United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R10-92/050
September 1992
SERA Superfund
Record of Decision:
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.
.
NOTICE
The appendIc:es Usted in the index that are not found in this document have been removed at the request of
the issuing agency. They contain materi88 which supplement, but adds no fu.rther appllcabkt information to
the content of the document. All supplemental material is. however. conlBined in the administrative record
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50272-101
REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Reclpien1'. Acce88ion No.
PAGE EPA/ROD/R10-92/050
4. TIlle end SubtiUe 5. Report Date
SUPERFUND RECORD OF DECISION 09/29/92
Eie1son Air Force Base, AI<
6.
First Remedial Action - Interim
7. Author(.) 8. Performing Organizetion Rapt. No'
9. ""rforming OrgaJnizetion Name end Addre.. 10. ProjecllT88klWorI< UnIt No.
11. ContraC1(C) or Gr8lll(G) No.
(C)
(G)
12. Sponeoring Orgonlz8tlon - end AdcIre.. 13. Type of Report. Period Co-
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
washington, D.C. 20460 14.
15. SUpplementary Nole.
PB93-964612
16. Abelr8ct (Umlt: 200 word.)
The 19,700-acre Eielson Air Force Base (EAFB) site, located 26 miles southeast of
Fairbanks, Alaska, is primarily a tactical air support installation. The 2-acre Blair
Lakes Target Range facility, approximately 25 miles southwest of the main base, has
been included in the EAFB site because of its geographical proximity. Land in the
surrounding area is used principally for military training associated with Fort
Wainwright, and there are few scattered residential and commercial activities close to
the base. The communities of Moose Creek, North Pole, and Salcha all lie within a
20-mile radius of the base. The aquifer beneath EAFB, which supplies drinking water to
private wells in Moose Creek and North Pole, has been designated a sole-source aquifer.
In addition, 70 percent of EAFB and virtually all of the Blair Lakes Target Range are
wetlands. Constructed in 1944, EAFB was originally a satellite installation of Fort
Wainwright. Used jointly by the Army and Air Force, the site was designated Eielson
AFB in 1948. Many industrial operations were conducted at the base, .which generated
waste oils, contaminated fuels and sludge, and spent solvents and cleansers. During
the mid-1980's, the Air Force Installation Restoration Program (IRP) identified
(See Attached Page)
17. Document Analyei. L o.ocriptora
Record of Decision - Eie1son Air Force Base, AI<
First Remedial Action - Interim
Contaminated Media: soil, gw
Key Contaminants: VOCs (benzene, toluene, xylenes), oils
b. IdentiflerolOpe...Endod ferme
c. COSAn FieldJGr-
18. AVlilability Statement 19. -ty Qua (ThJ. ReponJ 21. No. of P.gn
None 54
20. Security Qua (Thie Page) n Price
None
(See ANSI-Z39.18 See /ntllTuI;!iona on 4-771
1Ie-
(Formerty NTlS-35)
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EPA/ROD/R10-92/050
Eielson Air Force Base, AK
First Remedial Action - Interim
Abstract (Continued)
64 potential areas of contamination that were divided into six OUs. This ROD addresses
an interim remedy for OU1B to prevent further degradation of the ground water quality by
significantly reducing the volume of petroleum product in site soil and free product
floating on top of the ground water. OU1B contains four areas: ST20 Refueling Loop E-7
Complex, ST20 Refueling Loop E-9 Complex, ST48 Powerplant Fuel Spill Area, and ST49
Building 1300/ SS50-53 Blair Lakes Target Range. A future ROD will address additional
source control and final ground water response actions. The primary contaminants of
concern affecting the soil and ground water are VOCs, including benzene, toluene, and
xylenes; and oils.
The selected remedial action for this site includes in situ bioventing of BTEX
contaminated soil in the vadose zone, with monitoring of soil gases; collecting floating
petroleum hydrocarbons from the ground water through wells, culverts, or trenches;
incinerating recovered product onsite or transporting this offsite for recycling or
disposal; treating extracted ground water, as needed, using air stripping, oil-water
separation, or carbon filtration, as determined during the remedial design stage; and
discharging the residual water onsite; monitoring petroleum product levels; collecting
BTEX-LNAPLS using vacuum extraction wells, with carbon adsorption, followed by offsite
disposal of carbon residuals; treating collected liquids using an oil and water
separator, air stripper, or carbon adsorption; destroying air emissions using tip flare
incineration; and monitoring ground water. The estimated capital cost for this remedial
action is $3,867, with an annual O&M cost of $3,375 for 5 years.
PERFORMANCE STANDARDS OR GOALS:
No chemical-specific soil and ground water clean-up goals are provided for this interim
remedy. Final performance goals will be established in the final remedy for site soil
and ground water remediation. All air emissions and effluent discharges generated by
this interim remedy will comply with the applicable federal and state environmental
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I
II
III
IV
V
VI
VII
VIII
IX
X
RECORD OF DECXSXON
for the
UNXTED STATES AIR FORCE
EIELSON AIR FORCE BASE, ALASKA
TABLE OF CONTENTS
Declaration of the Record of Decision
Decision Summary
Introduction
Site Name, Location, and Description
site History and Enforcement Activities
Community Relations
Scope and Role of Response Action within Site Strategy
Summary of site Characteristics
Summary of site Risks
Description of Alternatives
Summary of Comparative Analysis of Alternatives
The Selected Remedy
Statutory Determinations
Responsiveness Summary
Page
1
3
4
5
6
11
12
17
21
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DECLARATION OF THE RECORD OF DECISION
site Name and Location
Eielson Air Force Base
North Star Borough, Alaska
Operable unit
Source Areas:
1B
ST20
ST48
ST49
SS50
Refueling Loop
Powerplant Fuel Spill Area
Building 1300
- SS53 Blair Lakes Target Range
statement of Basis and Purpose
This decision document presents the selected interim remedial
action for the removal of floating petroleum product at sites
within the Operable unit lB. This action was chosen in
accordance with the Comprehensive Environmental Response,
compensation, and Liability Act (CERCLA) as amended by the
Superfund Amendments and Reauthorization Act (SARA), the May
21 1991 Eielson Air Force Base Federal Facility Agreement
(FFA) , and to the extent practicable, the National oil and
Hazardous Substances Pollution contingency Plan (NCP). This
decision is based on the Administrative Record for Operable
unit lB.
The State of Alaska concurs with the selected remedy.
Assessment of the site
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response
action selected in this Record of Decision, may present an
imminent and substantial endangerment to public health,
welfare or the environment.
Description of the Selected Remedy
The interim action for the OUIB sites is intended ,to prevent
further degradation of the groundwater quality by
significantly reducing the volume of petroleum product
floating on the groundwater. To the extent practicable, the
interim action will be consistent with the final response.
action for OU1 scheduled to be determined in 1994. The OU1
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groundwater response actions, as appropriate.
The major components of the selected remedy for each site are
described below:
ST20 Refueling Loop E-7 Complex:
Bioventing
. Install vents. to inject oxygen into subsurface soils
to enhance microbial biodegradation of fuel hydrocarbons
in the vadose zone;
. Add nutrients and/or moisture and/or heat, as
necessary, to increase biodegradation rates; and
. Monitor: (1) soil gas monitoring probes to determine
local oxygen concentrations and degree of biodegradation;
(2) surface gas emissions, if any, (3) and floating
petroleum product.
ST20 Refueling Complex E-9 Complex:
Free Product Extraction
. Extract floating petroleum hydrocarbons from the
groundwater through wells, culverts, or trenches using
skimmer or dual pump systems;
. Recycle or dispose of recovered floating petroleum
product; and
. Treat extracted groundwater, as needed, through
physical/chemical processes and discharge appropriately.
.
Monitor floating petroleum product levels.
ST48 Powerplant Fuel spill Area:
Vacuum Extraction
. Install small diameter tubes to extract floating
petroleum product and to enhance aerobic degradation of
fuel hydrocarbons in the vadose zone;
. Treat offgas through an air emissions control system
prior to release to the atmosphere;
. Recycle or dispose of recovered floating petroleum
.product;
. Treat extracted groundwater, as necessary, through
physical/chemical processes and discharge appropriately;
and
. Monitor: (1) soil gas monitoring probes to determine
degree of biodegradation; and (2) floating petroleum
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ST49 Building 1300 and 8850-53 Blair Lakes Target Range:
Product Extraction
Free
. Extract floating petroleum hydrocarbons from on top of
the groundwater through wells, culverts, or trenches
using skimmer or dual pump systems;
. Recycle or dispose of recovered floating petroleum
product;
. Treat extracted groundwater, as needed, through
physical/chemical processes and discharge appropriately;
and '
..
Monitor floating petroleum product.
STATUTORY DETERMINATIONS
This interim acti9n is protective of human health and the
environment, complies with Federal and State applicable or
relevant and appropriate.requirements for this limited-scope
action, and is cost-effective. 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 utilizes treatment and thus is in
furtherance of that statutory mandate.
