PB97-964407
EPA/541/R-97/197
January 1998
EPA Superfund
Record of Decision:
Hill Air Force Base, OU 6
Ogden, UT
9/30/1997
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Hill Air Force Base, Utah
Final
Record of Decision
Operable Unit 6
Sites ST022, OT026, SD40B
August 1997
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Final
RECORD OF DECISION
OPERABLE UNIT 6
HILL AIR FORCE BASE, UTAH
Prepared by:
Radian International, LLC
8501 North Mopac Blvd.
P.O. Box 201088
Austin, Texas 78720-1088
USAF Contract No. F42650-92-D-0007, Delivery Order No. 5044
Prepared for:
Mr. Steve Hicken
USAF Project Manager
OO-ALC/EMR
Hill AFB, Utah 84056
August 1997
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RECORD OF DECISION
FOR OPERABLE UNIT 6
HILL AIR FORCE BASE, UTAH
This is a primary document for Operable Unit 6 at Hill Air Force Base. It will be available in the
Administrative Record, which will be maintained at the following locations:
Davis County Library
Central Branch
155 North Wasatch Drive
Layton, Utah 84041
Phone: (801)547-0729
Hours: Monday through Thursday 10:00 a.m. - 9:00 p.m.
Friday and Saturday 10:00 a.m. - 6:00 p.m.
Environmental Management Directorate
00-ALC/EMR
Building 5
7274 Wardleigh Road
Hill AFB, Utah 84056-5137
Hours: Monday through Friday 7:30 a.m. - 4:30 p.m.
Contact: Mr. Len Barry
Phone: (801) 775-6951 or 777-4435
Subroittal Date: 18 August 1997
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TABLE OF CONTENTS
Page
DECLARATION FOR THE RECORD OF DECISION 1
1.0 SITE NAME, LOCATION, AND DESCRIPTION 1-1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 2-1
2.1 History of Site Activities 2-1
2.2 Enforcement Activities 2-1
2.3 Investigation History 2-1
2.4 Highlights of Community Participation 2-2
2.5 Scope and Role of Operable Unit 6 Within Site Strategy 2-2
3.0 SUMMARY OF SITE CHARACTERISTICS 3-1
3.1 Topography and Hydrogeology 3-1
3.2 Nature and Extent of Contamination 3-1
3.2.1 Groundwater : 3-1
3.2.2 Springs, Field Drains, and Surface Water 3-3
3.2.3 Surface Soil 3-3
3.2.4 Subsurface Soil 3-5
3.3 Contaminant Fate and Transport 3-5
3.3.1 Fate 3-5
3.3.2 Transport 3-5
3.3.3 Exposure Potential 3-7
4.0 SUMMARY OF SITE RISKS 4-1
4.1 Human Health Risks 4-1
4.1.1 Contaminants of Potential Concern 4-1
4.1.2 Exposure Assessment 4-1
4.1.2.1 Current Off-Base Residential Exposure Scenario 4-1
4.1.2.2 Future Off-Base Residential Exposure Scenario • 4-3
4.1.2.3 Future On-Base Residential Exposure Scenario 4-3
4.1.2.4 On-Base Worker Scenario 4-3
4.1.3 Toxicity Assessment 4-4
4.1.4 Summary of Risk Characterization 4-4
4.2 Environmental Evaluation 4-10
4.3 Uncertainty Analysis 4-10
4.4 Overview of Site Risks 4-10
5.0 DESCRIPTION OF ALTERNATIVES 5-1
5.1 Elements Common to All Alternatives 5-1
5.2 • Alternative 1—No Further Action 5-2
5.3 Alternative 2—Alternative 1 Plus Institutional Actions 5-5
u
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TABLE OF CONTENTS (Continued)
Page
5.4 Alternative 3—Pump-and-Treat with Discharge of the Treated Water 5-5
5.5 Alternative 4—Alternative 2 Plus In Situ Remediation of On-Base Plumes 5-7
5.6 Alternative 5—Alternative 3 Plus Accelerated Treatment of On-Base Plumes
and Soil Remediation 5-9
6.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES 6-1
6.1 Threshold Criteria 6-1
6.1.1 Overall Protection of Human Health and the Environment 6-1
6.1.2 Compliai ;e with ARARs 6-1
6.2 Primary Balancing Criteria ; 6-5
6.2.1 Long-Term Effectiveness and Permanence .. 6-5
6.22 Reduction of Toxicity, Mobility, or Volume Through Treatment 6-5
6.2.3 Short-Term Effectiveness 6-5
6.2.4 Implementability 6-5
6.2.5 Cost 6-6
6.3 Modifying Criteria 6-6
6.3.1 State Acceptance 6-6
6.3.2 Community Acceptance 6-6
7.0 THE SELECTED REMEDY 7-1
7.1 Description of the Selected Remedy 7-1
7.1.1 Remediation Goals and Performance Standards 7-1
7.1.2 Restoration Timeframe 7-1
7.1.3 Costs 7-1
7.2 Statutory Determinations 7-3
7.2.1 Protection of Human Health and the Environment 7-3
7.22 Compliance with Applicable or Relevant and Appropriate Requirements ... 7-3
7.23 Cost Effectiveness 7-4
7.2.4 Utilization of Permanent Solutions and Alternative Treatment Technologies 7-5
7.2.5 Preference for Treatment as a Principal Element , 7-5
7.3 Documentation of Significant Changes 7-5
8.0 REFERENCES 8-1
9.0 RESPONSIVENESS SUMMARY 9-1
9.1 Overview 9-1
9.2 Background on Community Involvement 9-1
9.3 Summary of Public Comments 9-2
9.3.1 Comments on the Proposed Plan 9-2
9.3.2 Comments Made During the Public Meeting 9-2
APPENDIX A: Identification of ARARs
APPENDIX B: List of Attendees at the Hill AFB Operable Unit 6 Open House
111
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LIST OF FIGURES
Page
1-1 Location of Operable Unit 6 at Hill Air Force Base 1-2
1-2 Operable Unit 6 Site Map 1-3
3-1 Extent of Trichloroethene (TCE) Groundwater Plumes 3-2
3-2 Hydrogeologic Cross Section A-A' 3-4
3-3 Operable Unit 6 Conceptual Site Model , 3-6
5-1 Alternatives 1 and 2 Site Plan 5-3
5-2 Alternative 3 Site Plan 5-6
5-3 Alternative 4 Site Plan 5-8
5-4 Alternative 5 Site Plan 5-10
7-1 Selected Remedy for Operable Unit 6 7-2
IV
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LIST OF TABLES
Page
4-1 Media-Specific Chemicals of Potential Concern 4-2
4-2 Toxicity Values for Chemicals of Potential Concern 4-5
4-3 Summary of Carcinogenic Risks by Exposure Scenario 4-8
4-4 Exposure Scenarios Exceeding Acceptable Carcinogenic Exposures 4-9
4-5 Summary of Uncertainties ". 4-11
6-1 National Contingency Plan Evaluation Criteria for Detailed Analysis of Remedial
Alternatives 6-2
6-2 Summary of Remediation Times for Alternatives 3,4, and 5 and the Preferred Alternative .. 6-6
6-3 Summary of Costs for Alternatives 3, 4, and 5 and the Preferred Alternative 6-7
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LIST OF ACRONYMS
AFB Air Force Base
ARARs Applicable or Relevant and Appropriate Requirements
BACT Best Available Control Technology
bis Below Land Surface
BRA Baseline Risk Assessment
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
COCs Chemicals of Concern
COPCs Contaminant of Potential Concern
CPFs Cancer Potency Factors
DCE 1,1-Dichloroethene
EE/CA Engineering Evaluation/Cost Analysis
EPA U.S. Environmental Protection Agency
FS Feasibility Study
HI Hazard Index
HQ Hazard Quotient
IAS/SVE In Situ Air Sparging/Soil Vapor Extraction
IWTP Industrial Wastewater Treatment Plant
Kd Distribution Coefficient
MAMS Missile Assembly Maintenance and Storage (area)
MCL Maximum Contaminant Level
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NDCSD North Davis County Sewer District
NPL National Priorities List
PAHs Polynucleararomatic Hydrocarbons
PA/SI Preliminary Assessment/Site Investigation
PCBs Polychlorinated Biphenyls
POTW Publicly Owned Treatment Works
OU Operable Unit
R Retardation Factor
RAOs Remedial Action Objectives
RFCs Reference Concentrations
RfDs Reference Doses
RJ Remedial Investigation
RMEs Reasonable Maximum Exposures
ROD Record of Decision
SARA Superfund Amendments and Reauthorization Act
SFs Slope Factors
TCA 1,1,1-Trichloroethane
TCE Trichloroethene
TSCA Toxic Substances Control Act
UDEQ Utah Department of Environmental Quality
UPDES Utah Pollutant Discharge Elimination System
USAF U.S. Air Force
UST Underground Storage Tank
UVB Vacuum Vaporizing Well
VOCs Volatile Organic Compounds
VI
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DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
Operable Unit 6
Hill Air Force Base
Weber County, Utah
Statement of Basis and Purpose
This decision document presents the selected remedy for Operable Unit 6 (OU 6) at Hill Air
Force Buse (Hill AFB), Utah. It was selected in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act of 1986 (SARA), and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP). This decision is based on the
Administrative Record for this site.
The State of Utah concurs with the selected remedy.
Assessment of the Site
Actual or threatened releases of hazardous substances from the 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.
Description of the Selected Remedy
The selected remedy for OU 6 (IRP Sites ST022, OT026, and SD40B) is part of a Basewide
effort to clean up contaminated groundwater, surface water, and soil. At Hill AFB, there are n:r, ;
OUs, all of which are in different stages of investigation or cleanup. IRP Sites ST022 and
OT026 represent Building 1915 and the Asphalt Pad Area, respectively. Because of their
proximity, they were combined to form OU 6.'Operable Unit 6 includes the geographical area
associated with the 1900 and 2000 series buildings on Base, as well as adjacent off-Base areas.
including portions of the Craigdale and Fair Subdivisions of the City of Riverdale, Utah. Other
features included in OU 6 are the Roy Gate Pond and a section of the Davis-Weber Canal.
The selected remedy addresses groundwater contamination in on- and off-Base areas to reduce
concentrations of contaminants and prevent further expansion of the contaminant plume. It also
addresses contaminants in the subsurface soil.
August 1997 1 Hill AFB OU 6 Record of Decision
Final
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The selected remedy includes the following components:
»• Continued operation of the off-Base pump-and-treat groundwater remediation system;
» Collect and treat water from contaminated seeps/springs and discharge to storm sewer;
» Collect and treat water from spring U6-303 and Cooley's Pond and discharge to shallow
aquifer;
» Continued provision of alternate water supplies;
» A pump-and-treat system for the on-Base portion of the east groundwater contaminant
plume;
» Discharge options for the pump-and-treat system include injection wells, infiltration
fields, and discharge to publicly owned treatment works (POTW);
» Natural attenuation for the west groundwater contaminant plume;
» A groundwater monitoring program; and
> Institutional controls.
A remedial goal of 5 micrograms per liter (ug/L) for trichloroethene (TCE) in groundwater, seeps
and springs, and Cooley's Pond will achieve acceptable risk levels and will also meet the
maximum contaminant level (MCL) for TCE under the Safe Drinking Water Act
Polychlorinated biphenyl (PCB) contamination of surface soils at the electrical transformer
substation at Building 2501, discovered during the OU 6 remedial investigation (RI), is being
addressed under the Toxic Substances Control Act (TSCA).
The Building 1946 evaporation pond (IRP Site SD40B), investigated as part of OU 6, has been
found to pose insignificant risks to human health and the environment. No further action is
needed for this site.
Hill AFBOU 6 Record of Decision 2 August 1997
Final
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Statutory Determinations
The selected remedy is protective of human health and the environment, complies with federal
and State of Utah requirements that are legally applicable or relevant and appropriate
requirements (ARARs) to the remedial action, and is cost effective.
This remedy utilizes permanent solutions and alternative treatment technologies to the maximum
extent practicable for this site and satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a principal element. Because this remedy
will result in hazardous substances remaining on site above health-based levels, a review will be
conducted within five years after commencement of remedial actions to ensure that the remedy
continues to protect human health and the environment.
August 1997 3 Hill AFB OU 6 Record of Decision
Final
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
MaxH. Dodson, DATE
Assistant Regional Administrator
Office of Ecosystems Protection and Remediation
EPA Region VIII
Hill AFBOU 6 Record of Decision 4 . August 1997
Final
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STATE OF UTAH DEPARTMENT OF ENVIRONMENTAL
QUALITY
DianneR. Nielson, Ph.D.,
Executive Director
August 1997 5 Hill AFB OU 6 Record of Decision
Final
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HILL AIR FORCE BASE, UTAH
DATE
August 1997
Hill AFB OU 6 Record of Decision 6
Final
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DECISION SUMMARY
Section 1
SITE NAME, LOCATION, AND DESCRIPTION
Hill Air Force Base (Hill AFB) is located
in northern Utah, approximately 25 miles north of
Salt Lake City and about 5 miles south of Ogden.
Hill AFB occupies approximately 6700 acres in
Davis and Weber counties. The Base is bounded
on the west by Interstate 15, on the south by State
Route 193, and on the northeast by the Weber
River Valley (Figure 1-1). The Base is located on
a prominent terrace known as the Weber Delta.
Operable Unit 6 (OU 6), one of nine OUs
at Hill AFB, is located entirely within Weber
County. As is shown in Figure 1-2, OU 6 in-
cludes buildings and adjacent land in the 1900 and
2000 areas, as well as portions of the Craigdale
and Fair subdivisions of the City of Riverdale,
Utah. The 2000 area, along with buildings in the
2100 and 2200 areas, comprises a security area
known as the MAMS-2 (Missile Assembly Mainte-
nance and Storage) area. The on-Base buildings
within OU 6 are occupied and operated by the
Silo-Based ICBM Program Office. Other promi-
nent features within the site are the Waste Asphalt
Pile, the Roy Gate Pond, and a portion of the
Davis-Weber Canal.
Separating the on-Base portion of OU 6
from the off-Base portion is a steep, terraced,
north-facing escarpment that forms the south wall
of the Weber River Valley. There is over 200 ft of
relief between Hill AFB and the valley below. The
land surface in the on-Base portion of OU 6 and in
the Craigdale and Fair subdivisions is generally
level.
The Davis-Weber Canal is located off
Base (Figure 1 -1) and is situated about one-third of
the way down the escarpment. It is a privately
owned irrigation canal that supplies water diverted
from the Weber River from mid-April to mid-
October. The canal is concrete lined, but contains
several visible cracks in the stretch passing through
the site. Continuous monitoring of spring flow
volume in the Craigdale Subdivision indicates the
canal is not leaking appreciably in the OU 6 area.
Testing activities adjacent to the canal have shown
the shallow groundwater level to be about 80 ft
below land surface (bis), or about 75 ft below the
canal bottom.
Land use on Base at OU 6 is military
industrial and immediately off Base is mostly
residential with some agricultural use. There are
no hospitals, retirement or nursing homes, schools,
nurseries, or daycare centers currently located
within OU 6. The nearest daycare or school is 1.3
miles from contamination associated with the site.
It is approximately 1,600 ft from the
suspected groundwater plume source area at OU 6
to the Base boundary (traveling along the line of
the groundwater plume) and approximately 2,000
ft from the source area to the nearest off-Base
residence. Currently, the off-Base portion of the
groundwater contaminant plume underlies more
than 30 private residences in the community of
Riverdale.
Municipal water for the City of Riverdile
is supplied by the Weber Basin Conservancy
District. The district provides water from wells
that tap deep aquifers that are unaffected by con-
taminants associated with OU 6. Shallow ground-
water is not currently used as a source of drinking
water in the area, but is used for lawn and garden
irrigation and livestock and pet watering by some
of the off-Base residents.
August 1997
1-1
Hill AFB OU 6 Record of Decision
Final
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WEBER COUNTY
DAVIS COUNTY
HILL
AIR FORCE
BASE
Figure 1-1. Location of Operable Unit 6 at Hill Air Force Base
Hill AFB OU 6 Record of Decision
Final
1-2
Auaust I991]
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-026 BUILDING NUMBER
:.;o:«: FORMER BUILDING LOCATION
• BASE BOUNDARY
Figure 1-2. Operable Unit 6 Site Map
August 1997
1-3
Hill AFB OU 6 Record of Decision
Final
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Land within OU 6 is not located within the groundwater for drinking water, there are no uses
100-year floodplain. There are no jurisdictional or known occurrences of commercially valuable
wetlands, as regulated by the U.S. Army Corps of natural resources within the OU 6 area.
Engineers, within OU 6. Apart from deeper
Hill AFBOU 6 Record of Decision 1-4 August 1997
Final
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Section 2
SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 History of Site Activities
The mission of Hill AFB has generally
centered on the maintenance and management of
aircraft and missiles assembly. There are many on-
Base industrial facilities that support aircraft,
missile, vehicle, and railroad engine maintenance
and repair operations. These industrial operations
use numerous chemicals, including solvents and
degreasers, fuels, acids, bases, and metals. Histori-
cally, these chemicals and their associated waste
products were disposed of at the Base Industrial
Wastewater Treatment Plant (IWTP), in chemical
disposal pits, in waste disposal ponds, or in land-
fills.
Most of the on-Base buildings within the
OU 6 site have had a varied history of maintenance
and testing operations or of playing a support role
(e.g., storage) for these operations. These opera-
tions used various solvents for cleaning purposes
and fuels for testing purposes. Underground
storage tanks (USTs) and associated piping that
contained solvents may have leaked and contami-
nated the soil and groundwater. The specific cause
of the release of solvents to the environment is not
known.
2.2 Enforcement Activities
In 1987, fie U.S. Environmental Protec-
tion Agency (EPA; placed Hill AFB on the Na-
tional Priorities List (NPL) under CERCLA. On
April 10, 1991, Hill AFB entered into a Federal
Facilities Agreement with the Utah Department of
Environmental Quality (UDEQ) and the EPA to
establish a procedural framework and schedule for
developing, implementing, and monitoring appro-
priate response actions at the site in accordance
with existing regulations.
Prior response actions taken by Hill AFB
to prevent exposure to contamination associated
with the OU 6 site include the following:
»• Providing an alternate source of clean
irrigation water to two homes known to be
affected by shallow groundwater contami-
nation.
» Collecting and treating contaminated
water from springs and field drains. The
treated water is discharged to a storm
sewer.
» Extracting and treating contaminated
groundwater in the off-Base area as part of
a removal action described in the Action
Memorandum (Radian, 1996a).
The provision of alternate water supplies and
collecting and treating contaminated water from
springs and field drains were actions taken as part
of a Basewide removal to address such releases.
23 Investigation History
During 1988, investigative activities began
in the area now designated as OU 6 when the U.S.
Air Force (USAF) conducted water sampling in the
Craigdale subdivision area. This sampling discov-
ered chlorinated solvents (primarily trichloro-
ethene, or TCE) in shallow groundwater and
surface water. On the basis of the suspected
direction of shallow groundwater flow through the
area, Hill AFB began investigative activities in the
northern portion of the Base to determine the
source of the contamination.
These subsequent investigative activities
were performed under a Preliminary Assess-
ment/Site Investigation (PA/SI), and the findings
suggested locations within Hill AFB were the
source of the contamination found in the off-Base
water. However, detected concentrations of vola-
tile organic compounds (VOCs) in water were
lower on Base than off Base, and insufficient data
were available to determine the lateral or vertical
extent of contamination.
August 1997
2-1
Hill AFB OU 6 Record of Decision
Final
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Following the PA/SI, remedial investiga-
tion (Ri) activities were conducted to further
characterize the extent of contamination in unsatu-
rated and saturated soil zones, the seeps, springs,
and canal, and to evaluate potential downgradient
receptors, aquifer properties, and transport path-
ways. The work is documented in the Remedial
Investigation Report (RI) (Radian, 1995b).
The Baseline Risk Assessment Report
(BRA) for OU 6, which evaluated the potential
human health and environmental effects caused by
chemicals at the site, was released to the public in
April 1995 (Radian, I995a). The Feasibility Study
Report (FS) for OU 6, which identified and evalu-
ated remedial action alternatives, was released to
the public in September 1996 (Radian, 1996b).
At the request of Hill AFB in March 1994,
the Agency for Toxic Substances and Disease
Registry (ATSDR) commented on the public
health implications of contaminants at OU 6.
Their health consultation was based on a review of
site-related records and reports, interviews with
Base personnel and off-Base residents, and two site
visits. The conclusions of their evaluation were:
» VOCs are not present in the air in OU 6 at
levels which represent a health threat;
* VOCs are not present in groundwater or
spring water at levels which represent a
he?i':i threat for people who occasionally
contact the water or use it for irrigation;
and
» VOCs will not bioaccumulate in fruits or
vegetables grown in OU 6 at levels which
represent a health threat.
2.4 Highlights of Community Participation
The public participation requirements of
CERCLA Sections 113(k)(2XBXi-iv) and 117
were met for the remedy selection process. Hill
AFB has a Community Relations Plan, which was
finalized in February 1992. Specific to OU 6,
meetings were held with the public to discuss the
findings of the RJ and the proposed removal
action.
The Proposed Plan for OU 6 (Radian
1996c) was released to the public on November
IS, 1996, for public comment and was mailed to
federal, state, and local agencies, and the Adminis-
trative Record repositories. All documents of the
RI/FS, as they were finalized, were placed in the
Administrative Record, located at the Directorate
of Environmental Management at Hill AFB and at
the Central Branch of the Davis County Library in
Layton, Utah.
The notice of availability of the Proposed
Plan was announced in the Salt Lake Tribune,
Ogden Standard Examiner, Hilltop Times, and
Deseret News, in mid-November 1996. A public
comment period was held from November 15 to
December 16, 1996. No written comments on the
Proposed Plan were received during the public
comment period.
A public meeting in open-house format
was held on December 11,1996, at the Riverdale
Mobile Estates Clubhouse. All interested parties
on the Hill AFB mailing list, which includes
affected residents, were notified in writing about
the session. The purpose of the open house was to
answer questions and accept comments about the
remedial alternatives presented in the Proposed
Plan, including the preferred remedial alternative
for the site, and other topics relevant to OU 6 in an
informal setting. No formal comments were made
during the open house.
