EPA Superfund
Record of Decision:
Ellsworth Air Force Base,
Operable Unit 4, SD
5/16/1995
PB95-964414
EPA/ROD/R08-95/109
February 1996
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Final
Record of Decision for
Interim Action at Operable Unit 4
Landfill No. 3 Area
Ellsworth Air Force Base, South Dakota
United States Air Force
Air Combat Command
Ellsworth Air Force Base
May, 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base. South Dakota
TABLE OF CONTENTS
Chapter Page
1.0 DECLARATION 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 1-3
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY ..... 1-3
2.0 DECISION SUMMARY 2-1
2.1 SITE NAME AND LOCATION 2-1
2.2 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 2-2
2.4 SCOPE AND ROLE OF RESPONSE ACTION 2-3
2.5 SITE CHARACTERISTICS 2-4
2.5.1 Soils 2-4
2.5.2 Ground-water 2-4
2.6 OU-4 RISK SUMMARY 2-5
2.7 DESCRIPTION OF ALTERNATIVES 2-7
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 2-8
2.8.1 Overall Protection of Human Health and the Environment 2-8
2.8.2 Compliance with ARARs 2-8
2.8.3 Long-Term Effectiveness and Permanence 2-10
2.8.4 Reduction of Toxicity, Mobility, and Volume Through Treatment ... 2-10
2.8.5 Short-Term Effectiveness 2-11
2.8.6 Implementability 2-11
2.8.7 Cost 2-12
2.8.8 State Acceptance 2-12
2.8.9 Community Acceptance 2-12
2.9 SELECTED ALTERNATIVE ,.. 2-12
2.10 STATUTORY DETERMINATIONS 2-13
2.10.1 Protection of Human Health and the Environment 2-13
2.10.2 Compliance with ARARs 2-13
2.10.3 Cost Effectiveness 2-14
2.10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Extent Possible 2-14
2.10.5 Preference for Treatment as a Principal Element 2-15
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES 2-15
3.0 LIST OF ACRONYMS AND ABBREVIATIONS 3-1
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
LIST OF TABLES
Table 2-1 Evaluation of Federal and State ARARs That Apply to OU-4 2-16
LIST OF 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 OU-4 Map
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
1.0 DECLARATION
1.1 SITE NAME AND LOCATION
• Operable Unit 4 (OU-4), Landfill No. 3 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 interim remedial action for OU-4, 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-4, EAFB. The United
States Environmental Protection Agency Region VIE (EPA) and the South Dakota Department of
Environment and Natural Resources (SDDENR) concur with the selected interim remedial action.
1.3 ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this OU, if not addressed by implementing
the interim remedial 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 OUs, have been identified at EAFB. This ROD is for an
interim action at OU-4 and is the second ROD for EAFB. The ROD for the final action for OU-4 will
be prepared in April 1996.
The selected interim action remedy for ground-water contamination cleanup at OU-4 consists
of:
• ground-water removal using wells,
• treatment of ground-water,
• surface discharge of treatment effluent
This alternative involves collecting contaminated ground-water using wells located along and south
of the Base boundary in the area of the off-Base ground-water contamination. The contaminated
ground-water will be transported to a treatment system. The treatment system will consist of gravity
separation, air stripping, solids filtration, and use of liquid phase granular activated carbon. Air-
stripper off-gases will be treated by thermal oxidation. The liquid effluent from this treatment system
will be discharged to a natural drainage. The discharge will be in compliance with the requirements
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Final Record of Decision for Interim Action at Operable Unit 4
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of the Clean Water Act. The drainage leads to a retention pond. The discharge from the pond is
regulated under the National Pollution Discharge Elimination System (NPDES) program.
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Final Record of Decision for Interim Action at Operable Unit 4
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1.5 STATUTORY DETERMINATIONS
This interim action is protective of human health and the environment, complies with action- and
location-specific Federal and State applicable or relevant and appropriate requirements (ARARs), and
is cost effective. However, since this is an interim action, the interim action waiver is being invoked
for chemical-specific ARARs. These ARARs will be met in the final cleanup action.
Although this interim action is not intended to fully address the statutory mandate for permanence
and treatment to the maximum extent practicable, this interim action does utilize treatment and is in
furtherance of that statutory mandate. Because this action does not constitute the final remedy for
OU-4, the statutory preference for remedies that employ treatment that reduce toxicity, mobility, or
volume as a principle element, although partially addressed in this remedy, will be addressed by the
final response action Subsequent actions are planned to fully address the threats posed by conditions
at OU-4.
Because this remedy will result in hazardous substances remaining at the OU above health-based
levels, a review will be conducted to ensure that the remedy continues to provide adequate protection
of human health and the environment within five years after commencement of the final action.
Because this is a ROD for an interim action, review of this OU and of this remedy will be ongoing
as the Air Force continues to develop final remedial alternatives for OU-4.
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
THAD A. WOLFE (J
Lieutenant General, USAF
Vice Commander
Date
fTbUPR^Y, Dir
Hazardous Waste Manag
US Environmental Protectio
Region
Date
NETTIE HvfYERS, Secr
Department of Environment and Natural Resources
State of South Dakota
Date
1-3
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
2.0 DECISION SUMMARY
2.1 SITE NAME AND LOCATION
Ellsworth Air Force Base (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.
OU-4, which encompasses Landfill No. 3, is a forty-acre site located south of the control tower in
the southwest portion of the Base (Figure 2-2).
Open land, containing a few private residences, lies adjacent to EAFB on the north, south, and west.
Ranches lie to the north and west of the Base and residential and commercial areas lie to the east of
the Base. Residences and ranches lie south of EAFB.
2.2 DESCRIPTION/HISTORY AND REGULATORY OVERSIGHT ACTIVmES
2.2.1 Description/History
EAFB was officially activated in July 1942 as the Rapid City Army Air Base, a training facility for
the 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 n missile systems. The Base has provided support, training, maintenance, and/or
testing facilities. Presently, the 28th Bombardment Wing (B-1B bombers) and the 99th Tactics and
Training Wing are the host units of EAFB.
Landfill No. 3 at OU-4 was operated as a trench-and-fill landfill from 1965 to 1976. Shop wastes
(liquids and paints), industrial sewage sludge, waste oils, and miscellaneous refuse were placed in
excavated trenches and then subsequently covered with soil. During the mid-1970s, a waste-oil pit
was located in the southwest corner of OU-4. It was reported that the contents of approximately one
hundred 55-gallon drums, containing waste oil and diesel fuel, were dumped into the waste-oil pits.
During 1982 and 1983, OU-4 was also used as a disposal site for contaminated soils from other areas
of the Base. Most recently, the southwest comer of OU-4 was used as storage area for asphalt rubble.
The asphalt rubble pile was removed in 1993 to allow for the soil and ground-water investigations.
Both humans and livestock have used shallow (14 to 32 feet below grade) ground-water in the areas
south and west of OU-4. Although the shallow ground-water contamination has reached only one
residential well, as a precautionary procedure the Air Force is supplying several residences near the
Base boundary with potable water.
