EPA Superfund
Record of Decision:
Ellsworth Air Force Base,
Operable Unit 1, SD
5/16/1995
PB95-964413
EPA/ROD/R08-95/108
February 1996
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Final
Record of Decision for
Interim Action at Operable Unit 1
The Fire Protection Training 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 1
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, LOCATION, AND DESCRIPTION 2-1
2.2 SITE HISTORY AND REGULATORY OVERSIGHT ACTIVITIES 2-1
2.2.1 Historical Practices 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 2-4
2.5.1 Soils 2-5
2.5.2 Ground-water 2-5
2.6 OU-1 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 2-9
2.8.2 Compliance with ARARs 2-9
2.8.3 Long-Term Effectiveness and Permanence 2-11
2.8.4 Reduction of Toxicity, Mobility, and Volume Through Treatment 2-11
2.8.5 Short-Term Effectiveness 2-12
2.8.6 Implementability . 2-12
2.8.7 Cost 2-13
2.8.8 State Acceptance 2-13
2.8.9 Community Acceptance 2-13
2.9 SELECTED ALTERNATIVE 2-13
2.10 STATUTORY DETERMINATIONS 2-14
2.10.1 Protection of Human Health and the Environment 2-14
2.10.2 Compliance with ARARs 2-14
2.10.3 Cost Effectiveness 2-15
2.10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Extent Possible 2-16
2.10.5 Preference for Treatment as a Principal Element 2-16
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES 2-16
3.0 LIST OF ACRONYMS AND ABBREVIATIONS 3-1
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base, South Dakota
LIST OF TABLES
Table 2-1 Evaluation of Federal and State ARARs That Apply to OU-1 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-1 Map
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
1.0 DECLARATION
1.1 SITE NAME AND LOCATION
Operable Unit 1 (OU-1), the former Fire Protection Training Area (FPTA), 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-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 Region Vm (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-1 and is the first ROD for EAFB. The ROD for the final action for OU-1 will
be prepared in April 1996.
The selected interim action remedy for soil and ground-water contamination cleanup at OU-1
consists of:
soil vapor extraction (SVE),
ground-water removal by wells and an existing interceptor trench,
treatment of soil gas, condensate, and ground-water, and
surface discharge of treatment effluent
SVE wells will be installed in the burn-pit area of the former FPTA to remove source-area
contamination from the soil. Some of the SVE wells will also be constructed to allow for the removal
of contaminated ground-water beneath the bum-pit area. An existing interceptor trench, located
immediately downgradient of the bum-pit area, will also collect and remove contaminated ground-
water. The removed soil gas, condensate, and ground-water, containing volatile organic compounds
(VOCs) and petroleum related hydrocarbons, will be treated. The liquid treatment will consist of
gravity separation, air stripping, solids filtration, and use of liquid phase granular activated carbon.
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Final Record of Decision for Interim Action at Operable Unit I
Ellsworth Air Force Base, South Dakota
The soil gas and air-stripper off-gas will be treated by thermal oxidation. The liquid effluent from this
treatment system will be discharged to a natural surface water drainage. The discharge will be in
compliance with the requirements 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 1
Ellsworth Air Force Base. South Dakota
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-1, 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-1.
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-1.
1.6 SIGNATURE AND AGENCY CONCURRENCE ON THE REMEDY
THAD A. WOLFE Date
Lieutenant General, US
Vice Commander
L. DUPP&Y, DiVpdtor ' Bate
Hazardous Wast^f^dnagement Division
US Environmental Protection Agency Region VIII
retary . Date
Department of Enviroiment and Natural Resources
State of South Dakota
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base, South Dakota
2.0 DECISION SUMMARY
2.1 SITE NAME, LOCATION, AND DESCRIPTION
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
(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.
OU-1 contains the former Fire Protection Training Area (FPTA) and is located in the southwestern
segment of EAFB, northwest of the alert apron and east of Kenney (formerly Bismarck) Road (Figure
2-2). OU-1 covers approximately 10 acres and consists of a centrally located bermed burn pit, a steel
aircraft mock-up, and surrounding land. No containment (liner) was installed under the former
FPTA. The burn-pit area of the FPTA is the source area of contamination.
Both humans and livestock have used shallow (less than 70 feet below grade) ground-water in the
areas south and west of OU-1. 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 Distribution System obtains its water from two deep, high-capacity, wells
and four surface water intakes along Rapid Creek.
