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USASMDC public release review #6024 May 6, 2016

Engineering Technical, Operational and Support Services (ETOSS)

W9113M-11-D-0003

Delivery Order #0018

Draft Final Removal Action Memorandum

Carlos Power Plant Site

U.S. Army Garrison-Kwajalein Atoll (USAG-KA) Republic of the Marshall Islands

Site ID CCKWAJ-004

July 2016

Submitted By:

Bering-KAYA Support Services

4600 DeBarr Road, Suite 200

Anchorage, AK 99508

907-334-8307

DISTRIBUTION A. Approved for public release: distribution unlimited.

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W9113M-11-D-0003 TO 0018 Draft Final Removal Action Memorandum (RAM) Carlos Power Plant Site

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TABLE OF CONTENTS

EXECUTIVE SUMMARY .......................................................................................................ES-1

1.0 INTRODUCTION ........................................................................................................... 1-1

1.1 Project Information .............................................................................................. 1-1 1.2 Physical and Environmental Setting .................................................................... 1-1

1.2.1 Environmental Setting ............................................................................. 1-1 1.2.2 Climate ..................................................................................................... 1-2 1.2.3 Regional Geology .................................................................................... 1-2 1.2.4 Soil Characteristics .................................................................................. 1-2 1.2.5 Hydrogeology .......................................................................................... 1-3

1.3 Site Description and History ................................................................................ 1-3 1.3.1 Site History .............................................................................................. 1-4

1.4 Removal Objective and Goals ............................................................................. 1-4

2.0 PRE-REMOVAL ACTION DESIGN ACTIVITIES TO DATE .................................... 2-1

2.1 Previous Investigations ........................................................................................ 2-1 2.1.1 Sivuniq Investigation 2011-2012 ............................................................. 2-1 2.1.2 BKSS Investigation 2015 ......................................................................... 2-2

2.2 Conceptual Site Model ....................................................................................... 2-11 2.3 Cultural Resource Assessment ........................................................................... 2-11

3.0 APPLICABLE REMOVAL ACTION TECHNOLOGIES ............................................. 3-1

3.1 Scope and Purpose of Removal Action ............................................................... 3-1 3.2 Justification for the Proposed Action ................................................................... 3-1 3.3 Technology Identification and Description ......................................................... 3-2

3.3.1 Removal Action Options .......................................................................... 3-2

4.0 ENGINEERING EVALUATION AND COST ANALYSIS OF ALTERNATIVES............................................................................................................ 4-1

4.1 Enhanced Bioremediation .................................................................................... 4-1 4.1.1 Effectiveness ............................................................................................ 4-1 4.1.2 Implementability ...................................................................................... 4-2 4.1.3 Relative Cost ............................................................................................ 4-3

4.2 Bioventing ............................................................................................................ 4-3 4.2.1 Effectiveness ............................................................................................ 4-3 4.2.2 Implementability ...................................................................................... 4-4 4.2.3 Relative Cost ............................................................................................ 4-4

4.3 Soil Vapor Extraction .......................................................................................... 4-5 4.3.1 Effectiveness ............................................................................................ 4-5 4.3.2 Implementability ...................................................................................... 4-5 4.3.3 Relative Cost ............................................................................................ 4-6

4.4 Biopiles ................................................................................................................ 4-6 4.4.1 Effectiveness ............................................................................................ 4-6


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4.4.2 Implementability ...................................................................................... 4-7 4.4.3 Relative Cost ............................................................................................ 4-8

4.5 Landfarming ......................................................................................................... 4-8 4.5.1 Effectiveness ............................................................................................ 4-8 4.5.2 Implementability ...................................................................................... 4-8 4.5.3 Relative Cost ............................................................................................ 4-9

4.6 No Action ............................................................................................................. 4-9 4.6.1 Effectiveness ............................................................................................ 4-9 4.6.2 Implementability .................................................................................... 4-10 4.6.3 Relative Cost .......................................................................................... 4-10

4.7 Comparative Analysis of Alternatives ............................................................... 4-11 4.7.1 Implementability Comparison ............................................................... 4-11 4.7.2 Cost Comparison .................................................................................... 4-12

4.8 Remedy of Record ............................................................................................. 4-13 4.8.1 Estimated Cost of Implementing Remedy of Record ............................ 4-14

4.9 Cultural Resource Evaluation ............................................................................ 4-14

5.0 REMOVAL ACTION SYSTEM DESIGN PROCESS ................................................... 5-1

5.1 Removal Action System Elements ....................................................................... 5-1 5.2 Design and Performance Criteria ......................................................................... 5-1

5.2.1 Cleanup Goals .......................................................................................... 5-1 5.2.2 Performance Criteria ................................................................................ 5-3

5.3 System Design Concepts...................................................................................... 5-4 5.3.1 In-situ Enhanced Bioremediation ............................................................ 5-4 5.3.2 Soil Excavation ........................................................................................ 5-4 5.3.3 Landfarming Initiation ............................................................................. 5-5

5.4 Schedule ............................................................................................................... 5-9

6.0 PROPOSED WORK SUMMARY .................................................................................. 6-1

6.1 Schedule ............................................................................................................... 6-1 6.2 Project Reporting ................................................................................................. 6-1 6.3 Restoration Activities Approach .......................................................................... 6-2

6.3.1 Enhanced Bioremediation ........................................................................ 6-2 6.3.2 Contaminated Soil Excavation and Shipping .......................................... 6-2 6.3.3 Contaminated Soil Landfarming .............................................................. 6-2 6.3.4 Project Reporting ..................................................................................... 6-2

6.4 Sampling and Analysis Plan ................................................................................ 6-3 6.5 Quality Assurance Project Plan ........................................................................... 6-3 6.6 Health and Safety Plan ......................................................................................... 6-3 6.7 Archaeological Monitoring Plan .......................................................................... 6-3

7.0 REFERENCES ................................................................................................................ 7-1


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Tables

Table 1-1 UES Requirements Crosswalk ............................................................................. 1-1

Table 2-1 Frequency and Magnitude of Detected Compounds (Sivuniq, 2011).................. 2-1

Table 2-2 Data Gap Sampling Results (BKSS, 2015a) ........................................................ 2-3

Table 3-1 FRTR Screening Matrix Preferred Options ......................................................... 3-2

Table 3-2 Initial Evaluation of Removal Action Options for the Carlos Power Plant Site ....................................................................................................................... 3-3

Table 4-1 Enhanced Bioremediation Effectiveness Evaluation ........................................... 4-2

Table 4-2 Bioventing Effectiveness Evaluation ................................................................... 4-3

Table 4-3 Soil Vapor Extraction Effectiveness Evaluation .................................................. 4-5

Table 4-4 Biopiles Effectiveness Evaluation ....................................................................... 4-7

Table 4-5 Landfarming Effectiveness Evaluation ................................................................ 4-8

Table 4-6 No Action Effectiveness Evaluation .................................................................. 4-10

Table 5-1 Current COC Concentrations and Screening Criteria .......................................... 5-2

Table 5-2 Proposed Cleanup Levels ..................................................................................... 5-3

Figures

Figure 1-1 Carlos Power Plant Study Area............................................................................ 1-5

Figure 2-1 Carlos Power Plant Site Soil Boring Locations and Detections (as collected by Sivuniq, 2011) ................................................................................. 2-5

Figure 2-2 Carlos Power Plant Site Soil Boring Locations and Detections (Sivuniq, 2011 and BKSS, 2015a) ....................................................................................... 2-7

Figure 2-3 Carlos Power Plant Site Groundwater Sample Locations and Detections (Sivuniq, 2011) .................................................................................................... 2-9

Figure 2-4 Carlos Power Plant Fuel Spill Conceptual Site Model ...................................... 2-12

Figure 5-1 Proposed Maximum Extent of Soil Contamination at the Carlos Power Plant Site .............................................................................................................. 5-7

Attachments

Attachment A Project Schedule

Attachment B BKSS 2015 Investigation Boring Logs

Attachment C Risk-Based Cleanup Level Summary Memorandum


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LIST OF ACRONYMS AND ABBREVIATIONS % percent AEDB-CC Army Environmental Database for Compliance Cleanup AMP Archaeological Monitoring Plan ARSTRAT U.S. Army Forces Strategic Command AST Aboveground Storage Tank ATEC U.S. Army Test and Evaluation Command ATSC Atmospheric Technology Services Company bgs below ground surface °C degrees Celsius CEMML Center for Environmental Management of Military Lands cm2 square centimeters COC contaminant of concern CRE cultural resource evaluation CSM conceptual site model CY cubic yard DoD U.S. Department of Defense DRO diesel range organic DQO data quality objective EE/CA Engineering Evaluation/Cost Analysis EPA U.S. Environmental Protection Agency ESL environmental screening level °F degrees Fahrenheit FN facility number FRTR Federal Remediation Technologies Roundtable FSP Field Sampling Plan GRO gasoline range organics HASP Health and Safety Plan ICBM intercontinental ballistic missile KMR Kwajalein Missile Range KRS Kwajalein Range Services mg/kg milligram per kilogram mph miles per hour


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NFA/RC no further action/response complete O&M operations and maintenance ORNL Oak Ridge National Laboratory PAH polycyclic aromatic hydrocarbon POL petroleum, oil, and lubricants QA quality assurance QAPP Quality Assurance Project Plan QC quality control RAM Removal Action Memorandum RBCL risk-based cleanup level RMI Republic of the Marshall Islands RTS Ronald Reagan Ballistic Missile Defense Test Site SAP Sampling Analysis Plan SI Site Investigation SMDC U.S. Army Space and Missile Defense Command SVE soil vapor extraction SVOC semi-volatile organic compound UES U.S. Army Kwajalein Atoll Environmental Standards USACE U.S. Army Corps of Engineers USAEHA U.S. Army Environmental Hygiene Agency USAG-KA U.S. Army Garrison-Kwajalein Atoll USAKA U.S. Army Kwajalein Atoll USGS U.S. Geological Survey µg/L micrograms per liter


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ES-1

EXECUTIVE SUMMARY

This Removal Action Memorandum (RAM) conforms to U.S. Army Kwajalein Atoll (USAKA) Environmental Standards (UES) 3-6.5.8(g) for proposed removal actions at the Carlos Power Plant Site on Kwajalein Atoll, Republic of the Marshall Islands (RMI). The proposed remediation of petroleum contaminated soil is included as part of the RAM, as a removal action to protect human health and the environment. Risk-based Cleanup Levels were developed using the Tier 2 Pacific Basin Calculator with site-specific parameters and assuming unrestricted land use.

The power plant generated power for telemetry stations located on Ennylabegan (also known as Carlos) Island. As of October 2011, the power plant on Carlos is no longer operational. Diesel contamination of soil has been detected in proximity to the aboveground storage tanks (ASTs) that stored diesel fuel for the plant.

Petroleum contaminated soils were originally reported by workers while digging for construction activities in the area. During the site investigation, investigators identified a small surface spill of diesel fuel next to the storage tanks as a source of soil and groundwater contamination. Contaminants of concern (COCs) include diesel range organics (DRO) and polycyclic aromatic hydrocarbons (PAHs) in soil and DRO in groundwater.

Since the facility is out of service, uncontrolled, and potential residential exposures can occur, removal actions are appropriate. Seven treatment and disposal alternatives were evaluated for the removal action of contaminated soils near the ASTs:

Alternative 1 – No Action

Alternative 2 – Enhanced Bioremediation

Alternative 3 – Bioventing

Alternative 4 – Soil Vapor Extraction

Alternative 5 – Biopiles

Alternative 6 – Landfarming

Alternative 7 – Incineration

The evaluation includes comparison of effectiveness, implementability, and costs to determine the preferred option for this site. After evaluation and comparison, it was determined in-situ enhanced bioremediation, possibly in combination with landfarming, provides the best overall cleanup strategy in terms of effectiveness, implementability, and cost. The recommended actions will mitigate contaminant migration risks in soil and groundwater. In-situ enhanced bioremediation through the addition of nutrients and oxygen to the soil will efficiently degrade contamination. This alternative may include excavation and removal of the most highly contaminated soil and transport to the Kwajalein landfarm for treatment using ex-situ bioremediation. The need to remove any soil will be determined based on the rate of degradation achieved through in-situ enhanced bioremediation and other conditions encountered in the field. . As necessary, after the removal action event is complete, quarterly monitoring will be performed for 2 years. If in-situ remediation is incomplete, additional monitoring will be performed for 3


ES-2

years, followed by a 5-year review and report to document the reduction of contamination on-site.

The soil removal and remediation action is planned for mid- to late-2016. The approximate cost for this alternative is provided below. The in-situ enhanced bioremediation, and potential supplemental excavation and landfarming are estimated to cost approximately $124,000. Remediation of the site should provide response completion by the middle of 2018.


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1.0 INTRODUCTION

1.1 Project Information

The United States Army Garrison-Kwajalein Atoll (USAG-KA) proposes to remediate soil contaminated with petroleum hydrocarbons and nonhalogenated semi-volatile organic compounds (SVOCs) (for polycyclic aromatic hydrocarbons [PAHs]) near Facility Number (FN) 6006 on the island of Ennylabegan, also known as Carlos. The Army Environmental Database for Compliance Cleanup (AEDB-CC) denotes Carlos as site CCKWAJ-004.

This document is described as a Removal Action Memorandum (RAM) pursuant to U.S. Army Kwajalein Atoll Environmental Standards (UES) 3-6.5.8(g). Table 1-1 presents a crosswalk for the UES-required elements included in this RAM.

Table 1-1 UES Requirements Crosswalk

UES Requirement Section

RAM - §3-6.5.8(g) (1)(i) Identify source and nature of contamination Risk estimation Extent of threat Evaluation of factors

2.0 5.2.1 2.0 4.0

(1)(ii) Site background 1.3, 2.0 (1)(iii) Engineering Evaluation/Cost Analysis (EE/CA) Sampling and Analysis Plan (SAP) Quality Assurance Project Plan (QAPP) Health and Safety Plan (HASP)

4.0 6.4 6.5 6.6

(1)(iv) Schedule Attachment A

(1)(v) Resource damage restoration 5.0

(2) Review by Appropriate Agencies -

(3) Waste management 6.0

1.2 Physical and Environmental Setting

1.2.1 Environmental Setting

Kwajalein Atoll is located in the western chain of the Republic of the Marshall Islands (RMI) in the Pacific Ocean, just west of the international dateline. The atoll is 2,100 nautical miles southwest of Honolulu, Hawaii and approximately 4,200 nautical miles southwest of San Francisco, California (see Figure 1-1). Less than 700 miles north of the equator, Kwajalein Atoll is in the latitude of Panama and the southern Philippines, and in the longitude of New Zealand (2,300 miles south), and the Kamchatka Peninsula of the former Soviet Union (2,600 miles north). Kwajalein, at the atoll’s southern tip, and Roi-Namur, at its northern extremity, are the principal islands of the USAG-KA. The two islands are 50 miles apart; multiple other islands used by USAG-KA are situated between these two islands. Carlos Island is located approximately 9 miles northwest of Kwajalein Island and was used by USAG-KA as a support


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telemetry station with its own power plant. By 2011, operations of the FN 6007 power plant and associated FN 6006 Fuel Tanks had ceased.

1.2.2 Climate

Kwajalein Island has a marine tropical climate characterized by warm and humid conditions. A relatively dry windy season occurs from mid-December to mid-May, with a wet calm season occurring from mid-May to mid-December. The island receives approximately 100 inches of rainfall a year, over 70 percent (%) of which occurs in the form of showers during the wet season. Thunderstorms are infrequent on Kwajalein and only occur an average of 12 days a year. Additionally, tropical storms with sustained winds of 40 to 74 miles per hour (mph) typically only impact the atoll once every 4 to 7 years (ATSC/RTS, 2015). Yearly rainfall totals can vary considerably (59 to 138 inches/year) (Gingerich, 1992). The wettest month on Kwajalein is generally September (11.82 inches), whereas February is typically the driest month with a monthly average of 3.73 inches. The maximum monthly average temperature occurs in September (87 degrees Fahrenheit [°F]) with the minimum monthly temperature (85.6°F) occurring in January. Prevailing winds are from the east year-round. Humidity on Kwajalein is relatively high year-round, with an average annual humidity of approximately 80% (Sivuniq, 2010).

1.2.3 Regional Geology

The detailed geology of Kwajalein Atoll is primarily based on shallow boring logs prepared by the U.S. Army Corps of Engineers (USACE) and drilling logs prepared during the construction of monitoring wells by the U.S. Geological Survey (USGS) (Hunt, 1995).

Atolls have been studied intensively since the 1940s, and general models of atoll geology and hydrology have emerged. Shallow subsurface materials are mainly unconsolidated, reef-derived, carbonate sediments (sand, gravel, and rubble) with lesser amounts of consolidated rock (coral-algal boundstone, sandstone, conglomerate, and recrystallized limestone) (Hunt, 1995). Sediments of different ages are separated by erosional unconformities, which commonly are marked by soils and leached zones (USGS, 1963).

Studies on Kwajalein Island have shown that the lagoon side of the island consists of unconsolidated sediments that are thicker and contain a greater proportion of low-permeability back-reef sand than the ocean side. Drilling logs suggest a greater proportion of coarse, high-permeability rubble on the ocean side (Hunt, 1995). Conditions are expected to be similar for Carlos Island.

1.2.4 Soil Characteristics

Core samples and drilling logs at Kwajalein Island indicate mostly unconsolidated carbonate sediments down to approximately 100 feet below ground surface (bgs), with hard layers being more prevalent on the ocean side of the island (Hunt, 1995); Sivuniq and BKSS encountered similar conditions on Carlos Island during their respective investigations (Sivuniq, 2011 and BKSS, 2015a).


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1.2.5 Hydrogeology

The thick accumulation of limestone layers, unconformities caused by sea level changes over time, and tidal activity play an important role in the fresh groundwater dynamics. Groundwater is very shallow throughout the atoll; a thin freshwater lens lies atop the brackish groundwater on the largest islands, including Kwajalein and Roi-Namur. Lens thickness is proportional to island width and rate of groundwater recharge, and inversely proportional to hydraulic conductivity (Hunt, 1995).

The groundwater lens was identified as thickest near the lagoon (on Kwajalein Island), where unconsolidated sediments were thickest and contained a greater proportion of low-permeability back-reef sand. The lens was thinner near the ocean, where drilling logs suggested a greater proportion of coarse, high-permeability rubble and where core samples of conglomerate were obtained at a shallower depth than at a more lagoon-ward site (Hunt, 1995).

Groundwater flow paths radiate out from groundwater mounds near the center of the islands. The shallow depth to groundwater and the high permeability of the soils make the groundwater systems of the Kwajalein Atoll islands highly vulnerable to contamination by chemicals (USAEHA, 1991).

Studies on Kwajalein Island indicate that aquifer tidal efficiency (i.e., the ratio of feet of tidal change to feet of change in aquifer water level) increases with depth and proximity to the ocean and lagoon shores, and is somewhat higher on the ocean side (Hunt, 1995). This included areas of native soil and areas created with dredge fill.

On Carlos Island, Sivuniq measured depth to groundwater between 3.3 and 6.3 feet bgs. Groundwater conductivity measurements performed during previous groundwater sampling indicate that the aquifer salinity is too high to be used as a potable water source. Additionally, the small size of the island may limit the quantity of usable groundwater and prevent its development as a drinking water source.

1.3 Site Description and History

The U.S. Army control of Kwajalein Atoll was established in 1964 after being transferred from the U.S. Navy. The Navy operated the facility from 1944 to 1964 after the U.S. liberation of the atoll from the Japanese during World War II. The USAG-KA/Kwajalein Missile Range (KMR) was renamed as the Ronald Reagan Ballistic Missile Defense Test Site (RTS) on June 15, 2001.

RTS is a subordinate activity of the U.S. Army Space and Missile Defense Command/U.S. Army Forces Strategic Command (SMDC/ARSTRAT), headquartered in Huntsville, Alabama. Command of the site, with regard to its range mission as an element of the Department of Defense’s (DoD) Major Range and Test Facility Base (DoD Directive 3200.11), is exercised under funding guidance from the U.S. Army Test and Evaluation Command (ATEC).

The installation supports the RTS in support of theater missile defense, ballistic missile defense, and intercontinental ballistic missile (ICBM) testing. Kwajalein Atoll also has a missile and space objects tracking mission utilizing an array of powerful radar dishes located on Roi-Namur Island. In addition, Kwajalein Atoll supports other DoD training activities as well as commercial space launch operations.


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1.3.1 Site History

The Carlos power plant generated power for telemetry stations located on Carlos Island. As of October 2011, the power plant on Carlos is no longer operational.

Petroleum contaminants were originally discovered by workers while digging for construction activities in the area. Sivuniq performed a Site Inspection (SI) to evaluate the nature and extent of contamination in the area, and identified the diesel fuel aboveground storage tanks (ASTs) as the source of soil and groundwater contamination (Sivuniq, 2011). The investigation included a soil gas survey, direct push soil sampling, and low-flow groundwater sampling. Analytical results show soil and minor groundwater contamination from diesel fuel, centered on the existing diesel fuel ASTs; this area was also the historical location of former ASTs. Figure 1-1 presents the Carlos power plant site overview and study area.

1.4 Removal Objective and Goals

Per UES 3-6.5.8(g)(3), the scope of the removal action involves the mitigation of contamination which may pose undue harm or threat to human health or the environment prior to the completion of removal action activities. Target contaminants in soil (with cleanup criteria in milligrams per kilogram [mg/kg]) include: benzo(a)anthracene (1.6 mg/kg), naphthalene (223 mg/kg), and diesel range organics (DRO) (500 mg/kg). Though some low-level contaminants were detected in groundwater, only one detection of DRO (adjacent to the ASTs) was above the groundwater cleanup level of 640 micrograms per liter (µg/L). Due to its high salinity and relative lack of abundance, groundwater on Carlos Island is not used as a water source; however, it is proposed that cleanup of the groundwater will be achieved by treating the source of DRO contamination through soil removal and enhanced bioremediation. If USAG-KA demobilizes from Carlos, future residents may choose to use the groundwater, and they should be notified of the potential risks.

