PB95-964417
                                 EPA/ROD/R08-95/115
                                 March 1996
EPA  Superfund
       Record of Decision:
       Hill Air Force Base,
       Operable Unit 7, UT
       9/28//1995

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                          TABLE OF CONTENTS

                                                                     PAGE

DECLARATION FOR THE RECORD OF DECISION

DECISION SUMMARY FOR THE RECORD OF DECISION

1.0 SITE NAME, LOCATION, AND DESCRIPTION                          1-1 -

2.0 SITE HISTORY AND ENFORCEMENT ACnvmES                      2-1

      2.1 Site History                                                     2-1
      2.2 Investigation History                                             2-2
      2.3 Enforcement Activities                                           2-4
      2.4 Community  Relations History                                     2-5
      2.5 Scope and Role of Operable Unit 7 Within Site Strategy                2-5

3.0 SUMMARY OF SITE CHARACTERISTICS                              3-1

      3.1 Nature and Extent of Contamination                                 3-1
      3.2 Summary of Fate and Transport of Contaminants                     3-3

4.0 PUBLIC HEALTH  AND ENVIRONMENTAL IMPACTS                    4-1

      4.1 Human Health                                                  4-1
            4.1.1. Contaminant Identification                                4-1
            4.1.2. Exposure Assessment                                    4-1
            4.1.3. Toxicity Assessment                                     4-4
            4.1.4. Risk Characterization                                    4-4
            4.1.5. Uncertainties                                           4-7
      4.2 Threats to the Environment                                        4-9
            4.2.1. Surface Water, Ground Water, and Wetlands                 4-9
            4.2.2. Vegetation                                             4-9
            4.2.3. Wildlife                                               4-9
            4.2.4. Air Quality                                             4-9
            4.2.5. Archaeological Resources                                4-10
      4.3 Summary of Site Risks                                          4-10

5.0 DESCRIPTION OF ALTERNATIVES                                    5-1

      5.1 Development of Alternatives                                    .  5-1
      5.2 Detailed Analysis of Alternatives                                   5-3
      5.3 Comparative Analysis of Alternatives                     '          5-8
            5.3.1. Evaluation Criteria                                      5-8
            5.3.2. Comparative Analysis                                    5-9

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                             Table of Contents


6.0 SELECTED REMEDY                                                 6-1

      6.1 Description of the Selected Remedy                                 6-1
             6.1.1. Remediation Goals and Performance Standards               6-2
             6.1.2. Restoration Time Frame                                  6-3
             6.1.3. Costs                                                  6-3
      6.2 Statutory Determinations                                          6-4
             6.2.1. Protection of Human Health and the Environment             64
             6.2.2. Compliance with Applicable or Relevant and Appropriate       6-4
                    Requirements
             6.2.3. Cost Effectiveness                                       6-7
             6.2.4. Utilization of Permanent Solutions                         6-7
             6.2.5. Preference for Permanent Solutions and Treatment            6-8
                    Technologies that are Practical
      6.3 Documentation of Significant Changes                               6-8

RESPONSIVENESS SUMMARY

REFERENCES                                                          R-l

APPENDIX A -ARARs PERTAINING TO ACTIVITIES AT OU 7
APPENDIX B -PUBLIC MEETING TRANSCRIPT
APPENDIX C -WRITTEN COMMENTS AND RESPONSES

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                               Table of Contents


                              LIST OF TABLES

TABLE
  NO.                             TITLE                              PAGE

2-1    Summary of Previous Environmental Investigations at OU 7               2-3

3-1    Chemicals Detected in OU 7 Source Areas                              3-2

4-1    Hill OU 7 Chemicals of Concern for Soil                                4-2
4-2    Summary of Slope Factors for Potential Contaminants of Concern           4-5
4-3    Reference Doses                                                    4-6
4-4    Summary of Cancer Risks and Hazard Indices by Pathway: Future Exposures 4-8

5-1    Preliminary Remedial Goals for Soil at OU 7                            5-2
5^2    Development of Remedial Alternatives for OU 7 Soil                     5-4
5-3    Summary of Key ARARs for Each Alternative                          5-11

6-1    Summary of Key ARARs for the Selected Remedy                        6-6

A-l    Identification of Federal  Chemical-Specific ARARs
A-2    Identification of State Chemical-Specific  ARARs
A-3    Identification of Federal Act ion-Specific ARARs
A-4    Identification of State Action-Specific ARARs


                             LIST OF FIGURES

FIGURE                                                      FOLLOWING
  NO.                              TITLE                        PAGE NO.

1-1    Location of Operable Units                                            1-1
1-2    Buildings 225 and 220 Facilities Map                                   1-1
1-3    Base Supply Well 6 Location map                                      1-1

3-1    Isoconcentration Map for Hexavalent Chromium in Soil                   3-2
3-2    Isoconcentration Map for Cadmium in Soil                              3-2
3-3    Geologic Cross  Section of Former Metal Plating Shop Area Showing        3-2
       Vertical Distribution of Hexavalent Chromium Contamination
3-4    Generalized Conceptual Model  of Contaminant Transport                  3-3
3-5    Conceptual Model of Past Contaminant Transport                         3-3

6-1    Conceptual Remedial Action Implementation Schedule                    6-2
                                     111

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Hill Air Force Base, Utah
Operable Unit 7
Declaration for the Record of Decision

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Site Name and Location

Operable Unit 7
Hill Air Force Base, Utah
Weber and Davis Counties, Utah

Statement of Basis and Purpose

This decision document presents the selected remedy for Hill Air Force Base (Hill AFB)
Operable Unit 7 (OU 7) in Davis County, Utah. Sites addressed in this document include
the former Metal Plating Shop in Building 225, the PCB  Spill Area in Building 225,
Miscellaneous Areas in Building 225,  Base Supply Well 6, and Building  220.  The
selected remedy was chosen in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA)  as amended by the  Superfund
Amendments and Reauthorization Act of 1986 (SARA)  and, to the extent practicable,
with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).
This decision is based on the Administrative Record for Hill AFB.

The State of Utah, the U.S. Environmental Protection Agency (EPA), and Hill AFB
concur on the selected remedy.

Assessment of the Site

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

Current risks to human  health associated with the contaminants  at OU 7 are well below
levels considered by the EPA to be significant.  Remedial action for contaminated soils
beneath the former Metal Plating Shop is warranted based on  possible future risks  to
human health and the environment, and because of future  threats to the ground water
beneath OU 7.  Based  on the findings  of the OU 7 Remedial  Investigation and Risk
Assessment, Building 220, Base Supply Well 6, the PCB Spill Area and Miscellaneous
Areas in Building 225 do  not  require remedial  actions because risks posed  by the
contaminants at these sites are below significant levels.

Description of the Selected Remedy

OU 7 is one of nine operable units at Hill AFB.  OU 7 is a soils-only OU and consists of
soil contamination at several source areas in and around Buildings 220 and 225, and some
imported fill (from Building 225) at Base  Supply Well 6. The  two buildings lie in the
south central portion of the Base, west of the main runway in an industrial area that has
been used to service aircraft since the 1940s.  Base Supply Well 6 is located northwest of
the north end  of the main runway. Subsurface conditions are dominated by interbedded
silty sands, sandy silts, and clays. Ground water beneath OU 7 is addressed separately in
Operable Unit 8.  Therefore, references  to contaminated ground water in this document
are only mentioned and further discussion is outside the scope of this ROD.  The
remaining operable units are at  various stages in  the remedial  investigation/feasibility
study (RI/FS) process.  The selected remedy at OU 7 addresses the threat to human health
                                      -1-

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 and the environment posed by soils contamination associated with the former Metal
 Plating Shop in Building 225, through institutional controls. These controls will maintain
 existing structures over the contamination source area, restrict future access to the area
 where contaminated soil is present, and monitor the potential for future contaminant
 movement.

 The major components of the selected remedy for Hill AFB OU 7 include:
       •  Ground-water  quality  monitoring  in  areas  upgradient, beneath,  and
          downgradient of the area where contaminant concentrations in soils are above
          health-based risk levels.
       •  Soil moisture content monitoring around the perimeter of and within the area
          of contaminated soils.
       •  Maintaining and preserving the  building and  floor slab that overlay the
          contaminated soils.
       •  Issuance of a continuing order from the Base commander that will restrict
          worker access to the  contaminated  soils as long  as Hill AFB  owns the
          property.
       •  A notice to the deed will be filed by the Air Force detailing the restrictions of
          the continuing order.
       •  A covenant in the deed which incorporates the restrictions of the continuing
          order  and,  upon transfer of the property, establishes  the locations  and
          restrictions of use of the contaminated area, and retains rights of access for
          future response actions, if needed.  If land use is changed or Building 225 is
          removed, the Air Force will reevaluate  the protectiveness of the selected
          remedy and perform any necessary remedial actions.
       •  Posting warning signs regarding the presence of contaminated soils that could
          represent a threat to human health.

Statutory Determinations

The selected remedy is protective of human health and the environment, complies with
Federal and  State requirements that are legally  applicable or relevant and appropriate to
the remedial action, and is cost-effective. This remedy utilizes permanent solutions and
alternative  treatment (or resource recovery)  technologies, to the maximum extent
practicable for this site. However, because treatment of the principal threats of the site
was not found to be practicable, this remedy does not satisfy the statutory preference for
treatment as  a principal element. Because this remedy will result in hazardous substances
remaining on-site that are above health-based levels, a review will be conducted within
five years after commencement of the remedial action to ensure that the remedy continues
to provide adequate protection of human health and the environment.
                                       -2-

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Robert L. Duprey,
Director, Hazardous Wagfe^Mana^ement Division
                                            Date
                                -3-

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STATE OF UTAH DEPARTMENT OF ENVIRONMENTAL QUALITY
Dianne R. Nielson, Ph.D.,                         Date
Executive Director
                         Record of Decision for
                    Hill Air Force Base Operable Unit 7
                                -4-

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                   HILL AIR FORCE BASE, UTAH
                       OPERABLE UNIT 7
            DECLARATION FOR THE RECORD OF DECISION
LAWRENCE P. FARRELL, JR.
Lieutenant General, USAF
Vice Commander
  11 OCT 1995
Date

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Hill Air Force Base, Utah
Operable Unit 7
Decision Summary for the
Record of Decision

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               1.0 SITE NAME, LOCATION, AND DESCRIPTION

 Hill Air Force Base, Utah (Hill AFB) is located in northern Utah, about 25 miles north of
 Salt Lake City and about five miles south of Ogden, Utah in Weber and Davis counties
 (Figure 1-1). Hill AFB covers about 6,700 acres on the Weber River Delta, a terrace that
 lies about 300 feet above the surrounding valleys.  The delta  surface has slight to
 moderate relief with elevations varying from approximately 4,600 feet above National
 Geodetic Vertical Datum  (NGVD) along the western boundary  of Hill AFB to
 approximately 5,045 feet above NGVD along the eastern boundary.  In contrast, the
 Wasatch Mountains, about four miles to the east, rise abruptly from the valley floor to an
 elevation of over 9,000 feet above NGVD. The Great Salt Lake, approximately 12 miles
 to the west, is presently at an elevation of approximately 4,201 feet above NGVD.

 Most of the southern part of Hill AFB is occupied by industrial facilities, equipment
 storage areas, and administration buildings related to the aircraft maintenance mission of
 the Base. By contrast, the northern part of Hill AFB has large open areas with groups of
 buildings that were constructed as munition manufacturing plants, assembly plants, or
 storage facilities. Although the use of the old plants and storage facilities has changed in
 recent years to missile  storage,  maintenance, and testing, the buildings and facilities
 remain.  Off-Base land use includes residential, commercial, and agricultural. This area
 has undergone rapid residential development over the last 10 to 20 years, and agricultural
 use has declined. Crop production in the agricultural areas primarily is the cereal grains
 wheat and barley, and alfalfa. There is some pasture land, and in some areas livestock are
 raised.   In  July 1987,  the  Base was  placed  on the  Comprehensive Environmental
 Response, Compensation and Liability Act (CERCLA), National  Priorities List (NPL)
 because of several sites where hazardous liquid and solid wastes generated by installation
 operations were disposed.

 Operable Unit 7  (OU 7) is a soils-only OU and consists of soil  contamination at several
 source areas in and around Buildings 220 and 225, and some imported fill (from Building
 225) at Base Supply Well 6. The two buildings lie in the south central portion of the
 Base, west of the main runway in an industrial area that has been used to service aircraft
 since the 1940s (Figure 1-2). Base Supply Well 6 is located northwest of the north end of
the main runway (Figure 1-3).  Subsurface  conditions  in these areas are dominated by
 interbedded silty sand, sandy silt, and clay.  Ground water beneath OU 7 is addressed
separately in Operable Unit 8.

The OU 7 area overlies three aquifers, although these aquifers are not included as part of
OU 7.  The shallow aquifer consists of approximately 200 feet of relatively low-yielding
materials and lies  at about  110 to 140  feet below the ground surface at OU 7.  This
shallow aquifer is designated as Class II - Drinking Water Quality based on the State of
 Utah classification criteria and the quality of ground water taken from uncontaminated
wells.  The deeper Sunset and Delta aquifers are approximately 300 and 600 feet below
OU 7,  respectively.  They  are used by Hill AFB  and surrounding communities as
domestic water  supplies. The Sunset and Delta Aquifers are classified as Class I -
Irreplaceable Source of Drinking Water or Class IIA - Current Source of Drinking Water
(USGS, 1992). According to the Hill  AFB Comprehensive Plan (USAF, 1989), there are
no wetlands located on-Base in OU 7.
                                       1-1

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o
                                                                        Scale in Miles
                    f\ OPERABLE
                                             PERABLE UNIT 4
                                            OPERABLE UNIT 4
                    OPERABLE UNIT 5
                        OPERABLE UNIT 4
                      OPERABLE UNIT 7
                      (Base Supply Well
                                                                         SOUTH
                                                                         WEBER
                     HILL AIR FORCE BASE
                                              OPERABLE UNIT
                                                 (Soil beneath
                                               Bldgs 220 and 225)
OPERABLE UNIT 9
(Rest of the base)
    OPERABLE UNIT 5
                                                                        OPERABLE UNIT 1
                                                                        OPERABLE UNIT 3
             MAP AREA I  2000 Nonh
                        OPERABLE UNIT 8
     Source: Current Hill AFB Documentation.
                               HILL AIR FORCE BASE
                                 OPERABLE UNIT 7
                        LOCATION OF OPERABLE UNITS
                                    FIGURE 1-1

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  PROJECT NO. 2208.0875
  0     100     200-


    Scale in Feet
100
                             214
                Former
              wash rack
Hydraulic room
    location  •

Mop cleaning
room location
                 Former metal
                  plating shop
                    location v

                              X
225

  PCB spill I
  location
                    Former ~
                 degreaser pit
                   location
                                                                                              Concrete separator
                                                                                                tanks (removed)
                               20,000 gal
                              gasoline tank
                               (removed)
                                                                 .LT	
                                                                                                                EXPLANATION

                                                                                                                Industrial waste pipeline
                                                                                                                (post-1986 segments)
                                                                                            	Industrial waste pipeline
                                                                                               ~   (pre-1986 segments)

                                                                                             Shaded areas represent potential
                                                                                             source areas in this investigation.
                                                                                                          Unpaved area
                                                                                                Approximate alignment
                                                                                                of industrial sewer line
                                                                                          HILL AIR FORCE BASE
                                                                                            OPERABLE UNIT 7
                                                                                        BUILDINGS 225 AND 220
                                                                                            FACILITIES MAP
                                                                                               FIGURE 1-2

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                                        Trench where backfill soils from
                                         Building 225 were deposited
                                         (5 feet wide by 5 feet deep)
     Source: Modified from ENH Mapping Inc.,
           1983; Hill CE records.
fc
LU
 HILL AIR FORCE BASE
   OPERABLE UNIT 7
BASE SUPPLY WELL 6
   LOCATION MAP
       FIGURE 1-3

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            2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES

 2.1 SITE HISTORY

 Hill AFB has been the site of military activities since 1920, when the western portion of
 what is now the Base was activated as the Ogden Arsenal, an Army Reserve depot. In
 1940 and 1941, four runways were built and the Ogden Air Depot was activated. During
 World War n, the Ogden Arsenal manufactured ammunition and was a distribution center
 for motorized equipment,  artillery, and  general ordnance.   The Ogden Air Depot's
 primary operation was aircraft rehabilitation.  In 1948, the Ogden Air Depot was renamed
 Hill AFB, and in 1955,  the Ogden Arsenal was transferred from the U.S. Army to the
 U.S. Air Force.  Since 1955, Hill AFB has been a major center for missile assembly and
 aircraft maintenance. Currently, Hill AFB is part of the Air Force Materiel Command.

 On-Base industrial processes  associated  with aircraft,  missile, vehicle, and railroad
 engine maintenance and repair include metal plating, degreasing, paint stripping, and
 painting.  These processes use numerous chemicals including chlorinated and non-
 chlorinated solvents and degreasers, petroleum hydrocarbons, acids, bases, and metals.
 In the past, chemicals and waste products  were disposed of at the Industrial Waste
 Treatment Plant (IWTP), in chemical disposal pits and landfills, and off-Base.  Disposal
 in chemical pits and landfills was discontinued by 1980. All wastes currently are treated
 at the IWTP, recycled on-Base,  or sent to off-Base treatment or disposal facilities.

 Operable Unit 7 addresses contaminated soils beneath Buildings 225 and 220, and at a
 site where soils originating from Building 225 were used as backfill in a water line trench
 at Base Supply Well 6. The areas that compose OU 7 are depicted in Figures 1-2 and 1-3
 and described briefly below.

Building 225 Former Metal Plating Shop.  A metal plating shop was formerly located
along the east side of Building  225, as shown on Figure 1-2.  The plating shop  operated
from the 1940s until it was removed from Building 225 in 1972.  Contents of the plating
solution tanks  containing acids, bases, metal salts, and other chemicals frequently were
discharged into a floor drain system that was connected to the industrial waste  pipeline.
Over  time, the plating solutions corroded the drains and piping until leakage occurred.
Soil contamination was first identified beneath the former Metal Plating Shop area when
a utility trench was installed there in 1989. Samples revealed that soil beneath the area
was contaminated with several metals and low concentrations (less than 0.1 mg/kg) of
volatile organic compounds (VOCs). The principal metals of concern were hexavalent
chromium, total chromium, and  cadmium.

Building 225  PCB Spill Area. Polychlorinated biphenyls (PCBs) were found in soil
beneath Building 225 approximately 100 feet west of the former Metal Plating  Shop
(Figure 1-2). During excavation of a utility trench in 1989, unusual odors and discolored
soil were reported.  A subsequent investigation revealed  that the soil contained PCBs.
This area was the site of a former transformer storage area that  was removed in the 1960s.
As part of a cleanup effort, 95 tons of contaminated soil were removed and disposed of at
a facility permitted by the Toxic Substances Control Act.  Following the soil  removal,
additional soil samples revealed that only insignificant concentrations (less than 0.23
mg/kg) of residual PCBs remained in localized areas.
                                      2-1

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Miscellaneous Areas in Building 225. Soil beneath four other areas inside Building 225
was investigated during the Remedial Investigation at OU 7. These areas include:  the
former Wash Rack and Degreaser Pit, the Hydraulic Room, and the Mop Cleaning Room.
At each of these areas, only low concentrations of several VOCs  and metals were
detected.

Base Supply Well 6. This water well  is one of several production wells that supply
water to Hill AFB.   The well lies just west of the north end of the main runway
(Figures 1-1 and 1-3). Some soil excavated in the vicinity of the former Metal Plating
Shop in Building 225 was placed as fill along the discharge pipeline from Base Supply
Well 6.  Analytical results of subsequent  soil samples from the fill indicated low
concentrations of metals  and cyanide.

Building 220.  Building 220 is located  east  of Building 225 and adjacent to the main
runway (Figure 1-2).  This building was constructed in 1957 and has been used  as an
aircraft painting and paint stripping facility.  Painting and paint stripping activities have
used many types of paints, paint strippers, solvents, acids, and other chemicals.  Before
1986, three underground concrete separator tanks were located on the northwest side of
the building.  These tanks were used  to separate paint chips and  sludge from  the
wastewater solutions generated during paint stripping operations. Wastewater from  the
tanks in turn was discharged to the industrial wastewater pipeline and the IWTP.  In
1986, Building 220 was  renovated and an addition was constructed over the area where
the separator tanks  had been located. As part of the construction, the separator tanks and
attached piping system were redesigned and replaced. Sampling around the separator
tanks indicated that the soil beneath the tanks was contaminated with low concentrations
of VOCs,  semi-volatile organic compounds (SVOCs), and metals.   Some of  the
contaminated soil  was removed and taken  to an off-Base hazardous waste disposal
facility before the building addition was constructed, and additional soil sampling results
indicated that only low concentrations of organic chemicals and metals are present in  the
vicinity of the former separator tanks, pipeline locations, and around the perimeter of
Building 220.