Because this action does not constitute the final remedy for
the Eielson AFB Operable Unit 1 site, the statutory preference
for remedies that employ treatmen~ that reduces toxicity,
mobility, or volume as a principal element, although partially
addressed in this remedy, will be addressed by the final
response action.
Subsequent actions are planned to address fully the threats
posed by the conditions at Operable unit 1. Because this
remedy will result in hazardous substances remaining on site
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 remedial action. Because this
is an interim action ROD, review of this site and of this
remedy will be continuing during development of final remedial
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Signature sheet for the foregoing Eielson Air Force Base Record of Decision
between the United States Air Force and the U.S. Environmental Protection
Agency, with concurrence by the Alaska Department of Environmental
Conservation.
~
olonel, USAF
~ ~ ~ 11-
Date
Alaska
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signature sheet for the foregoing Eielson Air Force Base Record
of Decision between the United states Air Force and the U.S.
Environmental Protection Agency, with concurrence by the Alaska
Department of Environmental Conservation.
-f)~~
DANA A. RASMUSSEN
Regional Administrator
Region 10
U.S. Environmental Protection Agency
f/2f/tf2-
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Signature sheet for the foregoing Eielson Air Force Base Record of Decision
between the United States Air Force and the U.S. Environmental Protection
Agency, with concurrence by the Alaska Department of Environmental
Conservation.
.J! {/ ,/
."/'/ ./.......
9//7/ rj z:..
Date
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DECISION SUMMARY
Introduction
The Air Force has identified a number of potential contaminant
source areas at Eielson AFB. These potential source areas
were grouped into six operable units (OUs), based upon similar
contaminant and environmental characteristics. This"Record of
Decision addresses a group of sites ~alled OU1B which include
areas where surface and subsurface petroleum spills have
resulted in floating petroleum products on the groundwater.
I
site Name, Location, and Description
Eielson Air Force Base is located approximately 26 miles
southeast of Fairbanks, Alaska, and is primarily a tactical
air support installation. Typical activities at the base
include flight operation, aircraft maintenance, and support
functions. Since 1943, the major sources of hazardous
materials include industrial operations, fire suppression
training, and fuel management.
The main base, located along the Richardson Highway, is
approximately 19,700 acres in size~ The Blair Lakes Target
Range Facility which is located approximately 25 miles
southwest of the main base, is approximately 2 acres in size.
Because of its geographical proximity to Eielson AFB, the Air
Force is including the Blair Lakes Facility in the scope of
the investigation.
This Record of Decision establishes the selected remedy ~or
four sites at the base: (1)" ST20, the Refueling Loop; (2)
ST48, the Powerplant Fuel Spill Area; (3) ST49, Building
1300; and (4) SS50 through S853, Blair Lakes Target Range.
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. Three communities (Moose Creek, North Pole, and Salcha) lie
within a twenty-mile radius of the base. The land surrounding
Eielson AFB is primarily used for military training associated
with Fort Wainwright. All lands north and east of Eielson AFB
belong to the Department of the Army. Lands northwest, west,
and south of the base are predominantly Tanana River and Chena
River flatlands which are composed of river bottomlands, woods
and scrub lands. Besides the community of Moose Creek
(northwest of the base) there are few scattered residential
and commerc~al activities close to the base.
Drinking water for Moose Creek and North Pole is supplied
primarily by private wells. Eielson AFBreceives its drinking
water primarily from a water treatment plant which is supplied
by. on-base deep water wells. .The aquifer beneath Eielson AFB
has been designated as a sole-source aquifer.
The surface water bodies. nearest to the seven source areas are
Garrison Slough, French Creek, Moose Creek, Pil.e Dr.iver Slough
and the Tanana River .Approximately 70% of Eielson Air Force
Base and virtually all. of the Blair. .Lakes Target Range are.
wetl~nds. However, .all of the p~oposed actions will take'
place on previously filled land and will have no adverse
environmental impacts on wetlands.
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II
site History and Enforcement Activities
Eielson AFB was originally a satellite installation of Fort
Wainwright (previously Ladd Field) called Mile 26. Mile 26
was initially constructed between 1943 and 1944. The field
was deactivated at the end of World War II, but ~as reopened
again in 1947 as a future strategic base. Many of the base
facilities' were built during a major construction program from
1947 to 1954. The base was used jointly by the Army and the
Air Force during the 1950s. Mile 26 was officially
redesignated Eielson AFB in February 1948.
Eielson's primary mission was tactical air support for the
Alaskan Air Command but is currently included in the Pacific
Air Forces~ Currently, the host unit at Eielson AFB is the
343rd Wing. Airborne missions of the 343rd Wing include.
emergency war order and contingency planning, tactical air
forces training for close air support and battle field
"interdiction, and air refueling operations.
The majority of industrial operation at Eielson AFB have been
in existence since the early 1950s. Industrial operations and
related wastes were insignificant prior to 1950. Major
industrial operations at the base include propulsion shops,
pneumatic/hydraulics shops, aerospace ground equipment,
maintenance shops, nondestructive inspection labs, and vehicle
maintenance shops. Industrial wastes have generally been
grouped into three categories: waste oils, contaminated fuels
and sludges, and spent solvents and cleansers. For the period
from 1950 to 1982, the total quantity of industrial wastes is
estimated to range from 25,000 to 40,000 gallons per year.
Previous investigations regarding environmental contamination
at Eielson AFB were conducted under the Air Force Installation
Restoration Program (IRP). The four-phase IRP was initiated
in 1982 with a Phase 1 record search to identify past d4sposal
sites containing contaminants that may pose a hazard to human
health or the environment. Under the IRP, the Air Force
identified 64 potential areas of contamination at Eielson AFB.
Pbtential source areas include old landfills, storage and
disposal areas, fueling system leaks, and spill areas.
Eielson AFB was placed on the National Priorities ~ist in
November 1989. In May 1991, the Air Force, EPA, and the state
of Alaska entered into a Federal Facility Agreement (FFA)
which established the procedural framework and schedule for
developing, implementing, and monitoring CERCLA response
actions. Under the FFA, the 64 potential source areas were
placed in one of six operable units, based on similar
contaminant and environmental characteristics, or were
included for evaluation under a Source Evaluation Report.
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III Community Relations
In October, 1991, the Air Force held a public meeting to
describe the cleanup efforts being planned to address soil and
groundwater contamination at OU1. Announcements for the
meeting were published in the local newspaper. The Community
Relations Plan was made available in October 1991. The
Administrative Record was placed in the Rasmuson Library at
the University of Alaska, Fairbanks in March, 1992.
In accordance with sections 117 and 113(k) (2) (b), the
public was encouraged to participate in the remedy selection
process. The proposed plan for OU1B was mailed to over 130
interested parties and distributed to libraries at the
University of Alaska Fairbanks, North Pole and the Noel Wein
Library in Fairbanks in May 1992. The proposed plari
summarized the alternatives evaluated and presented the
preferred alternative. Approximately 15 people attended a
public meeting held on June 9, 1992 at the North Pole Middle
School. The pUblic meeting was annpunced by six
advertisements in the local newspaper and the base cable TV
network. . A news release was provided to the local news media
explaining the proposed plan. This resulted in a front page
article about the cleanup efforts in the Fairbanks Daily News
Miner. A 30-day comment period was held from May 15 to June
15, 1992. No requests for extensions were received during the
comment period. Responses to comments received at the public
meeting and written comments are included in the attached
Responsiveness Summary. .
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:IV
scope and Role of Response Action within site strateqy
The Air Force is currently conducting a comprehensive
investigation of groundwater and soil contamination for all
sites in this Operable unit. During this investigation,
floating petroleum products were found at several locations.
Under the Superfund program, early actions, or interim
actions, are used to expedite the completion of total site
cleanup. It is expected that this interim action will
accelerate the overall cleanup process for OU1.
The selected remedy for this interim action is intended to
begin the process of cleaning up four sites containing
floating petroleum products in OU1. The purpose of this.
interim action is to expedite the cleanup by eliminating the
primary source of the contamination and by reducing the. volume
of the floating product on the water table. It is anticipated
that activities under this interim action will continue for
approximately five years or until the practical limit is .
reached for floating petroleum product recovery, whichever is
sooner. To the extent practicable, this interim. action will
be consistent with the comprehensive investigation scheduled
to be completed in 1993. .. .
This interim action focuses on removing floating petroleum
product to prevent migration of contaminants and allow for
collection of sufficient information about the system response
to allow for a final remedy selection. The petroleum product
floating on the water table should be removed in its.
concentrated form, before harmful constituents such as
benzene, toluene, and xylene dissolve into the groundwater.
Once the contaminants are in the groundwater pathway, they can
begin to migrate, thereby increasing the volume of .
contaminated material and the potential risk to human health
and the environment.
This interim action is consistent with future actions that may
be undertaken to address contaminated soil and groundwater in
aU1. . .