Primary considerations are the stability of the wastes and the potential for public contact with the hazardous materials/wastes. This RAM describes actions to minimize or remove the hazard indicated by the presence of contaminants in the subsurface.

The soil remediation is considered important but not time critical as the affected facilities are no longer in use and there are currently no plans for additional construction. In spite of this, rapid and efficient mitigation of contamination is important as it must be accomplished before contaminant concentrations can be reduced to risk-free levels.


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Figure 1-1 Carlos Power Plant Study Area


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2-1

2.0 PRE-REMOVAL ACTION DESIGN ACTIVITIES TO DATE

2.1 Previous Investigations

2.1.1 Sivuniq Investigation 2011-2012

An SI was conducted by Sivuniq from 2011 through 2012 to evaluate the nature and extent of contamination in the vicinity of the Carlos Power Plant Site. The investigation, which included soil gas, soil, (Figure 2-1 and 2-2) and groundwater (Figure 2-3) sampling revealed that soil and groundwater contamination remains at the site. Soil boring locations shown as not sampled on the figure developed by Sivuniq (Figure 2-1), were field screened for soil gas first and then determined further sampling was unnecessary. Based on the work by Sivuniq, the DRO contamination has not migrated much more than 25 feet from the AST footprint. The primary contaminant in soil and groundwater is DRO; other contaminants of concern (COCs) identified were benzo(a)anthracene and naphthalene (in soil only). The frequency and range of detected compounds are presented in Table 2-1. Samples were also taken for bioremediation and physical parameters; these are discussed as part of the engineering evaluation in Section 4.0.

Sampling indicated contamination centers around the ASTs. These tanks were installed in 2006 to replace the original ASTs used for the same purpose. Surface soil (0 to 2 feet bgs) screening indicates the presence of low-level hydrocarbon contamination. Subsurface soil sampling shows the accumulation of DRO at the water table surface, between 3 and 6 feet bgs depending on the depth to groundwater at that specific location of the island. Because DRO is less dense than water, downward migration is halted by the saline groundwater, preventing the DRO from penetrating much further than the water table surface. Because DRO was detected in one groundwater sample, it can be reasonably assumed that DRO exists in soils at the water table surface and smear zone (zone of water table elevation fluctuation, likely from tidal influences) with minor contamination of the shallow groundwater by the DRO.

Table 2-1 Frequency and Magnitude of Detected Compounds (Sivuniq, 2011)

Soil

Compound Frequency Range of detects

(mg/kg) Average of detects

(mg/kg) Screening Criteria (mg/kg) Industrial1 Residential1

2-Methylnaphthalene 6 / 32 0.014 - 25.5 6.71 4,100 310 Acenaphthene 7 / 32 0.010 - 2.22 0.676 33,000 3,400 Acenaphthylene 20 / 32 0.001 - 0.645 0.106 132 133 Anthracene 17 / 32 0.001 - 2.16 0.373 170,000 17,000 Benzo(a)anthracene 11 / 32 0.003 - 0.338 0.093 2.9 0.16 Benzo(a)pyrene 7 / 32 0.004 - 0.058 0.028 2.9 0.16 Benzo(b)fluoranthene 8 / 32 0.005 - 0.133 0.055 2.1 0.15 Benzo(g,h,i)perylene 4 / 32 0.009 - 0.041 0.023 272 273 Benzo(k)fluoranthene 7 / 32 0.002 - 0.048 0.021 21 1.5 Chrysene 8 / 32 0.003 - 0.026 0.016 210 15 Dibenzo(a,h)anthracene 3 / 32 0.007 - 0.013 0.010 0.21 0.015

Fluoranthene 18 / 32 0.002 - 0.441 0.085 22,000 2,300

Fluorene 9 / 32 0.001 - 1.53 0.437 22,000 2,300

Indeno(1,2,3-cd) pyrene 4 / 32 0.009 - 0.035 0.021 2.1 0.15


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Table 2-1 Frequency and Magnitude of Detected Compounds (Sivuniq, 2011) (Continued)

Soil (Continued)



(mg/kg) Screening Criteria (mg/kg)

Naphthalene 7 / 32 0.001 - 7.96 1.93 17 3.8 Phenanthrene 13 / 32 0.004 - 8.97 1.46 112 113 Pyrene 20 / 32 0.002 - 1.35 0.229 17,000 1,700 DRO 20 / 33 0.412 – 38,100 3,930 4402 963 Gasoline Range Organics (GRO)

13 / 36 0.016 - 59.2 15.1 4002 1003

Groundwater

Compound Frequency Range of detections

(µg/L) Screening Criteria

(µg/L)4

1,2-Dichlorobenzene 1 / 5 0.25 600 1,3,5-Trimethylbenzene 1 / 5 0.10 875 Ethylbenzene 2 / 5 0.19 - 0.2 700 Isopropylbenzene 1 / 5 0.2 Not available Naphthalene 1 / 5 15.3 246 n-Butylbenzene 1 / 5 0.53 7805 n-Propylbenzene 1 / 5 0.25 5305 Xylene (total) 3 / 5 0.15 - 0.24 10,000 sec-Butylbenzene 1 / 5 0.22 Not available tert-Butylbenzene 1 / 5 0.16 Not available DRO 1 / 5 1,310 6406 1 Primary soil screening levels obtained from USEPA Regional Screening Level Table for industrial and residential land use

(EPA, 2011) 2 Secondary soil screening levels for commercial/industrial land use obtained from Pacific Basin Environmental Screening Level

Guidance, shallow soils with groundwater not a current or potential drinking water source (PACIFIC, 2009) 3 Secondary soil levels obtained for unrestricted land use from Pacific Basin Environmental Screening Level (ESL) Guidance,

shallow soils with groundwater not a current or potential drinking water source (PACIFIC, 2009) 4 Primary groundwater screening criteria obtained from USAKA Environmental Standards, Maximum Contaminant Levels

(USAKA, 2014) 5 Secondary groundwater screening criteria obtained from USEPA Regional Screening Level Table, for Tapwater (EPA, 2011) 6 Tertiary groundwater screening criteria obtained from Pacific Basin Environmental Screening Levels Guidance for sites with

groundwater not a current or potential drinking water source (PACIFIC, 2009) Compounds with any maximum detection that exceed screening criteria are presented with bold typeface in this table. Compounds identified as Contaminants of Concern are highlighted yellow in this table.

2.1.2 BKSS Investigation 2015

BKSS performed a supplemental investigation in June 2015 to fill data gaps remaining from the 2011 Sivuniq investigation (BKSS, 2015a). Thirteen (13) additional soil borings were advanced and samples were collected surrounding the ASTs to further define the extent of contamination (Table 2-2). These samples encircled the locations where Sivuniq had previously detected elevated levels of DRO contamination. The additional borings confirmed DRO contamination at this site originates from the power plant fuel storage ASTs, and has stayed relatively near to the source area; within 40 feet of the AST footprint. Of the 13 sample locations, only one exceeded the UES screening criteria for DRO, indicating low rates of contaminant migration. See the BKSS 2015 investigation boring logs in Attachment B.


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Table 2-2 Data Gap Sampling Results (BKSS, 2015a)

Sample ID Sample Date Analyte/Compound Detected Result

(mg/kg)

Laboratory Reporting Limit

(mg/kg)

UES Standard (mg/kg)

Exceedance (vs. UES)

007-0615-SB1-04 6/18/2015 Diesel Range Organics [C10-C28] 3.4 2.4 500 No

007-0615-SB2-04 6/18/2015 Diesel Range Organics [C10-C28] 17 2.5 500 No

007-0615-SB3-04 6/18/2015 Diesel Range Organics [C10-C28] 280 12 500 No


007-0615-SB5-04 6/18/2015 Diesel Range Organics [C10-C28] 44,000 1,400 500 Yes









007-0615-SB-DUP1 6/18/2015 Diesel Range Organics [C10-C28] 300 13 500 No

UES Exceedances are highlighted yellow in this table.


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Figure 2-1 Carlos Power Plant Site Soil Boring Locations and Detections (as collected by Sivuniq, 2011)


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Figure 2-2 Carlos Power Plant Site Soil Boring Locations and Detections (Sivuniq, 2011 and BKSS, 2015a)


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2-9

Figure 2-3 Carlos Power Plant Site Groundwater Sample Locations and Detections (Sivuniq, 2011)


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2.2 Conceptual Site Model

Based on historical information and data collected by the SI and supplemental investigation, Figure 2-4 summarizes the Conceptual Site Model (CSM) for the Carlos Power Plant Site.

Results from the groundwater piezometer immediately adjacent to the release point show detectable groundwater contamination. Water quality (conductivity) measurements performed during groundwater sampling suggest the water is brackish, containing dissolved salts at approximately 3-4 times the upper limit for drinking water. The groundwater on Carlos would not be suitable for drinking water purposes. Therefore, exposure pathways to residents from ingesting groundwater were excluded.

Although no in-situ human health risks are identified, secondary environmental exposures (such as groundwater discharge to the lagoon) are possible. The potential groundwater COCs have been identified to ensure they do not degrade marine water quality levels defined in Section 3-2 of the UES.

Potentially complete human health pathways related to each receptor are as follows:

Current / Future Installation personnel:

o Dermal contact to marine water or sediment

o Dermal contact to groundwater

o Dermal contact to and ingestion of subsurface soil

Current residents:


Future residents:

o Ingestion of biota


o Dermal contact to groundwater

o Dermal contact to and ingestion of subsurface soil

Screening levels used to determine COCs for the risk assessment reference occupational and residential land-use scenarios to encompass risk due to current and potential future exposures.

2.3 Cultural Resource Assessment

During the Sivuniq SI, archaeological monitoring was completed by the Center for Environmental Management of Military Lands (CEMML); archaeological information was obtained from their report (CEMML, 2011). Of the 53 soil borings advanced on the Carlos Power Plant Site during the SI, only five contained artifacts, consisting of non-diagnostic historic debris such as synthetic fibers, rusted metal, and glass. The soil on the surface contained no cultural materials; this is generally true of the soil borings observed at this site. BKSS provided archaeological monitoring during their supplemental investigation in 2015; no artifacts were noted by the archaeologist (BKSS, 2015a).


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Figure 2-4 Carlos Power Plant Fuel Spill Conceptual Site Model

Installation Personnel Residents

Current

SOURCE INTERACTION RECEPTORS

Fuel ASTs

ACTIVITY RELEASE MECHANISM TRANSPORT &

MIGRATION MECHANISMS

EXPOSUREMEDIA

EXPOSUREROUTES

Diesel

Figure 2-4: Carlos Power Plant Fuel Spill Conceptual Site Model

SECONDARY SOURCEPRIMARY SOURCE HUMAN HEALTH

Release of Diesel Fuel

Surface

Fugitive DustGeneration (Wind

Entrainment)

Human Activities

Run-Off (Precip)

Air

Surface Soil

Inland SurfaceWater/Sediment

Inhalation

Dermal Contact

Ingestion

Dermal Contact

Ingestion

Ingestion

Dermal Contact

Ingestion

Dermal Contact

Groundwater

Subsurface Soil

LeachingSubsurface

Current Future Future

Key

Complete Pathway

Incomplete Pathway

Surface SoilMarine

Water/Sediment

Potentially Complete Pathway

Biota Ingestion

Dermal Contact


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3.0 APPLICABLE REMOVAL ACTION TECHNOLOGIES

3.1 Scope and Purpose of Removal Action

The scope of the removal action at the Carlos Power Plant Site includes using in-situ bioremediation technologies to degrade the contamination and mitigate the secondary transport of the previously released petroleum liquids within the soil. If necessary, based on the rate of contaminant degradation and other conditions, removal of the former fuel ASTs and concrete slab and removal of the most highly contaminated soil for treatment at the Kwajalein landfarm will be performed to complete the remediation of the contaminated soil surrounding the point of release.

Delineation of the contamination at the Carlos Power Plant Site through sub-surface soil samples revealed the highest concentration of COCs near the fuel storage tanks. Subsurface soil sampling shows the accumulation of DRO at the water table surface, between 3 and 6 feet bgs depending on the depth to groundwater at that specific location of the island. Samples below 6 feet were not submitted for laboratory analysis; soils became saturated with water between 5 and 7 feet bgs and showed no signs of DRO contamination. Piezometers, set to depths from 6.5 to 8.5 feet bgs, provided groundwater samples from the topmost portion of the water table. Analyses of groundwater revealed the highest levels of fuel constituents occur directly adjacent to the ASTs with a concentration of 1.3 mg/L.

Soil COCs include DRO and PAH compounds (benzo(a)anthracene and naphthalene); DRO is the sole COC in groundwater.

The practicability of any removal action option depends on factors related to the type of contamination, site characteristics, cost, and performance. Removal action options were assessed using the Treatment Technologies Screening Tool developed by the Federal Remediation Technologies Roundtable (FRTR, 2007). The FRTR is an interagency work group that exchanges information between government agencies responsible for remediation of environmental sites. The screening tool grades removal action technologies on criteria such as cost, performance, and logistical requirements. This information is continually updated in response to new technologies.

Technologies were selected from the FRTR Screening Matrix primarily based on the ability to remediate DRO (“Fuels” in the screening matrix), although secondary consideration was given to the ability to remediate PAHs (nonhalogenated SVOCs). Technologies considered above average for these two contaminant groups were then researched further before the final technologies were selected for in-depth analysis (described below).

3.2 Justification for the Proposed Action

Sampling of soils and groundwater during the SI shows contamination remains from petroleum releases at the Carlos Power Plant Site. COCs in soil and groundwater are all fuel-related (DRO and PAH compounds). Additional data show that nutrient levels are lower in the contaminated areas; this is an indicator that natural (aerobic) bioremediation has occurred, but is likely limited by a scarcity of available oxygen and nutrients. Without removal action efforts, concentrations of contaminants at the site will likely degrade very slowly due to reduced bacteria populations.


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Without intervention, contamination in the soil and groundwater provides an ongoing threat to the surrounding environment. The actual impacted area is relatively small, but any future development around FN 6006 or FN 6007 may result in contact with these contaminants and adverse health effects. The groundwater is considered unsuitable for drinking water use, but may be used as a source of water for future residents. While minimally impacted, groundwater may also slowly discharge dissolved contaminants to the lagoon and reef flat.

3.3 Technology Identification and Description

Preliminary technologies provided by the FRTR Screening Matrix are presented in Table 3-1. The following options were selected from all available choices based on having above average performance for “Fuels” and “Nonhalogenated SVOCs.” It is important to note that this table represents an ideal situation and does not take into account the increased costs associated with work conducted on Kwajalein Atoll. Site-specific costs of the preferred removal action option are discussed in Section 4.0.

Table 3-1 FRTR Screening Matrix Preferred Options

Black = Above AverageGray = Average

White = Below Average D

evel

opm

ent S

tatu

s

Tre

atm

ent T

rain

Relative Overall Cost &

Performance

Ava

ilab

ilit

y

Non

halo

gena

ted

SV

OC

s

Fue

ls

O&

M

Cap

ital

Sys

tem

Rel

iabi

lity

&

Mai

ntai

nabi

lity

Rel

ativ

e C

osts

Tim

e

In situ Biological Treatment

No Action

Bioventing

Enhanced Bioremediation

In situ Physical/Chemical Treatment Soil Vapor Extraction

Ex situ Biological Treatment (assuming excavation) Biopiles

Landfarming

Ex situ Thermal Treatment (assuming excavation) Incineration Notes: Adapted from FRTR, 2007

3.3.1 Removal Action Options

The potential removal action options were evaluated at a screening-level to determine relative effectiveness, comparative cost, and their ability to reduce contaminant loading to soil and groundwater. The results are summarized in Table 3-2. Following is a description of the technologies associated with the proposed removal action options. No action, enhanced bioremediation, bioventing, and soil vapor extraction (SVE) are in-situ technologies; and landfarming, biopiles, and incineration are ex-situ technologies and require excavation of contaminated media and backfilling with clean materials.


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Table 3-2 Initial Evaluation of Removal Action Options for the Carlos Power Plant Site

Option Description Effectiveness Rationale Cost

Qualification (Reason)

Recommended for Further Evaluation

No-Action No supplement to site conditions; relies on natural processes

Poor Site remains the same; with the exception of natural processes, contaminants continue to impact soil and groundwater.

None Yes

In-Situ Technologies

Enhanced Bioremediation

Add nutrients to enhance the existing naturally-occurring biodegradation of contaminants. Use tilling or plowing to deliver nutrients to the top layers of soil in-situ. If necessary, use Geoprobe or similar to deliver at depth.

Good

Studies have shown that indigenous microorganisms on Kwajalein Atoll have the ability to degrade the COCs. The addition of nutrients to the surface and/or subsurface will enhance this natural bioremediation and contaminant desorption from subsurface materials. High annual rainfall totals will provide delivery of nutrients to deeper soils and groundwater.

Low Yes

Bioventing Install injection system to provide air flow through in-situ contaminated area

Good

The addition of oxygen will enhance naturally-occurring biodegradation. Requires installation, operation, and maintenance of system and piping throughout contaminated area to provide low flow-rate air source.

Medium-High Yes

Soil Vapor Extraction

Install injection and extraction system to force air through the in-situ contaminated area and collect extracted vapors.

Poor

The addition of oxygen will enhance naturally-occurring biodegradation. Does not work with PAHs. Does not treat groundwater. Requires installation, operation, and maintenance of system and piping throughout contaminated area to provide air injection and extraction. Extracted vapors may require treatment.

High No


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Table 3-2 Initial Evaluation of Removal Action Options for the Carlos Power Plant Site (Continued)

Option Description Effectiveness Rationale Cost

Qualification (Reason)

Recommended for Further Evaluation

Ex-Situ Technologies

Landfarming

Excavate soil from Carlos and transport to another location (Kwajalein landfarm). Use tilling or plowing to deliver nutrients to the soil ex-situ.

Good (This option

would only be effective in

addition to an in-situ

alternative.)

Contamination source area removal will lessen potential public contact, as well as decrease contamination available to migrate to soil and groundwater. Any remaining contamination may require additional in-situ treatment. Does not treat groundwater. Requires excavation and transport of soil to a suitable area in another location for treatment.

Medium-High Yes

Biopile Treatment

Excavate soil from Carlos and transport to another location (Kwajalein landfarm). Install injection system to provide air flow through ex-situ biopiles.

Good (This option



alternative.)

Contamination source area removal will lessen potential public contact, as well as decrease contamination available to migrate to soil and groundwater. Any remaining contamination may require additional in-situ treatment. Does not treat groundwater. Requires excavation and transport of soil to a suitable area in another location for treatment. Requires installation, operation, and maintenance of system and piping in biopiles to provide air source.

Medium-High Yes

Incineration

Excavate soil from Carlos and transport to another location (potentially Kwajalein). Incinerate soil to remove contamination.

Good (This option



alternative.)

Contamination source area removal will lessen potential public contact, as well as decrease contamination available to migrate to soil and groundwater. Does not treat groundwater. Any remaining contamination may require additional in-situ treatment. Requires excavation and transport of soil to a suitable area in another location for treatment. Requires installation, operation, and maintenance of incineration system. Requires fuel and high energy demand to operate. Off-gases and incinerator residuals will likely require treatment.

High No


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3.3.1.1 No Action

No action is the absence of providing supplemental removal action technologies and relies upon natural processes to perform degradation of contamination. This alternative is generally used on sites where contamination is low enough for natural processes to remediate contaminants, where control of the site is maintained by the property owner and no off-site migration is anticipated, and where there is no immediate threat to human health or the environment.

3.3.1.2 Enhanced Bioremediation

Enhanced bioremediation is a process in which indigenous or inoculated microorganisms degrade organic contaminants found in soil and groundwater, converting them to innocuous end products. Nutrients are added to the surface and subsurface to enhance natural bioremediation and contaminant desorption from subsurface materials (FRTR, 2007). This technology can be used in-situ on its own or in addition to another technology or used in tandem with an ex-situ technology; e.g., excavation of areas of high concentrations.

3.3.1.3 Bioventing

Bioventing is an in-situ process that stimulates the natural biodegradation of aerobically degradable compounds in soil by providing supplemental oxygen to existing microorganisms; enhancing degradation of the contamination within the soil. Bioventing uses low air flow rates to provide only enough oxygen to sustain microbial activity. Oxygen is most commonly supplied through direct air injection into contamination zones in soil (FRTR, 2007).

Bioventing is similar to enhanced bioremediation in that both are in-situ treatments that use the addition of nutrients to stimulate the growth and reproduction of aerobic microorganisms that degrade the petroleum constituents adsorbed in soil. While enhanced bioremediation can provide oxygen to the bacteria by tilling or plowing the nutrients into the top layers of the contaminated soil, bioventing uses forced air to aerate the soils. Bioventing aeration is typically done with air injection or extraction through slotted or perforated piping placed throughout the contaminated area.

3.3.1.4 Soil Vapor Extraction

SVE is an in-situ remediation technology in which a vacuum is applied to the soil to induce the controlled flow of air and remove volatile and some semi-volatile contaminants from the soil. The gas leaving the soil may need to be treated to recover or destroy the contaminants, depending on local regulations. This technology has proven to be very effective on fuels, but mostly ineffective when treating nonhalogenated SVOCs (FRTR, 2007).

3.3.1.5 Landfarming

Landfarming is a full-scale ex-situ technology that requires excavation and placement of contaminated soils at an offsite location. Landfarming is an above-ground remediation technology for soils that reduces concentrations of petroleum constituents through biodegradation. This technology usually involves spreading excavated contaminated soils in a thin layer on a liner or the ground surface and stimulating aerobic microbial activity within the soils through aeration and/or the addition of minerals, nutrients, and moisture. As with biopiles,


3-6

the enhanced microbial activity results in degradation of adsorbed petroleum product constituents through microbial respiration (EPA, 1994d).