2.2 INVESTIGATION HISTORY

As shown in Table  2-1, several environmental investigations of the OU 7 sites have been
performed.  An initial environmental investigation at Building 220 characterized  the
industrial wastewater generated by the paint  stripping and painting activities (Radian,
1984). When the industrial wastewater system was suspected of being a potential source
of environmental contamination, soil and ground-water sampling around the perimeter of
Building 220 was conducted under the Installation Restoration Program (IRP; Radian,
1988). Additional soil sampling was conducted in 1986 at the north end of the building
when the three underground oil/water separator tanks were removed during an expansion
of the building (Hill AFB, 1987).  The results of these investigations identified VOCs,
BNAEs, and metals contamination in the wastewater, and several VOCs and metals  in the
soils beneath the north end of Building  220 where the Oil/Water Separator Tanks had
been located.
                                      2-2

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                                  TABLE 2-1

                SUMMARY OF PREVIOUS ENVIRONMENTAL
                   INVESTIGATIONS AT OPERABLE UNIT 7
    Date of
  Document
                          Investigation
   May 1988


November 1989

December 1991


 February 1993


 February 1995
Installation Restoration Program Phase II-Confirmation/Quantification
Stage I Building 220, Paint Hangar

Hill AFB PCB Spill Sampling and Cleanup in Building 225

Site Characterization Report for a Portion of Building 225 and Site
Investigation of Fill at Base Supply Well 6

Remedial Investigation/Feasibility Study Planning Documents: Work
Plan, Sampling and Analysis Plan, and Health and Safety Plan

Remedial Investigation/Feasibility Study Report for Operable Unit 7
                                     2-3

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Environmental investigations in Building 225  focused initially on the utility trench
excavations that identified metals and PCB contamination in the soils beneath the hangar
floor.  Following removal of PCB-contaminated soils, confirmation soil samples were
collected from the walls of the excavation. Analysis of the samples indicated that only
insignificant concentrations (less than 0.23 mg/kg) of residual PCBs remained around the
excavation following the removal action (Hill AFB, 1989).

To evaluate the nature and extent of metals contamination beneath the former Metal
Plating Shop and in fill talcen to Base Supply Well 6, a site characterization soil sampling
program was conducted (JMM, 1991).  At the former Metal Plating Shop, 20 shallow soil
borings were drilled and soil samples were collected. At Base Supply Well 6, soil
samples were collected from backfill in the pipeline trench. The results of this program
indicated that elevated levels of total chromium, hexavalent chromium, and cadmium
were present beneath the former  Metal Plating Shop.  During the 1991 investigation, the
soil placed as backfill at Base Supply Well 6 was determined not to be a characteristic
hazardous waste through leachability testing.

A Remedial Investigation/Feasibility Study (RI/FS) of OU 7 began in the latter part of
1992  and continued until early 1995 (Montgomery Watson, 1995).  The  Remedial
Investigation (RI) confirmed the presence of contaminants inside of Building 220, at Base
Supply Well 6, in Building 225, at the PCB spill area, and in the former Metal Plating
Shop  area.  In  addition, four other possible  source areas were investigated inside of
Building 225, including the Mop Cleaning Room, a  former TCE Degreaser  Pit, the
former Wash Rack,  and the Hydraulic Room. As part of the RI/FS, an assessment of
risks to human health and the environment from chemicals at OU 7 was conducted.  The
results of this  evaluation are presented in the baseline risk assessment (BRA) that is
included as Section 6.0 in the RI/FS for OU 7. The results of the RI, BRA, and FS are
summarized in Sections 3.0, 4.0,  and 5.0 of this ROD respectively.  Section 6.0 contains
details about the selected remedial alternative. In the Feasibility Study (FS)  for OU 7,
remedial technologies with potential  applications at OU 7  were assembled into five
alternatives.  Each alternative then was evaluated according to  requirements of the
National Oil and Hazardous Substances Contingency Plan (NCP). Following the RI/FS,
a preferred alternative for remediation of OU 7 was identified by the Air Force, EPA, and
the State of Utah in the Proposed  Plan for OU 7, (Montgomery Watson, 1995a). The plan
was distributed to members of the community for review, comment, and to evaluate their
acceptance.

2.3 ENFORCEMENT ACTIVITIES

In July 1987, Hill AFB was placed on the CERCLA National Priorities List (NPL) by the
EPA.  In 1991, Hill AFB entered into a Federal Facilities Agreement (FFA) between the
U.S. Air Force (USAF),  the State of Utah Department of Health (now  the  Utah
Department of Environmental Quality [UDEQ]) and the U.S. Environmental Protection
Agency (EPA). The purpose of the agreement was to establish a procedural framework
and schedule for developing, implementing, and monitoring appropriate response actions
                                      2-4

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at Hill AFB in accordance with existing regulations. Seven operable units initially were
defined under the FFA. Two more operable units have since been added. This Record of
Decision (ROD) concludes all of the remedial investigation/feasibility study requirements
for OU 7. There have been no removal actions, remedial actions, Notices of Violation, or
other enforcement actions taken at OU 7 prior to this ROD.

2.4 COMMUNITY RELATIONS HISTORY

The public participation requirements of CERCLA  Section  113(k)(2)(B)(i-v) and
Section 117 were met. Hill AFB has a Community Relations Plan that was finalized in
February 1992.  The community relations activities include: (1) a Remedial Advisory
Board  (RAB) which meets at least quarterly and includes community representatives
from adjacent  counties  and towns, (2) a  mailing list for interested parties in  the
community, (3) a bimonthly newsletter called "EnviroNews," (4) visits to nearby schools
to discuss  environmental issues, (5)  community  involvement  in a  noise abatement
program, (6) semi-annual town council meetings, (7) opportunities for public comment
on remedial actions, (8) community interviews, and (9) support  for the community for
obtaining technical assistance grants (TAGs).

The RI/FS  Report  for Operable Unit 7 (Montgomery Watson, 1995) and the Proposed
Plan for Operable Unit 7 (Montgomery Watson, 1995a) were released to the public, and
are available in the Administrative Record maintained in the Davis County Library and at
the Environmental  Management Directorate at Hill AFB. The notices of availability for
these documents were  published in the Salt Lake Tribune. A public comment period was
held from February 20, 1995, through March 21, 1995. In addition, a public meeting was
held on March  1, 1995.  At this meeting, representatives from Hill AFB, EPA, and the
State of Utah answered questions about the site and the selected remedy. A court reporter
prepared a transcript  of the meeting.  Copies of the transcript and all verbal public
comments received at that meeting are presented in the Responsiveness Summary of this
document for inclusionjn the Administrative Record. In addition,  copies of the transcript
were sent to all meeting attendees who requested them. The decision for this site is based
on the Administrative Record.

2.5 SCOPE AND  ROLE OF OPERABLE UNIT 7 WITHIN SITE STRATEGY

OU 7 is one of nine operable units at  Hill AFB.  The remaining operable units are at
various stages in the  RI/FS process.  The  remedial actions planned for the various
operable units are independent of one another. This action addresses contaminated soil at
OU 7.  Ground water beneath OU 7 will be addressed as part of OU 8.  The remedy
selected for OU 7 will address threats to human health and the environment by requiring
that the existing floor remain intact so it will prevent direct exposure to contaminated
soil, and prevent further transport of metals to ground water.  Institutional controls will
provide for maintenance of the floor and land use restrictions. Through restrictions to the
deed for the property,  the restrictions will apply to both the present land use by the Air
Force, and in the future should property ownership change.
                                      2-5

-------
                 3.0 SUMMARY OF SITE CHARACTERISTICS

3.1 NATURE AND EXTENT OF CONTAMINATION

Data summarized in this section were collected during the OU 7 RI and the preceding
Building 225 site characterization effort.  Table 3-1 shows the maximum concentrations
of chemicals detected during these investigations at the various OU 7 sites including
Buildings 225 and 220, and Base Supply Well 6.

Beneath the former Metal Plating Shop, which is currently  covered by the concrete floor
inside of Building 225, hexavalent chromium and cadmium were detected. Figures 3-1
and 3-2  show the lateral distribution of these metals in  the subsurface soils, and
Figure 3-3 shows the vertical  distribution of hexavalent chromium.  The highest
concentrations generally occurred in the uppermost layer, found at approximately 10 feet
below the ground surface, as shown in Figure 3-3.  Hexavalent chromium was detected as
deep as 90 feet below the ground surface. Cadmium was detected only in the upper 10
feet of soil.

Mercury  was detected sporadically as deep as 90 feet below  the ground surface, having
been detected in five of 30 samples.  It was never detected in background samples. Other
metals were detected at concentrations elevated relative to background, but only by a
small amount (as indicated by the fact that the average site concentration was less than
twice the average background  concentration).   Cyanide was  detected in two of 35
samples at a maximum depth of 6 feet below ground surface.

Low concentrations of several VOCs also  were detected in soil beneath the former Metal
Plating Shop. These chemicals generally were found in the clay layer at 10 feet, although
trace concentrations of one VOC were detected  as  deep as 80 feet below the ground
surface.

In the PCB spill area, detections of PCBs and alpha and gamma chlordane were sporadic.
Only two of 36 samples contained detectable concentrations of PCBs.   Both PCB
detections were in soil samples collected  from 0.8 to 2 feet below ground surface, and
were at the perimeter of the soil removal performed in 1989. Three of the 36 soil samples
contained low but detectable concentrations of chlordane. These three samples ranged in
depth from 0.8 to 12 feet below ground surface.

At the Miscellaneous Areas inside of Building 225, only trace concentrations of several
VOCs, fuel hydrocarbons,  and metals  were detected in soil samples.   The  fuel
hydrocarbons were detected  in only two samples and  were tentatively identified  as a
hydraulic fluid. Aluminum, arsenic, barium, cobalt, nickel, and tin were present in most
or all samples, with average concentrations at least twice those observed in background
samples.  The highest concentrations of these metals all  were  in the upper 12 feet of soil.
All detections of contaminants in the Miscellaneous Areas were in soil samples collected
from less than  12 feet below ground surface.
                                     • 3-1

-------
              TABLE 3-1
CHEMICALS DETECTED IN OU 7 SOURCE AREAS
Maximum Source Area Concentrations (mg/kg)
Former Metal PCB Spill
Chemicals
Inorganic Chemicals
Aluminum
Arsenic
Barium
Beryllium
Cadmium
Chromium (total)
Chromium (VI)
Cobalt
Copper
Cyanide
Lead
Mercury
Nickel
Silver
Tin
Vanadium
Zinc
Volatile Organic Compounds (VOCs)
Chloroform
1,1 -Dichloroethane
1,1-Dichloroethene
Methyl ethyl ketone
Tetrachloroethene
Toluene
1,1,1 -Trichloroethane
Trichloroethene
Trichlorofluoromethane
Xylenes
Plating Shop

3,390
6.8
78.4
0.33
220
2,900
1,600
2.6
149
1.4
43.5
0.43
6.5
3.8
ND
7.7 -
172

ND
ND
ND
0.0067
ND
ND
0.0048
0.069
0.0027
ND
Area

NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA

NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Building 225
Misc. Areas

4,610
8.9
68.6
0.59
ND
8.2
0.72
17.8
46.3
ND
16.6
ND
9.3
1.3
27.6
13.8
28.0

ND
ND
ND
ND
ND
0.0072
0.0063
0.0089
ND
ND
Base Supply
Well 6

3,250
2.9
39.1
0.29
0.54
7.6
ND
2.0
6.7
6.3
52.9
0.24
6.7
2.0
ND
8.2
23.2

ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

Building 220
-
6,890
9.7
149
0.67
8.3
41.7
0.094
5.0
74.8
ND
25.7
0.068
637
ND
47.1
16.3
83.3

0.0017
0.021
0.018
0.02
0.0032
17
0.91
0.0039
0.002
2.4
Semivolatile Organic Compounds, Pesticides,
PCBs, and Furans
Chlbrdane
Chlorinated dibenzofurans
Di-n-butylphthalate
Di-n-octyphthalate
PCBs
Phenol
1 ,2,4-Trichlorobenzene

ND
ND
ND
ND
ND
ND
ND
ND Chemical not detected at or above the method
NA Chemical not analyzed for this o
ompound

0.0047
NA
NA
NA
0.23
NA
NA
detection limit


ND
ND
ND
ND
ND
ND
ND



ND
ND
ND
ND
ND
ND
ND



ND
0.0000054
0.53
2.1
0.14
0.83
0.57


              3-2

-------
1
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 DC
 Q.
                                          A t     10
                                         A U7-707
                                                             Chromium Plating
                                                                \ Silver Plating
                                                   (Central Area)
                                                      ...I II
            EXPLANATION
                                                              Chromium Plating
                                                                (South Area)
                                                              U7-OW
  •   Boring location and
U7-728 number
             Background boring
       U7-703 location and number
             Monitoring well location
       U7-008 a"11 number
n             Boundary of old metal
             nlatina areas
         /  Existing aircraft
        /    maintenance stalls
        (60)  Stall number
           ,.- Isoconcentration contour
          -  (mg/kg)
             (dashed where inferred)
      Cross section A-A'
                                                             HILL AIR FORCE BASE
                                                               OPERABLE UNIT 7
                                                                 BUILDING 225
                                                      ISOCONCENTRATION MAP FOR
                                                    HEXAVALENT CHROMIUM IN SOIL
                                                                   FIGURE 3-1
         0    10   20   30   40    50

          ••*=
                  Scale in Feet

-------
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EXPLANATION
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HILL AIR FORCE BASE
/— - \ OPERABLE UNIT 7
9 10 20 30 40 50 A/CM BUILDING 225
=t^=^=i=i ri^ry ISOCONCENTRATION MAP
ScaIeinFeet ^~S FOR CADMIUM IN SOIL
FIGURE 3-2 /

-------
PROJECT NO. 2208.0875 9/6MS
                      Area of former metal plating operations
                                            U7-710  U7-711  U7-712   U7-714
                                EXPLANATION
n                   Coarse-grained sediments
                   (sand and silty sand)
            - •..••.•I—.
I	I   Fine-grained sediments
       {clay, silt, and sandy silt)
       Area of attainment
       Ground-water level
     ,  Area of former metal plating
       operations
Cr6' 1-10 ppm


Cr6* 10-100 ppm


Cr^lOOppm
                                             Groundwater contaminated with
                                             Cr6* (addressed by OU 8)
                                                                                     HILL AIR FORCE BASE
                                                                                       OPERABLE UNIT 7
                                                                                GEOLOGIC CROSS SECTION
                                                                               kDnnen MJICTAI ni ATIKI/^ ourt
                                                                                                *— 140
       GEOLOGIC CROSS SECTION
 OF FORMER METAL PLATING SHOP AREA
  SHOWING VERTICAL DISTRIBUTION OF
HEXAVALENT CHROMIUM CONTAMINATION
                 FIGURE 3-3

-------
 Soil samples  from the backfill placed at Base Supply Well 6 contained average
 concentrations of lead, mercury, nickel, and cyanide that were at least twice their average
 background concentrations.  Lead, mercury, and nickel were detected in all three samples
 from this site; cyanide was detected in two of three samples.

 Samples of soil from beneath Building 220 contained several organic compounds and
 metals above natural background conditions,  although all of the contaminants were
 detected in low concentrations.  The organic compounds  included  VOCs,  fuel
 hydrocarbons, semivolatile organic  compounds (SVOCs), PCBs, and  chlorinated
 dibenzofurans. The VOCs were found at low concentrations in soil samples from several
 locations inside and outside of Building  220, and to depths up to 62 feet below ground
 surface.  The fuel hydrocarbons were tentatively  identified  as gasoline and other
 unknown, degraded fuel hydrocarbon components.  The fuel hydrocarbons were only
 detected in the upper 12 feet of soil.  In one sample from beneath the  former separator
 tank locations (12 to  14 feet below ground  surface), several  SVOCs, PCBs,  and
 chlorinated dibenzofurans were detected in low  concentrations.  A soil boring and
 monitoring well installed through the  Building 220 Source  Area, found that  soil
 contamination was limited in depth and had not reached the ground water.

 Metals present above background with an average site concentration  at least twice the
 average background concentration included chromium,  hexavalent chromium,  and
 mercury.   Chromium  was  present  in  all  soil  samples.   Its  maximum detected
 concentration  was in  the same sample  where SVOCs,  PCBs,  and chlorinated
 dibenzofurans were detected.  Hexavalent chromium was detected in 3  of 86 samples.
 All three of these samples were within  12 feet of the ground surface.  Mercury  was
 detected in eight out of 86 samples to a maximum depth of 82 feet below ground surface.

3.2 SUMMARY OF FATE AND TRANSPORT OF CONTAMINANTS

 A conceptual site model, depicting the  OU 7 source areas and the contaminants and
routes of contamination migration associated with each area, is shown in Figures 3-4 and
 3-5.  Metals and other chemicals seeped into the soil beneath OU 7 in wastewater
solutions.  These discharges have been stopped  because of building renovations and the
soils subsequently have dried out.  The metals  and other chemicals remain in the soils
mainly as precipitates and are not expected to become mobile again without percolating
water to act as a transport medium.  Figure 3-4  illustrates the spatial relationship in the
conceptual  model using a block diagram of the  site, and Figure 3-5 illustrates the
transport pathways and contaminants in each area. Specific characteristics and processes
that  affect  the fate and transport of OU 7 contaminants in soil, water, and  air are
summarized in the RI/FS for OU 7 (Montgomery Watson, 1995).

Fate. Numerous types of environmental contaminants were detected  in the OU 7 soil.
These include VOCs, BNAEs, pesticides/PCBs, furans, elevated metals, and cyanide. Of
these, natural degradation of non-chlorinated  VOCs, some  BNAEs, and  cyanide is
expected to occur fairly rapidly.  By  contrast,  some  BNAEs, chlorinated  VOCs,
pesticides/PCBs, furans, and metals tend to persist in the soil.
                                     3-3

-------
PROJECT NO.  2208.0875
                   PATHWAY
         Building 225 subsurface soil contamination
         Building 225 shallow ground-water contamination
         Building 220 subsurface soil contamination
         Building 220 shallow ground-water contamination
CONTAMINANTS
Metals, VOCs, Cyanide. TPH. Pesticides, PCBs
Metals. VOCs, TPH
VOCs, BNAEs. Metals, PCBs, Furans
None
         Base supply Well 6 shallow surface soil contamination  Metals, Cyanide
                       Predominent pathway
                       Minor pathway
                       Unlikely pathway
                       Soil Gas
                       Zone of contamination
           HILL AIR FORCE BASE
             OPERABLE UNIT 7
     GENERALIZED CONCEPTUAL
MODEL OF CONTAMINANT TRANSPORT
                FIGURE 3-4

-------
     PROJECT NO. 2208.0875
fit
                                                                         AIR
          Building 225 Metal
           Plating Shop and
          Transformer Vault
             Chlorinated
           Solvents, Metals,
           Cyanide, PCBs,
              Pesticides
                                Soil Gas
          Building 225
         Miscellaneous
             Areas
           Chlorinated
           Solvents,
         Hydraulic Fluid,
             Metals
                                 Soil Gas
        Building 220
       Paint Stripping
          Operation
     Chlorinated Solvents,
      Fuels, High Boiling
        Point Organic
       Compounds, Oils
      Base Supply
         Well 6
     Metals, Cyanide,
     (from Bldg. 225)
     SOIL/UNSATURATED ZONE

      Chromium, Cadmium, Arsenic,
    Beryllium, Lead. Cyanide, TCE. TCA,
      MEK. TCFM, PCBs, Chlordane
     TCA, TCE. Toluene, Arsenic,
   Beryllium, Chromium, Hydraulic Fluid
TCE, DCA, DCE, TCE, PCE. Xylene,
   Toluene, MEK, Hydraulic Fluid.
Phenol, Trichlorobenzene, Phthalates,
   PCB-1260, Furans, Chromium.
     Arsenic, Beryllium, Nickel
Cyanide, Arsenic, Beryllium, Lead
                                                   i
                                                   i
                                                   y
      SHALLOW GROUND WATER (ON BASE)
     TCE, DCE, TCA, PCE, Chloroform, Oichlorobenzene,
      Arsenic, Chromium, Lead, Petroleum Hydrocarbons
                                                                                          Not Evaluated
           I         I
I
I
       Predominant    Minor      Unlikely Pathway
         Pathway    Pathway   (not thought to occur
                            based on available data)
              Soil Gas
                                                 NOTE: All metals that trigger a health risk, cyanide, and all organic
                                                      contaminants detected in source areas are listed.
                                                                                                                  HILL AIR FORCE BASE
                                                                                                                    OPERABLE UNIT 7
                                                                                                          CONCEPTUAL MODEL OF PAST
                                                                                                            CONTAMINANT TRANSPORT
                                                                                                                        FIGURE 3-5

-------
Transport The least mobile compounds detected at OU 7 are pesticides/PCBs, BNAEs,
furans, and most metals due to their relatively strong sorptive nature.  There is no
evidence that the soil currently is high in moisture or that other fluids are present.
Consequently, those more soluble and less sorptive compounds such as VOCs, cyanide,
and hexavalent chromium that could mobilize under water-saturated conditions are not
expected to be transported further under current conditions.  If conditions change and
fluids are introduced, these chemicals could be transported through the subsurface soil to
ground water.  To quantitatively determine if these chemicals could be transported to
ground water, an equilibrium partitioning model was used. The results of this model
showed that only hexavalent chromium was in sufficient concentrations to be transported
to ground water. See Section 5.0 of this ROD and Section 7.0 of the OU 7 RI/FS
(Montgomery Watson, 1995) for more details of how the equilibrium partitioning model
was used.
                                      3-4

-------
           4.0  PUBLIC HEALTH AND ENVIRONMENTAL IMPACTS

4.1 HUMAN HEALTH

A baseline risk  assessment (BRA) was prepared for OU 7  as  part of the RI/FS
(Montgomery Watson, 1995).  The purpose of the risk assessment was to identify the
contaminants of concern present at OU 7, the current and future  exposure pathways for
humans and environmental receptors, and the probability of the  occurrence of harmful
effects resulting from current and future exposures. Based on the data collected and the
risk assessment results, the medium of concern at OU 7 is the shallow soil (0 to 12 feet
below ground surface).  The primary contaminants of concern for this medium are
hexavalent chromium and cadmium. These compounds are the primary contaminants of
concern because they are the most prevalent contaminants at the site and contribute most
to the risks. The current risks to human health due to OU 7 contamination are well below
levels considered  significant by EPA. The areas of contamination are beneath concrete
floor slabs under existing buildings,  which prevent exposure to humans  and the
environment. Also, the buildings and surrounding asphalt- and concrete-covered areas
act as a barrier to precipitation and other fluids that could carry the contaminants from the
soil to the ground water below.  It is anticipated that Hill AFB will remain an active
facility under Air Force control for the foreseeable future.  As long as the buildings
remain at OU 7, future cancer and noncancer health risks  are insignificant through direct
exposure routes.  However, it is also  possible that the  Base could be closed and the
current facilities and buildings removed. In that case, future residential housing could be
built on the site, which could expose construction workers and  residents to unhealthy
levels of heavy metals through inhalation and ingestion of contaminated soil.

