PB98-964502
                               EPA 541-R98-028
                               October 1998
EPA Superfund
      Record of Decision:
      Yuma Marine Corps Air Station
      OU2
      Yuma, AZ
      12/2/1997

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                     Final

Record of Decision for Operable Unit 2
         Marine Corps Air Station
               Yuma, Arizona
                              t
                 YUMA ARIZONA
                August 29,1997
                    Prepared for

                Southwest Division
           Naval Facilities Engineering Command
                 San Diego, California


                    Prepared by

                Uribe & Associates
                220 California Avenue
                 Palo Alto, CA 94306
                   (415) 325-9195


         ContractN68711-94-D-1611, Delivery OrderB

                 U&A Project 180-06

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                                   Final

              Record of Decision for Operable Unit 2
                       Marine Corps Air Station
                             Yuma, Arizona
                              YUMA ARIZONA
                              August 29,1997
I
          Prepared for

       Southwest Division
  Naval Facilities Engineering Command
        San Diego, California


          Prepared by

       Urlbe & Associates
       220 California Avenue
        Palo Alto, CA 94306
          (415) 325-8195

Contract N68711-94-D-1611, Delivery Order 6
        U&A Project 180-06

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         Draft Final Record of Decision for Operable Unit 2
                       Marine Corps Air Station
                            Yuma, Arizona

                               Contents

Section	Page

1 Declaration	1-1
   1.1  Introduction	1-1
   1.2  Site Name and Location	1-1
   1.3  Statement of Basis and Purpose	1-2
   1.4  Assessment of the Site	1-2
   1.5  Description of the Selected Remedy	1-3
   1.6  Statutory Determinations	1-7

2 Decision Summary	2-1
   2.1  Introduction	2-1
   2.2  MCAS Yuma Site Location and Description	2-2
   2.3  MCAS Yuma Installation Operational History	2-3
   2.4  Enforcement and Regulatory History	2-3
   2.5  Operable Unit 2 Site Selection History	2-4
   2.6  Operable Unit 2 Site Descriptions	2-6
      2.6.1 Introduction	2-6
      2.6.2 CAOC 1: Flight Line	2-6
      2.6.3 CAOC 2: Shop Areas	2-7
      2.6.4 CAOC 3: Auto Hobby Shop	2-7
      2.6.5 CAOC 4: Radar Hill Disposal Area	2-8
      2.6.6 CAOC 5: Old 2nd LAAMBN Compound	2-8
      2.6.7 CAOC 6: First Sewage Lagoon	2-9
      2.6.8 CAOC 7: Fire School Area	2-9
      2.6.9 CAOC 8: Southeast Station Landfill	2-10
      2.6.10 CAOC 9: Southeast Sewage Lagoon	2-11
      2.6.11 CAOC 10: Ordnance Munitions Disposal Area	2-11
      2.6.12 CAOC 11: Radiation Disposal Pipes	2-12
      2.6.13 CAOC 12: Tear Gas Burial Area	2-13
      2.6.14 CAOC 13: Drain Field Area	2-13
      2.6.15 CAOC 14: Drain Field South of Building 97	2-13
      2.6.16 CAOC 15: Hazardous Waste USTs 363 and 364	2-14
      2.6.17 CAOC 16: Hazardous Waste USTs, Building 230-2 and 230-4	2-14

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         Draft Final Record of Decision for Operable Unit 2
                       Marine Corps Air Station
                            Yuma, Arizona

                                Contents

Section	Page

      2.6.18 CAOC 17: Hazardous Waste Underground Storage Tank 1708-3	2-14
      2.6.19 CAOC 18: Old Drum Storage Area	2-15
   2.7 Highlights of Community Participation	2-15
   2.8 Scope and Role of Operable Unit 2	.....2-16
   2.9 Summary of Field Investigation	2-17
   2.10 Summary of Risk Assessment	2-18
      2.10.1 Human Health Risk Assessment	2-18
      2.10.2 Identification of COPCs	:	2-18
      2.10.3 Exposure Assessment	2-20
      2.10.4 Toxicity Assessment	2-21
      2.10.5 Development of Risk-Based Criteria	2-22
      2.10.6 Summary of Risks at Individual CAOCs	:	2-23
   2.11 Summary of Ecological Risks	2-26
   2.12 Description of Alternatives	2-27
      2.12.1 Introduction	2-27
      2.12.2 CAOCs Requiring Remediation of ACM in Soil	2-27
      2.12.3 Alternatives Considered for Remediating CAOCs 4, 7, and 9	2-28
      2.12.4 CAOCs with Potential Health Risks	2-30
      2.12.5 Alternatives Considered for Responding to Potential Health Risks at
            CAOCs 1,8A, and 10	f	2-30
   2.13 Summary of the Comparative Analysis of Alternatives	2-32
      2.13.1 Introduction	2-32
      2.13.2 Applicable or Relevant and Appropriate Requirements	2-33
      2.13.3 Preferred Alternative for ACM in Soil	2-34
      2.13.4 Preferred Alternative for Responding to Potential Health Risks at
            CAOCs 1,8A and 10	:	2-39
   2.14 The Selected  Remedies	2-42
      2.14.1 Selected  Remedy for ACM  in Soils	2-42
      2.14.2 Selected  Remedy for Potential Health Risks at CAOCs 1,
            8A,andlO	2-43
   2.15 Statutory Determinations	2-45
       2.15.1  Introduction	2-45

   180-06/sok/8/28/97/rod-dr4.doc              »

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         Draft Final Record of Decision for Operable Unit 2
                      Marine Corps Air Station
                           Yuma, Arizona

                              Contents

Section	Page

      2.15.2 Statutory Determinations for Selected Remedy for ACM in Soils	2-45
      2.15.3 Statutory Determinations for Selected Remedy for Potential
           Health Risks at CAOCs 1,8A, and 10	2-50
   2.16 Documentation of Significant Changes	2-53

3 Responsiveness Summary	3-1
   3.1 Overview	3-1
   3.2 Background on Community Involvement	3-1
   3.3 Summary of Comments Received During Public Comment Period and
      Department of the Navy Responses	3-2

4 References	4-1

5 Abbreviations /Acronyms	5-1
             9
Appendices	
A   Response to U.S. Environmental Protection Agency and Arizona Department
    of Environmental Quality Comments on the Draft Record of Decision for
    Operable Unit 2, Marine Corps Air Station, Yuma, Arizona
B   Community Relations Activities Conducted by Navy
   180-06/sak/8/28/97/rod-dr4.doc

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         Draft Final Record of Decision for Operable Unit 2
              Marine Corps Air Station, Yuma Arizona

                              Contents

Table	

2-1    Chemicals of Potential Concern (COPC) for OU2
2-2    Maximum Concentrations of Volatile Organic Compounds Detected as
      COPCs at 0 to 10 Feet
2-3    Maximum Concentrations of Semi-Volatile Organic Compounds and Total
      Petroleum Hydrocarbons Detected as COPCs
2-4    Maximum Concentrations of Pesticides and PCBs Detected as COPCs
      at 0 to 10 Feet
2-5    Maximum Detected Values and Background Threshold Limit Values (TLV)
      for Metals Detected at 0 to 10 Feet
2-6    ARARs for Remediation of Asbestos-Contaminated Soil at MCAS Yuma
2-7    ARARs for Potential Health Risks at MCAS Yuma
2-8    Human Health Based Guidance Levels (HBGLs) for Ingestion of
      Contaminants in Soil at CAOC 1,8A, and 10
2-9    Alternative 3, Soil Volume Estimates
2-10  Cost Estimate for Alternative 3: Cleanup of ACM on Soil Surface and
      Excavation and Disposal of Soil Mixed with ACM
2-11  Cost Estimate for Cleanup of ACM on Soil Surface
2-12  Potential ARARs for Remedial Action for MCAS Yuma
Figure
1-1 Location Map for MCAS Yuma
1-2 Location of CAOCs in OU2
2-1 CAOC 1: Feature and Boring Location Map
2-2 CAOC 1: Total PAH Concentration Contours for Surface Samples, Southern Detail
2-3 CAOC 1: Total PAH Concentration Contours for Surface Samples, Northern Detail
2-4 CAOC 4: Location of ACM and ACM-Contaminated Soil
2-5 CAOC 7: Location of Subunit 7A
2-6 CAOC 7: Location of Subunit 7B
2-7 CAOC 8: Feature and Boring Location Map
2-8 CAOC 9: Location of ACM Debris

    180-06/sak/8/28/97/rod-dr4.doc             iv

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        Draft Final Record of Decision for Operable Unit 2
             Marine Corps Air Station, Yuma Arizona

                              Contents

Figure	

2-9 CAOC 10: Feature Map
2-10 CAOC 10: PAH Sampling Locations with Total PAH Concentrations
   180-06/sak/8/28/97/rod-dr4.doc

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1  Declaration
1.1 Introduction

      This Record of Decision (ROD) for Operable Unit (OU2) documents the remedial
      action plan for OU2 at Marine Corps Air Station (MCAS), Yuma, Arizona. This
      ROD was prepared by Uribe & Associates (U&A) for Southwest Division Naval
      Facilities Engineering Command (Southwest Division) under Contract N68711-94-
      D-1611, Delivery Order 6.

1.2 Site Name and Location

      The Marine Corps Air Station (MCAS), covering approximately 3,000 acres, is
      located  in the City and County of Yuma, Arizona (Figure 1-1).  Marine Corps Air
      Station  Yuma (Station) was declared a permanent Air Force installation in 1954.
      In January 1959, the Station and its associated range facilities were transferred to
      the U.S. Navy.  The Station currently  operates the airport  facility  as a joint
      military/civilian airport. MCAS Yuma is located on the northern portion of Yuma
      Mesa, approximately 60 to 70 feet above and four miles from the Colorado River.
      The City of Yuma, the nearest municipality,  is located  approximately one mile
      northwest of the Station.

      The final Federal  Facility Agreement (FFA) was signed  in January, 1992, by the
      U.S. Environmental Protection Agency (U.S. EPA), the Department of the Navy
      (Navy),  and the  Arizona  Department  of Environmental Quality (ADEQ)  to
      establish  a  framework   and  schedule  for  implementing  environmental
      investigations and  appropriate  remedial  actions under the  Comprehensive
      Environmental  Response, Compensation, and  Liability Act  (CERCLA).  Two
      Operable Units (OUs) were established under the auspices of the FFA.  OU2
      includes surface disposal units and contamination shallower than ten  feet below
      ground  surface.   The OU2  Remedial  Investigation  included the  following
      CERCLA areas of concern (CAOCs), as shown on Figure 1-2:

      •  CAOC 1, Flight Line
      •  CAOC 2, Shops Area
      •  CAOC 3, Auto Hobby Shop

    180-06/saVdr4.doc8/27/97                 1-1

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      •  CAOC 4, Radar Hill Disposal Area
      •  CAOC 5, Old 2nd LAAMBN Compound
      •  CAOC 6, First Sewage Lagoon
      •  CAOC 7, Fire School Area
      •  CAOC 8, Southeast Station Landfill
      •  CAOC 9, Southeast Sewage Lagoon
      •  CAOC 10, Ordnance Munitions Disposal Area
      •  CAOC 11, Radiation Disposal Pile
      •  CAOC 12, Tear Gas Burial Area
      •  CAOC 13, Drain Field Area
      •  CAOC 14, Lagoon South of Building 97
      •  CAOC 15, Hazardous Waste USTs. 363 and 364
      •  CAOC 16, Hazardous Waste USTs, Building 230-2 and 230-4
      •  CAOC 17, Hazardous Waste Underground Storage Tank 1708-3
      •  CAOC 18, Old Drum Storage Area

1.3 Statement of Basis and Purpose
      This ROD presents a response action for OU2, which consists of 18 CAOCs that
      were identified as possible locations of soil contamination from past activities at
      MCAS Yuma. These areas were selected in accordance with CERCLA as amended
      by the Superfund Amendments and Reauthorization Act (SARA) of 1986 and to
      the extent practicable, the National Contingency Plan (NCP). This ROD explains
      the basis for selecting the response action for the 18 CAOCs comprising  OU2.
      Information supporting  the  selected response  action  is  contained  in  the
      Administrative Record for MCAS Yuma.  The U.S. EPA, Navy, and ADEQ concur
      with the selected response actions.

1.4 Assessment of the Site
      A Remedial Investigation  (RI) for OU2 was performed by Jacobs  Engineering
      Group (JEG, 1996).  As part of the  RI,  a human health  and ecological risk
      assessment was  performed for each of the 18 CAOCs to  assess the potential
      impacts  of hazardous  substances  on human health,  the environment, and
      groundwater quality (JEG, 1995b).  Based  on  the RI, U.S. EPA,  ADEQ,  and the
      Navy agreed that 12 of the CAOCs require no further action.  Six of the CAOCs
      require action:
    180-06/sak/dr4.doc8/27/97                 1-2

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      •  CAOCs  4, 7, and 9:   Asbestos-containing building materials  have been
         identified in construction debris and have the potential  to release asbestos
         fibers into the environment.
      •  CAOCs 1 and 10: The human health risk assessment indicated that residential
         use  of these CAOCs had a potential to present  an unacceptable level of
         carcinogenic risk.
      •  CAOC 8A:  Intrusive sampling was not conducted at the southeast  station
         landfill during the RI because of potential drilling hazards (Section 2.6.9).
         Based on the human health risk assessment, it was concluded that a  landfill
         cap was  not required under the current land use. However, since the interior
         of the landfill was not investigated during the RI, the risk from exposure to the
         landfill interior is unknown.

      A Feasibility Study  (FS) was conducted to evaluate remedial  alternatives  for the
      six CAOCs.  For CAOCs 4, 7, and 9, where surface disposal of asbestos waste was
      confirmed, the FS developed a remedial approach that minimizes potential health
      threats and  allows  unrestricted use of the CAOCs. Asbestos can affect  human
      health if left unmanaged.  Asbestos-containing material  in  these  three areas
      presents a substantial threat of release,  which may pose a significant  risk to
      human  health  and  the environment if not addressed  by  implementing  the
      response action selected  in this ROD.   This  ROD describes the rationale for
      selecting the alternative to cleanup ACM contamination at the three CAOCs.

      For CAOCs  1, 8A, and 10 the health risk assessment indicated that potential health
      risks were within acceptable levels under current land  use, but could become
      unacceptable if land  use changed. The FS evaluated institutional  controls to
      protect human health.

1.5 Description of the Selected Remedy

      On the basis of the  data collected at the OU2 sites, no further action is necessary
      for 12 of the 18 CAOCs included in OU2, because these sites do not pose a threat
      to human health or the environment.  However, remedial action is  required to
      protect  human health and comply with regulatory requirements at three of the
      CAOCs in  OU2 because of the presence of ACM.  In addition, institutional
      controls will be implemented to minimize potential health risks that might be
      associated with land use changes in CAOC 1, 8A, and 10.
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   Selected Remedy for ACM

   Four alternatives have been developed and evaluated for the remediation of ACM
   at MCAS Yuma.  The alternatives were based on the nine criteria established by
   U.S. EPA, listed below:

   •  Overall Protection of Human Health and the Environment
   •  Compliance with ARARs
   •  Long-Term Effectiveness and Permanence
   •  Reduction of Toxicity, Mobility, or Volume
   •  Short-Term Effectiveness
   •  Implementability
   •  Cost
   •  State Acceptance
   •  Public Acceptance

   The four alternatives evaluated are listed and briefly described below:

   Alternative 1—No Action

   The No-Action alternative was used as a baseline alternative Against which other
   alternatives were  judged. With this alternative, there would be no action to treat,
   contain, or  remove any of the surface ACM or ACM-contaminated soil.

   Alternative 2—Cleanup of Surface ACM Debris

   Under this  alternative, ACM fragments visible on soil surfaces would be collected
   manually.  Collection would include removing approximately the upper inch of
   soil beneath the ACM to reduce the potential for asbestos fibers remaining behind
   in the  soil.  The ACM  and soils would be  stockpiled, manifested,  loaded,
   transported, and disposed of at a permitted facility.

   Alternative 3—Cleanup of ACM on Soil Surface and Excavation of Soils Mixed
   with ACM

   Under this  alternative, ACM fragments visible on soil surfaces would be collected
   manually, as described under Alternative 2. In areas in which ACM is mixed with
   soil beneath the surface (CAOC 4A, north of Building 38; and CAOC 7A, limited
   area near the active bum pit), the contaminated soils would be excavated with
   conventional  construction equipment.

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      Alternative 4—Cleanup of ACM on Soil Surface, Partial Excavation, and Partial
      Capping

      Under this alternative, ACM fragments visible on soil surfaces would be collected
      manually, as described under Alternative 2. In the limited area near the active
      burn pit (CAOC 7A), where ACM is mixed with surface soils to a maximum depth
      of one  foot, the contaminated soils would be  excavated  with conventional
      construction equipment,  as  in Alternative 3.  This  alternative differs  from
      Alternative 3 in that only the central portion of the remedial unit north of Building
      38 (CAOC 4A) would be excavated, since the Station has plans to develop this
      area. The eastern portion of CAOC 4A would be capped with asphalt.

      The selected alternative for addressing asbestos at MCAS Yuma is Alternative 3,
      cleanup of ACM on soil surface and excavation of soils mixed with ACM. This
      alternative meets the  nine ranking criteria that the U.S. EPA uses  to evaluate
      alternatives.

      Selected Remedy for Potential Health Risks

      Two alternatives were developed and evaluated to  address potential health
      threats identified by the human health risk assessment for CAOC 1 and CAOC 10
      and the potential health threat associated with land use changes at CAOC 8A.
      These alternatives were based on the nine criteria listed above in the discussion of
      alternatives for ACM.  The alternatives are listed and briefly described below.

      Alternative 1—No Action

      This alternative does not reduce the potential risk to human health and is unlikely
      to be accepted by the state or the community.

      Alternative 2—Institutional Controls

      Institutional controls would  restrict the land use of CAOC 1 and CAOC  10 to
      industrial/commercial use  and  CAOC   8A  to the  current  use  (inactive
      landfill/surface disposal area). The institutional controls would be implemented
      through the MCAS Yuma Base Master Plan (BMP), which would reference  the
      OU2 ROD. Additions  to the BMP would include a map indicating the locations of
      the former disposal areas in CAOC 8A.  This would include execution and
      recordation of a VEMUR in accordance with and substantially in the form set out
      at Arizona Revised Statutes, Section 49-152.  The VEMUR would contain language

180-06/sak/dr4.docW/22/97                     1-5

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clarifying that it was executed and recorded by the federal government, or the
appropriate entity of the federal government,  "for itself only,  and not  as  a
covenant running with the land". In addition, it would clarify that:

   a.   The parties agree that no interest in real property on behalf of the State of
        Arizona is created either by this VEMUR or by any notice of cancellation
        of this VEMUR pursuant to A.R.S. 49-152.

   b.   The signature of an authorized representative of the Arizona Department
        of Environmental Quality (ADEQ) which appears herein acknowledges
        that the remediation of the property was conducted in accordance  with
        the provisions of A.R.S 49-152.

The MCAS Yuma Base Master Plan would require that any changes in activities or
land use in these CAOCs be coordinated through and reviewed by the MCAS
Yuma   Environmental  Department.    Before the land  use  restrictions  are
incorporated in the BMP, the Navy will obtain the approval of the U.S. EPA for
the language of the restrictions and the location in the BMP  at which the approved
language will be incorporated.  In the event that the Navy plans any future
changes in land use at CAOCs 1, 8A, or 10, the Navy in  consultation with U.S.
EPA and ADEQ would re-evaluate the remedy in light of  the intended land use.
If the change in land use is not compatible with the remedy, the  remedy may be
changed pursuant to CERCLA Sections 120 and 121  and the National  Oil and
Hazardous Substances Pollution Contingency Plan (NCP) Section  300.430(f)(4)(iii)
and the ROD may be amended. If the Navy plans to excess the property to a non-
federal entity, it will notify ADEQ and EPA in advance of the execution of any
such transfer. The Navy will consult with ADEQ and  EPA in revisiting existing
land  use classifications/restrictions for the CAOC (or, in the  alternative, the
remedial action selection) to determine if the foreseeable future land use differs
from the assumptions made at the time the original remedial action decision was
made.  At that time, a re-evaluation of the appropriate institutional controls will
be undertaken by the Navy, in consultation with ADEQ and EPA.

For CAOC 1 and CAOC 10, a change in land use from industrial to residential use
would require re-evaluation of the remedy. For CAOC 8A, a  change in land use
involving any activities that may disrupt and expose the  landfill interior would
require re-evaluation of the remedy. At the time of these future activities, further
investigation may be undertaken in order to determine if remediation is required
and if the ROD must be amended.

    .ilocltl/l 5/97                    1-6

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       The selected alternative for addressing potential health risks at CAOCs 1, 8A, and 10
       is Alternative 2, institutional controls. This alternative meets the nine ranking criteria
       that the U.S. EPA uses to evaluate alternatives.

1.6 Statutory Determinations

       No response action is necessary to protect human health or the environment at 12 of
       the 18 CAOCs within the OU2 site. This "no further action" alternative was selected
       because no contaminants found  at 12 of the CAOCs were present at concentrations
       that pose an unacceptable risk to  human health or the environment based on U.S. EPA
       risk guidelines. The "no further action" alternative is protective of human health and
       the environment and complies with federal and State of Arizona requirements that
       are legally applicable or relevant and appropriate to the remedial action.  This action
       is  a permanent solution  to the maximum extent practicable or necessary for these
       CAOCs. Because this action will not result in hazardous substances remaining on site
       exceeding unacceptable health-based levels, the five-year review will not apply to this
       action.

       Asbestos-containing materials (ACM) are to be removed from  three CAOCs.  The
       rationale for selecting Alternative 3 as the preferred alternative for the remediation of
       ACM at CAOCs 4, 7, and 9, was based on the U.S. EPA criteria  listed in Section 1.5.
       Alternative  3 is protective  of human health and the environment, complies with the
       State  of Arizona and federal requirements that are legally applicable or relevant and
       appropriate to the remedial action, is cost effective, and  would  be a permanent
       solution to the maximum extent practical or necessary for OU2. Because Alternative 3
       will not result in hazardous substances remaining on site exceeding acceptable health-
       based levels, the five-year review will not apply to this action.

       The asbestos-containing  material (ACM)  to be removed from  CAOCs 4, 7, and 9
       includes  transite  siding,  transite  pipe,  cement  pipe,  roofing  materials, vinyl,
       fiberboard and floor tile mastic.  This ACM is "nonfriable" which means that it cannot
       be crumbled, pulverized, or reduced to powder by hand pressure when dry (40 CFR
       Section 61.141).  Nonfriable ACM is a CERCLA hazardous substance, but not a RCRA
       hazardous waste.  See 40 CFR, Section 302.4 (CERCLA) and 40 CFR, Part 261 (RCRA).
       Since the ACM is  a CERCLA hazardous substance. Alternative 3 must be conducted
       in a way that complies with U.S.  EPA's Off-Site Policy (40 CFR Section 300.440).
    llU)-Ht)/fiik/,tr-i.,l,\-l(>/15/97
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      The institutional controls  will restrict the land use  of CAOC  1  and CAOC 10  to
      industrial/commercial use and CAOC 8A to the current use (inactive landfill /surface
      disposal area).  The institutional controls will be implemented  through the Base
      Master Plan, which will reference the OU2 ROD. Additions to the Base Master Plan
      will include a map indicating the locations of the former disposal areas in CAOC 8A.
      This would include execution and recordation of a VEMUR in accordance with and
      substantially in the  form set out at Arizona Revised Statutes, Section 49-152.  The
      VEMUR would contain language clarifying that it was executed and recorded by the
      federal government, or the appropriate entity  of the federal government,  "for itself
      only, and not as a covenant running with the land".  In addition, it would clarify that:

         a.  The parties agree that no interest in real property on behalf of the State  of
             Arizona is created  either by this VEMUR or by any notice of cancellation  of
             this VEMUR pursuant to A.R.S. 49-152.

         b.  The signature of an authorized representative of the Arizona Department  of
             Environmental Quality (ADEQ) which appears herein acknowledges that the
             remediation of the  property was conducted  in accordance with the provisions
             of A.R.S 49-152.

      The Base Master Plan will require that any changes in activities or land use in these
                 *
      CAOCs be coordinated  through and reviewed by  the MCAS Yuma Environmental
      Department.  Before the land use restrictions are incorporated in the BMP, the Navy
      will obtain the approval of the U.S. EPA for the language of the restrictions and the
      location in the BMP at which the  approved language will be incorporated.  In the
      event that the Navy plans any future changes in land use at CAOCs 1, 8A, or 10, the
      Navy in consultation with  U.S. EPA and ADEQ would re-evaluate the remedy in light
      of the intended land use.  If the Navy plans to excess the property to a non-federal
      entity, it will notify ADEQ and EPA in advance of the execution of any such transfer.
      The Navy will consult  with  ADEQ  and EPA  in revisiting  existing  land use
      classifications/restrictions for the CAOC (or, in the  alternative, the remedial action
      selection) to determine if the foreseeable future land use differs from the assumptions
      made at the time the original remedial action decision was made.  At that  time, a re-
      evaluation of the appropriate institutional controls will be undertaken by the Navy, in
      consultation with ADEQ and EPA.

      The rationale for selecting  Alternative 2 as  the preferred alternative for potential
      health risks at CAOCs  1, 8A, and  10 was based on the U.S. EPA criteria listed in
      Section 1.5. Alternative 2 will be  protective of human health and the environment,

18l>-(l»/siik/,1i J.,/,.r 10/15/97                      1 -8

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   comply with the State of Arizona and federal requirements that are legally applicable
   or relevant and appropriate to the remedial action, and  be cost effective.  Because
   Alternative 2 will result in hazardous substances remaining on site, a five-year review
   will apply to this action.
   Colonel C/f. Turner
   Commanding Officer
   MCAS Yuma
   Daniel D. Opalski
   Chief
   Federal Facilities Cleanup Branch
   U.S. EPA, Region 9
   Russell F. Rhoades
   Director
   Arizona Department of Environmental Quality
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2 Decision Summary
2.1 Introduction

       This section provides an overview of the site-specific factors and analysis that led
       to the selection of the "no further action" decision for 12 of the 18 CAOCs in OU2,
       the  selection of the preferred alternative for the clean-up of ACM at three of the
       CAOCs, and the implementation of institutional controls to minimize potential
       health risks that might be associated with land use changes at three of the CAOCs.
       The overview includes the  following descriptions,  histories, summaries,  and
       conclusions:

       •  A  general description of MCAS Yuma location and regional setting.
       •  A  brief history of past operations at MCAS Yuma.
       •  A  brief history of regulatory and enforcement actions for OU2.
       •  A  brief summary of reasons for including specific CAOCs in OU2.
       •  A  summary of characteristics for each CAOC within OU2.
               *
       •  A  summary of target analytes that were considered constituents of potential
          concern (COPCs) at the CAOCs during the remedial investigation of OU2.
       •  A  summary of the human health risk and ecological risk assessments for the
          CAOCs within OU2.
       •  A  summary  of the selection  of "no  further action" based  on the  risk
          assessment for 12 of the CAOCs within OU2  and the selected remedy for six
          CAOCs requiring remedial action.
       •   A  description of significant changes to the selected remedy.

       These reports are included in the Administrative Record for MCAS Yuma. Much
       of the information presented in  this  overview was derived  from previous
       assessments and  investigations performed by Southwest Division, Naval Facilities
       Engineering Command (Navy) and its contractors.   Results and conclusions  of
       these  assessments and investigations are presented in greater detail in the Initial
       Assessment Study (Stearns et al, 1985),  Confirmation Study Verification Phase
       (Malcolm  Pirnie, 1988), Site Inspection (Malcolm Pimie, 1990), Asbestos Survey
       Results  (Jacobs   Engineering Group,   Inc.  [JEG],  1995a),  Final  Remedial
       Investigation Report QEG, 1996), Assessment of  ACM  Contamination  (U&A,
       1996a), Feasibility Study (U&A, 1996b), and Proposed Plan (U&A, 1996c).
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2.2  MCAS Yuma Site Location and Description

       MCAS Yuma is located in a desert  environment, with mild  winters and hot
       summers. The total annual precipitation in the Yuma area is approximately two to
       three inches with total potential evapotranspiration exceeding 50  inches (JEG,
       1996).  MCAS Yuma has installed 51 dry wells that receive storm water  from
       precipitation events and  allow the storm water to infiltrate into  the  ground.
       Precipitation events generate small  areas of ponded water  on the base, but
       significant quantities of surface water runoff are not generated by  precipitation
       events. Winds are usually light (0 to 6 miles per hour [mph]) to moderate (6 to 16
       mph), with an average relative humidity of 20 percent.

       The site is located on  the northern portion of Yuma Mesa, approximately 60 to
       70 feet above the adjacent Colorado River Valley. Sedimentary deposits on Yuma
       Mesa are predominantly fluvial (river) deposits with minor eolian  (windblown)
       deposits in the upper 180 to 200 feet. These deposits overlie pre-Tertiary bedrock,
       which crops out in a series of low hills at  and around the Station.  Geologic
       materials encountered during previous investigations performed at MCAS Yuma
       consist of fine to coarse sand with interbeds of clay, silt, and gravel. Local soils
       are  characterized  as  excessively  drained  sand with  rapid  permeability.
       GroundWater in the vicinity of MCAS  flows to the northwest with a gradient of 15
       to 20 feet per mile.  The groundwater table is typically encountered  about 50 feet
       below ground surface.

       No natural surface  drainage occurs at MCAS Yuma because of its relatively level
       topography, low precipitation, and high evaporation.  No large surface water
       bodies are located within the immediate vicinity of MCAS Yuma. The Colorado
       River, the most significant surface water feature, is located approximately four
       miles north of MCAS Yuma. Local flooding occurs during storms at the Station,
       especially in areas where the ground surface is covered with concrete. Minor
       erosional  features,  such as  gullies   and rills,  have  been  noticed  near  the
       southwestern end of the  runway, as  a result of runoff following a storm  (JEG,
       1996).

       Plants and animals within MCAS Yuma are characterized as desert species and
       species associated with developed areas or species attracted by irrigated areas.  No
       state or federally listed threatened or  endangered species are currently known to
       be present at MCAS Yuma (JEG, 1995b).
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2.3 MCAS Yuma Installation Operational History

      In early 1928, the U.S. Government leased 640 acres of desert land near the City of
      Yuma to Yuma County to establish an airfield. The U.S. Bureau of Reclamation
      (Bureau) leased the airfield to Yuma County to construct a small aircraft hanger
      and runway in 1937.  From 1941 to 1946, the facility was leased to the U.S. Army
      Air Corps for pilot training and bomber crew training.  Field activity ceased with
      the end of World War II, and the area was returned to the control of the Bureau.

      Yuma County obtained rights to use the airfield for civilian purposes from the
      Bureau in  1948.  In July 1951, the U.S. Air Force reactivated the station as  a
      Weapons Proficiency  Center for fighter-interceptor  units.   The  Station was
      declared a permanent Air Force installation in 1954.

      In January 1959, the Station and its associated range facilities were transferred to
      the U.S. Department of the Navy.   MCAS Yuma was established in 1959 to
      provide services and materials support operations  to the Marine Aircraft Wing
      and its subordinate units. MCAS Yuma currently operates the airport facility as a
      joint military/civilian airport.  Since 1959, major improvements have included the
      construction of a 13,300-foot runway, development of the Instrumented Special
      Weapons'System, and the addition  of a Tactical  Air Crew Combat Training
      System.

2.4 Enforcement and Regulatory History

      During its 70 years of operation, the Station has generated industrial wastes such
      as used oil, fuels, solvents, paint residues, battery acid, pesticides, herbicides, and
      polychlorinated biphenyls (PCBs). In the early years, some of these wastes were
      disposed of in landfills, burn pits, and other areas located throughout the Station.
      Construction and improvement  activities also generated  construction debris,
      which has been disposed of in undeveloped portions of the Station.

      Remedial investigations were initiated in 1985 to investigate past disposal sites at
      MCAS Yuma.  Early studies  indicated the  presence  of chlorinated solvents in
      underlying groundwater.  As a result, in 1990, MCAS Yuma was placed on the
      Superfund National Priorities List (NPL). Section 120 of CERCLA requires federal
      facilities to investigate  and clean up  past releases of hazardous waste that may
      pose a risk to human health or the environment.
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      Investigations   performed   at   MCAS   Yuma   include   the   Remedial
      Investigation/Feasibility  Study (RI/FS) (]EG, 1996),  supplemental sampling
      programs at CAOC 10 (Uribe, 1996d; Uribe, 1997), Federal Facility  Agreement
      Assessment Program  (FFAAP) (Steams, 1985), and  underground storage  tank
      investigations (JEG, 1995b).

      In 1990, shortly following MCAS Yuma's listing on the NPL list, the Navy entered
      into a FFA with U.S. EPA and ADEQ to establish a framework and schedule for
      implementing environmental investigations and appropriate cleanup actions. The
      Final FFA was signed in January, 1992. The Navy and regulatory agencies agreed
      to subdivide the Station into two Operable Units (OUs), one to address potential
      areas of groundwater contamination and soil contamination deeper than 10 feet
      below ground surface (OU1) and one for soil contamination shallower than 10 feet
      below ground  surface (OU2).  OU1 will be addressed by a  separate ROD
      following completion of the investigative process.

      The Navy is the lead agency under the NCP for conducting investigation and
      remediation of MCAS Yuma pursuant to CERCLA. This process is conducted in
      consultation with U.S. EPA, as the lead regulatory agency, and with ADEQ, as the
      supporting state regulatory agency for these activities.   There  have been no
      enforcement actions for OU2.

2.5 Operable Unit 2 Site Selection History
      OU2 consists of surface disposal and disposal units within the upper 10 feet of soil
      underlying the Station, where disposal or releases of  petroleum products, paints,
      solvents,  metals, pesticides, and other process chemicals may have  occurred.
      Contamination of groundwater underlying the Station and soils greater than 10
      feet below the  ground surface are  addressed by  the  Installation  Restoration
      Program  (IRP) for OU1.  The objectives of the OU2 environmental restoration
      program  are to evaluate the environmental condition of the  CERCLA areas of
      concern  (CAOCs); identify threats  to  human  health, the environment, and
      groundwater quality; and develop cleanup actions to protect human health and
      the environment.   Based on  the human  health and environmental risk
      assessments, the RI recommended no remedial action for 12 of the 18 CAOCs in
      OU2.  ACM was identified at three of the 18 CAOCs, and these CAOCs are the
      only CAOCs  that require  remediation within OU2. In  addition, institutional
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   controls will be implemented for CAOCs 1, 8, and 10 to minimize potential health
   risks that might be associated with land use changes at these CAOCs.