Surface water from OU-1 drains to two drainage ditches which flow to a retention pond. Pond 001.
Pond 001 also receives drainage from the southern area of EAFB including some of the hanger
complex, the south dock area of the flight line, portions of adjoining taxiways, and runways. Outflow
from Pond 001 flows off-Base to a stock dam located several hundred feet south of OU-1.
In terms of ecological value, the natural environment at OU-1 has been highly altered by activities at
the former FPTA Notwithstanding the high level of alterations, habitat features such as grassy fields,
weedy fields, and wetlands are prevalent in the eastern and southern sections of the OU. These could
be used intermittently by some animal species.
2.2 SITE HISTORY AND REGULATORY OVERSIGHT ACTTVmES
2.2.1 Historical Practices
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 II 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.
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
The various training activities conducted at EAFB have included fire-protection training for Base fire-
fighting personnel for preparedness in the event of fires associated with fueling spills or aircraft
accidents. These training exercises took place at the former FPTA from 1942 to 1990. A steel
aircraft mock-up located in the burn pit of the former FPTA was set on fire and extinguished for
training exercises. The location of the burn area within the former FPTA has changed several times
over the years. The training exercises conducted at the FPTA involved simulation of aircraft fires and
spills and consisted of dispersing various fuels, oils, and solvents within the bum-pit area and
subsequently igniting and extinguishing the fire. Extinguishing chemicals used during the fire-training
exercises have included aqueous-film-forming foam, halon, protein-foams, carbon dioxide, dry
chemicals and chlorobromomethane. The former FPTA at OU-1 is no longer in use and all training
activity now takes place at the new FPTA.
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 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 n of the IRP investigation, field activities included soil vapor surveys; geophysical surveys;
soil borings; monitoring-well installation; hydrogeologic testing; and sampling and analysis of soils,
ground-water, sediment, tank contents, and water from storm drains. A ground-water recovery
system and treatment plant was installed, operated, and tested during September and October 1990
at OU-1. The purpose of the this system was to determine the feasibility of using a ground-water
pump and treat system at OU-1.
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 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 NCR 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-1. 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.
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Final Record of Decision for Interim Action at Operable Unit I
Ellsworth Air Force Base, South Dakota
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.
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.
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 in the Responsiveness
Summary, which is part of this ROD.
This ROD is based on the contents of the Administrative Record for 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
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Final Record of Decision for Interim Action at Operable Unit I
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Oil and Hazardous Substances Pollution Contingency Plan (NCP). The remedial investigation and
focused feasibility study reports and the Proposed Plan for OU-1 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
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 Hardfill No. 1
This ROD is for an interim remedial action (IRA) at OU-1 and is the first ROD for EAFB. The
objective of the IRA at OU-1 is to reduce the immediate risks posed by the contaminants in the
deeper subsurface soils of the burn-pit areas of the FPTA and to prevent the movement of
contaminants to shallow ground-water. The IRA also includes removal and treatment of contaminated
ground-water immediately downgradient of the bum-pit area. This will contain the portion of the
ground-water with the highest contaminant concentrations. Implementation of the IRA may result
in partial restoration of the shallow ground-water immediately downgradient of the burn-pit area and
reduce the concentration of contaminants in subsurface soils in the bum-pit area. The IRA does not
fully address risks posed by contaminants in surface and near surface soils and the remainder of the
contaminants in the shallow ground-water.
This action is not the final response action for OU-1; the ROD for the final action at OU-1 is due in
April 1996. Additional remedies will be implemented at OU-1 during the final action to clean up the
remaining contaminated media. The ERA will be consistent with any future actions.
2.5 SITE CHARACTERISTICS
This section describes the nature and extent of contamination as a result of past activities conducted
at the OU (Figure 2-3).
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
2.5.1 Soils
Soils at OU-1 contain JP-4 (jet fiiel), benzene, toluene, ethylbenzene and xylene (BTEX), and
chlorinated volatile organic compounds (VOCs) as depicted in the following table.
Contaminant
JP-4
Total BTEX
Total chlorinated VOCs
Vadose Zone Soil (A*g/kg)
100,000s to 1,000,000s
ND to 100,000s
ND to 10s
Capillary Fringe Soil
(Mg/kg)
100,000s to 1,000,000s
1,000s to 10,000s
ND to 100s
JP-4 concentrations are much higher than other compounds. The areal distribution of JP-4
contamination generally reflects the extent of all the contaminants in the soil (Figure 2-3). The highest
concentrations of soil contamination exist in the burn-pit area, which is the source area of
contamination.