4.1.1. Contaminant Identification

The initial step  of the risk assessment was to select the contaminants of concern, which
are toxic substances that have  the potential to come in contact with environmental
receptors.  Contaminants of concern were chosen for each of the source areas at OU 7 and
were based upon frequencies of detection, concentrations, and toxicities for the  relevant
exposure pathways.  The data used to select contaminants of concern for shallow soil
were from soil samples collected within 12 feet of the ground surface.  The data used to
select contaminants of concern for surface soil were from soil samples collected within
2 feet of the ground surface. A summary of the contaminants of concern for soil in the
OU 7 source areas is presented in Table 4-1.  A detailed breakdown of the contaminants
of concern according to specific OU 7 source areas is included  in the RI/FS for OU 7
(Montgomery Watson, 1995).

4.1.2. Exposure Assessment

An exposure assessment was performed to identify current and potential future exposure
pathways  through which  contaminants  of concern could travel to environmental
receptors.   The ground-water exposure pathway was not assessed in the OU  7 BRA;
however, it will  be addressed as part of the OU 8 BRA. A summary of this assessment is
provided below. A more detailed discussion is included in the BRA, which is Section 6.0
of the RI/FS for OU 7 (Montgomery Watson, 1995).


                                      4-1

-------
                                   TABLE 4-1

               HILL OU 7 CHEMICALS OF CONCERN FOR SOIL
Type of Chemical
Metals







Poly Chlorinated Biphenols
Pesticides
Volatile Organic Compounds
Compound
Arsenic
Barium
Beryllium
Cadmium
Chromium VI
Chromium HI
Mercury
Nickel
Silver
Vanadium
PCB-1254
PCB-1260
alpha-Chlordane
gamma-Chlordane
Toluene
NC
-------
 Current. Potential current exposures at OU 7 are associated with two media: surface
 soil (0 to 2 feet below ground surface) in uncovered areas, and air. Possible exposures by
 current maintenance personnel, who could inhale or ingest contaminated dust or have
 dermal contact with contaminated soil would only occur if excavating into soil. This is
 considered unlikely because no excavation into soils is needed because the utilities in
 Building 225 are located within concrete-lined trenches and the utilities within Building
 220 are located above ground.

 The degree of exposure to  surface soils in uncovered areas of OU 7  depends on the
 amount of vegetation (that may prevent or limit exposure) present at each of the areas.
 The open areas east of Building 220 and around Base Supply Well 6 are located near the
 flight line, where access is limited, and generally are covered with vegetation.  The only
 possible  exposure to soil in these areas would be to maintenance workers that cut the
 grass.  However, the exposure would be limited because these areas are  small and the
 grass is cut only twice each year.  Because  of the vegetative cover over the open areas of
 OU 7 and the limited potential for exposure of current workers through incidental contact
 with contaminated soil, inhalation of fugitive dust, and ingestion and dermal contact with
 contaminated soil were not evaluated under current conditions.

 No known  sources of contaminant emissions to the air currently  exist at OU 7.
 Volatilization from the soil into the air is considered to be very minor at OU 7, especially
 in areas that are covered with concrete or asphalt.  The exposure assessment concluded
 that no  current exposure pathways are  complete because areas  with contaminant
 concentrations in soil considered significant by EPA are located beneath existing concrete
 floor slabs.

 Future.  For future land use scenarios, it was assumed that residential, commercial, and
 industrial development could take place within the current boundaries of Hill AFB.  If
 Hill AFB is closed, residential, commercial, and industrial operations would  most likely
 replace the existing uses,  although there are no current plans to close the Base. Complete
removal of the heavy industrial infrastructure in the OU 7 area, followed by returning the
land to farming, is considered highly unlikely. If Hill AFB is closed, potential future land
use in  the OU 7 area may be similar to the current residential land use in  the area of
Layton, next to the Base. Potential future exposures at Hill AFB would  be associated
with two media:  soil (within 12 feet of the surface), and air.

Under potential future land use, residential, commercial, and industrial operations may be
developed within the present boundaries of Hill AFB. Where construction does occur,
shallow soil near the surface (to a depth of  12 feet) might.be considered  as a potential
exposure route because foundation and basement construction could penetrate to this
depth (i.e., construction workers building homes and industrial or commercial buildings
may become exposed to shallow soil during construction activities).  Three exposure
routes  were considered for  construction workers:  incidental ingestion, inhalation of
fugitive dust, and dermal contact with soil and fugitive dust. However,  employees of
future commercial or industrial operations were assumed to have no exposure to soil for
two reasons:  most employees were assumed to spend their working time indoors, and
                                       4-3

-------
paved land surfaces at these operations will prevent exposure to  soil among those
employees who do work  outdoors.  Like  construction workers,  persons living in
residential developments could  be exposed to chemicals in surface soil (to a depth of
2 feet) via three exposure routes: (1) incidental ingestion of soil (where food may be
ingested with unwashed hands or  unwashed hands may  be  placed in  the mouth),
(2) inhalation of fugitive dust from areas of exposed surface soil such as gardens, and
(3) dermal absorption as a result of dermal contact with surface soil or fugitive dust on
exposed skin.

There are no known current emissions to the air at OU 7.  Soil gas surveys were used to
qualitatively identify potential soil contamination by VOCs in order to select locations for
soil borings.  Samples from those borings showed low to no detectable concentrations of
volatiles in soil. Under the current exposure scenario, volatilization from the soil into
outdoor air is considered to be minor relative to other exposures. The concentrations at
points of potential human exposure are expected to be extremely low.  No evidence
suggests that the potential for volatile emissions will change in the future.

For more details regarding the assumptions, models, and parameters used to estimate the
concentrations at the receptors and the chronic daily  doses for each exposure pathway,
reference is made to the BRA, Section 6.0 of the RI/FS for OU 7 (Montgomery Watson,
1995).

4.1.3. Toxicity Assessment

Slope factors (SFs), are used to provide conservative  estimates of excess lifetime cancer
risks associated with exposure to potentially carcinogenic chemicals.  Slope factors are
derived from the results of human epidemiological studies and chronic animal bioassays
to which  animal-to-human extrapolation and uncertainty  factors have been applied.
Reference doses (RfDs)  are used to indicate the potential for adverse effects from
exposure  to chemicals exhibiting non-carcinogenic effects.   RfDs are estimates of
lifetime daily exposure  levels for humans, including sensitive individuals, which are
compared to estimated intakes of chemicals from environmental media. RfDs are derived
from human epidemiological studies and animal studies to which uncertainties have been
applied.   SFs and RfDs for the contaminants of concern at  OU 7 are presented in
Tables 4-2 and 4-3.  The  most toxic compounds  present at OU  7  are hexavalent
chromium and cadmium.  These compounds are the most  prevalent contaminants of
concern, and they pose both  carcinogenic and noncarcinogenic health risks. Contaminant
toxicity is discussed in detail in the BRA (Montgomery Watson, 1995).

4.1.4. Risk Characterization

Cancer and noncancer risks were calculated for each of the exposure pathways using
reasonable maximum exposure estimates for the potential contaminants of concern. The
results of these calculations were compared to acceptable levels of risk. For carcinogenic
exposures, an excess lifetime cancer risk of 1  x 10~6  indicates a  one in a million chance
that an individual will develop cancer after being exposed to a carcinogen under the site-
                                      4-4

-------
                                            TABLE 4-2

          SUMMARY OF SLOPE FACTORS FOR POTENTIAL CONTAMINANTS OF CONCERN



VOCs










Compound

2-Butanone (MEK)
1,1-Dichloroethene
Perchloroethylene
Toluene
1,1,1-Trichloroethane
Trichloroethene
Trichlorofluoromethane
Xylenes, Total
Ingestion
Slope Factor
(mg/kg/day)'1

—
0.6
5.1x10 =
—
'
1.1x10 =
—

Ingestion
Weight of
Evidence

D
C
B2
D
D
B2
—
D


Source

I
I
STSC
I
I
STSC
—
I
Inhalation
Slope Factor
(mg/kg/day)-1

--
1.20
2xlOs
—
—
6xlOJ
—
• -
Inhalation
Weight of
Evidence

D
C
B2
D
D
B2
—
D


Source
-
I
H
STSC
I
I
STSC
—
I
Pesticides and PCBs




Inorganic


















(a)
VOCs
PCBs
I
H
STSC
alpha-Chlordane
gamma-Chlordane
PCB-1254
PCB-1260

Aluminum
Arsenic
Barium
Beryllium
Cadmium
Chromium VI
Chromium III
Cobalt
Copper
Lead
Manganese
Mercury
Nickel Ca)
Silver
Tin
Vanadium
Zinc
Cyanide
Values are for nickel refinery
Volatile organic compounds
Polychlorinated biphenyls
1.3
1.3
7.7
7.7

—
1.8
—
4.3
—
-
—
—
-
—
~
	
—
—
—
.
-
~
dust.


B2
B2
B2
B2

—
A
—
B2
D
D
~
—
D
B2
D
D
„
D
—
---
D
—



I
I
I
I

—
I
—
I
H
1
—
—
I
I
I
I
—
1
—
—
I
—



1.3
1.3
—
—

—
15.0
—
8.4
6.3
41.0
—
—
-
—
-
	
0.84
—
—
—
—
—



B2
B2
B2
B2

—
A
—
B2
Bl
A
—
—
D
B2
D
D
A
D
—
—
D
—



I
I
I
I

—
1
—
1
I
I
—
0






—
—
I
—



IRIS database searched in March 1994
Health Effects Assessment Summary Tables (HEAST. 1993)
Superfund Technical Support
Center





         Not available on IRIS, HEAST, or from the Superfund Technical Support Center
mg/kg/day milligrams per kilogram per day
A        Human carcinogen
B1       Probable human carcinogen, based on limited human data
B2       Probable human carcinogen, based on animal data
C        Possible human carcinogen
D        Not classified
                                              4-5

-------
                                               TABLE 4-3
                                                ซ

                                           REFERENCE DOSES
ON
Compound
Benzene
Chloroform
1,1-Dichloroethene
1 ,2-Dichloroethane
1,2-Dichloroethene (trans)
1,2-Dichloroethene (cis)
Methyl Ethyl Ketone
Tetrachloroethene
Toluene
Trichloroethene
Xylenes
Arsenic
Barium
Boron
Cobalt
Nickel
Selenium
Chronic Oral
Reference Dose Uncertainty
(mg/kg/day) Factor Source
NA
1 x 10-2
9x 10-3
NA
2x10-2
1 x 10-2
6x 10-'
1 x 10-2
2x 10-'
7x 10-3
2x 100
3x lO'4
7x 10-2
9x 10-2
NA
2x 10-2
0.005
NA No information or data were available
LHA Lifetime Health Advisory
IRIS Integrated Risk Information System,
searched March and July 1993
NA
1,000
1,000
NA
1,000
1,000
3,000
1,000
1,000
NA
100
3
3
100
NA
300
3
HEAST
P
IRIS
IRIS
IRIS
IRIS
IRIS
HEAST
IRIS
IRIS
IRIS
LHA
IRIS
IRIS
IRIS
IRIS
—
IRIS
IRIS
Chronic
Inhalation
Reference Dose Uncertainty
(mg/kg/day) Factor
1 x lO-3
2x 10-3
5x 10-3
NA
NA
NA
2.9 x 10-'
NA
1.1 x lO-1
NA
9x lO-2
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1000
NA
100
NA
100
NA
NA
NA
NA
NA
NA
Source
P
P
P
IRIS
IRIS
IRIS
IRIS
IRIS
HEAST
NA
IRIS
IRIS
IRIS
IRIS
~
IRIS
IRIS
Health Effects Assessment Summary Tables, 1993
Proposed RfD, Hazardous Pollutant Assessment Branch,
Environmental Criteria and Assessment Office, EPA
Not Listed in HEAST or IRIS

-------
specific conditions  for a 70-year lifetime.  The target excess lifetime  cancer risk is
1 x 10~6 (one in one million) and the maximum limit for excess lifetime cancer risk is
1 x lO"4 (one in ten thousand). For exposures to noncarcinogenic compounds, a total
hazard index greater than one is considered to be an unacceptable risk.

For potential future exposure scenarios, risks were calculated for the construction worker
scenario and the residential scenario.   The construction worker scenario  assumes
exposure to shallow soil (from the surface to 12 feet bgs)  while the residential scenario
assumes exposure to the top two feet of soil only. Current surface soil exposure was not
quantified because  the potential for, and possible duration of,  exposure are minor
compared to other pathways evaluated in the BRA (e.g., future residential).  The risk
estimates for future exposure pathways for soil contaminants at all of the OU 7 source
areas are presented in Table 4-4. The following discussion focuses on the cancer risks;
the hazard indices at all sites were below the benchmark of 1.

The  former Metal Plating Shop site was divided into  three distinct  areas for risk
characterization. These areas included the North Area, South Area, and Central  Area.
The estimated excess cancer risk for future construction workers is 8 x 10"^ (8 in one
hundred thousand), 3 x 10"^ (three in ten thousand), and 2 x 10~6 (two in one million) for
these three areas, respectively.  These risk  values are due to inhalation exposure to
hexavalent chromium. For future residents, the risk estimates were 2 x 10"^ (two in one
hundred thousand) for the North and South Areas, and 1 x 10*6 (one in one million) for
the Central Area.

The other sites evaluated for construction  risk characterization at OU 7 include the PCB
Spill  Area, Base Supply Well 6, Miscellaneous Areas inside Building 225, and  the
Building 220 area.   For construction  workers, the  only one of these areas with a
potentially significant cancer risk is the Building 225 Miscellaneous  Areas, where  the
estimated risk was 3x10"^ (three in one million) from arsenic and nickel. Cancer risks
for the construction worker for all other sites were less than the 1 x  10~6 benchmark (see
Table 4-4).

All of the results for the residential risk characterization at these other OU 7 sites were
above the 1x10"" benchmark. For  the PCB  Spill area, the estimated excess cancer risk
is 3 x 10~6 (three in one million); for the Base Supply Well 6 area,  the estimated excess
cancer risk is  4  x 10"6 (four in one million);  for the Building 225 Miscellaneous Areas,
the estimated excess cancer risk is 3 x 10'5 (three in one hundred thousand), and for the
Building 220 area, the estimated excess cancer risk is 2 x 10'6 (two in one million).

4.1.5. Uncertainties

The risk estimates cited have uncertainties associated with them. There are uncertainties
in the risk factors (i.e., the slope factors and reference doses), in the risk summation, the
exposure parameters, the projected land use, and the chemicals present. Most risk factors
are based on animal data.  To  extrapolate to humans, uncertainty  or safety factors  are
                                        4-7

-------
                                                          TABLE 4-4

                                         SUMMARY OF CANCER RISKS AND HAZARD INDICES
                                               BY PATHWAY: FUTURE EXPOSURES
oo
Cancer Risk
Scenario
FUTURE - Reasonable Maximum Exposure
Soil On Base, Construction Workers
Former Building 225 Metal Plating Shop - North Area
Former Building 225 Metal Plating Shop - South Area
Former Building 225 Metal Plating Shop - Central Area
Building 225 PCB Spill
Base Supply Well 6
Building 225 Miscellaneous Areas
Building 220
Soil On Base, Residents
Former Building 225 Metal Plating Shop - North Area
Former Building 225 Metal Plating Shop - South Area
Former Building 225 Metal Plating Shop - Central Area
Building 225 PCB Spill
Base Supply Wejl 6
Building 225 Miscellaneous Areas
Building 220
Ingestion


NC
NC
NC
3x10"
8x10"
7x10'
NC

NC
NC
NC
1x10"
2xl06
2x10'
2x10"
Inhalation


8x10'
3x10"
2x10"
6x10"
5x10"
2x10"
IxlO'

2x10'
2x10"
1x10"
3x10"
2x10"
8x10'
1x10'
Dermal


NC
NC
NC
2x10'
IxlO'
8x10'
NC

NC
NC
NC
2x10"
2x10"
1x10'
5x10"
Total


8x10'
3x10"
2x10"
5x10"
1x10'
3x10"
1x10'

2x10'
2x10'
1x10"
3x10"
4xlOซ
3x10'
2x10"
Ingestion


IxlO'
2x1 0'1
6x10'
9x10'
3x10'
5xl02
8x10"

4xl02
6xl02
7x10'
2x10"
5x1'
7x10'
4x10'
Hazard
Inhalation


NC
2x10'
NC
NC
3x10'
4x10'
2x10"

NC
IxlO4
NC
NC
8x10'
IxlO'
9x10' '
Index
Dermal


2x10"
2x10'
7x10"
3x10'
4x10'
6x10'
IxlO'

IxlO3
IxlO3
2x10"
1x10"
2xl03
6x10'
IxlO"

Total


1x10'
2x10'
6xl03
IxlO"
3x10'
9x10'
IxlO3

4xlO!
6x10'
7xl03
3x10"
2x10"
IxlO'
IxlO2
             alculated

-------
 included  in the reference doses, and the slope factors are based on a conservative
 interpretation of the dose-response curve obtained from the animal data. The risks were
 assumed to be additive; any antagonistic  or synergistic  effects were not quantitatively
 accounted for.  Exposure parameters, such as the frequency, duration, and the amount of
 intake or  contact, were selected so that the potential for underestimating exposure was
 small. The risk estimates were based on two projected land uses (i.e., construction and/or
 residential). If these land uses do not occur, the risk estimates will not reflect the actual
 potential risks at OU 7. The chemicals present on site have been assumed to be the ones
 detected  during  the  field sampling  program.  If there are continuing sources  of
 contamination  or if chemicals such as TCE or PCE degrade in the environment, risks
 could be underestimated.

 In general,  the methodology used in the risk assessment tends to overestimate the
 potential risks.  Conservative health-protective assumptions were made  for exposure
 duration, dosage, toxicity, and absorption. The exposure scenarios were conservative and
 represented activities that might occur in the future. Overall, the methodology used for
 this risk assessment makes it unlikely that the true risks are higher than the calculated
 risks.

 4.2 THREATS TO THE ENVIRONMENT

 4.2.1. Surface Water, Ground Water, and Wetlands

 No streams, rivers, or lakes exist on Hill AFB. Numerous wetlands have been identified
 on Hill  AFB, but none occur within 400 feet of OU 7. No impacts  to surface waters  or
 wetlands are known as a result of contaminants at OU 7.

4.2.2. Vegetation

Vegetation in the vicinity of Operable Unit 7 primarily consists of small strips of grass.
Contaminants  at Operable Unit 7 primarily are beneath buildings where they cannot
affect vegetation; therefore, no adverse effects on the local ecosystem are anticipated.
There are no endangered or threatened plant species on Base; therefore, no adverse
effects on  these species in the local ecosystem will occur.

4.2.3. Wildlife

Hill AFB  does  not provide critical or important  habitat for any wildlife species, and no
threatened or endangered species are known to inhabit the Base. Operable Unit 7 and the
surrounding areas are already  developed, and  the remedial activities and additional
human presence will add no significant impact to wildlife.

4.2.4. Air Quality

The contaminants at OU 7 are in subsurface soil (primarily beneath buildings) and do not
have a substantive effect on air quality.
                                       4-9

-------
4.23.  Archaeological Resources

There  are no known cultural or archeological resources on Hill AFB in the vicinity of
OU 7.

4.3 SUMMARY OF SITE RISKS

Exposure to chemicals at OU 7 has the potential to arise if the concrete slab is removed
from Building 225. A cancer risk above 1 x 10"4 was estimated for future construction
workers for the Building 225 South Area. All other areas of Building 225 have estimated
cancer risks between 1 x 10~4 and 1 x 10~6 for future construction workers and residents.
These  risks are primarily from hexavalent chromium  and  (to a lesser extent) cadmium.
Potential future risks between 1 x 10~4 and 1 x 10~6 also were calculated for construction
workers and residents for the Building 225 Miscellaneous Areas. At all other sites, the
cancer risk was between 1 x 10~4 and 1 x 10"^ for potential future residents but less than
1 x 10 "6 for the construction worker.  It should be emphasized that these all are potential
future risks. There are no current health risks at OU 7 because the areas of contamination
are beneath concrete floor slabs under existing buildings which prevents exposure from
occurring.

Contamination at OU 7 does not pose an ecological risk to plants or wildlife. This is due
to the  fact that  OU 7 primarily is covered by  buildings, concrete, and asphalt, and
contaminants are only in subsurface soil.  A qualitative evaluation did not indicate a
significant potential for ecological threats to exist.