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v
SUMMARY OF SITE CHARACTERISTICS
Subsurface Conditions
Eielson Air Force Base is located in the Tanana Valley and is
underlain by approximately 200 feet of unconsolidated fluvial
and glaciofluvial sediments. These sediments consist of
predominantly interbedded layers of well-graded sand and
gravel and are underlain by metamorphic and intrusive bedrock
materials. Permafrost conditions occur in undeveloped
locations within the valley; however, in areas of surface
development, only localized pockets of permafrost remain.
Permafrost conditions are reported at the Blair Lakes Target
Range, but are net expected beneath most Eielson AFB
locations. It is anticipated that seasonal frost zones may
extend into the shallow water table at the Base during winter;
however, site-specific winter data On the groundwater
conditions have not been collected to date..
Groundwater Conditions
The upper unconfined aquifer extends from. the ground surface
to a depth of' about 200 feet. Groundwater at ~he.Eielson and.
Blair Lakes sites typically occurs at depths of l~ss than 10
feet below.. ground. surface and flows regionallytowarQ. the
north-northwest (HLA, 1989). Horizontal. gro~ndwa~er gradients
are reported to be 4 to 6 .feet per mile at the Base, resulting
in relatively slow groundwater movement. Thehydraulic
properties of the aquifer are not well characterized at this
time; however, hydraulic conductivities are typically high
(approximately 200.feet per day) for sand .and gravel.
sediments. Groundwater within the sedimentary aquifer occurs
under unconfined to semi-confined conditions. verti'cal .
gradient data for the study .area are not currently available
but will be evaluated as needed for' indIvidual source areas.
No distinct aquitard horizons have been identified in the
unconsolidated deposits. .
Shallow groundwater beneath the sites is classified as a sole-
source aquifer and provides the base with drinking .water as
well as domestic, irrigation, and industrial water supplies.
A brief summary of selected information on facility operations
and subsurface environmental conditions for source areas of
concern is presented below. A summary of floating petroleum.
product thickness measurements is given in Table 1. -
Approximate areas and extent of floating product for each site
are shown in Figures 2. through 7. A summary of analytical
results for groundwater sampling are presented in Tables 2
through 8.
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ST20 Refueling Loop
Source Area ST20 is an active aircraft refueling loop and
includes three refueling complexes, E-7, E-8, and E-9 (see
Figures 2 through 4). The complexes contain underground fuel
tanks, piping, and associated pump houses. The refueling loop
is generally flat, consisting of asphalt-covered taxiway and
refueling pads with adjacent unpaved areas of gravel and
grass. site data indicate a range in depths to shallow
groundwater of between 3 and 9 feet below ground surface and a
northwesterly direction of flow. Sediments at ST20 generally
include sand and gravel deposits.
The sources of petroleum, oil, and/or lubricants (POL)
contamination at ST20 include historic surface spills and
leaky underground pipes. Considerable subsurface
investigation has been performed at the source are~ since
1982, including borehole soil sampling, soil vapor sampling,
groundwater probe sampling, monitor and extraction well
installations, and surface water sampling. A summary of
analytical results of the groundwater investigations is
presented in Tables 2 and 3.
Floating petroleum product has been measured above the shallow
. groundwater at each of the three refueling complexes. Results
are summarized in Table 1. The approximate extent of each of
the pools of floating petroleum product at complexes E-7, E-8,
and E-9 was investigated using temporary groundwater probes
(HLA, 1990). Floating petroleum product was observed at the
E-8 complex in 1989, but not in more recent monitoring.
ST48 Powerplant Fuel Spill Area
Source Area ST48 shown in Figure 5, is located in the east-
central portion of Eielson AFB, near the intersection of
Division Street and Industrial Drive. The site is adja~ent to
a coal-generated powerplant, an ash storage house, active
railroad lines, two cooling water supply wells and one
drinking water supply well, and abandoned below-grade fuel
lines.
The abandoned gasoline and diesel pipelines reportedly served
as delivery lines from bulk storage tanks to an old military
service station located at the intersection of Division Street
and Industrial Drive. It is not known if the fuel pipelines
were drained and purged when they were taken out of service.
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,Previous findings from a soil vapor survey, product level
measurements, and analytical soil and groundwater data
indicate that the greatest amount of fuel contamination lies
along the abandoned fuel pipelines passing beneath Industrial
Drive. A summary of analytical results for groundwater are
presented in Tables 4 and 5. Floating petroleum product has
been found at a number of locations near the abandoned fuel
pipelines where they cross beneath Industrial Drive. A
summary of floating product measurements is presented in Table
1. Floating petroleum product sampled from Well 48M01 may be
arctic diesel, based on hydrocarbon fingerprint analytic
results (HLA, 1990). The extent of floating petroleum product
is estimated to be approximately 100 feet by 100 feet. The
maximum observed floating product thickness was over
1.51 feet.
Based on available data, the direction of groundwater flow at
ST48 varies from east to northeast, and is probably influenced
by pumping from water supply wells located approximately
500 feet east (Wells 1 and 2 -- powerplant cooling water
wells) and 500 feet north (Well D) of the floating product
pool. Permafrost conditions were not encountered during field
investigations near ST48, nor were permafrost conditions
reported for Wells land 2.
Floating petroleum product was also detected at the newly
constructed Ash storage House, approximately 225 feet north of
Well 48M01. Dewatering activities during construction of the
Ash storage House may have induced migration of the floating
petroleum product from the vicinity of 48MOl toward the Ash
Storage House. No potential source areas near the Ash Storage
House are known.
ST49 Building 1300
ST49 is located just ~outh of the main runway, in the southern
portion of the base as shown in Figure 6. The source area is
approximately 8 acres in size and includes Building 1300 and
the adjacent taxiway, which together comprise an active combat
alert hangar complex (CAC). The site is relatively flat with
elevated taxiway and hangar construction.
A utility room is located on the east side of the hangar and
contains a 550-gallon above-ground diesel fuel tank for the
CAC generator. The above-ground tank is supplied on an
approximately daily basis by two lO,OOO-gallon below-grade
fuel tanks located at the southern end of the hangar. There
is a floor drain in the utility room that has received diesel
overspill. It is not known whether the floor drain line is
connected to the CAC septic system and drain field. Floor
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drains are also located within the hangar and are reportedly
connected to the septic system and drain field located just
south of the hangar.
six monitoring wells and one product recovery well are located
at the source area. Water level data from these wells
indicate that depth to groundwater ranges from 7 to 10.5 feet
below ground surface and flows toward the north. Permafrost
conditions were reported at depths of approximately 25 feet in
1988 in HLA well logs for wells 49M04 and 53M05 located just
north of the complex.
ST49 was investigated during the HLA 1988 (Phase II, stage 3)
and 1989 (Phase II, Stage 4) field investigations, which
included borehole soil sampling, soil_,vapor sampling,
groundwater sampling from probes and ~onitoring wells. .A
summary of analytical results of these groundwater ..
investigations are presented in Tables 6 and 7.
Floating petroleum product was detected above the shallow
water table at the north end of the hangar in 1988 and 1989
(wells 49M02 and 49M06), and just north of the utility room
(we.ll 49GMW). Product probes were installed to further
delineate the lateral extent of floating product. in the area;
however, access .restrictions prevented product;, delineation
beneath the hangar and surrounding paved areas. Floating
product thickness measurements are presented in Table 1. The
estimated extent of floating product is approximately 200 feet
by 75 feet with a maximum reported thickness of 2.15 feet in
49M02 in 1988. Product recovery was implemented for a time
beginning in 1988 at Well 49GMW and occasional product removal
was conducted in Well 49M02. Hydrocarbon identification
analyses were performed on product samples collected from
Wells. 49M02 and 49GWM, and indicated the product is
predominantly C9~C19 die~el fuel~
8850 through 8853 Blair Lakes Target Range
The Blair Lakes Target Range shown in Figure 7 is located
approximately 24 miles southwest of Eielson AFB and can be
reached in summer by helicopter or in winter by way of an ice
bridge across the Tanana River. The site includes a vehicle
maintenance shop, above-ground diesel and gasoline tank farm
(and associated product delivery lines), generators, and
storage outbuildings on a central gravel pad area. Aircraft
target ranges and drum disposal areas are located outside the
gravel pad area.
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Groundwater flows toward the north at Blair Lakes and occurs
at depths of approximately 9 feet below ground surface.
Permafrost was encountered at a depth of 7 feet in an HLA
boring adjacent to the tank farm area and is expected to be
present beneath portions of the gravel pad that are not
subject to thawing effects from adjacent heated buildings.
Permafrost was not encountered during HLA's drilling
activities in the areas outside the gravel pad.
Potential source areas at the Blair Lakes facility were
investigated by HLA in 1988 (Phase II, stage 3) and 1989
(Phase II, Stage 4) and included borehole soil sampling, soil
vapor sampling, groundwater sampling from probes and
monitoring wells. A summary of analytical results of the
groundwater investigations is presented in Tables 8 and 9.