2.5.2 Ground-water
Shallow ground-water exists at OU-1 and flows in the southern direction. An 800 feet thick layer of
impermeable clays and silts limits the shallow aquifer from infiltrating to deeper ground-water
aquifers. Therefore, these deeper aquifers were not affected by contaminants present at OU-1.
The past practices at the FPTA have resulted in the contamination of the shallow aquifer. VOCs such
as trichloroethylene (TCE), benzene, perchloroethylene (PCE), 1,1-dichloroethylene (1,1-DCE) and
1,2-dichloroethane (1,2-DCA) exist in the shallow ground-water at or above established Safe
Drinking Water Act Maximum Contaminant Levels (MCLs) at OU-1. Benzene represents the extent
of organic compounds exceeding MCLs. The ground-water contamination does not extend beyond
the Base boundary (Figure 2-3).
Dense non-aqueous-phase liquids (DNAPLs) are not present in OU-1 ground-water. However, light
non-aqueous phase liquids (LNAPLs) (JP-4 and related BTEX compounds) were found in ground-
water at the northern and southern ends of the FPTA.
2.6 OU-1 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-1;
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Final Record of Decision for Interim Action at Operable Unit 1
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(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 values of the COCs; and,
(7) Uncertainties in the assessments of exposure, toxicity, and general risks.
Noncarcinogenic and carcinogenic risks were calculated for the following four potential exposure
groups:
(1) Current Base personnel engaged in site inspection who are exposed to surface soil, surface
water and sediment;
(2) Future residents who are exposed to surface soil and ground-water;
(3) Future adolescents who are exposed to surface water and sediment through wading
activities; and,
(4) Future adult construction workers who excavate for building residences.
Noncarcinogenic Risks
Unacceptable noncarcinogenic risks at OU-1 exist for the future residential adult who either ingests
shallow ground-water or showers with shallow ground-water. Risk is driven by the volatile compound
1,2-dichloroethene (1,2-DCE).
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 1 x 10"*.
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:
Carcinogenic risks indicate the sources of unacceptable risks (in excess of 1 x 10"6) are due primarily
to a large number of contaminants in the ground-water. These risks may be incurred during ingestion
or showering with contaminated ground-water by a future resident.
In addition, there is unacceptable risk associated with the ingestion of contaminants in the surface soil
(ingested by a future residential adult) and combined risks from dermal contact with surface soil.
Many different types of compounds contribute to the unacceptable risk.
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 as follows:
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
A variety of animal species could forage in OU-1 habitats. These range from the bentnic
invertebrates and amphibians inhabiting the drainage channels to birds and mammals. Any of
these are potential receptors of contaminants detected at the OU.
Rare, threatened, or endangered species are unlikely to use OU-1 for more than very transient
habitat. Most of these species would not be expected to occur on OU-1 at all because of the
highly altered natural environment and lack of habitat.
Terrestrial vegetation and soil fauna communities sampled outside the burn pit and surrounding
gravel area do not reveal characteristics indicating chemical-related impacts. This finding is
consistent with the relatively low levels and limited distribution of contaminants in soil outside
the burn-pit area, and with the active and disturbed nature of the site which appears to be the
primary influence of the biotic community structure.
Interim Action Risk Reduction
The IRA will reduce risks associated with VOCs in subsurface soils present in the capillary fringe
beneath the burn pit by reducing VOC concentrations in those soils. Reducing the VOC
concentrations in the subsurface soils will also result in reduction of the amounts of contaminants
currently available to move downward into the shallow ground-water beneath the burn pit. Removal
and treatment of contaminated ground-water downgradient of the bum pit will result in reduced
concentrations of contaminants in that area and reduce the rate of contaminant movement.
Subsequent actions are planned to fully address the threats posed by contaminants at OU-1. Because
this remedy will result in hazardous substances remaining on 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-1.
2.7 DESCRIPTION OF ALTERNATIVES
Alternative 1
No Action
The no action alternative represents the baseline condition at OU-1 and refers to taking no further
action until the final remedy is selected for OU-1.
