                                                             ELLSWORTH AFB
                 Ropid Cfty
                                              Scale in Uiln
                                              APPROXIMATE
           ELL-SWORTH
           AIR   FORCE  BASE
                      ELLSWORTH AFB
                    RAPCCflY. SOUTH MKOTA
                          AREA LOCATION  MAP
ROJECT VO
            DESIGNED BY
OWWN BY
   STAFF
                                      CHECXED BT
SCALE
 AS  SHOWN
                                                               DATE
                                                                  SEP 95
PROJECT NO
  60378.93
                                                                                         FORE:
2-1

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in
£
a
or
§i
cr-
o1"
                                                                            OU-5
     OU-1

     OU-2
     OU-3
     OU-4
     OU-5
     OU-6
     OU-7
     OU-8
     OU-9
     OU-10
     OU-11
     OU-12
   OPERABLE UNITS

 FIRE PROTECTION TRAINING
   AREA
 LANDFILLS 1 &  6
 LANDFILL 2
 LANDFILL 3
 LANDFILL 4
 LANDFILL 5
 LOW LEVEL RADIATION WASTE BURIAL AREA
 EXPLOSIVE ORDNANCE DISPOSAL AREA  &. PRAMITOL  SPILL
 OLD AUTO HOBBY SHOP AREA
"NORTH HANGAR  COMPLEX
 BASEWIDE  GROUND WATER
 HARDFILL NO. 1
                EL.USWORTH
                AIR  FORCE   BASE
                                                     ELLSWORTH  AFB
                                                    RAPID CITY. SOUTH DAKOTA
                                                                         SITE LOCATION  MAP
     ROJCCT UCR
                 DESIGNED BY
                               DRAWN BY

                                  STAFF
                                            CHECKED BY
                                                          SCALE
                                                           AS SHOWN
                                                                       DATE
                                                             SEP 95
PROJECT NO

  60378.93
                                                                                                  FIGURE:
2-2

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o
£
 i
UJOT
2 ,_
               LEGEND:
               LANDFILL  NO.
               COVER AREA
               PROPOSED FENCE LOCATION
       	 BASE BOUNDARY FENCE
              TOPOGRAPHIC ELEVATION ABOVE
              MSL -  CONTOUR INTERVAL=10'
              ELLSWORTH
              AIR  FORCE  BASE
 ELLSWORTH AFB
RAPID OTY. SOUTH DAKOTA
           OPERABLE UNIT  5
            LANDFILL NO. 4
    ROJEC7 UCR
               DESIGNED BY
                           DRAWN 8r

                              STAFF
                                      CHECKED BY
     SCALE
      AS SHOWN
                                                              DATE
SEP 95
PROJECT NO

  60378.93
                                                                                      FIGURE
2-3

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                                                        Final Record of Decision Operable Unit 5
                                                         Ellsworth Air Force Base, South Dakota
                                      APPENDIX B


                             RESPONSIVENESS SUMMARY
F-\pnn.MnniHfi\F!&oU5.ROD\FINAL\OU5ROD.FNL                                           May 7, 1996

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                                                      Final Record of Decision Operable Unit 5
                                                       Ellsworth Air Force Base, South Dakota
                                Responsiveness Summary
                          Remedial Action at Operable Unit Five
                          Ellsworth Air Force Base, South Dakota
 1.     Overview

 The United States Air Force (USAF) established a public comment period from December 28, 1995
 to January 27, 1996 for interested parties to review and comment on remedial alternatives considered
 and described in the Proposed Plan for Operable Unit 5 (OU-5). The Proposed Plan was prepared
 by the USAF in cooperation with the U.S. Environmental Protection Agency (USEPA) and the South
 Dakota Department of Environment and Natural Resources (SDDENR).

 The USAF also held a public meeting at 7:30 p.m. on January 11, 1996 in the Box Elder Middle
 School to outline the proposed remedy to reduce risk and control potential hazards at the Operable
 Unit (OU).

 The Responsiveness Summary provides a summary of comments and questions received from the
 community at the public meeting and during the public comment period as well as the USAF's
 responses to public comments.

 The  Responsiveness Summary is organized  into the following sections:

       •      Background on Community Involvement

       •      Summary of Comments and Questions Received During the Public Comment Period
             and USAF Responses

       •      Remaining Concerns

2.     Background on Community Involvement

On August 30, 1990 EAFB was listed on the USEPA's National Priorities List (NPL).  A Federal
Facilities Agreement (FFA) was signed in January 1992 by the Air Force, EPA,  and the State and
went into effect on April 1,  1992. The FFA establishes a procedural framework and schedule for
developing, implementing, and monitoring appropriate response actions for EAFB.
F:\PROM037886\FS\OU5.ROD\F1NAL\OU5ROD.FNL          B-l                              May 7, 1996

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                                                        Final Record of Decision Operable Unit 5
                                                         Ellsworth Air Force Base, South Dakota
 Community relations activities that have taken place at EAFB to date include:

              FFA process.  After preparation of the FFA by the USAF, EPA, and SDDENR, the
              document was published for comment.  The FFA became effective April 1, 1992.