2.5 Scope and Role of Operable Unit 6
Within Site Strategy
Response actions at Hill AFB are struc-
tured into nine OUs; most of them, including OU
6, are geographically defined and address all
contaminated media within each unit. Remedial
actions are addressed separately for each OU, and
each of the OUs are at different stages of investiga-
tion or remediation.
The selected remedy for OU 6 incorporates
or builds on prior response actions described in
Hill AFB OU 6 Record of Decision
Final
2-2
August 1997
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Section 2.2 that will continue as part of this rem- plume. Subsurface soil contamination will be
edy. Extraction and treatment of groundwater in addressed by institutional controls. Collection and
the off- and on-Base areas will reduce concentra- treatment of contaminated springs and field drains
tions of contaminants, and hydraulic controls will and the provision of alternate water supplies will
prevent further expansion of the contaminant continue.
August 1997 2-3 Hill AFB OU 6 Record of Decision
Final
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Section 3
SUMMARY OF SITE CHARACTERISTICS
3.1 Topography and Hydrogeology
OU 6 is located in and adjacent to the
northernmost portion of Hill AFB. The topogra-
phy is relatively flat in the on-Base portion of OU
6, dropping steeply to the northeast in the direction
of the City of RJverdale to form a steep hillside.
The OU 6 site overlies two deeper con-
fined aquifers. The Sunset and Delta aquifers are
generally first encountered about 200 and 300 ft
below land surface (bis), respectively. Municipal
groundwater supplies in the area are obtained from
these aquifer systems. It is unclear if the Sunset
and Delta are separate aquifer systems beneath OU
6. Both aquifers are Class HA aquifers under
EPA's groundwater quality classification system.
Under the State of Utah, the Delta aquifer is
classified as a Class lA-Pristine Ground Water
aquifer, and the Sunset Aquifer as a Class II-
Drinking Water Quality aquifer. Natural regional
flow directions for these aquifers is westward.
Under OU 6, the uppermost shallow
(unnamed) aquifer is first encountered at depths
ranging from about 50 to 100 ft in the on-Base
area, and at about 6 to 12 ft in the off-Base area.
Groundwater flow in the shallow system is north to
northeast. Because the extent of the shallow
aquifer at OU 6 is probably relatively limited ?..d
there are no known users of the water for drinking
water purposes, it would probably be classified as
an EPA Class IIB aquifer and as a Class II under
the State of Utah classification.
The major sources of groundwater re-
charge consist of infiltration of precipitation and
seepage from streams and irrigated areas. Shallow
groundwater generally flows from the recharge
areas along the mountain front and on top of the
plateau (on which Hill AFB is located) downslope
to the north and east toward the Weber River
Valley. As the shallow groundwater underlying
the plateau migrates toward the Weber River, seeps
and springs often emanate along the lower portion
of the steep escarpment formed from the
downcutting of the plateau by the Weber River.
These are probably depression springs, resulting
where the water table intersects the land surface.
32 Nature and Extent of Contamination
Environmental samples were taken from
soil, sediment, groundwater, surface water, and air
at the site during the RI. The chemical contami-
nants detected in these media are primarily chlori-
nated VOCs, with TCE being the most prevalent.
3.2.1 Groundwater
As shown in Figure 3-1, there are two
groundwater contaminant plumes at the OU 6 site
which represent TCE in groundwater. TCE is by
far the most widespread and concentrated contami-
nant in both plumes. These plumes are confined to
the shallow aquifer where there are no known users
of the groundwater for domestic purposes. A
comprehensive survey determined that non-munici-
pal water is used for vegetable garden, fruit tree,
lawn irrigation and livestock and pet watering.
TCE and methylene chloride are the only contami-
nants which have been found at concentrations in
excess of their respective maximum contaminant
levels (MCLs) for drinking water. The highest
concentration for methylene chloride has been 7
micrograms per liter (ug/L), but all results above
the MCL (5 ug/L) have been unreproducible. Test
well U6-23, adjacent to the Davis-Weber Canal
(Figure 3-1), had the 7 ug/L detection in the April
1993 sampling event, but concentrations have been
below 5 ug/L in the subsequent eight semiannual
sampling events.
The larger groundwater plume to the east,
which covers approximately 22 acres on Base and
16 acres off Base, is generally first encountered at
about 80 to 100 ft bis in the on-Base area and 5 to
10 ft bis in the residential portion of the off-Base
area. The groundwater surfaces as springs at some
locations along the escarpment. The total volume
of groundwater with TCE concentrations above the
August 1997
3-1
Hill AFB OU 6 Record of Decision
Final
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FAfiR
SUBDIVISION
HOLDING
PONDS
RIVERSIDE
GOLF
COURSE
HILL AFB
MUSEUM
CRAIGDALE
SUBDIVISION
1900 AREA
• tmm V\ff NEW JERSEY DRIVE -1
HILL
AIR FORCE
BASE
NORTH CAROLINA LANE <
LEGEND
Test Well Location
Seeps and Springs
TCE Isoconcentration Contour
(microgram/liter)
Groundwater Flow Direction ;
A — —A' Cross Section Location
1000
Figure 3-1. Extent of Trichloroethene (TCE) Groundwater Plumes
Hill AFB OU 6 Record ot" Decision
Final
3-2
Aueust
-------
MCL of 5 ug/L is estimated at 61 million gallons
for the east plume.
In this plume, TCE concentrations in the
on- and off-Base groundwater are comparable; the
high concentrations detected through test well
sampling are 321 ug/L on Base and 329 ug/L off
Base (near the Davis-Weber Canal). The highest
concentration detected from test wells in the
Craigdale subdivision is 187 ug/L.
The western plume is smaller, contains
lower concentrations of TCE, generally occurs a
little over 100 ft bis, and is entirely within the Base
boundary. The surface area of this plume is ap-
proximately 6 acres, the highest TCE concentration
detected to date is 63 ug/L, and it is estimated to
contain 5 million gal. of groundwater exceeding
the MCL.
The shape of the groundwater contaminant
plumes at the site are based to a large degree on the
lithologic variations in the subsurface. The plumes
are traveling in a primarily sand matrix, with finer-
grained silts and clays limiting lateral and vertical
contaminant migration. Vertical contaminant
distribution profiling has shown decreased concen-
trations with depth through the shallow aquifer,
and no contaminants in the silt and clay confining
strata underlying the aquifer. Hydrogeologic cross
section A-A' (Figure 3-2), which is oriented
northwest to southeast along the Base boundary
(see Figure 3-1 for location), shows the vertical
distribution of TCE in this area. Note that the
contamination is generally found in the 105 to 135
ft bh interval, and concentrations decrease with
depth.
Monitoring of basement air in 17 homes in
the Craigdale subdivision detected several chlori-
nated VOCs, including TCE, chloroform, and
1,1,1 -trichloroethane (TCA), that may be associ-
ated with the groundwater contamination.
3.2.2 Springs, Field Drains, and Surface
Water
Three significant springs or field drains
exist at OU 6. These consist of a spring referred to
as U6-303, which discharges into an off-Base pond
(Cooky's Pond), as well as field drains U6-
603/604 and U6-606 (see Figure 3-1). Groundwa-
ter, springs, and field drains at OU 6 are hydrauli-
cally connected; therefore, springs and field drains
that occur within or near the groundwater plume
area as well as Cooley's Pond contain contami-
nants. However, in comparison with the surround-
ing groundwater, the contaminated springs and
field drains and Cooley's Pond contain fewer
contaminants and concentrations are generally
lower. Field drains U6-606 and U6-603/604 lie
outside the defined groundwater plume, while
spring U6-303 and Cooley's Pond occur within the
groundwater plume. The four volatile organic
compounds (VOCs) which have been detected in
the springs and their maximum detected concentra-
tions (in parentheses) are TCE (180 ug/L), chloro-
form (3 ug/L), 1,1,1-TCA (2.5 ug/L), and cis-1,2-
dichloroethene (2.1 ug/L).
Sediment samples collected from Roy Gate
Pond and the off-Base pond did not contain signifi-
cant contaminant levels. Groundwater is about 75
ft below the Davis-Weber Canal; therefore, there is
no potential for groundwater to contaminate the
water in the canal.
.U Surface Soil
Chemicals detected in surface soil (soil
depths of 0 to 2 ft bis) include pesticides, polynu-
clear aromatic hydrocarbons (PAHs), and
polychlorinated biphenyls (PCBs). Except for
PCBs, these contaminants have been found in
random locations following no discernible pattern.
PCB contamination of surface soils is confined to
the electrical transformer substation at Building
2501 (see Figure 1-2), where detected concentra-
tions range from less than 1 part per million (ppm)
to 34 ppm. PCBs at the active substation are being
addressed under the Toxic Substances Control Act
(TSCA); therefore, PCBs were removed from
further consideration in the CERCLA process for
OU6.
August 1997
3-3
Hill AFB OU 6 Record of Decision
Final
-------
=
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3
-------
3.2.4 Subsurface Soil
Although soil was sampled throughout
both the on- and off-Base areas, contaminated soil
was found only in the on-Base area of OU 6.
Contaminated subsurface soil (soil depths greater
than 2 fit bis) exists in one location in the vicinity
of the 2000 area. The subsurface soil near the
location of two former USTs located near test well
U6-6 (see Figure 3-1) contains chlorinated VOCs-
primarily TCE, TCA, and 1,1-dichloroethene (1,1-
DCE); other VOCs such as ethylbenzene and
xylene; and "unidentified organic compounds"
which may be constituents of stoddard solvent:
The occurrence of organic compounds appears to
be limited to depths of 10 to 22 ft bis, with the
interval from 18 to 22 ft bis containing the highest
concentration. The highest concentrations of TCE
and 1,1-DCE detected in the subsurface soil are
0.467 milligrams per kilogram (mg/kg) and 0.439
mg/kg, respectively. The maximum concentration
of what is believed to be stoddard solvent is 4660
mg/kg.
3.3 Contaminant Fate and Transport
Populations and environmental receptors
that could be affected, if exposed, include Hill
AFB personnel, off-Base residents, future on-Base
residents, and plants and animals in the vicinity.
The OU 6 conceptual model provided as Figure 3-
3 illustrates some of the contaminant fate and
transport principles. Some of the more important
things to note from the model are the residential
nature of the off-Base area and the depths to
groundwater in the on- and off-Base areas.
3.3.1 Fate
Chlorinated VOCs are most likely to
partition to air, followed by groundwater and soil,
and are least persistent in surface water. After
migrating to the air phase, they are usually quickly
dispersed and degraded, except for areas with
limited ventilation such as basements. The parti-
tioning between groundwater and soil of remaining
VOCs can be highly variable, depending on the
soil type. In general, clays more readily sorb
chlorinated VOCs and thus leave fewer contami-
nants to partition to the water phase. In a princi-
pally sandy matrix, such as the shallow aquifer at
OU 6, the majority of contaminants are found in
the water phase. In surface water chlorinated
VOCs tend to readily volatilize to the air because
of the large area for water-air contact, particularly
in turbulent flowing streams with little vegetative
cover. At OU 6, relatively low levels of TCE
have been found in suspected source area soils,
suggesting volatilization and/or degradation pro-
cesses have removed a large portion of the original
source. Modeling has indicated that the TCE and
1,1-DCE present in subsurface soil at OU 6 will
not reach the groundwater at concentrations that
exceed the MCLs. The consistent TCE concentra-
tions over a large portion of the groundwater
plume, coupled with the general absence of degra-
dation products, suggest that TCE is very persistent
in the OU 6 shallow aquifer environment.
3.3.2 Transport
Mechanisms for contaminant transport at
OU 6 include groundwater advection, surface
runoff, volatilization, and infiltration. Each of
these mechanisms is shown on the conceptual
model. Figure 3-3.
Groundwater advection has resulted in the
transport of VOCs into off-Base areas. Testing
performed in the contaminated portion of the
shallow aquifer at the site has resulted in an esti-
mate of the average travel rate for groundwater of
one-third foot per day. Also, desorption tests
performed with aquifer materials from the on- and
off-Base port is of the contaminated aquifer
resulted in estimates for the distribution coefficient
(Kd) of TCE, which is an indicator of whether the
contaminant will remain in soil or travel with the
groundwater. The Kd was then used to determine
the retardation factor (R), which provides an
indication of contaminant migration retardation
relative to natural groundwater flow. The R for the
shallow aquifer materials at OU 6 indicates the
contaminant plume front would be expected to
migrate at about 60% of the rate of advective
groundwater flow.
Groundwater advection has in turn re-
sulted in the contamination of seeps and springs
August 1997
3-5
Hill AFB OU 6 Record of Decision
Final
-------
T)
CO
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O
3.
o
o
SW
Pivcipnation and
inliiiiation ol watei
cany 9Otv»n(j to
(jiuutxltfrataf
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Springs with VOCs
i* catltu and
liurt iietfj U|Xalie
Ciaigdale Subdivision
VOCs m shallow gioundwalui
c
fro
c
VOC«. in Oroundwater and/ex
Air Eiiioiiiig tiasemenl
LEGEND
L»J MtfSKlu.ll BulVIHllS
(hypulhetcal, al Inie ol iatoaa«)
Ailsoibud and Disvihiod Phase
I I Coiiiamnania (imyralmg ttownwaid
1—' lo satwated ion* with intiAiatiog
walei)
BS Ossotveij Pliaso Contaminants
^** (liavgling hi gtoundwalai)
[3 VOCs HI Ihe Sort Gas
—(• Giuuiidwaie' Flow Duaclnn
J-J. ()|KT;il)lc I (nil 6 Conrcptmil Site Model
-------
and when combined with the volatilization mecha-
nism, also has contributed to the presence of VOCs
in indoor basement air. Modeling has indicated
that VOCs in the subsurface soil will not leach to
the groundwater in concentrations that will exceed
the MCLs. Also, other chemicals detected in
surface soils at the site, such as PAHs and pesti-
cides, are not likely to volatilize appreciably or
leach to the groundwater. These contaminants
tend to adhere to soil particles in the surface soil;
however, they may be transported via fugitive dust
or surface water runoff.
3.3.3 Exposure Potential
Current on-Base land use at OU 6 is
restricted to buildings involved in maintenance and
testing operations. Shallow groundwater in the
area is not used as a domestic water source, edible
plants are not cultivated, and the area is not subject
to cattle grazing. Because of the depth of contami-
nation, there is little potential for exposure to
contaminated soil. Therefore, current exposures to
site-related contamination within the OU 6 on-
Base area are not anticipated.
Current land use in off-Base areas is
mostly residential with some agricultural use. Off-
Base residents rely on municipal water for their
domestic supply. Shallow groundwater is not used
as a source of drinking water in the area, but has
been used for lawn and garden irrigation and pet
and livestock watering. There are no contaminated
soils located off Base. The most likely current
exposure to contaminants would be via inhalation
of VOCs migrating upward from the shallow
aquifer.
Effects of exposures to nearby ecosystems
are expected to be minimal. Details regarding the
population and environmental receptors that could
be affected are discussed in Section 4, which
summarizes the findings of the human health and
environmental assessments.
August 1997
3-7
Hill AFB OU 6 Record of Decision
Final
-------
Section 4
SUMMARY OF SITE RISKS
A BRA (Radian, 1995a) was prepared for
OU 6 to evaluate potential health and environmen-
tal effects caused by actual or potential releases of
and exposure to OU 6-related chemicals under
current and hypothetical future conditions. The
risk assessment identifies the contaminants of
potential concern (COPCs), current and future
exposure pathways for humans and environmental
receptors, and the probability of adverse effects
resulting from exposure. The four basic compo-
nents of the risk assessment are summarized in this
section: identification of chemicals of potential
concern, exposure assessment, toxicity assessment,
and risk characterization. Detailed descriptions of
the risk assessment are available in the BRA.
4.1
4.1.1
Human Health Risks
Contaminants of Potential Concern
COPCs are "chemicals that are potentially
site-related and whose data are of sufficient quality
for use in the quantitative risk assessment" (EPA,
1989b). All data of acceptable quality from the RI
were used to identify COPCs. Detailed descrip-
tions of the screening and identification process
and criteria are described in the risk assessment
document. Criteria used to select COPCs followed
EPA guidance. In addition, chemicals were
screened against conservative risk-based concen-
trations using calculated preliminary remediation
goals for a residential exposure scenario.
Table 4-1 lists the media-specific CCPCs
and associated exposure concentration data used
for risk characterization.
The COPC list was further refined into a
list of chemicals of concern (COCs), which are
chemicals that pose the greatest risk or exceed
regulatory standards, and are shown below:
> Groundwater-TCEi
•• Seeps and Springs-TC E; and
»• Subsurface soil-1,1 -DCE.
A detailed description of the process used to
identify COCs is presented in the FS (Radian,
I996a).
4.1.2 Exposure Assessment
Exposure assessment is the determination
or estimation of the magnitude, frequency, dura-
tion, and route of human and environmental expo-
sures to COPCs present at or migrating from a site.
Human exposure to COPCs from OU 6 was evalu-
ated by performing the following tasks: 1) charac-
terizing the potentially exposed population,
2) developing exposure scenarios, 3) identifying
exposure pathways, and 4) quantifying exposures
for each scenario.
4.1.2,1 Current Off-Base Residential Exposure
Scenario
The current land use in the off-Base areas
immediately northeast of the Hill AFB boundary
consists of mostly residential homes and some
small areas used for gardening and livestock
grazing.
Pathways for both child and a<*'ilt recep-
tors include the following:
» Inhalation of volatile compounds from
basement seepage;
*• Ingestion of locally grown fruits and vege-
tables irrigated with contaminated ground-
water; and
» Ingestion of locally produced beef prod-
ucts from animals fed contaminated water
or contaminated feed.
August 1997
4-1
Hill AFB OU 6 Record of Decision
Final
-------
Table 4-1
Media-Specific Chemicals of Potential Concern
JSrtq£tJ5fJPfct5^£B
BBiNtJiBflfaJOBPi*^**K^htfMlM
Grouodwater (pg/L)
Tricblorethene
1,1-Dichloroethene
alpha-BHC
gamma-BHC
i^igsrei
SW8240
SW8240
SW8080
SW8080
"^""^Wffttfrfl^^H
! .v. A^^^^jbt'^ite ;:l
. I
16/24
2/24
2/23
2/23
321
4.81
0.014
0.012
5.0
7.0
_
0.2
Svrface Water Gtg/L)
Trichloroetheoe
Chloroform
Benzo(a)aoihracene
alpha-BHC
gamma-BHC
Chloromethane
bis(2-Ethylhexyl)phthalate
SW8240
SW8240
SW8310
SW8080
SW8080
SW8240
SW8270
3/8
3/8
2/8
1/8
3/8
1/8
1/8
Surface Soils (rag/kg)
Benzo(a)pyrene
Benzo(a)amhracene
Benzo(b)fluoranthene
Indeno( 1 ,2.3-cd)pyrene
2-Methylnapthalene
Phenanthrene
Aldrin
Subsurface Soils (rag/kg)
Stoddard solvent
1,1-Dichloroethene
PCB-1260
SW8270
SW8270
SW8270
SW8270
SW8270
SW8170
SW8080
SW8015ME
SW8240
SW8080
Sediments (mg/kg)
Heptachlor epoxide
Arsenic
SW8080
SW7060
2/12
2/12
2/12
1/12
1/12
2/12
2/12
1/7
7/53
2/31
100
1.9
0.013
0.0085
0.0105
0.81
26.4
0.53
0.51
0.33
0.23
0.07
0.97
0.00799
4660
439
0.0265
1/6
3/6
0.0645
10.2
5.0
3.0
0.1
_
0.2
_
-
_
_
..
—
_
..
—
.
—
—
..
..
' Reporting units expressed in itgfL for groundwater and surface water and mg/kg for soils.
Hill AFB OU 6 Record of Decision
Final
4-2
August 1997
-------
The BRA (Radian, 1995a) used standard
equations and assumptions in available EPA guide-
ance to quantify chemical intake and documents all
the equations and assumptions used.
4.1.2.2 Future Off-Base Residential Exposure
Scenario
According to population demographics for
Davis County, the population increased by 22%
from 1980to 1987 (146,540 to 179,000). Other
areas near Hill AFB saw population increases;
adjacent Weber County population experienced an
8.5% increase. The City of Ogden also experi-
enced slight population growth.
The most likely future changes in land use
in the area include increases in residential housing
and decreasing agricultural activities. New resi-
dents will most likely be connected to the munici-
pal water supply but could use shallow wells and
drains for lawn and garden irrigation. New resi-
dents may elect to install shallow groundwater
wells even though higher quality water is readily
available from other sources (i.e., municipal
sources and deeper aquifers).
Pathways for both child and adult recep-
tors include the following:
» Inhalation of volatile compounds from
basement seepage;
» Inhalation of volatile compounds while
showering;
» Dermal contact with contaminated water
while showering;
» Ingestion of contaminated drinking water;
»• Ingestion of locally grown fruits and vege-
tables irrigated with contaminated ground-
water: and
» Ingestion of locally produced beef prod-
ucts from animals fed contaminated water
or contaminated feed.
4.1.2 J Future On-Base Residential Exposure
Scenario
Residential development is not a likeli-
hood in the on-Base areas of OU 6. However, to
provide a conservative assessment of the potential
risks associated with OU 6, health risks based on a
future on-Base residential development were
evaluated. The future potential exposure pathways
associated with unrestricted, on-Base residential
land use include the following:
*• Inhalation of contaminated fugitive dust
from the site;
* Inhalation of volatile compounds while
showering;
» Dermal contact with contaminated water
while showering;
» Dermal contact with and incidental inges-
tion of contaminated soils;
» Ingestion of contaminated drinking water,
» Ingestion of locally grown fruits and vege-
tables irrigated with contaminated ground-
water; and
» Ingestion of locally produced beef prod-
ucts from animals fed contaminated water
or contaminated feed.
4.1.2.4 On-Base Worker Scenario
If development occurs at OU 6 in the
absence of remediation, on-Base construction
workers could be exposed to site-related chemicals.
Exposure pathways affecting workers engaged in
construction activities include the following:
• Inhalation of contaminated fugitive dust
from the site;
• Inhalation of volatile compounds close to
the source; and
» Dermal contact with and incidental inges-
tion of contaminated soils.