Deeper bedrock aquifers also exist in excess of 1000 feet 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 directly beneath the Base for its water supply. Presently, EAFB obtains
its potable water from the Rapid City Municipal Distribution System. The Rapid City Municipal
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Ellsworth Air Force Base, South Dakota
Distribution System obtains its water from two deep, high-capacity, wells and four surface water
intakes along Rapid Creek.
In terms of ecological value, the natural environment at OU-4 has been highly altered by the
landfilling activities. Notwithstanding the high level of alterations, habitat features such as grassy and
weedy fields are prevalent at the OU. These could be used intermittently by some animal species.
2.2.2 Regulatory Oversight Activities
Environmental investigation activities at EAFB were initiated by the Air Force in 1985 through the
preparation of an Installation Restoration Program (IRP) Phase I Installation Assessment/Records
Search and Phase H, 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 D, 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 hi 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 in accordance with CERCLA as amended by SARA, and the NCP. It also states the
oversight procedures for EPA and the State to ensure Air Force compliance with the FFA
requirements. The FFA identified 11 potential source-area operable units as well as a Base-wide
ground-water operable unit.
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 these 12 operable units. In 1993 and 1994, an
extensive RI field program was conducted to characterize site conditions at OU-4. The program
included completion of boreholes, installation of monitoring wells, geotechnical analysis of soil
samples, ecological investigations, 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.
• Administrative Record. An Administrative Record for information was established in
Building 8203 at EAFB. This repository contains information used to support USAF
decision-making.
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• Information repositories. An administrative Record outline is located at the Rapid City
Library (public repository).
• Community Relations Plan (CRP). A Community Relations Plan was prepared and has
been accepted by the EPA and State and is currently being carried out. An update to this
plan will be prepared in 1995.
• Restoration Advisory Board (RAB). The RAB has been formed to facilitate public
involvement 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 the
Base and updated regularly.
• Fact sheets. A fact sheet describing the status of the IRP at the Base 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 the Base 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.
A public comment period was held from March 25 to April 24, 1995, and a public meeting was held
on April 18, 1995. At this meeting, representatives from EAFB answered questions about the interim
action. A response to the comments received during this period is included hi the Responsiveness
Summary, which is part of this ROD.
This ROD is based on the contents of the Administrative Record for OU-4, hi 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 to the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP). The remedial
investigation and focused feasibility study reports and the Proposed Plan for OU-4 provide detailed
information about the OU and interim action. 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
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
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 for an interim remedial action (IRA) at OU-4 and is the second ROD for EAFB. The
scope of the IRA is to reduce the immediate risks posed by the contaminants in ground-water by
preventing further transport off-Base and by removing contaminated ground-water which is already
off-Base. The IRA includes construction of ground-water wells downgradient of Landfill 3 and wells
near the Base property boundary. These wells will be operated to contain the contamination. In
addition, the wells will be constructed in the most highly contaminated areas of the off-Base plume
and operated to contain and remove this area of off-Base ground-water contamination.
Implementation of the IRA will result in partial restoration of the shallow ground-water downgradient
of Landfill 3.
This action is not the final action for OU-4; the ROD for the final action is due in April 1996.
Additional remedies will be implemented at OU-4 during the final action to clean up the remaining
contaminated media. The IRA will be consistent with any future actions.
2.5 SITE CHARACTERISTICS
This section describes the nature and extent of contamination at OU-4 as a result of past activities
conducted at the OU.
2.5.1 Soils
Surface and subsurface soil samples obtained during the RI field program indicated the presence of
contamination consisting of volatile organic compounds (VOCs), semi-volatile organic compounds
(SVOCs), and pesticides within the Base boundary. The southern portion of the landfill is a likely
source of significant JP-4 jet fuel contamination and benzene, toluene, ethylbenzene, and xylene
(BTEX) contamination. VOCs and pesticides are also present at relatively low concentrations in the
subsurface soil beyond the Base boundary in areas corresponding to the ground-water contamination.
2.5.2 Ground-water
Shallow ground-water at OU-4 flows in the southern direction. An 800 feet thick layer of
impermeable clays and silts exists beneath the shallow aquifer and limits the shallow aquifer from
infiltrating to the deeper ground-water aquifers. These deeper aquifers were not affected by
contaminants at OU-4.
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Final Record of Decision for Interim Action at Operable Unit 4
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Past practices at OU-4 have resulted in the contamination of the shallow aquifer. The shallow ground-
water contamination at OU-4 extends approximately 150.0 feet south of the Base boundary. VOC
contaminants such as benzene, trichloroethene (TCE), 1,1-dichloroethylene (1,1-DCE) and 1,2-
dichloroethane (1,2-DCA) exist in the ground-water at or above established Safe Drinking Water Act
Maximum Contaminant Levels (MCLs) at OU-4. The area of ground-water contamination is
illustrated in Figure 2-3 .
Dense non-aqueous-phase liquids (DNAPLs) and light non-aqueous phase liquids (LNAPLs) are not
present in OU-4 ground-water.
2.6 OU-4 RISK SUMMARY
Human Health Risks
The assessment of human health risks for this OU considered the following topics:
(1) Contaminants of concern (COCs) in ground-water, surface water, sediment, and soil
samples taken at OU-4;
(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 Base maintenance personnel;
(2) Current off-Base residents using shallow ground-water for drinking and showering;
(3) The future resident living on-Base who plays/walks on surface soil, ingests and showers with
shallow ground-water,
(4) Future adult construction workers who excavate on-site for building residences and;
(5) Future off-Base residential adults who ingest and shower with off-Base shallow ground-
water.
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Final Record of Decision for Interim Action at Operable Unit 4
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Noncarcinogenic Risks
On-Base: There is one exposure pathway at OU-4, ingesti'on of shallow ground-water by a future
resident, for which noncarcinogenic risks were estimated greater than acceptable levels.
This is a result of the cumulative risk associated with a variety of contaminants.
Off-Base: There were no noncarcinogenic risks for individual exposure pathways at OU-4 that
were estimated in excess of acceptable levels.
Carcinogenic Risks
Carcinogenic risks were estimated as the incremental probability of an individual developing cancer
over a lifetime as a result of exposure to a potential carcinogen. The acceptable risk level expressed
as a probability is one cancer incident in a million people. This level of risk is also denoted by 1x10"*.
Risks at or below this level cannot be differentiated from the background occurrence of cancer in the
population. Risks calculated in a risk assessment are potential risks and are excess (i.e., over
background) cancer risks due to exposure from contaminants at the OU.
Carcinogenic risks for the exposure groups are summarized as follows:
On-Base: Potentially unacceptable carcinogenic risks were estimated for future residential land
use. Both the soil and ground-water contamination at OU-4 contribute to the
unacceptable cancer risk.
Off-Base: Potentially unacceptable risks were only associated with future residential land use.
The unacceptable risk off-Base is primarily due to the contamination in the ground-
water.
