EPA Superfund
Record of Decision:
PB96-964410
EPA/ROD/R08-96/122
October 1996
Ellsworth Air Force Base,
Operable Unit 5, Rapid City, SD
6/7/1996
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Final
Record of Decision for
Remedial Action at Operable Unit 5
Ellsworth Air Force Base, South Dakota
United States Air Force
Air Combat Command
Ellsworth Air Force Base
June 1996
Project No.: FXBM947002
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Final Record of Decision Operable Unit 5
Ellsworth Air- Force Base, Souti; Dakota
TABLE OF CONTENTS
Chapter ' Page
1.0 DECLARATION FOR THE RECORD OF DECISION 1-1
1.1 SITE NAME AND LOCATION 1-1
1.2 STATEMENT OF BASIS AND PURPOSE 1-1
1.3 ASSESSMENT OF THE SITE 1-1
1.4 DESCRIPTION OF SELECTED REMEDY 1-1
1.5 STATUTORY DETERMINATION 1-1
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY 1-2
2.0 DECISION SUMMARY 2-1
2.1 SITE NAME AND LOCATION 2-1
2.2 OPERABLE UNIT 5 (OU-5) DESCRIPTION/HISTORY AND REGULATORY OVERSIGHT
ACTIVITIES 2-1
2.2.1 Description/History 2-1
2.2.2 Regulatory Oversight Activities 2-2
2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION 2-3
2.4 SCOPE AND ROLE OF RESPONSE ACTION 2-3
2.5 SITE CHARACTERISTICS 2-4
2.5.1 Soils 2-5
2.5.2 Ground Water 2-6
2.5.3 Surface Water/Sediment . 2-6
2.6 SITE RISK SUMMARY 2-7
2.6.1 Human Health Risk 2-7
2.6.2 Ecological Risks 2-9
2.7 DESCRIPTION OF ALTERNATIVES 2-9
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 2-10
2.8.1 Overall Protection of Human Health and the Environment 2-11
2.8.2 Compliance with ARARs 2-11
2.8.3 Long-Term Effectiveness and Permanence 2-13
2.8.4 Reduction of Toxicitv. Mobility, and Volume Through Treatment 2-13
2.8.5 Short-Term Effectiveness 2-13
2.8.6 Implementability 2-14
2.8.7 Cost 2-14
2.8.8 State Acceptance 2-15
2.8.9 Community Acceptance 2-16
2.9 SELECTED ALTERNATIVE 2-16
2.10 STATUTORY DETERMINATIONS 2-18
2.10.1 Protection of Human Health and the Environment 2-1 "5
2.10.2 Compliance with ARARs 2-19
2.10.3 Cost Effectiveness 2-19
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies to the Extent
Possible 2-19
2.10.5 Preference for Treatment as a Principal Element 2-20
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES 2-20
3.0 LIST OF ACRONYMS AND ABBREVIATIONS 3-1
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Final Record of Decision Operable Unit 5
Ellsworth A ir Force Base. South Dakota
APPENDICES
Appendix A Figures
Appendix B Responsiveness Summary
LIST OF FIGURES
Figure 2-1 Area Location Map
Figure 2-2 Site Map
Figure 2-3 Operable Unit 5
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
1.0 DECLARATION FOR THE RECORD OF DECISION
1.1 SITE NAME AND LOCATION
Operable Unit 5 (OU-5), Landfill No. 4 Area, Ellsworth Air Force Base (EAFB),
National Priority List Site.
Meade and Pennington Counties, South Dakota
1.2 STATEMENT OF BASIS AND PURPOSE
This decision document describes EAFB's selected remedial action for Operable Unit 5 (OU-5),
in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act
of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986
(SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).
This decision is based on the contents of the Administrative Record for OU-5, EAFB. The US
Environmental Protection Agency (EPA) and the South Dakota Department of Environment and
Natural Resources (SDDENR) concur with the selected remedial action.
1.3 ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from OU-5, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, or the environment.
1.4 DESCRIPTION OF SELECTED REMEDY
Twelve potentially contaminated areas, or operable units, have been identified at EAFB. This
ROD is for a remedial action at OU-5.
The selected alternative, Covering, includes the following major components:
Placing a soil cover capable of sustaining perennial vegetation over the landfill
area;
Institutional controls for the landfill area;
Long-term ground-water monitoring; and, long-term maintenance of soil cover.
1.5 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with Federal
and the State of South Dakota requirements that are legally applicable or relevant and appropriate
to the remedial action and is cost-effective. This remedy utilizes permanent solutions and
alternative treatment (or resource recovery) technologies, to the maximum extent practicable for
OU-5. However, because treatment of the principal threats of the OU was not practicable, this
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
remedy does not satisfy the statutory preference for treatment as a principal element. The size of
the landfill and the fact that there are no apparent onsite hot spots that represent major sources of
contamination precludes a remedy in which contaminants could be excavated and treated
effectively.
Because this remedy will result in low levels of hazardous substances remaining onsite beneath the
landfill cover area, a review will be conducted within five years after commencement of remedial
action to ensure that the remedy continues to provide adequate protection of human health and
the environment.
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
/?
BRETT M. DULA Date
Lieutenant General, USAF
Vice Commander
JACK W. MCGRAW Date
Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary Date
Department of Environment and Natural Resources
State of South Dakota
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
1.0 DECLARATION FOR THE RECORD OF DECISION
1.1 SITE NAME AND LOCATION
Operable Unit 5 (OU-5), Landfill No. 4 Area, Ellsworth Air Force Base (EAFB),
National Priorities List Site.
Meade and Pennington Counties, South Dakota
1.2 STATEMENT OF BASIS AND PURPOSE
This decision document describes EAFB's selected remedial action for Operable Unit 5 (OU-5),
in accordance with the Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP).
This decision is based on the contents of the Administrative Record for OU-5, EAFB. The US
Environmental Protection Agency (EPA) and the South Dakota Department of Environment and
Natural Resources (SDDENR) concur with the selected remedial action.
1.3 ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from OU-5, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, or the environment.
1.4 DESCRIPTION OF SELECTED REMEDY
Twelve potentially contaminated areas, or operable units, have been identified at EAFB. This
ROD is for a remedial action at OU-5.
The selected alternative, Covering, includes the following major components:
Placing a soil cover capable of sustaining perennial vegetation over the landfill
area;
Institutional controls for the landfill area;
Long-term ground-water monitoring; and, long-term maintenance of soil cover.
1.5 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with Federal
and the State of South Dakota requirements that are legally applicable or relevant and appropriate
to the remedial action and is cost-effective. This remedy utilizes permanent solutions and
alternative treatment (or resource recovery) technologies, to the maximum extent practicable for
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Final Record of Decision Operable Unit 5
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O' '. However, because treatment of the principal threats of the OU was not practicable, this
R y does i satisfy the statutory preference for treatment as a principal element. The size of
ti ;dfill ai..: the fact that there are no apparent onsite hot spots that represent major sources of
cor, . rnination precludes a remedy in which contaminants could be excavated and treated
effectively.
Because this remedy will result in low levels of hazardous substances remaining onsite beneath
the landfill cover area, a review will be conducted within five years after commencement of
remedial action to ensure that the remedy continues to provide adequate protection of human
health and the environment.
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
BRETT M. DULA Date
Lieutenant General, USAF
Vice Commander
C
JACK W. MCGRAW Dale
Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary Date
Department of Environment and Natural Resources
State of South Dakota
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base. South Dakota
1.0 DECLARATION FOR THE RECORD OF DECISION
1.1 SITE NAME AND LOCATION
Operable Unit 5 (OU-5), Landfill No. 4 Area, Ellsworth Air Force Base (EAFB),
National Priorities List Site.
Meade and Pennington Counties, South Dakota
1.2 STATEMENT OF BASIS AND PURPOSE
This decision document describes EAFB's selected remedial action for Operable Unit 5 (OU-5),
in accordance with the Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP).
This decision is based on the contents of the Administrative Record for OU-5, EAFB. The US
Environmental Protection Agency (EPA) and the South Dakota Department of Environment and
Natural Resources (SDDENR) concur with the selected remedial action.
1.3 ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from OU-5, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, or the environment.
1.4 DESCRIPTION OF SELECTED REMEDY
Twelve potentially contaminated areas, or operable units, have been identified at EAFB. This
ROD is for a remedial action at OU-5.