August 1997
4-3
Hill AFB OU 6 Record of Decision
Final
-------
4.13 Toxicity Assessment
Contaminants may have carcinogenic
(cancer-causing) effects or noncarcinogenic/
systemic effects. Exposure to some of the chemi-
cals detected at OU 6 could potentially result in
both types of effects. For carcinogens, it is as-
sumed any amount of exposure to a carcinogenic
chemical poses a potential for generating a carcino-
genic response in the exposed organism.
Noncarcinogenic or systemic effects
include a variety of toxicological end points and
may include effects on specific organs or systems,
such as the kidney, liver, lungs, and others.
Threshold levels generally exist for
noncarcinogenic effects (i.e., a dose exceeding a
certain level must be reached before health effects
are observed). No adverse effects are assumed for
doses below the threshold.
Cancer potency factors (CPFs), or slope
factors (SFs), are used to provide conservative
estimates of excess lifetime cancer risks associated
with exposure to potentially carcinogenic chemi-
cals. SFs, which are expressed in units of (mg/kg-
day)'1, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an
upper bound estimate of the excess lifetime cancer
risk associated with exposure at the intake level.
The term "upper bound" reflects the conservative
estimate of the risks calculated from the SF. Use
of this approach makes underestimation of the
actual cancer risk unlikely. SFs are derived from
the results of human epidemiological studies or
chronic animal bioassays to which animal-to-
human extrapolation and uncertainty factors have
been applied (e.g., to account for the use of animal
data to predict effects on humans).
Reference doses (RfDs) are used to indi-
cate the potential for adverse health effects from
exposure to chemicals causing noncarcinogenic
effects. RfDs, which are expressed in units of
mg/kg-day, are estimated threshold levels for daily
exposure below which exposure is considered safe
for humans, including sensitive individuals.
Estimated intakes of COPCs from environmental
media (e.g., the amount of a COPC ingested from
contaminated drinking water) can be compared
with the RfD. RfDs are derived from human
epidemiological studies or animal studies to which
uncertainty factors have been applied.
Toxicity values used in the health risk
assessment are presented in Table 4-2. SFs and
RfDs are specific to the route of exposure; for
example, oral SFs are used to evaluate risk
through ingestion of a carcinogenic COPC.
Most of the toxicity values in Table 4-2
were obtained from IRIS searches conducted in
August, September, and October 1994 (EPA,
1994a)orfromHEAST(EPA, 1994b). Carcino-
genic values for some PAHs were also calculated
using methods in provisional guidance for calculat-
ing the potential potency on the basis of values for
benzo(a)pyrene (EPA, 1993). Table 4-2 does not
list dermal toxicity values. The RfDs for most of
the COPCs pertain to applied oral doses. To
evaluate dermal exposures, oral toxicity values
were used to derive dermal values initially using a
default value of 5% for oral absorption, according
to EPA guidance provided in RAGS Volume A,
Appendix A (EPA, 1989b). For chemicals contrib-
uting significantly to risks using this conservative
method, chemical-specific gastrointestinal absorp-
tion rates were identified and used to adjust oral
toxicity values, also according to guidance in
RAGS.
4.1.4 Summary of Risk Characterization
Carcinogenic and noncarcinogenic risks
were calculated for each of the exposure pathways
for the COPCs and compared with acceptable
levels of risk. For each potentially carcinogenic
COPC, the probability that an individual will
develop cancer over a lifetime was estimated from
projected intake levels and the cancer SF or the
inhalation unit risk. Risks are probabilities that are
generally expressed in exponential form. An
excess lifetime cancer risk of 1 x 10"6 indicates that
an individual has a 1-in-l million additional
chance of developing cancer as a result of site-
related exposure to a carcinogen over a 70-year
lifetime under specific exposure conditions at OU
6.
Hill AFB OU 6 Record of Decision
Final
4-4
August 1997
-------
Table 4-2
Toxicity Values for Chemicals of Potential Concern
oo
o
i/> «
2.3.
!•••
Aldrin
alpha-BHC
Arsenic
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
bis(2-Ethylhexyl)phthalate
Chloroform
Chloromethane
1,1-Dichloroethene
Fluoride
gamma-BHC
Heptachlor epoxide
Indeno( 1 ,2,3-cd)pyrene
2-Methylnaphthalene
Phenanthrene
9SS
•MH^HB
B2
B2
A
B2
B2
B2
B2
B2
C
C
—
B2/C
B2
B2
D
D
^^^^^^^^•IDMfJL
^^^^^^^^^HM""M*£
f^^^^^^^^^K
3 E-05 •
2.16E-04'
3E-041
_.
_
—
2E-021
1 E-02*
—
9 E-031
6 E-021
3E-041
1.3E-051
..
—
—
EggMBHI
3 E-05 b
2. 16 E-03 e
3E-04"
..
—
..
—
lE-02b
—
9E-03"
6 E-02 b
3E-03b
1.3E-05b
..
—
—
li^Hw^Sl^^B^^I^^^^I
—
—
—
—
..
—
—
—
—
—
—
—
—
_
—
—
J-liF-U .. ........ i
i-'i.:!i.iiiv.'Lj- J
—
~
~
—
—
_
2 E-01 '
—
—
—
—
—
—
—
—
--
•r •v'*-*»'iri v['
1.7E+01 '
6.3E+001
1.75E+00*
7.3 E-01 d
7.3E+001
7.3 E-01 d
1.4E-021
6.1 E-03*
I.3E-02"
6 E-011
—
1.3E+OOb
9.1E+001
7.3 E-01 d
—
--
iSffiffij
mfimSSm
4.9 E-03 '
1.8 E-031
4.3E-03 '
—
._
—
4.0E-06 '
2.3 E-05 '
1.8E-06"
5 E-05 '
-.
—
2.6E-03 '
—
—
-
o
r>
-------
fi
ife
»
3.
8,
D
Table 4-2
(Continued)
Stoddard solvent
1,1,1 -Trichloroethane
Trichloroethene
„
D
B2/C
6E-OI*
9E-02"
—
__
9E-01h
—
„
2E+00'
—
__
—
—
»_
_-
1.1 E-02f
__
..
1.7E-06'
EPA Class
A - Human Carcinogen (sufficient evidence of carcinogenicity in humans)
B2 - Probable Human Carcinogen (sufficient evidence of carcinogenicity in animals with inadequate or lack of evidence in humans)
C - Possible Human Carcinogen (limited evidence of carcinogenicity in animals and inadequate or lack of human data)
D - Not classifiable as to Human Carcinogenicity (inadequate or no evidence)
' IRIS on-line search. August to October 1994 (EPA. I994a).
b HEAST (EPA. 19946)
c Derived value; based on relative potency to ginuni-Bf"" See Appendix H of BRA (Radian. 1995a) for discussion.
d Calculated using potential potency factors (EPA, 1993).
c Derived provisional value; Superfund Health Risk Technical Support Center (EPA. I994c).
' Recommended value; Superfund Health Risk Technical Support Center (EPA. 1994c).
' Derived value; see Appendix H of BRA (Radian I995a) for discussion.
b HEAST (EPA. 1992).
-------
To address the range of exposures that
may occur now and in the future, both average and
reasonable maximum exposures (RMEs) were
considered. Inclusion of both average and RME
values allows risks to be estimated for the upper
bound exposure situation and the more typical or
average exposure. The resulting risk estimates then
present a range of possible risks based on the range
of possible exposure conditions.
The EPA Superfund site remediation goal
set forth in the National Oil and Hazardous Sub-
stances Pollution Contingency Plan (NCP) allows
a cancer risk of 10" (1 in 10,000) to 10'''(! in 1
million). This range is designed to be protective of
human health. The cancer risk of 10"*, based on
reasonable maximum exposure, is the required
point of departure for addressing risks. A cancer
risk of 1 in 1 million is considered a de minimis
level, or a level of negligible risk, for risk manage-
ment decisions.
Table 4-3 summarizes the cancer risk
estimates for each exposure scenario. The average
and reasonable maximum risk estimates for
the present off-Base beef consumer and the aver-
age risk estimates for the off-Base resident are
below the Superrund site remediation threshold for
cancer risk of 1O*6 (1 in 1 million).
Those exposure scenarios in Table 4-3 that
had a risk greater than 10"4 were the future off-
Base resident (adult), and the future on-Base
resident (age-adjusted and adult). These scenarios
were then reviewed further and the contribution of
individual contaminants to the total exposure
scenario risk was determined. Table 4-4 details the
contribution of all contaminants that individually
contribute a risk greater than 10"6 for these scenar-
ios. The following contaminant/media combina-
tions generally represent the vast majority (i.e.,
greater than 95%) of risk at this site: 1,1 -DCE and
TCE in water. Other contaminant/media combina-
tions cumulatively contributing less than 5% of the
risk include 1,1 -DCE in subsurface soil,
benzo(a)pyrene in surface soil, aldrin in surface
soil, and chloroform in basement air. 1,1-DCE,
aldrin, benzo(a)pyrene, and chloroform were
eliminated as COCs on the basis of the discussion
below. For a more detailed discussion of these
contaminants, see the FS (Radian, 1996a).
The RI results indicate that 1,1 -DCE is not
prevalent in the groundwater and that the low
concentrations of this compound do not warrant
remediation. This chemical has been detected in
only one well and has not been detected in concen-
trations that exceed its MCL.
The aldrin detection which caused a risk
greater than 104was in a sample collected from a
well-maintained park area north of Building 1915.
It is likely that aldrin was associated with former
routine Base pesticide spraying and not with waste
disposal activities at OU 6. The calculated risk
from aldrin was slightly 6ver 10"6 and was deter-
mined using very conservative assumptions which
overestimate the risk. Thus, aldrin was not consid-
ered to pose a risk significant enough to retain it
as a COC.
Benzo(a)pyrene was detected in soils at
levels which show a risk greater than 10"6. Each
location had a detection of benzo(a)pvrene in the
surface or shallow soils, but no contaminants were
found in soils deeper than 9 ft. Both locations are
adjacent to roads. One is in an off-Base area along
the dirt road adjacent to, and on the north side of
the Davis-Weber Canal. The presence of
benzo(a)pyrene at this location midway down the
hillside is unlikely to be associated with operations
on the Base. The other location is on Base in the
2000 area adjacent to an asphalt road. PAHs are
often associated with the incomplete combustion of
organic material (e.g., petroleum products), and are
commonly found in vehicle exhaust and asphaltic
road materials. Due to the common occurrence of
this chemical near roads and the locations of the
detections at OU 6, it was not retained as a COC or
recommended for remediation.
Data on chloroform sampling and results
indicates mat occurrences of chloroform in ground-
water are scattered and appear unrelated both to the
VOC groundwater plume and to the detected
August 1997
4-7
Hill AFB OU 6 Record of Decision
Final
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Table 4-3
Summary of Carcinogenic Risks' by Exposure Scenario
Present
Off-Base Residents
Off-Base Beef Consumers
On-Base Workers
6E-07
5E-11
NA
Future
Off-Base Residents
On-Base Residents
On-Base Construction Workers
2E-05
2E-05
NA
4E-06
4E-10
NA
8E-05
1E-04
NA
4E-07
2E-11
6E-08
4E-06
2E-10
4E-07
IE-OS
IE-OS
3E-08
1E-04
2E-04
5E-07
NOTE: Risk estimates printed in bold type equal or exceed the Superfund site remediation threshold of l(f (1 in one million) for
carcinogens.
NA - N« Applicable '
* Carcinogenic risk is expressed as a unities* probability of an individual developing cancer.
'For residential exposure scenarios, risks were estimated for an individual whose exposure begins at birth and extends for nine yean
(avenge case) or 30 yean (reasonable maximum case).
Hill AFB OU 6 Record of Decision
Final
4-8
August 1997
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Table 4-4
Exposure Scenarios Exceeding Acceptable Carcinogenic Exposures
Future Off-Base Residents
Adult-RME
1E-04
1,1-Dichloroethene
Trichloroethene
Chloroform
All others
0
6E-07
2E-06
0
5E-05
5E-05
0
SE-07
SE-05
5E-05
2E-06
5E-07
Future Hypothetical On-Base
Residents
Age-adjusted - RME
1E-04
1,1-Dichloroethene
Trichloroethene
Benzo(a)pyrene
Aldrin
All others
4E-05
5E-05
0
0
4E-07
3E-05
0
IE-OS
4E-06
3E-06
7E-05
4E-05
IE-OS
4E-06
3E-06
Future Hypothetical On-Base
Residents
Adult - RME
2E-04
1,1-Dichloroethene
Trichloroethene
Benzo(a)pyrene
Aldrin
All others
5E-05
5E-05
0
0
4E-07
2E-05
0
6E-06
2E-06
2E-06
7E-OS
SE-05
6E-06
2E-06
3E-06
1 Air pathways include:
Inhalation of basement air.
2 Water (i.e., groundwater, seeps and springs) pathways include:
Ingestion of contaminated water;
Inhalation while showering with contaminated water,
Dermal contact while showering with contaminated water, and
Ingestion of fruits and vegetables irrigated with contaminated water (as appropriate).
3 Soil pathways include:
Inhalation of fugitive dust from contaminated soil;
Ingestion of contaminated soil;
Dermal Contact with contaminated soil; and
Ingestion of fruits and vegetables grown in contaminated soil (as appropriate).
RME = Reasonable Maximum Exposure scenario
August 1997
4-9
Hill AFB OU 6 Record of Decision
Final
-------
concentrations in indoor air at off-Base locations.
Additionally, the chloroform concentrations in
basement air were below the nationwide back-
ground mean for chloroform in indoor air (Shah
and Singh, 1988).
To characterize the potential systemic
effects of chemicals, comparisons were made
between projected intakes of COPCs over a speci-
fied time and toxicity values, primarily oral and
dermal RfDs and inhalation reference concentra-
tions (RfCs). A hazard quotient (HQ), which is the
ratio between exposure to a chemical and that
chemical's toxicity value, was calculated for each
COPC and exposure pathway. Chemical-specific
HQs were then summed for each COPC and each
pathway of exposure to calculate the total hazard
index (HI) for each exposure scenario.
The HI is not a statistical probability of a
systemic effect occurring. If the exposure level
exceeds the appropriate toxicity value (i.e., the HQ
is greater than 1), there may be cause for concern.
The Superrund site remediation goal for
noncarcinogens is a total HI of 1.
The BRA indicates that none of the hazard
indices calculated for the potentially exposed
populations exceeded 1.0; however, the separate
analysis for "unidentified organic compounds"
assumed to be stoddard solvent indicated a hazard
index greater than 1.0 for a hypothetical future
child exposure. This exposure would be pos'.ble
only if contaminated soils 18 to 22 ft deep were
brought to the surface (e.g., during excavation for
a basement or home foundation), and were then
part of the residential exposure scenario. Stoddard
solvent was not detected in groundwater at the site.
Furthermore, the hazard index for stoddard solvent
was unconventionally derived using an unverified
toxicity value. Complex organic mixtures like
stoddard solvent are generally not amenable to
evaluation by conventional toxicological methods.
the impact of using unverified toxicity values to
unconventionally determine a hazard index is
typically an overestimation of risk. Because of
unlikely exposure and a probable overestimation of
related risk, stoddard solvent was not included as
aCOC.
After reviewing risk-based, regulatory, and
other considerations associated with identifying
COCs, the following contaminant/media combina-
tions warrant remediation and hence designation as
COCs:
» Groundwater-TCE;
» Seeps and Springs-TCE; and
» Subsurface soil-\, 1-DCE.
4.2 Environmental Evaluation
A qualitative ecological risk assessment
was performed as part of the BRA (Radian, 1995a)
that evaluated the adverse effects on ecological
receptors at OU 6. No areas at OU 6 have been
classified as critical habitats for endangered spe-
cies; currently, no threatened or endangered.spe-
cies included on current lists of endangered and
threatened wildlife and plants are full-time resi-
dents of the Base. Although no threatened or '
endangered species reside on Base, two endan-
gered species, bald eagles and peregrine falcons,
reside nearby. The BRA concluded that no signifi-
cant accumulation of chemicals should occur in
animals at the site because of the contaminants at
OU6.
4 J Uncertainty Analysis
Uncertainty is inherent to the risk assess-
ment process. The uncertainty analysis identifies
key uncertainties so that a level of confidence in
the cancer and noncancer risk estimates can be
considered when risk management decisions are
made. Table 4-5 summarizes uncertainties associ-
ated with the risk assessment for OU 6.
4.4 Overview of Site Risks
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.
Hill AFB OU 6 Record of Decision
Final
4-10
August 1997
-------
Table 4-5
Summary of Uncertainties
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3S*QuanttntfT6tt£?
z^ia^ffiasrsftSZ
-T.-._;rTjjsnecr ----^-v
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Physical Setting/Potentially Exposed Populations
On-Base residential
land use
Residential use of shal-
low groundwater
Use of default
assumption
Use of default
assumption
Overestimates risk
Overestimates risk
Chemicals of Potential Concern
Pesticide presence
PAH presence
Chloroform
Sporadic presence
Sporadic presence
Source of contam-
inant
Overestimates risk
Overestimates risk
Appears to overesti-
mate risk
Removal of condition would make risks
from on-Base surface soils negligible.
Removal of condition would make shallow
groundwater negligible contributor to risk
for all but basement air pathway.
Risks of exposure to aldrin and other
pesticides may not be attributable to waste
management activities at OU 6. Risk
characterization **«""?$ site-wide
occurrence.
Risks of exposure to PAHs may not be
attributable to waste management activities
at OU 6. Risk characterization assumes site-
wide occurrence.
Major contributor to basement air risks, but
not believed to be site related.
Exposure Assessment
Pathways combine
maximally in single
individual
Exposure concentration
based on detected
concentrations
Use of default
assumption
Possibility that
breakdown
products of
existing chemicals
might appear in
the future
Overestimates risk
Possibly
underestimates risk
Unlikely that significant population will be
maximally exposed by all pathways.
Although vinyl chloride has not been
detected at the site, and only very low
concentrations of other TCE breakdown
products have been detected, their
appearance in the future could increase site-
related risks.
Toxicity Assessment
Toxiciry values missing
for some compounds
Use of unverified val-
ues for trichloroethene
and other chemicals
Possible synergistic or
antagonistic effects of
multichemical exposure
Values lacking
Verified values
lacking
Whether combined
chemicals will
have synergistic or
antagonistic
effects
Underestimates risk
Overestimates risk
Likely overestimates
risk
Because materials lacking values are
generally of low toxicity. and only two
COPCs lacked values, the impact is
probably negligible.
Not including trichloroethene in risk
characterization would significantly reduce
site-related risks.
Cancer risk and hazard indices are summed
to account for possible synergistic effects.
August 1997
4-11
Hill AFB OU 6 Record of Decision
Final
-------
Remedial action at OU 6 is warranted on ally warranted when MCLs are exceeded. TCE
the basis of potential future risks to human health associated with domestic groundwater use accounts
and the environment (i.e., to prevent a significant for the majority of the risk by ingestion, inhalation,
risk to residents). Also, remedial action is gener- and dermal pathways.
Hill AFBOU 6 Record of Decision 4-12 August 1997
Final
-------
Section 5
DESCRIPTION OF ALTERNATIVES
This section describes the alternatives that
were developed to meet the remedial action objec-
tives (RAOs) for OU 6. More detailed information
on the alternatives is presented in the Feasibility
Study Report (Radian, 1996b). The RAOs are as
follows:
» Restore the groundwater aquifer and seeps
and springs, and the Cooky's Pond water
to TCE concentrations of 5 ug/L or less
(i.e., the drinking water standard), which
results in a risk that is protective of human
health.
» Prevent human exposures to 1,1 -DCE in
subsurface soil that lead to a total excess
cancer risk for 1,1 -DCE greater than 10"6.
This corresponds to a concentration of 26
ug/kg or lower.
The area of groundwater with contaminant
concentrations that exceed the MCL for TCE is 6
acres in the west plume and 38 acres (22 acres on
Base; 16 acres off Base) in the east plume. The
volume of contaminated groundwater in the west
plume is estimated to be 5 million gal.; that of the
east plume is estimated to be 61 million gal. (see
Figure 3-1).
The area of subsurface soil that exceeds
the RAO for soil is limited to an area of approxi-
mately 3300 ft2 and a thickness of 4 ft (18 to 22 ft
bis). The volume of soil contamination is esti-
mated to be 490 yd3.
5.1 Elements Common to All Alternatives
There are two elements common to all of
the alternatives which are discussed here for
conciseness.
1. Because these alternatives will result in
hazardous substances on-site above
health-based levels, a review will be
conducted within five years after com-
mencement of the remedial action to
ensure that the remedy continues to
provide adequate protection of human
health and the environment.
2. The Utah Department of Natural Re-
sources, Division of Water Rights has
developed a groundwater management
plan for the Weber Delta sub-area of the
East Shore area, which includes Hill
AFB. Areas of groundwater contamina-
tion surrounding Hill AFB are identified
as restricted. No new wells will be
permitted in the restricted areas nor will
change applications which propose to
transfer water into these areas be
granted. When the contamination is
successfully cleaned up and no longer
poses a threat to groundwater aquifers.
the State Engineer will consider allowing
the construction of wells in these areas.
Before that time, alternate water supplies
will be provided if necessary.
Alternatives 2 through 5 all include
additional institutional controls to prevent com-
pletion of potential exposure pathways or to
protect facilities installed as pan of the remedy.
Institutional controls for properties not
fee-owned by the Air Force will include: (1)
water rights and well drilling restrictions and
advisories to prevent exposure to contaminated
groundwater; and (2) fencing with warning signs
to restrict access to exposure areas, construction
areas, and treatment facilities. Leases or ease-
ments may be needed to enact some of the institu-
tional controls.
Institutional controls for Air Force fee-
owned property will include: (1) issuing a contin-
uing order which remains in effect as long as the
property is owned by the Air Force which re-
August 1997
5-1
Hill AFB OU 6 Record of Decision
Final
-------
stricts access to or disturbance of contaminated
soil, restricts construction activities, and restricts
installing water supply wells in zones of contami-
nated groundwater; (2) filing a notice to the deed
detailing the restrictions of the continuing order,
and (3) a covenant to the deed in the event of
property transfer.
In the case of the sale or transfer of
property within OU 6 by the United States to any
other person or entity, the Air Force will place
covenants in the deed which 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 succes-
sors in interest. The Air Force will also include
in the deed the covenants required by Section
120(hX3) 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; and (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 correc-
tive action that might be required after the date of
transfer. The righ' of access referenced in the
preceding sentence Jaail include the State of Utah
for purposes of conducting or participating in any
response or corrective action that might be
required after the date of transfer.