   Based on the results of preliminary investigations, the RI was conducted at the
   following CAOCs within OU2 at MCAS Yuma:

   •  CAOC1, Right Line
   •  CAOC 2, Shops Area
   •  CAOC 3, Auto Hobby Shop
   •  CAOC 4, Radar Hill Disposal Area
   •  CAOC 5, Old 2nd LAAMBN Compound
   •  CAOC 6, First Sewage Lagoon
   •  CAOC 7, Fire School Area
   •  CAOC 8, Southeast Station Landfill
   •  CAOC 9, Southeast Sewage Lagoon
   •  CAOC 10, Ordnance Munitions Disposal Area
   •  CAOC 11, Radiation Disposal Pile
   •  CAOC 12, Tear Gas Burial Area
   •  CAOC 13, Drain Field Area
   •  CAOC 14, Lagoon South of Building 97
   •  CAOC 15, Hazardous Waste USTs 363 and 364
   •  CAOC 16, Hazardous Waste USTs 230-2 and 230-4
   •  CAOC 17, Hazardous Waste Underground Storage Tank 1708-3
   •  CAOC 18, Old Drum Storage Area

   The  RI was conducted in  1995  and included an assessment of each CAOC.  RI
   activities included a surface reconnaissance and historic information search, aerial
   photography review, interviews with former employees and personnel stationed
   at the base, geophysical  surveys (to look  for  buried tanks, drums,  or other
   underground objects that might contain hazardous substances), surface and
   subsurface soil  sampling, soil gas surveys (to look for hazardous substances that
   might have vaporized in soils), and human health and ecological risk assessments.
   The results of the RI are presented in the document titled Marine Corps Air Station,
   Yuma, Arizona, Operable Unit 2, Remedial Investigation, Final Report, dated March 26,
   1996, prepared by Jacobs Engineering Group, Inc. (JEG, 1996). The RI, along with
   reports  of  previous  assessments  and investigations,  are contained  in  the
   Administrative Record.
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2.6 Operable Unit 2 Site Descriptions

   2.6.1 Introduction

       The location of the 18 CAOCs investigated under the RI are shown on Figure 1-2.
       CAOC-specific figures are provided in Figures 2-1 though 2-10 for the six CAOCs
       at which remedial actions are required.  A brief description of the facilities, past
       operations, and potential sources of contaminants is provided in the following
       paragraphs. Because groundwater  issues are included in the IRP for OU1, and
       surface water is not present at MCAS Yuma, potential pathways for released
       contaminants are limited to contact  with site soils, site-derived soil dusts, or site-
       derived soil vapors.

   2.6.2 CAOC1: Flight Line

       CAOC 1 consists of the pre-1960 flight line (runways, aprons, and taxiways) and
       associated  aircraft maintenance/hangar facilities (Figure 2-1).   This CAOC  is
       located in the north-central portion of MCAS Yuma and occupies approximately
       170 acres.   Used oils were frequently drained from aircraft engines directly onto
       the ground surface beneath parked  aircraft. Used oil was also used routinely for
               *
       dust control around hangars, runways, taxi ways, and apron edges.

       The primary finding of  the field sampling  and  analysis  program was the
       widespread detection of Total Recoverable Petroleum Hydrocarbons (TRPH)  in
       surface soil and localized occurrences around the flight line. Polycyclic Aromatic
       Hydrocarbons (PAHs) were detected in surface soil.  Polychlorinated biphenyls
       (PCBs, often formerly used for  the lubrication of  electric transformers)  were
       detected in surface soil at the northern  edge  of the flight line and current  wash
       rack.    Solvents  (volatile  organic compounds  and   semi-volatile   organic
      •compounds), pesticides,  and metals were  detected  in  shallow soil  samples
       collected throughout the area.  The  results of the investigation did not reveal
       significant soil contamination in the areas of the specific units (drywells, oil/water
       separators, wash racks, etc.) included in this study.  PAHs were the major COPC
       posing  a  potentially  unacceptable  health  risk  in  CAOC 1.   Total  PAH
       concentrations are summarized in Figures 2-2  and 2-3.
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2.6.3 CAOC2: Shop Areas

   CAOC 2 consists of the area bounded by Worley Street on the south, Building 603
   on the west, Shaw Avenue on the east, and the flight line and Fuel Farm area on
   the north.  It is located within the northeastern portion of the industrial area of
   MCAS Yuma and occupies approximately 28 acres. This area was used between
   the 1940s and the early 1980s for public works shops and vehicle maintenance.
   Various chemical spills and disposals onto the ground surface were  reported
   throughout this area between the 1940s and 1980s. In addition, two underground
   fuel storage tanks were found to be leaking and were replaced. Suspected waste
   streams associated with this area include used oils, fuel-related wastes, used
   paints, solvents, and vehicle-related wastes.

   The primary finding of the field sampling and analysis program was the isolated
   detection of residual TRPH and PAHs. Pesticides, Total Petroleum Hydrocarbons
   (TPH) as  diesel, volatile organic compounds (VOCs),  semi-volatile organic
   compounds (SVOCs), metals, and organic lead were also detected. The results of
   the investigation did not reveal significant soil contamination in the areas of the
   specific units (drywells, oil/water separators, former buildings, etc.) included in
   RI field investigation.

2.6.4 CAOC 3: Auto Hobby Shop

   CAOC 3 consists of an  open area adjacent to the Auto Hobby Shop (Building 561)
   at the southeast  corner of Quilter Street  and Halstead Avenue.  The original
   fenced area of CAOC 3 covered approximately 0.3 acres of unpaved land.  The
   ground surface  outside the .Auto Hobby Shop was reportedly used for the
   disposal of motor oil, cleaning solvents, battery acid, and anti-freeze between 1960
   and the early  1980s.  Stoddard solvent, commonly used to clean shop floors and
   automotive parts, was also likely to have been disposed of within this area.

   The primary finding of the field sampling and analysis program was the detection
   of  residual TRPH in  the shallow soils underlying  this area.   However, no
   individual components of TRPH, such as benzene, toluene, ethylbenzene, and
   total xylenes (BTEX), were detected.  Significant concentrations of other analytes
   were not detected.
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2.6.5 CAOC 4:  Radar Hill Disposal Area

   CAOC 4, comprising approximately 14 acres, is located south of Radar Hill within
   the central portion of MCAS Yuma (Figure 2-4). This area was used for burning or
   burying municipal waste (household waste) generated at MCAS Yuma and, more
   recently, for the disposal of construction debris, including broken concrete slabs.
   Sometime during the 1950s, this area was  covered with soil.  Suspected waste
   steams associated with this area include used oils, used paints, solvents, thinners,
   vehicle-related wastes, pesticides, and herbicides.

   The primary findings of the field sampling and analysis program were the
   detection of residual TRPH and the isolated detection of PAHs and lead. Organics
   and metals were  also found in  the  shallow soils underlying this  area.  No
   individual components of TRPH, such as BTEX, were  found. The surface soil
   samples collected from CAOC 4 did not contain detectable asbestos.  However,
   during the field sampling program, several  debris piles were identified in which
   potential ACM was noted.  Subsequent analysis of these materials confirmed the
   materials to be ACM (JEG, 1996).

2.6.6 CAOC 5:  Old 2nd LAAMBN Compound

   CAOC 5, occupying approximately two-thirds of an acre, is  located within the
   south-central portion of  MCAS Yuma, south of Loesch Road between Baseball
   Field 1268 and the residential housing area. This CAOC was  the site of the 2nd
   Light Anti-Aircraft Missile Battalion (LAAMBN) vehicle maintenance and storage
   yard between the late 1960s and 1974.  Routine vehicle servicing, maintenance,
   and fueling operations have occurred within this area  and have resulted in the
   disposal and spills of fuel, motor oil, and solvents.  In  addition, used motor oil,
   transmission   fluid,   cleaning  and   degreasing   solvents  (trichloroethene,
   trichloroethane,  and  Stoddard  solvent),  antifreeze  (ethylene glycol),  and
   neutralized battery acid were sprayed along the exposed soil  ground surface for
   dust control purposes.

   The primary finding of the field sampling and analysis program was the detection
   of residual TRPH.  However, no individual components of TRPH, such as BTEX,
   were detected.  Pesticides, TPH as  diesel, VOCs, SVOCs,  and metals were also
   detected.
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2.6.7  CAOC6:  First Sewage Lagoon

   CAOC 6 is located west of County Road 3E and south of Loesch Street in an area
   currently used for military family housing. This area encompasses approximately
   30 acres.  Treated industrial sewage and municipal sewage (domestic sewage)
   from MCAS Yuma was discharged  into an unlined evaporation/infiltration
   lagoon and sludge beds during the early 1940s.  The sewage treatment  facility
   ceased operations in 1943 and was covered. The sludge was also buried in place
   at that time, and in the 1970s, a housing development was constructed on top of
   the buried lagoon and sludge beds.  Suspected waste steams associated with this
   area include vehicle-related wastes, used oils, solvents, thinners, paints, caustics,
   photo processing wastes, herbicides, and pesticides.

   The primary finding of the field sampling and analysis program was the detection
   of residual TRPH. However, no individual components of TRPH, such as BTEX,
   were detected.  Solvents, pesticides and metals were also found  in the shallow
   soils underlying this area.

2.6.8  CAOC 7: Fire School Area

   CAOC 7 is divided into two subunits:  CAOC 7A (northern unit) and CAOC 7B
   (southern  unit).  CAOC 7A,  occupying  approximately 40 acres,  is  located
   southwest of Radar Hill and north/north west of the Combat Aircraft Loading
   Apron (CALA)  (Figure 2-5).  CAOC 7B consists of several small debris  piles
   located south of the CALA (Figure 2-6).  During the RI field investigation, only
   CAOC 7A was investigated.  CAOC 7B was investigated subsequently in an
   investigation documented in MCAS Yuma - Asbestos Survey Results (JEG, 1995a).

   CAOC 7A consists of 16 unlined fire pits that were used between 1952 and 1985
   for fire training. The current lined fire pit (Facility 1220) has been used since 1985.
   There are seven former fuel bladder areas that were used between approximately
   1967 and 1984.  Fires at CAOC 7A were created by floating flammables on water
   in shallow, unlined pits.  The fuel in  the fire pit was ignited, and trainees
   extinguished the fire.  Water and unburned  flammables were washed into the
   surrounding soil and left to infiltrate.  Suspected waste steams associated with this
   area include aviation fuels, used oils, solvents, and thinners.

   The primary finding of the field sampling and analysis program in CAOC  7A was
   the widespread  detection of residual TRPH, generally in former fire pits and fuel

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   bladders.  Low concentrations of VOCs, SVOCs, PCBs, pesticides, dioxins/furans,
   TPH as diesel, and metals were also detected.

   Small broken pieces of asbestos-containing materials were identified south and
   east of the active  fire-training  pit.  The area contaminated with  ACM is
   approximately 170,000 square feet. Over most of the unit, the ACM occurs only as
   surface scatter. In a limited area near the active bum pit, the ACM contamination
   reaches a maximum of one foot deep (up to 1,200 cubic yards). The RI (JEG, 1996)
   concluded that asbestos is the only COPC at CAOC 7A that may pose a  risk to
   human health or the environment.

   CAOC 7B consists of debris piles  south of CALA:  The area immediately south of
   CALA has been used  for dumping construction debris. Seven sites within this
   area were confirmed  to contain ACM debris.  These  sites consist of isolated,
   coherent piles (in one case, a single piece) containing one or more of the following
   types of ACM:  floor tile with asbestos-containing mastic,  transite, and/or ACM
   pipe.  The total volume of ACM debris is approximately 10 cubic yards (JEG,
   1995a).

2.6.9 CAOC 8: Southeast Station  Landfill

   CAOC 8  is located within the southeastern portion of MCAS Yuma, between
   Loesch Street and the southern Station property lines. This area was subdivided
   into two  units:   CAOC  8A (southern  unit) and CAOC 8B (northern unit)
   (Figure 2-7).  CAOC 8A includes a landfill that  was used to dispose of waste
   generated at MCAS Yuma, and CAOC 8B includes the housing development that
   now covers the area north of Ordnance Road.  Combined, CAOCs 8A and 8B
   occupy approximately 68 acres.  This area was used primarily for  the disposal of
   municipal wastes that were generated at MCAS  Yuma between 1953 and 1961.
   Before disposal, most of the wastes were burned. During disposal, approximately
   10 to 20 pits were used for the burial of wastes.  A portion of the area was used for
   rubble disposal and as a borrow area for fill soil. At an unknown date, the  pits
   were backfilled, and housing units were developed.  Suspected  waste streams
   associated with this  area include vehicle-related wastes,  used  oils, solvents,
   thinners, paints, fuel-related wastes, pesticides, and herbicides.

   Drilling within the landfill  was not performed because of potential drilling
   hazards and difficult drilling  conditions caused by construction debris buried in

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   the landfill. Therefore, the landfill investigation was directed at evaluating the
   exposure scenario for the present site conditions and future (capped) conditions.

   The primary findings of the  field  sampling and analysis program were the
   detection of residual TRPH, PAHs, PCBs, solvents, pesticides, and metals in the
   shallow soils underlying this area.  These contaminants were generally found in
   the portion of the CAOC south of  North Ordnance  Road.   Low levels of
   trichloroethene, tetrachloroethene, xylenes, and methane were also detected in soil
   gas samples. PCBs were the major COPC posing a potentially unacceptable health
   risk for current land uses at CAOC 8A.

2.6.10  CAOC 9:  Southeast Sewage Lagoon

   CAOC 9 is located within the southeast corner of MCAS Yuma, southwest of the
   intersection of North Ordnance Road and  County Highway 3E (Figure 2-8). This
   CAOC formerly consisted  of  two Imhoff tanks, sludge drying beds,  and six
   lagoons occupying approximately 14 acres.  This area was used  for wastewater
   treatment between  1944 and 1970, when the Station began discharging to the
   Yuma wastewater  treatment  plant.    The  sewage  lagoons  were  unlined.
   Periodically, the sludge beds were scraped for cleaning.  The lagoons were closed
   in 1970. The sludge was  left in place and covered with fill materials.  Suspected
   waste streams associated  with  this area include used oils, used paints, solvents,
   thinners, and photograph processing waste.

   The primary findings were the detection of residual TRPH in near-surface soil and
   the isolated detection of  PAHs.  Metals detected above RBC at CAOC 9 were
   antimony, arsenic, and lead, but the RI (JEG, 1996) concluded that the  elevated
   metal concentrations detected in the  samples were anomalous and were not
   representative of concentrations at the CAOC.

   Asbestos was  not detected in the surface soil samples.  However, asbestos was
   detected in samples from one  debris pile north of the horse stables within the
   CAOC. The RI (JEG, 1996) concluded  that the asbestos at CAOC 9 was  the only
   COPC that may pose a risk to human health or the environment.

2.6.11  CAOC 10: Ordnance Munitions Disposal Area

   CAOC 10 was used during World War II as a shooting range for bomber gun
   crews (Figure  2-9).  Since the early 1950s, ordnance materials have been  stored in

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   magazines around the central portion of Ordnance Loop Road.  The area has also
   been used for surface tank and drum storage.  Surface spills have been reported
   within this area. This area continues to be used for the storage and handling of
   ordnance.  Suspected waste steams associated with this area include used oils,
   ordnance waste associated with nitroaromatics, fuel-related wastes, and metals.

   The primary finding of the field sampling and analysis program was the detection
   of TRPH, PAHs, and one anomalous lead concentration in  surface soil.  PAHs
   were detected in surface soil at four locations during the RI. Follow-up sampling
   programs in August  1996  and  February 1997  (U&A, 1996d; U&A,  1997)
   demonstrated the presence of PAHs  over a wider area than indicated by the RI.
   Several sampling locations had total  PAH concentrations an  order of magnitude
   higher than were  detected in the RI.   Figure  2-10 shows the  total  PAH
   concentrations detected in the August 1996 and February 1997 samples with the
   isoconcentrarion contours defined  in the RI Report.  Although the August 1996
   and February 1997 data support the presence of elevated PAH concentrations at
   the four areas of elevated PAHs identified in the RI  Report, the  later data also
   indicate that elevated PAH concentrations are present at locations that do not
   correspond to features identified  based on aerial photographs or geophysical
   anomalies*

2.6.12 CAOC11:  Radiation Disposal Pipes
   CAOC 11 is located near the south-central boundary of MCAS Yuma, south of
   CAOC 10 and west of CAOC 8. During Air Force operations (between 1951 and
   1959),  two sealed  iron pipes containing radioactive material (electron tubes,
   luminous markers, radium dials, and radium knobs) were buried at this location.
   The pipes were examined in April  1980 and subsequently removed and disposed
   of off Station.  Swipe tests on each pipe indicated the presence of radium 226 at
   less than one microcurie QEG, 1996).  Soil samples from  the burial pit were
   analyzed and compared to  soil from 20 to 200 feet away. No signs of residual
   radiation were found in the soil.  Because radiological contamination was not
   detected  during the radiological characterization survey, the RI concluded that
   additional soil sampling was not necessary.
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2.6.13 CAOC12: Tear Gas Burial Area

   CAOC 12 is located within the southwestern portion of the Station, approximately
   550 feet northwest of Building 1597 on the southern edge of the Combat Aircraft
   Loading Apron (CALA). This area comprises approximately 0.4 acre. The Marine
   Wing Weapons Unit (MWWU) was constructed in 1962, at which time this area
   consisted of an unpaved road that led to the MWWU. Between 1977 and 1978, 300
   pounds of dry crystal tear gas were reported to have been buried at this site. Oil
   was  also reported to have been sprayed across the surface of this area for dust
   control purposes.   This area was graded in  late  1984 when the CALA was
   constructed; no tear gas bags were revealed.  The bags may be buried deeper than
   the soils excavated during grading activities or the contents may have been mixed
   with the soil.  Suspected  waste steams in this  area  include  tear gas waste
   (including  solvents) and trihalomethanes.  Two VOCs,  methylene chloride and
   toluene, and three SVOCs were detected in soil samples; all detected values were
   below RBC values (See Section 2.10.5).  The RI found  no evidence of tear gas
   wastes at this CAOC.

2.6.14 CAOC 13:  Drain Field Area
   CAOC  13  consists of the drain field  that was formerly  used  for the MWWU
   compound when it was located at the end of Hamilton Street. This drain field is
   beneath the  14-inch-thick  concrete  at  CALA,  which  is  located within the
   southwestern portion of the center  of  MCAS Yuma,  approximately 500 feet
   northwest  of Building 1597. This area covers  approximately two acres of land.
   The  MWWU compound was constructed in 1962 and operated until 1984, when it
   was replaced by CALA. Liquid rinsates from filling and mixing equipment used
   for simulated chemical weapons (tear gas and napalm) at the MWWU were
   disposed of at a  drain field south of former Building 1585.  An estimated one
   million gallons of wastewater were discharged  to the drain field between 1970 to
   1985. Suspected waste steams associated with this CAOC include used oils, fuel-
   related wastes, solvents,  and  thinners.   PAHs,  pesticides, and metals were
   detected within the shallow soils beneath this area.

2.6.15  CAOC 14:  Drain Field South of Building 97

   CAOC 14 is located north of Building 40 and south of Building 97, comprising an
   area of approximately one acre.  A lagoon south of Building 97 has been used for

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   the collection of surface stormwater runoff since 1955.  In 1985, another lagoon
   area was constructed northwest of Building 40; in 1989, the lagoon was extended
   to the northeast. These pit configurations currently direct stormwater to the area
   northwest of Building 40. Suspected waste streams within this area include used
   oils, fuel-related waste, solvents, and thinners.

   The primary finding of the field sampling and analysis program was the detection
   of residual TRPH and isolated PAHs.  However, no individual components of
   TRPH, such as BTEX, were detected. Solvents, pesticides, PCBs, and metals were
   also detected in the shallow soils beneath this area.

2.6.16 CAOC15: Hazardous Waste USTs 363 and 364

   CAOC 15 is located  at the  Fuel Farm within the northeastern comer of MCAS
   Yuma, east of the flight line.  This area, which occupies approximately 0.3 acre,
   formerly contained two underground  storage tanks (USTs).  The USTs  were
   installed in  1943 and removed in 1987, after they failed a leak test.  Suspected
   waste streams within this area include used oils, fuel-related waste, used paints,
   solvents, and thinners. Hydrocarbons, solvents, and metals have been detected in
   the shaltow soils underlying this area.

2.6.17 CAOC 16: Hazardous Waste USTs, Building 230-2 and 230-4

   CAOC 16 is located within the northeastern comer of the flight line,  adjacent to
   Building 230, the Airframe Shop. Both tanks were removed in 1989.  Tank 230-2
   was reported to be leaking, and tank 230-4 failed a leak test. Suspected waste
   streams in this area include used paints, solvents, and thinners.

   The sampling and analysis of soil samples detected residual TRPH concentrations.
   However, no individual components of TRPH,  such as BTEX, were detected.
   Trichloroethene (in one sample  only), SVOCs and metals were  also detected.
   Metals were all within background levels.

2.6.18 CAOC 17:  Hazardous Waste Underground Storage Tank 1708-3

   CAOC 17 is the former location of a UST adjacent to Building 1708 within the
   southwest portion of MCAS Yuma.  The UST was installed in 1985 to collect
   rinsate from the decontamination pad adjacent to Building 1708.  The tank was
   abandoned in 1988 and removed in 1995. At the time the UST was removed, three

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      soil  samples were collected beneath  the tank  for laboratory  analysis.   The
      analytical results did not reveal the presence of TRPH or halogenated VOCs,
      indicating that a past release from the tank had not occurred.  Waste streams
      associated with this area include used oils, fuel-related waste, solvents, thinners,
      and vehicle-related waste.

      The primary finding of the field sampling and analysis program was the detection
      of residual TRPH. However, no individual components of TRPH, such as BTEX,
      were detected.  In addition, SVOCs, pesticides, and metals were detected, but the
      metals were within background ranges.

   2.6.19 CAOC18:  Old Drum Storage Area

      CAOC 18, comprising approximately 0.45 acres, is located within the northeastern
      corner of MCAS Yuma, north of the  Fuel Farm.  Approximately 102 55-gallon
      drums were stored within a fenced area between 1987 and 1989.   The drums,
      which contained investigation-derived wastes and waste personnel  protective
      equipment,  were removed and crushed in 1990, and the area is currently vacant.
      No historical information suggests the storage of waste within this area before
      1987. Suspected waste streams include used oils, fuel-related waste, used paints,
      solvents,  thinners,  vehicle-related   wastes,  photo  processing  waste,  and
      nirroaromatics.

      The primary finding of the field sampling and analysis program was the detection
      of residual TRPH and isolated PAHs. However, no individual  components of
      TRPH, such as BTEX, were detected.  Solvents, pesticides, and metals have also
      been detected at isolated locations in the shallow soils underlying this area.

2.7 Highlights of Community Participation

      The Community Relations Program was designed and implemented in accordance
      with the Community Relations Plan QEG, 1994a). This program is intended to
      both inform the public and to provide the public with opportunities to participate
      in the decision-making  process  for environmental cleanup at the Station.  A
      Restoration  Advisory Board (RAB), comprising representatives from  the Navy,
      U.S. EPA, the Arizona Department of Environmental Quality, and members of the
      general public, has been established and meets periodically to involve the public
      in  decisions regarding investigation results, proposed work,  and  potential

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      remedial options.  The Navy has also presented RI plans and results at public
      meetings conducted on January 18 and April 11,1996.

      The Navy has prepared a Proposed Plan for OU2 at MCAS Yuma for public
      review and comment.  The plan was presented on March 20,1997. The Proposed
      Plan  summarizes  information   collected  during  the  OU2  Preliminary
      Assessment/Site  Inspection  (PA/SI) and  Remedial Investigation/Feasibility
      Study (RI/FS) and other documents that are available at the local repositories.

      Comments regarding the Proposed Plan were accepted during a 30-day public
      review and comment period that extended from March 21,1997 to April 28,, 1997.
      A public meeting was held on April 9,  1997, to provide the community an
      opportunity to ask questions and express concerns about the Plan. Responses to
      comments  received during the public  comment  period  are  included  in  the
      Responsiveness Summary (Section 3) of this ROD.  The public comment period is
      a  continuation  of the Navy's commitment  to community  involvement in  the
      MCAS Yuma IRP and is required by CERCLA.

2.8 Scope and Role of Operable Unit 2
              0
      Response actions for MCAS Yuma are addressed as Operable Units (OUs). Two
      OUs  have  been identified at  MCAS Yuma.  OUl  addresses contamination of
      groundwater and  soils greater than 10 feet below the  ground  surface.  OU2
      consists of surface disposal and disposal units within the upper 10 feet of  soil
      underlying the Station, where  disposal or releases of petroleum products, paints,
      solvents, metals, pesticides, and other process chemicals may have occurred. OU2
      is limited to depths of 10 feet because this is the maximum likely depth for
      footings associated with any new construction at MCAS Yuma.  This ROD
      documents the remedial action plan for OU2. Remedial objectives and goals for
      OUl will be addressed in a separate ROD.

      The OU2 IRP has the following objectives:

      •   Evaluate the environmental condition of the CAOCs
      •   Identify potential threats to human health or the environment
      •   Develop cleanup actions to protect human health and the environment

      The RI investigated 18 CAOCs  at which surface  or near-surface disposal or
      releases of wastes may have occurred. The investigation of OU2 was limited to an

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      assessment of the risk/hazard posed by contaminants in the upper 10 feet of soil.
      No risk to the environment was identified at the 18 CAOCs (See Section 2.11).
      Based on the human health risk assessments summarized in Section 2.10,15 of the
      18 CAOCs are acceptable for residential land use, while chemicals identified at
      CAOCs 1 and 10 present acceptable health risks if their current, non-residential
      land uses are maintained.  Since the chemical contents of CAOC 8A (the inactive
      Southeast Station Landfill) are not known, activities that disturbed the interior of
      the landfill would have an unknown impact on human health risks. Institutional
      controls will be implemented for CAOCs 1, 8A, and 10 to minimize  potential
      health risks that might be associated with land use changes at these CAOCs.

      ACM, which was not included in the quantitative risk assessments because risk
      criteria  have not been established for asbestos, was identified in three  of the 15
      CAOCs that were assessed  to be otherwise acceptable for  residential land use.
      The ACM at these three CAOCs (4, 7, and 9) is the only material within OU2 for
      which remedial actions are recommended.

      No remedial action is recommended  for the 12 CAOCs that are acceptable for
      residential land use and have no  identified ACM. Although these areas do not
      present human health risks or ecological risks, they are still referred to as CAOCs
      (CERCLA Areas of Concern) in this document because, although  the term
      "CAOC"  is  used to identify a  potentially hazardous  site,  a CAOC is  not
      necessarily a site that requires remediation.

2.9 Summary of Field Investigation

      The field sampling effort was preceded by  extensive scoping activities that
      included a records search, personnel interviews, an aerial infrared thermographic
      survey, and acquisition and interpretation of aerial photographs.  Information was
      also  obtained   from   geophysical  subsurface   surveys   (magnetic   and
      electromagnetic)  that identified  anomalies at  several  CAOCs.  Geophysical
      surveys were performed at CAOCs 4, 8, 9,10,14,16, and 17.

      Based on past and current activities at the CAOCs, several potential waste streams
      were identified, including lubricating oils, fuel products, paints and waste paints,
      solvents and thinners, vehicle-related  wastes, photographic processing materials,
      pesticides, and herbicides. These waste streams were used as the primary basis in
      the selection of chemicals of potential concern (COPC) at each CAOC.  COPCs are
      listed in Table 2-1.

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      The RI field investigation program included soil gas surveys and soil sample
      collection and analyses. Analyses for COPCs were performed at an off-site and an
      on-site laboratory. The on-site laboratory provided data that were used for rapid
      soil screening, while the off-site laboratory data were used in the risk assessments
      for the CAOCs.   Narrative  summaries of the primary findings  of  the field
      investigation for  each of the 18 CAOCs in OU2 are included in Sections 2.6.2
      through 2.6.19.

      Tables  2-2 through  2-5  summarize  maximum  concentrations  of  volatiles,
      semivolatiles, pesticides, and metals detected in samples submitted to the off-site
      laboratory  at each CAOC, as well as the RBC values calculated for each COPC
      (Section 2.10.5). Off-site data are summarized in these tables because only off-site
      data were used in the human health risk assessment.  Samples submitted for  off-
      site analysis consisted of confirmatory splits of samples analyzed by the on-site
      laboratory  and samples collected from suspected  "hot  spots".   Hot spots  are
      localized regions where COPC  concentrations exceed risk based  criteria (See
      Section 2.10.5). Table 2-5 also includes the CAOC-specific background levels (or
      TLV  values) for  the  metals.  An  evaluation of potential human health  and
      ecological risks is presented in Sections 2.10 and 2.11.
               »
2.10 Summary of Risk Assessment

   2.10.1 Human Health Risk Assessment

      Human health risk assessments were performed on a site-by-site basis for the 18
      CAOCs within OU2.  A detailed discussion of the risk assessment procedures is
      presented in Section 4.16 and  Appendix P of the RI Report (JEG, 1996).  Results of
      the risk assessment are included  in  the site-by-site discussions in Sections  6
      through 22 of  the  RI Report. The human health  risk assessment  includes the
      identification of the COPCs,  exposure assessment, toxicity assessment, and the
      development of risk-based concentrations (RBC). The individual components of
      the risk assessment process are described below.

   2.10.2 Identification of COPCs

      The COPCs included in the risk assessment process included target  analytes  that
      were detected during the field sampling for OU2.  Table 2-1 presents the target
      analytes that constituted potential COPCs. Note that asbestos was not included in

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   the quantitative risk assessment because there are no established risk criteria for
   asbestos. The criteria for exclusion of a detected analyte from risk-based screening
   are given below:

   •  Metals that are essential human nutrients. These metals include calcium, iron,
      magnesium, potassium, and sodium.
   •  Metals that did not exceed local background values; these background values
      were expressed as threshold limit values (TLVs).
   •  Analyte concentrations less than 10 times those detected in the method blank
      for  common laboratory  contaminants.    Analytes considered  common
      laboratory contaminants include acetone, methylene chloride, and phthalates.
      The exclusion criteria stipulated are consistent with U.S. EPA recommended
      procedures (U.S. EPA, 1992a).
   •  Analytes that have no published toxicity data available (i.e., cancer potency
      factors or reference doses  as  published in  the Integrated Risk Information
      System (IRIS) and the Health Effects Assessment Summary Table (HEAST)).
   •  Analytes detected at sampling depths greater than 10 feet.
   •  Unquantified compounds (e.g., unknown ketones).

   Threshold limit values (TLVs)  were calculated for all CAOC-specific metals data
   using an U.S. EPA-approved method (U.S. EPA 1989a) that determines how many
   standard deviations from  the mean are required to have 95  percent confidence
   that the upper threshold of a normal population is at the 95th percenrile. The TLV
   method uses a K-factor that is inversely related to the size of the population data
   set (i.e., as the population size increases the K-factor decreases). TLV values for
   the individual CAOCs are included in Table 2-5.

   The maximum concentrations  from the off-site laboratory samples  taken  at hot
   spot and confirmatory splits from the upper five feet of soil were evaluated in the
   ecological risk assessment; those from the upper 10 feet of soil were evaluated for
   the human health risk assessment.  Risk assessments were not performed for
   CAOC 11 or CAOC 15. At CAOC 11, soil samples were not collected, because
   only a radiological survey was performed. At CAOC 15, soil samples were only
   collected from depths greater than 10 feet, because the investigation was focused
   on a UST buried beneath this depth.
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2.10.3 Exposure Assessment

   Exposure is the contact of a receptor (human or ecological) with a chemical or
   physical agent.  Exposure magnitude is determined by estimating the amount of
   the contaminant (analyte) available at the exchange boundary (skin, lungs) during
   a specified period of time.   Exposure assessment is the determination of the
   magnitude, frequency, duration, and pathway and route of exposure.  The RI
   exposures were assessed for reasonable  maximum exposure (RME) scenarios,
   which represent an upper-bound conservative exposure that is within the range of
   possible exposures.  If the  receptor is exposed via more than  one route  (e.g.,
   dermal contact, inhalation, etc.), the combination of exposures across all relevant
   routes must also represent an RME.

   Because ground water issues are included in the IRP for OU1, and surface water is
   not present at MCAS Yuma, potential pathways for released contaminants are
   limited to the following:

   •  Incidental ingestion of soil contaminants
   •  Dermal contact with soil  contaminants
   •  Inhalation of volatile emissions from soil
   •  Inhalation of suspended  soil particulates

   Exposure scenarios were developed for  both  current and future land  uses at
   MCAS Yuma. Because the  future land use scenarios involve a higher degree of
   exposure to chemicals at MCAS Yuma, risk management decisions were made on
   the basis of the future use scenarios.  Use of the future use scenarios, therefore,
   provided a more conservative estimate of risk.

   Exposure scenarios for  current uses at  MCAS Yuma included the following:
   military workers, for the CAOCs that are currently industrial /commercial; and
   military children, for those CAOCs in close proximity to base housing. For both of
   these scenarios, the risk assessment used an exposure duration of three years,
   which was considered to be an upper bound of the typical duty assignment at
   MCAS Yuma (JEG, 1996).

   Future use scenarios were developed assuming that MCAS Yuma was no longer
   operative and the property would be re-developed  for either residential housing,
   industrial/commercial, or agricultural activities. RME exposure scenarios were
   evaluated in terms of either an industrial /commercial scenario  or a residential
   scenario; these two  scenarios provided more  significant exposure than the

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   agricultural exposure scenario. The RME future use scenarios used standard U.S.
   EPA-approved  default  exposure  parameters.   In  particular,  the  residential
   exposure scenario used .in the assessment is not representative of base housing,
   but is based on future residential land use and represents an RME scenario of a 30-
   year lifetime exposure. Similarly, the industrial exposure scenario for future use
   includes a 25-year exposure period, rather than the three-year exposure period for
   military workers. Both residential and industrial/commercial exposure scenarios
   were used for all CAOCs, although only CAOCs 4, 6, and 8 are actually located at,
   or adjacent to, residential housing. RBC values in Tables 2-2 through 2-5 are for
   the future use  scenarios, because these represent the most conservative RBC
   values.

   Note that the Arizona Health Based Guidance Levels (HBGL) discussed in the
   ARAR  discussion in Section 2.13.4 are  derived using the  assumption that
   incidental ingestion of soil contaminants is the only significant exposure pathway.
   Therefore,  the RBC values (See  Section 2.10.5) are more conservative  than the
   HBGL values.   HBGL values are derived by ADEQ for residential and non-
   residential scenarios that are analogous to the future use industrial/commercial
   and residential scenarios used in developing RBC values.
            »
2.10.4  Toxicity Assessment

   Exposure  to  the  identified  constituents  of   concern  may, in  sufficient
   concentrations,  adversely  effect  human  health.    Therefore,  U.S.  EPA  has
   developed Cancer Potency Factors and References Doses to evaluate  potential
   toxicity.

   Cancer potency  factors (CPFs) have been developed by U.S. EPA's Carcinogenic
   Assessment Group for  estimating excess  lifetime cancer risks  associated with
   exposure to potentially carcinogenic chemicals.  CPFs,  which are expressed in
   units of (mg/kg-day)', are multiplied  by the estimated intake of a  potential
   carcinogen, in mg/kg-day, to provide an  upper-bound estimate of the excess
   lifetime cancer risk associated with exposure at that intake level. The term "upper
   bound" reflects  the conservative estimate  of the risks calculated 'from the CPF.
   Use of this approach makes underestimation of the actual cancer risk highly
   unlikely.   Cancer potency factors are derived from the results of  (1) human
   epidemiological  studies  or (2)  chronic animal  bioassays  to  which animal-to-
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   human extrapolations and uncertainty factors have been applied to account for
   the use of animal data to predict the effects on humans.

