PB96-964406
EPA/ROD/R08-96/118
October 1996
EPA Superfund
Record of Decision:
Ellsworth Air Force Base,
Operable Unit 1, Rapid City, SD
5/10/1996
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Final
Record of Decision for
Remedial Action at Operable Unit 1
Ellsworth Air Force Base, South Dakota
United States Air Force
Air Combat Command
Ellsworth Air Force Base
April 1996
AF Project No.: FXBM 94-7002
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Final Record of Decision Operable Unit 1
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 OPERABLE UNIT 1 (OU-1) DESCRIPTION/HISTORY AND
REGULATORY OVERSIGHT ACTIVmES 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 2-4
2.5 SITE CHARACTERISTICS 2-5
2.5.1 Soils 2-5
2.5.2 Sediment 2-6
2.5.3 Ground Water 2-6
2.5.4 Surface Water 2-7
2.6 SITE RISK SUMMARY 2-7
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 , 2-14
2.8.4 Reduction of Toxicity, Mobility, and Volume Through Treatment 2-14
2.8.5 Short-Term Effectiveness 2-15
2.8.6 Implementability 2-15
2.8.7 Cost : 2-15
2.8.8 State Acceptance 2-17
2.8.9 Community Acceptance 2-17
2.9 SELECTED ALTERNATIVE 2-17
2.10 STATUTORY DETERMINATIONS 2-20
2.10.1 Protection of Human Health and the Environment 2-20
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 2-21
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES 2-21
3.0 LIST OF ACRONYMS AND ABBREVIATIONS '. 3-1
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Final Record of Decision Operable Unit 1
Ellsworth Air 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 1
Figure 2-4 Area of Attainment for Source Area Soils
Figure 2-5 Area of Attainment for Ground Water
LIST OF TABLES
Table 2-1 OU-1 Cleanup Goals - Ground Water
Table 2-2 OU-1 Cleanup Goals - Soils
Table 2-3 Evaluation of Federal and State ARARs That May Apply to OU-1, Ellsworth
AFB, South Dakota
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::--..:: 1.0. DECLARATION FOR THE RECORD OF DECISION (ROD)
1.1 SITE NAME AND LOCATION
Operable Unit 1 (OU-1), Abandoned Fire Protection Training 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 1 (OU-1),
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-1, EAFB. The United
States 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-1, 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.
1.4 DESCRD7TION OF SELECTED REMEDY
Twelve contaminated areas, delineated as operable units (OUs) for investigative purposes, have
been identified at EAFB. This ROD is for a remedial action at OU-1.
The selected alternative, source area soil and ground-water treatment, includes the following
major components:
Continued operation of the interim remedial action (IRA) which consisted of
contaminated ground-water removal, soil vapor extraction (SVE), and treatment;
Installation of additional SVE wells within the historical burn-pit area to be added to the
existing ERA SVE system;
Removal of contaminated ground water using additional ground-water wells and
collection trenches to be added to the IRA ground-water recovery system;
Treatment of ground water at the existing IRA treatment plant;
Institutional controls for the area;
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Long-term monitoring; and,
Long-term operation and maintenance of equipment.
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-1.
A review will be conducted no less often than every five years after signing of the ROD 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
JACKW.MCGRAW Date
Acting Regional Administrator
LTS. Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary - Date
Department of Environn\ent>tnd Natural Resources
State of South Dakota
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Long-term monitoring; and,
Long-term operation and maintenance of equipment.
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-1.
A review will be conducted no less often than every five years after signing of the ROD 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 Environmental Protection Agency Region 8
NETTIE H. MYERS, Secretary Date
Department of Environment and Natural Resources
State of South Dakota
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2.0 DECISION:SJJMMARY
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 1 (OU-1) 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 used EAFB
for support, training, maintenance, and/or testing facilities. Presently, the 28th Bombardment
Wing (B-1B bombers) is the host unit of EAFB.
OU-1 consists of the former Fire Protection Training Area (FPTA), Pond 001, and a portion of
the drainage channel which leads into Pond 001. The former FPTA is approximately ten acres in
size and is located in the southwestern segment of EAFB (Figure 2-3). The FPTA was operated
by the EAFB Fire Department at this location from 1942 to 1990. The location of the burn area
within the former FPTA has changed several times over the years. Aerial photographs of EAFB
dated 28 May 1952, 8 October 1954, 25 August 1962 and 19 June 1968 show numerous areas of
staining presumed to be a result of fire training activities within the former FPTA. The training
exercises conducted at the FPTA involved simulation of aircraft fires and spills. Various types of
fuels, oils, and solvents were dispersed within the burn-pit area and subsequently ignited and then
extinguished.
The topography at OU-1 is characterized by a local topographic high in the area where fire
training was conducted, which is bounded on the southwest and southeast by converging drainage
channels. Pond 001 was included in OU-1 to determine if it contained contaminants which
originated at the former FPTA.
A shallow aquifer has been identified at depths of 10 feet to 50 feet beneath the ground surface.
This 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). The shallow
aquifer may also discharge to the surface.
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Deeper bedrock aquifers also exist beneath EAFB. These deeper aquifers are separated from the
shallow aquifer by 800 feet of low-permeability 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
Installation Restoration Program (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
Priorities List (NPL). A Federal Facilities 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 Superfund 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 Base-wide ground-water OU. 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 U.S. 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-1. The program included
drilling and sampling of boreholes, installation of ground-water 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.
A ROD for an interim remedial action (IRA) for OU-1 was signed on 16 May 1995. The
objectives of the ERA were (1) to remediate the deeper soils within the burn-pit area and (2) to
remediate ground-water contamination immediately downgradient from the burn-pit area. The
remediation of the deeper soils within the bum-pit area consists of a soil vapor extraction system
and subsequent treatment by thermal oxidation. The remediation of contaminated ground water
immediately downgradient of the burn-pit area consists of removal of contaminated ground-water
using wells and an existing ground-water recovery trench. Treatment of the contaminated ground
water consists of filtration, air stripping, and activated-carbon adsorption. The treatment system
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was constructed as'part of the IRA.- -- '- --_
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 decisions. 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 implemented. 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 ERP
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 September 18, 1995 to October 18, 1995, and a public
meeting was held on September 26, 1995. At this meeting, representatives from EAFB answered
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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).