In the event that the land use is changed
or structures are removed, the Air Force will
re-evaluate the protectiveness of the remedy
selected for OU 6, and will take any appropriate
remedial action.
5.2 Alternative 1—No Further Action
In Alternative 1, no actions beyond those
proposed in the Hill AFB OU 6 Action Memoran-
dum (Radian, 1996a) are implemented. The Action
Memorandum, which addresses mainly off-Base
actions, proposes a phased approach. The objec-
tive and recommended actions for each phase are
as follows:
> Phase I: Slop Plume Migration in Off-
Base Area. The recommended pump-and-
treat system began operating in the sum-
mer of 1996.
> Phase II: Remove Concentrated Portion
of Off-Base Plume. The recommended
pump-and-treat system began operating in
the summer of 1996.
*> Phase HI: Removal of Canal Contribution
to Plume. Relining the Davis-Weber
Canal is recommended; however, further
data need to be collected to 1) identify
exact sections of the canal requiring refin-
ing, and 2) evaluate the effects of the
anticipated relining. Monitoring the water
levels in wells located above and below
the canal is also included in Phase HI.
» Phase IV: Stop Off-Base Migration. A
pump-and-treat system is recommended;
however, pending the results of an ongo-
ing treatability study of in situ treatment
technologies at OU 6, this recommended
action may be replaced with either the in
situ air sparging/SVE or UVB technology.
» Phase V: Remove Northern Arm of Off-
Base Plume. A pump-and-treat system is
recommended; however, this action will
not be implemented until after the effects
of the other phases can be evaluated.
In Alternative 1, all groundwater in the
east plume is treated until remediation is complete
by the components of the OU 6 Phase I, II, and V
systems, which consist of groundwater extraction,
air stripping, and discharge into a storm drain.
Seep and spring water is also treated until
remediation is completed. No action is taken for
soils. The west groundwater contaminant plume is
remediated by natural attenuation. Figure 5-1
shows the site plan for Alternatives 1 and 2.
Hill AFB OU 6 Record of Decision
Final
5-2
August 1997
-------
Groundwater Extraction
Well Location
Monitor Well Location
Seeps and Springs
Treatment Building
TCE Isoconcentration
Contour
(microgram/liter)
1000
Figure 5-1. Alternatives 1 and 2 Site Plan
Aueust 1997
5-3
Hill AFB OU 6 Record of
r-nui
-------
Phases I and II of the OU 6 removal action
consist of two rows of extraction wells (seven total
wells) in the off-Base area. Extracted groundwater
is treated in a low-profile air stripper, which uses
trays in place of packing for air-water contact.
Treated water is discharged to an existing storm
drain. During initial operation of the treatment
system, the rates of natural attenuation of the TCE
concentrations in the northern arm of the off-Base
portion of the plume (see Figure 3-1) will be
monitored. Groundwater modeling has shown
that TCE concentrations in the northern arm will
decrease to 5 ug/L (the MCL) within five years
through natural attenuation. It is also anticipated
that the concentrations will decrease because of the
Phase I and II treatment system actions.
If the concentrations in the northern arm
are reduced to or below the MCL by natural atten-
uation and operation of the Phase I and II systems,
no additional treatment will be implemented in the
off-Base area. However, if after five years concen-
trations remain above the MCL, additional treat-
ment will be conducted. This treatment, which
corresponds with Phase V, will consist of a row of
two extraction wells in the northern arm of the off-
Base plume. If it becomes necessary to install the
Phase V system, additional soil gas and groundwa-
ter sampling will be conducted to determine the
most appropriate locations for the extraction wells.
Water from three springs and field drains
in the JU 6 area will be collected, treated, and
discharged. At spring U6-303, the spring water
and water from the nearby off-Base pond (Coo-
ley's Pond) will be pumped to a treatment system.
Treatment options include an air stripping system
and an activated carbon adsorption system. A best
available control technology (BACT) analysis
(R307-1 -3, UAC) will be performed if air stripping
is chosen to determine if off-gas collection and
treatment is required. The treated water will be
discharged to the far southeast end of the pond.
The overflow from the pond discharges into the
shallow aquifer.
At field drain U6-603/604 (shown in
Figure 3-1), TCE is remediated by volatilization as
the water cascades into a piped channel and is
discharged to an existing storm sewer. This collec-
tion and treatment system is already in place. At
seep U6-606, if contaminated flow remains five
years after startup of the off-Base treatment system,
water will be collected in the existing cistern and
treated in the air stripper for the off-Base system.
Treated water from the springs and field drains will
meet UPDES requirements (UAC R317-8).
Adoption of this alternative should prevent
groundwater contamination from migrating later-
ally in the direction of the hydraulic gradient (i.e.,
north to northeast away from the Base). Existing
water rights restrictions would prevent access to
the contaminated groundwater. For the west
contaminant plume, this alternative relies on
natural attenuation through natural physical,
chemical, and biological processes to reduce
groundwater contaminant concentrations.
The results of groundwater modeling
indicate that the portion of the off-Base plume
between the Phase I and Phase II treatment systems
will be remediated quickly (2 to 3 years); however,
the remaining portion of the east plume may take
significantly longer to remediate. The rates of
natural attenuation for all areas will be monitored,
and remedial actions will be installed if concentra-
tions do not decrease as predicted.
This alternative incorporates an ongoing
program of semiannual monitoring for groundwa-
ter and seeps and springs at OU 6. Monitoring for
the Davis-Weber Canal, which corresponds with
Phase III, is also included.
Remediation times required to reduce TCE
concentrations in groundwater to the MCL of 5
ug/L are estimated to be the following:
» West groundwater plume: 28 to 35 years
(by natural attenuation);
» East groundwater plume, off Base: SO to
75 years; and
Hill AFB OU 6 Record of Decision
Final
5-4
August 1997
-------
»• East groundwater plume, on Base: 50 to
75 years.
The net present value of Alternative 1 is approxi-
mately $2,550,000. This includes a capital cost of
$850,000 and a present worth O&M cost of ap-
proximately $1,700,000. A 30-year period of
operation is assumed for costing purposes.
S3 Alternative 2—Alternative 1 Plus Insti-
tutional Actions
In Alternative 2, all aspects of Alternative
1 are included. Additional monitoring of the
groundwater is included to ensure the effectiveness
of natural attenuation. The site plan is shown in
Figure 5-1.
An expanded monitoring system will be
installed to monitor natural attenuation of both the
east and west plumes. The expanded system will
include the installation and monitoring of four
additional wells and monitoring of four existing
wells that are not monitored under the current
semiannual monitoring programs at the Base. If
concentrations do not decrease as predicted within
five years, remedial actions will be implemented to
remediate the plumes more quickly. The
remediation time frames are the same as for Alter-
native 1.
The net present value of Alternative 2 is
approximately $2,900,000. This includes a capital
cost of $1,000,000 and a present worth "NfcM cost
of approximately $ 1,900,000. A 30-year period of
operation for all components is assumed for cost-
ing purposes.
5.4 Alternative 3—Pump-and-Treat with
Discharge of the Treated Water
This alternative includes all aspects of
Alternative 2. In addition, it includes an on-Base
pump-and-treat system for the west plume and die
on-Base portion of the east plume. The entire west
plume is located on Base, while the east plume is
located partly on Base and partly off Base. For
both areas, the groundwater is treated by air strip-
ping. The groundwater pump-and-treat systems are
intended to shorten the remediation times and act
as hydraulic barriers to prevent the further migra-
tion of the plumes. Figure 5-2 shows the site plan
for Alternative 3.
For the on-Base portion of the east plume,
groundwater will be extracted using two rows of
extraction wells. A row of wells along the Base
boundary will hydraulically contain the groundwa-
ter to prevent it from flowing off Base. These
wells will be monitored for their effectiveness in
hydraulically containing the plume. If the plume is
not contained, additional extraction wells will be
installed until the plume is contained. Another row
of wells will be installed hydraulically upgradie..t
of the Base boundary to capture the plume more
quickly. Pumping tests will be performed to assist
the determination of the final number and spacing
of the extraction wells in the system. The place-
ment of the wells and associated piping may
require rerouting of Perimeter Road. The extracted
groundwater from all of the wells will be combined
and piped to a low-profile air stripper. An analysis
of the best available control technology (BACT)
requirements (R307-1-3, UAC) was conducted.
The analysis indicated that off-gas collection and
treatment will not be necessary for the air stripper.
The air stripper will reduce the TCE
concentrations in the extracted groundwater to 125
ug/L (one-fourth the MCL) or lower. Discharge
options considered for the treated groundwater
include: 1) discharge to the shallow aquifer
through underground injection wells or a subsur-
face drain field, and 2) discharge to the sanitary
sewer, which flows to the North Davis County
Sewer District (NDCSD) publicly owned treatment
works (POTW). Because the discharge to the
shallow aquifer will be essentially the same
whether the drain field or injection wells are
selected, the drain field option will be included for
the purpose of describing this alternative. The
discharge to the POTW will also be included.
The drain field will be installed in a loca-
tion hydraulically upgradient of the plume, as
shown in Figure 5-2. The existing geologic infor-
mation for the area proposed for the drain field
indicates the presence of permeable zones capable
August 1997
5-5
Hill AFB OU 6 Record of Decision
Final
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SANITARY SEWER
CONNECTION
EAST \
UME
Grounowater Extraction
Wan Lo canon
Monitor WeH Location
Seeps and Springs
Treatment Building
TCE Isocorcentranon Contour
(microqram/liter)
500
?•
SCALE: FEET
Figure 5-2. Alternative 3 Site Plan
Hill AFB OL" A Record of Decision
Final
5-6
-------
of receiving the treated water. Percolation tests
have confirmed this capability. The drain field
will be approximately 500 ft long and 200 ft wide.
Piping will be installed to carry treated water from
the air stripper system to the drain field.
Piping will also be installed to carry
treated water from the air stripper to a sanitary
sewer line connection. The POTW is not on or
immediately adjacent to OU 6; however, Hill AFB
currently has a permit to discharge to the NDCSD
POTW. Because the costs for the discharge to the
POTW are higher than for the discharge to the
drain field, the discharge to the POTW will be
used only in the event that the drain field requires
any maintenance activity.
At the west plume, groundwater will be
extracted using a system of extraction wells located
along the downstream edge of the plume. The
extracted groundwater from all of the wells will be
combined and piped to a low-profile air stripper.
A BACT analysis indicated that off-gas collection
and treatment will not be necessary for the air
stripper. Following treatment, the water will be
discharged to a drain field located upgradient of
the plume. Piping will also be installed so that the
treated water can be discharged to the POTW in
case the drain field requires any maintenance.
Remediation times required to reduce TCE
concentrations in groundwater to the MCL of 5
ug/L are estimated to be the following:
> West groundwater plume: 6 to 9 years;
» East groundwater plume, off Base: 2 to 3
years; and
» East groundwater plume, on Base: 20 to
30 years.
The net present value for Alternative 3 is
approximately $5,740,000. This includes a capital
cost of $2,490,000 and a present worth O&M cost
of approximately $3,250,000.
A 30-year period of operation is assumed
for costing purposes for components other than the
groundwater remediation system for the west
plume. For the west plume treatment system, a
conservative remediation time of nine years is
assumed for costing purposes.
5.5 Alternative 4—Alternative 2 Plus In
Situ Remediation of On-Base Plumes
Alternative 4 includes all the elements of
Alternative 2. In addition, it includes in situ
treatment for the west plume and the on-Base
portion of the east plume. The in situ technologies
of air sparging and soil vapor extraction
(IAS/SVE) and UVB {vacuum vaporizing well)
have been evaluated in a treatability study at OU 6
for their effectiveness for the site conditions.
Details of the treatability study are presented in the
Treatability Study Work Plan (Radian, 1994b).
The UVB technology was selected as the represen-
tative in situ technology for the purposes of com-
paring the alternatives.
At the east plume, it is assumed for cost
estimating purposes that one row of UVB wells is
installed at the Base boundary (this row incorpo-
rates the existing UVB well used for the treatabil-
ity study), while additional UVB wells are installed
upgradient along the axis of the plume (see Figure
5-3). The row of UVB wells at the Base boundary
is intended to prevent further off-Base migration of
TCE. Therefore, these wells are placed such that
some overlap of the radius of influence occurs to
ensure effective capture and treatment of the
groundwater plume. The UVB wells along the
axis are placed to treat the hot spot. The placement
of the wells at the Base boundary may require the
rerouting of Perimeter Road. One row of UVB
wells is installed at the west plume. The UVB
wells at the west plume are spaced according to
their estimated radius of influence (with some
overlap). The wells extend past the edges of the
existing plume to allow for expansion of the
August 1997
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/
LEGEND
UVB Wen Location
Groundwaier Extraction
Well Location
Monitor W«0 Location
Seeps and Springs
Treatment Budding
TCE Isoconcentraoon Contour.
(mcrogramfliterj
1000
f n
u
Figure 5-3. Alternative 4 Site Plan
Hil! AFB OLr 6 Record or' Decision
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5-8
Aucust
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plume. The upgradient portion of the plume is
wider than the downgradient portion. If this
expansion continues as the water moves
downgradient, the UVB wells placed outside the
existing boundaries of the plume will capture and
treat this water.
A BACT analysis indicated that off-gas
collection and treatment will not be necessary for
the UVB system.
Remediation times required to reduce TCE
concentrations in groundwater to the MCL of 5
ug/L are estimated to be the following:
» West groundwater plume: 7 to 14 years;
» East groundwater plume, off Base: 2 to 3
years; and
»• East groundwater plume, on Base: 25 to
50 years.
The net present value of this alternative is approxi-
mately $7,170,000. This includes a capital cost of
$3,450,000 and a present worth O&M cost of
approximately $3,720,000.
A 30-year period of operation for compo-
nents other than the west plume treatment system
is assumed for cost estimating purposes. For the
west plume remediation system, a conservative
remediation time of 14 years is used for costing
purposes.
5.6 Alterative 5—Alternative 3 Plus Ac-
celerated Treatment of On-Base Plumes
and Soil Remediation
This alternative includes all the elements
of Alternative 3. In addition, it includes an exten-
sive series of extraction wells to shorten the
remediation timeframe. The presumptive remedy
for soils (i.e., SVE) is implemented for the area of
subsurface 1,1-DCE contamination. Figure 5-4
shows the site for Alternative 5
For the on-Base portion of the east plume,
ground water'will be extracted using a system of
extraction wells located along the Base boundary
and an estimated seven rows of wells along the
length of the plume. The wells along the Base
boundary will hydraulically contain the groundwa-
ter flow off Base. These wells will be monitored
for their effectiveness in hydraulically containing
the plume; if the plume is not contained, additional
extraction wells will be installed until the plume is
contained. The wells along the length of the plume
are placed according to the estimated radius of
influence to achieve complete capture of all water
in the plume as quickly as possible. Pumping tests
will be performed to determine the final number
and optimum spacing of the extraction wells in the
system. The placement of the wells and associated
piping may require rerouting of Perimeter Road
and North Carolina Road. The extracted ground-
water from all of the wells will be combined and
piped to a low-profile air stripper. An analysis of
BACT requirements (R307-1-3, UAC) was con-
ducted, and indicated that off-gas collection and
treatment will not be necessary for the air stripper.
The discharge options for the treated groundwater
are the same as for Alternative 3.
At the west plume, groundwater will be
extracted using a system of extraction wells. The
extracted groundwater from all of the wells will be
combined and piped to a low-profile air stripper.
A BACT analysis indicated that off-gas collection
and treatment will not be necessary for the air
stripper The discharge options considered for die
west pin • ic are the same as those for Alternative 3.
An SVE system is installed to reduce the
concentrations of 1,1 -DCE in the subsurface soil to
the remedial goal of 26 ug/kg. This level corre-
sponds with a total excess cancer risk of 10"6,
assuming direct exposure. The SVE system will
also reduce the concentrations of other VOCs such
as TCE. A cluster of three SVE wells is installed
in the vicinity of the subsurface soil contamination
near test well U6-6. The three wells are screened
at different intervals as follows: 1) 15 to 30 ft,
2) 30 to 45 ft, and 3) 45 to 60 ft. Although con-
tamination was detected in only the 18- to 22-ft
interval, the SVE wells completed at the lower
August 1997
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SANITARY SEWER
CONNECTION
o
* WEST
PLUME
Soil Vapor Extraction
Well Location
Groundwater Extraction
Wen Location
Monitor Well Location
Seeps and Springs
Drain Field
Treatment Building
/ TCE Isoconcentration Contour
(microgranviiier)
500
z
SCALE: FEET
Figure 5-4. Alternative 5 Site Plan
Hill AFB OU 6 Record of Decision
Final
5-10
Aueusi
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intervals will ensure that any other VOCs in the
soil below is removed.
Remediation times required to reduce TCE
concentrations in groundwater to the MCL of
5 ug/L are estimated to be the following:
» West groundwater plume: 4 to 6 years;
*• East groundwater plume, off Base: 2 to 3
years; and
» East groundwater plume, on Base: 12 to
18 years.
Although modeling has indicated that most areas
of the on-Base portion of the east plume could
potentially be remediated in six to nine years, the
presence of the Waste Asphalt Pile will slow the
remediation of the portion of the plume below it.
The net present value for Alternative 5 is
approximately $6,960,000. This includes a capital
cost of $4,320,000 and a present worth O&M cost
of approximately $2,640,000.
A five-year period of operation is assumed
for costing purposes for the SVE system. A 9-year
period of operation is assumed for costing pur-
poses for the east plume groundwater remediation
system, except for monitoring and reporting activi-
ties, which are assumed to be 12 years. For the
west plume treatment system, a conservative
remediation time of six years is assumed for cost-
ing purposes.
August 1997
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Hill AFB OU 6 Record of Decision
Final
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Section 6
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
This section presents a comparative analy-
sis of the five alternatives according to the nine
evaluation criteria specified in the NCP. These
evaluation criteria are divided into three categories:
threshold, primary balancing, and modifying
criteria. The two threshold criteria must be met by
the selected remedy. The five primary balancing
criteria form the basis for comparing alternatives.
The two modifying criteria consider state and
community acceptance. The three categories and
the criteria they include are described further in
Table 6-1.
In the Proposed Plan for Operable Unit 6,
Hill AFB identified its preferred alternative as a
modification to Alternative 3. The preferred
alternative includes all elements of Alternative 3
except it uses natural attenuation, rather than a
pump-and-treat system, to address the west plume
on Base. For this reason, the discussions of Alter-
native 3 in the balancing criteria sections will
specifically address both treatment and natural
attenuation for the west plume. The preferred
alternative and Alternative 3 include the same
discharge options for the treated water that is
extracted from the on-Base portion of the east
plume.
6.1
6.1.1
Threshold Criteria
Overall Protection of Roman Health
and the Environment
Alternative 1, the No Further Action
alternative, is not protective of human health. The
other four alternatives protect human health and
the environment, because they address the risks
posed at the site. All of the alternatives eventually
meet the remedial action objectives of restoring the
groundwater aquifer and seeps and springs to TCE
concentrations of 5 ug/L or less, but only Alterna-
tives 3,4, and 5 do so in a reasonable timeframe.
Alternatives 2, 3,4, and 5 are additionally protec-
tive because they include institutional actions to
ensure that land use in the on-Base area remains
industrial, the groundwater is not extracted from
the shallow aquifer, and the contaminated subsur-
face soil is not excavated. Alternative 5 further
reduces risk by remediation of the subsurface soil.
6.1 J Compliance with ARARs
.The ARARs identified for OU 6 are
presented in Tables A-1 through A-6 of Appendix
A. Tables A-7 and A-8 present the alternative-
specific identification of, and compliance with,
ARARs. Alternatives 1 and 2 will not meet
ARARs because they will not restore the ground-
water in the east plume to beneficial use in a
reasonable timeframe. Because Alternatives 1 and
2 do not meet the threshold criteria, they were
considered no further in the comparison of the
alternatives. Alternatives 3,4, and 5 will comply
with all their applicable chemical-, location-, and
action-specific ARARs. They will meet the MCLs
for groundwater and comply with emissions stan-
dards. Because Alternatives 3, 4, and 5 include
discharge of treated water from the off-Base
treatment systems, they will be required to meet the
substantive requirements for a Utah Pollutant
Discharge Elimination System (UPDES) permit.
For Alternatives 3,4, and 5, the water in
Cooley's Pond will comply with the MCLs be-
cause it will be treated by a ca?' jn adsorption or
air stripping treatment system. For Alternatives 3
and 5, both the injection well and drain field
options for discharge of treated water from the on-
Base treatment systems, as well as the discharge
from Cooley's Pond, will comply with the applica-
ble chemical-specific ARARs, which include the
Utah Groundwater Quality Protection Standards
(R317-6 UAC). They will also comply with the
action-specific ARARs, which include the Federal
and State Underground Injection Control Stan-
dards (40 CFR Parts 144-147 and R317-7 UAC).
Also for Alternatives 3 and 5, the discharge to the
POTW will comply with the action-specific
ARARs, which include the National Pretreatment
Standards (40 CFR Part 403).
August 1997
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Hill AFB OU 6 Record of Decision
Final
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Table 6-1
National Contingency Plan Evaluation Criteria
for Detailed Analysis of Remedial Alternatives
Threshold criteria.
Overall protection of
human health and the
environment and
compliance with
ARARs (unless a spe-
cific APAR is
waived) are threshold
requirements that
each alternative must
meet to be eligible for
selection.
Overall pro-
tection of hu-
man health
and the envi-
ronment
Compliance
with ARARs
Alternatives shall be assessed to determine whether they can ade-
quately protect human health and the environment, in both the short-
and long-term, from unacceptable risks posed by hazardous sub-
stances, pollutants, or contaminants present at the site by eliminating,
reducing, or controlling exposures to levels established during the
development of remediation goals consistent with 40 CFR
§ 300.430(aX2XO- Overall protection of human health and the
environment draws on the assessments of other evaluation criteria,
especially long-term effectiveness and permanence, short-term
effectiveness, and compliance with ARARs.
The alternatives shall be assessed to determine whether they attain
applicable or relevant and appropriate requirements under federal
environmental laws and state environmental or facility siting laws or
provide grounds for invoking one of the waivers under 40 CFR
§300.43
-------
Table 6-1
(Continued)
Primary balancing
criteria (com.)
