PB96-964408
EPA/ROD/R08-96/120
October 1996
EPA Superfund
Record of Decision:
Ellsworth Air Force Base,
Operable Unit 3, Rapid City, SD
6/7/1996
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Final
Record of Decision for
Remedial Action at Operable Unit 3
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 3
Ellsworth Air Force Base. South 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 1-2
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 OU-3 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 2A
2.5 SITE CHARACTERISTICS 2-5
2.5.1 Soil Vapor 2-5
2.5.2 Ground Water 2-5
2.5.3 Soil 2-7
2.6 SITE RISK SUMMARY 2-8
2.7 DESCRIPTION OF ALTERNATIVES 2-11
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 2-12
2.8.1 Overall Protection of Human Health and the Environment 2-13
2.8.2 Compliance with ARARs 2-13
2.8.3 Long-Term Effectiveness and Permanence 2-15
2.8.4 Reduction of Toxicity, Mobility, and Volume Through Treatment 2-15
2.8.5 Short-Term Effectiveness 2-15
2.8.6 Implementability 2-16
2.8.7 Cost 2-16
2.8.8 State Acceptance 2-18
2.8.9 Community Acceptance 2-18
2.9 SELECTED ALTERNATIVE 2-18
2.10 STATUTORY DETERMINATIONS 2-20
2.10.1 Protection of Human Health and the Environment 2-21
2.10.2 Compliance with ARARs 2-21
2.10.3 Cost Effectiveness 2-21
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies to the
Extent Possible 2-21
2.10.5 Preference for Treatment as a Principal Element . 2-22
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES 2-22
3.0 LIST OF ACRONYMS AND ABBREVIATIONS 3-1
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Final Record of Decision Operable Unit 3
__ Ellsworth-Air-ferce-Base.-South Dakota
APPENDICES
Appendix A Figures
Appendix B Responsiveness Summary
LIST OF FIGURES
Figure 2-1 Area Location Map
Figure 2-2 Site Location Map
Figure 2-3 OU-3 Site Area Map
Figure 2-4 OU-3 Area of Attainment
LIST OF TABLES
Table 2-1 Evaluation of Federal and State ARARs That Apply to OU-3, Ellsworth AFB,
South Dakota
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Final Record of Decision Operable Unit 3
Ellworth Air Force Base, South Dakota
1.0 DECLARATION FOR THE RECORD OF DECISION
1.1 SITE NAME AND LOCATION
Operable Unit 3 (OU-3), Landfill No. 2 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 OU-3, 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-3, 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-3, 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-3.
The selected alternative, capping, includes the following major components:
Placing a soil cover capable of sustaining perennial vegetation, over the landfill
area;
A pre-design study to examine the need for landfill gas control measures;
Institutional controls for the landfill area;
Long-term ground-water monitoring, and long-term maintenance of soil cover.
Implementation of the remedy will reduce the future risk to human health and the environment to
acceptable levels.
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
1.5 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with Federal
and 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-3. However, because treatment of the principal threats of the OU was not found to be
practicable, this 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 on-site hot spots that
represent major sources of contamination preclude a remedy in which contaminants could be
excavated and treated effectively.
Because this remedy will result in hazardous substances remaining on-site beneath the landfill
cover area at low levels, 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
rt .X-U--J
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 3
Ellsworth Air Force Base. South Dakota
1.0 DECLARATION FOR THE RECORD OF DECISION
1.1 SITE NAME AND LOCATION
Operable Unit 3 (OU-3), Landfill No. 2 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 OU-3, 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-3, 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-3, 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-3.
The selected alternative, capping, includes the following major components:
Placing a soil cover capable of sustaining perennial vegetation, over the landfill
area;
A pre-design study to examine the need for landfill gas control measures;
Institutional controls for the landfill area;
Long-term ground-water monitoring, and long-term maintenance of soil cover.
Implementation of the remedy will reduce the future risk to human health and the environment
to acceptable levels.
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
1.5 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with Federal
and 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-3. However, because treatment of the principal threats of the OU was not found to be
practicable, this 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 on-site hot spots that
represent major sources of contamination preclude a remedy in which contaminants could be
excavated and treated effectively.
Because this remedy will result hi hazardous substances remaining on-site beneath the landfill
cover area at low levels, 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
Vide Commander
Date
- n 1
Jll -
IACK w. MCGRAW
'Acting Regional Administrator
U.S. Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary
Department of Environment and Natural Resources
State of South Dakota
Date
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May 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
1.0 DECLARATION FOR THE RECORD OF DECISION
1.1 SITE NAME AND LOCATION
Operable Unit 3 (OU-3), Landfill No. 2 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 OU-3, 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-3, 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-3, 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-3.
The selected alternative, capping, includes the following major components:
Placing a soil cover capable of sustaining perennial vegetation, over the landfill
area;
A pre-design study to examine the need for landfill gas control measures;
* Institutional controls for the landfill area;
Long-term ground-water monitoring, and long-term maintenance of soil cover.
Implementation of the remedy will reduce the future risk to human health and the environment to
acceptable levels.
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Final Record of Decision Operable Uni: 3
Ellsworth Air Force Base, South Dakota
1.5 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with Federal
and 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-3.
However, because treatment of the principal threats of the OU was not found to be practicable,
this 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 on-site hot spots that represent major sources
of contamination preclude a remedy in which contaminants could be excavated and treated
effectively.
Because this remedy will result in hazardous substances remaining on-site beneath the landfill
cover area at low levels, 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
US^ฃnvironmenta|Protection Agency Region 8
ฃ-7-76
NETTIE H. MYERS, Se^pefaiW Date
Department of Environment anjd Natural Resources
State of South Dakoti
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Final Record of Decision Operable Unit 3
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 OU-3 DESCRIPTION/HISTORY AND REGULATORY OVERSIGHT ACTIVITIES
2.2.1 Description/History
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.