This ROD is based on the contents of the Administrative Record for OU-1, in accordance with
the CERCLA, as amended by SARA, and the NCP. The RI/FS reports and the Proposed Plan for
OU-1 provide information about OU-1 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 site-specific OUs and a Base-wide ground-water OU. 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 documents the selected remedial action (RA) at OU-1 and is the fourth ROD for
EAFB. The remedial action objectives (RAOs) are: (1) the cleanup of ground water to regulatory
levels and, for contaminants where regulatory levels are not available, to levels considered safe for
public drinking water, and (2) the cleanup of source area soils to levels that would not pose a
threat of contaminating ground water.
The development of alternatives was conducted under EPA's Presumptive Remedies Approach
[Presumptive Remedies: Policy and Procedures (OSWER Directive 9355.0-47FS); Presumptive
Remedies: Site Characterization and Technology Selection for CERCLA Sites with Volatile
Organic Compounds in Soils (OSWER Directive 9355.0-48FS)/. 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 soil vapor extraction (SVE) as the primary remedy for soils
that are contaminated with volatile organic compounds (VOCs). In addition, thermal desorption
is being retained as a secondary source area soil treatment option. The response action, source-
area soil and ground-water treatment, combines the presumptive remedies for soil with ground-
water extraction and treatment to reduce risk associated with the ingestion exposure pathway.
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The area over v/hich remediation goals would be achieved is defined as the area of attainment, and
is based on the RAOs. The area of attainment would include areas within OU-1 which present an
unacceptable risk to human health or the environment.
2.5 SITE CHARACTERISTICS
This section describes the presence and distribution of contaminants at OU-1 as a result of past
activities.
2.5.1 Soils
Organic Contaminants
Organic compounds reported in soil samples from OU-1 include volatile organic compounds
(VOCs), jet fuel, semivolatile organic compounds (SVOCs), pesticides, and dioxins/furans. Total
petroleum hydrocarbon (TPH) concentrations, analyzed as jet fuel, above the State of South
Dakota action level (500 ppm) were reported in 4 surface-soil samples and 11 capillary fringe soil
samples located in and adjacent to the burn pit. Soil which has been impacted by past activities at
OU-1 extends from the surface to the capillary fringe beneath the former FPTA, and within the
capillary fringe from the former FPTA to approximately 800 feet to the south.
In general, the most prevalent organic contaminant in the soil is jet fuel. The State of South
Dakota regulations for petroleum-contaminated soils have been recently revised and effective
December 18, 1995; new risk-based criteria are used to determine if petroleum-contaminated soil
requires removal or treatment. The new regulations establish a three-tiered approach in
determining what action will be taken at petroleum release sites (ARSD Chapter 74:03:13). The
regulations establish Tier 1 action levels for five petroleum related components (benzene,
ethylbenzene, toluene, xylene, and naphthalene) and TPH. Two of the five chemicals (benzene
and ethylbenzene) for which soil action levels have been established by the State were detected in
the soil above their respective action levels in three different borings in the vicinity of the burn pit.
Concentrations of TPH (as jet fuel) in the soil were above the 500 ppm Tier 1 action limit in 12
different soil boring locations in and around the burn pit area. Based on this, a Tier n evaluation
is required. Because pathways and receptors are present, remediation of jet fuel is required.
Also, State guidance concerning the need for installation of monitoring wells at a petroleum
release site (Handbook for Investigation and Corrective Action Requirements for Discharges from
Storage Tanks. Piping Systems, and Other Releases. SDDENR Ground-Water Quality Program,
Version 1.1, December 18, 1995) indicates that monitoring wells will be required at this site.
Inorganic Contaminants
In general, the subsurface-soil samples which contained the highest concentrations of inorganic
compounds were from the former burn-pit area. The source of the inorganic compounds in OU-1
subsurface-soil samples is believed to be from a combination of burn pit activities and
naturally-occurring geologic deposits and soil type. No distinct pattern was observed for the
higher concentrations of inorganic compounds in OU-1 surface-soil samples.
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2.5.2 Sediment
Organic Contaminants
VOCs, SVOCs, and pesticides were reported in sediment samples collected from the drainage
channel both upgradient and downgradient of OU-1, from within the drainage channel at OU-1,
and within Pond 001. Although OU-1 may have contributed to the contaminants in sediment, the
presence of these organic compounds in samples collected upstream of OU-1 indicates that the
primary source of contaminants in sediments is from areas upgradient of OU-1. The highest
concentrations of contaminants were in Pond 001 where sediments are likely to build up over
time. It is not possible to distinguish the exact source of contaminants in the sediments in the
pond. Possible upgradient sources for the organic compounds in sediment samples are the
operations areas along the taxiways and flightlines.
Inorganic Contaminants
Many of the inorganic analytes were reported only once in each of the nine sediment samples with
the exception of cyanide, thallium, and mercury. The source of the inorganic analytes is thought
to be a combination of surface-water runoff from both outside and within OU-1 as well as
naturally-occurring geologic deposits and soil type.
2.5.3 Ground Water
Organic Contaminants
Contaminants were found in ground-water samples from both within and downgradient of the
former FPTA. The most frequently reported organic contaminant in ground-water samples from
OU-1 were VOCs. SVOCs were reported in ground-water samples to a lesser extent. VOCs and
SVOCs in the ground water are a result of historical use of fuels, waste oils, and solvents in the
burn-pit area. Seven VOCs, one SVOC, and one pesticide were reported at least once at
concentrations exceeding the Safe Drinking Water Act Maximum Contaminant Level (MCL).