   Reference doses (RfDs) have  been developed by U.S.  EPA for indicating  the
   potential  for  adverse health effects  from exposure  to chemicals exhibiting
   noncarcinogenic effects.  RfDs, which are expressed in units of mg/kg-day, are
   estimates of lifetime daily exposure levels for  humans,  including  sensitive
   individuals. Estimated intakes of chemicals from environmental media (e.g., the
   amount of chemical incidentally ingested with soil) can be compared to the RfD.
   RfDs are derived from (1) human epidemiological studies or (2) animal studies to
   which uncertainty factors have been applied to account for the use of animal data
   to predict the effects on humans.  These uncertainty factors help ensure that the
   RfDs will not underestimate the potential for adverse noncarcinogenic effects to
   occur.

2.10.5 Development of Risk-Based Criteria

   Risk-based criteria (RBC)  are chemical-specific concentrations for a given set of
   exposure assumptions (e.g.,  residential,  military worker) and for a  particular
   medium (e.g., soil).   For the OU2 RI, COPCs in  soil were the only  evaluated
   medium (Note: This medium includes volatilization of organics from soil).

   The maximum COPC values at each CAOC were compared  to RBC. These RBC
   values are functions  of the inherent toxicity of the individual COPC and  the
   default exposure  parameters for each  of the  evaluated  exposure  scenarios.
   Consequently, different RBC values were derived for each exposure scenario that
   was considered probable at MCAS Yuma. The algorithms and the description of
   the methodology used to calculate RBC are presented in Appendix P of the RI
   (JEG, 1996).

   RBC for carcinogenic compounds were calculated by inserting the appropriate
   exposure parameters and toxicity values into the chemical intake equation, and
   setting the target cancer risk summed over all probable pathways  equal  to 10'6.
   The 10"6  risk level is considered de minimus;-a risk level exceeding 1(H is the level
   that generally warrants action at a site. An excess lifetime cancer  risk of 1 x 10"6
   indicates that, as a plausible upper bound, an individual has a one in one  million
   chance of developing cancer as a result of site-related exposure to a carcinogen
   over a 70-year lifetime under the specific exposure conditions at a site.  RBC
   values for  noncarcinogenic  effects were  calculated similarly with  the target

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   noncarcinogenic hazard index (HI) set equal to 1.0. An HI equal to or less than 1.0
   identifies a level of exposure to the chemical at which even sensitive populations
   are unlikely to experience adverse health effects.   For chemicals  with both
   carcinogenic and noncarcinogenic health effects, RBC values were determined for
   each of these health effects.

   Note  that the Arizona Health Based Guidance Levels (HBGL) discussed in  the
   ARAR discussion in Section 2.13.4 are derived using a target cancer risk of 1 x 10"*
   for carcinogens and a HI of 1.0 for noncarcinogens.

   RBC were used to evaluate cumulative cancer risk and/or non-cancer hazard at
   each CAOC. Selected samples (10 percent splits) from the on-site samples were
   sent to an  off-site laboratory  for analysis.  The maximum soil concentration
   detected at the off-site laboratory for  each analyte detected at the CAOC was
   compared to the cancer and/or noncancer RBC for that analyte.  Risk quotients
   were calculated by dividing the maximum concentration of the analyte  by  the
   applicable RBC for carcinogenic compounds. For carcinogens, a risk quotient of 1
   is equivalent to a cancer risk of 10*, while a risk quotient of  10 is equivalent to a
   cancer risk of 10"5.  Hazard quotients for non-carcinogenic COPCs  were calculated
   similarly. • The carcinogenic and non-carcinogenic quotients for each analyte were
   then each summed to provide CAOC-specific cumulative indices.

2.10.6 Summary of Risks at Individual CAOCs

   Introduction

   Health risks were calculated for OU2 on a  CAOC-by-CAOC basis.  For each
   CAOC, risks were calculated for both residential and industrial use scenarios. The
   RBC values and maximum COPC values that were used for  each CAOC-specific
   risk assessment are included in Tables 2-2 through 2-5. Calculated excess lifetime
   cancer risks are within the range of acceptable risk defined by the U.S. EPA (10*6
   to 10"*) (U.S. EPA 1994c) for current land uses.  However,  as discussed  below,
   excess cancer risks for unrestricted  land use (residential) may  be higher than
   acceptable at CAOCs 1 and 10. The calculated excess cancer risks for these two
   CAOCs  are discussed below.  Since the chemical contents of CAOC 8A (the
   inactive Southeast Station  Landfill)  are not known,  potential  cancer risks
   associated with exposure  to the landfill interior are not known. Based on the RI,
   U.S. EPA, ADEQ, and  the Navy concluded that  HI values  were acceptable for
   residential exposure at  16 of the CAOCs and that HI values were acceptable for

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   industrial exposure at the remaining CAOCs, 1 and 10.  The following discussion
   focuses on cancer risk at CAOCs 1,8A, and 10.

   CAOC1: Flight Line

   The excess cancer risk for CAOC 1 is 6.48 x 10'5 for the commercial/industrial
   exposure scenario.  Approximately 90 percent of the excess CAOC cancer risk is
   attributable to PAHs, 4 percent to PCBs, 2 percent to pesticides, and 4 percent to
   metals.  The RI concluded that the 0- to 10-foot soils at CAOC 1 do not pose an
   unacceptable risk to human health under the commercial/industrial use scenario,
   which coincides with the current use of the CAOC (JEG, 1996).

   For a residential exposure scenario, the calculated excess lifetime cancer risk is
   2.19 x 10"4, 83 percent of which is attributable to PAHs.  The excess lifetime cancer
   risk at CAOC 1 is greater than the acceptable range for an unrestricted residential
   use scenario.

   CAOC 8A: Southeast Station Landfill South of North Ordnance Road.

   The portion of CAOC 8 south of  North Ordnance Road has  been designated
   CAOC 8A,  Landfill/Surface Disposal Area.   In CAOC 8A,  Landfill/Surface
   Disposal Area,  the excess cancer risk is  9.94 x 10'5 for the residential  exposure
   scenario, which is at the upper end of the acceptable range of  risk (10"6 to 10"4)
   defined by the U.S. EPA. PCBs contribute approximately 74 percent of the overall
   cancer risk.  Aroclor-1254 was detected at three surface sampling locations at soil
   concentrations of 4.045, 0.99,  and  0.32  mg/kg.  For a commercial/industrial
   exposure scenario, the excess cancer risk  is 3.02 x 10'5.  Based on the fact that the
   landfill interior has not been fully characterized  and therefore the human health
   risks associated with exposure to the landfill interior are not known, U.S. EPA,
   ADEQ, and the Navy have made a risk management decision to  restrict the use of
   CAOC 8A to the current use and to prohibit any land  use that  could potentially
   disturb the interior of the landfill.

   The maximum concentration of lead detected at CAOC  8A (659 mg/kg)  is greater
   than  the U.S. EPA  Region  9 residential soil  screening value of 400 mg/kg.
   Therefore, lead represents a potential health risk for future residents at the CAOC
   8A Land fill/Surface Disposal Area.
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   CAOC 10:  Ordnance Munitions Disposal Area

   The excess cancer risk calculated from the RI data is 7.62 x 10~5 for the residential
   exposure scenario and is primarily attributable to PAHs.  Benzo(a)pyrene is the
   PAH driver, with an incremental cancer risk of 5.62 x 10~5.  The excess cancer risk
   for the industrial exposure scenario is 2.42 x 10"5.

   Based on data from the August, 1996 and February, 1997 field investigations and
   the RBCs derived in the RI, the excess cancer risk from PAHs for the residential
   exposure scenario was recalculated as  4.6 x 10"*  and for the  industrial scenario,
   1.5 x 10"4 (U&A, 1997). The recalculated industrial excess lifetime cancer risk is at
   the up'per end of the range of risks that are potentially acceptable for industrial
   exposure scenarios.

   The  RI Risk-Based Criteria (RBCs) used to calculate carcinogenic risk  were
   developed in 1993 using U.S. EPA exposure factors. U.S. EPA's dermal exposure
   factors have  since been revised.  If the RBCs were calculated  with the  current
   (1996) EPA-approved  factors, the RBCs  for PAHs would be identical to U.S. EPA
   Preliminary Remediation Goals (PRGs). Using the same data and calculating the
   risks using PRGs, the industrial and residential excess lifetime cancer risks are
   7.0 x 10"s and 2.9 x 10"4, respectively.  The industrial excess  lifetime cancer risk
   calculated with PRGs is in the middle of the range of risks that are acceptable for
   industrial exposure scenarios.

   Conclusion

   The risk assessment performed for the 18 OU2 CAOCs indicates that constituents
   detected in the soil do not pose a significant risk to human populations under
   current use scenarios.  However,  at CAOCs 1, 8A,  and 10 risks for unrestricted
   land use may be higher than acceptable. In addition, asbestos was not included in
   the risk assessment because  no risk criteria have been established for asbestos.

   ACM was identified  at three of  the CAOCs.   The major risk associated with
   asbestos is the potential for  inhalation of airborne  asbestos  fibers.  Asbestos
   exposure  can cause a number of  disabling  and  fatal diseases.   The  risk of
   developing asbestos-related disease is related  to  the intensity, duration, and
   nature of the exposure.  Large doses of asbestos fibers are clearly linked to a
   higher incidence of disease.  The amount of ACM in the CAOCs at MCAS Yuma is
   relatively low, and exposure  would only occur  in  the open  air. Therefore, the

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      potential for humans to inhale significant amounts of airborne asbestos fibers
      from the ACM in soils is extremely low; air monitoring conducted during the RI
      did not detect any asbestos fibers. Risks to ecological receptors from ACM in the
      environment have not been documented. Although current risks from ACM are
      low, weathering of ACM in  the soils could degrade the ACM and release fibers
      into the environment. These fibers could become airborne.  For this reason, a risk
      management decision has been made to take remedial action.

      Hazardous substances from this site present a substantial threat of release, which
      may pose a significant risk to human health and the environment if not addressed
      by implementing the response action selected in this ROD (see Section 2.14).

2.11 Summary of Ecological Risks

      The objective of the ecological risk assessment  was to evaluate the impact to the
      environment if remedial actions are not taken. A phased approach was used.  The
      first step, Qualitative Assessment, screened areas based on the physical, chemical,
      and biological attributes and  the potential  for a complete exposure pathway.
      CAOCs with no significant exposure pathways  were recommended for no further
      ecological investigation.  The second step was to further evaluate CAOCs with
      significant exposure  pathways by  comparing concentrations of chemicals of
      potential ecological concern (COPECs) with ecological soil screening criteria.  Soil
      screening criteria are discussed in Section 4.16 of the RI Report and  derived in
      Appendix Q of the RI report QEG, 1996).  COPEC concentrations exceeding soil
      screening criteria were identified as posing a potential risk to vertebrate receptors.
      Conversely, COPECs that did not exceed soil screening criteria were concluded to
      not pose a risk.  If a CAOC contained COPECs  exceeding screening criteria, other
      supporting  evidence was used  to  identify whether  a significant impact  had
      occurred or was likely to occur.

      With the exception of migratory  birds that have been observed in the airspace
      above MCAS Yuma, no state or federally listed threatened or endangered species
      are currently known to be present at MCAS Yuma. No critical habitats or habitats
      of endangered species are affected by COPECs at OU2.

      In general,  the  COPECs identified  at  the CAOCs are fairly immobile and the
      majority of detected inorganic risk drivers can be attributed to background. In
      addition, the majority of the CAOCs either have only a small portion of the CAOC
      that could provide contact between receptors  and potentially contaminated soil,
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       have been significantly altered by vehicular traffic and disposal activities, or have
       only a limited area of remaining natural habitat.  Therefore, the ecological risk
       assessment performed for the 18 OU2 CAOCs indicated that constituents detected
       in the soil and surface water do not pose a significant risk to ecological receptors.

2.12 Description of Alternatives

   2.12.1 Introduction

       Based upon the human health and ecological risk assessments, U.S. EPA, ADEQ,
       and the Navy agreed that no further action is required at 12 of the 18 CAOCs to
       protect human health or the environment.  However, because of the presence of
       ACM  in three CAOCs, remedial action (cleanup)  is required to protect human
       health, since the ACM could release asbestos fibers into the environment if left to
       weather under current conditions.  In addition, institutional controls are necessary
       for  CAOCs  1, 8A, and 10 to minimize potential health risks that might  be
       associated with land use changes at these CAOCs.

   2.12.2 CAOCs Requiring Remediation of ACM in Soil
               *
       The OU2 RI identified CAOCs 4, 7, and 9 as containing ACM. These CAOCs were
       evaluated in the  FS for remedial action (U&A, 1996b). Two of the CAOCs have
       been divided into soil remedial units; a  remedial  unit is defined as the area or
       volume of ACM or ACM-contaminated soil to be remediated. The following
       describes the lateral and vertical extent of ACM in soil requiring remedial action.

       CAOC 4—Radar Hill Disposal Area

       CAOC 4 is located south  of Radar Hill in the central portion of  MCAS Yuma
       (Figures 1-2 and 2-4).  Two areas were confirmed to contain ACM:

       4A    Area north of Building 38 and  east of Building  40:  Small  pieces of
             asbestos-containing transite, cement pipe,  and roofing materials  mixed
             with soil and other construction debris. The ACM was observed scattered
             over the surface in an area of approximately 56,400 square feet.  A field
             investigation found that  the  contamination  extended to approximately
             seven feet in depth in a limited area of approximately 12,550 square feet
             near the central portion of the unit (approximately 4,000 cubic yards after
             excavation).

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   4B    Area west of Radar Hill: One debris pile containing approximately three
         cubic yards of ACM fiberboard is located in this area.

   CAOC 7—Fire  School Area and Debris Piles  South of the Combat Aircraft
   Loading Apron (CALA)

   CAOC 7 contains two remedial units designated CAOC 7A (Fire School Area)
   (Figure 2-5) and CAOC 7B (Debris Piles South of CAM) (Figure 2-6).

   7A    Fire School Area:  Small broken pieces of asbestos-containing  transite
         siding and transite pipe were observed at the surface south and east of the
         active fire-training pit. The area contaminated with ACM is approximately
         179,000 square feet.  Over most of the unit, the ACM occurs only as surface
         scatter. In a limited area near the active bum pit, the ACM contamination
         reaches a maximum of one foot deep  (up to  1,200 cubic yards after
         excavation).

   7B    Debris Piles South of CALA:  The area immediately south of CALA  has
         been used for dumping construction debris. Seven sites within this area
         were confirmed to contain ACM debris. These sites consist of isolated,
         coherent piles  (in one case, a single piece) containing one or more of the
         following types of  ACM:   floor tile  with asbestos-containing mastic,
         transite,  and/or ACM  pipe.   The  total   volume  of  ACM  debris is
         approximately 10 cubic yards.

   CAOC 9—Horse Stable Area

   A small pile of construction debris, north of the horse stable, was confirmed to
   contain   asbestos-containing  mastic  (cement) adhered  to  non-ACM   riles
   (Figure 2-8). The maximum volume of ACM at this CAOC is estimated to be  less
   than one cubic yard.

2.12.3  Alternatives Considered for Remediating CAOCs 4,7, and 9

   Four alternatives have been developed and evaluated for the remediation of ACM
   at MCAS Yuma. The alternatives are listed and described below.
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   Alternative 1—No Action

   The No-Action alternative was used as a baseline alternative against which other
   alternatives were  judged.  With this alternative, there would be no action to treat,
   contain, or remove any of the surface ACM or ACM-contaminated soil.  In the
   long term, ACM  fragments may degrade and release  asbestos fibers into the
   environment.  Short-term conditions would remain unchanged.  There are no
   costs associated with this alternative.

   Alternative 2—Cleanup of Surface ACM Debris

   Under this alternative, ACM fragments visible on soil surfaces would be collected
   manually.  Collection would include removing approximately the upper inch of
   soil beneath the ACM to reduce the potential for asbestos fibers remaining behind
   in the soil.   The ACM  and soils  would  be stockpiled, manifested, loaded,
   transported, and disposed of at a permitted facility.

   The ACM mixed with soils beneath the surface in  CAOCs 4A and 7A would
   remain in place.  Because ACM  would remain in place in the eastern portion of
   CAOC 4A,  this area would require  long-term maintenance to prevent buried
   ACM from  becoming exposed and  dispersed in the environment, and a  Base
   Master Plan restriction indicating that ACM is present.  The total estimated cost
   for implementing this alternative is approximately $90,000.

   Alternative  3—Cleanup of ACM on Soil Surface and Excavation of Soils Mixed
   with ACM

   Under this alternative, ACM fragments visible on soil surfaces would be collected
   manually, as described under Alternative 2. In areas in which ACM is mixed with
   soil beneath the surface (CAOC 4A, north  of Building 38; and CAOC 7A, limited
   area near the  active burn pit), the contaminated soils would be excavated with
   conventional construction equipment. The ACM and soils would be stockpiled,
   manifested, loaded, transported, and disposed of at a permitted facility.  The total
   estimated cost for implementing this alternative is approximately $710,000.

   Alternative 4—Cleanup of ACM on  Soil Surface, Partial Excavation, and Partial
   Capping

   Under this alternative, ACM fragments visible on soil surfaces would be collected
   manually, as described under Alternative 2.  In the  limited area near the  active

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     bum pit (CAOC 7A), where ACM is mixed with surface soils to a maximum depth
     of one  foot,  the contaminated soils would be  excavated with  conventional
     construction equipment,  as  in Alternative 3.   This  alternative  differs  from
     Alternative 3 in that only the central portion of the remedial unit north of Building
     38 (CAOC 4A) would be excavated,  since the Station has plans to develop this
     area. The eastern portion of CAOC 4A would be  capped with asphalt. Because
     ACM would remain in place in the eastern portion of CAOC 4A, this area would
     require long-term maintenance of  the cover and a Base Master Plan restriction
     indicating that ACM is present. The total estimated cost for implementing this
     alternative is approximately $880,000.

  2.12.4 CAOCs with Potential Health Risks
     The human health  risk assessment associated with  the OU2  RI indicated that
     residential use of CAOCs 1 and 10 had a potential to present an unacceptable level
     of carcinogenic risk. In addition, unrestricted use of CAOC 8A has the potential to
     pose an unacceptable health risk because the landfill interior has not been fully
     characterized. The use of institutional controls for  these CAOCs was evaluated in
     the FS (U&A, 1996b).
             *

  2.12.5 Alternatives Considered for Responding to Potential Health Risks at
     CAOCs 1,8A, and 10

     In accordance with the U.S. EPA Interim Final Guidance for Conducting Remedial
     Investigations and Feasibility Studies  Under CERCLA (U.S.  EPA, 1988), general
     response actions (GRAs) are identified as those general classes of actions that can
     be taken to manage or control a particular problem at a site.  Based on discussions
     between U.S. EPA, ADEQ, MCAS Yuma, and the Navy1, two GRAs were selected
     for consideration as potentially applicable at CAOCs 1, 8A, and 10.

     •  No Action (included in accordance with CERCLA guidance)
     •  Institutional controls

     Alternative 1,  No Action:   The no  action  alternative  does not present  an
     unacceptable risk to human health under current use  scenarios.   However,
     unrestricted future uses of the three CAOCs could lead to unacceptable risk levels.
Meeting between representatives of U.S. EPA, ADEQ, MCAS Yuma, the Navy, and U&A held on June 20,
1996 in San Francisco, California.

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Alternative 2, Institutional Controls:  The institutional controls would restrict the
land use of CAOC 1 and CAOC 10 to industrial/commercial use and CAOC 8A to
the current use (inactive landfill /surface disposal area). The institutional controls
would be implemented through  the Base Master Plan, which would reference the
OU2 ROD. Additions to the Base Master Plan would include a map indicating the
locations of the former disposal  areas in CAOC 8A. This would include execution
and recordation of a VEMUR in accordance with and substantially in the form set out
at Arizona Revised Statutes, Section 49-152. The VEMUR would contain language
clarifying that  it was executed and recorded  by  the federal  government, or the
appropriate entity of the federal government, "for itself only, and not as a covenant
running with the land". In addition, it would clarify that:

   a. The parties  agree that no interest in real property  on behalf of the State of
      Arizona is created  either by this VEMUR or by any notice of cancellation of
      this VEMUR pursuant to A.R.S. 49-152.

   b. The signature of an authorized representative of the Arizona Department of
      Environmental Quality  (ADEQ) which appears herein acknowledges that the
      remediation of the  property was conducted in accordance with the provisions
      of A.R.S 49-152.

The Base Master Plan would require that any changes in activities in these CAOCs
or land  use changes be coordinated through and reviewed by the MCAS Yuma
Environmental Department. Before the land use restrictions are  incorporated in
the BMP, the Navy will obtain the approval of the U.S. EPA for the language of
the restrictions and the location in the BMP at which the approved language will
be incorporated. In the event that the Navy plans any future  changes in land use
at CAOCs 1, 8A, or 10, the Navy in consultation with U.S. EPA and ADEQ would
re-evaluate the remedy in light of the intended land use.  If the change in land use
is not compatible  with the remedy, the remedy may be changed pursuant to
CERCLA Sections  120 and  121  and the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP) Section 300.430 (0 (4) (iii) and the ROD may be
amended. If the Navy plans to  excess the property to a non-federal entity, it will
notify ADEQ and EPA in advance of the execution of any such transfer. The Navy
will  consult   with   ADEQ   and  EPA  in  revisiting  existing  land   use
classifications/restrictions for the CAOC (or, in the alternative, the  remedial
action selection) to determine if the foreseeable future land use differs  from the
assumptions made at the time the original remedial action decision was made.  At
that  time, a  re-evaluation of  the  appropriate  institutional controls  will  be
undertaken by the Navy, in consultation xvith ADEQ and EPA.  For CAOC 1 or

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      CAOC 10, a change in land use from industrial to residential use would require
      re-evaluation of the remedy. For CAOC 8A, a change in land use involving any
      activities that may require disruption and exposure of the landfill interior would
      require re-evaluation of the remedy.  At the time of these future activities, further
      investigation may be undertaken in order to determine if remediation is required
      and if the ROD must be amended.

2.13 Summary of the Comparative Analysis of Alternatives

   2.13.1  Introduction
      The remedial alternatives developed in the FS were analyzed in detail using the
      nine evaluation criteria  required by the NCP (Section 300.430 (e) (7)).  These
      criteria are classified as threshold  criteria,  primary balancing criteria,  and
      modifying criteria. Threshold criteria are listed below:

      •   Overall protection of human health and the environment
      •   Compliance with ARARs

      Primary balancing criteria are as follows:
               9
      •   Long-term effectiveness and permanence;
      •   Reduction of toxicity, mobility, or volume through treatment
      •   Short-term effectiveness
      •   Implementability
      •   Cost

      Modifying criteria:

      •   State/support agency acceptance
      •   Community acceptance

      The proposed alternatives were evaluated to identify the alternative providing the
      best balance among the nine criteria for each CAOC at which remedial actions are
      required. Evaluation of the four alternatives  for ACM with respect to the nine
      criteria are summarized  in Section 2.13.3, and the two alternatives for CAOCs that
      may present a health risk are similarly evaluated in Section 2.13.4.  Note that for
      the 12 CAOCs that require no further action, ARARs are not triggered because
      remedial action is not required at these CAOCs.

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2.13.2  Applicable or Relevant and Appropriate Requirements

   Pursuant  to Section 121(d)(l)  of CERCLA  [42 USC Section 9621(d)], remedial
   actions must attain a degree of cleanup that assures protection of human health
   and the  environment.   In addition, remedial  actions that leave  hazardous
   substances,  pollutants,  or  contaminants  on  site  must  meet  standards,
   requirements, limitations, or criteria that are ARARs. Federal ARARs may include
   requirements under any federal  environmental laws  or state  requirements
   adopted  pursuant to a federally-authorized  program.  State ARARs  include
   promulgated requirements under state environmental or facility-siting laws that
   are more stringent than federal ARARs and that have been identified to the lead
   federal agency by the State in a timely manner.

   Applicable requirements are those cleanup standards, control  standards, and
   other substantive environmental protection  requirements, criteria, or limitations
   promulgated under federal or state law that specifically address a hazardous
   substance,  pollutant,   contaminant,  remedial   action,   location,  or   other
   circumstances at a CERCLA site.

   Relevant and appropriate requirements include those that, while not "applicable"
   to a hazardous substance, pollutant, contaminant,  remedial action, location, or
   other  circumstances at  a  CERCLA  site,  nevertheless address  problems or
   situations sufficiently similar to those encountered at the CERCLA site to indicate
   that their use is well suited to the particular site. A requirement must be both
   relevant and appropriate to be designated an ARAR.  If no ARAR addresses a
   particular situation, or  if an ARAR is insufficient to protect human health or the
   environment, then nonpromulgated standards,  criteria,  guidance, and to-be-
   considered (TBC) advisories may be used to provide a protective remedy.

   On-site response actions may proceed without  obtaining permits pursuant to
   CERCLA  Section 121(e).  This permit exemption allows the response action to
   proceed in an expeditious manner, free from potential lengthy delays of approval
   by  administrative bodies.  This  permit exemption  applies to all administrative
   requirements,  whether or  not they are actually styled  as  "permits."   Thus,
   administrative requirements cannot be ARARs.

   Off-site remedies  must comply  with all applicable laws  and must obtain all
   necessary permits and fulfill all administrative procedures.
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   ARARs are identified on a site-specific basis from information  about specific
   chemicals at the site, specific actions that are being considered as remedies, and
   specific features of the site location. There are three categories of ARARs.

   Chemical-specific ARARs are numerical  values or methodologies that,  when
   applied to site-specific conditions, result in the establishment of numerical values.
   They are used  to determine  acceptable  concentrations of specific hazardous
   substances, pollutants, and contaminants in the environment.

   Location-specific ARARs  are  restrictions  placed  on  the  concentrations  of
   hazardous substances or the conduct of activities solely because the site occurs in
   a special location, such as a wetland or floodplain.

   Action-specific  ARARs  are  technology  or activity-based  requirements  or
   limitations on actions taken with respect to hazardous waste.  In some  cases,
   ARARs that may be associated with a particular remedial action (such as closure,
   discharge, or land placement) can be characterized as both action-specific ARARs
   and chemical-specific ARARs, because they include numerical values for chemical
   concentrations.
            »
2.13.3  Preferred Alternative for ACM in Soil

   The preferred alternative for addressing asbestos at MCAS Yuma is Alternative 3,
   cleanup of ACM on  soil surface and excavation  of soils mixed with ACM. This
   alternative meets the nine ranking criteria  that the U.S. EPA uses to evaluate
   alternatives. The remainder of this section  summarizes the performance  of the
   preferred alternative against  the nine evaluation  criteria and  notes how it
   compares to the other alternatives considered.  Because the No Action alternative
   is not protective of human health and the environment, it is not considered in the
   " evaluation.

   Overall Protection of Human Health and the Environment

   Alternatives 2,  3, and 4 are considered  protective of human health  and the
   environment.    The preferred alternative  (Alternative 3)  provides  the best
   protection of human health and the environment, since all ACM is removed from
   the site.
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   Compliance with ARARs

   The federal ARARs are summarized below:

   Federal Chemical-Specific ARARs for ACM at MCAS Yuma: No federal chemical-
   specific ARARs have been identified for ACM at MCAS Yuma OU2.

   Federal Location-Specific ARARs for ACM at MCAS Yuma:  Federal laws that
   were identified by the  Navy as potential location-specific ARARs QEG, 1995d)
   include the following:

   •  National Historic Preservation Act, 16 USC Section 470-470w-6 [36 CFR Part
      800] and the Archeological Resource Protection Act,  16 USC Section 470ii
      [36 CFR Part 299]:  Scientific, prehistoric, or archaeological artifacts may be
      present at MCAS Yuma.

   •  Endangered  Species  Act, 16  USC  1531  et set}.;  and  Fish and  Wildlife
      Coordination Act, 16 USC 661 et seq. [50 CFR Parts 200 and 402, and 33 CFR
      Parts 320-330]: With the exception of migratory birds that have been observed
      in the airspace above MCAS Yuma, no state  or federally listed threatened or
      endangered species  are currently known to be present at MCAS Yuma.

   •  Migratory Bird Treaty Act of 1972,16 USC 703:  Migratory birds have been
      observed in the airspace above MCAS Yuma.

   ACM waste at MCAS Yuma was disposed of at the land surface. The federal laws
   given above do not appear to apply to the remedial action alternatives because the
   alternatives are not anticipated  to disturb habitats or excavate native soils.  In
   addition, the Station is  not expected to be included in or eligible for the National
   Register of Historic Places. A 1997 archeological survey of MCAS Yuma identified
   a circa 1940s historic trash site and three isolated  occurrences of Native American
   Pottery; none of these sites are impacted by remedial activities for OU2.  Thus, no
   federal location-specific asbestos ARARs pertaining specifically to asbestos or to
   the selection of remedial action alternatives have been identified.

   Federal Action-Specific ARARs:   Federal  action-specific ARARs  include  the
   following:
   •  Clean Air Act,  National Emission Standard for Hazardous Air Pollutants
      (NESHAP) USC 7401 to  7671(q):   Asbestos was  first designated  as a
      hazardous air pollutant under the Clean Air Act  in 1971.  The National
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      Emission Standard  for Hazardous Air Pollutants (NESHAP)  for  asbestos
      found at 40 CFR Section 61, Subpart M is considered an action-specific ARAR
      for the site. ADEQ is the lead agency for asbestos NESHAP compliance.  The
      requirements listed below  are not applicable, because they address  asbestos
      from operations (i.e., demolition, renovation, fabricating, and spraying)  that
      are not related to the proposed remedial action. The substantive requirements
      are  considered  relevant and appropriate, however,  because they  address
      problems similar to those encountered at CERCLA sites.

      •  Section 61.145:  Applicability, Notification Requirements, and Asbestos
         Emission Control:   NESHAP applies to demolition or renovation of
         facilities with ACM.  Remediation of ACM at MCAS Yuma is neither a
         renovation nor demolition operation. Notification (Section 61.145(b)) is an
         administrative requirement that is not  applicable to CERCLA actions.
         However, procedures for asbestos emission control (Section 61.145(c)) are
         substantive requirements that are considered relevant and appropriate.

      •  Section 61.150:   Standards  for  Waste Disposal  for  Manufacturing,
         Fabricating,  Demolition,  Renovation  and  Spraying  Operations:
         Procedures  for ACM waste handling, transportation, and  disposal are
         considered  relevant  and appropriate.   Both  the  administrative  and
         substantive  requirements of this section are considered  ARARs because
         transportation and disposal will occur off site.

   The state ARARs are summarized below:

   State Chemical-Specific ARARs for ACM at  MCAS Vuma:  No state chemical-
   specific ARARs have been identified for ACM at MCAS Yuma OU2.

   State Location-Specific ARARs for ACM at MCAS Yuma: The following state law
   was identified by the Navy as a potential location-specific ARAR (JEG, 1995d):

   •  Arizona Revised Statutes, Title 41: State Government; Chapter 4.1, History,
      Archaeology and State Emblems; Article  4:   Archaeological Discoveries
      [ARS 41-844A]: Archaeological, palaeontological, or historical features may be
      discovered at  MCAS Yuma during  the course of surveys, excavations, or
      construction that occur during a remedial action.

   ACM waste at MCAS Yuma was disposed of at the land surface. The state law
   identified in this  section  does  not  appear  to apply to  the  remedial  action
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   alternatives.  MCAS Yuma is currently consulting  with the  Arizona historic
   preservation office.  Although a final determination has not yet been made, the
   Station is not expected to be included in or eligible for the National Register of
   Historic Places. A 1997 archeological survey of MCAS Yuma identified a circa
   1940s historic trash site and three isolated occurrences of Native American
   Pottery; none of these sites are impacted by remedial activities for OU2. Thus, no
   state location-specific asbestos  ARARs pertaining specifically to asbestos or to the
   selection of remedial action alternatives have been identified.

   State Action-Specific ARARs:  ADEQ  is  the lead agency for implementing
   NESHAP, which was identified as an ARAR under the  discussions of federal
   ARARs.
   Other Criteria:  As discussed above, if no ARAR addresses a particular situation,
   or if an ARAR is insufficient to protect human health or  the environment, then
   nonpromulgated standards,  criteria,  guidance, and  to-be-considered (TBC)
   advisories may be used to provide a protective remedy. Other criteria that were
   evaluated as potential TBC include the following:

   •  Chief of Naval  Operations Instruction (OPNAVINST) 5100.23D, Chapter 17:
      The Navy manual  provides guidance for  controlling or  eliminating  the
      exposure of Navy personnel to asbestos during the use, removal, and disposal
      of ACM.

   These provisions apply  primarily to building structures  and facilities  and  are
   guidance only.  Since  compliance with the  NESHAP requirements discussed
   above  under federal  action-specific  ARARs  and  with  federal OSHA  are
   considered sufficient to provide a remedy that is protective of human health and
   the environment, the Navy manual is not considered TBC.

   Summary of Compliance of  with ARARs:   Alternatives  2, 3, and 4 are in
   compliance  with ARARs.  A brief summary of the ARARs applicable to the
   remediation of ACM contamination at OU2 is given in Table 2-6.

   Long-Term Effectiveness and Permanence

   Alternatives 3 and 4 provide adequate long-term effectiveness and permanence.
   For Alternative 2, in areas where ACM  is mixed with subsurface soil,  this
   alternative is not effective for several reasons:
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   •  Wind and water erosion may remove surface  soils, exposing  the ACM
      fragments mixed with subsurface soils. If ACM become uncovered, additional
      cleanup would be required.
   •  The Station would have to place a Base Master Plan restriction indicating that
      ACM is present in these areas. Future development may be limited.

   Reduction ofToxicity, Mobility, or Volume by Treatment

   This criterion is not applicable because none of the alternatives reduce toxicity,
   mobility, or volume through treatment.

   Short-Term Effectiveness

   There may be minimal short-term health and safety risks to nearby workers from
   dust emissions during remedial actions.  Overall, Alternatives 2, 3,  and 4 are
   considered effective in the short term for the following reasons:

   •  Controls, such as dust control and air monitoring, would be implemented to
      minimize environmental impacts.
   •  Workers would be  adequately protected  during  the remedial  action  by
      compliance  with  Occupational Safety  and Health  Administration  (OSHA)
      requirements.
   •  Can be implemented within a few weeks.

   Implementability

   There are no technical, administrative, or availability of services and materials
   concerns regarding the implementability of the remedial alternatives.  Loading
   and  transportation of soil  and ACM  debris are  widely  used and  can  be
   accomplished using well established, conventional construction techniques and
   equipment.

   Cost

   Alternatives 3 and 4 are considered the most protective of human health and the
   environment  and  have the highest  long-term effectiveness.   The  preferred
   alternative, Alternative 3,  is more cost effective ($710,000)  than Alternative 4
   ($880,000).
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   State Acceptance

   ADEQ agrees with the preferred alternative (Alternative 3).

   Community Acceptance

   Based  on public input on the Proposed Plan (see  Section 3.3)  the  preferred
   alternative is acceptable to the community (Alternative 3).