OU-3, located in the northeast portion of EAFB, consists of Landfill 2, an approximately one
acre site, the four identified trenches to the north and two disturbed soil areas in the southeast
and southwest corners (Figure 2-3). The landfill was active for approximately one year
(1964-1965) until operational concerns with trash containment resulted in its discontinued use.
Methods used to dispose of the refuse included surface filling of a low-lying area (fill area)
and trench and fill operations. Combustible trash, described as shop wastes, were burned
daily in a burn pit. Four trenches located north of the fill area were used for the disposal of
metal and industrial and household refuse. Possible burial sites were identified in the
24 August 1971 aerial photo, but the trench origination dates are not known. Some metal
debris currently exposed at OU-3 may be the result of surface disposal of metal waste. Areas
of disturbed soil in the southwestern and southeastern corner of OU-3, which may have been
dump areas, were also identified in historical aerial photographs of EAFB.
A sign had been located within the boundary of OU-3 indicating a missile disposal/burial site
(USAF, 1988). The missile disposal site is basically scrap metal which was salvaged from a
test flight and is not a source of chemical release to the environment. According to the USAF,
the missile dates from a test firing in the mid-1960s. Information on the missile is still
classified at this time.
The area west of Landfill 2 slopes very gently to the south, whereas the area east of Landfill 2
slopes to the east where a tree-like pattern of intermittent drainages has dissected the area.
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The southern drainage leads to Boxelder Creek. The eastward drainage at OU-3 is part of an
overall northern sloping tree-like pattern that drains toward intermittent drainages which lead to
Elk Creek. OU-3 is currently undeveloped and is dominated by relatively undisturbed grassland.
Some exposed rubble is evident in fill trenches in the northern portion of the OU.
The shallow aquifer (10 - 50 ft below ground surface) 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. The deep aquifer wells are no longer serviceable and have
been scheduled for abandonment. 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
Installation Restoration Program (IRP) Phase I Installation Assessment/Records Search and Phase
II, Confirmation/Quantitation. 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
Priorities List (NPL). A Federal Facility Agreement (FFA) was signed in January 1992 by the Air
Force, the U.S. Environmental Protection Agency (EPA), and the State of South Dakota
(SDDENR) 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 Superfund Amendments and
Reauthorization Act (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 Base-wide ground-water operable unit. The Base-wide ground-water OU is
primarily used to address contaminated ground water that was not addressed during the
investigation of a site-specific OU.
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-3. The program
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Final Record of Decision Operable Unit 3
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included completion of boreholes, installation of monitoring wells, 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.
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. An open house format was used during the
November 16, 1995 RAB meeting.
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.
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.
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base. South Dakota
A public comment period was held from December 28, 1995 to January 27, 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 pan of this ROD.
This ROD is based on the contents of the Administrative Record for OU-3, in accordance with
the CERCLA, as amended by SARA, and the NCP. The RI/FS reports and the Proposed Plan for
OU-3 provide information about OU-3 and the selected remedy. These documents are available
at the Information Repositories at EAFB 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-3.
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 EPA's Presumptive
Remedies Approach [Presumptive Remedies: Policy and Procedures (EPA 1993a); Presumptive
Remedy for CERCLA Municipal Landfill Sites (EPA 1993b)J. By using this approach, selecting
an alternative for remediation is streamlined by using preferred technologies based on historical
patterns of remedy selection and 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 placement of a vegetated soil cover, would remove risk
associated with the ingestion, dermal contact, and inhalation exposure pathways. The area of
attainment defines the area over which preliminary remediation goals would be achieved, and is
based on the RAOs. The area of attainment would include landfill areas not meeting appropriate
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closure standards. The remedy does not address leachate remediation since identified wastes
placed in the landfill do not typify that which would normally be associated with leachate
production. Ground-.water monitoring will identify whether leachate is being produced in the
future.
2.5 SITE CHARACTERISTICS
This section describes the presence and distribution of contaminants at OU-3 as a result of past
activities. Potential constituents of concern (COCs) exceeding background levels were evaluated
in the OU-3 risk assessment.
2.5.1 Soil Vapor
The most commonly reported compound in the trench-area samples was tetrachloroethylene
(PCE) with a maximum concentration of 0.192 parts per million (ppm) near the middle part of the
western trench. Toluene and xylenes were also reported in soil vapor samples, at concentrations
up to 38.23 ppm, total reported benzene, toluene, ethylbenzene, and xylenes (BTEX)
concentrations up to 99.53 ppm, and trichloroethylene (TCE) at concentrations up to 0.297 ppm.
Methane was reported at concentrations up to 50,722 ppm, primarily in samples for which other
compounds were also reported. The lower explosive limit for methane is 50,000 ppm, with an
upper explosive limit of 150,000 ppm.
Toluene was reported in two samples collected from the burn-pit area at concentrations of
0.53 ppm and 1.21 ppm, respectively. Xylene, methylene chloride, Dichloroethene (DCE), and
TCE were reported in samples at concentrations of 1.109 ppm, 0.57 ppm, 1.149 ppm, and
0.003 ppm, respectively. TCE was also reported in a sample at a concentration of 0.014 ppm.
TCE was reported in six samples collected from the southwest corner of OU-3 at a maximum
concentration of 0.169 ppm. One sample had a reported total DCE concentration of 0.264 ppm.
2.5.2 GROUND WATER
Volatile Organic Compounds (VOCs)
In the trench area, nine VOCs were reported above quantitation limits for ground-water samples.