Actual or threatened releases of hazardous substances  from this site, if not addressed by
implementing the response  action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or the environment.
                                      4-10

-------
                   5.0 DESCRIPTION OF ALTERNATIVES

As part of the feasibility study (FS) for OU 7 (Montgomery Watson, 1995), five specific
remedial alternatives  were developed for soil cleanup to meet the remedial action
objectives (RAOs) for contaminated soils beneath the former Metal Plating Shop in
Building 225.  Under Section 121 of CERCLA, a selected remedial action must be
protective of human health and the environment, and it must comply with applicable or
relevant and appropriate requirements (ARARs). The alternatives for soil cleanup were
evaluated for short-term effectiveness; long-term effectiveness and permanence,
reduction of toxicity, mobility or volume through treatment; technical and administrative
implementability; and cost effectiveness.  Alternatives were then compared against these
criteria for selecting the recommended remediation measures. Additionally, State and
community acceptance were also required before selection of the remedy.  This section
summarizes how the remedy selection process for OU 7 addressed these requirements.

5.1 DEVELOPMENT OF ALTERNATIVES

Remedial alternatives were developed by assembling technologies into combinations that
are applicable for the medium of concern at OU 7 (soil).  The steps that were used to
develop remedial alternatives for OU 7 included development of response objectives,
remedial action objectives, and general response actions for contaminated soil, followed
by a preliminary screening and evaluation of technologies and process options. Response
objectives include prevention of human  exposure to contaminated soil through direct
contact, ingestion, or  inhalation, and long-term attainment  of shallow ground-water
remedial action objectives. RAOs were developed to define the extent of the remedial
action. The RAOs for OU 7 include:

       •   Reduce  contaminant transport within source areas  and reduce chemical
          transport from soil to ground water by minimizing surface water infiltration.

          Prevent human exposure to contaminated soil through ingestion, inhalation,
          and dermal contact, such that the additional risk to an individual for cancer is
          below 1 x 10~6 and the threshold non-cancer hazard index is less than 1.0.

       •   Reduce  contaminant concentrations to meet risk levels  and/or reduce
          contaminant transport to rates that will not impact ground-water quality above
          Maximum Contaminant Levels.

Included  within  the RAOs are preliminary  remedial goals,  areas of attainment, and
estimated restoration time frames. The preliminary remedial cleanup goals are shown in
Table 5-1 and are based on health risks and on the contaminants potential to leach to
ground water. The remedial cleanup goals for shallow soils (i.e., the upper 12 feet) were
determined using risk-based concentrations from calculated risk factors (see the BRA,
Section 6.0, of the OU 7 RI/FS; Montgomery Watson, 1995).  Cadmium and hexavalent
chromium, in the vicinity of the  former Metal Plating Shop in Building 225, were
determined to exceed these risk-based concentrations (RBCs) in the shallow soils. For
soils deeper  than 12 feet and to determine if ground-water quality standards could be
                                      5-1

-------
                                TABLE 5-1

          PRELIMINARY REMEDIAL GOALS FOR SOIL AT OU 7
    Contaminants
   Risk-Based
   Preliminary
Remedial Goals )
     (mg/kg)
Cadmium
Hexavalent chromium
7.57
1.16
NM
13 to 1017
53.9
348
Only compounds requiring cleanup are listed.

NM  Cadmium not expected to be mobile in soil under normal pH conditions.

(a)  Risk-based preliminary remediation goals were calculated from health-based risk
    levels from Tables 6-29 through 6-30 of the BRA (Section 6.0 of the OU 7 RI/FS;
    Montgomery Watson, 1995).

(b)  Values obtained from Table 7-1 of the FS (Section 7.0 of the OU 7 RI/FS;
    Montgomery Watson, 1995).
                                   5-2

-------
exceeded if the contaminants in the soil were transported to ground water, a chemical
equilibrium and partitioning model was used to calculate the maximum concentrations of
chemicals that could remain in soil while allowing Utah and Federal ground-water quality
standards to be met.  The results of this equilibrium modeling indicated that only
hexavalent chromium was in sufficient concentrations to impact ground-water quality.
Based on the hexavalent chromium concentration that corresponds to the concentration
that would trigger a lxl(H> cancer risk (1.16 mg/kg), an area of attainment of 11,000
cubic yards was determined within the former Metal Plating Shop.

General response actions for the soil identify basic actions that might be undertaken as
part of a remedial action. Several technologies  may exist for each general response
action.  The preliminary screening of technologies for each general response action
involved evaluation of technical implementability.  In the process option evaluation,
technically implementable technologies were evaluated with respect to effectiveness,
implementability, and cost.  Details of the technologies evaluated and the evaluation
process used are presented in the FS portion of the RI/FS report (Montgomery Watson,
1995).

The alternatives assembled for the cleanup of contaminated soil begin with the no action
alternative, which is required by the NCP to be  included in the comparison process.
Subsequent alternatives represent an increasing degree of technical complexity. Each
alternative contains different processes and degrees of remediation for contaminated soil.
The assembled alternatives are presented in Table 5-2.

5.2 DETAILED ANALYSIS OF ALTERNATIVES

During the detailed analysis in the OU  7 FS, each alternative  was assessed against nine
evaluation criteria developed by  the EPA to compare the relative performance of the
alternatives and to identify the advantages and disadvantages of each. This approach was
designed to provide sufficient information to adequately compare the alternatives, select
an appropriate site remedy, and satisfy CERCLA remedy selection requirements.  The
detailed analysis of alternatives  included further definition of the  volumes or areas of
conta'minated soil to be addressed, the technologies to be used, and the performance
requirements associated with those technologies.  Also included in the FS was  an
assessment and summary profile of each alternative, and a comparative analysis among
the alternatives.

Alternative 1:  No Action

As Alternative 1 implies, no remedial action would be taken. This alternative is included
as a basis for comparison  with other alternatives, and consists of ground-water and soil
moisture monitoring in addition to the statutory requirement for site reviews that are
required at least every five years when hazardous  substances  are left in place above
health-based levels. Ground-water monitoring would include testing the ground-water
quality upgradient, beneath, and downgradient of the former  Metal Plating Shop.  Soil
moisture monitoring would occur within the plating shop boundaries and would reveal
                                       5-3

-------
                                                   TABLE 5-2



                               DEVELOPMENT OF REMEDIAL ALTERNATIVES FOR OU 7 SOIL
V
Remedial Alternatives
General
Response
Actions

Institutional
Controls
Treatment
Extraction/
Disposal
Technology
Type
Long-term Monitoring
Program
Notice to Deed
Continuing Order from
Base Commander
Warning Signs
Soil Washing
Solidification
Excavation
(backhoc/front loader/
clamshell)
Landfill Disposal
Backfill
Alternative
1
No Action
•






Alternative
2
Institutional
Controls
•
•





Alternative
3
Excavation/
OIT-Site
Disposal




•
•
(off-site)
•
Alternative
4
Excavation/Soil
Washing/
Disposal


•
(ex-situ)

•
' •
(off-site)
•
Alternative
5
In-Situ
Solidification
•
•

• •
(in-silu)




-------
the potential for contaminants to leach downward, where they could eventually affect
ground-water quality.

The building and concrete slab currently act as a barrier over the contaminated soil that
limits infiltration and prevents exposure. However, removal of the building and floor
slab would allow accidental human exposures and may allow fluids to infiltrate and
threaten ground water.  Removal of the building and  floor slab would require a re-
evaluation of the remedial alternative because Alternative 1 would no  longer be
protective of human health and the environment. Also, this alternative does not include-
provisions to limit future access to the soil beneath the former Metal Plating Shop and
development of the contaminated area. Under Alternative 1, construction workers could
be exposed to contaminated soil if they were to excavate beneath the building floor. In
addition, there are no provisions to maintain the building and floor slab.

Capital  cost requirements for Alternative 1 are $108,000, and the annual operation and
maintenance for years 1  through 10 is $36,600 per year and for years 11 through 30 is
$30,900. The estimated 30-year present-value cost is $468,000.

Alternative 2:  Institutional Controls

Alternative 2 includes the same elements as Alternative 1 but adds controls that will limit
access to contaminated soils that could pose significant health risks. Additional elements
of Alternative 2 include: having the Base Commander issue a continuing  order that
restricts access by Air Force employees  and personnel,  posting warning signs, filing a
notice to the deed  for Hill AFB, and in the event that ownership of the property is
transferred, specific covenants in the deed to continue restrictions and allow future
response actions, if needed.  Each of these  additional elements is described in further
detail below.

The continuing order would:

      •  Restrict the installation of any  new underground utilities or other construction
          activities beneath the floor in the former Metal Plating Shop  Area, thus
          preventing accidental exposures to the construction worker.

      •  Provide for the use of proper protective equipment if for  any  reason the
          concrete floor slab in the former Metal Plating Shop area is to be removed.

      •  Require that the integrity of the concrete floor slab be maintained (i.e.,  repair
          cracks that may develop) so that fluids cannot infiltrate to  the subsurface.
          Maintenance  of the floor  slab  would  require development of standard
          operating procedures (SOPs)  to provide for  inspections, floor repairs, and
          responses to spills in critical areas. The continuing order would be in effect as
          long as the property is owned by Hill AFB.
                                       5-5

-------
Warning signs would be posted stating that hazardous chemicals are present beneath the
floor slab in the former Metal Plating Shop area and  that no excavation is permitted
without proper authorization.

A notice to the deed would be filed by the Air Force in the real property records of Davis
County detailing the restrictions in the continuing order.  In addition, the Air Force would
include a restrictive covenant to the deed for affected property that allows access for
maintenance and monitoring following property transfer and notifies the transferee of the
locations and restrictions on use of the affected areas.

The capital  cost associated with the institutional control alternative is $184,000.  The
annual operating and maintenance cost for Alternative 2 is $39,500 per year for years
1 through 10 and $33,800 per year for years  11 through 30. In addition, five-year site
reviews are anticipated to cost $25,000 every five years. The total 30-year present worth
cost of the institutional control alternative is $627,000.

Alternative 3: Excavation/Off-Site Disposal

Alternative  3  consists of excavation and off-site  disposal  of contaminated soil.  Soil
would be excavated from  areas with hexavalent chromium concentrations greater than
1.2 mg/kg, which would be protective of a construction worker and potential future
resident, as  well  as prevent leaching to ground water in concentrations above MCLs.
Affected soil would be removed  to  a depth  of approximately 15  feet at the northern
chromium plating area, to 15 feet in the cadmium plating area, to  12 feet in the central
chromium plating area, and to  a depth of 50 feet at the southern end of the plating shop
for a total of approximately 11,000 cubic  yards of soil.  Removal of the soil also would
reduce concentrations of other chemicals at OU 7 to health-protective levels. Because of
the large percentage of fine sand in the soil, the excavation walls would need to be sloped
to prevent cave-in and eliminate the need for shoring. The total volume of excavated soil,
including the 1:1 sloped walls and a small contingency for additional soil contamination,
is estimated to be approximately 30,000 cubic yards.  Clean soil from either an on-Base
or off-Base  source  would be  placed into the excavated area as backfill to replace the
removed soil.

Long-term environmental monitoring is not needed in this alternative, and no future land-
use restrictions apply because contamination would be removed from the site.  The only
costs associated with this alternative are capital costs of $7,332,000.

Alternative 4: Excavation/Soil Washing/Disposal

Alternative 4, Soil Washing, would significantly reduce  the volume of contaminated soil
that must be  disposed  off-site.  The soil washing process includes excavating the
contaminated soil, treating the soil with water and chemicals, and returning the clean
portion of the soil to the excavation pit.  The soil volume requiring treatment would be
the same as for Alternative 3, including sloped walls and a small volume contingency.
                                       5-6

-------
 Soil washing would involve both chemical and physical treatment. In the chemical
 treatment process, the soil is suspended in an aqueous solution and the contaminants are
 leached from the soil using reagents, which react with and solubilized the contaminants.
 The chemical process results in transformation of the contaminants into less toxic forms.
 The physical treatment process consists of separating and  screening  the soils  to
 concentrate and reduce the volume of contaminated soil/sludge that must be disposed off
 site. A typical soil washing system will treat both coarse and medium-grained particles,
 but is  less effective in treating fine-grained soil.  A separate component of the soil
 washing process is necessary to treat the fine particles.   Because of uncertainties
 associated with this alternative, a treatability study would be needed to confirm the
 effectiveness of this technology and to provide data necessary to design the treatment
 system.

 The concentrated sludge resulting from the fine-particle soil washing process would be
 dewatered to produce a sludge cake.  The sludge cake, which would be disposed off-site
 at a permitted hazardous waste landfill, would have substantially less volume than the
 original contaminated soil.  The treated soil then would be placed back in the excavation
 and compacted. Additional clean soil from either an on-Base or off-Base source would
 be backfilled into the excavation and compacted, as necessary.  The leachate from the soil
 washing process would be discharged to the IWTP for treatment.

 Because contaminants would be removed from the soil and disposed off-site, there would
 be no long-term monitoring needed with this alternative. The only costs associated with
 this alternative are capital costs totaling $5,221,000.

 Alternative 5:  In-Situ Solidification

 Alternative 5 consists of in-situ solidification of the contaminated soil, environmental
 monitoring, and the five-year site reviews required when hazardous substances are left in
 place in concentrations above health-based levels.  In this alternative, soil would be
 mixed  in-place with treatment agents using a specialized auger equipped with nozzles
 capable of injecting  the treatment agents into the soils as the auger mixes them.  This
 method of mixing results in a cylinder of treated soil with a diameter equal to that of the
 auger,  which typically ranges from 6 to 10 feet. Alternative configurations use multiple
 augers that affect a rectangular footprint, approximately 4 to 6 feet across. The process is
 repeated across the treatment area with each  new cylinder or rectangle overlapping the
 previously treated soil until the entire area of concern has been treated.  A large dome
 would  be  placed over the auger system during  the  mixing process to capture excess
 VOCs  that may escape during mixing and channel them through a granulated activated
 carbon (GAC)  bed before they are discharged to the atmosphere.  The low levels of
 VOCs  detected in the subsurface soils are not expected to effect the actual solidification
process.

Typical treatment agents used for solidification include cement kiln  dust, Portland
cement, hydrated lime, and fly ash.  Bench tests would be necessary to determine the
most appropriate solidifying agent for the chemicals in affected soil at OU 7.  A pilot test
 also may be necessary to determine the most effective mix of solidifying agent, water,
                                       5-7

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 and contaminated soil.  Pretreatment and post-treatment representative samples of the soil
 cylinder would be collected and analyzed to verify that contaminants are immobilized
 and that acceptable transport rates had been achieved.  A limited clay cap may be placed
 over the area to limit infiltration of water into the stabilized soil.

 Because contaminants are left in the soil and the soil matrix is disturbed with this
 alternative,  institutional controls  would be required after solidification to ensure that
 contaminants  are not transported to ground  water.  Land use restrictions would  be
 implemented to prohibit subsurface development in the vicinity of the treated area.

 The capital cost for this alternative is  $1,887,000.   The  annual  operating cost  of
 Alternative 5 would be $36,600 for years 1 through 10 and $30,900 for years 11 through
 30. The total 30-year present worth cost for Alternative 5 is $2,247,000.

 5.3 COMPARATIVE ANALYSIS OF ALTERNATIVES

 The five alternatives were compared to assess the relative advantages and disadvantages
 of each and to identify key tradeoffs that were balanced in selecting an alternative for soil
 cleanup. The preferred alternative  was developed based upon the following comparisons,
 considering the expected results of the combination of alternatives from each set.

 5.3.1. Evaluation Criteria

 The alternatives were compared with respect to nine evaluation criteria that have  been
 developed under CERCLA to address the technical and policy considerations associated
 with selecting among the  remedial  alternatives.  The  nine  evaluation  criteria are
 described below.

Threshold Criteria

Threshold criteria include overall  protection of human health and the environment and
compliance with Applicable or Relevant and Appropriate Requirements (ARARs). These
threshold criteria must be met by any given alternative before it can be evaluated under
the five balancing criteria.

 1.     Overall Protection of Human Health and the Environment describes  whether
       the alternative as a whole achieves  and maintains adequate protection of human
       health and the environment.

2.     Compliance  with  ARARs  describes whether the alternative  complies  with
       ARARs or, if a waiver is required, how it is justified. Other information  from
       advisories, criteria, and the  guidance "to be considered" is also addressed.

Balancing Criteria

The five balancing criteria form the basis of the comparative analysis because they allow
tradeoffs among the alternatives offering different degrees of performance.
                                       5-8

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3.     Long-Term Effectiveness and Permanence refers to the ability of an alternative
       to provide reliable protection of human health and the environment over the long
       term.

4.     Reduction of Mobility, Toxicity, and Volume Through Treatment refers to the
       preference for treatment technologies that meet this criteria.

5.     Short-Term Effectiveness   examines the  effectiveness of alternatives in
       protecting  human health and  the environment  during the construction and
       implementation of a remedy and until the response objectives have been met. The
       length of time to achieve remedial action objectives also is a part, of short-term
       effectiveness.

6.     Implementability evaluates the technical and administrative feasibility of the
       alternatives and the availability of the goods  and services needed to implement
       them.

7.     Cost refers to the capital, indirect, and operation and maintenance costs  of each
       alternative. Costs are estimated and expected to provide  an accuracy of  plus 50
       percent to minus 30 percent for a 30-year period. The 30-year period is used as a
       common point of comparison. Cost can only be a deciding factor for alternatives
       equally protective of human health and the environment.

Modifying Criteria

The modifying criteria described below generally are addressed in response to comments
from the State and the public, after the issuance of the Proposed Plan.

8.     State  Acceptance indicates whether  the State agrees with, opposes, or has no
       comment on the preferred alternative.

9.     Community Acceptance indicates whether the community agrees with, opposes,
       or has no comment on the preferred alternative.

5.3.2. Comparative Analysis

In this section, the alternatives are compared to evaluate their relative  performances
according to each of the evaluating criteria. The objective of the comparison is to assess
the relative advantages arid disadvantages of the alternatives and to identify the key
tradeoffs that must  be  balanced  in selecting a preferred alternative.  A  comparison
between alternatives for each criterion is discussed briefly in the following paragraphs.

Protection of Human Health and the Environment.  Every alternative except the no
action alternative provides long-term protection of human health and the environment.
Although the no action  alternative currently provides protection  against exposure risks,
the absence of access restrictions or warning signs may allow future accidental exposure
                                       5-9

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 to contaminants.  Institutional controls are protective because leaving the building in
 place and maintaining the slab will act as an extensive barrier over the contaminated soil
 without having to construct anything or disturb the soil. The institutional controls restrict
 access, require potentially exposed workers to use personal protective equipment, and
 provide administrative controls for future changes. Alternative 2 and the three treatment
 alternatives (3, 4 and 5) all are protective because all exposure pathways are addressed.
 The in-situ solidification (Alternative 5) is additionally protective because it limits health
 risks to construction workers during remediation.

 Compliance with ARARs. All alternatives, except Alternative 1 would comply with
 ARARs.  ARARs  for storage and treatment of contaminated soil are necessary  for
 Alternatives 3, 4, and 5. Alternatives 3,4, and 5 must also meet air quality requirements
 for VOC emissions and dust emissions.

 Table  5-3  lists the key ARARs with  which each alternative  must comply and how
 compliance would be achieved.  This table also indicates  whether the  ARARs are
 applicable or relevant and appropriate, and whether they are location, action, or chemical
 specific.

 Long-Term Effectiveness and Permanence.  Because the chemicals detected at OU 7
 are primarily metals, the alternatives  (except no action) all are effective at  isolating the
 metals from further transport. The excavation and soil washing alternatives (Alternatives
 3 and 4) are very effective in the long term because they remove the metals from the soil,
 dispose of them in proper disposal facilities, and do not limit future development at the
 site.  In-situ  solidification (Alternative 5) also is  effective but is  rated below the
 excavation alternatives.  This alternative stabilizes the metals to prevent further transport,
 but because the contaminants will remain on-site, it is possible that the solidification
 agent could break down with time. The institutional  controls  alternative is rated below
the treatment and excavation alternatives  because management controls must be used to
 maintain the effectiveness of the cover,  and because contaminants remain in the soil.
 However, as long as the institutional controls are in place, this  alternative is a permanent
solution.

 Reduction of Toxicity, Mobility, and Volume. Reduction of toxicity, mobility, and
 volume (TMV) refers to  reduction of TMV through treatment at the site.  The. soil
washing alternative (Alternative  4) has the highest rating as this alternative removes
COCs from soil by  on-site treatment, with a large reduction  in toxicity.  The excavation
 and off-site disposal alternative  (Alternative 3) and soil solidification (Alternative 5) rate
the next highest due to their reduction  in contaminant mobility. Alternative 2 reduces
mobility for the long term, but does not utilize  treatment.  Alternative  1  is similar to
 Alternative 2, but without the long-term  controls.