The selected alternative, Covering, includes the following major components:
Placing a soil cover capable of sustaining perennial vegetation over the landfill
area;
Institutional controls for the landfill area;
Long-term ground-water monitoring; and, long-term maintenance of soil cover.
1.5 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with Federal
and the State of South Dakota requirements that are legally applicable or relevant and appropriate
to the remedial action and is cost-effective. This remedy utilizes permanent solutions and
alternative treatment (or resource recovery) technologies, to the maximum extent practicable for
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Final Record of Decision Operable Unit 5
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OU-5. However, because treatment of the principal threats of the OU was no- racticable, this
remedy does not satisfy the statute; preference for ireatment as a principal e; 'nent. The size of
the landfill and the fact that there are no apparent onsite hot spots that represen. major sources of
contamination precludes a remedy in which contaminants could be excavated and treated
effectively.
Because this remedy will result in low levels of hazardous substances remaining onsite beneath
the landfill cover area, a review will be conducted within five years after commencement of
remedial action to ensure that the remedy continues to provide adequate protection of human
health and the environment.
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
BRETT M. DULA
Lieutenant General, USAF
Vice Commander
Date
JACKW. MCGRAW
Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
Date
NETTIE H. MYERS^Secretary
Department of Environment and Natural Resources
State of South
Date
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
2.0 DECISION SUMMARY
2.1 SITE NAME AND LOCATION
EAFB is a U.S. Air Force Air Combat Command (ACC) installation located 12 miles east of
Rapid City, South Dakota, and adjacent to the small community of Box Elder (Figure 2-1).
EAFB covers approximately 4,858 acres within Meade and Pennington counties and includes
runways and airfield operations, industrial areas, and housing and recreational facilities
(Figure 2-2). Open land, containing a few private residences, lies adjacent to EAFB on the north,
south, and west, while residential and commercial areas lie to the east of the Base.
2.2 OPERABLE UNIT 5 (OU-5) DESCRIPTION/HISTORY AND REGULATORY
OVERSIGHT ACTIVITIES
2.2.1 Description/History
Ellsworth Air Force Base (EAFB) was officially activated in July 1942 as the Rapid City Army
Air Base, a training facility for B-17 bomber crews. It became a permanent facility in 1948 with
the 28th Strategic Reconnaissance Wing as its host unit. Historically, EAFB has been the
headquarters of operations for a variety of aircraft, as well as the Titan I Intercontinental Ballistic
Missile, and the Minuteman I and Minuteman II missile systems. The Air Force has provided
support, training, maintenance, and/or testing facilities. Presently, the 28th Bombardment Wing
(B-1B bombers) is the host unit of EAFB.
Operable Unit 5 (OU-5) is the current designation for the area surrounding and including Landfill
No. 4, a 10-acre site located near the northern perimeter of EAFB (Figure 2-3). From the 1940s
through 1990, Landfill No. 4 was used primarily for the disposal of construction demolition and
hardfill materials; however, reports and visual observations from previous installation restoration
program (IRP) studies noted that this site was also used for general refuse and drum disposal.
Numerous empty unlabeled drums as well as empty historic investigation derived waste (IDW)
drums were observed at the landfill during the 1993/95 remedial investigation (RI). The Base
commander terminated waste disposal activities at this landfill after 1990.
Topographically, the northern portion of Landfill No. 4 dips steeply to the north-northwest. The
eastern portion of the OU dips less steeply to the south and southeast. Several incised valleys
exist to the north and east of Landfill No. 4. These valleys carry storm-water runoff off-Base,
north and northeast of OU-5 into several unnamed ephemeral tributaries of Elk Creek, which is
north of the Base boundary. The southern portion of the landfill slopes slightly to the south,
while southwest of the landfill the topography is fairly level with a slight rise associated with a
Base perimeter service road. While part of the landfill has an existing soil cover that is
vegetated, portions of the former disposal area contain exposed landfill materials.
The uppermost geologic deposits at OU-5 are predominantly silt and clay, underlain in places by
coarse sand and gravel. These deposits are typically thicker on terraces and drainage slopes (25
to 35 feet) and thinner in drainage bottoms (2 to 5 feet). Where present, gravels are usually
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
deposited directly on the Pierre Shale and range in thickness from less than 2 feet to more than 20
feet. Depth to shallow ground water at OU-5 ranges from approximately 12 to 36 ft.
The shallow aquifer at EAFB is considered a potential drinking water source and possibly
discharges to the surface. The ground water is classified as having a beneficial use as a drinking
water supply suitable for human consumption (ARSD Chapter 74:03:15, Groundwater Quality
Standards).
Deeper bedrock aquifers also exist beneath EAFB. These deeper aquifers are separated from the
shallow aquifer by 800 feet of impermeable clays and silts. In the past, EAFB utilized these deeper
aquifers for its water supply. Presently, EAFB obtains its potable water from the Rapid City
Municipal Distribution System.
2.2.2 Regulatory Oversight Activities
Environmental investigation activities at EAFB were initiated by the Air Force in 1985 through an
IRP Phase I Installation Assessment/Records Search and Phase II, Confirmation/ Quantification.
The Phase I study, dated September 1985, identified a total of 17 locations at EAFB where
releases involving hazardous substances potentially occurred.
In Phase II of the IRP investigation, field activities included soil vapor surveys, geophysical
surveys, surface and subsurface soil sampling, ground-water sampling, ground-water hydrologic
testing, and ecological investigations.
On August 30, 1990 (55 Federal Register 35509), EAFB was listed on the U.S. EPA's National
Priority List (NPL). A Federal Facility Agreement (FFA) was signed in January 1992 by the Air
Force, EPA, and the State of South Dakota (State) and went into effect on April 1, 1992. The
FFA establishes a procedural framework and schedule for developing, implementing, and
monitoring appropriate response actions for EAFB in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Super-fund Amendments and Reauthorization Act of 1986 (SARA), and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP). It also states the oversight procedures
for EPA and the State to ensure Air Force compliance with the specific requirements. The FFA
identified 11 site-specific operable units (OUs) and a Basewide ground-water OU. The Basewide
ground-water OU is primarily used to address contaminated ground water that was not addressed
during an investigation of a site-specific operable unit.
Listing on the NPL and execution of the FFA required the Air Force to perform a remedial
investigation/feasibility study (RI/FS) to investigate the 12 OUs. In 1993 and 1994, an extensive
RI field program was conducted to characterize conditions at OU-5. The program included
drilling and sampling of boreholes, installation of monitoring wells, ground-water sampling,
geotechnical analysis of soil samples, ecological evaluation, assessment of human health risks, and
review and compilation of previous IRP investigations. Collection and laboratory analysis of soil,
ground water, surface water, and sediment samples were included in the RI field program.
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2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION
Community relations activities that have taken place at EAFB to date include:
FFA process. After preparation of the FFA by the USAF, EPA, and SDDENR, the
document was published for comment. The FFA became effective April 1, 1992.
Administrative Record. An Administrative Record for information was established in
Building 8203 at EAFB. The Administrative Record contains information used to
support USAF decision-making. All the documents in the Administrative Record are
available to the public.
Information repositories. An Administrative Record outline is located at the Rapid
City Library (public repository).
Community Relations Plan (CRP). The CRP was prepared and has been accepted by
EPA and the State of South Dakota and is currently being carried out. An update to this
plan will be prepared in 1996.
Restoration Advisory Board (RAB). The RAB has been formed to facilitate public
input in the cleanup and meets quarterly. In addition to USAF, EPA, and South Dakota
oversight personnel, the RAB includes community leaders and local representatives
from the surrounding area.
Mailing list. A mailing list of all interested parties in the community is maintained by
EAFB and updated regularly.
Fact sheet. A fact sheet describing the status of the IRP at EAFB was distributed to the
mailing list addressees in 1992.
Open house. An informational meeting on the status of the IRP and other
environmental efforts at EAFB was held on May 6, 1993. An open house was held
November 16, 1995 in conjunction with the Restoration Advisory Board meeting.
Information on the status of environmental efforts at EAFB was provided at the open
house.
_ Newspaper articles. Articles have been written for the Base newspaper regarding IRP
activity.
Proposed Plan. The proposed plan on this action was distributed to the mailing list
addressees for their comments.
A public comment period was held from December 28, 1995 to January 26, 1996. and a public
meeting was held on January 11, 1996. At this meeting, representatives from EAFB answered
questions about the remedial action. A response to the comments received during this period is
included in the Responsiveness Summary, which is part of this Record of Decision (ROD).