Vinyl chloride was reported in two of the samples (11.0 micrograms per liter [ng/L] and
4.2 ng/L), exceeding the federal MCLs and state ground water quality standards. 1,2-
dichloroethane was reported in one sample at 17.0 jag/L exceeding the federal MCLs and State
Ground Water Quality standard standards. Downgradient from the fill area, VOC samples were
obtained from three monitoring wells, but because of insufficient water, no other constituents
were analyzed in one of the wells. A total of six VOCs were reported: PCE, TCE, total 1,2-
dichloroethene, benzene, ethylbenzene, and xylenes.
Jet Fuel
In the trench area, jet fuel was reported in one sample at a concentration of 370 ug/L. This
sample was collected near the southwestern trench.
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Semi-Volatile Organic Compounds (SVOCs)
In the trench area, diethyl phthalate, a SVOC, was reported at 6.0 /J.gfL.
Pesticides/Polychlorinated Biphenyls (PCBs)
No pesticides/PCBs were reported above quantitation limits in the ground-water samples at any
of the OU-3 locations.
Inorganics
In the trench area, the following inorganics were reported above background: total aluminum,
dissolved calcium, total and dissolved chromium, cobalt, total and dissolved copper, iron, total
and dissolved manganese, total and dissolved nickel, total and dissolved potassium, total and
dissolved sodium, dissolved zinc, and total and dissolved mercury. In addition, three
ground-water samples were reported above background for total and dissolved arsenic at
concentrations ranging from 6.9 ^g/L to 2.2 /zg/L. There was no reported background values for
arsenic. As a result, background levels for arsenic was reported as one-half the average detection
limit for the compound (2.2 /zg/L for total arsenic and 2.15 ^g/L for dissolved arsenic).
Downgradient of the fill area, MW870302 and MW950301 were the only wells sampled which
yielded sufficient water for inorganic analysis. Total copper (14.7 Mg/L), total and dissolved
potassium (38,500 ^g/L and 37,400 /zg/L, respectively), total and dissolved sodium
(1,330,000 ^g/L and 1,300,000 ;zg/L), total chromium (7.1 /zg/L), total and dissolved barium
(50.4 /zg/L, and 55.1 /zg/L), total and dissolved mercury (0.25 /zg/L and 0.21 /zg/L) and zinc
(54.8 /zg/L) were reported at concentrations which exceeded Basewide background
concentrations.
In the bum pit area, total and dissolved sodium, total and dissolved potassium, dissolved
chromium, total and dissolved mercury, and total and dissolved selenium were reported at
concentrations exceeding background. Total and dissolved selenium were reported at 1,580 /zg/L
and 1,130 ug/L respectively, compared to the background concentrations of 112.61 and
156.44 ug/L, respectively.
In the southwest comer of OU-3, aluminum, total chromium, iron, nickel, and total and dissolved
selenium were reported above the corresponding background concentrations. In the southeast
comer of OU-3, inorganics reported at concentrations above the corresponding background range
included: total chromium, copper, and total and dissolved mercury, dissolved vanadium,
dissolved arsenic, and total and dissolved selenium.
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2.5.3 SOIL "
VOC
In the southeast comer of OU-3, acetone and acetonitrile were reported in a surface soil sample.
No subsurface soil VOCs were reported in the southeast comer samples. No surface or
subsurface soil VOCs were reported in the southwest corner samples.
In the bum pit, fifteen VOCs were reported in the subsurface soil samples. The highest reported
subsurface soil concentration was 12.0 ,ug/L (1,2-dichloroethene, total).
In the trenches, chloroform and toluene were reported in subsurface soil samples at maximum
concentrations of 6.0 Mg/kg and 9.0 Mg/kg, respectively.
Jet Fuel
No jet fuel was reported in any of the subsurface soil samples. In both the fill area and the bum
pit, jet fuel was reported at a maximum concentration of 180 Mg/kg in surface soil samples. In
the southeast corner of OU-3, jet fuel was reported at 170 mg/kg in surface soil samples. No jet
fuel was reported in the trenches or in the southwestern comer.
svoc
In the trench area, di-n-butyl phthalate and bis(2-ethylhexyl) phthalate were reported in
subsurface soil samples at a maximum concentration of 2,300 ^tg/kg (di-n-butyl phthalate).
Surface soil samples reported fifteen different SVOCs at a maximum concentration of 860 Mg/kg
(di-n-butyl phthalate) near the northwestern trench.
In the fill area, no SVOCs were reported in the subsurface soil samples, but fourteen SVOCs
were reported in the surface soil samples with a maximum concentration of 2,600 jug/kg
(di-n-butyl phthalate).
In the bum pit, twenty different SVOCs were reported in the surface soil samples at
concentrations up to 3,900 /ug/kg (pyrene). Two SVOCs were reported in the bum pit subsurface
soil samples at a maximum concentration of 340 Mg/kg (di-n-butyl phthalate).
In the southeastern comer of OU-3, two SVOCs were reported in the subsurface soil samples, the
maximum concentration was 3,700 Mg/kg (bis(2-ethylhexyl)phthalate). Seven different SVOCs
were reported in the surface soil samples at this southeastern location with a maximum .
concentration of 160 Mg/kg (fluoranthene). No SVOCs were reported in the southwestern comer.
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Final Record of Decision Operable Unit 3
E//JWJJTT/) 'Air Force Base. South Dakota
Pesticide/PCB
In the fill area, four-different pesticides were reported i -.e surface soil samples at
concentrations up to 57 /^g/kg (gamma-chlordane). No pesticides were reported in the fill area in
the subsurface soil samples.
In the bum pit, two pesticides were reported in the surface soil samples at concentrations up to
7.7 Mg/kg (p,p'-DDE). No pesticides were reported in the bum pit area in the subsurface soil
samples. No pesticides were reported in either the surface or subsurface soil samples at the
southeastern or southwestern corner locations. In the trench area, one pesticide
(heptachlor epoxide) was reported at a concentration of 1.2 tig/kg.