HLA. investigations indicated several potential sources for,
fuel-related contamination at Blair Lakes. A' diesel spill
from an above-ground diesel day tank is . b,elieved to be the
primary source of fuel contamination detected ,in ~he ~base
water supply well, located in the eastern, corner of the'
vehicle maintenance shop. Monitoring Well 50M01 was installed
in 1988 approximately 35 feet southeast of the supply well and
, 0.7 feet of floating petroleum product was measured. Product
probes w~re installed in ,the vicinity in 1989 to investigate
floating product; however, no produc~ measurements were made
at that time. Floating product thickness measurements made at
the Blair Lakes facility in 1991 are listed in Table 1.
The tank farm and,vicinity are. potential ~ources; based on
elevated total petroleum hydrocarbon (~PH.) concentrations in
soil samples, near the tanks. other'nearby potential sources
include spills at the fuel pump island approximately 30 feet
west of the tank farm, or leaks in the associated underground
piping. An additional area of concern is a former underground
fuel line construction ditch located,between the vehicle
'maintenance shop and the tank farm. The ditch was excavated
in 1986, floating product was observed above the water table,
and the ditch was backfilled. The specific source of the
product is not known.
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TABlE 1. RMtint '-troleum Product M...ure_-
at-t , 04 3
Produot TNc:kMM
lite WeiNumber 0... '.~"d IftJ Comment
ST20 2OM04 ,-5-1, 1.7 Product JI'4
E-7 C~.x '-21-" 0.85
2OPPOI 8-17-8' 0.01
8121/81 0.00
20PPO. 8-17-8. 0.7'
8121/81 0.00
20PPU '-17-8' 0.3.7
8121/81 0.00
20PP'4 9-17-89 1.14
8121191 0.00
20PP16 ..,7-8. 0.50
1/21/81 0.00
2OPP18 9-17.81 0.38
1/21191 0.00
2OPP17 9-17-19 0.01
1/21191 0.00
20PP35 9-17-19 0.01
1/21/81 NY
20PP38 9-17-89 0.13
1/21191 NY
ST20 20M08 9-&-19 0.58
E-I Complex 10-1-89 0.50
1-21-91 0.0
20f>i>51 10-1-89 0.01
10-27-19 0.01
1-21-91 NM
20PPS2 10-27-19 0.01
8.21-91 NM
20PPn 10-27-89 0.01
1.21-91 NM
20PPSO 10-27-89 0.01
1-21.91 NM
ST20 20M01 9-4-89 0.14
E-9 Complex 10-10-89 0.30
8.21-91 0.0
20M07 9-1.89 1.70
10-10-89 1.60 Ught yellow
1-21.91 0.94 product IJP-4)
201.425 10-18-19 1_41 Datk brown
8-21-91 0.14 ploduct (unknown)
20PPS7 10-10-89 0.29
1-21-91 NM
20PP60 10-10-19 0.21
8-21-91 NM
20PP71 10-10-89 0.58
20PP72 10-10-89 1.13
20PP73 10-10-89 1..28
20PP78 10-10-89 1.13
ST20 Gener. M 8-22-91 0.81
N 8-22-91 0.42
P 8-22-91 0.63
S 8-22-91 0.11
-------
TABlE 1. Ro.dne "troleUIII Product M......_-
ShMt Z of 3
Produot ~
1118 W.. Numbef 0.18 '."'P..d (ftJ Com"*"
8T48 48M01 "23-8' 0
'.20-81 0.11
8.28.81 0.80
10-8-88 0.83
8.22-81 0.12
48 PPO 1 9.23-8' 0.08
48PP08 ,.23.888 0.42
IH7.88 0.21
10-22.89 0.27
48PP08 9.23-8 0.82
11.1-89 0.70
9.17.89 0.71
10-22.89 0.78
8.20-81 0.75
10-10-81 0.72
48PP09 9.23-88 0.88
11-1-88 0.75
9.17-89 1.32
10-22-89 1.27
8-20-91 1.51 +
48PP11 11-1-88 0.11
9.17-89 0.54
10-22-89 0.57
48PP28 9-23-88 0.11
10-31-88 0.21
9.17-89 0.81
11.22.89 0.12
10-1 8-28.91 0.19
10-8 8.28-91 1.32 .
48PP84 11-22-89 0.02
48PP68 11-22.89 0.11
ST49 49M02 9-23.88 1.28
10-28-88 2.15
9-18.89 0.81
8-20-91 0.82
49GMW 9-23-88 1.89
10-28-88 1.42 Heedspace roadi~
8- 20-91 NM 0.00 ppm OYM
49PP24 9-23-88 1.13
10-28.88 1.17 Product prot>.
89 NM destroyed
49M08 9-22.89 0.08
8-20-91 0.00
-------
TABU! ,. FIoIIting "'croIeum Product M.--_- :
8Me' S of S
Procluc1 ~
Sk8 W.. NUmMr Da.. Sampled (ftJ eomm.n.
SS50-U end DP64 SOM01 t-3O-8I 0.70
111* lAb 8-2&-'1 0.40 W" oaeIng hMwd
5OPP81 8-2&-' 1 0.7&
5OPP85 10-10-81 0.70
'-2&-' 1 0.32
10-10-81 0.30
NM - not IMMUred.
-------
v
o
O.
. R,,~i- V
o ".. ~o'" 0 -
()
~
) IJ
J,)
DIRECTION OF
GROUNDWATER. FLOW
~ 20M21
~
Existing monitoring
well location
o .100
~..
200
300
J
FIGURE 2
Source Area ST20 E-9 Complex
Approximate areal extent 01
floating prOduct based on
HLA data and 1991
Observations by CH2M HILL
SCALE I" I 200'
OU- 18 Proposed Plan. Eielson Air Force Base
..,." ,."',.....
-------
)~ ~
20M'''';' V
~ 20M19
20M18 ~
20M 15 ~
DIRECTION OF
~ 20MO
FUEL ~. 0
PUMPHOUSE <> <>..
1321 0
GROUNDWATER FLOW
.FW
20M02 ~
~~
~
o 100
~;v:».
SCALE I" . 200'
200
3(X)
I
FIGURE 3 So
urce Area $T20 E -8 Complex
ou- 18 Proposed Plan, Eielson Air Force Base
cJ
~\..'t.i- \
eOV'
't.-~
o
.
Fire Well
~
Existing monitoring
-------
. .
~ 20M12
.PW
~ 20M11
20M03
DIRECTION OF
GAOUNDWA TEA
()
of.
~\,
-------
~ --
.. .
r
o
"1-
lr)
~.
8201
L
---= 0
ASH STORAGE
HOUSE
'1-1 S
C-W~/S,
0",
~Q
Vc.
Iy
~~
COOIIOg water well
Existing pr()().JCt prObe
loca tlon
.
Base water Sl.PPIY
AbandOned well
Exlsthg monitoring
well location
well
o
S
o XX)
JIII- - ----
200
:m
I
FIGURE
5
-
SOlt'ce Area ST 48
=,oxmato aroal extent of
HLA prOOJct basecJ on
8t8 and 1991
""""""VAtlnn.. hv (:H~ HILL
.. -. ---
-------
.. .
.3010
~
~~
~
(9
C 100 ~
I"'..~.
SCAlE r . 200
"f1J
6
FIGURE
SOlI'ce Area ST A9
Record of DedslOn for OU-1. Elelson At Force Base
NA...r :()I I ~ .nON
c;::J
\.::
Ex/sthg morItorhg
well lOCatIOn
ApJYo)(mate areal extent 0'
floatlnQ prociJct baaed on
HLA data and 1991 .
-------
HELICOPTER FUEL
BL.1DDER AREA
DI/i~
01"'0",
G/i OF
OV.\oIy
-1 1"C/i
1'"(01y
TN-IKfARM
CENERATORS
6)'01.,0
S
SOMOI NEw
TOWER~
S'OMOS
rUEL PUMP
ISL N-ID
o
VEH'CLE. ~N~N~ DC
. SOMOI S ~~ APPROXIMATE
LOCATION OF
"". S NEW DRINKINC
, ~ SOMoa WATER WELL
S50MO. ~TD C~CO
HELlP,6D
S Exlsthg monItor~
well location
Approximate areal extent of
SOl.t'ce area
Approximate areal extent of
of . flQ8thg procllct
(Based on HLA data and
. . _. .-.. ,....
Sf: w ACt: POt-()
~~
~
') ~
....-
m
150
I
FIGURE
7
-------
Table' 2 Summary or Groundwater Results ror Site 20
(Groundwater Probes)
ConcentraUoD
Detection Detected! Range Detected Location or
Constituent Umit (ugIL) Analyzed (uglL) MaxImum
E-7 Complex
Benzene I 18/31 1-330 20FW18
Toluene 1 8/31 1-3 20FW56
Ethylbenzene 1 2/31 1 20FW61
m,p-Xylene I 3/31 1-2 20FW74
o-Xylene 1 2/31 1-2 20FW75
Methylene 1 3/25 . 4-5 20FW55
Chloride
1, I-Dichloro- 5 4/25 6-32 20FW56
ethylene
E-8 Complex
Benzene ,I 8/49 1-830 20FW70
Toluene 1 24/49 1-1,400 20FW70
Ethylbenzene 1 3/49 3-470 20FW02
m,p-Xylene 1 21/49 1-640 20FW02
o-Xylene 1 13/49 1-380 20FW70
E-9 Complex -
Benzene 1 12/31 2-25, 20FW42
Toluene 1 14/31 2-21, 20FW42
Ethylbenzene 1 9/31 1-1,600 20FW46
m,p-Xylene 1 16/31 1-4,700 20FW39
o-XyJene 1 14/31 1-1,400 20FW42
-------
Table 3 SnmltUlry oC Groundwater Results Cor Site 20
(Monitorin& WeUs)
Location
Detection Concentration of
Limit Detected! RaDle Maximum
Constituent (pglI) Analylzed DeUded (.acfl> (complex)
VOLATILES
Benzene 0.2 17/30 0.32-7170 20M04
(E-7)
Ethylbenzene 0.5 10/30 1.21-1120 53M04
(E-7)
Toluene 0.3 16130 0.56-15900 53M04
(E-?)