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
" -is ROD is based on the contents of the Administrative Record for OU-5, in accordance with
^CLA, as amended by SARA, am ne NCP. The RI/FS reports and the Proposed Plan for
Ul>5 provide inforjnation about OU- and the selected remedy. These documents are available
at the Information Repositories at EAi;B and the Rapid City Public Library.
2.4 SCOPE AND ROLE OF RESPONSE ACTION
The FFA identified 11 potential source area operable units (OUs) as well as a Base-wide
ground-water operable unit. The 12 operable units are identified as follows:
OU-1 Fire Protection Training Area
OU-2 Landfills Nos. 1 and 6
OU-3 Landfill No. 2
OU-4 Landfill No. 3
OU-5 Landfill No. 4
OU-6 Landfill No. 5
OU-7 Weapons Storage Area
OU-8 Explosive Ordnance Disposal Area (Pramitol Spill)
OU-9 Old Auto Hobby Shop Area
OU-10 North Hangar Complex
OU-11 Base-wide Ground Water
OU-12 HardfillNo. 1
This ROD is to document the selected remedy for the preferred remedial action (RA) at OU-5.
The remedial action objectives (RAOs) are to reduce the potential risks posed by contaminants in
surface soils and to reduce the mobility of potential contaminants in the landfill through
containment.
The development of alternatives for the landfill was conducted under the EPA's Presumptive
Remedies Approach [Presumptive Remedies: Policy and Procedures (OSWER Directive
9355.0-47FS). Presumptive Remedy for CERCLA Municipal Landfill Sites (OSWER Directive
9355.0-49FS)y. By using this approach, selecting an alternative for remediation is streamlined
by using preferred technologies based on historical patterns of remedy selection and the EPA's
scientific and engineering evaluation of performance data on technology implementation.
The presumptive remedy stipulates containment as the appropriate remedy for landfills. The
response action, containment by covering, would remove risk associated with the ingestion,
dermal contact, and inhalation exposure pathways. The area over which remediation goals will
be achieved pfter remediation is complete is defined as the area of attainment, and is bac=id on the
RAOs For "-5, the area of attainment consists of the identified boundarie7 of LandfiL No. 4.
This include e areas of the landfill not meeting appropriate State of South: »akota closure
standards. i\ sures to address leachate or gas collection were not considered since identified
wastes placed .n the landfill are not likely to produce significant amounts of gas, nor does the
waste typify that which would normally be associated with leachate production.
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Final Record of Decision Operable Unit 5
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2.5 SITE CHARACTERISTICS
This section describes the presence and distribution of contaminants at OU-5 as a result of past
activities.
2.5.1 Soils
Soil Vapor
A total of 150 soil vapor samples were collected within the landfill boundary and analyzed
during the field investigation at OU-5. From these samples, three volatile organic compounds
(VOCs), 1,1,1,-tetrachloroethane (TCA), methylene chloride, and cis-l,2-dicholoroethene, were
each detected once, trichloroethylene (TCE) was detected twice, and perchloroethylene (PCE)
was detected in six samples.
Volatile Organic Compounds (VOCs)
Eight soil samples were analyzed for VOCs during the RI. These samples were collected out of
the fill and downgradient from the landfill. There were no VOCs reported from surface or
capillary fringe (subsurface) samples collected at OU-5.
Semivolatile Organic Compounds (SVOCs)
Nine separate SVOCs were reported from the eight soil samples from OU-5. Surface soil
samples had reported concentrations of eight different polycyclic aromatic hydrocarbons (PAHs)
at estimated values (48 micrograms per kilogram [//g/kg] to 250 /zg/kg), which are below the
sample quantitation limit. No PAHs were .reported in capillary fringe soil samples. The source
of the reported PAHs is considered a result of disposal of fill over the north edge of the landfill
area.
Total Petroleum Hydrocarbons (TPH) as Jet Fuel
Eight soil samples were analyzed for TPH as jet fuel (JP-4). Jet fuel was reported in one surface
soil sample at a concentration of 190 milligrams per kilogram (mg/kg).
Pesticides
Two pesticides (endrin and heptachlor epoxide) were reported from the eight samples analyzed.
The pesticides were detected from a single surface soil sample at levels below quantitation limits.
No pesticides were reported in the capillary fringe soil samples.
Inorganic Contaminants
Four samples from OU-5 were sampled for inorganics. Manganese, potassium, and silver were
reported at values greater than the background range. The risk assessment indicated that no
unacceptable risk exists for these inorganic compounds.
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Final Record of Decision Operable Unit 5
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2.5.2 Ground Water
Volatile Organic Compounds (VOCs)
Six monitoring wells were sampled for VOCs at OU-5. Four VOCs were detected in the
ground-water samples. Three of the four detected VOCs were from a sample from a single well
from which samples were deemed to be non-reportable according to the Final Sampling and
Analysis Plan, Volume II: Quality Assurance Project Plan (QAPP). The fourth VOC was
reported at an estimated value below the sample quantitation limit. There were no exceedances of
federal MCLs or state ground water quality standards.
Semivolatile Organic Compounds (SVOCs)
The most frequently detected SVOC, bis(2-ethylhexyl) phthalate, was detected twice at a
maximum concentration of 6.0 micrograms per liter (ug/L), however, bis (2-ethylhexyl) phthalate
was also reported in the associated laboratory blank at a concentration above EPA usability
criteria values identified in the QAPP and is therefore not considered reportable.
TPH (Jet Fuel)
Jet fuel was reported in one sample at a concentration of 100 ng/L.
Pesticides/Polychlorinated Biphenyls (PCBs)
No pesticides or PCBs were reported from the five locations sampled at OU-5.
Inorganic Contaminants
Four wells were sampled for inorganic contaminants at OU-5. Thirteen inorganics were reported
at concentrations exceeding the background range. The risk assessment indicated that no
unacceptable risk exists for these inorganic compounds.
2.5.3 Surface Water/Sediment
One surface water sample was analyzed for VOCs, SVOCs, pesticides/PCBs, and inorganics.
One VOC and one tentatively identified SVOC were reported from this sample. No pesticides or
PCBs were reported. Eleven inorganics were reported.
One sediment sample was also analyzed for VOCs, SVOCs, pesticides/PCBs, and inorganics.
One VOC and two SVOCs were reported from this sample. No pesticides or PCBs were
reported. Twenty inorganics were reported.
As there was only a single sample collected for surface water and sediment, a site mean and upper
confidence limit could not be calculated. The source of the reported inorganics is considered a
result of both landfill activity and naturally-occurring geologic deposits.
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Final Record of Decision Operable Unit 5
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2.6 SITE RISK SUMMARY
2.6.1 Human Health Risks
Risk Assessment Process
The assessment of human health risks for this OU considered the following topics:
(1) Contaminants of concern (COCs) in ground-water, surface water, sediment, and soil
samples taken at OU-5;
(2) Current and future land-use conditions;
(3) Potential environmental pathways by which populations might be exposed;
(4) Estimated exposure point concentrations of COCs;
(5) Estimated intake levels of the COCs;
(6) ToxicityoftheCOCs;and
(7) Uncertainties in the assessments of exposure, toxicity, and general risks.
Noncarcinogenic and carcinogenic risks were calculated for the following four potential exposure
groups:
(1) Current adult trespasser who ingests surface soil;
(2) The future child/adult living onsite who ingests surface soil;
(3) The future adult living onsite who ingests and showers with shallow ground water;
(4) Future adult construction workers who excavate onsite for building residences.
A quantitative risk assessment was performed for the ground water, surface water, soil, sediment,
and air. The risk assessment evaluated potential effects on human health posed by exposure to
contaminants within OU-5. Carcinogenic risks were estimated as the incremental probability of
an individual developing cancer over a lifetime as a result of exposure to a potential cancer
causing chemical. The acceptable risk range expressed as a probability is one cancer incident in
ten thousand people to one cancer incident in a million people. This level of risk is also denoted
by 1 x 10"4 to 1 x 10'6. Risks within the acceptable risk range may or may not warrant remedial
action depending upon site-specific circumstances. Risks below this range cannot be
differentiated from the background occurrence of cancer in human populations. Risks calculated
in a risk assessment are potential risks and are excess (i.e., over background) cancer risks due to
exposure from contaminants at the OU.