   Based on U.S.  EPA evaluation criteria, the rationale for selecting Alternative 3 as
   the preferred alternative is as follows:

   •   It provides long-term protection of human health and the environment.
   •   It does not require long-term operation and maintenance.
   •   It allows unrestricted future Station use.
   •   It is acceptable to the Navy, regulatory agencies, and the community.

2.13.4  Preferred Alternative for Responding to Potential Health Risks at
   CAOCs 1,8A and 10

   The preferred alternative for addressing potential health risks at CAOCs 1, 8A,
            *                             '                     	
   and 10 at MCAS Yuma is Alternative 2, institutional controls.  This alternative
   meets the nine ranking criteria that the U.S. EPA uses to evaluate alternatives. The
   remainder of this section summarizes the performance of the preferred alternative
   against the nine evaluation criteria and notes how it compares to the No Action
   alternative.

   Overall Protection of Human Health and the Environment

   Alternatives  1  and   2  are  considered  protective of human health and the
   environment under current use scenarios for CAOCs 1, 8A, and 10.  The preferred
   alternative (Alternative 2) provides the best protection of human health and the
   environment,  since risk would be managed for any future changes in land use
   scenarios at these CAOCs.

   Compliance with ARARs

   Compliance with Federal ARARs: Federal ARARs have not been identified  for
   PAHs in soils at CAOC 1 and CAOC 10 or PCBs in soils at CAOC 8A.
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   Compliance with State Location- and Action-Specific ARARs: State location- and
   action-specific ARARs have not been identified for PAHs in soils at CAOC 1 and
   CAOC 10 or PCBs in soils at CAOC 8A.

   Compliance with State Chemical-Specific ARARs:

   Under the authority of Arizona Revised Statutes Section 49-151 and Section
   49-152,  ADEQ has established  Department-wide standards applicable  to soil
   remediation activities.  The Amended Soil Remediation Rules  were adopted in
   Arizona Administrative Code (AAC) Title 18, Chapter 7, Article 2, Interim Soil
   Remediation  Standards (Sections R18-7-201 through R18-7-209) in 1996.   These
   regulations are not considered  "applicable", since  remedial actions are being
   conducted pursuant to federal law (i.e., CERCLA), rather than  under one of the
   State regulatory programs listed in AAC, Title 18, Section R18-7-202.A. Nor is the
   Marine Corps requesting a "close-out document", as described in R18-7-202.B, for
   a cleanup under  State law.  State concurrence is being sought in the remedy
   selected under federal law. However, the Marine Corps has determined certain
   substantive requirements of AAC, Title 18, Chapter 7, Article 2 to be relevant and
   appropriate to the soil remediation activities described in this ROD.
           f
   The regulations allow soil remediation activities that attain one of three standards
   (Section R18-7-203):  1) remediation  to background levels; 2) remediation to the
   Health  Based Guidance Levels (HBGLs) presented  in Appendix A of Title 18,
   Chapter 7, Article 2; or 3) remediation to levels derived from a site-specific risk
   assessment. HBGL values for the PAHs and PCBs detected at CAOCs 1, 8A, and
   10 are presented in Table 2-8.

   Other Criteria: As discussed above, if no ARAR addresses a particular situation,
   or if an ARAR is insufficient to protect human health or the environment, then
   nonpromulgated  standards,  criteria, guidance,  and to-be-considered  (TBC)
   advisories may be used to provide a protective remedy. Other  criteria that were
   evaluated as potential TBC include the following:

   •  U.S. EPA  Guidance  USEPA/540/G-90/007:   This  guidance describes the
      recommended approach for evaluating  and remediating  sites  with PCB
      contamination.

   CAOC 8A was the only CAOC at which PCB concentrations were higher than are
   acceptable for unrestricted, residential land use.   Since a human health risk

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   assessment has been performed for current land use at CAOC 8A, Alternative 2 is
   considered to provide a remedy at CAOC 8A that is protective of human health
   and the environment. Therefore, the EPA guidance is not considered TBC.

   Summary  of Compliance with  ARARs:  Alternative 2  is  in compliance with
   ARARs. A brief summary of the ARARs applicable to CAOCs 1,  8A, and 10 is
   given in Table 2-7.

   Long-Term Effectiveness and Permanence

   Alternative  2 provides  adequate  long-term  effectiveness and  permanence.
   Alternative 1 is  not  as effective because changes in land  use  could  result in
   potentially unacceptable risks to human health.

   Reduction ofToxicity, Mobility, or Volume by Treatment

   This criterion is not applicable because none of the  alternatives  reduce toxicity,
   mobility, or volume through treatment.

   Short-Term Effectiveness

   Since the'human health risk is acceptable for current land uses at CAOCs 1, 8A,
   and 10, both alternatives are considered effective in the short term.

   Implementability

   There are no technical or availability of services and materials concerns regarding
   the implementability of a No-Action alternative.  However, the administrative
   implementability may be an obstacle.  It is unlikely that ADEQ and U.S.  EPA
   would  accept Alternative 1, because it does not reduce the potential risk to human
   health  in the event of land use changes. There are no barriers to implementing
   Alternative 2, Institutional Controls.

   Cost

   There are no costs associated with Alternative!. For Alternative 2, there would be
   a small cost associated with the proposed addition to  the Base Master Plan. In the
   future, the language  added to the Base Master Plan  could incur costs related to
   future soil investigation, revised risk assessments, and possible remedial activities.
   These potential future costs cannot be estimated at the present time.  However, the
   activities associated with these costs would likely result only after the ROD has

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       been amended; thus, the cost estimates would be part of the amended ROD and
                                                             •
       not necessarily part of the present ROD.

       State Acceptance

       ADEQ agrees with the preferred alternative (Alternative 2).

       Community Acceptance

       Based on  public  input on the Proposed Plan  (see Section 3.3)  the preferred
       alternative is acceptable to the community (Alternative 2).

       Based on U.S. EPA evaluation criteria, the rationale for selecting Alternative 2 as
       the preferred alternative is as follows:

       •  It provides long-term  monitoring  of  land  uses to ensure  that any  future
          changes in land use would not result in unacceptable risks to human health.

       •  It is acceptable to the Navy, regulatory agencies, and the community.

2.14 The Selected Remedies

   2.14.1 Selected Remedy for ACM in Soils

       Under the selected alternative, Alternative 3 (Cleanup of ACM on Soil Surface and
       Excavation of Soils  Mixed with ACM), ACM fragments visible on soil surfaces
       will be collected at the  Radar  Hill area of CAOC 4B; the bum pit area in CAOC
       7A; the ACM piles in the area  "south of CALA" (CAOC 7B); and the floor tiles in
       CAOC 9.  In areas in which ACM is mixed with soil beneath the surface (CAOC
       4A, north of Building 38; and CAOC 7A, limited area near the active burn pit), the
       contaminated soils will be excavated with conventional construction equipment.
       Table 2-9  summarizes the  parameters used in the soil volume estimates for the
       two areas in which ACM is mixed with subsurface soil.

       During excavation, air monitoring stations will be established up and downwind
       of the site to  evaluate potential health risks resulting from dust  and asbestos
       exposure during excavation. Air samples will be collected and  analyzed off site
       for total particulate  and asbestos when on site wind velocities exceed a threshold
       level that could potentially transport dust off site. During excavation, the soil will

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   be watered to minimize dust generation.  The bottom  and sidewalls  of  the
   excavation area will be inspected for the presence of ACM fragments.  Remaining
   soils will be  compacted and graded to  drain.  The ACM and  soils will be
   stockpiled, manifested,  loaded, transported,  and disposed  of  at a  state and
   federally  permitted facility, Copper  Mountain  Landfill  Facility, in  Wellton,
   Arizona.

   The total estimated cost developed for this alternative is approximately $710,000.
   Capital costs include excavation, transportation and disposal, and site restorations
   costs.  There is no cost for O&M  for this  alternative  because  groundwater
   monitoring is not required and there are no remedial systems to operate. Tables 2-
   10 and 2-11 provide a detailed cost estimate.

2.14.2 Selected Remedy for Potential Health Risks at CAOCs 1,8A, and 10
   Under the selected alternative, Alternative 2, the following institutional controls
   will be implemented through additions to the Base Master Plan:

   •  CAOC 1 and 10: In order to control the potential risk from exposure to PAHs
      in soils, the institutional controls will restrict the land use of CAOC 1 and
      CAOC 10 to industrial/commercial use. A change in land use from industrial
      to residential use will require re-evaluation of the remedy.  The institutional
      controls will be implemented  through  the Base Master Plan, which will
      reference the OU2 ROD.  The Base Master  Plan will require that any changes
      in land use or activities at CAOC  1 or CAOC 10 be coordinated through and
      reviewed by the MCAS Yuma Environmental Department.  The locations of
      the PAH detections will also be documented in the Base Master Plan.

   •  CAOC 8A:  In order to  control the potential risk from  the exposure to the
      landfill interior, institutional controls will restrict the land use of CAOC 8A to
      the current use.  A change in land use at CAOC 8A involving any activities
      that may disrupt and expose the landfill  interior will require re-evaluation of
      the remedy.  The institutional controls will be implemented through the Base
      Master Plan, which will reference the OU2 ROD.  The Base Master Plan will
      require that any changes in activities or land use at CAOC 8A be coordinated
      through and reviewed by the MCAS Yuma Environmental Department. The
      locations of the former disposal areas and the locations of the PCB detections
      will also be documented in the Base Master Plan.


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Before the land use restrictions are incorporated in the BMP, the Navy will obtain
the approval of the U.S. EPA for the language of the restrictions and the location
in the BMP at which the approved language will be incorporated.

This would include execution and recordation of a VEMUR in accordance with and
substantially in the form set out at Arizona Revised Statutes, Section 49-152.  The
VEMUR would contain language clarifying that it was executed and recorded by the
federal government, or the appropriate entity  of the federal government, "for  itself
only, and not as a covenant running with the land". In addition, it would clarify that:

    a.  The parties agree that no interest in real property on behalf of the State of
       Arizona is created either by this VEMUR or by any notice of cancellation of
       this VEMUR pursuant to A.R.S. 49-152.

    b.  The signature of an authorized representative of the Arizona Department of
       Environmental Quality (ADEQ) which appears herein acknowledges that the
       remediation of the property was conducted in accordance with the provisions
       of A.R.S 49-152.

In the event that the Navy plans any future changes in land use at CAOCs 1, 8A,
or 10, the Navy in consultation with U.S. EPA and ADEQ would re-evaluate the
remedy in light of the intended use changes. For CAOC 1 or CAOC 10, a change
in land use .from industrial use to residential use will require re-evaluation of the
remedy. For CAOC 8A, a change in land use involving any activities that may
disrupt and expose the landfill interior will  require re-evaluation of the remedy.
At  the time of these future activities, further investigation may be undertaken in
order to determine if remediation is required  and if the ROD must be amended. If
the change in land use is not compatible with the remedy, the remedy may be
changed pursuant to CERCLA Sections  120 and  121 and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP) Section 300.430(f)(4)(iii)
and the ROD may be amended. If the Navy plans to excess the property to a non-
federal entity, it will notify ADEQ and EPA in advance of the execution of any
such transfer. The Navy will consult with ADEQ and EPA in revisiting existing
land use classifications/restrictions for  the CAOC (or, in the  alternative, the
remedial action selection) to determine if the foreseeable future land use differs
from the assumptions made at the time the original remedial action decision was
made. At that time, a re-evaluation of the appropriate institutional controls will
be  undertaken by the Navy, in consultation with ADEQ and  EPA.

There are no costs associated with Alternative 1. For Alternative 2, there may be a
small cost associated with the proposed addition to the Base Master Plan. In the
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       future, the language added to the master plan could incur costs related to future
       soil investigation,  revised risk  assessments, and possible  remedial activities.
       These potential future costs cannot be estimated at the present time. However, the
       activities associated with these costs would likely result only after the ROD has
       been amended; thus, the cost estimates will be part of the amended ROD and not
       part of the present ROD.

2.15 Statutory Determinations

   2.15.1 Introduction

       In accordance with DERP, 10 U.S.C. Sec. 2701, et seq. and Executive Order 12580,
       the Department of Defense (DoD) has been delegated the Presidential authority to
       respond under CERCLA to releases of  hazardous substances, pollutants, and
       contaminants whenever a release or threat of release occurs on a DoD installation
       or the sole source of the release is from that installation.".  In addition, Section 121
       of CERCLA establishes several other statutory requirements and  preferences.
       These specify that when complete, the selected remedial action for a site must
       comply  with applicable or relevant and appropriate environmental standards
       established  under federal and state environmental laws unless a statutory waiver
       is justified.  The selected remedy also must be cost effective and utilize permanent
       solutions and alternative treatment technologies  or resource recovery technologies
       to the maximum extent practicable. Finally, the statute includes a preference for
       remedies that  permanently  and significantly  reduce the  volume, toxicity, or
       mobility of hazardous wastes as their principal  element.  The following sections
       discuss how the selected remedies meet these statutory requirements.

   2.15.2 Statutory Determinations for Selected Remedy for ACM in Soils

       Protection of Human Health and the Environment

       The selected remedy protects human health  and the environment by removing
       friable asbestos from the surface and subsurface of CAOCs with ACM present.

       Compliance with Applicable or Relevant and Appropriate Requirements

       The selected remedy of collection of surface ACM, excavation of subsurface ACM,
       and off-site disposal of ACM and associated soils will comply with applicable or
       relevant and appropriate chemical-, action-, and location- specific requirements

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   (ARARs). The ARARs are presented below. The selection process is summarized
   in Table 2-12.

   Chemical-Specific ARARs for Asbestos

   No chemical-specific ARARs were identified for ACM at MCAS Yuma OU2.

   Location-Specific ARARs

   Federal and state location-specific ARARs identified by the Navy (JEG, 1995d)
   include the following:

   •  National Historic Preservation Act, 16 USC Section 470-470w-6 [36 CFR Part
      800] and the Archeological Resource Protection Act,  16 USC Section 470ii
      136 CFR Part 299]:  Scientific, prehistoric, or archaeological artifacts may be
      present at MCAS Yuma.

   •  Endangered  Species Act, 16  USC  1531  et set}.; and Fish and Wildlife
      Coordination Act, 16 USC 661 et seq. [50 CFR Parts 200 and 402, and 33 CFR
      Parts 320-330]: With the exception of migratory birds that have been observed
      in the airspace above MCAS Yuma, no state or federally listed threatened or
      endangered species are currently known to be present at MCAS Yuma.

   •  Migratory Bird Treaty Act of 1972, 16 USC 703: Migratory birds have been
      observed in the airspace above MCAS Yuma.

   •  Arizona Revised Statutes, Title 41: State Government; Chapter 4.1, History,
      Archaeology and  State Emblems; Article 4:   Archaeological Discoveries
      [ARS 41-844A]: Archaeological, palaeontological, or historical features may be
      discovered at MCAS Yuma during  the course of surveys, excavations, or
      construction that occur during a  remedial action.

   ACM waste  at  MCAS Yuma  was  disposed  of  at  the land  surface.    The
   requirements  identified in this section do not appear to  apply to the remedial
   action  alternatives because these  alternatives  are  not anticipated  to disturb
   habitats or  excavate native soils. MCAS Yuma  is currently consulting with the
   Arizona historic  preservation office. Although a final determination has not yet
   been made, the  Station is  not  expected to be included  in or eligible for the
   National Register of Historic Places. A 1997 archeological survey of MCAS Yuma
   identified a circa 1940s historic trash site  and three isolated occurrences of Native

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   American Pottery; none of these sites are impacted by remedial activities for OU2.
   Thus, no location-specific  ARARs pertaining specifically  to asbestos or  to the
   selection of remedial action alternatives have been identified.

   Action-Specific ARARs

   Action-specific ARARs include the following:

   Clean  Air  Act,  National  Emission Standard  for Hazardous  Air Pollutants
   (NESHAP):   The National  Emission Standard for Hazardous Air Pollutants
   (NESHAP) for asbestos found at 40 CFR Section 61, Subpart M is considered an
   action-specific ARAR for the site.  ADEQ is the lead agency for asbestos NESHAP
   compliance.  Although the requirements in 40 CFR sections 61.145, 61.150, and
   61.154  are not applicable  because they address asbestos  from operations (i.e.,
   demolition, renovation, fabricating,  and spraying) that are not  related  to the
   proposed remedial action.  The substantive requirements are considered relevant
   and  appropriate, however,  because they address problems  similar to those
   encountered at CERCLA sites. NESHAP includes the following:

   •  Section 61.145:   Applicability,  Notification Requirements,  and Asbestos
      Emission  Control:  NESHAP  applies to demolition or renovation of facilities
      with ACM. Remediation of ACM at MCAS Yuma is neither a renovation nor
      demolition operation.  Notification (Section 61.145(b)) is an  administrative
      requirement that is not applicable to CERCLA actions.  However, procedures
      for asbestos emission control (Section 61.145(c)) are substantive requirements
      that are considered relevant and appropriate.

   •  Section  61.150:    Standards for  Waste  Disposal   for  Manufacturing,
      Fabricating, Demolition, Renovation and Spraying Operations:  Procedures
      for ACM waste handling, transportation, and disposal are considered relevant
      and appropriate.  Both the administrative and substantive requirements of this
      section are considered ARARs because transportation and disposal will occur
      off-site.

   There are no RCRA or state equivalent RCRA requirements that are applicable to
   the selected remedy.
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   Other Criteria to Be Considered (TBC)

   In implementing the selected remedy, U.S. EPA and the State have agreed  to
   consider  procedures  that  are  not  legally  binding.    This  category of  to-
   be-considered (TBC) procedures consists of advisories, criteria, or guidance that
   were developed by  EPA, other federal agencies, or states that may be useful  in
   developing CERCLA remedies.  Such criteria are used if no ARAR addresses a
   particular situation,  or if an ARAR is insufficient to protect human health or the
   environment. One such criterion has been identified as a potential TBC.

   •  Chief of Naval Operations Instruction (OPNAVINST) 5100.23D, Chapter 17:
      The  Navy manual provides  guidance for  controlling  or  eliminating the
      exposure of Navy personnel to asbestos during the use, removal, and disposal
      of ACM.

   These provisions apply primarily to building structures and facilities and are
   guidance only.  Since compliance with the NESHAP  requirements discussed
   above under federal action-specific  ARARs and federal OSHA are considered
   sufficient to provide  a remedy that  is protective  of  human  health  and the
   environment, the Navy manual is not considered TBC.
           #
   Cost Effectiveness

   The selected remedy is cost effective because it has been identified as providing
   overall effectiveness proportional to its costs. The estimated cost for removal of
   surface  and subsurface  ACM  under the selected  remedy, Alternative  3,  is
   approximately $710,000. The estimated cost for Alternative 4, removal of surface
   ACM and capping of subsurface ACM in place at MCAS Yuma, is approximately
   $880,000; because ACM would remain in place in the eastern portion of CAOC 4A,
   this area would require long-term maintenance of the cover and a Base Master
   Plan restriction indicating that ACM is present.  Therefore, the selected remedy is
   less costly than Alternative 4 and also does not incur future maintenance costs and
   land use restrictions.   Alternative 2 costs less ($90,000), but does not provide
   adequate long-term  control of the ACM.

   Utilization of Permanent Solutions and Alternative Treatment Technologies to
   the Maximum Extent Practicable

   The preferred alternative provides a permanent solution because  the ACM in OU2
   will  be  removed.  Therefore, no  long-term monitoring or maintenance will  be
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   required.  Alternative treatment technologies or resource recovery technologies
   are not relevant to the ACM cleanup and disposal.

   The preferred alternative is effective in the short term for the following reasons:

   •   Community impacts: None.  The community is not in the immediate vicinity.
       Dust control measures, such as spraying soil with water, will be implemented
       to minimize  environmental impacts.  Air monitoring will be conducted to
       evaluate potential impacts.

   •   Protection of  workers:    Loading  contaminated  soil  into   trucks  for
       transportation to a landfill has  the potential to have an adverse short-term
       impact on the health of construction workers because of dust and asbestos
       fibers  potentially generated during excavation and loading.  These potential
       adverse impacts will be  minimized through use of dust control measures.
       Workers  will  be  adequately   protected  during  remedial activities by
       compliance with  Occupational  Safety and Health Administration (OSHA)
       regulations (51 CFR Part 22612 and 29 CFR 1910.120).

   •   Length  of remedial  action:   This  alternative  can  be implemented  in
       approximately 13 days.
           #
   There are no  technical, administrative,  or availability of services and materials
   concerns  regarding  the implementability of this  alternative.  Soil  excavation,
   loading, and transportation are widely used and can be accomplished using well
   established, conventional construction techniques and equipment.  There are no
   technical  considerations  that  would  prohibit  excavating,  transporting, and
   disposing of the soil at a permitted landfill. U.S. EPA and ADEQ have determined
   that this alternative is administratively acceptable.  The services and materials
   required to implement this alternative are readily available.

   In  summary,  the preferred  alternative would minimize the potential  risk to
   human  health and  the environment from  ACM and complies with ARARs.
   Because the preferred alternative complies with ARARs and no ACM will be left
   in place, it is  has been accepted by the state. Based on public comment on the
   alternative, the preferred alternative is acceptable to the community
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      Preference for Treatment as a Principal Element

      This criterion is not applicable because none of the alternatives reduce toxicity,
      mobility, or volume through treatment.

   2.15.3   Statutory Determinations for  Selected Remedy for Potential Health
      Risks at CAOCs 1,8A, and 10

      Protection of Human Health and the Environment

      Potential risks  to on-site workers  are  currently  within  acceptable ranges.
      Compliance with the institutional controls will ensure that future development of
      the CAOCs will not result in unacceptable risks.

      The institutional controls will restrict the land use of CAOC 1 and CAOC 10 to
      industrial/commercial use and  CAOC 8A to the  current use.  The institutional
      controls will be implemented through the Base Master Plan, which will reference
      the OU2 ROD. Additions to the Base Master Plan will include a map indicating
      the locations of the former disposal areas in CAOC 8A.  This would include
      execution and recordation of a VEMUR in accordance with and substantially in
      the form set out at Arizona Revised Statutes, Section 49-152. The VEMUR would
      contain language  clarifying that it was executed and recorded by the federal
      government, or the appropriate  entity of the federal government, "for itself only,
      and not as a covenant running with the land". In addition, it would clarify that:

         a.  The  parties agree that no interest in real property on behalf of the State of
             Arizona is created either by this VEMUR or by any notice of cancellation of
             this VEMUR pursuant to A.R.S. 49-152.

         b.  The signature of an authorized representative of the Arizona Department
             of Environmental Quality  (ADEQ) which appears herein  acknowledges
             that the remediation of the property was conducted in accordance with the
             provisions of A.R.S 49-152.

      The  Base Master Plan will require that any changes in activities or land  use in
      these CAOCs be coordinated  through and reviewed by  the  MCAS  Yuma
      Environmental Department. Before the land use  restrictions are incorporated in
      the BMP, the Navy will obtain the approval of the U.S. EPA for the language of
      the restrictions and the location in the BMP at which the approved language will
      be incorporated.  In the event that the Navy plans any future changes in land use
      at CAOCs 1,8A, or 10, the Navy in consultation with U.S. EPA and ADEQ would

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      re-evaluate the remedy in light of the intended land use. If the change in land use
      is not compatible with the remedy, the remedy may be changed pursuant to
      CERCLA Sections 120 and 121 and the National Oil and Hazardous Substances
      Pollution Contingency Plan (NCP) Section 300.430 (f) (4) (iii) and the ROD may be
      amended.

      For CAOC 1 or CAOC 10, a change in land use from industrial to residential use
      will require re-evaluation of the remedy. For CAOC 8A, a  change in land use
      involving any activities that may require disruption and exposure of the landfill
      interior will require re-evaluation of the remedy.  At the time of these future
      activities, further investigation may be undertaken in  order to determine if
      remediation is required and if the ROD must be amended. If the Navy plans to
      excess the property to a non-federal entity, it will notify ADEQ and EPA in
      advance of the execution of any such transfer. The Navy will consult with ADEQ
      and EPA in revisiting existing land use classifications/restrictions for the CAOC
      (or, in the alternative, the remedial action selection) to determine if the foreseeable
      future land use differs from the assumptions  made at  the  time the original
      remedial action decision was  made.   At  that time, a re-evaluation of the
      appropriate institutional controls will be undertaken by the Navy, in consultation
      with ADEQ and EPA.

      Compliance with Applicable or Relevant and Appropriate Requirements

      The ARARs are presented below and the selection process is summarized in Table
      2-12.

      Compliance with federal ARARs:  Federal ARARs have not been identified for
      PAHs in soils at CAOC 1 and CAOC 10 and PCBs in soils at CAOC 8A.

      Compliance with State Location- and Action-Specific ARARs: State location- and
      action-specific ARARs have not been identified for PAHs in soils at CAOC 1 and
      CAOC 10 and PCBs in soils at CAOC 8A.

      Compliance with State Chemical-Specific ARARs:

      Under the authority of Arizona Revised Statutes Section 49-151 and Section 49-
      152,  ADEQ has established  Department-wide standards  applicable  to  soil
      remediation activities.  The Amended Soil Remediation  Rules were adopted in
      Arizona Administrative Code Title  18,  Chapter  7, Article 2, Interim  Soil
      Remediation Standards (Sections R18-7-201 through R18-7-209) in 1996.  These
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      regulations are not considered "applicable", since remedial actions  are being
      conducted pursuant to federal law (i.e., CERCLA) rather than under one of the
      State regulatory programs listed in Arizona Administrative Code (AAC), Title 18,
      Sec. R18-7-202.A. Nor is the Marine Corps requesting a "close-out document",  as
      described in R18-7-202.B, for a cleanup  under State law. State concurrence is
      being sought in the remedy selected under federal law. However, the Marine
      Corps  has determined  certain substantive requirements  of AAC,  Title  18,
      Chapter?, Article  2 to  be relevant and  appropriate  to the soil  remediation
      activities described in this ROD.

      The regulations allow soil remediation activities that attain one of three standards
      (Section R18-7-203): 1) remediation to background levels; 2) remediation to the
      Health Based Guidance  Levels (HBGLs) presented in Appendix A to Title 18,
      Chapter 7, Article 2; or 3) remediation to levels derived from a site-specific risk
      assessment. HBGL values for the PAHs and PCBs detected at CAOCs 1 and 10 are
      presented in Table 2-8.

      There are no RCRA or state equivalent RCRA requirements that are applicable to
      the selected remedy.

      Other Criteria: As discussed above, if no ARAR addresses a particular situation,
      or if an ARAR is insufficient to protect human health or the environment,  then
      nonpromulgated  standards,  criteria, guidance,   and   to-be-considered  (TBC)
      advisories may be used to provide a protective remedy.  Other criteria that were
      evaluated as potential TBC include the following:

      •  U.S. EPA guidance  USEPA/540/G-90/007:   This  guidance describes  the
         recommended  approach  for evaluating and  remediating sites with  PCB
         contamination.

      Since a human health risk assessment has been performed for current land use at
      CAOC 8A, Alternative 2 is considered to provide a remedy at CAOC 8A that is
      protective of human health and the environment.  Therefore, the EPA guidance is
      not considered TBC.

      Summary  of  Compliance of with ARARs:  Alternative  2 is in compliance  with
      ARARs. A brief summary of the ARARs for CAOCs 1, 8A, and 10, is given in
      Table 2-7.
180-06/sak/dr4.docW/22/97                    2-52

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       Cost Effectiveness

       A small cost is associated with the proposed institutional controls. In the future,
       the language added to the master plan could incur costs related to future  soil
       investigation, revised  risk assessments, and possible remedial activities.  The
       selected remedy is cost effective because these future costs will only be incurred if
       land uses at the three CAOCs actually are changed in the future.

       Utilization of Permanent Solutions and Alternative Treatment Technologies to
       the Maximum Extent Practicable

       The preferred alternative requires, long-term control of land uses at the three
       CAOCs.  However, permanent solutions that require no control of  land uses
       would  require extensive soil investigations and, potentially, expensive remedial
       activities.  Such expenditures are not required to maintain acceptable risk levels
       under current use scenarios.  Therefore, the selected alternative is more cost
       effective than a permanent solution.

       Alternative treatment  technologies or resource recovery  technologies  are  not
       relevant to the potential health risks at CAOCs 1, 8A, and 10.
               *
       Implementability

       There are no technical, administrative, or availability of services and materials
       concerns regarding the implementability of the selected alternative. U.S. EPA and
       ADEQ have determined that this alternative is administratively acceptable. The
       selected alternative is also acceptable to the community.

       Preference for Treatment as a Principal Element
       This criterion is not applicable because none of  the alternatives reduce toxicity,
       mobility, or volume through treatment.

2.16 Documentation of Significant Changes

       As described in the Responsiveness Summary (Section 3), the Proposed Plan was
       released for public comment on March 20,1997 and a public meeting was held on
       April 9, 1997. This Proposed Plan identified "no action" as the selected response
       action for 12 of the 18  CAOCs in OU2 because these sites do not pose a threat to
       human health or the environment. Because of the presence of ACM in three of the
       CAOCs in OU2, remedial action is required to protect human health and comply

    180-06/sak/dr4.doc8/28/97                   2-53

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   with regulatory requirements.   The selected remedial action consists of the
   collection of ACM on soil surfaces and the excavation of soils mixed with ACM.
   At two CAOCs, a human health risk assessment indicated that residential land
   use could potentially present an unacceptable health risk and at one other CAOC
   any change in land use could potentially present an unacceptable health risk; the
   selected action for these CAOCs is the inclusion of institutional controls for these
   CAOCs in  the Base  Master  Plan.  Comments collected over the 30-day public
   review period between March 21,  1997 and April  28, 1997 are addressed in
   Section 3.3.

   Responses to the public comments did not require any changes to this Record of
   Decision.
180-06/sak/dr4.doc8/28/97                   2-54

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3  Responsiveness Summary
3.1 Overview

      This section provides a summary of the public comments and concerns regarding the
      Proposed Plan at MCAS, Yuma. At this time, the Navy has selected the "no further
      action" preferred alternative for 12 of the 18 CAOCs in OU2 because these sites do not
      pose a threat to human health or the  environment.  The selected remedial action for
      three CAOCs at which ACM were identified in construction debris consists of the
      collection of ACM on soil surfaces and the excavation of soils mixed with ACM.  At an
      additional two CAOCs, a human health risk assessment indicated that residential land
      use could potentially present an unacceptable health risk, and at one other CAOC, any
      change in land use could potentially present an  unacceptable health risk;  the selected
      action for these CAOCs is the inclusion of institutional controls for these CAOCs in the
      Base Master Plan.

3.2 Background on Community Involvement

      The Navy has implemented a progressive public relations and involvement program for
      environmental activities at MCAS Yuma.  A  Restoration Advisory  Board (RAB),
      comprising representatives  from the  Navy, U.S.  EPA, the Arizona Department of
      Environmental Quality, and members  of the  general public, has been established and
      meets periodically to involve the public in decisions regarding investigation results,
      proposed work, and potential remedial options. The Navy has also presented RI plans
      and results at public meetings conducted on January 18 and April 11,1996. Before each
      of these public meetings, the Navy distributed over 40 copies of a fact sheet to interested
      parties and to the information repositories (Section 2.7). These fact sheets described the
      installation restoration  program at MCAS Yuma, including a  discussion  of  how the
      public could access more information  and  become more involved in the program.  A
      synopsis of community relations activities conducted  by the Navy is presented in
      Appendix B.

      The Navy held  a public comment period  on  the OU2  preferred alternative  from
      March 21 through April 28,1997. Copies of the Proposed Plan were placed  in the above
      discussed  repositories  (Section 2.7) and were mailed  to the  public for  review and

    180-06/sak/rod-dr4.doc                        3-1

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      comment.  The Proposed Plan also invited readers to a public meeting to discuss the
      preferred alternative and voice their concerns. The meeting was held on April 9, 1997,
      from 6:00 to 7:20 p.m., in the Yuma County Main Library at 350 South Third Avenue,
      Yuma, Arizona.  Comments received during the public comment period are addressed
      below.
3.3 Summary of Comments Received During Public Comment Period and
      Department of the Navy Responses

      Four verbal comments were received at the Public Hearing on the Proposed Plan. The
      one written comment on the Proposed Plan is included in Appendix B. This written
      comment did not require a response.

      Public Comment

      Mr. John Colvin asked Amanda Stone of the Arizona Department of Environmental
      Quality to explain the proposed land use restrictions in greater detail. After Ms. Stone
      provided further information on the legal issues, Mr. Colvin asked if such a land use
      restriction would also be applicable to the  proposed asbestos removal.   Mr.  Colvin
      asked  if the  use of  a land use restriction for asbestos debris sites would save the
      estimated $710,000 cost of excavating asbestos, as long as the $90,000 surface cleanup
      was performed. Mr. Colvin suggested that if the buried asbestos were left in place, the
      cost of removal could be borne be any future private developer of the sites, rather than
      by public money.

      Response

      Amanda Stone, Remedial Project Manager, Arizona Department of Environmental
      Quality, answered the question. Ms. Stone explained that a land  use restriction at the
      asbestos sites would be much more  restrictive  than  the land  use restrictions that
      maintain the current uses of CAOCs 1, 8A, and 10.  Some of the  asbestos sites are
      currently slated for development by the Navy and any excavation at these sites would
      require removal of the buried asbestos.  In addition, as long as the asbestos remains in
      the ground, there is a potential for accidental breakdown of the asbestos materials and
      the resulting release of fibers.

      Public Comment

      Ms. Maria Lewis  commented that removing the asbestos now would probably be
      cheaper than waiting till some unspecified date in the future.

    180-06/sak/rod-dr4.doc                       3-2

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   Response

   Ms. Stone observed that the cleanup cost for these sites was not bad compared to many
   other sites.

   Public Comment

   Mr. Kevin Shaffer asked why the cleanup was not being paid for by Superfund.

   Response

   Nadine  Spertus,  Remedial Project  Manager,  Southwest Division,  Naval Facilities
   Engineering Command, answered the question. Ms. Spertus explained that the Marine
   Corps and Navy have a separate fund of money called the Environmental Restoration
   Navy Account.  Superfund was specifically set up for private parties and is intended to
   be a revolving fund that is repaid by identified responsible parties.

   Public Comment

   Ms. Dottie  Lofstrom asked if monitoring wells had been used  to study the landfill
   (CAOC 8A).
              #
   Response

   Rachel Simons, Remedial Project Manager,  U.S.  Environmental Protection Agency,
   Region IX, answered the question.  Ms. Simons explained that, although soil samples
   were not taken from within the landfill, soil samples were collected from the surface of
   the landfill, soil vapor samples were collected from within the landfill, and groundwater
   samples were collected  from around the perimeter of the landfill.
180-06/sak/rod-dr4.doc                         3-3

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4  References
       Arizona Department  of  Environmental Quality (ADEQ), 1992.   Human Health-based
          Guidance Levels for the Ingestion of Contaminants in Drinking Water and Soil.

       Environmental Protection Agency (U.S. EPA), 1989a.  Statistical Analysis of Groundwaler
          Monitoring Data at RCRA Facilities (Interim Final Guidance).