Short-Term  Effectiveness.  The no action and  institutional controls  alternatives
 (Alternatives 1 and 2) rated the highest for this criterion because, with no construction,
 there are no risks to on-site workers. In-situ treatment (Alternative 5) rates lower than no
 action and institutional controls because some COCs on dust particles would be generated
during the treatment.  Proper shrouding, ventilation, and personal protective equipment
                                       5-10

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                                                                                         TABLE 5-3

                                                                   SUMMARY OF KEY ARARs FOR EACH ALTERNATIVE
       Alternative
                              Key ARARs With Which the Alternatives Must Comply (a)      ARAR  Type
                                                                                                          Would Alternative Meet ARAR?
Alternative 1
(No Action)
Alternative 2
(Insiiiulional Controls)
Alternative 3
(Excavation and Off-Site
Disposal)
• R3II-2II UAC
  (Slate of Utah corrective action standards for CF.RCLA and UST
  sites)

• R315-8-6 UAC
  (Slate of Utah ground-water protection rule)

• R315-8-7 UAC
  (Closure and post closure standards)

• R3I5-IOI UAC
  (Slate of Utah cleanup action and risk-bated closure standards)

• R3 17-6 UAC
  (Slate of Ulah ground-water quality protection standards)

• 40 CFR Part 264. Subparl F
  (Requirements for detection and containment of releases)
• 40 CKR Part 264. Subpart G
  (Closure and post closure standards)

• R.1II-2II UAC
  (Stale of Ulah rnrrccti\e action slaml.trds for CKRCLA and UST
  sites)

• R315-8-6 UAC
  (Stale of Ulah ground waii-r protection rule)
• R.I 15 8-7 UAC
  (Closure ami post cliwurr standards)
• R315-101 UAC
  (Stale of Ulah cleanup action and risk-based closure standards)

•R.I 17-6 UAC
  (State of Utah ground-waler quality protection standards)
• 40 CFR Part 264. Subparl F
  (Requirements Tor detection and containment of releases)
• 40 CFR Part 264, Subpart G
  (Closure and post closure standards)

• R307-I-3UAR
  (Emission standards for control of installations)

•R307-I-4UAC
  (Establishes emission standards)

•R307-IOUAC
  (NESHAPs Standards)

• R3II-2IIUAC
  (Slate of Utah corrective action standards for CERCLA and UST
  sites)

•R315-8-6 UAC
  (State of Ulah ground-water protection rule)

• R315-8-7 UAC
  (Closure and post-closure standards)
• R3I5-IOI UAC
  (State of Ulah cleanup action and risk-based closure standards)

•R3I7-6UAC
  (State of Utah ground-water quality protection standards)
Ap    A, C  No - Meets this ARAR with environmental monitoring, but does not meet the ARAR due to lack of
            source control.


Ap      A   Yes - Complies with this ARAR by providing ground-waler monitoring.


 R      A   No - Does not comply with this ARAR because no provisions ore made to control and minimize
            access to hazardous constituents.

Ap    A. C  No - Partially meets ARAR with environmental monitoring, but does not meet closure
            requirements.
Ap    A. C  No - Does not meet this ARAR because it does not maintain the concrete slab or prevent leachate
            from reaching ground water.
 R      A   Yes - Complies with this ARAR by providing ground-water monitoring.

 R      A   No - This alternative does not make provisions for landfill closure regulations.


Ap    A. C  Yes - Meets this ARAR with environmental monitoring and source control (leaving and maintaining
            the concrete slab).

Ap      A   Yes - Complies with this ARAR by providing ground-water monitoring.

 R      A   Yes -Complies with relevant and appropriate portions of hybrid landfill closure regulations. The
            soil cover requirement is relevant, but not appropriate in this case.

Ap    A. C  Yes - Meets this ARAR with environmental monitoring, source control (leaving and maintaining
            the concrete slab), and post-closure requirements.

Ap    A, C  Yes - Complies with ground-water quality protection standards because it prevents leachate from
            reaching ground water by leaving and maintaining the concrete slab.
 R      A   Yes - Complies with this ARAR by providing ground-water monitoring.

 R      A   Yes-Complies with relevant and appropriate portions of hybrid landfill closure regulations. The
            soil cover requirement is relevant, but not appropriate in this cose.

Ap    A. C  Yes - Air emissions during remediation will be controlled to comply with air emissions
            requirements.

Ap    A. C  Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.
Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.

Ap    A, C  Yes - Meets this ARAR with environmental monitoring and source removal.
                                                                                            Ap     A    Yes - Complies with this ARAR by providing ground-water monitoring.

                                                                                             R      A    Yes - Complies with clean closure.

                                                                                            Ap    A, C  Yes - Meets this ARAR with environmental monitoring, source removal, and post-closure
                                                                                                         requirements.                                        '
                                                                                            Ap    A, C  Yes - Complies with ground-water quality protection standards because it removes the
                                                                                                         contaminated soil in the source area.

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                                                                                             TABLE 5-3

                                                                      SUMMARY OF KEY ARARs FOR EACH ALTERNATIVE
                                                                                           (CONTINUED)
           Alternative
    Key ARARs With Which the Alternatives Must Comply (8)      ARAR  Type
                                                                                                                                        Would Alternative Meet ARAR?
    Alternative 3 (ron't)
    (Excavation and
    Off-Site Disposal)
    Alternatjve 4
    (Excavation, On-Sile. Soil
    Washing, and Backfill)
V
• 40 CFR 50 (Primary and secondary air quality standards)


• 40CFR6I (NESHAPs standards)


• 40 CFR Part 264, Subparl F
  (Requirements Tor detection and containment of releases)

• 40 CFR Part 264, Subparl G
  (Closure and post closure standards)

•R307-I-3UAR
  (Emission standards Tor control or installation!:)

• R307-I-4UAC
  (Establishes emission standards)

•R307-IOUAC
  (NKSHAPs standards)

•R3II.-2IIUAC
  (Slate of Ulan corrective action standards for CKRCLA and UST
  sites)

• R.I 15 8-6 U AC
  (Slate of Utah ground-water protection rule)

• R.I 15 8-7 UAC
  (Slate of Utah closure and post-closure standards)
• R3I5-8-I6UAC
  (Design and operation requirements for miscellaneous units)

• R315-8-21  UAC
  (Corrective action management units and temporary units)

• R315-13 UAC
  (State of Utah land disposal restrictions)

•R3I5-IOIUAC
  (State of Utah cleanup action and risk-based closure standards)

• R317-6 UAC
  (State of Utah ground-water quality protection standards)

• R317-8 UAC
  (Stale of Utah pollutant discharge elimination systems)

• 40 CFR SO (Primary and secondary air quality standards)


• 40 CFR 61 (NESHAPs standards)


• 40 CFR Part 264 Subpart B, 264.18
  (Characteristics for location of hazardous waste management units)

•40 CFR Part 264 Subpart F
  (Requirements for detection and containment of releases)

• 40 CFR Part 264 Subpart G
  (Closure and post closure standards)

• 40 CFR Part 264 Subpart X
  (Design and operational requirements for miscellaneous units)
Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.

Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirement!!.

 R      A   Yes - Complies by monitoring ground water.


 R      A   Yes - Complies with clean closure.


Ap    A, C  Yes - Air emissions during remediation will be controlled to comply with air emissions
            requirements.

Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.

Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.

Ap    A, C  Yes - Meets this ARAR with environmental monitoring and source control.


Ap      A   Yes - Complies with this ARAR by providing ground-water monitoring.


Ap      A   Yes - Complies with clean closure.

Ap      A   Yes - Any on-sile treatment will be designed and operated in accordance with this requirement.


Ap      A   Yes - All remedial technology units will be managed in accordance with this ARAR.


Ap    A, C  Yes - All residual sludge generated during soil washing will be required to meet BOAT
            technologies and/or constituent concentrations.

Ap    A, C  Yes - Meets this ARAR with environmental monitoring, source control, and post-closure
            requirements.

Ap    A. C  Yes - Complies with ground-water quality protection standards because it controls the source area
            by reducing the toxicity of the contaminants.

Ap      A   Yes - Complies by discharging all waste fluids to the IWTP (a permitted facility).


Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.

Ap      C   Yes - Air emissions during excavation would be controlled to comply with air emissions
            requirements.

        A   Yes - Soil washing units will be sited in accordance with this ARAR.
                                                                                                Ap


                                                                                                Ap

                                                                                                Ap

                                                                                                Ap
        A    Yes - Complies by monitoring ground water.

        A    Yes - Complies with clean closure.

        A    Yes - Any on-site treatment will be designed and operated in accordance with this requirement.

-------
                                                                                        TABLE 5-3

                                                                  SUMMARY OF KKY ARARs FOR EACH ALTERNATIVE
                                                                                      (CONTINUED)
       Alternative
    Key ARARs With Which the Alternatives Must Comply (a)
                                                                                         ARAR  Type
                                  Would Alternative Meet ARAR?
Alternative 4 (con'l)
(Excavation. On-Sile. Soil
Washing, and Backfill)
Alternative 5
(In-Silu Solidification)
• 40 CrU Part 268                                                 Ap
  (Land disposal restrictions)

• 40 CFR Part 40.1                                                 Ap
  (Standards to control discharge through POTWs)

• R307-I-3UAR                                                  Ap
  (Emission standards Tor control of installations)

•R307-I-4UAC                                                  Ap
  (Establishes emission standards)

•R307-IOUAC                                                   Ap
  (NESHAPs standards)

•R3II-2IIUAC                                                  Ap
  (Stale nf Utah corrective action standards for CKRCLA and UST
  sites)

• R.I 15-8-6 UAC                                                  Ap
  (Slate of Utah pround-wairr protection rule)
•R.I 15 8-7 LI AC                                                  R
  (Closure and post closure standards)
• R.I 15-101 UAC                                                  Ap
  (Stale of Iliah cleanup action and risk-hased closure standards)

• R.I 17-6 U AC                                                    Ap
  (Slate of Utah ground water quality protection standards)

• 40 O-'R SO (Primary and secondary air quality standards)               Ap

• 40 CFR 61 (NESHAPs standards)                                  Ap

• 40 CFR Part 264 Suhpart F                                        R
  (Requirements Tor detection and containment of releases)

• 40 CFR Part 264 Subpart G                                        R
  (Closure and post closure standards)

• 40 CFR Part 264 Subpart X                                        Ap
  (Design and operational requirements for miscellaneous units)
A. C  Yes - All residual sludge generated during soil washing will be managed according to this
      requirement.

 A    Yes - Discharge from soil washing alternative will comply with this ARAR.


A. C  Yes - Air emissions during remediation will be controlled to comply with air emissions
      requirements.

A, C  Yes - Complies with this ARAR by collecting all emissions and discharging them through a vapor
      phase activated carbon canister.
 C    Yes - Air emissions during solidification would be controlled to comply with air emissions
      requirements.
A. C  Yes - Meets this ARAR with environmental monitoring and source control (immobilization of
      contaminants).


 A    Yes - Complies with this ARAR by providing ground-water monitoring.

 A    Yes - Complies wilh landfill closure.

A. C  Yes - Meets this ARAR wilh environmental monitoring, source control (immobilization of
      contaminants), and post-closure requirements.

A, C  Yes - Complies wilh ground-water quality protection standards because it controls the source area
      by immobilizing the contaminants using solidification.
 C    Yes - Air emissions during solidification would be controlled to comply with air emissions
      requirements.
 C    Yes - Air emissions during solidification would be controlled to comply with air emissions
      requirements.

 A    Yes - Complies with this ARAR by providing for ground-water monitoring.


 A    Yes - Complies wilh landfill closure.

 A    Yes - Any on-site treatment will be designed and operated in accordance with this requirement.
ARAR     Applicable or relevant and appropriate requirement                         BDAT
RCRA     Resource Conservation and Recovery Act                                 UAC
Ap        Applicable                                                           R
CERCLA   Comprehensive Environmental Response, Compensation, and Liability Act     UST

(a) A more complete list of the ARARs pertaining to OU 7 appears in Appendix A.
                                                              Best demonstrated available technology        A
                                                              Utah Administrative Code                   C
                                                              Relevant and Appropriate                    L
                                                              Underground Storage Tank                   POTW
                                              Action-Specific ARAR
                                              Chemical-Specific ARAR
                                              Location-Specific ARAR
                                              Publicly-Owned Treatment Works

-------
 for on-site workers could effectively mitigate any adverse impacts.  Excavation/soil
 washing and disposal (Alternative 4) and excavation and off-site disposal (Alternative 3)
 rate lower than in-situ treatment because excavation of the area of attainment could
 generate greater amounts of dust.  Potential health effects from contaminated dust on
 workers could be mitigated by restricting excavation on windy days, covering excavated
 soils, and requiring dust-protective personal protective equipment.

 Implementability.  All the  remedial alternatives are  considered implementable.  No
 action  (Alternative 1) and institutional controls (Alternative 2) are most easily
 implemented technically and administratively.

 In-situ treatment (Alternative 5) rates lower because, although it is technically feasible,
 there would be administrative difficulties. Implementation of this  alternative would
 require demolition of much of the eastern portion of Building 225 to allow access to the
 area of attainment.  Because Hill AFB and the U.S. Air Force rely on the maintenance
 operation in Building  225, implementation of this remedy would  disrupt Air Force
 operations.

 Excavation and off-site  disposal and  excavation, soil  washing,  and disposal
 (Alternatives 3 and 4) rate below in-situ treatment. These alternatives, while technically
 feasible, would have the same impacts on Air Force operations as in-situ treatment. In
 addition, because contaminants would be transported off-site, land disposal restrictions
 (LDRs) may require treatment of wastes prior to disposal.

 Costs.  The no action  followed by institutional controls alternatives have the  lowest
 overall costs ($460,000 and $627,000 respectively). In-situ solidification has the next
 lowest cost ($2,247,000), followed by excavation/soil washing/disposal ($5,221,000).
The excavation and off-site disposal alternative has the highest cost ($7,332,000).

State and Community  Acceptance. The State  of  Utah agrees with the  preferred
 alternative.  Although a member of the community raised minor concerns at the public
meeting, these concerns were addressed and  resulted in  no change to the  preferred
alternative (see Part One of the Responsiveness Summary). On this basis, the preferred
alternative is  acceptable to the  State and community and is  thereby selected for
implementation at OU 7.
                                      5-14

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                            6.0 SELECTED REMEDY

 6.1 DESCRIPTION OF THE SELECTED REMEDY

 The selected remedy at Hill AFB Operable Unit 7 is Alternative 2-Institutional Controls.
 Alternative 2 consists of limiting access to the area of attainment beneath Building 225
 by having the Base Commander issue a continuing order, posting warning  signs, and
 providing for restrictions on future land use  in the deed for Hill AFB.  Also, because
 contaminants above  risk-based levels will remain on  site, long-term environmental
 monitoring and five-year site review are required.

 Continuing Order.  The continuing order  will restrict access to or disturbance  of
 contaminated soils as long as Hill AFB owns the property. Specifically it will:

       •   Restrict the installation of any new underground utilities or other construction
           activities  beneath the floor  in the area  of attainment,  thus preventing
           accidental exposures to the construction worker.

       •   Provide  for the use of proper protective equipment if,  for any reason, the
           concrete floor slab in the former Metal Plating Shop Area is to be removed.

       •   Require that the integrity of the concrete floor slab be maintained (i.e., repair
           cracks that may develop) so that  fluids  cannot infiltrate to the subsurface.
           Maintenance of the floor slab will require development of SOPs to provide for
           inspections, floor repairs, and responses to spills in critical areas.

 Warning Signs.  Warning signs would be posted around the area of attainment stating
 that hazardous  chemicals  are present beneath the floor slab, and that  no excavation is
 permitted without proper authorization.

 Deed Restrictions.  A notice to the deed would be filed by the Air Force in the real
 property records of Davis County incorporating the  restrictions in the continuing order.
 In the case of the sale or transfer of property within OU 7 by the United States to any
 other person or entity, the Air Force will place covenants in the deed that will restrict
 access and prohibit disturbance of contaminated soils or the remedial action without
 approval of the United States. These covenants will  be in effect until removed upon
agreement of the State of Utah, the U.S. Environmental Protection Agency,  and the U.S.
 Air Force or their successors in interests. The  Air Force also will include in the deed the
 covenants required by section 120(h)(3) of the Comprehensive Environmental  Response,
 Compensation and Liability Act (CERCLA). which include (1) a warranty that the United
 States will conduct any remedial action found to  be necessary after the date of the
 transfer; (2) a right of access in behalf of the U.S. Environmental Protection Agency and
 the Air Force or their  successors in interest to  the property to participate in any response
 or corrective action that might be required after the date of transfer. The right of access
 referenced in the preceding sentence shall include the  State of Utah for purposes  of
 conducting or participating in any response iOr corrective action that might be required
 after the date of transfer.
                                       6-1

-------
Long-term environmental monitoring will include ground-water sampling and  soil
moisture measurements so that the potential for contaminant transport can be monitored.
Building  225 and the surrounding pavement currently act as a barrier  over the
contaminated soil, limiting infiltration and preventing exposure to the soils. If the current
land use changes or structures over the area of attainment are removed, the Air Force will
conduct an immediate site review and re-evaluate the protectiveness  of the remedy
selected for OU 7. Also, the Air Force will take any appropriate remedial action.

Figure  6-1 shows  a conceptual schedule for the order of implementation of the
components of the selected remedy. The actual schedule will be negotiated according to
the terms of the Federal Facility Agreement (FFA) for Hill AFB. The first activities will
include issuance of the continuing order and installation of the ground-water and soil
moisture monitoring network.  The continuing order will limit access to contaminated soil
and the ground-water and soil  moisture monitoring network will monitor the potential for
contaminant movement in the saturated and unsaturated zones beneath the former Metal
Plating Shop Area. Ground-water and soil moisture monitoring are scheduled on a semi-
annual basis and will continue as long as the remedy is in place.  Following the initial
activities, Hill AFB will file a notice  to the  deed for  its on-Base property  and post
warning signs in the former Metal Plating Shop area.

6.1.1. Remediation Goals and Performance Standards

The goals of this remedial action are described in the following section. The performance
of this  alternative with respect to meeting the remediation goals will be monitored
according to the Performance Monitoring Plan to be developed during implementation of
the institutional controls.

As stated in Section 5.1, the remedial action objectives (goals) for OU 7 are to:

       •  Reduce contaminant  transport  within  source  areas and reduce chemical
          transport from soil to ground water by minimizing surface water infiltration.

       •  Prevent human exposure to contaminated soil through ingestion, inhalation,
          and dermal contact, such that the additional risk to an individual for cancer is
          below 1 x 10~6 and the non-cancer threshold is less than 1.0.

       •  Reduce contaminant concentrations  to meet risk levels and/or reduce
          contaminant transport to rates that will not impact ground-water quality above
          Maximum Contaminant Levels.

Chemical-specific cleanup goals were developed for alternatives that involve treatment
and/or excavation. These goals were  based on  chemical partitioning models to prevent
ground-water contamination  above maximum contaminant levels or correspond to a
1 x 10'6 (one in a million) additional cancer risk. Although the selected remedy will not
meet these chemical-specific  goals, implementation of institutional controls will meet
each of the remediation goals. Maintaining the floor above the areas of attainment  will
                                       6-2

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         HB  Construction or Initiation phase

         UillUUUl  Implementation phase
 NOTES: "Time zero' Is defined as the beginning of substantial, continuous physical Improvement.
       which will begin IS months after this ROD Is signed.

       Schedule Is schematic and does not Include remedial design. Actual schedule will be
       negotiated under the Federal Facility agreement for Hill AFB.
  Hill AFB OU 7 ROD
         HILL AIR FORCE BASE
           OPERABLE UNIT 7
CONCEPTUAL REMEDIAL ACTION
  IMPLEMENTATION SCHEDULE
              FIGURE 6-1

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 reduce contaminant transport within the area of attainment and movement from soil to
 ground water by eliminating surface water infiltration.  Keeping the floor intact and
 restricting excavations will prevent human exposures to contaminated soil,  both for
 current exposure scenarios (through signs and a continuing order) and for future scenarios
 (through restrictions to the deed for Hill AFB).  Finally, by reducing the contaminant
 transport rates, ground-water quality will not be impacted above Maximum Contaminant
 Levels.

 To evaluate whether water that could initiate chemical transport is moving into the area
 of attainment, or whether contaminants have moved into the ground water, a performance
 and compliance sampling program (PCSP) will be implemented during the remedial
 action to monitor performance and compliance with remediation goals. This program
 will be developed during  the implementation of the selected remedy and will  include
 locations of soil moisture and ground-water monitoring points, monitoring frequency,
 analytical parameters for ground-water  samples, sampling and analytical methods, and
 statistical  methods  for evaluating data.   The  PCSP will be designed  to  provide
 information to evaluate the effectiveness of the remedial action with respect to levels of
 contamination in ground water and the potential for contaminant transport, and provide
 for site evaluations. The PCSP may be  modified during the remedial action to take into
 consideration changing site conditions.

 6.1.2.  Restoration Time Frame

 Institutional controls for long-term management will be in  place within approximately
 one year of commencement of the remedial action. The restoration time frame for the
 preferred alternative will extend indefinitely. For as long as the floor remains intact over
 the areas of attainment, unacceptable exposure and chemical transport are controlled.
 However, because there is no reduction in  toxicity, mobility, or volume, restoration  is
 not expected in  any foreseeable time frame.  This alternative cannot rely on natural
 attenuation as means to remediate this site because  the contaminants (cadmium and
 hexavalent chromium) that .are in the soil  beneath the former Metal  Plating Shop are
persistent and are not expected to attenuate to any great extent.

6.1.3.  Costs

The estimated costs for remediating OU  7 using the selected remedy are as follows. The
total capital cost of the project is estimated  at $285,000. The total capital cost includes:
installation of the ground-water and soil moisture monitoring network, administrative and
legal cost of initiating the institutional controls, filing a notice to the deed for Hill AFB,
and posting warning signs in the contaminated areas of Building 225.  The indirect capital
cost for the project is estimated at  S34.300.  Indirect capital costs are included in the
estimated total capital costs above, and  include engineering, contingency, and  contract
administration.

Operation and maintenance (O&M) costs change over the duration of the remedial action.
Operation and maintenance costs are calculated for a  30-year period and do not reflect
costs that may be incurred if the remediation period lasts longer than 30 years.   Annual
O&M  is estimated at $165,000 for years 1  through 5, $102,000 for years 6 through  10,
and $281,000 for years 11  through 29. An additional $25,000 will be required for O&M
                                      6-3

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every fifth year for the five-year site reviews, and $3,000 will be required every tenth
year for well rehabilitation. O&M costs include monitoring program costs  as well as
maintenance of equipment and the concrete floor.  The total present worth cost of the
selected remedy over a 30-year period, using an interest rate of ten percent, was estimated
at $729,000. The costs discussed here are estimated with +50/-30 percent accuracy for a
30-year period.  During the implementation process for the selected alternative, some
changes could occur as a result of the remedial design process.  These changes reflect
modifications resulting from the engineering design process and could result in changes
to the estimated costs for this alternative.