Alternative 2:
soil vapor extraction (SVE),
sou vapor extraction (5>viLj,
ground-water removal using wells and an existing interceptor trench,
treatment of ground-water, condensate, and soil gas, and,
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
Soil Vapor Extraction
The area targeted for treatment by SVE is the burn-pit area (Figure 2-3). The number and placement
of the SVE wells will be further evaluated during the design. A gravel layer that underlies the burn-pit
area will be treated by SVE system. This gravel layer includes both vadose zone (unsaturated zone)
and capillary fringe zone (saturated zone where ground-water is held up by capillary forces against
the force of gravity) soils. The IRA will not address fill material in the bum-pit area near the surface
or portions of the vadose zone in native silty clay above the gravel layer.
Ground- Water Removal
Ground-water wells will also be located in the burn-pit area. These wells will be located at some of
the SVE well locations, possibly within the same well or borehole. The number and placement of
wells will be evaluated during the design. The ground-water wells will collect and remove the most
highly contaminated ground-water at OU-1 which is located beneath the burn-pit area. The ground-
water wells will also dewater the capillary-fringe gravelly-soil layer, allowing those soils to be treated
by SVE.
An existing interceptor trench will also collect a highly contaminated portion of ground-water
immediately downgradient of the bum-pit area. The existing interceptor-trench sump will be provided
with new pumping equipment. Pumping rates based on the 1990 treatability study involving the
interceptor trench are anticipated to be adequate to remove ground-water for this alternative.
Treatment
Extracted soil gas, and condensate from the SVE wells, and ground-water removed by wells and the
interceptor trench will contain both VOCs and petroleum hydrocarbons and 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. Soil gas and air stripper off-gas
will be treated using a thermal oxidation unit.
Discharge of Treatment Effluent
The treatment-plant water effluent will be discharged into a 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 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 Primary Discharge Elimination System (NPDES) permit (SD-0000281). Off-
gas 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 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.
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
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 (SVE and ground-water removal and treatment) provides for removal of VOCs from
soils in the capillary fringe beneath the FPTA and from shallow ground-water collected from wells
in the burn-pit area and from the existing trench. This will reduce potential risks to human health.
This alternative will also prevent the transport of additional contaminants from the burn-pit area.
The treatment system to be used in alternative 2 will result in a permanent reduction in source
contamination in the capillary-fringe area. In addition, liquid removal will effectively limit the degree
of downgradient transport of contaminants. As a result, Alternative 2 will decrease contaminant
concentrations and the lateral extent of contaminant movement that present a potential health risk.
During the installation of the interim remedy, the RI/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:
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 (SVE and ground-water removal and treatment):
w:\ii3ai\ufOKKfnuLsaviKOD.tfA 2-9 May. 1995
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Final Record of Decision for Interim Action at Operable Unit I
Ellsworth Air Force Base. South Dakota
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 burn-pit area and the gravelly soils in the capillary fringe
beneath the burn-pit area. 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-1 will be
conducted during implementation of the IRA to determine the progress and effectiveness of the IRA.
Currently, there are no Federal chemical-specific ARARs for contaminated soils. The State of South
Dakota has set the maximum allowable JP-4 (as total petroleum hydrocarbons) concentration at
10,000 Mg/kg for OU-1. The interim action waiver is being invoked for the chemical-specific ARARs
in soil and ground-water.
Location Specific ARARs:
National Historic Preservation Act (NHPA) of 196616 USC470 etsea) - Section 110 requires that
any restoration activities will not effect 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 containments 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 determine 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.
*:\s}im\REK>KTS(riNAisouiRoD.trA 2-70 Mov. 1995
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base, South Dakota
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 soil and 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 most of the VOCs
from the capillary fringe gravelly soils beneath the burn-pit area (source area) at the OU. In addition,
removing ground-water immediately downgradient of the source area will prevent further
downgradient movement of contaminants in ground-water from the source area while the final
remedy for the OU is evaluated. Contaminants in surface and near surface soils which overlie the
gravelly soils at OU-1 must be addressed in the final remedy.
Due to uncertainties in the hydrogeological characteristics of the shallow aquifer, the interim action
is only focusing on containment of the source-area 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.
Potential inorganic contaminants must be determined and addressed by the final action implemented
at OU-1.
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 organic
contaminants in the capillary fringe gravelly soils beneath the bum-pit area and in ground-water
immediately downgradient of the source area.