3.3.1.6 Biopile Treatment

Biopile treatment is an ex-situ technology performed above-ground with excavated contaminated soils at an offsite location. Biopiles are used to reduce concentrations of petroleum constituents in excavated soils through the use of enhanced biodegradation and bioventing. This technology involves heaping contaminated soils into piles and stimulating aerobic microbial activity within the soils through the aeration and/or addition of minerals, nutrients, and moisture. The enhanced microbial activity results in degradation of adsorbed petroleum-product constituents through microbial respiration (EPA, 1994c).

Biopiles are similar to landfarms in that they are both above-ground, engineered systems that use oxygen, generally from air, to stimulate the growth and reproduction of aerobic bacteria which, in turn, degrade the petroleum constituents adsorbed to soil. While landfarms are aerated by tilling or plowing, biopiles are aerated most often by forcing air to move by injection or extraction through slotted or perforated piping placed throughout the pile (EPA, 1994c).

3.3.1.7 Incineration

High temperatures (870 to 1,200 degrees Celsius [ºC]) are used to volatilize and combust (in the presence of oxygen) halogenated and other refractory organics in hazardous wastes. Often auxiliary fuels are employed to initiate and sustain combustion. Off gases and combustion residuals may require treatment depending upon local air quality regulations.


4-1

4.0 ENGINEERING EVALUATION AND COST ANALYSIS OF ALTERNATIVES

Each technology described above was analyzed for effectiveness, implementability, and relative cost, as prescribed by UES 3-6.5.8(g)(1)(iii) for RAMs. A summary of the technologies carried forward is presented below, along with a comparison of the alternatives.

These costs are relative to each other in order to compare technologies and can be used for comparative purposes since they are based upon the same assumptions.

A summary of each technology is presented below, along with a comparison of the alternatives. Differences between these technologies are described in respective implementability assessments included below. Note that enhanced in-situ bioremediation is a supplemental component of the biopile and landfarming alternatives. Therefore, the in-situ effectiveness of enhanced bioremediation dictates the effectiveness of both the biopile and landfarming alternatives.

4.1 Enhanced Bioremediation

4.1.1 Effectiveness

The U.S. Environmental Protection Agency (EPA) recommends an initial screening for effectiveness before a more detailed analysis is conducted (EPA, 2004). For enhanced bioremediation systems, the initial screening focuses on the following overall assessments for viability:

Free mobile product is present and the corrective action plan does not include plans for its recovery.

Potentially excessive risks to human health or the environment have been identified and the corrective action plan does not include a supplemental mitigation plan.

The target contaminant zone includes unstratified dense clay.

None of these conditions are true for the Carlos Power Plant Site. While concentrations of contaminants are likely above the saturation point in soil, enhanced bioremediation is still viable over the range of concentrations encountered. Since initial screening has confirmed enhanced bioremediation will potentially be effective, a more detailed analysis of effectiveness was conducted.

Table 4-1 summarizes the effectiveness of enhanced bioremediation for known on-site conditions.


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Table 4-1 Enhanced Bioremediation Effectiveness Evaluation

Parameter Effective Reason

Indigenous Microbial Populations / Population Density

Yes

A 1992 study to evaluate bioremediation potential for petroleum, oils, and lubricant (POL) soils from the Kwajalein Power Plant (Oak Ridge National Laboratory [ORNL], 1992) concluded that biodegradation of soil contaminants was possible using indigenous microbes.

Moisture Content Yes Soil moisture is amenable to bacterial growth.

Temperature Yes Soil temperatures on Kwajalein are between 20 and 36°C, which is well within the range for viable bacterial growth.

Oxygen Availability Yes A 1992 study (ORNL, 1992) on bioremediation on Kwajalein found addition of air/oxygen to be important in maintaining microbial density.

Soil pH Yes Soil on Carlos tends to have a neutral to slightly alkaline pH.

Exogenous Materials Yes Soil boring logs indicate few exogenous materials are present in the soils.

Nutrient Supply Yes Previous studies (ORNL, 1992) of bioremediation in soil on Kwajalein confirmed that the addition of nutrients led to definite increases in microbial population density.

Contaminant Constituents and Concentration

Yes DRO and associated compounds are generally amenable to biodegradation. Concentrations are below 50,000 mg/kg.

Intrinsic Permeability Yes Enhanced bioremediation is effective if the intrinsic permeability is greater than 10-9 square centimeters (cm2) (EPA, 2004), which estimates indicate is the case.

4.1.2 Implementability

The applicable advantages and disadvantages of enhanced bioremediation are described below, as derived from generalized advantages and disadvantages (EPA, 2004).

Advantages:

Enhances natural biodegradation through native microorganisms

Produces no significant wastes

Requires a low amount of energy

Works well with moist and sandy soils, the type found on Carlos

Relatively inexpensive, does not require excavation

Can complement more aggressive ex-situ technologies

Causes minimal disturbance to site operations

Has simple operation and monitoring requirements

Likely more reliable than other more active removal action technologies

Disadvantages:

May have longer removal action time frames than more aggressive approaches


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Requires additional oxygen as well as nutrients

May not be able to reduce contaminants to very low concentrations

Typically requires long-term monitoring of residual contamination in soil and groundwater

High constituent concentrations may initially be toxic to microorganisms

May not be fully effective on all petroleum hydrocarbons and product additives

Unprotected on-island facilities (if necessary) may be at risk of being damaged or creating a contamination pathway to the local population

Lack of established transportation service to Carlos for both personnel and equipment, potentially incurring additional costs for operations and maintenance (O&M)

4.1.3 Relative Cost

Enhanced bioremediation has the potential to be a very low-cost option. Costs for this technology could be as limited as the price of the nutrients and the addition of those nutrients through tilling. It is possible that tilling on its own will not provide enough oxygen to reach the depth of the water table. In this case additional oxygen will be required in the form of vents (bioventing), chemicals, or other oxygen source.

4.2 Bioventing

4.2.1 Effectiveness

Table 4-2 summarizes the effectiveness of bioventing for known on-site conditions.

Table 4-2 Bioventing Effectiveness Evaluation


Microbial Presence Yes A 1992 study to evaluate bioremediation potential for POL soils from the Kwajalein Power Plant (ORNL, 1992) concluded that biodegradation of soil contaminants was possible using indigenous aerobic microbes.

Moisture Content Yes Soil moisture is amenable to bacterial growth.



Depth to Groundwater Yes Groundwater depth on Carlos ranges from 3.3-6.3 feet bgs.

Nutrient Supply Yes* Previous studies (ORNL, 1992) of bioremediation in soil on Kwajalein confirmed that the addition of nutrients (including air/oxygen) led to definite increases in microbial population density.



Intrinsic Permeability Yes Bioventing is effective if the intrinsic permeability is greater than 10-9 cm2 (EPA, 2004), which estimates indicate is the case.

*Previous studies indicate the microbial population was sufficient to achieve natural remediation, but benefited noticeably from the addition of nutrients, increasing the speed of remediation.


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The applicable advantages and disadvantages of bioventing are described below, as derived from generalized advantages and disadvantages (EPA, 1994b).

Advantages:

Enhances natural biodegradation through native microorganisms

Proven effective at a wide range of sites

Works well with moist and sandy soils, the type found on Carlos

Uses readily available equipment; easy to install

Creates minimal disturbance to site operations; can be used to address inaccessible areas

Requires short treatment times: usually 6 months to 2 years

Easily combinable with other technologies

Very effective on fuels and nonhalogenated SVOCs (i.e., PAHs)

Does not require soil removal

Disadvantages:

Not effective with excessive moisture content in soil

Does not address groundwater contamination

May require off-gas treatment

High constituent concentrations may initially be toxic to microorganisms

Cannot always achieve very low cleanup standards

Requires system installation and maintenance

Unprotected on-island facilities may be at risk of being damaged or creating a contamination pathway to the local population

Regular and continued system monitoring and maintenance required

Lack of established transportation service to Carlos for both personnel and equipment, potentially incurring additional costs for O&M

4.2.3 Relative Cost

Bioventing has the potential to be a medium-high cost option. The costs associated with bioventing are essentially made up of the cost of materials, the number of vents, and the depth of vents. Due to the high water table on Carlos, the vents would be constructed horizontally rather than vertically, reducing the total number required. Fencing would be required to maintain security for system components.


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4.3 Soil Vapor Extraction

4.3.1 Effectiveness

Table 4-3 summarizes the effectiveness of soil vapor extraction for known on-site conditions.

Table 4-3 Soil Vapor Extraction Effectiveness Evaluation


Soil Type Yes Soils on Carlos are made up of sand and gravel.

Soil Structure Yes Soil on Carlos is free of impermeable layers or other conditions that would disrupt air flow.

Moisture Content Yes Soils on Carlos have a low moisture content.


Depth to Groundwater Yes Groundwater depth on Carlos ranges from 3.3-6.3 feet bgs.


Limited SVE is generally more successful when applied to the more volatile petroleum products such as gasoline as compared to diesel. Not applicable to PAHs.

Intrinsic Permeability Yes SVE is effective if the intrinsic permeability is greater than 10-9 cm2 (EPA, 2004), which estimates indicate is the case.


The applicable advantages and disadvantages of soil vapor extraction are described below, as derived from generalized advantages and disadvantages (EPA, 1994a).

Advantages:

Proven performance; readily available equipment; easy installation

Short treatment times (0.5 to 2 years)

May provide oxygen to enhance natural bioremediation

Easily combined with other technologies (e.g., air sparging, bioremediation)

Can be used under buildings and other locations that cannot be excavated

High system reliability

Does not require soil removal

Disadvantages:

More successful with lighter, more volatile contaminants such as gasoline as compared to diesel

Does not address nonhalogenated SVOC (i.e., PAH) remediation

Concentration reductions greater than about 90% are difficult to achieve

May require costly treatment for atmospheric discharge of extracted vapors


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Air emission permits may be required

Only treats unsaturated-zone soils; other methods may also be needed to treat saturated-zone soils and groundwater

Due to high water table, special controls will be required (e.g., horizontal wells or groundwater pumping)

Porous soils and shallow groundwater could result in a system that frequently draws in atmospheric air as opposed to soil vapors; a cap could be necessary


Unprotected on-island facilities may be at risk of being damaged or creating a contamination pathway to the local population


Lack of established transportation service to Carlos for both personnel and equipment, potentially incurring additional costs for O&M

4.3.3 Relative Cost

SVE has the potential to be a high cost option. Costs are dependent on the size of the site, the nature and amount of contamination, and the hydrogeological setting (EPA, 1994a). These factors affect the number of wells, the blower capacity and vacuum level required, and the length of time required to remediate the site. A requirement for off-gas treatment adds significantly to the cost. Water is also frequently extracted during the process and usually requires treatment prior to disposal. Due to the high water table on Carlos, the vents would be constructed horizontally rather than vertically, reducing the total number required. Fencing would be required to maintain security for system components.

4.4 Biopiles

4.4.1 Effectiveness

The effectiveness of biopiles as a removal action technology is contingent upon supplementing with an in-situ technology. The general factors that are discussed in Section 4.1 for the effectiveness of enhanced bioremediation should be considered as supplemental actions. Table 4-4 summarizes the factors of effectiveness of biopiles for known on-site conditions.


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Table 4-4 Biopiles Effectiveness Evaluation

Parameter Effective? Reason

Soil Texture Yes Soils on Carlos are made up of sand and gravel.


Moisture Content Yes Soils on Carlos have a low moisture content.


Nutrient Concentrations Yes Previous studies (ORNL, 1992) of bioremediation in soil on Kwajalein confirmed that the addition of nutrients led to definite increases in microbial population density.

Microbial Population Density Yes

A 1992 study to evaluate bioremediation potential for POL soils from the Kwajalein Power Plant (ORNL, 1992) concluded that biodegradation of soil contaminants was possible using indigenous aerobic microbes.


The applicable advantages and disadvantages of biopiles are described below, as derived from generalized advantages and disadvantages (EPA, 2004).

Advantages:

Relatively simple to design and implement

Does not require extensive O&M


Effective on organic constituents with slow biodegradation rates

Requires less land area than landfarming

Utilizes indigenous microorganisms to accomplish bioremediation

New biopile site on Kwajalein would be more secure and accessible

Can be a closed system—vapor emissions can be controlled

Would reduce the risk of in-situ contaminant migration towards lagoon

Disadvantages:

Excavation and transport of contaminated soil is required

Requires backfilling of excavation and imported fill likely sourced from Kwajalein Island

Static treatment may lead to less uniform treatment than processes that involve periodic mixing

Additional remediation may still be required on-site as excavation may not be successful for contaminated material below the water table



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Requires system installation and maintenance.


4.4.3 Relative Cost

Biopile has the potential to be a medium-high cost option. Biopiles are relatively simple and require few personnel for operation and maintenance, and costs are generally dependent on the contaminant, procedure to be used, need for additional pre- and post-treatment, and need for air emission control equipment. However, soil excavation, transportation, and backfill are a significant portion of the relative cost as moving equipment and soil between islands and providing backfill will result in a significant cost increase to this relatively simple alternative.

4.5 Landfarming

4.5.1 Effectiveness

The effectiveness of landfarming as a removal action technology is contingent upon supplementing with an in-situ technology. The general factors that are discussed in Section 4.1 for the effectiveness of enhanced bioremediation should be considered as supplemental actions. Table 4-5 summarizes the effectiveness of landfarming for known on-site conditions.

Table 4-5 Landfarming Effectiveness Evaluation

Parameter Effective? Reason

Soil Texture Yes Soils on Carlos are made up of sand and gravel.


Moisture content Yes Soils on Carlos have a low moisture content.


Nutrient Concentrations Yes Previous studies (ORNL, 1992) of bioremediation in soil on Kwajalein confirmed that the addition of nutrients led to definite increases in microbial population density.

Microbial Pop. Density Yes

A 1992 study to evaluate bioremediation potential for POL soils from the Kwajalein Power Plant (ORNL, 1992) concluded that biodegradation of soil contaminants was possible using indigenous aerobic microbes.


The applicable advantages and disadvantages of landfarming systems are described below, as derived from generalized advantages and disadvantages (EPA, 1994d).

Advantages:

Relatively simple to design and implement

Does not require extensive O&M


Effective on organic constituents with slow biodegradation rates


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Landfarm site on Kwajalein would be more secure and accessible

Does not require overly complicated or expensive infrastructure

Would reduce the risk of in-situ contaminant migration towards lagoon

Disadvantages:

Excavation and transport of contaminated soil is required

Requires backfilling of excavation

A larger amount of space is required than for biopiles

Volatile constituents tend to evaporate rather than biodegrade during treatment

Additional remediation may still be required on-site as excavation may not be successful for contaminated material below the water table




4.5.3 Relative Cost

Landfarming has the potential to be a medium-high cost option. Landfarms are relatively simple and require few personnel for operation and maintenance and costs are generally dependent on the contaminant, procedure to be used, and need for additional pre- and post-treatment. However, soil excavation, transportation, and backfill are a significant portion of the relative cost as moving equipment and soil between islands and providing backfill will result in a significant cost increase to this relatively simple alternative.

4.6 No Action

4.6.1 Effectiveness

The no action alternative would rely on natural attenuation of contaminants to accomplish the clean-up goals for the site. It is possible that the natural attenuation of contaminants on Carlos would be efficient and timely enough to negate the need for any additional removal action efforts. The FN 6007 power plant is no longer in use, and with the decommissioning of the FN 6006 fuel tanks, the source of contamination will be removed as well. A 1992 study (ORNL, 1992) showed that native microorganisms on Kwajalein Atoll are capable of degrading the COCs naturally.

Table 4-6 summarizes the effectiveness of the no action alternative for known on-site conditions.


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Table 4-6 No Action Effectiveness Evaluation


Indigenous microbial populations / population density

Yes A 1992 study to evaluate bioremediation potential for POL soils from the Kwajalein Power Plant (ORNL, 1992) concluded that biodegradation of soil contaminants was possible using indigenous microbes.

Moisture content Yes Soil moisture is amenable to bacterial growth.

Temperature Yes Soil temperatures are between 10° and 45°C.

Oxygen availability No A 1992 study (ORNL, 1992) on bioremediation on Kwajalein found addition of air/oxygen to be important in maintaining microbial density.


Exogenous materials Yes Soil boring logs indicate few exogenous materials are present in the soils.

Nutrient supply No

Previous studies (ORNL, 1992) of bioremediation in soil on Kwajalein confirmed that the addition of nutrients led to definite increases in microbial population density; thereby increasing the speed of remediation.

Contaminant constituents and concentration


Intrinsic permeability Yes Bioremediation is effective if the intrinsic permeability is greater than 10-9 square cm2 (EPA, 2004), which estimates indicate is the case.


The applicable advantages and disadvantages of the no action alternative are described below.

Advantages:

The most cost-effective alternative to implement

Effective on organic constituents with high to moderate biodegradation rates


No construction or additional infrastructure required

Disadvantages:

Possibility that contamination levels never reach minimum clean-up criteria

Much slower remediation time-frame; greater than 2 years

Potential for contamination to migrate into the lagoon

Increased risk for human interaction with contaminants

4.6.3 Relative Cost

There is no cost associated with this alternative.


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4.7 Comparative Analysis of Alternatives

4.7.1 Implementability Comparison

The remote location of Carlos Island creates a unique situation for comparison of removal action technologies. In-situ remediation may allow the entire contaminant plume to be treated in one place at one time, and does not require excavation and transport of soils. If used independently, in-situ enhanced bioremediation requires the least amount of infrastructure construction, time, and materials, and is the simplest technology to implement. However, simply tilling in the nutrient and oxygen mixture may not be sufficient for the additives to reach the water table, and experimentation would be necessary to determine effectiveness. Both bioventing and SVE require vent construction, O&M, and site security. The infrastructure would require some form of additional security on Carlos to prevent damage or creating a contamination pathway to the local population. O&M on Carlos could become relatively expensive as there is no regular transportation service to the island. Enhanced bioremediation and bioventing are known to be successful when used to remediate petroleum hydrocarbons and nonhalogenated SVOCs. Bioventing and SVE would likely increase the speed at which the contamination degrades, and thus the time required to achieve contamination levels below the UES standards, but that may be unnecessary for the size, location, and severity of the contamination when factoring in additional costs for these technologies. While known to be successful with petroleum hydrocarbon remediation, SVE does not address the need for nonhalogenated SVOC remediation. Additionally, if off-gas treatment is required for the SVE system, additional facilities, monitoring, and maintenance will be required. Due to these limitations, SVE is not considered as a viable option for remediation on Carlos.

Instead of in-situ remediation, contaminated soils on Carlos could be excavated and transported off-site for remediation through landfarming or biopile. This process would be more expensive overall due to the transportation of contaminated soils and backfill between islands. Advantages would include faster mitigation of contaminant migration, reduced exposure risks to the local population and wildlife, and decreased time required to achieve contamination levels below UES action levels; however, because COC contamination has been detected in and below the water table surface at the site, in-situ remediation would be required to supplement the removal action associated with these alternatives. This alternative may be unnecessary for the size, location, and severity of the contamination when factoring in additional costs for this technology. In this case, the material and associated treatment infrastructure could be transported to a more accessible location with less risk of potential damage. If the excavated soils are treated on Kwajalein Island, they would be more accessible to operation and maintenance personnel.

A “source” removal or excavation of only the most densely contaminated soils would allow multiple technologies to be used where they would be most effective. In this case, material from 0-3 feet bgs is not contaminated above action levels requiring treatment, so it may be used as backfill once the underlying contaminated soils have been removed. The soils excavated from 3-6 feet bgs, with concentrations above the action level, would be transported to the existing Kwajalein landfarm for ex-situ bioremediation. The remaining contaminated soil would undergo in-situ enhanced bioremediation through the addition of nutrients and oxygen releasing compounds at the bottom of the excavation prior to backfill. The removal of the primary source of contamination would improve access for nutrient/oxygen addition to the remaining less contaminated material surrounding the excavation allowing for better sustainment of the


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biological processes necessary to complete remediation. Removal of the primary DRO source of contaminants, subsurface soils between 3 and 6 feet bgs, will not only expedite the remediation of subsurface soils, but is anticipated to effectively remediate the groundwater contamination at the site.

4.7.2 Cost Comparison

Due to the high costs of the excavation, transport and backfilling associated with ex-situ alternatives, creating a sizable cost difference between in-situ and ex-situ remediation, the in-situ technologies will be considered first. Of the three in-situ technologies, enhanced bioremediation, bioventing, and soil vapor extraction, enhanced bioremediation is the sole option that does not require structural facilities. Typical costs for enhanced bioremediation range from $20 to $80 per cubic yard (CY) of soil. Factors that affect cost include the soil type and chemistry, type and quantity of amendments used, and type and extent of contamination (FRTR, 2007). Bioventing requires the installation of lateral vents and a blower system. Typical costs for bioventing range from $709 to $742 per CY of soil. Factors that affect cost include contaminant type and concentration, soil permeability, well spacing and number, pumping rate, and off-gas treatment. Fortunately, this technology does not require expensive equipment and relatively few personnel are involved in the operation and maintenance of a bioventing system (FRTR, 2007).

SVE requires the installation of extraction wells and construction of a vapor catchment and treatment facility. Typical costs for SVE range from $944 to $1,100 per CY of soil. Key cost drivers include the amount of material being treated, soil type, and off-gas treatment, as well as amount of contamination. A barrier such as a geomembrane is often required on the ground surface to reduce the amount of ambient air drawn in by the extraction system. Water is also frequently extracted during the process and usually requires treatment prior to disposal, further adding to the cost (FRTR, 2007).

Due to the added costs of materials, construction, O&M of facilities required for both bioventing and SVE, enhanced bioremediation is the most cost-effective approach available.

Costs for landfarming and biopiles are approximately the same price, as the O&M required for landfarming is approximately equivalent to the infrastructure for biopiles and both require the same soil excavation, transport, and backfill. However, implementability for landfarming is more feasible than for biopiles, as additional batches of soil (from Carlos Island or from other sites around Kwajalein Atoll) can be processed easily with landfarming, whereas biopiles are constructed specifically for each batch of soil. Sampling is also more difficult with biopiles due to the infrastructure added to the body of the soil. Therefore, potential future costs for biopiles would likely be higher than that for landfarming.