Ecological Risks
An ecological risk evaluation of OU-4 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-4 habitats. These range from invertebrates,
small mammals, and reptiles living close to the soil to wide-ranging birds and larger mammals.
Because to the altered natural environment of the OU, rare, threatened, or endangered species are
unlikely to utilize OU-4.
Terrestrial vegetation and soil faunal communities do not reveal characteristics that indicate
chemical-related impacts. This finding is consistent with the relatively low levels and limited
distribution of high levels of contaminant concentrations in the soil.
Because initial findings of the RI indicate that the contaminants at OU-4 are not altering the ecology
to noticeable levels, specific ecological risk assessment was not conducted. A Base-wide Ecological
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Final Record of Decision for Interim Action at Operable Unit 4
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Risk Assessment will be conducted as part of OU-11, and OU-4 will be included in this Base-wide
evaluation.
Interim Action Risk Reduction
The interim action will reduce risks associated with potential future uses of the ground-water by
preventing further spread of contaminated ground-water. This will prevent an increase in the amount
of contaminated ground-water. Removing ground-water along the Base boundary will prevent the
flow of contamination off the Base. Off-Base ground-water removal will prevent the further spread
of the contaminants from the areas containing the highest levels of contamination. Removal and
treatment of contaminated ground-water will result in reduced concentrations of contaminants in that
area. This partial restoration of the portion of the contaminated ground-water will reduce potential
future risks.
Subsequent actions are planned to fully address the threats posed by contaminants at OU-4. Because
this remedy will result in hazardous substances remaining at OU-4 above health-based levels, a review
will be conducted to ensure that the remedy continues to provide adequate protection of human
health and the environment within five years after commencement of the final action. Because this is
a ROD for an interim action, review of this OU and of this remedy will be ongoing as the Air Force
continues to develop final remedial alternatives for OU-4.
2.7 DESCRIPTION OF ALTERNATIVES
• Alternative I
• No Action
The no action alternative represents the baseline condition at OU-4 and refers to taking no further
action until the final remedy is selected for OU-4.
• Alternative 2 consists of:
• ground-water removal using wells,
• treatment of ground-water,
• surface discharge of treatment effluent.
Ground-Water Removal
The ground-water wells will be located along the eastern half of the southern landfill boundary and
off-Base in the southwest and central area of the ground-water contamination. The number and
placement of wells will be evaluated during the design. The ground-water wells will collect and
remove (1) contaminated ground-water that is about to move off-Base and (2) the most highly
contaminated ground-water off-Base.
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Final Record of Decision for Interim Action at Operable Unit 4
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Treatment
The contaminated ground-water removed by the wells will be treated at a centrally located treatment
plant. Water treatment will consist of gravity separation, air stripping, solids filtration, and use of
liquid phase granular activated carbon. Air-stripper off-gases will be treated using a thermal-oxidation
unit.
Discharge of Treatment Effluent
The liquid effluent from the treatment system will be discharged into a natural drainage, which flows
into a retention pond (Pond 001). The effluent will be monitored prior to discharge to determine the
effectiveness of the treatment system. Effluent discharge standards and monitoring requirements will
be determined during the design phase of the IRA and are subject to State and EPA reviews and
approvals. The discharge will comply with the requirements of the Clean Water Act. Pond 001
effluent is regulated under the conditions of a National Pollutant Discharge Permit Elimination System
(NPDES) permit (SD-0000281). Off-gases from the thermal oxidizer will be monitored to ensure
compliance with Federal, State, and local requirements under the provisions of the Clean Air Act.
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
The NCP includes nine criteria that the alternatives must be evaluated against. In the following
sections, the alternatives are evaluated against each of these criteria and then against each other to
determine the preferred alternative.
2.8.1 Overall Protection of Human Health and the Environment
Alternative 1 (no action) does nothing to reduce threats and potential threats to human health and the
environment until the final remedy(ies) are selected and implemented.
Alternative 2 (ground-water removal and treatment): Ground-water removal and treatment will result
in a permanent reduction in ground-water contamination. Even though the objective of this remedy
is containment, some restoration of the ground-water may occur. On-Base contamination will be
prevented from crossing the Base boundary. The ground-water off-Base which contains the highest
contaminant concentrations will be contained and removed. As a result, the potential risk to human
health will be reduced. During the installation of the interim remedy, the RJ/FS will continue to
address the remaining contamination and risk at the OU.
2.8.2 Compliance with ARARs
Applicable requirements include cleanup standards, standards of control and other substantive
environmental protection requirements, criteria or limitations promulgated under federal or state laws
that 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. ARARs are grouped into these three
categories:
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Final Record of Decision for Interim Action at Operable Unit 4
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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.
Alternative 1 (no action):
There are no ARARs under this alternative since no activity would occur.
Alternative 2 (ground-water removal and treatment):
The analysis of ARARs in this document has been limited to the scope of the interim action. Other
ARARs may apply to final remedies. A summary evaluation of Federal and State ARARs pertinent
to this interim action is provided in Table 2-1 at the end of this section.
This alternative provides a preliminary step toward achieving chemical-specific ARARs for the
shallow ground-water downgradient of the landfill. The interim action waiver is being invoked for the
chemical-specific ARARs in ground-water. The scope of the interim action is to prevent further
transport of contaminants and to quickly achieve significant risk reduction. Restoration of ground-
water to beneficial use will.be addressed in the final remedy. Ground-water monitoring at OU-4 will
be conducted during implementation of the IRA to determine the progress and effectiveness of the
IRA.
Location Specific ARARs:
National Historic Preservation Act (NHPA) of 1966 (16 USC 470 etseq) - Section 110 requires
that any restoration activities will not affect the historical characteristics of the property. The building
which will house the treatment system is a historical building. All external building renovations will
be conducted to conform with the historical qualities of the building, thereby complying with
Section 110 of the Act.
Action Specific ARARs:
Clean Water Act (CWA) - The CWA requires the establishment of guidelines and standards to
control the direct or indirect discharge of pollutants to waters of the U.S. Effluent limitations
developed for the contaminants will be applied to this point source discharge of the treated ground
water. The standards of control for direct discharges are derived from Title ffl of the CWA. CWA
Section 301(b) requires all direct dischargers to meet technology-based requirements. These
requirements include application of best available technology economically achievable (BAT). The
numerical effluent discharge limits are derived by applying the levels of performance of the treatment
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Final Record of Decision for Interim Action at Operable Unit 4
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technology to the wastewater discharge. The CWA Section 303(b)(l)(C) requires that pollutants
contained in direct discharges be controlled beyond BCT equivalents when necessary to meet
applicable water-quality standards set by the State. The State water-quality standards are based on
Federal water quality criteria. To comply with this ARAR, BAT (air stripping and carbon absorption)
will be used and effluent limits will be determined during the remedial design and subject to State and
Federal review and approvals, the limits will be based on BAT performance and water quality
standards and criteria All residuals from the treatment system will be disposed of according to State
and Federal waste disposal requirements.