Inorganic Contaminants
Thirteen inorganic compounds were detected in ground-water samples at concentrations which
were above general background levels. However, due to variations in soil type and geologic
deposits, localized high concentrations of inorganic compounds in the EAFB area are common.
Two-compounds, manganese and antimony, were reported at least once at concentrations
exceeding the MCL. Regional and site-specific background results indicate that these two
inorganic compounds naturally occur at levels in ground water that exceed the MCL and their
presence is not thought to be a result of historical activities at OU-1. Arsenic was reported in
four ground-water samples at concentrations of two to six times background from locations
within and downgradient of the burn pit. In general, the remaining inorganic compounds were
also detected in samples from locations within, and immediately downgradient of, the burn-pit
area. The source of the remaining inorganic compounds is considered to be primarily a result of
historical activities at the FPTA, although some compounds may be a result of the natural
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variations in soil type and geologic deposits.
2.5.4 Surface Water
Organic Contaminants
Three VOCs, one phthalate, and one polynuclear aromatic hydrocarbon (PAH) were reported in
surface-water samples from the drainage channel and Pond 001. The organic compounds
reported in surface-water samples were not reported in soil or ground-water samples from within
OU-1 and are believed to be a result of surface spills outside of OU-1.
Inorganic Contaminants
Of the inorganic contaminants detected in surface-water samples, arsenic, manganese and nickel
exceeded Federal Ambient Water Quality Criteria (FAWQC) and State Water Quality Standards.
The source of the inorganic analytes in OU-1 surface-water samples is not known, but is
suspected to be from the flightline area, which is upstream and outside of OU-1.
2.6 SITE RISK SUMMARY
Human Health Risks
Risk Assessment Process
The assessment of human health risks for this OU considered the following topics:
(1) Chemicals of concern (COCs) in ground-water, surface water, sediment, and soil
samples taken at OU-1;
(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) Toxicity of the COCs; 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;
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(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, surface water, soil, sediment,
and air. The risk assessment evaluated potential effects on human health posed by exposure to
contaminants from OU-1. 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 incidence 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 excess (i.e., over background) cancer risks due to exposure from contaminants.
Noncarcinogenic health risks are evaluated using a hazard index (HI). 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-1 indicated unacceptable risk in the shallow ground water for the
residential exposure scenarios. The chemicals which contributed the majority of the risk in
shallow ground water were VOCs. Of the VOCs, benzene, 1,2-dichloroethane, (1,2-DCA)
1,1-dichloroethylene (1,1-DCE), 1,2-dichloroethylene (1,2-DCE), 1,1,1-trichloroethane,
perchloroethylene (PCE), trichloroethylene (TCE), and vinyl chloride were identified as being
above their respective MCLs.
The risk assessment indicated that unacceptable risk exists in the soils of the burn-pit area,
primarily from the potential for contaminating the underlying ground water. In order to prevent
future contamination of the ground water, four VOCs were identified for remediation in soils:
benzene, 1,2-DCE, PCE, and TCE. These chemicals were selected for remediation on the basis
of a contaminant transport model. Remediation of jet fuel in the soil at OU-1 is also required
because concentrations of jet fuel (and related components) exceed State of South Dakota
regulations. Risks from exposure to pesticides and dioxins/furans in surface and subsurface soils
at OU-1 were well below the acceptable range and do not warrant remediation.
The risk from the contaminants in the sediments and surface water at OU-1 is within the
acceptable risk range. Several compounds were detected in surface water at above the FAWQC,
but the risk to human health from these contaminants is within the acceptable risk range. Because
of the risk being within the acceptable risk range, remediation of these chemicals in surface water
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and sediment is not warranted.
Risk Assessment Conclusions
Remediation of the ground water is warranted based on the risk to human health from ingesting
and contacting contaminated ground water. Remediation of soil is warranted based on the
potential for contaminants in the soil to be transported to the underlying ground water. Actual or
threatened releases of hazardous substances from OU-1, 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.
Ecological Risks
An ecological risk evaluation of OU-1 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-1 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-1, 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 and the identified exposure pathways, the contaminants do not pose
an unacceptable risk to these species. In addition, the limited contact these species would have
with the OU-1 area ensures unacceptable risk to a single individual will not occur.
Findings of the RI indicate that the contaminants at OU-1 are not altering the ecology to
unacceptable levels. A Base-wide ecological risk assessment will be conducted as part of OU-11,
and OU-1 will be included in this Base-wide evaluation.
2.7 DESCRIPTION OF ALTERNATIVES
Presumptive Remedies: Site Characterization and Technology Selection for CERCLA Sites with
Volatile Organic Compounds in Soils (OSWER Directive 9355.0-48FS) was the basis of the
streamlined feasibility study (FS). This presumptive remedy was incorporated into the remedial
action at OU-1 to develop the following alternatives.
Alternative 1 - No Further Action
The no further action alternative represents the baseline condition at OU-1 and
refers to taking no further action at the operable unit.
Alternative 2 - Source Area Soil Treatment with Ground-water Containment
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Continued-operation-of the-interim remedial action-(IEA)v-
Installation and use of additional SVE wells, ground-water wells and/or collection
trenches to contain the existing soil and ground-water contamination.
Soil gas and contaminated ground water would be treated at the IRA treatment
plant. The water effluent will either be discharged to a surface water drainage,
pumped to the Base waste-water treatment plant, or injected underground.
Long-term maintenance and monitoring.
Institutional controls (access restrictions and deed restrictions).
Alternative 3 - Source Area Soil Treatment and Ground-water Treatment
Same as Alternative 2 with additional ground-water wells and trenches.
This alternative is the same as Alternative 2 except that the ground-water removal system would
be designed to not only contain the contaminated ground water, but to permanently lower the
contaminant concentrations in the ground water to the levels listed in Table 2-1.
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-1.
The remedial action objectives for OU-1 are as follows:
Achieve the ground-water clean-up goals set forth in Table 2-1.