Xylenes, Total 0.4 11130 1.21-3820 20M04
(&7)
SEMIVOLA TILES
Anthracene 1.0 1/19 1.7 20MOl
(E-9)
Bis(2 -eth y lhex yl)phthaJate 2.0 11/19 6.4-2900 20M06
(E-8)
F1uoranthene 1.0 1/19 6.3 20MOI
(E-9)
2-Methylnaphthalene 1.0 3/19 39-260 20M07
(E-9)
Naphthalene 1.0 3/19 12-160 20M07 -
(E-9)
Phenanthrene 1.0 1/19 6.6 20MOl
(E-9)
Pyrene 1.0 1/19 5.S 20MOI
(E-9)
Petroleum Hydrocarbom 0.2 4/29 1.4-6.3 20MOI
(mgII) (&9)
Notes:
Samples from E-7 Complex wells were not analyzed for semivolatiles.
-------
Table 4 Summary of Groundwater Results Cor Site 41
(Groundwater Probes)
Concentration
Detection Detected! Rall2e Detected LocatIon of
Constituent Limit (uefL) Analyzed (ugIL) Maximum
Benzene I 6124 80-7.100 48FWll
Toluene 1 7/24 40-6.600 48FWll
Ethylbenzene 1 9124 3-950 48FW12
m.p-Xylene 1 9/24 5-3.300 48FW12
o-Xylene 1 8124 5-1.300 48FW12
t-Dichloro- 5 2/24 17-490 48FW12
ethylene
-------
Table 5 SummAry of Groundwater Results for Site 48
(MonJtorln& Wells)
. Page 1 of 1
Concentration
Detection Ranee Location
Limit Detectedl Detected of
Constituent (ug/L) Analylzed (ugIL) Maximum
1988 RESULTS
VOLATILFS
Benzene 0.15 5/10 0.34-1330 . 48MOI
Ethylbenzene 0.46 2/10 89.2-160 48MO 1
Toluene 0.25 2/10 53.2-88.0 48MO 1
Xylencs, Total 0.85 3/10 1.62-929 48MO 1
SEMIVOLA TILES '
.-
ButylbenzyJphthaIate 1.5 1/10 520 48POIWI
Bis(2-etJ1ylhexyl)phthalate 2.0 1/10. 700 48POIWI
2,4-DimethylphenoI 0.28 1/10 5.1 48MO 1
2-Methylnaphthalene 0.9 2/10 130-251 53M03b
Naphthalene 0.26 2/10 230-440 53M03
Petroleum Hydrocarbons" 0.1 2/10 3.4-44.0 48MOI
(mgIL)
1989 RESULTS
VOLATILES
Benzene 0.20 4/10 3.01-1,390 48MO 1
Ethylbenzene 0.50 1/10 143 48MO 1
Toluene 0.30 2/10 48.8-230 48MOI
Total Xylenes 0.40 2/10 1550-1990 48MO 1
SEMIVOLA TILES
Bis(2-eth ylhexyl)phthalate 2.0 2/10 44-52 48M07
2- MethylnaphthaJene 1.0 4/10 24-140 48MO 1
-------
Table 5 Summary 01 Groundwater Results lor Site 48
(Monltorln& Wells)
Pale 2 01 2
Concentration
Detection Ran&e Location
Limit Detected! Detected of'
Constituent (ugIL) Analylzed (ugIL) MaxImum
Naphthalene 1.0 4/10 24-270 48MOI
Pef.n)lewn Hydrocarbons 0.2 5/10 0.3-10.6 48MOI
(mgIL)
Notes:
.Hydrocarbon fingerprint analysis for wells 48MOI and 48M02 indicated 4.2 mglI,.
Arctic Diesel and 13 rngIL of a C8-C20 hydrocarbon. respectively.
"Well 53M03 also has been analyzed for major cations. major anions and selected
metals.
-------
Table 6. Snmmuy oC Groundwater Results Cor Site 49
(Groundwater Probes)
Concentration
Detection Detededl Ranle Detected Location or
Constituent Umlt (ug/L) Analyzed (ug/L) MaxImum
Benzene 1 12/24 1-6 49FW08
Toluene 1 0/24 - -
. Ethylbenzene 1 4/24 1-8 49FW03
m,p-Xylene 1 6/24 3-37 49FW03
<>-Xylene 1 3/24 2-24 49FW03
Trichloroethylene 1 10/24 . 1-4 49FWI0
49FWIS
t-Dich1oro- 1 1/24 . 2 49FW12
ethylene
-------
Table 7 SnmmAry or Groundwater Results for Site 49
(Monlt«inl Wells)
Page 1 or 3
Co~tratJon
DetectJOD Raqe Location
Limit Detected! Detected or
Constituent (ugIL) Analylzed (ugIL) Maximum
1988 RESULTS
VOLATILES
1, I-Dichloroethane 0.46 1/8 1.57 53~OS"
Trans-l,2-Dichloroethene '0.38 1/8 0.40 53M05
1, 1 , I-Trichloroethane 0.2 .218 0.447-4.77 53MOS
Trichloroethene' 0.52 2/8 3.14-14.0 53MOS
Tric~orof1uoromethane 0.32 118 0.788 49MOl
Benzene 0.15 4/8 0.35-4.71 49M03
Chlorobenzene 0.34 1/8 0.432 49M02
1,2-Dichlorobenzene 0.2 1/8 0.21 . 49MOJ
Ethylbenzene 0.46 3/8 0.55-5.37 49M02
Toluene 0.25 2/8 0.31-{).49 49M02
Xylenes, Total 0.85 2/8 3.99-18.1 49M02
SEMIVOLA TILES -
Dibenzofuran 0.01 1/8 0.620 49M02
2-Methylnaphthalene 0.9 2/8 117 49M02 .
Naphthalene 0.26 2/8 6.2-62 49M02
Petroleum Hydrocarbons 0.01 1/8 28.4 49M02
(mg/L)
1989 RESULTS
VOLA TILES
l,l-Dichloroethane 0.400 2/8 0.457-1.01 49MOS
-------
Table 7 " SummAry of Groundwater Results ror Site 49
(Monitoring Wells)
Page 2 of 3
Concentration
Detection Ran&e Location
Limit Detected! Detected or
Constituent (ugIL) AnalyIzed (ugIL) MaxImum
1, 1, 1-1rrichJoroethane 0.200 5/8 0.333-1.50 49M06
Trichloroethene 0.600 5/8 0.963-6.93 49M05
Benzene 0.20 7/8 0.33-4.35 . ~9M03
1,4- Dichlorobenzene 1.00 1/8 4.53 49M03
Ethylbenzene 0.50 5/8 0.63-3.26 49M06
1roIuene 0.30 3/8 0.72':'1.04 49M06
1rotal Xylenes 0.40 2/8 0~94-5.95 49M02
SEMIVOLA TILES "
Acenaphthene 1.12 4/8 1.19-12.8 49M02
Acenaphthylene 0.655 5/8 1.3O-{).43 49M02
Anthracene 0.019 2/8 0.031-0.034 49M04
Benzo(A)Anthracene 0.0004 8/8 0.0006-0.026 49M02
Benzo(B)Fluoranthene 0.0003 8/8 0.0003-0.012 49M02
Benzo(K)Fluoranthene 0.0001 7/8 0.0004-0.008 49M02 "-
Benzo(G ,H,I)Perylene 0.001 5/8 0.001-0.023 49M03
Benzo(A)Pyrene 0.0003 7/8 0.0004-0.015 49M02
Chrysene 0.008 4/8 0.01-0.03 49M04
Dibenz(A,H)Anthracene 0.0009 5/8 0.0009-0.005 49M02
Fluoranthene 0.0003 8/8 0.003-0.356 49M02
F1 uorene" "" 0.125 6/8 0.142-10.8 49M02
Indeno(l,2,3-
-------
Table 7 Snml1Ullry of Groundwater Results tor Site 49
(Monltorfn& Wells)
Paee 3 of 3
Concentration
Detection Ranee Location
Umlt Detected! Detected or
Constituent (ugIL) Analylzed (ugIL) Maximum
Phenanthrene 0.02 7/8 0.02-21 49M02
Pyrene 0.011 7/8 0.015-0.850 49M02
Petroleum HydrocarbonS- 0.2 3/8 1.6-32.3 49MOS
(mgIL)
Notes:
. Hydrocarbon fingerprint analysis for well 49M02 indicated 5.4 mg/L of a C9-CI9
hydrocarbon, based on an Arctic JP-7 reference.
