PB96-964605
EPA/ROD/R10-96/137
June 1996
EPA Superfund
Record of Decision:
Fort Wainwright, Operable Unit 3,
Fairbanks-North Star Borough, AK
4/9/1996
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RECORD OF DECISION
for
OPERABLE UNIT 3
FORT WAINWRIGHT
FAIRBANKS, ALASKA
JANUARY 1996
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DECLARATION STATEMENT
for
RECORD OF DECISION
FORT WATNWRIGHT
FAIRBANKS, ALASKA
OPERABLE UNIT 3
JANUARY 1996
SITE NAME AND LOCATION
Operable Unit 3
Fort Wainwright
Fairbanks, Alaska
STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) presents the selected remedial actions for Operable Unit 3 at
Fort Wainwright in Fairbanks, Alaska. Operable Unit 3 comprises the following areas: the
Tank Farm; the Railcar Off-Loading Facility; and Mileposts 2.7, 3.0, and 15.75 of the
Fairbanks-Eielson Pipeline. The ROD was developed in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 as amended by the
Superfund Amendments and Reauthorization Act of 1986; 42 United States Code, Section
9601 et seq.; and, to the extent practicable, in accordance with the National Oil and Hazard-
ous Substances Pollution Contingency Plan, 40 Code of Federal Regulations 300 et seq. This
decision is based on the Administrative Record for this operable unit.
The United States Army; the United States Environmental Protection Agency; and the State of
Alaska, through the Alaska Department of Environmental Conservation, have agreed to the
selected remedies.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from the site, if not addressed by imple-
menting the response action selected in this ROD. may present an imminent and substantial
endangerment to public health, welfare, or the environment. Specific hazardous substances
include benzene, toluene, ethylbenzene, xylenes, 1,2-dichloroethane, isopropylbenzene,
trimethylbenzene, and inorganic lead.
DESCRIPTION OF SELECTED REMEDIES
This is the first operable unit to reach a final-action ROD. This ROD addresses soil and
groundwater contamination at Operable Unit 3.
The remedies were selected to reduce and prevent the risks associated with potential current
or future exposure to the contaminants. The remedial action objectives of this ROD are
designed to:
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• Restore groundwater to drinking water quality;
• Clean up soil to prevent further leaching of contaminants into grou-
ndwater; and
• Reduce or prevent further migration of contaminated groundwater.
The major components of the remedies are:
• In situ soil vapor extraction and air sparging of groundwater will be
implemented to remove fuel-related contaminants to a level that
attains Safe Drinking Water Act levels; and
• After achieving Safe Drinking Water Act levels, natural attenuation
will be relied upon to attain Alaska Water Quality Standards.
Groundwater monitoring will be used to evaluate effectiveness of selected remedies and to
ensure that cleanup standards are attained.
STATUTORY DETERMINATIONS
The selected remedies are protective of human health and the environment, comply with state
and federal requirements that are legally applicable or relevant and appropriate to the remedial
actions, and are cost-effective. The remedies utilize permanent solutions and'alternative
treatment to the maximum extent practicable and satisfy the statutory preference for remedies
that employ treatment to reduce toxicity, mobility, or volume as a principal element.
Because the remedy will result in hazardous substances remaining on site above health-based
levels, a review will be conducted within five years after commencement of remedial action.
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r
Signature sheet for the foregoing Operable Unit 3,' Fort Wainwright, Record of Decision
between the United States Army and the United States Environmental Protection Agency,
Region X, with concurrence by the Alaska Department of Environmental Conservation.
Robert L. OrdJII
Lieutenant General,U.S. Army
Commanding
Date
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n
Signature sheet for the foregoing Operable Unit 3, Fort Wainwright, Record of Decision
between the United States Army and the United States Environmental Protection Agency,
Region X, with concurrence by the Alaska Department of Environmental Conservation.
Chuck Clarke Date
Regional Administrator, Region X
United States Environmental Protection Aeencv
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Signature sheet for the foregoing Operable Unit 3, Fort Wainwright, Record of Decision
benveen the United States Army and the United States Environmental Protection Agency,
Region X, with concurrence by the Alaska Department of Environmental Conservation.
• Kur/Fre^iksson bate7
Director, Spill Prevention and Response
Alaska Department of Environmental Conservation
VI
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TABLE OF CONTENTS
Section Page
DECLARATION STATEMENT ii
1.0 SITE NAME, LOCATION, AND DESCRIPTION .2
1.1 SITE LOCATION AND DESCRIPTION 2
1.1.1 Tank Farm Source Area 2
1.1.2 Railcar Off-Loading Facility Source. Area 5
1.1.3 Milepost Source Areas 5
1.2 HYDROGEOLOGY 8
1.3 LAND USE 10
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES , 11
2.1 SITE HISTORY 11
2.1.1 Tank Farm Source Area 11
2.1.2 Railcar Off-Loading Facility Source Area 11
2.1.3 Milepost Source Areas 11
2.2 ENFORCEMENT ACTIVITIES 12
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 13
4.0 SCOPE AND ROLE OF OPERABLE UNIT OR RESPONSE ACTION 14
5.0 SITE CHARACTERISTICS 15
5.1 TANK FARM SOURCE AREA 15
5.1.1 Hydrogeology and Groundwater Use 15
5.1.2 Current Land Use 16
5.1.3 Previous Investigations . 16
5.1.4 Remedial Investigation Results 16
5.1.5 Remedial Results for Soils 17
5.1.6 Remedial Investigation Results for Groundwater 19
5.2 RAILCAR OFF-LOADING FACILITY SOURCE AREA 21
5.2.1 Hydrogeology and Groundwater Use 21
5.2.2 Current Land Use 21
5.2.3 Previous Investigations 21
5.2.4 Remedial Investigation Results 22
5.2.5 Remedial Investigation Results for Soils 22
5.2.6 Remedial Investigation Results for Groundwater 23
5.3 MILEPOST SOURCE AREAS 24
5.3.1 Milepost 2.7 24
5.3.2 Milepost 3.0 25
5.3.3 Milepost 15.75 27
6.0 SUMMARY OF SITE RISKS 73
6.1 HUMAN HEALTH RISKS 73
6.1.1 Contaminant Screening and Evaluation 73
vii
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Table of Contents (Cont.)
Section Page
6.1.2 Exposure Assessment 74
6.1.3 Toxicity Assessment 76
6.1.4 Risk Characterization : 77
6.1.5 Major Uncertainties 81
6.2 ECOLOGICAL RISKS . 82
6.2.1 Summary of Uncertainties 83
7.0 REMEDIAL ACTION OBJECTIVES 85
7.1 NEED FOR REMEDIAL ACTION 85
7.2 REMEDIAL ACTION OBJECTIVES 86
7.2.1 Groundwater 86
7.2.2 Soil 86
7.3 GOALS OF REMEDIAL ACTION 86
7.3.1 Groundwater 86
7.3.2 Soil 87
7.4 APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS 87
8.0 SUMMARY OF REMEDIAL ACTION ALTERNATIVES 88
8.1 REMEDIAL AREAS 88
8.2 REMEDIAL ACTION ALTERNATIVE TECHNOLOGIES 88
8.2.1 No Action 88
8.2.2 Institutional Controls 88
8.2.3 Remedial Areas Ib, 2, and 3: Soil Vapor Extraction of
Petroleum-Contaminated Soil 90
8.2.4 Remedial Areas Ib, 2, and 3: Steam Injection of Petroleum-
Contaminated Soil 90
8.2.5 Remedial Areas Ib, 2, and 3: Bioventing of Petroleum-
Contaminated Soil 91
8.2.6 Remedial Area 3: Soil Pile Aeration of Petroleum-
Contaminated Soil 91
8.2.7 Remedial Areas Ib, 2, and 3: Bioremediation of
Petroleum-Contaminated Groundwater 91
8.2.8 Remedial Areas Ib, 2, and 3: Air Stripping and Carbon
Adsorption of Petroleum-Contaminated Groundwater 91
8.2.9 Remedial Areas Ib, 2, and 3: Air Sparging of Petroleum-
Contaminated Groundwater 91
9.0 REMEDIAL ALTERNATIVE EVALUATION .93
9.1 ALTERNATIVES FOR REMEDIAL AREA IB 93
9.2 EVALUATION OF ALTERNATIVES FOR REMEDIAL AREA IB . . 96
9.2.1 Overall Protection of Human Health and the Environment .... 96
9.2.2 Compliance with Applicable or Relevant and Appropriate
Requirements 96
9.2.3 Long-Term Effectiveness and Permanence 97
viii
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Table of Contents (Cont.)
Section Page
9.2.4 Reduction of Toxicity, Mobility, and Volume Through
Treatment 97
9.2.5 Short-Term Effectiveness 97
9.2.6 Implementability 97
9.2.7 Cost 98
9.2.8 State Acceptance 98
9.2.9 Community Acceptance 98
9.3 ALTERNATIVES FOR REMEDIAL AREA 2 100
9.4 EVALUATION OF ALTERNATIVES FOR REMEDIAL AREA 2 . . 102
9.4.1 Overall Protection of Human Health and the Environment . . . 102
9.4.2 Compliance with Applicable or Relevant and Appropriate
Requirements 102
9.4.3 Long-Term Effectiveness and Permanence 103
9.4.4 Reduction of Toxicity, Mobility, and Volume Through
Treatment 103
9.4.5 Short-Term Effectiveness 103
9.4.6 Implementability 104
9.4.7 Cost 104
9.4.8 State Acceptance 104
9.4.9 Community Acceptance 104
9.5 ALTERNATIVES FOR REMEDIAL AREA 3 108
9.6 EVALUATION OF ALTERNATIVES FOR REMEDIAL AREA 3 . . 109
9.6.1 Overall Protection of Human Health and the Environment ... 109
9.6.2 Compliance with Applicable or Relevant and Appropriate
Requirements 109
9.6.3 Long-Term Effectiveness and Permanence 110
9.6.4 Reduction of Toxicity, Mobility, and Volume Through
Treatment 110
9.6.5 Short-Term Effectiveness 110
9.6.6 Implementability 110
9.6.7 Cost Ill
9.6.8 State Acceptance Ill
9.6.9 Community Acceptance Ill
10.0 SELECTED REMEDIES 114
11.0 STATUTORY DETERMINATIONS 117
11.1 PROTECTIVE OF HUMAN HEALTH AND THE
ENVIRONMENT 117
11.2 ATTAINMENT OF APPLICABLE OR RELEVANT AND
APPROPRIATE REQUIREMENTS OF ENVIRONMENTAL LAWS . 117
11.2.1 Action-Specific Applicable or Relevant and
Appropriate Requirements 117
11.2.2 Chemical-Specific Applicable or Relevant and
Appropriate Requirements 118
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Table of Contents (Cont.)
Section
Page
11.2.3 Location-Specific Applicable or Relevant and
Appropriate Requirements 118
11.2.4 Information To-Be-Considered 119
11.3 COST EFFECTIVENESS 119
11.4 UTILIZATION OF PERMANENT SOLUTIONS AND
ALTERNATIVE TREATMENT TECHNOLOGIES TO THE
MAXIMUM EXTENT PRACTICABLE 119
11.5 USE OF PERMANENT SOLUTIONS, ALTERNATIVE
TREATMENT, OR RESOURCE RECOVERY TECHNOLOGIES
TO THE MAXIMUM EXTENT PRACTICABLE 119
11.6 PREFERENCE FOR TREATMENT AS A PRINCIPAL
ELEMENT 120
12.0 DOCUMENTATION OF SIGNIFICANT CHANGES 121
12.1 PROPOSED ALTERNATIVE 121
12.2 SIGNIFICANT CHANGES 121
12.3 REASON FOR CHANGE 121
Appendix
A RESPONSIVENESS SUMMARY A-l
B ADMINISTRATIVE RECORD INDEX B-1
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LIST OF TABLES
Table Page
1 Summary of Groundwater Sampling Results, Off Post Wells 42
2 Summary of Surface and Subsurface Soil Results, Tank Farm—Birch Hill
AST Sub-Area 43
3 Summary of Surface and Subsurface Soil Results, Tank Farm—Building 1173
Sub-Area 45
4 Summary of Surface and Subsurface Soil Results, Tank Farm—Truck Fill
Stand Sub-Area . . 47
5 Summary of Surface and Subsurface Soil Results, Lazelle Road Sub-Area 48
6 Summary of Surface and Subsurface Soil Results, Shannon Park Subdivision
Sub-Area 49
7 Summary of Subsurface Soil Results, Tank Farm—CANOL Service Road
Sub-Area 50
8 Summary of Subsurface Soil Results, Tank Farm—Valve Pit A Sub-Area 51
9 Summary of Groundwater Results, Tank Farm—Birch Hill AST Sub-Area 52
10 Summary of Groundwater Results, Tank Farm—Building 1173 Sub-Area 53
11 Summary of Groundwater Results, Tank Farm—Truck Fill Stand Sub-Area 54
12 Summary of Groundwater Results, Lazelle Road Sub-Area 55
13 Summary of Groundwater Results, Shannon Park Subdivision Sub-Area 56
14 Summary of Groundwater Results, CANOL Road Sub-Area 57
15 Summary of Groundwater Results, Tank Farm—Valve Pit A Sub-Area 58
16 Summary of Subsurface Soil Results, ROLF—Valve Pit B Sub-Area 59
17 Summary of Surface and Subsurface Soil Results, Central ROLF Sub-Area 60
18 Summary of Subsurface Soil Sample Results, ROLF—Front Street Sub-Area .... 62
19 Summary of Groundwater Results, ROLF—Valve Pit B Sub-Area 63
20 Summary of Groundwater Results, Central ROLF Sub-Area 64
21 Summary of Groundwater Sample Results, ROLF—Front Street Sub-Area 65
22 Summary of Surface and Subsurface Soil Results, Pipeline Milepost 2.7 Source
Area 66
23 Summary of Groundwater Results, Pipeline Milepost 2.7 Source Area 68
24 Summary of Subsurface Soil Results, Pipeline Milepost 3.0 Source Area 69
25 Summary of Groundwater Results, Pipeline Milepost 3.0 Source Area 70
26 Summary of Surface and Subsurface Soil Results, Pipeline Milepost 15.75 Source
Area 71
27 Summary of Groundwater Results, Milepost 15.75 Source Area 72
28 Contaminants of Potential Concern, Human Health Risk Assessment 75
29 Current and Future RME Excess Lifetime Cancer Risks 78
30 Current and Future RME Hazard Indices 79
31 Contaminated Media Volume Estimates 89
32 United States Environmental Protection Agency's Nine Evaluation Criteria 94
XI
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33 Remedial Area Ib—Cost Comparison Table 95
.34 Remedial Area 2—Cost Comparison Table 101
35 Remedial Area 3—Cost Comparison Table 107
XII
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LIST OF ILLUSTRATIONS
Figure Page
1 Fort Wainwright Location Map 3
2 Tank Farm Source Area Location Map 4
3 Railcar Off-Loading Facility (ROLF) Source Area Location Map 6
4 Mileposts 2.7 and 3.0 Source Areas 7
5 Milepost 15.75 Source Area 9
6 North-South Geologic Cross Section from the ASTs to the TFS 29
7 Tank Farm Source Area Soil Borings and Monitoring Wells Location Map 30
8 East-West Geologic Cross Section C-C' of Tank Farm Sub-Area 31
9 Tank Farm Sub-Area Location Map • ... 32
10 Maximum Lead Concentrations in Surface Soil, Birch Hill AST Sub-Area ...... 33
11 Total BTEX and Fuel ID Concentrations, TFS Sub-Area 34
.12 Total BTEX and Fuel ID Concentrations, Valve Pit A Sub-Area . 35
13 Benzene Concentrations in Groundwater Samples at the Tank Farm
Source Area - 36
14 Railcar Off-Loading Facility Sub-Area Map 37
15 Total BTEX and Fuel ID Concentrations, Railcar Off-Loading Facility-
Valve Pit B Sub-Area Cross Section 38
16 Benzene Concentrations in Groundwater at the Railcar Off-Loading
Facility 39
17 Benzene Concentrations in Groundwater at Milepost 2.7 and 3.0
Source Areas 40
18 Benzene Concentrations in Groundwater at Milepost 15.75 Source Area 41
19 Remedial Area Ib, Groundwater Injection and Extraction Well Placement,
Truck Fill Stand and Building 1173 99
20 Remedial Area 2, Groundwater Injection and Extraction Well Placement,
Tank Farm Source Area—Valve Pit A 105
21 Remedial Area 2, Groundwater Injection and Extraction Well Placement
(Options 3, 4 & 5), Railcar Off-Loading Facility (ROLF) Source Area 106
22 Remedial Area 3, Groundwater Injection and Extraction Well Placement,
Pipeline Milepost 2.7 & 3.0 Source Areas 112
23 Remedial Area 3, Groundwater Injection and Extraction Well Placement,
Pipeline Milepost 15.75 113
XIII
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LIST OF ACRONYMS
AAC Alaska Administrative Code
ADEC Alaska Department of Environmental Conservation
ARARs Applicable or relevant and appropriate requirements
ASTs Aboveground storage tanks
BGS Below ground surface
BTEX Benzene, toluene, ethylbenzene, and total xylenes
CANOL Canadian Oil Line
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
cfm Cubic feet per minute
Corps United States Army Corps of Engineers, Alaska District
COPCs Chemicals of potential concern
COCs Contaminants of concern
EPA United States Environmental Protection Agency
EPCs Exposure point concentrations
ERA Ecological Risk Assessment
FFA Federal facility agreement
FS Feasibility Study
GRO Gasoline-range organics
HHRA Human Health Risk Assessment
MCL Maximum contaminant level
MCLG Maximum Containment Level Goals
/ig/L Micrograms per liter
mg/kg Milligrams per kilogram
mg/L Milligrams per liter
MSL Mean sea level
MUS Municipal Utilities System
NCP National Contingency Plan
NOAELs No observed adverse effect levels
NPL National Priorities List
OU-3 Operable Unit 3
RBCs Risk-based concentrations
RCRA Resource Conservation and Recovery Act
RI Remedial Investigation
RfDs Reference doses
RME Reasonable maximum exposure
ROD Record of Decision
ROLF Railcar Off-Loading Facility
SARA Superfund Amendments and Reauthorization Act
TCLP Toxicity characteristic leaching procedure
TFS Truck Fill Stand
USC United States Code
USTs Underground storage tanks
VES Vapor extraction system
VOC Volatile organic compound
XIV
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RECORD OF DECISION
FORT WAINWRIGHT
FAIRBANKS, ALASKA
OPERABLE UNIT 3
JANUARY 1996
This Record of Decision for Operable Unit 3 presents the remedial alternatives considered,
provides the rationale for the remedial actions selected, and states how the remedial actions
satisfy the Comprehensive Environmental Response, Compensation, and Liability Act of 1980
(CERCLA) statutory requirements. Fort Wainwright was listed on the National Priorities List
in August 1990 under CERCLA, as amended by the Superfund Amendments and Reauthoriza-
tion Act of 1986.
The United States Army completed a Remedial Investigation (RI) to provide information
regarding the nature and extent of soil and groundwater contamination. A baseline Risk
Assessment was developed and used in conjunction with the RI to determine the need for
remedial action and to aid in selecting remedies. A Feasibility Study was completed to
evaluate remedial options.
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1.0 SITE NAME, LOCATION, AND DESCRIPTION
1.1 SITE LOCATION AND DESCRIPTION
Fort Wainwright, also referred to as ihe site, is located on the east edge of the City of
Fairbanks in the Fairbanks-North Star Borough in interior Alaska (see Figure 1). Primary
missions at Fort Wainwright include training of infantry soldiers in the arctic environment,
testing of equipment in arctic conditions, preparation of troops for defense of the Pacific Rim,
and rapid deployment of troops worldwide. On-site industrial activities include fixed-wing
aircraft, helicopter, and support vehicle maintenance. The 918,000-acre site includes the
main post area, a range complex, and two maneuver areas.
Fort Wainwright originally was established as a cold-weather testing station in 1938.
Renamed Ladd Army Airfield in 1939. the site next served as a resupply point for remote
field stations and a crew transfer point in the Lend-Lease Program through which military
aircraft and other supplies were ferried to the Soviet Union during World War II. In 1947,
the site was redesignated as Ladd Air Force Base and began serving as a resupply and
maintenance base for remote distance early warning sites and experimental stations in the
Arctic Ocean. The site was renamed Fort Wainwright on January 1, 1961, and all of its
operations were transferred to the United States Army.
Most of Operable Unit 3 (OU-3) is located in the main cantonment area of Fort Wainwright.
It consists of the following source areas: the Tank Farm on Birch Hill and associated Truck
Fill Stand (TFS) at the base of Birch Hill, a Railcar Off-Loading Facility (ROLF), and three
mileposts along the Fairbanks-Eielson Pipeline (Mileposts 2.7, 3.0, and 15.75). Figure 1
illustrates the entire installation and each source area.
1.1.1 Tank Farm Source Area
The Tank Farm is located north of the main cantonment area and is illustrated in Figure 2.
The boundaries of this source area extend from the aboveground storage tanks (ASTs) on
Birch Hill to Valve Pit A, which is on the northwest bank of the Chena River. The Tank
Farm includes 14 bolted-steel, 10,000-barrel tanks and two welded-steel, 25,000-barrel tanks
on the southwest slope of Birch Hill: three buildings; two underground storage tanks (USTs);
pipelines connecting the tanks; two welded-steel, 2,250-barrel ASTs at the TFS area; the
Canadian Oil Line (CANOL) pipeline: and Valve Pit A.
All the tanks were used to store fuel for Fort Wainwright and Eielson Air Force Base. Fuel
stored in the tanks included arctic-grade diesel fuel, aviation-grade leaded gasoline, aircraft
turbine and jet engine fuel (JP-4), leaded vehicle motor gasoline, and unleaded and regular
motor fuel. All tanks have been emptied and cleaned. The pipelines have been purged. The
two original USTs were removed; one was replaced with a double-walled tank in the 1980s.
The elevation of the north section of the Tank Farm, the AST area on Birch Hill, ranges from
441 feet to 748 feet above mean sea level (MSL). Except in developed areas, Birch Hill is
densely forested. No permanent surface water bodies are located on Birch Hill near the
ASTs. However, snow and ice meltwater accumulate in the depressions and in the diked
areas around the ASTs.
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CORPS OF ENGINEERS
U.S. ARMY
BIRCH HILL UST
FACILITY
SHANNON PARK
BAPIST CHURCH
MORMON CHURCH
BIRCH
HILL SKI
AREA
SHANNON PAW
SUBDIVISION
_. FAIRBANKS-EIELSON
O\ PIPELINE MILEPOST 2.7
OPFRABLF UNIT .l-SOURCF AREAS
rAIRBANKS-CIELSON
PIPELINE MILEPOST 1.0
RAILCAR
OFF-LOADING
FACILITY
LAURANCE ROAD
•-801 HOUSING
AMILTONJ SUBblVlJlON
FORT WAINWRIGHT —
DRINKING V
U 5 ARMY
INUINUR DlbfRICr. ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
Figure 1
FORT WAINWRIGHT
LOCATION MAP
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CORPS OF ENGINEERS
U S. ARMY
RESERVATION BOUNDARY
TRUCK FILL
STAND AREA
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
\\BIRCH HILL ROAD
0 250 500 1.000 1,500 2.000
5CAU: FtEl
Figure 2
TANK FARM
LEGEND
ROAD
— INTERMITTANT DRAINAGE SLOUCH
FORT WAINVKRIGHT
BOUNDARr
SOURCE AREA
LOCATION MAP
PIPELINE
FENCE
RAILROAD
ABOVEGROUNO STORAGE TANK.
IDENTIFICATION NUWER.
AND RECENT CONTENTS
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The south section of the Tank Farm, including the TFS area and Valve Pit A, is located in the
Chena River floodplain. This section is characterized by nearly flat topography that gently
slopes southward. The subsurface is typified by discontinuous permafrost and poorly drained
soils covered by thick organic mats. Surface water ponding is common throughout the area
from spring breakup until early to mid-summer. Wetlands are scattered throughout the area.
. 1.1.2 Railcar Off-Loading Facility Source Area
The ROLF, which is located south of the Tank Farm, is illustrated in Figure 3. A pipeline
connects the ROLF to the Tank Farm. The ROLF is bounded on its north and west sides by
the Chena River and Gaffney Road on the south side. The ROLF was built in 1939 to receive
fuel from tanks on railcars and to distribute the fuels to the airfield refueling points, quarter-
master fuel, and the Birch Hill AST Tank Farm. The facility is no longer used, but the
following structures are still present: a TFS, one area with 16-tank-car unloading headers and
another with eight-tank-car unloading headers, three 8-inch and four 3-inch pipelines that
traverse the facility, five valve pits (B, C, D, E, and F), and two warehouses (Buildings 1129
and 1130). Fuel was stored in USTs at this facility until they were removed in 1990.
The ROLF is located on a nearly flat floodplain of the Chena River. Brush and birch trees
grow along the Chena River and adjacent to Valve Pits B and C. Trees and brush have been
cleared elsewhere in the ROLF. Surface water bodies are not present in the central region of
the ROLF. A steep west-facing embankment is west of Valve Pit C. Small ponds and
wetlands occur in the area between the embankment and the Chena River.
1.13 Milepost Source Areas
The Fairbanks-Eielson Pipeline was constructed in 1953 and 1954 and put into service in 1955
to transport fuel from Haines to Fairbanks. The portion of the pipeline between Fort
Wainwright and the Mapco refinery was decommissioned in 1992. Spills have been reported
at two locations along the pipeline at Milepost 2.7 and at Laurance Road and Robyn Drive in
the City of North Pole (Milepost 15.75). Contamination was detected at Milepost 3.0 during
an investigation of the Birch Hill UST facility.
The Milepost 2.7 Source Area includes areas that were contaminated by the pipeline break.
TFSs 1 and 2, a water separator, valve pits, and some pipelines associated with the Birch HU1
UST facility. Figure 4 illustrates Milepost 2.7. The Milepost 2.7 Source Area consists of a
moderately to steeply south-facing hillside north of the pipeline and a shallow, south-facing
slope south of the pipeline. The source area is located within a surface water drainage
pathway from the upland Birch Hill UST facility, northeast of the pipeline source area. Soils
in the Milepost 2.7 Source Area are poorly drained. Ponded surface water is common from
spring breakup until mid-summer. A black spruce-scrub-shrub wetland borders the south side
of the source area. The area is densely vegetated. Discontinuous permafrost is typical in the
area's subsurface soils.
The Milepost 3.0 Source Area includes contaminated areas associated with the Fairbanks-
Eielson Pipeline, a TFS, a water separator, valve pits, and some pipelines associated with the
Birch Hill UST facility (see Figures 1 and 4). Site descriptions provided for Milepost 2.7
are accurate for the Milepost 3.0 Source Area as well.
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CORPS OF ENGINEERS
I) S ARM i
TRA>NER GATE\
RAILROAD
• -^—r vjnwtL.
r: r-1; r-^ MOGAS
VALVE//PIT n-'
16 TANK CAR
UNLOADING HEADERS
V«VE PIT E
ALVE PIT E
EORMER LOCATION Of
EIGHT TANK C
UNLOAD ING
HEADERS
LEGEND
===^ ROAD
— -._. DRAINAGE SLOUGH
I1 FORMER UST LOCATION
.-'"" PIPELINE LOCATION
tod cBTtronmtQl, lac.
U S ARMY
ENGINEER OMRICT ALA4M
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
CAll ( A(\
FAIRBANKS
Figure 3
I I >AOIN<'. I Al II II | (!•'( l| I
SOURCt AKfA
LOCATION MAP
ya.
a
joe NO
.IT2040
FILE NO
J12I 1C DWG
DATE.
04 -19-
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02. H.\lir>lUC/iO ...V..UH
n irs i
KEY:
TFS Truck Fill Stand
VP Valve Pit
NOT TO SCALE
pipri INI: MM EPOST 2.7
FAIRBANKS-ElllSON PIPELINE
PIPELINE MIIEPOST 30
TFS-3
BIRCH HILL
Figure 4 MILEPOST 2.7 AND 3.0 SOURCE AREAS
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The Milepost 15.75 Source Area is located in a residential area approximately 1 mile south of
North Pole between the Chena River to the nonh and east and the Tanana River to the west.
The source area is located on an off-post right-of-way for a military fuel pipeline. Figure 5
illustrates Milepost 15.75. This source area includes all contaminated areas associated with a
fuel spill from a 1989 underground pipeline break. The site is flat except for drainage ditches
that parallel Laurance Road. The drainage ditch on the south side of Laurance Road usually
.contains water. Soils in the area are sandy with little gravel and generally are moderately
well-drained. The surrounding area is forested with trees and shrubs.
1.2 HYDROGEOLOGY
The main aquifer in the Fort Wainwright area, including the Milepost 15.75 Source Area, is
an alluvial aquifer in a buried river valley. According to United States Geological Survey
maps, this aquifer ranges from a few feet thick at the base of Birch Hill to at least 300 feet
thick under the fort's main cantonment area. The aquifer may reach a thickness of 700 feet in
the Tanana River valley.
Groundwater in the Tanana-Chena floodplain generally occurs under unconfmed conditions.
A confined layer of groundwater may develop seasonally where the depth to the water table is
less than the depth of the seasonal frost penetration. A confined groundwater layer also may
occur beneath permafrost, where the frozen ground forms a wall around the water.