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Noncarcinogenic health risks are evaluated using a hazard index. If the hazard index is less than
or equal to one, the contaminant concentration is considered an acceptable level and generally
assumes that the human population may be exposed to it during a 30-year period without adverse
health effects.
Risk Assessment Results
The risk assessment for OU-5 indicated that the carcinogenic risk was within the acceptable risk
range of 1 x 10~4 to 1 x 10"6. Part of the site risk present at OU-5 includes risk from exposure to
surface soil contaminants from within the landfill. Due to the heterogeneity of the landfill
contents, uncertainty is associated with the calculated risk values for the surface soil.
The risk assessment for OU-5 indicated that there were no noncarcinogenic risks resulting in an
HI above 1.0.
Results of the risk assessment indicated shallow ground water and surface water were not media
of current concern. Therefore, remedial action is not warranted for the ground water and surface
water at this time. The ground water at OU-5 will still be retained as part of the Base-wide
ground water evaluation for OU-11.
Risk Summary
Remedial action is warranted for the landfill based on the potential risk to human health from
future releases of unidentified hazardous substances in the landfill. Contaminants in the landfill
may leach downward to contaminate the underlying ground water. Off-Base residents may then
ingest or come in contact with the contaminated ground water. Also, the surface of the landfills
may erode, thus exposing off-Base residents to contaminants in both surface water and air. Due
to the potential heterogeneity of the waste materials present within the landfill, uncertainty is
associated with the calculated risk values for surface soil.
Rather than attempting to gain more certainty in the risk assessment for the landfill contents, the
Air Force utilized guidance developed by EPA titled Presumptive Remedy for CERCLA
Municipal Landfill Sites (OSWER Directive 9355.0-49FS). The presumptive remedy for
landfills is onsite containment of landfill contents. Using the presumptive remedy strategy, a
quantitative risk assessment is not necessary to evaluate whether the containment remedy
addresses all exposure pathways and contaminants potentially associated with a landfill. Rather,
all potential exposure pathways can be identified using the conceptual site model and compared
with the pathways addressed by the presumptive remedy. Containment of the landfill contents
addresses exposure pathways and risks normally associated with landfills. The contaminant
exposure pathways for the potential risks at OU-5 include (1) direct physical contact with the
landfill contents, and (2) consumption or contact with ground water that is or may become
contaminated.
Actual or threatened releases of hazardous substances from OU-5, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, and the environment.
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2.6.2 Ecological Risks
An ecological risk evaluation of OU-5 was based on a combination of data and literature reviews,
field and laboratory analyses, analyte evaluation and screening, and preliminary risk screening.
The pertinent findings are summarized below.
A variety of animal species may live, forage, or nest in OU-5 habitats. These species include
various types of invertebrates, amphibians, birds, and mammals. Terrestrial vegetation and soil
faunal communities do not reveal characteristics that indicate chemical-related impacts. This
finding is consistent with the relatively low levels of contaminants in the soil.
Because of the altered natural environment at OU-5, rare, threatened, or endangered species, are
unlikely to utilize the area for more than a brief, periodic habitat. Due to the low levels of
contaminant concentrations, the contaminants do not pose an unacceptable risk to these species.
In addition, the limited contact these species would have with the OU-5 area ensures
unacceptable risk to a single individual will not occur. Chapter 6 of the OU-5 RI gives a detailed
evaluation of the ecological risk assessment and lists the potential ecological receptors.
Findings of the RI indicate that the contaminants at OU-5 are not altering the ecology to
noticeable levels. A Base-wide ecological risk assessment will be conducted as part of OU-11,
and OU-5 will be included in this Base-wide evaluation.
2.7 DESCRIPTION OF ALTERNATIVES
Presumptive Remedy for CERCLA Municipal Landfill Sites, (OSWER Directive 9355.3-1 IPS)
was the basis for the abbreviated feasibility study (FS). The OSWER directive established
containment of the contamination within the landfill and the collection and treatment of landfill
gas and contaminated ground water within the landfill boundary as the presumptive remedy for
CERCLA municipal landfills.
Although not specifically identified as a municipal landfill, OU-5 exhibits characteristics that
make this presumptive remedy applicable. The landfill contents at OU-5 do not have the
characteristics to produce any significant leachate or gases. The risk assessment did not identify
the ground water at OU-5 as a pathway of concern. Though the landfill contents were not
identified as a source of unacceptable risk to human health, the heterogeneity of the landfill
contents causes uncertainties in the risk assessment. Therefore, the presumptive remedy focuses
on containment of the landfill contents.
Alternative I - No Action
No Action.
The no action alternative represents the baseline condition at OU-5 and refers to
taking no further action at OU-5. It is expected that'any existing maintenance
(e.g., grass mowing) would be continued.
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The no action alternative does not meet remedial action objectives for OU-5.
Alternative 2 - Institutional Controls
Implementing access restrictions.
Restricting future land and ground-water use.
Developing long-term ground-water monitoring.
Developing a long-term maintenance plan for the existing soil cover.
This alternative does not meet the remedial action objectives for OU-5.
Alternative 3 - Vegetative Soil Cover
Placing a soil cover capable of sustaining perennial vegetation over the landfill
area;
Institutional controls for the landfill area;
Long-term ground-water monitoring; and, long-term maintenance of soil cover.
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
The analysis of alternatives coupled with the use of the presumptive remedy combine for a
narrower range of feasible approaches to address remedial activities at OU-5.
The remedial action objectives for OU-5 are as follows:
Landfill
Provide protection against direct contact or ingestion of the landfill contents.
Minimize infiltration through the landfill.
Control surface water runoff and erosion of the landfill cover.
The area of attainment is defined as the area that will achieve the remedial action objectives after
remediation is completed. The area of attainment for OU-5 is the extent of Landfill No. 4 that is
approximately 10 acres in size.
Pursuant to Section 300.430(e)(9)(iii) of the EPA's revised National Contingency Plan, the
remedial action to be implemented should be selected based upon consideration of nine
evaluation critei.a. These criteria are as follows:
1. Overall protection of human health and environment.
2. Compliance with applicable or relevant and appropriate requirements (ARARs).
3. Long-term effectiveness and permanence.
4. Reduction of toxicity, mobility, or volume of contamination.
5. Short-term effectiveness.
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6. Implementability.
7. Cost.
8. State acceptance.
9. Community acceptance.
The following sections provide a brief review and comparison of the remedial alternatives
according the EPA's evaluation criteria.
2.8.1 Overall Protection of Human Health and the Environment
The assessment of this criterion considers how the alternatives achieve and maintain protection
of human health and the environment.
Alternative 1 (no action) does nothing to reduce risk at OU-5. Alternative 2 (Institutional
Controls) provides for care of the OU through maintenance of erosional and/or non-vegetated
areas. Access restrictions would reduce risk by reducing exposure. Alternative 3 (Covering)
provides containment of the surface soil and the landfill contents. This would eliminate risk
associated with exposure to soil and the future risk associated with potentially contaminated
ground water.
2.8.2 Compliance with ARARs
Alternatives are assessed under this criterion in terms of compliance with ARARs. Applicable
requirements include cleanup standards, standards of control and other substantive environmental
protection requirements, criteria or limitations promulgated under Federal or state laws. These
laws specifically address a hazardous substance, pollutant, contaminant, remedial action, location
or other circumstances at a CERCLA site.
ARARs are grouped into these three categories:
Chemical-Specific ARARs are health or risk-based numerical values or
methodologies that, when applied to site-specific conditions, result in
establishment of the amount or concentration that may be found in, or discharged
to, the environment.
Location-Specific ARARs restrict the concentration of hazardous substances or
the conduct of activities solely because they are in specific locations such as flood
plains, wetlands, historic places, and sensitive ecosystems or habitats.
Action-Specific ARARs are usually technology or activity-based requirements or
limitations on actions taken with respect to hazardous wastes.
State of South Dakota guidelines for petroleum in soils are the only known chemical-specific
ARARs for soil at OU-5. Detected levels of petroleum-related compounds do not exceed State
ARARs at OU-5. Ground water at OU-5 is not contaminated above State or Federal MCLs.
Inorganics detected in the one surface water sample collected that were above Federal Ambient
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Water Quality Criteria were determined to be naturally occurring and are not considered for
remediation. There are no State or Federally promulgated standards for chemicals in sediments.
A summary evaluation of Federal and State ARARs pertinent to this remedial action is provided in
Table 2-1 at the end of Section 2.0, and a narrative discussion of compliance with ARARs is
provided below for the alternatives considered.