Achieve the soil clean-up goals set forth in Table 2-2.
The area of attainment is defined as the area which will achieve the remedial action objectives
after remediation is completed. The areal extent of the source-area soil attainment area for OU-1
is based on reported concentrations of chemicals of concern and is shown in Figure 2-4. The
ground-water attainment area was based on MCLs for the reported chemical concentrations at
OU-1 and is shown in Figure 2-5.
Pursuant to Section 40 CFR 300.430(e)(9)(iii), 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.
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4. Reduction of toxicity, mobility, or volume of contaminauon.
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 does nothing to reduce risk levels at OU-1. Alternatives 2 and 3 both reduce the
risk of source-area soils contaminating the underlying aquifer and address ground-water
remediation. Alternatives 2 and 3 would remediate ground water to levels at or below MCLs.
However, the primary goal of Alternative 2 is to only contain contaminated ground water. Under
Alternative 2, the aquifer may eventually be restored to the levels listed in Table 2-1. It would
take approximately 10-15 years longer for the ground water to be remediated to levels listed in
Table 2-1 under Alternative 2 as compared to Alternative 3.
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 that specifically address a hazardous substance, pollutant, contaminant, remedial
action, location or other circumstances at a CERCLA site.
Relevant and appropriate requirements address problems that do not specifically address a
hazardous substance, pollutant, or remedial action. Rather, these requirements address problems
or situations that are similar to those encountered at a particular CERCLA site, and therefore,
these requirements are suited for use at the site because of these similarities. 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, tKe 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.
TABLE 2-1
OU-1 Clean-up Goals
Ground Water (|ig/L)
Analyte
Clean-up Goal
Basis
1,2-Dichloroethane (1,2-DCA)
1 , 1 -Dichloroethylene ( 1 , 1 -DCE)
1,2-Dichloroethylene (1,2-DCE)
1,1,1 -Trichloroethane
Benzene
Tetrachloroethylene (PCE)
Trichloroethylene (TCE)
Vinyl Chloride
TPH
Ethylbenzene
Toluene
Xylene
5.0
7.0
70.0
5.0
5.0
5.0
5.0
2.0
10,000
700 '
1,000
10,000
MCL
MCL
MCL
MCL
MCL
MCL
MCL
MCL
State Regulation
State Regulation
State Regulation
State Regulation
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TABLE 2-2
OU-1 Clean-up Goals
Soils (ug/kg)
Analyte
1,2-Dichloroethylene (1,2-DCE)
Benzene
Tetrachloroethylene (PCE)
Trichloroethylene (TCE)
JP-4
Toluene
Ethylbenzene
Xylene
Naphthalene
Clean-up
Goal
41
10(2)
10
10(2)
500,000(3)
15,000(3)
10,000(3)
300,000(3)
25,000(3)
Model
Estimates05
41.4
2.5
10.5
3.3
-
-
-
-
-
Basis
Ground water protection
Ground water protection
Ground water protection
Ground water protection
State Regulation
State Regulation
State Regulation
State Regulation
State Regulation
(1)Note: Based on SUMMERS Model (Summers, 1980)
(2)Note: When the model estimates are less than standard detection limits, remediation clean-up goals will be
based on standard detection limits.
(3)Note: State of South Dakota Remediation Criteria for Petroleum Contaminated Soil, Tier 1 action levels at
petroleum release sites which would require a corrective action plan or Tier 2 analysis
(ARSD Chapter 74:03:33).
A summary evaluation of Federal and State ARARs pertinent to this remedial action is provided in
Table 2-3 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):
Since there are no remedial activities currently being conducted and none are proposed under this
alternative, there are no remediation ARARs applicable. The No Action alternative does not
comply with CERCLA ARARs as a stand-alone action. The ground water at the site would
remain contaminated.
Alternatives 2 and 3 (Source Area Soil Treatment with Ground-water Containment/Treatment):
The Safe Drinking-Water Act will be complied with by extracting and treating ground water so
that contaminant concentrations in the shallow aquifer are below the MCLs. State ground-water
quality standards (ARSD Chapter 74:03:15) will also be complied with. However, compliance
with MCLs will take approximately 10-15 years longer under Alternative 2 as compared to
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Alternative 3. The discharge of the treated ground water will comply with State of South Dakota
discharge requirements (ARSD Chapter 74:03:17 for indirect or direct discharges into surface
waters and ARSD Chapter 74:03:13 for reinjection of discharged water underground). State
discharge requirements comply also with Federal requirements of the Clean Water Act (CWA).
The proposed SVE system will reduce the concentrations of JP-4 in the soils to levels in
compliance with South Dakota Petroleum-Contaminated Soils regulations (ARSD Chapter
74:03:33).
Treatment-process residuals such as spent carbon will be disposed of in a manner complying with
State and Federal solid waste disposal restrictions (40 CFR 268). Construction of the collection
trench will not degrade onsite wetlands and therefore will comply with the Executive Order on
Protection of Wetlands and Section 404 of the CWA. Air and water discharges from the IRA
treatment facility will comply with South Dakota Air Pollution Control Regulations (ARSD
Chapter 74:26) and water discharge permit rules and water quality standards as stated above.
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 does not provide long-term effectiveness in achieving the remedial action objectives
established for this site. No further controls for the OU would be developed under this
alternative.
For Alternatives 2 and 3, residual risk levels would be low enough that source-area soils would
not pose a risk to ground water. MCLs would be met for ground water. However, it would take
approximately 10-15 years longer for the ground water to be remediated to the MCLs under
Alternative 2 as compared to Alternative 3. The ground-water collection system for Alternative 2
would be designed to preclude further transport of the ground-water contamination. The ground-
water collection system for Alternative 3 would be designed to also remediate the ground water
to the levels listed in Table 2-1. Long-term monitoring of vapor extraction rates and
concentrations would be necessary to maintain proper system operation.
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.