The depth to groundwater at the fort varies from approximately 20 feet at the base of Birch
Hill to 7 feet below ground surface (BGS) south of the Fort Wainwright airfield. Close to the
Chena River, the depth to groundwater may range from 5 feet to 15 feet. The depth to
groundwater in the North Pole area by the Tanana River varies from 5 feet to 10 feet BGS.
It should be noted that the depth to groundwater varies with seasonal changes, changes to the
normal weather trends, and the stages of the Tanana and Chena Rivers.
Groundwater movement between the Tanana and Chena Rivers follows a northwest regional
pattern but fluctuates seasonally because of the effects of changing river stages. Although the
level of the Chena River is controlled, seasonal fluctuations in levels do occur.
Groundwater levels near the Chena River may fluctuate greatly because of river stages.
Typically, groundwater levels increase when the river stage increases, particularly during
spring breakup and late summer runoff. Groundwater levels usually decrease during fall and
winter, when precipitation becomes snow. When river water levels go down, the groundwa-
ter seeps into surface water bodies, such as the Chena River.
In addition to shifts in the groundwater flow direction because of the surface water hydrology,
the groundwater flow direction may be impacted by high-volume pumping for dewatering
operations.
Where present, permafrost forms discontinuous confining layers that influence groundwater
movement and distribution. The presence of near-surface permafrost usually restricts
groundwater movement within the shallow subsurface. Three types of aquifers are associated
with permafrost: suprapermafrost aquifers, intrapermafrost aquifers, and subpermafrost
aquifers. A suprapermafrost aquifer is situated above the permafrost table in the active layer,
and the permafrost tables act as a relatively impermeable basal boundary. Suprapermafrost
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02: K\JTXDU3G«OJ COR
DRAINAGE DITCH
O
03
PIPELINE MILE 15.75
(Intersection of Robyn Dr. and Laurance Road, North Pole, Alaska)
DRAINAGl DITCH
-x-
FAIRBANKS-EIELSON RPEUNE
/fiPPROXIMATE LOCAnON
OF PIPELINE BREAK
LAURANCE ROAD
DRAINAGE DITCH
Figure 5 MILEPOST 15.75 SOURCE AREA
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aquifers are usually seasonal aquifers that freeze or experience significant storage depletion in
the winter. Many of the monitoring wells at Fort Wainwright and some domestic wells are
completed in the suprapermafrost aquifer. Intrapermafrost aquifers are found in unfrozen
talik zones within the body of permafrost. Subpermafrost aquifers are situated below the
permafrost serving as a relatively impermeable boundary.
• Groundwater characterization conducted during the Remedial Investigation (RI) indicates the
presence of thaw channels in the Tank Farm area.
The Chena River flows through Fort Wainwright to the City of Fairbanks and into the Tanana
River. The ROLF, Valve Pit A, and Valve Pit B are located directly on the banks of the
Chena River. The wells that are located downstream along the Chena River include the
Fairbanks Municipal Utilities System (MUS; 1 mile), College Utilities (1:5 miles), and
numerous residential wells located on the north bank of the river less than 0.5 mile down-
stream.
1.3 LAND USE
Land use at the OU-3 source areas is generally light industrial. There are residential areas
directly adjacent to and hydrogeologically downgradient of the Tank Farm Source Area and
Milepost 15.75. Recreational uses are known to occur at all source areas because of the
presence of the Chena River and dense wooded areas.
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2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 SITE HISTORY
The Tank Farm and associated TFS are part of the Fairbanks Fuel Terminal, which was
constructed in 1943 beginning with the installation of the fourteen 10,000-barrel-capacity,
bolted-steel tanks on Birch Hill. The mission of the Fairbanks Fuel Terminal was to provide
backup fuel support for Eielson Air Force Base. Fuel was transported via the CANOL
pipeline and the Haines-Fairbanks pipeline. At Fort Wainwright, the CANOL pipeline
connected the Birch Hill UST facility to the ROLF and ran west to the Tank Farm. The
portion of the pipeline between the ROLF and the Tank Farm remains in place. The Haines-
Fairbanks pipeline was constructed from 1954 to 1955. The only active portion of this
pipeline, now called the Fairbanks-Eielson Pipeline, runs between Eielson Air Force Base and
the Mapco refinery in North Pole.
2.1.1 Tank Farm Source Area
Petroleum spills occurred in and around the tanks and the TFS throughout the fuel terminal's
history. The bolted-steel.tanks were subject to minor leaks, and many truck spills occurred in
the TFS area. In addition, the tanks were painted with lead-based paints, which subsequently
were sandblasted. As a result, surface soils around the ASTs are contaminated with lead-
based paint. Surface and subsurface soils at the Fairbanks Fuel Terminal also are contaminat-
ed with petroleum. Groundwater beneath the terminal at the base of Birch Hill also contains
petroleum constituents.
2.1.2 Railcar Off-Loading Facility Source Area
Available records indicate that one 20-gallon spill of fuel occurred at the ROLF between 1970
and 1987. However, it is known that the tank car headers were prone to minor leaks, and at
least one major spill of JP-4 occurred at one of the headers. Additionally, the USTs formerly
at the ROLF reportedly were overfilled on numerous occasions. In 1991, a pipeline from
Valve Pit C to the airfield failed a hydrostatic pressure test and was taken out of service.
Valve pits on either side of the Chena River and at the ROLF had leaks. Subsurface soil and
groundwater are contaminated with petroleum constituents.
2.1.3 Milepost Source Areas
Between 1956 and 1972, 40 ruptures were reported along the former Haines-Fairbanks
pipeline. In the late 1970s, the multiproduct Fairbanks-Eielson Pipeline was ruptured by a
contractor operating excavation equipment near Milepost 2.7. The pipeline contained fuel at
the time. The damaged section was isolated at the nearby valve pits.
As previously stated, the Fairbanks-Eielson Pipeline has suffered numerous leaks since its
construction. However, no specific ruptures in the pipeline have been documented at the
Milepost 3.0 Source Area. Subsurface soil contamination was documented at Milepost 3.0
during previous area investigative activities, which originally were intended to characterize
potential contaminant migration from the Birch Hill UST facility. The Army suspected that
contamination at Milepost 3.0 was the result of a leak in the Fairbanks-Eielson Pipeline.
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On August 26, 1989. the Fairbanks-Eielson Pipeline at Milepost 15.75 was ruptured when a
contractor was upgrading Laurance Road and establishing a subgrade level for Robyn Drive.
Following notification that the pipeline had ruptured, the pipeline was closed at the north
Chena River flood control isolation valve and at the isolation valve at Milepost 14.75. An
earthen berm contained most of the spilled fuel. Sorbent materials and a vacuum truck from
the Mapco refinery recovered approximately 2,400 gallons within 2 hours of the spill. At
•least 4.200 gallons are estimated to have spilled. Contaminated soils were removed from the
spill area immediately following the recovery of liquid fuel.
2.2 ENFORCEMENT ACTIVITIES
Fort Wainwright was placed on the Comprehensive Environmental Response, Compensation.
and Liability Act (CERCLA) National Priorities List in August 1990. Consequently, a federal
facility agreement (FFAi was executed in spring 1992 among the United States Environmental
Protection Agency (EPA). Alaska Department of Environmental Conservation (ADEC), and
United States Department of Defense. The FFA details the responsibilities and authority
associated with each parry pursuant to the CERCLA process and the associated environmental
investigation and remediation requirements associated with Fort Wainwright. The FFA
divided Fort Wainwright into five OUs, one of which is OU-3, and outlined the general
requirements for investigation and/or remediation .of OU-3.
The OU-3 RI and Feasibility Study (FS) were performed in accordance with the RI/FS
Management Plan for OU-3. The RI fieldwork was conducted during September and October
1993, and the final RI and Risk Assessment Reports were submitted to EPA in October 1994.
The OU-3 FS was submitted to EPA in April 1995.
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3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The public was encouraged to participate in the selection of the remedies for OU-5 during a
public comment period from April 19 to May 19, 1995. The Fort Wainwright Proposed Plan
~or Operable Unit 3 presented more than 25 combinations of options, considered by the
Army, EPA. and ADEC. to address contamination in soil and groundwater at OU-3. The
Proposed Plan was released to the public on April 19, 1995, and copies of a Proposed Plan
summary fact sheet were sent to all known interested parties, including approximately 150
elected officials and concerned citizens. An informational Fact Sheet dated March 1995,
providing information about the Army's entire cleanup program at Fort Wainwright. was
mailed to the same known interested parties.
The Proposed Plan summarized available information regarding the OU. Additional materials
were placed in two information repositories, one at the Noel Wien Library in Fairbanks and
:he other at the Fort Wainwright Post Library. An Administrative Record, including all items
placed in the information repositories and other documents used in the selection of the
remedial actions, was established in Building 3023 on Fort Wainwright. The public was
•.velcome to inspect materials available in the Administrative Record and the information
repositories during business hours.
Interested citizens were invited to comment on the Proposed Plan and the remedy selection
process by mailing comments to the Fort Wainwright Project Manager, by calling a toll-free
Telephone number to record a comment, or by attending and commenting at a public meeting
on April 25, 1995, at the Noel Wien Library in Fairbanks. One organization submitted
comments in writing, no comments were recorded on the toll-free telephone line, and one
person provided oral comments at the public meeting. Twenty-four people attended the public
meeting, which also included presentations on an interim action for a source area in OU-1.
Display advertisements in the Fairbanks Daily News-Miner, published on April 12. 16. 19,
23. 24, and 25, 1995, also included information regarding the information repositories, the
:oll-free telephone line, and an address for submitting written comments.
The Responsiveness Summary, Appendix A to this document, summarizes and addresses
public comments on the Proposed Plan.
This decision document presents the selected OU-3 remedial action, chosen in accordance
with CERCLA as amended by the Superfund Amendments and Reauthorization Act (SARA)
of 1986 and. to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). The decision for OU-3 is based on the Administrative Record. An
index to the documents contained in the Administrative Record for OU-3 is provided in
Appendix B.
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4.0 SCOPE AND ROLE OF OPERABLE UNIT OR RESPONSE ACTION
As with many CERCLA sites, the problems at Fort Wainwright are complex. As a result, the
Army, EPA, and ADEC divided the fort into five OUs. one of which is OU-3. OU-3 is the
first OU at Fort Wainwright to have completed the RI/FS process and to begin final remedial
action activities.
The remedial action described in this Record of Decision (ROD) addresses threats to human
health and the environment posed by contamination at OU-3. The RI/FS has defined potential
risks because of the possibility of contaminant migration to residential and public drinking
water supply wells that are downgradient from the OU-3 source areas if remediation does not
occur.
EPA, ADEC, and the Army have agreed to address petroleum-contaminated soils at the Tank
Farm ASTs under 18 Alaska Administrative Code (AAC) 78 in the Two-Party Agreement
between ADEC and the Army. It has also been agreed to defer selection of the final remedy
for the lead-based paint in soils at the ASTs: this source will be addressed in the ROD for
OU-5.
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5.0 SITE CHARACTERISTICS
The OU-3 RI results indicate that soil and groundwater are contaminated with petroleum fuel
products in all the areas investigated. The specific chemicals of concern associated with the
petroleum contamination include benzene, toluene, ethylbenzene, and total xylenes (BTEX):
1.2-dichloroethane: isopropylbenzene; and trimethylbenzene. Groundwater contaminated with
.petroleum may be discharging from the ROLF and Valve Pit A into the Chena River. In
addition, surface soils surrounding ASTs at the Tank Farm are contaminated with lead and
petroleum.
Refer to the end of this section for tables and illustrations cited in Section 5.
5.1 TANK FARM SOURCE AREA
5.1.1 Hydrogeology and Groundwater Use
The Tank Farm Source Area has three distinct hydrogeologic areas: the ASTs on Birch Hill:
the area between the TFS and the base of Birch Hill; and the area south of the TFS, including
Valve Pit A.
Birch Hill consists of loess overlaying Birch Creek schist and other bedrock units. Figure 6
illustrates a geologic cross section for a portion of the Tank Farm Source Area. Groundwater
is known to occur in the Birch Creek schist but was not encountered during an investigation at
the ASTs on Birch Hill. The static water level in a well approximately 300 feet north of the
ASTs historically has been 500 feet above MSL. Groundwater flow in the bedrock aquifer at
the Tank Farm is expected to occur mainly in fractures and to flow to the southwest.
Monitoring well locations at the Tank Farm are illustrated in Figure 7.
The presence, location, and extent of permafrost from the base of Birch Hill southward to
Chena River significantly affect the groundwater flow direction in this part of the Tank Farm
source area, as illustrated in Figure 8. Groundwater occurs at approximately 20 feet to 22
feet BGS in the TFS area at the base of Birch Hill in the suprapermafrost groundwater zone.
Groundwater in this area flows to the southwest. Shallow discontinuous permafrost in this
area may channel groundwater into thawed corridors that occur in meander scars, and'a
hydraulic connection may exist between the suprapermafrost groundwater zone in the thawed
areas and the subpermafrost groundwater zone.
South of the TFS. while no suprapermafrost aquifer is known to exist, a subpermafrost
aquifer and thaw bulbs occur (see Figure 6). Hydraulic gradients measured in this area
indicate that groundwater from the unconfmed aquifer may flow downward in an unfrozen
area into the confined subpermafrost aquifer. In the adjacent Shannon Park Subdivision.
groundwater occurs at approximately 10 feet to 12 feet in a suprapermafrost groundwater
zone. Shannon Park residents use city water; they do not use water in the aquifer located
immediately below the subdivision.
An apparent groundwater divide exists in the vicinity of Valve Pit A. Groundwater immedi-
ately adjacent to the valve pit flows east toward the Chena River; however, groundwater
several hundred feet west of the valve pit flows consistent with the westward regional
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groundwater flow direction. Near Valve Pit A. groundwater occurs a: a depth of approxi-
mately 13 feet BGS. No permafrost exists in this area.
The closest drinking water wells to the Tank Farm Source Area are located at the Shannon
Park Baptist Church and Mormon Chapel on Lazelle Road approximately 0.25 mile down-
gradient of the Tank Farm buildings (see Figure 1).
5.1.2 Current Land Use
The Tank Farm is the only OU-3 source area that borders Fairbanks. Some residential
development is north of the ASTs on Birch Hill. The area immediately downgradient of the
TFS is undeveloped and is known as the Bentley Trust Property. The Shannon Park
Subdivision, a residential development, is immediately south of the Bentley Trust Property.
Valve Pit A is located less than 0.25 mile northeast of the 801 Housing Subdivision (Birch-
wood) on Fort Wainwright. Approximately 1,580 people live in this subdivision. Scrub-
shrub and forested wetlands border the southern portion of the TFS area.
5.1.3 Previous Investigations
In 1988, a soil-gas survey was conducted at the Tank Farm. Contamination was detected in
soil-gas samples collected from the base of Birch Hill within the Tank Farm area. In 1987,
five monitoring wells (AP-5271, AP-5272, AP-5273, AP-5274, and AP-5275) were installed
along the west boundary of the Tank Farm and the wells were sampled periodically as part of
the basewide groundwater monitoring program. These wells were screened below the top of
the water table in suprapermafrost groundwater. Samples collected from most of the
monitoring wells contained petroleum products and significant quantities of BTEX above
maximum contaminant levels (MCLs) during sampling events. Monitoring wells installed as
part of the United States Army Corp of Engineers, Alaska Distict. (Corps) groundwater
monitoring program are identified by GWM in this document. In 1992. monitoring wells in
the TFS area and in the area between the Tank Farm and the Chena River were installed, and
these wells are known as the picket wells because they are situated in a fence-like pattern
along the west boundary of Fort Wainwright. The picket wells are sampled biarmually.
Monitoring wells AP-5782, AP-5783, AP-5785 (a subpermafrost well). AP-5787, AP-5788,
and AP-5791 were sampled during the OU-3 RI. Monitoring wells included in the Fort
Wainwright picket well program are identified by PW in this document.
Two churches with drinking water supply wells are located off post 0.25 mile downgradient
of the Tank Farm near Lazelle Road (Figure 1). Table 1 summarizes the results of all
contaminants detected during sampling events of these wells from 1991 to 1994. 1,2,-
dichloroethane has been the only volatile organic compound (VOC) detected at concentrations
close to Safe Drinking Water Act levels.
5.1.4 Remedial Investigation Results
For the RI, the Tank Farm Source Area was divided into seven sub-areas based on geographic
locations and differing physical characteristics. Accordingly, RI results are discussed relative
to the individual sub-areas. The sub-areas' boundaries are illustrated in Figure 9.
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5.1.5 Remedial Results for Soils
Birch Hill Aboveground Storage Tanks Sub-Area
Petroleum hydrocarbons were found in surface and subsurface'soils, with the most significant
levels within the bermed areas around the ASTs. Petroleum hydrocarbon levels decrease with
.depth and distance from the tanks. At the ASTs with less than 15 feet of underlying silt, soil
contamination was generally highest at the interface between silt and schist bedrock.
In surface soil and subsurface soil, petroleum hydrocarbons (quantified as Jet A fuel) were
detected at a maximum concentration of 5.500 milligrams per kilogram (mg/kg). Low levels
of VOCs also were detected. Total lead was detected in surface soils up to a maximum
concentration of 7,840 mg/kg; the highest toxicity characteristic leaching procedure (TCLP)
result for lead in surface soil was 5.4 milligrams per liter (mg/L), which exceeds the
Resource Conservation and Recovery Act (RCRA) hazardous waste characteristic criterion of
5 mg/L for lead (see Figure 10). Table 2 summarizes soils results in the Birch Hill sub-area.
Building 1173 Sub-Area
Subsurface soil contamination is present in the Building 1173 sub-area from the water table to
approximately 7 feet above the water table. Subsurface soil contamination in this area is most
concentrated near the base of Birch Hill. The subsurface soil contamination likely contributes
to groundwater contamination observed in the Lazelle Road sub-area.
Low levels of petroleum hydrocarbons i quantified as diesel and Jet A fuel) were detected in
surface soils in this area. VOCs were not detected in surface soil. Total lead concentrations
in surface soil were less than 13 mg/kg.
In subsurface soil, petroleum hydrocarbons (quantified as diesel fuel) were detected at a
maximum concentration of 340 mg/kg. The highest VOC concentration detected in subsur-
face soil was 97 mg/kg of ethylbenzene. Total lead concentrations in subsurface soil were
less than 17 mg/kg. Table 3 summarizes the analytical data for surface and subsurface soils
in the Building 1173 sub-area.
Truck Fill Stand Sub-Area
The extent and distribution of contamination in the TFS sub-area appear to be discontinuous,
with no apparent spatial trends. This area is underlain by discontinuous zones of permafrost
(see Figure 11). The ASTs located adjacent to the TFS have been a source of petroleum
contamination either through spills and overfilling or leaking tanks.
In surface soil, low levels of petroleum hydrocarbons (quantified as bunker C-range organic
compounds) were detected. VOCs were not detected in surface soil. Total lead concentra-
tions in surface soil were less than 18 mg/kg.
In subsurface soil, low levels of petroleum hydrocarbons (quantified as bunker C-range
organic compounds) and VOCs (toluene) were detected. Total lead concentrations in
subsurface soil were less than 15 mg/kg. Table 4 summarizes the analytical data for soils at
the TFS sub-area.
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Lazelle Road Sub-Area
Surface soils in this sub-area do not appear to be impacted by subsurface releases from the
Tank Farm. Contaminant levels in subsurface soil decrease with distance west of the Tank
Farm Source Area. Permafrost to the south of Lazelle Road and bedrock to the north appear
'to restrict the southern and northern extent of subsurface contamination.
In surface soil, petroleum hydrocarbons (quantified as diesel fuel by field screening analysis)
were detected up to a maximum concentration of 109 mg/kg. None of the surface soil
samples were submitted for VOC or total lead analyses:
In subsurface soil, low levels of petroleum hydrocarbons (quantified as bunker C-range
organic compounds) were detected. VOCs were not detected in subsurface soil. Total lead
concentrations were less than 79 mg/kg. Table 5 summarizes the analytical data for soils in
the Lazelle Road sub-area.
Shannon Park Subdivision Sub-Area
Localized areas of subsurface soil contamination were found in the Shannon Park Subdivision:
however, this contamination appears to originate from sources other than' the Fort Wainwright
Tank Farm. This conclusion is based on the types of fuel detected (diesel fuel similar to
heating oil) and the localized nature of the contamination.
In subsurface soil, low levels of petroleum hydrocarbons (quantified as bunker C-range
organic compounds) were detected. VOCs were not detected in subsurface soil. Total lead
concentrations were less than 15 mg/kg. Table 6 summarizes the analytical data for soils in
the Shannon Park Subdivision sub-area.
CANOL Road Sub-Area
Low levels of petroleum hydrocarbons (quantified as diesel fuel by field screening analysis)
were detected in surface soils in this sub-area. None of the surface soil samples were
submitted for VOC or total lead analyses.
In subsurface soil, low levels of petroleum hydrocarbons (quantified as bunker C-range
organic compounds) and VOCs were detected. Total lead concentrations in subsurface soil
were less than 17 mg/kg. Table 7 summarizes the analytical data for soils in the CANOL
Road sub-area..
Valve Pit A Sub-Area
Soil contamination at Valve Pit A is concentrated around the valve pit structure and extends at
least 200 feet north and south of the valve pit. Figure 12 illustrates soil contamination in this
sub-area and proximity to the Chena River.
Low levels of petroleum hydrocarbons (quantified as diesel fuel by field screening analysis)
were detected in surface soils. None of the surface soil samples were submitted for VOC or
total lead analyses.
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In subsurface soil, petroleum hydrocarbons (quantified as kerosene) were detected up to a
maximum concentration of 3,800 mg/kg. Low levels of VOCs also were detected. Benzene
in subsurface soil-was detected at a concentration of 10 mg kg in one sample. Total lead
concentrations were less than 8 mg/kg. Table 8 summarizes the analytical data for soils in the
Valve Pit A sub-area.
5.1.6 Remedial Investigation Results for Groundwater
Birch Hill Aboveground Storage Tanks Sub-Area
Monitoring wells in this sub-area include AP-6053 (RI). AP-6054 (RI), AP-6055 (RI), and
AP-5271 (GWM). All of these wells are located at the base of Birch Hill.
The highest detected concentration of petroleum hydrocarbons (quantified as gasoline) was
23,000 micrograms per liter (^g/L). The highest concentration of VOCs detected in this area
was 150 /xg/L for benzene, which exceeds the MCL of 5 MS L. Low levels of other VOCs
also were detected in groundwater in this sub-area. Total lead was detected up to a maximum
concentration of 140 ng/L; however, dissolved lead concentrations were less than 5 /xg/L,
which is below the MCL of 15 /xg/L. Total lead samples were more turbid than dissolved
lead samples because of filtering of the dissolved lead samples before containerization.
Refer to Figure 13 for an illustration of benzene concentrations in groundwater. Table 9
summarizes all of the analytical data for groundwater at this sub-area.
Building 1173 Sub-Area
Monitoring wells in this sub-area include AP-6056 (RI). AP-5272 (GWM), and AP-5273
(GWM). All of these wells are located between the base of Birch Hill and the TFS area.
The highest detected concentration of petroleum hydrocarbons (quantified as Jet A fuel) was
380 iig/L. The highest concentration of VOCs detected in this sub-area was 120 ^ig/L for
benzene, which exceeds the MCL of 5 [tg/L. Low levels of other VOCs also were detected
in groundwater in this sub-area. Total lead was detected up to a maximum concentration of
73 /xg/L; however, dissolved lead was not detected in any of the monitoring well samples.
Total lead samples were more turbid than dissolved lead samples because of filtering of the
dissolved lead samples before containerization.
Table 10 summarizes all of the analytical data for groundwater at this sub-area.
Truck Fill Stand Sub-Area
Monitoring wells in this sub-area include AP-6066 (RI). AP-5274 (GWM), AP-5275 (GWM),
AP-5782 (PW), AP-5783 (PW), and AP-5785 (PW). These wells are located along the
western boundary of the fort and adjacent to the TFS area.
The highest detected concentration of petroleum hydrocarbons (quantified as bunker C-range
organic compounds) was 1,000 ng/L. The highest concentration of VOCs detected in this
sub-area was 11 /xg/L for benzene, which exceeds the MCL of 5 ng/L. Low levels of other
VOCs also were detected in groundwater in this sub-area. Total lead was detected up to a
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maximum concentration of 150 jtg/L; however, dissolved lead was not detected in any of the
samples. Total lead samples were more turbid than dissolved lead samples because of
filtering of the dissolved lead samples before containerization.
Refer to Figure 13 for an illustration of benzene concentrations in groundwater in the TFS
sub-area. Table 11 summarizes all of the analytical data for groundwater at this sub-area.
Lazelle Road Sub-Area
One monitoring well. AP-6071 (RI), is located within this sub-area. Petroleum hydrocarbons
(quantified as gasoline) were detected at a concentration of 6,800 /xg/L. VOCs were not
detected in the well in two separate sampling events. Total lead was detected at a concentra-
tion of 10 fjLg/L, but dissolved lead was not detected in the monitoring well. Table 12
summarizes the analytical data for groundwater in the Lazelle Road sub-area.
Shannon Park Subdivision Sub-Area
Monitoring wells in this sub-area include AP-6057 (RI), AP-6067 (RI), AP-6068 (RI),
AP-6069 (RI), and AP-6070 (RI). These wells are located off post within the Shannon Park
Subdivision west of the Tank Farm Source Area.
The highest detected concentration of petroleum hydrocarbons (quantified as bunker C-range
organic compounds) was 1.100 /xg/L. VOCs were not detected in any of the monitoring wells
in this sub-area. Total lead was detected up to a maximum concentration of 150 /xg/L;
however, dissolved lead was not detected in any of the wells. Total lead samples were more
turbid than dissolved lead samples because of filtering of the dissolved lead samples before
containerization. Table 13 summarizes the analytical data for groundwater in the Shannon
Park Subdivision sub-area.
CANOL Road Sub-Area
Monitoring wells in this sub-area include AP-5787 (GWM), AP-5788 (GWM), AP-6058 (RI),
AP-6059 (RI), AP-5791 iGWM), AP-6060 (RI), AP-6061 (RI), AP-6062 (RI), and AP-6063
(RI). These wells are generally located along the corridor formed by the CANOL pipelines
and associated service road.
The highest detected concentration of petroleum hydrocarbons (quantified as gasoline) detected
in this sub-area was 6,900 jug. L; however, this well did not contain detectable levels of
petroleum hydrocarbons when re-sampled. VOCs were not detected in any of the monitoring
wells. Total lead was detected up to a maximum concentration of 88 ftg/L; however, detected
dissolved lead concentrations were less than 5 Mg/L, which is less than the MCL of 15 ng/L.
Total lead samples were more turbid than dissolved lead samples because of filtering of the
dissolved lead samples before containerization. Table 14 summarizes the analytical data for
groundwater samples from the CANOL Road sub-area.
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Valve Pit A Sub-Area
Monitoring wells -located in this sub-area include AP-6064 (RI) and AP-6065 (RD. Both wells
are located adjacent to the concrete valve pit structure.
Petroleum hydrocarbons (quantified as gasoline) were detected up to a maximum concentra-
tion of 43,000 ng/L. Three VOCs were detected above MCLs in this sub-area: benzene at a
'maximum concentration of 1,700 ng/L, ethylbenzene at a maximum concentration of 1,600
Mg/'L. and toluene at a maximum concentration of 12,000 ng/L. Total lead concentrations
ranged up to a maximum concentration of 300 /ig/L; however, dissolved lead was detected at
a maximum concentration of 2.7 /xg/L, which is less than the MCL of 15
Refer to Figure 16 for an illustration of benzene concentrations in groundwater at the Valve
Pit A sub-area. Table 15 summarizes all of the analytical data for the Valve Pit A sub-area.
5.2 RAILCAR OFF-LOADING FACILITY SOURCE AREA
5.2.1 Hydrogeology and Groundwater Use
Groundwater occurs at approximately 12 feet BGS at the ROLF Source Area. The water
table occurs in the coarse-grained facies of the Chena alluvium. Groundwater flows to the
west-northwest in the area around the ROLF Source Area. Variations to flow direction are
due to the stage of the Chena River. Because it was not encountered in this area, shallow
permafrost is not expected to affect groundwater flow.
The Pioneer wells in the Hamilton Acres Subdivision are a Class A drinking water source
approximately 1 mile downgradient of the ROLF. Four drinking water supply wells serving
Fort Wainwright are located approximately 1 mile south of the ROLF (see Figure 1). The
ROLF, Valve Pit A, and Valve Pit B are located directly on the banks of the Chena River.
The wells that are located downstream along the Chena River include the Fairbanks MUS ( 1
mile), College Utilities (1.5 miles), and numerous residential wells located on the north bank
of the river less than 0.5 mile downstream.
5.2.2 Current Land Use
The ROLF is located immediately north of the Fort Wainwright airport and is approximately
0.3 mile from the 801 Housing Subdivision. The Chena River is located between the ROLF
and the 801 Housing Subdivision. The North Post Housing Subdivision is 0.7 mile from the
ROLF and houses 698 people. A scrub-shrub wetland borders the northeast edge of the
ROLF. This area of the Chena River is used heavily by residents and nonresidents involved
in recreational sport fishing, boating, and hiking.