Impacted soil excavation and transportation to Kwajalein and clean backfill soil transportation to Carlos essentially make ex-situ remediation infeasible. The resources required to transport the volume of materials (approx. 300 CY) between islands required to perform ex-situ remediation are non-existent without significant interruption to USAG-KA’s mission. Therefore, in-situ remediation is preferred over ex-situ remediation.


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4.8 Remedy of Record

Comparisons of the technologies in terms of implementability and relative cost indicate using available in-situ technologies would allow the most implementable, efficient, and cost-effective approach. Of the in-situ technologies considered, enhanced bioremediation is the most practicable when considering the evaluation criteria. It can be implemented with minimal resources, capital costs, and if managed properly would provide effective results in reducing DRO and PAH concentrations to below cleanup goals. In-situ enhanced bioremediation would be less efficient at areas with contaminant levels high enough to be toxic to the bacteria. In these areas the bacteria will have to slowly work their way in from less contaminated areas, potentially extending the remediation timeframe. If it is determined areas of high concentrations are resistant to in-situ remediation, these areas may be mixed in place with adjacent, less contaminated soils, or possibly excavated and placed in a landfarm or biocell for ex-site remediation.

Multiple feasibility studies and data collected during the initial SI (Sivuniq, 2011) have determined that conditions on the Kwajalein Atoll are amenable for enhanced bioremediation. The installation of bioventing or SVE wells is not necessary as the high permeability of soils on Carlos and shallow depth of the water table combine to make enhanced bioremediation viable. Additionally, due to the porosity of the soil and the likelihood the prior diesel releases resulting in the soil contamination at the site were deflected by the concrete pad beneath the ASTs, it has been determined unnecessary to remove the ASTs and the concrete pad at the site to meet cleanup goals.

Design concepts for this treatment train are provided in Section 5.0.

Section 6.0 provides the management plan for implementation, including the work plan elements required by the UES.

Proposed project phases include:

Phase 1: Initiate in-situ bioremediation by applying nutrient compounds across the original source area and till the area to mix the nutrients into the subsurface or, if necessary, utilize a Geoprobe drill rig or similar to insert nutrients at depth. After tilling, it is anticipated the high amount of annual rainfall at the atoll will provide transport for the nutrients to work their way through the soil and eventually reach the water table and below. This process will eliminate the need for any significant infrastructure installation, keeping overall costs down considerably.

Phase 2: Monitor soil remediation progress on-site through Geoprobe borings to depths greater than 6 feet bgs, as appropriate. If the bioremediation process seems slow or to have stalled, apply additional nutrient compound in the same manner as the initial application. Progress will be monitored until the DRO concentrations at the site are below 100 mg/kg, approved unrestricted use concentrations.

Phase 3: If the in-situ remediation process appears unsuccessful in degrading high concentrations of DRO within a reasonable timeframe, identify the extent of most affected areas and mix or excavate the source of contaminated soil. Based on prior investigations, soil from 0 to 3 feet bgs is not contaminated and will be excavated, stored on-site, and used for backfill of the excavation. Soil from 3 to 6 feet bgs shows the highest concentrations of DRO and the volume determined necessary to remove will be transported to the existing landfarm on Kwajalein Island


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where it will undergo ex-situ enhanced bioremediation. Nutrients and oxygen releasing compounds will be added to the remaining soil surrounding the excavation to improve in-situ remediation. The excavation will be backfilled with the clean soil stored on site and additional soil brought from Kwajalein Island.

4.8.1 Estimated Cost of Implementing Remedy of Record

After evaluation and comparison, it was determined that in-situ enhanced bioremediation and if necessary, landfarming, provides the best overall cleanup strategy in terms of effectiveness, implementability, cost, and time.

As necessary, after the removal action event is complete, quarterly monitoring will be performed for 2 years. If in-situ remediation is incomplete, additional monitoring will be performed for 3 years, followed by a 5-year review and report to document the reduction of contamination on-site.

The soil remediation action is planned for mid- to late-2016. The enhanced bioremediation, and supplemental excavation and landfarming are estimated to cost approximately $124,000. These costs include soil excavation and removal and landfarming for the maximum volume of contaminated soil within the source area and represent maximum cost for the action. Remediation of the site should provide response completion by the middle of 2018.

4.9 Cultural Resource Evaluation

A dig permit was submitted for the investigative work performed by BKSS in 2015, and it was determined that a Cultural Resource Evaluation (CRE) was not necessary for the work proposed at that time (BKSS, 2015a). Based on that finding, it is anticipated that a CRE would not be required to perform the proposed removal action related work at the site; however, as in compliance with the previous dig permit, BKSS will have an archaeologist present during excavation work greater than 6 inches and all work will be performed in accordance with the approved BKSS project Archaeological Monitoring Plan (AMP).


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5.0 REMOVAL ACTION SYSTEM DESIGN PROCESS

This section describes the system elements, system design concepts, and schedule for the removal action system design. The design and construction of removal action system components will be performed concurrently, where appropriate, to expedite the removal action schedule and allow system design and schedule to be flexible as contaminant concentrations change.

5.1 Removal Action System Elements

The primary elements of the selected technologies to be used in the removal action described in Section 4.0 include:

In-situ treatment of soil and groundwater exceeding UES levels on Carlos with nutrients and oxygen

If in-situ treatment is stalled after repeated nutrient addition and monitoring cycles:

o Excavation of source area soils with highest levels of contamination

Transport of contaminated soils to Kwajalein Island landfarm Long-term O&M

o Monitoring of residual DRO soil concentrations through the use of Geoprobe sampling until defensible data are collected to show in-situ remediation is complete

o Addition of nutrients through tilling and/or Geoprobe borings based on sampling results

5.2 Design and Performance Criteria

5.2.1 Cleanup Goals

Section 3-6.5.8(g)(vii) of the UES indicates “The scope of a removal action involves the “mitigation of contamination,…which may pose undue harm or threat...to remove/minimize the impending hazard.” Under ideal circumstances, the removal action provides complete removal of the source. For situations where site conditions do not allow complete removal; adequate removal provides hazard reduction to levels that protect human health and the environment.

Previously collected chemical data and screening criteria identified potential COCs summarized in Table 5-1. The chemicals are grouped as compounds within specific fuel fractions (DRO) and PAHs.


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Table 5-1 Current COC Concentrations and Screening Criteria

Soil



(mg/kg) Screening Criteria (mg/kg) Industrial1 Residential1

Benzo(a)anthracene 11 / 32 0.003 - 0.338 0.093 2.9 0.16

Naphthalene 7 / 32 0.001 - 7.96 1.93 17 3.8

DRO 20 / 33 0.412 – 38,100 3,930 5002 2603 Groundwater

Compound Frequency Range of detections

(µg/L) Screening Criteria

(µg/L)4,5

DRO 1 / 5 1,310 6406 1 Primary soil screening levels obtained from USEPA Regional Screening Level Table for industrial and residential land use

(EPA, 2011) 2 Secondary soil screening levels for commercial/industrial land use obtained from Pacific Basin Environmental Screening

Level Guidance, shallow soils with groundwater not a current or potential drinking water source (PACIFIC, 2013) 3 Secondary soil levels obtained for unrestricted land use from Pacific Basin ESL Guidance, shallow soils with groundwater not

a current or potential drinking water source (PACIFIC, 2013) 4 Primary groundwater screening criteria obtained from USAKA Environmental Standards, Maximum Contaminant Levels

(USAKA, 2011) 5 Secondary groundwater screening criteria obtained from USEPA Regional Screening Level Table, for Tapwater (EPA, 2011) 6 Tertiary groundwater screening criteria obtained from Pacific Basin Environmental Screening Levels Guidance for sites with groundwater not a current or potential drinking water source (PACIFIC, 2013).

The SI (Sivuniq, 2011) uses UES appropriate screening criteria to provide a generic baseline for comparing measured results and potential health threats under conservative exposure scenarios. Because the EPA Preliminary Remediation Goals /Regional Screening Level tables did not provide risk-based screening criteria for petroleum products, Sivuniq screened the DRO soil analytical results against Pacific Basin environmental screening level (ESL) guidance for shallow soils with groundwater not a current or potential drinking water source (Sivuniq, 2011).

Screening values for DRO in groundwater were based on tertiary groundwater screening criteria obtained from Pacific Basin ESL guidance for sites with groundwater not a current or potential drinking water source (Sivuniq, 2011), as well. Screening levels are not designed to consider site-specific receptor groups and environmental conditions and are developed on the most conservative scenarios for human or ecological receptor exposure; e.g., 8-hour per day exposure to a media over a 30-year period. As a rule, screening levels identify the potential for a COC to impact a receptor and once the potential is identified, more realistic exposures scenarios are evaluated and used to develop remedial action (cleanup) goals.

Based upon the anticipated exposure of humans and ecological receptors to the identified COCs for this site the following cleanup goals were identified. RBCLs for site COCs were developed to provide adequate protection of human health and the environment in accordance with Section 3-6.5.8(r) of the UES. Through the considerations of the multiple regulatory sources referenced in Section 3-6.5.8(l)(2) of the UES and the anticipated level of exposure to human receptors, Table 5-2 provides a summary of cleanup levels that provide for site-appropriate assessment considering site-specific receptors and environmental conditions. The risk evaluation considered a resident’s exposure to COCs in soil via ingestion, dermal contact, and inhalation of soil vapors and particulates. The RBCLs were developed using the Pacific Basin Tier 2 calculator spreadsheet (Guam EPA, 2012) for soil direct exposure action levels, and unrestricted land use


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was utilized. The calculator was modified to site-specific conditions. The site-specific parameters and calculations are provided in the Summary Memorandum included as Attachment C. The Pacific Basin Tier 2 RBCLs for unrestricted use with 2-foot contamination thickness were identified as the cleanup levels for the Carlos Power Plant Site (Table 5-2).

Table 5-2 Proposed Cleanup Levels

Soil



(mg/kg)

Proposed Soil Cleanup Level (mg/kg)1

Residential

Benzo(a)anthracene 11 / 32 0.003 - 0.338 0.093 1.6

Naphthalene 7 / 32 0.001 - 7.96 1.93 223

DRO 20 / 33 0.412 – 38,100 3,930 500 Groundwater

Compound Frequency Range of detections (µg/L) Proposed Groundwater Cleanup Level (µg/L)2

DRO 1 / 5 1,310 640 All soil cleanup levels, screening levels and concentrations are in units of mg/kg. Site-specific soil concentrations greater than the risk-based cleanup level (RBCL) are shaded. 1 The RBCLs for DRO, were capped at their saturation limit, which is a default option in the Pacific Basin Tier 2 calculator. 2 Proposed groundwater cleanup level based on tertiary screening level obtained from Pacific Basin Environmental Screening Levels Guidance for sites with groundwater not a current or potential drinking water source (PACIFIC, 2013).

Based on proposed cleanup levels for the removal action, COCs requiring further action include DRO, benzo(a)anthracene, and naphthalene in soil. There are minor DRO impacts to the groundwater resource, which are anticipated to be addressed through remediation of the soil; in other words, removal of the source and bioremediation of the residue will remediate the impacts to the groundwater.

5.2.2 Performance Criteria

Requirements for measuring the effectiveness of the removal action are described in UES 3-6.5.8(i). Pursuant to UES 3-6.5.8(i)(2) the overall goal of the removal action is to render a No Further Action/Response Complete (NFA/RC) determination for the site. All supporting data and rationale to support this determination shall be documented in a formal report which will be made available for 30 days for public review and comment. This report will detail evidence that removal has been completed and/or that the associated exposure risks have been reduced to acceptable levels. An NFA/RC designation is an endpoint, meaning that all requisite mitigation work and evaluation has been fully implemented.

Effectiveness will be monitored throughout the project to ensure that the endpoint will be a NFA/RC designation; modifications to remedial implementation may be necessary if measured effectiveness is not indicating the endpoint will be achieved in the anticipated two-year timeframe. Quarterly monitoring and reporting will be performed for 2 years or until determined NFA/RC by four sequential quarters of data indicating concentrations below the clean-up goals, whichever is sooner. If NFA/RC is not met in the first 2 years, annual monitoring for 3 additional years may be required, followed by a 5-year review. Monitoring of in-situ remediation will consist of subsurface soil sampling through the use of a Geoprobe or similar to sample COC impacted soil around the excavation zone. Applicable performance criteria for each phase of the


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removal action are described below, along with potential modifications to the process to improve efficiency.

5.2.2.1 Contamination Reduction

The rate of contaminant concentration reduction of the remaining soil contamination on Carlos is a function of the amount of hydrocarbon-degrading bacteria, the amount of available oxygen in the soil and groundwater, and the amount of nutrients available. These components will be monitored through the duration of the removal action through the sampling described above in Section 5.2.2, and augmented on a schedule determined by on-site conditions encountered to optimize site conditions for bioremediation.

5.3 System Design Concepts

This removal action will consist of in-situ enhanced bioremediation for contaminant reduction in soil and groundwater. The general design for this system is described below.

5.3.1 In-situ Enhanced Bioremediation

In-situ enhanced bioremediation will be initiated by using a Geoprobe drill rig or similar equipment to drill between 3 to 6 feet across the source area and introduce nutrients. In addition, nutrient compound will be spread over the surface and tilled in to introduce the nutrients and oxygen to the shallow subsurface. The contamination has been measured in the area around the ASTs, so removal of the ASTs at this point is not necessary. The soils are sandy and porous, so even though the contamination is between 3 and 6 feet bgs, it is anticipated that the surface-applied nutrients will quickly infiltrate to the subsurface with precipitation. The remediation progress will be monitored approximately quarterly. If the bioremediation appears slow or stalled, additional nutrients may be added, or it may be determined that the bioremediation cannot be effective in areas with the highest DRO concentrations. If that occurs, then the extent of the area where the remediation is stalled will be determined and the soil will be aerated or excavated for ex-situ treatment.

5.3.2 Soil Excavation

If soil excavation is determined necessary, and the extent of the area where the enhanced remediation is not effective extends beneath the two ASTs, the ASTs and associated pipelines within the excavation zone will be cleaned and removed. The tanks will be drained, cleaned, capped, or plugged to prevent further leaking or infiltration by precipitation, and set aside from the removal action area for disposition by others. Remaining pipelines heading towards the pier and power plant will be drained and cleaned to remove any remaining contaminant sources and capped. After AST removal is completed, any pipelines within the excavation zone will be cut and removed. The remaining lines will be cleaned and then capped to ensure additional contamination does not occur.

During excavation, soils will be screened onsite with field assays (e.g., PetroFLAG® or similar) to confirm the extent of the excavation. Confirmation samples will be collected post-excavation. All soils accessible and contaminated above the cleanup level from within the area where the in-situ remediation has stalled will be transported to a landfarm treatment cell. Based on analytical data, the soil is clean from the surface to 3 feet bgs and will not be removed from the site; these


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uncontaminated soils will be excavated to reach the contaminated soils beneath, stockpiled, and used for fill material for the excavation.

5.3.3 Landfarming Initiation

The excavated soils will be transported to the landfarm treatment cell for processing. The rate of contaminant concentration reduction is a function of the amount of hydrocarbon-degrading bacteria, the amount of available oxygen in the soil, and the amount of nutrients available. These components will be monitored through the duration of the landfarming, and augmented on a schedule as determined by landfarm sampling results.


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Figure 5-1 Proposed Maximum Extent of Soil Contamination at the Carlos Power Plant Site


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5.4 Schedule

After obtaining all required approvals and authorizations, the in-situ remediation will commence during 2016. Appropriate data will be collected from respective media for verification assessment during the removal action and duration of the in-situ and ex-situ treatment (if initiated).

The in-situ (and if required, ex-situ) contaminated soil will undergo remediation until contaminant concentrations are reduced to below cleanup goals or, potentially for in-situ treatment, until reduction becomes asymptotic (approximately 1-2 years, dependent on site conditions). The duration that will be required for the in-situ treatment is uncertain; however, conditions on Carlos are suitable for bioremediation. Because the soil in the landfarm cell will be contained and able to be easily supplemented, remediation should be readily achieved in the proposed time frame. Sampling will be performed to monitor progress for both in-situ and ex-situ remediation (if performed) of the soils over this time. Data collection, validation, and review will be summarized in status reports on a regular schedule thereafter, with a final summary document upon conclusion of remediation. It is anticipated the in-situ remediation will require quarterly monitoring for 2 years and that remediation will be completed by the end of those 2 years; however, if final concentrations are not met, annual monitoring may be required for an additional 3 years, followed by a 5-year review. The project schedule is presented in Attachment A.


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6.0 PROPOSED WORK SUMMARY

This section summarizes the field activities planned for the removal action activities at the Carlos Power Plant Site, and will outline installation of components described in Section 5.1, as well as associated sampling and monitoring activities. The Work Plan elements identified in previous sections and appendices to this document include screening, sampling, and analysis strategies, safety considerations, operating procedures, and data validation approaches. Specific and detailed procedures for these activities were included in the BKSS project Work Plan (BKSS, 2015b) and will be adapted for future work at this site. If determined necessary, a Removal Action Work Plan will provide site-specific details beyond the generalized discussion presented in this document.

The SAP, presented in Appendix A to the BKSS project Work Plan (BKSS, 2015b), provides generalized procedures related to the collection and analysis of soil and water samples as well as other field activities that will be used by the BKSS field team. The QAPP, presented in Appendix B to the BKSS project Work Plan (BKSS, 2015b), describes the policies, organization, functional activities, and the data quality objectives (DQOs) and measures necessary to obtain adequate data.

The HASP presented in Appendix C to the BKSS project Work Plan (BKSS, 2015b) examines the hazards associated with performing investigative work and describes the practices to be implemented to ensure worker safety.

An AMP is provided in Appendix D to the BKSS project Work Plan (BKSS, 2015b) and addresses the significant concerns related to protecting and preserving cultural and historical resources at the site.

6.1 Schedule

After obtaining all required Stakeholder and Regulatory approvals and authorizations, BKSS will execute the proposed removal action in a timely fashion. Considering approvals and planned USAG-KA activities, it appears the earliest fieldwork could commence is September 2016. The project schedule is located in Attachment A of this document.

6.2 Project Reporting

Data collection, validation, and review will be summarized in status reports on a regular schedule during excavation activities. Post-excavation sampling events both on Carlos and the Kwajalein landfarm will occur quarterly for the first 2 years, then annually the following 3 years with a final 5-year Verification Assessment.

The removal action and remediation of soils should be complete within 2 years after initiation. If there is a delay in the project start time, a semiannual update on the project schedule along with a written status report will be submitted to the appropriate agencies, starting from the date of final approval of this RAM. After completion of the removal action and the assessment of all data, a Verification Assessment Report with accompanying findings and recommendations will be provided to the appropriate agencies for a 30-day review (UES 3-6.5.8(i)(2)).


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6.3 Restoration Activities Approach

Each of the necessary steps of the proposed remedy is outlined below.

6.3.1 Enhanced Bioremediation

The in-situ bioremediation will be performed by introducing nutrients to the subsurface through use of a Geoprobe drilling rig or similar equipment, and spreading the nutrient compound on the ground surface and tilling to mix it into the shallow subsurface. As noted, the soils are porous and sandy, and the surface-applied nutrients are anticipated to percolate with precipitation to the subsurface zone of contamination. The bioremediation activity tends to work inward toward the highest concentrations from areas with lower concentrations, so this approach of applying the nutrients from the surface or shallower depths is anticipated to be effective. The remediation progress will be monitored approximately quarterly, and additional nutrient addition cycles may be necessary based on the monitoring results.

6.3.2 Contaminated Soil Excavation and Shipping

If the in-situ remediation has stalled in part of the source area after multiple nutrient addition cycles and within a reasonable timeframe, contaminated soil may be excavated from the site and placed in a landfarm cell for ex-situ treatment. If the excavation zone extends beneath the FN 6006 ASTs, they must be removed, along with fuel lines within the excavation zone. This includes identifying and locating the pipelines, valves, and associated equipment. The tanks will be drained, cleaned, capped, or plugged to prevent further leaking or infiltration by precipitation, and set aside from the removal action area for disposition by others. Remaining pipelines heading towards the pier and power plant will be drained and cleaned to remove any remaining contaminant sources and capped. The remaining fuel lines will be washed to ensure additional contamination does not occur.

6.3.3 Contaminated Soil Landfarming

Once the excavated soil has been transported to the landfarm, it will be spread out in lifts so that the total thickness is approximately 18 inches. Nutrients will be supplemented during start-up, as deemed necessary, and also each time the soil is tilled. Tilling will occur on a regular schedule. The landfarm cell will be covered unless it is being tilled to prevent runoff and wind erosion.

Contaminant concentrations will be monitored using PetroFLAG® test kits or other petroleum hydrocarbon screening methods. Once concentrations are low enough for the soil to be used as fill material, multi-incremental sampling will be used to confirm the final concentration of contaminants.

6.3.4 Project Reporting

Following contaminant removal, a verification assessment will be conducted to evaluate whether hazards have been adequately mitigated. The verification assessment will include sampling and analysis in consonance with the SAP and QAPP.

Per UES 3-6.5.8(i)(2), the verification assessment and accompanying findings and recommendations will be provided to the appropriate agencies and the public, which will have a period of 30 days for review and comment. If, in conjunction with/following the comment period, USAG-KA determines that an unacceptable risk remains, removal action efforts will be


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continued. In circumstances where it is determined that the immediate hazards have been mitigated, all supporting data and rationale will be documented in a formal report which will be made available for 30 days for public review and comment. The report will indicate which of two possible courses of action is proposed:

1. The mitigation efforts are deemed complete and effective, rendering a determination of NFA/RC; or

2. Potential contamination remaining may be addressed in additional non-time critical removal action efforts.

A final report will address all comments and concerns presented and include a determination of which course of action will be followed.