Clean Air Act (CAA) - The air emissions from the treatment system will comply with the substantive
permitting process requirements for a minor source under Titles I and V of the CAA Conditions will
be placed on the emissions to prevent the source from becoming a major source or major
modification. Use of thermal treatment will be provided as needed to ensure compliance.
Resource Conservation and Recovery Act - RCRA Regulations Applicable to Control Devices
Required by the Organic Air Emission Standards (40 CFR Parts 264 and 265 subparts AA and BB).
These subparts, being relevant and appropriate to this action, apply to process vents and equipment
leaks associated with air stripping operations that manage hazardous wastes with organic
concentrations of at least 10 parts per million by weight.
2.8.3 Long-Term Effectiveness and Permanence
Alternative 1 delays any action until the final remedy is selected and is unlikely to provide long-term
effectiveness and permanence. Contamination will move farther outward into the ground-water,
increasing the volume of contaminated materials and the subsequent cost of remedial actions.
Although Alternative 2 is an interim action, it will permanently remove and destroy much of the
contamination in the ground-water at the OU. In addition, removing ground-water along the Base
boundary will prevent further downgradient movement of contaminants from the landfill area while
the final remedy for the OU is evaluated.
Due to uncertainties in the hydrogeological characteristics of the shallow aquifer, the interim action
is only focusing on containment of the ground-water contamination. Information provided by the
system operation will be used to evaluate potential long-term effectiveness and permanence of the
interim remedy and to provide information for development of the alternatives for the final remedy.
2.8.4 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternative 1 delays reduction of toxicity, mobility, and volume since no treatment would take place.
Contaminants will continue to move farther into the environment, resulting in a greater volume of
contaminated materials.
Alternative 2 utilizes established treatment technologies to reduce the risks posed by the contaminants
in ground-water immediately downgradient of the landfill and in the area of off-Base ground-water
contamination.
w:\suormiroKrswMisav
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base. South Dakota
Contaminant concentrations in the ground-water will also be permanently reduced through collection
and treatment ground-water. VOCs in the removed ground-water will be partitioned to the air phase
and thermally destroyed. Other organic contaminants will be removed from the air phase by carbon
absorption. The carbon absorbent material will be periodically disposed or reactivated. No residuals
from the treatment will remain on the OU.
2.8.5 Short-Term Effectiveness
Alternative 1 will not pose any addition risks associated with the OU to human health or the
environment Delay of action allows for contaminants to move farther, offering a long term concern
and no reduction in risk.
Alternative 2 will be designed to protect the community and workers during remedial actions.
Worker protection will be consistent with the OSHA requirements in 29 CFR 1910.120 and the site
Health and Safety Plan and Contingency Plan during construction and operation.
The air will be monitored during the construction of the ground-water wells to determine that safe
ambient VOC concentrations in the air are not exceeded. Soil removed during construction of the
wells will be handled according to the procedures outlined in Investigation Derived Waste Evaluation
and Disposal. No adverse environmental impacts are expected from implementation of Alternative
2. Ground-water monitoring will be conducted to assess the effectiveness of the alternative in
reducing contaminant concentrations in shallow ground-water downgradient of the landfill.
2.8.6 Implementability
Alternative 1 offers no implementability concerns since no action will take place.
Alternative 2 will utilize proven "off-the-shelf1 technology and standard construction methods.
Adequate construction equipment and services are available. The equipment for on-site treatment is
commercially available.
Access to the OU is available through existing roadways and the topography will not impede access
for the construction and drilling equipment. Road construction will be limited to that needed to install
the treatment facilities and provide access for system monitoring and maintenance. Activities are
underway to obtain construction, operation and maintenance easements for off-Base property.
Uncertainties associated with this operation involve methods to maximize the effectiveness of ground-
water removal. Changes in pumping rates, alternating operating wells and/or sporadic pumping may
be necessary to determine the most effective removal methods.
The action is administratively feasible. Discharge of the treated water will comply with substantive
State and Federal requirements. Amendment of the existing NPDES permit for the Pond 001 outfall
may be necessary. During the remedial design phases of the IRA, discharge effluent limits for the
treated ground-water will be determined. Monitoring of the treated water will be conducted to insure
compliance with Federal and State discharge requirements. Also, discharge of treated air from the
thermal oxidizer system will be monitored at the thermal oxidizer stack to ensure compliance with
substantive Federal and State air quality requirements.
w:\si3oi\Kifoias(rouisA 2-11 May, 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
2.8.7 Cost
Alternative 1 does not result in any cost for design or implementation. The cost for quarterly
monitoring (operation and maintenance) is $8,250 per quarter for a present worth cost of $31,000.
Alternative 2 is estimated to cost $1,316,000 in capital cost and $686,000 per year to operate. The
operation cost represents the total operation and maintenance cost associated with the treatment
facility which will be used for actions at other locations. Assuming a one year operational life until
the full scale remedy(ies) is/are enacted, the present worth cost is estimated to be $1.9 million The
cost presented above are the total costs for the treatment facility. These costs will be allocated among
concurrent interim actions at other locations.
2.8.8 State Acceptance
The State concurs with the selected remedy. The State provided comments on the remedial
investigation, focused 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 interim 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 this 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 SDDENR, the Air Force has determined that Alternative 2
(ground-water removal and treatment) is the most appropriate alternative for the interim action. The
major components of Alternative 2 are:
• ground-water removal using wells,
• treatment of ground-water, and
• surface discharge of treatment effluent
This alternative will prevent further transport of contaminants off the Base and contain portions of
the off-Base ground-water contamination.
The removed ground-water will contain contaminants such as VOCs, SVOCs, and hydrocarbons and
will be treated. The treatment will consist of gravity separation, air stripping, solids filtration, and use
of liquid phase granular activated carbon. Air-stripper off-gases will be treated with a thermal-
oxidation unit. The liquid treatment effluent will be discharged to a natural surface water drainage.
The drainage leads to a retention pond (Pond 001). The discharge from Pond 001 is regulated under
an NPDES permit (SD-0000281).
2-12 May, 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base. South Dakota
Remediation Goals
This alternative will reduce contaminant concentrations in portions of OU-4 ground-water, control
the transport of contamination beyond the Base boundary, thereby reducing the risks associated with
those contaminants. Restoration is not the objective of the interim action. Contaminants will be
contained during the interim action to allow for easier implementation of the final remedial action.
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, and preference for treatment as a principle element. The interim action is not designed
or expected to be the final cleanup action, but the selected interim remedy represents the best balance
of tradeoffs among the alternatives considered, with respect to pertinent criteria, given the limited
scope of the action.
The manner in which the selected interim remedy meets each of these requirements is discussed in the
sections below. The statutory determinations for the final cleanup remedy for OU-4 will be provided
in the ROD for the final cleanup action, which will be prepared following this interim action.
2.10.1 Protection of Human Health and the Environment
The selected interim remedy provides for removal and treatment of contaminated ground-water. This
will reduce potential risks to human health and retard future transport of contaminants from OU-4.