Reduction of
toxicity, mo-
bility, or vol-
ume through
treatment
Short-term
effectiveness
The degree to which alternatives employ recycling or treatment that
reduces toxicity, mobility, or volume shall be assessed, including
how treatment is used to address the principal threats posed by the
site. Factors that shall be considered, as appropriate, include the
following:
(1) The treatment or recycling processes the alternatives employ
and materials they will treat;
(2) The amount of hazardous substances, pollutants, or contami-
nants that will be destroyed, treated, or recycled;
(3) The degree of expected reduction in toxicity, mobility, or
volume of the waste due to treatment or recycling and the speci-
fication of which reduction(s) are occurring;
(4) The degree to which the treatment is irreversible;
(5) The type and quantity of residuals that will remain following
treatment, considering the persistence, toxicity, mobility, and
propensity to bioaccumulate of such hazardous substances and
their constituents; and
(6) The degree to which treatment reduces the inherent hazards
posed by principal threats at the site.
The short-term impacts of alternatives shall be assessed considering
the following:
(1) Short-term risks that might be posed to the community
during implementation of an alternative;
(2) Potential impacts on workers during remedial action and the
effectiveness and reliability of protective measures;
(3) Potential environmental impacts of the remedial action and
the effectiveness and reliability of mitigative measures during
implementation; and
(4) Time until protection is achieved.
August 1997
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Hill AFB OU 6 Record of Decision
Final
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Table 6-1
(Continued)
Primary balancing
criteria (cont.)
Implement-
ability
Cost
The ease or difficulty of implementing the alternatives shall be
assessed by considering the following types of factors as appropriate:
(1) Technical feasibility, including technical difficulties and
unknowns associated with the construction and operation of a
technology, the reliability of the technology, ease of undertaking
additional remedial actions, and the ability to monitor the effec-
tiveness of the remedy.
(2) Administrative feasibility, including activities needed to
coordinate with other offices and agencies and the ability and
time required to obtain any necessary approvals and permits
from other agencies (for off-site actions);
(3) Availability of services and •materials, including the avail-
ability of adequate off-site treatment, storage capacity, and
disposal capacity and services; the availability of necessary
equipment and specialists, and provisions to ensure any neces-
sary additional resources; the availability of services and materi-
als; and availability of prospective technologies.
The types of costs that shall be assessed include the following:
(1) Capital costs, including both direct and indirect costs;
(2) Annual operation and maintenance costs; and
(3) Net present value of capital and O&M costs.
Modifying criteria.
State and community
acceptance are modi-
fying criteria that
shall be considered in
remedy selection.
State accep-
tance
This assessment includes determining which components of the
alternatives the state supports, has reservations abou>, or opposes.
Community
acceptance
This assessment includes determining which components of the
alternatives interested persons in the community support, have
reservations about, or oppose.
Note: From 40 CFR Section 300.430(eX9)
Hill AFB OU 6 Record of Decision
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6-4
August 1997
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6.2 Primary Balancing Criteria
6.2.1 Long-Term Effectiveness and Perma-
nence
At the conclusion of remedial activities for
Alternatives 3, 4, and 5 and the preferred alterna-
tive, the TCE concentrations in groundwater will
be at or below the MCL of 5 ug/L. For groundwa-
ter, Alternatives 3 and 5 and the preferred alterna-
tive are rated higher than Alternative 4 because
they provide a low level of residual risk while
using an extensive system of groundwater extrac-
tion and air stripping, which are technologies that
have proved to be reliable.
Alternative 5 is ranked slightly higher than
Alternative 3 and the preferred alternative, which
may require longer operation and monitoring.
However, Alternative 5 will require a higher level
of operation and maintenance because of the
additional treatment systems that will be operated.
Alternatives 3 and S and the preferred alternative
are equal in their adequacy and reliability of
controls to manage treatment residuals. The long-
term effectiveness of the preferred alternative,
which includes natural attenuation for the west
plume, is the same as for Alternative 3, which
includes a pump-and-treat system for the west
plume.
For soils, Alternatives 3 and 4 and the
preferred alternative would rank equally. Alterna-
tive 5 receives the highest ranking, because it
results in a slightly lower magnitude of residual
risk because it reduces the contaminant concentra-
tions in the subsurface soil.
6.2.2 Reduction of Toxicity, Mobility, or
Volume Through Treatment
For Alternatives 3, 4, and 5 and the pre-
ferred alternative, the off-Base groundwater extrac-
tion system reduces the volume (and mass) of TCE
in the groundwater and reduces the mobility of the
contaminants through hydraulic containment.
Alternatives 3 and 5 and the preferred alternative
are rated higher than Alternative 4 because they
reduce the mobility of the contaminants in the on-
Base portions of the east and west plumes through
hydraulic containment, and they also significantly
reduce the mass of contaminants in the groundwa-
ter within the west plume and the on- and off-Base
portions of the east plume. Alternative 5 receives
a slightly higher rating than Alternative 3 and the
preferred alternative because it also reduces the
volume (and mass and toxicity) of 1,1-DCE in the
subsurface soil. The preferred alternative, which
includes natural attenuation for the west plume is
ranked slightly lower than Alternative 3, which
includes a pump-and-treat system. The pump-and-
treat option would use treatment to a greater degree
to reduce contaminant volume.
6.2.3 Short-Tenn Effectiveness
There are no additional short-term risks
(from truck traffic, construction dust, noise, etc.) to
the community or the environment that could not
be avoided or minimized. A summary of the
remediation time for Alternatives 3,4, and 5 and
the preferred alternative is presented in Table 6-2.
Alternatives 3 and 5 and the preferred alternative
are rated higher than Alternative 4 because they
require shorter time periods to meet the cleanup
objectives and protect against human exposure to
TCE in groundwater. Alternative 5 receives a
slightly higher rating for short-term effectiveness
than Alternative 3 and the preferred alternative
because it meets the cleanup goals in a shorter time
period. Note that Alternative 3, which includes a
pump-and-treat system for the west plume, is
ranked equally with the preferred alternative,
which includes natural attenuation.
6.2.4 Implementability
The administrative implementability for
Alternatives 3, 4, and 5 and the preferred alterna-
tive is about equal. Alternative 4 is rated lower
than Alternatives 3 and 5 and the preferred alterna-
tive because the reliability of UVB systems has yet
to be demonstrated. Also, the equipment, person-
nel, materials, and services required to implement
the UVB technology are not as readily available as
August 1997
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Hill AFB OU 6 Record of Decision
Final
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Table 6-2
Summary of Remediation Times for Alternatives 3,4, and 5 and the Preferred Alternative
Preferred Alternative
they are for the components of the other alterna-
tives. Alternative 3 and the preferred alternative
are rated higher than Alternative 5 because they
require significantly less equipment and fewer
services to be implemented. The preferred alterna-
tive is rated higher than Alternative 3 because of
its use of natural attenuation, rather than a pump-
and-treat system, for the west plume. Natural
attenuation would require less equipment and
fewer services. The rerouting of roads, if neces-
sary, for Alternatives 3, 4, or S or the preferred
alternative would not significantly affect the
implementabiliry of the alternatives.
6.2.5 Cost
Table 6-3 presents a summary of the
capital, operation, and maintenance costs for
Alternatives 3,4, and 5-and the preferred alterna-
tive. Note that for alternatives with remediation
times of 30 years or longer, a 30-year period was
used for costing purposes. For alternatives with
estimated remediation times shorter than 30 years,
the upper ranges of remediation times were used in
the cost estimates. The preferred alternative has
the lowest cost, followed by Alternative 3, Alterna-
tive 5, and Alternative 4, respectively.
63 Modifiying Criteria
6.3.1 State Acceptance
The State of Utah agrees with the selected
remedy. No change to the selected remedy is
necessary.
6.3.2 Community Acceptance
A public meeting was held on 11 Decem-
ber 1996 to discuss the Proposed Plan. The com-
ments received from the public regarding the
selected remedy are discussed in the Responsive-
ness Summary, which is part of this ROD. No
comments were offered that agreed with or op-
posed the preferred alternative.
Hill AFB OU 6 Record of Decision
Final
6-6
August 1997
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Table 6-3
Summary of Costs for Alternatives 3,4, and 5 and the Preferred Alternative
52,490,000
$3,250,000
$5,740,000
$3,450,000
$3,720,000
$7,170,000
$4,320,000
$2,640,000
$6,960,000
Preferred Alternative
$1,950,000
$2,760,000
$4,710,000
August 1997
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Final
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Section 7
THE SELECTED REMEDY
This section describes the selected remedy
and explains how the selected remedy meets the
statutory requirements.
7.1 Description of the Selected Remedy
The selected remedy is Alternative 3 with
the following modification: the west plume will be
addressed through natural attenuation, rather than
by a pump-and-treat system. Natural attenuation,
rather than pump and treat, was selected to address
the west plume because it provides the same level
of protection of human health and the environ-
ment, and its cost is lower. The selected remedy
includes the following components (see Figure
7-1):
Continued operation of
pump-and-treat system.
the off-Base
A pump-and-treat system for the on-Base
portion of the east plume. The treated
water is discharged into the shallow aqui-
fer via a subsurface drain field. Discharge
piping to a sanitary sewer connection of
the NDCSD POTW will be installed as a
back-up discharge provision.
Natural attenuation of the west plume,
rather than pump and treat.
Treatment of the springs and field drains.
Spring U6-303 and the water in Cooley's
Pond will be treated by an activated car-
bon or air stripping treatment system; field
drain outfall U6-603/604 will be treated
by volatilization in a piped channel; and
U6-606 will be treated in an air stripper if
contaminated flow remains five years after
startup of the off-Base treatment system.
A groundwater monitoring program.
Institutional controls.
» Provisions of alternate water supplies, if
needed, to any residents who are using
spring or field drain water for irrigation.
7.1.1 Remediation Goals and Performance
Standards
The remediation goals for OU 6 are to:
> Restore the groundwater aquifer, seeps
and springs, and Cooley's Pond water to
TCE concentrations of 5 ug/L or less (i.e.,
the drinking water standard), which results
in a risk that is protective of human health.
» Prevent human exposures to 1,1-DCE in
on-Base subsurface soil that lead to a total
excess cancer risk for 1,1-DCE greater
than 10~*. This corresponds to a concen-
tration of 26 ug/kg or lower.
The area of attainment for groundwater is the area
in which TCE exceeds the MCL, and the area of
attainment for subsurface soil is the area in which
1,1-DCE concentrations exceed 26 ug/kg.
7.1.2 Restoration Timeframe
The restoration timeframe for the selected
remedy is as follows:
» East Plume, off Base: 2 to 3 years;
» East Plume, on Base: ?0 to 30 years; and
• West Plume: 28 to 35 years.
7.1.3 Costs
The capital, operation, and maintenance
costs for the selected remedy are as follows:
«• Capital Costs: $1,950,000;
» Operation and Maintenance Costs:
$2,760,000; and
August 1997
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Hill AFB OU 6 Record of Decision
Final
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SANITARY SEWER
CONNECTION
WEST
PLUME
Groundwater Extraction
Wall Location
Monitor Well Location
Seeps and Springs
Drain Field
Treatment Building
' TCE Isoconceniration Contour
(microgram/liter)
On-Base Groundwater
Extraction:
Extraction Wells
Treatment:
Air Snipper
Discharge:
Dram Field/POTW
Natural Attenuation:
West Plume
Off-Base Groundwater
Extraction:
Extraction Wells
Treatment:
Air Stnpper
Discharge:
Pipe to Siorm Drain
Springs. Field Drains, and Pond
Collection:
Sump/Sump Pump iL'6-303)
Treatment:
GAC (U6-303 and Coulcy's Pond)
Discharge:
Pipe to' Storm Drain
Figure 7-1. Selected Remedy for Operable Unit 6
Hill AFB OU 6 Record of Decision
Final
7-2
Aueust
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> Total Present Worth Costs: $4,710,000.
7.2 Statutory Determinations
The selected remedy for OU 6 meets the
statutory requirements of Section 121 ofCERCLA
as amended by SARA. These statutory require-
ments include the following:
» Protection of human health and the envi-
ronment;
»• 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 discussion below explains how the selected
remedy meets the statutory requirements.
7.2.1 Protection of Human Health and the
Environment
The selected remedy for OU 6 protects
human health and the environment through treat-
ment and institutional controls as follows:
» The on- and off-Base pump-and-treat
systems will collect and treat the ground-
water in the east plume until the TCE
concentrations are reduced to 5 ug/L or
less (i.e., the MCL), which results in a risk
that is protective of human health.
» Collection and treatment systems will treat
the water from field drain U6-603/604,
seep U6-606, spring U6-303, and Coo-
ley's Pond until the TCE concentrations
are reduced to 5 ug/L or less, which re-
sults in a risk level that is protective of
human health.
» Institutional controls, including long-term
management of the contaminated subsur-
face soil, deed restrictions for Hill AFB
property, and water rights restrictions, will
be implemented to prevent access to con-
taminated groundwater and soil.
» Monitoring of the groundwater, springs,
and field drains will be conducted to as-
sess progress toward achieving
remediation goals.
Natural attenuation of the west plume is
protective of human health and the environment.
The concentrations of contaminants are relatively
Ic *, and are expected to attenuate to concentra-
tions below drinking water standards before the
groundwater travels off Base. The groundwater in
the shallow aquifer is not currently used, and the
institutional controls described will prevent future
use until remediation is complete. Groundwater is
available from the deeper aquifer systems and is
expected to provide adequate supplies for a
timeframe longer than the attenuation timeframe of
the west plume. The timeframe for natural attenua-
tion is also reasonable in that it is similar to that of
the pump and treat portion of the remedy which
remediates the east plume.
The selected remedy will not cause any
unacceptable short-term risks or cross-media
impacts. Appropriate health and safety procedures
will be followed during implementation of the
selected remedy to minimize short-term risks to the
community, workers, and the environment. A
review will be conducted within five years after the
selected remedy is implemented to ensure that it
provides adequate protection of human health and
the environment.
7.2.2 Compliance with Applicable or Rele-
vant and Appropriate Requirements
Federal and state ARARs are presented in
Tables A-l through A-6 in Appendix A. The
alternative-specific identification of, and compli-
ance with, ARARs is summarized in Tables A-7
and A-8. The ARARs for the preferred alternative
are the same as for Alternative 3 in Table A-8.
The selected remedy will comply with the
August 1997
7-3
Hill AFB OU 6 Record of Decision
Final
-------
chemical-, location-, and action-specific ARARs as
discussed below.
order restricting access to contaminated groundwa-
ter and contaminated soil.
Chemical-Specific ARARs-The selected
remedy will comply with the chemical-specific
ARARs for groundwater, seeps and springs, air
quality, and discharge limits from groundwater
treatment systems.
The selected remedy will comply with the
MCLs, which are specified in the National and
Utah Primary Drinking Water Standards, as resto-
ration goals for the groundwater, seeps, springs,
and Cooley's Pond. By extracting and treating the
contaminated groundwater in the east plume, the
selected remedy will also comply with the Utah
Groundwater Quality Protection Standards. Natural
attenuation of the west plume will meet the MCL
for TCE within a reasonable timeframe given the
circumstances of the site.
The emissions from the air stripping
systems will meet the National Ambient Air Qual-
ity Standards, National Emissions Standards for
Hazardous Air Pollutants, Utah Emissions Stan-
dards for Hazardous Air Pollutants, and Utah
Standards for the Control of Installations.
Location-Specific ARARs-Emissions
from the air stripping systems will meet the Re-
quirements for Ozone Nonattainment Areas, Davis
and Salt Lake Counties, specified in the Utah
Emission Standards.
Action-Specific ARARs-The selected
remedy will comply with the action-specific
ARARs listed in Appendix A.
By extracting and treating the contami-
nated groundwater, the selected remedy will meet
the requirements of the Utah Corrective Action
Cleanup Standards Policy for UST and CERCLA
Sites and the Utah Groundwater Quality Protec-
tion Standards. The selected remedy will comply
with the Utah Cleanup Action and Risk-Based
Closure Standards because it will also implement
long-term management, consisting of water rights
restrictions, deed restrictions, and a continuing
The discharge of the treated groundwater
from the off-Base treatment system and the treated
water from the springs and field drains will comply
with the substantive requirements of the Utah
Pollutant Discharge Elimination System (UPDES).
All activities associated with discharging the
treated groundwater from the on-Base treatment
system into the subsurface drain field and the
discharge from Cooley's Pond will comply with
the Federal and State Underground Injection
Control Standards, as well as the Utah Ground
Water Quality Protection Rule (UAC R317-6).
The discharge of treated water from the on-Base
system to the NDCSD POTW will comply with the
National Pretreatment Standards. The groundwa-
ter monitoring provisions will comply with the
Federal and State of Utah Requirements for Re-
leases From Solid Waste Management Units.
The emissions from the air stripping
systems will comply with the requirements of the
Federal and State Air Emissions Standards, the
Utah Definitions and General Requirements for
Air Conservation, and the Utah Standards for the
Control of Installations.
Cost Effectiveness
The selected remedy, Alternative 3 (with
natural attenuation, rather than pump and treat, for
the west plume) provides a more cost-effective
solution than any of the other alternatives that meet
the threshold criteria. The selected remedy is more
cost effective than Alternative 3 with pump and
treat, because it is equally protective of human
health and the environment, and its cost is lower.
The selected remedy is superior to Alternative 4
for all the balancing criteria. It is also more imple-
mentable and more protective of workers than
either Alternative 3 with pump and treat or Alter-
native 5. Alternatives 3 and 5 and the selected
remedy include the same controls to prevent
exposure to contaminants in groundwater. All
three alternatives would reach the remedial goals,
but Alternative 3 and the selected remedy could
take up to 12 years longer. In Alternative 3, the
Hill AFB OU 6 Record of Decision
Final
7-4
August 1997
-------
west plume will naturally attenuate in approxi-
mately the same timeframe as the east plume is
remediated by the pump-and-treat system. There-
fore, the use of natural attenuation instead of pump
and treat does not substantially change the
remediation timeframe for groundwater restoration
at OU 6. The water rights restrictions imposed
through the State Engineer's Office will prevent
the use of the shallow groundwater until it is
restored. Therefore, the timeframe for the selected
remedy is acceptable, and the additional costs of
Alternative 3 with pump and treat and Alternative
5 are not warranted for the reduced timeframe.
Alternative 3 and the selected remedy are
rated slightly lower than Alternative 5 for long-
term effectiveness and permanence and reduction
of toxicity, mobility, and volume through treatment
only because they do not include treatment for the
contaminants in the on-Base subsurface soils. The
potential risks for soils are within the low end of
the 10"4 to 10°* risk range, which is acceptable but
which still may be potentially significant. How-
ever, the potential risks are based on an unlikely
exposure scenario in which the soils are excavated
and brought to the surface. This scenario is partic-
ularly unlikely because the small volume of con-
taminated soils is deeper than most excavations for
basements for housing construction. Excavation
could be controlled or prevented through the use of
the institutional controls provided in Alternative 3
and the selected remedy. Also, modeling indicates
that ilie contaminants in the soil will not cause
further contamination of the groundwater. There-
fore, the institutional controls in Alternative 3 and
the selected remedy are more cost effective to
implement than the SVE in Alternative 5.
7.2.4 Utilization of Permanent Solutions and
Alternative Treatment Technologies
The selected remedy meets the statutory
requirement to utilize permanent solutions and
treatment technologies, to the maximum extent
practicable. The selected remedy provides the best
balance of tradeoffs among the alternatives with
respect to the five balancing criteria.
The evaluation criteria that were most
critical in the selection decision were long-term
effectiveness and permanence, implementability,
and cost. The selected remedy is superior to
Alternative 4 for all the balancing criteria. The
selected remedy provides the same level of long-
term effectiveness and permanence for groundwa-
ter restoration as Alternative 3 with pump and treat
and Alternative 5. The selected remedy is also
more implementable and cost effective than either
Alternative 3 with pump and treat or Alternative 5.
7.2.5 Preference for Treatment as a Principal
Element
The selected remedy satisfies the prefer-
ence for treatment as a principal element for the
east groundwater plume. The on- and off-Base
pump-and-treat systems will permanently and
significantly reduce the concentrations of TCE in
the groundwater aquifer, seeps, and field drains.
This preference is not satisfied for the west
groundwater plume, where TCE concentrations are
expected to naturally attenuate.
7 J Documentation of Significant Changes
The Proposed Plan for Hill AFB OU 6 was
distributed for public comment on 15 November
1996. A public meeting on the Proposed Plan was
held on 11 December 1996. The Proposed Plan
identified Alternative 3 with natural attenuation
(instead of groundwater extraction/treatment) for
the west plume as the preferred alternative.
Since that time, a new treatment option has
been proposed for spring U6-303 and Cooley's
Pond as part of the preferred alternative. The
existing air stripper treatment system may be
upgraded or replaced by a carbon adsorption
treatment system with a prefilter. Both treatment
options will meet the remedial goal (i.e., the MCL)
for spring U6-303 and the pond water.
Because the configuration of the extraction
wells for the on-Base portion of the east plume has
been modified, the estimated restoration timeframe
for that area has become 20 to 30 years instead of
30 to 45 years.
August 1997
7-5
Hill AFB OU 6 Record of Decision
Final
-------
Also, the discharge option for the on-Base wells. Discharge piping is also included so that
treatment system for the east plume has changed treated water can be discharged to the NDCSD
slightly. The preferred alternative now includes POTW in case of any maintenance problems or
discharge of the treated water through a subsurface activities associated with the drain field.
drain field instead of an underground injection
Hill AFBOU 6 Record of Decision 7-6 August 1997
Final
-------
Section 8
REFERENCES
Agency for Toxic Substances and Disease
Registry (ATSDR), 1994. Health Consultation
for Hill Air Force Base OH 6. Ogden, Utah.
July 1994.
Radian, 1994a. Final Engineering Evaluation/
Cost Analysis for Operable Unit 6, Hill AFB,
Utah, October 1994.
Radian, 1994b. Final Treatability Study Work
Plan for Operable Unit 6. Sites ST22, OT26,
Hill AFB. Utah, October 1994.
Radian, 1995a. Final Baseline Risk Assessment
for Operable Unit 6, Sites 5772, OT26, Hill
AFB. Utah. April 1995.