. Well 53M05 also has been analyzed for major cations, major anions and selected
metals.
-------
Table 8 Summary Or Groundwater Results Cor SIte 50
(Groundwater Probes) '.
Concentration
Deted10n Detectedl Ran&e Detected Location of
Constituent LImIt (ug/L) Analyzed (uglL) MaxImum
Toluene 1 3/21 1 SOFWOl
SOFW04
SOFW06
Note:
Samples from the groundwater probes were analyzed by the HLA field laboratory.
-------
Table 9 Summary Or Groundwater Results lor Site 50
(Momtorio& Wells)
Page 1 or 2 .
Concentration
Detection Ran&e Location
Umlt Detected! Detected or
Constituent (ugIL) Aoalyhed (ugIL) Maximum
1988 RESULTS
VOLATILES
Chloromethane 0.4 4/7 0.58-1.32 . 50M03
Benzene 0.15 3/7 3.0-65.2 50MOI
Chlorobenzene 0.34 1/7 1.73 50MOS
Ethylbenzene 0.46 2/7 136-332 50MOI
Toluene 0.25 2/7 52.5-261 50MOI
Xylenes, Total 0.85 2/7 602-1860 50MOI
SEMIVOLA Tll-ES
Butylbenzylphthalate I.S 3/7 3.7-12 SOMOS
DiethylphthaIate 1 1/7 6.6 SOMOS
2,4-Dimethylphenol 0.28 1/7 4.7 50MOS
2-Methylnaphthalene 0.9 1/7 454 50MOI
Naphthalene 0.26 1/7 540 50MOI -
Phenol 1 1/7 6.8 50MOS
Petroleum Hydrocarbons" 0.1 1/7 119 50MOI
(mgIL)
1989 RESULTS
VOLATILES
Chloroform' 0.2 1/12 1.01 50M08
Benzene 0.20 4/12 3.08-335 50MOI
Ethylbenzene 0.50 3/12 0.99-2,210 50MOI
1w'6-3-92ICVOR1S 1/016.5 1
-------
~
Table 9 .Summary or Groundwater Results for Site SO
(Monitoring Wells)
Page 2 of2
Concentration
Detection RaD&e Location
Limit Detected! Detected or
Constituent (ugIL) Analylzed (ugIL) MaxImum
Toluene 0.30 3/12 2.69-2,080 50MOI
Total Xylenes 0.40 3/12 11.3-6,940 50MOl
SEMIVOLA TILES
Bis(2-eth ylhex yl)PhthaJate 2.0 1/12 4.1 50M02
2,4-Dimethylphenol 2.0 1/12 12 50MOS
2-MethylnaphthaJene 1.0 3/12 1.3-12,000 50MOI
Naphthalene 1.0 2/12 32-5700 50MOI
Petroleum Hydrocarbons 0.2 2/12 0.3-1,980 50MOI
(mgIL)
Notes:
"Hydrocarbon fingerprint anaJysis for well 50MOI indicated 7.6 mgIL of .we3thered
product., based on an Arctic JP-7 reference.
"Chloroform not detected in resample.
cl988sampling round aJso included anaJysis for major C4tions, major anions and
selected trace metaJs. -
-------
r
VI
SUMMARY OF SITE RISKS
The primary risk being addressed by this interim r.emedial
action is exposure to groundwater contaminated with organic
constituents. Because petroleum products contain toxic
chemicals that dissolve into water, the first step in reducing
risk at these sites is to minimize the volume of petroleum
product in contact with the groundwater. Although petroleum
products contain many chemicals, those of primary concern are
benzene, toluene, ethylbenzene, and xylene~
Based on existing information, the areas of floating petroleum
product are relatively localized' and de not appear to be
spreading quickly. However, .if not removed, these floating
petroleum products will continue to dissolve into the
groundwater and may migrate, thus contaminating larger areas
of groundwater in the future.
Contaminants such as benzene, ethylbenzene, toluene, and total
petroleum hydrocarbons are present at levels exceeding their
respective drinking water standards in the upper regions of
the groundwater near the areas of floating petroleum products.
One Base drinking water supply well (Well D) is located close
to the"Powerplant Fuel Spill Area. The upper regions of the
aquifer are not presently used as a drinking water source at
Eielson AFBi however, it would pose an unacceptable risk if
used for domestic purposes (e.g., drinking and showering). In.
addition, if not addressed, the contaminants may migrate both
horizontally and vertically and may contaminate the existing
deeper drinking water supply wells.
-------
, ~
VII
DESCRIPTION OF ALTERNATIVES
The following alternatives for reducing floating petroleum
products on top of the water table and preventing further
migration of the contamination were evaluated:
Alternative 1 -- No Action
Alternative 2 -- Free Product Extraction
Alternative 3 -- Vacuum Extraction
Alternative 4 -- Soil Excavation / Free Product Removal
Alternative 5 -- Bioventing
Alternative 1:
No Action
The no action alternative is presented as a baseline for
comparison against other alternatives. Under this
alternative, the Air Force would not take further action to
remove floating petroleum product contamination. The floating
petroleum product would remain on top of the water table. and
continue to dissolve into the groundwater and migrate away
from the source.
Alternative 2:
Free Product Extraction
This alternative would remove floating petroleum product from
the top of the water table by pumps installed in groundwater
wells, culverts, or trenches. Viable pump configurations
include skimmer pumps and dual pump systems. The type and
number of pumps used would be determined based on source-
specific conditions to achieve optimal floating petroleum
product removal. The goal of efficient pumping is to maximize
removal of floating product while minimizing extraction of
large volumes of groundwater.
Extracted groundwater would be monitored to determine whether
it required treatment using physical/chemical processes such
as air stripping, oil-water separation or carbon filtration.
Depending on the volume, the treated effluent would then be
discharged to the ground surface, surface water bodies or to
the subsurface soils via trenches or wells. Small volumes of
extracted groundwater may be discharged to the Base sewage
treatment plant in accordance with state and federal
regulations.
-------
Depending on its quality, the recovered floating petroleum
product would then be burned on-b~se at the waste oil
incinerator or recycled or disposed of off-base through the
Defense Reutilization and Marketing Office. .
Alternative 3
Vacuum Extraction
This alternative includes the extraction of floating petroleum
product using vacuum extraction wells (VEWs). The objective
of vacuum extraction is to accomplish removal of the floating
petroleum product. In addition, the VEWs would remediate some
of the residual contamination in the soil. .
Well casings will be installed to below groundwater level and
smaller diameter drawdown tubes or "slurp" tubes will be
inserted. The open end of the slurp tube will be placed at.
the interface of the floating petroleum product and the
watertable~ The top of the casing. will be sealed and a vacuum
pump connected to the slurp tube. . with the tip of the slurp
tube located at or slightly above the interface, the floating
petroleum product will. be removed but very little, if any,
groundwater will. be removed. The well head will be.
. constructed so the depth. of the draw~down tube can be
adjusted...An operator will manually place and maintain the
tip of the tube slightly above the interface between the
floating petroleum product and the watertable within the well
casing. .
As a vacuum is applied at the end. of the drawdown tube, a
vacuum is created within the perforated will casing. The
influence of the vacuum spreads radially from the well casing.
The actual radius of influence depends on a number of site-
specific soil parameters (e.g., air permeability, particle .
size distribution, moisture.content, etc.). . Ambient air will
. be pulled through the so.il within the radius of influence
generated around each vacuum well.
The floating petroleum product removal rate i~ dependent on
the rate the product enters each perforated well casing. This
system does not establish a cone of depression because very
little, if any, groundwater will be extracted by the slurp
tube. The product flows to the vacuum well because of a
difference in hydrostatic pressure.
The two phase flow rate (i.e.
tube and' vacuum header piping
can be manually controlled at
to achieve a desired floating
air and liquid in the drawdown
to the vacuum pump) at each well
the wellhead and may be changed
petroleum product removal rate.
-------
The air and liquid mixture from the vacuum wells will flow to
,a knock-out tank immediately upstream of the vacuum pump. The
purpose of the knock-out tank is to separate the liquid/air
streams. The liquid will be pumped from the tank to an oil
water separator. Petroleum product will be removed from the
tank by gravity flow. The product will either be reused,
recycled or sent off base for disposal. The effluent water
will either be treated using physical/chemical processes
before discharge to a surface water or subsurface or
discharged to the base wastewater treatment plant. The exit
air from the air/water separator tank will flow to an elevated
tip flare where the volatile hydrocarbons will be thermally
destroyed. Propane may be added to the exit air to maintain
desire4,cornbustion temperatures. .