6.4 Sampling and Analysis Plan

Additional soil and water sampling to monitor remediation progress will follow guidelines set forth in the project Field Sampling Plan (FSP) in accordance with UES 3-6.5.8(i)(1). These guidelines are outlined in the BKSS Work Plan (BKSS, 2015b). The FSP is presented as Appendix A in the BKSS Work Plan (BKSS, 2015b). This FSP will be used with the understanding that field conditions may dictate a change in the plan as written. Field conditions that dictate a change in the FSP will be noted by the Project Manager and presented to the client point of contact for review and approval.

6.5 Quality Assurance Project Plan

A QAPP has been developed to describe the policies, organization, functional activities, and DQOs necessary to ensure that collected data are adequate for the project needs. The QAPP is presented as Appendix B in the BKSS Work Plan (BKSS, 2015b).

BKSS will meet the project-specific DQOs for sampling, analysis, and quality assurance/quality control (QA/QC) by collecting the proper quantities and types of samples, using the correct analytical methodologies, implementing field and laboratory QA/QC procedures, and using various data validation and evaluation processes.

6.6 Health and Safety Plan

A HASP has been developed to identify the anticipated potential hazards associated with performing the field work tasks and describe procedures to be implemented in order to mitigate those hazards and ensure worker safety. The HASP is provided as Appendix C in the BKSS Work Plan (BKSS, 2015b).

6.7 Archaeological Monitoring Plan

An AMP has been developed to address the significant concerns related to protecting and preserving cultural and historical resources at the sites. A qualified professional archaeologist implements the requirements of this Plan. The AMP is provided as Appendix D in the BKSS Work Plan (BKSS, 2015b).


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7.0 REFERENCES

ATSC/RTS, 2015. Weather Station website. http://www.rts-wx.com/climatology/. Accessed 16 January 2015.

BKSS, 2015a. Carlos Power Plant Site Supplemental Investigation and Data Gap Sampling. June.

BKSS, 2015b. Investigation and Remediation of Contaminated Sites at U.S. Army Garrison-Kwajalein Atoll, Task Order Work Plan. Prepared for U.S. Army Space and Missile Defense Command, Huntsville, AL. March 2015.

Center for Environmental Management of Military Lands (CEMML), 2011. Archaeological Monitoring Report. 2011.

Federal Remediation Technologies Roundtable (FRTR), 2007. Remediation Technology Screening Matrix and Reference Guide, Version 4.0. Retrieved 8 December 2015 from http://www.frtr.gov/matrix2/top_page.html

Environmental Protection Agency, Pacific Basin (Pacific), 2009. Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater, Volume 2: Background Documentation for the Development of Tier 1 Environmental Screening Levels, Appendix 1: Detailed Look up Tables. Summer 2008 (updated March 2009).

Guam Environmental Protection Agency. 2012. Pacific Basin Environmental Screening Levels (PBESLs). Rev April 2013. Available online: http://epa.guam.gov/rules-regs/regulations/pacific-basin-environmental-screening-levels/.

Gingerich, S.B., 1992. Numerical Simulation of the freshwater lens on Roi-Namur Island, Kwajalein Atoll, Republic of the Marshall Islands: University of Hawaii Master’s Thesis, August 1992.

Hunt Jr., C.D, Spengler, S.R., and Gingerich, S.B. (Hunt), 1995. Lithologic Influences on Freshwater Lens Geometry and Aquifer Tidal Response at Kwajalein Atoll. Water Resources and Environmental Hazards: Emphasis on Hydrologic and Cultural Insight in the Pacific Rim. American Water Resources Association. June 1995.

Leeson, A. and Hinchee, R.E. (Leeson and Hinchee), 1996. Principles and Practices of Bioventing Volume I: Bioventing Principles. Prepared by Battelle Memorial Institute for U.S. Air Force and U.S. EPA, September, 1996.

Siegrist, R.L. et al. (ORNL, 1991). Bioremediation Demonstration on Kwajalein Island: Site Characterization and On-Site Biotreatability Studies. Oak Ridge National Laboratory, September 1991.

Adler, H.I. et al. (ORNL, 1992). Bioremediation of Petroleum-Contaminated Soil on Kwajalein Island: Microbiological Characterization and Biotreatability Studies. Oak Ridge National Laboratory, May 1992.


7-2

PACIFIC, 2013. Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater, Volume 2: Background Documentation for the Development of Tier 1 Environmental Acton Levels, Appendix 1: Detailed Lookup Tables. Pacific Basin Edition. Guam Environmental Protection Agency, Fall 2012, revised April 2013.

Sivuniq Inc., 2010. Final 2010 Work Plan, Site Investigation of Nine Sites at the U.S. Army Kwajalein Atoll/Reagan Test Site (USAKA/RTS). Republic of the Marshall Islands. United States Army Space and Missile Defense Command. October 2010.

Sivuniq, 2011. Draft Carlos Power Plant Site Investigation Report. November 2011.

U.S. Army Environmental Hygiene Agency (USAEHA), 1991. Soil and Groundwater Contamination Study No. 38-26-K144-91 Kwajalein Atoll. October 1990 – August 1991.

U.S. Army Environmental Center (USAEC), 2002. Federal Remediation Technologies Roundtable Remediation Technologies Screening Matrix and Reference Guide. Version 4.0. http://www.frtr.gov/matrix2/. January 2002.

U.S. Army Kwajalein Atoll (USAKA), 2014. Environmental Standards and Procedures for United States Army Kwajalein Atoll (USAKA) Activities in the Republic of the Marshall Islands. Thirteenth Edition, October 2014.

U.S. Environmental Protection Agency (EPA), 1994a. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, Chapter II: Soil Vapor Extraction. Office of Solid Waste and Emergency Response, Washington, D.C. October 1994.

EPA, 1994b. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, Chapter III: Bioventing. Office of Solid Waste and Emergency Response, Washington, D.C. October 1994.

EPA, 1994c. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, Chapter IV: Biopiles. Office of Solid Waste and Emergency Response, Washington, D.C. October 1994.

EPA, 1994d. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, Chapter V: Landfarming. Office of Solid Waste and Emergency Response, Washington, D.C. October 1994.

EPA, 1995a. Bioventing Principles and Practice Vol. I: Bioventing Principles, Washington D.C. 1995.

EPA, 1995b. Bioventing Principles and Practice Vol. II: Bioventing Design, Washington D.C. 1995.

EPA, 2001. Use of Bioremediation at Superfund Sites. Office of Solid Waste and Emergency Response, Washington, D.C. September 2001.


7-3

EPA, 2004. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers, Chapter XII: Enhanced Aerobic Bioremediation. Office of Solid Waste and Emergency Response, Washington, D.C. May 2004.

EPA, 2011. USEPA Regional Screening Level Table for Industrial and Residential Land Use. Washington D.C. November.

U.S. Geological Survey (USGS), 1963. Subsurface Geology of Eniwetok Atoll. Professional Paper 260-BB, Schlanger, S.O. 1963.


7-4



Attachment A Project Schedule




A-1


A-2



Attachment B BKSS 2015 Investigation Boring Logs



DRILLING INFORMATION

DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:

USCSLITHOLOGYPROFILE/ PID

/ ft.Blows

ppmSOIL DESCRIPTION SAMP.

GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973542.09 788053.04

Kwajalein

Direct Push

72SB01

Carlos

N. Hanrahan

SM

SP

SP

SP

SP

Silty Fine Sand, grass and coconut fibers, some coarse sand,moist, medium dense, 10YR 3/2 very dark grayish brown

Medium Sand, some coral fragments, moist, medium dense,10YR 6/2 light brownish gray

Medium Coral Sand, large coral fragements, moist, mediumdense, 10YR 8/1 white

Fine to Medium Sand, moist, medium dense, 10YR 7/2 light gray

Medium Coral Sand, some coarse, wet, medium dense, 10YR 8/2very pale brown 007-0615

SB1-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973548.22 788057.85

Kwajalein

Direct Push

72SB02

Carlos

N. Hanrahan

SM

SM

SP

SP

SM

Silty Fine Sand, roots, some coral fragments, moist, mediumdense, 10YR 3/3 dark brown

Silty Sand, large coral fragments, moist, medium dense, 10YR6/2 light brownish gray

Medium Coral Sand, large coral fragements, moist, mediumdense, 10YR 8/2 very pale brown

Fine Sand, some coral fragments, moist medium dense, 10YR6/1 gray

Silty Fine Sand, some coarse sand gravel, wet at 50", mediumdense, 10YR 8/2 very pale brown

007-0615SB2-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

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20

25

30

35

40

45

50

55

60

65

70

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973545.42 788065.4

Kwajalein

Direct Push

72SB03

Carlos

N. Hanrahan

SM

SM

SM/SP

SM

Silty Very Fine Sand, some gravel, roots, moist, medium dense,10YR 3/3 dark brown

Silty Medium Sand, coral fragments, moist, medium dense, 10YR6/2 light grayish brown

Slightly Silty Fine Sand, coral fragments, moist, medium dense,10YR 7/3 very pale brown

Silty Very Fine Sand, wet, medium dense, petroleum odor, SB-Dupl

007-0615SB3-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

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20

25

30

35

40

45

50

55

60

65

70

75

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973543.06 788071.89

Kwajalein

Direct Push

76SB04

Carlos

N. Hanrahan

SM

SM

SM

SP

SM/SP

SM/SP

Silty Fine Sand, roots, moist, medium dense, 10YR 3/2 very darkgrayish brown

Silty Sand with coarse and gravel, coral fragments, moist,medium dense, 10YR 5/2 grayish brown

Silty Sand, some coarse, moist, medium dense, 10YR 6/2 lightgrayish brown

Fine to Medium Sand, some large coral fragments, moist,medium dense, 10YR 7/2 light gray

Slightly Silty Sand, moist, medium dense, 10YR 3/1 very darkgray

Slightly Silty Fine Sand, wet, medium dense, slight petroleumodor 007-0615

SB4-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973533.53 788076.41

Kwajalein

Direct Push

79SB05

Carlos

N. Hanrahan

SM

SM

SM

SM

SM

Silty Fine Sand, roots, some gravel and coral fragments, moist,medium dense, 10YR 5/1 gray

Silty Medium Sand, gravel and coral fragments, moist, mediumdense, 10YR 6/1 gray

Silty Sand, large coral fragments, moist, medium dense, slightpetroleum odor, 10YR 7/1 light gray

Silty Sand, gravel and large coral fragments, wet at 44", strongpetroleum odor, 10YR 7/2 light gray

Sitly Fine Sand, wet, medium dense, petroleum odor, 10YR 8/2very pale brown, SB5-04, SB5-04MS, SB5-04MSD, fuel at 60"

007-0615SB5-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973526.48 788069.82

Kwajalein

Direct Push

72SB06

Carlos

N. Hanrahan

SM

SM/SP

SP

SM/SP

SP

Sitly Fine Sand, roots, moist, medium dense, 10YR 5/1 gray

Slightly Silty Sand, sand is fine to medium, coral fragments,moist, medium dense, 10YR 5/1 gray

Medium Coral Sand, some coral fragments, moist, mediumdense, 10YR 8/2 very pale brown

Slightly Silty Fine Sand, gravel and coral fragments, moist,medium dense, 10YR 5/1 gray

Fine to Medium Sand, coral fragments, wet, medium dense,10YR 8/2 very pale brown 007-0615

SB6-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973526.96 788064.10

Kwajalein

Direct Push

80SB07

Carlos

N. Hanrahan

SM

SM

SM/SP

SP

Silty Fine Sand, roots, coral fragments, moist, medium dense,10YR 3/1 very dark gray

Silty Sand, sand is fine to medium, coral and gravel throughout,moist, medium dense, 10YR 7/2 light gray

Slightly Silty Fine Sand, gravel, moist, medium dense, 10YR 7/1light gray

Fine to Medium Sand, coral fragments, wet, medium dense,10YR 7/1 light gray

007-0615SB7-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

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5

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35

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45

50

55

60

65

70

75

80

007-0615

J. Bills

6/18/16

6/18/16

HDR Inc.

GeoProbe

973526.82 788056.19

Kwajalein

Direct Push

80SB08

Carlos

N. Hanrahan

ML

GM

SM/SP

SM

ML/SMSP

SM

SM

Top Soil, silty very fine sand, some gravel, moist, medium dense,10YR 4/2 dark grayish brown

Fine to Medium Gravel, some roots, gravel and coral fragments,moist, 10YR 7/1 light gray

Slightly Silty Very Fine Sand, tarpauline fragments, moist,medium dense, 10YR 7/2 light gray

Silty Medium Sand, gravel and coral fragments, moist, mediumdense, 10YR 7/2 light gray

Silty Very Fine Sand, moist, medium dense, 10YR 7/3 very palebrown

Medium Coral Sand, shell fragments, moist, medium dense,7.5YR 8/3 pink

Silty Fine Sand, some gravel, moist, medium dense, 10YR 7/1light gray

Silty Fine Sand, some shell and coral fragments, wet, mediumdense, 10YR 7/1 light gray

007-0615SB8-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

007-0615

J. Bills

6/19/16

6/19/16

HDR Inc.

GeoProbe

973536.55 788053.86

Kwajalein

Direct Push

90SB09

Carlos

N. Hanrahan

SM

SM

SM

SM

ML/SM

Silty Fine Sand, roots, coral fragments, moist, medium dense,10YR 4/1 dark gray

Silty Fine Sand, some gravel and coral fragments, moist, mediumdense, 10YR 6/2 light brownish gray

Silty Sand with gravel, moist, medium dense, 10YR 6/1 gray

Silty Fine Sand, coral fragments, moist, medium dense, 10YR 6/2light brownish gray

Silty Very Fine Sand, bits of charcoal at 60", wet, medium dense,10YR 7/2 light gray

007-0615SB09-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

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5

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20

25

30

35

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45

50

55

60

65

70

75

80

85

90

95

007-0615

J. Bills

6/19/16

6/19/16

HDR Inc.

GeoProbe

973541.59 788054.28

Kwajalein

Direct Push

86SB10

Carlos

N. Hanrahan

SM

SP

SM

SM

SP

Silty Fine Sand, roots, coral fragments, moist, medium dense,10YR 2/2 very dark brown

Fine to Medium Sand with gravel and coral fragments, someroots, moist, medium dense, 10YR 5/2 grayish brown

Silty Fine Sand, coral fragments, moist, medium dense, 10YR 7/2light gray

Silty Fine Sand, coral fragments, wet at 36", medium dense,10YR 5/1 gray

Fine to Medium Coral Sand, wet, medium dense, 10YR 8/2 verypale brown

007-0615SB10-003


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

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55

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65

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75

80

85

90

95

007-0615

J. Bills

6/19/16

6/19/16

HDR Inc.

GeoProbe

973547.16 788058.55

Kwajalein

Direct Push

96SB11

Carlos

N. Hanrahan

SM

SM/SP

SM

SP

SM/SP

SP

Silty Fine Sand, roots, moist, medium dense, 10YR 3/1 very darkgray

Slightly Silty Medium Sand, gravel, moist, medium dense, 10YR6/2 light brownish gray

Silty Fine Sand, some roots, moist, medium dense, 10YR 6/3 palebrown

Medium Sand with large coral fragments, moist, medium dense,10YR 7/2 light gray

Slightly Silty Medium Sand, some coral fragments, wet at 45",medium dense, 10YR 5/1 gray

Medium Coral Sand, some coral and shell fragments, wet,medium dense, 10YR 8/2 very pale brown

007-0615SB11-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

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55

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80

85

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95

007-0615

J. Bills

6/19/16

6/19/16

HDR Inc.

GeoProbe

788058.55 788070.98

Kwajalein

Direct Push

96SB12

Carlos

N. Hanrahan

SM

SM/SP

SP

SM/SP

SM

SP

Silty Fine Sand, roots, moist, medium dense, 10YR 3/1 very darkgray

Slightly Silty Medium Sand, some gravel, moist, medium dense,10YR 6/2 light brownish gray

Fine to Medium Sand, moist, medium dense, 10YR 7/3 very palebrown

Slightly Silty Medium Sand, moist, medium dense, 10YR 6/2 lightbrownish gray

Silty Fine Sand, some gravel and coral fragments, wet at 46",10YR 5/2 grayish brown

Fine Coral Sand, some shell fragments, wet, medium dense,10YR 8/2 very pale brown 007-0615

SB12-004


DRILLING CO.:

DRILLER:

RIG TYPE:

METHOD OF DRILLING:

SAMPLING METHODS:


/ ft.Blows


GROUND SURF ELV.:

E:

BOREHOLE NO.:

FIELD BOREHOLE LOG

CHECKED BY:

TOTAL DEPTH (IN.):

DEPTH(In.)

PROJECT INFORMATION

PROJECT:

SITE LOCATION:

JOB NO.:

END DATE:

BEGIN DATE:

COORD.: N:

FIELD GEOLOGIST:

Page 1 of 1NOTES:

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007-0615

J. Bills

6/19/16

6/19/16

HDR Inc.

GeoProbe

973542.10 788079.66

Kwajalein

Direct Push

96SB13

Carlos

N. Hanrahan

SM

SM

SM

SP

Silty Fine Sand, roots, coral fragments, moist, medium dense,10YR 4/2 dark grayish brown

Silty Fine Sand, some gravel, moist, medium dense, 10YR 7/2very pale brown

Silty Fine Sand, wet at 41", medium dense, 10YR 2/1 black

Fine to Medium Coral Sand, wet, medium dense, 10YR 8/2 verypale brown

007-0615SB13-004



Attachment C Risk-Based Cleanup Level Summary Memorandum



hdrinc.com 1 International Boulevard, 10th Floor, Suite 1000, Mahwah, NJ 07495-0027 (201) 335-9300

1

Memo Date: Monday, April 25, 2016

Project: U.S. Army Garrison-Kwajalein Atoll (USAG-KA)

To: Craig A. Vrabel, Project Manager

From: Lisa Voyce and Mayble Abraham, Risk Assessors

Subject: Development of Risk-Based Cleanup Levels

HDR prepared this memorandum to describe the risk-based cleanup levels (RBCLs) developed for the

Carlos Power Plant, Echo Pier Fuel Lines and Hotline Refueling sites at USAG-KA in the Republic of the

Marshall Islands. The following attachments are included in support of the RBCL development:

Table 1 – RBCLs summary

Tables 2a to 2s – Supporting tables for soil RBCLs using Pacific Basin Tier 2 Calculator

Tables 3a to 3e – Supporting tables for ecological soil RBCLs

A. CONTAMINANTS OF CONCERN

Petroleum-related contaminants of concern (COCs) were determined by Bering-Kaya Support Services

(BKSS 2016a, b, c). Based on exceedances of conservative screening criteria at each of the three sites to

identify potential impacts to receptors present, 16 COCs in soil and one COC in groundwater were

noted:

Contaminants of Concern

Medium COC Site

Soil Benzene Echo; Hotline

Soil Benzo(a)anthracene Carlos; Echo; Hotline

Soil Benzo(a)pyrene Echo; Hotline

Soil Benzo(b)fluoranthene Echo; Hotline

Soil Chloroform Echo

Soil Dibenz(a,h)anthracene Echo; Hotline

Soil Diesel Range Organics (DRO) Carlos; Echo; Hotline

Soil Ethylbenzene Echo; Hotline

Soil Gasoline Range Organics (GRO) Echo; Hotline

Soil Indeno(1,2,3-cd)pyrene Hotline

Soil Methylene chloride Echo; Hotline

Soil 1-methylnaphthalene Echo; Hotline

Soil 2-methylnaphthalene Echo; Hotline

Soil Methyl Isobutyl Ketone (MIBK; 4-methyl-2-pentanone ) Hotline

Soil Naphthalene Carlos; Echo; Hotline


2

Medium COC Site

Soil Xylenes Echo

Groundwater Diesel Range Organics (DRO) Carlos

B. RISK BASED CLEANUP LEVELS (RBCLS) FOR RESIDENTIAL EXPOSURE TO COCS IN SOIL

For evaluation of a resident’s exposure to COCs in soil via ingestion, dermal contact and inhalation of soil

vapors and particulates, the Pacific Basin Tier 2 calculator spreadsheet (Guam EPA 2012) for soil direct

exposure action levels and unrestricted land use was utilized. The calculator was modified to site-

specific conditions as follows:

Soil physical characteristics were updated to reflect likely site-specific conditions (i.e., soil bulk

density of 1.50 g/cm3, particle density of 2.66 g/cm3 and soil moisture content of 20 mL/g); the

default value of 0.006 for fraction organic carbon in soil recommended by the calculator was

applied as it appropriately reflects the low organic content in the unconsolidated carbonate soil

at Kwajalein.

The thickness of contaminated soil was defined to be 0.6 m or approximately 2 ft. Remediation

efforts at Carlos Power Plant plan to leave 1 ft of soil at the groundwater surface, 2 ft at the

Echo Pier site and 1.5 ft at the Hotline Refueling site. The water table has a range of 3 – 7 ft

across the three sites. Typically, petroleum-based contamination will remain above the water

table; therefore this likely represents a conservative scenario.

Exposure factors were updated to reflect current USEPA-recommended exposure factors in the

2014 OSWER Directive 9200.1-120 (e.g., body weight of an adult increased from 70 kg to 80 kg;

USEPA 2014).

Toxicity values were updated, using those from the November 2015 United States

Environmental Protection Agency (USEPA) Regional Screening Level (RSL) tables (USEPA 2015c).

The RSL tables incorporate toxicity values using the same sources as those in Pacific Basin’s

calculator that were last updated in 2013. Since 2013, the toxicity values for xylenes and

methylene chloride have decreased; inhalation toxicity values for 1-methylnaphthalene and 2-

methylnaphthalene and the oral reference dose for methyl isobutyl ketone are no longer used,

having been removed due to insufficient data.

Note that the Pacific Basin Tier 2 calculator applies a target cancer risk of 1E-05 for polycyclic

aromatic hydrocarbons (PAHs) in the derivation of the RBCL based on the ubiquitous, low-level

contamination with PAHs in urban soils from asphalt; all other contaminants use a target cancer

risk of 1E-06.