Inorganics
In the trench area, ten inorganics were reported in surface and subsurface soil samples at
concentrations above background concentrations. Most of these concentrations were only
slightly higher than the corresponding upper limit of the background concentrations. Only
calcium, sodium, thallium, mercury, and manganese (in the surface soil) were reported at
concentrations greater than approximately twice the background concentration.
In the fill area, seven inorganics were reported in surface samples at concentrations above
background concentrations. Among the highest were lead (495 mg/kg), zinc (837 mg/kg), total
chromium (55.8 mg/kg), and mercury (0.34 mg/kg). No subsurface samples were taken within
the fill area.
In the burn pit, mercury (0.13 mg/kg) was reported in one surface sample at concentrations only
slightly above background (0.10 mg/kg). Cobalt, manganese, nickel, silver, and sodium were
reported in one subsurface sample above background. Of these subsurface samples, only
manganese (3,190 mg/kg at a depth of 24 ft and 9,000 mg/kg at 42 ft) was substantially above its
background concentration of 1,513 mg/kg.
In the southeast corner, no inorganics were reported above background concentrations for surface
soil; and beryllium, cadmium, lead, thallium, vanadium, and manganese were reported higher
than background for subsurface samples. Of the subsurface samples, only manganese
(3,050 mg/kg) was reported at a concentration that exceeded its background concentration
(1,513 mg/kg) by more than a slight amount.
2.6 SITE RISK SUMMARY
Human Health Risks
Risk Assessment Process
The assessment of human health risks for this OU considered the following topics:
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(1) Contaminants of concern (COCs) in ground-water and soil samples taken at OU-3;
(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 five potential exposure
groups:
(1) Current EAFB maintenance personnel mowing grass on-site;
(2) The future child/adult living on-site who ingests surface soil;
(3) The future adult living on-site who ingests and showers with shallow ground water;
(4) Future adolescents who are exposed to surface water and sediment through wading; and,
(5) Future adult construction workers who excavate on-site for building residences.
A quantitative risk assessment was performed for the ground water, soil, sediment, and air. The
risk assessment evaluated potential effects on human health posed by exposure to contaminants
within OU-3. 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. 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.
Risks calculated in a risk assessment are potential risks and are excess (i.e., over background)
risks due to exposure from contaminants at the OU.
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Final Record of Decision Operable Unit 3
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Risk Assessment Results
The risk assessment for OU-3 indicated that the total carcinogenic site risk, calculated using
average exposure assumptions, is within the acceptable risk range for the residential scenario.
Total carcinogenic risk calculated using the RME exposure assumptions is greater than 1 x 10"4.
The majority of the total carcinogenic site risk for the residential scenario is from exposure to
VOC and arsenic in the ground water. The noncarcinogenic risk is due to naturally occurring
selenium in ground water. However, due to the heterogeneity of the landfill contents, great
uncertainty is associated with the calculated risk values.
Based on the OU-3 risk assessment, the calculated carcinogenic and non-carcinogenic risks for
ground water is 2 x 10"* and 4.8, respectively. The calculated carcinogenic risk level for
surface soil is 1 x 10'5, due to the presence of SVOCs. This is within the acceptable risk
range. Based on this calculated acceptable risk, and the low concentrations of contaminants
detected in surface soil samples, remediation is not warranted for surface soil as part of OU-3.
Risk Assessment Conclusions
Remedial action is warranted for the landfill based on the uncertainty associated with the
calculated risk values. Based on the OU-3 risk assessment, the calculated carcinogenic and
non-carcinogenic risks for ground water exceed the acceptable carcinogenic and non-
carcinogenic risk ranges. However, remediation is not warranted for ground water at OU-3.
The sporadic reported concentrations and lack of localizations of contaminants detected in
ground water at OU-3 result in the risk assessment model estimates developed for this site
being highly conservative and therefore present uncertainty for interpretation of risks for these
contaminants within an OU-wide context. The data do not support the existence of plumes of
these contaminants, therefore monitoring of the ground water will provide for the protection of
the environment and human receptors as degradation of the COC (vinyl chloride) is monitored
overtime.
Rather than attempting to perform additional sampling to gain more certainty in the risk
assessment, the Air Force utilized guidance developed by the EPA titled Presumptive Remedy
for CERCLA Municipal Landfill Sites (OSWER Directive 9355.0-49FS). The presumptive
remedy for landfills is containment (capping) 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 to 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 associated with the
landfill contents at OU-3 include: (1) direct physical contact with the landfill contents, (2)
consumption or contact with ground water that may become contaminated, and (3) surface
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erosion of the landfill, thus exposing off-Base residents to contaminants in both surface water
and air. Based on these contaminant exposure pathways, remedial action is warranted for the
landfill due to the potential risk to human health from future releases of unidentified hazardous
substances in the landfill.
Actual or threatened releases of hazardous substances from OU-3, if not addressed by
implementing the response action selected in the Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, and the environment.
Ecological Risks
An ecological evaluation of OU-3 was based on a combination of data and literature reviews,
field and laboratory analyses, analyte evaluation and screening, and preliminary risk screening.
The ecological risk assessment was performed in three phases, or tiers. Tier I was a
screening-level risk assessment. Tiers II and III were progressively more detailed risk
assessments. The pertinent findings are summarized below.
OU-3 presents a relatively undisturbed environment consisting primarily of mixed grass prairie
habitat. Several small weedy areas cover the former landfill and trench areas. A variety of
potential receptors were identified that could nest and/or forage in OU-3 habitats. These species
include various types of invertebrates, amphibians, birds, and mammals. Because of the altered
natural environment at OU-3, rare, threatened, or endangered species are unlikely to utilize the
area for more than 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-3 area ensures unacceptable risk to a single
individual will not occur.