5.2.3 Previous Investigations
A soil-gas survey was conducted at the ROLF and associated valve pits in 1988. Samples
collected from soil-gas probes installed at the ROLF revealed a contaminant plume centered
on the railroad spur containing the 16-tank-car unloading headers and the former USTs.
Monitoring well AP-5527 was installed at the ROLF in 1989 and contained free-floating
product in most of the sampling events since its installation.
21
-------
5.2.4 Remedial Investigation Results
For the RI. the ROLF Source Area was divided into three sub-areas based on geographic
location and differing physical characteristics. Accordingly, the RI results are discussed
relative to these sub-areas. The ROLF sub-area boundaries,are illustrated in Figure 14.
5.2.5 Remedial Investigation Results for Soils
Valve Pit B Sub-Area
Petroleum-contaminated soils extend from Valve Pit B to the Chena River. Soil boring data
suggest that subsurface contamination extends approximately 500 feet north and south of the
valve pit. Fluctuating groundwater levels, a result of Chena River stage variations, have
created a smear zone of petroleum contamination in subsurface soil. This smear zone extends
from the water table to approximately 4 feet above the water table. Figure 15 shows the
proximity of the Chena River to Valve Pit B.
In surface soil, petroleum hydrocarbons (quantified as diesel fuel by field screening analysis)
were detected up to a maximum concentration of 28 mg/kg. No surface soil samples were
submitted for VOC or lead analyses.
In subsurface soil, petroleum hydrocarbons (quantified as Jet A fuel) were detected at a
maximum concentration of 2,700 mg/kg. Low levels of VOCs were detected in subsurface
soils throughout the Valve Pit B sub-area. Total lead concentrations were less than 15 mg/kg.
Table 16 summarizes the analytical data for soils at the Valve Pit B sub-area.
Central Railcar Off-Loading Facility Sub-Area
The central ROLF sub-area has been impacted by petroleum releases originating from Valve
Pit C and from a complex system of valve pits, off-loading headers, and former UST sites
located in the center of the sub-area.
In surface soil, petroleum hydrocarbons (quantified as diesel fuel) were detected up to a
maximum concentration of 5,900 mg/kg. VOCs were not detected in surface soils. Total
lead was detected up to a maximum concentration of 101 mg/kg.
In subsurface soil, petroleum hydrocarbons (quantified as Jet A fuel) were detected up to a
maximum concentration of 2,600 mg/kg. Benzene was detected up to a maximum concentra-
tion of 2.4 mg/kg in subsurface soil. Total lead in subsurface soil was detected at a maxi-
mum concentration of 18.2 mg/kg. TCLP lead was detected at a maximum concentration of
0.032 mg/L, which is below the RCRA hazardous waste characteristic criterion of 5 mg/L for
lead. Table 17 summarizes the analytical data for soils at the central ROLF sub-area.
Front Street Sub-Area
Contamination of soils in the Front Street sub-area appears to originate from a source located
east of the ROLF. Because another source area included in OU-5 is located in this direction,
this sub-area is thought to represent the leading edge of a contaminant plume unrelated to
historical operations at the ROLF Source Area.
22
-------
In subsurface soil, petroleum hydrocarbons (quantified as Jet A fuel) were detected at a
maximum concentration of 260 mg/kg. Low levels of VOCs were detected in subsurface soil.
Total lead concentrations were less than 8 mg/kg. Table 18 summarizes the analytical data
for soils at the Front Street sub-area.
5.2.6 Remedial Investigation Results for Groundwater
Valve Pit B Sub-Area
Monitoring wells in this sub-area include AP-5998 (RI) and AP-6018 (RI), which are located
adjacent to the Valve Pit and the Chena River.
The highest level of petroleum hydrocarbons (quantified as Jet A fuel) was detected at a
concentration of 3.600 ng/L; however, free-floating petroleum product has been observed in
groundwater in this sub-area. VOCs detected include benzene at a maximum concentration of
1.400 /xg/L. which exceeds the MCL of 5 ^g/L, and toluene at a maximum concentration of
3.900 /-tg/L. which exceeds the MCL of 1,000 ng/L. Total lead was detected at a maximum
concentration of 160 /xg/L, and dissolved lead was detected at a maximum concentration of
9.9 jug/L, which is less than the MCL of 15 jig/L for lead.
Refer to Figure 16 for an illustration of benzene concentrations in groundwater at this sub-
area. Table 19 summarizes all of the analytical data for groundwater at the Valve Pit B sub-
area.
Central Railcar Off-Loading Facility Sub-Area
Monitoring wells in this sub-area include AP-5999 (RI), AP-6000 (RI), AP-6001 (RI),
AP-6002 (RI). AP-6003 (RI), AP-6004 (RI), AP-6005 (RI), AP-6006 (RI), AP-6007 (RI).
AP-6008 (RI). AP-6009 (RI), AP-6010 (RI), AP-6013 (RI), AP-6014 (RI), AP-6015 (RI). and
AP-5527 (GWM).
The highest concentration of petroleum hydrocarbons (quantified as JP-4 fuel) detected in
groundwater was 120,000 /*g/L. Four VOCs were detected above MCLs: benzene at a
maximum concentration of 5,800 ^g/L, which is above the MCL of 5 fig/L; ethylbenzene at a
maximum concentration of 1,100 /ig/L, which is above the MCL of 700 ;ig/L; toluene at a
maximum concentration of 15,000 jtg/L, which is above the MCL of 1,000 pg/L; and
1,2-dichloroethane at a maximum concentration of 6 ng/L, which is above the MCL of 5
(j.g/L. In addition. 1.2,4-trimethylbenzene was detected at a maximum concentration of 710
jtg/L, 1,3,5-trimethylbenzene was detected at a maximum concentration of 190 pg/L, and
isopropylbenzene was detected at a maximum concentration of 1,200 /xg/L. Total lead was
detected at a maximum concentration of 330 /xg/L, and dissolved lead was detected at a
maximum concentration of 160 /ig/L, both of which exceed the MCL of 15 /zg/L for lead.
Figure 16 illustrates benzene concentrations in groundwater. Table 20 summarizes the
analytical data for groundwater at the central ROLF sub-area.
23
-------
Front Street Sub-Area
Monitoring wells in this sub-area include AP-6011 (RI), AP-6012 (RIi. AP-6016 (RI), and
AP-5537 (GWM). These monitoring wells are located east of the centra] ROLF near Front
Street.
The highest detected concentration of petroleum hydrocarbons (quantified as diesel fuel) was
10,000 /xg/L. VOCs detected include 1,2,4-trimethylbenzene up to 250 ug/L, 1,3,5-trimeth-
ylbenzene up to 530 ^g/L. and benzene up to 140 ^g/L, which is above the MCL of 5 fj.g/L
for benzene. Total lead was detected at a maximum concentration of 260 ng/L, but dissolved
lead was not detected in groundwater samples from this sub-area.
Refer to Figure 16 for an illustration of benzene concentrations in groundwater. Table 21
summarizes the analytical data for groundwater at the Front Street sub-area.
5.3 MILEPOST SOURCE AREAS
5.3.1 Milepost 2.7
Hydrogeology and Groundwater
Groundwater occurs approximately 2 feet BGS at the Milepost 2.7 Source Area. The water
table occurs in an alluvial suprapermafrost aquifer in the Fairbanks loess. Groundwater flows
to the southwest across the source area. The main groundwater flow path may be in the thaw
bulb beneath Birch Hill Road and the Fairbanks-Eielson Pipeline.
The closest drinking water well to Milepost 2.7 is located at the Birch Hill Ski Area,
approximately 1 mile west (see Figure 1). However, this well is completed in the Birch
Creek schist aquifer, not the alluvial aquifer. These aquifers are not hydraulically connected.
Current Land Use
The Milepost 2.7 Source Area is located within a military training area approximately 1 mile
and across the Chena River from any residential development. This area also has recreational
uses. A black spruce-scrub-shrub wetland complex borders the southern extent of this source
area.
Previous Investigations
A soil-gas survey was conducted along the Fairbanks-Eielson Pipeline in 1989. Benzene was
detected at elevated concentrations.
The Corps also conducted a subsurface investigation at the Fairbanks-Eielson Pipeline and
collected subsurface soil and groundwater samples from four soil borings. Analysis of
samples collected near the Milepost 2.7 Source Area revealed petroleum hydrocarbon
contamination, with the highest concentrations occurring in a subsurface soil sample collected
from borehole AP-5650 at 15 feet BGS. Analytes detected in a sample collected from a
monitoring well contained benzene concentrations ranging from 120 ug L to 318 /ig/L.
Gasoline or gasoline-range organics (GRO) were detected each time the well was sampled.
24
-------
Diesel-range organics also were detected. The diesel was detected in a quality control sample
but not in any other replicate samples. Isopropylbenzene; 1,2,3-trimethylbenzene; and 1,2,4-
trimethylbenzene were detected when they were analyzed for during the most recent sampling
event.
Remedial Investigation Results
Surface soil contamination extends approximately 120 feet south of the Milepost 2.7 pipeline
break location into adjacent wetlands. This surface contamination could result from upwelling
contaminated groundwater or contaminated surface runoff originating from the TFS-2 area.
Subsurface soil contamination extends laterally underneath Birch Hill Road adjacent to TFS-1
and TFS-2. This subsurface soil contamination likely is bounded to the south by shallow
permafrost and to the north by schist bedrock associated with the Birch Hill formation.
Remedial Investigation Results for Soils
In surface soil, petroleum hydrocarbons (quantified as gasoline) were detected at a maximum
concentration of 470 mg/kg. Low levels of VOCs were detected in surface soils. Total lead
was detected at concentrations less than 44 mg/kg.
In subsurface soil, petroleum hydrocarbons (quantified as gasoline) were detected at a
maximum concentration of 290 mg/kg. Low levels of VOCs were detected in subsurface soils
throughout the source area. Total lead concentrations in subsurface soil were less than 17
mg/kg. One subsurface soil sample analyzed for TCLP lead contained lead at a concentration
of 0.034 mg/L, which is below the RCRA hazardous waste characteristic criterion of 5 mg/L
for lead. Table 22 summarizes the analytical data for surface and subsurface soils at the
Milepost 2.7 Source Area.
Remedial Investigation Results for Groundwater
Monitoring wells in this source area include AP-5650 (GWM), AP-5651 (GWM), AP-6034
(RI), AP-6035 (RI), and AP-6036 (RI).
The highest detected concentration of petroleum hydrocarbons (quantified as gasoline). was
2,100 jig/L. Benzene was detected at a concentration of 140 /ig/L, which exceeds the MCL
of 5 Mg/L; low levels of other VOCs also were detected in Milepost 2.7 groundwater. Total
lead was detected up to a maximum concentration of 150 /ig/L, but dissolved lead was
detected at a maximum concentration of 4 ng/L, which is below the MCL of 15
Refer to Figure 17 for an illustration of benzene concentrations in groundwater at Milepost
2.7. Table 23 summarizes all of the analytical data for groundwater at the Milepost 2.7
Source Area.
5.3.2 Milepost 3.0
Hydrogeology and Groundwater Use
Groundwater ranges from 12 feet to 18 feet BGS at the Milepost 3.0 Source Area. The water
table occurs in an alluvial suprapermafrost aquifer in the Fairbanks loess. Groundwater flows
25
-------
to the southwest across Mileposts 2.7 and 3.0. The main groundwater flow path at these
source areas may be in the thaw bulb beneath Birch Hill Road and the Fairbanks-Eielson
Pipeline.
The closest well to Milepost 3.0 is located at the Birch Hill Ski Area, approximately 1.25
miles away (see Figure 1). However, this well is completed in the Birch Creek schist aquifer.
.not the alluvial aquifer: therefore, these wells are not hydraulically connected.
Current Land Use
The Milepost 3.0 Source Area is located within a military training area approximately 1 mile
from and across the Chena River from any residential development. This area also has recre-
ational uses. A black spruce-scrub-shrub wetland complex borders the southern extent of this
source area.
Praious Investigations
Monitoring well AP-5522 was installed near Milepost 3.0 at TFS-3 in August 1989 as pan of
the Fort Wainwright basewide groundwater monitoring program. Subsurface soil samples
contained gasoline, bunker oil, and xylenes. To date, all groundwater samples collected from
monitoring well AP-5522 during basewide sampling events contained GRO, benzene, and
xylenes: benzene and xylene concentrations consistently have exceeded MCLs.
Remedial Investigation Results for Soils
Petroleum contamination in subsurface soil at Milepost 3.0 is concentrated mostly along Birch
Hill Road. The contamination extends northwest toward Milepost 2.7; no discernable break
in subsurface soil contamination between Milepost 2.7 and Milepost 3.0 has been found.
Subsurface soil contamination also extends approximately 250 feet southeast from the Milepost
3.0 Source Area underneath Birch Hill Road and approximately 200 feet south of the road
under adjacent wetlands. A smear zone of subsurface soil contamination extended from the
water table to 10 feet below the water table at the time of the RI.
In subsurface soil, petroleum hydrocarbons (quantified as bunker C-range organic compounds)
were detected at a maximum concentration of 82 mg/kg. Benzene was detected at a maxi-
mum concentration of 19 mg/kg in subsurface soil. Low levels of other VOCs also were
detected. Total lead concentrations were less than 18 mg/kg. Table 24 summarizes the
analytical data for soil in the Milepost 3.0 Source Area.
Remedial Investigation Results for Groundwater
Monitoring wells in this source area include AP-5522 (GWM), AP-5846 (GWM). AP-5848
(GWM), AP-5849 (GWM), AP-5850 (GWM), AP-6037 (RI), AP-6038 (RI), AP-6039 (RI).
and AP-6040 (RI).
The highest detected concentration of petroleum hydrocarbons (quantified as gasoline) was
5.400 /ig/L. Three VOCs were detected above MCLs: benzene at a maximum concentration
of 7.200 /xg/L, which is above the MCL of 5^g/L; ethylbenzene at a maximum concentration
of 1.100 Mg/L, which is above the MCL of 700 Mg/L; and toluene at a maximum concentra-
26
-------
tion of 2,300 /xg/L, which is above the MCL of 1.000 jug/L. Low levels of other VOCs also
were detected. Total lead was detected at a maximum concentration of 280 ng/L, but
dissolved lead was detected at a maximum concentration of 11 ug/L, which is below the MCL
of 15 /ig/L for lead.
Refer to Figure 17 for an illustration of benzene concentrations in groundwater at the
•Milepost 3.0 Source Area. Table 25 summarizes the analytical data for groundwater at the
Milepost 3.0 Source Area.
5.3.3 Milepost 15.75
Hydrogeology and Groundwater Use
Groundwater occurs at approximately 12 feet BGS at the Milepost 15.75 Source Area. The
water table occurs in the coarse-grained facies of the floodplain alluvium. Groundwater flows
northwest through the source area. Variations in the flow direction may occur because of the
influence of the Tanana River.
The nearest drinking water wells are located at residences on Robyn Drive and Laurance
Road. These wells are located approximately 205 feet downgradient from the former spill
location at Milepost 15.75.
Current Land Use
The Milepost 15.75 Source Area is in a residential area west of North Pole. The population
of North Pole is 1,456. Wetlands occur within 0.25 mile of the source area.
Previous Investigations
A soil-gas survey was conducted at the Milepost 15.75 Source Area in 1989. Elevated levels
of benzene concentrations were detected in 1992, four soil borings were installed, and one
soil boring (AP-5658) was completed as a well. Elevated levels of petroleum products were
detected at this site.
Remedial Investigation Results for Soils
The extent of subsurface petroleum contamination at the Milepost 15.75 Source Area is
confined to an area extending 50 feet to 100 feet downgradient of the spill location. The
shallow groundwater gradient in this area may have contributed to lateral spreading of
contaminants in subsurface soil and groundwater.
In subsurface soil, petroleum hydrocarbons (quantified as bunker C-range organic compounds)
were detected at a maximum concentration of 40 mg/kg. Low levels of VOCs were detected
in subsurface soils. Total lead concentrations were less than 9 mg/kg. Table 26 summarizes
the analytical data for soils at the Milepost 15.75 Source Area.
27
-------
-------
Remedial Investigation Results for Groundwater
Monitoring wells in this source area include AP-6041 (RI), AP-6042 (RI), AP-6043 (RI), and
AP-6044 (RI). The highest detected concentration of petroleum hydrocarbons (quantified as
bunker C-range organic compounds) was 300 pig/L. VOCs detected in the groundwater
include 1.2-dichloroethane at a maximum concentration of 8 pg/L, which is above the MCL
•of 5 ^ig/L, and benzene at a maximum concentration of 34 /xg/L, which is above the MCL of
5 Mg/L. Total lead was detected at concentrations up to 170 pig/L; however, dissolved lead
was not detected in any of the monitoring wells.
Refer to Figure 18 for an illustration of benzene concentrations in groundwater. Table 27
summarizes all of the analytical data for groundwater at the Milepost 15.75 Source Area.
28
-------
-------
CORPS OF ENGINEERS
U.S. ARMY
A'
SOUTH
ABOVE GROUND
STORAGE TANK
LOCAllON
TRUCK FILL S1AND AND
ABOVE GROUND
STORAGE TANK
, LOCATIONS
A
NORTH
NOTE: CROSS SECTION LOCATION PRESENTED OH FIGURE 7
HORIZONTAL SCALE
150 300
VERTICAL SCALE
20 40
AP-5785 MONITORING WELL OR SOIL SORING DESIGNATION
460' ELEVATION ABOVE MEAN SEA LEVEL (AMSL)
T GROUNOWATER/VADOSE ZONE INTERFACE
AST ABOVE GROUND STORAGE TANK
NOTE: WATER TABLE ELEVATIONS BASED ON OCTOBER 25. 1993
WATER LCVEL READINGS.
FINE-GRAINED SAND AND SILT
(Fairbanks Lo«*s on Birch HIM,
China Alluvium in Ch«na River
lloodploln)
SAND AND GRAVEL
(Ch«na Alluvium)
BIRCH (RffK SCHISI
PERMAfROSI
e
U.S ARMY
ENGINEER DISTRICT. ALASKA
CORPS Of ENGINEERS
ANCHORAGE. ALASKA
NORTH-SOUTH GEOLOGIC CROSS SECTION
FROM THE ASTS TO THE TFS
OPERABLE UNIT 3
FAIRBANKS
ALASKA
-------
CORPS OF ENGINEERS
U.S. ARMY
STEESE CHAPEL.-^
CHURCH OF \
UTTER DAY \
SAINTS --
SHANNON
PARK BAP1ST
CHURCH
LEGEND
4-AP-6057 AP-5791
AP-6117 '
f
X , ', ^-AP-6039 1 /^
-J
AP-6060 \ ^
i-AP-578
/
ROAD
SOIL BORING/MONITORING
WELL DESIGNATION
ABOVEGROUKD STORAGE TANK
UNDERGROUND PIPE
PI SOIL BORING
41 MONITORING WELL
CORPS OF ENGINEERS GROUNOWATER
MONITORING PROGRAM WELL
1992 PICKET WELL
jFF-POSJ DRINKING WATER WELL
GSOUNOWATER FLOW DIRECTION
, Ap-sm
/ AP-8121-
AP-6U»- ^AP-6118 y-
P-^12B-- s,
^VALVE P" a AP-6019
I'
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
C' I
Figure 7
Tank Farm Source Area
Soil Borings and Monitoring Wells
FAIRBANKS Location Map ALASKA
B
JT1950
ILE NO.
JTTANKB.DWG
JATF..
09/95
30
-------
CORPS OF ENGINEERS
U.S. ARMY
CANOl SERVICE
ROAD AND PIPELINES
r-
PETROLEUM PlPLUNES
SHANNON PARK SUBDIVISION
At ( iHtDINi. 10 i 1(10 t INN KI'UI l
INI. no HUM ui rt KMAI i;(t ,i MAI I
JHE IOP Of BEDROCK tN IH( AHtA
THE FORT WAINWRIGHT WESTERN BOUNDARY
AND CANOL SERVlCt ROAD
SUBPERMAFROST ALLUVIAL AQUlfER
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE, ALASKA
MONITORING WELL OR SOIL BORING DESIGNATION
ELEVATION ABOVE MEAN SEA LEVEL (AMSL)
GROUNDWATER/VADOSE ZONE INTERFACE
FINE-GRAINED SAND AND SILT
(Ghana Alluvium)
HORIZONTAL SCALE
300 600
Figure 8
EAST-WEST GEOLOGIC CROSS SECTION C-C1 01
TANK FARM
SUB-ARE A
FAIRBANKS ALASK/
SAND AND GRAVEL
(China Alluvium)
POTCNIIOMCTRIC SURFACE OF SUBPERMAf ROST
ALLUVIAL AQUIFIR
COLD REGIONS RESEARCH AND ENGINEERING LABORATORY
NOTE: CROSS SECTION LOCATION
PRESENTED ON FIGURE 7.
NOTE: WAIC8 TABLE ELEVATIONS BASED ON OCTOBER 25. 199]
WATER LEVEL READINGS. POTENTIOMETRIC SURFACE ELEVATION
BASED ON OCTOBER 21. 199] WATER LEVEL READING
-------
Birch HilUAST Sub-Area-
Lazelle Road Sub-Area;.. _
Building 1173.Sub-Area |
[Truck hll Stand Sub-Area
. f .*-•• _ _--—- —— —_
i Shannon Park Stfbdj-Vusion Sub-Area
CANOL Road Sub-Area
Valve Fit
A Sub-Area
LEGEND
Monitoring Wells
gecology and environment, inc.
U=. ARMY
ENGINEER ^.'STRICT. ALASKA
CORPS or ENGINEERS
ANCHORAGE. ALASKA
FIGURE 9
TANK FARM SUB-AREA
LOCATION MAP
32
SIZE
8
j JOB. NO. I FILE NO.
i JT-2 i
DATE. PLATE
'09/05/95
-------
ttf
>v
20
3/3 )
2960'>
/3BZV.
.163
.
302
38*
250
500
750
BOO
Feet
LEGEND
. K) - Sample Location and
Lead Concentration in mg/kg
301 - Tank Number
0 - 1,000 mg/kg
Greater Ihan 1000 mg/kg
US. ARMY
ENGINEER DISTRICT. AUSHA
CORPS OF CNCINiXRS
ANCHORAGE. AUSCA
FIGURE 10
MAXIMUM LEAD CONCENTRATIONS IN SURFACE SOI
BRCH HLL AST SUB-AREA
"sTii " "I" JOB"NO I RUB HO Tain [ njfii
B JJT-2 | J 09/05/^5
-------
CORPS OF ENGINEERS
U.S. ARMY
GROUNDWATER (OCT.93
3TTX: ' (11)
GROUNDWATER (OCT.93'
FUEL ID:
BUNKER (960)
TRUCK FILL STAND AND
ABOVE GROUND
STORAGE TANKS
LOCATION
IGROUNDWATER(OCT.93)
(FUEL ID:
JET FUEL (180)
BUNKER (1,000)
GROUNDWATER (OCT.93
BTEX: (12)
NOTE: CROSS SECTION LOCATION PRESENTED ON FIGURE 7.
LEGEND
AP-6039 MONITORING WELL OR SOIL BORING DESIGNATION
440' ELEVATION ABOVE MEAN SEA LEVEL (AMSL)
BTEX BENZENE, TOLUENE, ETHYLBENZENE, AND XYLENES
FUEL ID FUEL IDENTIFICATION
(10,000) SOIL CONCENTRATION IN MICROGRAUS PER KILOGRAM ( MSAs
GROMJWATER CONCENTRATION IN UICROGRAUS PER LITER ( fJ-g/L)
I GROUNDWATER/VADOSE ZONE INTERFACE
SAND AND GRAVEL
(Chena Alluvium)
BIRCH CREEK SCHIST
FINE-GRAINED SAND AND SILT
(Fairbanks Loess ON BIRCH HILL.
Chena Alluvium IN CHENA RIVER
FLOODPLAIN.)
PERMAFROST
NOTE: WATER TABLE ELEVATIONS BASED ON
OCTOBER 25, 1993, WATER LEVEL READINGS.
HORIZONTAL SCALE
0 '50 300 450 FEET
VERTICAL SCALE
0 20 40 60 FEET
Jp ecology and environment, inc.
^W/bitenimicna SMOdiits in Uw £nwwn*pt
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE, ALASKA
Figure 1 1
TOTAL BTEX AND FUa ID CONCENTRATIONS
TFS SUB-AREA
FAIRBANKS ALASKA
SIZE
A
JOB. NO.
JT2950
FILE NO.
JT2C016A
DATE:
08/95
P. A"
-------
CORPS OF ENGINEERS
U.S. ARMY
NORTHWEST
IGROUNDWATER (OCT.33)
JFUEL ID:
j GASOLINE (43,000 J]
JBTEX: (10,130)
D'
SOUTHEAST
RIVER
ROAD
RAILROAD
TRESTLE
450
CHENA RIVER
GROUNDWATER (OCT.93)
FUEL ID:
GASOLINE (26,000 J)
BTEX: (22,570)
SEDIMENT
AND SURFACE
WATER SAMPLE
TFMSD5
SOIL (SEPT.93)
FUEL ID:
JET FUEL (390,000)
BTEX: (58,600)
SOIL
FUEL ID:
KEROSENE (500,000)
BTEX: (387,000)
SOIL
FUEL ID:
KEROSENE (1,200,000)
BTEX: (296,000)
450
440
430
SOIL
FUEL ID:
JET FUEL
BTEX:
(SEPT.93)
(59,000)
(790)
420
SOIL
FUEL ID:
JET FUEL
BTEX:
(SEPT.93)
(5.000)
(21)
410
SOIL
FUEL ID:
KEROSENE (3,800,000)
BTEX: (599,000)
.SOIL
ID:
JET FUEL
STEX:
(SEPT.93)
(270,000)
(23)
NOTE:
CROSS SECTION LOCATION
PRESENTED ON FIGURE 7.
SOIL
FUEL ID:
JET FUEL
(SEPT.93)
(260,000)
LEGEND
AP-6064
440*
BTEX
FUEL ID
(10,000)
MONITORING WELL OR SOIL BORING DESIGNATION
ELEVATION ABOVE MEAN SEA LEVEL (AMSL)
BENZENE, TOLUENE, ETHYLBENZENE, AND XYLENES
FUEL IDENTIFICATION
SOIL CONCENTRATION IN MICROGRAMS PER KILOGRAM (
GROUNDWATER CONCENTRATION IN UOOGRAUS PER UTER ( M9/L)
GROUND WATER/VADOSE ZONE INTERFACE
DIRECTION OF GROUNDWATER FLOW
FILL
„ . FINE-GRAINED SAND AND SILT
- - - (Ch«na Alluvium)
SAND AND GRAVEL
(Chena Alluvium)
NOTE: WATER TABLE ELEVATIONS BASED ON
OCTOBER 25, 1993, WATER LEVEL READINGS.
HORIZONTAL SCALE
100 200
300 FEET
VERTICAL SCALE
10 20
30 FEET
and environment, inc.
U.S. ARMY
ENGINEER DISTRICT, ALASKA
CORPS OF ENGINEERS
ANCHORAGE; ALASKA
figure 12
TOTAL BTEX AND FUEL ID CONCENTRATIONS
VALVE PIT A
SUB-AREA
FAIRBANKS ALASKA
SIZE
j'Os. NO.
JT295C
--_£ NO.
JT2C014A
08/95
35
-------
//D
120
LEGEND
Benzene Not Detected
10 - Benzene Detected ug/L
Intermittent Slough
VS. ARMY
and environment, inc. ' ENGINEER DISTRla. ALASKA
u ^_,_. , u. i.«_~,t ^RPS or ENGINEERS
^ "m>n" • "" "™"~» I ANCHORAGE ALASKA
I FIGURE 13
: BENZENE CONCENTRATIONS IN GROUNDWATER SAMPLES
; AT THE TANK FARM SOURCE AREA
JSIZE JOB. NO. TILE NO. ,DATE.PUTS i
j 9 i JT-2 ; . M/05/S5
36
-------
VAM: I'll I) sun
IPITRAI. KOI.F Sllli .IKEA
.„•<.
1000
1500
HONT STKI:I:T
CORP OF ENGINEOI3
ANCHOfUCt AU3KA
Rgure 14
RAII.CAR OFF-LOADING FACIITY
SUB-AREA MAP
joa NO
JZ-8
InL
I
-------
CORPS OF ENGINEERS
U.S. ARMY
SOUTHWEST
CHENA RIVER
450
E
NORTHEAST
450
VALVE PIT B
GROUNDWATER(OCT.93)
FUEL ID:
JET FUEL (3,600)
BTEX: (256)
GROUNDWATER(OCT.93
SOIL
FUEL ID:
JET FUEL( 1.100,000)
BTEX: (22,600)
SOIL
FUEL ID:
JET FUEL (180,000)
BTEX: (9,600)
SOIL
FUEL ID:
JET FUEL
BUNKER
BTEX:
(12,000
(47,000
(257
SOIL
FUEL ID:
JET FUEL( 1.300,000)
BTEX: (244.000 J)
NOTE:
CROSS SECTION LOCATION
PRESENTED ON FIGURE 18
SOIL (SEPT.93)
FUEL ID:
JET FUEL(1,400,000)
BTEX: (23.240)
SOIL
FUEL ID:
JET FUEL
BTEX:
(SEPT.93)
(560.000)
(40,100)
SOIL (SEPT.93)
FUEL ID:
JET FUEL( 1,300,000)
BTEX: (493,000)
LEGEND
BTEX BENZENE. TOLUENE. ETHYLBENZENE, AND XYLENES
FUEL ID FUEL IDENTIFICATION
(10,000) SOIL CONCENTRATION IN MICROGRAUS PER KILOGRAM ( MSAg
GROUNDWATER CONCENTRATION IN UlCftOCRAUS PER UTER ( M9/L)
J ESTIMATED
AP-6018 MONITORING WELL OR SOIL BORING DESIGNATION
440' ELEVATION ABOVE MEAN SEA LEVEL (AMSL)
GROUNDWATER/VADOSE ZONE INTERFACE
DIRECTION OF GROUNDWATER FLOW
FINE-GRAINED SAND AND SILT
(Chvno Alluvium)
SAND AND GRAVEL
(Ch«na Alluvium)
NOTE: WATER TABLE ELEVATIONS BASED ON
OCTOBER 25, 1993, WATER LEVEL READINGS.