The Pacific Basin Tier 2 Calculator indicated the model cannot be applied for indeno(1,2,3-

cd)pyrene, but a cleanup level is provided; no further explanation is provided in guidance.

The calculated Tier 2 RBCLs are presented on Table 1. For comparison, the Pacific Basin Tier 1

Environmental Screening Levels (PBESLs) for soil samples collected less than 3 m (about 10 ft) and the

USEPA Residential Tapwater RSLs (at a target cancer risk of 1E-06 and target hazard quotient of 1) are

also presented, which are screening levels commonly used in the region (Guam 2012, USAKA 2014).


3

The calculated Tier 2 RBCLs range from within an order of magnitude to three orders higher than the

Tier 1 PBESLs; they are within an order of magnitude to two orders higher than the USEPA RSLs.

Tables 2a to 2s provide the supporting information for the calculation of the Tier 2 RBCLs with exposure

factors presented on Table 2a, toxicity values on Table 2b, health effects of COCs on Table 2c and the

calculator outputs for each COC on Tables 2d to 2s. Any site-specific changes or updates made to the

calculator are identified and shaded tan on these tables.

Comparison of Residential Soil RBCLs to Site Data

Comparison of the maximum detected soil concentrations for each of the three sites (Carlos Power

Plant, Echo Pier Fuel Lines and Hotline Refueling) to the RBCLs indicates DRO has concentrations greater

than the RBCL at Carlos Plant, whereas benzo(a)pyrene and DRO are both of potential concern at the

Echo Pier Fuel Lines and Hotline Refueling sites and GRO also for the Hotline Refueling site.

C. ECOLOGICAL RBCLS FOR TERRESTRIAL EXPOSURE TO COCS IN SOIL

To evaluate the potential impact soil COCs, RBCLs were calculated for terrestrial wildlife exposure

scenarios. The ecological RBCLs are presented in Table 3a and the supplemental tables in Tables 3b to

3e.

Review of potentially present wildlife species and feeding guilds (e.g., herbivore or plant eating species)

in the Marshall Islands (RMI 2008, USAPHC 2014) and available literature-based exposure factors (USEPA

1993) resulted in the identification of three terrestrial mammals to represent the feeding guilds. These

include the deer mouse (peromyscus maniculatus) for small mammal herbivores, short-tailed shrew

(Blarina brevicauda) for carnivores and omnivores, and the goat (various) for large animal herbivores.

Using one species to represent a feeding guild is common practice in ecological risk assessment, given

the limited available literature studies that provide species’ exposure factors and toxicity values.

Exposure factors for these three species are presented in Table 3b. Mammalian toxicity values and

bioaccumulation factors for each COC are provided in Tables 3c and d.

RBCLs were calculated for both the no observed adverse effect level (NOAEL) and lowest observed

adverse effect level (LOAEL). The NOAEL-based RBCLs are more conservative and are often applied if

threatened and/or endangered species are potentially present or use a site; using both provides a range

of values to better evaluate the potential range of potential risk. The RBCLs are calculated in Table 3e.

Comparison of Terrestrial Soil RBCLs to Site Data

A comparison of the soil maximum detected concentrations for each site to the terrestrial wildlife soil

RBCLs is presented in Table 3a and indicates the following soil COCs are of potential concern:

Carlos Power Plant: 2-methylnaphthalene, naphthalene and benzo(a)anthracene using the

NOAEL, but not using the LOAEL;

Echo Pier Fuel Lines: benzo(a)anthracene, naphthalene and xylenes using the NOAEL, xylenes

only using the LOAEL;


4

Hotline Refueling: benzo (b)fluoranthene, indeno (1,2,3-cd)pyrene, methylene chloride and

naphthalene using the NOAEL, methylene chloride only using the LOAEL.

D. REFERENCES

Bering-KAYA Support Services (BKSS). 2016a. Internal Draft Removal Action Memorandum Carlos Power

Plant Site. U.S. Army Garrison-Kwajalein Atoll (USAG-KA), Republic of the Marshall Islands, Site ID

CCKWAJ-004. February.

BKSS. 2016b. Internal Draft Removal Action Memorandum Echo Pier Fuel Lines. USAG-KA, Republic of

the Marshall Islands, Site ID CCKWAJ-006. February.

BKSS. 2016c. Internal Draft Removal Action Memorandum Hotline Refueling Site. USAG-KA, Republic of

the Marshall Islands, Site ID CCKWAJ-006. February.

Guam Environmental Protection Agency. 2012. Pacific Basin Environmental Screening Levels (PBESLs).

Rev April 2013. Available online: http://epa.guam.gov/rules-regs/regulations/pacific-basin-

environmental-screening-levels/

Sivuniq. 2011. Draft Carlos Power Plant Site Investigation. U.S. Army Kwajalein Atoll/Reagan Test Site,

Republic of the Marshall Islands, Site ID CCKWAJ-004. November.

United States Army Kwajalein Atoll (USAKA). 2014. Environmental Standards and Procedures for USAKA

Activities in the Republic of the Marshall Islands. 13th Ed. October. Available online:

http://usakacleanup.info/assets/images/uploads/UES_13_Ed_Oct2014_PDF_Pro_rd.pdf

United States Army Public Health Command (USAPHC). 2014. Draft Kwajalein Landfill Baseline Risk

Assessment. Project No. S.0010319-13. U.S. Army Garrison-Kwajalein Atoll, Republic of the Marshall

Islands.

USEPA. 2014. Human Health Evaluation Manual, Supplemental Guidance: Update of Standard Default

Exposure Factors. OSWER Directive 9200.1-120. February 6. Available online:

https://www.epa.gov/risk/update-standard-default-exposure-factors

USEPA. 2015c. Regional Screening Level (RSL) Generic Tables. November. Available online:

https://www.epa.gov/risk/regional-screening-levels-rsls

USEPA. 2015d. Regional Screening Level (RSL) Calculator. November. Available online:

https://www.epa.gov/risk/regional-screening-levels-rsls

United States Geological Survey (USGS). 1991. Ground-water Geochemistry of Kwajalein Island, Republic

of the Marshall Islands, 1991. Water-Resources Investigations Report 97-4184. Available online:

http://pubs.usgs.gov/wri/wri97-4184/pdf/wri97-4184.pdf

Weatherbase. N.d. Kwajalein Atoll, Marshall Islands. Retrieved March 29, 2016. Available online:

http://www.weatherbase.com/weather/weather.php3?s=66319


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E. ECOLOGICAL REFERENCES

Beyer, WN; Connor, EE; Gerould, S. 1994. "Estimates of soil ingestion by wildlife." J. Wildl. Manage.

58(2):375-382.

Pattanayek M. and DeShields B. N.d. Characterizing Risks to Livestock from Petroleum Hydrocarbons.

Blasland, Bouck and Lee, Inc. (BBL).

Chynoweth, M.W., et. al. 2015. Home Range Use and Movement Patterns of Non-Native Feral Goats in a

Tropical Island Montane Dry Landscape. PLOS One: 10(3).

Department of Energy (DOE). 2014. ECORISK Database (Release 3.2). LANL (Los Alamos National

Laboratory). LA-UR-14-28010. Los Alamos, NM. October. Available online:

http://www.lanl.gov/community-environment/environmental-stewardship/protection/eco-risk-

assessment.php

Lyons, R.K., et. al. N.d. Understanding Forage Intake in Range Animals. Texas A&M System, AgriLife

Extension. E-393.

Nagy, K.A. 2001. Food Requirements of Wild Animals: Predictive Equations for Free-living Mammals,

Reptiles, and Birds. Nutrition Abstracts and Reviews, Series B: Livestock Feeds and Feeding: 71(10).

Republic of the Marshall Islands (RMI). 2008. Republic of the Marshall Islands Biodiversity Clearing

House Mechanism. Office of Environmental Planning and Policy Coordination. Last Updated: Oct 2,

2008. Available online: http://biormi.org/index_nav_left.shtml?en/db_search.shtml

USEPA. 1993. Wildlife Exposure Factors Handbook Volume I of II. EPA/600/R-93/187. Office of Health

and Environmental Assessment, Office of Research and Development, Washington, D.C. Available

online:

http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=2799&CFID=42907397&CFTOKEN=88506585

USEPA. 2005. Guidance for Developing Ecological Soil Screening Levels. OSWER Directive 9285.7-55.

February. Available online: https://www.epa.gov/chemical-research/guidance-developing-ecological-

soil-screening-levels

USEPA. 2007. Guidance for Developing Ecological Soil Screening Levels (Eco-SSLs), Attachment 4-1.

OSWER Directive 9285.7-55. April. Available online: https://www.epa.gov/chemical-research/guidance-

developing-ecological-soil-screening-levels

USEPA. 2010. Ecological Soil Screening Levels. Various documents. October 20. Available online:

http://www2.epa.gov/risk/ecological-soil-screening-level-eco-ssl-guidance-and-documents

Table 1Risk-Based Cleanup LevelsU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

Proposed RBCL

Pacific Basin Tier 2 Calculator

Unrestricted - Using Site-

Specific Conditions

Pacific Basin Tier 1 ESL

Unrestricted - Soil <3 m, GW

Potable

Pacific Basin Tier 1 ESL

Unrestricted - Soil <3 m, GW

Not Potable

Value Value Value Value Basis

Benzene 71-43-2 7.9 0.30 0.67 1.2 c* NA 0.0065 0.0011Benzo(a)anthracene 56-55-3 1.6 10 1.5 0.16 c 0.34 0.61 0.18Benzo(a)pyrene 50-32-8 0.16 5.7 0.15 0.016 c 0.058 0.26 0.31Benzo(b)fluoranthene 205-99-2 1.6 5.4 1.5 0.16 c 0.13 NA 0.48Chloroform 67-66-3 5.4 0.023 0.023 0.32 c NA 0.0027 NADibenz(a,h)anthracene 53-70-3 0.16 12 18 0.016 c 0.013 0.027 0.073Diesel Range Organics (DRO)** DRO 500 100 500 96 ns 38100 27000 23000Ethylbenzene 100-41-4 321 2.1 2.1 5.8 c NA 7.4 18Gasoline Range Organics (GRO)** GRO 1520 100 400 82 n 59 1300 4300Indeno(1,2,3-cd)pyrene 193-39-5 1.6 9.6 30 0.16 c 0.035 NA 0.26Methylene chloride 75-09-2 340 0.11 1.1 57 c** NA 0.005 4.71-methylnaphthalene 90-12-0 240 0.79 0.79 18 c NA 8 112-methylnaphthalene 91-57-6 313 0.87 0.87 240 n 26 8.7 10Methyl Isobutyl Ketone (MIBK; 4-methyl-2-pentanone)

108-10-1 5242 0.50 0.50 33000 ns NA NA 0.3

Naphthalene 91-20-3 223 0.51 0.51 3.8 c* 8 2.1 2Xylenes 1330-20-7 397 2.1 11 580 ns NA 1 NA

Notes:All soil cleanup levels, screening levels and concentrations are in units of mg/kg.Site-specific soil concentrations greater than the risk-based cleanup level (RBCL) are shaded. The RBCLs for DRO, MIBK and xylenes were capped at their saturation limit, which is a default option in the Pacific Basin Tier 2 calculator.

Abbreviations: RSL Basis:** For the PBESLs, "TPH (gasolines)" was used as a surrogate for GRO and "TPH (middle distillates)" for DRO. * = n RSL < 100 x c RSLCOC = Contaminant of concern ** = n RSL < 10 x c RSLUSEPA RSL = United States Environmental Protection Agency Regional Screening Level c = cancer basisGW = Groundwater n = noncancer basisNA = Not available s = concentration may exceed saturation levelPBESL = Pacific Basin Environmental Screening LevelRBCL = Risk-based cleanup level

References:

USEPA. 2015. Regional Screening Level (RSL) Generic Tables. TR=1E-06, THQ=1. November. Available online: https://www.epa.gov/risk/regional-screening-levels-rsls

Guam Environmental Protection Agency. 2012. Pacific Basin Environmental Screening Levels (PBESLs). Rev April 2013. Available online: http://epa.guam.gov/rules-regs/regulations/pacific-basin-environmental-screening-levels/

USAKA. 2014. Environmental Standards and Procedures for USAKA Activities in the Republic of the Marshall Islands. 13th Ed. October. Available online: http://usakacleanup.info/assets/images/uploads/UES_13_Ed_Oct2014_PDF_Pro_rd.pdf

The Pacific Basin Tier 2 Calculator indicated the model cannot be applied for indeno(1,2,3-cd)pyrene, but a cleanup level is provided; no further explanation is given in the guidance.

Site-Specific Maximum Detected Soil Concentrations

Carlos Power

Plant Site

Echo Pier Fuel Lines

Site

Hotline Refueling

Site

Tier 1 PBESLs

Contaminant of Concern CASRN

USEPA RSLs

Residential Tapwater -TR of 1E-06 /

THQ of 1

Page: 1 of 1

Table 2aExposure Factors for Determination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to SoilU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

HUMAN EXPOSURE PARAMETER VALUES AND TARGET RISKS

Highlight and justify all changes in text of Environmental Risk Assessment Report (writeprotect password = ESL)1Human Receptor Parameters Tier 1 Default Values Tier 2 Values Site-specific Update

Bioavailability (ingestion only) BA % chemical specific 100%

25% surface area - adult resident SAa cm2 5700 6032Updated from 5,700 to 6,032 per EPA 2014 OSWER Directive 9200.1-120.

25% surface area - child resident SAc cm2 2800 2373Updated from 2,800 to 2,373 per EPA 2014 OSWER Directive 9200.1-120.

25% surface area - adult occupational worker SAa cm2 3300 3527Updated from 3,300 to 3,527 per EPA 2014 OSWER Directive 9200.1-120.

25% surface area - construction/trench worker SAc/t cm25800 5800

Adherence factor - adult resident AFa mg/cm20.07 0.07

Adherence factor - child resident AFc mg/cm20.2 0.2

Adherence factor - adult occupational worker AFa mg/cm2 0.2 0.12Updated from 0.2 to 0.12 per EPA 2014 OSWER Directive 9200.1-120.

2Adherence factor - construction/trench worker AFc/t mg/cm20.3 0.3

Skin absorption factor ABS unitless chemical specific chemical specificInhalation Rate - adult residents/workers IRAa m3/d 20 20Inhalation Rate - children IRAc m3/d 10 10Soil ingestion rate - adult residents IRSa mg/d 100 100Soil ingestion rate - children IRSc mg/d 200 200Soil ingestion rate - occupational worker IRSo mg/d 100 1002Soil ingestion rate - construction/trench worker IRSc/t mg/d 330 330Exposure frequency - residents EFr d/y 350 350Exposure frequency - occupational worker EFo d/y 250 2502Exposure frequency - construction/trench worker EFc/t d/y 35 35

Exposure duration - residents total EDr yrs 30 26Updated from 30 to 26 per EPA 2014 OSWER Directive 9200.1-120.

Exposure duration - children EDc yrs 6 6Exposure duration - occupational worker EDc yrs 25 252Exposure duration - construction/trench worker EDc yrs 7 7Exposure duration (0-2yrs) EDc yrs 2 2Exposure duration (2-6yrs) EDc yrs 4 4Exposure duration (6-16yrs) EDc yrs 10 10Exposure duration (16-30yrs) EDc yrs 14 14Exposure duration (16-70yrs) - Vinyl Chloride EDc yrs 54 54Exposure Time - Resident ETr hrs/day 24 24Exposure Time - Workers ETw hrs/day 8 8

Body weight - adult BWa kg 70 80Updated from 70 to 80 per EPA 2014 OSWER Directive 9200.1-120.

Body weight - child BWc kg 15 15Averaging time (years) AT yrs 70 70Days/year conversion d/yr 365 365*Target Risk - Unrestricted/Residential TR 1.00E-06 1.0E-06*Target Risk - Commercial/Industrial Only 1.00E-06 1.0E-06*Target Hazard Quotient THQ 0.2 1.0

*Default target risks used in Tier 1 EALs vary with respect to contaminant and exposure scenario

Other variables (fixed)2CALCULATIONS

VARIOUS CALCULATIONS

Ingestion exposure factor IFS mg-yr/kg-d 105

Skin contact exposure factor SFS mg-yr/kg-d 295

Ingestion exposure factor (mutagenic) IFSM mg-yr/kg-d 482

Skin contact exposure factor (mutagenic) SFSM mg-yr/kg-d 1245

Soils - General

Soil porosity Pt 0.40

Soil air-filled porosity Pa Lair/Lsoil 0.08

Soil water-filled porosity Pw Lwater/Lsoil 0.32

NOTES:

1. Default human exposure parameter values from USEPA Regional Screening Levels Guidance (USEPA 2011) unless otherwise noted.

2. Refer to Appendx 1 for and Appendix 2 OF DOH EHE guidance for discussion of construction/trench worker exposure scenario (HDOH 2011).

REFERENCES:

HDOH, 2011, Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater: Hawai’i Department of Health, Office of Hazard Evaluation and Emergency Response, Fall 2011, www.hawaii.gov/health/environmental/hazard/eal2005.html.

USEPA, 2011, Screening Levels for Chemical Contaminants: U.S. Environmental Protection Agency, June 2011, prepared by Oak Ridge National Laboratories, http://www.epa.gov/region09/waste/sfund/prg/

Hawai'i DOHFall 2011 Page: 1 of 4

Table 2bToxicity Values for Determination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to SoilU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

TABLE J. PHYSIO-CHEMICAL AND TOXICITY CONSTANTS USED IN MODELS.

Organic Pure Cancer Cancer

carbon component GI Skin Slope Unit Risk Reference Reference

partition Diffusivity Diffusivity water Henry's Henry's Absorption Absorption Factor Factor Dose Concentration

Modeled coefficient, in air, in water, solubility, Law constant Law constant Factor Factor Oral (Inhalation) Oral (Inhalation)

Molecular Molecular Koc Da Dw S H H' GIABS ABS CSFo IUR RfDo RfC

CHEMICAL PARAMETER Weight Weight (cm3/g) (cm2/s) (cm2/s) (mg/L) (atm-m3/mol) (unitless) (unitless) (unitless) (mg/kg-d)-1 (ug/m3)-1 (mg/kg-d) (mg/m3)BENZENE V L 78 78 1.46E+02 9.00E-02 1.00E-05 1.79E+03 5.61E-03 2.30E-01 1.0 5.5E-02 7.8E-06 4.0E-03 3.0E-02

BENZO(a)ANTHRACENE NV S 228 228 1.77E+05 9.40E-03 1.20E-05 4.90E-04 1.0 0.13 7.3E-01 1.1E-04

BENZO(a)PYRENE NV S 252 252 5.87E+05 1.62E-03 4.63E-07 1.90E-05 1.0 0.13 7.3E+00 1.1E-03

BENZO(b)FLUORANTHENE NV S 252 252 5.99E+05 1.50E-03 6.59E-07 2.70E-05 1.0 0.13 7.3E-01 1.1E-04

CHLOROFORM V L 119 119 3.18E+01 7.70E-02 1.10E-05 7.95E+03 3.66E-03 1.50E-01 1.0 3.1E-02 2.3E-05 1.0E-02 9.8E-02

DIBENZO(a,h)ANTHTRACENE NV S 278 278 1.91E+06 1.03E-03 1.22E-07 5.00E-06 1.0 0.13 7.3E+00 1.2E-03

ETHYLBENZENE V L 106 106 4.46E+02 6.80E-02 8.50E-06 1.69E+02 7.80E-03 3.20E-01 1.0 1.1E-02 2.5E-06 1.0E-01 1.0E+00

INDENO(1,2,3-cd)PYRENE NV S 276 276 1.95E+06 1.90E-04 3.41E-07 1.40E-05 1.0 0.13 7.3E-01 1.1E-04

METHYL ISOBUTYL KETONE V L 100 100 1.26E+01 7.00E-02 8.30E-06 1.90E+04 1.37E-04 5.60E-03 1.0 3.0E+00

METHYLENE CHLORIDE V L 85 85 2.17E+01 1.00E-01 1.30E-05 1.30E+04 3.17E-03 1.30E-01 1.0 2.0E-03 1.0E-08 6.0E-03 6.0E-01

METHYLNAPHTHALENE, 1- V S 142 142 2.26E+03 5.30E-02 7.80E-06 2.50E+01 5.12E-04 2.10E-02 1.0 2.9E-02 7.0E-02

METHYLNAPHTHALENE, 2- V S 142 142 2.48E+03 5.20E-02 7.80E-06 2.50E+01 5.12E-04 2.10E-02 1.0 4.0E-03

NAPHTHALENE V S 128 128 1.54E+03 6.00E-02 8.40E-06 3.10E+01 4.39E-04 1.80E-02 1.0 0.13 3.4E-05 2.0E-02 3.0E-03

TPH (gasolines) V L 119 119 5.00E+03 7.00E-02 1.00E-05 1.50E+02 7.20E-04 3.22E+01 1.0 0.1 3.0E-02 1.3E-01

TPH (middle distillates) V L 201 150 5.00E+03 7.00E-02 1.00E-05 5.00E+00 7.20E-04 2.32E+01 1.0 0.1 2.0E-02 1.3E-01

XYLENES V L 106 106 3.75E+02 6.80E-02 8.40E-06 1.61E+02 7.07E-03 2.90E-01 1.0 2.0E-01 1.0E-01

Notes on Individual Chemicals

TPH as gasolines and middle distillates diffusivity constants based on xylenes. Required for direct exposure models - Does not significantly affect action levels. See Chapter 5 of Appendix 1.

TPH toxicity factors discussed in Appendix 1, Chapter 5.

Xylenes physio-chemical and toxicity constants based on m-xylene.

Toxicity Updates using EPA November 2015 RSL Tables (tan shading):

Oral reference dose of 0.08 mg/kg-d for methyl isobutyl ketone has been removed.

Inhalation unit risk of 8.3E-06 (ug/m 3)-1 and inhalation reference concentration of 0.25 mg/m 3 for 1-methylnaphthalene have been removed.