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. However, terrestrial vegetation and soil fauna communities differ
between OU-3 and a reference area. This prompted movement of the OU from Tier I to Tier II
ecological evaluation.
Findings of the RI indicate that the contaminants at OU-3 are not affecting species identified in
the vicinity of EAFB to sustain themselves in a healthy fashion on a population basis. Due to the
small size of the OU-3 source areas (less than 1 acre), an OU-specific Tier III assessment was not
conducted. However, the identified contaminants were carried forward into a Tier III Base-wide
ecological risk assessment which will be conducted as part of OU-11.
2.7 DESCRIPTION OF ALTERNATIVES
Presumptive Remedy for CERCLA Municipal Landfill Sites, (OSWER Directive 9355.3-11FS)
was the basis for the abbreviated feasibility study (FS). The OSWER directive established
containment of the contamination within the landfill as the presumptive remedy for CERCLA
municipal landfills.
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Although not specifically identified as a municipal landfill, OU-3 exhibits characteristics that make
this presumptive remedy applicable. The landfill contents at OU-3 exhibits: 1) the potential to
produce landfill gas,_and 2) no potential to produce significant leachate. The risk assessment did
not identify the ground water as a pathway of concern. Even 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 1 - No Action
The no-action alternative represents the baseline condition at OU-3 and refers to taking no
action at OU-3.
Alternative 2 - Institutional Controls
Institutional controls (access restrictions and annotation of base records).
Long-term monitoring of ground water, and long-term maintenance of existing soil cover.
Alternative 3 - Capping
Placing a soil cover capable of sustaining perennial vegetation, over the landfill area;
A pre-design study to examine the need for landfill gas control measures;
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-3.
The remedial action objectives for OU-3 are as follows:
Landfill
Prevent ingestion and dermal contact with landfill contents.
Reduce mobility of potential contaminants in the landfill.
Control surface water runoff and erosion of the landfill cover.
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The area of attainment is defined as the area which will achieve the remedial action objectives
after remediation is completed. The area of attainment for OU-3 is the extent of Landfill No. 2
and the four trenches, which is approximately five acres in size (Figure 2-4).
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 criteria. 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.
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-3. Alternative 2 (institutional
controls) provides for maintenance of non-vegetated areas. Access restrictions would reduce risk
by reducing exposure. Alternative 3 (soil cover) provides containment of 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 of South Dakota laws. These laws specifically address a hazardous substance, pollutant,
contaminant, remedial action, location or other circumstances at a CERCLA site.
Relevant and appropriate requirements address problems or situations sufficiently similar to
those encountered at a CERCLA site that their use is well suited to the environmental and
technical factors at a particular site. The determination of "relevant and appropriate" emphasizes
the similarity and appropriateness of the requirement to a site. ARARs are grouped into these
three categories:
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Chemical-Specific ARARs are health or risk-based numerical values or methodologies
which; 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.
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 of South Dakota Solid Waste Management
Regulations. The OU-3 RI concluded that ground water has not been adversely affected and was
not a potential transport pathway; therefore ground-water ARARs at the OU are met. Alternative
1 does not meet the remedial action objectives for OU-3. An action would not be taken to
prevent human contact with surface soil contaminants, and 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 Management Regulations.
The OU-3 RI concluded that ground water has not been adversely affected and was not a
potential transport pathway; therefore, ground-water ARARs at the OU are met. Alternative 2
does not meet the remedial action objectives for OU-3.
Alternative 3 (Vegetated Soil Cover):
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 74:27:15. 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). The resulting cover along with natural attenuation will bring
OU-3 into compliance with the Safe Drinking Water Act Maximum Contaminant Levels (MCLs)
and State Ground Water Quality Standards by preventing the downward transport of
contaminants to the ground water.
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.... .. . -
Implementation of the presumptive remedy strategy for landfills has been shown by EPA to
prevent ingestion and dermal contact with landfill contents, reduce mobility of potential
contaminants in the landfill, and control surface water runoff and erosion of the landfill cover.
2.8.3 Long-Term Effectiveness and Permanence
The assessment of this criterion considered the 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. No further controls for the OU would be
developed under this alternative.
Alternative 2 would provide for increased effectiveness of access restrictions (in addition to the
general EAFB access restrictions). Additionally, maintaining vegetation on the landfill would
reduce erosion potential. Permanency and reliability of these controls would be enhanced
through long-term monitoring and maintenance of the OU. Uncertainties exist for the ability to
provide long-term access restrictions.
Alternative 3 would offer the highest level of long-term effectiveness. Reduction of risk would
be accorded by the vegetated soil cover. Erosion would be limited by the development and
maintenance of a vegetated area. Upon completion, long-term maintenance of the cover and
monitoring of ground water would be provided. 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 Toxicity, 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 potential
contaminants within the landfill. Alternative 2 would reduce the mobility of contaminants in
surface soil through long-term erosion maintenance of existing cover soil. Alternative 3 does not
use treatment technologies, but reduces the mobility of the contaminants in the landfill through
containment.
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.
It is not anticipated that the proposed alternatives would significantly impact worker or
community health and safety during the implementation period. Alternatives 2 and 3 may impact
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Final Record of Decision Operable Unit 3
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community and worker health and safety through dust emissions during the initial construction
phase. The impact could be minimized through dust 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, aside from long-term monitoring, 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 restrictions (or annotation of base
records) can be implemented at EAFB by various administrative means.