6.2 STATUTORY DETERMINATIONS

The selected remedy for Hill AFB OU 7 meets the statutory requirements of Section 121
of CERCLA as amended by SARA. These statutory requirements include protection of
human  health  and the environment, compliance  with ARARs,  cost effectiveness,
utilization of permanent solutions and alternative treatment technologies to the maximum
extent practicable, and preference for treatment as a principal element.  The  manner in
which the selected remedy for OU 7 meets each of the requirements is presented in the
following discussion.

6.2.1. Protection of Human Health and the Environment

The selected remedy for OU 7 protects human health and the environment by  restricting
direct contact with contaminants through issuing a continuing order, posting warning
signs, and filing a notice to the deed to Hill AFB.  The continuing order from the Base
Commander will include maintaining the concrete slab, restricting concrete cutting, and
limiting excavations unless proper  protective equipment is used. Upon transfer of the
property, the Air  Force would provide a deed covenant notifying the transferee of the
locations and the restrictions on use of the contaminated areas.  As part of this alternative,
a provision will be made to re-evaluate the effectiveness of this alternative every five
years and again  at the time the building and slab are removed.

6.2.2. Compliance with Applicable or Relevant and Appropriate Requirements

Section  121(d)(l)  of CERCLA, as amended by SARA, requires that the remedial actions
at OU 7 must attain a degree of cleanup that assures protection of human health and the
environment.   In addition, remedial  actions that leave any hazardous  substances,
pollutants, or contaminants on the site must, upon completion, meet a level or standard
that at least attains legally applicable or relevant and appropriate standards, requirements,
limitations, or  criteria that are applicable or relevant and appropriate requirements
(ARARs) under the circumstances of the release.  ARARs include Federal  standards,
requirements, criteria, and limitations and any promulgated standards, requirements,
criteria,  or limitations under the State of Utah environmental or facility siting regulations
that are  more stringent than Federal  standards. In addition, State of Utah ARARs include
all  promulgated standards and  rules associated with delegated State  environmental
programs.
                                      6-4

-------
 "Applicable" requirements are those cleanup standards, standards of control, and other
 substantive environmental protection requirements, criteria, or limitations promulgated
 under Federal or State law that specifically address the hazardous substances, pollutants,
 or contaminants, remedial  actions, locations, or other circumstances at the OU 7 site.
 "Relevant and appropriate" requirements are cleanup standards, standards of control, and
 other substantive environmental protection requirements, criteria,  or limitations
 promulgated under Federal or State law that, while not "applicable" to the hazardous
 substance, pollutant or contaminant, remedial actions, locations, or other circumstances at
 a remedial action site, address problems  or situations sufficiently similar to those
 encountered at the site that their use is well suited to the particular site.

 In evaluating which requirements are applicable or relevant and appropriate, the criteria
 differ depending on whether the type of requirement is chemical-specific, location-
 specific, or action-specific.  According to the NCP, chemical-specific ARARs usually are
 health  or  risk-based numerical values  that  establish the acceptable  amount  or
 concentration of a chemical that  may  remain in, or be discharged to,  the ambient
 environment.   Location-specific ARARs  generally  are restrictions  placed upon the
 hazardous substances or activities solely because they are in special  locations.  Some
 examples of special locations include floodplains, wetlands, historic places, and sensitive
 ecosystems or habitats. Action-specific ARARs usually are technology or activity-based
 requirements or limitations on  actions taken  with  respect to hazardous wastes, or
 requirements to conduct certain actions to address particular circumstances at the site.

 Utah Groundwater Quality Protection Standards and the Federal Safe Drinking Water Act
 Maximum  Contaminant Levels (MCLs)  were used as a  basis for calculating soil
 contaminant levels that are protective of ground  water beneath the OU 7 area. Ground-
 water protection standards and MCLs also  will be used  to  evaluate ground-water
 monitoring results.  Chemical-specific  relevant and appropriate  standards for OU 7
 include portions of the Solid Waste Disposal Act and the Utah Solid and Hazardous
 Waste Act. Federal and State chemical-specific ARARs are presented in Appendix A,
 Tables A-l  and A-2, respectively.

 Federal and State location-specific ARARs are  not applicable or  relevant to.the OU 7
 selected remedy.

 Action-specific ARARs that pertain to  the selected remedy at OU 7 include: the State of
 Utah  standards for drilling and abandoning wells, Corrective Action Cleanup Policy for
 UST  and CERCLA  Sites, Cleanup and  Risk-Based  Closure  Standards,  and air
conservation  regulations.  Federal and State action-specific ARARs are  identified in
Appendix A, Tables A-3 and A-4, respectively.

Table 6-1 summarizes the ARARs for the selected  remedy for OU 7.   The  remedy
 selected for OU 7 will meet ARARs.  However, because contaminants are left  in place
 the remedial action time frame likely will exceed 30 years.  As long as the institutional
 controls are in place, this selected remedy will be a permanent  solution that  will be
 protective of human health and the environment.
                                       6-5

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                                                         TABLE 6-1

                                    SUMMARY OF ARARs FOR THE SELECTED REMEDY
                       Alternative
         ARARs With Which the Selected Remedy Must Comply
        Alternative 2 (Institutional Controls)
ON
• R311-211 UAC
  (State of Utah corrective action standards for CERCLA and UST sites)

• R315-8-6 UAC
  (State of Utah ground water protection rule)

• R315-8-7 UAC
  (Closure and post closure standards)

• R315-IOI UAC
  (State of Utah corrective action standards for RCRA sites)
• R317-6 UAC
  (State of Utah ground-water quality protection standards)
• R655-4 UAC
  (Standards for drilling and abandonment of wells)
• 40 CFR Part 264, Subpart F
  (Requirements for detection and containment of releases)

• 40 CFR Part 264, Subpart G
  (Closure and post closure standards)
        ARAR     Applicable or relevant and appropriate requirement
        CERCLA   Comprehensive Environmental Response, Compensation, and Liability Act
        RCRA     Resource Conservation and Recovery Act
        UAC       Utah Administrative Code
        UST       Underground Storage Tank

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A decision to invoke any changes to this selected remedy may be made during a periodic
review of the remedial action, which will occur at least every five years in accordance
with CERCLA Section 121(c).

6.23. Cost Effectiveness

Overall cost effectiveness can be defined as the reduction of the threat to human health
and the environment per dollar expended on a remedy.  The selected remedy for OU 7
was chosen to provide the necessary protection to human health and the environment.
When two alternatives had an equal measure of protection, the alternative with the lower
cost was selected.   An example of this is solidification of contaminants  versus
institutional controls.  Both of these remedies would provide protection by limiting access
to contaminated soils and potential  for contaminant transport to ground water.  However,
the solidification alternative would cost approximately three times more than the selected
remedy not including the cost of tearing down the building to gain access  to the
contaminated soils and relocating the current work missions in Building 225.  When this
is taken into consideration the cost of Alternative 5  would possibly be more than 20 times
that of the selected remedy.

6.2.4. Utilization of Permanent Solutions

The selected remedy  provides the  best balance of tradeoffs among all the alternatives
with respect to the five summary balancing criteria which include:

       •   Long-term effectiveness  and permanence
       •   Reduction of toxicity, mobility, or volume through treatment
       •.   Short-term effectiveness
       •   Implementability
       •   Cost.

The criterion that was critical in the selection decision was implementability.  While all
the alternatives are technically feasible  and the needed goods and services are available,
removing part of Building 225 to implement the treatment and/or excavation alternatives
would have a large impact on the Air Force's operations at Hill AFB.  Only no action or
the selected alternative could be implemented without demolishing a portion of Building
225.  The modifying criteria, which are State and community acceptance have had no
effect on selection of the remedy since the State agrees with the  alternative selected, and
the community concerns  related to the  proposed alternative have been addressed. The
selected remedy meets the statutory requirement  to utilize permanent solutions to the
maximum extent practicable.
                                       6-7

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6.2.5. Preference for Permanent Solutions and Treatment Technologies or Resource
      Recovery Technologies to the Maximum Extent Practicable

The selected remedy for OU 7 utilizes permanent solutions and treatment technologies to
the maximum extent practicable. The institutional controls alternative was  the most
practicable alternative for OU 7. The selected remedy is expected to permanently contain
and isolate the contaminants.  The potential future risks are exposure to contaminated soil
for construction workers and future residents.  Because of the current industrial use of
this part of the Base it is highly unlikely that this area will be  used for residential
neighborhoods. To ensure the effectiveness of the selected treatment remedy, Hill AFB
will conduct  a review within five years after initiating the selected remedy and the
remedy will be reevaluated if there is a change in land use for Building 225.

6.3 DOCUMENTATION OF SIGNIFICANT CHANGES

The Proposed Plan for Hill AFB OU 7 was released for public comment in February
1995. The Proposed Plan identified Alternative 2-Institutional Controls as the preferred
alternative. This remedy includes: issuing a continuing order by the Base Commander,
filing a notice to the deed for Hill AFB, posting warning signs, and ground-water and soil
moisture monitoring.  All written and verbal comments received during the public
comment period were reviewed, and it was determined that no significant changes were
necessary  to the remedy identified in the Proposed Plan. A copy of the proceedings of
the Proposed Plan public meeting as well as  the comments received  are included as
Appendices B and C, respectively.
                                      6-8

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Hill Air Force Base, Utah
Operable Unit 7
Responsiveness Summary

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Overview

This responsiveness summary provides information about the views of the community
with regard to the proposed remedial action for Hill Air Force Base (AFB) Operable
Unit 7 (OU 7), documents how public comments have been considered  during the
decisionmaking process, and provides responses to concerns.

The public was informed of the preferred alternative in the following ways:

       •   All items contained within the Administrative Record have been on file at the
          subject repositories since the final version of each document was issued

       •   A copy of the Proposed Plan was sent to all affected and interested parties
          prior to the public comment period

       •   A public comment period was  held from  February 20, 1995, through
          March 21, 1995

       •   A public meeting was held on March  1,  1995, at the Base Theater,
          Building 441, Hill AFB, Utah

       •   Written comments by the public were encouraged.

The public meeting was poorly attended and residents voiced few concerns about the
nature  and extent of contamination. A transcript of the public meeting is attached as
Appendix B.  No comments were made that affect the proposed remedial action for OU 7.
No written comments were received during the public comment period.

Background on Community Involvement

The public participation requirements of CERCLA Sections 113(k)(2)(B)(i-v) and 117
were met. Hill AFB has a Community Relations Plan that was finalized in January 1993.
The community  relations  activities include: (1)  a Remedial Advisory Board (RAB),
which  meets at least quarterly and includes community  representatives from adjacent
counties and towns, (2) a mailing list for interested parties in the community, (3) a bi-
monthly  newsletter called "EnviroNews,"  (4)  visits to nearby schools  to discuss
environmental issues, (5) community involvement in a noise abatement program, (6)
semi-annual town council meetings, (7) opportunities for public comment on remedial
actions, and (8)  support  for the  community in obtaining technical  assistance grants
(TAGs).

The Remedial Investigation/Feasibility Study (RI/FS) Report for OU 7 (Montgomery
Watson, 1995), and the Proposed Plan for Operable Unit 7 (Montgomery Watson, 1995a)
were released to the public, and are available in  the Administrative  Record maintained at
the Davis County Library and at the Environmental Management Directorate at Hill AFB.
The notices of availability for these documents were published in the Salt Lake Tribune.
A public comment period was held from February 20,  1995 through March 21, 1995. In
                                      -1-

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 addition, a public meeting was held on March 1, 1995. At this meeting, representatives
 from Hill AFB, EPA, and the State of Utah answered questions about the site and the
 selected remedy. A court reporter prepared a transcript of the meeting.  Copies of the
 transcript and all written public comments received during the comment period have been
 placed in the Administrative Record. In addition, copies of the transcript were sent to all
 meeting attendees who requested them.  Responses to the comments received during the
 public comment period are included in this Responsiveness Summary, which is pan of
 the ROD. The decision process for this site is based on the Administrative Record.

 Summary of Public Comments and Agency Responses

 Part I - Summary and Response to Local Community Concerns. The community
 comments and concerns are discussed in the following section.

 Expected Lifetime of Building 225. A member of the community  was interested in
 knowing how long the Air Force was planning to keep Building 225 as an operating
 facility because this is a measure of how long the institutional controls would be in effect.
 In response to this comment, an Air Force  representative stated that there  is every
 indication that the building will stay in operation for the foreseeable future.  Any exact
 time frame of how long the building will be in operation is impossible to estimate.

 Ground-Water and Soil Moisture Monitoring System.  Several questions  were
 directed towards the ground-water and soil moisture monitoring system by a member of
 the community. These questions included;

       (1)   How many monitoring points are currently in the ground?

       (2)   Are the monitoring wells sufficient to indicate the potential for contaminant
            migration?

       (3)   Are you looking at one monitoring point?

       (4)   Is there going to be monitoring around the edge of the slab?

       (5)   Is soil moisture monitoring adequate to show there is no further migration?

In response to the first question, the citizen was told that there is currently one monitoring
well located within  the area of contamination and one upgradient well.  Hill AFB will
need to install an additional well or two downgradient of the contaminated area.  At this
time there are no available borings for the soil moisture monitoring systems. These
borings will need to be installed.

In response  to question 2, it was indicated that using just the monitoring wells alone
could make contaminant migration difficult to detect.  The response to question 3 was
also a continuation of the response to question 2.  In this response it was stated that
upgradient and downgradient wells are used. There are also other monitoring wells in the
area that receive standard monitoring.  If contaminant concentrations increase in the
                                      -2-

-------
 ground water it would be an indication that contamination from the soil is entering the
 ground water.  However, without soil moisture monitoring it would not  be certain
 whether the contamination was coming from the former Metal Plating Shop source or if
 there was another source that  had not yet been identified. The soil moisture data will
 provide a second piece of information that will determine if there has been contaminant
 transport or not.  For example, if there was a significant increase in soil moisture six or
 seven months before the contaminant concentrations in ground water are  seen to increase,
 it would be likely that contaminant transport from the former Metal Plating Shop was
 occurring.  However, if there was a rise in ground-water contaminant concentrations and *
 there is no change to the dry conditions within the plating shop area, then it would be
 likely that the contaminants are coming from another source.

 In response to the last question,  the community member was told that while the soil is
 dry, there is no potential for contaminant  transport. However, if soil moisture increases
 and the potential for contaminant transport increases, the selected remedy would  be
 revisited.  In addition, the Air Force feels that with the ground-water and soil moisture
 monitoring programs, they will have a good feel for contaminant transport potential.

 Monitoring for  Chromium. A community member asked if there was going to be
 chromium monitoring as part  of the selected remedy.  In response, he was told that a
 significant number of samples were analyzed for chromium during the investigation, and
 that the results were sufficient  to make decisions regarding remedial action.  Additional
 characterization would  be done in the future, when and if  the building is removed.
 However, soil moisture will be  monitored, and if it increases to a level where transport of
 chromium may take place, then the remedial action will be re-evaluated and appropriate
 action taken. This action would include collection of additional soil samples.

 Costs of Treatment Alternatives.  In a comment to the public, a statement was made by
 a representative of the Utah  Department of Environmental Quality to the effect that the
 costs of Alternatives 3 through  5 do not include removal of the  building for those types of
 remediation. The cost would significantly increase for those alternatives if the  existing
 building was to be removed and a new facility built to take care  of the existing Building
 225 operations.

 Part II - Comprehensive Response to Specific Legal and Technical Questions
 No specific legal and technical  questions were raised by the community.

 Remaining Concerns

There are no remaining public concerns that were not addressed directly during the RI/FS
process.
                                       -3-

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Hill Air Force Base, Utah
Operable Unit 7

References

-------
                                REFERENCES
Alloway, 1990.  Heavy Metals in Soils. Halsted Press, N.Y., John Wiley and Sons, Inc.

Hem, 1985.  Study and Interpretation of Chemical Characteristics of Natural Water, Third
       Edition.  U.S. Geological Survey Water Supply Paper 2254,263 p.

Hill AFB, 1987. Paint Chip Settling Tanks at Building 220. Hill AFB, Utah. May 1987.

Hill AFB, 1989. PCB Spill Sampling and Cleanup in Building 225, Hill AFB, Utah.  Hill
       AFB, Environmental Management Directorate Restoration Division, November
       .1989.

Howard, 1990. Handbook of Environmental Fate and Transport Data, Volumes I through
       ffl. Lewis Publishers, Chelsea, Michigan.

JMM,  1991. Final Site Characterization Report for a Portion of Building 225 and Site
       Investigation of Fill Soils at Base Supply Well 6, Hill AFB, Utah.  Prepared for Hill
       AFB/EMR, December, 1991.

JMM,  1993. Remedial Investigation/Feasibility Study Work Plans for Operable Unit 7
       (Including: Sampling and Analysis Plan; Health and Safety Plan; and Work Plan).
       Prepared for U.S. Air Force Logistics Command, January 1995.

Montgomery Watson, 1995. Final RI/FS for OU 7.  Prepared for U.S. Air Force Logistics
       Command, February, 1995.

Montgomery Watson, 1995a. Final Proposed Plan for OU 7.  Prepared for U.S. Air Force
       Logistics Command, March 1995.

National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part
       300.

Owen,  1994. Personal Communication with John Owen, Hill AFB Employee, to Mark
       Loucks (Montgomery Watson). September 1994.

Radian, 1984.  Final Treatment System  or Toxic Organics Removal  from  Aircraft
       Paint/Strip Facility Wastewaters; Prepared for Hill AFB, Utah. June 1984.

Radian, 1988. Installation Restoration Program Phase II - Confirmation/Quantification
       Stage I Building 220, Paint Hangar; Prepared for Hill AFB, Utah. May 1988. .

USAF, 1989. Hill Air Force Comprehensive Plan.

USGS, 1992. Final RI Report of Operable Unit 4. Prepared for U.S. Air Force Logistics
       Command. September 1992.
                                      R-l

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FEDERAL AND STATE ARARs
      Appendix A

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                                 APPENDIX A

                ARARs PERTAINING TO ACTIVITIES AT OU 7
 A.0.0.1.  This appendix presents the ARARs applicable or relevant and appropriate to the
 five alternatives evaluated in the OU 7 Feasibility Study. The ARARs are organized into.
 tables that identify them as Federal or State requirements and according to whether they
 are chemical- or location-specific. The tables report the Standard, Requirement, Criterion
•or Limitation applicable to the chosen remedy for OU 7, the citation, a description, and a
 discussion  of whether the ARAR is applicable and/or relevant and appropriate, and
 comments on how the ARAR may be  applied.

 A.0.0.2.  Tables A-1 and A-2 identify Federal and State chemical-specific ARARs for the
 chosen remedy for OU 7 and Tables A-3 and A-4 identify Federal and State action-
 specific ARARs for  OU 7.  There are no location-specific ARARs that pertain to the
 alternatives evaluated for OU 7.
                                     A-l

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                                                        TABLE A-l

                                IDENTIFICATION OF FEDERAL CHEMICAL-SPECIFIC ARARs
Standard, Requirement,
Criteria, or Limitation
Citation
Description
Applicable/
Relevant
and
Appropriate
Comment
Solid Waste Disposal Act -42 USC งง690 1-6987 ; -
Criteria for the Identification
and Listing of Hazardous
Waste
Requirements for Releases
from Solid Waste
Management Units
Land Disposal Restrictions
40 CFR Part 261
40 CFR Part 264,
Suhpart F
40 CFR Part 268
Establishes solid wastes that are
subject to regulation as hazardous
waste under 40 CFR Parts 124, 262-
265, 268, and 270.
Establishes maximum
concentrations for hazardous
constituents in the groundwater.
Establishes maximum
concentrations for hazardous
constituents prior to land disposal.
Yes/~
No/Yes
Yes/~
Wastes generated during the remediation
phase which are determined to contain RCRA
hazardous constituents, will be subject to
these requirements.
The groundwater cleanup standards may be
based on these maximum concentrations if
they are more stringent than MCLs or non-
zero MCLGs, or if no standards exist.
Hazardous wastes generated during the
remediation phase will be subject to land
disposal restrictions and may be required to
meet BOAT technologies and/or constituent
concentrations.
Clean Air Act - 42 USC งง 7401-7642
NESHAPs Standards
National Primary and
Secondary Ambient Air
Quality Standards
40 CFR Part 61
40 CFR Part 50
Establishes air emission standards
for hazardous pollutants.
Establishes standards for ambient
air quality to protect public health
and welfare (including standards for
paniculate matter and lead).
Yes/ป
Yes/ป
Applicable to alternatives that will generate
hazardous emissions, and must meet these
requirements.
Applicable to activities that result in air
emissions during remedial activity.
Modified from Montgomery Watson 1993
AQS   National Ambient Air Quality Standards      UST
PSD   Prevention of significant deterioration        CERCLA
RCRA  Resource Conservation and Recovery Act     NESHAPs
POTW Publicly Owned Treatment Works
Underground storage tanks
Comprehensive Environmental Response, Compensation, and Liability Act
National Emission Standards for Hazardous Air Pollutants  i

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                  TABLE A-2



IDENTIFICATION OF STATE CHEMICAL-SPECIFIC ARARs
Standard, Requirement,
Criteria, or Limitation
Citation
Description
Applicable/
Relevant
and
Appropriate
Comment
Utah Solid and Hazardous Waste Act - Title 19 UCA Chapter 6*
Corrective Action Cleanup
Standards - CERCLA, UST
Sites
Land Disposal Restrictions
(LDRs)
Criteria for the Identification
and Listing of Hazardous
Waste
Cleanup Action and Risk-
Based Closure
Groundwater Quality
Protection Standards
R3II-2II
UAC
R3I5-I3
UAC
R3 15-2-1
UAC
R3I5-IOI
UAC
R3I7-6
UAC
Corrective action cleanup standards policy for
CERCLA and UST sites.
Outlines land disposal restrictions for hazardous
waste. Utah incorporates federal LDRs by
reference.
Establishes solid wastes that are regulated as
hazardous wastes under the Utah Solid and
Hazardous Waste Act. Definition of hazardous
waste mirrors federal definition.
Corrective action clean-up standards policy.
Details, standards, classes, protection levels, and
implementation criteria for groundwater
protection. Also, outlines certain activities
permitted by rule.
Yes/ป
YesA-
Yes/~
YesA-
YesA-
Lists general criteria to be considered in
establishing cleanup standards at CERCLA and
UST sites. Refer to Site Drinking Water Act
and Clean Air Act. Requires removal or control
of the source.
Hazardous wastes generated during remediation
will be subject to land disposal restrictions and
may be required to meet BOAT technologies
and/or constituent concentrations.
If wastes generated during the remediation phase
are determined to contain hazardous constituents,
they will be subject to these requirements.
Lists general criteria to be considered in
establishing clean-up standards. Refer to Safe
Drinking Water Act and Clean Air Act.
Requires removal or control of the source.
Groundwater quality protection standards will be
applicable for all remediation alternatives.
Utah Air Conservation Act - Title 26 UCA Chapter 1 3
State Emission Standards Tor
Control of Installations .
R307-1-3
UAC
Specifies standards for six pollutants PM|0' SO2,
CO, ozone, NO2, and lead. State adoption of
federal-AQS and BACT.
YesA-
Emissions from the remediation process will be
subject to the standards for the six pollutants.