2.10.2 Compliance with ARARs
This alternative provides a preliminary step toward achieving chemical-specific ARARs for the
shallow ground-water downgradient of the landfill. The interim-action waiver is being invoked for
the chemical-specific ground-water ARARs. The scope of the interim action is to prevent further
transport of contaminants and to quickly achieve significant risk reduction. Restoration of ground-
water to beneficial use will be addressed in the final remedy. Ground-water monitoring at OU-4 will
be conducted during implementation of the IRA to determine the progress and effectiveness of the
IRA
Location Specific ARARs:
National Historic Preservation Act (NHPA) of 1966 (16 USC 470 etsea) - Section 110 requires
that any restoration activities will not affect the historical characteristics of the property. The building
which will house the treatment system is a historical building. All external building renovations will
be conducted to conform with the historical qualities of the building, thereby complying with
Section 110 of the Act.
2-13 May, 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base. South Dakota
Action Specific ARARs:
Clean Water Act (CWA) - The CWA requires the establishment of guidelines and standards to
control the direct or indirect discharge of pollutants to waters of the U.S. Effluent limitations
developed for the contaminants will be applied to this point source discharge of the treated ground
water. The standards of control for direct discharges are derived from Title HI of the CWA. CWA
Section 301(b) requires all direct dischargers to meet technology-based requirements. These
requirements include application of best available technology economically achievable (BAT). The
numerical effluent discharge limits are derived by applying the levels of performance of the treatment
technology to the wastewater discharge. The CWA Section 303(b)(l)(C) requires that pollutants
contained in direct discharges be controlled beyond BCT equivalents when necessary to meet
applicable water-quality standards set by the State. The State water-quality standards are based on
Federal water quality criteria. To comply with this ARAR, BAT (air stripping and carbon absorption)
will be used and effluent limits will be determined during the remedial design and subject to State and
Federal review and approvals. The limits will be based on BAT performance and water quality
standards and criteria. All residuals from the treatment system will be disposed of according to State
and Federal waste disposal requirements.
Clean Air Act (CAA) - The air emissions from the treatment system will comply with the substantive
permitting process requirements for a minor source under Titles I and V of the CAA. Conditions will
be placed on the emissions to prevent the source from becoming a major source or major
modification. Use of thermal treatment will be provided as needed to ensure compliance.
Resource Conservation and Recovery Act - RCRA Regulations Applicable to Control Devices
Required by the Organic Air Emission Standards (40 CFR Parts 264 and 265 subparts AA and BB).
These subparts, being relevant and appropriate to this action, apply to process vents and equipment
leaks associated with air stripping operations that manage hazardous wastes with organic
concentrations of at least 10 parts per million by weight.
2.10.3 Cost Effectiveness
The selected remedy will permanently remove much of the contamination from portions of the
ground-water and reduce future costs associated with the final cleanup remedy(ies) selected for
OU-4. This alternative is cost effective because with a net present worth cost for one year of
operation of the alternative of $1.9 million, a large quantity of contamination will be removed from
the subsurface. This alternative will also allow for easier implementation of the final remedial action.
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies to the
Extent Possible
Since this is an interim action, the selected remedy is not designed or expected to be final. The
selected remedy utilizes an established treatment technology to address the principal threats posed
by contaminants in shallow ground-water downgradient of the source area and will reduce the amount
and mobility of contaminants present at OU-4.
2-14 May, 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
2.10.5 Preference for Treatment as a Principal Element
VOCs in the removed ground-water will be partitioned to the air phase and thermally destroyed.
Other organic contaminants will be removed by carbon absorption. The preference for treatment as
a principal element has been satisfied.
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES
The selected interim action is the same as the preferred alternative presented in the Proposed Plan for
interim action. There have been no changes relative to the Proposed Plan.
2-15 May, 1995
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-4, ELLSWORTH AFB, SOUTH DAKOTA
Potentially 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
General Pretreatment Regulations
for Existing and New Sources of
Pollution
Guidelines Establishing Test
Procedures for Analyses of
Pollutants
Citations
42 USC 300, f, g
40 CFR Part 141
40 CFR Part 143
Public Law No. 99-
330, 100 Stat. 642
(1986)
33 USC 1251-1376
40 CFR Part 131
40 CFR Part 125
40 CFR Part 403
40 CFR Part 136
Description
Establishes health based standards for
public water systems (maximum
conluminunt 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 responsibilities of federal,
state and local government and of the
POTW in providing guidelines for and
developing, submitting, approving and
modifying state pretreatment programs.
Specifies standards for pretreatment
Specifies analytical procedures for
NPDES applications and reports
ARARType
Chemical
Chemical
Chemical
Chemical
Chemical
Action
Action
Applicability
Relevant and appropriate for
federal Class II aquifers.
Relevant and appropriate.
Relevant and appropriate.
Relevant and appropriate.
Aquifer may be a federal Class
II A (discharge to surface
water)
Applicable; potential discharge
stream or to EAFB WWTP.
Applicable, potential discharge
to EAFB WWTP.
Applicable because of
treatment and discharge of
ground-water.
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-4, ELLSWORTH AFB, SOUTH DAKOTA
(Continued)
Potentially Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria
or Limitation
Clean Air Act
National Primary and Secondary
Ambient Air Quality Standards
National Emission Standards for
Hazardous Air Pollutants
Resource Conservation and
Recovery Act
Land Disposal Restrictions
Hazardous Waste Management
System: General
Identification and Listing of
Hazardous Wastes
Citations
(see below)
40CFRPart50
40CFRPart61
(see below)
40 CFR Part 268
40 CFR Part 260
40 CFR Part 261
Description
Establishes standards for ambient air
quality to protect public health and
welfare
Establishes regulatory standards for
specific air pollutants
Identifies hazardous wastes that are
restricted from land disposal and defines
limited circumstances when a prohibited
waste may continue to be land disposed
Establishes definitions, procedures and •
criteria for modification of any
provision in 40 CFR Parts 260-265
Defines those solid wastes which are
subject to regulation as hazardous
wastes under 40 CFR Parts 262-265
ARARType
Action
Action
Action
Action
Action
Applicability
Applicable.
Applicable. Alternative would
require discharge to air
following treatment.
Relevant and appropriate.
Alternative may include
disposal of residual waste due
to treatment
Applicable.
Applicable.
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-4, ELLSWORTH AFB, SOUTH DAKOTA
(Continued)
Potentially Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria or
Limitation
Standards Applicable to Generators
of Hazardous Wastes
Standards Applicable to
Transporters of Hazardous Wastes
Toxic Substances Control Act
Archaeological and Historic
Preservation Act
National Historic Preservation Act
Executive Order on Protection of
Wetlands
Citations
40 CFR Part 262
40 CFR Part 263
40 CFR Part 761
16 USC 469
40 CFR Part 6.30 l(c)
16 USC 470
E.G. No. 11,990
40 CFR 6.302(a) &
Appendix A
Description
Establishes standards for generators of
hazardous waste
Establishes standards which apply to
persons transporting hazardous waste
within the U. S. if the transportation
requires a manifest under 40 CFR Part
262
Substances regulated include, but are
not limited to, soils and other materials
contaminated as a result of spills
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
Addresses preservation of historic
resources and development of
preservation programs.