2.8.7 Cost
A summary of the costs for each alternative is as follows:
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Final Record of Decision Operable Unit 3
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Alternative No, 1 (No Action)
Total Capital Costs
Total Annual Costs
TOTAL 30-Year Present Value1
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
Annual Cost = 570,500 (Years 1-5)
Annual Cost = $36,800 (Years 6-30)
Discount Rate = 5%
TOTAL 30- Year Present Value1
581,800
570,500
536.800
5711,300
5793,100
Alternative No. 3 (Vegetated Soil Cover)
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
Annual Cost = 570,500 (Years 1-5)
Annual Cost = 536,800 (Years 6-30)
Discount Rate = 5%
TOTAL 30-Year Present Value'
5632,200
570.500
536.800
5711,300
51,343,500
Notes
0 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
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Final Record of Decision Operable Unit 3
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2.8.8 State Acceptance
The assessment of this criterion considered the State's preferences for or concerns about the
alternatives.
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 which 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, Vegetated Soil Cover. 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-3
following completion of remedial action. Major components of Alternative 3 are:
Placing a soil cover capable of sustaining perennial vegetation, over the landfill
area;
A pre-design study to examine the need for landfill gas control measures;
Institutional controls for the landfill area;
Long-term ground-water monitoring, and long-term maintenance of soil cover.
Installation of Soil Cover
An earthen cover will be placed over Landfill No. 2 where existing cover does not comply
with State landfill closure requirements (approximately 1 acre). The cover will be graded and
contoured to maintain stability and route surface-water runoff away from previously active fill
areas and prevent ponding of the water ^he cover will be vegeta: 'd to enhance
evapotranspiration and reduce infiltrat md soil erosion. A pre- ign study will be
conducted to examine the need for lan._..j gas control measures.
This alternative will meet the remedial action objectives and reduce the potential risk for OU-3
by reducing the mobility of potential contaminants in the landfill. This will be achieved by the
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~COnEtrUCtion~of thfl Ifludfill ^n^'ฐr ?IT^ maintpnanr-p anrl pnssihlft mnHifirptinn nf a drainage ^_
channel. If required, wetlands mitigation (as a result of potential drainageway modifications)
could also be implemented with standard construction equipment, materials, and methods.
This alternative meets the statutory requirements of Section 121 of CERCLA as amended by
SARA. These statutory requirements include protectiveness of human health and the environment,
compliance with ARARs, cost effectiveness, and use 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 (containment) developed by EPA for landfills.
Alternative 3 would achieve significant risk reduction by limiting exposure to landfill materials and
to contaminants present in surface soils and ground water at the OU. The selected alternative will
be protective of human health and the environment and will comply with ARARs.
Institutional Controls
Institutional controls would be implemented to prevent human exposure to contaminated soil and
ground water. These controls will include: (1) issuing a continuing order by the Installation
Commander to restrict access to the landfill and to 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 appropriation permit applications to install ground-water
wells within the landfill boundary and any area which may be affected by potential contaminants;
(3) making appropriate annotations to base records.
A continuing order would be issued by the Installation Commander to restrict access to or
disturbance of the landfill 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 landfill; 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 cover be maintained. Limit future land
uses to non-intrusive activities only (or to activities that will not effect the landfill
cover). To assist with the institutional controls, a fence may be placed around the
landfill and authorized personnel would have access through a locked gate. Access
would only be allowed to perform landfill monitoring and maintenance activities.
Warning signs would be posted at the landfill to deter unauthorized access.
The continuing order also would mandate that, if the landfill cover was ever removed or
breached, the area of attainment would be re-evaluated to determine the need for a
replacement cap or other remedial action.
Continuing order requirements will be in effect as long as the property is owned by Ellsworth
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The continuing order also would mandate that, if the landfill cover was ever removed or
breached, the area of attainment would be re-evaluated to determine the need for a
replacement cap .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-3 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
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 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 required by law after the date of the transfer; (2) a right of 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 Long-Term 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 landfill cover. If ground
water contaminants move beyond the landfill boundary, additional work may be required.
A maintenance program would be established to ensure the long-term integrity of the landfill
conditions remedy would be maintained. The maintenance program would include
development of standard operating procedures (SOPs) to provide for inspections, repairs, and
general maintenance of the landfill.
2.10 STATUTORY DETERMINATIONS
The selected remedy meets the statutory requirements of CERCLA as amended by SARA.
These requirements include protection of human health and the environment, compliance with
ARARs, cost effectiveness, utilization of permanent solutions and alternative treatment
technologies to the extent practicable. 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 the alternatives considered.
F:\PROJt,6037886ttOU3J*OD\FINAL\FNLOU3.ROD 2-20 May 1996
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Final Record of Decision Operable Unit 3
ir ฃprrce.Base, South_Dakota
The manner in which the selected remedy meets each of these requirements is discussed in
the sections below.
2.10.1 Protection of Human Health and the Environment
The selected remedy addresses health and environmental issues that were identified in the
OU-3 RI report. Specifically, the capping alternative:
Eliminates exposure to landfill contents by installing an earthen cap.
Reduces the potential infiltration 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-3.
2.10.2 Compliance with ARARs
Alternative 3 will meet State landfill closure requirements by providing containment of
landfill contents, access/development restrictions and long-term monitoring. The OU-3 RI
concluded that ground water has not been adversely affected and was not a potential
transport pathway; therefore, ground water ARARs at the OU are met. Additional
information about ARAR compliance is contained in Section 2.8.2.
Implementation of the presumptive remedy (containment by capping) strategy for landfills
has been shown by EPA to meet the remedial action objectives by preventing direct contact
with landfill contents.
2.10.3 Cost Effectiveness
The selected remedy provides overall effectiveness in reducing human health risks relative
to its costs. The presumptive remedy process insures 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 of cover necessary for the landfill. Based on
the information provided during the remedial investigation, a more costly landfill cover
would not be cost effective.