Inhalation reference concentration of 0.014 mg/m 3 has been removed.

Oral reference dose of 2 mg/kg-d for xylenes has been decreased to 0.2 mg/kg-d.

All of the toxicity values for methylene chloride have decreased: From 0.0075 to 0.002 (mg/kg-d)-1 for the cancer slope factor, from 4.7E-07 to 1.0E-08 (ug/m3)-1 for the inhalation unit risk, from 0.06 to 0.006 for the oral reference dose and from 1.1 to 0.6 for the inhalation reference concentration.

Physical

State

TPH -Total Petroleum Hydrocarbons. See text for discussion of different TPH categories. Molecular weights form ATSDR (gasolines) and NIOSH (middle distillates). TPH physiochemical constants based on assumed carbon range makeup of fuel type and constants for carbon ranges published in MADEP 2002. See Section 6 of Appendix 1.

Hawai'i DOHSummer 2008 Page: 2 of 4

Table 2cToxicity Health Effects for Determination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to SoilU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

TABLE J. TARGET ORGANS AND CHRONIC HEALTH EFFECTS(For general reference only. May not be adequately comprehensive for some chemicals.

Some noted effects may be insignificant. Refer to original documents for additional information.)Reference: Pacific Basin EHE guidance, Appendix 1 (PBEHE 2012). Writeprotect Password: "ESL

Target Organs And Health Effects

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x BENZENE A 2 1,3 1,2,3 2 1

x BENZO(a)ANTHRACENE B2 M 3 3 No chronic toxicity factors.

x BENZO(a)PYRENE B2 M 3 2 3 No chronic toxicity factors.

x BENZO(b)FLUORANTHENE B2 M 3 3 No chronic toxicity factors.x CHLOROFORM B2 1,2,3,5 1 1,2,3x DIBENZO(a,h)ANTHTRACENE B2 M 3 2,3x ETHYLBENZENE D 1,4,5 1,3,5 1 1,4,5 2 2 2x INDENO(1,2,3-cd)PYRENE B2 M 3 3 No chronic toxicity factors.x METHYL ISOBUTYL KETONE D 6x METHYLENE CHLORIDE B2 2,5 1 2 1x METHYLNAPHTHALENE, 1- C 4,5 3 3 = Fluorenex METHYLNAPHTHALENE, 2- D 4,5 3 3 = Fluorenex NAPHTHALENE C 2 2 3 1,5 3x TPH (gasolines) D 8 8 8 8 Decreased body weightx TPH (middle distillates) D 8 8 8 8 Decreased body weight

CHEMICAL PARAMETER

Hawai'i DOH(Summer 2008) Page: 3 of 4

Table 2cToxicity Health Effects for Determination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to SoilU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

TABLE J. TARGET ORGANS AND CHRONIC HEALTH EFFECTS(For general reference only. May not be adequately comprehensive for some chemicals.

Some noted effects may be insignificant. Refer to original documents for additional information.)Reference: Pacific Basin EHE guidance, Appendix 1 (PBEHE 2012). Writeprotect Password: "ESL

Target Organs And Health Effects

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x XYLENES D 1,2,3,4,5 1

Carcinogen ClassificationA: Human carcinogenB: Probable human carcinogen (B1: limited human evidence; B2 Sufficient evidence in animals and inadequate or no evidence in humans)C: Possible human carcinogenD: Not classifiable as to human carcinogenicityE: Evidence of noncarcinogenicity for humansNA: Carcinogen classification information not available

References:1. CalEPA, 2005, Consolidated Table of Chronic Reference Exposure Levels: California Environmental Protection Agency, Office of Environmental Health Hazard Assessment/Air Resources Board, April 2005,http://www.arb.ca.gov/toxics/healthval/healthval.htm2. CDC, 2007, International Chemical Safety Cards: International Programme on Chemical Safety: United Nations Environment Program, International Labour Officeand World Health Organization (accessed December 2007); published through US Department of Health and Human Services, Centers for Disease Control and Prevention,http://www.cdc.gov/niosh/ipcs/icstart.html3. ATSDR, 2007, ToxFAQs™: Agency for Toxic Substances and Disease Registry (accessed December 2007), http://www.atsdr.cdc.gov/toxfaq.html

5. USEPA, 2007, IRIS: U.S. Environmental Protection Agency, IRIS Database (accessed December 2007); (Critical effect used for derivation of USEPA RfD as presented in IRIS database; may not be inclusiveof all potentially significant health effects), http://www.epa.gov/iris/subst/index.html6. ORNL, 2007, Risk Assessment Information System (RAIS), Toxicity Profiles: Oak Ridge National Laboratory/U.S. Department of Energy (accessed December 2007), RAGs A Format, especially CriticalEffect used for derivation of RfDs, http://risk.lsd.ornl.gov/tox/rap_toxp.shtml

8. TPH whole product toxicity based review of TPH Working Group petroleum carbon fraction guidance (TPHWG 1998, Volume 4) and Massachusetts DEP VPH/EPH guidance (MADEP 2002a).For additional online references, see also: Hazardous Substances (On-line) Database: U.S. National Library of Medicine, Toxicology Data Network, http://toxnet.nlm.nih.gov

4. Illinois, 2001, Tiered Approach to Corrective Action Objectives (TACO): Illinois Environmental Protection Agency, Title 35, Subtitle G, Chapter I, Subchapter f, Part 742, Appendix A, Table E, Similar-Acting Noncarcinogenic Chemicals (accessed December 2007), http://www.ipcb.state.il.us/SLR/IPCBandIEPAEnvironmentalRegulations-Title35.asp

7. USEPA National Primary Drinking Water Standards (March 2001): U.S. Environmental Protection Agency, Office of Water, EPA 816-F-01-007, http://www.epa.gov/safewater/consumer/pdf/mcl.pdf (selectively used)

Hawai'i DOH(Summer 2008) Page: 4 of 4

Table 2dDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - BenzeneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

Tier 2 Soil Direct-Exposure Action LevelsPacific Basin EHE Guidance (Fall 2012, rev April 2013)

Notes:

3. Does not address potential cumulative effects posed by multiple contaminants (evaluate separately).3. Does not address potential vapor intrusion concerns, nuisance concerns, leaching concerns or ecological concerns. 4. Use default values in absence of site-specific data. 5. Natural background concentration of metals replaces risk-base action level if higher (e.g., arsenic).5. Password to unprotect worksheets is "ESL."

(Steps 1 through 3 - Use pull-down boxes to select options.)

Step 1. Select Contaminant:

Step 2. Select Exposure Scenario:

Step 3. Input Site Data: *Tier 1 Default Site-Specific Site-Specific Update

Thickness impacted soil (m) infinite 0.6

Soil density (g/cm3) 1.50 1.59Particle density (g/cm3) 2.65 2.66Soil moisture content (ml/g) 0.10 0.20

Fraction organic carbon in soil 0.006 0.006

*Default site parameter values from USEPA RSLs (USEPA 2008).

BENZENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 7.9E+00

Mutagenic Concerns: -Noncancer Concerns: 2.7E+02

Final Tier 2 Direct-Exposure Action Level: 7.9E+00

PROJECT NAME: U.S. Army Garrison-Kwajalein Atoll Site ID No.: CCKW AJ-004

SPREADSHEET PREPARED BY: DATE: 04/22/2016SIGNATURE:

COMPANY: HDR

SUPPORTING SITE INVESTIGATION REPORT(S) (Note report title, date, and preparer's name and address):

Notes:

Step 4. *Adjust Default Exposure Assumptions (see attached worksheet)*Generally not recommended in a Tier 2 assessment. Includes Tier 1 chemical toxicity factors.

*Saturation limits and Construction/Trench worker action levels take precedence if lower. Refer to detailed calculations worksheet.

1. Calculates Tier 2 direct-exposure action levels (screening levels) for soil. Assumes exposure by ingestion, inhalation and dermal contact.

Unrestricted (Residential) Land Use

BENZENE

2. Addresses mass-balance issues for volatile chemicals by accounting for thickness of contaminated soil (nonvolatile chemicals not affected).

2 feet contamination, water table ranges from 3 - 7 ft.

site-specific datasite-specific datasite-specific data

default, soil in Marshall Islands is carbonate.



Reference:

USEPA, 2002, Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites : U.S. Environmental Protection Agency, Solid Waste and Emergency Response, OSWER 9355.4-24, December 2002, http://www.epa.gov/superfund/resources/soil/ssg_main.pdf


Tier 2 model based on USEPA Regional Screening Levels model (USEPA 2011) with option for mass-balance Volatilization Factor as presented in USEPA Soil Screening Guidance document (USEPA 2002). Refer to Tier 2 Calculations worksheet and Appendix 2 of Pacific Basin EHE guidance (PBEHE 2012). Addresses direct exposure hazards only. Other potential environmental hazards must be evaluated separately (vapor intrusion, leaching, ecotoxicity, gross contamination, etc.).

PBEHE 2012, Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (Pacific Basin Edition): Prepared by Roger Brewer, Hawai’i Department of Health, Office of Hazard Evaluation and Emergency Response, Fall 2012, www.hawaii.gov/health/environmental/hazard/eal2005.html.



Calculation of Tier 2 Soil Direct-Exposure Action Levels

CHEMICAL PARAMETERS

Physical State (volatile/nonvolatile) V

Physical State (solid/liquid/gas) L

Molecular Weight (modeled) 78.11

Koc cm3/g 146

Diffusivity in Air cm2/sec 9.0E-02

Diffusivity in Water cm2/sec 1.0E-05

Solubility in water ug/L 1.8E+03

Henry's Constant (atm-m3/mol) 5.6E-03

Henry's Constant unitless 2.30E-01

Saturation (Csat, liquids only) mg/kg 1.95E+03

GI Absorption Factor unitless 1.0E+00

Skin Absorption Factor unitless 0.0E+00

Mutagen? No

Cancer Slope Factor (oral) (mg/kg-d)-1 5.5E-02

Cancer Unit Risk Factor (inhalation) (ug/m3)-1 7.8E-06

Reference Dose (oral) mg/kg-d 4.0E-03

Reference Concentration (inhalation) mg/m3 3.0E-02

Bioavailability (ingestion only) 100%

CALCULATED PARAMETERSKd cm3/g 8.8E-01Saturation (Volatile Liquids Only) mg/kg 1.9E+03Air dispersion term (SSGs) g/m2-sec 68.81Apparent Diffusivity (SSGs) cm2/sec 2.0E-05Inhalation Age-Adjusted Factor

ResidentialInfinite-source Volatilization Factor m3/kg 2.6E+04Finite-source Volatilization Factor m3/kg 5.8E+04Final Volatilization Factor m3/kg 5.8E+04Particulate Emission Factor m3/kg 1.4E+09

Commercial/IndustrialInfinite-source Volatilization Factor m3/kg 2.6E+04Finite-source Volatilization Factor m3/kg 5.6E+04Final Volatilization Factor m3/kg 5.6E+04Particulate Emission Factor m3/kg 1.4E+09

Construction/trench WorkerInfinite-source Volatilization Factor m3/kg 2.6E+04Finite-source Volatilization Factor m3/kg 1.6E+04Final Volatilization Factor m3/kg 2.6E+04Particulate Emission Factor m3/kg 1.4E+06

Selected Site Exposure Scenario:Unrestricted (Residential) Land Use

Tier 2 Soil Action Level (mg/kg)

Carcinogenic Effects 7.88E+00

Mutagenic Effects -

Noncancer Effects 2.67E+02Construction/Trench Worker Exposure 3.18E+02

Saturation 1.95E+03Final Action Level 7.88E+00

BENZENE




BENZENE

RESIDENTIAL

Carcinogenic Effects Tier 1 AL

Ingestion mg/kg 1.3E+01

Dermal mg/kg -Inhalation (vapors+particulates) mg/kg 2.1E+01Inhalation (particulates only) mg/kg 4.9E+05

1/Ingestion kg/mg 7.9E-02

1/Dermal kg/mg 0.0E+001/Inhalation (vapors+particulates) kg/mg 4.8E-021/Inhalation (particulates only) kg/mg 2.0E-06Carcinogenic Effects Final Action Level mg/kg 7.9E+00

Mutagenic Effects

Ingestion mg/kg -

Dermal mg/kg -Inhalation (vapors+particulates) mg/kg -Inhalation (particulates only) mg/kg -

1/Ingestion kg/mg -

1/Dermal kg/mg -1/Inhalation (vapors+particulates) kg/mg -1/Inhalation (particulates only) kg/mg -Mutagenic Effects Final Action Level mg/kg -

Noncarcinogenic Effects




1/Dermal kg/mg 0.0E+001/Inhalation (vapors+particulates) kg/mg 5.5E-041/Inhalation (particulates only) kg/mg 2.4E-08Noncancer Effects Final Action Level mg/kg 2.7E+02Final Tier 2 Action Level: mg/kg 7.9E+00




BENZENE

COMMERCIAL/INDUSTRIAL











CONSTRUCTION/TRENCH WORKERS











NOTES:

REFERENCES:






Table 2eDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Benzo(a)anthraceneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










BENZO(a)ANTHRACENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 7.0E+00

Mutagenic Concerns: 1.6E+00Noncancer Concerns: -




COMPANY: HDR


Notes:





BENZO(a)ANTHRACENE







Reference:








CHEMICAL PARAMETERS

Physical State (volatile/nonvolatile) NV

Physical State (solid/liquid/gas) S


Koc cm3/g 176900

Diffusivity in Air cm2/sec 0.0E+00

Diffusivity in Water cm2/sec 0.0E+00

Solubility in water ug/L 9.4E-03



Saturation (Csat, liquids only) mg/kg NA


Skin Absorption Factor unitless 1.3E-01

Mutagen? Yes



Reference Dose (oral) mg/kg-d 0.0E+00

Reference Concentration (inhalation) mg/m3 0.0E+00


CALCULATED PARAMETERSKd cm3/g 1.1E+03Saturation (Volatile Liquids Only) mg/kg NAAir dispersion term (SSGs) g/m2-sec N/AApparent Diffusivity (SSGs) cm2/sec NAInhalation Age-Adjusted Factor 8.4E-03

ResidentialInfinite-source Volatilization Factor m3/kg NAFinite-source Volatilization Factor m3/kg N/AFinal Volatilization Factor m3/kg 0.0E+00Particulate Emission Factor m3/kg 1.4E+09

Commercial/IndustrialInfinite-source Volatilization Factor m3/kg NAFinite-source Volatilization Factor m3/kg N/AFinal Volatilization Factor m3/kg 0.0E+00Particulate Emission Factor m3/kg 1.4E+09

Construction/trench WorkerInfinite-source Volatilization Factor m3/kg NAFinite-source Volatilization Factor m3/kg N/AFinal Volatilization Factor m3/kg 0.0E+00Particulate Emission Factor m3/kg 1.4E+06




Mutagenic Effects 1.55E+00

Noncancer Effects -Construction/Trench Worker Exposure 2.04E+01

Saturation NAFinal Action Level 1.55E+00

BENZO(a)ANTHRACENE




BENZO(a)ANTHRACENE

RESIDENTIAL



Dermal mg/kg 2.6E+01Inhalation (vapors+particulates) mg/kg -Inhalation (particulates only) mg/kg 3.5E+05


1/Dermal kg/mg 3.8E-021/Inhalation (vapors+particulates) kg/mg -1/Inhalation (particulates only) kg/mg 2.9E-06Carcinogenic Effects Final Action Level mg/kg 7.0E+00

Mutagenic Effects




1/Dermal kg/mg 1.6E-011/Inhalation (vapors+particulates) kg/mg 0.0E+001/Inhalation (particulates only) kg/mg 8.4E-06Mutagenic Effects Final Action Level mg/kg 1.6E+00


Ingestion mg/kg -


1/Ingestion kg/mg

1/Dermal kg/mg1/Inhalation (vapors+particulates) kg/mg1/Inhalation (particulates only) kg/mgNoncancer Effects Final Action Level mg/kg -Final Tier 2 Action Level: mg/kg 1.6E+00




BENZO(a)ANTHRACENE








Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg


NOTES:

REFERENCES:






Table 2fDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Benzo(a)pyreneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










BENZO(a)PYRENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 7.0E-01

Mutagenic Concerns: 1.6E-01Noncancer Concerns: -

Final Tier 2 Direct-Exposure Action Level: 1.6E-01



COMPANY: HDR


Notes:





BENZO(a)PYRENE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 587400









Mutagen? Yes

Cancer Slope Factor (oral) (mg/kg-d)-1 7.3E+00











Carcinogenic Effects 6.97E-01

Mutagenic Effects 1.55E-01


Saturation NAFinal Action Level 1.55E-01

BENZO(a)PYRENE




BENZO(a)PYRENE

RESIDENTIAL


Ingestion mg/kg 9.5E-01


1/Ingestion kg/mg 1.1E+00

1/Dermal kg/mg 3.8E-011/Inhalation (vapors+particulates) kg/mg -1/Inhalation (particulates only) kg/mg 2.9E-05Carcinogenic Effects Final Action Level mg/kg 7.0E-01

Mutagenic Effects


Dermal mg/kg 6.2E-01Inhalation (vapors+particulates) mg/kg -Inhalation (particulates only) mg/kg 1.2E+04


1/Dermal kg/mg 1.6E+001/Inhalation (vapors+particulates) kg/mg 0.0E+001/Inhalation (particulates only) kg/mg 8.4E-05Mutagenic Effects Final Action Level mg/kg 1.6E-01


Ingestion mg/kg -


1/Ingestion kg/mg

1/Dermal kg/mg1/Inhalation (vapors+particulates) kg/mg1/Inhalation (particulates only) kg/mgNoncancer Effects Final Action Level mg/kg -Final Tier 2 Action Level: mg/kg 1.6E-01




BENZO(a)PYRENE






1/Dermal kg/mg 1.2E+001/Inhalation (vapors+particulates) kg/mg -1/Inhalation (particulates only) kg/mg 6.6E-05Carcinogenic Effects Final Action Level mg/kg 2.9E-01


Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg


NOTES:

REFERENCES:






Table 2gDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Benzo(b)fluorantheneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










BENZO(b)FLUORANTHENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 7.0E+00





COMPANY: HDR


Notes:





BENZO(b)FLUORANTHENE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 599400









Mutagen? Yes





















RESIDENTIAL






Mutagenic Effects






Ingestion mg/kg -


1/Ingestion kg/mg













Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg


NOTES:

REFERENCES:






Table 2hDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - ChloroformU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










CHLOROFORM (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 5.4E+00





COMPANY: HDR


Notes:





CHLOROFORM







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 31.8









Mutagen? No













Mutagenic Effects -



CHLOROFORM




CHLOROFORM

RESIDENTIAL






Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -










CHLOROFORM























NOTES:

REFERENCES:






Table 2iDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Dibenz(a,h)anthraceneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










DIBENZO(a,h)ANTHTRACENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 7.0E-01

Mutagenic Concerns: 1.6E-01Noncancer Concerns: -

Final Tier 2 Direct-Exposure Action Level: 1.6E-01



COMPANY: HDR


Notes:





DIBENZO(a,h)ANTHTRACENE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 1912000









Mutagen? Yes












Carcinogenic Effects 6.97E-01

Mutagenic Effects 1.55E-01


Saturation NAFinal Action Level 1.55E-01






RESIDENTIAL





1/Dermal kg/mg 3.8E-011/Inhalation (vapors+particulates) kg/mg -1/Inhalation (particulates only) kg/mg 3.1E-05Carcinogenic Effects Final Action Level mg/kg 7.0E-01

Mutagenic Effects




1/Dermal kg/mg 1.6E+001/Inhalation (vapors+particulates) kg/mg 0.0E+001/Inhalation (particulates only) kg/mg 9.2E-05Mutagenic Effects Final Action Level mg/kg 1.6E-01


Ingestion mg/kg -


1/Ingestion kg/mg











1/Dermal kg/mg 1.2E+001/Inhalation (vapors+particulates) kg/mg -1/Inhalation (particulates only) kg/mg 7.2E-05Carcinogenic Effects Final Action Level mg/kg 2.9E-01


Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg


NOTES:

REFERENCES:






Table 2jDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - DROU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










TPH (middle distillates) (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: -





COMPANY: HDR


Notes:



Saturation Limit; refer to calculations worksheet.