Alternative 4:
soil Excavation I Free Product Removal
Under this alternative, soils overlying floating petroleum
products would be excavated and .treated to remove
contamination. The options for treating contaminated soils
include soil washing followed by land farming or
biorernediation. Soil washing segregates the soil particles by
size to separate larger soil particles from the smaller'
particles that contain the majority of the contamination. The
reduced volume of smaller soil particles would then be treated
by compost landfarming or bioremediation, both of which
enhance the biological degradation of petroleum in soils.
Recovered petroleum product recycling would occur as described
in Alternative 2. The excavated area would be backfilled with
clean soil.
This alternative was not evaluated for the refueling loop
(5T20), the powerplant area (ST48), or Building 1300 (ST49)
because the presence of existing buildings or runways preclude
the excavation of large areas of soils. This alternative was
only evaluated for the Biair Lakes Facility (SS50 through
S553).
Alternative 5
Bioventing
Bioventing is one of the technologies proposed for site
remediation at Eielson AFB. Petroleum hydrocarbons in the
environment are, to some extent, broken down by native
microorganisms. This is generally an aerobic process, in which
the limiting substrate is oxygen. Bioventing enhances this
natural biodegradation by supplementing oxygen to the native
organisms in the subsurface soil.
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Air is pumped through a system of manifolds by a pump. A low
volume of air is pumped through each of these manifolds which
can be controlled individually. These manifolds then
distribute the air to the subsurface. The air injection rate
is determined by two factors: there must be enough air flow to
assure an adequate'radius of influence, across the site, yet
the air flow should be as low enough to minimize surface
emissions. This is accomplished by saturating the soil with
air and adjusting air flow down to where the desired radius of
influence is maintained. The air is injected just above the
water table at approximately six feet.
Bioventing is monitored for microbial activity by measuring
respiration rate. Periodic soil borings will be taken and
analyzed to determine if the bioventing is significantly
enhancing product degradation. Potential surface emissions are
monitored by taking air samples at the surface of the site via
evacuated canisters. Methods for heating bioventing sites may
be utilized to extend the operating season and/or increase
microbiological activity. '
. ,
Although bioventing acts primarily to remediate petroleum-
contaminated soils, it is also applicable to the removal of
relatively thin layers of floating petroleum products, which
are difficult to pump effectively. One objective of
bioventing is to minimize further leaching of contaminants
from subsurface soils into the groundwater. In addition, as
the soil is remediated, the cleaner soils ~ay draw the
floating petroleum products up into the soil directly above
the groundwater where it can undergo biological degradation.
Discussion of ARARs
The purpose of the interim remedial action is to remove
floating petroleum product, a known source of contamination
from the groundwater surface until the final remedy is
implemented. This interim action is neither intended tQ
restore the aquifer to drinking water conditions, nor to
attain all federal and state ARARs relating to cleanup of the
'aquifer or the soil. The USAF, USEPA and ADEC expect that
such ARARs will be addressed by the final remedy to be
selected for the site.
The ARARs for this interim remedy relate to the treatment and
disposal of groundwater that is collected and treated during
implementation of the interim remedial action and for air
emissions resulting from the treatment.
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Air emissions resulting from the operations of a flare or an
air stripper to the extent that they meet the criteria of a
hazardous waste shall comply with the requirements of 40 CFR
265 Subparts AA & BBand the substantive requirements of State
of Alaska Air Quality Control regulations' (1SAAC 50).
(Alternatives 2,3 and 5) .
Spent carbon from a carbon adsorption unit and filters and/or
residual materials from the pretreatment system which meet the
criteria of a characteristic waste will be stored, treated,
recycled, or disposed of in accordance with the Resource
Conservation and Recovery Act, 40 CFR Parts 262-264, 266, and
268. (Alternatives 2,3 and 5)
To the extent that effluent will be discharged to surface.
water bodies or subsurface, such discharge shall comply with
the substantive requirements of Alaska Water Quality Standards
set forth in 18 AAC 70 and Alaska Wastewater Disposal
regulations set forth in 18 AAC 72. (Alternatives 2,3 and.5)
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VI: I: I:
Summary of the Comparative Analysis of Alternatives
EPA Evaluation criteria
The alternatives presented above were evaluated based on the
following nine EPA evaluation criteria. Brief definitions of
criteria are summarized below:
Threshold criteria
.
overall protection of human health and the
environment -- How well does the alternative protect
human health and the environment, both du~ing and
after construction?
.
compliance with regulations -- Does the alternative
meet all 'applicable or relevant and appropriate
state and federal laws?
Primary balancing criteria
.
long term effectiveness and permanence --
does the alternative'protect human health
environment after completion of cleanup?
any, risks will remain at the site?
How well
and 'the
What, if
.
reduction of toxicity, mobility, or volume through
treatment -- Does thea~tern~tive effectively treat
the contamination to significantly reduce the
toxicity, mobility, and volume of the hazardous
substances?
.
short term effectiveness -- Are
adverse effects to either human
environment, during construction
the alternative? How fast does
reach the , cleanup goals?
implementability -- Is the alternative both
technically and administratively feasible? Has the
technology been used successfully at similar sites?
there potential
health or the
or implementat~on of
the alternative
.
.
cost -- What are the relative costs of the
alternative?
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Modifying criteria
.
state/support agency acceptance -- What are the
state's comments or concerns about the alternatives
considered and about the preferred alternative?
Does the state support or oppose the preferred
alternative?
.
community acceptance -- what are the community's
comments or concerns about the alternatives
considered and about the preferred alternative?
Does the community generally support or oppose the
preferred alternative?
Evaluation of Alternatives
The following section compares the alternatives using the EPA
evaluation criteria.
Overall Protection of Human Health and the Environment.
Alternative 1 is not protective of human health and the
environment because the floating petroleum product would
continue to migrate into the groundwater increasing the area
of groundwater contamination.
Alternatives 2, 3, 4, and 5 enhance protection of human health
and the environment by minimizing fur~her degradation of the
groundwater through removal of the floating petroleum products
that are acting as' a continuing source of groundwater
contamination. In Alternatives 3, 4, and 5 the extraction by
treating petroleum products adhering to subsurface soils that
may also be acting as a source of groundwater contamination
further enhances protection of human health and the
environment.
compliance with Applicable or Relevant and Appropriate
Requirements. Because this interim action is focused on the
.removal of floating petroleum product, it is not anticipated
that groundwater or soil cleanup standards will be achieved.
Groundwater and soil cleanup standards will be addressed as
part of the final action for this operable unit. Applicable
or relevant and appropriate requirements will be met for
actions taken under Alternatives 2, 3, 4, and 5.
Short-Term Effectiveness. Alternatives 2, 3, and 4 would
begin floating petroleum product removal in the least amo~nt
of time. Alternative 5, which uses bioremediation in the
soils, would achieve floating petroleum product removal more
slowly than the other alternatives.
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Alternative 4 is constrained by existing underground utility
infrastructure and existing roadways, and requires excavation
and treatment of large volumes of soil.
Alternative 5 has been extensively described in the literature
and used for remediation in warmer climates~ However, the
viability of bioventing in colder climates is still being
tested and may impact implementation.
Cost. The relative estimated cost (minus 30% to plus 50%) for
each alternative at a given source is presented in table
below. The cost for Alternative 2 may increase if large
volumes of groundwater require treatment. The Cost of
Remedial Actions (CORA) model was used to develop the cost for
Alternatives 2 and 4. Alternatives 3 and 5 are innovative
technologies, thus making cost estimates more difficult. Cost
estimates were developed for these alternatives using cost
data from treatability studies. .
state Acceptance. The ADEC .has been involved with the
preparation of this Record of Decision and concurs with the
selected alternatives.
community Acceptance. The community has accepted the selected
remedies based on the community response to the proposed plan
and public meeting as documented in the attached
Responsiveness Summary.
Alternative 2 Alternative 3 Alternative 4 Alternative 5
ST20 Refueling. Loop Skimmer Pump Dual Pump Trenches Vacuum Extraction Excavation Bioventing
Capital 155 1710 290 279 NA2 125
O&M' 25 190 225 375 NA 375
Total 180 1900 515 654 NA 500
ST48 Power Plant Fuel Spill
Capital 310 1300 2760 252 NA2 NA3
O&M' 25 1450 2175 325 NA NA
Total 335 2750 4935 577 NA NA
ST49 Building 1300
Capital 2~5 990 2110 248 NA2 NA3
O&M' 25 1000 1400 275 NA
NA
Total 270 1990 3510 523 NA
NA
ST5D-53 Blair Lakes
Capital 155 880 1090 239 720 NA3,
O&M'
55 725 1050. 275 145 NA
Total 210 1605 2140 514 865
NA
1) Operati~g and Maintenance (O&M), costs are for a,projected 5 year length of operation.
2) Alternat~ve 4 was evaluated for Blair Lake~ only because of site constraints at the 'other areas.
3) Alternative 5 ~as evalu~ted for the Refueling Loop only. Relatively thick layers floating petroleum products at the other
areas make thIs alternative unfeasible. ,
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No short-term adverse impacts to workers or .the environment
during construction or operation are anticipated that could
not be readily addressed using standard engineering practices.