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies
to the Extent Possible
EPA has established that proper capping 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
F:\PROJ\6037SS6\FS\OU3.ROD\FIS4L\FNLOU3.ROD 2-21 Mm 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base. South Dakota
monitoring to detect movement of chemical? from the area. A five-year review of the
selected remedy will be performed because . ntaminants may be remaining in the landfill
area. The review will be conducted every five years after the signing of the ROD to
ensure the remedy continues to provide adequate protection of human health and the
environment.
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-3. No identifiable hot spots were reported present and the risks
associated with OU-3 can be addressed by eliminating exposure to the landfill contents by
capping.
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES
The selected action is the same as the preferred alternative presented in the Proposed Plan
for OU-3 remedial action. There have been no changes relative to the Proposed Plan.
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT APPLY TO OU-3, 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
Criteria and Standards for the
National Pollutant Discharge
Elimination System
Archaeological and Historic
Preservation Act
Clean Air Act of 1983
National Primary and Secondary
Ambient Air Quality Standards
National Emission Standards for
Hazardous Air Pollutants
Citations
42 USC 300, f, g
40CFRPart 14I.60-.63
40 CFR Part 143.3
40 CFR 14 1.50 and
Public Law No. 99-330,
100 Slat. 642(1986)
33 USC 1251-1376
40 CFR Part 131.36
40 CFR Part 125.1 -.3
16 USC 469
40 CFR Part 6.30 1 (c)
40 CFR Part 50.1 -.6, .8,
.9, .11,. 12
40 CFR Part 61
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 criteria and standards for
technology-based requirements in permits
under the Clean Water Act
Establishes procedures to provide for
preservation of historical and archaeological
data which might be destroyed through
alteration of terrain as a result of a federal
construction project for a federal licensed
activity or program
Establishes standard for ambient air quality to
protect public health and welfare.
Establishes regulatory standard for specific air
pollutants.
ARAR
Type
Chemical
Chemical
Chemical
Chemical
Chemical
Location
Action
Action
Applicability
Relevant and appropr/ate for fedet
Class II aquifers.
Relevant and appropriate.
t
Relevant and appropriate.
Relevant and appropriate. Aquifci
may be a federal Class 11 A
(discharge to surface water).
Relevant and appropriate.
Applicable. OU-3 was used for
landfilling activities. No known
historic or archaeological value,
although no confirmation study h:
been performed. Applicability wi
determined during the Remedial
Design (RD).
Applicable. Methane treatment may 1
required.
Applicable. Methane treatment may 1
required.
it
s
Ibe
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TABLE 2-1 (continued)
Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Solid Waste Disposal Act as
amended by Resource
Conservation and Recovery Act of
1976
Solid Waste Disposal Facility
Criteria
Land Disposal P ' ' ปions
Guidelines fin ' <
Alternatives may include u... 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.
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TABLE 2-1 (continued)
Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Standards for Owners and
Operators of I lazardous Waste
TSDF's
Standards for Owners and
Operators of Hazardous Waste
TSDF's with Interim Status
Criteria and Standards for the
National Pollutant Discharge
Elimination System
Toxic Substances Control Act
Executive Order No. 1 1988 on
Floodplains Management
Citations
40 CFR Part 264
40 CFR Part 265
40 CFR Parti 25
40 CFR Part 76 I.I
42 USC 7401
40 CFR 6.302 (b) &
Appendix A
Description
F.stablishes standards for acceptable hazardous
waste management.
Establishes standards for acceptable hazardous
waste management during interim status.
Establishes criteria and standards for
technology-based requirements in permits
under the Clean Water Act
Substances regulated include, but are not
limited to, soils and other materials
contaminated as a result of spills
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.
ARAR
Type
Action
Action
Chemical
Action
Location
Applicability
i
i
Relevant and Appropriate for .
performance guidelines for landfill
closure.
Relevant and Appropriate for
performance guidelines for landfill
closure.
Relevant and appropriate.
Applicable.
Applicable.
1
i
2-25
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TABLE 2-1 (Continued)
Applicable or Relevant and Appropriate Stau Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
South Dakota Waste Management
Regulations
South Dakota Waste Management
Regulations
South Dakota Waste Management
Regulations
South Dakota Waste Management
Regulations
South Dakota Water Quality
Standards
South Dakota Ground 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
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 treatment, storage, and/or disposal
(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.
2-26
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
3.0 LIST OF ACRONYMS AND ABBREVIATIONS
ACC: Air Combat Command
ARARs: Applicable or Relevant and Appropriate Requirements
CERCLA: Comprehensive Environmental Response, Compensation and Liability Act
CFR: Code of Federal Regulations
COC: Chemicals of Concern
CRP: Community Relations Plan
DCE: Dichlorethene
EAFB: Ellsworth Air Force Base
EPA: Environmental Protection Agency
FFA: Federal Facilities Agreement
HQ: Hazard quotient
IRP: Installation Restoration Program
JP-4: Jet Propulsion Fuel Number Four; contains both kerosene and gasoline fractions.