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
ARAR Type
Action
Action
Action
Location
Locution
Action/Location
Applicability
Applicable.
Applicable.
Applicable.
Potential ARAR. No known
historic or archaeological
value. Confirmation study
has not been performed.
Applicable.
Potential ARAR.
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-4, ELLSWORTH AFB, SOUTH DAKOTA
(Continued)
Potentially Applicable or Relevant and Appropriate State Standards, Requirements, Criteria and Limitations
Standard, Requirement, Criteria or
Limitation
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 Surface Water
Quality Standards
South Dakota Ground- Water
Standards
Citations
74:26:01:09,24-28
74:03:18:01-17
74:03:19:01-08
74:03:01
74:03:04:02, 10
74:03:02
74:03:15
Description
Establishes permit requirements for
construction, amendment and operation
of air discharge services
Establishes surface water discharge
permit application requirements
Establishes surface water permit
conditions
Establishes requirements for individual
and small on-site wastewater systems
Defines use of Box Elder Creek and
certain tributaries
Establishes surface water quality
standards
Defines ground-water classifications by
beneficial use and sets chemical
standards
ARARType
Action
Action
Action
Action
Action
Action
Chemical
Applicability
Applicable.
Applicable.
Applicable.
Applicable.
Relevant and appropriate.
Applicable.
Relevant and appropriate.
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
ACC:
AF:
AFB:
3.0 LIST OF ACRONYMS AND ABBREVIATIONS
Air Combat Command
Air Force
Air Force Base
ARARs: Applicable or Relevant and Appropriate Requirements
CERCLA: Comprehensive Environmental Response, Compensation and Liability Act
COC: Chemicals of Concern
DNAPL: Dense non-aqueous phase liquid
EAFB: Ellsworth Air Force Base
EP: Extraction Procedure, the EPA's standard laboratory procedure for leachate generation.
EPA: Environmental Protection Agency
FFA: Federal Facilities Agreement
FPTA: Fire Protection Training Area
FTA: Fire Training Area
GPR: Ground Penetrating Radar
HQ: Headquarters
IN SITU: In the original place.
IRIS: Integrated Risk Information System
IRP: Installation Restoration Program
JP-4: Jet Propulsion Fuel Number Four; contains both kerosene and gasoline fractions.
LNAPL: Light Non-Aqueous Phase Liquid
MCL: Maximum Contaminant Levels
mgd: Million Gallons per Day
V:\3SXn\XZPOKTStfrMLSOlHRODtfA
3-1
May. 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base, South Dakota
Micrograms per liter
Milligrams per liter
Mean Sea Level
Non Aqueous Phase Liquid
National Oil and Hazardous Substances Contingency Plan
National Environmental Policy Act
National Pollutant Discharge Elimination System
National Primary Drinking Water Regulations
National Priorities List
Operable Unit
Symbols for oil and grease
Polynuclear Aromatic Hydrocarbon
Polychlorinated Biphenyl; liquids used as a dielectrics in electrical equipment
Perchloroethylene; liquids used in degreasing or paint removal.
Public Law
Parts per million by weight
Resource Conservation and Recovery Act
Remedial Investigation/Feasibility Study
Superrund Amendments and Reauthorization Act
Superfund Accelerated Cleanup Model
Semivolatile Organic Compound
1,1, 1,-Tetrachloroethane
Trichloroethylene
Target Compound List
mg/l:
MSL:
NAPL:
NCP:
NEPA:
NPDES:
NPDWR:
NPL:
OU:
O&G:
PAH:
PCS:
PCE:
PL:
ppm:
RCRA:
RI/FS:
SARA:
SACM:
SVOC:
TCA:
TCE:
TCL:
3-2
May, 1995
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Final Record of-Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base. South Dakota
TCLP: Toxicity Characteristic Leaching Procedure
IDS: Total Dissolved Solids
TOC: Total Organic Carbon
TSD: Treatment, storage or disposal sites/methods
USAF: United States Air Force
USEPA: United States Environmental Protection Agency
USD A: United States Department of Agriculture
USFWS: United States Fish and Wildlife Service
USGS: United States Geological Survey
VES: Vertical Electrical Sounding
VOC: Volatile Organic Compound
WQC: Water Quality Criteria
WWTP: Wastewater Treatment Plant
W: \S5HnVUfOIOS(nNAIS0V4ROD.U'A
3-3
May, 1995
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Final Record of Decision for Interim Action at Operable Unit 4
Ellsworth Air Force Base. South Dakota
APPENDIX A
FIGURES
MOV, 1995
-------
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ELLSWORTH AF3
FIGURE 2-1
AREA LOCATION MAP
ELLSWORTH AFB. SOUTH DAKOTA
PREPARED FOR U.S. ARMY CORPS OF ENGINEERS
-------
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OU
OU
OU
OU
OU
OU
OU
OU
OU
OU
OU
OU
LEGEND
OPERABLE UNITS
FIRE PROTECTION TRAINING AREA
LANDFILLS I S 6
LANDFILL 2
LANDFILL 3
LANDFILL 4
LANDFILL 5
LOW LEVEL RADIATION WASTE BURIAL AREA
EXPLOSIVE ORDNANCE DISPOSAL AREA 8 PRAMITOL
OLD AUTO HOBBY SHOP AREA
NORTH HANGAR COMPLEX
BASEWIOE GROUND WATER
HAROFILL NO.I
NOTE;
.CITY,
SOURCE: OU-4 Rl REPORT
-------
fiDFILL NO. 3
T
GROUND WATER
EXTRACTION WEL
'ilTYP. OF 5»
CONCENTRATIONS
RBONS
---.CHLORlNATEl
OFF BASE PLUME
GROUND WATER
! EXTRACTION WELL
ITYP. OF 31
FIGURE 2-3
Oil-4 MAP
EiiswoHiM Are. sou in
PRfl'*Rri) FOH U.S. ARUT CORPS 01 INI.INI Id
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Final Record oj'Decision for Interim Action at Operable L'nit 4
Ellsworth Air Force Base. South Dakota
APPENDIX B
RESPONSIVENESS SUMMARY
-------
Responsiveness Summary
Operable Units One and Four
Appendix B
Responsiveness Summary
Interim Actions at Operable Units One and Four
Ellsworth Air Force Base, South Dakota
1. Overview
Ellsworth Air Force Base (EAFB), with the approval of the U.S. EPA and State of South Dakota
Department of Environment and Natural Resources (SDDENR), held one Public Meeting to cover both
of the interim action Proposed Plans for Operable Units (OUS) 1 and 4. This procedure was agreed upon
due to the similarities of the two actions and the use of one treatment plant for cleaning up the ground
water. As a result, the comments received at the Public Meeting are, for the most part, related to both
OUs. Rather than attempt to separate these comments and answers by OU, identical Responsiveness
Summaries were used for each ROD.
