hotline refueling ram final 061317 · ues u.s. army kwajalein atoll environmental standards u.s....

Engineering Technical, Operational and Support Services (ETOSS)

W9113M-11-D-0003 Delivery Order #0018

Final

Removal Action Memorandum Former Hotline Refueling System

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

Republic of the Marshall Islands Site ID CCKWAJ-006

August 2017

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. Document No. 7050

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W9113M-11-D-0003 TO 0018 Final Removal Action Memorandum Former Hotline Refueling System

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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 .............................................................................................. 1-3

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 BKSS Investigation 2015 ......................................................................... 2-1

2.2 Conceptual Site Model ....................................................................................... 2-13 2.3 Cultural Resource Assessment ........................................................................... 2-13

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 4.4.2 Implementability ...................................................................................... 4-7


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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 .......................................................................................... 4-11

4.7 Comparative Analysis of Alternatives ............................................................... 4-11 4.7.1 Implementability Comparison ............................................................... 4-11 4.7.2 Cost Comparison .................................................................................... 4-13

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

4.9 Cultural Resource Evaluation ............................................................................ 4-15 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 Performance Criteria ................................................................................ 5-3 5.3 System Design Concepts...................................................................................... 5-4

5.3.1 Fuel Line Cleaning ................................................................................... 5-4 5.3.2 Bioventing and In Situ Enhanced Bioremediation................................... 5-4

5.4 Schedule ............................................................................................................... 5-5 6.0 PROPOSED WORK SUMMARY .................................................................................. 6-1

6.1 Schedule ............................................................................................................... 6-1 6.2 Project Reporting ................................................................................................. 6-1 6.3 Sampling and Analysis Plan ................................................................................ 6-2 6.4 Quality Assurance Project Plan ........................................................................... 6-2 6.5 Health and Safety Plan ......................................................................................... 6-2 6.6 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 Former Hotline Refueling System MIP Results (ASC, 2015) ............................. 2-1 Table 2-2 Former Hotline Refueling System Screening Level Exceedances ...................... 2-3 Table 2-3 Former Hotline Refueling System Petroleum Sources ........................................ 2-6 Table 3-1 FRTR Screening Matrix for Preferred Options ................................................... 3-2 Table 3-2 Initial Evaluation of Removal Action Options for the Former Hotline

Refueling System ................................................................................................. 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 Biopile Effectiveness Evaluation ......................................................................... 4-6 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 Risk-Based Cleanup Levels ................................................................................. 5-3

Figures

Figure 1-1 Former Hotline Refueling System Location ........................................................ 1-5 Figure 1-2 Kwajalein POL Schematic (R.M. Towill Corporation, 1964) ............................. 1-7 Figure 1-3 Kwajalein POL Schematic Inset of Former Hotline Refueling System

(R.M. Towill Corporation, 1964) ......................................................................... 1-9 Figure 2-1 Operations Apron Locations of Hydrocarbon Odors (Pacific Geotechnical,

2013) .................................................................................................................... 2-7 Figure 2-2 Former Hotline Refueling System Soil Boring Locations and DRO Results ...... 2-9 Figure 2-3 Former Hotline Refueling System Soil Boring Locations and GRO Results .... 2-11 Figure 2-4 Former Hotline Refueling System Conceptual Site Model ............................... 2-14 Figure 5-1 Former Hotline Refueling System DRO/GRO Plume and Proposed

Remediation Area ................................................................................................ 5-7

Attachments

Attachment A Project Schedule Attachment B Membrane Interface Probe Field Services Report (ASC, 2015) 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 Archeological Monitoring Plan ARSTRAT U.S. Army Forces Strategic Command ASC ASC Tech Services ATEC U.S. Army Test and Evaluation Command ATSC Atmospheric Technology Services Company bgs below ground surface °C degrees Celsius 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 FID flame ionization detector FN facility number FRTR Federal Remediation Technologies Roundtable FSP Field Sampling Plan GRO gasoline range organics HASP Health and Safety Plan HDD Horizontal Directional Drilling HDPE high-density polyethylene Hotline Former Hotline Refueling System KMR Kwajalein Missile Range mg/kg milligram per kilogram MIBK 4-methyl-2-pentanone MIP membrane interface probe