Alternative 1 (No Action):
The No Action alternative does not comply with State solid waste landfill closure requirements.
The OU-5 RI concluded that ground water has not been adversely affected and has not been a
potential transport pathway; therefore, ground water ARARs at the OU are met. No permits are
required for this alternative. However, Alternative 1 does not meet the remedial action objectives
for OU-5 because an action would not be taken to prevent human contact with surface-soil
contaminants, and because potential contaminants within the landfill may leach to the ground
water.
Alternative 2 (Institutional Controls):
Alternative 2 does not comply with State of South Dakota solid waste landfill closure
requirements. The OU-5 RI concluded that ground water has not been adversely affected and has
not been a potential transport pathway; therefore, ground-water ARARs at the OU are met. No
Federal or State permits are required for this alternative. However, Alternative 2 does not meet
the remedial action objectives for OU-5 because an action would not be taken to prevent human
contact with surface-soil contaminants and because potential contaminants within the landfill may
leach to the ground water.
Alternative 3 (Covering):
Alternative 3 would meet State of South Dakota Waste Management Regulations for the disposal
of solid waste by providing a two-foot minimum earth cover capable of sustaining perennial
vegetation; implementing institutional controls including maintaining access control; filling,
grading, and contouring the site; maintenance of the cover and vegetation; and other
requirements as set forth in ARSD Chapter 74:27: 1 5. The State is Federally authorized for the
Resource Conservation and Recovery Act (RCRA) Subtitle D Municipal Solid Waste Program
(8 October 1993, 58 FR 52486).
Long:term ground-water monitoring will be used to verify continued compliance with Federal
MCLs (National Primary Drinking Water Regulations, 40 CFR 141.1 1-12) and State Ground
Water Quality Standards beyond the boundary of the landfill. By following the presumptive
remedy approach, the MCLs are not considered ARARs for the ground water within the
boundaries of the landfill.
Implementation of the presumptive remedy strategy for landfills has been shown by EPA to meet
the remedial action objectives by preventing direct contact with landfill contents and ingestion of
surface soils.
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2.8.3 Long-Term Effectiveness and Permanence
The assessment of this criterion included long-term effectiveness of alternatives in maintaining
protection of human health and the environment after response action objectives have been met.
Alternative 1 would not provide additional effectiveness or permanence in reducing the potential
for direct contact or ingestion of the surface soil or sediments. No further controls for the OU
would be developed under this alternative.
Alternative 2 would be effective in reducing direct exposure to landfill contents by restricting
access to the site (in addition to the general EAFB access restrictions). This alternative would
not reduce the potential impacts to ground water from percolation of rainwater through those
areas of the landfill not adequately covered. Long-term maintenance of the existing cover and
vegetation at Landfill No. 4 would somewhat reduce the potential for erosion of the existing
cover. Permanency and reliability of these controls would be evaluated through long-term
ground-water monitoring and maintenance of the existing landfill soil cover. Uncertainties exist
for the ability to provide long-term access restrictions.
Alternative 3 would offer the highest level of long-term effectiveness in reducing risk due to
exposure of contaminants in the landfill, and would significantly reduce the potential for landfill
contents to impact ground-water quality. Access restrictions would deter unauthorized access to
the site. Installing an .earth cover would effectively contain the contents of the landfill and
reduce the potential for exposure to contaminants. Providing positive drainage off the site would
also reduce ponding on the landfill and further reduce the potential for infiltration. Erosion
would be limited by the development and maintenance of vegetation. Permanency and
reliability would be evaluated through long-term ground-water monitoring and maintenance of
the existing landfill cover and vegetation. Future land uses will be allowed for the landfill only if
the integrity of the landfill cover is not compromised.
2.8.4 Reduction of Toxiciry, Mobility-, and Volume Through Treatment
The assessment of this criterion involves considering the anticipated performance of specific
treatment technologies an alternative may employ.
Alternative 1 would not provide for the reduction of toxicity, mobility, or volume of the
chemicals of concern in the surface soil and sediment. Alternative 2 would reduce the mobility
of contaminants in surface soils through long-term erosion maintenance of existing cover soils.
Alternative 3 reduces infiltration and potential wind-blown contamination through containment;
however, treatment of the contamination is not being proposed.
2.8.5 Short-Term Effectiveness
The assessment of this criterion considers the effectiveness of alternatives in maintaining
protection of human health and the environment during the construction of a remedy until
response action objectives have been met.
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It is not anticipated that the_proposed alternatives vould significantly impact worker or
community health and safety during the implemen 'on period. Alternatives 2 and 3 may impact
community and worker health and safety through c. .t emissions during the initial construction
phase. The impact could be minimized through du^c mitigation.
Alternatives 2 and 3 may create a short-term increase in risk during remedial activities due to the
inhalation exposure pathway. Disturbance of surface soil through earthwork and soil disturbance
would result in exposure to workers. Dust mitigation during these activities would minimize this
potential impact. Alternative 3 would present the potential for temporarily increasing the
opportunity for erosion of the disturbed soils, although erosion and sediment control measures
will help to minimize this adverse impact.
2.8.6 Implementability
The assessment of this criterion considers the administrative and technical feasibility of
implementing the alternatives and the availability of necessary goods and services for
implementation of the response action.
Alternative 1 would not be difficult to implement since, besides long-term monitoring using
existing monitoring wells, no further action would be undertaken.
Alternative 2 requires no special or unique activities and could be implemented using locally
available materials and contractors. Long-term monitoring would indicate whether additional
action would need to be implemented in the future.
Alternative 3 could be implemented with standard construction equipment, materials, and
methods. The availability of an on- or off-Base supply of cover material will require further
consideration during the Remedial Design Analysis. Land use (or deed) restrictions can be
implemented at EAFB by various administrative means.
2.8.7 Cost
The assessment of this criterion considers the capital and operation and maintenance (O&M)
costs associated with each alternative. Alternatives are evaluated for cost in terms of both capital
costs and long-term O&M costs necessary to ensure continued effectiveness of the alternatives.
Capital costs include the sum of the direct capital costs (materials and labor) and indirect capital
costs (engineering, licenses, permits). Long-term O&M costs include labor, materials, energy,
equipment replacement, disposal, and sampling necessary to ensure the future effectiveness of
the alternative. The objective of the cost analysis is to eliminate those alternatives that do not
provide measurably greater protection of human health and the environment for additional costs
that may be incurred. Cost estimates do nc>j T :lude yearly escalation adjustments. Final costs
developed in the Remedial Design will be -:'.;uctured using the Remedial Action Work
Breakdown structure. A summary of the costs for each alternative is as follows:
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Alternative No. 1 (No Action) _
Total Capital Costs
Total Annual (Sampling/Analysis) Costs
30-Year Present Value for Annual Costs
Annual Cost = $13,500
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value*
SO
SO
so
so
Alternative No. 2 (Institutional Controls)
Total Capital Costs
Total Annual (Sampling/Analysis/O&M2) Costs - Years 1-5
Total Annual (Sampling/Analysis/O&M) Costs - Years 6 -30
30-Year Present Value for Annual Costs
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value*
545,198
570,552
536,752
S71 1,044
5756,242
Alternative No. 3 (Capping)
Total Capital Costs
Total Annual (Sampling/Analysis/O&M) Costs - Years 1-5
Total Annual (Sampling/Analysis/O&M) Costs - Years 6-30
30- Year Present Value for Annual Costs
Years = 30
Discount Rate = 5%
TO TAL30- Year Present Value1
51,063,133
570,552
536,752
5711,044
57,774,777
Notes
1) The Total 30 Year Present Value is the sum of the total capital costs and the 30-Year Present
Value for annual costs.
2) Operations & Maintenance.
2.8.8 State Acceptance
The assessment of this criterion considered the State's preferences for or concerns about the
alternatives.
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Final Record of Decision Operable Unit 5
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The State concurs with the selected remedy. The State provided comments on the remedial
investigation, feasibility study, Proposed Plan, and this ROD. After incorporating adequate
responses to the comments into the respective documents, the State concurred with the remedy.
2.8.9 Community Acceptance
Comments offered by the public were used to assess the community acceptance of the proposed
alternative. The community expressed their concerns about the selected remedy during the public
comment period. The questions and concerns of the community are discussed in detail in the
Responsiveness Summary that is Appendix B of the ROD.