The public has reviewed the Proposed Plans and the interim remedial actions and is in general support
of implementing the interim actions.
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 United States Air
Force's (USAF) 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.
B-l May, 1995
-------
Responsiveness Summary
Operable Units One and Four
Appendix B
• Administrative Record. An Administrative Record for information was established in
Building 8203 at EAFB. This repository contains information used to support USAF
decision-making.
• Information repositories. An administrative Record outline is located at the Rapid City
Library (public repository).
Community Relations Plan (CRP). The draft final CRP was submitted on October 26,
1992 to the EPA and the State of South Dakota. The EPA and State have approved the
CRP. An update to this plan will be prepared in 1995.
• Restoration Advisory Board (RAB). The RAB has been formed to facilitate public
involvement in the cleanup and has meetings 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 the
Base and updated regularly.
• Fact sheets. A fact sheet describing the status of the IRP at the Base 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 the Base 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.
The Proposed Plans for these interim actions were distributed to the mailing list addressees for their
comments and additional copies of the Proposed Plans were available at the April 18, 1995 public
meeting. A transcript of comments, questions and responses provided during the public meeting was
prepared.
The USAF established a public comment period from March 25, 1995 to April 24, 1995 for interested
parties to review and comment on interim cleanup alternatives considered and described in the Proposed
Plans for OU-1 and OU-4. The Proposed Plans were prepared by the USAF in cooperation with the EPA
and SDDENR.
The USAF also held a public meeting at 8:00 p.m. on April 18, 1995 in the 28th Bomb Wing Auditorium
at EAFB to outline the proposed interim remedies to reduce risk and control potential hazards at the two
OUs.
w:\sfxn\nzpaiaRrBiusiov4ROD.erA . B-2 May, 1995
-------
Responsiveness Summary
Operable Units One and Four
Appendix B
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 and of written comments received during the
public comment period did not indicate community objections to the proposed interim actions.
The majority of the comments received during the public meeting were in the form of questions about
the interim actions (what would be done, how it would done, when it would be started and completed
and what effects the actions might have); questions about existing data and collection of additional
data; and, questions about on-going Base operations. Representatives of the USAF and USEPA were
available to provide answers to the questions and also provided an overview presentation during the
meeting to describe the interim actions.
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 April 18, 1995 public meeting. Written comments received during the public
comment period are so noted at the end of the comment summaries.
Comment 1. Eris Johnson
Asked why ground water quality sampling results collected in 1990 seem so much different
(lower) compared to results from samples collected through 1994.
Response 1: The data collected in 1993 and 1994 was subjected to rigorous quality control and
quality assurance requirements that were mandated for this project and the analyses
were performed in accordance with approved US EPA methods. It is possible
different types of tests and methods were used in 1990 which could cause differences
in the reported results. Differences in sampling locations, natural concentration
variations and natural degradation of some of the organic compounds over time could
also have resulted in the differences.
Comment 2. Eris Johnson
Asked if the proposed interim actions would remove contaminants from soils.
Response 2: Removal and treatment of both soil (by soil vapor extraction) and ground water
contaminants will occur during the interim actions at OU-1; removal and treatment
of ground water contaminants will occur during interim actions at OU-4. Remaining
contamination at OU-4 will be evaluated as part of the final action at OU-4.
B-3 May, 1995
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Responsiveness Summary
Operable Units One and Four
Appendix B
Comment 3. Eris Johnson
Expressed concern about wind-home contaminants causing exposure and risk to downwind,
off-Base residents during construction activities for the interim actions.
Response 3: Air quality monitoring will be conducted as construction proceeds and, if hazardous
levels are detected, measures will be taken to ensure operations do not endanger on-
site workers or off-Base residents.
Comment 4. John Luxem
Asked if his currently out-of-service well west of OU-4 might be useful as a ground water
extraction well.
Response 4: Possible use of the well for that purpose will be evaluated as part of the interim action
for OU-4; if the well cannot be used as an extraction well, a new extraction well will
be constructed in the same general vicinity.
Comment 5. Pat O' Gorman
Asked what the time-frame was for starting the interim actions.
Response 5:
The USAF plans to begin construction at the end of May, 1995.
Comment 6. Jan Deming
Asked if the monitoring and residential wells would continue to be sampled during the interim
cleanup actions.
Response 6: Sampling of residential wells has been done hi the past; installation of the water line
for some residents will decrease the need for future sampling of domestic wells in
those areas. However, current plans are to continue off-Base sampling through the
first quarter of 1996.
Comment 7. Marsha Amo
Asked how ground water flow directions were determined, whether flow directions are
affected by rainfall and whether ground water contamination was affecting surface water
(creeks) in the area.
Response 7: Ground water elevations were measured over time and the results were plotted on
maps. A triangulation technique is then used to determine flow direction. This is the
standard method of determining flow direction. In general, flow direction usually
w:\sntnvieroiasfnuisatHRODjrA B-4 May, 1995
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Responsiveness Summary
Operable Units One and Four
Appendix B
follows the topography of the land; i.e. from higher points to lower points. Data from
pumping tests was used to estimate the rate that ground water flows through the
subsurface material. Precipitation can affect the rate of flow at any given time but not
necessarily the direction of flow. Surface water contamination was found to be mainly
caused by surface water runoff rather then by ground water contamination.
Comment 8. Marsha Amo
Asked what kinds of chemicals are used to wash off the Base runways.
Response 8: Potassium acetate is used infrequently (once last year for instance) for deicing the
runways. In addition, an EPA-approved detergent is used two or three times a year
to wash rubber off the runways. It is applied with spraying equipment, scrubbed with
brushes and vacuumed up when the USAF crew is done.
Comment 9. Phyllis Engleman
Asked if the city (Box Elder) wells had been tested for contaminants from the Base and if they
were in any danger.
Response 9: The Box Elder city wells are all well outside of the known limits of Base-related
contamination and are not in any danger of being affected by contamination from the
Base.
Comment 10. Jan Deming
Asked how close wells could be placed in relation to OU-1 and OU-4 and whether the county
was involved in placing restrictions on well development in the area.
Response 10: Even with the aid of computer models available, it would be very difficult to predict
what a safe distance might be for well placement in the area. The USAF has no
control over off-Base activities and residents are encouraged to work with the county
concerning development in the area.
Comment 11. Lee Weiraer
Asked what kinds of systems, products and procedures have been put into use at the Base to
prevent future, costly releases of materials from the Base?
Response 11: Several changes have been implemented to more tightly control the use and
distribution of chemicals and other materials at the Base. Examples include use of a
centralized purchasing and distribution system for materials to control the types and
amounts of chemicals being used for a given purpose. Education and recycling
programs are also in place to reduce use of materials and to encourage responsible
handling of the materials in use.
B-5 May, 1995
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Responsiveness Summary
Operable Units One and Four
Appendix B
Comment 12. Eris Johnson
Asked if water being provided by the Base to residents in the area was free or whether it had
to be purchased and whether the Base would provide water to future new homes in the area.