       U.S.J5PA, 1989b. Health Effects Assessment Summary Tables (HEAST), National Library of
          Medicine.

       U.S. EPA, 1992. Guidance for Data Usability in Risk Assessment (Part A).  OSWER 9285.7-
          09A. Office of Emergency and Remedial Response. USEPA/540/G-90/008 (Interim
          Final).

       U.S. EPA, 1994a. Integrated Risk Information System (IRIS) Database.

       U.S.  EPA,  1994b.   Region IX Preliminary Remediation  Goals  (PRGs) First Half  1994.
          Stanford J. Smucker, Ph.D., Regional Toxicologist.

       U.S. EPA, 1^94c.  Memorandum on the Role of the  Baseline Risk Assessment in  Superfund
          Remedy Selection Decision. OSWER Directive 9355.0-30.

       Federal Facilities Agreement (FFA),  1991.  Federal Facility Agreement Under CERCLA
          Section 120. Signed by U.S. EPA Region 9, State of Arizona, and the U.S. Department
          of the Navy.

       Jacobs Engineering Group Inc. (JEG), 1994a. Community Relations Plan (Final).

       JEG, 1994b.  Final Residential Surface Soil Investigation Report  (Draft).

       JEG, 1994c. Technical Memorandum 3, Human Health Risk-Based  Criteria for Decision
          Making (Final).

       JEG, 1995a.  MCAS  Yuma, Asbestos  Survey Results.   Technical  Memorandum dated
          February 14.

       JEG, 1995b. Preliminary Draft Chemical-Specific and Location-Specific Applicable or Relevant
          and Appropriate Requirements Analysis  Report,  MCAS, Yuma,  Arizona.  Revision 1,
          January 3.

       JEG, 1996.  Final Remedial Investigation Report, MCAS YUMA. March 26.

    180-06/sak/rod-dr4.doc                         4-1

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   Malcolm Pimie,  Inc.,  1988.   Confirmation  Study  Verification  Phase,  Naval Facilities
      Engineering Command, Southwest Environmental Section, San Diego, California.

   Malcolm Pimie, Inc., 1990. Site Inspection Report (Draft).

   Steams, Conrad, Schmidt and Landau Associates (Stearns et al.), 1985. Initial Assessment
      Study of Marine Corps Air Station, Yuma, Arizona.  Prepared for the Naval Energy and
      Environmental Support Activity, NEESA 13-077.

   Uribe & Associates (U&A), 1996a. Assessment of ACM Contamination at CAOCs 4, 7, and 9
      at Marine Corps Air Station Yuma, Arizona, prepared for Southwest Division  Naval
      Facilities Engineering Command, San Diego, California.

   U&A, 1996b.  Feasibility Study for Operable Unit 2, Marine Corps Air Station Yuma, Arizona,
      prepared for Southwest Division Naval Facilities  Engineering Command, San Diego,
      California.

   U&A, 1996c.  Proposed Plan for Operable Unit 2, Marine Corps Air Station Yuma, Arizona,
      prepared for Southwest Division Naval Facilities  Engineering Command, San Diego,
      California.

   U&A, 1996d.  Report of Soil Sampling Program For Polycylcic Aromatic Hydrocarbons at
      CAOC 10 Operable, Unit 2, Marine Corps Air Station Yuma, Arizona,  prepared for
      Southwest Division Naval Facilities Engineering Command, San Diego, California.

   U&A,  1997.   Report  of  Supplemental Soil Sampling Program  For Polycylcic Aromatic
      Hydrocarbons at CAOC 10 Operable, Unit 2, Marine Corps Air Station Yuma, Arizona,
      prepared for Southwest Division Naval Facilities  Engineering Command, San Diego,
      California.
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5 Abbreviations /Acronyms
AAC
ACM
ADEQ
ADOSH
ARARs
ARS
ASTM
bgs
BTEX
Bureau
CALA
CAOC
CERCLA

CFR
CLP
COPC
COPEC
CPF
cy
DDT
DoD
ea
U.S. EPA
EM
f/cc
FD
FFA
FS
FSP
ft
GPR
HBCL
HE AST
HI
IAS
1R
IRIS
Arizona Administrative Code
Asbestos-Containing Material
Arizona Department of Environmental Quality
Arizona Department of Occupational Safety and Health
Applicable or Relevant and Appropriate Requirements
Arizona Revised Statutes
American Society for Testing and Materials
below ground surface
Benzene, Toluene, Ethylbenzene, and Total Xylenes
U.S. Bureau of Reclamation
Combat Aircraft Loading Apron
CERCLA Area of Concern
Comprehensive   Environmental   Response,    Compensation,    and   Liability
Act
Code of Federal Regulations
Contract Laboratory Program
Chemical Of Potential  Concern
Chemical Of Potential  Ecological Concern
Cancer Potency Factor
cubic yard
1,1,1 -trichloro-2,2-bis(4-chlorophenyl)ethane
Department of Defense
each
U.S. Environmental Protection Agency
Electromagnetic (survey)
fibers per cubic centimeter
Field Duplicate
Federal Facilities Agreement
Feasibility Study
Field Sampling Plan
foot
Ground Penetrating Radar
Health-Based Guidance Level
Health Effects Assessment Summary Table
Hazard Index
Initial Assessment Study
Installation Restoration
Integrated Risk Information System
    180-06/sak/rod-dr4.doc
                                                 5-1

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IRP
JEG
kg
LAAMBN
Mag.
MCAS
mg/kg
mg/l
mph
MWWU
NCP
NAVFACENGCOM
Navy
NESHAP
NFESC
NPL
O&M
OSHA
OPNAVINST
OU
PAHs
PA/SI
PCBs
PCE
PEL
ppb
PR
PRG
PR/VSI
PVC
RAB
RBC
RCRA
RfD
RI
Rl/FS
RME
ROD
SARA
sf
SI
Station
svoc
Installation Restoration Program
Jacobs Engineering Group Inc.
kilogram
Light Anti-Aircraft Missile Battalion
Magnetic (survey)
Marine Corps Air Station
milligrams per kilogram
milligrams per liter
miles per hour
Marine Wing Weapons Unit
National Oil and Hazardous Substances Contingency Plan
Naval Facilities Engineering Command
Department of the Navy
National Emission Standards for Hazardous Air Pollutants
Naval Facilities Engineering Services Center (Formerly NEESA)
National Priorities List
Operations and Maintenance
Occupational Health and Safety Administration or Act (1970)
Chief of Naval Operations Instructions
Operable Unit
Polynuclear/Polycyclic Aromatic Hydrocarbons
Preliminary Assessment/Site Inspection
Polychlorinated Biphenyls
Perchloroethene(tetrachloroethene)
Permissible Exposure Limit
parts per billion
Preliminary Review
Preliminary Remediation Goals
Preliminary Review/Visual Site Inspection
Polyvinyl Chloride
Restoration Advisory Board
Risk-Based Criteria
Resource Conservation and Recovery Act
Reference Dose
Remedial Investigation
Remedial Investigation/Feasibility Study
Reasonable Maximum Exposure
Record  of Decision
Superfund Amendment and Reauthorization Act
square foot
Site Inspection
Marine  Corps Air Station, Yuma
Semivolatile Organic Compound
     180-06/sak/rod-dr4.doc
                                                    5-2

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Southwest Division
TBC
TCA
TCE
TLV
TPH
TRPH
U&A
use
USCA
USDA
USFWS
UST
VEMUR
VOC
VSI
US/1
Southwest Division, Naval Facilities Engineering Command
To Be Considered
1,1,1-Trichloroethane
Trichloroethene (preferred over trichloroethylene)
Threshold Limit Value
Total Petroleum Hydrocarbons
Total Recoverable Petroleum Hydrocarbons
Uribe & Associates
United States Code
United States Code Annotated
United States Department of Agriculture
U.S. Fish and Wildlife Service
Underground Storage Tank
Voluntary Environmental Mitigation Use Restriction
Volatile Organic Compound
Visual  Site Inspection
micrograms per liter
     J80-06/sak/rod-dr4.doc
                                                    5-3

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A: Response to
  Comments

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                       Appendix A
Response to U.S. Environmental Protection Agency and Arizona
    Department of Environmental Quality Comments on the
               Draft OU2 Record of Decision
                         and the
             Draft Final OU2 Record of Decision

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                  U.S. EPA Review Comments on the
        Draft Record of Decision (ROD) for Operable Unit 2
               Marine Corps Air Station, Yuma, Arizona
                         Report Dated July 31,1996
                     Comments Dated October 1,1996

General Comments:

EPA Comment
1.  CAOC 8A - Southeast Station Landfill
The conclusion that institutional controls are being implemented at CAOC 8A based on
the detection of PAHs and PCBs in the soils is incorrect. Institutional controls are being
implemented at CAOC 8A because the interior of the landfill was not investigated
during the OU2 Remedial Investigation (RI).

The RI was directed at evaluating the exposure for current land use and future capped
conditions. No intrusive sampling was done. Based on the human health risk
assessment, it was concluded that a landfill cap was not required under the current land
use.  Since the interior of the landfill was not investigated under the RI, the risk from
exposure to the landfill interior is unknown.

In order to control the potential risk from exposure to the landfill interior, institutional
controls will be implemented to restrict the land use to the current use. Please revise the
report to reflect this comment.

(This is the same comment as General Comment 1 from the Draft Final OU2 Feasibility
Study.)

U&A Response
The following paragraph (or similar language) has been incorporated into Section 1.4 (page 1-3)
and Section 2.10.6 (page 2-23) of the Final Record of Decision:

"CAOC 8A: Intrusive sampling was not conducted at the southeast station landfill during the
RI. Based on the human health risk assessment, it was concluded that a landfill cap was not
required under the current land use. However, since the interior of the landfill was not
investigated during the RI, the risk from  exposure to the landfill interior is unknown."

EPA Comment
2.  Institutional Controls
The following language should be included in the ROD for CAOCs 1, 8A and 10:

"The institutional controls will restrict the land use of CAOCs 1 and 10 to
industrial/commercial use and CAOC 8A to the current use. The institutional controls
will be implemented through the Base Master Plan (BMP) and the BMP will reference
the OU2 ROD. the BMP will indicated that any activities in these CAOCs or land use
changes must be coordinated through and reviewed by the MCAS Yuma Environmental
Department.

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In the event of any future change in land use, the remedy may need to be re-evaluated
in light of the land use changes. If the change in land use is not compatible with the
remedy, the remedy may be changed pursuant to CERCLA Section 120 and the National
Oil and Hazardous Substances Pollution Contingency Plan (NCP) Section 300.430 (f)
(iii) and the ROD may be amended.

For CAOCs 1 and 10, a change in land use from industrial use to residential use would
require re-evaluation of the remedy. For CAOC 8A, a change in land use involving any
activities which may require disruption and exposure of the landfill interior would
require re-evaluation of the remedy. At the time of these future activities, further
investigation may be undertaken in order to determine if remediation is required and if
the ROD must be amended."

(This is the same comment as General Comment 2 for the Draft Final OU2 Feasibility
Study. The language in the first sentence of the second paragraph has been slightly
modified.)

U&A Response
The requested language (or similar language) has been incorporated into Section 1.5 (page 1-6),
Section 1.6,  Section 2.12.5, Section 2.14.2, and Section 2.15.3. In addition,  the following
sentence has been included in the text: "If the land is transferred to a non-federal agency, the
Department of the Navy will file a Voluntary Environmental Mitigation Use Restriction
(VEMUR),,indicating that the property has been remediated to less than residential levels and
that the property shall not be used for residential purposes in the future. The VEMUR will be
recorded in accordance with Arizona Revised Statutes Section 49-152, as implemented in
Arizona Administrative Code Sections R18-7-206 (D)(2)(a) and R18-7-207 (A)."

EPA Comment
3.  Please propose the language that will be added to the BMP restricting the land use
    of CAOCs 1, 8A and 10 and referencing the MCAS YUMA Environmental
    Department and the OU2 ROD.

U&A Response
In a discussion between Southwest Division and U&A, it was agreed that the language to be
added to the BMP need not be included in the ROD.'

EPA Comment
4.  The rational used for implementing institutional controls  at CAOC 10 should be the
    same as CAOC 1.

U&A Response
The Record  of Decision has been revised to include the same rational for the use of institutional
controls at CAOC 10 as at CAOC 1.
    Phone conversation on December 3,1996 between N. Spertus and M. Pound of Southwest
    Division and S. Knott of U&A.

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Specific Comments:

EPA Comment
1. Section 1.2, Site Name and Location, page 1-1
The second sentence of this section states, "Yuma Marine Corps Air Station (Station)
was declared a permanent Air Force installation in 1954."  From this statement, it
sounds like the Base is still operated by the Air Force. Please add a subsequent sentence
stating when the Marine Corps took over operation of the Base.

U&A Response
The following sentence has been added to Section 1.2

"In January 1959, the Station and its associated range facilities were transferred to the U.S.
Navy."

EPA Comment
2. Section 1.4 Assessment of the Site, page 1-3
CAOC 8A should be deleted from the bullet on the top of this page and identified under
a separate bullet.  The bullet should explain that CAOC 8A requires action because the
interior of the landfill has not been fully characterized and therefore, the risk to human
health is unknown (see General Comment 1).

U&A Response
The requested edits have been made (See response to General Comment I).

EPA Comment
3. Section 1.5 Description of the Selected Remedy, page 1-5
Alternative 2 - Additions to the Base Master Plan
Please state in the first paragraph that the locations of the former disposal'areas for
CAOC 8A will be documented in the BMP.

This comment also applies to the first sentence of the last paragraph of Section 1.6,
Statutory Determination, page 1-6.

U&A Response
The requested edits have been made.

EPA Comment
4. Section 2.4 Enforcement and Regulatory History, page 2-4
Please rewrite the third sentence of the second paragraph on this page as follows, "One
to address potential areas of groundwater contamination and soil contamination deeper
than 10 feet below ground surface (OU1)."

U&A Response
The requested edit,has been made.

EPA Comment
5. Section 2.6.8 CAOC 7: Fire School Area, page 2-8

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The text reports CAOC 7 to occupy an area of approximately 0.45 acre. The RI report
describes that the entire area encompasses approximately 40 acres. Please correct.

U&A Response
The requested edit has been made.

EPA Comment
6. Section 2.6.9 CAOC 8: Southeast Station Landfill, page 2-9
The text describes the finding of hydrocarbons, PCBs, solvents, pesticides, and metals in
the shallow soils at CAOC 8. The detection of polynuclear aromatic hydrocarbons
(PAHs) should also be discussed. The term hydrocarbons was earlier defined as fuel-
related chemicals (i.e. TRPH).

U&A Response
The requested edit has been made.

EPA Comment
7. Section 2.6.11 CAOC 10: Ordinance Munitions Disposal Area, page 2-9
The text describes that hydrocarbons and one anomalous elevated lead concentration
have been detected in the shallow soils underlying this area. The text should also
discuss the finding of PAHs in soil.

U&A Response
The requested edit has been made.

EPA Comment
8. Section 2.6.14 CAOC 13: Drain Field Area, page 2-10
The text describes that rinse fluids from filling and mixing equipment for chemical
weapons at the MWWU were disposed at CAOC 13. It is suggested that the text be
expanded to indicate that the chemical weapons were limited to tear gas and napalm.

U&A Response
According to the MCAS Yuma Environmental Department, chemical weapons have not actually
been used at MCAS Yuma (See MCAS Yuma Environmental Department Comment 12). The
text has been revised as follows:

"Liquid rinsates from filling and mixing equipment used for simulated chemical weapons (tear
gas and napalm) at the MWWU were disposed of to a drain field south of former Building
1585."

EPA Comment
9. Section 2.7 Highlights of Community Participation, page 2-12
Please remove the text from the third sentence of this section beginning with, "For
additional information, contact...." through the address for "Rachel Simons".  This
information is too much detail for the ROD.

U&A Response
The text has been removed as requested.

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EPA Comment
10. Section 2.8 Scope and Role of Operable Unit 2, page 2-15
In preceding sections, the 18 CAOCs are described in great detail identifying what
contaminants were found in these areas. However in the last paragraph of this section,
13 CAOCs are dismissed as needing no further action with no explanation other than a
reference to the RI. In lieu of the RI reference, please explain briefly why the 13 areas
are no longer considered areas of concern and reference the appropriate supporting
sections in the ROD.

It is also confusing why the 13 CAOCs which are no longer areas of concern are
continually referring to as CAOCs. Please explain that "CAOC" is a term used to
identify a potential hazardous waste site, but a CAOC is not necessarily a site that
requires remediation.

U&A Response
The number of CAOCs that are no longer areas of concern has been reduced to 12 because CAOC
10 has been included in the CAOCs at which institutional controls will be implemented. The
following text has been inserted into Section 2.8:

"The RI investigated 18 CAOCs at which surface or near-surface disposal or releases of wastes
may have occurred. The investigation ofOU2 was limited to an assessment of the risk/hazard
posed by contaminants in the upper 10 feet of soil. No risk to the environment was identified at
the 18 CAOCs (See Section 2.11).  Based on the human health risk assessments summarized in
Section 2.10,15 of the  18 CAOCs may safely be used for residential land use, while chemicals
identified at CAOCs 1, 8A, and 10 present acceptable health risks if their current, non-
residential land uses are maintained. Institutional controls will be implemented for CAOCs 1,
8A, and 10 to minimize potential health risks that might be associated with land use changes at
these CAOCs.

ACM, which was not included in the risk assessments because acceptable exposure limits have
not been established for ACM, was identified in three of the 15 CAOCs that were assessed to be
acceptable for residential land use.  The ACM at these three CAOCs (4, 7, and 9) is the only
material within OU2for which removal actions are recommended.

No remedial action is recommended for the 12  CAOCs that are acceptable for residential land use
and have no identified ACM.  Although these areas do not present human health risks or
ecological risks, they are still be referred to as CAOCs (CERCLA Areas of Concern) in this
document because, although the term "CAOC" is used to identify a potentially hazardous site, a
CAOC is not necessarily a site that requires remediation."

EPA Comment
11. Table 2-2 Analyte Groups and Associated Methods, page 2-17
Please remove this table because it contains too much detail for the ROD.

U&A Response
Table 2-2 has been deleted as requested.

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EPA Comment
12.  Section 2.9 Site Characteristics, page 2-18
A detailed description of the RI approach is not required for the ROD.  Please remove
the text from "Soil Gas Surveys" through the end of page 2-19

U&A Response
The text has been removed as requested.

EPA Comment
13.  Section 2.9.1 CAOC 1: Flight Line, page 2-20
Since the OU2 RI/FS is referenced in the ROD, it is not necessary to summarize detailed
site information and contaminant concentrations.  Section 2.6.2 through 2.6.18 provide
sufficient detail for describing the CAOCs. EPA recommends deleting Section 2.9.1
(page 2-20) through Section 2.9.18 (page 2-38).

U&A Response
Section 2.9.1 through Section 2.9.18 have been deleted as requested. The final paragraphs of
these sections, which briefly summarize the findings of the Field Investigation, have been
incorporated into Sections 2.6.1 through 2.6.18.

EPA Comment
14.  Table 2-5 Maximum concentration of Pesticides and PCBs Detected as COPCs at 0 to
    10 Feet, MCAS Yuma, Operable Unit 2, page 2-23a
The Risk-Based Criteria for Pesticides and PCBs, and the results for CAOCs 1 and 2
appear to be omitted from Table 2-5.
               0

U&A Response
The first page of Table 2-5 was accidentally not bound with the Draft Record of Decision. This
error has been corrected. Note that the tables have been moved to the end of the ROD, behind the
Tab labeled "Tables".

EPA Comment
15.  Section 2.10.6  Summary of Risks at Individual CAOCs, page 2-43; and Table 2-7
    Summary of Risk Assessment Results, MCAS Yuma, Operable Unit 2, page 2-44
The text and table report the Residential Scenario Hazard Index and Commercial/
Industrial Hazard Index as incremental values over that contributed by background
metals. This is an inaccurate presentation of nononcer health risk. For substances
which have a threshold of action (non-carcinogens), the background level plus the
concentration of the chemical from site activities might produce a combined exposure
which exceeds the threshold for toxic effects. Subtracting the background levels before
calculating risk could therefore misrepresent the threat to public health associated with
the site-related contamination, resulting in the false conclusion that the site-related
chemicals do not impose a risk of adverse effects on health. The text and table should
summarize the findings of the RI in which the table should summarize the findings of
the RI in which the cumulative noncancer hazard index was evaluated, and if necessary,
a target organ system analysis was performed.

U&A Response

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Based on a discussion on October 10, 1996 between U&A, Southwest Division, and the U.S.
EPA, the contents of Section 2.10.6 have been significantly abridged.  The CAOCsfor which the
RI found that there was no significant health risk are not discussed in detail in the revised text of
Section 2.10.6.  It was agreed that the ROD would state that the health risks are acceptable for
all CAOCs other than 1, 8A, and 10. Only CAOCs 1, 8A, and 10, at which unrestricted land
use could lead to unacceptable health risks, are discussed in detail in Section 2.10.6. Therefore,
the table and the majority of the text addressed by this comment are not present in the current
draft of the Record of Decision.

EPA Comment
16. Table 2-7 Summary of Risk Assessment Results, page 2-44
Please change the title of the second column for Most Likely Use Scenario to Current
Use Scenario.

The second column titled Risk Assessment Scenario is confusing since both the
residential and industrial scenarios were calculated in the risk assessment. A clearer
title would be Risk Assessment Scenarios within the Accetable Risk Rane
     to
      Response
Table 2-7 has been deleted from the Record of Decision (See response to Specific Comment 15).

EPA Comment
17. Table 2-7 Summary of Risk Assessment Results, MCAS Yuma, Operable Unit 2,
    page 2-44
a)  The Residential Scenario Excess Cancer Risk for CAOC 18 should be changed from
    <3 E-08 to E-08.
b)  The Residential Scenario Hazard Index for CAOC 2 should be changed from zero to
    0.08. (Refer to Specific Comment 15).
c)  The Residential Scenario Hazard Index for CAOC 9 should be changed from 0.18 to
    0.04 (Refer to Specific Comment 15).

U&A Response
Table 2-7 has been deleted from the Record of Decision (See response to Specific Comment 15).

EPA Comment
18. Section 2.10.6.1 CAOC 1: Flight Line, page 2-45
Please rewrite the fourth sentence as follows, "The excess cancer risk for CAOC 1 is
6.48 x 10"5 for the industrial /commercial exposure scenario."

U&A Response
This sentence (now the first of the paragraph) has been edited as requested.  Note that this text is
now in revised Section 2.10.6 and that the current draft of the Record of Decision does not
include a Section 2.10.6.1.

EPA Comment
19. Section 2.10.6.8 CAOC 8:  Southeast Station Landfill, page 2-46
In the second paragraph, please delete the following statement:

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"...even though the area is almost entirely enclosed by a chain-link fence, access to
vehicles is limited, and the period of time a human receptor is inside the area is
relatively short."

The role of the risk assessment is to evaluate the potential future land uses as well as the
current land use.

U&A Response
The requested edit has been made.  Note that this text is now in revised Section 2.10.6 and that
the current draft of the Record of Decision does not include a Section 2.10.6.8.

EPA Comment
20. Section 2.10.6.8 CAOC 8: Southeast Station Landfill, page 2-47
Please delete the last sentence of the second paragraph of this section.  This sentence
should be rewritten as'follows:

"Based on the fact that the landfill interior has not been fully characterized and
therefore the human health risks associated with exposure to the landfill interior are not
known, US EPA, ADEQ, and the Navy has made a risk management decision to restrict
the land use of CAOC 8A to the current use and to prohibit any land use that could
potentially disrupt and expose the interior of the landfill."

U&A Response
The requested edit.has been made.  Note that this text is now in revised Section 2.10.6 and that
the current draft of the Record of Decision does not include a Section 2.10.6.8.

EPA Comment
21. Section 2.11.6 CAOC 5: Old 2nd LAAMBN Compound, page 2-51
The text states that two metals and two pesticides were found to exceed the soil toxicity
criteria. However, the RI concluded that it is unlikely that vertebrate receptors would
be significantly impacted. The text should indicated that this conclusion was based on
the observations that the COPECs are fairly immobile and do not appear to be related to
site releases.

U&A Response
Based on a discussion on October 10,1996 between U&A, Southwest Division, and the U.S.
EPA, the contents of Section 2.11 have been significantly abridged. The requested language has
been incorporated into a general discussion of the ecological risk at OU2.  The discussion of
individual CAOCs has been removed.

EPA Comment
22. Section 2.12.4 CAOCs with Potential Health Risks, page 2-57
Please explain that CAOC 8A poses an unacceptable risk because that landfill interior
has not been fully characterized and not because the residential scenario presents an
unacceptable human health risk (see General Comment 1).

U&A Response

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The text has been amended as requested

EPA Comment
23. Section 2.12.5 Alternatives .Considered for Responding to Potential Health Risks at
    CAOC 1 and CAOC 8A, page 2-57
Alternative 2. Additions to the Base Master Plan

Please state in the first paragraph that the locations of the former disposal areas for
CAOC 8A will be documented in the BMP.

U&A Response
The text has been amended as requested

EPA Comment
24. Section 2.13.1 Introduction, page 2-58
It is helpful to add the citation that requires the evaluation of the nine criteria and to
mention the criteria classifications. The following is suggested language for the ROD:

"The remedial alternatives developed in the FS were analyzed in detail using the nine
evaluation criteria required by the NCP (Section 300.430 (e) (7)). These criteria are
classified  as threshold criteria, primary balancing criteria, and modifying criteria.
Threshold criteria are:

•   Overall protection of human health and the environment; and
•   Compliance with ARARs.

Primary balancing criteria are:

•   long-term effectiveness and permanence;
•   reduction of toxicity, mobility, or volume through treatment;
•   short-term effectiveness;
•   implementability; and
•   cost.

Modifying criteria are:

•   state/support agency acceptance; and
•   community acceptance."

The resulting strengths and weaknesses of the alternatives were weighted to identify the
alternative providing the best balance among the nine criteria for each landfill site. The
nine criteria are summarized in the following sections."

U&A Response
The suggested text has been incorporated in Section 2.13.1.  The final paragraph has been revised
to incorporate references to appropriate discussions of the ARARs for sites with ACM and sites
with Potential Health Risks, as well as to incorporate language recommended in Specific
Comment 25.

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EPA Comment
25.  Section 2.13.2 Preferred Alternatives for ACM Soil, page 2-59
Compliance with ARARs

This section should include an explanation of what ARARs are, when they are used, and
what the ARAR categories are. In addition for the 13 sites that require no further action,
a sentence should be added explaining that ARARs will not be triggered at these sites
because they do not require remedial action.  Thus, ARARs only apply to those sites
were there will be an action.

The following is suggested language for the ROD:

"Pursuant to Section 121 (d) (1) of CERCLA [42 USC Section 9621 (d)], remedial actions
must attain a degree of cleanup which assures protection of human health and the
environment. Additionally, remedial actions-that leave hazardous substances,
pollutants, or contaminants on site must meet standards, requirements, limitations, or
criteria that are ARARs. Federal ARARs may include requirements under any federal
environmental laws. State ARARs include promulgated requirements under State
environmental or facility-siting laws that are  more stringent than federal ARARs and
that have been identified to US EPA by the State in a timely manner.

Applicable requirements are those clean-up standards, control standards, and other
substantive environmental protection requirements, criteria, or limitations promulgated
under federal or State law that specifically address a hazardous substance, pollutant,
contaminant, remedial action, location, or other circumstances at a CERCLA site.

Relevant and appropriate requirements include those that, while not "applicable" to a
hazardous substance, pollutant, contaminant, remedial action, location, or other
circumstances at a CERCLA site, nevertheless address problems or situations
sufficiently similar to those encountered at the CERCLA site to indicate their use is well-
suited to the particular site. A requirement must be both relevant and appropriate to be
designated an ARAR. If no ARAR addresses a particular situation, or if an ARAR is
insufficient to protect human health or the environment, then nonpromulgated
standards, criteria, guidance, and to-be-considered (TBC) advisories may be used to
provide a protective remedy.

On-site response actions may proceed without obtaining permits pursuant to CERCLA
Section 121 (e). This permit exemption allows the response action to proceed in an
expeditious manner, free from potential lengthy delays of approval by administrative
bodies.  This permit exemption applies to all  administrative requirements, whether or
not they are actually styled as "permits.". Thus, administrative requirements can not be
ARARs.

Off-site remedies must comply with all applicable laws and must obtain all necessary
permits and fulfill all administrative procedures.
                                      10

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ARARs are identified on a site-specific basis from information about specific chemicals
at the site, specific actions that are being considered as remedies, and specific features of
the site location. There are three categories of ARARs:

Chemical-specific ARARs are numerical values or methodologies which, when applied
to site-specific conditions, result in the establishment of numerical values. They are
used to determine acceptable concentrations of specific hazardous substances,
pollutants, and contaminants in the environment;

Location-specific ARARs are restrictions placed on the concentrations of hazardous
substances or the conduct of activities solely because the site occurs in a special location,
such as a wetland or floodplain; and

Action-specific ARARs are technology or activity-based requirements or limitations on
actions taken with respect to hazardous waste.

The Federal ARARs are summarized below ... The State ARARs are summarized
below..."

Uf-fA Response
The suggested text generally describing ARARs has been incorporated in Section 2.13.2.
ARARs for the remediation of ACM are discussed in Section 2.13.3. ARARS for CAOCs 1, 8A,
and 10 are discussed in Section 2.13.4. The language stating that ARARs are not triggered at
sites that require no further action has been incorporated in the last paragraph of Section 2.13.1.

EPA Comment
25. Section 2.13.3 Preferred Alternative for Responding to Potential Health Risks at
   CAOC 1 and CAOG 8A, page 2-62
Compliance with ARARs

It is stated that ARARs have not been identified for PAHs and PCBs in soils at CAOC 1
and CAOC 8A.  Please note that last year Arizona passed soil clean-up standards.
Please contact the ADEQ representative for the citation.

U&A Response
Uf-fA has obtained the appropriate citation from ADEQ and the following language has been
inserted in Section 2.13.4

"Under the authority of Arizona Revised Statutes Section 49-151 and Section 49-152, ADEQ
has established Department-wide standards applicable to soil remediation activities. The
Amended Soil Remediation Rules were adopted in Arizona Administrative Code Title 18,
Chapter 7, Article 2, Interim  Soil Remediation Standards (Sections R18-7-201 through R18-7-
209) in 1996. These regulations are considered applicable.

The regulations allow soil remediation activities that attain one of three standards (Section R18-
7-203): 1) remediation to background levels; 2) remediation to the Health Based Guidance Levels
(HBGLs) presented in Appendix A of Title 18, Chapter 7, Article 2; or 3) remediation to levels
derived from a site-specific risk assessment."
                                         11

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EPA Comment
26. Section 2.14.2 Selected Remedy for Potential health Risks at CAOC 1 and CAOC 8A,
   page 2-67
In the last paragraph, it is stated, "In the future, the language added to the master plan
could incur costs related to future soil investigations, revised risk assessments, and
possible remedial activities. These potential costs cannot be estimated at the present
time" Please note that the activities mentioned would likely result only after the ROD
has been amended; thus, the cost estimates would be part of the amended ROD and not
necessarily part of this ROD.

U&A Response
The following text has been added to Section 2.13.4 and the last paragraph of Section 2.14.2:

"However, the activities associated with these costs would likely result only after the ROD has
been amended; thus, the cost estimates would be part of the amended ROD and not part of the
present ROD."

EPA Comment
27. Section 2.15.2 Statutory Determination for Selected Remedy for ACM in Soils, page
   2-68
Location-Specific ARARs

A string of citations is provided with little or no discussion of how they apply to the
remedy. Please identify which particular sections of the regulations apply to the
remedy and why they apply to the remedy.

U&A Response
The text of Section 2.15.2 has been revised to clarify that  the cited regulations and laws do not
apply to the selected remedy.

EPA Comment
28. Section 2.15.2 Statutory Determination for Selected Remedy for ACM in Soils,
   page 2-69
Action-Specified ARARs

This section should incorporate the following comments:

a) Sections 61.145 and 61.154: Do these sections include administrative requirements?
   Only substantive requirements, not administrative requirements, need to be
   complied with for actions that take place on-site. For actions that take place off-site,
   both substantive and administrative requirements need to be complied with.

   U&A Response
   The text has been revised to clarify which of the requirements are administrative and which
   of the comments are substantive.
                                        12

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b) Are there any RCRA requirements or state equivalent RCRA requirements that
   would apply to the remedy i.e., fugitive dust limits; treatment, storage or disposal
   requirements, etc.?

   U&A Response
   The text has been revised to clarify that there are no RCRA requirements or state equivalent
   RCRA requirements that would apply to the remedy for ACM.

EPA Comment
29. Section 2.15.2 Statutory Determination for Selected Remedy for ACM in Soil, page
   2-69
Other Criteria to Be Considered (TBO

Please include a discussion of what a TBC is before listing the TBCs.

U&A Response
The text has been revised as follows:

"In implementing the selected remedy, U.S. EPA and the State have agreed to consider
procedures that are not legally binding. This category of to-be-considered (TBC) procedures
consists of advisories, criteria, or guidance that were developed by EPA, other federal agencies, or
states that may be useful in developing CERCLA remedies. Such criteria are used if no ARAR
addresses a particular situation, or if an ARAR is insufficient to protect human health or the
environment.  One such criterion has been identified as a potential TBC."

EPA Comment
30. Section 2.15.2 Statutory Determination for Selected Remedy for ACM in Soil,
   page 2-71
In the second paragraph after the bullets, it is stated that "Community acceptance will
be evaluated after the public has commented on the alternative." Please note that the
proposed plan must  go through the public comment period before the ROD can be
signed. After the public comment period, community acceptance of the selected remedy
must be documented in the ROD.

U&A Response
The text has been amended to note the proper sequence of public review for the Proposed Plan
and the ROD.

EPA Comment
31. Section 2.15.3 Statutory Determinations for Selected Remedy for Potential Health
   Risks at CAOC 1 and CAOC 8A, page 2-71
The first paragraph states, "Compliance with the additional language in the base master
plan would ensure that the future development of the CAOCs would not result in
unacceptable risks."  How will the BMP be used so that compliance with the land use
restrictions are enforced?

U&A Response
The text has been revised as follows:
                                        13

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"The institutional controls would restrict the land use ofCAOC 1 and CAOC 10 to
industrial/commercial use and CAOC 8A to the current use. The institutional controls would be
implemented through the Base Master Plan, which would reference the OU2 ROD. Additions to
the Base Master Plan would include a map indicating the locations of the former disposal areas
in CAOC 8A.  The Base Master Plan would require that any changes in activities or land use in
these CAOCs be coordinated through and reviewed by the MCAS Yuma Environmental
Department. In the event that the Navy plans any future changes in land use at CAOC s 1, 8A,
or 10, U.S. EPA would be requested to re-evaluate the remedy in light of the intended land use.
If the change in land use is not compatible with the remedy, the remedy may be changed
pursuant to CERCLA Section 120 and the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP) Section 300.430 (f)(4)(iii) and the ROD may be amended."