2.9 SELECTED ALTERNATIVE
Based on the requirements of CERCLA, comparative analysis of the nine criteria, public
comments, and in consultation with EPA and the State, the Air Force has determined that the
selected alternative is Alternative 3, Vegetative Soil Covering. This alternative includes
institutional controls in conjunction with physical modification of the OU to reduce potential risk.
Five-year reviews of the remedy will be required because potential contaminants will remain at
OU-5 following completion of remedial action.
Major components of Alternative 3 are:
Placing a soil cover capable of sustaining perennial vegetation over the landfill
area;
Institutional controls for the landfill area;
Long-term ground-water monitoring; and, long-term maintenance of soil cover.
Each item is discussed below.
Installation of Soil Cover
A pre-design study will be conducted to verify the defined limits of the landfill and determine the
type and extent of cover needed. It is anticipated that a single-layer earth cover, two feet thick
will be placed over the area of attainment (approximately 10 acres). The cover will meet State
landfill closure requirements. The cover material must be capable of sustaining vegetation.
Borings drilled during the pre-design study would be used to determine the quantity of material
required to construct a cover of the required thickness. The pre-design study would also be used
to determine the type of cover needed to reduce infiltration of precipitation through the landfill
and ensure continued compliance with the Federal MCLs and State Ground Water Quality
Standards.
The area of attainment will be filled, graded, and contoured to maintain stability, eliminate
slumping, settling, or ponding of water above previously active disposal areas, and to provide
positive drainage off the landfill area. Vegetation will be established in areas of OU-5 that are
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under-vegetated and areas disturbed by. new construction and.cover placement to enhance
evapotranspiration and reduce infiltration and soil erosion.
Institutional Controls
Institutional controls will be implemented to prevent human exposure to contaminated soil and
ground water. These controls will include: (1) issuing a continuing order to restrict onsite worker
access to contaminated soil, and restrict or control temporary construction activities unless proper
protective equipment is worn; (2) filing a notice with the State of South Dakota to recommend
denial of water appropriations permit applications to install ground-water wells within the landfill
boundary and the area of potential contamination; (3) annotating base records in the event of
property transfer.
A continuing order would be issued by the Installation Commander to restrict access to or
disturbance of the landfills as long as Ellsworth AFB owns the property. Specifically, it would:
Restrict or place limitations on the installation of any new underground utilities or
other construction activities in the area of the landfills, thus preventing accidental
exposures to construction workers.
Provide for the use of proper protective equipment, in the event that access
through the landfill cover is required.
Require that the integrity of the landfill covers are maintained. Limit future land
uses to non-intrusive activities only (or activities that will not effect the landfill
cover). Maintenance of the landfills will require development of standard '
operating procedures (SOPs) to provide for inspections and repairs. To assist with
the institutional controls, a fence will be placed around the landfill and authorized
personnel would have access through a locked gate. Access would only be
allowed to perform landfill maintenance and monitoring activities. Warning signs
will be posted at the landfill to deter unauthorized access.
The continuing order also will mandate that, if the landfill covers were ever removed or
destroyed, the area of attainment will be reevaluated to determine the need for a replacement
cover or other remedial action.
Continuing order requirements will be in effect as long as the property is owned by Ellsworth
AFB. In the case of the sale or transfer of property within OU-5 by the United States to any
other person or entity, the Air Force will place covenants in the deed that will restrict access
and prohibit disturbance of the landfill or the remedial action without approval of the United
States. These covenants will be in effect until removed upon agreement of the State of South
Dakota, the U.S. Environmental Protection Agency, and the U.S. Air Force or their
successors in interest. The Air Force will also include in the deed the covenants required by
section 120(h)(3) of CERCLA, which include (1) a warranty that the United States will
conduct any remedial action to be required by law after the date of the transfer; (2) a right of
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access in behalf of EPA and the Air Force or their successors in interest to the property to
participate in any response or corrective action that might be required after the date of
transfer. The right of access referenced in the preceding sentence shall include the State of
South Dakota for purposes of conducting or participating in any response or corrective action
that might be required after the date of transfer.
Long-Term Monitoring and Maintenance
A long-term monitoring program will be developed and implemented during remedial action
and is subject to approval of both EPA and SDDENR. Contaminant concentrations in the
ground water will be monitored to evaluate the effectiveness of the existing landfill cover and
to determine if the ground-water is being further impacted by the contents of the landfill.
A maintenance program will be implemented to ensure the long-term integrity on the existing
landfill conditions that will be maintained. The maintenance program will include
development of SOPs to provide for inspections, repairs, and general maintenance of the
landfills.
This alternative will meet the remedial action objectives and reduce the potential risk for
OU-5 by preventing future exposure to contaminants in the surface soils and by reducing the
mobility of potential contaminants in the landfill.
For Landfill No. 4, Alternative 3 will achieve significant risk reduction by limiting exposure
to landfill materials and to contaminants present in surface soils and would reduce the
potential for future movement of contaminants in the ground water beneath the landfill. The
selected alternative will be protective of human health and the environment and will comply
with ARARs.
2.10 STATUTORY DETERMINATIONS
This selected remedy meets the statutory requirements of Section 121 of CERCLA as
amended by SARA. These requirements include protectiveness of human health and the
environment, compliance with ARARs, cost effectiveness, and utilization of permanent
solutions and alternative treatment technologies to the extent practicable. The statutory
preference for treatment is not satisfied; however, the selected alternative is the presumptive
remedy for landfills. Containment, by definition, does not attempt to reduce the toxicity or
volume of potentially hazardous materials; rather, it reduces the likelihood of exposure to
these materials by preventing the movement of materials beyond the boundaries of the
landfill and preventing direct contact with landfill materials. The selected remedy represents
the best balance of tradeoffs among th- alternatives considered, with respect to pertinent
criteria, given the scope of the action.
The manner in which the selected remedy meets each of these requirements is discussed in
the sections below.
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2.10.1 Protection of Human Health and the Environment
Implementation of the presumptive remedy (containment by covering) strategy for landfills
has been shown by EPA to meet the remedial action objectives and to protect human health
and the environment by preventing (1) direct contact with landfill contents and (2) ingestion
of surface soils. Specifically, the covering alternative:
Eliminates exposure to landfill contents by installing an earth cover.
Reduces the potential infiltration of rainwater and leaching of contaminants to
the ground water.
Prevents unauthorized access to the area by installing a perimeter fence and
restricted access signs.
Provides for long-term monitoring of ground water to identify potential future
risks associated with OU-5.
2.10.2 Compliance with ARARs
Alternative 3 will meet State landfill closure requirements by providing the required amount
of cover over the landfill, site improvements, access/land and ground-water use restrictions,
and long-term monitoring. The OU-5 RI concluded that ground water has not been adversely
affected and has not been a potential transport pathway; therefore, ground water ARARs at
OU-5 are met. Additional information about ARAR compliance is contained in
Section 2.8.2.
2.10.3 Cost Effectiveness
The selected remedy provides overall effectiveness in reducing human health risks relative to
its costs. The presumptive remedy process ensures cost-effective remedies are chosen. The
chosen landfill cover type ensures containment of the landfill contents. Site specific
conditions were used to determine the type and extent of cover necessary for the landfill.
Based on the information provided during the remedial investigation and the predesign study,
the most effective cover will be installed.
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies to
the Extent Possible
EPA has established that installing a proper cover has proven effective in containing landfill
contents. This alternative provides long-term prevention of exposure to potential landfill
material, prevents unauthorized access, and provides for long-term ground water monitoring
to detect movement of chemicals from the area. A five-year review of the selected remedy
will be performed due to the uncertainty of characterizing landfill contents. The review will
be conducted no less than every five years after signing of the ROD to ensure the remedy
continues to provide adequate protection of human health and the environment. Results of
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the review will be used to determine if modification of any or all parts of the selected remedy
will be required.
2.10.5 Preference for Treatment as a Principal Element
Treatment of the landfill contents is not supported based on the findings of the remedial
investigation for OU-5. No identifiable hot spots were detected that would warrant removal
and/or separate treatment. The risks associated with OU-5 can be addressed by eliminating
exposure to the landfill contents by installing a cover and restricting access.
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES
The selected action is the same as the preferred alternative presented in the Proposed Plan for
OU-5 remedial action. There have been no significant changes relative to the Proposed Plan.