Radian, 1995b. Final Remedial Investigation
for Operable Unit 6. Sites 5722, 0726", Hill
AFB. Utah. July 1995.
Radian, 1996a. Action Memorandum for
Operable Unit 6. Sites 5722. 0726, SD40B, Hill
AFB. Utah, December 1996.
Radian, 1996b. Final Feasibility Study for
Operable Unit 6. Sites 5722. O72<5, Hill AFB.
Utah, September 1996.
Radian, I996b. Final Proposed Plan for
Operable Unit 6. Hill AFB, Utah, November
1996.
Shah, J.J., and H.B. Singh, 1988. "Distribution
of Volatile Organic Chemicals of Volatile
Organic Chemicals in Outdoor and Indoor Air, A
National VOCs Data Base." Environmental
Science and Technology, Volume 22 (1988).
Number 12.
U.S. Environmental Protection Agency (EPA),
1989a. Guidance on Preparing Superfund
Decision Documents, Interim Final.
EPA/540/G-89/007, July 1989.
U.S. Environmental Protection Agency (EPA),
1989b. Risk Assessment Guidance for
Superfund. Volume 1: Human Health Evaluation
Manual. Part A. EPA/540/1-89/002, December
1989.
U.S. Environmental Protection Agency (EPA),
1992. Health Effects Assessment Summary
Tables (HEAST). Annual FY-1992. OHEO
ECAO-CIN-82 I.March 1992.
U.S. Environmental Protection Agency (EPA),
1993. Provisional Guidance for Quantitative
Risk Assessment ofPolycyclic Aromatic
Hydrocarbons. EPA/600/9-93/089, July 1993.
U.S. Environmental Protection Agency (EPA)
1994a. Integrated Risk Information System
(IRIS). Database search. August-October, 1994.
U.S. Environmental Protection Agency (EPA),
1994b. Health Effects Assessment Summary
Tables (HEAST). Annual FY-1994. EPA 540-
R-94-020, March 1994.
U.S. Environmental Protection Agency (EPA),
1994c. Superfund Health Risk Technical Sup-
port Center. Request for interim guidance on
pending toxicity values. August 1994.
August 1997
8-1
Hill AFB OU 6 Record of Decision
Final
-------
Section 9
RESPONSIVENESS SUMMARY
9.1 Overview
This responsiveness summary provides
information about the views of the community with
regard to the proposed remedial action (RA) for
Hill Air Force Base (Hill AFB) Operable Unit 6
(OU 6), documents how public comments have
been considered during the decision-making
process, and provides responses to concerns.
The public was informed of the selected
RA in the following ways:
» All items contained within the Adminis-
trative Record have been on file in the
Davis County Library and at the Environ-
mental Management Directorate at Hill
AFB since the final version of each docu-
ment was issued. The documents include
the Remedial Investigation Report (Ra-
dian, 199Sb), Baseline Risk Assessment
Report (Radian, 1995a), Feasibility
Study Report (Radian, I996b), and the
Proposed Plan for OU 6 (Radian, 1996c).
» The notices of availability for the docu-
ments in the Administrative Record were
published in the Salt Lake Tribune. Ogden
Standard Examiner, Hilltop Times, and
Deseret News.
»• A newsletter describing the Proposed
Plan was sent to all affected and interested
parties prior to the public comment period.
The newsletter listed the locations where
copies of the Proposed Plan were avail-
able.
»• A public comment period for the Pro-
posed Plan was held from November 15,
1996 through December 16, 1996.
»• A notice about the public meeting was
published in the Salt Lake Tribune. Ogden
Standard Examiner, Hilltop Times, and
Deseret News.
» A public meeting in open-house format
was held on December 11, 1996, at
Riverdale Mobile Estates Clubhouse in
Riverdale Utah.
» Written comments by the public were
encouraged.
9.2 Background on Community Involve-
ment
The public participation requirements of
CERCLA Sections 113(kX2)(B)(i-v)and 117 were
met. Hill AFB has a Community Relations Plan,
based on community interviews that was finalized
in February 1992. The ongoing community rela-
tions activities include:
> A Restoration Advisory Board that meets
at least quarterly and includes community
representatives from adjacent counties and
towns;
*• A mailing list for interested parties in the
community;
» A bimonthly newsletter called
EnviroNews',
» Visits to nearby schools to discuss envi-
ronmental issues;
» Community involvement in a noise abate-
ment program;
»• Periodic briefings to local City Councils:
» Semiannual town council meetings;
» Opportunities for public comment on
remedial activities;
August 1997
9-1
Hill AFB OU 6 Record of Decision
Final
-------
» Support for the community for obtaining
technical assistance grants ; and
» Administrative record and information
repository.
93 Summary of Public Comments
9 J.I Comments on the Proposed Plan
Hill AFB did not receive any formal,
written questions or comments on the Proposed
Plan for OU6 (Radian, 1996c) or any other docu-
ment during the public comment period.
9.3.2 Comments Made During the Public
Meeting
An open house public meeting for OU 6
was held from 4:00 pjn. until 8:00 p.m. on
Wednesday, 11 December 1996 at the Riverdale
Mobilft Estates Clubhouse in Riverdale, Utah.
Representatives from Hill AFB, EPA Region VIII,
and UDEQ were available to explain, and answer
questions about, the results of the investigations,
health issues, and the proposed remedy for OU 6.
A list of all participants in the meeting is included
in Appendix B.
Mr. Esrafil Rahimzadegan and
Ms. Rebecca Rahimzadegan, who attended the
open house, asked whether their residence, which
is located at 5621 South 1150 West in Riverdale,
Utah, was within the area of the OU 6 TCE plume.
Using the posters that were displayed at the open
house, Mr. Steve Hicken (Hill AFB) pointed out
that the plume boundary did not extend to their
residence. Mr. and Ms. Rahimzadegan asked
whether the person who sold them their house
would have known about the TCE in the ground-
water in the OU 6 area. After discussing when they
bought their house, Mr. Hicken stated that the
extent of the TCE plume had not been defined
prior to that time, so the seller may not have been
aware of the location of the plume.
Hill AFB OU 6 Record of Decision
Final
9-2
August 1997
-------
APPENDIX A
Identification of ARARs
-------
Table A-l
Identification of Federal Chemical-Specific ARAJRs: Hill AFB, OU 6
ar:irrr^-m--ih-T-nTigT|
BSsgJsSfflEtSiJFi
^t^Sv^fQSsSlSt^^f^SEs^fSESSl^S^t^^lfftfltft^SuSfflfSfySS''S3B^^S8ffl^Smil^^f^St3^S^^3SSSifB^S^3Of^tH^S^i^^
itiri^™WBSHBSM
Safe DrinklBf Water Act -72 USC J 300
National Primary
Drinking Water
Standards
National Secondary
Drinking Water
Standards
Water Quality Criteria
Toxic Pollutant Effluent
Standards
Criteria for the
Identification and Listing
of Hazardous Waste
Requirements for
Releases from Solid
Waste Management
Units
Land Disposal
Restrictions
40 CFR
Part 141
40CFR
Part 143
Establishes health-based
standards for public water
systems and specifies
maximum contaminant levels
(MCLs); establishes drinking
water quality goals set at levels
of no known or anticipated
adverse health effects, with an
adequate margin of safety.
Establishes wel Are-based
standards for public water
systems and specifies
secondary maximum
contaminant levels (SMCLs).
No/Yes
No/No
OCM Water Act -33DSCH 1251-1376
40CFR
Part 131
40CFR
Pan 129
40CFR
Pan 261
40CFR
Part 264.
SubpanF
40 CFR
Part 268
Establishes criteria for water
quality based on toxicity to
human health and aquatic
organisms-
Establishes effluent standards
or prohibition for certain toxic
pollutants: aldrin/ dieldrin,
DDT, endrin, toxaphene. benri-
dine, and PCBs.
Yes/-
No/No
Solid Waste DispMal Act «tUSC |f W01-69S7
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 (he groundwater.
Establishes maximum
concentrations for hazardous
constituents prior to land
disposal.
Yes/-
No/Yes
No/No
Cleanup standards may be based
on MCLs and/or MCLGs since
groundwater and surface water are
potential future sources of
drinking water. MCLforTCEU
5ug/L.
An MCL which is protective of
human health exists for TCE;
SMCLs are not based on health
risks.
The groundwater cleanup
standards could be based on water
quality criteria if other standards
for drinking water clean up an not
available, since groundwater is a
potential water supply. Would be
applicable if remedial action
includes discharge to surface
waters.
None of these pollutants have been
detected in groundwater or surface
water.
Wastes generated during the
remediation phase (e.g., spent
carbon) may contain RCRA
hazardous constituents and will be
subject to characterization and
disposal as hazardous waste, if
appropriate.
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.
No hazardous wastes will be
disposed of on site. The disposal
facility will be responsible for
meeting the requirements of the
land disposal restrictions.
A-l
-------
Table A-l
(Continued)
ll^iSKftMMBPflMMMfllbHliMpd
jt ^-WBWgpjr.^JRAwflBp]
afSi^^aioS^fSKS^f^^^ffSSKSK^^f^^^f^^Sffff^^^^^Efs^^^^^^S^^^^SSS^KSSSSfS^f^
Toik Sabattica CoBtral Act - IS US.C H U05. 2607, 261 1. U14, ajMl 261«
EPA Rules for
Controlling
Polychlorinated
Biphenyls (PCBs>-
Storage and Disposal
EPA Rules for
Controlling
Polychlorinated
Biphenyls (PCBs)-Spill
Cleanup Policy
40CFR
Pan 761.
SubpanD
40CFR
Pan 761.
SubpanC
Establishes procedures for the
management of PCBs.
including storage and disposal
requirements.
Establishes procedures for
remedial., ig PCB spills,
including specifying cleanup
criteria for different land uses.
No/No
No/No
The PCB contamination of surface
soils near Building 2SOI has been
removed from CERCLA
jurisdiction and is being addressed
under TSCA.
Pursuant to an agreement between
Hilt AFB. EPA, and UDEQ, PCB
contamination at the electrical
substation will be addressed under
TSCA, and will not be evaluated
in this feasibility study.
0«u Air Act -42 USC 1 744)1
National Ambient Air
Quality Standards
National Emissions
Standards for Hazardous
Air Pollutants
40CFR
Part SO
40CFR
Pan 61
Establishes primary and
pollutants: PMIOtSO,,CO.
ozone, NO], and lead.
Establishes regulatory
standards for specific air
pollutants: arsenic, asbestos.
benzene, beryllium, mercury.
radionuclides. vinyl chloride.
and volatile hazardous air
pollutants.
Yes/-
Yes/-
Emissions from the remediation
process will be subject to the
National Ambient Air Quality
Standards unless state standards
are more stringent
Standards for volatile hazardous
air pollutants will be met.
A-2
-------
Table A-2
Identification of State Chemical-Specific ARARs: Hill AFB, Operable Unit 6
If£±ggags55a^
Utafc Safe Drl»U*g Water Act - Tide 26 UCA Chapter 12
Utah Primary Drinking
Water Standards
Utah Secondary Drinking
Water Standards
R309-
103-1
UAC
R309-
103-2
UAC
Establishes maximum
contaminant levels for inorganic
and organic chemicals as
primary drinking water
standards.
Establishes maximum .
contaminant levels for inorganic
and organic chemicals as
secondary drinking water
standards.
No/Yes
No/No
Requirements are relevant and
appropriate. SomeMCLs
established for contaminants are not
federally regulated. State MCL for
TCE is 5 ug/L (same as federal
MCL).
MCLs for all contaminants of
concern are specified in R309-103-I
UAC.
Utah Water FoUrta* Coatrol Act - Tim U UCA Cfcapter 11
Groundwater Quality
Standards
R3I7-6
UAC
Establishes groundwaier quality
standards for different aquifer
classes.
*
The Utah Ground Water Quality
Protection Rule establishes
numerical cleanup levels and other
contaminated groundwaier.
Although no determination has been
made concerning whether this Rule
is an applicable or relevant and
standards required by the Ground
Water Quality Protection Rule will
be met by complying with drinking
water MCLs.
Utah SoUd tad Hazardow Waste Act - Tide 19 UCA Chapter «
Corrective Action Clean-
up Standards Policy-
UST and CERCLA Sites
Land Disposal
Restrictions
Criteria for the
Identification and Listing
of Hazardous Waste
Groundwater Protection
Standards for TSD
Facilities
R3I1-
211
UAC
R315-13
UAC
R3 15-2-1
UAC
R3 15-8-6
UAC
Establishes cleanup standards for
hazardous substances. State
adoption of Federal Safe
Drinking Water Act and Federal
Clean Air ACL
Outlines land disposal
restrictions for hazardous waste.
Utah incorporates Federal LDRs
by reference.
Establishes solid wastes that are
regulated as hazardous waste*
under the Utah Solid and
Hazardous Waste Act
Definition of hazardous waste
mirrors federal definition.
Establishes maximum .
concentrations for hazardous
constituents in the groundwaier.
Yes/-
No/No
Yes/-
No/Yes
TCE has been detected in water
above MCL. Migration to basement
air has been determined to be
significant pathway.
No hazardous wastes will be
disposed of on site. The disposal
facility will be responsible for
meeting the requirements of the
land disposal restrictions.
Wastes generated during the
remediation phase (e.g.. spent
carbon) may contain hazardous
constituents and will be subject to
identification and listing as
hazardous wastes, if appropriate.
The groundwater cleanup standards
may be based on these maximum
concentrations.
Utah Water Qnlily Act - TWe 19 UCA Chapter 5
Water Quality Standards
R317-2
UAC
Establishes standards for the
quality of surface waters in the
State.
Yes/-
These rules are specific to Ulan.
although they are derived, in pan.
surface waters will be in accordance
with these standards.
A-3
-------
Table A-2
(Continued)
Pesticide Cmitrol Act - TlUc 4 UCA Chapter 14
Pesticide Control «nd Use
Standards
R68-7
UAC
Establishes standards for
pesticide control and the safe and
appropriate use of pesticides.
No/No
No pesticides have been identified
as being contaminants of concern.
Utak Air CwatmtfM Act - Tide It UCA Chapter 13
Standards for the Control
of Installations
R307-I-3
UAC
Specifies standards for six.
pollutants: PMIO,SO*CO,
ozone, NO,, and lead. State
adoption of Federal NAAQS and
BACT.
Yes/-
Emissions from the remediation
process will be subject to the
standards for the six pollutants.
Emissions Standards
R307-M
UAC
Establishes standards for visible
emissions.
Yes/-
Emissions from the remediation
process will be subject to the
standards for visible emissions.
Emissions Standards for
Hazardous Air Pollutants
R307-10
UAC
State adoption of Federal
NESHAPs.
Yes/-
Standards for volatile hazardous air
pollutants will be met
Fugitive Emissions and
Fugitive Dust Standards
R307-12
UAC
Establishes standards for fugitive
emissions and fugitive dust.
Yes/-
Construction activities may
generate fugitive dust.
• See Documentation column.
A-4
-------
Table A-3
Identification of Federal Location-Specific ARARs: Hill AFB, Operable Unit 6
r^sjfyj^
wnKiJaitagBB •Ban.
£g|£!Oj|MfloS^3S||N
yjjyf?|ffjfjjfti^/Yi|f%
£f^j5SjTff3'*'^^r
||(4eaittIaAaiBnt*M3n
^0fi£»^-j . J^S^r^^Lnj^jA
•L«fc!ri^-L!li.'JgmT'*ayft
^HSjisjSSiZSfeSiKiaalKII
Sottd Waste Dtspwal Act -42 USC ff 6902-6987
Location Standards for
Hazardous Waste
Management Units
40 CFR j 264.18
Establishes site
characteristics which are
unsuitable for location
of hazardous waste man-
agement units.
Ycs/-
Standard is an ARAR
for hazardous waste
remediation units;
however, remediation
units would not be
located on a fault or in a
100-year floodplain.
NattoMl Historic PrcMrmtim Art - 16 USC 1 470 .
Accounting for Historic
Places
32 CFR Part 229.
40 CFR { 6 JO l(b).
36 CFR Part 800
Establishes a
requirement for federal
agencies to lake into
account the effect of any
federally assisted
undertaking or licensing
on any district, site,
building, structure, or
object that is included in
or eligible for inclusion
in the National Register
of Historical Places.
No/No
There are no temporary
or permanent structures
at the site. There are no
items at the site which
are included in or are
eligible for inclusion in
the National Register of
Historical Place).
AKkeotofical ««d HbtarfcaJ Praervatkw Act - 16 USC ( 4*9
Preservation of
Historical and
Archeological Data
Accounting for Natural
Landmarks
40CFR$6.30l(c)
Establishes procedures
to provide for preser-
vation of historical and
archeological data which
might be destroyed
through alteration of
terrain as a result of a
federal construction
projector a federally
licensed activity or
program.
No/No
Historic Sites. BilhHaf, awl AMtqaitto Act - 16 USC 1 461-467
40 CFR: 6.301 (a)
Eidaa
Conservation of
Endangered Species
50 CFR Part 17.
50 CFR Pan 222.
50 CFR Pan 402
Establishes a
requirement for federal
agencies to consider the
existence and location of
landmarks in the
National Registry of
Natural Landmarks to
avoid undesirable
impacts on such
landmarks.
No/No
There are no temporary
or permanent structures
at the site. No historical
or archeological data are
known to exist at the
site.
There are no items at the
site which are included
in the National Registry
of Natural Landmarks.
gercd Specks Act - 16 USC § 1S31
Establishes requirements
for actions to conserve
endangered species
within critical habitats
upon which endangered
species depend.
No/No
There are no known
endangered species
which reside at the site,
and there are no
designated critical
habitats at the site.
A-5
-------
Table A-3
(Continued)
^^^^^^£^SS^SSSmS^^S^^^^^^^^E5£^S^^^^^^^^^fi*^B^SS5S3^£5^^^^3SS5££m
PrateedM of WctfuMta - Eienttvc Ordt
Requirements for
Actions Taken in •
Wetlind
40 CFR § 6.302(1) and
Appendix A
Establishes requirements
for federal agencies to
•void to the extent
possible, the advene
the destruction or loss of
wetlands and to avoid
construction in wetlands.
r No. 11^90
No/No
There are no wetlands
present at the site.
Eiccitto Order M FloodpUli Miuftaett - Eieewtrve Order No. 11388
Requirements for
Actions Taken in the
100-Year Floodplain
Executive Order No.
11.988
Establishes requirement!
for federal agencies to
evaluate the effects of
actions taken in a 100-
year floodplain to avoid
advene impacts.
No/No
The site is not located in
a 100-year floodplain.
WMcncM Act - U USC H UI1-1I34
Impacts on Wilderness
Areas
50 CFR 5 35.1
Establishes the National
Wilderness Preservation
System in order to
preserve wilderness
areas.
No/No
Nadmul Wildlife Reflate Systeai - 16 USC 1 685
Impacts on Wildlife
Refuges
50 CFR Part 27
Establishes restrictions
on activities within a
National Wildlife
Refuge.
No/No
There are no wilderness
areas associated with the
she.
There are no National
Wildlife Refuges
associated with the site.
Wild •MSSeokRhvrt Act -1* USC f 1271
Impacts on Wild and
Scenic Rivers
40 CFR $ 6.302(e)
Establishes requirements
that are applicable to
water resources projects
affecting wild, scenic, or
recreational rivei. in or
to be studied for
inclusion in the National
Wild and Scenic Riven
System.
No/No
No water resources
projects' are associated
with remediation. There
are no riven at the site
in the National Wild and
Scenic Rivers System.
Coastal ZOM ftteuferat Act - 16 USC H MS1-1464
Impacts on Coastal
Zones
I6USC§§ 1451
through 1464
Establishes prohibitions
on federal agencies
taking activities not
consistent with a state's
approved coastal zone
management program.
No/No
There are no coastal 1]
zones at the site. |
A-6
-------
Table A-4
Identification of State Location-Specific ARARs: Hill AFB, Operable Unit 6
£MSJSfiatMMMM^^HtolC^tf
gtiMiriatojigigiiaa
T^'-^* =*T^SBBB3B3B^B8BaBBH^BB
^-S^s>a?licacil|ioo(a«(laH(UP
f&s&u&rVtUmSi
flSFftBQ*Approftr*Hts£c3
Aai»al Welfare Act - Title 76 UCA Chapter 9
General Wildlife
Protection Standards
Certificate of
Registration
Requirements
Requirements for
Hunting and Fishing
Licenses and Fees
R636
R657
UAC
R657-I9
UAC
R657-5
R657-I3
UAC
Establishes provisions covering
the taking, possession, and use of
wildlife and migratory birds.
Establishes that a Certificate of
Registration must be obtained
prior to taking any nonprohibited
scientific or educational
purposes.
Establishes requirements for
persons engaged in hunting or
fishing to produce a license,
permit, or tag.
No/No
No/No
No/No
The remediation strategy would not
harm wildlife and would not
involve taking, possession, or use of
wildlife or migratory birds.
The remediation strategy would not
involve taking of wildlife for
scientific or educational purposes.
No hunting or fishing would be
associated with the remediation
strategy.
RefmlatkNi of Coal MM* awl RedaMtfM Operatic** - TWe 40 UCA Chapter 10
Standards for Discharges
from Coal Mining
Activities
Standards for the
Reclamation of Mined
Land
R64S-
301
UAC
R643
UAC
Establishes a prohibition on
discharges from coal mining
activities causing pollution of
waters containing protected
aquatic wildlife.
Establishes standards for the
reclamation of mined lands.
No/No
No/No
No coal mining activities will be
associated with the remediation
strategy.
No mining activities have been
conducted at this site.
AaOqrtlei Act -TMeCI UCA Chapter 18 •
Standards for the
Protection of State
Antiquities
R212
UAC
Establishes standards relating to
the protection of archaeological,
anthropological, and
paleontological resources.
No/No
No significant scientific,
prehistoricai. historical, or
archaeological data exist at the site.
Utah Air CoMerratiM Act • Tide 19 UCA Chapter 2
Emission Standards -
Requirements for Ozone
Nonanainment Areas and
Davis and Salt Lake
Counties
R307-I4
UAC
Requires > iplementation of
reasonably kvailable control
technology (RACT) for control
of Volatile Organic Compounds
areas.
Yes/-
Davis County is an ozone
remediation processes will be
subject to RACT for VOCs.