       •      Administrative Record. An Administrative Record for information was established
              in Building 8203 at EAFB. The Administrative Record contains information used to
              support USAF decision-making.  All the documents in the Administrative Record are
              available to the public.

       •      Information repositories.  An Administrative Record outline is located at the Rapid
              City Library (public repository).

       •      Community Relations Plan (CRP).  The CRP was prepared and has been accepted
              by EPA and the State of South Dakota and is currently being carried out. An update
              to this plan will be prepared in 1996.

       •      Restoration Advisory Board (RAB). The RAB has been formed to facilitate public
              input in  the cleanup and meets quarterly.  In addition to USAF, EPA, and  South
              Dakota  oversight personnel, the RAB includes  community  leaders and  local
              representatives from the surrounding area.

       •      Mailing list.  A mailing list of all interested panics in the community is maintained
              by EAFB and updated regularly.

       •       Fact sheet.  A fact sheet describing the status of the IRP  at EAFB was distributed to
              the mailing list addressees in 1992.

       •       Open  house.   An  informational meeting on the  status  of the IRP and  other
              environmental efforts at EAFB was held on May 6, 1993.  An open house was held
              November 16,  1995 in  conjunction with the Restoration Advisory Board meeting.
              Information on the status of environmental efforts at EAFB was provided.

       •       Newspaper articles.  Articles have been written for the Base newspaper regarding IRP
              activity.
F:\PROJ\60m86\FS\OU5.ROD\FlNAL\OV5ROD.FNL         B-2                              May 7, 1996

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                                                         Final Record of Decision Operable Unit 5
                                                          Ellsworth Air Force Base, South Dakota
 The Proposed Plan for this remedial action was distributed to the mailing list addressees for their
 comments and additional copies of the Proposed Plan were available at the January 11, 1996 public
 meeting.  A transcript of comments, questions, and responses provided during the public meeting was
 prepared.

 3.      Summary of Comments and Questions Received During the Public Comment Period and
        USAF Responses

              Part I - Summary and Response to Local Community Concerns

 Review of the written transcript of the public meeting did not indicate community objections to the
 proposed remedial action.  No written comments were received during the public comment period.

              Part II - Comprehensive Response to Specific Technical, Legal and Miscellaneous
              Questions

 The comments and questions below have been numbered in the order they  appear in the written
 transcript of the January 11, 1996 public meeting.

 Comment 1. Mayor Baldwin

       Asked how you can justify a preferred method (Alternative 3 - installing a final cover) costing
       $7 to $8 million for three or four OUs that show no present or future risk, when you could spend
       $3 million to monitor the existing cover (Alternative 2 - institutional controls) and take care of
       all the problems, given the government does not have sufficient money for cleanup activities.

 Response 1.  The Air Force is doing all it can to address risks that may be present at OU-8. This is an
              area where there is something to be  gained by preventing human contact with the
              contaminants, even though the contaminant levels are low. A good deal of the cost is in
              the long-term monitoring, and it is very likely that the monitoring can be cut back as time
              goes by. The costs you are seeing are worst case costs. The actual costs will probably
              be less.

              The other thing to look at is, not only human risk, but to make sure the Base complies
              with all of the closure requirements that are in federal and state regulations, particularly
              for the landfills.  Even though risk based analyses are conducted, there are still  other
              requirements to meet to close a landfill so that no one comes in contact with materials

F:\PROJ\6037886\FS\OU5.ROD\F1NAL\OU5ROD.FNL          B-3                               May 7, 1996

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                                                          Final Record of Decision Operable Unit 5
                                                           Ellsworth Air Force Base, South Dakota
               that have beenplaced in the landfills. Whether it is a landfill on the Base or a landfill at
               Rapid City, South Dakota, final covers are needed to be in compliance with landfill
               closure regulations. At some point the Base is going to have to put final covers on the
               landfills. The costs involved include a 30-year long-term operation and maintenance
               period, which contributes to a lot of the cost. However, at the end of five years, under
               the CERCLA process, a review of the monitoring results will be conducted, and if the
               results are favorable, the monitoring can be significantly cut back. The intent of placing
               covers  over these  landfills  will be to eliminate the potential for future releases of
               hazardous substances to humans and the environment.

 Comment 2. Ms. Vivian Pappel

        Asked whether state law on the closure of a landfill allows for a revisitation of the post-closure
        plan. Stated she didn't think that provision was in the state closure.

 Response 2.   State regulations call for a 30-year operation and maintenance period.  The five-year
               review will provide information on the effectiveness of the remedial alternative. If the
               results are favorable  it is possible to reduce the monitoring from quarterly to semi-
               annually, or annual monitoring, or even less. That would result in significant cost
               savings. It may not be possible to totally stop monitoring after five years but there is
               definitely potential  for cost savings.
F:\PROJ\60m86\FS\OU5.ROD\FIKAL\OU5ROD.FNL          B-4                                May 7, 1996

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