The mass of VOCs in the gravelly soils beneath the source area will be permanently reduced through
treatment and the potential for further movement of VOCs to the ground-water beneath the source
area will be decreased. Also, the mass of VOCs in the removed ground-water will also be
permanently reduced through treatment and the collection of ground-water near the source area will
prevent further downgradient movement of contaminants. VOCs in the removed soil gas and 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.
w:\ii2ta\KiPOMSfiMLsouiROD.cfA 2-11 May. 1995
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Final Record of Decision for Interim Action at Operable L'mt I
Ellsworth Air Force Base. South Dakota
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 SVE and 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 placed back onto the burn-pit area of the FPTA, graded, covered with clean fill and
left in-place. All air discharges from the SVE treatment operations will be thermally treated to destroy
the VOCs. No adverse environmental impacts are expected from implementation of Alternative 2 and
risks associated with OU-1 source areas will be reduced. Ground-water monitoring will be conducted
to assess the effectiveness of the alternative in reducing contaminant concentrations in shallow
ground-water downgradient of the source area.
2.8.6 Implementabiliry
Alternative 1 offers no implementability concerns since no action will take place.
Alternative 2 will utilize proven "off-the-shelf' technology and standard construction methods. SVE
is the primary presumptive remedy identified in EPA guidance for sites with soils contaminated with
VOCs. 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 in the burn-pit area
allows access to 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. Off-Base
access for implementation of this IRA is not required since all SVE wells and the existing ground-
water recovery trench are located on the Base.
Uncertainties associated with this operation involve methods to maximize the effectiveness of soil gas
and 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 discharge from
Pond 001 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, State, and local air quality requirements.
w:\SMUvtifonTarnuLSiouiROD.epA 2-12 May, 1995
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Final Record of Decision for Interim Action at Operable Unit 1
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 $9,500 per quarter for a present worth cost of $36,000.
Alternative 2 is estimated to cost $1,266,000 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. The present worth cost for one year of
operation is approximately $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 adequate responses to
the State's comments were incorporated 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 (SVE
and ground-water removal and treatment) is the most appropriate alternative for the interim action.
The major components of Alternative 2 are:
soil vapor extraction (SVE),
ground-water removal using wells and an existing interceptor trench,
treatment of ground-water, condensate, and soil gas, and
surface discharge of treatment effluent.
This alternative will remove some of the source contamination and contain portions of the
downgradient ground-water contamination.
SVE wells will be installed in the burn-pit area of the former FPTA to remove source-area
contamination from the soil. Some of the SVE wells will also be constructed to allow for the removal
of contaminated ground-water beneath the burn-pit area. An existing interceptor trench, located
immediately downgradient of the burn-pit area, will also collect and remove contaminated ground-
water. The removed soil gas, condensate, and ground-water, containing volatile organic compounds
(VOCs) and petroleum related hydrocarbons, will be treated. The liquid treatment will consist of
gravity separation, air stripping, solids filtration, and use of liquid phase granular activated carbon.
2-13 May. 1995
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base, South Dakota
The soil gas and air-stripper off-gas will be treated by thermal oxidation. The liquid effluent from this
treatment system will be discharged to a natural surface water drainage. The discharge will be in
compliance with the requirements 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.
Remediation Goals
This alternative will reduce organic contaminant concentrations in portions of OU-1 soils and ground-
water, control the transport of source area contamination in the bum-pit area to ground-water arid
reduce 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 final but the selected 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 remedy meets each of these requirements is discussed in the
sections below. The statutory determinations for the final cleanup remedy for OU-1 will be provided
in the ROD for the final cleanup action, which is due in April 1996.
2.10.1 Protection of Human Health and the Environment
The selected remedy provides for removal of VOCs from subsurface gravelly soils in the capillary
fringe beneath the source area and for removal and treatment of organic contaminants in shallow
ground-water immediately downgradient of the source area. This will reduce potential risks to human
health and retard future transport of VOCs and other organic contaminants from OU-1.
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 burn-pit area and for the gravelly soils in the capillary
fringe beneath the bum-pit area. The interim-action waiver is being invoked for the chemical-specific
soil and 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-1 will be
conducted during implementation of the IRA to determine the progress and effectiveness of the IRA.
Currently, there are no federal chemical-specific ARARs for contaminated soils. The State of South
Dakota has set the maximum allowable JP-4 (as total petroleum hydrocarbons) concentration at
10,000 Mg/kg for OU-1.