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                                                                    TABLE A-2

                                            IDENTIFICATION OF STATE CHEMICAL-SPECIFIC ARARs
                                                                  (CONTINUED)
 Standard, Requirement,
  Criteria, or Limitation
Citation
               Description
Applicable/
  Relevant
    and
Appropriate
                Comment
Emission Standards
R307-I-4
  UAC
Establishes standards for participate matter and
opacity as well as fugitive emissions and VOCs in
non-attainment areas. Rule also details unavoidable
breakdown criteria, fugitive dust requirements.
   Yes/--
Remediation strategies that include pollutant
emissions must meet partkulate matter and
opacity standards. Since Davis County is a non-
attainment area for ozone, VOC standards must
be met. Davis County is not non-attainment for
participate matter. Fugitive dust requirements
must also be met.
State NESHAP Siandards
R307-IO
  UAC
Establishes air emission standards for hazardous
pollutants.
   Yes/-
Applicable to alternatives that will generate
hazardous emission; these emissions must meet
these requirements.
Modified from Montgomery Waison 19V3

AQS      National Ambient Air Quality Standards         UST
PS D      Prevention of sign! (leant deterioration           CERCLA
RCRA    Resource Conservation and Recovery Act       NESH APs
POTW    Publicly Owned Treatment Works             BACT
NSPS     New Source Performance Standards
                               Underground storage tanks
                               Comprehensive Environmental Response, Compensation, and Liability Act
                               National Emission Standards for Hazardous Air Pollutants
                               Best Available Control Technology

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                  TABLE A-3



IDENTIFICATION OF FEDERAL ACTION-SPECIFIC ARARs
Standard, Requirement,
Criteria, or Limitation
Citation
Description
Applicable/
Relevant
and
Appropriate
Comment
Solid Waste Disposal Act -42 USC งง6901-6987 '
General Facility Standards
Standards of Preparedness
and Prevention
Contingency Plan and
Emergency Procedures
Manifest System,
Recordkeeping, and
Reporting Requirements
Requirements for Releases
From Solid Waste
Management Units
Closure and Post-Closure
Standards
Standards for Corrective
Action Management Units
and Temporary Units
40 CFR Part 264,
Subpart B
40 CFR Part 264,
Subpart C
40 CTR Part 264,
Subpart D
40 CFR Part 264,
Subpart E
40 CFR Part 264,
Subpart F
40 CFR Part 264,
Subpart G
40 CFR Part 264,
Subpart S
(264.552 and 264.553)
Establishes general facility management
standards for hazardous waste treatment,
storage, and/or disposal facilities. .
Establishes requirements for preparedness
and prevention at hazardous waste
treatment, storage, and/or disposal
facilities.
Establishes requirements fora
contingency plan and emergency
procedures at hazardous waste treatment,
storage, and/or disposal facilities.
Establishes requirements for the manifest
system as well as for recordkeeping and
reporting at hazardous waste treatment,
storage, and/or disposal facilities.
1 Mishes requirements for detection
in; i containment of releases from waste
management units at hazardous waste
treatment, storage, and/or disposal
facilities.
Establishes general standards for closure
and, if required, post-closure at hazardous
waste treatment, storage, and/or disposal
facilities.
Establishes operational requirements for
corrective action
No/Yes
No/Yes
No/Yes
No/Yes
No/Yes
No/Yes
No/Yes
Facility management plans may be developed,
as needed, to implement other 40 CFR Part
264 requirements.
Preparedness and prevention measures may be
developed, as needed, to implement other 40
CFR Part 264 requirements.
A contingency plan and emergency procedures
may be developed, as needed, to implement
other 40 CFR Part 264 requirements.
Not a substantive requirement. Requirements
for the manifest system, recordkeeping, and
reporting may be developed, as needed, to
implement other 40 CFR Part 264
requirements.
Groundwater monitoring and source control
requirements are relevant and appropriate.
Closure and, if required, post-closure will be
needed for any remedial action.
Relevant and appropriate for alternatives in
which a temporary onjsitc treatment unit is
established.

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                                                           TABLE A-3

                                     IDENTIFICATION OF FEDERAL ACTION-SPECIFIC ARARs
                                                          (CONTINUED)
Standard, Requirement,
Criteria, or Limitation
Miscellaneous Units
Air Emissions Standards
Land Disposal Restrictions
Standards to Control
Discharge through POTWs
Citation
40 CFR Part 264,
Subpart X
40 CFR Part 264,
Suhparts AA and BB
40 CFR Part 268
40 CFR Part 403
Description
Establishes design and operational
requirements for miscellaneous hazardous
waste management units
Establishes monitoring and recordkeeping
requirements for process vents and
equipment leaks.
Establishes ha/ardous wastes that are
restricted from land disposal and
describes those circumstances where
trcalcd waste may be land disposed.
Establishes standards application
requirements and permit conditions, and
provisions for discharge to a POTW.
Applicable/
Relevant
and
Appropriate
Yes/--
No/Yes
Yes/--
Yes/-
Comment
Applicable for on-site treatment units.
Equipment will be monitored in accordance
with the requirements of these subparts.
Hazardous wastes generated during
remediation will be managed in accordance
with the requirements of this part.
Applicable to generated wastes that are
discharged to the IWTP (a permitted facility).
Modified from Montgomery Watson 1993

AQS   National Ambient Air Quality Standards
PSD   Prevention of significant deterioration
RCRA  Resource Conservation and Recovery Act
POTW  Publicly Owned Treatment Works
UST      Underground storage tanks
CERCLA  Comprehensive Environmental Response, Compensation, and Liability Act
NESHAPs  National Emission Standards for Hazardous Air Pollutants

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                 TABLE A-4



IDENTIFICATION OF STATE ACTION-SPECIFIC ARARs
Department, Division
or Commission
Statute
Subject
Applicable/
Relevant and
Appropriate
Comment
UCA 73-3-25
State Engineer,
Department of Natural
Resources
R655-4
UAC
Establishes standards for
drilling and abandonment
of wells.
Yes/~
Remediation strategies may include
ground-water and soil moisture
monitoring.
Utah Air Conservation Act - Title 26 UCA Chapter 13
State Emission Standards
for Control of Installations
Emission Standards
R.107-1-3
UAC
R 307- 1-4
UAC
Specifies standards for six
pollutants PM i(r SO2, CO,
ozone, NO2, and lead. State
adoption of federal-AQS and
BACT.
Establishes standards for
paniculate matter and
opacity as well as fugitive
emissions and VOCs in
non-attainment areas. Rule
also details unavoidable
breakdown criteria, fugitive
dust requirements, and
State NESHAPs.
Yes/-
Yes/~
Emissions from the remediation process
will be subject to the standards for the six
pollutants.
Remediation strategies that include
pollutant emissions must meet particulate
matter and opacity standards. Since
Davis County is a non-attainment area for
ozone, VOC standards must be met.
Davis County is not non-attainment for
particulate matter. Fugitive dust
requirements must also be met.
Utah Solid and Hazardous Waste Act - Title 19 UCA Chapter 6
Definitions and General
Requirements for Solid
and Hazardous Waste
Hazardous Waste
Generator Requirements
R315-1
R315-2
UAC
R315-5
UAC
Outlines general
requirements and provides
definitions for Utah Solid
and Hazardous Waste
Regulations.
Outlines requirements for
generators of hazardous
waste.
Yes/ป
Yes/~
General requirements and definitions will
be applicable for the management of solid
and/or hazardous waste.
Generator requirements will be applicable
for all hazardous wasfe generated during
remediation.

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                  TABLE A-4

IDENTIFICATION OF STATE ACTION-SPECIFIC ARARs
                (CONTINUED)
Department, Division
or Commission
Requirements for
Hazardous Waste Facilities
Ground Water Protection
Rule
Miscellaneous Units
Requirements for
Corrective Action
Management Units
Land Disposal Restrictions
Clean-up action and risk-
based closure standards
Statute
R3I5-8
UAC
R3 15-8-6
UAC
R3 15-8- 16
UAC
R3I5-8-2I
UAC
R3I5-I3
UAC
R315-101
UAC
Subject
Establishes general
requirements for facility
management and specific
requirements for hazardous
waste management units.
Provides for the protection
of ground water at
hazardous waste sites.
Establishes design and
operational requirements
for miscellaneous
hazardous waste
management units.
Establishes requirements
for operations of Corrective
Action Management Units
and Temporary Units
Outlines land disposal
restrictions for hazardous
waste. Utah incorporates
federal LDRs by reference.
Provides a framework for
using risk-based standards
in remediating RCRA sites
Applicable/
Relevant and
Appropriate
Yes/~
Yes/--
Yes/--
Yes/~
Yes/~
Yes/~
Comment
General facility management plans
(R3 15-8-2 through R3 1 5-8-4) may be
developed, as needed, to implement other
requirements of R315. Standards for
ground water protection (R3 15-8-6);
closure and post closure (R3 15-8-7); use
and management of containers (R3I5-8-
9); tanks (R3 15-8- 10); and miscellaneous
units (R3 15-8- 16) may be applicable
depending on the remediation strategy.
Remediation strategy must be protective
of ground water and provide a monitoring
program.
Applicable for on-site treatment units.
Requirements applicable to corrective
actions where generated waste are stored
or temporarily stored and managed
Hazardous wastes generated during
remediation will be managed in
accordance with the requirements of this
rule. ,
Remediation strategy must achieve
compliance with risk-based closure
standards.

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                                                            TABLE A-4

                                     IDENTIFICATION OF STATE ACTION-SPECIFIC ARARs
                                                          (CONTINUED)
  Department, Division
     or Commission
 Statute
        Subject
 Applicable/
Relevant and
Appropriate
             Comment
Corrective action clean-up
standards policy — UST
and CERCLA sites
R311-211
  UAC
Specifies the State of
Utah's policy for cleanup at
UST and CERCLA sites.
   Yes/--
Remediation strategy must achieve
compliance with risk-based closure
standards.
                                       Utah Water Pollution Control Act - Title 26 UCA Chapter 11
Groundwater Quality
Protection Standards
 R3I7-6
  UAC
Details, standards, classes,
protection levels, and
implementation criteria for
groundwater protection.
Also, outlines certain
activities permitted by rule.
   Yes/--
Groundwater quality protection standards
will be applicable for all remediation
alternatives.
Utah Pollutant Discharge
Elimination System
(UPDES)
 R3I7-8
  UAC
Details, standards,
application requirements,
and permit conditions and
provisions for discharge of
any pollutants from a point
source into any water
system in the state.
   Yes/-
All liquid waste will be required to be
discharged to a permitted treatment
facility.
Modified from Montgomery Watson 1993

AQS      National Ambient Air Quality Standards
PSD      Prevention of significant deterioration
RCRA    Resource Conservation and Recovery Act
POTW    Publicly Owned Treatment Works
                    UST        Underground storage tanks
                    CERCLA   Comprehensive Environmental Response, Compensation, and Liability Act
                    NESHAPs   National Emission Standards for Hazardous Air Pollutants

-------
PUBLIC MEETING TRANSCRIPT
      Appendix B

-------
   OUR FILE NO.   54298-060
                      COMMUNITY  MEETING




                     HILL AIR  FORCE BASE




                       OPERABLE  UNIT 7
V

-------
 1                           *****
 2       Community Meeting of Hill Air Force Base regarding
 3       Operable Unit 7, held on Wednesday, March 1, 1995,
 4       7:15 p.m., at the Base Theater,  Hill Air Force
 5       Base, Ogden, Utah.
 6
 7                           *****
 8
 9  IN ATTENDANCE:                   Colonel Larry Wheeler
10                                   Ms.  Gwen Brewer
11                                   Mr.  Steven Hicken
12                                   Mr.  Rob Stites
13                                   Capt.  Gary Chesley
14                                   Mr.  Greg Steven
15                                   Mr.  Jerry Mansfield
16                                   Ms.  Nan Tate
I"7                                   Mr.  Albert BadeaO
18                                   Ms.  Vickie L. Wheeler
19                                   Ms.  Diane Simmons
20                                   Mr.  Harold Dunning
21                                   Mr.  Andrew Gemperline
22                                   Mr.  George Srader
23                                   Mr.  Dave Fulton
24                                   Ms.  Traci Thomas
25                                   Other members of the public

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 ,1       OGDEN, UTAH, WEDNESDAY, MARCH 1,  1995 - 7:15 P.M.
 2                           *****
 3            MS. BREWER:  We appreciate that you
 4  have...(inaudible).
 5            THE REPORTER:  I can't hear you.
 6            MS. BREWER:  I think we'd better start — go ahead
 7  and get started, just to go through the meeting so we can
 8  have it recorded — there come some people.
 9                           (Laughter)
10            This is really one of the larger groups that we've
11  had.  We're really happy to see all of you.  We'll give you
12  a good opportunity to meet our new Wing Commander, Colonel
13  Larry Wheeler.  I hope you will all get behind him, and if
14  you have any questions, he will answer them for you.
15            So, Commander Wheeler.
16            CMDR. WHEELER:  Since it is such a large mass of
17  public folks that... (inaudible)...things of that nature, I
18  don't think it will —
19            THE REPORTER:  I can't hear you.
20            CMDR. WHEELER:  — come to this Air Force base.
21  On behalf of General Condon, we are pleased we had the
22  opportunity to get everybody here'to our Air Force base,
23  give you an opportunity for public comment.  We have a
24  ...(inaudible) —
25            THE REPORTER:  I can't hear you.  Please use the

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95

 1  raic.
 2            CMDR. WHEELER:  — on hand that is going to
 3  comment about our plan for the Operating Unit No.7 and our
 4  proposed plan, what we're going to do to clean up this
 5  particular area.
 6            This area that we're interested in is exclusively
 7  on the base.  It is under — if you're familiar with the
 8  base, under Hangar 225 or Building 225.  It will be his
 9  proposal and the proposal at Hill Air Force Base on how to
10  do the cleanup.                                                !
11            So, Steve Hicken, come up here and tell us how you
12  are going to do that.  After you talk awhile, we'll have it
13  available for questions and answers and any additional
14  information.
15            You want to start, Steve?
16            MR. HICKEN:  Thank you, Colonel Wheeler.
17            Most of you are already fairly familiar with
18  Operable Unit 7.  For others of you, this will be an
19  education in process.  So actually, I think it is a good
20  exercise to go through this.
21            Before I begin tonight, just for those of you who
22  may not know, we do have representatives — without getting
23  into individuals, we do have representatives  of the EPA,
24  State Department of Environmental Quality, representatives
25  to Hill Air Force Base...(inaudible) —

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








 1            THE REPORTER:  I can't hear you.



 2            MR. HICKEN:  — and so we're well represented here



 3  tonight.



 4            We also have quite a crew here from Montgomery



 5  Watson, who was the prime contractor for Operable Unit 7 and



 6  had done the majority of the work for us here on the base.



 7            I'm going to try to avoid using acronyms tonight.



 8  It has become so ingrained for us, sometimes we slip.  If I



 9  use them, the first time I will try to define them.  If I



10  don't, you can call me on that.  And if I could ask that we



11  please defer questions until the end.  It is not a very long



12  presentation, but if we could just hold the questions to the



13  end, we can then go back to any of the overheads you might



14  like to see again.



15            For the past four years, we have been carrying out



16  an investigation at Operable Unit 7, and under the auspices



17  of EPA and the State department of Environmental Quality.



18  This has been carried out in phases.  We have just closed



19  the remedial investigation and feasibility study, RI/FS.



20            Can we have the first slide, please.



21            MS. BREWER:  If any of you don't have the



22  material, you can have a. copy of this if you would like to.



23            MR. HICKEN:  This first slide shows the objectives



24  we have tried to accomplish during the RI/FS process on



25  Opperable Unit 7.  collect data to characterize site

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95

    conditions.  And second was to determine the nature and
    extent of soil contamination.  Third was to evaluate risks
    to human health and environment.
              From those objectives, determine cleanup
    alternatives and take those cleanup alternatives and select
    a preferred alternative based on EPA requirements.
              Part of the reason for this meeting tonight is
 81 to — partially, is to obtain community acceptance.
              Let's go to the next slide.  This next slide shows
10  Hill Air Force Base in relation to Operable Unit 7.  As you
11  can see, there are a number of operable units.  We've shown
12  them all on the slide.  There are eight currently.
13            As you can also see, most of them are around the
14  perimeter of the base.  Operable Unit 7 is different in this
15  regard.  It is in the heart of the industrial complex area.
16  It consists of Buildings 225, 220 and Base Supply Well 6.
17  Base Supply Well 6 is off to the northwest of the main
18  runway at the top.
19            I should say at this point, OU 7 is the soils only
20  under the operable unit.  The groundwater you can see
21  beneath the box that represents the heart of Operable Unit
22  7, that groundwater is being treated under Operable Unit 8.
23  So, this will only deal with soil remediation.
24            This next slide shows Buildings 225 and 220 in
25  more detail.  As you're probably aware, Building 225 is the

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








    primary maintenance hangar for the base.  It has been in



    operation since the 1940's.  Areas we have investigated in



    Building 225 include the former metal plating shop.  This



    shop was used from the 1940's until about the 1970's, and



    plating solutions composed of a variety of chemicals, acids,



    base metals, solvents that were discharged through a floor



    grate system that eventually developed some leakage.



 8            We also investigated a PCB area, the location of a



    former transformer.  You can see it immediately to the west



10  of the plating shop area.  That was moved in the 1960's.



11  Here again, we got some leakage from that transformer that



12  discharged some PCB-containing liguids into the soils



13  beneath the building.



14            We also investigated some miscellaneous  areas of



15  Building 220.  These included a wash rack, a hydraulic room,



16  a mop cleaning room and former degreaser pit.  These were



17  particular, areas that former workers within 225 record that



18  chemicals had been used in the area or discharged  in the



19  grates, or we expected might have been.  They were likely



20  areas that some contamination might have been.



21            On the same slide, up to the northeast is Building



22  220.  And Building 220 has been the primary stripping and



23  cleaning facility for the base from 1957, and still is



24  today.  Paints, paint thinners, strippers, solvents and



25  other chemical wastes are discharged through a floor drain

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95

    system that then connects to the industrial waste pipeline.
    Historically, much larger volumes of liquid waste were
    discharged in that system.
              -As many of you are aware today, we do the majority
    of our heavy stripping by using a bead blast operation which
    is completely dry.
              There was an investigation in 220, including three
 8  paint chip settling tanks on the northwest of the building.
    These were the tanks that received the discharge from those
10  industrial lines.
11            We also investigated a 20,000 gallon diesel tank
12  just immediately to the other end of the discharge tanks,
13  the settling tanks.  We also investigated the industrial
14  discharge lines that go underneath the building and flow
15  into those tanks.
16            in 1986, those three tanks and the diesel storage
17  tanks were all removed.  We are now connected directly to
18  the industrial waste line.  At the time of the removal of
19  those tanks, we found some contamination of the soil at that
20  time.
21            The next slide shows a picture of the Base Supply
22  Well 6.  What happened at Base Supply Well 6 is that, during
23  construction of the subsurface of the building, trench 225,
24  that trench happened to cut through a portion of the old
25  plating shop.  In fact, this is how the contamination was

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








    originally discovered there.  Some of those soils from that



    trench were taken out to Base Supply Well 6 and used as



    backfill over the trench.  So, we did some investigation to



    determine if there was contamination present.



              This next figure shows a conceptualized model for



    Operable Unit 7.  As I mentioned, in Building 225, the



    plating shop did discharge some of those wastes into the



    soils beneath.  Some of those contaminants actually made it



    to groundwater, and that is really the bulk of the



10  contamination that is present in Building 225, and the one



11  we're most concerned with.