EPA Comment
32. Figure 2-1 CAOC 1:  Feature and Boring Locations Map 1 through Figure 2-28
   CAOC 18: Feature and Boring Location Map
These figures show too much detail. It is recommended that all of the figures be
removed with the exception of the CAOCs where a remedy is being implemented
(CAOC 1, 4, 7, 8A, 9, and 10). The figures of the CAOCs where a  remedy is being
implemented should only show the features relevant to the remedy. For example, the
location of the ACM-areas should be shown for CAOC 4 and the location of the former
disposal pits should be shown for CAOC 8A.
      Response
The figures have b,een deleted/revised as requested.
                                        14

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  Arizona Department of Environmental Quality (ADEQ) Review
         of the Draft Record of Decision for Operable Unit 2
               Marine Corps Air Station, Yuma, Arizona
                         Report Dated July 31,1996
                      Comments Dated October 1,1996

ADEQ Comment
1. 1.2 Site Name and Location (page 1-1)
A Federal Facility Agreement (FFA) was signed by the U.S. Environmental Protection Agency
(U.S. EPA), the Department of the Navy (Navy), and the Arizona Department of
Environmental Quality (ADEQ) in 1990 to establish a frame work and schedule for
implementing environmental investigations and appropriate remedial actions under the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

Comments:   The final FFA was signed in January, 1992. Please correct the date at this
             location and other locations as appropriate throughout the document.

U&A Response
The text has been corrected as requested.

ADEQ Comment
2. 1.4 Assessment of the Site (page 1-2)
Based on the Rl, U.S. EPA, ADEQ and the Navy agreed that 13 of the CAOCs require no
further action.  ."

Comment:   The final status of CAOC 10, and other PAH sites, has not yet been
            determined. Additional comments may be submitted following review of
            recent sampling data.

U&A Response
Based on the August 1996 sampling effort at CAOC 10, the number of sites requiring no further
action is now 12. Institutional controls will be implemented at CAOC 10.  In addition, in
response to U.S. EPA's request for further characterization of CAOC 10, the following text has
been added to Section 2.4:

"Investigations performed at MCAS Yuma include the Remedial Investigation/Feasibility Study
(RI/FS) (/EG, 1996), a supplemental sampling program at CAOC 10 (Uribe, 1996b), Federal
Facility Agreement Assessment Program (FFAAP), and underground storage tank
investigations (/EG, 1995b). In addition, further characterization of CAOC 10 will be
performed in 1997."

ADEQ Comment
3.  1.5 Description of the Selected Remedy, Alternative 2-Additions to the Base Master
    Plan (page 1-5)
It is expected that this alternative would be acceptable by the state and the community.

Comment:   Please provide justification or clarification to this statement.
                                      15

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U&A Response
The text of Section 1.5 has revised been as follows:

"The state has indicated that Alternative 2 would be acceptable if the substantive requirements of
R18-7-208 and R18-7-209 are met.  Based on interaction with the Restoration Advisory Board
(RAB), Alternative 2 is expected to be accepted by the community."

ADEQ Comment
4.   1.6 Statutory Determination (page 1-7)
Comment:     Please correct the ADEQ signature block as follows - Russell F. Rhoades,
              Director, Arizona Department of Environmental Quality.

U&A Response
The spelling of Russell F. Rhoades' name has been corrected as requested.

ADEQ Comment
5.   2.7 Highlights of Community Participation (page 2-13)
Comment:     General information on the community relations program, and contact
              names is unnecessary. Please remove this portion.

U&A Response
The text has been removed as requested

ADEQ Comment
6.   2.9 Site Characteristics (page 2-15)
Comment:   In general, the information presented in this section should be simplified.
            Individual site characteristics should be incorporated in the general site
            descriptions presented in section 2.6. Text briefly summarizing significant
            sample results should be developed in place of the numerous data tables
            currently present in this section.

U&A Response
In conformance with a similar U.S. EPA comment (Specific Comment 13), the text of Sections
2.9.1 through 2.9.18 has been deleted, with the exception of the closing paragraphs that
summarized the significant sample results; these summaries have been incorporated into
Sections 2.6.2 through 2.6.19.  However, since U.S. EPA requested corrections to a data
summary table (Specific Comment 14), these tables have been retained in the Record of Decision.
Note that the tables have been moved to the end of the ROD, behind the Tab labeled  "Tables".

ADEQ Comment
7.   Table 2-2 Analyte Groups and Associated Methods (page 2-17)
Comment:     The information provided in this table is not necessary in the ROD.
              Please remove the table.

U&A Response
Table 2-2 has been removed as requested.
                                        16

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ADEQ Comment
8.  2.10.3 Exposure Assessment (page 2-40)
Comment:  The state Amended Soil Remediation rules discussed in comment 10 must
            be considered in evaluating default exposure parameters described in this
            section.

U&A Response
The following text has been added to Section 2.30.3

"Note that the Arizona  Health Based Guidance Levels (HBGL) discussed in the ARAR
discussion in Section 2.13.3 are derived using the assumption that incidental ingestion of soil
contaminants is the only significant exposure pathway.  Therefore, the RBC values (See Section
2.10.5) are more conservative than the HBGL values.  HBGL values are derived by ADEQ for
residential and non-residential scenarios that are analogous to the future use
industrial/commercial and residential scenarios used in developing RBC values. "

ADEQ Comment
9.  2.15 Statutory Determinations (page 2-67)
Comments:   A brief description of the ARARs determination process, and a table
              presenting all ARARs should be added to this section.

U&A Response
U.S. EPA requested a similar edit for Section 2.13 (Specific Comment 25).  See the response to
U.S. EPA Specific Comment 25 for the additional text concerning the ARARs determination
process.  The requested  table has been incorporated as Table 2-12 of the Final Record of Decision.

ADEQ Comment
10. 2.15.3 Statutory Determinations for Selected Remedy for Potential Health Risks at
   CAOC 1 and CAOC 8A (page 2-71)
ARARs have not  been identified for PAHs and PCBs in soils at CAOC 1 and CAOC 8A.

Comment:  As stated in previous correspondence regarding the OU2 Feasibility Study
            (FFU97.021), ADEQ has established Department-wide standards applicable
            to soil redemption activities. The amended soil Remediation Rules should
            be considered an Applicable, Relevant and Appropriate Requirement
            (ARAR). Please make the appropriate changes throughout the ROD.
      Response
The text of sections 2.13.3 and 2.15.3 have been amended as follows:

"Under the authority of Arizona Revised Statutes Section 49-151 and Section 49-152, ADEQ
has established Department-wide standards applicable to soil remediation activities. The
Amended Soil Remediation Rules were adopted in Arizona Administrative Code Title 18,
Chapter 7, Article 2, Interim Soil Remediation Standards (Sections R18-7-201 through R18-7-
209) in 1996. These regulations are considered applicable.

The regulations allow soil remediation activities that attain one of three standards (Section R18-
7-203): 1) remediation to background levels; 2) remediation to the Health Based Guidance Levels
                                         17

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(HBGLs) presented in Appendix A to Title 18, Chapter 7, Article 2; or 3) remediation to levels
derived from a site-specific risk assessment. HBGL values for the PAHs and PCBs detected at
CAOC1, 8A, and 10 are presented in Table 2-7."
                                          18

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       MCAS Yuma Environmental Department Review Comments for
                 Draft Record of Decision for Operable Unit 2
                   Marine Corps Air Station, Yuma, Arizona
                          Report Dated July 31,1996
                       Comments Dated October, 1996

MCAS Yuma Comment
1.  Page 1-1, Section 1.2, first paragraph, a reference to when the Navy/Marine Corps
   took control of the Air Station form the Air Force is needed .

U&A Response
The following sentence has been added to Section 1.2

"In January 1959, the Station and its associated range facilities were transferred to the U.S.
Navy."

MCAS Yuma Comment
2.  Page 1-1, Section 1.2, second paragraph, OU3 has been identified in the OUl RI
   report and should also be identified in this document.

U&A Response
OU3 has not yet been defined. Therefore, OU3 is not discussed in the ROD.

MCAS Yuma Comment
3.  Page 1-3, Section 1.4, second bullet item, should identify that the risk is due to the
   presence of PAC's and PCB's in the soil.  Should also reference that sampling was
   not performed in the landfill.

U&A Response
The following paragraph (or similar language) has been incorporated into Section 1.4 (page 1-3)
and Section 2.10.6 (page 2-23) of the Final Record of Decision for Operable Unit 2, MCAS
Yuma, to respond to this comment:

"CAOC 8A: Intrusive sampling was not conducted at the southeast station landfill during the
RI. Based on the human health risk assessment, it was concluded that a landfill cap was not
required under the current land use. However, since the interior of the landfill was not
investigated during the RI, the risk from exposure to the landfill interior is unknown."

The classes of chemicals responsible for the risk (i.e., PAHs and PCBs) are discussed in the
context of the more detailed risk assessment discussions in Section 2.10.6.

MCAS Yuma Comment
4.  Page 1-6, Section 1.6, last paragraph on the page, there should be some criteria
   placed in the base master plan which is acceptable to EPA/ADEQ to evaluate the
   planned activities or land use changes in CAOCs 1 and 8A.

U&A Response
The following text has been incorporated in Section 1.6:
                                       19

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"The institutional controls would restrict the land use ofCAOC 1 and CAOC 10 to
industrial/commercial use and CAOC 8A to the current use. The institutional controls would be
implemented through the Base Master Plan, which would reference the OU2 ROD. Additions to
the Base Master Plan would include a map indicating the locations of the former disposal areas
in CAOC 8A. The Base Master Plan would require that any changes in activities in these
CAOCs or land use changes be coordinated through and reviewed by the MCAS Yuma
Environmental Department.  In the event that the Navy plans any future changes in land use at
CAOCs 1, 8A, or 10, U.S. EPA will be requested to re-evaluate the remedy in light of the
intended land use. If the change in land use is not compatible with the remedy, the remedy may
be changed pursuant to CERCLA Section 120 and the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP) Section 300.430(f)(4)(iii) and the ROD may be amended.

If the land is transferred to a non-federal agency, the Department of the Navy would file a
Voluntary Environmental Mitigation Use Restriction (VEMUR), indicating that the property
has been remediated to less than residential levels and that the property cannot  be used for
residential purposes in the future. The VEMUR would be recorded in accordance with Arizona
Revised Statutes Section 49-152, as implemented in Arizona Administrative Code Sections R18-
7-206 (D)(2)(a) and R18-7-207(A).

The rationale for selecting Alternative 2 as the preferred alternative for potential health risks at
CAOCs 1, 8A, and  10 was based on the U.S. EPA criteria listed in Section 1.5. Alternative 2
would be protective of human health and the environment, comply with the State of Arizona and
federal requirements that are legally applicable or relevant and appropriate to the remedial
action, and be cost effective. Because Alternative 2 would result in hazardous substances
remaining on site, a five-year review will apply to this action."

MCAS Yuma Comment
5.  Page 1-7, The Marine Corps did not sign the FFA, therefore, the signatures for the
    ROD should be of the same agencies as the FFA. However, if necessary. The MCAS
    Yuma Commanding Officer's signature would be appropriate.
      Response
Southwest Division has determined that the MCAS Commanding Officer, Colonel C. J. Turner,
is to be the Department of the Navy signatory.

MCAS Yuma Comment
6.  Page 2-7, Section 2.6.4, CAOC 3 is not completely paved.

U&A Response
The typographical error has been corrected and the text now reads, "The original fenced area of
CAOC 3 covered approximately 0.3 acre ofunpaved land."

MCAS Yuma Comment
7.  Page 2-7, Section 2.6.5, no municipal waste was disposed at CAOC 4. Municipal
    waste should be reworded to station household waste or words to that effort.

U&A Response
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The text has been revised to clarify that all of the municipal waste was generated at MCAS
Yuma. Note that the term "municipal waste", as used by U.S. EPA, refers to waste streams that
contain household waste. Therefore, "municipal waste" refers to the contents of the waste stream
and does not necessarily imply that the waste originated from a municipality.

MCAS Yuma Comment
8.  Page 2-8, Section 2.6.7, same discussion as above concerning municipal waste.

U&A Response
The text has been revised to clarify that all of the municipal waste was generated at the Station.

MCAS Yuma Comment
9.  Page 2-8, Section 2.6.9, same discussion as above concerning municipal waste.

U&A Response
The text has been revised to clarify that all of'the'municipal waste was generated at the Station.

MCAS Yuma Comment
10. Page 2-9, Section 2.6.9, Facilities Management Department should be able to
    determine a period when the pits were backfilled and housing units were
    developed.

U&A Response
The Facilities Management Department was unable to provide the date for the backfilling of the
pits. Therefore, this edit was not made.

MCAS Yuma Comment
11. Page 2-9, Section 2.6.10, DRMO does not use this area as a salvage yard or as an
    overflow area.

U&A Response
The text has been edited to remove the statement concerning  use of the area as a salvage yard or
as an overflow area.

MCAS Yuma Comment
12. Page 2-10, Section 2.6.14, Chemical weapons were not used at MCAS Yuma. Change
    any reference of "chemical weapons" to "simulation of chemical weapons" or words
    to that effect.

U&A Response
References to chemical weapons have been deleted from the text.

MCAS Yuma Comment
13.   Page 2-12, Section 2.6.19, waste stored in the drums was I.D.W. and PPE (see page
      22-1 of the OU2 RI report).

U&A Response
The text has been revised to include the contents of the drums.
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MCAS Yuma Comment
14.   Page 2-12, Section 2.7, change the Public Affairs address to the following:
          United States Marine Corps
          JPAO
          Box 99113
          Yuma, AZ 85369-9113
          (520) 34[9?]l-2275

U&A Response
U.S. EPA and ADEQ requested that Section 2.7 be significantly abridged. The Public Affairs
address is no longer included in the text.

MCAS Yuma Comment
15.   Section 2.7, Personal names should not be used because people change jobs.
     Position titles and project names should be used in place of names.

U&A Response
EPA and ADEQ requested that Section 2.7 be significantly abridged. The position titles and
project names have been deleted from Section 2.7.

MCAS Yuma Comment
16.   Pages 2-21a through 2-24g, photocopies of the table are hard to read. Include a
     clean table in the final version of the ROD.

U&A Response
Clean copies are provided.

MCAS Yuma Comment
17.   Page 2-26, Section 2.9.1, change RFA Units to FFAAP Units.

U&A Response
At the request of U.S. EPA and ADEQ, this section has been condensed and combined with
Section 2.6.2. The reference to RFA Units was removed when the section was condensed.

MCAS Yuma Comment
18.   Page 2-41, Section 2.10.3 "two-year tour of duty" is not an appropriate designation.
     Marine Corps policy has changed over the years such that personnel may be
     assigned to a duty station up to six years. Please change "two-year tour of duty" to
     "duty assignment."

U&A Response
The text has been edited as requested.

MCAS Yuma Comment
19.   Page 2-46, Section 2.10.6.5, a glossary should be added so that certain terms, such
     as "excess cancer risk" can be defined.
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U&A Response
"Excess cancer risk" is defined in Section 2.10.5. Because Section 2.10 has been greatly abridged
in accordance with a discussion between U.S. EPA, Southwest Division, and U&A on October
10,1996, Section 2.10.6.5 is no longer a component of the ROD. The abridged version of Section
2.10 keeps all references to "excess cancer risk" closer to the definition of the term.

MCAS Yuma Comment
20.    Page 2-49, Section 2.11.1, soil screening criteria should be defined.

U&A Response
Based on a discussion between U.S. EPA, Southwest Division, and U&A on October 10,1996,
Section 2.11  has been greatly abridged, and in the present version of the ROD, Section 2.11 is
less than one page of text. The revised text states that; "Soil screening criteria are discussed in
Section 4.16  of the RI Report and derived in Appendix Q of the RI Report (JEG, 1996)." A full
discussion of the screening criteria is beyond the scope of the condensed discussion of
environmental risk that is now included in the ROD.

MCAS Yuma Comment
21.    Page 2-50, top two lines are duplicate lines of the previous paragraph.

U&A Response
Text has been corrected.

MCAS Yuma Comment
22.    Page 2-50,.Section 2.11.2, soil toxicity criteria should be defined.

U&A Response
The phrase "soil toxicity criteria" was an inconsistent name for "soil screening criteria".  The
text of Section 2.11 has been revised to consistently use "soil screening criteria".

MCAS Yuma Comment
23.    Page 2-51, Section 2.11.6, this section should repeat the  Ecological Risk Assessment
      on page 9-5 of the OU2 RI Report.

U&A Response
In accordance with a discussion between U.S. EPA, Southwest Division, and U&A on October
10,1996, Section 2.11.1  through 2.11.20 have been significantly abridged into Section 2.11.  The
level of detail on page 9-5 of the OU2 RI Report is no longer appropriate to the abridged Section
2.11

MCAS Yuma Comment
24.    Pages 2-64 through 2-66, photocopies of the tables are hard to read. Include clean
      tables in the final version of the ROD.

U&A Response
Clean copies are provided.
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MCAS Yuma Comment
25.  Page 2-67, Section 2.14.2, both bullet items, how will MCAS Yuma know the risks
     involved in changes in land use or activities planned in CAOCs 1 and 8A.

U&A Response
The text has been revised as follows:

"Under the selected alternative, Alternative 2, the following institutional controls would be
implemented through additions to the Base Master Plan:

•   CAOC1 and 10: In order to control the potential risk from exposure to PAHs in soils, the
    institutional controls would restrict the land use of CAOC 1 and CAOC 10 to
    industrial/commercial use. A change in land use from industrial to residential use would
    require re-evaluation of the remedy.  The institutional controls would be implemented
    through the Base Master Plan, which would reference the OU2 ROD.  The Base Master Plan
    would require that any changes in activities or land use at CAOC 1 or CAOC 10 be
    coordinated through and reviewed by the MCAS Yuma Environmental Department. The
    locations of the PAH detections would also be documented in the Base Master Plan.

•   CAOC 8A: In order to control the potential risk from the exposure to the landfill interior,
    the institutional controls would restrict the land use of CAOC 8A  to the current use. A
    change in land use at CAOC 8A involving any activities that  may disrupt and expose the
    landfill interior would require re-evaluation of the remedy. The  institutional controls would
    be implemented through the Base Master Plan, which would reference the OU2 ROD. The
    Base Master Plan would .require that any changes in activities or land use at CAOC 8A be
    coordinated through and reviewed by the MCAS Yuma Environmental Department. The
    locations of the former disposal areas and the locations of the PCB detections will also be
    documented in the Base Master Plan.

In the event that the Navy plans any future changes in land use at CAOC 1, CAOC 8A, or
CAOC 10, EPA would be requested to re-evaluate the remedy in light of the intended use
changes.  For CAOC 1 or CAOC 10, a change in land use from industrial use to residential use
would require re-evaluation of the remedy. For CAOC 8A, a change in land use involving any
activities that may disrupt and expose the landfill interior would require re-evaluation of the
remedy. At the time of these future activities, further investigation may be undertaken in order
to determine if remediation is required and if the ROD must be amended. If the change  in land
use is not compatible with the remedy, the remedy may be changed pursuant to CERCLA Section
120 and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) Section
300.430 (f) (4) (Hi) and the ROD may be amended.  If the land is transferred to a non-federal
agency, the Department of the Navy would file a Voluntary Environmental Mitigation  Use
Restriction (VEMUR). "

MCAS Yuma Comment
26.  Page 2-70, Utilization of Permanent Solutions and Alternative Technologies to the
     Maximum. Extent Practicable, Community impacts bullet items, what is the impact
     on the community in filling Wellton landfill.
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U&A Response
Impacts on filling the Wellton landfill are considered to be out of the scope of the OU2 Feasibility
Study and ROD. Because the Wellton landfill is a permitted facility, general community
impacts of disposal at the facility are expected to be dealt with in the context of the facility's
operating permit.

MCAS Yuma Comment
27.   Page 5-2, change RFA to FFAAP.

U&A Response
At U.S. EPA and ADEQ request. Sections 2.9.1  through 2.9.18 and Sections 2.6.1 through
2.6.19 have been condensed and combined into a revised Section 2.6.1 through 2.6.19. The
reference to RFA Units was removed when the sections were condensed.  Therefore, "RFA" is no
longer needed in the glossary.

     Review Comments from Charles Saltzer, MCAS Yuma for
             Draft Record of Decision for Operable  Unit 2,
               Marine Corps Air Station, Yuma, Arizona
                          Report Dated  July 31, 1996
                    Comments Dated September 17, 1996

MCAS Yuma Comment
1.  Page 1-6 What base master plan would be revised?
              *
U&A Response
The text has been revised to emphasize that the institutional controls will be implemented
through the MCAS Yuma Base Master Plan.

MCAS Yuma Comment
2.  Page 2-12 Par. 2.7 Lt.  Connor is not the Public Affairs Officer. His replacement is 1st.
   Lt. Jimenez.

U&A Response
In response to U.S. EPA and ADEQ comments, the text of Section 2.7 has been significantly
abridged. The revised version of 2.7 no longer includes the name of the Public Affairs Officer.

MCAS Yuma Comment
3.  Page 2-41 Par. 2.10.3 Exposure Assessment. Is it reasonable to consider re-
   development of areas for residential housing?  With Yuma County having only
   MCAS Yuma as an airport the property would not be ever zoned for residential
   development.
     Response
Use of residential exposure scenarios is a standard practice in developing risk assessments for
CERCLA sites.  In addition, residential development is a reasonable exposure scenario for land at
MCAS Yuma because this scenario includes use of the land for military housing.
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MCAS Yuma Comment
4.  Figure 1-1 Location Map The Station boundary is not represented correctly. This
   needs to be corrected or someone in the public comment stages could state that not
   all areas of the Station were investigated thus the findings are invalid.

U&A Response
Based on a discussion with the MCAS Yuma Environmental Department1, it was decided that
changes to the figure are not warranted. Note that slight inaccuracies in the Station boundary
on Figure 1-1 would not impact the validity of the ROD for OU2, which is only concerned with
the 18 CAOCs identified as the components ofOU2 in previous studies. Prior documents
should have evaluated the full extent of potential contamination on Station property.
    Phone conversation between S. Knott of U&A and L. Leake at MCAS Yuma, December 2,
    1996.
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                             EPA Comments on the
            Draft Final Record of Decision (ROD) for Operable Unit 2
                    Marine Corps Air Station, Yuma, Arizona
                        Report Dated December 20,1996
                        Comments Dated February 5,1997

General Comments

EPA Comment
1. In EPA's General Comment #3 on the Draft ROD, EPA requested that the Navy
propose language that will be added to the Base Master Plan (BMP) for the institutional
controls at CAOCs 1, 8A and 10. This comment was not adequately addressed.  For the
institutional controls at CAOCs 1, 8A and 10, EPA requests the following:

       1) The Navy propose the language that will go in the BMP and that EPA
       approve the language.

U&A Response
See response to General Comment 1,3).

       2) The Navy propose the location where the language will go in BMP and that
       EPA approve the location.

U&A Response
The Navy proposes to incorporate the language in Chapter 8, Proposed Land and
Facility Use Plans, of the BMP.

       3) the language and location of the language for the BMP be included as an
       appendix to the ROD.  Alternatively if the language can not be agreed upon
       before the ROD is finalized, it must be clearly stated in the ROD that EPA will
       approve the language and the location of the language for the BMP.

U&A Response
The following text has been added to Sections 1.5,1.6, 2.12.5,2.14.2 and 2.15.3,
specifying that U.S. EPA will be asked to approve the language and the location of the
language for the BMP.

   Before the land use restrictions are incorporated in the BMP, the Navy will obtain
   the approval of the U.S. EPA for the language of the restrictions and the location
   in the BMP at which the approved language will be incorporated.

EPA Comment
2.  In EPA's Specific Comment #31 on the Draft ROD, EPA asked "How will the BMP be
used so that compliance with the land use restrictions are enforced?". This comment
was not adequately addressed. Please provide a brief description of how the BMP is
used for planning purposes. For example, if a construction activity was proposed for
CAOC 10, what process would the Base go through and how would the BMP be used.
This description should be included in the ROD.
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U&A Response
The following excerpt from the MCAS Yuma BMP explains how the BMP is used:

   2.0 Introduction
   Purpose of the Plan
   Guidance for Masterplanning of Naval and Marine Corps installations is
   contained in NAVFAC INST 11010.63B, dated October 20,1982. The purpose is to
   provide a comprehensive and practical planning process that will support current
   and projected mission requirements; improve operational capabilities; and protect
   infrastructure investments, resources and the environment. The Plan
   demonstrates the commitment of the Navy and the Marine Corps to the
   implementation of Department of Defense (DOD) and other federal policies.

   The activity master planning process has been designed to ensure the logical,
   orderly, and efficient use of land and facility resources, and of military
   construction funding. The process includes mechanisms to meet operation, safety
   and environmental requirements in the siting and designing of activity projects.

   This Masterplan of the Marine Corps Air Station, Yuma, Arizona provides the
   Navy and Marine Corps with realistic and orderly development guidance for the
   maintenance and further improvement of the installation. It is a decision-making
   tool for all levels of command that addresses current issues and provides the
   necessary background for planning and review. A preferred development
   program and .plan is recommended that has been selected by the Navy and
   Marine Corps as the most viable alternative, taking into consideration the
   Station's current situation and the planned future of both the Station and its
   environment. This Plan has been based upon information provided by the
   Station, and these recommendations reflect the evaluations, judgments and
   decisions of base personnel.

The Navy will also use Voluntary Environmental Mitigation Use Restrictions (VEMURs)
to restrict the land uses at CAOCs 1,8A, and 10. The following language has been
added to Sections 1.5,1.6, 2.12.5, 2.14.2, and 2.15.3:

   The institutional controls would be implemented through the MCAS Yuma Base
   Master Plan, which would reference the OU2 ROD. Additions to the Base Master
   Plan would include a map indicating the locations of the former disposal areas in
   CAOC 8A. In addition, the Navy would execute and record Voluntary
   Environmental Mitigation Use Restrictions (VEMURs) in accordance with and
   substantially in the form set out at Arizona Revised Statutes, Section 49-152,
   where appropriate.  Each VEMUR would state that it was executed and recorded
   by the federal government "for itself only, and not as a covenant running with the
   land". In addition, the VEMUR would state that:
           "a.  No interest in real property is created by the VEMUR;
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           b.  The State's approval of any VEMUR notice, or cancellation of same, is to
              verify the propriety of the format of the notification, and the accuracy of
              any  assertion that  the  cleanup  conducted  is  protective for non-
              residential uses."
EPA Comment
3.  For information purposes, please provide a copy or relevant sections of the BMP to
EPA.

U&A Response
Copies of relevant sections of the BMP have been included as an attachment to this
response to comments.

Specific Comments
EPA Comment
1 Section 1.5 Description of the Selected Remedy, page 1-6

Alternative 2 - Institutional Controls

Please revise the second sentence on this page as follows, "In the event that the Navy
plans any future changes in the land use at CAOCs 1, 8A, and 10, the Navy in
consultation with U.S. EPA and ADEQ would re-evaluate the remedy in light of the
intended land use." Please also revise the sentence in Sections 1.6, 2.12.5, 2.14.2 and
2.15.3.

U&A Response
The text has been revised as requested.

EPA Comment
2.  Section 2.6.11 CAOC 10: Ordnance Munitions Disposal Area, page 2-12

This section must be updated after the additional PAH sampling is completed at CAOC
10. The additional characterization work must be completed before the ROD is
finalized.
      Response
As requested, the discussion of sampling at CAOC 10 has been revised using the
additional information obtained in February of 1997. The following text replaces the
last three sentences of Section 2.6.11:

       Follow-up sampling programs in August 1996 and February 1997 (U&A, 1996d;
       U&A,  1997)  demonstrated the presence of PAHs  over a wider  area  than
       indicated by the RI.  Several sampling locations had total PAH concentrations an
       order of magnitude higher than were detected in the RI.  Figure 2-10 shows the
       total PAH  concentrations  detected in the August  1996 and  February 1997
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       samples with the isoconcentration contours defined in the RI Report.  Although
       the August 1996 and February 1997 data support the presence of elevated PAH
       concentrations at the four areas of elevated PAHs identified in the RI Report, the
       later data also indicate that elevated PAH concentrations are present at locations
       that do not correspond to features identified  based on aerial photographs or
       geophysical anomalies.


EPA Comment
3.  Section 2.10.6 Summary of Risks at individual CAOCs page 2-24

CAOC 10: Ordnance Munitions Disposal Area

Please note that this section will have to be revised after the additional PAH sampling is
completed. Also, it is inconsistent to calculate risk using EPA PRGs when the risk at the
other CAOCs was calculated using RBCs. The reference to PRGs should be discussed
with EPA before it is revised.

U&A Response
As requested, the discussion of risk for CAOC 10 has been revised using the additional
information obtained in February of 1997. The second paragraph of the discussion of
CAOC 10 has been revised as follows:

   Based on data from the August, 1996 and February,  1997 field investigations and
   the RBCs derived in the RI, the excess cancer risk from PAHs for the residential
   exposure scenario was recalculated as 4.6 x 10"1 and for the industrial scenario,
   1.5 x 10"*(U&A, 1997). The recalculated industrial excess lifetime cancer risk is at
   the upper end of the range of risks that are potentially acceptable for industrial
   exposure scenarios.
   The RI Risk-Based Criteria (RBCs) used to calculate carcinogenic risk were
   developed in 1993 using U.S. EPA exposure factors.  U.S. EPA's dermal exposure
   factors have since been revised. If the RBCs were calculated with the current
   (1996) EPA-approved factors, the RBCs for PAHs would be identical to U.S. EPA
   Preliminary Remediation Goals (PRGs). Using the same data and calculating the
   risks using PRGs, the industrial and residential  excess lifetime cancer risks are
   7.0 x 10s and 2.9 x 10"1, respectively. The industrial excess lifetime cancer risk
   calculated with PRGs is in the middle of the range of risks that are acceptable for
   industrial exposure scenarios.

As discussed in Section 6.3 of the Report of Supplemental Soil Sampling Program for
Poll/Cyclic Aromatic Hydrocarbons at CAOC 10, Operable  Unit 2, MCAS Yuma, April 8,1997
(prepared by Uribe & Associates), the most significant  difference between the  RBC
values and PRG values are the default exposure values for dermal exposure. The RBC
values use the EPA-approved dermal exposure factors that were current in 1993, while
the PRG values used the EPA-approved dermal exposure factors that are presently in
effect. U&A believes that it is appropriate to include the RBC-derived risk values in the
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discussion of CAOC 10 for the purpose of consistency with the risk values reported for
the other CAOCs, while also reporting the PRG-derived risk numbers to support risk
management decisions.

For the other CAOCs at OU2, use of the RBC values has demonstrated the absence of
significant risk for industrial exposure scenarios. Since the current PRGs include a
smaller exposure component for dermal exposure, revision of the hazard indices and
cancer risks for the other CAOCs would result in risks that were equal to or less than the
risks obtained using the RBC values. Therefore, the use of PRGs to re-calculate the
hazard indices and excess cancer risks for the other CAOCs would not provide
additional protection to human health, since the previous calculations have already
demonstrated that site conditions are sufficiently health protective.
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                     MCAS Yuma Review Comments on the
             Draft Final Record of Decision (ROD) for Operable Unit 2
                    Marine Corps Air Station, Yuma, Arizona
                         Report Dated December 20,1996
                       Comments Dated February 24,1997

MCAS Yuma Comment
1.  Paragraph 2.6.5, page 2-8, please define municipal wastes or find new term.

U&A Response
The text has been revised as follows:

"This area was used for burning or burying municipal waste (household waste)
generated at MCAS Yuma."

MCAS Yuma Comment
2.  Paragraph 2.6.7, page 2-9, please define municipal sewage or find new term.

U&A Response
The text has been revised as follows:

"Treated industrial sewage and municipal sewage (domestic sewage) from MCAS Yuma
MCAS Yuma C6mment
3. Paragraph 2.8, page 2-16, in the last paragraph on the page, remove the word "be"
from the sentence "... they are still be referred.. "

U&A Response
Text has been corrected  as requested.

MCAS Yuma Comment
4. Paragraph 2.10.3, page 2-19, were civilian employees included in the exposure
scenarios for current uses at MCAS Yuma for CAOCs that are currently
industrial/commercial.

U&A Response
Civilian employees were included in the future industrial/commercial use scenarios;
the civilian employees are assumed to have a 25-year exposure period in comparison to
the three-year exposure period of the military worker. The text has been revised to
emphasize that risk management decisions were made on the basis of the future use
scenarios because the use of these scenarios was more conservative than the use of the
current use scenarios.

The following paragraph has been inserted following the bullet items on the bottom of
page 2-19:
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"Exposure scenarios were developed for both current and future land uses at MCAS
Yuma. Because the future land use scenarios involve a higher degree of exposure to
chemicals at MCAS Yuma, risk management decisions were made on the basis of the
future use scenarios.  Use of the future use scenarios, therefore, provided a more
conservative estimate of risk."

In addition, the following sentence has been inserted after the fourth sentence of the
first complete paragraph on page 2-20.

"Similarly, the industrial exposure scenario for future use includes a 25-year exposure
period, rather than the three-year exposure period for military workers."

MCAS Yuma Comment
5. Paragraph 2.10.6, page 2-24, 2.2 x 10"1 is not within the 10^ to 10* risk range as set
forth by the EPA as being an acceptable risk range. The EPA and ADEQ should be
made aware of this and should concur that the 2.2 x 10"* is an acceptable risk for this
CAOC.

U&A Response
Based on the additional data obtained at CAOC 10 in February 1997, the excess cancer
risk has been revised from 2.2 x 10"* to 1.5 x 10"4. This value is sufficiently close to 1 x 10"1
for  the risk management decision proposed in this ROD. EPA and ADEQ are aware of
the calculated risk values.

MCAS Yuma Cpmment
6. Paragraph 2.11, page 2-25, states "No state or federally listed or threatened
endangered species are currently known to be present at MCAS Yuma. No critical
habitats or habitats of endangered species are affected by the COPECs at OU2".
However, Paragraph 2.13.3, page 2-34 states "Federal threatened and endangered
species have been observed on and in the immediate vicinity of MCAS Yuma". These
paragraphs conflict with each other.

U&A Response
The only federal threatened and endangered species that have been observed at MCAS
Yuma are migratory birds that have been observed in the air space above the base.
These species have not been observed in any of the CAOCs in OU2. The text on page
2-25 has been revised as follows:

       With the exception of migratory birds that have been observed in the airspace
       above MCAS Yuma, no state or federally listed threatened or endangered species
       are  currently known  to be present at MCAS Yuma.  No critical habitats or
       habitats of endangered species are affected by COPECs at OU2.
The text on page 2-34 has been similarly revised.
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MCAS Yuma Comment
7.  Paragraph 1.13.4, page 2-38, states that Alternative 2, Institutional controls is the
preferred alternative for CAOCs 1 and 8A. This paragraph should state that Alternative
2 is also the preferred alternative for CAOC 10.

U&A Response
The text has been revised as requested.

MCAS Yuma Comment
8.  Paragraph 2.14.1, page 2-41, "during excavation, soil should be watered to minimize
dust: should be specified.

U&A Response
The text has been revised as requested.

MCAS Yuma Comment
9.  Paragraph 2.15, seems to repeat topics that were discussed in previous paragraphs.
Is this paragraph necessary?