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT APPLY TO OU-5, ELLSWORTH AFB, SOUTH DAKOTA
Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Safe Drinking Water Act
National Primary Drinking
Water Standards
National Secondary
Drinking Water Standards
Maximum Contaminant
Level Goals
Clean Water Act
Water Quality Criteria
Clean Air Act of 1983
National Primary and
Secondary Ambient Air
Quality Standard
Solid Waste Disposal Act as
amended by Resource
Conservation and Recovery Act of
1976
Solid Waste Disposal Facility
Criteria
Citations
42 DSC 300 f, g
40 CFR Part 141.11-12
40CFRPart 143.03
40CTRPart 141.50 & Public
Law No. 99-330, lOOStat. 642
(1986)
33 USC 1251-1376
40 CFR Part 131
42 USC 7401
40 CFR Part 50.1-6, 8,9,1 1,12,
and Appendices A, H, J, K
42 USC 6901
40 CFR Parts 257 and 258
Description
Establishes health-based standards for
public water systems (maximum
contaminant levels)
Establishes aesthetic-based standards for
public water systems (maximum
contaminant levels)
Establishes drinking water quality goals
set at concentrations of unknown or
anticipated adverse health effects with
an adequate margin of safety
Establishes criteria for water quality
based on toxicity to aquatic organisms
and human health
Establishes national primary and
secondary ambient air quality standards
to protect public health and welfare.
Sets forth revised minimum federal
criteria for Municipal Solid Waste
Landfills (MSWLFs) for existing and
new units
ARAR
Type
Chemical
Chemical
Chemical
Chemical
Action
Action
Applicability
Relevant and appropriate for federal
Class II aquifers.
Relevant and appropriate. ' ;
Relevant and appropriate. (
i
i
i
\
I
Relevant and appropriate. Aquifer
may be a federal Class II A '
(discharge to surface water). [
1
i
Applicable [
E
5
i
i
i
Relevant and appropriate for
addressing landfill closure
performance standards. i
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TABLE 2-1 (Continued)
Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Land Disposal Restrictions
Guideline.,,. ;;;L Land
Disposal of Solid Waste
Resource Conservation and
Recovery Act of 1976
Hazardous Waste
Management System:
Geneia!
Identification and Listing
of Hazardous Wastes
Standards Applicable to
Generators of Hazardous
Wastes
Standards Applicable to
Transporters of
Hazardous Wastes
Standards for Owners
and Operators of
Hazardous Waste
TSDF's
Citations
40 C? R Part 268
40 CFR Part 24 1.1 00-2 13
40 CFR Part 260
40 CFR Part 261
40 CFR Part 262
40 CFR Part 263
40 CFR Part 264
Description
Identifies hazardous wastes that are
restricted from land disposal and
defines those limited circumstances
under which a prohibited waste may
continue to be land disposed
Establishes requirements and
procedures for the disposal of solid
waste.
Establishes definitions as well as
procedures and criteria for
modification or revocation of any
provision in 40 CFR Parts 260-265
Defines those solid wastes which
are subject to regulations as
hazardous wastes under 40 CFR
Parts 262-265
Establishes standards for generators
of hazardous waste
Establishes standards which apply
to persons transporting hazardous
waste within the U.S. if the
transportation requires a manifest
under 40 CFR Part 262
Establishes standards for acceptable
hazardous waste management.
ARAR
Type
Action
Action
Action
Action
Action
Action
Action
Applicability
Relevant and Appropriate.
Alternatives may include the
disposal of residual waste due to
treatment.
Relevant and appropriate for
meeting landfill closure '
performance guidelines.
Applicable for identifying
hazardous waste during soil
placement at OU-2.
Applicable for identifying
hazardous waste during soil
placement at OU-2.
Applicable to alternatives relating
to removal or offsite transport of
a hazardous material.
Applicable for any transport of
hazardous materials offsite.
Relevant and Appropriate for
performance guidelines for
landfill closure.
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TABLE 2-1 (Continued)
Applicable or Relevantand Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Crkeria or,
Limitation
Citations
Description
ARAR
Type
Applicability
Standards for Owners and
Operators of Hazardous
Waste TSDF's with Interim
Status
40 CFR Part 265
Establishes standards for acceptable
hazardous waste management during
interim status.
Action
Relevant and Appropriate for
performance guidelines for landfill
closure.
Criteria and Standards for the
National Pollutant Discharge
Elimination System
40 CFR Part 125
Establishes criteria and standards for
technology-based requirements in
permits under the Clean Water Act
Chemical
Relevant and appropriate.
Toxic Substances Control Act
40 CFR Part 761.1
Substances regulated include, but are
not limited to, soils and other materials
contaminated as a result of spills
Action
Applicable.
Executive Order No. 11988 on
Floodplains Management
42 USC 7401
40 CFR 6.302 (b) & Appendix A
Requires federal agencies to evaluate
the potential effects of actions they may
take in a floodplain to avoid, to the
extent possible, the adverse impacts
associated with direct and indirect
development of a floodplain.
Location
Applicable.
Executive Order on Protection of
Wetlands
E.G. No. 11,990
40 CFR 6.302(a) & Appendix A
Requires federal agencies to avoid, to
the extent possible, the adverse impacts
associated with the destruction or loss of
wetlands and to avoid support of new
construction in wetlands if a practicable
alternative exists
Action/Location
Applicable.
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TABLE 2-1 (Continued)
Applicable or Relevant and Appropriate State Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
So n (li Dnkoln Wnstc Management
Regulations
South Dakota Waste Management
Regulations
South Dakota Waste Management
Regulations
South Dakota \\astc Management
Regulations
South Dakota Water Quality
Standards
South Dakota Gi ..uud Water
Standards
South Dakota Surface Water
Quality Standards
South Dakota Remediation Criteria
for Petroleum-Contaminated Soils
Citations
74:26:03:04
74:27:03:11
74:27:09:06
74:27:15
74:03:04:02, 10
74:03:15
74:03:02
74:03:32,33
Description
Establishes requirements for disposal of
hazardous wastes in sanitary landfills
Defines requirements for closure of solid waste
disposal facilities
Defines criteria for permit applications for other
solid waste TSD facilities
Establishes standards for landfill closure and
post-closure monitoring
Defines use of Box Elder Creek and certain
tributaries
Defines ground water classifications by
beneficial use and sets chemical standards
Establishes surface water quality standards.
Establishes requirements for the remediation of
soil contaminated with petroleum products.
ARAR Type
Action
Action
Action
Action
Action
Chemical
Chemical
Chemical
Applicability
Relevant and appropriate.
Relevant and appropriate. '
Relevant and appropriate. '
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
3.0 LIST OF ACRONYMS AND ABBREVIATIONS
ACC: Air Combat Command
AFB: Air Force Base
ARARs: Applicable or Relevant and Appropriate Requirements
CERCLA: Comprehensive Environmental Response, Compensation and Liability Act
COC: Contaminant of Concern
CRP: Community Relations Plan
EAFB: Ellsworth Air Force Base
EPA: Environmental Protection Agency
FFA: Federal Facilities Agreement
IRP: Installation Restoration Program
JP-4: Jet Propulsion Fuel Number Four; contains both kerosene and gasoline fractions.
Mg/L: Micrograms per liter
Mg/kg: Micrograms per kilogram
mg/kg: Milligrams per kilogram
NCP: National Oil and Hazardous Substances Contingency Plan
NPL: National Priorities List
O&M: Operation and Maintenance
OU: Operable Unit
PAH: Polynuclear Aromatic Hydrocarbon
PCB: Polychlorinated Biphenyl; liquids used as a dielectrics in electrical equipment
PCE: Perchloroethylene; liquids used in degreasing or paint removal.