HORIZONTAL SCALE
100 200
300 FEET
VERTICAL SCALE
10 20
30 FEET
: ecology and environment, inc.
v r:e-jtJOfXM So«6otitts in toe E
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
Figure 15
TOTAL BTEX AND FUEL ID CONCENTRATIONS
RAILCAR OFF-IOADING FACILITY-VALVE PIT B SUB-AREA CROSS SECTION
OPERABLE UNIT 3
FAIRBANKS ALASKA
S:E
JOB. NO.
JT2950
FILE NO.
JZ8C011A
DATE:
08/95
PLATE
CAC,
DELIVERY ORDER Me
38
-------
u
11
n
HO
LEGEND
I I Benzene Not Detected
A K) - Benzene Delected ug/L
IKS AHMY
t:N<,im:KH m;rrm
-------
0 125 250 375 500
Feel
LEGEND
n Benzene Not Detected
A10 - Benzene Detected ug/L
Foirbanks-Eielson Pipeline
Pecology and environment, inc.
PhlMlltaMl >.iliMi In th> In li mill..I
US. ARMY
ENGINEER DISTRICT. AUSKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
FIGURE 17
BENZENE CONCENTRATIONS IN GROUNDWATER
AT MILEPOST 2.7 AND 3.0 SOURCE AREAS
SIZE
A
JOE NO.
JT-2
FILE NO.
DATE:
09/05/95
PLATE
-------
CORPS OF ENGINEERS
U.S. ARMY
DRAINAGE DITCH
y/
FEP FEP FEP
DRAINAGE DITCH
APPROXIMATE CENTER OF PIPELINE DITCH
FEP FEP FEP
LAURANCE ROAD
DRAINAGE DITCH
LEGEND
--FEP—
10
15
FAIRBANKS-EIELSON PIPELINE
APPROXIMATE PIPELINE BREAK
BENZENE NOT DETECTED
BENZENE DETECTED ug/L
SOURCE: DEPARTMENT OF TRANSPORTATION, 1992; USAGE. 1991
APPROXIMATE SCALE IN FEET
APPROXIMATE 3/4'-'0'
•jecology and environment, inc.
"iMiriMtlwol Sfxclol Illl In Ih. En.liotn.nl
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
Figure 18
BENZENE CONCENTRATIONS IN GROUNDWATER
AT MILEPOST 15.75 SOURCE AREA,
OPERABLE UNIT 3
FAIRBANKS ALASKA
SIZE
JOB. NO.
JT2950
FILE NO.
JT2-28A.DWG
DATE:
09-05-95
PLATE
-------
-------
Page 1 .>;" i
Table 1
SUMMARY OF GROUNDWATER SAMPLING RESULTS
OFF POST WELLS
FORT WAINWRIGHT, ALASKA
(Mg/L)
MCL"
orRBC*
11/91
Steese Chapd
1,2 dichloroethane
Isopropylbenzene
m+p xylenei
1 ,2,4-trimethyIbenzene
5«
820*"
lO.OOO*-6
14b
1.8
ND
ND
ND
12/91
1.6
ND
ND
ND
6/93
1/94
2/94
6/94
7/94
2
1
0.26
ND
3.4
1.0
ND
ND
2.6
0.7
ND
ND
ND
ND
ND
ND
1.26
1.30
0.3
0.23
Shannon Park Baptist Church
1 ,2 dichloroethane
Isopropylbenzene
sec-Butylbenzene
n-Propylbenzene
1 ,2,4-trimethyIbenzene
5*
820b
*
*
14b
2.7
4.4
ND
ND
ND
2.9
6
ND
ND
ND
NA
NA
NA
NA
NA
5.04
7.98
0.67
0.46
0.26
4.4
7.9
ND
ND
0.4
5.35
7.27
ND
ND
0.3
5.38
8.13
0.65
ND
0.32
* No maximum contaminant levei exists; no risk-based concentration or derived remediation goal was generated for this
contaminant in the Operable Unk 3 risk assessment.
a Safe Drinking Water Act Maximum Contaminant Level for Public Water Supply Systems.
" Risk Based Concentration assumes residential groundwater ingestion, inhalation, and dermal contact and is based on a
hazard quotient of 1.0.
c This value is reported for total xylenes.
Key:
NA = Not applicable.
ND = Not detected.
42
-------
Page 1 of 2
Table 2
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
TANK FARM-BIRCH HILL AST SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPII (Mod. 418.1) (mg/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
49/16
Range of Detected
Concentrations
20-2,040
Location of
Maximum
Concentration
AP-6090
Mean
Concen-
tration'
392
Subsurface Soil
No. of
Samples
Analyzed/
Detected
64/22
Range of Detected
Concentrations
22-6,730
Location of
Maximum
Concentration
AP-6087, 5'
Mean
Concen-
tration*
990
Fuel ID (Mod. 8015) (mg/kg)
Gasoline
Diesel No. 2
Jet A
JP-4
Bunker C-range organic compounds
44/2
44/18
44/3
44/0
44/23
300-340
3-1, 200 J
16 J-5,500
—
29 J-220 J
TFM307V
TFM305V
AP-6090
—
—
320
274.572
2,638.667
—
67.174
25/0
25/2
25/7
25/2
25/8
—
5-8.3
13-300
5.5-91
28-140
—
AP-6080, 15'
AP-6091, 6'
AP-6090, 7'
AP-6090, 7'
—
6.65
125.571
48.250
56.875
VOCs (EPA 8260) (mg/kg)
1 ,2,4-Trimclhylbcn/.cne
1 ,2-Dibromoethane
1 ,3,5-Trimethylbenzene
Ben/.cne
Elhylbcn/.cne
Isopropylbenzene
Naphthalene
Toluene
m + p xylene
o-xylene
n-Butylbenzene
40/2
40/0
40/4
40/0
40/1
40/1
40/0
40/1
40/4
40/3
40/0
1 .7-28
—
0.009-44
—
16
2.9
—
49
0.008-100
0.007-39
—
TFM303V
^
TFM303V
—
TFM303V
TFM303V
—
TFM303V
TFM303V
TFM303V
—
14.850
—
12.097
-
—
—
—
—
26. 777
1 1 .727
—
24/4
24/1
24/5
24/1
24/3
24/3
24/3
24/3
24/4
24/4
24/3
1658
0067
0.260-92
3
2.5-23
0.960-62
2.2-11
0.830-47
64-220
3.1-82
1 .66
AP-6083, 4'
AP-6075, 11'
AP-6090, 7'
AP 6083, 4'
AP 6083, 4'
AP-6090, 7'
AP-6083, 4'
AP 6090, 7'
AP 6090, 7'
AP 6090, 7'
AP 6083, 4'
36.25
—
37.32
15.833
23.653
7.1
27.61
82.85
33.025
3 633
Key ;il end of table.
-------
Page 2 of 2
Table 2
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
TANK FARM-BIRCH HILL AST SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
n-Propylbcnzenc
p-isopropyltoluene
sec-Butylben/ene
tcrt-Bulylbenzcnc
Total Lead (EPA 7421) (ing/kg)
Lead (TCLP) (EPA 7421/1311) (mg/L)
Surface Soil
No. of
Samples
Analyzed/
Detected
40/1
40/2
40/0
40/0
43/43
3/3
Range of Detected
Concentrations
5.2
1.2-1.4J
—
—
8.3-7,840
1.7-5.4
Location of
Maximum
Concentration
TFM303V
TFM303V
—
—
TFM314V
TFM303V
Mean
Concen-
tration'
—
1.3
—
—
727
3
Subsurface Soil
No. of
Samples
Analyzed/
Detected
24/4
24/5
24/2
24/1
24/24
0/0
Range of Detected
Concentrations
1.9-12
0.071-10
0.8-4
1.9
3.6-35.7
—
Location of
Maximum
Concentration
AP-6083, 4'
AP-6083. 4'
AP-6083, 4'
AP.6091, 6'
AP-6090, 7'
—
Mean
Concen-
tration*
5.95
2.766
2.400
-
14
-
a Rounded mean of detected concentrations.
Key:
AST
EPA
FSPH
Fuel ID
J
mg/kg
mg/L
TCLP
VOCs
Aboveground storage tank.
United States Enviromental Protection Agency.
Field screening petroleum hydrocarbons.
Fuel identification.
Estimated concentration.
Milligrams per kilogram.
Milligrams per liter.
Toxicily characteristic leaching procedure.
Volatile organic compounds.
-------
Page 1 of 2
Table 3
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
TANK FARM-BUILDING 1173 SUB-AREA
OPERABLE UNIT 3
FORT VVAINW RIGHT, ALASKA
Analyte and Concentration Units
FSPH (Mod. 418.1) (mg/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
7/4
Range of
Detected
Concentrations
28-780
Location of
Maximum
Concentration
AP-6122
Mean
Concen-
tration*
264
Subsurface Soil
No. of
Samples
Analyzed/
Detected
28/7
Range of
Detected
Concentrations
22-4,954
Ixxralion of
Maximum
Concentration
AP-6095, 19'
Mean
Concen-
tration*
1.459
Fuel ID (Mod. 8015) (mg/kg)
Diesel No. 2
Jet A
Bunker C-range organic compounds
2/1
2/1
2
33
12
—
AP-6123
AP-6096
—
—
—
—
12/1
12/1
12/2
340
180
42-50
AP-6122, 18'
AP-6096, 16'
AP-6056, 6'
—
—
46
VOCs (EPA 8260) (mg/kg)
1 ,2,4-Trimelhylbenzene
1 ,3,5-Trimethylbenzene
Benzene
Ethylbenzene
Isopropylbenzene
Naphthalene
Toluene
m + p xylcne
o-xylene
n-Bulylhcn/cnc
n-Propyllwn/.cnc
|) isylluliiriii:
2/0
2/0
2/0
2/0
2/0
2/0
2/0
2/0
2/0
2/0
2/0
2/0
—
—
—
—
—
—
—
• —
—
—
—
—
_
—
—
—
—
—
—
-
-
-
—
—
—
—
—
—
—
—
—
—
—
11/1
11/1
11/2
11/1
11/1
11/1
11/2
11/1
11/1
11/1
ll/l
ll/l
37 E
58 E
0.016-2.3
97
9.2
5
0.007-39 E
43 E
42 E
3.6
II
h.l
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-6122, 18'
AP-612">, 18'
AP6I22, 18'
APM22. 18'
—
_
1.158
—
—
—
19.504
—
—
—
-
Kcv .il iml ul l;il
-------
Page 2 of 2
Table 3
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
TANK FARM-BUILDING 1173 SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
sec-Butylbenzene
Total Lead (EPA 7421) (mg/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
2/0
2/2
Range of
Detected
Concentrations
—
3.9-12.4
Location of
Maximum
Concentration
—
AP-6123
Mean
Concen-
tration*
—
8
Subsurface Soil
No. of
Samples
Analyzed/
Detected
11/1
13/13
Range of
Detected
Concentrations
3.8
2.2-16.7
Location of
Maximum
Concentration
AP-6122, 18'
AP-6056, 6'
Mean
Concen-
tration*
—
7.2
CTv
3 Rounded mean of detected concentrations.
Key:
E = Concentration exceeds the calibration range for the analytical instrument.
EPA - United Stales Environmental Protection Agency.
FSPH = Field screening petroleum hydrocarbons.
Fuel ID = Fuel identification.
mg/kg = Milligrams per kilogram.
VOCs = Volatile organic compounds.
-------
Page 1 of 1
Table 4
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
TANK FARM— TRUCK FILL STAND SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Surface Soil Subsurface Soil
No. of
Samples
Analyzed/
Analyte and Concentration Units Detected
FSPII (mg/kg) 5/1
Range of
Detected
Concentrations
35
Location of
Maximum
Concentration
AP-6099
No. of
Mean Samples
Concen- Analyzed/
(ration" Detected
- 19/4
Range of
Detected
Concentrations
20-2,079
1 .oral km of
Maximum
Concentration
AP-6125, 7'
Mean
Concen-
tration"
1,262
Fuel ID (mg/kg)
Diesel No. 2 | 2/0
Bunker C-range organic compounds || 2/1
—
48 J
—
AP-6088
-1
- 1 6/1
7.8
41
AP-6099, 21'
AP-6066, 18'
—
—
VOCs (mg/kg)
Toluene 2/0
Total Lead (mg/kg) || 2/2
—
10-17.8
—
AP-6088
— I! 6/1
14 1 6/6
0.009
3.4-14.8
AP-6126, 4'
AP-6099, 21'
—
7
a Rounded mean of delected concentrations.
Key.
J = Estimated concentration.
FSPH = Field screening petroleum hydrocarbons.
Fuel ID = Fuel identification.
mg/kg = Milligrams per kilogram.
VOCs = Volatile organic compounds
-------
Page I iif I
TableS
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
LAZELLE ROAD SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Surface Soil
No. of
Samples
Analyzed/
Analyte and Concentration Units Detected
FSPII (Mod. 418.1) (mg/kg) | 4/4
Range of
Detected
Concentrations
42-109
Location of
Maximum
Concentration
AP-6097
Mean
Concen-
tration"
69.5
Subsurface Soil
No. of
Samples
Analyzed/
Detected
20/20
Range of
Detected
Concentrations
3-31
Location of
Maximum
Concentration
AP-6097
Mean
Concen-
tration8
7.9
Fuel ID (mg/kg)
—
-
—
—
—
—
- I! 6/2
— || 6/6
12-18
5.1-78.7
AP-6098
AP-6098
15
31.3
oo
Rounded mean of detected concentrations.
Key:
EPA = United States Environmental Protection Agency.
I-SPH = Field screening petroleum hydrocarbons.
Fuel ID - Fuel identification.
ing/kg = Milligrams per kilogram.
-------
Page 1 of 1
Table 6
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
SHANNON PARK SUBDIVISION SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPII (Mod. 418.1) (rag/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
1/1
Range of
Detected
Concentrations
—
Location of
Maximum
Concentration
AP-6070
Mean
Concen-
tration'
10
Subsurface Soil
No. of
Samples
Analyzed/
Detected
31/31
Range of
Detected
Concentrations
0-288
Location of
Maximum
Concentration
AP-6067
Mean
Concen-
tration"
37
Fuel ID (mg/kg)
Bunker C-range organic compounds || 1/1
Total Lead (EPA 7421) (mg/kg) 1/1
—
—
AP-6070
AP-6070
39 I! 11/4
12.2 | 11/11
15-120
2.7-14.8
AP-6067
AP6129
55.5
7.94
a Rounded mean of delected concentrations.
Key:
EPA = United States Environmental Protection Agency.
FSPH = Field screening petroleum hydrocarbons.
Fuel ID = Fuel identification.
mg/kg = Milligrams per kilogram.
-------
Pajre i of
Table 7
SUMMARY OF SUBSURFACE SOIL RESULTS
TANK FARM-CANOL SERVICE ROAD SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPH (Mod. 418.1) (rag/kg)
Subsurface Soil
No. of
Samples
Analyzed/
Detected
58/2
Range of
Detected
Concentrations
20-32
Location of
Maximum
Concentration
AP-6107 8'
Mean
Concen-
tration3
26
Fuel ID (rag/kg)
Bunker C-range organic compounds | 25/6
38 J - 79
AP-6060 11'
52.5
VOCs (EPA 8260) (mg/kg)
1 ,3 ,5-Trimethylbenzenc
Toluene
m+p xylene
o-xylene
Total Lead (EPA 7421) (mg/kg)
25/1
25/1
25/1
25/1
25/25
0.003 J
0.008
0.024
0.007
2.5-16.2
AP-6101 16'
AP-6101 16'
AP-6101 16'
AP-6101 16'
AP-6102 6'
AP-6107 4'
7
a Rounded mean of detected concentrations.
Key:
EPA = United States Environmental Protection Agency.
FSPH = Field screening petroleum hydrocarbons.
Fuel ID = Fuel identification.
J = Estimated concentration.
mg/kg = Milligrams per kilogram.
VOCs = Volatile organic compounds.
-------
Page 1 of 1
Table 8
SUMMARY OF SUBSURFACE SOIL RESULTS
TANK FARM-VALVE PIT A SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPH (Mod. 418.1) (mg/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
25/11
Range of
Detected
Concentrations
24-9,620
Location of
Maximum
Concentration
AP-611011'
Mean
Concen-
tration*
3,411
Fuel ID (MOD 8015) (mg/kg)
Jet A
Kerosene
12/6
12/3
5-390
500J-3.800J
AP-6121 IT
AP-611016'
167.667
1,833.333
VOCs (EPA 8260) (mg/kg)
1 ,2,4-Trimethylbenzene
1 ,3 ,5-TrimethyIbenzene
Benzene
Ethylbenzene
Itopropylbcnzene
Naphthalene
Toluene
m+p xylene
o-xylene
n-Butylbenzene
n-Propylbenzene
p-isopropyholuene
tec-Butylbenzene
11/8
11/8'
11/1
11/6
11/5
11/5
11/5
11/8
11/6
11/7
11/5
11/7
11/6
0.077-200 E
0.044-270 E
10
0.1 10-50 E
0.052-13
0.050-16
0.1 10-200 E
0.016-360 E
0.007-150 E
0.017-18
0.084-22
0.025-26
0.008-8.7
AP-6110 11'
AP-6110 IT
AP-6110 16'
AP-6110 16'
AP-6110 16'
AP-6110 11'
AP-6110 16'
AP-6110 11'
AP-6110 IT
AP-6110 11'
AP-6110 16'
AP-6110 IT
AP-6110 11 '
76.951
104.354
—
23.118
8.11
9.11
106.022
125.057
61.36
8.783
13.217
10.448
4.890
BNAs (EPA 8270) (mg/kg)
2-Methylnaphthaiene
Napthhalene
Total Lead (EPA 7421) (mg/kg)
TCLP Lead (EPA 7421/1311) (mg/L)
1/1
1/1
14/14
1/1
0.730
0.270 J
2.1-7.6
0.03
AP-6064 11'
AP-6064 IT
AP-6064 K'
AP-6064 IT
—
—
5
—
a Rounded mean of detected concentrations.
Key:
E =
EPA =
FSPH =
Fuel ID -
J =
mg/kg =
VOCt =
Concentration exceeds the calibration range for the analytical instrument.
United States Environmental Protection Agency.
Field screening petroleum hydrocarbons.
Fuel identification.
Estimated concentration.
Milligrams per kilogram.
Volatile organic compounds.
51
-------
Page 1 of 1
Table 9
SUMMARY OF GROUNDWATER RESULTS
TANK FARM-BIRCH HILL AST SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
TRPH (Mod. 418.1) Gig/L)
No. of Samples
Analyzed/
Detected
4/2
Range of
Detected
Concentrations
810-10,400
Location of
Maximum
Concentration
AP-6053
Mean
Concen-
tration2
6,000
Fuel ID (Mod. 8015) G*/L)
Gasoline
Bunker C-range organic compounds
3/1
3/2
23,000
960-1,000
AP-6053
AP-6055
—
980
VOCs (EPA 8260) G«g/L)
1 ,2,4-Trimethyibenzene
1 ,3 ,5-Trimethy Ibenzene
Benzene
Ethylbenzene
Iiopropylbenzene
Naphthalene
Toluene
m+p xylene
o-xylene
n-Propylbenzene
p-isopropyltoluene
Total Lead (EPA 7421) 0«/L)
Dissolved Lead (EPA 7421) G*/L)
4/1
4/2
4/1
4/2
4/2
4/2
4/2
4/2
4/1
4/1
4/1
4/4
4/1
32
9-20
150
10-64
9-20
8-23
14-24
10-100
23
14
15
9.3-140
4.8
AP-5271
AP-6053
AP-5271
AP-5271
AP-5271
AP-6053
AP-5271
AP-5271
AP-5271
AP-5271
AP-6053
AP-6053
AP-6053
—
14
—
37
14
16
19
55
—
—
—
55
—
a Rounded mean of detected concentrations.
Key:
AST = Aboveground storage tank.
EPA = United States Environmental Protection Agency.
Fuel ID = Fuel identification.
/ig/L = Micro grams per liter.
TRPH = Total recoverable petroleum hydrocarbons.
VOCt = Volatile organic compounds.
52
-------
Page 1 of 1
Table 10
SUMMARY OF GROUNDWATER RESULTS
TANK FARM-BUILDING 1173 SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Aawlyteand
CoaeeotratioA Units
No. of Samples
Analyzed/
Detected
Fud ID 0«/L)
Gasoline || 3/1
Jet A 1 3/1
Range of
Detected
Concentrations
Location of
Maximum
Concentration
Mean
Concentration3
110 J
380
AP-5273
AP-6056
—
—
VOCiG«/L)
Benzene
Ifopropylbenzene
Total Lead Oig/L)
2/1
2/1
3/3
120
8
30-73
AP-6056
AP-6056
AP-6056
—
—
51
a Rounded mean of detected concentrations.
Key:
J
Fuel ID
VOCi
Estimated concentration.
Fuel identification.
Micrograms per liter.
Volatile organic compounds.
53
-------
Page 1 of 1
Table 11
SUMMARY OF GROUNDWATER RESULTS
TANK FARM-TRUCK FILL STAND SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
TRPH (EPA 418.1) Gg/L)
6/1
6/1
6/1
6/6
11
7
5
2.4-150
AP-5274
AP-5783
AP-5783
AP-6066
—
—
—
42
* Rounded mean of detected concentrations.
Key:
EPA = United States Environmental Protection Agency.
Fuel ID = Fuel identification.
jig/L = Micrognms per liter.
TRPH = ToUl recoverable petroleum hydrocarbons.
VOCi = Volatile organic compounds.
54
-------
Page J of 1
Table 12
SUMMARY OF GROUNDWATER RESULTS
Analyte and
Concentration Units
LAZELLE ROAD SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
No. of Samples
Analyzed/
Detected
Range of
Detected
Concentrations
Location of
Maximum
Concentration
Mean
Concentration3
Fuel ID G«/L)
Gasoline I
m
6,800
AP-6071
—
VOCi G*/L) None detected
Total Lead fog/L) f 1/1
10
AP-6071
—
a Rounded mean of detected concentrations.
Key:
Fuel ID
HgfL
VOCs
= Fuel identification.
= Micrograms per liter.
= Volatile organic compounds.
55
-------
Pase 1 of 1
Table 13
SUMMARY OF GROUNDWATER RESULTS
SHANNON PARK SUBDIVISION SUB-AREA
OPERABLE UNIT 3
FORT WAINWRJGHT, ALASKA
No. of
Samples
Analyzed/
Analyte and Concentration Units Detected
Fuel ID 0*/L)
Bunker-C range organic compounds II 5/1
Range of
Detected
Concentrations
Location of
Maximum
Concentration
1,100
AP-6070
Mean
Concentration3
—
VOCs («/L) None detected
Total Lead Oig/L) | 5/5
3.5-150
AP-6068
74.3
a Rounded mean of detected concentrations.
Key:
Fuel ID = Fuel identification.
HgfL = Micrograms per liter.
VOCs = Volatile organic compounds.
56
-------
Page 1 of 1
Table 14
SUMMARY OF GROUNDWATER RESULTS
CANOL ROAD SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyteand
Concentration Units
No. of Samples
Analyzed/
Detected
Fuel ID Oig/L)
4/1
Range of
Detected
Concentrations
Location of
Maximum
Concentration
Mean
Concentration8
6,900
AP-6059
—
VOCs (pg/L) None detected
Dissolved Lead (mg/L)
Total Lead Oig/L)
9/1
9/9
4.8
5.5-88
AP-6061
AP-6061
—
42.9
3 Rounded mean of detected concentrations.
Key:
Fuel ID = Fuel identification.
pg/L = Micrograms per liter.
VOCs = Volatile organic compounds.
57
-------
Page 1 of 1
Table 15
SUMMARY OF GROUNDWATER RESULTS
TANK FARM- VALVE PIT A SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
TRPH (EPA 418.1) fcg/L)
No. of Samples
Analyzed/
Detected
2/2
Range of Detected
Concentrations
11,600J-11,700J
Location of
Maximum
Concentration
AP-6065
Mean
Concen-
tration3
11,700
Fuel ID (Mod. 8015) G*/L)
Gasoline f 2/2
26,000 J-43,000 J
AP-6065
34,500
VOCs (EPA 8260) G*/L)
1 ,2,4-TrimethyIbenzene
1 ,3 ,5-Trimethy Ibenzene
Benzene
Ethylbenzene
Toluene
m+p xyiene
o-xylcoc
Total Lead (EPA 7421) («/L)
Dissolved Lead (EPA 7421) (pg/L)
212
2/2
2/1
2/2
2/2
2/2
2/2
212
2/1
1,100-1,400
1,400-1,700
1,700
930-1,600
4,100-12,000
3,700-6,400
1,400-2,400
110-300
2.7
AP-6064
AP-6064
AP-6064
AP-6064
AP-6064
AP-6064
AP-6064
AP-6065
AP-6064
1,250
1,530
—
1,265
8,050
5,050
1,900
210
—
a Rounded mean of detected concentrations.
Key:
EPA = United States Environmental Protection Agency.
Fuel ID = Fuel identification.
J = Estimated concentration.
/»g/L = Micrograms per liter.
NA = Not applicable.
TRPH = Total recoverable petroleum hydrocarbons.
VOCs = Volatile organic compounds.
58
-------
1 of 1
Table 16
SUMMARY OF SUBSURFACE SOIL RESULTS
ROLF- VALVE PIT B SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPH (Mod 418.1) (rag/kg)
Subsurface Soil
No. of
Samples
Analyzed/
Detected
13/9
Range of Detected
Concentrations
26-19,800
Location of
Maximum
Concentration
AP-6028. 11'
Mean
Concen-
tration3
4,697
Fuel ID (Mod 8015) (mg/kg)
Jet A II 9/8
Blinker C -range organic compound || 9/2
12-2,700
47-58
AP-6027. 11'
AP-6027. 6'
1,069
52.5
VOCs (mg/kg)
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethylbenzene
Benzene
Ethylbenzene
Iiopropylbenzene
Naphthalene
Toluene
m+p xylene
o-xylene
n-Butylbenzene
n-Propyibenzene
p-iiopropyltoluenc
fec-Butylbenzene
Total Lead (mg/kg)
9/6
9/4
9/1
9/5
9/6
9/8
9/4
9/7
9/8
9/6
9/3
9/8
9/4
9/9
0.450-140
0.160-69 E,J
0.170J-.640 J
0.730 J-l 10 E,J
0.076-33
0.150-16
0.170J-120
0.210-240
0.047 J-88
0.039-15
1.9-16
0.068-20
0.7-7.1
0.003.2-14.5
AP-6028. 11'
AP-6030. 11'
AP-5998. IT
AP-6030. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11'
AP-6028. 11 '
AP-6028. 6'
33.958
21.635
—
35.3
8.579
5.544
36.750
52.173
18.868
4.888
8.033
6.059
3.375
8
3 Rounded mean of detected concentrations.
Key:
E = Concentration exceeds the calibration range for the analytical instrument.
FSPH = Field icreening petroleum hydrocarbons.
Fuel ID - Fuel identification.
J = Estimated concentration.
mg/kg = Milligrams per kilogram.
UJ = Estimated detection limit.
VOCt = Volatile organic compounds.
59
-------
Page 1 of 2
Table 17
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
CENTRAL ROLF SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSI'll (Mod 418.1) (ing/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
18/11
Range of
Detected
Concentrations
10
Location of
Maximum
Concen-
tration
AP-6033. 11'
Mean
Concen-
tration"
1,725
Subsurface Soil
No. of
Samples
Analyzed/
Detected
62/28
Range of Detected
Concentration
21-10,291
Location of
Maximum
Concentratkm
AP6033, II'
Mean
Concen-
tration"
1,422
Fuel ID Mod 8015) (ing/kg)
Diesel No. 2
Jet A
Bunker C-runge organic compound
Kocasene
16/3
16/0
16/12
16/1
5,900 J
—
2,100 J
56 J
—
—
—
—
2,060.667
—
434.923
—
31/7
31/5
31/7
31/2
5.1 J-150 J
20-2,600 J
32-110 J
4-11 J
AP6020, 16'
AP-6007. 13'
AP-6026. 11'
AP-6025, 6'
33.986
914
55.429
7.5
VOCs (EPA 8260) (mg/kg)
1 ,2,4-Triraethylbenzene
1 ,3,5-Trimelhylbenzenc
Benzene
Ethylbenzene
Isopropylbenzene
Naphthalene
Toluene
m + p xylene
o-xylene
n-Butylbenzene
n-Propylbenzene
16/0
16/0
16/0
16/0
16/0
16/0
16/0
16/0
16/0
16/0
16/0
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
28/7
28/4
28/2
28/4
28/5
28/6
28/6
28/6
28/6
28/3
28/2
0.009-140
0.005 J-25,000
0.016-2.4
2.1 E-91
0.140-360
0.007-8.6
0.019-320,000
0.008-610
0.016-230
0.530-5
0.970-6.6
AP-6007. 13'
AP-6033, 14'
AP-6015, 13'
AP-6007, 13'
AP-6007, 13'
AP-6015, 13'
AP-6007, 13'
AP-6007, 13'
AP-6007, 13'
AP-6015, 13'
AP-6015, 13'
33.853
6.841
1.208
37.05
86.008
3.006
77.862
152.706
56.536
2.663
5.5
Key at end of table.