Long-term Effectiveness and Permanence. Although this interim
remedial action is not intended to fully address the statutory
mandate for permanence, the removal of floating petroleum
product which is a primary source of groundwater contamination
is in furtherance of the statutory mandate for permanence.'
The alternatives offer varying degrees of long-term
effectiveness and permanence, depending on the success. of the
technology. Removal of the floating petroleum products is the
critical first step toward cleanup by removing the continuing
source of groundwater contamination. .
Alternative 2 is intended to remove floating petr~leum product
only and is not designed to treat subsurface soils above the
groundwater table. Alternatives 3,4, and 5 would provide a
greater degree of long-term effectiveness and permanence by
addressing subsurface soil contamination that also may. be
acting as a continuing source of groundwater contamination.
Reduction of Toxicity, MObility, or Volume Through Treatment
The goal of Alternatives 2,3,4,and 5 is to significantly
reduce the volume of floating~etroleum product and to
minimize further migration of contamination into the
groundwater. Alternative 3, Vacuum Extraction, and
Alternative 5, Bioventing, would achieve this reducticn
through treatment by enhancing biodegradation of the petroleum
product in the vadose zone.
Implementability. Alternative 2 has been used with varying
degrees of success to address similar spills in the Fairbanks
area. However, this alternative may be limited. if large
volumes of groundwater are removed as part of the extraction
process. The extracted groundwater would require treat~ent
. before disposal.
Because it is still considered an innovative technology,
Alternative 3 may have difficulties that complicate full-scale
implementation.. However, if proven successful, this
alternative should produce smaller volumes of groundwater than
Alternative 2,
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IX
The Selected Remedy
The following alternatives were selected for the four areas in
QUl:
.
ST20 Refueling Loop E-7 Complex:
Bioventing
Alternative 5 -
ST20 Refueling Loop E-9 Complex:
Free Product Extraction
Alternative 2 -
.
ST48 Powerplant Fuel Spill Area:
Vacuum Extraction
Alternative 3 -
.
ST49 Building 1300: Alternative 2 - Free Product
Extraction
.
ST50 - ST53 Blair- Lakes Target Range:
- Free Product Extraction
Alternative 2
Remediation Goals
The primary goal and minimum objective of this interim action
is to-remove floating petroleum product from the groundwater
-in an attempt to co~~rol the source of continu{ng
- contamination~ The--Air Force will conduct free product
removal in a manner that minimizes the spread of contamination
into previously uncontaminated zones by using recovery and -
disposal techniques appropriate to hydrogeologic conditions at
the site. The Air Force will properly treat, discharge, or
dispose of recovery byproducts using methods approved by and
in compliance with federal, state, and local law.
Floating petroleum product will be removed to the extent
technically practicable as agreed to by the USAF, the USEPA
and the ADEC or until the final remedy for QUI is in place.
Performance of the selected remedy will be evaluated
periodically to determine if modifications are needed. -For
example, if in Alternative 2, static recovery systems
initially installed fail to recover suff~cient product, more
recovery systems will be installed, maintenance and pumping of
existing systems may be monitored more frequently, or the
system may be replaced with more traditional dual pump
systems, bioventing or vacuum extraction. It is the intent of
these projects to operate during the seasonal temperatures of
winter at Eielson. Based on changing site conditions or
implementability difficulties, it may be appropriate to modify
the system or utilize one of the other alternatives described
in this Record of Decision.
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ST20 Refueling Loop E-7 complex
Alternative 5 was selected for this site because of the
relatively thin layer of floating product and the favorable
subsurface geology, which allows sufficient airflow to
encourage bioremediation. Alternatives 2 and 3 were
eliminated because of the marginal cost effectiveness
associated with removal of thin layers of floating petroleum
products.
A treatability study began in the summer 1991. This study
will provide additional data to allow the treatment
alternative to be fully developed and evaluated and to reduce
cost and performance uncertainties.
ST20 Refueling Loop E-9 Complex
Alternative 2 was selected for this area. The relatively
thick layer of floating petroleum product and the large number'
of existing wells allow for rapid removal of significant
volumes of floating petroleum product. Alternatives 3 and 5
are constrained by the access and safety concerns caused by
the adjacent flightline.
ST48 Powerplant Fuel spill
Alternative 3 was selected because this relatively small area
of contamination is suitable for bioremediation. Alternative
3 is also expected to result in smaller volumes of groundwater
requiring treatment than.Alternative 2. Alternative 5 is not,
appropriate because it is not capable of removing floating
petroleum product of the thickness found at this site.
A vacuum extraction treatability study is planned for the fall
of 1992. This study will provide additional data to allow the
treatment alternative to be fully developed and evaluated.
ST49 Building 1300
Alternative 2 was selected for this area. The relatively
thick layer of floating petroleum product and the large number
of existing wells allow for rapid removal of significant
volumes of floating petroleum product. Alternatives 3 and 5
are constrained by the access and safety concerns caused by
the adjacent flightline.
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STSO through STS3 Blair Lakes Target Range Facility
Alternative 2 was selected for this facility because of the
large area affected by floating petroleum product.
Alternatives 3 and 5 would require an extensive number of
wells to treat an area of this size. Alternative 4 is not
preferred because contamination was identified under several
buildings, precluding excavation as a viable alternative.
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.X
STATUTORY DETERMINATIONS
This interim action is protective of human health and the
environment, complies with Federal and state applicable or
relevant and appropriate requirements for this limited scope
action, and is cost effective. 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 utilizes treatment and thus is in
furtherance of that statutory mandate.
Because this action does not constitute the final remedy for
the Eielson AFB Operable Unit.l site; the statutory preference
for remedies that employ treatment that reduces toxicity,
mobility, or volume as a principal element, although partially
address~d in this remedy, will be addressed by the final
response action.
Subsequent actions are planned to address fully the threa.ts
posed by the conditions at Operable Unit 1. Because this
remedy will result in hazardous substances remaining on site
above health-based levels, a review will be conducted to
ensure that the remedy continues to provide adequate
protection of human health and the env{ronment within five
years after commencement of the remedial action. Because this
is an interim action ROD, review of this site and of this
remedy will be continuing during development of final. remedial
alternatives for Operable unit 1. .
Protection of Human Health and the Environment
The selected remedy aids' protection of human health and the
environment by minimizing further degradation of the
groundwater through removal of the floating petroleum products
that are acting as a continuing source of groundwater
contamination. The vacuum extraction remedy selected for ST48
and the bioventing remedy selected for ST20 will also treat
residual subsurface soil contamination that may also be acting
as a source of groundwater contamination.
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Compliance with Applicable or Relevant and Appropriate
Regulations
The purpose of the interim remedial action is to remove
floating petroleum product, a known source of contamination
from the groundwater surface until the final remedy is
implemented. This interim action is neither intended to
restore the aquifer to drinking water conditions, nor to
attain all federal and state ARARs relating to cleanup of the
aquifer or the soil. The USAF, USEPA and ADEC expect that
such ~~s will be addressed by the final remedy to be
selected for the site.
The ARARs for this interim remedy relate to the treatment and
disposal of groundwater that is collected and treated during
implementation.of the interim remediai action and for air
emissions resulting from the treatment.
Air emissions resulting from the operations of a flare or an
air.stripper to the extent that they meet- the criteria of a
hazardous waste shall comply with the requirements of 40 CFR.
265 .Subparts AA & BB and the substantive requirements of State
of Alaska Air Quality Control regulations (18AAC 50).
(Alternatives 2,3 and 5)
Spent carbon from a.carbon adsorption unit and filters and/or
residual. materials .from the pretreatment system which meet the
criteria of a characteristic waste will be stored, treated,
recy~led, or disposed of in accordance with the Resource
~onservation and Recovery Act, 40 CFR Parts 262-264, 266, and
268. (Alternatives 2,3 and 5)
To the extent that effluent will be discharged to surface
water bodies or subsurface, such discharge shall comply with
the substantive requirements of Alaska Water Quality Standards
set forth in 18 AAC 70 and Alaska Wastewater Disposal. -
regulations set forth in 18 AAC 72. (Alternatives 2,3 and 5)
Cost Effectiveness
The selected remedy is cost effective because it provides
overall effectiveness proportionate to the cost.
utilization of Permanent Solutions and Alternative Treatment
Technologies
This inte~im action is not designed or expected to be the
final action for OU1, but the selected remedy represents the
best balance of trade-offs among the alternatives with respect
to the degree of overall protection of human health and the
environment, compliance with ARARs, implementablity and cost
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effectiveness, given the limited scope of this action.
preferenc~ fo~ Treatment as a Principal Element
Because this action does not constitute the final remedy for
Operable Unit 1, the statutory preference for a remedy that
employs treatment that reduces toxicity, mobility, or volume
as a principal element, although partially addressed in this
remedy, will be addressed by the final response action.
The selected remedies will significantly reduce the volume of
floating petroleum product on the top of the water table and
minimize further migration of contamination. The vacuum
extraction and bioventing remedies reduce toxicity through
removal and treatment of contaminants from subsurface soils~
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