No reduction of potential source area chemicals with respect to toxicity, mobility, or volume
would be achieved with Alternative 1. Alternatives 2 and 3 would reduce the volume of VOCs in
source-area soils to levels protective of ground-water quality. The ground-water collection
system would reduce the mobility of the ground-water contamination by preventing further
downgradient movement. The removal and treatment of contaminants would also reduce the
volume of contaminated ground water. The volume of contaminated ground water would be
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reduced faster under Alternative 3 as compared to Alternative 2.
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.
Alternative 1 does not provide any short-term effectiveness in reducing potential threats from this
site to human health or the environment. Since no construction activities would take place, risk
from remedial action would not exist.
Adverse environmental impacts due to the construction and implementation of Alternatives 2 and
3 are expected to be minor. Construction would comply with OSHA requirements to help
eliminate the risk to construction workers. Community risk is expected to be minimal due to low
levels of contaminants in the surface soil and dust control measures would be implemented.
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.
There is nothing to implement under Alternative 1. Alternatives 2 and 3 require no special or
unique activities and could be implemented using locally available materials and contractors. Any
implementability concerns were addressed during the IRA.
2.8.7 Cost
The assessment of this criterion considers the capital and operation and maintenance (O&M) costs
associated with each of the alternatives. 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 evaluate the alternatives
based on the ability to protect human health and the environment for additional costs that may be
incurred. 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 = $0
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value
$0
$0
$0
so
Alternative No. 2 (Source Area Soil Treatment and Ground-water Containment)
Total Capital Costs
Total Annual (Sampling/Analysis/O&M) Costs
30-Year Present Value for Annual Costs
Annual Cost = $25,000
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value
$782,000
$150,000
$2,306,000
53,088,000
Alternative No. 3 (Source Area Soil Treatment and Ground-water Treatment)
Total Capital Costs
Total Annual (Sampling/Analysis/O&M) Costs
30-Year Present Value for Annual Costs
Annual Cost = $25,000-
Years = 30
Discount Rate = 5%
TOTAL 30-Year Present Value
$986,000
$96,000
$1,479,000
52,465,000
The majority of the costs for Alternatives 2 and 3 are from long-term monitoring and
maintenance. The capital costs for Alternative 3 are approximately $204,000 greater than the
capital costs for Alternative 2. This is due to the additional ground-water extraction wells and/or
trenches needed to remediate the ground water under Alternative 3 rather than contain the ground
water under Alternative 2. Because Alternative 2 will operate approximately 10-15 years longer
than Alternative 3, the long-term monitoring and maintenance costs are much greater for
Alternative 2. These additional long-term monitoring and maintenance costs are much greater
than the additional capital costs to remediate the ground water under Alternative 3. Alternative 3
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is the most cost-effective alternative.
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, and Proposed Plan. In accordance with the requirements of the
NCP, the State of South Dakota was also provided the opportunity to review and comment on
the ROD. As a result of that review and 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. Community members did not
express any concerns about the Proposed Plan which would require a change in the chosen
alternative.
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, Source Area Soil Treatment and Ground-water Treatment.
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 contaminants
at OU-1 will remain above health-based levels following completion of installation of the
extraction components of the remedy Major components of Alternative 3 are:
Continued operation of the IRA which consists of (1) SVE to remediate a portion
of the source area soils and (2) ground-water wells and an existing collection
trench to remove contaminated ground water near the source area.
Installation and use of additional SVE wells, ground-water wells and/or collection
trenches.
Soil gas and contaminated ground water would be treated at the IRA treatment
plant. The water effluent will either be discharged to surface water, injected
underground, or discharged to the Base waste-water treatment plant.
Implementing institutional controls (deed and land use restrictions) to restrict the
future use of the area while the remedy is being implemented.
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Providing for long-term ground-water monitoring at the OU to identify
development of future risks associated with the OU, Providing long-term
maintenance of the remedial actions taken at the OU.
Each of these items is discussed below.
Continued Operation of the ERA
The IRA consisted of (1) SVE to remediate a portion of the source area soils and (2) ground-
water wells and an existing collection trench to remove contaminated ground water near the
source area. The IRA also included the construction of a treatment plant for the treatment of the
soil gas and contaminated ground water. The IRA will be operated and the additional SVE wells,
. ground-water wells, and collection trenches described below will be added to the system.
SVE Wells, Ground-Water Wells and/or Trenches
The objective of this alternative is to decrease soil contaminant concentrations within the bum-pit
to the levels listed in Table 2-2 and to remediate the shallow aquifer to levels listed in Table 2-1.
The area targeted for SVE is the burn-pit area (Figure 2-4). Additional SVE wells will be placed
in the bum-pit area to remove soil contamination that was not addressed in the IRA. The
number and placement of the SVE wells will be further evaluated during the design.
Ground-water wells and/or collection trenches will be installed at OU-1 to remediate the
contaminated shallow aquifer at OU-1 to the levels listed in Table 2-1. The number and
placement of wells and/or trenches will be evaluated during the design. The ground-water wells
and trenches will collect and remove contaminated ground water at OU-1. The aquifer is
expected to be remediated in 10-15 years,
Treatment
Extracted soil gas, condensate from the SVE wells, and ground water removed by wells and
trenches will contain both VOCs and petroleum hydrocarbons. These contaminants will be
treated at the treatment plant built for the IRA. Treatment of the soil gas and contaminated
ground water consists of filtration, air stripping, activated-carbon adsorption, and thermal
oxidation.
The water effluent from the treatment plant is expected to be discharged into a drainage which
flows into Pond 001. The effluent will be monitored prior to discharge to determine the
effectiveness of the treatment system. Effluent discharge standards and monitoring will be
determined during the design phase and are subject to State and EPA reviews and approvals.
Underground injection or discharge to the Base waste-water treatment plant may be chosen as the
discharge option based on the allowable discharge standard. The expected surface water
discharge will comply with the requirements of the Clean Water Act. Off-gas from the thermal
oxidizer will be monitored to ensure compliance with Federal, State, and local requirements
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under the provisions of the Clean Air Act.