-------
Page 2 of 2
Table 17
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
CENTRAL ROLF SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Unite
p-isopropyltoluene
sec-Butylbenzenc
Surface Soil *
No. of
Samples
Analyzed/
Detected
16/0
16/0
Range of
Detected
Concentration]
—
—
Location of
Maximum
Concen-
tration
—
—
Mean
Concen-
tration*
—
—
Subsurface Soil
No. of
Samples
Analyzed/
Detected
28/3
28/3
Range of Detected
Concentration
0.910-8.1
0,340-2.7
Location of
Maximum
Concentration
AP-6015, 13'
AP-6015, 13'
Mean
Concen-
tration'
4.37
2
BNAs (EPA 8270) 0
-------
Page 1 of 1
Table 19
SUMMARY OF GROUNDWATER RESULTS
ROLF- VALVE PIT B SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Aulyte and Concentration links
TRPH (EPA 418.1) 0*/L)
No. of
Samples
Analyzed/
Detected
' 2/2
Range of
Detected
Concentrations
6,900 J-5 1,600
Location of
Maximum
Concentration
AP-5998
Mean
Concen-
tration8
24,000
Fuel (Mod. 8015) ID 0«/L)
Jet A | 1/1
3,600
AP-6018
—
VOC* (EPA 8260) 0
-------
Page 1 of 1
Table 20
SUMMARY OF GROUNDWATER RESULTS
CENTRAL ROLF SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
TRPH (EPA 418.1) G*/L)
No. of
Samples
Analyzed/
Detected
15/11
Range of Detected
Concentrations
710-1,190,000
Location of
Maximum
Concentration
AP-6015
Mean
Concen-
tration9
138,000
Fud ID (Mod. 8015) Gig/L)
Gasoline
Diesel No. 2
JP-4
Bunker C-range organic compounds
11/4
11/2
11/1
11/2
2,900-22,000
190J-4.000
120,000
320-640 J
AP-6005
AP-6008
AP-5527
AP-6001
14,975
2.095
—
480
VOO (EPA 8260) 0
-------
Page 1 of
Table 21
SUMMARY OF GROUNDWATER SAMPLE RESULTS
ROLF-FRONT STREET SUB-AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Aoalyte and Concentration Units
TRPH (EPA 418.1) («/L)
No. of
Samples
Analyzed/
Detected
5/3
Range of Detected
Concentrations
260 J-7,300
Location of
Maximum
Concentration
AP-6016
Mean
Concen-
tration"
4,000
Pud ID (Mod 8015) Gig/L)
Gasoline
Diesel No. 2
5/1
5/1
6,100 J
10,000
AP-6016
AP-5537
—
—
VOCs (EPA 8260) G«g/L)
1 ,2,4-TrimcthyIbenzene
1 ,3 ,5-Trimethy Ibenzene
Benzene
Ethytoenzene
Iiopropylbenzene
Naphthalene
Toluene
m+p xylcnc
n-Propylbenzene
5/2
5/2
5/2
5/2
5/1
5/2
5/2
5/3
5/1
41-250
22-530
15-140
21-240
5
26-420
7-140
5-500
6
BNAi (EPA 8270) (jtg/L)
Naphthalene
2-Methylnaphthalene
Total Lead (EPA 7421) G#/L)
5/1
5/1
5/5
9 J
4 J
6.4-260
AP-6016
AP-6016
AP-6016
AP-6016
AP-5537
AP-6016
AP-6016
AP-6016
AP-5537
146
276
78
131
—
223
74
181
—
AP-5537
AP-5537
AP-6011
—
—
62
a Rounded mean of detected concentrations.
Key:
BNAt = Base/neutral and acid cxtractable organic compounds.
EPA = United States Environmental Protection Agency.
Fuel ID = Fuel identification.
J = Estimated concentrations.
HgfL = Micrograms per liter.
TRPH = Total recoverable petroleum hydrocarbons.
VOCs = Volatile organic compounds.
65
-------
Page 1 of 2
Table 22
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
PIPELINE MILEPOST 2.7 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPII (Mod 418.1) (mg/kg)
Surface Soil
No. of
Samples
Analyzed/
Detected
10/0
Range of
Detected
Concentrations
—
Intention of
Maximum
Concentration
—
Mean
Concen-
tration*
—
Subsurface Soil
No. of
Samples
Analyzed/
Detected
7/4
Range of Detected
Concentrations
25-574
l/ocation of
Maximum
Concentration
AP-6036, 6'
Mean
Concen-
tration"
181
Fuel ID (Mod 8015) (mg/kg)
Gasoline
Kerosene
Bunker C-range organic compounds
7/3
7/0
7/7
8.6-470
—
37-370
SS-3
—
SS-3
164,533
—
121,571
4/2
4/2
4/3
22 J-290
2.3 J
49 J-65 J
AP-6036, 6'
AP-6035, 6'
AP-6035, 16'
AP-6035, 16'
156
2.3
58
VCCs (EPA 8260) (mg/kg)
1 ,2,4-Trichlorobenzene
1 ,2,4-Trimethylbenzene
1 ,3,5-Trimethylbenzene
Benzene
Ethylbenzene
Isopropylbenzene
Toluene
m+p xylene
o-xylene
7/0
7/2
7/2
7/1
7/0
7/2
7/1
7/1
7/0
—
0.120-2.1
0.091-2.5
1,500
—
43-1,500
3,400
86
—
—
SS-3
SS-3
SS-3
—
SS-1
SS-3
SS-1
—
—
1,110
1,296
—
—
772
—
—
-
4/1
4/1
4/2
4/2
4/3
4/3
4/1
" 4/3
4/3
0.108
0.53 E
0.079-.69 E
0.008-.19
0.058-.16
0.021-.4 E
0.21
0.38-.66 E
0.14-.28
AP-6036, 16'
AP-6035, 6'
AP-6035, 6'
AP-6034, 11'
AP-6034, 11'
AP-6035, 6'
AP-6035, 6'
AP-6035, 6'
AP6034, 11'
—
—
0.385
0.099
0.106
0.165
—
0.48
0.220
Key at end of table.
-------
Page 2 of 2
Table 22
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
PIPELINE MILEPOST 2.7 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
n-Propylbenzene
p-isopropyltoluene
scc-Butylbenzene
Total Lead (EPA 7421) (rag/kg)
Lead (TCLP) (EPA 7421/1311) (mg/L)
Surface Soil
No. of
Samples
Analyzed/
Detected
7/0
7/0
7/0
7/7
2/0
Range of
Detected
Concentrations
—
—
—
11.8-43.8
—
Location of
Maximum
Concentration
—
-*
—
SS-3
—
Mean
Concen-
tration*
—
—
—
26.1
—
Subsurface Soil
No. of
Samples
Analyzed/
Detected
4/2
4/2
4/1
4/4
2/1
Range of Detected
Concentrations
0.013-.077
0.033-.610
0.01
10.5-16.9
0.034
Location of
Maximum
Concentration
AP-6035. 6'
AP-6034, 11'
AP-6035, 6'
AP-6034, 11'
AP-6034, 6'
Mean
Concen-
tration"
0.045
0.322
—
14
—
3 Rounded mean of detected concentrations.
Key:
E = Concentration exceeds the calibration range for the analytical instrument.
EPA = United States Environmental Protection Agency.
FSPH = Field screening petroleum hydrocarbons.
Fuel ID = Fuel identification.
J l:slii>i:iU-
-------
Page 1 of
Table 23
SUMMARY OF GROUNDWATER RESULTS
PIPELINE MILEPOST 2.7 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Aaalyte and Concentration Units
TRPH (EPA 418.1) (pg/L)
No. of
Samples
Analyzed/
Detected
5/4
Range of Detected
Concentrations
2.100-5,700
Location of
Maximum
Concentration
AP-6034
Mean
Concen-
tration8
4,000
Pud ID (Mod. 8015) G*g/L)
Gasoline
Bunker Orange organic compounds
4/4
4/1
390-2,100 J
1,200
AP-5651
AP-6035
1,103
—
VOCs (EPA 8260) G*g/L)
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimethy Ibenzene
Benzene
Ethylbenzene
Ifopropyibenzene
Toluene
m+p xylene
o-xylene
n-Propylbenzene
p-uopropyltoluene
Total Lead (EPA 7421) feg/L)
Dissolved Lead (EPA 7421) (pg/L)
5/5
5/5
5/4
5/5
5/5
5/4
5/5
5/5
5/4
5/1
5/5
5/3
29-240 E
11-320 E
37-140
8-330 E
94-320 E
23-700 E
42-1,200 E
9-400 E
6-31
10
25-150
2-4
AP-5651
AP-5651
AP-6034
AP-5651
AP-5651
AP-6034
AP-5651
AP-5651
AP-5651
-AP-5651
AP-6034
AP-5651
97
91
85
134
155
253
484
151
15
—
66
2.8
3 Rounded mean of detected concentrations.
Key:
E = Concentration exceeds the calibration range for the analytical instrument.
EPA = United States Environmental Protection Agency.
Fuel ID = Fuel identification.
J = Estimated concentration.
jtg/L — Micro grams per liter.
TRPH = Total recoverable petroleum hydrocarbons.
VOCs = Volatile organic compounds.
68
-------
Page 1 of 1
Table 24
SUMMARY OF SUBSURFACE SOIL RESULTS
PIPELINE MILEPOST 3.0 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
FSPH (Mod. 418.1) (mg/kg)
Subsurface Soil
No. of
Samples
Analyzed/
Detected
15/5
Range of Detected
Concentrations
21-85
Location of
Maximum
Concentration
AP-6037, 6'
Mean
Concen-
tration3
46
Fuel ID (Mod. 8015) (mg/kg)
Gasoline
Dietel No. 2
Jet A
Bunker C-range organic compound
9/3
9/2
9/1
9/9
7.6-23
8.5-18
7.5
45-82
AP-6038, 6'
AP-6039, 4'
AP-6037, 6'
AP-6037, 6'
12.733
13.25
—
55
VOCs (EPA 8260) (mg/kg)
Benzene
Ethylbenzene
Toluene
m+p xytene
8/3
8/1
8/1
8/2
0.070-19
1.8
0.028
0.009-1.4
AP-6048, 5'
AP-6048, 5'
AP-6048, 15'
AP-6048, 5'
8.523
—
—
0.705
BNAs (EPA 8270) (mg/kg)
2-Methylnaphthalene
Total Lead (EPA 7421) (mg/kg)
4/1
9/9
0.064 J
10-17.3
AP-6037, 6'
AP-6048, 5'
—
14
a Rounded mean of detected concentrations.
Key:
BNA
EPA
FSPH
Fuel ID
J
mg/kg
VOCs
Base/neutral and acid extractable organic compounds.
United States Environmental Protection Agency.
Field screening petroleum hydrocarbon.
Fuel identification.
Estimated concentration.
Milligrams per kilogram.
Volatile organic compounds.
69
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Page 1 of 1
Table 25
SUMMARY OF GROUNDWATER RESULTS
PIPELINE MILEPOST 3.0 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Aaalyte and Concentration Units
TRPH (EPA 418.1) dg/L)
No. of
Samples
Analyzed/
Detected
8/6
Range of Detected
Concentrations
270-15,600 J
Location of
Maximum
Concentration
AP-5522
Mean
Concen-
tration3
6,000
Fuel ID (Mod. 8015) 0*g/L)
Gasoline
Diesel No. 2
JP-4
Bunker C-range organic compound
8/3
8/1
8/1
8/2
180-5,400 J
200 J
1,200 J
750 J-900 J
VOCs (EPA 8260) 0
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Page 1 of 1
Table 26
SUMMARY OF SURFACE AND SUBSURFACE SOIL RESULTS
PIPELINE MILEPOST 15.75 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Analyte and Concentration Units
Subsurface Soil
No. of
Samples
Analyzed/
Detected
FSP1I (Mod 418.1) (mg/kg) || 6/3
Range of Detected
Concentrations
165-1,670
Location of
Maximum
Concentration
AP-6051, IT
Mean
Concen-
tration*
725
Surface Soil
No. of
Samples
Analyzed/
Detected
0/0
Range of
Detected
Concentration
—
Location of
Maximum
Concentration
—
Range
—
Mean
—
Fuel ID (Mod 8015) (mg/kg)
Gasoline
Diesel No. 2
Bunker C-range organic compounds
VOCs (EPA 8260) (mg/kg)
1 ,3,5-Trimethylbenzene
Benzene
m+p xylene
Total Lead (EPA 7421) (mg/kg)
TRPII (mg/kg)
Total Lead (mg/kg)
—
5/2
5/2
—
5/1
5/1
5/1
5/5
—
—
—
6.2 J-14.0
31.0-40.0
—
0.260 J
0.033
0.290 J
5.7-8.6
—
—
—
AP-6051,6'
AP-6043, 6'
—
AP-6051,6'
AP-6050, 6'
AP-6051,6'
AP-6041,8'
—
—
—
10.1
35.5
—
—
—
—
7
—
—
4/3
4/0
4/4
•4/0
—
—
—
—
4/4
4/4
0.081
—
0.280
—
—
—
—
—
503
19
0.554
—
0.554
—
—
—
—
—
553
553
0.0079-.08I
—
0.050-.280
—
—
—
—
—
296-503
7.1-19
0044
—
0.205
—
—
—
—
—
387
10.8
a Rounded mean of detected concentrations.
Key:
EPA = United States Environmental Protection Agency.
FSPH = Field screening petroleum hydrocarbons.
Fuel ID = Fuel identification.
J = Estimated concentration.
nig/kg = Milligrams per kilogram.
TRPH - Total recoverable petroleum hydrocarbons.
VOCs = Volatile organic compounds.
-------
Table 27
SUMMARY OF GROUNDWATER RESULTS
MILEPOST 15.75 SOURCE AREA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Aoalyte and Concentration Units
No. of
Samples
Analyzed/
Detected
Fuel ID (Mod. 8015) G*/L)
Bunker C-nage organic compound | 3/1
Range of
Detected
Concentrations
Location of
Maximum
Concentration
Mean
Concen-
tration9
300
AP-6041
—
VOC< (EPA 8260) G*/L)
l,2-Dichk>roctfaane
Benzene
m+p xylene
Total Lead (EPA 7421) G*/L)
3/1
3/2
3/1
3/3
8 J
7-34
5
29-170
AP-6041
AP-«041
AP-6043
AP-6041
—
21
—
94
a Rounded mean of detected concentrations.
Key:
EPA
Fuel ID
J
VOCi
United States Environmental Protection Agency.
Fuel identification.
Estimated concentration.
Microgranu per liter.
Volatile organic compounds.
72
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6.0 SUMMARY OF SITE RISKS
Human Health and Ecological Risk Assessments were conducted to determine the potential
risks associated with the source areas at OU-3. The presence and concentration of contami-
nants were determined from the sample analytical data collected during the RI field investiga-
tion performed during summer 1993.
In summary, potentially unacceptable excess lifetime cancer risks and hazard indices are
associated with domestic use of groundwater at all source areas. With respect to soil,
sediment, and ah-, the overall conclusion of the risk assessments for current and future
exposure scenarios is that excess lifetime cancer risks and hazard indices are acceptable as
defined by EPA's Superfund program. However, because the potential exists for contaminant
migration to downgradient groundwater users, risks could increase if no action is taken.
While soil contaminant levels do not pose a hazard for direct human contact, the levels are
high enough to pose a threat to potential downgradient groundwater receptors.
The Risk Assessment Report for OU-3 is available at the information repositories.
6.1 HUMAN HEALTH RISKS
The OU-3 baseline Human Health Risk Assessment (HHRA) evaluated potential adverse
health effects attributable to site-related contaminants. This section summarizes the HHRA.
The HHRA was conducted according to the following tasks:
• Contaminant screening and evaluation to select chemicals of
potential concern (COPCs);
• Exposure assessment;
• Toxicity assessment; and
• Risk characterization.
Uncertainties associated with each step in the risk assessment also were presented. The
following section presents a brief discussion of the risk assessment steps described above.
6.1.1 Contaminant Screening and Evaluation
The chemicals to be evaluated in the HHRA were identified in this task. The COPCs were
selected from data collected during the 1993 field program. Briefly, the COPC selection
process involved the following tasks:
• Initial data review and analysis. Only those samples appropri-
ate for risk assessment were selected for evaluation, based on
data validation and laboratory contaminant criteria;
• Comparison of maximum detected concentrations with tabulat-
ed risk-based concentrations (RBCs) provided by EPA,
73
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Region 3. These RBCs reflected residential exposure assump-
tions and 10"^ and 10 risks associated with groundwater and
soils, respectively, or a hazard quotient of 0.1 for all media;
• Comparison of maximum detected concentrations of inorganics
(i.e., metals) with naturally occurring background concentra-
tions; and
• Evaluation of the potential for chemicals to bioaccumulate in
aquatic organisms to identify COPCs in surface water and
sediments. Chemicals with octanol water partition coefficients
greater than 3 were selected as COPCs.
Chemicals were selected as COPCs for further evaluation in the risk assessment if the data
passed the above validation criteria and the maximum detected concentrations exceeded the
RBCs and background levels (for inorganics only). Table 28 shows the COPCs for each
medium of concern. The following chemicals were retained as COPCs in at least one
environmental medium: lead; 1,2-dibromoethane; 1,2-dichloroethane; 1,2,4-trimethylbenz-
ene; 1.3.5-trimethylbenzene; benzene: chloroform; ethylbenzene; isopropylbenzene; xylenes;
naphthalene; toluene; trichlorofluoromeihane; and 2-methylnaphthalene. COPCs were not
identified in surface water or sediments because the chemicals present in the surface water or
sediments do not have the potential to bioaccumulate in the aquatic environment.
6.1.2 Exposure Assessment
The exposure assessment identified the human populations, in the OU-3 vicinity, which could
come into contact with COPCs. The routes, duration, frequency, and magnitude of potential
exposures were estimated in this section. The exposure assessment included the following
steps:
• Characterizing the exposure setting,
• Identifying the potential exposure pathways,
• Identifying exposure scenarios, and
• Quantifying exposure.
For the purposes of the HHRA, OU-3 was divided into the following sub-areas: the Tank
Farm and AST area; Valve Pit A: Valve Pit B; the central ROLF; and Mileposts 2.7, 3.0,
and 15.75. These sub-areas reflect differences in geographic location, in addition to the
nature and extent of contamination. Consequently, the exposure scenarios and COPCs varied
at the different sub-areas.
Exposure factors were obtained principally from EPA, Region X, Supplemental Risk Assess-
ment Guidance for Superfund. The default exposure factors were modified in the OU-3 risk
assessment to reflect site-specific meteorological and other factors at Fort Wainwright. For
example, soil, air, and dermal pathway exposure durations were assumed to be shorter
because of snow cover six months of the year. To calculate exposure point concentrations
74
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Page 1 of 1
Table 28
CONTAMINANTS OF POTENTIAL CONCERN
HUMAN HEALTH RISK ASSESSMENT
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
COPC
Lead
1 ,2-Dibromoethane
1 ,2-Dichloroethane
1 ,2,4-Trimethylbenzene
1 ,3 ,5-Trimcthy Ibenzcne
Benzene
Chloroform
Ethylbenzene
Isopropylbenzene
m+p-Xylene
Naphthalene
o-Xylene
Toluene
Trichlorofiuoromethane
2-Methylnaphthalene
Source Area
Tank Farm
ssa
—
GW
SS, SBC,GW
SS.SB.GW
SB.GW
—
GW
—
GW
—
GW
GW
GW
—
ROLF
GW6
—
GW
SB.GW
SB.GW
SB.GW
GW
GW
GW
GW
GW
GW
GW
—
GW
Mileposts
2.7 and 3.0
—
GW
—
GW
GW
SB.GW
—
GW
GW
GW
—
GW
GW
—
—
Milepost 15.75
—
—
GW
—
—
GW
—
—
—
—
—
—
—
—
—
a COPC in surface soil.
" COPC in groundwatcr.
c COPC in subsurface soil.
Key:
— = Not identified as a COPC in environmental media at this source area.
COPC = Chemical of potential concern.
GW = Groundwater.
ROLF = Railcar Off-Loading Facility.
SB = Subsurface soil.
SS = Surface soil.
75
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(EPCs) in soil, the maximum detected concentration and upper 95% confidence limit on the
mean were compared and the smaller value was used. For groundwater, the EPC was the
maximum detected concentration at each monitoring well location. Off-site COPC concentra-
tions in groundwater also were evaluated in the risk assessment. Exposure scenarios that
represent current land use and hypothetical future land use at OU-3 were developed.
"Current Land Use
Current land use for recreational and light industrial scenarios was considered. Individuals
potentially could be exposed to COPCs in soil by ingesting soil and inhaling vapors and dust.
Exposures to groundwater under the source areas were not evaluated under current land use
conditions because the groundwater beneath OU-3 is not currently used as a drinking water
supply. A brief discussion of the individuals who potentially could be exposed to COPCs
under current land use conditions (i.e., receptors) is presented below:
• At Valve Pit A, Valve Pit B, the central ROLF, and Mileposts
2.7 and 3.0, the only plausible exposures are to site visitors
who may use the areas for recreational activities. However,
because COPCs were identified only in subsurface soils at
these sub-areas, risks associated with-incidental ingestion of
soil and inhalation of particulates were not evaluated; and
• No COPCs were identified in soils at Milepost 15.75. There-
fore, a quantitative risk assessment of this sub-area could not
be performed.
Future Land Use
The future land use scenario for all areas except Milepost 15.75 is considered light industrial
(troop training area), recreational, and residential. The following exposure pathways were
evaluated: incidental ingestion of soil; inhalation of soil-derived vapors and particulates; and
exposure to COPCs in groundwater by ingestion. inhalation, and dermal contact. Milepost
15.75 is expected to remain a residential area for an indefinite period of time. Potential
exposures to adult and child residents were evaluated at all sub-areas. These residents were
assumed to use the groundwater beneath OU-3 as a source of drinking water.
6.1.3 Toxicity Assessment
The purpose of the toxicity assessment is to compile toxicity data for the COPCs identified at
OU-3 and to estimate the relationship between the extent of exposure to a COPC (i.e., dose
level) and the likelihood or severity of adverse effects. This dose-response relationship
provides the basis for deriving the toxicity values (i.e.. slope factors and reference doses
[RfDs]) used in the HHRA. The slope factors and reference doses for all the COPCs were
obtained from the Integrated Risk Management System or Health Effects Assessment
Summary Table, with the exception of those for 1,2.4- and 1,3,5-trimethylbenzene, which
were obtained from the Environmental Criteria Assessment Office. It should be noted that an
uncertainty factor of 10,000 is associated with the RfDs for 1,2,4- and 1,3,5-trimethylben-
zene. Thus, the hazard quotients associated with these compounds are likely to considerably
76
-------
overestimate the actual risks. Qualitative descriptions of the potential toxic properties of the
COPCs also wert provided.
6.1.4 Risk Characterization
The risk characterization combines the information developed in the exposure and toxicity
assessments to identify the contaminants of concern (COCs) at the site and to obtain estimates
of the potential risks posed to human health. Risks were calculated for carcinogenic (cancer-
causing) and noncarcinogenic (toxic) effects. EPA considers excess lifetime cancer risks
between 1 in 1 million (1 x 10~6) and 1 in 10,000 (1 x 10"4) to be within the generally
acceptable range; risks greater than 1 in 10,000 usually suggest the need to take action at a
site. Noncarcinogenic effects are evaluated by calculating a ratio between the estimated intake
of a contaminant and its corresponding RfD (i.e., the intake level at which no adverse health
effects are expected to occur). If this ratio, called a hazard index, exceeds 1, then adverse
noncarcinogenic health effects may be expected at the site. The potential risks and hazard
indices described in this summary were calculated using reasonable maximum exposure
(RME) assumptions. A complete exposure pathway must exist for a contaminant to pose a
human health risk (i.e., the potential for a receptor to be exposed to a contaminant must
exist).
Under current land use conditions, the estimates for carcinogenic and noncarcinogenic effects
for OU-3 source areas fell within or below the acceptable risk range for CERCLA sites.
These estimates apply to contaminants detected in soil in all the OU-3 source areas.
However, under a future residential land use scenario, including use of groundwater as
drinking water, several contaminants were detected in groundwater and soil at concentrations
above EPA's acceptable risk range. These contaminants (or COCs) include benzene; 1,2-
dichloroethane; 1,2-dibromoethane; 1,2,4-trimethylbenzene; 1,3,5-trimethylbenzene; and lead.
The excess lifetime cancer risks and hazard indices calculated for OU-3 are summarized in
Tables 29 and 30.
EPA's methodology for evaluating potential health effects associated with lead contamination
(i.e., the integrated uptake/biokinetic model) is appropriate only for evaluating child expo-
sures. Consequently, the risks associated with exposures to adult residents and workers and
adolescent site visitors could not be assessed quantitatively.
Tank Farm Source Area
At the Tank Farm, which includes Valve Pit A, the complete exposure pathway at this time is
to recreational users of the area near Valve Pit A; these users may inhale benzene vapors.
The excess lifetime cancer risk was 6 x 10~8. No noncarcinogenic contaminants were
associated with this exposure pathway, so no hazard quotients were calculated.
The potential receptors of contamination at the Tank Farm include downgradient groundwater
users; i.e., public drinking water supplies (the two churches), Class A municipal drinking
water wells, and residential and recreational use areas. The excess lifetime cancer risks for
exposure to COPCs in soil for residential and recreational scenarios were 6 x 1CT6 and 6 x
10'8, respectively. Hazard indices of less than 1 were determined assuming future residential,
industrial, and recreational exposures at any location within the entire source area, except for
77
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Page 1 of 1
-J
CO
Table 29
CURRENT AND FUTURE RME EXCESS LIFETIME CANCER RISKS
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Subarea
Tank Farm ASTs
Valve Pit A
Valve Pit B
Central ROLF
Mileposts 2.7 and 3.0
Milepost 15.75
Current Scenarios
Recreational Soil
NAb"
6 X 1
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Page 1 of 1
Table 30
CURRENT AND FUTURE RME HAZARD INDICES
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Sub- Area
Tank Fiinm ASTs
Viilvc Pil A
Valve Pit B
Central ROLF
Mileposts 2.7 and 3.0
Milepost 15.75
Current Scenarios
Recreational Soil
NAb
NAh
NAb
NAb
NAb
NAb
Industrial Soil
NAb
NAe
NAC
NAC
NAC
NAC
Future Scenarios
Recreational Soil
0.0008
0.02
0.008
0.004
NAb
NAb
Industrial Soil
0.007
NAC
NAC
NAC
NAC
NAC
Residential Soil
0.2
5
0.2
1
NAb
NAb
Residential
Ground water*
2
200
40
50
60
0
a Groundwaler risks are 95th percentile values.
No noncarcinogcnic chemicals of potential concern.
c Industrial scenario not evaluated at this sub-area.
Key:
ASTs = Aboveground storage tanks.
NA = Not applicable.
RME = Reasonable maximum exposure.
I»:JT2*>1 A585 TWO) 07 95 Dl
-------
Valve Pit A, where the hazard index was from the incidental ingestion of 1,2,4- and 1,3,5-
trimethylbenzene under the residential exposure scenario.
Potential cancer risks associated with groundwater were calculated for each well sampled.
RME cancer risks of 6 x 10 for ingestion of residential exposure to on-site groundwater
were found at one of the Valve Pit A wells. The hazard index for wells at Valve Pit A was
• 200. The COCs were 1,2- and 1,3,5-trimethyIbenzene and benzene.
The total excess lifetime cancer risk associated with exposure to groundwater originating from
the Shannon Park Baptist Church well was 6 x 10"^. The sole contributor to this risk
estimate was 1,2-dichloroethane. The hazard indices associated with a future residential
ingestion of this same water source were less than 1.
Railcar Off-Loading Facility Source Area
There are complete exposure pathways associated with contaminated soil and groundwater at
the ROLF, which includes Valve Pit B.
The potential exposure pathways at the ROLF include Class A municipal drinking water
wells, and residential and recreational use of contaminated groundwater by downgradient
groundwater users. A soil exposure pathway hazard index of less than 1 was calculated using
future RME residential, industrial, and recreational exposures at the Valve Pit B area. The
hazard index for the central ROLF area under the residential soil ingestion scenario was 1.
Carcinogenic COPCs were identified at the central ROLF and Valve Pit B.