RAB: Restoration Advisory Board
RAO: Remedial Action Objective
RI/FS: Remedial Investigation/Feasibility Study
ROD: Record of Decision
SARA: Superfund Amendments and Reauthorization Act
SDDENR: South Dakota Department of Environment and Natural Resources
SVOC: Semivolatile Organic Compound
TCA: 1, 1,1,-tetrachloroethane
TCE: Trichloroethylene
TPH: Total Petroleum Hydrocarbon
TSD: Treatment, storage or disposal sites/methods
USAF: United States Air Force
VOC: Volatile Organic Compound
F: \PROJ\603 7886\FS\OU5. ROD\F1NAL \OU5ROD. FNL
3-1
May 7, 1996
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
APPENDIX A
FIGURES
F:\PROJ\60378S6\FS\OU5.ROD\FINAL\OU5ROD.FNL May 7. 1996
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N
MMNtSOTA
NORTH DAKOTA
: '
SOUTH DAKOTA
ELLSWORTH AFB
Ropid Cfty
Scale in Uiln
APPROXIMATE
ELL-SWORTH
AIR FORCE BASE
ELLSWORTH AFB
RAPCCflY. SOUTH MKOTA
AREA LOCATION MAP
ROJECT VO
DESIGNED BY
OWWN BY
STAFF
CHECXED BT
SCALE
AS SHOWN
DATE
SEP 95
PROJECT NO
60378.93
FORE:
2-1
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in
£
a
or
§i
cr-
o1"
OU-5
OU-1
OU-2
OU-3
OU-4
OU-5
OU-6
OU-7
OU-8
OU-9
OU-10
OU-11
OU-12
OPERABLE UNITS
FIRE PROTECTION TRAINING
AREA
LANDFILLS 1 & 6
LANDFILL 2
LANDFILL 3
LANDFILL 4
LANDFILL 5
LOW LEVEL RADIATION WASTE BURIAL AREA
EXPLOSIVE ORDNANCE DISPOSAL AREA &. PRAMITOL SPILL
OLD AUTO HOBBY SHOP AREA
"NORTH HANGAR COMPLEX
BASEWIDE GROUND WATER
HARDFILL NO. 1
EL.USWORTH
AIR FORCE BASE
ELLSWORTH AFB
RAPID CITY. SOUTH DAKOTA
SITE LOCATION MAP
ROJCCT UCR
DESIGNED BY
DRAWN BY
STAFF
CHECKED BY
SCALE
AS SHOWN
DATE
SEP 95
PROJECT NO
60378.93
FIGURE:
2-2
-------
o
£
i
UJOT
2 ,_
LEGEND:
LANDFILL NO.
COVER AREA
PROPOSED FENCE LOCATION
BASE BOUNDARY FENCE
TOPOGRAPHIC ELEVATION ABOVE
MSL - CONTOUR INTERVAL=10'
ELLSWORTH
AIR FORCE BASE
ELLSWORTH AFB
RAPID OTY. SOUTH DAKOTA
OPERABLE UNIT 5
LANDFILL NO. 4
ROJEC7 UCR
DESIGNED BY
DRAWN 8r
STAFF
CHECKED BY
SCALE
AS SHOWN
DATE
SEP 95
PROJECT NO
60378.93
FIGURE
2-3
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
APPENDIX B
RESPONSIVENESS SUMMARY
F-\pnn.MnniHfi\F!&oU5.ROD\FINAL\OU5ROD.FNL May 7, 1996
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
Responsiveness Summary
Remedial Action at Operable Unit Five
Ellsworth Air Force Base, South Dakota
1. Overview
The United States Air Force (USAF) established a public comment period from December 28, 1995
to January 27, 1996 for interested parties to review and comment on remedial alternatives considered
and described in the Proposed Plan for Operable Unit 5 (OU-5). The Proposed Plan was prepared
by the USAF in cooperation with the U.S. Environmental Protection Agency (USEPA) and the South
Dakota Department of Environment and Natural Resources (SDDENR).
The USAF also held a public meeting at 7:30 p.m. on January 11, 1996 in the Box Elder Middle
School to outline the proposed remedy to reduce risk and control potential hazards at the Operable
Unit (OU).
The Responsiveness Summary provides a summary of comments and questions received from the
community at the public meeting and during the public comment period as well as the USAF's
responses to public comments.
The Responsiveness Summary is organized into the following sections:
Background on Community Involvement
Summary of Comments and Questions Received During the Public Comment Period
and USAF Responses
Remaining Concerns
2. Background on Community Involvement
On August 30, 1990 EAFB was listed on the USEPA's National Priorities List (NPL). A Federal
Facilities Agreement (FFA) was signed in January 1992 by the Air Force, EPA, and the State and
went into effect on April 1, 1992. The FFA establishes a procedural framework and schedule for
developing, implementing, and monitoring appropriate response actions for EAFB.
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
Community relations activities that have taken place at EAFB to date include:
FFA process. After preparation of the FFA by the USAF, EPA, and SDDENR, the
document was published for comment. The FFA became effective April 1, 1992.
Administrative Record. An Administrative Record for information was established
in Building 8203 at EAFB. The Administrative Record contains information used to
support USAF decision-making. All the documents in the Administrative Record are
available to the public.
Information repositories. An Administrative Record outline is located at the Rapid
City Library (public repository).
Community Relations Plan (CRP). The CRP was prepared and has been accepted
by EPA and the State of South Dakota and is currently being carried out. An update
to this plan will be prepared in 1996.
Restoration Advisory Board (RAB). The RAB has been formed to facilitate public
input in the cleanup and meets quarterly. In addition to USAF, EPA, and South
Dakota oversight personnel, the RAB includes community leaders and local
representatives from the surrounding area.
Mailing list. A mailing list of all interested panics in the community is maintained
by EAFB and updated regularly.
Fact sheet. A fact sheet describing the status of the IRP at EAFB was distributed to
the mailing list addressees in 1992.
Open house. An informational meeting on the status of the IRP and other
environmental efforts at EAFB was held on May 6, 1993. An open house was held
November 16, 1995 in conjunction with the Restoration Advisory Board meeting.
Information on the status of environmental efforts at EAFB was provided.
Newspaper articles. Articles have been written for the Base newspaper regarding IRP
activity.
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
The Proposed Plan for this remedial action was distributed to the mailing list addressees for their
comments and additional copies of the Proposed Plan were available at the January 11, 1996 public
meeting. A transcript of comments, questions, and responses provided during the public meeting was
prepared.
3. Summary of Comments and Questions Received During the Public Comment Period and
USAF Responses
Part I - Summary and Response to Local Community Concerns
Review of the written transcript of the public meeting did not indicate community objections to the
proposed remedial action. No written comments were received during the public comment period.
Part II - Comprehensive Response to Specific Technical, Legal and Miscellaneous
Questions
The comments and questions below have been numbered in the order they appear in the written
transcript of the January 11, 1996 public meeting.
Comment 1. Mayor Baldwin
Asked how you can justify a preferred method (Alternative 3 - installing a final cover) costing
$7 to $8 million for three or four OUs that show no present or future risk, when you could spend
$3 million to monitor the existing cover (Alternative 2 - institutional controls) and take care of
all the problems, given the government does not have sufficient money for cleanup activities.
Response 1. The Air Force is doing all it can to address risks that may be present at OU-8. This is an
area where there is something to be gained by preventing human contact with the
contaminants, even though the contaminant levels are low. A good deal of the cost is in
the long-term monitoring, and it is very likely that the monitoring can be cut back as time
goes by. The costs you are seeing are worst case costs. The actual costs will probably
be less.
The other thing to look at is, not only human risk, but to make sure the Base complies
with all of the closure requirements that are in federal and state regulations, particularly
for the landfills. Even though risk based analyses are conducted, there are still other
requirements to meet to close a landfill so that no one comes in contact with materials
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Final Record of Decision Operable Unit 5
Ellsworth Air Force Base, South Dakota
that have beenplaced in the landfills. Whether it is a landfill on the Base or a landfill at
Rapid City, South Dakota, final covers are needed to be in compliance with landfill
closure regulations. At some point the Base is going to have to put final covers on the
landfills. The costs involved include a 30-year long-term operation and maintenance
period, which contributes to a lot of the cost. However, at the end of five years, under
the CERCLA process, a review of the monitoring results will be conducted, and if the
results are favorable, the monitoring can be significantly cut back. The intent of placing
covers over these landfills will be to eliminate the potential for future releases of
hazardous substances to humans and the environment.
Comment 2. Ms. Vivian Pappel
Asked whether state law on the closure of a landfill allows for a revisitation of the post-closure
plan. Stated she didn't think that provision was in the state closure.
Response 2. State regulations call for a 30-year operation and maintenance period. The five-year
review will provide information on the effectiveness of the remedial alternative. If the
results are favorable it is possible to reduce the monitoring from quarterly to semi-
annually, or annual monitoring, or even less. That would result in significant cost
savings. It may not be possible to totally stop monitoring after five years but there is
definitely potential for cost savings.
F:\PROJ\60m86\FS\OU5.ROD\FIKAL\OU5ROD.FNL B-4 May 7, 1996
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