MCL: Maximum Contaminant Levels
//g/KG: Micrograms per kilogram
^g/1: Micrograms per liter
mg/KG: Milligrams per kilogram
mg/1: Milligrams per liter
MSWLF: Municipal Solid Waste Landfill
NCP: National Oil and Hazardous Substances Contingency Plan
NPL: National Priorities List
OU: Operable Unit
OU-3: Operable Unit Number 3, the Landfill 2 study area
O&M: Operation and maintenance
PAH: Polynuclear Aromatic Hydrocarbon
PCB: Polychlorinated Biphenyl; liquids used as a dielectrics in electrical equipment
PCE: Perchloroethylene; liquids used in degreasing or paint removal.
ppnr Parts per million by weight
RAB: Restoration Advisory Board
RAO: Remedial action objective
RCRA: Resource Conservation and Recovery Act
RD: Remedial design
RI/FS: Remedial Investigation/Feasibility Study
ROD: Record of Decision
F:\PROJ\6037886\FS\OU3.ROD\FINAL\FXLOU3.ROD
3-1
May 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
SARA: Superfund Amendments and Reauthorization Act
SACM: Superfund Accelerated Cleanup Model
SDDENR: South Dakota Department of Environment and Natural Resources
SVOC: Semivolatile Organic Compound
TCE: Trichloroethylene
TPH: Total petroleum hydrocarbons
TSD: Treatment, storage or disposal sites/methods
UCLM: Upper confidence limit mean
USAF: United States Air Force
USC: United States Code
U.S. EPA: United States Environmental Protection Agency
VOC: Volatile Organic Compound
F:\PROJ\6037886\FS\OU1.ROD\FINAL\FNLOU3.ROD
3-2
May 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
APPENDIX A
FIGURES
F:\PROJ\6037886\FS\OU3.ROD\FINAL\FNLOU3.ROD May 1996
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a
o
cc
N
MINNESOTA
NORTH DAKOTA
-
SOUTH DAKOTA
ELLSWORTH AFB
RopU Oty
Seal* in UilM
APPROXIMATE
V Ot
<-^L
Z r-
EL.1-S WORTH
AIR FORCE BASE
ELLSWORTH AFB
RAPID CITY. SOUTH DAKOTA
AREA LOCATION MAP
ROJECr UCR
DESIGNED BT
DRAWN BY
MRG
CHECKED BY
SCALE
AS SHOWN
DATE
DEC 95
PROJECT NO
60378.93
FIGURE:
2-1
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N
WASTEWATER,
/TREATMENT'
PUNT I
1200 2400
SCALE IN FECT
LEGEND
OPERABLE UNITS
OU-1 FIRE PROTECTION TRAINING
AREA (FT-01)
OU-2 LANDFILLS 1 & 6 (LF-02)
00-3 LANDFILL 2 (LF-03)
OU-4 LANDFILL 3 ' ~ ~"
OU-5 LANDFILL 4
OU-6 LANDFILL 5
OU-7 LOW LEVEL RADIATION WASTE BURIAL AREA (RW-07)
OU-8 EXPLOSIVE ORDNANCE DISPOSAL AREA & PRAMITOL SPILL
OU-9 OLD AUTO HOBBY SHOP AREA (OT-15)
OU-10 NORTH HANGAR COMPLEX (ST-19)
OU-11 "BASEWIDE GROUND WATER
OU-12 HARDFILL NO. 1
2ฃ
r'i'
ELLSWORTH
AIR FORCE BASE
ELLSWORTH AFB
RAPID OTt. SOUTH DAKOTA
SITE LOCATION MAP
ROJECT UCR
DESIGNED BT
DRAWN BT
STAFF
CHECKED ffT
SCALE
AS SHOWN
DATE
DEC 95
PROJECT NO
60378.93
FIGURE:
2-2
-------
o
o
IT
o
I*
O"~
X
TRENCH LOCATION
POSSIBLE DISTURBED SOIL
BASE BOUNDARY FENCE
SURFACE DRAINAGE
POSSlBtฃ|BURN
PIT
OU-3
SHE AREA MAP
ELLSWORTH AFB
RAPE OTY. SOUTH QUOTA
ELLS WORTH
AIR FORCE BASE
DRAWN BY
STAFF
SCALE
AS SHOWN
PROJECT NO
60378.93
-------
D .
o
LEGEND:
TRENCH LOCATION
AREA OF ATTAINMENT
BASE BOUNDARY FENCE
SURFACE DRAINAGE
250-
! /
SCALE
32
z^1
tr <
oo
El_l_S WORTH
AIR rORCE BASE
ELLSWORTH AFB
RAPID OTY, SOUTH DAKOTA
OU-3
AREA OF ATTAINMENT
ROJCCI MCR
DESICNCD BY
DRAWN BY
STAFF
CHECKED BY
SCALE
AS SHOWN
DATE
DEC 95
PROJECT NO
60378.93
FIGURE
2-4
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
APPENDIX B
RESPONSIVENESS SUMMARY
F:\PROM037S86\FS\OU3.ROD\FINAL\FNLOU3.ROD May 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
J-.! 1! ^ Responsiveness Summary
Remedial Action at Operable Unit Three
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 Three (OU-3). 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.
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
F:\PROJ\6037886\FS\OU3.ROD\FINAL\FNLOU3.ROD B-l May 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
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.
Newspaper articles. Articles have been written for the base newspaper regarding IRP
activity.
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.
The majority of the comments received during the public meeting were in the form of questions
about the remedial investigation findings, the remedial action; i.e., what would be done, how it
would be done, and what effects the action might have. Representatives of the USAF were available
F:\PROJ\6037886\FS\OU3.ROD\FINAL\FNLOU3.ROD B-2 May 1996
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Final Record of Decision Operable Unit 3
Ellsworth Air Force Base, South Dakota
to provide answers to the questions and also provided an overview presentation during the meeting
to describe the proposed actions.
Part II - Comprehensive Response to Specific Technical, Legal and Miscellaneous
Questions
The comments and question below are in the order they appear in the written transcript of the
January 11,1996 public meeting.
Comment 1. Vivian Pappel
Asked about whether the landfill was officially closed before, whether the cover present was
daily cover, and what type of soil would be used for the proposed closure action.
Response: The landfill was used briefly, and then its use was discontinued. The landfill was not
officially closed under State regulations. When use was discontinued, the daily cover
was graded. Due to erosion of the cover, a new cover is required. The new cover soil
will consist of clay soil that will meet the criteria defined in the State regulations.
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