Potential future cancer risks associated with the ingestion of groundwater were calculated for
each well sampled. RME cancer risks in excess of 4 x 10"^ and 1 x 10"^ were found at
Valve Pit B and the central ROLF areas, respectively, for a scenario of future residential use
of on-site groundwater. The principal COC was benzene. The hazard indices are 40 and 50,
respectively, for Valve Pit B and the central ROLF.
Milepost Source Areas
Mileposts 2.7 and 3.0
The complete current exposure pathway at Mileposts 2.7 and 3.0 is to recreational users who
may inhale carcinogenic vapors. The excess lifetime cancer risk was 6 x 10"°. No
noncarcinogenic contaminants were associated with this exposure pathway, so no hazard
quotients were calculated.
The complete future exposure pathways at Mileposts 2.7 and 3.0 include residential and
recreational scenarios. The estimates of potential excess lifetime cancer risks for exposure to
soil for these residential and recreational scenarios were 5.9 x 10"6 and 5.8 x 10"8, respec-
tively.
Potential cancer risks associated with groundwater were calculated for each well sampled.
The highest cancer risk estimate was derived from monitoring well AP-6040 in a future
residential ingestion scenario; the total cancer risk was 3 x 10"1. The principal COCs were
80
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benzene and 1,2-dibromoetharie. The RME hazard index for monitoring well AP-5522
was 80 because of 1,2,4- and 1,3,5-trimethylbenzene.
Milepost 15.75
At Milepost 15.75, a potential exposure pathway is ingestion of contaminated groundwater
because of potential contaminant migration. Monitoring wells AP-6041 and AP-6043 were
used in this evaluation. The potential risks were 2 x 10"5 because of benzene and 1,2-
dichloroethane. No noncarcinogens were detected at Milepost 15.75.
6.1.5 Major Uncertainties
Uncertainty is associated with every step of the risk assessment process. The principal
uncertainties associated with the OU-3 risk assessment are:
• The rate and extent of contaminant migration. This is the
largest uncertainty in this risk assessment process. While
there is a potential pathway for contaminants to migrate to
downgradient users, the actual pathway and rate of migration
are uncertain;
• Estimated concentrations. Several of the high COPC concen-
trations in groundwater were £-qualified, or estimated, reflect-
ing exceedance of the linear portion of the calibration curve.
Consequently, risk estimates derived from these concentrations
are likely underestimates;
• Oral RfDs for 1,2,4-, and 1,3,5-trimethylbenzene derived
from inhalation studies. Low confidence is placed in these
RfDs, resulting in considerable uncertainty in the hazard
quotients associated with these COCs. Because an uncertainty
factor of 10,000 was applied to the inhalation lowest observed
adverse effect level, the resulting RfDs are extremely conser-
vative and would overestimate noncancer risk;
• Screening-level models used to evaluate the outdoor paniculate
and vapor inhalation pathways. These relatively simplistic
approaches yield very conservative estimates of potential
exposure. In particular, the soil-to-air volatilization model
assumes that the contaminant concentration in soil is homoge-
neous from the soil surface to depth of concern. Additionally,
the model assumes that the contaminated soil is not covered by
contaminant-free soil material. Consequently, the models tend
to overestimate exposures and risks;
• Derivation of future surface soil concentrations from subsur-
face soil data. The assumption that subsurface soil would be
disturbed and mixed with the present surface soil layer is
conservative. Additionally, when no surface soil analytical
81
-------
data were available, future receptors were assumed to be
exposed to undiluted subsurface soil. Both of these assump-
tions serve to overestimate exposures and risks;
• Use of the Baptist church well data and hydraulically cross-
gradient well data to assess potential off-site groundwater
impacts from the Tank Farm and Milepost 15.75, respectively.
These data serve to overestimate off-site groundwater expo-
sures and risks;
• The risk associated with petroleum hydrocarbons other than
individual constituents. This risk is unknown, and these
contaminants were not considered in the risk assessment; and
• Existing concentrations assumed to be the concentrations or
exposure source terms in the future. No reduction through
natural degradation or attenuation over time is taken into
account. This assumption may overestimate risk.
Because numerous conservative assumptions were used in the selection of COPCs and the
exposure and toxicity assessments, the risk characterization results likely overestimate risks
associated with COPCs at OU-3.
6.2 ECOLOGICAL RISKS
An Ecological Risk Assessment (ERA) addresses the impacts and potential risks posed by
contaminants to natural habitats, including plants and animals, in the absence of remedial
action. The OU-3 ERA evaluated the contaminants found in surface soils, surface waters, and
sediments in habitats in and around the source areas to estimate the contaminants' impacts or
potential risks to the natural environment.
The OU-3 ERA was conducted using available ecological information and data collected
during the RI. The potential ecological risks were evaluated using established effects criteria
and RME assumptions. The ERA was conducted according to EPA's current national and
regional guidance, which includes:
• Framework for Ecological Risk Assessment (EPA/630/R92/
001);
• Ecological Assessment of Superfund Sites: An Overview, ECO
Update 1(2) (Office of Solid Waste and Emergency Response
9345.0-051); and
• Statement of Work for the Remedial Investigation/Feasibility
Study Environmental Evaluation for Superfund Sites, Region X
Guidance.
Consistent with this guidance, the ERA was conducted in four main steps:
82
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• Problem formulation describes the site; habitats on and near
the source areas: selection of contaminants of potential ecolog-
ical concern; contaminant release, migration, fate, and path-
ways of exposure; receptors of concern; ecological end points;
and the conceptual ecological exposure model;
• Exposure assessment provides quantitative exposure scenarios
and estimates for selected indicator species;
• Ecological effects assessment provides toxicological profiles of
the COCs and summarizes the toxicity reference values for
selected measurement species; and
• Risk characterization combines the information from the
exposure assessment and ecological effects assessment to
obtain estimates of potential ecological risk. This process
includes an evaluation of the uncertainties of the assessment
process, and a summary of and conclusions regarding the
ecological significance of the predicted risks.
Unlike the HHRA, the ERA focused on the contaminants' effects on populations or communi-
ties, rather than on individuals. If a potential risk to individuals of a population was
identified during the ERA, the risk was evaluated to determine whether it was biologically or
ecologically significant. Potential risks to individual threatened or endangered species were
considered.
No potential ecological risks were predicted for the ROLF or Mileposts 2.7, 3.0, and 15.75.
The results of the ERA did indicate potential effects to wildlife because of lead; 1,2,4- and
1,3,5-trimethylbenzene; isopropylbenzene; and toluene exposure at the Tank Farm. Lead
posed potential risks to all terrestrial biota except the red fox, while the other four contam-
inants posed potential risks only to the red squirrel and marten, which are unlikely to inhabit
the Tank Farm Source Area. Consequently, the only potentially significant risks at OU-3 are
because of wildlife exposure to lead in soils at the Tank Farm. However, given the conserva-
tive nature of the ERA, these potential risks are likely to be overestimated.
6.2.1 Summary of Uncertainties
The ERA is subject to uncertainties because virtually every step in the risk assessment process
involves assumptions involving professional judgment. Principle uncertainties associated with
the OU-3 ERA include the following:
• A limited number of samples was collected from the source
areas, and the samples were biased toward areas of expected
soil contamination. These factors are likely to result in an
overestimation of potential risks to the OU-3 ecological recep-
tors:
• Exposure parameters for all measurement species were select-
ed based on professional judgment. The amount of food
83
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consumed daily, the different types of food consumed, and the
percentage of the whole diet that each food item contributes
were estimated based on a combination of scientific literature
and limited field observation information. In addition, the
•amount of time spent foraging on site is estimated using
similar information. Without extensive site-specific field data.
it is unclear whether potential risks are under- or overestimat-
ed using the selected exposure parameters;
• Frequently, toxicity and exposure data from literature sources
were not specific to the target receptors; therefore, extrapola-
tion of the data to the species of concern was necessary.
Differences in toxic response between species are well-docu-
mented, even among species of the same genus. Therefore,
actual risk may be over- or underestimated;
• Uncertainty factors obtained from available literature and
based on best professional judgment were applied to normalize
toxicological data to chronic no observed adverse effect levels
(NOAELs). Considerable uncertainty is associated with their
application. However, the desired result is a conservative
estimate of the NOAEL, which should result in a conservative
estimate of any potential risks;
• Most of the available toxicity values were determined with
laboratory animals under laboratory conditions. Such studies
may not accurately reflect the effects of similar doses on free-
ranging wildlife; and
• Toxicity values determined with indirect effect measures, (i.e.,
increased body weight) may not represent other significant
indirect effects, such as behavioral changes that may be real-
ized in wild populations.
The approach described in this ERA used realistic assumptions wherever possible; reasonable
and conservative assumptions were used when empirical data were unavailable. As a
consequence, potential ecological risks to OU-3 species are more likely to be overestimated
than underestimated.
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7.0 REMEDIAL ACTION OBJECTIVES
7.1 NEED FOR REMEDIAL ACTION
Actual or threatened releases of hazardous substances from the site, if not addressed by
implementing the response action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or the environment. Remedial actions
were deemed necessary to protect human health and the environment:
Source Area
Tank Farm, bottom of Birch
Hill
Tank Farm, Valve Pit A
ROLF
Mileposts 2.7 and 3.0
Milepost 15.75
Reasons for Implementing Remedial Actions
Benzene detected above Safe Drinking Water Act
levels in groundwater
Proximity to site boundary, residential drinking
water wells, and Class A public water supply
system
Reduce contaminant migration in groundwater
Potential risk above 1 x 10 for groundwater
ingestion
Benzene, ethylbenzene, and toluene were detected
above Safe Drinking Water Act levels
Reduce contaminant migration into the Chena
River
Potential risk above 1 x 10"4 for groundwater
ingestion
Benzene, ethylbenzene, toluene, and 1,2-
dichloroethane were detected above Safe Drinking
Water Act levels
Reduce contaminant migration into the Chena
River
Potential risk above 1 x 10 for groundwater
ingestion
Benzene, ethylbenzene, toluene, and ethylene
dibromide were detected above Safe Drinking
Water Act levels
Prevent further contaminant migration into nearby
wetlands and groundwater
Benzene and 1,2-dichloroethane were detected
above Safe Drinking Water Act levels
Proximity to residential area and private drinking
water wells
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7.2 REMEDIAL ACTION OBJECTIVES
The remedial action objectives are as follows:
7.2.1 Groundwater
• Restore groundwater to drinking water quality within a reasonable time frame:
• Reduce further migration of contaminated groundwater; and
• Prevent use of groundwater with contaminants at levels above Safe
Drinking Water Act levels.
7.2.2 Sou
• For petroleum-contaminated soil, prevent migration of contaminants
from soil into the groundwater that would result in groundwater
contamination and exceedance of Safe Drinking Water Act standards.
7.3 GOALS OF REMEDIAL ACTION
The following remediation goals have been generated for COCs for active remediation of
groundwater and soil:
7.3.1 Groundwater
Chemicals of Concern Remediation Goal 0*g/L)
Benzene 5a
Toluene l,000a
Ethylbenzene TOO3
1,2-dibromoethane 0.05a
1,2-dichloroethane 5a
1,2,4-trimethylbenzene 14^
1,3,5-trimethylbenzene 12b
a Based on Safe Drinking Water Act Levels.
k Based on an RBC equivalent to a noncancer hazard
quotient of 1 using residential groundwater exposure assumptions.
After Safe Drinking Water Act levels are achieved, it is anticipated that natural attenuation
will continue and achieve final cleanup levels.
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7.3.2 Soil
The remedial action goal for in situ soils contaminated with volatile organic and petroleum
compounds is protection of the groundwater. Because the soils are acting as a continuing
source of contamination to the groundwater, active remediation of the soils will continue until
Safe Drinking Water Act levels are consistently met. Natural attenuation will continue until
Alaska Water Quality Standards are achieved.
Petroleum-contaminated soils that are treated ex situ will be treated to State of Alaska Matrix
Level A standards before they are returned to the source area.
7.4 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
The following applicable or relevant and appropriate requirements (ARARs) are the most
significant regulations that apply to the remedy selection:
• Safe Drinking Water Standards established MCLs, nonzero Maxi-
mum Contaminant Level Goals (MCLG), and action levels that are
relevant and appropriate for groundwater. This requirement sets the
active remediation goals for the groundwater. Alaska Water Quality
Standards are also applicable; and
• Alaska Oil Pollution regulations are applicable, and Alaska regula-
tions for leaking USTs are relevant and appropriate. These regula-
tions require cleanup of petroleum-contaminated soils.
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8.0 SUMMARY OF REMEDIAL ACTION ALTERNATIVES
8.1 REMEDIAL AREAS
Appropriate technologies were identified and screened for applicability to site conditions. The
potential technologies then were combined into media-specific sitewide alternatives. Potential
. remedial alternatives for OU-3 were identified, screened, and evaluated in the FS, which is
available at the information repositories. During the FS, OU-3 was divided into the following
areas according to the type of contamination, hydrogeologic property, and presence of
permafrost:
• Remedial Area la: Lead-based-paint-contaminated soil located near
ASTs within the Tank Farm Source Area. The Army; EPA; and
State of Alaska, through ADEC, have agreed to defer selection of a
final remedy for the AST area located on the Birch Hill portion of
the Tank Farm. This source area will be addressed in the ROD for
OU-5. See Section 12.0 of this ROD for documentation of signifi-
cant changes;
• Remedial Area lb: Petroleum-contaminated soil and groundwater
found at the area that extends south from the base of Birch Hill to the
TFS at the southwest comer of the Tank Farm Source Area and that
extends west toward Lazelle Road;
• Remedial Area 2: Petroleum-contaminated soil and groundwater
found at Valve Pit A and the ROLF Source Area; and
• Remedial Area 3: Petroleum-contaminated soil and groundwater
found at Mileposts 2.7 and 3.0, including TFS-1 and -2, and Mile-
post 15.75 along the Fairbanks-Eielson Pipeline.
Remedial technologies in different combinations were proposed to address the contamination
at each remedial area. Table 31 summarizes the volume of contaminated soil and ground-
water for each remedial area and the type of contamination present.
8.2 REMEDIAL ACTION ALTERNATIVE TECHNOLOGIES
The following are alternatives evaluated in the initial screening for remedial action:
8.2.1 No Action
A no-action alternative is presented for each remedial area to serve as a comparison against
other alternatives.
8.2.2 Institutional Controls
Each remedial area includes an alternative involving institutional controls. Institutional
controls are methods to restrict access to a site or use of groundwater or land. Institutional
controls are used to decrease or eliminate human exposure to contaminants and are usually
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Page 1 of 1
Table 31
CONTAMINATED MEDIA VOLUME ESTIMATES
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Remedial
Area
la
Ib
2 (full area)
3
Estimated Soil
Quantity
(cubic yards)
3,200
25,000
960,000
24,200
Estimated
Groundwater
Quantity
(gallons)
N/A
5.8 x ID"6
10.2 x W6
1.55 x IQ-6
Contaminants of Concern
Lead8
Petroleum hydrocarbons and VOCs
Petroleum hydrocarbons and VOCs
Petroleum hydrocarbons and VOCs
a Lead-contaminated soil is comingled with petroleum hydrocarbon contaminated soil.
Key:
N/A =Not applicable. Groundwater contamination not included in Remedial Area la.
VOCs = Volatile organic compounds.
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relatively inexpensive to implement. However, the contamination is not removed or
destroyed. Periodic review of the institutional controls is required to ensure that the
protection of human health is maintained over time. Institutional controls for OU-3 include
fencing, signs, long-term groundwater monitoring, access restrictions, site inspections, and
combinations of these activities.
8.2.3 Remedial Areas Ib, 2, and 3: Soil Vapor Extraction of Petroleum-Contaminated
Soil
Vapor extraction is a proven and reliable technology for the removal of VOCs from unsaturat-
ed soils. Petroleum hydrocarbon vapors in soil pore spaces in the vadose zone are transported
from the soil by convection of pore-space air. As air flows through the soil, the lighter
petroleum hydrocarbons volatilize into the air, provided the air is not already in equilibrium
with the hydrocarbon contained within the soil. A series of extraction wells is installed, and
vacuum blowers are attached to the extraction wells to create a vacuum in each well to
increase the movement of air through the soil. The vacuum forces the volatile contaminants
from the soil to the extraction wells and into a central treatment building, where vapors can
be collected and treated by activated carbon or discharged directly into the atmosphere',
depending on concentration.
Because the more volatile gasoline constituents (those with higher vapor pressures) are
removed first, the product remaining in the soil contains a proportionately greater quantity of
the less-volatile compounds with time. Because of this change in composition, the vapor
concentrations and mass removal rates decrease with time. In addition to volatilizing
hydrocarbons, the vapor extraction system (VES) supplies oxygen to soil microbes, which
metabolize (biodegrade) a portion of the hydrocarbons.
An in situ VES typically uses vacuum blowers to pull air from perforated pipe installed in
drilled wells without excavating the contaminated soil. An in situ VES is most applicable for
remediating large soil volumes, where excavation is prohibitively expensive, or for remedia-
ting soils that cannot be excavated because of current land use or hydrogeologic conditions.
Successful in situ VES design and operation depends on understanding the horizontal and
vertical distribution of hydrocarbons relative to the extraction wells, the concentration of
volatile hydrocarbons in the soil, and the air conductivity of the site soils. This type of
information can be generated only through a site-specific subsurface investigation and pilot
study.
Soils suitable for VES cell treatment include gravel, sand, silty sand, and nonplastic sandy
silt. Because of their low air conductivity, clays are best treated by other remedial technolo-
gies. Organic soils should be analyzed on a site-specific basis because of their high potential
for adsorption of hydrocarbons.
8.2.4 Remedial Areas Ib, 2, and 3: Steam Injection of Petroleum-Contaminated Soil
Steam injection typically is used in conjunction with other remedial technologies to increase
the efficiency of removal of volatile contaminants from soil; it can be especially useful in cold
climates. The injection of steam into the ground raises the temperature of the surrounding
soil, making it easier to remove volatile contaminants using methods such as soil vapor
extraction.
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8.2.5 Remedial Areas Ib, 2, and 3: Bioventing of Petroleum-Contaminated Soil
Bioventing is the process of supplying oxygen and nutrients to subsurface soil to stimulate the
aerobic degradation of contaminants. Oxygen and nutrients, such as nitrogen and phosphorus.
are injected into the subsurface through wells similar to vapor extraction wells. This
technology works well at sites with large quantities of petroleum-contaminated soil. Biovent-
ing employs a low-flow process that will promote biodegradation but is relatively slow and
temperature-dependent.
8.2.6 Remedial Area 3: Soil Pile Aeration of Petroleum-Contaminated Soil
This technology involves excavating contaminated soil and placing it on a geotextile liner in a
bermed area. Perforated pipes are laid horizontally through the contaminated soil pile, and
petroleum vapors are collected by creating a vacuum in the pipes. This technology is similar
to vapor extraction, except that this technology requires that soil be excavated.
8.2.7 Remedial Areas Ib, 2, and 3: Bioremediation of Petroleum-Contaminated Ground-
water
In this technology, oxygen and nutrients are injected directly into the aquifer to enhance
natural degradation processes.
8.2.8 Remedial Areas Ib, 2, and 3: Air Stripping and Carbon Adsorption of Petro-
leum-Contaminated Groundwater
Similar to the approach for bioremediation, this technology involves pumping contaminated
groundwater to the surface and treating it through an air stripping tower. The treatment
process involves the introduction of air through the contaminated water to strip it of petroleum
contaminants. The water then is passed through carbon filters to remove residual petroleum
contamination from the water. The cost of this groundwater treatment technology is directly
proportional to the volume of contaminated groundwater. Furthermore, the efficiency of
pump-and-treat treatment is limited by chemical solubility and adsorption coefficients.
8.2.9 Remedial Areas Ib, 2, and 3: Air Sparging of Petroleum-Contaminated Ground-
water
Air sparging is a remedial technology in which air is injected into groundwater below the
layer of contamination. Air bubbles floating up through the contaminated groundwater cause
contaminants to evaporate upward into the overlying soil. The vapors could be captured by a
soil VES, as previously described. Air sparging, coupled with soil VES, remediates the
volatile portion of the petroleum contamination by volatilization and by promoting biodegrada-
tion of the heavier portion of the petroleum without addition of nutrients.
In situ air sparging technology involves injecting a gaseous medium into the saturated zone
below the areas of contamination. In most applications, air is used as the injected gas. The
technology is based on the premise that contaminants dissolved in the groundwater and sorbed
onto particles will partition into the air phase. Air phase contaminants then are transported
into the vadose zone. Typically, air sparging is used in conjunction with a VES, which
collects the air-phase contaminants and transfers them to a vapor treatment system, such as
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carbon adsorption. In addition, sparging using air increases the dissolved oxygen concentra-
tion in the groundwater, which in rum may increase naturally occurring biodegradation.
Gas flow rates are varied in order to provide the ideal air-to-water ratio to optimize the
•contaminant mass transfer from the liquid phase to the water phase. Air flow rates typically
used range from 3 cubic feet per minute (cftn) to 10 cfm. Gas flow rate depends directly on
the injection pressure. Injection pressure, in turn, depends on the static water head above the
sparge point and the soil grain size. Higher pressures are required for fine-grained soils.
Excessively fine-grained soils can result in the formation of subsurface gas pockets.
Additionally, high injection pressures may result in subsurface fractures, which decrease the
system's efficiency.
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9.0 REMEDIAL ALTERNATIVE EVALUATION
The specific remedial action alternatives for each remedial area are discussed in this section.
In many cases, several technologies and strategies are combined into one alternative. This
section presents the alternatives for each remedial area in OU-3 and compares the selected
alternatives to the other alternatives. The selection of alternatives was based on an evaluation
using the nine Superfund criteria specified in Table 32. The first two criteria are known as
threshold criteria that must be met by all selected remedial actions. The following five
criteria are known as balancing criteria, and the final two criteria as modifying criteria.
The OU-3 FS should be consulted for more information about the alternatives and the
comparisons among alternatives. It is available for review by the public in the Administrative
Record and the information repositories.
9.1 ALTERNATIVES FOR REMEDIAL AREA IB
Remedial Area Ib consists of petroleum-contaminated soil and groundwater between the base
of Birch Hill and near the TFS at the southwest corner of the Tank Farm. The presence of
localized areas of permafrost is a limiting factor for evaluation and placement of remedial
alternatives. The remediation will be focused in areas with known sources of contamination
and at locations where MCLs have been exceeded. The cost for each alternative is based on
an estimated number of years to achieve remedial goals. A cost comparison table is presented
in Table 33. The following alternatives were considered for Remedial Area Ib:
• Alternative 1: No action. Petroleum-contaminated soil and ground-
water would remain in place. Passive remediation probably would
occur with the natural degradation of the petroleum. No costs would
be associated with this alternative;
• Alternative 2: Institutional controls. Petroleum-contaminated soil
and groundwater would remain in place. Passive remediation proba-
bly would occur with natural degradation of the petroleum. Institu-
tional controls would include fencing and signs, site maintenance,
semi-annual groundwater monitoring, and site inspections every five
years. Long-term groundwater monitoring also would be part of this
alternative and is considered in the cost estimate. The cost was
based on a 20-year monitoring period;
• Alternative 3: Soil vapor extraction, bioventing, steam injection of
petroleum-contaminated soils, and bioremediation of petroleum-
contaminated groundwater. Soil vapor extraction would remove
petroleum hydrocarbon vapors from petroleum-contaminated soil.
Bioventing would be utilized to stimulate aerobic degradation of
contaminants. Steam injection would increase the efficiency of the
other technologies by raising ground temperatures. Bioremediation
would be employed to enhance natural degradation processes in the
petroleum-contaminated groundwater. Long-term groundwater
monitoring also would be pan of this alternative and is considered in
the cost estimate. The cost was based on a 20-year monitoring period;
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Pace 1 o
Table 32
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY'S
NINE EVALUATION CRITERIA
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
1. Overall Protection of Human Health and the Environment
Addresses whether a remedy provides adequate protection of human health and the environment and describes
how riski posed through each exposure pathway are eliminated, reduced, or controlled through treatment.
engineering controls, or institutional controls.
2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Addresses whether a remedy will meet all the ARARs or other federal and state environmental laws, or
justifies a waiver.
3. Long-Term Effectiveness and Permanence
Refers to expected residual risk and the ability of a remedy to maintain reliable protection of human health
and the environment over time once cleanup goals are met.
4. Reduction of Toxkity, Mobility, and Volume through Treatment
Focuses on the anticipated performance of the treatment technologies that may be used as a cleanup
alternative.
5. Short-Tcrm Effectiveness
Refers to the period of time needed to achieve protection and any adverse impacts on human health and the
environment that may be poaed during the construction and implementation period until cleanup goals are
achieved.
6. ImpiemenUbility
Addresses the technical and administrative feasibility of a remedy, including the availability of materials and
services needed to implement a specific solution.
7. Cost
Includes estimated capital and operations and maintenance costs.
8. State Acceptance
Considers whether the state, based on its review of the remedial investigation/feasibility study (RI/FS) and
Proposed Plan concurs, opposes, or has no comment on the preferred alternative.
9. Community Acceptance
Considers all comments received from the public during the 30-day comment period on the RI/FS and
Proposed Plan.
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Page 1 of
Table 33
REMEDIAL AREA IB-COST COMPARISON TABLE
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Alternative
1 : No Action
2: Institutional Controls
3: Soil Vapor Extraction, Bioventing, Steam
Injection of Soil; Bioremediation of
Groundwater
4: Soil Vapor Extraction, Bioventing, Steam
Injection of Soil; Air Stripping/Carbon
Absorption of Groundwater
5: Soil Vapor Extraction of Soil; Air Sparging
of Groundwater
Capital Cost
($)
0
0
2,200,000
2,200,000
2,600,000
Operations and
Maintenance3
($)
0
200,000
200,000
200,000
200,000
Years to
Achieve
Remedial Goals
_b
20
5
10
5
a Operations and Maintenance cost includes the estimated costs for 20 years of groundwater monitoring.
° The No Action alternative is not expected to achieve remedial goals.
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• Alternative 4: Soil vapor extraction, bioventing, steam injection of
petroleum-contaminated soil, and extraction followed by air stripping
and carbon adsorption of petroleum-contaminated groundwater. As
in Alternative 3, soil vapor extraction, bioventing, and steam injec-
tion would be utilized to remove petroleum hydrocarbons from
contaminated soil. Air stripping and carbon adsorption would be
used to pump contaminated groundwater to the surface and strip it of
petroleum contaminants with air and filters. Long-term groundwater
monitoring for 20 years also would be part of this alternative and is
considered in the cost estimate. The cost was based on a 20-year
monitoring period; and
• Alternative 5: Soil vapor extraction of petroleum-contaminated soils
and air sparging of petroleum-contaminated groundwater. Soil vapor
extraction would be used to remove petroleum hydrocarbons from
petroleum-contaminated soil in this alternative. Air sparging would
be used to force evaporation of contaminants and capture the result-
ing vapors with a vapor-extraction process. Long-term groundwater
monitoring also would be part of this alternative and is considered in
the cost estimate. The cost was based oh a 20-year monitoring
period.
9.2 EVALUATION OF ALTERNATIVES FOR REMEDIAL AREA IB
The following sections summarize the evaluation of each alternative in reference to EPA's
nine evaluation criteria.
9.2.1 Overall Protection of Human Health and the Environment
Alternative 1, the no-action alternative, would not protect human health and the environment
because contamination would remain in place. Institutional controls, Alternative 2, would not
protect human health because they would not prevent off-site migration of contaminants.
Alternatives 3, 4, and 5 would protect human health and the environment by reducing risk
associated with contaminated groundwater and soil through implementation of active treatment
technologies. These alternatives also would eliminate further leaching of contaminants from
soil to groundwater and reduce the potential for further migration of contaminated ground-
water.
9.2.2 Compliance with Applicable or Relevant and Appropriate Requirements
No action and institutional controls, Alternatives 1 and 2, would not achieve applicable
cleanup standards for soil and groundwater within reasonable time frames; therefore, the two
alternatives will not be discussed further.
The groundwater remediation portion of Alternatives 3,4, and 5 would achieve chemical-
specific ARARs, such as federal Safe Drinking Water Act standards, within a reasonable time
frame. The soil remediation portion of Alternatives 3,4, and 5 would achieve chemical-
96
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specific ARARs. such as Alaska petroleum-contaminated soil regulations (18 AAC 78). to
protect groundwater for drinking water use. All the alternatives would be implemented in
compliance with action-specific ARARs, such as the federal Clean Air Act.
9.2.3 Long-Term Effectiveness and Permanence
.The groundwater treatment portion of Alternatives 3, 4, and 5 would involve active irrevers-
ible reduction of contaminant concentrations and therefore would reduce risk to acceptable
levels below ARARs. Current groundwater use restrictions would remain in place during
remedial action implementation. Groundwater monitoring also would be required to evaluate
the performance of the selected alternative. Vapor samples and air flow readings taken from
the soil vapor monitoring probes and system exhaust sampling ports would be necessary to
monitor the progress of cleanup, and to estimate the volume of hydrocarbons removed by the
system. The soil treatment portion of each alternative would prevent further leaching of
contaminants to groundwater. The VES could be expanded if additional contamination were
discovered.