2-14 May, 1995
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Final Record of Decision for Interim Action at Operable Unit I
Ellsworth Air Force Base, South Dakota
Location Specific ARARs:
National Historic Preservation Act (NHPA) of 196616 USC 470 etsegj - Section 110 requires that
any restoration activities will not effect 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 containments will be applied to this point source discharge of the treated ground
water. The standards of control for direct discharges are derived from Title III 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 determine 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 VOCs from the capillary fringe zone
beneath the bum-pit area and immediately south of the source area and reduce future costs associated
with the final cleanup remedy(ies) selected for OU-1. This alternative is cost effective since a net
present worth cost for one year of operation of the alternative of $1,888,400 will remove a large
quantity of contamination from the subsurface. This alternative will also allow for easier
implementation of the final remedial action.
w:\isioivufoiasfiNAisoviitoD.iPA 2-15 Mav, 1995
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Final RecordofDecision for Interim Action at Operable Unit I
Ellsworth Air Force Base. South Dakota
2.10.4 Utilization of Permanent Solutions and Alternative Treatment Technologies to the
Extent Possible
As this is an interim action, the selected remedy is not designed or expected to be final. The selected
remedy utilizes established treatment technologies to address the principal threats posed by the VOCs
in subsurface soils beneath the source area and by organic contaminants in shallow ground-water
downgradient of the source area and will reduce the amount and mobility of contaminants present at
OU-1.
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.
VOCs carried by the removed soil gas will be thermally treated. 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.
f:\iSXUVttfOKTSiriNAiaOUtltOD.LPA 2-16 MaV. 1995
-------
TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-1, 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, lOOStat. 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
contaminant levels)
Establishes aesthetic based standards
for public water systems (maximum
contaminant levels)
Establishes drinking water quality goals
set at concentrations of unknown or
anticipated adverse health effects with
an adequate margin of safety
Establishes criteria for water quality
based on toxicity to aquatic organisms
and human health
Establishes criteria and standards for
technology-based requirements in
permits under the Clean Water Act
Establishes responsibilities of federal,
stale and local government and of the
POTW in providing guidelines for and
developing, submitting, approving and
modifying stale pretrealment 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 lo surface
water)
Applicable; potential discharge
stream or to EAFB WWTP.
Applicable; potential discharge
to EAFB WWTP.
Applicable because of
treatment and discharge of
ground-waler.
-------
TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-1, 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)
40 CFR Part 50
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
(Continued)
EVALUATION OF FEDERAL AND STATE ARARS THAT MAY APPLY TO OU-1, ELLSWORTH AFB, SOUTH DAKOTA
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
40CFR6.302(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
Location
Action/Location
Applicability
Applicable.
Applicable.
Applicable.
Potential ARAR. OU-I was
used for fire training activities.
No known historic or
archaeological value.
Confirmation study has not
been performed.
Applicable.
Potential ARAR, OU-I has
wetland areas adjacent to
potential remediation areas.
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TABLE 2-1 EVALUATION OF FEDERAL AND STATE ARARS TIIAT MAY APPLY TO OU-1, 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 Remediation Criteria
for Petroleum-Contaminated Soils
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
74:03:32
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
Establishes requirements for
remediation of soil contaminated with
petroleum products
Defines ground-water classifications by
beneficial use and sets chemical
standards
ARARType
Action
Action
Action
Action
Action
Action
Chemical
Chemical
Applicability
Applicable.
Applicable.
Applicable.
Applicable.
Relevant and appropriate.
Applicable.
Relevant and appropriate. OU-
1 has had impacts from
petroleum products used during
fire training activities.
Relevant and appropriate.
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Final Record of Decision for Interim Action at Operable Unit 1
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
3-1
May, 1995
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Final Record of Decision for Interim Action at Operable Unit I
Ellsworth Air Force Base. South Dakota
£tg/l: Micrograms per liter
mg/1: Milligrams per liter
MSL: Mean Sea Level
NAPL: Non Aqueous Phase Liquid
NCP: National Oil and Hazardous Substances Contingency Plan
NEPA: National Environmental Policy Act
NPDES: National Pollutant Discharge Elimination System
NPDWR: National Primary Drinking Water Regulations
NPL: National Priorities List
OU: Operable Unit
O&G: Symbols for oil and grease
PAH: Polynuclear Aromatic Hydrocarbon
PCB: Polychlorinated Biphenyl; liquids used as a dielectrics in electrical equipment
PCE: Perchloroethylene; liquids used in degreasing or paint removal.