Response 12: At the current time, water is being provided at no charge to the residents and the Base
is evaluating the issue of providing water to future new homes.
Comment 13. Mary McGriff
Asked whether drainage area near the Base gate (Crum property) had been sampled and
whether or not the discharge water from the Base wastewater treatment plant was a concern.
Response 13: Sampling in that area is planned but has not yet been scheduled. The discharge from
the treatment plant is monitored regularly and must meet discharge restrictions
required by US EPA.
Comment 14. John Osnes
Asked what the anticipated duration of the interim actions would be.
Response 14: The duration is difficult to estimate at this time and will be different at each of the
sites with some sites requiring longer amounts of time than others. The progress arid
effectiveness of each action will be monitored closely and adjusted as needed to
reduce the problems as quickly as possible.
Comment 15. Eris Johnson
Asked about the pumping rate for the ground water extraction systems and the potential for
the eventual dewatering of private wells to the south of the Base.
Response 15: The total design withdrawal rate is on the order of from 50 to 100 gallons per minute.
Water levels in the extraction area will go down over time which will accelerate the
biological degradation of contaminants in soils as contaminated ground water is being
removed and treated. If off-Base wells are adversely impacted by the interim actions,
the USAF will take measures to supply water to affected parties.
Comment 16. Jim Corbett
Asked if the extracted ground water would be pumped into Box Elder Creek and whether the
proposed technology had been used successfully elsewhere.
Response 16: All of the extracted water will be treated in the treatment facility that will be
constructed and the treated water must meet applicable US EPA standards before
tr:\is303\jtEroja5\riNALsawKOD.iFA B-6 May, 1995
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Operable Units One and Four
Appendix B
being discharged to an unnamed tributary that drains to Box Elder Creek. Pump and
treat ground water systems and soil vapor extraction systems are standard
technologies in use throughout the nation today. A regional example of a similar
system is operating at the Hill Air Force Base near Salt Lake City, Utah
Comment 17. Eris Johnson
Asked if air stripping is safe.
Response 17: Yes; if the air from the stripper is contaminated at high levels, it has to be treated
(burned essentially) using a thermal oxidizer before the air is discharged to the
environment.
Comment 18. Marsha Amo
Asked if there are plans to remove and clean contaminated soil.
Response 18: Soil removal and treatment is not part of the proposed interim action but will be
evaluated during consideration of the future final remedy.
Comment 19. Bob Mallow
Asked if fuel-contaminated soil could be treated by aerating it.
Response 19: Yes it can, depending on soil conditions and that is one of the alternatives being
considered in review of the final remedy.
Comment 20. Jim Corbett
Asked how contamination levels at Ellsworth compared to contamination at other Air Force
Bases.
Response 20: Some Bases have more serious problems while other Bases have less serious
problems. Ellsworth is fortunate to have the funding in place to investigate and begin
correcting contamination problems now.
Comment 21. Marcia Elkins
Asked how the extracted water would be transported to the treatment facility.
Response 21: The water will be pumped through double-walled pipe to the treatment plant.
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Operable Units One and Four
Appendix B
Comment 22 (Written). Michael McMahon, Western Pennington Flood Management
Commission, Rapid City, SD - letter of April 11,1995
Asked if it would be feasible to inject treated ground water into a series of wells upgradient
of the contaminant 'plume to promote more rapid cleanup or, alternatively, providing the
treated water to local ranchers and fanners for livestock or irrigation use.
Response 22: Because of the variability in the near surface geology at Ellsworth and the desire to
implement the interim actions as quickly as possible (without the time for studies to
adequately evaluate and implement a reinjection system), reinjection was not
considered for the interim actions. Reinjection would need to be studied closely
because of concerns over the potential for negative impacts. Reinjection would
change the local ground water flow environment and could result hi the spread of
contamination. The feasibility of reinjection will be evaluated for the final actions at
OU-1 and OU-4. The near-Base residents to the south and west of the sites are
currently provided with water supplied by the Base. As such, they would have no
current need to use the treated water for livestock or irrigation purposes.
Comment 23 (Written). Perry H. Rahn, Ph.D., P.E., Professor, South Dakota School of
Mines and Technology, Rapid City, SD - letter of April 20,1995
Suggested using site geologic data to make isopach maps of the subsurface gravel unit and
using a mathematical model to better define the ground water flow environment.
Response 23: The interim action ground water extraction components were designed with the aid
of a simple analytical computer model. The gravel thickness varies greatly across the
Base and there is a significant level of heterogeneity within both the gravel and the
fractured shale units which make up the aquifer. The hydraulic conductivity and
saturated thickness vary greatly at any given operable unit and even between adjacent
borehole locations due to a significant variation in clay content in the gravel and
fracturing in the shale. For these reasons, it may be difficult to make a useful isopach
map and may not be practical to perform more rigorous modeling. More information
will become available with the operation of the interim action ground water extraction
components and that information will be used to design the final remedial action
components at the Base.
Comment 24 (Written). James R.D. Cox, CET, Quality Assurance Manager, Engineers
Technical Services, Plantation, Florida - letter of April 24,1995
The commenter indicated that in 1985, a contractor performing runway rehabilitation and
upgrading at the Base placed soil, concrete and asphalt debris on property located west of
OU-1 and now owned by the commenter and Michael J.D. Cox. Concern was expressed that
the property is located in close proximity to an area being investigated for ground water
contamination, material from a Superfund site had been placed on the property and no
sampling or testing was performed on the property.
IT:\3S20:W£fOXTSVINALS&WRODlfA B-8 May, 1995
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Operable Units One and Four
Appendix B
Response 24: An extensive remedial investigation was performed at Ellsworth in 1993 and 1994
which included the collection of numerous soil, sediment, surface water and ground
water samples. The USAF, with the concurrence of the USEPA and the SDDENR,
believes sufficient data was collected to determine the extent and magnitude of
contamination associated with OU-1 and OU-4 and to develop several effective
alternatives for cleaning up the contamination. Review of the information collected
during the investigation indicated ground water contaminant plumes are present to the
south and southwest of the southwest comer of OU-4. The plume to the southwest
of OU-4 was shown to be located east of the apparent location of the commenter's
property. The interim action proposed for OU-4 will address ground water
contamination to the south of OU-4. The final action for OU-4 will address cleanup
of the plumes located to the south and to the southwest of OU-4. Authorized or
unauthorized placement of construction debris on the commenter's property is not
part of either the interim remedy or the final remedy selection process and would be
more appropriately addressed by other means available to the commenter.
4. Remaining Concerns
Based on review of the transcript of the oral comments received during the public meeting and of the
written comments received during the public comment period, there are no outstanding issues
associated with implementation of the proposed interim actions. Remaining concerns related to
implementation of the interim actions will be addressed by: performing air monitoring during
construction and operation of the system components as needed to protect on-site workers and off-
Base residents; collection of samples from a drainage area near the Base gate; and, collection of
system operation and monitoring data to determine the effectiveness of the interim actions in the
future.
B-9 Mav, 1995
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