Utah Solid and Haardov Watte Act - Ti He 19 UCA Chapter <
Location Standards for
Hazardous Waste
Management Units
R3I5-8-
2.9
UAC
Establishes site characteristics
which are unsuitable for location
of hazardous waste management
units.
Yes/-
Standard is an ARAR for hazardous
waste remediation units; however.
remediation units would not be
located on a fault or in a 100-year
flood plain.
UAC • Utah Administrative Code.
A-7
-------
Table A-5
Identification of Federal Action-Specific ARAIfe: Hill AFB, Operable Unit 6
^^^^g^£J2^
SaSffiflESteSSP
y>PPPC«llBBrJIOC¥M»»^
tgg3»teffiS:^'jEE5^ffi
.S^-^^^fi^rfti^^^
Safe DriaUat Water Act - 43 USC { 309
Underground Injection
Control Standards
40CFR
Parts 144
through
147
Natioral Polluunt
Discharge Elimination
System Requirements
Effluent Guidelines and
Standards for the Point
Source Category
National Prtbtaunetu
Standards
EPA Toxic Pollutant
Effluent Standards
Dredge or Fill
Requirements
40CFR
Part 122
40CFR
Parts 404
through
474
40CFR
Part 403
40CFR
Part 129
40CFR
Parts 230
and 231
and 33
CFRPart
323
Establishes regulations for
subsurface injections.
Regulations are designed to pro*
vide for protection of
groundwater used for drinking
water.
Ocu Water Act -33 USC 1
Establishes requirements for
permits to authorize the point
source discharge of pollutants
into waters of the Unites States.
Also, regulates discharges of
stormwater.
Establishes requirements for
specific effluent limitations and
guidelines as well as
pretreatment standards for
specific industrial discharges
under NPDES permits.
Establishes standards for
controlling pollutants which pass
through or inter fere with treat*
mem processes in publicly
may contaminate sewage sludge.
Establishes effluent standards
and prohibitions for discharges
of certain pollutants into
navigable waters.
• .
permits to authorize the
discharge ->f dredged or fill
material into navigable waters.
Yes/-
Applicable to alternatives that
include discharge of treated
groundwater into the shallow
aquifer.
1 1251-1376
Yes/-
No/No
Yes/-
No/No
No/No
Applicable to alternatives that
include discharge of treated water
to storm sewers or surface waters.
No industrial operation exists at
the site.
Applicable to discharge
alternatives which include
discharge to a sanitary sewer.
None of the pollutants regulated in
this pan have been identified as
contaminants at the site.
Discharge into navigable waters
would not occur.
Remedial strategies undergoing
detailed analysis do not consider
dredge or fill operations.
MariM ProftcftM, Research, aa4 Saacfturiet Act - 13 USC H 1401-1445
Protection and Research
Requirements
13 USC }}
1401-1445
dumping.
No/No
Remedial strategies undergoing
detailed analysis do not consider
ocean dumping.
Solid Waste Disposal Act - 4J USC f§ C9014997
Guidelines for Source
Separation for Material
Recovery
40CFR
Pan 246
Establishes guidelines for federal
agencies with regard to source
separation of residential.
commercial, and institutional
solid wastes.
No/No
Remedial strategies undergoing
detailed analysis will not result in
residential, commercial, or
industrial solid wastes requiring
separation.
A-8
-------
Table A-5
(Continued)
fc-Jtj'-'^r-i;: Tt-'a i*3»
H rlUita.^r i JstrttitoBg
Criteria for Classification
of Solid Waste Disposal
Facilities and Practices
Criteria for Municipal
Solid Waste Landfills
Standards Applicable to
Generators of Hazardous
Waste
Standards Applicable to
Hazardous Waste
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 Postclosure
Standards
ffififirgfr
40 CFR
Part 257
40 CFR
Pan 258
40 CFR
Pan 262
40 CFR
40 CFR
Pan 264,
Cutmtwf R
40 CFR
Pan 264,
SubpanC
40 CFR
Pan 264.
SubpanD
40 CFR
Pan 264.
SubpanE
40 CFR
Part 264,
SubpanF
40 CFR
Part 264,
Subpan G
^^^•m-^-^r i
>*f» »• r am immpimu " \\ mmm
Establishes criteria for use in
determining when solid waste
disposal facilities pose a rea-
sonable probability of adverse
effects on health or the
environment
Establishes minimum national
criteria under RCRA for all
municipal solid waste landfill
units.
Establishes requirements for
generators of hazardous waste.
Establishes requirements for
Establishes general facility
management standards for
age. and/or disposal facilities.
Establishes requirements, for
preparedness and prevention at
hazardous waste treatment.
storage, and/or disposal
facilities.
Establishes requirements for a
contingency plan and emergency
procedures at hazardous waste
treatment, storage, and/or dis-
posal facilities.
Establishes requirements f ••» the
manifest system, as well as
recordkeeping and reporting at
hazardous waste treatment.
storage, and/or disposal
facilities.
Establishes requirements for
detection and containment of
releases from waste management
units at hazardous waste treat-
ment, storage, and/or disposal
facilities.
Establishes general standards for
closure and, if required.
postclosure at hazardous waste
treatment, storage, and/or
disposal facilities.
'• -'45^-Sagttir*!
• ••IHI|l|ll»pilBII II
No/No
No/No
Yes/-
No/No
Yes/-
Yes/-
Yes/-
No/No
Yes/-
Yes/-
^•VifelfQt^B^fcWi^B^MrtB^BtfB^B^B^BMMkil
1
Remedial strategies undergoing
detailed analysis do not consider
land disposal of solid waste.
Remedial strategies undergoing
detailed analysis do not consider
the construction of a municipal
solid waste landfill unit
Remedial strategies may generate
hazardous waste (e.g., spent
carbon).
This regulation applies to an off-
however, it is a requirement that
will be met if hazardous waste
to an off-she facility.
Facility management plans may be
developed, as needed, to
requirements.
Preparedness and prevention
measures may be developed, as
needed, to implement other 40
CFR Pan 264 requirements.
A contingency plan and
emergency procedures may be
developed, as needed, to
implement other 40 CFR Pan 264
requirements.
This regulation applies to an off-
site activity and is not an ARAR;
however, it is a requirement that
will be met if hazardous waste
(e.g., spent carbon) is transported
to an off-site facility.
Solid waste management units will
require secondary containment to
prevent releases of hazardous
constituents.
Closure and, if required, post- 1
closure will be needed for any 1
hazardous waste management 1
units. 1
A-9
-------
Table A-5
(Continued)
If ^rrr.'rrfu^^— : t-: ; >.- •, >-< l-j^ :-..:;
fc" '•5"'''U'W:-*5«rA '•WSS' 3 t T*-rc>>;j.ri
Ih l*il -,IH .d»Pl' .... L it \*.~- t_
Financial Requirements
Standards for the Use and
Management of
Containers
Standards for Tank
.Systems
Standards for Surface
Impoundments
Standards for Waste Piles
Standards for Land
Treatment
Standards for Landfills
Standards for Incinerators
Standards for
Miscellaneous Units
40CFR
Pan 264.
Subpan H
40CFR
Pan 264,
Subpart I
40CFR
Part 264,
Subpart J
40CFR
Part 264.
Subpart K
40CFR
Pan 264,
Subpan L
40CFR
Pan2f4,
Subpan N'
40CFR
Pan 264,
Subpan N
40CFR
Pan 264,
Subpan O
40CFR
Pan 264,
Subpan X
ffjgBa^^a^S^^^^^L^Bi^^^Bi^^LaU •^^S^P^^^* U* S F<
Establishes financial
requirements for liability
insurance and financial
assurance for closure and. if
required, postdosure at
hazardous waste treatment,
storage, and/or disposal
facilities.
Establishes design and
operational requirements for the
use and management of con-
tainers containing hazardous
waste at hazardous waste
treatment, storage, and/or dis-
posal facilities.
Establishes design and
operational requirements for the
storage and/or treatment of
hazardous wastes in tanks at
hazardous waste treatment,
storage, and/or disposal
facilities.
Establishes design and
operational requirements for
surface impoundments used for
the treatment, storage, and/or
disposal of hazardous wastes.
Establishes design and
operational requirements for
waste piles used for the treat-
ment, storage, and/of disposal of
hazardous wastes.
Establishes design and
operational requirements for
hazardous waste land ueaanem
units.
Establishes design and
operational requirements for
hazardous waste landfills.
Establishes design and
operational requirements for
hazardous waste incinerators.
Establishes design and
operational requirements for
miscellaneous hazardous waste
management units.
No/No
Yes/-
Yes/-
No/No
No/No
No/No
No/No
No/No
No/No
Not a substantive requirement
Permanent storage of containers
containing hazardous wastes will
not be pan of the remediation
strategy. However, all temporary
storage of containers containing
hazardous waste should be in
accordance with the requirements
of this subpart
Remedial strategies, including the
use of tank systems which store or
treat hazardous waste should be
designed and operated in
accordance with the requirements
of this subpart
Remedial strategies undergoing
detailed analysis do not consider
the use of surface impoundments.
Remedial strategies undergoing
detailed analysis do not consider
the use of waste piles.
Remedial strategies undergoing
detailed analysis do not consider
the use of a hazardous waste land
treatment unit
Remedial strategies undergoing
detailed analysis do not include
operation of a hazardous waste
landfill.
Remedial strategies undergoing
detailed analysis do not consider
the use of incinerators on site.
Remedial strategies undergoing
detailed analysis do not include
operation of miscellaneous units as
tun of the remedial strategy
A-10
-------
Table A-5
(Continued)
fejggiCtfMffttHM.
wSli&Sl&toiiJ?
Air Emissions Standards
Interim Standards for
Owners and Operators of
Hazardous Waste
Treatment, Storage, and
Disposal Facilities
Standards for Thermal
Treatment
Standards for the
Management of Specific
Hazardous Wastes and
Specific Types of
Hazardous Waste
Management Facilities
Land Disposal
Restrictions
Standards for
Underground Storage
Tanks
Standards of Performance
for New Stationary
Sources
Standards of Performance
for Incinerators
Standards of Performance
for New Stationary
Sources
Standards of Performance
for Volatile Organic
Liquid Storage Vessels
(Post 7/23/84)
iigpMSHi
40CFR
Part 264,
Subparts
AAand
BB
40CFR
Pan 265
40CFR
Pan 265,
SubpanP
40CFR
Part 266
40CFR
Part 268
40CFR
Part 280
40CFR
Pan 60,
Subparts
C-D.
40CFR
Part 60,
SubpanE
40CFR
Part 60,
Subparts
E.-K,
40CFR
Part 60.
Subpin K,
Establishes monitoring and
recordkeeping requirements for
process vents and equipment
leaks.
Establishes standards for
hazardous waste treatment,
storage, and disposal facilities
that are not permitted.
Establishes standards for other
thermal treatment of hazardous
wastes.
Establishes requirements for
recyclable materials and
materials burned for energy
recovery in boilers or industrial
furnaces.
Establishes hazardous wastes
that are restricted from land
disposal and describes those
circumstances where treated
waste may be land disposed.
Establishes technical standards
and corrective action
requirements for owners and
operators of underground storage
tanks containing regulated
substances.
Yes/-
No/No
No/No
No/No
No/No
No/No
OCM Air Act -42 USC 1 74*1
Established standards of
performance for six types of
sources.
Establishes standards of
performance for solid waste
incinerators.
Establishes standards of
performance for eight types of
sources.
Establishes standards of
performance for storage tanks
containing volatile organic
liquids.
No/No
No/No
No/No
Yes/-
Equipment meeting the
applicability requirements will be
monitored in accordance with the
requirements of these subparts.
Remediation is based on the more
substantial requirements for
permitted facilities as specified in
40 CFR Part 264.
Remedial strategies undergoing
detailed analysis do not consider
the use of thermal treatment on
site.
Remedial strategies undergoing
detailed analysis do not consider
recycling of materials or materials
boilers or industrial furnaces.
No hazardous wastes will be
disposed of on site. The disposal
facility will be responsible for
meeting the requirements of the
land disposal restrictions.
detailed analysis do not consider
the use of underground storage
tanks.
Remediation strategy does not
include any of the six sources
identified in these subparts.
Remedial strategies undergoing
detailed analysis do not consider
the use of thermal treatment.
Remediation strategy does not
include any of the eight sources
identified in these subparts.
as volatile organic liquids will be
stored in accordance with the
requirements of this subpan.
A-ll
-------
Table A-5
(Continued)
ip32f5£%@£3i
•CHterta, orUarita&M i'
Standards of Perfomunce
for New Stationary
Sources
^^ClTfff*
?£atatio« •<
40CFR
Part 60.
Subparts
L-VW
*Mi^Ma*d^i^i^i^BM^ili1i^i^i^ULi^i^i^i^itt^it4iV
^^?^-fie«BripaiaV«^r;^i?
Establishes standards of
performance for 54 types of
sources.
gKppliaiDiejiUlmigS
f^rt Appropriate^
No/No
IjULTJjijilJii.
Remediation strategy does not
include any of the 54 sources
identified in these subparts.
HnardwH Matertab Tranportatto* Act - 49 USC || 1MI-UU
Hazardous Materials
Transponation
Requirements
49CFR
Parts 107
and 171-
177
Establishes requirements for
transportation of hazardous
materials.
Yes/-
Remedial strategies undergoing
detailed analysis may result in
hazardous wastes (e.g., spent
carbon) which require
transportation.
AftMfc EMTO Act - 42 USC 1 2073
Standards for Protection
Against Radiation
IOCFR
Part 20
Establishes radiation exposure
limitations for workers.
No/No
No radioactive contaminants have
been detected at the site.
Twfc SBbftraca Control Act - 15 USC 1 2605
Polychlorinued
Biphenyls (PCBs)
Manufacturing,
Processing, Distribution
in Commerce, and Use
Prohibitions
40CFR
Part 761
Establishes requirements for the
manufacturing, distribution,
storage, and disposal of PCBs.
No/No
The PCB contamination of surface
soils near Building 2501 has been
removed from CERCLA
jurisdiction and is being addressed
under TSCA.
Federal toectidde F««ftetd« ud ttodeatfcUe Act - 7 USC { 1M
Requirements for the
Treatment and Disposal
of Insecticides,
Fungicides, and
Rodenticides
40CFR
Part 161
Establishes requirements for the
treatment and disposal of
insecticides, fungicides, and
rodenticides.
No/No
Riven aid Uarbora Act «f 1999 - 33 USC ?401
Dredge and Fill Permit
Requirements
33CFR
Parts 320
through
330
Establishes permitting
requirements for structures or
work in or affecting navigable
waters.
No/No
No insecticides, fungicides, or
rodenticides are identified as
contaminants of concern.
Remedial strategies undergoing
detailed analysis do not consider
any dredge or fill operations.
A-12
-------
Table A-6
Identification of State Action-Specific ARARs: Hill AFB, Operable Unit 6
•r^Tjgxj/j?* l~ '•Sr???
Well Drilling Standards
flggjJBRJi
^^tmopft- jB
R6S5-4
UAC
flc^SSSIRQBQBBBMHnttBMHMBBI
?&S3!E8&£p3SmmS9K
UCA7W-2S
Establishes standards for
drilling and abandonment of
wells.
vuua^fvffftitik' t ?
Yes/-
B3RDKB9JHHBH^^BB9EB^IH^BB^BB^B^BB^^9t
^^M^S^^a^aBBBB^^^aB^I^B^I^BlBB^BBjtX
i^^nijTWipacMMlitiooiiTiBiB^BCT
Remedial strategies undergoing
detailed analysis consider the
installation of groundwater
extraction and injection wells and
soil vapor extraction wells.
UCA27.12.lMud 27-12-121 — ,
Highway Noise
Abuemem Critcrii
Definitions and General
Requirements for Air
Conservation
Standards for the Control
of Installations
Criteria for De Minimis
Emissions from Air
Strippers and Soil
Venting Projects
R930-3
UAC
R307-I-1
R307-1-2
UAC
R307-1-3
UAC
R307-6
UAC
Establishes standards for noise
abatement associated with new
and existing highway projects.
No/No
Utih Air Coawnmtieai Act -TWe M UCA Chapter 13
Outlines general requirements
and provides definitions for
Utah Air Conservation rules.
Establishes notification
requirements, details opeiaiinf
limitations, and specifics
criteria for NAAQS violations
and prevention of significant
deterioration review.
Establishes criteria for when
emissions from air suippeis and
soil venting projects are
considered de minimis and do
not require an Air Quality
Approval Order.
Ulafc SoHd a*d Haardow Waste Act
Corrective Action Clen-
up Standards Policy-
UST and CERCLA Sites
Definitions and General
Requirements for Solid
and Hazardous Waste
Hazardous Waste
Manifest Requirements
Hazardous Waste
Generator Requirements
R31 1-211
UAC
R3IS-I
R3IS-2
UAC
R31S-4
UAC
R315-5
UAC
Requires that initial step in
corrective actions be to remove
or control source of
contamination.
Outlines general requirements
and provides definitions for
Utah Solid and Hazardous
Waste Regulations.
Details requirement* for
manifesting shipments of
hazardous waste in the state.
Outlines requirements for
generators of hazardous waste.
Yes/-
Yes/-
No/No
Remedial strategies undergoing
detailed analysis are not related to
highway projects.
Emissions from air stripping and
SVE systems will meet the
standards of these regulations.
Remedial strategies undergoing
detailed analysis consider remedial
strategics having air emissions
subject to best available control
technology requirements.
Apply to emissions of petroleum
concern are chlorinated solvents.
.Tltte 19 UCA Copter <
Yes/-
Yes/-
No/No
Yes/-
Modeling has indicated that
constituents in soil will not act as a
source of groundwater contamina-
tion.
General requirements and
definitions will be applicable for the
management of solid and/or
hazardous wastes.
This regulation applies to an off-s ite
activity and is not an ARAR;
however, it is a requirement that
will be met if hazardous waste is
Remedial strategies undergoing
detailed analysis may include
generation of hazardous waste (e.g.,
scent carbon).
A-13
-------
Table A-6
(Continued)
^j^^wrnggga
eottraarSSSSi
Hazardous Waste
Transporter
Requirements
General Facility
Standards
Standards of
Prevention
Contingency Plan and
Emergency Procedures
Manifest System.
Recordkeeping, and
Reporting Requirements
Requirements for
Releases From Solid
Waste Management Units
Ch-fure and Post-Closure
Standards
Financial Requirements
WEHfeTS
i§3£~
R3IS-6
UAC
R31 5-8-2
UAC
R3 15-8-3
1 1AP
R3 15-8-4
UAC
R3 15-8-5
UAC
R3 15-8-6
UAC
R3 15-8-7
UAC
R3 15-8-8
UAC
f**f*"g*agggfi^tffin^M
ISs»55ra58§il
Outlines requirements for the
transportation of hazardous
waste.
Establishes general facility
management standards for
hazardous waste treatment.
facilities.
Establishes requirements for
hazardous waste treatment.
storage and/or disposal
facilities
Establishes requirements for a
contingency plan and
emergency procedures at
hazardous waste treatment,
storage, and/or disposal
facilities
Establishes requirements for the
manifest system, as well as
recordlceeping and reporting at
hazardous waste treatment.
storage, and/or disposal
facilities.
Establishes requirements for
detection and containment of
releases from waste
management units at hazardoi
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 financial
requirements for liability
insurance and financial
assurance for closure and. if
required, post-closure at
hazardous waste treatment.
storage, and/or disposal
facilities
»• «n'ig«fr ayv^aa*.
PrtjNii flilrfEni i ••! "
9»iM7(pprapfnte. K.
No/No
Ves/-
YeV-
Yes/-
No/No
Yes/-
Yes/-
No/No
j^pfe^^ijamj
This regulation applies to an off-site
activity and is not an ARAR;
however, it is a requirement that
will be met if hazardous waste (e.g.,
spent carbon) is transported to an
off-lite facility.
Facility management plans may be
developed, as needed to implement
other 40 CFR Part 264
Preparedness and prevention
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.
This regulation applies to an off-site
activity and is not an ARAR;
however, it is a requirement that
will be met if hazardous waste (e.g..
spent carbon) is transported to an
off-site facility
Solid waste management units will
require secondary containment to
prevent releases of hazardous
constituents.
Closure and, if required, post-
closure will be needed for any
hazardous waste management units.
Not a substantive requirement.
A-14
-------
Table A-6
(Continued)
pggapffiSi^
Standards for the Use and
Management of
Containers'
Standards for Tank
Systems
Standards for Surface
Impoundments
Standards for Waste Piles
Standards for Land
Treatment
Standards for Landfills
Standards for Incinerators
Standards for
Miscellaneous Units
Air Emission Standards
Emergency Control
Requirements
R3 15-8-9
UAC
R3I5-8-IO
UAC
R3 15-8- 11
UAC
R3I5-8-12
UAC
R315-8-I3
UAC
R3 15-8-14
UAC
R315-8-15
UAC
R3I5-8-16
UAC
R315-8-I7
UAC and
R3 15-8- 18
UAC
R3I5-9
UAC
Establishes design and
operational requirements for
the use and management of
containers containing
hazardous waste at hazardous
waste treatment, storage, and/or
disposal facilities.
Establishes design and
operational requirements for
the storage and/or treatment of
hazardous wastes in tanks at
storage, and/or disposal
facilities.
Establishes design and
the treatment, storage, and/or
disposal of hazardous wastes.
Establishes design and
opeiational Rquiieineiiu fix
waste pipes used for the
treatment, storage, and/or
disposal of hazardous waste.
Establishes design and
hazardous waste land treatment
units.
Establishes design and
operational requirements for
hazardous waste landfills.
Establishes design and
operational requirements for
Establishes design and
operational requirements for
miscellaneous hazardous waste
management units.
Establishes monitoring and
recordkeeping requirements for
process vents and equipment
leaks.
Outlines the immediate action.
clean-up, and reporting
requirements for spills
involving hazardous waste.
Yes/-
Yes/-
No/No
No/No
No/No
No/No
No/No
No/No
Yes/-
Yes/-
Permanent storage of containers
containing hazardous wastes will
not be pan of the remediation
strategy. However, til temporary
storage of containers containing
hazardous waste should be in
accordance with the requirements of
this subpart. •
Remedial strategies, including the
use of tank systems which store or
treat hazardous waste should be
designed and operated In
accordance with the requirements of
mis subpart
Remedial strategies undergoing
detailed analysis do not consider the
use of surface impoundments.
detailed analysis do not consider the
use of waste piles.