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 on-site
worker access to contaminated soil, and to restrict or control temporary construction activities
unless proper protective equipment is worn; (2) filing a notice with the State to recommend denial
of water appropriation permit applications to install ground-water wells within the area of
contamination and any area which may be effected by potential contaminants; (3) filing a notice to
the deed detailing the restrictions of the continuing order and ground-water well restrictions; and
(4) a covenant to the deed in the event of property transfer.
Continuing order requirements will be in effect as long as the property is owned by Ellsworth
AFB and the remedial action has not reached remediation goals. In the case of the sale or transfer
of property within OU-1 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 Maintenance
A maintenance program would be established to ensure the long-term integrity of the removal and
treatment system. The maintenance program would include development of standard operating
procedures (SOPs) to provide for inspections, repairs, and leak response actions.
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 from the
treatment plant vapor stream and treated ground water will be monitored to evaluate the
effectiveness of the system in removing VOCs from the contaminated media. Contaminant
concentrations in the burn-pit area and in the ground water will also be monitored. Continued
analysis and monitoring of the ground-water remedial action system performance will be
conducted to determine if the remediation system is approaching an asymptotic level due to
physical limitations of the site, or the benefits of the remedial action no longer justify long-term
operation of the system. Remediation goals and the remedial alternative will be re-evaluated at
that time.
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This alternative will meet the remedial action objectives and reduce the potential risk at OU-1 by
treating contaminated ground water to levels considered safe for public drinking water and by
preventing future contamination of the shallow aquifer by reducing the volume of contaminants in
the soil above the shallow aquifer. This will be achieved by the installation of ground-water wells
and/or collection trenches, installation of SVE wells, and treatment of removed ground water and
soil vapor.
Alternative 3 would achieve significant risk reduction at the OU by treating ground water to
reduce contaminant concentrations to below the MCLs. The selected alternative will be
protective of human health and the environment and will comply with ARARs.
2.10 STATUTORY DETERMINATIONS
The selected remedy meets the statutory requirements of Section 121 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. The selected remedy represents the best balance of
tradeoffs among the 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.
2.10.1 Protection of Human Health and the Environment
The selected remedy addresses health and environmental issues that were identified in the OU-1
RI report. Specifically, the alternative:
Reduces contaminant concentrations in ground water to MCLs.
Reduces the potential infiltration of contaminants to the ground water.
Prevents unauthorized access and use of the area while remediation is taking place
thereby preventing exposure to contaminants by Base personal and potential future
residents.
Provides for long-term monitoring of ground water to identify potential future
risks associated with OU-1.
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2.10.2 Compliance with ARARs
Alternative 3 will meet Safe Drinking Water Act MCLs and South Dakota Ground Water Quality
Standards (ARSD Chapter 74:03:15). Treated discharge water will comply with the requirements
of an NPDES permit. The proposed SVE system will reduce concentrations of JP-4 to comply
with South Dakota Petroleum-Contaminated Soils regulations. Additional information about
ARAR compliance is contained in Section 2.8.2.
2.10.3 Cost Effectiveness
The selected remedy has been determined to provide overall effectiveness proportional to its costs
and is therefore considered cost effective. The presumptive remedy process insures cost effective
remedies are chosen. The estimated costs of the selected remedy are less than the costs
associated with a similar alternative that utilizes only ground-water containment. The selected
remedy provides a higher degree of protectiveness at a lower cost than the containment
alternative. All the technologies included in the remedy are readily implementable and have been
widely used and demonstrated to be effective.
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies to
the Extent Possible
The selected remedy represents the maximum extent to which permanent solutions and treatment
technologies can be utilized in a cost-effective manner for OU-1. EPA has established that SVE
has proven effective in remediating soils containing VOCs. This alternative prevents unauthorized
access and provides for long-term ground water monitoring to detect movement of chemicals
from the area. A review will be conducted no less often than 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 soil within the former FPTA and contaminated ground water satisfies the statutory
requirement of treatment as a principal element.
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES
The selected action is the same as the preferred alternative presented in the Proposed Plan for
OU-1 remedial action. There have been no changes relative to the Proposed Plan.
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TABLE 2-3 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-1, ELLSWORTH AFB, SOUTH DAKOTA
Potentially Applicable'!* Relevtnl ซnd Appropriate Federal Slandifdi, Requirements. Criteria and Limitations
Standard Requirement. Criteria, or Limitation
Safe Drinking Water Act
National Primary Drinking
Water Regulations
National Secondary Drinking
Water Standards
Maximum Contaminant Level
Goals
Clean Water Act
Water Quality Criteria
Criteria and Standards for the National Pollutant
Discharge Elimination
General Pretreatment Regulations for Existing and
New Sources of Pollution
Guidelines Establishing Test Procedures for the
Analysis of Pollutants
General Program Requirements for injection
Clean Air Act
National Primary and
Secondary Ambient Air
Quality Standard
National Emission Standards
for Hazardous Air Pollutants
Citations
42 USC 300g
40 CFR Part 14160-63
40 CFR Part 14303
40 CFR 141. 50 and
Pub L No 99-330. 100 Slat 642 (1986)
33 USC 1251-1376
40 CFR Part 131 36
40 CFR 125 1-3
40CFR4031-4, 8-.I1.1B
40 CFR 136 1-.5 and AppA-C
40 CFR 144. 12
40 CFR 144. 13
40 CFR 50. 1-6. 8. 9. 11, !2,andApp
A.IU.K
40 CFR 61 .01. 12
40 CFR 61 240-247
Description
Establishes health based standards for public
water systems (maximum containment
levels)
Establishes welfare based standards for the
public water systems (secondary maximum
contaminant levels)
Establishes drinking water quality goals set at
levels of unknown or anticipated adverse
health effects, with an adequate margin of
safety
Sets 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 CWA
Establishes responsibilities of federal, state,
and local government and of the POTW in
providing guidelines for and developing.
submitting, approving, and modifying state
presentment programs. Specifies standards
for prctreatmcnt.