\1&A Response
Although Section 2.15 contains some duplication of previous material, it serves a unique
purpose in the required contents of the ROD, as specified in the EPA guidance
document for the preparation of a ROD (OSWER Directive 9335.3-02).

MCAS Yuma Comment
10. Figure 2-8, CAOC 9: Location of ACM Debris, the location of the ACM pile on the
figure is incorrect. The ACM pile is west of the location specified on the map.

U&A Response
Figure 2-8 has been revised as requested.
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                          Attachment

        Excerpts from Marine Corps Airs Station Yuma
                       Base Master Plan
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1.0   EXECUTIVE SUMMARY

PURPOSE OF THE PLAN
Activity V.oster Planning of  Naval ond Marine Corps installations is directed
by NA"FAC INST I IOI0.63B doted October 22, 1982.  The primary planning
instructions for Marine Corps  facilities ore contained in MCO PHOOO-I2C.
The purpose is to provide a comprehensive and practical planning process that
will support current  and projected mission requirements; improve operational
capabilities;  and  protect  infrastructure  investments,  resources,  and  the
environment.  The MasterpJan Update of the Marine Corps Air Station Yuma,
Arizona  provides  the  Navy  and  Marine Corps with realistic and orderly
developrrerit guidance  for  the  maintenance ond further  improvement of the
installation.  It is a decision-making tool  for  all levels  of command thai
addresses current issues and  provides a preferred ond recommended develop-
ment program ond plan.

The Plan will  serve as a  base document that  will continue to be updated
formally within the six-year  cycle mandated by NovOl Facilities Engineering
Command (NAVFACENGCOM) in  conjunction with the Headquarters Marine
Corps (HOMC). It will be revised informally, os  required, by those responsible
for its  implementation.  The plan has been prepared not only os  a facility
scoping and siting guide, but os on information source ond catalyst for base
development beyond its time frame ond as future conditions may require.


FEATURES OF THE MASTERPLAN

MCAS Yumo has expanded significantly in the post decode, both in terms of
increases of base loading ond operations and  the importance of its missions.
The Station is now one of  the most heavily utilized stateside air facilities in
the U.S. Navy system ond is o crucial element for both air combat training and
operational  readiness  for  the U.S.  Marine Corps.   This  development has
resulted  in severe problems  for  land and  facility use planning,  however,
because  the Station  is small  in area  ond is bounded by civilian aviation uses
ond an aggressive program of development by the community that hove  mode
expansion difficult and expensive.

A result of the changes, both of missions and aircraft that hove occurred  at
MCAS Yumo, has been a lack of  development of a comprehensive land use
plan.   This Masterplon offers such a land ond facility use plan for the  first
time.   The attention of the plan is directed toward the siting of  facilities ond
activities within the requirements of the Station's Air Installation Compatible
Use Zone (AICUZ) program and the promotion of greoter coordination among
the functions of the Station.  The plan is based on a concept of on ideal station
configuration.

A principal feature of the plan has been the proposal to move ordnance storage
activities from the Main  Station  to  on accessible  location  near the desert
training facilities. This will enable the Station to meet the requirements of on
                                   l-l

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ossignment  as  o secondary ordnance  stocking  point for the Novy and  the
combat reodiness ond training missions.  Additionally; this will increase safety
on the base, especially in family housing areas,  and free a significant amount
of land for housing ond billeting, personnel support, training, and operational
uses.
ACTIVITY DESCRIPTION

MCAS Yumo is located  in the southwestern corner  of  the State of Arizona
near both the California border ond the international border with Mexico.  The
Main Station is located on land within the City of Yuma at the southeastern
limits of the city.  The airfield utilized by MCAS Yumo for military operations
is a  joint-use facility that includes commerciol, general  aviation, ond aircraft
manufacturer facilities ond operations under agreement with the Yuma County
Airport Authority.

In addition to the Moin Station, MCAS Yumo maintains or schedules the use of
other nearby--focilities.  These  include the P-Ml Desert Training Facility,
utilized for Anti-Aircraft Missile  training; Auxiliary Airfield-2 that includes a
practice landing (LHA) pod; other Auxiliary Airfields; ond bombing ranges ond
targets in coordination with  other military commands.   There is a small o'ff-
bose family housing unit  within the City of Yuma and recreation facilities ot
nearby Martinez Lake that are also owned by the Station.
MISSION

The primary mission of MCAS Yuma is to maintain ond operate facilities and
provide services  ond materials  to  support  operations of  a Marine  Aircraft
Wing, or -units thereof, ond other  activities and  units as designated by the
Commandant of the Marine  Corps  in  coordination with the  Chief of Naval
Operations. Important tasks assigned  to MCAS Yumo include aircraft main'
tenonce, operational training support, and odministrotive and logistic services.
The Station provides ordnance storage, orming, and disposal for tenant and
training activities ond serves os o secondary ordnance stocking point for the
Navy.

Major Tenant groups, squodrons, ond units include:

      Marine  Aircraft Croup-13 (MAC-13)
      Marine  Aviation Weapons ond Tactics Squodron One (MAWTS-l)
      Marine  Wing Weapons Unit One (MWWU-I)
      Marine  Wing Weapons Unit Three (MWWU-3)
      Marine  Wing Support Squadron 371 (MWSS-371)
      Second  Light Anti Aircraft Missile Batolion (2nd LAAM Bn)
      Marine  Air Control Squadron  Seven (MACS-7)
                                   1-2

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MAJOR FINDINGS AND RECOMMENDATIONS

A series of findings hove been generotcd by the Mosterplan process at MCAS
Yumo.  These ore the basis for fhe plans ond recommendations included in the
Moslerplan Updote. Significant findings ond recommendations ore summarized
below:

   Finding:  The primary  task ond responsibility of MCAS Yumo during the
   period covered by  the  Mosterplon will  be  the stand-up of  o new  tenant
   group,  MAC-13.    This tocticol air  group  is replacing o Combat Crew
   Readiness Training  Group (MCCRTG-IO) that has been the major tenant of
   the Station,  This will involve new aircraft  (AV-8B), increases end changes
   of base loading, and requirements for  new facilities.

   Recommendation:   Developments ot MCAS Yuma  during  the  planning
   period  will  focus  on  the installation  of   MAG-13.   This will  require
   concentration  in  planning  of facilities ot the main station ond the P-llt,
   Desert Training  Site.   New  ond improved  facilities  are  required  for
   MACi-13 and  other homeported, tenant, ond rototionof  operations  ot  the
   main station.  The P-IM  Site  will be  utilized for 2nd LAAM Bn  ond
   MACS-7.   MAG-13 will utilize the facilities these units hove been using ot
   the Station.


   Finding:   There  is on acute shortage  of  developable  land  on the main
   station that presents severe limitations to development.  This has resulted
   in the  past  siting  of  housing,  personnel support, ond  training activities
   within Noise Zone 3 in potential violation of the  Station's AlCUZ; siting of
   housing and personnel support  adjacent  to ordnance  ESQD areas; and  the
   siting of family housing units off station.
          *
   Recommendation:  A land use  plon is recommended in the Masterplan for
   the  siting  of  facilities and activities that  will  minimize future land  use
   conflicts.

   Recommendations   Land  to  be  purchased  from  the U.S.  Bureau  of
   Reclamation (BUREC)  during the  Mosterplan period  will be utilized  for
   bachelor housing ond personnel support activities only.  Although much of
   the land to be acquired is  within Noise Zone  3, it is at the outer edge of the
   zone and is ideally  situated for personnel billeting because of  access to the
   flight line. Noise attenuation wilt be required for oil construction.

   Recommendation:  Ordnance storage will be moved from the main station
   ond  sited  in the vicinity of P-l II. This will remove  ESOD arcs that  arc
   restricting the development of significant land parcels on station.  The
   relocation of ordnance storage will begin with  MILCON Project, P-3^6,
   during the Mosterplan period.

   Recommendation:   An Ultimate  Land  Use Plan  is  recommended to be
   developed  beyond the planning  period.  This should  include  siting  of oil
                                   1-3

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housing and personnel support activities on  the  main station outside  of
Noise Zone 3 and  well  oway  from ESQO or Hazardous Electromagnetic
Radiation Arcs.  The Ultimate  Land Use Plan  should  also  include the
development of on Outlying Landing Field (OLF)  to relieve congestion  of
the Station and provide additional training capabilities.
Finding:  The present location of  ordnance storage requires a permanent
waiver at the south border of the Station, where ESQD arcs cross a public
rood, and special  waivers during peak  activity  times such as Weapons
Training  Instruction.  These  waivers may not be continued, which would
limit ordnance storage capacity and training activities.

Recommendations:  The relocation of ordnance storage to the vicinity of
P-lll, beginning  with MILCON P-346,  will  eliminate  the need for the
permanent woiver.  It will also allow eventual expansion of the Combat
Aircraft Loading Apron (CALA) and relocation of  the bomb build-up areas
that will eliminate the need for the special waivers.
Finding:   The changes  of mission and increases of base  loading  have
resulted  in  traffic  circulation  and  parking  shortages  and  problems,
particularly during peak work hours.

Recommendation:  A comprehensive traffic  circulation study  should be
requested of  the  Military Traffic  Management  Command, Transportation
Engineering Agency.  The study will provide a basis for traffic planning for
the Station for future development.

Recommendation: The circulation network should incorporate the BUREC
property to be acquired during the planning into the Station street system.

Recommendation:    A   designated  parking  area  system,  with  decol
designations,  is recommended for key  areas  of the Station.   Peak-hour
shuttle  bus service, from the  parking areas  and off-base housing,  is
recommended.

Recommendation: The principal road at the flight line will be designated
as a one-way street  to  relieve congestion  and potential traffic hazards
during peak hours.

Recommendation: Sidewalks for pedestrian use should be included in new
street improvements.

Recommendation:  Staggered work  hours should be  adopted to  relieve
congestion at peak times.

Recommendation: Supply functions should be consolidated in one area at
the northeast area of the flight line to improve supply and circulation.

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Finding: Public roods odjocent to the Stotion and public roods utilized for
Station activities require improvements to ensure the safety of military
and civilian personnel.

Recommendation:    County  Road l*»  will  become a  route  for  regular
transport of ordnance with the relocation of ordnance  storage.  The rood
should be designated o U.S. Defense  Highway.  This will provide federal
funds for the county and state for needed improvements to this road.

Recommendation:    Coordination should be  initiated with the county of
Yuma's Transportation Department and the Arizona Deportment of Trans-
portation for improvements  to  off  station roadways utilized  by base
personnel.  These should include:

   -   a designated bicycle path along Avenue 3E

   -   a pedestrian overhead walkway across Avenue 3E to o planned new
       shopping mall; the traffic lights currently in place hove not provided
       safe pedestrian crossing areas

       noise attenuation structures and sound absorbing materials to be
       installed along Avenue 3£ in the vicinity of housing and personnel
       support areas
Finding:   With  the  changes of aircraft resulting from new tenant and
transient training operations, the Station's AlCUZ must be updated.

Recommendation:  The A1CUZ Update should be undertaken in 1992/93,
one year after the fourth AV-8B squadron has received its full complement
of aircraft.
Finding:   The main station currently contains a mixture of building types
and buildings of different ages that lack visual appeal or esthetic qualities
and that  thus affect morale and pride in the base.

Recommendation: Future developments and improvements should be made
following the  Basic  Exterior Architectural  guidelines provided  in  the
Masterplan Update.
                                1-5

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2.0    INTRODUCTION

PURPOSE OF THE PLAN

Guidance for  Mosterplanning  of Novol and  Morinc Corps  installations is
contained in NAVFAC INST 11OI0.63B, doted October 20, 1982.  The purpose
is to provide o comprehensive and practical planning process thai will support
current ond projected mission requirements; improve operational capabilities;
ond protect infrastructure investments,  resources ond the environment.  The
Plan demonstrates the commitment of the Navy and the Marine Corps to the
implementation of Deportment of Defense (DOD) ond other federal policies.

The ortivity master planning process has been designed to ensure the logical,
orderly and efficient use of  land  ond facility resources, and of military
construction program funding.   The process includes mechanisms to meet
operation, safety and  environmental  requirements in the siting ond designing
of activity projects.

This Masterplan of the Marine Corps Air Station, Yuma, Arizona provides the
Novy and Marine Corps  with realistic and orderly development guidance for
the maintenance ond further improvement of the installation.  It is a decision-
making toot for  oil  levels of command that addresses  current issues and
provides the  necessary  background  for planning  ond review.  A  preferred
development program and plan is recommended that  has been selected by the
Novy and Marine Corps as the most viable alternative, taking into considera-
tion the Station's current situation and the planned future of both the Station
ond its environment.   This Plan has  been based upon information provided by
the Station, ond these recommendations reflect the evaluations, judgments and
decisions of base personnel.

The  Plan will serve  as  a base document  that will continue  to be updated
formally within the six-year cycle  mandated  by  NAVFAC and solicited by
HQMC.  It  will be revised informally, as required, by those involved with its
implementation. The  Plan has been prepared not only as a facility scoping and
siting guide, bul as an information source  and catalyst for bose development
beyond its time frame and as future conditions may require.


PLANNING  ASSUMPTIONS

During  the preparation of the Masterplon, several assumptions concerning the
planning period were  made that directly guided its development.  These are
described in the body of this report and include:

   •   MCAS  Yuma  will continue to exist ot its present location and  will
       continue  to be o vital  element in  Pacific  Fleet  air  training  and
       operations.
                                   2-1

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   •   Aircroft  operations ot  the Air Station wilt reonoin o1 least  al the
       200,000 per year level and may be increased with planned new tenants
       and aircraft.

   •   The Station personnel and aircraft loading  will continue to increase to
       meet  Navy  and  Marine  Corps  operations  requirements  (projected
       increase in loading ore provided in the Masterplan report).

   •   MCAS Yumo will  continue to host both tenant and transient activities,
       and will  be required  to provide  both base  and  community support
       facilities for these activities.

   •   Yuma International  Airport will  continue  to contribute a significant
       portion of total airfield operations.

   •   Pressures  for development of the City  ond County of Yumo, in the
       vicinity of the Station, will continue that  could jeopardize air opera-
       tions  and* the "  public  safety  by  incompatible  development  in
       inappropriate locations.

   •   Land use controls within determined noise  and safety zones around the
       airfield will continue to be valid in base and community planning for the
       health, safety and welfare of the citizenry.

   •   The effort to ensure the compatibility  of development  within  and
       around the Station will continue.

The  Masterplon  is  on  update  of  the   1981  Mosterplon  to  bring 5t  into
conformonce with new DOD ond NAVFAC guidelines, existing conditions, ond
new and projected base loadings.  Several major new conditions have come into
existence since the 1981 Plan, including:
         *

   •   Changes in missions, aircraft, and operations at the Station.

   •   Increased development and changes in land uses in the vicinity of the
       Station.

   •   Increases in civilian ond private air  traffic ot the airport, ond in the
       airspace utilized by the Station.

   •   Property values in the area hove continued to rise.


MASTER PLANNING PROCESS

Masterplanning for Naval and  Marine Corps facilities has been designed as a
dynamic approach to analysis and program design.  The process is based upon
the operational requirements of  the installation, Navy and  Marine Corps
policies and instructions,  and is sensitive to man-made and natural constraints,
fiscal resources nnd human  concerns.
                                   2-2

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The process wos designed in incrementol steps thot allowed for review at each
stage of development of the Plan. The principal steps were the establishment
of goals and objectives; data collection  and  analysis;- the development of
planning  concept  alternatives;  development  of  recommendations  (giving
priority to the Military Construction Program, environmental and community
concerns, and fiscal constraints); Command and public review of proposals; and
synthesis of programs, concerns and constraints into the final Plan.

Figure 2-1 provides a flow diagram of planning steps and accomplishments.


PLANNING GOALS

The primary focus  of the Wasterplan is to provide a planning  document that
will accurately reflect and provide for current and projected mission require-
ments.   IT is based on  a comprehensive review of  current and proposed
development, and  mission  changes  that  require revision  of the  existing
Mosterplan.   The  recommendations  of  the  Plan provide  a  basis for  the
continuing efficient and orderly development of the Station.

Major planning goals include:

   •   Support of  rhe  Station's  mission  through provision of the facilities
       needed for  future expansion  requirements.    Priority is  given  to
       functions most directly related to the Station's primary mission.

   •   Document existing conditions data base as a foundation for planning.

   •   Identify and  correct  deficiencies  in  existing facilities,  focusing  on
       recommendations that will solve station-wide problems.
            •
   •   Provide guidance for future facility improvements that can be adapted
       to changing conditions.

   •   Provide a clear  documentation of  the planning  process that will
       facilitate future evaluation and adjustment to changing conditions,

   •   Increase the quality of life  for military and civilian personnel of  the
       Station by improvements in work and living conditions.

   •   Propose the  siting of new  facilities  to take advantage of  existing
       infrastructure  and circulation  systems, and  to  avoid duplication  of
       facilities and conflicts of use.

   •   Incorporate findings from other studies, as applicable.

   •   Develop a Capital  Improvements Plan  (CIP) program with appropriate
       phasing   recommendations   to  satisfy  deficiencies   and   future
       requirements identified in the Masterplan.
                                   2-3

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PLANNING STEPS AND  ACCOMPLISHMENTS
                  ESTABLISH GOALS 4
                     OBJECTIVES
                                                    EXISTING
                                                   CONOmONS
     FAClfTY
 REQUIREMENTS DATA
                                   DATA
                                 COUfCTON
                                                    REVIEW
                                                 PUNNING DATA
     BASIC
FAOUTYREOXMREMENT
                                                 MAN-MADE AND
                                               NATURAL CONSTRAINTS
 DETERMNE PROGRAM
  AND DEFICIENCIES
                                 PLANNING
                                 ANALYSIS
                                               RECOMMEND LAND USE
                                                 ALTERNATIVES
     PROPOSE
  PLANNING ACTIONS
                                               MCORPORATE AICUZ
                                               AND ENVIRONMENTAL
                                                ASSESSMENT
                             SUBMrr EXISTMG CONOmONS
                              * CONOEPTOEVEIOPMENT
                                    REPOKT
   DCVELOPCP
   PROGRAM
                                                  RNAUZELANO
                                                   USE PLAN
                               SUBMIT PRELIMINARY
                                  DRAFT PLAN
   ULTIMATE
DEVELOPMENT PLAN
                     SUBMIT DRAFT
                     MASTER PLAN
                   SUBMfT PRE-FMAL
                    MASTER PLAN
                     SUBMIT FINAL
                     MASTER PLAN
                        2- 4
                                                              FIGURE 2.1

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   •   Develop the Stotion in o way that is compatible wilh the surrounding
       community and that recognizes oil noturol orid man-made constraints.

   •   Provide o  logical  and  functional  land  and  facility  use plan  thai
       maximizes  the use of land resources, improves installation efficiency,
       promotes lond use compatibility  both within and in the vicinity of the
       Station, and permits future expansion if required.

   •   Comply with all applicable federal and, to the extent possible, state and
       local plans  and directives that promote public  safety, conservation of
       energy, and environmental resource protection.


DATA COLLECTION

Two primary dota collection strategies were employed: on-site inspection plus
interviews  to provide  surveys   of  existing  land use  and  facilities;  and
administration of  a comprehensive questionnaire to representatives of Station
deportments and tenants.  The questionnaire solicited information on missions
and  tasks, building  and space utilization,  facility  requirements, numbers  of
authorized on-boord and projected personnel, relationships with on-station ond
off-station organizations ond personnel, condition ond  adequacy of location of
structures ond facilities, traffic circulation ond access, utility requirements,
problems and solutions, adverse environmental  conditions,  ond planned  or
proposed future projects and activities.

Data  from the questionnaires were classified and expanded by  follow-up
interviews with department representatives.

Additional data were obtained concerning local and regional civilian and other
military installation planning.  This  included o comprehensive historical and
socioeconomic community  profile for the City  and  County  of  Yuma.   An
environmental  data  base  was   prepared,  including  climate,  air  quality,
geomorphology, scismicity, soils, vegetation, ond wildlife.  A cultural resource
assessment included archaeological and historic assessments.

Data collection provided a base for concept development and evaluation at an
early stage of the process, but continued throughout as odditional information
was required ond new concepts explored.
ANALYSIS, PLAN DEVELOPMENT AND EVALUATION

The  analysis  of data  ond  the  development  of  conceptual plans  were
accomplished with the guidance of NAVFAC INST 110I0.63B.  This included
the review of existing and required facilities according to the procedures of
Bosic  Facility  Requirements  ond  other  planning  documents.    Facility
deficiencies, surpluses, ond other planning requirements were identified, based
on NAVFAC P-BO planning criteria.
                                    2-5

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Wilh these identificotions of  facility requirements,  solutions and  develop-
mental strategies  were devised.  Land use plans.and recommendations  for
development  were  prepared  to  remedy  deficiencies  and meet  future
requirements.  These recommendations ore based on  the priority of mission
requirements  and fiscal resources.  The resulting Mosterplan of land use end
facility development provides o phased program of  facility siting to accom-
modate future growth.
COMMAND REVIEW

A review of development concepts was conducted by the Commending Officer,
MCAS Yuma, and his staff.  A pre-draft Plan was  then reviewed by Western
Division Novol Facilities Engineering Command (WESTNAVFACENGCOM) and
by MCAS Yurno.  The draft Plon was reviewed by  MCAS Yumo Commander,
Marine Corps Air Bases Western Area (COMCABWEST),  Commandant Marine
Corps (CMC), ond WESTNAVFACENGCOM.
PUBLIC REVIEW

A draft of the final Masterplan was  presented to the City of Yumo, Yumo
County, and  the State of Arizona  for intergovernmental coordination  in
compliance with DOD directions and Executive Order 12372.
FINAL PLAN

When approved  by  WESTNAVFACENGCOM,  COMCABWEST,  HQMC,  ond
CMC, this Final Plan will become the official plan ond future development
guide for the Marine Corps Air Station, Yuma, Arizona.


ORGANIZATION OF THE REPORT

The report of the Masterplon has been prepared in 12 chapters with appendices
to provide supporting documentation.  In addition  to the Executive Summary
ond this Introduction, these chapters ond appendices ore:

   Chapter 3 -   Regional Setting
   Chapter ^ -   Activity Description
   Chapter 5 -   Installation Description ond Analysis
   Chapter & -   Development Impacts
   Chapter 7 -   Concept Development
   Chapter 8 -   Proposed Land and Facility Use Plans
   Chapter 9 -   Base Exterior Architecture Plon
   Chapter 10 -  Capitol Improvements Plon
   Chapter 11 -  Air Installation Compatible Use Zone (AICUZ) Program
   Chapter 12 -  Preliminary Environmental Assessment
                                 2-6

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Appendix A - Facility Requirements Program (FRP)
Appendix B - Facility Index (Building and Structural Use Summary)
Appendix C - MILCON Program - MCAS Yumo
Appendix O - Acronyms
Appendix E - Hazardous Waste Storage ond Dump Sites
Appendix F - Electromagnetic Hazards Survey for Transmitters at MCAS
            Yumo
Appendix C - Airfield Safety Waivers
Appendix H - References
                              2-7
                                                               TOTftL P.613

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B: Community
  Relations

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                 Appendix B
Community Relations Activities Conducted by Navy

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    Community Relations Activities Conducted by Navy.
A public hearing on the Proposed Plan for Operable Unit 2 (OU2) was held on April 9,
1997 at the Yuma County Main Library. The hearing began at 6:00 p.m. and concluded
at 7:20 p.m. The Navy and regulatory agencies were represented by:

•  Gary  Kiger, Clean Project Manager,  Jacobs  Engineering, 251 S. Lake Avenue,
   Pasadena, CA 91101
•  Larry Leake, IR Program Manager, MCAS Yuma, Building 228, Yuma, Arizona.
•  Bob Carpenter, Environmental Director, MCAS, Yuma.
•  Nadine Sperrus, Remedial Project Manager, Southwest Division, Naval Facilities
   Engineering Command, 1220 Pacific Highway, San Diego, CA 92132-5181.
•  Amanda Stone, Remedial Project Manager, Arizona Department of Environmental
   Quality, 3033 North Central Avenue, Phoenix, AZ 85012.
•  Rachel Simons, Remedial Project Manager, U.S. Environmental Protection Agency,
   Region IX, 75 Hawthorne Street, San Francisco, CA, 94104-3901.

Mr. Carpenter explained  the purpose of the public meeting and summarized the work
to date at OU2.  Nadine Spertus explained the CERCLA process, the Department of
Defense Installation Restoration Program,  and the contents of the Proposed Plan.  Ms.
Spertus explained the planned removal of asbestos-containing material from three of the
CAOCs,  as well as  the  other alternatives  that were considered.   Ms.  Sperrus  also
described the three CAOCs at which land use restrictions will be used to manage risk
levels.

Amanda Stone explained that the State agreed in principal with the land use restrictions
for the three CAOCs.  Ms. Stone explained that the State and the Navy were still
working  out the legal details of implementing the land use restrictions, but that the
details would be worked out before the Record of Decision was signed.

Ms. Spertus closed the presentation part of the Public Meeting by inviting the public to
make verbal or written comments on the  Proposed Plan.  Because the Proposed  Plan
had been distributed later than anticipated, Ms. Spertus announced that the end of the
period for submitting written comments on the Proposed Plan would be extended from
April 21 to April 28,1997.

                                    B-l

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Following  the  presentation,  several  members  of  the  public  asked for  further
explanations of the Proposed Plan.

Mr. John Colvin asked Amanda Stone to explain the proposed land use restrictions in
greater detail.  After Ms. Stone provided further information on the legal issues, Mr.
Colvin asked if such a land use restriction would also be applicable to the proposed
asbestos removal.  Mr. Colvin asked if the use of a  land use restriction for asbestos
debris sites would save the estimated $710,000 cost of excavating asbestos, as long as the
$90,000  surface cleanup was performed.  Mr. Colvin suggested that if the  buried
asbestos were left in place, the cost  of removal could be borne by any future  private
developer of the sites, rather than by public  money.  Ms. Stone explained that the
decision to excavate the buried asbestos was a group decision made by many members
of the project team. A land use restriction at the asbestos sites would be much more
restrictive than the land use restrictions that maintain the current uses of CAOCs 1, 8A,
and 10. Some of the asbestos sites are currently slated for development by the Navy and
any excavation at these sites would require removal of the buried asbestos. In addition,
as long as the  asbestos remains in the ground, there is a potential for  accidental
breakdown of the asbestos materials and the resulting release of fibers.

Ms. Maria Lewis commented that removing  the  asbestos now would probably be
cheaper than waiting till some unspecified date in the future. Ms. Stone observed that
the cleanup cost for these sites was not bad compared to many other sites.

Mr. Kevin Shaffer asked why the cleanup was not being paid for  by Superfund.  Ms.
Spertus explained that the Marine Corps and Navy  have a separate fund of money
called the Environmental Restoration Navy Account. Superfund was specifically set up
for private parties and is intended to be a revolving  fund that is repaid by identified
responsible parties.

Ms. Dottie Lofstrom asked if monitoring wells  had  been used to study the  landfill
(CAOC 8A).  Ms. Simons explained that, although soil samples were not taken from
within the landfill, soil samples were collected from the surface of the landfill, soil vapor
samples  were  collected  from  within  the  landfill, and  groundwater samples were
collected from around the perimeter of the landfill.

One written comment was received during the comment period. This comment is
included as an attachment to this appendix.  The comment consisted of a favorable
evaluation of the  Proposed Plan and a question on the feasibility  of using alternative
                                    B-2

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forms of energy in the pollution management process. The comment did not result in
any changes to the Proposed Plan.
                                    B-3

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Tables
                                   I:

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            Table 2-1: Chemicals of Potential Concern (COPC) for OU2
Petroleum Products
   TPH-Diesel
   TPH-Gasoline

Volatile Organics
   Benzene
   Toluene
   Ethyl benzene
   Xylene (Total)
   2-Butanone
   4-Methyl-2-pentanone
   Carbon tetrachloride
   Methylene chloride
   Trichloroethene (TCE)
   1,1,2,2-Tetrachloroethane
   1,1,1 -Trichloroethane
   Tetrachloroethene (PCE)
   Chlororrifluoromethane**
    trifluoroethane
   Methyl tert-butyl ether

Semivolatile Organics
   Naphthalene
   2-MethylnaphthaIene
   Acenapthene
   Acenaphthylene
   Fluorene
   Phenanthrene
   Anthracene
   Fluoranthene
   Pyrene
   Benzo(a)anthracene
   Chrysene
Semivolatile Organics
    (Cont'd.)
  Benzo(b)fluoranthene
  Benzo(k)fluoranthene
  Benzo(a)pyrene
  Indeno( l,2,3
-------
                   Table 2-2: Maximum Concentrations of Volatile Organic Compounds
              Detected by Off-Site Laboratory at 0 to 10 Feet, MCAS YUMA, Operable Unit 2
                                    Concentrations in milligrams per kilogram
Analyte
1,1-Dichloroethene
2-Butanone
Carbon Disulfide
Chloromethane
Freon 113
VIethylene Chloride
Tetrachloroethene
Toluene
Trichlorofluoromethane
Xylene
Residential Ris
Cancer
-
3.17
6.44
3.51
c-Based Criteria
Noncancer
2.22
2,770
3.89
1,130
1,930
338
484
142
1,930
Industrial Risk-Based Criteria
• . Cancer
-
5.82
12
8.84
Noncancer
14.5
3,070
25.4
1,130
1,930
338
48.4
933
1,930
i
*
2.31
0.11
0.16
0.09
CA
2
*
*
0.077
*
#
*
oc
3
*
*
0.3
4
*
*
*
*
*
                       Notes:
                        -- indicates that this constituent does not have cancer and/or noncancer toxicity.
                        *  indicates that this constituent was not a constituent of potential concern (COPC) for this CAOC.
ROD-VtlCl
                                                                                                   Pa

-------
                  Table 2-2: Maximum Concentrations of Volatile Organic Compounds
             Detected by Off-Site Laboratory at 0 to 10 Feet, MCAS YUMA, Operable Unit 2
                                 Concentrations in milligrams per kilogram

Analyte
1 , 1 -Dichloroethene
2-Butanone
Carbon Disulfide
Chloromethane
Freon 113
Methylene Chloride
Tetrachloroethene
Toluene
Trichlorofluoromethane
Xylene
CAOC , , i
5
4
*
4
*
4
4
4
4
0.38
»
6 | 7
*
*
*
*
*
0.092
0.11
4
4
*
*
4-
0.089
4
4
0.23
*
*
*
4
8A J 8B
4
4
»
*
4
4
if
*
*
»
»
*
4
»
4
*
4
»
4
4
-9
0.075
4
4
0.22
*
*
*
*
4
*
10
#
4-
+
*
*
4
4
4
4
4
12
4>
4
*
4
4
4
4
0.053
*
4
13 | 14
4
»
t
4
»
6.44
4
»
4
4
4
4
4
4
4
4
4
4
4
4
15 | 16
»
4-
4
4
*
»
4
4
4
»
*
*
»
«•
*
4
4
*
4
*
17
*
4
4-
*
4
*
»
4
»
4
18
»
*
4
4
0.05
0.106
4
4
4
4
ROD-V(XI.XLS
8/28/97 M2PM
Page 2 of 2

-------
Table 2-3: Maximum  Concentrations of Semi-Volatile Organic Compounds and Total
     Petroleum Hydrocarbons Detected by Off-Site Laboratory,  Operable Unit 2,
                        Concentrations in milligrams per kilogram
, ..-'';••'. •• Analyte. :f •' • •••' •:/•$
Semi-volatile organic compounds
1,2,3,5-Tetrachlorobenzene
l-Methyl-2-Pyrrolidinone
2-Cyclohexen-l-OI
2-Cyclohexen-l-One
2-Methylnaphtha lene
2-Pentene, 2-Methoxy
2-Pyrrolidinone, 1-Methyl
2,4-Dinitrotoluene
2-Pentanone, 4-Hydroxy-4-Methyl
4-Methylphenol
7H-Benz(DE)Anthracen-7-One
9,10-Anlhracenedione
Acenaphthene
Acenaphthylene
Anthracene
>enzene, l,4-Dimethoxy-2,3
Benzo(e) Pyrene
Benzo(a) Anthracene
)enzo(a) Pyrene
Jenzo(b) Fluoranthene
Jenzo (g,h,i) Perylene
)enzo(k) Fluoranthene
Benzo(b) Naphtho(23-D)Furan
Bis(2-Ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Carbazole
Chrysene •
Cyclopenta(deO Phenanthrenon
Di-n-Octylphthalate
Di-n-Butylphthalate
Dibenzo(a,h) Anthracene
3ibenzo(uran
Diethyl Phthalate
Ethanol. 2-[2-|4-(l,l,3.3-T
ithanone, 1-Oxiranyl
Sthylene Glycol
:luoranthene
Fluorene
Hexanedioic Acid. Bis(2-Ethyl)
ndeno (l,2,3
-------
Table 2-3: Maximum Concentrations of Semi-Volatile Organic Compounds and Total
     Petroleum Hydrocarbons Detected by Off-Site Laboratory, Operable Unit 2,
                    Concentrations in milligrams per kilogram
. '.'.:•" viAhalyte..H:'--;:'--:;.- ••.->
Semi-volatile organic compounds
1 ,2,3,5-Tetrachlorobenzene
l-Methyl-2-Pyrrolidinone
2-Cyclohexen-l-OI
2-Cyclohexen-l-One
2-Methylnaphthalene
2-Pentene, 2-Methoxy
2-Pyrrolidinone, 1-Methyl
2,4-Dinitrotoluene
2-Penlanone, 4-Hydroxy-4-Methyl
4-Methylphenol
7H-Benz(DE)Anthracen-7-One
9,1 0-Anthracenedione
Acenaphlhene
Acenaphthylene
Anthracene
Benzene, l,4-Dimethoxy-2,3
3«nzo(e) Pyrene
Benzo(a) Anthracene
Benzo(a) Pyrene
3enzo(b) Fluoranlhene
Benzo (g,h,i) Perylene
Benzo(k) Fluoranlhene
Benzofb) Naphtho(2,3-D)Furan
Bis(2-Ethylhexyl) Phlhalate
Butyl Benzyl Phthalale
Carbazole
Chrysene '
Cyclopenta(deO Phenanthrenon
Di-n-Octylphthalate
Di-n-Butylphthalate
Dibenzo(a.h) Anthracene
Dibenzofuran
Diethyl Phthalate
Ethanol. 2-|2-|4-(l,U,3-T
Ethanone, 1-Oxiranyl
Elhylene Clycol
Fluoranthene
Fluorene
Hexanedioic Acid, Bis(2-Ethyl)
lndeno(l,2,3.;• •.
''*£.:'

0.43
»
*
•
0.033
•
•
*
*
0.17
*
»
•
*
»
*
*
*
0.12
»
0.17
*
*
0.12
0.043
»
•
•
0.035
*
»
0.054
*
•
•
0.073
•
»
0.065
«
•
0.45
0.057
0.044
2.7
0.061
*
1,000
52
*
CA
•»A:\

0.13
•
•
•
•
•
*
*
*
•
*
*
*
*
•
*
0.2
0.24
0.42
0.035
0.2
»
0.387
*
»
0.27
•
»
4.038
•
*
»
*
»
0.344
*
*
0.074
0.049
*
*
*
0.14
*
*
0.344
•
860
*
*
oc
•s8B;|
-" ,*--. • • -
•.;-:v""- .
*
•
•
»
*
•
•
•
*
*
*
*
*
*
•
»
*
*
*
•
*
*
*
•
•
*
•
•
1.738
•
*
*
*
*
»
*
*
*
*
*
*
*
*
»
•
•
22
»
»
: 9-;:

»
0.1
*
•
•
•
•
11
*
»
»
•
•
•
»
»
0.081
0.075
0.11
0.04
0.064
*
0.054
*
*
0.11
»
*
*
*
*
»
»
0.11
*
0.044
*
•
»
•
0.05
»
0.14
*
21
*
*
't*o!
- .,-'•/;"
*
*
•
•
•
*
•
•
»
•
*
0.166
•
0.388
*
*
2.718
2.197
3.482
0.322
»
*
*
»
0.19
2.873
*
*
3.359
*
*
*
*
*
*
4.132
•
•
1.531
*
0.112
»
1.746
»
4.057
*
25
'.:- '.: ,
12 .
:• V- ••' '••
•
*
*
*
*
*
*
•
•
*
»
•
*
*
•
»
•
»
»
*
*
0.844
0.614
*
»
•
•
2.426
*
»
•
»
•
•
•
»
*
*
»
•
*
*
»
*
*
•
•
»
*
»
'''IS-''.