Remedial strategies undergoing
detailed analysis do not consider the
use of a hazardous waste land
treatment unit.
Remedial strategies undergoing
detailed analysis do not include
operation of a hazardous waste
landfill.
Remedial strategies undergoing
detailed analyst to not consider the
•use of incineration on site.
Remedial strategies undergoing
detailed analysis do not include
operation of miscellaneous units as
pan of the remedial strategy.
Equipment meeting the applicability
requirements will be monitored in
accordance with the requirements of
these subpans.
Contingency and emergency
response plans may be developed, D
as needed, to comply with these E
requirements. I
A-15
-------
Table A-6
(Continued)
•n^gygf'V'* .'• MattfBfUari^i'm'iaCTiaS'rfttff
^^^^^a^s^
Land Disposal
Restrictions (LDRs)
Cleanup Action and
Risk-Based Closure
Standards
R315-I3
UAC
R315-10I
UAC
9^I^^M^^^^^H^^^H^^^^^I|^^^I^^^^^B
9|K£|u^9BB^B^^^9^^^^^^B
Outlines land disposal
restrictions for hazardous
waste. Utah incorporates
Federal LDRs by reference.
Specifies the State of Utah's
policy for management of sites
contaminated with hazardous
waste or hazardous
constituents.
:^vsAaanMcaiBMt>BMA
^WXpw^ftrWK
No/No
Yes/-
^^^sni
No hazardous wastes will be
disposed of on site. The disposal
facility will be responsible for
meeting the requirements of the
land disposal restrictions.
Site is considered a CERCLA site.
Utah Water FotlttkM Cratral Act - Tide 26 UCA Chapter 11
Definitions and General
Requirements
Design Requirements for
Wastewater Collection,
Treatment, and Disposal
Systems
Ground water Quality
Protection Standards
Underground Injection
Control (UIC) Standards
Utah Pollutant Discharge
Elimination System
Requirements
R317-1
UAC
R3I7-3
UAC
R3I7-6
UAC
R317-7
UAC
R317-8
UAC
Details definitions and general
in Utah.
Outlines design requirements
for the collection, treatment.
and disposal of domestic
wastewaier.
Details standards, classes.
protection levels, and
implementation criteria for
groundwater protection. Also,
outlines certain activities
permitted by rule.
Establishet , neral
requirements, definitions.
permitting procedures, and
operating standards. UIC
standards adopt by reference
the federal UIC regulations
with the exception of a two-
mile radius from the borehole
instead of a one-quaner-mile
radius from the borehole to an
underground source of drinking
water.
Establishes general
requirements, definitions,
permitting procedures, and
criteria/standards for
technology-based treatment for
point source discharges of
wastewater. Also establishes
pretreatment standards for
discharge to a POTW.
Yes/-
No/No
•
Yes/-
Yes/-
General requirements and
definitions will be applicable for
remediation strategies including
Treatment of domestic wastewater
will not be pan of remedial
strategies.
The Utah Ground Water Quality
Protection Rule establishes
numerical cleanup levels and other
performance standards for
Although no uctcinunauon has been
is an applicable or relevant and
appropriate standard at OU 6, the
remedy will meet the action-specific
requirements of the rule.
Applicable to alternatives that
include discharge of treated water to
the shallow aquifer.
Applicable to discharge alternatives
which include discharge of treated
water to storm sewers, surface
waters, or sanitary sewers
* See Documentation column.
A-16
-------
Table A-7
Identification of ARARs for OU 6 Alternatives
^•HMIH^i^i^ilMimfimnHIHmH^i^i^i^i^i^i^i^HH1
'nim'll'"? M*'.t""-E Mtr-T-1 1—' -<•••-• — -wrr- -•
rf. •'-•;. .'!•:•,•• . •••(•;. • .; '
M: I'!!;-:' '.. : : - :-,^:=::i:,-j
r.:'-'.«i:,..:..' . I.-JQ^U-I
•n't'*lr;nr'l«.y"«T'fr'*'~'"- 'vl T"-— ' •"• • •• "•*-"* *^*^ !«* •»•• f-r-T— Ti :
.••.:.. i ^liiJV_ -__L'.^.ii. .-L — tJ.-j--J_L..._^-ii^ul^clL-jakliJ.J
r~'T, ''" ,'f '"" "•'"" "" j' ""' ""irar^^ ^"•r-r*
r:l.^^-j'l.:[ •.'.;? ^i.;..-i!: .^:::^,,:XU(L!L!^uJ^.)]
' ClwsflfciMpcdflcARAiU !
National Primary Drinking Water Standards
Utah Primary Drinking Water Standards
Water Quality Standards
Groundwater Quality Protection Standards
Criteria for the Identification and Listing of Hazardous
Waste
Requirements for Releases from Solid Waste
Management Units
National Ambient Air Quality Standards
Emissions Standards for Hazardous Air Pollutants
Corrective Action Clean-up Standards Policy-US? and
CERCLA Sites
Standards for the Control of Installations
Emissions Standards
Fugitive Emissions and Fugitive Dust Standards
• .
Location Standards for Hazardous Waste Management
Units
Emission Standards - Requirements for Ozone
Nonattainment Areas. Davis and Salt Lake Counties
40 CFR Part 141
R309- 103-1 UAC
40 CFR Part 131
R317-2 UAC
R3 17-6 UAC
40 CFR Part 261.
R3 15-2-1 UAC
40 CFR Part 264.
SubputF
R3 15-1-6 UAC
40 CFR Pan SO
40 CFR Part 61
R307-10 UAC
R31 1-211 UAC
R307-I-3 UAC
R307-1-4 UAC
R307-I2UAC
'•'.' ' Yii,iiiiii
40 CFR f 264. 18.
R3I5-82.9UAC
R307-I4 UAC
No/Yes
No/Yes
Yes/-
_b
Vet/-
No/Yes
Yes/-
Yes/--
Yes/-
Yes/-
Yes/-
Yei/-
SoedflcAitui.
Yes/-
Yes/--
No/Yes
No/Yes
Yes/~
b
Yes/~
No/Yes
Yes/-
Yes/-
Yes/-
Yes/-
Yes/--
Yes/»
;: -: . '
Yes/-
Yes/-
No/Yes
No/Yes
Yes/-
b
Yes/-
No/Yes
Ye«/-
Yes/~
Yes/-
Yes/«
Yes/-
Yes/-
Yes/-
Yes/--
NoTYes
No/Yes
Yes/-
b
Yes/--
No/Yes
Yes/--
Yes/-
Yes/~
Yes/-
Yes/-
Yes/--
Yes/-
Yes/--
No/Yes
No/Yes
Yes/--
b
Yes/
No/Yes
Yes/--
Yes/-
Yes/-
Yes/-
Yes/-
Yes/--
Yes/-
Yes/-
-------
Table A-7
(Continued)
iil'iPrJi1!!' V-'il:|i;''i|'<|5;1:(<;V^.'V-i-fi' -IDi
hMfMlB^ ttMiiito( H
IITHHS aPfOm *
LPIN UJM !•!•; f pop*
?ro!8lft^^?
BO^IIHS^^ISTOBSWIiPS^si
AcHoo-SpedtV ARAJU
Underground Injection Control Standards
National Pollutant Discharge Elimination System
Requirements
Utah Pollutant Discharge Elimination System
Requirement!
National Pretreatmeni Standards
Standard* Applicable to Generators of Ihmdnus Waste
General Facility Standards
Standards of Preparedness and Prevention
Contingency Plan and Emergency Procedures
Requirements for Releases From Solid Waste
Management Units
Closure and Post Closure Standards
Standards for the Use and Management of Containers
Standard* for Tank Systems
40 CFR Parts 144
through 147.
R3I7-7 UAC
40 CFR Pan 122
R3I7-8 UAC
40 CFR Pan 403
40 CFR Pan 262.
R3IS-5 UAC
40 CFR Pan 264.
Subpan B.
R3I5-8-2 UAC
40 CFR Pan 264.
Subpan C,
R3IJ 8-3 UAC
40 CFR Part 264.
Subpan D,
R3I5-8-4 UAC
40 CFR Part 264.
Subpan F.
R3IS-8-6 UAC
40 CFR Part 264.
Subpan 0.
R3I5-8-7 UAC
40 CFR Pan 264.
Subpan I.
R3 15-8 9 UAC
40 CFR Pan 264.
Suhpan J.
R3I3-N-KMIAC
Yes/--
Yes/--
Ye«/--
No/No
Yes/-
Yes/-
Yes/--
Yes/--
Yes/
Yei/--
Yes/--
Yes/-
Yes/-
Yes/-
Yes/"
No/No
Yes/--
Ye,--
Yes/-
Ye,/--
Yes/-
Yes/--
Ye,
, Yes/-
Yes/--
Yes/--
Yes/-
Ye,--
Yes/-
Yes/.-
Ye,/-
Yes/--
Ye,/--
Yes/--
Yes/»
Yes/-
Yes/-
Yes/--
Yes/--
No/No
Yes/-
Yes/--
Yes/--
Yes/--
Yes/--
Yes/--
Yes/-
Yes/--
Ye«/-
Yei/-
Yes/-
Yes/-
Yes/-
Yes/-
Yes/-
Yes/-
Yes/-
Yes/-
Yes/-
Yes/
-------
Table A-7
(Continued)
Air Emissions Standards
40 CFR Part 264.
Subparts AA and BB.
R3I5-8-I7 uid 18 UAC
Yes/--
Slandards of Performance for Volatile Organic Liquid
Storage Vessels (Post 7/23/84)
40 CFR Part 60.
SubpartK,
Yes/--
Yes/-
Yes/-
Yes/-
Yes/-
Hazardous Materials Transportation Requirements
49 CFR Pans 107 and
171-177
Yes/--
Yes/-
Yes/»
Yes/-
Yes/--
Well Drilling Standards
R6S5-4 UAC
Yes/-
Yes/--
Yes/-
Yes/--
Yes/--
Definitions and General Requirements for Air
Conservation
R307-I-I UAC
R307-I-2 UAC
Yes/»
Yes/--
Yes/»
Ye$/»
Yes/-
Standards for die Control of installations
R307-I-3 UAC
Yei/~
Yei/-
Yes/~
Yes/-
Yes/--
I
MD
Coneclive Action Clean-Up Standards Polky-UST and
CERCLA Sites
R3II2IIUAC
Yet/-
Yes/-
Yes/-
Yes/-
Yes/--
Dennitions and General Requirements for Solid and
Hazardous Waste
R3I5 I UAC
R3I5-2 UAC
Yes/-
Yes/-
Yes/--
Ye$/-
Yes/-
Emergency Control Requirements
R3IS 9 UAC
Yes/--
Yes/-
Yes/~
Yes/--
Yes/--
Cleanup Action and Risk-Based Closure Standards
R3I5-I01 UAC
Yes/-
Yes/-
Yes/-
Yes/--
Yes/-
Defmitiom and General Requirements for Water Quality
R3I7-I UAC
Yes/-
Yes/--
Yes/--
Yes/-
Yes/-
Groundwater Quality Protection Standards
R3I7-6 UAC
*Where it applies, both UK federal and the analogous state regulations are listed.
""The Utah Ground Water Quality Protection Rule establishes numerical cleanup levels and other performance standards for contaminated groundwater. Although no determination has been made
concerning whether this Rule is an applicable or relevant and appropriate standard at OU 6. die standards required by die Ground Water Quality Protection Rule will be met by complying with
drinking water MCLs.
"The Utah Ground Water Quality Protection Rule establishes numerical clean-up levels and other performance standards for contaminated groundwater. Although no determination has been made
concerning whether this rule is an applicable or relevant and appropriate standard at OU 6. the remedy will meet the action-specific requirements of the rule.
-------
Table A-8
Summary of Alternative-Specific Compliance with ARARs
ChtmkakSpedfle ARAJb
National Primary Drinking Water Standards
Ulan Primary Drinking Water Standards
Water Quality Standards
Groundwaler Qualify Protection Standards
Criteria for the Identification and Listing of Hazardous
Waste
Requirements for Releases from Solid Waste Management
Units
National Ambient Air Quality Standards
Emissions Standards for Hazardous Air Pollutants
Corrective Action Clean-up Standards Policy-UST and
CERCLA Sites
Standards for the Control of Installations
Emissions Standards
Fugitive Emissions and Fugitive Dust Standards
40 CFR Part 141
R309- 103-1 UAC
40 CFR Pan 131
R317-2 UAC
R31745 UAC
40 CFR Part 261
R3 15-2-1 UAC
40 CFR Part 264.
SubpartF
R315-4-6 UAC
40 CFR Part 50
40 CFR Pan 61
R307-10 UAC
R3I1-2II UAC
' R307-I-3 UAC
R307-1-4 UAC
R307-I2 UAC
Alternatives 3. 4. and 5 will meet MCLs. Alternatives 1 and 2 will not meet MCLs in a
reasonable timeframc.
Alternatives 3, 4, and 5 will meet MCLs. Alternatives 1 and 2 will not meet MCLs in a
reasonable timeframe.
Extracted groundwater will be treated by air stripping to meet the water quality criteria set by
these regulations. Cooler's Pond water will be treated by carbon adsorption or air stripping.
Alternatives 3. 4. and 5 will meet the standards of mis regulation by extracting and (rearing
contaminated groundwater. Alternatives 1 and 2 will not meet the standards in this regulation
because RAOs will not be met in a reasonable limeframe.
It is not anticipated that any hazardous wastes will be generated during remedial actions.
However, all wastes generated during the remedial actions (e.g.. spent carbon) will be
characterized, and disposed of as hazardous wastes, if necessary.
All requirements for detection and containment of releases from waste management units (e.g. .
the air strippers) will be met. Secondary containment will be used to prevent releases. The
monitoring reojuiftmenu of this regulation.
Emissions from the air stripping systems will meet the standards of this regulation unless slate
standards are more stringent.
Standards for volatile hazardous air pollutants (including TCE) will be met.
Alternative 1 will not comply. In Alternatives 2 through 5. the source of contamination in soil
will be controlled through institutional actions .including a continuing order by the Base
commander. Alternative 5 will also eliminate the source by using an SVE system. In
Alternatives 3, 4, and 5. die source of contamination in groundwater (i.e., the "hot spots") will
be controlled by remedial actions. Cleanup standards for soil and groundwater have been selected
in accordance with this raie.
Emissions from the air stripping and SVE systems will meet the best available control technology
(BACT) requirements.
Remedial actions are not expected to cause significant visible emissions.
Fugitive dust will be controlled during excavation activities.
LoatfH»«pecMcAKAJti
Location Standards for Hazardous Waste Management
Units
Emission Standards • Requirements for Ozone
Nonanainment Areas. Davis and Salt Like Counties
40 CFR 1264.18
R3I5-8-2.9 UAC
R307-I4 UAC
Hazardous wane management units will be located in accordance with die requirements of this
regulation.
Emissions from air stripping and SVE systems will meet die standards of this regulation.
-------
Table A-8
(Continued)
tBIBM&t&ift49UfBt&^iiRt9UHUUiUMltNfUHiftM
Underground Injection Control Standard*
National Pollutant Discharge Elimination System
Requirements
Utah Pollutant Discharge Elimination System
National Preireatment Standards
Standards Applicable to Generators of Hazardous Waste
General Facility Standards
Standards of Preparedness and Prevention
Contingency Plan and Emergency Procedures
Requirements for Releases From Solid Waste Management
Units
Closure and Pottclosure Standards
Standards for the Use and Management of Containers
Standards for Tank Systems
Air Emissions Standards
Standards of Performance for Volatile Organic Liquid
Storage Vessels (Post 7/23/84)
40 CFR Parts 144
through 147
R3I7-7 UAC
40 CFR Pan 122
R317-8 UAC
40 CFR Pan 403
40 CFR Part 262
R3I5-5 UAC
40 CFR Part 264.
SubpartB,
R315-8-2 UAC
40 CFR Part 264.
diiwM*« r*
suDpani.,
R315-8-3 UAC
40 CFR Part 264.
SubpartD.
R3 15-8-4 UAC
40 CFR Pan 264.
SubpartF
R3I5-8-6 UAC
40 CFR Part 264.
SubpartG.
R3I5-8-7 UAC
40 CFR Part 264,
Subpartl.
R3I5-8-9 UAC
40 CFR Put 264.
Subpart J,
R3 15-8- 10 UAC
40 CFR Part 264.
Subpartl AA and BB.
R3I5-8-I7 and 18 UAC
40 CFR Pan 60.
SubpanK.
49 CFR Parti 107 anl
171 177
"">:,'-' ':"j;! ' i'jf r^^-r^T-y^n-:.. -•••-* •.'•T*-"|1TTV77Tr?T^
All activities associated with discharging treated groundwater into the shallow aquifer will comply
with this regulation.
Extracted groundwater will be treated by the air stripping systems to meet the requirements of
mis regulation.
Extracted groundwater will be treated by die air stripping systems to meet the requirements of
this regulation.
All extracted groundwater will be treated by the air stripping systems to meet the requirements of
this regulation.
It is not anticipated dial any hazardous wastes will be generated during remedial activities.
However, if hazardous waste is generated, all remedial activities will comply with this regulation.
It is not anticipated mat any hazardous wastes will be generated during remedial activities.
However, if hazardous waste is generated, all remedial activities will comply with these
regulations.
Preparedness and prevention measures will be developed as needed in accordance with these
•c4JUlTCIDCQDr
The Base has a spill response plan appropriate for remedial action activities.
All requirements for detection and containment of releases from waste management units (e.g..
die air strippers) will be met. Secondary containment will be used to prevent releases. The
ongoing semi-annual groumjwater monitoring program will comply with the groundwaier
monitoring requirements of this regulation.
Alternatives 3. 4 and 5, will meet all standards for closure and. if required, post-closure.
Because Alternatives 1 and 2 will not comply whh groundwater cleanup standards within a
reasonable dmeframe. ctaure/pMtclosure requirements will not be met.
It is not anticipated mat hazardous waste will be generated during remedial activities. However.
if hazardous waste it generated, all management of containers holding hazardous waste will be in
accordance whh dtit subpart.
All remediation systems (e.g.. the air strippers) will be designed and operated in accordance with
this subpart.
All air emissions from air stripping and SVE systems will meet die standards of these regulations.
All htranrtont wastes defined as volatile organic liquid will be stored in accordance with this
requirements of this subpart.
with these requirements
-------
Table A-8
(Continued)
Well Drilling Standards
Definitions and General Requirements for Ait Conservation
Standards for the Control of Installations
Corrective Action Cleanup Standards Polky-UST and
CERCLA Sites
Definitions and General Requirements for Solid and
Hazardous Waste
Emergency Control Requirements
Cleanup Action and Risk-Based Closure Standards
Definitions and Genertl Requirements
Croundwater Quality Protection Standards
MttattKB^HBHaMfeHl
R655-4 UAC
R307-I-I UAC
R307-I 2 UAC
R307-1-3 UAC
R31 1-211 UAC
R315-I UAC
R3I5-2 UAC
R3IS-9 UAC
R3I5-IOI UAC
R3I7-I UAC
R3I7-6 UAC
All activities associated with drilling of wells will comply with this regulation. '
Emissions from air stripping and SVE systems will meet the standards of these regulations.
Emissions from die air stripping and SVE systems will meet dte BACT requirements.
Modeling has indicated that constituents in soil will not act as a source of groundwater
contamination.
All wastes generated through remedial actions will be classified according to this subpart.
The Base has a spill response plan appropriate for remedial action activities.
Alternative 1 will not comply with this rule because it does not provide long-term management of
all contaminated media. Because risks are between 10* and 10*. Alternatives 2 through 5 will
implement long-term site management, consisting of water rights restrictions, deed restrictions.
and a continuing order restricting access to groundwater and contaminated soils, to comply with
these standards. Alternatives 3. 4. and 5 will also comply because in addition to institutional
controls, diese alternatives will include remedial actions for groundwater.
All discharges to die storm sewer will be in accordance with these requirements.
Alternatives 3. 4. and 5 wilt meet die standards of mis regulation by extracting and treating
contaminated groundwater. Alternatives 1 and 2 will not meet die standards in this regulation
because RAOs will not be met in a reasonable utneframe.
K)
K>
'Where it applies, both the federal and die analogous state regulations are listed.
'Unless otherwise specified, all alternatives comply with die ARAR as described.
A-22
-------
APPENDIX B
List of Attendees at the Hill AFB Operable Unit 6 Open House
-------
List of Attendees at the Hill AFB Operable Unit 6 Open House
Riverdale Mobile Estates Clubhouse, Riverdale, Utah
4:00 pm - 8:00 pm, 11 December 1996
Name
Esrafil Rahimzadegan
Rebecca Rahimzadegan
Harold Dunning
Robert Stites
Jerry Mansfield
Diane Simmons
Kevin Bourne
Steve Hicken
Len Barry
Pete Breed
SSgt. Joe Emery
SrA. Darci Gamble
Dave Fulton
Tad Dean
Stephen Fain
Clive Mecham
Robert Michna
Whitney Wheeless
Address/Affiliation
5621 South 11 50 West,
Riverdale, UT 84405
5621 South 11 50 West,
Riverdale, UT 84405
EPA Region 8, Denver, CO
EPA Region 8, Denver, CO
UDEQ, Salt Lake City, UT
UDEQ, Salt Lake City, UT
EMR, Hill AFB, UT
EMR, Hill AFB, UT
PA, Hill AFB, UT
Bioenvironmental,
Hill AFB, UT
Bioenvironmental,
Hill AFB, UT
Bioenvironmental,
Hill AFB, UT
Montgome . Watson,
Salt Lake City, UT
Radian International,
Salt Lake City, UT
Radian International,
Austin, TX
Radian International,
Salt Lake City, UT
Radian International,
Austin, TX
Radian International,
Austin, TX
Phone Number
(801)393-2060
(801)393-2060
(303)312-6633
(303)312-6664
(801)536-4237
(801) 536-4481
(801)777-8790
(801) 775-3648
(801) 777-4435 .
(801) 777-9842
(801) 777-4358
(801)777-1048 .
(801)272-1900
(801)261-2187
(512)419-5240
(801)261-2187
(512)419-5609
(512)419-5096
------- |