PL: Public Law
ppm: Parts per million by weight
RCRA: Resource Conservation and Recovery Act
RI/FS: Remedial Investigation/Feasibility Study
SARA: Superfund Amendments and Reauthorization Act
SACM: Superfund Accelerated Cleanup Model
SVOC: Semivolatile Organic Compound
TCA: 1,1,1,-Tetrachloroethane
TCE: Trichloroethylene
TCL: Target Compound List
3-2 May, 1995
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Final Record of Decision for Interim Action at Operable Unit 1
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
3-3 May, 1995
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Final Record of Decision for Interim Action at Operable [..'mi I
Ellsworth Air Force Base. South Dakom
APPENDIX A
FIGURES
W:\iUO}Mt£fOKT^fOUlSaUIKOD.EfA MdV, 1995
-------
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_
SOUTH DAKOTA
ELLSWORTH AF3
FIGURE 2-1
AREA LOCATION MAP
ELLSWORTH AFB. SOUTH DAKOTA
PREPARED FOR U.S. ARMY CORPS OF ENGINEERS
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1200
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SCALE IN FEET
LEGEND
OPERABLE UNITS
OU-! FIRE PROTECTION TRAINING AREA
OU-2 LANDFILLS I a 6
OU-3 LANDFILL 2
OU-4 LANDFILL 3
OU-5 LANDFILL 4
OU-6 LANDFILL 5
OU-7 LOW LEVEL RADIATION WASTE BURIAL AREA
ou-e EXPLOSIVE ORDNANCE DISPOSAL AREA a PRAMITOL SPILL
OU-9 OLD AUTO HOBBY SHOP AREA
OU-10 NORTH HANGAR COMPLEX
ou-n BASEWIDE GROUND WATER
OU-12 HAROFILL NO.)
ELLSWORTH AFB IS 12 MILES EAST OF RAPID CITY,
JUST NORTH OF AND ADJACENf TO BOX ELDER
SOURCE: OU-4 Rl REPORT
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PROPOSED, GRQUN
SOIL
TYPICA'
FIGURE 2-3
OU-I MAP
ELLSWORTH AFB. SOUTH DAKOTA
PREPARED FOR U.S. ARMY CORPS OF ENGINI fll
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Final Record of Decision for Interim Action at Operable Unit 1
Ellsworth Air Force Base. South Dakota
APPENDIX B
RESPONSIVENESS SUMMARY
W:\iiMl\KefOKTSUTNAlSVUIROD.ZPA MaV. 1995
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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, 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's) responses to public comments.
The Responsiveness Summary is organized into the following sections:
Background on Community Involvement
Summary of Comments and Questions Received During the Public Comment Period and USAF
Responses
Remaining Concerns
2. Background on Community Involvement
On August 30,1990 EAFB was listed on the USEPA's National Priorities List (NPL). A Federal Facilities
Agreement (FFA) was signed in January 1992 by the Air Force, EPA, and the State and went into effect
on April 1,1992. The FFA establishes a procedural framework and schedule for developing, implementing,
and monitoring appropriate response actions for EAFB.
Community relations activities that have taken place at EAFB to date include:
FFA process. After preparation of the FFA by the USAF, EPA, and SDDENR, the document was
published for comment.
Administrative Record. An Administrative Record for information was established in Building
8203 at EAFB. This repository contains information used to support USAF decision-making.
w:\iS30i\xironariNALsouiitoD.EPA B-l May, 1995
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Responsiveness Sjtnvnary
Operable Units One (aid Four
Appendix B
Information repositories. An administrative Record outline is located at the Rapid City Library
(public repository).
Community Relations Plan (CRT). 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 it the two
OUs.
B-2 May, 1995
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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 II - Comprehensive Response to Specific Technical, Legal and
Miscellaneous Questions
The comments and questions below have been numbered in the order they appear in the written transcript
of the 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-borne 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 in 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 follows the
topography of the land; i.e. from higher points to lower points. Data from pumping tests
B-4 May, 1995
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Responsiveness Summary
Operable Units One and Four
^ Appendix B
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-apprdved 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 Weimer
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.
w\isxn\AiPOKTS(riNAi$ouiROD.tPA 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 and
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 being discharged to
B-6 May, 1995
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Responsiveness Summary
Operable Units One and Four
Appendix B
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.
W:\5S2
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Responsiveness Summary
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 farmers 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 in 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.
B-8 May, 1995
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Responsiveness Summary
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^. 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 May, 1995
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