TPH (middle distillates)







Reference:








CHEMICAL PARAMETERS



Molecular Weight (modeled) 150

Koc cm3/g 5000





Henry's Constant unitless 2.32E+01




Mutagen? No


Cancer Unit Risk Factor (inhalation) (ug/m3)-1 0.0E+00




CALCULATED PARAMETERSKd cm3/g 3.0E+01Saturation (Volatile Liquids Only) mg/kg 1.6E+02Air dispersion term (SSGs) g/m2-sec 68.81Apparent Diffusivity (SSGs) cm2/sec 5.3E-05Inhalation Age-Adjusted Factor






Carcinogenic Effects -

Mutagenic Effects -


Saturation 5.00E+02Final Action Level 5.00E+02 =Saturation Limit






RESIDENTIAL


Ingestion mg/kg -


1/Ingestion kg/mg

1/Dermal kg/mg1/Inhalation (vapors+particulates) kg/mg1/Inhalation (particulates only) kg/mgCarcinogenic Effects Final Action Level mg/kg -

Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -




Dermal mg/kg 6.6E+03Inhalation (vapors+particulates) mg/kg 7.6E+03Inhalation (particulates only) mg/kg 1.8E+08


1/Dermal kg/mg 1.5E-041/Inhalation (vapors+particulates) kg/mg 1.3E-041/Inhalation (particulates only) kg/mg 5.6E-09Noncancer Effects Final Action Level mg/kg 1.1E+03Final Tier 2 Action Level: mg/kg 5.0E+02 =Saturation Limit







Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg







NOTES:

REFERENCES:






Table 2kDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - EthylbenzeneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










ETHYLBENZENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 3.2E+02





COMPANY: HDR


Notes:





ETHYLBENZENE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 446









Mutagen? No













Mutagenic Effects -



ETHYLBENZENE




ETHYLBENZENE

RESIDENTIAL






Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -










ETHYLBENZENE






















1/Dermal kg/mg 0.0E+001/Inhalation (vapors+particulates) kg/mg 7.8E-071/Inhalation (particulates only) kg/mg 2.2E-08Noncancer Effects Final Action Level mg/kg 2.1E+05Final Tier 2 Action Level: mg/kg 4.9E+02 =Saturation Limit

NOTES:

REFERENCES:






Table 2lDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - GROU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










TPH (gasolines) (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: -





COMPANY: HDR


Notes:





TPH (gasolines)







Reference:








CHEMICAL PARAMETERS



Molecular Weight (modeled) 119

Koc cm3/g 5000





Henry's Constant unitless 3.22E+01




Mutagen? No













Mutagenic Effects -



TPH (gasolines)




TPH (gasolines)

RESIDENTIAL


Ingestion mg/kg -


1/Ingestion kg/mg


Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -






1/Dermal kg/mg 1.0E-041/Inhalation (vapors+particulates) kg/mg 1.3E-041/Inhalation (particulates only) kg/mg 5.6E-09Noncancer Effects Final Action Level mg/kg 1.5E+03Final Tier 2 Action Level: mg/kg 1.5E+03




TPH (gasolines)



Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg







NOTES:

REFERENCES:






Table 2mDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Indeno(1,2,3-cd)pyreneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:



Step 1. Select Contaminant: Model not applicable







INDENO(1,2,3-cd)PYRENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 7.0E+00





COMPANY: HDR


Notes:





INDENO(1,2,3-cd)PYRENE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 1951000









Mutagen? Yes





















RESIDENTIAL






Mutagenic Effects






Ingestion mg/kg -


1/Ingestion kg/mg













Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg


NOTES:

REFERENCES:






Table 2nDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Methylene ChlorideU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










METHYLENE CHLORIDE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 3.4E+02





COMPANY: HDR


Notes:





METHYLENE CHLORIDE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 21.7









Mutagen? No













Mutagenic Effects -



METHYLENE CHLORIDE




METHYLENE CHLORIDE

RESIDENTIAL






Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -










METHYLENE CHLORIDE























NOTES:

REFERENCES:






Table 2oDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - 1-MethylnaphthaleneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










METHYLNAPHTHALENE, 1- (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 2.4E+02





COMPANY: HDR


Notes:





METHYLNAPHTHALENE, 1-







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 2258









Mutagen? No






CALCULATED PARAMETERSKd cm3/g 1.4E+01Saturation (Volatile Liquids Only) mg/kg NAAir dispersion term (SSGs) g/m2-sec 68.81Apparent Diffusivity (SSGs) cm2/sec 1.3E-07Inhalation Age-Adjusted Factor







Mutagenic Effects -








RESIDENTIAL





1/Dermal kg/mg 0.0E+001/Inhalation (vapors+particulates) kg/mg 0.0E+001/Inhalation (particulates only) kg/mg 0.0E+00Carcinogenic Effects Final Action Level mg/kg 2.4E+02

Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -






1/Dermal kg/mg 0.0E+001/Inhalation (vapors+particulates) kg/mg 0.0E+001/Inhalation (particulates only) kg/mg 0.0E+00Noncancer Effects Final Action Level mg/kg 5.5E+03Final Tier 2 Action Level: mg/kg 2.4E+02



























NOTES:

REFERENCES:






Table 2pDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - 2-MethylnaphthaleneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










METHYLNAPHTHALENE, 2- (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: -





COMPANY: HDR


Notes:












Reference:








CHEMICAL PARAMETERS




Koc cm3/g 2478









Mutagen? No













Mutagenic Effects -








RESIDENTIAL


Ingestion mg/kg -


1/Ingestion kg/mg

1/Dermal kg/mg1/Inhalation (vapors+particulates) kg/mg 0.0E+001/Inhalation (particulates only) kg/mgCarcinogenic Effects Final Action Level mg/kg -

Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -













Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg







NOTES:

REFERENCES:






Table 2qDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - Methyl Isobutyl KetoneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










METHYL ISOBUTYL KETONE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: -





COMPANY: HDR


Notes:






METHYL ISOBUTYL KETONE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 12.6









Mutagen? No













Mutagenic Effects -








RESIDENTIAL


Ingestion mg/kg -


1/Ingestion kg/mg


Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -



Ingestion mg/kg -










Ingestion mg/kg -


1/Ingestion kg/mg



Ingestion mg/kg -






Ingestion mg/kg -


1/Ingestion kg/mg



Ingestion mg/kg -




NOTES:

REFERENCES:






Table 2rDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - NaphthaleneU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










NAPHTHALENE (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: 2.2E+02





COMPANY: HDR


Notes:





NAPHTHALENE







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 1544









Mutagen? No













Mutagenic Effects -



NAPHTHALENE




NAPHTHALENE

RESIDENTIAL


Ingestion mg/kg -




Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -










NAPHTHALENE



Ingestion mg/kg -











Ingestion mg/kg -









NOTES:

REFERENCES:






Table 2sDetermination of Pacific Basin Tier 2 RBCL for a Marshallese Resident's Exposure to Soil - XylenesU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands


Notes:










XYLENES (mg/kg)Unrestricted (Residential) Land Use Cancer Concerns: -





COMPANY: HDR


Notes:






XYLENES







Reference:








CHEMICAL PARAMETERS




Koc cm3/g 375









Mutagen? No













Mutagenic Effects -



XYLENES




XYLENES

RESIDENTIAL


Ingestion mg/kg -


1/Ingestion kg/mg


Mutagenic Effects

Ingestion mg/kg -


1/Ingestion kg/mg -










XYLENES



Ingestion mg/kg -


1/Ingestion kg/mg









Ingestion mg/kg -


1/Ingestion kg/mg







NOTES:

REFERENCES:






Table 3aEcological Risk-Based Cleanup LevelsU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

Terrestrial Wildlife w/

NOAEL

Terrestrial Wildlife w/

LOAEL

Value Value

Benzene 71-43-2 3.3 33 NA 0.0065 0.0011Benzo(a)anthracene 56-55-3 0.29 1.4 0.34 0.61 0.18Benzo(a)pyrene 50-32-8 0.47 2.3 0.058 0.26 0.31Benzo(b)fluoranthene 205-99-2 0.2 1.1 0.13 NA 0.48Chloroform 67-66-3 1.8 4.8 NA 0.0027 NADibenz(a,h)anthracene 53-70-3 0.29 1.5 0.013 0.027 0.073Diesel Range Organics (DRO) DRO NA NA 38100 27000 23000Ethylbenzene 100-41-4 NA NA NA 7.4 18Gasoline Range Organics (GRO) GRO NA NA 59 1300 4300Indeno(1,2,3-cd)pyrene 193-39-5 0.25 1.3 0.035 NA 0.26Methylene chloride 75-09-2 0.53 4.5 NA 0.005 4.71-methylnaphthalene 90-12-0 11 56 NA 8 112-methylnaphthalene 91-57-6 11 56 26 8.7 10Methyl Isobutyl Ketone (MIBK; 4-methyl-2-pentanone)

108-10-1 2.3 23 NA NA 0.3

Naphthalene 91-20-3 1.7 8.5 8 2.1 2Xylenes 1330-20-7 0.38 0.47 NA 1 NA

Notes:All risk-based cleanup levels (RBCLs) and concentrations are in units of mg/kg.Site-specific soil concentrations greater than the RBCLs are shaded. Input parameters and calculations for the derivation of the ecological RBCLs are presented in Tables 3b to 3e.

Abbreviations:COC = Contaminant of concernLOAEL = Lowest observed adverse effect levelNA = Not availableNOAEL = No observed adverse effect levelRBCL = Risk-based cleanup level

References:USEPA. 2005. Guidance for Developing Ecological Soil Screening Levels. OSWER Directive 9285.7-55. February. Available online: https://www.epa.gov/chemical-research/guidance-developing-ecological-soil-screening-levels

Contaminant of Concern CASRN

Ecological RBCLsSite-Specific Maximum Detected

Soil Concentrations

Carlos Power

Plant Site

Echo Pier Fuel Lines

Site

Hotline Refueling

Site

Page: 1 of 6

Table 3bWildlife Exposure FactorsU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

Value Basis Value Basis

Terrestrial Mammalian Herbivore Deer MousePeromyscus maniculatus

0.0615Average; range is 0.014 -

0.128 ha1 0.021

Average for adults: range is 14.8 - 31.5 g

80% 20% 0.076 2% 0.0015

TerrestrialMammalian Carnivore / Omnivore

Short-Tailed Shrew

Blarina brevicauda 0.39 Average 1 0.017Average for adults; range is 12.5 - 22.5 g (Pennsylvania)

10% 85% 5% 0.0052 2% 0.000104

Terrestrial Mammalian Herbivore Goat Various types 3,170Average; range is 3.4 - 60

km2 on Hawaii1 31

Average for Angora and Spanish species; range is 65 - 70 lbs

100% 7.4 2% 0.15

Notes:(1) The foraging home range values are chosen based on locality or most similar region to the Site; otherwise, the average of available adult values is calculated (USEPA 1993, Chynoweth 2015).(2) Body weights are chosen based on locality or most similar region to the Site; otherwise, the average of available adult values is calculated (USEPA 1993, Lyons n.d.).(3) Dietary composition of food types from EPA 1993 and using professional judgment. (4) Estimated daily food ingestion rate in units of kg dry weight food/day are obtained from Nagy (2001):

Herbivorous mammals: [0.859*(Body Weight)^0.628] for a deer mouse; andCarnivorous mammals: [0.153*(Body Weight)^0.834] for a short-tailed shrew (USEPA 1993).

(5) Percent soil in food are obtained from Beyer et al. (1994).

Abbreviations:AUF -- Area use factor - assumed conservatively to be 1 EPA -- Environmental Protection Agencyha-- HectareIR -- Ingestion ratekg -- KilogramL -- Liter

References:Beyer, WN; Connor, EE; Gerould, S. 1994. "Estimates of soil ingestion by wildlife." J. Wildl. Manage. 58(2):375-382Chynoweth, M.W., et. al. 2015. Home Range Use and Movement Patterns of Non-Native Feral Goats in a Tropical Island Montane Dry Landscape. PLOS One: 10(3).

Lyons, R.K., et. al. N.d. Understanding Forage Intake in Range Animals. Texas A&M System, AgriLife Extension. E-393. Nagy, K.A. 2001. Food Requirements of Wild Animals: Predictive Equations for Free-living Mammals, Reptiles, and Birds. Nutrition Abstracts and Reviews, Series B: Livestock Feeds and Feeding: 71(10).

Receptor Exposure Factors

Habitat Type

Receptor GroupRepresentative

SpeciesCommon Name

Representative Species

Scientific Name

Foraging Home Range(ha) (1)

Area UseFactor(AUF)

Incidental Soil

Ingestion Rate

(kg dry wt soil/day)

USEPA. 1993. Wildlife Exposure Factors Handbook Volume I of II. EPA/600/R-93/187. Office of Health and Environmental Assessment, Office of Research and Development, Washington, D.C. Available online: http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=2799&CFID=42907397&CFTOKEN=88506585

RMI. 2008. Republic of the Marshall Islands Biodiversity Clearing House Mechanism. Office of Environmental Planning and Policy Coordination. Last Updated: Oct 2, 2008. Available online: http://biormi.org/index_nav_left.shtml?en/db_search.shtml

Dietary Fraction of Food Item (DF) (3)

Body weight(kg) (2)

Ingestion Rates (IR)

Pla

nt

Mat

eria

l

Ter

rest

rial

Inve

rteb

rate

s

Mam

mal

s

Daily Food Ingestion

Rate (kg dry wt food /day)

(4)

PercentSoil in Food

(5)

Page: 2 of 6

Table 3cWildlife Toxicity Reference ValuesU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

Benzene 71-43-226 264

NOAEL recommended by source, Tier 4 chronic critical study, deer mouse, soil model. LOAEL from same study as that of NOAEL.

2

Benzo(a)anthracene 56-55-3

0.62 3.1NOAEL for high molecular weight PAHs recommended by source, from Culp et al. 1998. LOAEL from same study as that of the NOAEL.

1

Benzo(a)pyrene 50-32-8


1

Benzo(b)fluoranthene 205-99-2


1

Chloroform 67-66-315 41

NOAEL recommended by source, Tier 4 chronic critical study, rat, soil model. LOAEL from same study as that of NOAEL.

2

Dibenz(a,h)anthracene 53-70-3


1

Diesel Range Organics (DRO) DRO Not availableEthylbenzene 100-41-4 Not availableGasoline Range Organics (GRGRO Not availableIndeno(1,2,3-c,d)pyrene 193-39-5


1

Methylene chloride 75-09-25.9 50


2

1-methylnaphthalene 90-12-0

66 328

NOAEL for low molecular weight PAHs recommended by source, from Verschuuren et al. 1976. LOAEL from same study as that of the NOAEL.

1

2-methylnaphthalene 91-57-6

66 328


1

Methyl Isobutyl Ketone (MIBK; 4-methyl-2-pentanone )

108-10-125 250


2

Naphthalene 91-20-3

66 328


1

Xylenes 1330-20-72.1 2.6

NOAEL recommended by source, Tier 4 chronic critical study, deer mouse, soil model. LOAEL from same study as that of NOAEL.

2

Mammalian

Constituent CASRN NOAEL(mg/kg-d)

LOAEL(mg/kg-d)

Basis Ref

Page: 3 of 6

Table 3cWildlife Toxicity Reference ValuesU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

Notes:

Abbreviatoins: DOE -- Department of EnergyEco SSL -- USEPA Ecological Soil Screening LevelEPA -- United States Environmental Protection AgencyGRO -- GrowthIRIS -- Integrated Risk Information SystemLANL -- Los Alamos National LaboratoryLOAEL -- Lowest observed adverse effect levelmg/kg-d -- Milligrams per kilogram per dayNA -- Not availableNOAEL -- No observed adverse effect levelORNL -- Oak Ridge National LaboratoryPAH -- Polycyclic aromatic hydrocarbonTRV -- Toxicity reference value

References:

USEPA. 2015. Integrated Risk Information System (IRIS). February 27. Available online: http://www2.epa.gov/iris

TRVs for polycyclic aromatic hydrocarbons (PAHs) were applied based on the type of PAH, which is based on the number of aromatic rings in the compound. Low molecular weight PAHs have less than four aromatic rings while high molecular weight

(1) USEPA. 2010. Ecological Soil Screening Levels. Various documents. October 20. Available online: http://www2.epa.gov/risk/ecological-soil-screening-level-eco-ssl-guidance-and-documents(2) DOE. 2014. ECORISK Database (Release 3.2). LANL (Los Alamos National Laboratory). LA-UR-14-28010. Los Alamos, NM. October. Available online: http://www.lanl.gov/community-environment/environmental-stewardship/protection/eco-risk-Sample et al. 1996. Toxicological Benchmarks for Wildlife: 1996 Revision. DOE Oak Ridge National Laboratory (ORNL). ES/ER/TM-86/R3. June. Available online: http://rais.ornl.gov/documents/tm86r3.pdf

Toxicity reference values (TRVs) are chosen based on a hierarchy from the following sources: EPA Eco-SSLs, DOE LANL ECORISK database, DOE ORNL Sample 1996 and EPA IRIS. When EPA Eco-SSL documents did not identify a LOAEL with the recommended NOAEL, a LOAEL was chosen that was the lowest value above the NOAEL for reproductive, growth or survival effects in which the study design was chronic (> 2 weeks) and exposure routes not gavage-related in accordance with EPA guidance (1997).

Page: 4 of 6

Table 3dWildlife Bioaccumulation FactorsU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

LogKow BAF BAF BAF

Benzene 71-43-2 2.1 2.5 1 1Benzo(a)anthracene 56-55-3 5.8 0.32 1.6 0Benzo(a)pyrene 50-32-8 6.1 0.10 1.3 0Benzo(b)fluoranthene 205-99-2 5.8 0.31 2.6 0Chloroform 67-66-3 2.0 2.7 1 1Dibenz(a,h)anthracene 53-70-3 6.8 0.13 2.3 0Diesel Range Organics (DRO)** DRO 5.7 0.60 1 1Ethylbenzene 100-41-4 3.2 1.7 1 1Gasoline Range Organics (GRO)** GRO 2.1 2.5 1 1Indeno(1,2,3-c,d)pyrene 193-39-5 6.7 0.11 2.9 0Methylene chloride 75-09-2 1.3 3.6 1 11-methylnaphthalene* 90-12-0 3.9 1.2 3.0 02-methylnaphthalene* 91-57-6 3.9 1.2 3.0 0

Methyl Isobutyl Ketone (MIBK; 4-methyl-2-pentanone ) 108-10-1 1.3 3.5 1 1Naphthalene 91-20-3 3.3 12 4.4 0Xylenes 1330-20-7 3.16 2 1 1

Notes:

When no BAF was available, a value of 1 was input as recommended by EPA 2007.

Abbreviations:BAF = Soil to plant bioaccumulation factorCOC = Contaminant of concern

References:

COC CASRNSoil to Terrestrial

Plants BAF

USEPA. 2007. Guidance for Developing Ecological Soil Screening levels (Eco-SSLs). OSWER Directive 9285.7-55. Attachment 4-1. April. Available online: http://www.epa.gov/ecotox/ecossl/SOPs.htm

Soil to Invertebrates

Soil to Small Mammals

The median soil to plant BAF was applied as recommended by USEPA Guidance for Developing Ecological Soil Screening Levels, Attachment 4-1, Appendix C. If a median BAF was not identified, the BAF was calculated using the LogKow of the COC in the following equation of Figure 5 (USEPA 2007): LogBAF = -0.4057 * LogKow + 1.781.The BAFs for soil to invertebrates (earthworms) and soil to small mammals were taken from Table 4b of Attachment 4-1 (USEPA 2007).

* Applied the BAF of total Low Molecular Weight Polycyclic Aromatic Hydrocarbons (LMW PAHs) to 1-methylnaphthalene and 2-methylnaphthalene.** Applied the LogKow of TPH Aliphatic Low for GRO and TPH Aliphatic Medium for DRO based on the number of carbons and chemical composition of each mixture

Page: 5 of 6

Table 3eDetermination of RBCLs for Terrestrial Ecological SpeciesU.S. Army Garrison-Kwajalein Atoll (USAG-KA)Republic of Marshall Islands

NOAEL LOAEL NOAEL LOAEL NOAEL LOAEL NOAEL LOAEL

Soil Benzene 71-43-2 3.3 33 75 752 43 435 3.3 33Soil Benzo(a)anthracene 56-55-3 0.29 1.4 1.5 7.3 7.5 38 0.29 1.4Soil Benzo(a)pyrene 50-32-8 0.47 2.3 1.8 8.8 21 106 0.47 2.3Soil Benzo(b)fluoranthene 205-99-2 0.22 1.1 0.91 4.5 7.7 39 0.22 1.1Soil Chloroform 67-66-3 1.8 4.8 42 115 23 63 1.8 4.8Soil Dibenz(a,h)anthracene 53-70-3 0.29 1.5 1.0 5.1 17 85 0.29 1.5Soil Diesel Range Organics (DRO) DRO NA NA NA NA NA NA NA NASoil Ethylbenzene 100-41-4 NA NA NA NA NA NA NA NASoil Gasoline Range Organics (GRO) GRO NA NA NA NA NA NA NA NASoil Indeno(1,2,3-cd)pyrene 193-39-5 0.25 1.3 0.83 4.2 20 98 0.25 1.3Soil Methylene chloride 75-09-2 0.53 4.5 15 130 6.8 58 0.53 4.5Soil 1-methylnaphthalene 90-12-0 11 56 80 401 217 1087 11 56Soil 2-methylnaphthalene 91-57-6 11 56 80 401 216 1082 11 56

SoilMethyl Isobutyl Ketone (MIBK; 4-methyl-2-pentanone )

108-10-12.3 23 66 656 30 296 2.3 23

Soil Naphthalene 91-20-3 1.7 8.5 44 219 22 112 1.7 8.5Soil Xylenes 1330-20-7 0.38 0.47 6.5 8.0 5.2 6.5 0.38 0.47

Notes:

RBCLs were not calcluated for DRO, GRO and ethylbenzene because no mammal toxicity reference values (TRVs) were available.

RBCL Equation:

Abbreviations:ABS = Dietary fraction of foodAUF = Area use factor of 1, assuming full use of siteBAF = Soil to plant/invertebrate/mammal bioaccumulation factorBW = Body weightCOC = Contaminant of concernFIR = Food ingestion rateIR = Ingestion rateLOAEL = Lowest observed adverse effect levelNOAEL = No observed adverse effect levelRBCL = Risk based cleanup levelTHQ = Target hazard quotient of 1TRV = Toxicity reference value (i.e., NOAEL or LOAEL)

References:

USEPA. 2007. Guidance for Developing Ecological Soil Screening Levels (Eco-SSLs), Attachment 4-1. OSWER Directive 9285.7-55. April. Available online: https://www.epa.gov/chemical-research/guidance-developing-ecological-soil-screening-levels

Medium COC CASRNDeer Mouse RBCL

(mg/kg)Short-tailed Shrew RBCL

(mg/kg)Goat RBCL

(mg/kg)Terrestrial Wildlife RBCL

(mg/kg)

Soil risk-based cleanup levels (RBCLs) were calculated for terrestrial species that are representative of receptor groups potentially present on-site and for which there are literature-based exposure factors available (e.g., deer mouse for small herbivores). See Tables 5a and 5c.For each representative species, a RBCL was calculated for two noncancer health endpoints: a no observed adverse effect level (NOAEL) and lowest observed adverse effect level (LOAEL). See Table 5b.

USEPA. 2005. Guidance for Developing Ecological Soil Screening Levels. OSWER Directive 9285.7-55. February. Available online: https://www.epa.gov/chemical-research/guidance-developing-ecological-soil-screening-levels

Page: 6 of 6

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