9.2.4 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternatives 3,4, and 5 would include technologies that treat and reduce the toxicity and
volume of soil and groundwater contaminants. Furthermore, the groundwater remediation
portion of all the alternatives would prevent further migration of contaminated groundwater,
while the soil remediation portion would prevent further leaching of contaminants into
groundwater. All three alternatives would include technologies that have been used success-
fully in Alaska to clean up petroleum-contaminated sites. Soil vapor extraction, coupled with
air sparging, is a technology that is being used to treat petroleum-contaminated soil and
groundwater at other locations on Fort Wainwright. All the technologies are expected to
reduce contamination to levels that do not pose risks to human health and the environment.
9.2.5 Short-Term Effectiveness
Alternatives 3,4, and 5 would involve some short-term impacts associated with treatment
system construction activities. A major advantage of the in situ soil VES would be the ability
to install the system and conduct remediation with minimal disruption to the sites or surround-
ing environment. However, some construction impacts, such as dust emissions from
operating heavy equipment and temporary disruption to daily operations or normal use near
the Remedial Area Ib source areas, are expected to occur. The potential risks would be mini-
mized by standard construction methods and engineering controls. Current groundwater use
restriction would remain in place during the implementation of the remedial action. Alterna-
tives 3 and 5 are expected to accomplish remediation goals in five to 10 years for soil and
groundwater. Alternative 4 is expected to accomplish the groundwater remediation goals in
10 to 20 years, because pump-and-treat systems are limited by compound solubility and
adsorption characteristics.
9.2.6 Implementability
Alternatives 3. 4, and 5 would be complex to implement, but all technologies are technically
implementable. Construction methods and materials needed to implement all three alternatives
are standard and available in Fairbanks. Alternative 3 is slightly less implementable than
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Alternatives 4 and 5 because bioremediation technology would require some specialized
materials and equipment, such as exogenous petroleum-degrading microorganisms and
specialized bioreactor vessels not immediately available in the Fairbanks area. For treating
the contaminated groundwater, Alternative 3 would require extensive hydrogeologic modeling
and bioassessment screening studies. Alternative 4 would employ proven wastewater
treatment technologies, such as air stripping and carbon adsorption. However, contaminant
solubility in groundwater and soil adsorption coefficients may be the limiting factors,
especially for removing contaminants in the smear zone. Alternatives 3 and 5 must be
controlled properly to ensure that contaminants do not migrate from the site. Each alternative
would require temperature-control devices for treatment to be effective because temperature
remains an important variable for all three alternatives. The presence of permafrost would
require that the selected technology system be placed in thaw channels because the treatment
systems would be most effective in the thaw channels where the contaminants are most
concentrated. Alternative 5 is the selected alternative because it has been implemented at Fort
Wainwright with positive results. All three alternatives would require preliminary testing
before full-scale construction to obtain site-specific design parameters; more time would be
required for preliminary testing of Alternatives 3 and 5 because of their complexity.
9.2.7 Cost
Table 33 compares the costs of the alternatives considered for Remedial Area Ib. The cost
for all three alternatives are comparable, and are based on present worth values with 10%
discount rates. The estimated years to achieve Safe Drinking Water Act levels for each
technology are based on contaminant levels detected during the RI, soil and groundwater
physical data, and published treatment efficiency estimates for specific technologies. The
estimated costs do not include those associated with preliminary testing of remedial technolo-
gies. For cost purposes, a 20-year monitoring program is assumed to achieve Alaska Water
Quality Standards. Figure 19 shows the approximate location and number of wells used for
cost estimation.
9.2.8 State Acceptance
ADEC has been involved with the development of remedial alternatives for OU-3 and concurs
with the selected alternative for Remedial Area Ib.
9.2.9 Community Acceptance
On April 25, 1995, the Army conducted a public meeting to discuss the Proposed Plan for
final remedial action at OU-3. Before the public meeting, a Proposed Plan summary fact
sheet was sent to all known interested parties, totaling approximately 150. Proposed Plans
were available by request. Results of the public meeting indicate that there is no opposition to
any of the preferred alternatives. The written comment received during the public comment
period supported the preferred alternatives for Remedial Areas la and Ib. One adjacent
landowner expressed concern about the extent of the contamination at the Tank Farm.
Community responses to the remedial alternatives are presented in the Responsiveness
Summary, which addresses comments received during the public comment period (see
Appendix A).
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CORPS OF ENGINEERS
LAZELLE RD.
500
1,000
SCALE: FEET
LEGEND
o
KEY PLAN
APPROXIMATE LIMITS OF
GROUNDWATER CONTAMINATION
APPROXIMATE LIMITS OF
SOIL CONTAMINATION
EXTRACTION WELL AND
ZONE OF INFLUENCE
INJECTION WELL LOCATION
GROUNDWATER FLOW DIRECTION
11 ecology tnd •ofironmuit, inc.
l SHtUlllIt li Iht CmlrMMit
U.S. ARMY
ENGINEER DISTRICT, ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
Figure 19
REMEDIAL AREA 1 b
GROUNDWATER INJECTION AND
EXTRACTION WELL PLACEMENT
TRUCK FILL STAND AND BUILDING 1173
FAIRBANKS ALASKA
SIZE
JOS. NO.
JY9040
RLE NO.
JY94-7C.DWG
DATE:
02-21-95
PLATE
99
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Selected Alternative for Remedial Area Ib
The selected alternative for Remedial Area Ib is Alternative 5 (soil vapor extraction and air
sparging of groundwater). The groundwater treatment technology will achieve the cleanup
goals in a reasonable time frame at locations where MCLs have been exceeded in permafrost
. thaw channels. This alternative is also a more direct approach at treating the contaminants in
the smear zone and saturated soil than the other alternatives. The soil treatment technology
will achieve the primary goal of protecting groundwater for drinking water use. Furthermore,
the effectiveness of the selected alternative has been proven at Fort Wainwright. In addition
to the technologies chosen, long-term groundwater monitoring will be conducted to ensure
that the treatment systems effectively reduce contamination and that off-site migration of
contaminants does not occur. The monitoring will include periodical sampling of off-post
wells, such as the church wells.
9.3 ALTERNATIVES FOR REMEDIAL AREA 2
Remedial Area 2 consists of petroleum-contaminated soil and groundwater at Valve Pit A and
the ROLF. No permafrost is known to occur at this source area. Treatment will occur in
known source areas and at a location where MCLs have been exceeded; this location is known
as the "hot spot" option described in the Proposed Plan. The cost for each alternative is .
based on an estimated number of years to obtain remedial goals. A cost comparison is
presented in Table 34. The following alternatives were considered for Remedial Area 2:
• Alternative 1: No action. Petroleum-contaminated soil and ground-
water would remain in place. Passive remediation probably would
occur with the natural degradation of the petroleum. No costs would
be associated with this alternative;
• Alternative 2: Institutional controls. Petroleum-contaminated soil
and groundwater would remain in place. Passive remediation proba-
bly would occur with the natural degradation of the petroleum.
Institutional controls would include fences and signs, site mainte-
nance, and semi-annual groundwater monitoring. Costs associated
with the groundwater monitoring are based on a 20-year monitoring
period;
• Alternative 3: Soil vapor extraction, bioventing, steam injection of
petroleum-contaminated soils, and bioremediation of petroleum-
contaminated groundwater. Soil vapor extraction would remove
petroleum hydrocarbon vapors from petroleum-contaminated soil.
Bioventing would be utilized to stimulate aerobic degradation of
contaminants. Steam injection would increase the efficiency of the
other technologies by raising ground temperatures. Bioremediation
would be employed to enhance natural degradation processes in the
petroleum-contaminated groundwater. Long-term groundwater
monitoring also would be part of this alternative and is considered in
the cost estimate. The cost was based on a 20-year monitoring
period;
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Paee 1 of 1
Table 34
REMEDIAL AREA 2-COST COMPARISON TABLE
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Alternative
1 : No Action
2: Institutional Controls
3: Soil Vapor Extraction, Bioventing, Steam
Injection of Soil; Bioremediation of
Groundwater "Hot Spot" Treatment
4: Soil Vapor Extraction, Bioventing, Steam
Injection of Soil; Air Stripping/Carbon
Absorption of Groundwater "Hot Spot"
Treatment
5: Soil Vapor Extraction of Soil; Air Sparging
of Groundwater "Hot Spot" Treatment
Capital Cost
($)
0
0
1,400,000
1,500,000
900,000
Operations and
Maintenance3
($)
0
300,000
300,000
1,000,000
100,000
Estimated Years
to Achieve
Remedial Goals
_b
20
5
10
5
a Operations and Maintenance cost includes the estimated costs for 20 years of groundwater monitoring.
" The No Action alternative is not expected to achieve remedial goals.
101
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• Alternative 4: Soil vapor extraction, bioventing, steam injection of
petroleum-contaminated soil, and extraction followed by air stripping
and carbon adsorption of petroleum-contaminated groundwater. As
in Alternative 3, soil vapor extraction, bioventing, and steam injec-
tion would be utilized to remove petroleum hydrocarbons from
contaminated soil. Air stripping and carbon adsorption would be
used to pump contaminated groundwater to the surface and strip it of
petroleum contaminants with air and filters. Long-term groundwater
monitoring for 20 years also would be part of this alternative and is
considered in the cost estimate. The cost was based on a 20-year
monitoring period; and
• Alternative 5: Soil vapor extraction of petroleum-contaminated soils
and air sparging of petroleum-contaminated groundwater. Soil vapor
extraction would be used to remove petroleum hydrocarbons from
petroleum-contaminated soil in this alternative. Air sparging would
be used to force evaporation of contaminants and capture the result-
ing vapors with a vapor-extraction process. Long-term groundwater
monitoring also would be part of this alternative and is considered in
the cost estimate. The cost would be based on a 20-year monitoring
period.
9.4 EVALUATION OF ALTERNATIVES FOR REMEDIAL AREA 2
The following sections summarize the evaluation of each alternative in reference to EPA's
nine evaluation criteria.
9.4.1 Overall Protection of Human Health and the Environment
No action, Alternative 1, would not protect human health or the environment because
contamination at Remedial Area 2 would remain in place. Institutional controls, Alternative
2, would provide a mechanism for protecting human health by limiting access to contaminated
soil and groundwater. No additional protection to environmental receptors, such as fish in the
Chena River or other forms of wildlife, would be ensured by the implementation of institu-
tional controls alone.
Alternatives 3, 4, and 5 would protect human health and the environment by reducing risk
associated with contaminated groundwater and soil through implementation of active treatment
technologies. These alternatives also would eliminate further leaching of contaminants from
soil to groundwater and would reduce the potential for further migration of contaminated
groundwater.
9.4.2 Compliance with Applicable or Relevant and Appropriate Requirements
No action and institutional controls. Alternatives 1 and 2, would not achieve ARARs because
contamination at Remedial Area 2 would remain in place; therefore, these two alternatives
will not be discussed further.
102
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The groundwater remediation portion of Alternatives 3,4. and 5 would achieve chemical-
specific ARARs, such as federal Safe Drinking Water Act standards, within a reasonable time
frame. The soil remediation portion of Alternatives 3, 4. and 5 would achieve chemical-
specific ARARs, such as Alaska petroleum-contaminated soil regulations (18 AAC 78), to
protect groundwater for drinking water use. All the alternatives would be implemented in
compliance with action-specific ARARs, such as the federal Clean Air Act.
9.4.3 Long-Term Effectiveness and Permanence
The groundwater treatment portion of Alternatives 3,4, and 5 would involve active irrevers-
ible reduction of contaminant concentrations and therefore would reduce risk to acceptable
levels below ARARs. Current groundwater use restrictions would remain in place during
remedial action implementation. Groundwater monitoring also would be required to evaluate
the performance of the selected alternative. Vapor samples and air flow readings taken from
the soil vapor monitoring probes and system exhaust sampling ports would be necessary to
monitor the progress of cleanup, and to estimate the volume of hydrocarbons removed by the
system. The soil treatment portion of each alternative would prevent further leaching of
contaminants to groundwater. The VES could be expanded if additional contamination were
discovered.
9.4.4 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternatives 3, 4, and 5 would include technologies that treat and reduce the toxicity and
volume of soil and groundwater contaminants. Furthermore, the groundwater remediation
portion of all the alternatives would prevent further migration of contaminated groundwater,
while the soil remediation portion would prevent further leaching of contaminants into
groundwater. All three alternatives would include technologies that have been used success-
fully in Alaska to clean up petroleum-contaminated sites. Soil vapor extraction, coupled with
air sparging, is a technology that is being used to treat petroleum-contaminated soil and
groundwater at other locations on Fort Wainwright. All the technologies are expected to
reduce contamination to levels that do not pose risks to human health and the environment.
9.4.5 Short-Term Effectiveness
Alternatives 3,4, and 5 would involve some short-term impacts associated with treatment
system construction activities. A major advantage of in situ soil VES would be the ability to
install the system and conduct remediation with minimal disruption to the sites or surrounding
environment. However, some construction impacts, such as dust emissions from operating
heavy equipment and temporary disruption to daily operations or normal use near the
Remedial Area 2 source areas, are expected to occur. The potential risks would be minimized
by standard construction methods and engineering controls. Current groundwater use
restrictions would remain in place during the implementation of the remedial action. Alterna-
tives 3 and 5 are expected to accomplish remediation goals in five to 10 years for soil and
groundwater. Alternative 4 is expected to accomplish the groundwater remediation goals in
10 to 20 years, because pump-and-treat systems are limited by compound solubility and
adsorption characteristics.
103
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9.4.6 Implementability
Alternatives 3, 4, and 5 would be complex to implement, but all technologies are technically
implementable. Construction methods and materials needed to implement all three alternatives
are standard and available in Fairbanks. Alternative 3 is slightly less implementable than
Alternatives 4 and 5 because bioremediation technology would require some specialized
materials and equipment not immediately available in the Fairbanks area. For treating the
contaminated groundwater, Alternative 3 would require extensive hydrogeologic modeling and
bioassessment screening studies. Alternative 4 would employ proven wastewater treatment
technologies, such as air stripping and carbon adsorption. However, contaminant solubility in
groundwater and soil adsorption coefficients may be the limiting factors, especially for
removing contaminants in the smear zone. Alternatives 3 and 5 must be controlled properly
to ensure that contaminants do not migrate from the site. Each alternative would require
temperature-control devices for treatment to be effective because temperature remains an
important variable for all three alternatives. Alternative 5 is the selected alternative because it
has been implemented at Fort Wainwright with positive results. All three alternatives would
require preliminary testing before full-scale construction to obtain site-specific design parame-
ters; more time would be required for preliminary testing of Alternatives 3 and 5 because of
their complexity.
9.4.7 Cost
Table 34 compares the costs of the alternatives considered for Remedial Area 2. The cost for
Alternative 5 is approximately $500,000 to $700,000 less than that for Alternatives 3 and 4.
All the cost information is based on present worth values with 10% discount rates. The
estimated years to achieve Safe Drinking Water Act levels for each technology are based on
contaminant levels detected during the RI, soil and groundwater physical data, and published
treatment efficiency estimates for specific technologies. The estimated costs do not include
those associated with preliminary testing of remedial technologies. Figures 20 and 21 show
the approximate location and number of wells used for cost estimation. For cost purposes, a
20-year monitoring program is assumed to achieve Alaska Water Quality Standards. Table 34
compares the costs of the alternatives and options considered for Remedial Area 2.
9.4.8 State Acceptance
ADEC has been involved with the development of remedial alternatives for OU-3 and concurs
with the selected alternative for Remedial Area 2.
9.4.9 Community Acceptance
On April 25, 1995, the Army conducted a public meeting to discuss the Proposed Plan for
final remedial action at OU-3. Before the public meeting, a Proposed Plan summary fact
sheet was sent to all known interested parties, totaling approximately 150. Proposed Plans
were available by request. Results of the public meeting indicate that there is no opposition to
any of the preferred alternatives.
Community responses to the remedial alternatives are presented in the Responsiveness
Summary, which addresses comments received during the public comment period (see
Appendix A).
104
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COFpS C~ ENGINEERS
U.S. ARMY
LEGEND
KEY PLAN
APPROXIMATE UMITS OF
GROUNDWATER CONTAMINATION
APPROXIMATE UMITS OF
SOIL CONTAMINATION
EXTRACTION WELL AND
ZONE OF INFLUENCE
INJECTION WELL LOCATION
GROUNDWATER FLOW
DIRECTION
•jecoloty and environment, inc.
"lni.fintl.MI SMcUlltli ii tta Ewlr
U.S. ARMY
ENGINEER DISTRICT, ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
Figure 20
REMEDIAL AREA 2 GROUNDWATER INJECTION
AND EXTRACTION WELL PLACEMENT
TANK FARM SOURCE AREA - VALVE PIT A
FAIRBANKS ALASKA
SIZE
JOB. NO.
JY9040
RLE NO.
JY94-2A2.DWG
DATE:
11-08-94
PLATE
105
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CORPS OF ENGINEERS
U.S ARMY
FORMER LOCATION OF'
EIGHT TANK CAR
UNLOADING HEADERS
LEGEND
ROAD
FORMER UST LOCATION
RAILROAD
LIMI1ED TR£A1MEN1
AREAS DEFINED FOR
REMEDIAL AREA 2
o
EXTRACTION WELL ZONE OF INFLUENCE
(g) INJECTION WELL LOCATION
GROUNDWMER FlOW DIRECTION
- h
cnvlroDlDent. Inc.
US ARMr
ENGINEER OISFRICI. AIASKA
CORPS OF ENGINEfRS
HirHC'HAl.t. ALASKA
Figure 21
Rl I.ILUIAL AKLA ^
(.ROUNDWA7ER INJECTION AND
I.XlHAUluN WELL PLACLMENT (OPIIONb i.-l V.)
RAILCAR OFF LOADING fACIIIlr (HOI I-)
fAIKUANKS SOURCE ARfA
SIZE
y
JY9040
OAIE
ur94 -AC DWG o;> :>i 9'
-------
Pase 1 of 1
Table 35
REMEDIAL AREA 3-COST COMPARISON TABLE
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Alternative
1 : No Action
2: Institutional Controls
3: Soil Pile Aeration; Bioremediation of
Groundwater
4: Soil Pile Aeration; Air Stripping/Carbon
Absorption of Groundwater
5: Soil Vapor Extraction of Soil; Air Sparging
of Groundwater
Capital Cost
($)
0
0
640,000
610,000
480,000
Operations and
Maintenance3
($)
0
200.000
30,000
60,000
80,000
Estimated Years
to Obtain
Remedial Goals
_b
20
5
10
5
a Operations and Maintenance cost includes the estimated costs for 20 years of groundwater monitoring.
" The No Action alternative is not expected to achieve remedial goals.
107
-------
Selected Alternative for Remedial Area 2
The selected alternative for Remedial Area 2 is Alternative 5 (soil vapor extraction and air
sparging of groundwater). The groundwater treatment technology will achieve the cleanup
goals in a reasonable time frame at locations where MCLs have been exceeded. This
alternative also is a more direct approach at treating the contaminants in the smear zone than
the other alternatives. The soil treatment technology will achieve the primary goal of
protecting the groundwater for drinking water use. The treatment effectiveness of Alternative
5 has been proven in similar situations at Fort Wainwright. In addition to the technologies
chosen, long-term groundwater monitoring will be conducted to ensure that the treatment
systems effectively reduce contamination and that discharges of contamination to the Chena
River do not occur.
9.5 ALTERNATIVES FOR REMEDIAL AREA 3
Remedial Area 3 consists of petroleum-contaminated soil and groundwater at Mileposts 2.7,
3.0, and 15.75 along the Fairbanks-Eielson Pipeline. The presence of localized areas of
permafrost is a limiting factor for evaluation and placement of remedial alternatives for
Mileposts 2.7 and 3.0. For all three milepost source areas, the selected alternative is
expected to be placed in areas with known sources of contamination and at locations where
MCLs have been exceeded. The cost for each alternative is based on an estimated number of
years to obtain remedial goals. A cost comparison is presented in Table 35. The following
alternatives were considered for Remedial Area 3:
• Alternative 1: No action. Petroleum-contaminated soil and ground-
water would remain in place. Passive remediation of petroleum
contamination likely would occur by natural processes. No costs
would be associated with this alternative;
• Alternative 2: Institutional controls. Petroleum-contaminated soil
and groundwater would remain in place. Passive remediation of
petroleum contamination likely would occur by natural processes.
Institutional controls would include semi-annual groundwater sam-
pling and site inspections every five years. Long-term groundwater
monitoring also would be part of this alternative and is considered in
the cost estimate. The cost is based on a 20-year monitoring period;
• Alternative 3: Soil pile aeration and bioremediation of groundwater.
Soil pile aeration would involve excavation of contaminated soil and
vapor extraction with perforated pipes. Bioremediation would
involve injection of oxygen and nutrients directly into the aquifer to
enhance natural degradation processes. Long-term groundwater
monitoring also would be part of this alternative and is considered in
the cost estimate. The cost was based on a 20-year monitoring
period;
• Alternative 4: Soil pile aeration and groundwater extraction followed
by air stripping and carbon adsorption. Soil pile aeration would be
108
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conducted similar to the description in Alternative 3. Air stripping
and carbon adsorption of petroleum-contaminated groundwater would
involve pumping contaminated groundwater to the surface, introduc-
ing air to evaporate the petroleum contaminants, and passing the
water through carbon filters. Long-term groundwater monitoring
also would be part of this alternative and is considered in the cost
estimate. The cost was based on a 20-year monitoring period; and
• Alternative 5: Soil vapor extraction of petroleum-contaminated soils
and air sparging of petroleum-contaminated groundwater. Only soil
vapor extraction would be used to remove petroleum hydrocarbons
from petroleum-contaminated soil in this alternative. Air sparging
would be used to force evaporation of contaminants and capture the
resulting vapors with a vapor extraction process. Long-term ground-
water monitoring also would be part of this alternative and is consid-
ered in the cost estimate. The cost was based on a 20-year monitor-
ing period.
9.6 EVALUATION OF ALTERNATIVES FOR REMEDIAL AREA 3
The following sections summarize the evaluation of each alternative in reference to EPA's
nine evaluation criteria.
9.6.1 Overall Protection of Human Health and the Environment
No-action and institutional controls, Alternatives 1 and 2, would not protect human health and
the environment because contamination at Remedial Area 3 would remain in place. The
institutional controls alternative would not protect the environment because it would not
prevent further migration of petroleum contaminants into the nearby wetland.
Alternatives 3, 4, and 5 would protect human health and the environment by reducing risk
associated with contaminated groundwater and soil through implementation of active treatment
technologies. These alternatives also would eliminate further leaching of contaminants from
soil to groundwater and reduce the potential for further migration of contaminated ground-
water.
9.6.2 Compliance with Applicable or Relevant and Appropriate Requirements
No action and institutional controls, Alternatives 1 and 2, would not achieve applicable
cleanup standards for soil and groundwater until natural degradation of the contaminants
occurs; therefore, the two alternatives will not be discussed further.
The groundwater remediation portion of Alternatives 3,4, and 5 would achieve chemical-
specific ARARs, such as federal Safe Drinking Water Act standards, within a reasonable time
frame. The soil remediation portion of Alternatives 3, 4, and 5 would achieve chemical-
specific ARARs. such as Alaska petroleum-contaminated soil regulations (18 AAC 78), to
protect groundwater for drinking water use. All the alternatives would be implemented in
compliance with action-specific ARARs, such as the federal Clean Air Act.
109
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9.6.3 Long-Term Effectiveness and Permanence
The ground water" treatment portion of Alternatives 3. 4, and 5 would involve active irrevers-
ible reduction of contaminant concentrations and therefore would reduce risk to acceptable
levels below chemical-specific ARARs. Current groundwater use restrictions would remain in
place during remedial action implementation. Groundwater monitoring also would be
. required to evaluate the performance of the selected alternative. Vapor samples and air flow
readings taken from the soil vapor monitoring probes and system exhaust sampling ports
would be necessary to monitor the progress of cleanup, and to estimate the volume of
hydrocarbons removed by the system. The soil treatment portion of each alternative -.vould
prevent further leaching of contaminants to groundwater.
9.6.4 Reduction of Toricity, Mobility, and Volume Through Treatment
Alternatives 3, 4, and 5 would include technologies that treat and reduce the toxicity and
volume of soil and groundwater contaminants. Furthermore, the groundwater remediation
portion of all the alternatives would prevent further migration of contaminated ground vater,
while the soil remediation portion would prevent further leaching of contaminants into
groundwater. Soil vapor extraction, coupled with air sparging, is a technology that is being
used to treat petroleum-contaminated soil and groundwater at other locations on Fort Wain-
wright. All the technologies are expected to reduce contamination to levels that do not pose
risks to human health and the environment.
9.6.5 Short-Term Effectiveness
Alternatives 3 and 4 would involve excavation, removal, and treatment of soil. These
alternatives would involve relatively rapid removal of soil contaminants from Remedial
Area 3. Alternatives 3 and 4 would involve more severe short-term impacts associated with
excavation. All three alternatives would result in short-term impacts, such as dust emissions
from heavy operation equipment and temporary disruption to daily operations or normal use
of the Remedial Area 3 areas. The impacts would be managed with engineering controls and
standard construction methods. Alternatives 3 and 5 are expected to accomplish remediation
goals in five to 10 years for soil and groundwater. Alternative 4 is expected to reach the
groundwater remediation goals in 10 to 20 years.
9.6.6 Implementability
For treating the contaminated groundwater, Alternative 3 would require extensive hydrogeo-
logic modeling and bioassessment screening studies. Alternative 4 would employ proven
wastewater treatment technologies, such as air stripping and carbon adsorption. However,
contaminant solubility in groundwater and soil adsorption coefficients may be the limiting
factors, especially for removing contaminants in the smear zone. Alternatives 3 and 5 must
be controlled properly to ensure that contaminants do not migrate from the site. Each
alternative would require temperature-control devices for treatment to be effective because
temperature remains an important variable for all three alternatives. Because of the presence
of permafrost, the selected technology system will be placed in thaw channels because the
treatment systems would be most effective in the thaw channels where the contaminants are
most concentrated. Alternative 5 is the preferred alternative because it has been implemented
110
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at Fort Wainwright with positive results. Alternatives 3, 4, and 5 would require preliminary
testing before full-scale construction.
9.6.7 Cost
Table 35 compares the costs of the alternatives considered for Remedial Area 3. The cost for
' Alternative 5 is approximately 5100,000 less than that for Alternatives 3 and 4. All cost
information is based on present worth values with 10% discount rates. The estimated years to
achieve Safe Drinking Water Act levels for each technology are based on contaminant levels
detected during the RI, soil and groundwater physical data, and efficiency estimates for
specific technologies. The estimated costs include those associated with pilot testing of in situ
remedial technologies. For cost purposes, a 20-year monitoring program is assumed to
achieve Alaska Water Quality Standards, as presented in Table 35. Figures 22 and 23 show
the approximate location and number of wells used for cost estimation.
9.6.8 State Acceptance
ADEC has been involved with the development of remedial alternatives for OU-3 and concurs
with the selected alternative for Remedial Area 3.
9.6.9 Community Acceptance
On April 25, 1995, the Army conducted a public meeting to discuss the Proposed Plan for
final remedial action at OU-3. Before the public meeting, a Proposed Plan summary fact
sheet was sent to all known interested parties, totaling approximately 150. Proposed Plans
were available by request. Results of the public meeting indicate that there is no opposition to
any of the preferred alternatives.
Community responses to the remedial alternatives are presented in the Responsiveness
Summary, which addresses comments received during the public comment period (see
Appendix A).
Selected Alternative for Remedial Area 3
The selected alternative for Mileposts 2.7. 3.0, and 15.75 in Remedial Area 3 is Alternative 5
(soil vapor extraction and air sparging of groundwater). This alternative was chosen because
its effectiveness with similar petroleum contamination has been proven at Fort Wainwright.
The groundwater treatment technology will achieve the cleanup goals in a reasonable time
frame at locations where MCLs have been exceeded and in the thaw channels where present.
This alternative is also a more direct approach at treating the contaminants in the smear zone
than the other alternatives. The soil treatment technology will achieve the primary goal of
protecting groundwater for drinking water use. In addition to the technologies included in
Alternative 5, long-term groundwater monitoring will be conducted at Mileposts 2.7, 3.0, and
15.75 to ensure that the treatment systems reduce contamination in nearby wetlands.
111
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CORPS OF ENGINEERS
U.S. ARMY
ABANDONDED
BIRCH HILL
UST SITE
BIRCH HILL LOOP
BIRCH HILL ROAD
_ . ABANDONDED
TFS~2'7 BIRCH HILL
UST SITE
LEGEND
APPROXIMATE LIMITS OF
GROUNDWATER CONTAMINATION
APPROXIMATE LIMITS OF
SOIL CONTAMINATION
EXTRACTION WELL AND
ZONE OF INFLUENCE
INJECTION WELL LOCATION
GROUNDWATER FLOW DIRECTION
KEY PLAN
•ecolofy and environment, inc.
U.S. ARMY
ENGINEER DISTRICT. ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
Figure 22
REMEDIAL AREA 3-
GROUNDWATER INJECTION AND
EXTRACTION WELL PLACEMENT
PIPELINE MILEPOST 2.7 & 3.0 SOURCE AREAS
FAIRBANKS ALASKA
SIZE
JOB. NO.