12            The PCB area that I mentioned, at the time that



13  PCB contamination was discovered, it was actually during the



14  installation of another utility trench.  At the time it was



15  discovered, a significant quantity of the soil was removed.



16  Approximately 95 tons were removed and disposed of in a



17  proper facility.  We believed from that, that the bulk of



18  the contaminations were removed, because our borings in that



19  area discovered only minor amounts of contamination



20  remaining.  Also, in the miscellaneous areas, we were only



21  able to detect minor amounts of VOC organic compounds.  I



22  mean, solvents like TCE, TCA, things we used as degreasers



23  or solvents.



24            At Building 225, we also found a very low level of



25  contaminants were detected in the soils beneath the

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95

    building.  And Base Supply Well 6, we found very minor
    amounts of contamination.
              Although we did identify soil contamination at
    every site at Operable Unit 7, comparison of the types and
    concentrations of these compounds with health-based
    standards provided by the EPA show that the former metal
    plating shop was the only area that poses any risks to human
 8  health or the environment.
              Although we do have detailed information on the
10  sites, these other sites where the compounds were detected
11  there, we're going to kind of leave that and focus on the
12  plating shop area right now.
13            Let's go to the next slide.  Before we do that,
14  though, one thing I want to make sure is clear.  This is a
15  model showing the groundwater beneath Hill Air Force Base.
16  This is kind of generalized, but it is to scale, showing the
17  approximate depths of the aquifers that exist below Hill Air
IS  Force Base.
19            I mentioned that the contamination from the
20  plating shop had reached groundwater and that is true.  The
21  groundwater we are referring to is the shallow aquifer right
22  there at the very top.  Between that and the next aquifer
23  down is a clay layer, and then you hit the Sunset aquifer,
24  and then another clay layer and...(inaudible)...  aquifer.
25  Those are hundreds of feet deep, and since it is the Sunset

                                                             10

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








    and Delta aquifers that are tapped for drinking water, right



    now, we are not  contaminating any aquifers that are used for



    drinking water.  It  is only that shallow, upper aquifer that



    has been contaminated.



              This figure summarizes the types of chemicals



    detected and the frequency of detection and maximum



    concentrations observed in Building 225.  And as you can



    see, hexavalent  chromium and cadmium are highlighted in



    yellow.  These are the only compounds that were detected in



10  concentrations that  would cause a risk to on-site workers or



11  future residents if  they were exposed to these soils.



12            Other  compounds were detected, but they were not



13  in high enough concentrations to pose a risk.  Total



14  chromium, lead,  cyanide, and those last four are organic



15  compounds or V-o-C's.  Based on that, we would like to focus



16  in on hexavalent chromium and cadmium.



17            This is what we call an isoconcentration map.



18  All this is doing is looking down, kind of a plan view,



19  looking at the aerial here, hexavalent chromium.  As you can



20  see, there are two specific zones of contamination, one in



21  the north and one in the south.  These just happen to



22  coincide with the area where chromium plating took place.



23            Next slide, please.  This shows the cadmium



24  concentration.   Very similar looking in the south area.  We



25  again have two distinct areas, but the north area is very,





                                                            11

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB,  3-1-95








 1  very slight contamination with the highest concentrations in



 2  that south area.



 3            Next slide.  This shows a cross-section,  north to



 4  south, cut through the plating shop area so that you can now



 5  see the vertical distribution of these contaminants.  The



 6  majority of the contamination is confined in the upper 50



 7  feet.  The cadmium is not shown here.   This shows the



 8  hexavalent chromium.  But if you can remember from the



 9  previous slide, the majority of it is focused on the plume



10  area to the right.  It would have a similar vertical



11  distribution but of lower concentrations.  Hexavalent



12  chromium is the highest of the concentrations of the metals.



13            This also shows the soils condition beneath the



14  building.  It is very fine sands with intermittent levels of



15  fine silts and clays.  Those silts and clays are the darker



16  streamers that you see going across.  That has had a



17  significant impact on what's happened here because that...



18  (inaudible)...precipitated that movement downwards.  The



19  bulk of the contamination is trapped right above those clay



20  layers in those upper areas.



21            So, although we know the contamination has reached



22  the groundwater, the majority of the mass is still captured



23  above the clay layers.  Since the plating shop was removed



24  in 1972, the discharges to that line have stopped.  We no



25  longer have any solutions flowing underneath that building.





                                                             12

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    PUBLIC MEETING RE  OPERABLE UNIT 7 AT HILL AFB, 3-1-95







    As a result, the conditions there have become very dry.  We



    verified this during our early program.  Knowing what these



    dry conditions are, we don't believe any further migration



    of contaminants is taking place right now.



              Let's move on to the risk assessment summary.



    This is part of the remedial investigation and feasibility



    study that takes place.  To give you a little background,



 8  this shows the three components of a human health risk



    assessment.



10            First is to identify, chemicals of concern that we



11  have at the site.  The second is to do an assessment of how



12  exposure to either humans or animals can take place from



13  these chemicals.   Exposure, like ingesting the soil that's



14  contaminated or drinking water that is contaminated, that is



15  an exposure scenario.  At the same time, looking at toxicity



16  assessment — toxicity is how toxic these are.   When you



17  put these three steps together, you end up with a complete



18  risk characterization for the site and the compounds there.



19



20            This next slide shows the summary for Operable



21  Unit 7.   As you can see, we looked at current health risk to



22  workers in the building, and also future risk to



23  construction workers or "residents who might be living there.



24  The findings of this study show that no current health risk



25  exists on that site.  I should say, under current health





                                                            13

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB,  3-1-95







 1  risk, there is a little different rationale why there is  no



 2  current health risk.



 3            In the case of PCB in the Base Supply Well 6 and



 4  Building 220, the reason there is no health risk is just on



 5  low concentration.  They are not high enough concentrations



 6  to form a risk.



 7            in the case of the former metal plating shop,, the



 8  reason we have no current risks in there, we have 12 to 18



 9  inches of concrete separating that contamination from our



10  workers who are maintaining airplanes above that.



11            When we go to the future, we will show where the



12  former metal shop does pose a risk.  If the construction



13  workers come in, break through the floor, they can become



14  exposed to the soils.  Dermal contact or dust or ingestion,



15  that's a possibility.  That's a substantial threat.  If the



16  property were ever to be sold and that building removed and



17  turned over to residential use, you have the possibility



18  then of people who are constructing a house to be exposed.



19  The homes would be exposed and also the residents who work



20  around their homes in their gardens or on their homes.  That



21  is what poses the future health risk at Operable Unit 7.



22            Let's go to the next one.  Let's talk for just a



23  few minutes about selection of our cleanup alternatives.



24  These are determined by considering technologies, cleanup



25  technologies that may be applicable.  Once they have been





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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








    identified, they are assembled into alternatives that will



    address the needs we have at Operable Unit 7.   We do a



    comparative analysis of the alternatives based on nine



    alternatives established by EPA.



              This next slide shows those nine criteria.  The



    first criteria, and the most important,  is overall



    protection of human health and environment.  That is the



    number one thing.



              The second is compliance with  applicable or



10  relevant or appropriate requirements. That is called ARARS,



11  and that is kind of a mouthful and not easy to understand.



12  But these are laws, like groundwater or  drinking water



13  protection laws.  Those first two requirements, two criteria



14  are called threshold criteria.  Any alternatives that we



15  look at have to meet at least those two  criteria.



16            The next five are what is called balancing

                                                                   i

17  criteria.  In Operable Unit 7, we will see implementability    j

                                                                   i

18  is the most important of the balancing criteria.  And          i



19  finally, we have state acceptance and community acceptance.    !



20            Let's go through the alternatives.  Alternative      j
                                                                   i


21  No. 1 is No Action, and inclusion of a "no action"             !



22  alternative is required by the EPA.  What it is, it sets a     |



23  basis for the comparison with the other  alternatives.



24            The component that is first, there will be no



25  cleanup action taken.  However, there will be groundwater





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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95

 1  monitoring and soil moisture monitoring.  Groundwater
 2  monitoring will take place from standard monitoring wells,
 3  upgradient of the contamination right in the midst of this,
 4  and downgradient soil monitoring will be done with neutron
 5  probes that'll be, again,  in the zone of contamination, to
 6  make sure we have those dry conditions that we talked about
 7  maintained.  We don't have a significant amount of water
 8  precipitation coming down  through there.  The building and
 9  floor are acting as a deterrent for that kind of thing
10  happening.
11            It also includes a five-year review standard for
12  SERCLA, for SuperFund sites for cleanup.  Every five years,
13  we want to come back in and take a look again at the
14  alternatives that we've selected.  See if it is still
15  viable.  See if it is still protecting and doing the things
16  we want to do.  The cost of this alternative, over a 30-year
17  period, is approximately $500,000.
18            Right now, this  alternative can be implemented and
19  it would cause virtually no interruption to the operations
20  in Building 225.  But it is not protective of human health
21  and does not meet ARARS for groundwater.  It is not
22  protective of the groundwater.
23            Let's go to the  next alternative.  This is
24  Alternative No.2, and this is Institutional Controls.  This
25  contains the same components as for Alternative No.l,  except

                                                            16  .

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








    for the first three bullets there.  That is issuing a



    continuing order by the  Base Commander.  What this will do



    is, it will restrict development and access to contaminated



    areas.



              We essentially have this in place right now.



    Anytime construction takes place in Building 225, an order



    is put through, or a request, and it goes through our



    office.  In that way,  if they are going to be breaking



    through the floor, we  will know about it and we can then



10  warn them if they are  in an area of contamination so that



11  they can be properly protected.  Both the construction



12  workers and also the workers...(inaudible)...them.



13            It also entails maintaining the concrete floor in



14  the building.  That is the key to that alternative, is



15  keeping that floor in  good shape and in place.



16            Also, filing a notice to the Deed by Hill Air



17  Force Base, if the property ever changes hands.  That way,



18  the new owner will be  aware that there is contamination



19  present.



20            And also, warning signs in the area.  These will



21  be similar — like warnings for electrical lines or things



22  like that.  Just a warning that there is contamination



23  beneath the floor, should that floor seal be broken or if



24  they break through the soil beneath.



25            Cost for this  alternative, over a 30-year period,





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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95







    was $627,000, and this can be implemented under the current



    site conditions.



              Alternative 3 is the first of the active



    alternatives where we're actually taking action to actually



    remove the contamination.  And this alternative includes



    excavation and removal of all contaminated soils and...



    (inaudible)...helps.  The excavated soils would be placed in



 8  the hazardous waste landfill.  And this alternative is not



    currently viable as implementation would require removal of



1.0  a large portion of Building 225, and probably a disruption



11  of the work that went on in the rest of the building.  It is



12  not implementable right now in the current conditions.



13          The cost for this one is very high, over $7 million



14  over a 30-year cost.



15            This is alternative 4, Excavation and Soil



16  Washing.  This involves removal of contaminated soils; that



17  is, soils that pose a risk to human health.  Only, in this



18  case, those soils will be treated on site by washing.  The



19  soils will be put back into the original hole.



20            As Alternative 3, it is not currently



21  implementable while Building 225 is in place because of the



22  size of the excavation that would be required to go down



23  that 50 feet to get those soils that pose a risk.  And



24  again, this is a fairly expensive alternative at over



25  $5 million.





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    PUBLIC MEETING  RE  OPERABLE UNIT 7 AT HILL AFB, 3-1-95







              Our last alternative is Alternative 5.  This is



    In-Situ Solidification.  Essentially, what in-situ



    solidification  involves is taking the soils that pose a risk



    and mixing them with a solidifying agentr such as concrete



    or fly ash.  This  creates a solid block that's thoroughly



    impermeable to  leaching those metals out.  That block is



    placed right back  there in the original place that it is



    now, but it would  require continued monitoring to make sure



    that we don't have leaching out from that block.



10            This  alternative would cost approximately



11  $2 million to implement.  But there again, we're looking at



12  an alternative  that would require the removal of a good



13  portion of Building 225 to see this alternative



14  accomplished.



15            Based on these site conditions and the need to



16  keep the facility  in Building 225 working and operational,



17  and considering the current lack of risk to on-site workers,



18  Hill Air Force  Base proposes that Alternative No. 2 be the



19  preferred alternative.  This alternative can be implemented



20  under the current  conditions.  It can still meet the



21  requirements of those threshold criteria.  It is protective



22  of both human health and also the groundwater aquifer



23  conditions, and also meets the state and federal



24  regulations.  If site conditions ever change, if the



25  building should be removed, then other alternatives will





                                                            19.

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95

 1  have to be looked at and other actions taken at that time.
 2            This next figure just shows some of the components
 3  of Alternative No.2.  As I said, we would have monitoring
 4  wells upgradient, in the midst of the contamination plume,
 5  and then downgradient.  What we would be looking for is
 6  significant increases in the concentrations of the metals in
 7  the groundwater.  This would be an indication that we
 8  actually had some continuing transport of groundwater.  Soil
 9  moisture monitoring would give us the second checkup on
10  that.  What it would do is merely to examine the soil
11  moisture within that zone to make sure we are not seeing the
12  radical increases that would be indicative of things like
13  rain water or infiltration coming through that could then
14  dissolve those metals and mobilize them and carry them to
15  the groundwater.  It is kind of the double-check to make
16  sure we're keeping those dry conditions in place.
17            AS I stated earlier, this alternative is currently
18  implementable, does meet the requirements.  In the event
19  that conditions ever do change, then we would obviously have
20  to look at other actions if the building were removed.
21            Are there any questions that I can answer?
22  George?
23            MR. SRADER:  Do you have any idea or any estimate
24  of the relation of time that the...(inaudible)...building
25  would be used .to last, or when this might be reviewed?

                                                            20  .

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    PUBLIC MEETING  RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








              MR. HICKEN:  Reviewed again?   Is there anyone



    here who knows  how?



              CMDR. WHEELER:  I don't think we do.  Much of that



    just depends on probably what happens on even the global



    scale.  You know, with the cold war going away, we've



    obviously seen  some changes as far as what our national



    level of defense is, and we were even anticipating that



    there was the possibility that Hill would come out on the



    Base Realignment and Closure list, but it was released today



10  and it was not  on the list.  There is every indication that



11  the building would stay in operation for the future that we



12  know of.



13            MR. .HICKEN:  Any other questions?



14            MR. . SRADER:  On your monitor points, those are



15  wells that are  in the ground now, and usable?



16            MR. HICKEN:  We have the well right now that is in



17  the midst of that contamination that was put in during the



18  investigation.   We have an upgradient well.  We would have



19  to put another  downgradient well closer'to the site.  So, we



20  would probably  have one or two more wells that we would need



21  to put in right now.  Right now, we don't have any available



22  borings for the soil moisture monitoring.  That would have



23  to be done.



24            We've done...(inaudible) ...the building before.



25  Obviously,  we were doing remedial investigation.  It takes





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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








    some coordination, but it has been able to be done and there



    has been a lot of cooperation with those who supervise



    Building 225 work.  There is work to be done, but part of it



    is in place and part of it yet has to be put in.



              MR. MANSFIELD:  Jerry Mansfield.  Steve, I think



    it is important that you make it clear that the costs of



    Alternatives 3 through 5 do not include removal of the



    building for that remediation.



              MR. HICKEN:  That's correct.  As high as those



10  costs are, they do not include the cost that would be



11  incurred by the Air Force to remove that operation.  I



12  really don't have an estimate of what that would be, but



13  that would be very high, to build another facility like that



14  to take care of that operation.   Thanks.



15            MR. SRADER:  Are these monitoring wells, or the



16  ones that you have, sufficient to indicate or to show there



17  is no migration or show what migration might be in the



18  future, as you are monitoring those places?



19            MR. HICKEN:  We've discussed that and I think,



20  alone, you might have a difficult time.  If you only had the



21  monitoring wells, you would be —



22            MR. SRADER:  You are looking at one point that is



23  fixed.




24            MR. HICKEN:  That is why we have an upgradient and



25  a downgradient well.  We do have other wells around the





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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95







    area, and those receive standard monitoring, on the base.



    So, we really do have a feel.



              If we see those concentrations rise in the



    groundwater, yeah, we can say: Okay, it must be coming from



    water contamination.  However, without that soil moisture



    monitoring, we wouldn't be certain.  Maybe there is another



    source that we have not found.  But that soil moisture



    monitoring gives us a second opinion, a second piece of data



    to say: Hey, we had significant increase in soil moisture



10  here six or seven months ago and now we are seeing a



11  subsequent rise in groundwater concentrations.  It makes



12  sense, we're getting transport.  If we see a rise of



13  groundwater and we have dry conditions up here, we will be



14  suspicious that perhaps there is another source somewhere.



15  So, is it sufficient?  I think so.  I think it is.



16            MR. SRADER:  Are you going to be monitoring around



17  the edges of the slab, to get some idea where — to find if



18  there is, at some later date, a migration out from beneath



19  the slab?



20   ,         MR. HICKEN:  Migrating?



21            MR. SRADER:  Just to check that you are not



22  getting any migration out from under the slab.  Are you



23  monitoring the edges of the slab?



24            MR. HICKEN::   We will have soil moisture probes



25  out there, yes.  So, those probes will kind of act as our





                                                             23

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95







 1  guide for the soils, to make sure that they are still



 2  maintaining the dry condition.  Yes, there will be



 3  monitoring done, yes.



 4            MR. SRADER:  How about, are you monitoring the



 5  chromium concentration?



 6            MR. HICKEN::   We won't be pulling soil samples.



 7  We already accomplished that in the remediation, quite a



 8  significant number.  We feel we have a good handle on the



 9  zone of contamination, enough to make the decisions we are



10  making now.  If that building is removed, we will probably



11  have to do some additional characterization work, because we



12  will now have that wide open station.  Then we will go



13  anywhere we want to poke holes in it.  At that time, there



14  would be more characterization work done.



15            MR. SRADER:  You are presuming that the monitoring



16  of the soil moisture is adequate to show there is no further



17  migration?



18            CMDR. WHEELER:  I think that is the whole premise



19  here, while that soil is dry, that there is no migration.



20  Hence, we have the moisture monitors that show that they



21  continue to stay dry, then.there would be no migration.   If



22  all of a sudden there is some type of indication of



23  moisture, then that would allow some type of migration.   At



24  which time, they would, you know, raise the level of local



25  investigation or go back in and see what would be causing





                                                            24

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95







 1  that.



 2            MR. HICKEN::   We would have to revisit it.  If



 3  site conditions change,  obviously, that's something that



 4  will have to be discussed.  And we are having continuing



 5  checks.  Those two  checks, we  feel, will give us a good view



 6  of what is going on.



 7            MS. BREWER:  What I  was recommending, that you



 8  might want to mention the groundwater is being studied under



 9  a different operable unit.  That would be the only way they



10  would know is if it were included in the groundwater.  So,



11  right now, he is only talking  about the soil, not the



12  groundwater.



13            MR. HICKEN::   The groundwater, as I said, is



14  being treated in another operable unit study.



15            Any more  questions?



16            MS. BREWER:  No questions?  Jerry, would you like



17  to say something?



18            MR. STITES:  Generally, we support the action.



19            CMDR. WHEELER:  Any  comments from any of the folks



20  in support of the conditional  things that you want to bring



21  forth?  We will just note it in the public record.   You're



22  the expertise out here.  Now is the time to say it.  Right



23  back here.



24            MR. FULTON:  David Fulton.  You mentioned the fact



25  that the OU 7 lies  within the  larger groundwork and you have





                                                            25

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    PUBLIC MEETING RE OPERABLE UNIT 7 AT HILL AFB, 3-1-95








 1  constant monitoring?



 2            MR. STITES:  That was in there.



 3            CMDR. WHEELER:  Anything else?  Well then, all I



 4  would say.is, thank you very much for coming out tonight.



 5  We were hoping that we might have a few more interested



 6  public, but in light of the release of information on the



 7  BRAC closure, maybe everybody is home celebrating tonight.



 8  Who knows.  Thank you for coming out.  Thank you for



 9  demonstrating your interest.  Thank you for the questions.



10  That allows us, as far as showing on our record, that some



11  folks were interested in having an opportunity to address



12  some of their questions.



13            So, if there are no other questions, we would



14  bring this to a close this evening.  Thank you.



15            MS. BREWER:  We do have some materials up here and



16  if any of you haven't signed in, please sign in to make that



17  a part of the record.



18                           *****




19             (Whereupon the meeting was concluded.)



20



21



22



23



24



25
                                                            26

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     PUBLIC MEETING RE OPERABLE UNIT  7 AT HILL AFB,  3-1-95



                         REPORTER'S CERTIFICATE



      STATE OF UTAH        )

                           )  ss.

      COUNTY OF SALT LAKE  }



               I,  SHIRLYN SHARPE, R.P.R.,  C.M.  and Notary Public

     in and for the State of Utah, do hereby certify;

               That the foregoing transcript of the  Public

10   Meeting for Operable Unit 7 at Hill  Air Force Base

11   was prepared  by me from my stenographic notes taken at the

12   time of the proceedings therein reflected;

13             That the foregoing transcript represents all

14   proceedings had of record at the time of  the meeting, with

15   the exception of the portions which  were  inaudible to me,

16   which  portions are so noted in the transcript;

17             And I hereby further certify that the foregoing

18   typewritten transcript, as typed by  me, is a correct record

19  of my  stenographic notes so taken;

20             IN  WITNESS WHEREOF, I have subscribed my name and

211  affixed my  seal  this 7th day of March, 1995.

22

23

24
                                       SHIRLYfl SHARPE, RPR, CM
25

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WRITTEN COMMENTS AND RESPONSES
         Appendix C

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                             APPENDIX C
No written comments were received.
                                 C-l

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