*
•
*
•
*
*
*
*
»
*
*
*
*
m
*
•
0.0391
+
*
*
*
20.4
*
*
*
*
»
*
*
*
»
*
•
•
•
*
*
*
*
*
*
•
»
*
*
*
»
•
*
»
14

*
•
*
•
*
•
»
*
•
*
•
•
*
*
*
*
0.13
0.15
0.24
«
0.2
*
18
0.86
•
0.27
*
»
*
*
11
•
*
0.35
•
•
»
*
6.1
*
0.095
*
0.37
*
900
•
                                                                            Page 2 of 3

-------
Table 2-3: Maximum Concentrations of Semi-Volatile Organic Compounds and Total
     Petroleum Hydrocarbons Detected by Off-Site Laboratory,  Operable Unit 2,
                    Concentrations in milligrams per kilogram
, :.'t -;.-.?•;>• ./,; v ; : .' '• .; _.;;•?
/ :- .:>-:;^'&^Aniiyte:; -.--I- ".; O-;-.^
Semi-volatile organic compounds'
1 ,2,3,5-Tetrachlorobenzene
1 -Methy 1-2-Pyrrolidinone
2-Cyciohexen-l-OI
2-Cy clohexen- 1 -One
2-Methylnaphthalene
2-Pentene, 2-Methoxy
2-Pyrrolidinone, 1-Methyl
2,4-DinitrotoIuene
2-Pentanone, 4-Hydroxy-4-Methyl
4-Methylphenol
7H-Benz(DE)Anthracen-7-One
3,10-Anthracenedione
Acenaphthene
Acenaphthylene
Anthracene
Jenzene, l,4-Dimethoxy-2,3
Benzo(e) Pyrene
Benzo(a) Anthracene
Benzo(a) Pyrene
)enzo(b) Fluoranthene
Jenzo (g,h,i) Perylene
Benzo(fc) Fluoranthene
Benzo(b) Naphtho(23-D)Furan
Bis(2-Ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Carbazole
Chrysene
Cyclopenta(deO Phenanthrenon
Di-n-Octylphthalate
Di-n-Butylphthalate
3ibenzo(a,h) Anthracene
Dibenzofuran
Diethyl Phthalate
Ethanol, 2-[2-|4-(l,U3-T
Ethanone, 1-Oxiranyl
Ethylene Glycol
Fluoranthene
Fluorene
Hexanedioic Acid, Bis(2-Ethyl)
Indeno (1,2,3-cd) Pyrene
N-Nitrosodiphenylamine
Naphthalene
Nonylphenol
Pentachlorobenzene
Phenanthrene
Phenol
Phenol, 2,2' - Methylenebis (6
Pyrene
Trans-Chlordane
Total Petroleum Hydrocarbons '
Diesel
Gasoline
Total Petroleum Hydrocarbons
iis;
•
»
*
*
•
•
*
*
»
*
*
*
*
*
»
•
»
»
•
•
»
*
•
•
»
•
•
*
*
•
*
*
•
»
*
*
»
•
*
»
*
•
•
*
•
*
»
*
CA
16
•
•
*
*
*
•
»
*
»
*
*
»
*
*
*
*
»
•
*
*
*
*
0.055
0.565
»
•
*
*
1.052
*
*
*
*
*
•
*
*
*
*
»
*
»
*
*
•
»
»
»
*
*
it
OC .;
17
»
*
•
*
•
*
»
*
•
•
*
•
•
*
•
*
•
•
•
*
»
»
»
»
•
»
»
*
•
*
*
»
*
*
•
*
»
•
*
*
*
•
•
*
•
*
29
*
*
18
•
•
•
*
•
*
*
•
*
*
*
»
•
*
*
•
*
*
»
*
*
*
»
*
*
*
•
*
2.45
*
»
*
»
*
*
0.056
•
*
*
•
*
•
»
0.037
*
•
0.047
»
*
*
»
                                                                           Page 3 of 3

-------
                            Table 2-4:  Maximum Concentrations of Pesticides and PCBs
                                   Detected by Off-Site Laboratory at 0 to 10 Feet,
                                            MCAS YUMA, Operable Unit 2
                                         Concentrations in milligrams per kilogram
• • . " • < Analyte • . •'..• ;:.:\;;:v'"
4,4-DDD
4,4-DDE
4,4-DDT
aldrin
aroclor 1242
aroclor 1254
aroclor 1260
dieldrin
endosulfan I
endosulfan II
endosulfan sulfate
endrin
endrin aldehyde
endrin ketone
heptachlor
heptachlor epoxide
alpha-benzene hexachloride
alpha-chlordane
beta-benzene hexachloride
delta-benzene hexachloride
gamma-chlordane
gamma-benzene hexachloride (lindane)
methoxychlor
prometon
Residential Ris
^•^G^cer^^.
0.935
0.66
0.66
0.0132
0.0473
0.0473
0.0473
0.014
-
0.0499
0.0247
0.0453
0.173
0.158
0.158
0.173
0.173
c-Based Criteria
;;'^§Ji^ieam^!f
15.6
0.973
1.56
1.56
1.56
1.56
9.37
9.37
9.37
15.6
0.406
1.87
1.87
9.37
156
468
Industrial Risk
..X;B.V«^ .'.•;••' •*i«OVyvi'j»v>; v
\?$&is$^
2.63
1.86
1.86
0.0371
0.176
0.176
0.176
0.0395
--
0.14
0.0694
0.143
0.486
0.499
0.499
0.486
0.486
-Based Criteria
">-J^b'iriiM$&-:';
113
6.76
11.3
11.3
11.3
11.3
67.6
67.6
67.6
113
2.93
13.5
13.5
67.6
1,130
3,380
CA
-:i>'
0.021
0.14
0.026
0.000088
t
0.02
0.39
0.014
»
0.015
0.013
0.0067
0.0097
0.018
#
0.0065
0.00027
0.17
*
0.0063
0.14
»
0.063
*
oc
'./.2'v
0.0076
0.092
0.044
0.00071
*
*
*
0.00457
»
»
0.00287
0.00414
0.00598
0.0018
»
4
*
0.0067
*
0.00122
0.009
*
0.00918
0.056
                                      Notes:
                                        - indicates that this
                                        *  indicates that this
                                          for this CAOC.
constituent does not have cancer and/or noncancer toxicity.
constituent was not a constituent of potential concern (COPC)
ROrj-PSTl XI.S
»/:H/17(> 1.1PM
                                                       Page 1 of 3

-------
                         Table 2-4: Maximum Concentrations of Pesticides and PCBs
                                Detected by Off-Site Laboratory at 0 to 10 Feet,
                                       MCAS YUMA, Operable Unit 2
                                    Concentrations in milligrams per kilogram
Analyte
4,4-DDD
4,4-DDE
4,4-DDT
aldrin
aroclor 1242
aroclor 1254
aroclor 1260
dieldrin
endosulfan I
endosulfan II
endosulfan sulfate
endrin
endrin aldehyde
endrin ketone
heptachlor
heptachlor epoxide
alpha-benzene hexachloride
alpha-chlordane
beta-benzene hexachloride
delta-benzene hexachloride
gamma-chlordane
gamma-benzene hexachloride (lindane)
methoxychlor
prometon
,'v3
0.00123
0.003
0.0034
4
*
4
0.00164
4
4
0.0053
0.0016
0.00061
4
4
4
0.00094
0.0002
0.0014
*
4
4
4 | 5,.
0.125
0.07
0.026
0.0006
*
4
0.00098
4
4
0.0013
0.0037
0.00036
0.0016
4
0.00094
4
0.0052
0.0005
4
0.0057
*
4
4
0.014
0.013
0.011
0.00074
4
4
4
0.035
*
0.0042
0.00462
0.00793
0.0025
0.0045
4
0.19
0.00019
0.0021
0.16
0.00403
*
6 , -•
0.00088
0.0065
0.0037
4
*
4
0.0034
0.001
0.00086
0.0012
4
4
4
.0.00093
0.00057
0.0083
4
0.00075
0.0082
4
0.0041
CAOC,
^ •)! «* 4* v^ » i
% i^*7 IV«fc"*vH j»j|* > i
0.002
0.016
.0.0051
0.00027
0.016
4
0.55
0.00043
0.021
0.0047
0.0028
0.013
0.00066
0.00069
4
4
0.00054
0.00036
0.00046
0.00032
0.0025
*
0.00805
0.0079
0.0023
0.00248
4
4.045
0.0695
0.00136
0.0027
0.00098
0.04176
0.0174
0.01142
4
0.05873
0.00041
0.00756
0.00072
A8B; •!'* \9 •»'
0.00087
0.00207
0.00792
4
4
*
4
0.00506
*
*
*
0.01161
0.0869
0.00145
0.10152
4
4
4
0.0088
0.084
0.0077
4
0.048
0.0045
0.00094
0.00084
0.0013
0.0011
0.00044
0.012
*
0.0006
0.011
id
4
0.002
4
4
4
0.00079
4
0.00137
4
4
4
4
4
4
0.00067
4
4
4
•••12
*
4
4
*
4
4
4
4
4
4
4
*
4
4
4
4
4
4
4
4
ROD-rsn xi.
K/2R/97AI3
I

-------
                         Table 2-4: Maximum Concentrations of Pesticides and PCBs
                               Detected by Off-Site Laboratory at 0 to 10 Feet,
                                       MCAS YUMA, Operable Unit 2
                                    Concentrations in milligrams per kilogram
Analyte
4,4-DDD
4,4-DDE
4,4-DDT
aldrin
aroclor 1242
aroclor 1254
aroclor 1260
dieldrin
endosulfan I
endosulfan II
endosulfan sulfate
endrin
endrin aldehyde
endrin ketone
heptachlor
heptachlor epoxide
alpha-benzene hexachloride
alpha-chlordane
beta-benzene hexachloride
delta-benzene hexachloride
gamma-chlordane
gamma-benzene hexachloride (lindane)
methoxychlor
prometon
:-3S
4
0.0004
4
4
4
4
*
4
4
4
4
4
*
4
0.00108
4
*
4
0.00065
4
4
4
*
4
!§rf
0.0012
0.008
0.0047
*
*
*
»
0.0012
*
*
0.00052
4
4
4
»
0.0003
0.00072
0.0014
»
0.0039
0.0012
*
0.01
4
lilt
»
*
»
t
»
*
»
»
»
»
*
*
*
*
*
*
*
*
*
*
4
*
*
*
WiS
»
»
*
*
»
»
»
»
*
*
»
*
»
*
4
»
»
*
»
*
*
*
4
4

4
*
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
|1«
4
0.002
0.00191
*
*
*
*
*
*
0.00061
»
»
»
*
»
*
*
0.00206
0.00056
4
0.00144
4
4
4
ROP-PST! XIS
                                                                                                  Page 3 of 3

-------
                        Table 2-5:  Maximum Values Detected by Off-Site Laboratory and
                                    Background Threshold Limit Values (TLV)
                                         for Metals Detected at 0 to 10 Feet
                                        Concentrations in milligrams per kilogram
Analyte
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Chromium VI
Cobalt
Copper
Lead '
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cyanide
Residential Ris
Cancer
0.302
0.129
26.5
4.07
--
--
--
--
c-Based Criteria
Noncancer ;'
71,100
28.4
21.3
1,520
356
35.6
71,100
356
4,540
2,630
136
21
1,420
356
356
4.98
498
21,300
1,420
Industrial Risk-1
1.9
0.859
45.4
6.97
~
-
-
--
Jased Criteria -.;,,.

100,000
532
399
12,400
6,650
665
100,000
6,650
29,600
49,200
1,180
382
26,600
6,650
6,650
93.1
9,310
100,000
26,600

iSlfcw
20,800
6.98
8.59
187
1.97
1.04
49.2
nd
12.2
15.4
15.8
319
nd
19.5
2.26
1.15
4.21
37.7
37.9
nd
$W4&£;-
26,200
16
437
0.43
6.2
32.2
*
16.6
47.1
102
727
1.3
39.3
0.59
42.1
0.5
56.7
101
*
                     Notes:
                      ~  indicates that this constituent does not have cancer and/or noncancer toxicity.
                      *  indicates that this constituent was not a constituent of potential concern (COPC) for this CAOC
                      nd  indicates that no data were obtained for TLV calculations.
                      1   EPA Region IX residential and industrial soil screening levels for lead are 400 mg/kg and 1,200 mg/kg,
                         respectively. Concentrations below these values are not considered to have a negative health effect.
ROD-MET I.X(J
                                                                                                             Pagl

-------
                     Table 2-5: Maximum Values Detected by Off-Site Laboratory and
                               Background Threshold Limit Values (TLV)
                                    for Metals Detected at 0 to 10 Feet
                                  Concentrations in milligrams per kilogram
Analyte
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Chromium VI
Cobalt
Copper
Lend '
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cyanide
CA(
TLV
12,000
6.72
8.5
143
0.39
0.59
38-2
nd
8.13
10.5
9.6
193
nd
17.9
3.07
1.2
6.1
23.4
23.3
nd
>C2
Maximum
5,450
10.2
3.5
124
*
3.4
24.6
»
3.5
22.8
232
145
0.12
9.5
+
*
1.2
22.9
135
*
CA(
TLV
9,980
6
4.24
223
0.33
0.48
45.4
nd
6.41
4.8
7.91
193
if
6.65
2.27
1.15
2.75
20.2
14.3
nd
)C3
Maximum,
5,160
4
5.1
129
»
2.4
21.4
0.36
3.9
42.6
103
201
*
24.9
0.65
»
*
19.1
112
4
CA(
*v \ ,
18,600
6
16.8
226
0.89
0.89
61.2
nd
6.94
8.25
11.5
521
4
9.25
5.94
1
16.8
43.1
35.4
nd
>C4, f ,
Maximum
12,800
»
6.3
171
»
3
24.4
»
6.5
33.8
88.5
574
0.35
15.9
0.69
4.4
*
40.3
220
4
CA(
t Ttv
26,400
7.78
21.3
675
0.85
6.38
30.0
nd
9.02
21.4
19.8
1,050
nd
20.1
4.87
1.34
11.5
43.1
49.2
nd
3C5
Maximum
6,120
*
3
92
*
4
17.2
»
3.3
15.5
43.5
170
*
7.6
0.61
4
4
33.8
79.2
*
RCID-METl.XLS
                                                                                              Page 2 of 6

-------
                     Table 2-5: Maximum Values Detected by Off-Site Laboratory and
                                Background Threshold Limit Values (TLV)
                                    for Metals Detected at 0 to 10 Feet
                                   Concentrations in milligrams per kilogram
Analyte
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Chromium VI
Cobalt
Copper
Lead '
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cyanide
CAC
TLV
20,500
6.52
6.06
270
0.7
1.03
30.1
nd
11.2
22.5
14.3
397
nd
15.4
3.76
1.19
3.54
27.5
37.5
nd
DC 6
Maximum
4,690
6.5
6.3
156
0.25
1
12.1
*
3.4
112
25.2
159
0.06
9.7
0.61
*
*
21
113
0.31
CAC
TLV -
31,400
7.44
15.6
334
4.02
1.09
38.8
nd
19.7
24.8
21.6
460
nd
27.4
2.93
1.01
3.9
61.6
60.8
nd
DC 7
Maximum
18,300
7.4
10.5
247
0.54
7.1
56.3
*
14.2
84.6
195
678
0.06
33.1
1.4
*
*
107
199
*
CAQG.8
' ''TLV; :.::.'
7,770
6
9.68
133
0.28
0.8
10.6
nd
6.12
21.7 '
8.79
137
nd
6.7
1.89
1.47
6.76
22.6
28.0
nd
8Ar Landfill
;Maxiirium
11,700
8.5
4.7
160
0.14
1.2
15.7
0.22
6.5
582
659
278
0.17
14.9
0.98
10.2
0.5
28
58.9
•
SB-Housing
Maximum
5,900
*
3.7
137
*
*
12.5
*
3.2
50.8
22.2
150
*
8
»
0
»
22.1
52.5
*
ROD-METl
K/2S/176-1B
.1
Pa

-------
                    Table 2-5:  Maximum Values Detected by Off-Site Laboratory and
                               Background Threshold Limit Values (TLV)
                                   for Metals Detected at 0 to 10 Feet
                                  Concentrations in milligrams per kilogram

Analyte
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Chromium VI
Cobalt
Copper
Lead '
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cyanide
CAOC9
TLV
10,200
7.91
9.06
277
0.46
0.63
29.9
nd
9.47
8.37
9.88
183
*
1.88
nd
1
4.65
26.8
27.7
nd
Maximum
5,150
13.4
5
103
0.08
6.7
12.5
1.2
3.9
36.7
19.5
136
0.12
6.3
0.61
3.2
1.3
24.8
39.6
0.41
CAOC 10
TLV
6,310
7.11
8.99
184
0.28
1.64
25.1
nd
7.31
5.83
6.79
157
nd
9.83
1.9
1.14
7.88
26.9
30.2
nd
Maximum
5,290
*
3.9
85.3
0.67
1.7
11.2
»
3.7
5.5
31
176
*
6.8
0.63
0.78
*
22.3
157
»
CAOC 12
TLV
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Maximum
*
»
«
»
4
*
*
*
*
*
»
*
#
*
+
»
*
*
#
*
CAOC 13
TLV
239,000
56.5
139
259
8.38
4.39
56.9
nd
48.9
45.9
103
2,280
nd
75
48.8
1
1
126
228
nd
Maximum
*
*
+
*
*
+
if
*
*
*
*
*
*
*
*
*
+
*
*
+
HOD-METl XLS
                                                                                             Page 4 of 6

-------
                     Table 2-5: Maximum Values Detected by Off-Site Laboratory and
                               Background Threshold Limit Values (TLV)
                                    for Metals Detected at 0 to 10 Feet
                                  Concentrations in milligrams per kilogram
Analyte
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Chromium VI
Cobalt
Copper
Lead '
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cyanide
CAOC 14
TLV | Maximum
59,000
6
13.1
408
2.68
1.97
40.2
nd
44.0
45.1
29.2
511
nd
46.5
13.1
1
3.66
79.6
78.2
nd
16,900
*
9.7
245
0.86
3.8
18.9
0.15
12.5
28.5
25.8
718
0.06
29.2
0.82
»
»
34
54.8
»
CAC
TLV
7,410
6
7.53
148
0.26
0.72
27.4
nd
5.81
4.14
9.71
166
nd
7.24
6.04
1
6.95
20.3
17.6
nd
>C15
Maximum
»
»
»
*
»
*
*
*
»
*
*
»
»
*
*
»
*
*
#
4
CAC
TLV L
19,100
8.26
10.6
135
0.55
1.72
17.8
nd
12.1
13.9
14.1
245
nd
16.0
3.43
1.18
7.98
30.7
40.1
nd
)C16
Maximum
4,460
*
4.2
170
*
»
6.6
*
2.5
90.4
4.6
138
»
5.3
*
*
*
21.9
148
»
CAC
TLV
10,800
8.36
11.9
120
0.38
0.68
43.4
nd
11.7
8.55
9
286
nd
18.7
3.34
1
7.35
41.6
29.5
nd
)C17
Maximum
3,800
*
4.3
105
»
*
7
»
3.3
26
4.5
130
*
7.2
*
*
*
20.2
57.6
»
ROD-METl.X
                                                                                              Pa

-------
                     Table 2-5:  Maximum Values Detected by Off-Site Laboratory and
                                Background Threshold Limit Values (TLV)
                                    for Metals Detected at 0 to 10 Feet
                                   Concentrations in milligrams per kilogram
Analyte '
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Chromium VI
Cobalt
Copper
Lead '
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cyanide
::.- :;-.:',CAG
\M$:fi-;
10,900
8.27
11.1
127
0.42
0.73
19.3
nd
9.89
10.1
9.06
205
nd
11.7
3.07
1.48
7.16
35.6
39.9
nd
|q,18.;&.;:;-:,^
Maximum^
6,240
»
3.1
126
*
4-
13
*
*
10.4
13.5
148
»
6.7
»
»
*
28.8
31.2
*
ROD-MET).XLS
S/ZS/^MIKPM
Page 6 of 6

-------
        Table 2-6:  ARARs for Remediation of Asbestos-Contaminated Soil
                                  MCAS Yuma
ARAR
Comments
Action-Specific:
Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP)
Clean Air Act (42 USCA
Ch85)
40  CFR   Subpart  M,
Section  61.145,  61.150,
and 61.154
NESHAP applies to demolition or renovation of facilities with
ACM.   Remediation of ACM at MCAS  Yuma is  neither a
renovation nor demolition operation.  However, procedures for
asbestos emission control  (Section 61.145(c)); procedures  for
ACM waste handling, transportation, and disposal (61.150); and
compliance of disposal facilities accepting ACM waste (Section
61.154) are considered relevant and appropriate.
                      Table 2-7: ARARs for CAOCs 1 and 10
                                  MCAS Yuma
ARAR
Comments
Chemical-Specific:
Arizona Revised Statutes (ARS), Title 49 The Environment; as implemented in Arizona
Administrative Code (AAC)  Title 18,  Chapter 7, Article  2, Interim Soil  Remediation
Standards
Arizona Revised Statutes
(ARS)
Title 49-151 and 152
Title 18, R18-7-201
through R18-7-209
Requires that soils be remediated to either: 1) background levels;
2) Health Based  Guidance Levels;  or  3)  remediation  levels
derived from a  site-specific risk assessment.  This ARAR is
relevant and appropriate.

-------
            Table 2-8: Human Health Based Guidance Levels (HBGLs)
      for Ingestion of Contaminants in Soil for COPCs at CAOC 1,8A, and 10
                   Appendix A to Title 18, Chapter 7, Article 2
                              June 1995 Update
Chemical
Acenaphthene
Acenaphthylene (PAH)
Anthracene(PAH)
Benz[a]anthracene(PAH)
Benzo[a]pyrene(PAH) (BaP)
Benzo[b]fluoranthene(PAH)
Benzo[k]fluoranthene(PAH)
Chrysene(PAH)
Dibenz[a,h]anthracene(PAH)
Fluoranthene(PAH)
Fluorene(PAH)
Indenopyrene(PAH)
Naphthalene(PAH)
Polychlorinated biphenyls (PCBs)
Polychlorinated b'iphenyls
Pyrene(PAH)
Cancer
Group
ND
D
D
B2
B2
B2
B2
B2
B2
D
D
B2
D
B2
ND
D
Residential Oral
HBGL
(mg/kg)
7000.0
7000.0
35000.0
1.1
0.19
1.1
1.1
110.0
0.11
4700.0
4700.0
1.1
4700.00
0.18
8.2
3500.0
Non-Residential
Oral HBGL
(mg/kg)
24500.0
24500.0
122500.0
4.6
0.80
4.6
4.6
462.0
0.46
16450.0
16450.0
4.6
16450.0
0.76
28.7
12250.0
Cancer Groups:
   B2    Probable human carcinogen
   D    Not classifiable as to human carcinogenicity
   ND  No data

-------
Table 2-9: Alternative 3, Soil Volume Estimates
*&»
Gene^pesjOTjjJtiktt^^r s
A 5 - r <^
Approximate Area (sf)
Depth (ft)
Volume in Place (cy)
Excavated Volume (cy)
Soil requiring Disposal (cy)
-Unit North of
- ^Building 38 ,..
(CAOC 4A)
12,744
7 (average)
3,300
4,000
4,000
<; SubunitNear
Active Burn Pit Area
(CAOG7A)
26,400
1 (maximum)
1,000
1,200
1,200
Excavated volumes include 20 percent bulking factor
Totals rounded to nearest 100 cubic yards (cy)
Areas and volumes estimated from data collected in a field survey conducted
by U&A in February, 1996 (U&A, 1996a).

-------
                            Table 2-10:  Cost Estimate
                Alternative 3:  Cleanup of ACM on Soil Surface and
                 Excavation and Disposal of Soil Mixed with ACM
il«™L ' -' -I *\
Capital Cost
Sefwp
Mobilization
Fence Removal
Cleanup of ACM on Soil Surface
(See Table 2-11)
Excavation of Soil
Surveying
Excavation
Dust Control
Off Site Disposal
Waste Characterization
Rollup Bin Rental
Waste Disposal1
Transportation ;
Site Restoration
Site Grading
Sampling
Air Monitoring
Compaction Testing
Construction Cost Subtotal
Construction Management
(15%, excluding disposal)


1
1
1
1
5,180
13
2
100
6,750
207

3
13
3


fjJnir.^ ;

allowance
allowance
allowance
allowance
cy
day
allowance
ea
tons
load

allowance
day
ea


iUnitCo,

$5,000
$3,500
$91,000
$7,000
$12.00
$500
$1,000
$550
$32.25
$200

$2,540
$250
$400


Capital Cost Subtotal
Contingency (30%)
Total Capital Cost
(rounded to the nearest
Operation and Maintenance Costs
None.
Total Capital and O&M Costs


$1,000)







$5,000
$3,500
$91,000
$7,000
$62,160
$6,500
$2,000
$55,000
$217,700
$41,400

$7,620
$3,250
$1,200
$503,300
$42,800
$546,100
$163,800
$710,000

$710,000
'Tons of waste based on 1.20 tons per cubic yard and a wetting factor of 8 percent.

-------
    Table 2-11 Cost Estimate
Cleanup of ACM on Soil Surface
i?8K"":: • "••
Capital Cost
Setup
Mobilization
Removal of ACM
Removal Activities
Dust Control
Off Site Disposal
Waste Characterization
Rollup Bin Rental
Waste Disposal
Transportation
Sampling
Air Monitoring
Construction Cost Subtotal
;,;iVf; ^v$yf

i
12
12
2
2
2
2
12

Unit

allowance
day
day
allowance
ea
load
load
day

Construction Management
(15%, excluding disposal)


Operation and Maintenance
None.
Capital Cost Subtotal
Contingency (30%)
Total Capital Cost
(rounded to the nearest
Costs

$1,000)

Total Capital and O&M Costs
' ••••.:*f*£j*i}i.VM''
Unit Cost .;.Tqtal|pU|^

$5,000 $5,000
$3,500 $42,000
$500 $6,000
$1,000 $2,000
$550 $1,100
$560 $1,120
$200 $400
$250- $3,000
$60,620
$9,100
$69,720
$20,900
$91,000

$91,000

-------
Table 2-12:  Potential ARARs for Remedial Action for MCAS Yuma
Medium/
Location
Requirements
Prerequisite
Citation
ARAR
Determination ..
'•'•'• " ''.".• Comments . .
CHEMICAL-SPECIFIC:
Arizona Revised Statutes (ARS), Title 49 The Environment; as implemented in Arizona Administrative Code (AAC) Title 18, Chapter 7, Article 2, Interim Soil Remediation Standards
Contam-
inated soil
Sites that are legally
required to conduct soil
remediation.
Soils contaminated with
constituents identified in
Appendix A to the
regulation.
ARS 49-151 and 152.
R18-7-201 through. .
R18-7-209
Relevant and
Appropriate at
CAOC 1, 8A,
and 10
Requires that soils be remediated to either: 1) background levels; 2)
Health Based Guidance Levels; or 3) remediation levels derived
from a site-specific risk assessment.
U.S. EPA Guidance on Remedial Actions for Superfund Sites with PCB Contamination USEPA/540/G-90/007
Soils with
PCB
Contamina-
tion
Approach for evaluating
and remediating sites
with PCB
contamination.
Soils contaminated with
PCBs.
USEPA/540/G-90/007
Potential TBC
for PCBs at
CAOC 8A
Describes recommended approach for evaluating and remediating
sites with PCB contamination. Since compliance with ARS 49-151
and 152 is sufficient to protect human health and the environment,
this guidance is not considered TBC.
LOCATION-SPECIFIC:
National Historic Preservation Act, 16 USC Section 470-470w-6 [36 CFR Part 800] and the Archeolo
Within area
where action
m.iy cause
irreparable
harm, loss or
distraction of
significant
artifacts
Action to recover and
preserve artifacts.
Alteration of terrain that
threatens significant
scientific, prehistoric,
historic, or archaeological
data.
36 CFR Part 65
rical Resource Protection Act, 16 USC Section 470ii [36 CFR Part 299]:
Not an ARAR
Scientific, prehistoric, historic, or archaeological artifacts may be
present at MCAS Yuma. However, response actions for ACM at
MCAS Yuma do not require alteration of terrain or excavation of
native soil.
Endangered Species Act, 16 USC 1531 et stq.; and Fish and Wildlife Coordination Act, 16 USC 661 et seq.
Critical
habitat upon
which
endangered
spc-cii'S (ir
threatened
species
depend
Action to conserve
endangered species
including consultation
with the Department of
Interior.
Determination of effect
upon endangered or
threatened species its
habitat.
50 CFR Part 200,
50 CFR Part 402 and
33 CFR Parts 320 - 330
Not an ARAR
Federal threatened and endangered species have been recorded as
being potentially present on MCAS Yuma. Sites with ACM are
located on populated and highly trafficked area and do not support
wildlife. Response actions at MCAS Yuma is not anticipated to
affect habitat.
                                                                                 Iof3

-------
Table 2-12: Potential ARARs for Remedial Action for MCAS Yuma
Medium/
Location
Requirements
Prerequisite
Citation
ARAR
Determination
• '..,''. •- ,-.„!'•'.. •: - Comments ••
LOCATION SPECIFIC - Continued:
Migratory Bird Treaty Act of 1972, 16 USC 703
Migratory
bird area
Protects almost all
species of native birds in
the U.S. from
unregulated "take,"
which can include
poisoning at hazardous
waste sites.
Presence of migratory
birds.
16 USC 703
* ,
Not an ARAR
Migratory birds have been observed on and in the immediate
vicinity of MCAS Yuma. Sites with ACM are located on populated
and highly trafficked area and do not support wildlife.
Arizona Revised Statutes, Title 41 - State Government; Chapter 4.1 - History, Archaeology, and State Emblems; Article 4 - Archaeological Discoveries
Within state-
owned or
controlled
Kind
containing
archaeologic
al at historic
features
Prohibits excavation in
or upon, defacing, or
altering archaeological
or historical site or
objects; and require
notification upon
discovery of any such
site or object.
Existence of
archaeological,
paleontological, or
historic site or object at
least 50 years old..
ARS41-844A
Not an ARAR
Archaeological or historical site may be present at MCAS Yuma.
Sites with ACM are not located on archaeological or historical sites
or objects. Response actions for MCAS Yuma do not anticipate
excavation of native soil.
ACTION-SPECIFIC:
Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP); USC 7401 to 7671(q)
Waste, Soil,
and Debris
Management of ACM
and notification
requirements
Demolition, renovation,
or removal of ACM
40 CFR Subpart M;
Section 61. 145, 61.150,
and 61. 154
Relevant and
Appropriate
NESHAP apply to demolition or renovation of facilities with ACM.
Remediation of ACM at MCAS Yuma is neither a renovation nor
demolition operation. However, procedures for asbestos emission
control (Section 61.145(c)); procedures for ACM waste handling,
transportation, and disposal (61.150); and compliance of disposal
facilities accepting ACM waste with Section 61.154 is considered
relevant and appropriate.
                                                                              2of3

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Table 2-12:  Potential ARARs for Remedial Action for MCAS Yuma
Medium/
Location
Requirements
Prerequisite
Citation
ARAR
Determination
Comments
To Be Considered (TBC):
Chief of Naval Operations Instruction (OPNAVINST), 5100.23D, Cha)
Waste, Soil,
and Debris
Exposure to asbestos
fibers
Use, removal, and
disposal of ACM
>ter 17
5100.23C, Chapter 17
* .
Potential TBC
for ACM at
CAOC 4, 7,
and 9
The Navy manual provides guidance for controlling or eliminating
the exposure of Navy personnel to asbestos during the use,
removal, and disposal of ACM. Since these provisions apply
primarily to building structures and facilities, it is not considered to
be relevant and appropriate. In addition, since compliance with
NESHAP and federal OSHA is sufficient to protect human health
and the environment, this manual is not considered TBC.
U.S. EPA Guidance on Remedial Actions for Superfund Sites with PCS Contamination USEPA/540/G-90/007
. Soils with
PCB
Contamina-
tion
Approach for evaluating
and remediating sites
with PCB
contamination.
Soils contaminated with
PCBs.
USEPA/540/G-90/007
Potential TBC
for PCBs at
CAOC8A
Describes recommended approach for evaluating and remediating
sites with PCB contamination. Since compliance with ARS 49-151
and 152 is sufficient to protect human health and the environment,
this guidance is not considered TBC.
                                                                                 3of3

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Figures

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                FIGURE 3-1:
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 CAOC1: TOTAL PAH CONCENTRATION CONTOURS
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                                                                                                                                       FOR SURFACE SAMPLES. NORTHERN DETAIL
                                                                                                                                   B ;

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                                                                                                  ACM-CONTAMINATEO SOIL

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           FIGURE 2-S:
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                                                                              i" AS NOICO
                                                                                              | «•»•

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                                                           CAOC 8: FEATURE AND BORING LOCATION MAP

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                                                                                                                    FIGURE J-»:
                                                                                                         CAOC 9: LOCATION Ol ACM DEBRIS


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                                                                                                                                           FIGURE 5-9:
                                                                                                                                      CAOC 10: FEATURE MAP
                                                                                                                                                   -7=7^

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£
                                                                     I10P-2-0    42.40
                                                                       	--.-.........-J««»»
                                                                                                                             •I10P2-02-1   
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Use This Space to Write Your Comments
Your input on the proposed remedies for Operable Unit 2  is important to MCAS Yuma.
Comments provided by the public are valuable in helping MCAS Yuma select a final remedy
for the various CAOCs. You may use the space below to write your comments, and then fold
and mail. Comments must be postmarked no later than April 21,1997.

                 ^
Additional comments on a separate piece of paper may be included.
Nc-me   /t^.
A(«d
Ci;y
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