JT2101
RLE NO.
JY24-5A.DWG
PATE:
04-04-95
PLATE
112
-------
CORPS OF ENGINEERS
U.S. ARMY
DRA/NXpE DITCH
///////////X//\////
XIMATE CENTER OF PIPELINE DITCH
FEP
10
is
20
APPROXIMATE SCALE IN FEET
3/4--IQ'
LEGEND
— FEP--
I .
FAtRBANKS-EIELSON PIPELINE
APPROXIMATE PIPELINE BREAK
AREA OF SOIL EXCAVATION
FOLLOWING PIPELINE BREAK
APPROXIMATE LIMITS OF
SOIL CONTAMINATION
INJECTION WELL LOCATION
o
EXTRACTION WELL AND
ZONE OF INFLUENCE
APPROXIMATE LIMITS OF
GROUNDWATER CONTAMINATION
GROUNOWATER FLOW DIRECTION
SOURCE: DEPARTMENT OF TRANSPORTATION. 1992. USAGE, 1991
Jecolofy end environment, Inc.
VltlttMllxMl Sfr*cl«lllll In
U.S. ARMY
ENGINEER DISTRICT, ALASKA
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
FAIRBANKS
Figure 23
REMEDIAL ARLA .3 -
GROUNDWATER INJECTION AND
EXTRACTION WELL PLACEMENT
PIPELINE MILEPOST 15.75
SIZE
ALASKA
JOB. NO.
JY9040
FILE NO.
JY94-6A2.DWG
PATE:
11-08-94
PLATE
-------
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10.0 SELECTED REMEDIES
Selected remedie's were chosen to actively treat contaminated groundwater to meet Safe
Drinking Water Act levels and naturally attenuate to meet Alaska Water Quality Standards
within a reasonable time frame, and to reduce further migration. These remedies also will
prevent further contamination of groundwater and restore it to drinking water quality
standards. The selected remedies are:
• Remedial Area Ib: Soil vapor extraction of petroleum-contaminated
soil and air sparging of petroleum-contaminated groundwater in
permafrost-free areas to achieve Safe Drinking Water Act levels and
natural attenuation to meet Alaska Water Quality Standards;
• Remedial Area 2: Soil vapor extraction of petroleum-contaminated
soil and air sparging of petroleum-contaminated groundwater at
known contaminant sources and at locations where MCLs are ex-
ceeded (i.e., "hot spots") to achieve Safe Drinking Water Act levels
and natural attenuation to meet Alaska Water Quality Standards; and
• Remedial Area 3: Soil vapor extraction of petroleum-contaminated
soils and air sparging of petroleum-contaminated groundwater in
permafrost-free areas at Milepost 2.7 and 3.0, and known source
areas where MCLs were exceeded at Milepost 15.75 to achieve Safe
Drinking Water Act levels and natural attenuation to meet Alaska
Water Quality Standards.
These remedies meet the two threshold criteria because they protect human health and the
environment by permanently reducing the risk to an acceptable level for ingestion of
groundwater and comply with ARARs. These remedies also best meet the five balancing
CERCLA evaluation criteria. They are effective at providing protection in reducing
contamination in the short- and long-term, are implementable, cost-effective, and acceptable to
the public and the State of Alaska.
Based on the assumption that land use is not anticipated to change in the foreseeable future.
the reasonable time frame for remediation at each source area is set for no more than 30
years. Following is a more detailed description of the selected remedies for each remedial
area.
Subsurface soils and groundwater contaminated with petroleum fuels at Remedial Areas Ib. 2,
and 3 will be treated using a combination of two in situ technologies: vapor extraction for
soil contamination and air sparging for groundwater contamination. A combination of these
two technologies was selected because they are the most cost-effective and implementable
technologies available to remediate petroleum-contaminated groundwater and soil at OU-3.
Furthermore, it is also the combination of technologies that has been proven effective at Fort
Wainwright.
Based on previous experience with the soil VES. approximately 60% to 80% of the total
gasoline-range hydrocarbons in soil may be volatilized and the remaining 20% to 40%
biodegraded. A removal of more than 80% by volatilization is expected to occur with VOCs
114
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like benzene. It is expected that vapor concentration and mass removal will decrease with
time as the VOCs are removed. However, soil VESs are effective in promoting biodegrada-
tion of the less-volatile compounds. The air sparging system for groundwater employs the
. same concept as the VES for soil. That is, the air sparging system will remove VOCs via
volatilization and will remove the less-volatile compounds by promoting biodegradation in the
saturated zone.
Soil conditions at Remedial Areas Ib, 2, and 3 are expected to be conducive to VES treatment
based on grain size and soil moisture data generated during the RI. Site-specific design
information will be collected in the pilot study.
The goal of the selected remedy is to restore groundwater to Safe Drinking Water Act levels.
Based on the information obtained in the RI and on a careful analysis of all remedial
alternatives, it is believed that the selected remedy will achieve this goal within a reasonable
time frame. It may become apparent, during implementation or operation of the groundwater
treatment system and its modifications, that contaminant levels cease to decline and are
remaining constant at levels higher than the remediation goal. In such a case, the system
performance standards and/or the remedy may be re-evaluated.
The selected remedy of soil VES, coupled with air sparging of groundwater, will be placed at
known contaminant source areas and at locations where Safe Drinking Water Act levels are
exceeded. For Remedial Areas Ib and 3 where localized areas of permafrost exist, air
sparging, and vapor extraction wells will be installed in the permafrost-free areas or thaw
channels.
The selected remedy, air sparging and soil VES, is expected to meet the groundwater
remediation goals, as established in Sections 7.2 and 7.3, in five to 10 years. The soil VES is
estimated to achieve protection of groundwater for drinking water use in approximately five
years. After active remediation goals are achieved, additional remediation is expected to
occur in groundwater through natural attenuation. It is anticipated that natural attenuation will
achieve Alaska Water Quality Standards. Soil cleanup levels will be protective of groundwa-
ter as defined in Section 7.0. During the implementation period, the treatment system's
performance will be carefully monitored on a regular basis and adjusted as warranted by the
performance data collected during operation. Modification may include installation of
additional treatment units.
Long-term groundwater monitoring is a component of the selected remedy for each of
Remedial Areas Ib, 2, and 3. Estimated costs for the selected remedies (see Tables 33, 34,
and 35) include groundwater monitoring costs over a 20-year period at monitoring wells
presently in place at these remedial areas. Periodic off-post sampling is also pan of the
remedial action, and additional sampling will be determined on an as-needed basis. For
example, the Army will collect groundwater samples from domestic wells located at the two
churches west of the Tank Farm on a regular basis while remedial activities at OU-3 are
conducted. The Army is currently providing bottled water to the two churches because of
exceedances of MCLs. The source of the contamination has not been clearly determined. If
contaminant levels increase above MCLs in these wells, and if contamination of the church
wells is clearly demonstrated to originate from the Tank Farm, the Army agrees to provide a
permanent replacement water supply to the two churches.
115
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In addition to sampling for the petroleum and VOCs for the long-term groundwater monitor-
ing program, lead in groundwater will also be sampled. Groundwater samples collected
during the RI showed that dissolved lead concentrations were lower than the MCL of 15 /xg/L
at all the source areas except for one sample at the ROLF. Total lead concentrations
exceeded the lead MCL at all the source areas. Because of the significant difference between
dissolved and total lead concentrations, and because total lead samples were visibly turbid
during sampling, long-term monitoring of lead in groundwater will employ methods that will
reduce or eliminate sample turbidity so that the sampling data will confirm the actual degree
of lead that is present in groundwater.
116
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11.0 STATUTORY DETERMINATIONS
The selected remedies satisfy the requirements under Section 121 of CERCLA, as amended
by SARA, and to the extent practicable, the NCP. The evaluation criteria, as discussed in
this section, are to:
• Protect human health and the environment;
• Attain ARARs of federal and state environmental laws and comply
with ARARs;
• Be cost-effective; and
• Utilize permanent solutions and alternative treatment technologies to
the maximum extent practicable.
11.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedies protect human health and the environment through the removal of the
principal sources of groundwater contamination. BTEX and VOC contamination in the
groundwater will be reduced to acceptable levels by actively remediating groundwater and
soils, which currently act as a continuing source of contamination to the groundwater.
Treatment of groundwater will reduce the risk to acceptable levels for human ingestion,
reduce the possibility of off-site migration of contaminants, and prevent the potential future
exposure to contaminated groundwater.
Before and during the cleanup, institutional controls will be in place to eliminate the threat of
exposure to contaminated groundwater.
No unacceptable short-term risks will be caused by implementation of the remedy.
Current points of exposure include on-site workers, burrowing animals, and recreational
users' inhalation of carcinogenic vapors in soil. Treatment will reduce the extent of contami-
nation to levels acceptable under federal and state guidelines.
11.2 ATTAINMENT OF APPLICABLE OR RELEVANT AND APPROPRIATE RE-
QUIREMENTS OF ENVIRONMENTAL LAWS
The selected remedies will comply with action-, chemical-, and location-specific ARARs of
federal and state environmental and public health laws. The ARARs are listed in the
following sections.
11.2.1 Action-Specific Applicable or Relevant and Appropriate Requirements
Remedial treatment activities will meet the action-specific ARAR of 42 United States Code
(USC) 7411 Clean Air Act, Standards of Performance for New Stationary Sources. This
ARAR is applicable for air discharge limits on the soil vapor extraction and air sparging
units.
117
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11.2.2 Chemical-Specific Applicable or Relevant and Appropriate Requirements
Remedial treatment activities will meet the following chemical-specific ARARs:
• 40 Code of Federal Regulations 141, National Primary Drinking
Water Standards regulations, and 18 AAC 80. State of Alaska
Drinking Water Regulations. These regulations are relevant and
appropriate for cleanup of groundwater that may be used for a
drinking water supply. MCL, nonzero MCLG, and action levels are
established under the Safe Drinking Water Act for groundwater:
• 18 AAC 70, Alaska Water Quality Standards for protection of Class
1(A) water supply for groundwater, are applicable. This ARAR will
be met through natural attenuation after active remediation achieves
MCLs;
• 18 AAC 75, Alaska Oil and Hazardous Substance Pollution Control
regulations, are applicable. Under these regulations, responsible
parties are required to clean up oil or hazardous material releases.
The Army anticipates achieving a cleanup level consistent with this
regulation; and
• 18 AAC 78, Alaska Underground Storage Tanks regulations, are
relevant and appropriate. Contaminated surface water or groundwa-
te^ will have sufficient reduction of all contaminants of concern, if
the applicable water quality criteria of 18 AAC 70 are met. The
Army intends to meet this requirement through active treatment of
soil and groundwater until MCLs and nonzero MCLG are achieved.
Natural attenuation will be relied upon until Alaska Water Quality
Standards are met.
Additionally, petroleum-contaminated soils that are removed from the source area will be
treated to State of Alaska Matrix Level A concentrations before being reused as fill materials
for the source area. Actual soil cleanup levels are anticipated to be determined during post-
ROD activities and will be based on protecting groundwater in accordance with drinking
water standards.
11.2.3 Location-Specific Applicable or Relevant and Appropriate Requirements
Remedial treatment activities will meet the following location-specific ARARs:
• 404 (33 USC 1344) Clean Water Act, Permits for Dredged or Fill
Materials, is applicable to protect the wetlands adjacent to the Tank
Farm and pipeline areas from fill or dredging operations; and
• Executive Order 11990, Protection of Wetlands, is applicable to
prevent damage to the wetlands adjacent to the Tank Farm and
pipeline areas from remediation activities.
118
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11.2.4 Information To-Be-Considered
The following information to-be-considered will be used as guidelines when implementing the
selected remedy:
• State of Alaska Interim Guidance for Non-UST Contaminated Soil
Cleanup Levels (July 17, 1991);
• State of Alaska Guidance for Storage, Remediation, and Disposal of
Non-UST Petroleum Contaminated Soils (July 29, 1991); and
• State of Alaska Interim Guidance for Surface and Groundwater
Cleanup Levels (September 26, 1990).
11.3 COST EFFECTIVENESS
The selected remedies represent the most cost-effective of the alternatives in comparison to
their overall effectiveness proportional to their costs.
11.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREAT-
MENT TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE
The Army, State of Alaska, and EPA determined that the selected remedies represent the
maximum extent to which permanent solutions and treatment technologies can be used cost-
effectively at OU-3. Of those alternatives that are protective to human health and the
environment and comply with ARARs, the Army, State of Alaska, and EPA have determined
that the selected remedies provide the best balance of trade-offs in terms of long-term
effectiveness and permanence; reduction in toxicity, mobility, or volume achieved through
treatment; short-term effectiveness; implementability; cost; and the statutory preference for
treatment as a principal element and considering state and community acceptance.
All selected remedies would use readily available technologies and would be feasible to
construct.
Installation of soil vapor extraction and air sparging remedial systems will be focused in the
areas of highest soil contamination, nonpermafrost soils, and where MCLs have been
exceeded. Additionally, the remedial technologies chosen have been used at or near Fort
Wainwright and have shown to be the most implementable and effective technologies
available.
11.5 USE OF PERMANENT SOLUTIONS, ALTERNATIVE TREATMENT, OR
RESOURCE RECOVERY TECHNOLOGIES TO THE MAXIMUM EXTENT
PRACTICABLE
The selected remedies will provide permanent solutions and alternative treatment technologies
for contaminated soil and groundwater. The remedies utilize treatment of the contaminant
source and affected soil and groundwater. Soil vapor extraction of petroleum-contaminated
soil, in conjunction with air sparging of petroleum-contaminated groundwater, provides a
119
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permanent solution by eliminating the source of contaminants and treating the off-site
migration pathway ^
Risk from petroleum-contaminated soils and groundwater is reduced permanently through
treatment. The selected remedies provide the best balance of long-term effectiveness and
permanence: reduction in toxicity, mobility, and volume achieved through treatment; short-
term effectiveness; implementability; and cost.
11.6 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The selected remedies satisfy the statutory preference for treatment by utilizing treatment as a
main method to permanently reduce the toxicity, mobility, and volume of contaminated soil
and groundwater.
120
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12.0 DOCUMENTATION OF SIGNIFICANT CHANGES
CERCLA Section 117(b) requires an explanation of any significant changes from the preferred
alternatives originally presented in the Proposed Plan. The selected remedies were the same
as the preferred alternatives presented in the Proposed Plan with the exception of Remedial
Area la, lead-contaminated soil around the ASTs at the Tank Farm.
12.1 PROPOSED ALTERNATIVE
The original preferred alternative for Remedial Area la, lead-contaminated soils around the
ASTs located on the Birch Hill portion of the Tank Farm, was excavation and soil washing of
lead-contaminated soils. A contingency remedy of off-site disposal would have replaced soil
washing as the selected remedy if soil washing did not achieve cleanup goals in a cost-
effective manner.
12.2 SIGNIFICANT CHANGES
The Army, EPA, and State of Alaska have agreed to defer selection of a final remedy for
Remedial Area la at the AST area located on the Birch Hill portion of the Tank Farm. This
source area will be addressed in the ROD for OU-5.
12.3 REASON FOR CHANGE
The agencies would like additional time to select an appropriate cleanup level and remediation
goal for lead-based paint in soils.
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APPENDIX A
RESPONSIVENESS SUMMARY
A-l
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RESPONSIVENESS SUMMARY FOR THE RECORD OF DECISION FOR
REMEDIAL ACTION AT OPERABLE UNIT 3, FORT WAINWRIGHT, ALASKA
OVERVIEW
The United States Army, Alaska (Army), United States Environmental Protection Agency
(EPA), and Alaska Department of Environmental Conservation (ADEC), collectively referred
to as the Agencies, distributed a Proposed Plan for remedial action at Operable Unit 3 (OU-
3), Fort Wainwright, Alaska. OU-3 comprises five source areas: the Tank Farm; Railcar
Off-Loading Facility (ROLF); and Mileposts 2.7, 3.0, and 15.75 of the Fairbanks-Eielson
Pipeline (FEP). The five source areas were reorganized into four remedial areas based on the
type of contamination present. These areas are:
• Remedial Area la—Lead-contaminated soil near aboveground storage
tanks (ASTs) within the Tank Farm;
• Remedial Area Ib—Petroleum-contaminated soil and groundwater at
the base of Birch Hill and near the Truck Fill Stand at the southwest
corner of the Tank Farm;
• Remedial Area 2—Petroleum-contaminated soil and groundwater at
Valve Pit A and the ROLF; and
• Remedial Area 3—Petroleum-contaminated soil and groundwater at
Mileposts 2.7, 3.0, and 15.75 along the FEP.
The Proposed Plan identified preferred remedial alternatives for the four remedial areas within
OU-3. The major components of the remedial alternatives are:
• Soil washing of approximately 3,200 tons of lead-contaminated soils
at the Tank Farm to reduce the amount of lead-contaminated soil to
approximately 1,100 tons, which will be transported off site for
treatment and disposal; and
• In situ vapor extraction of petroleum-contaminated soil in conjunction
with air sparging of petroleum-contaminated groundwater to remove
volatile contaminants in the groundwater and vadose zone. This
component will be implemented at the Tank Farm, ROLF, and
Mileposts 2.7, 3.0, and 15.75. Groundwater monitoring will be
conducted for 20 years following the initiation of remedial action.
Two formal comments regarding the Proposed Plan for the OU-3 remedial action were
received during the public comment period; these comments are summarized and presented
in this Responsiveness Summary. In addition, numerous questions were asked at the public
meeting held on April 25, 1995. These questions focused on the results of contamination
investigations performed at OU-3, potential impacts to nearby property, the rationale for
selection and estimated time frames for preferred remedial alternatives, and issues relating to
A-2
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the cost of cleanup. These questions and Agency responses are available in the Administra-
tive Record. ..
BACKGROUND OF COMMUNITY INVOLVEMENT
The public was encouraged to participate in the selection of the final remedies for OU-3
during a public comment period from April 19 to May 19, 1995. The Fort Wainwright
Proposed Plan for Operable Unit 3 presented more than 25 combinations of options consid-
ered by the Agencies to address contamination in soil and groundwater at OU-3. The
Proposed Plan was released to the public on April 19, 1995, and copies of a Proposed Plan
summary fact sheet were sent to all known interested parties including approximately 150
elected officials and concerned citizens. An informational fact sheet dated March 1995,
providing information about the Army's entire cleanup program at Fort Wainwright, was
mailed to the addresses on the same mailing list.
The Proposed Plan summarized available information regarding the OU. Additional materials
were placed into two information repositories, one at the Noel Wien Library in Fairbanks and
the other ~at the Fort Wainwright Post Library. An Administrative Record, including all items
placed in the information repositories and other documents used in the selection of the
remedial actions, was established in Building 3023 on Fort Wainwright. The public was
welcome to inspect materials available in the Administrative Record and the information
repositories during business hours.
Interested citizens were invited to comment on the Proposed Plan and the remedy selection
process by mailing comments to the Fort Wainwright project manager, by calling a toll-free
telephone number to record a comment, or by attending and commenting at a public meeting1
on April 25, 1995, at the Noel Wien Library in Fairbanks.
Basewide community relations activities conducted for Fort Wainwright, which includes
OU-3, have included:
• July 1992—Community interviews with local officials and interested
parties;
• April 1993—Preparation of the Community Relations Plan;
• July 1993—Distribution of an informational fact sheet covering all
OUs at Fort Wainwright;
• July 22, 1993—An informational public meeting covering all OUs;
and
• April 22, 1994—Establishment of information repositories at the
Noel Wien Library and the Fort Wainwright Post Library and the
Administrative Record at Building 3023 on Fort Wainwright.
'The public meeting referred to in this Responsiveness Summary was a joint meeting for
final remedial action at OU-3 and interim remedial action at the Chemical Agent Dump Site, a
source area in OU-1, Fort Wainwright, Alaska.
A-3
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Community relations activities specifically conducted for OU-3 included:
• April 12, 16, 19, 23, 24, and 25, 1995—Display advertisement
announcing public meeting in the Fairbanks Daily News-Miner;
• April 19, 1995—Distribution of Proposed Plan for final remedial
action at OU-3;
• April 19 to May 19, 1995—30-day public comment period. No
extension was requested;
• April 19 to May 19, 1995—Establishment of a toll-free telephone
number for citizens to provide comment. The toll-free telephone
number was advertised in the Proposed Plan and the newspaper
display advertisement that announced the public meeting; and
• April 25, 1995—Public meeting at the Noel Wien Library to provide
information, a forum for questions and answers, and an opportunity
for public comment regarding OU-3.
SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT
PERIOD AND AGENCY RESPONSES
The public comment period on the Proposed Plan for remedial action at OU-3 was from April
19 to May 19, 1995. Two comments were received during the public comment period: one
comment was provided during the public meeting, and the second comment was mailed to the
Army. Comments received during this time are summarized below.
1. Public Comment: The comment received during the public meeting acknowledged the
Agencies' commitment during the cleanup process to identify and characterize source areas in
OU-3. The commentor, representing an environmental consulting firm, indicated that soil
vapor extraction and air sparging to remediate petroleum-contaminated soils and groundwater
is an effective remediation technology for the Fairbanks area.
Agency Response: Thanked the responder and noted.
2. Public Comment: A letter was received during the public comment period from attorneys
representing the Bentley Family Trust (Trust), adjacent landowners. The letter states that the
Trust generally is pleased with the Agencies' selected remedy for the Tank Farm source area.
However, the letter raises some concerns. One of the concerns, quoted from the letter, states,
"If the Army has not completely delineated the size of the contamination, we do not believe
that it can competently devise and responsibly implement an adequate remediation plan which
will directly and effectively remediate all of the contamination and related health risks and
damages to properties." A second concern is related to groundwater monitoring west of the
Tank Farm source area. The letter recommends that the Army collect samples from existing
monitoring wells concurrently to provide indication whether groundwater quality in this area
exceeds regulatory standards.
Agency Response: Based on current information, the Army believes that sufficient data have
been generated at OU-3, including the Tank Farm source area, to select the final remedies.
A-4
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However, additional investigations likely will be performed to aid in the development of
remedial design for the site.
The Army has reviewed the list of wells provided in the letter. Several of these wells,
including the United States Geological Survey wells, Cold Region Research and Engineering
Laboratory (CRREL) MW-C, and the CRREL well points, were not constructed in a manner
conducive to collecting representative groundwater samples. For example, the CRREL well
points were designed to provide screening-level field data for optimizing placement of
standard groundwater monitoring wells. However, the AP wells listed in the letter will be
sampled during the installation and operation of the remediation systems planned for OU-3.
The Army notes that wells AP-5782 and AP-5785 are pan of a groundwater monitoring
program and are sampled quarterly. Concurrent sampling of the AP wells referenced in the
letter will be conducted as part of the long-term monitoring program associated with the final
remedy.
A-5
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APPENDIX B
ADMINISTRATIVE RECORD INDEX
B-l
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Page 1 of 3
ADMINISTRATIVE RECORD INDEX
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Start
Page
26716
26798
27170
29771
29773
31514
34573
35956
08305
08392
08403
08408
End
Page
26734
26836
27189
29772
29787
34572
34939
36634
08391
08402
08407
08472
Date
9/8/94 •
9/1/93
7/29/94
9/18/93
9/2/93
9/1/94
2/1/95
9/1/94
6/1/83
4/J8/88
8/27/89
6/6/90
Title
Technical Memorandum regarding Operable Unit 3
Feasibility Study, Task 3
Descriptive Inventory of Wildlife and Vegetation, Operable
Unit 3
Technical Memorandum regarding Feasibility Study,
Operable Unit 3, Fort Wainwriglu, Alaska
Operable Unit 3, Fort Wainwright Decision Document
Amendment to Operable Unit 3 Remedial Investigation
Management Plan, Sampling Analysis Plan for Facility
Investigations, Fairbanks-Eielson Pipeline Mile 3.0
Remedial Investigation Report, Operable Unit 3, Fort
Wainwright, Alaska; Volumes 1, 2, and 3
Feasibility Study, Operable Unit 3, Fort Wainwright,
Alaska
Risk Assessment Report, Operable Unit 3, Fort
Wainwright, Alaska; Humai\,.Mealth Risk Assessment,
Ecological Risk Assessment
Pollution Spill Control Plans, Petroleum Division Terminal
Review Comments for Oil Discharge Contingency Plans for
FTW Oil Terminal
Initial Petroleum Pipeline Spill Incident
Fairbanks Fuel Terminal, FTW, A-F. Quality Control Plan
OU
No.
3
3
3
3
3
3
3
3
3
3
3
3
Category
No.
4.2
3.1.1
4.2
3.1.2
3.1.1
3.1.2
4.2
3.1.2
1.1
1.1
1.1
1.2.1
Author
Name/Affiliation
Bill Richards/E & E
Junior D. Kerns/DPW
Bill Richards/E & E
None given/None given
None given/E & E
None given/E & E
None given/E & E
None given/E & E
Harlan Moore/COE
Dick Warren/ADEC
Chris Putnam/DOL,
Petroleum Division
None given/1- & (•
Recipient
Name/Affiliation
Ted Bales/COl;
None given
Ted Bales/COE
None given/None given
None given/None given
None given/None given
None given/COE
None given/COE
AFZT-EH-PSE/US
Army
Col. Alexander
John/DEH
Mr. Walty/Petroleum
Division, FTR
Dave Williaiii.s/COl'
Key at end of table.
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Page 2 of 3
ADMINISTRATIVE RECORD INDEX
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Start
Page
08473
08778
08836
08856
08985
09154
09211
09217
09275
09278
09282
10073
10075
End
Page
08718
08835
08855
08984
09153
09210
09216
09274
09277
09281
10072
10074
10076
Date
6/6/90
11/16/90
11/16/90
11/1/91
1/1/92
10/1/89
12/12/90
9/12/91
7/12/93
3/24/92
2/1/93
8/27/92
9/24/92
Tiile
Fairbanks Fuel Terminal, Part I, Sampling and Analysis,
QA/QC Plan, FTW '
DRAFT Work Plan: Part I, Sampling Analysis and QA/QC
Plan for Fairbanks-Eielson Pipeline
DRAFT Work Plan: Part II Site Safety and Health Plan
for Fairbanks-Eielson Pipeline
Chemical Data Acquisition Plan, Fairbanks Fuel Terminal,
FTW
Fairbanks Fuel Terminal Work Plan, Part I, Sampling
Analysis Plan
DRAFT Fairbanks-Eielson POL Pipeline Soil Gas Survey
USATHAMA Property and Waste Site Report
Summary of Field Work and Chemical Data for Fairbanks
Eielson Pipeline Study
Statement from a Local Resident Concerning the Possibility
of Oil Silt- Migration of Contamination from Ihu Fairbanks-
Eielson Multiproduct POL feline
USEPA Region 10 Comments on Preliminary Draft
Conceptual Model Operable llnii 3
I'iual Management 1'l.ui lor Kcincili.il
Investigation/Feasibility Study at Operable Unit 3, FTW
Treatability Study Requirements
Treatability Study Requirements
OU
No.
3
3
3
3
3
3
3
3
3
3
3
3
3
Category
No.
1.2.1
1.2.1
1.2.1
1.2.1
1.2.1
1.2.2
1.2.2
1.2.2
1.6
2.1.3
3.1.1
3.2
3.2
Author
Name/Affiliation
None given/E & E
Mat'ls & Instru-
mentation/COE
Mat'ls & Instru-
mentation/COE
None given/E & E
None given/E & E
None given/Hart
Crowser
None given/
USATHAMA
Delwyn Thomas/COE
Joe Malen/DEH
Dianne Soderlund/EPA
None given/1: & 1:
Lyle Diedeker/E & E
David Williams/COE
Recipient
Name/Affiliation
Dave Williams/COE
Cristal Fosbrook/DPW
Cristal Fosbrook/DPW
Dave Williams/COE
Dave Williams/COE
Cristal Fosbrook/DPW
None given/None given
None given/None given
None given/None given
distal Fosbrook/DPW
Da v id Williani.s/C'Oi;
David Williams/COE
Peter Brokx/E & E
Key al end of table.
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Page 3 of 3
ADMINISTRATIVE RECORD INDEX
OPERABLE UNIT 3
FORT WAINWRIGHT, ALASKA
Start
Page
10077
10114
10123
10125
TUA
End
Page
10113
10122
10124
10126
TUA
Date
10/15/92
10/16/92
6/2/92
3/9/93
5/19/95
Title
Review Comments on the Draft Management Plan for
Remedial Investigation/Feasibility Study at Operable Unit 3
Review Comments on the Draft Management Plan for
Remedial Investigation/Feasibility Study at Operable Unit 3
Use of the Geoprobe, an Innovative Sampling Device for
Operable Unit 3
Use of Modified EPA Method 8015 at FTW
Letter Re: Remedial Investigation Report, Operable Unit
3, Foil Wiiinwriglit
OU
No.
3
3
3
3
3
Category
No.
3.3
3.3
11.2
11.3
TUA
Author
Name/Affiliation
Marie Jennings/EPA
Rielle Markey/ADEC
Marie Jennings/EPA
Ronan Short/ADEC
Michael P. Monroe/
Reed McClurc
Recipient
Name/Affiliation
Cristal Fosbrook/DPW
Cristal Fosbrook/DPW
FTW RPM's/COE
Cristal Fosbrook/DPW
Col. Albert J. Kraus/
DPW
CD
I
Key:
TBA = To be added.
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