Specify analytical procedures for NPDES
applications and reports
Prohibition of movement of fluids into
underground sources of drinking water.
Reinjection of treated contaminated
groundwater.
Establishes standard for ambient air quality to
protect public health and welfare.
Establishes regulatory standard for specific air
pollutants
ARARType
Chemical
Chemical
Chemical
Chemical
Chemical
Action
Action
Action
Action
Action
Action
Applicability to OU-1
Relevant and appropriate for Federal
Class II aquifer. ,
Relevant and appropriate.
t
Relevant and appropriate.
Relevant and appropriate. Aquifer may
be a Federal Class IIA (discharge to
surface water).
Applicable because of potential discharge
stream or to EAFD WWTP.
Applicable because of potential discharge
to EAFB WWTP.
Applicable because of treatment and
discharge of ground water.
Applicable to discharge options
involving reinjection.
Applicable to discharge options
involving reinjection.
Applicable for discharge of olT-gases for
groundwater treatment processes.
Applicable. Several alternatives would
require discharge to the air following
F.\PROJ\603 7884\FS\OU1 -ROD\F1NAL\OU1ROD. FNL
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May 2. 1996
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Final Record of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
Standard Requirement, Criteria, or L/mitation
Land Disposal Restrictions
Executive Order on Protection of Wetlands
Citations
40 CKR 268 M. 268 7-43 except
268 42(b) and 268 50. and App 1 - VII
Exec Order No 11.990
40 CFR 6 302(i) * Appendix A
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
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
ARARType
Action
Action/Location
Applicability to OU-I
treatment.
Relevant and Appropriate. Alternatives
may include the disposal of residual
waste due to treatment (e.g., spent
carbon).
Relevant and Appropriate. OU-1 has
wetland areas adjacent to po^ntial
remediation areas.
Potentially Applicable or Relevant and Appropriate SUtc Standards. Requirements. Criteria, and Limitations
South Dakota Air Pollution Control Regulations
South Dakota Water Discharge Permit Rules
South Dakota Water Discharge Permit Rules
South Dakota Water Discharge Permit Rules
South Dakota Water Quality Standards
South Dakota Remediation Criteria for Petroleum-
Contaminated Soils
South Dakota Ground Water Standards
74:26:01 :09. 24. 25, 26-28
7403:1801-17
74:03:1901-08
74:0301
74:03:0402.10
74:03:32
74:03:15
Establishes permit requirements for
construction, amendment, and operation of air
discharge services
Establishes surface water discharge permit
applications requirements
Establishes surface water permit conditions
Establishes requirements for individual and
small onsite wastewater systems
Defines use of Boxelder Creek and certain
tributaries.
Establishes requirements for the remediation
of soil contaminated with petroleum products.
Defines ground water classifications by
beneficial use and sets chemical standai Js.
Action
Action
Action
Action
Action
Chemical
Chemical
Applicable to alternatives requiring
discharge of off-gases
Applicable for any discharge of treated
ground water.
Applicable for any discharge of treated
ground water
Applicable for any discharge of treated
ground water.
Relevant and appropriate for any
discharge of treated ground water.
Relevant and appropriate. OU-1 has had
impacts from petroleum products used
during fire training activities.
Relevant and appropriate.
F: \PROJ\603 7884\FS\OUI -ROD\FINAL\OU1ROD.FNL
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May 2, 1996
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Final Record of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
3.0 LIST OF ACRONYMS AND ABBREVIATIONS
1,2-DCA: 1,2-Dichloroethane
1,1-DCE: 1,1-Dichloroethylene
1,2-DCE: 1,2-Dichloroethylene
ACC: Air Combat Command
ARARs: Applicable or Relevant and Appropriate Requirements
ARSD: Administrative Rules of South Dakota
CERCLA: Comprehensive Environmental Response, Compensation and Liability Act
CFR: Code of Federal Regulations
COC: Chemicals of Concern
CRP: Community Relations Plan
CWA: Clean Water Act
EAFB: Ellsworth Air Force Base
EPA: Environmental Protection Agency
FAWQC: Federal Ambient Water Quality Criteria
FFA: Federal Facilities Agreement
FPTA: Fire Protection Training Area
FS: Feasibility Study
IRA: Interim Remedial Action
IRP: Installation Restoration Program
JP-4: Jet Propulsion Fuel Number Four; contains both kerosene and gasoline fractions.
MCL: Maximum Contaminant Levels
Hg/kg: Micrograms per kilogram
ug/L: Micrograms per liter
NCP: National Oil and Hazardous Substances Contingency Plan
NPDES: National Pollutant Discharge Elimination System
NPL: National Priorities List
O&M: Operation and Maintenance
OSHA: Occupational Safety and Health Administration
OSWER: Office of Solid Waste and Emergency Response
OU: Operable Unit
PAH: Polynuclear Aromatic Hydrocarbon
PCE: Perchloroethylene; liquids used in degreasing or paint removal.
ppm: Parts per Million
RA: Remedial Action
3-1
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Final Record of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
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
SOP: Standard Operating Procedures
SVE: Soil Vapor Extraction
SVOC: Semivolatile Organic Compound
TCE: Trichloroethylene
TPH: Total Petroleum Hydrocarbon
USAF: United States Air Force
VOC: Volatile Organic Compound
3-2
F:\PROJ\6037884\FSvOUl-ROD\FINAL\QUlRODfNL April 1996
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Final Record of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
APPENDIX A
FIGURES
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o
/
o
5ฐ
o ป
N
MINNESOTA
NORTH DAKOTA
.
SOUTH DAKOTA
ELLSWORTH AFB
Rapid City
Scale in Miles
APPROXIMATE
EUL-SWORTH
7JH AIR FORCE BASE
ELLSWORTH AFB
RAPID OTY. SOUTH MKOTA
AREA LOCATION MAP
ROJECT UCR
DESIGNED BY
DRAWN BY
MRG
CHECKED BY
SCALE
AS SHOWN
DATE
OCT 95
PROJECT NO
60378.85
FIGURE:
2-1
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DRAWING NAME: F:\HOPIZONS\NEW\OUI\BCWELll
DAFEOI/I9/I996 IIME:IJ53
o
Q
(O
o
I
fO
a
CD
I/)
m
5
o
ooooooooooo
ccccccccccc
I I I I I I I I I I I
L
-------
Is
N
BASE
BOUNDARY
APPROXIMATE
OU-1 BOUNDARY
EXTENT OF
HISTORICAL
TRAINING AREA
BOUNDARY FENCE
\
ALERT
APRON
200'
LEGEND
SURFACE DRAINAGE
;OURCE: EPA 1991, BURN PIT HISTORICAL AREAS FROM AERIAL PHOTOGRAPHS. 1952-1992
El_l_S WORTH
AIR FORCE BASE
ELLSWORTH AFB
RAPID CITY. SOUTH DAKOTA
SITE AREA
[OJECT MCR
DESIGNED 6Y
DRAWN BY
WGL
CHECKED BY
SCALE
AS SHOWN
DATE
OCT 95
PROJECT NO
60378.84
FIGURE
2-3
-------
N
SOURCE-AREA SOILS
AREA OF ATTAINM
ฎSBS30107
/T\SB930148
EXTENT OF HISTORICAL
BURN PIT AREAS
ei_l_SWORTH
AIR FORCE: BASE
TITLE:
AREA OF ATTAINMENT FOR
SOURCE-AREA SOILS
FIGURE:
2-4
OWN BY:
STAFF
DATE:
MAR 96
APP'D:
TR
PJT NO:
60378.841
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N
GROUNtPto
AREA OF A
BUILDING 6908
IRA TREATMENT
PLAN
EXTENT OF HISTORICAL
BURN PIT AREAS
12
a: .-
EI_I_SWORTM
AIR FORCE BASE
TITLE:
AREA OF ATTAINMENT FOR
GROUND WATER
FIGURE:
2-5
OWN BY:
STAFF
DATE:
MAR 95
APP'D:
TR
PJT NO:
60378.841
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Final Record of Decision Operable L'nit 1
Ellsworth Air Force Base, South Dakota
APPENDIX B
RESPONSIVENESS SUMMARY
F:\PROJ\6037884\FS\OU1-ROD\FINAL\OU1RODJWL April 1996
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Final Record of Decision Operable Unit I
Ellsworth Air Force Base, South Dakota
Responsiveness Summary
Remedial Action at Operable Unit One
Ellsworth Air Force Base, South Dakota
1. Overview
The United States Air Force (USAF) established a public comment period from August 8 to
October 16, 1995 for interested parties to review and comment on remedial alternatives
considered and described in the Proposed Plan for Operable Unit One (OU-1). 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 6:30 p.m. on September 26, 1995 in the 28th Bomb Wing
Auditorium at Ellsworth Air Force Base (EAFB) to outline the proposed remedy to reduce risk
and control potential hazards at Operable Units 1, 2, and 4.
Some of the public comments pertained to the selected remedies in the Proposed Plans for all the
operable units. Rather than attempting to separate out the comments which pertained to an
individual operable unit, one Responsiveness Summary was prepared to address all the comments
for all the operable units.
The Responsiveness Summary provides a summary of comments and questions pertaining to OU-
1, 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
The selected remedy for OU-1 is alternative 3, source area soil and ground-water treatment,
which includes the following major components:
Continued operation of the interim remedial action (IRA) which consisted of
contaminated ground-water removal, soil vapor extraction (SVE), and treatment;
Installation of additional SVE wells within the historical burn-pit area to be added
to the existing IRA SVE system;
B-l
F:\PROJ\6037884\FS\Oifl-ROD\FINAL\OUlROD.FNL April 1996
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Final Record of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
Removal of contaminated ground water using additional ground-water wells and
collection trenches to be added to the IRA ground-water recovery system;
Treatment of ground water at the existing IRA treatment plant;
Institutional controls for the area;
Long-term monitoring; and,
Long-term operation and maintenance of equipment.
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 US AF, 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.
B-2
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Final Record of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
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.
The Proposed Plan for this remedial action was distributed to the mailing list addressees for their
comments. Additional copies of the Proposed Plan were available at the September 26, 1995
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 for OUs 1,2 and 4 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. In addition, one question
addressed purchase of off-Base property. Representatives of the USAF were available to provide
answers to the questions and also provided an overview presentation during the meeting to
describe the proposed actions. The following are questions and responses pertaining to OU-1.
For questions and responses pertaining to OU-2 and OU-4, refer to the Records of Decision for
these OUs.
Part n - 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 September 26, 1995 public meeting.
Comment 1. Jan Deming
Asked about whether the stream running from the northeast to the southwest in OU-1
B-3
F:(PROJ\603788^fS\OLfl-ROD\FINAL\OUlRODJ:NL April 1996
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Final Reaord of Decision Operable Unit 1
Ellsworth Air Force Base, South Dakota
was contaminated, or was transporting contaminants.
Response 1: Evidence of jet fuel and pesticides were found in the sediments. The human health
and ecological risk assessments indicated that there was no unacceptable risk to
human and ecological receptors. The storm drains were deferred to OU-11 to
allow additional investigation of the ecological conditions on the Base. The
oil/water skimmer in Pond 001 will remove any contamination floating on the pond
surface if a fuel spill were to occur upstream of the OU. The monthly NPDES
sampling for a range of chemicals helps ensure that no contamination is going off-
Base.
4. Remaining Concerns
Based on review of the transcript of the oral comments received during the public meeting, there
are no outstanding issues associated with implementation of the proposed remedial action.
B-4
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