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mph miles per hour ND Non-Detect NFA/RC no further action/response complete O&M operations and maintenance ORNL Oak Ridge National Laboratory PAH polycyclic aromatic hydrocarbon PID photoionization detector 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 Reagan Test Site SAP Sampling Analysis Plan 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 U.S. United States 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 VOC volatile organic compound


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ES-1

EXECUTIVE SUMMARY

This Removal Action Memorandum (RAM) conforms to United States (U.S.) Army Kwajalein Atoll Environmental Standards (UES) 3-6.5.8 (g) for proposed removal actions at the Former Hotline Refueling System (Hotline) on Kwajalein Atoll, Republic of the Marshall Islands (RMI). The proposed remediation of contaminated soil is included as part of the RAM as a removal action to protect human health and the environment. Risk-Based Cleanup Levels (RBCLs) were developed using the Tier 2 Pacific Basin Calculator with site-specific parameters and assuming unrestricted land use. The Army Environmental Database for Compliance Cleanup (AEDB-CC) number for the Kwajalein Fuel Farm is CCKWAJ-006 and includes Hotline.

Hotline runs under the runway apron at the northern end of the airfield on Kwajalein Island and consists of a series of 8-inch and 6-inch aviation gas lines. Based on the age and historical use of the installation, aviation gas and the jet fuels JP-4 and JP-5 were likely stored in tanks at the adjacent Kwajalein Fuel Farm and conveyed through the system fuel lines for aircraft refueling operations. The Hotline fuel lines are no longer in use.

A 2013 geotechnical investigation of the Operations Apron of the Bucholz Army Airfield (Pacific Geotechnical, 2013) identified petroleum odors from soils removed during borings near Hotline. A subsequent 2015 BKSS investigation further characterized the nature and extent of petroleum contamination at Hotline. Sampling results identified contaminants of concern (COCs) in soil, including the following compounds:

Gasoline range organics (GRO)

Diesel range organics (DRO)

Volatile organic compounds (VOCs) (including 4-Methyl-2-pentanone, benzene, ethylbenzene, and methylene chloride)

Polycyclic aromatic hydrocarbons (PAHs) (including benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenz(a,h)anthracene, 1-methylnaphthalene, 2-methlynaphthalene, indeno(1,2,3-cd)pyrene, and naphthalene).

The VOC and PAH concentrations have been found to correlate with the DRO and GRO exceedances. As such, addressing the DRO and GRO contamination is expected to address the other COCs identified above.

Seven treatment and disposal alternatives were evaluated for the removal action of contaminated soils near the fuel lines:

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


ES-2

The evaluation includes comparison of effectiveness, implementability, and cost to determine the preferred option for this site. After evaluation and comparison, it was determined that in-situ bioventing and enhanced bioremediation provide the best overall cleanup strategy in terms of effectiveness, cost, and time.

The Hotline fuel lines will be accessed, drained, cleaned, and capped to remove any potential future contamination source. Fuel lines will be cleaned and all liquids removed for disposal or recycling. In-situ enhanced bioremediation through the addition of nutrients and oxygen-releasing compounds will degrade contamination at the source area without creating additional costs required to excavate a large area and will reduce significant disruptions to flight operations. During the installation of the bioventing and enhanced bioremediation system, any excavated contaminated soils discovered will be transported to and treated at the existing landfarm treatment cells on Kwajalein, thereby mitigating contamination migration risks.

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 at Hotline. Sampling locations will be established in approved locations as not to impact existing utilities or infrastructure and also to be representative of the contaminated areas.

The soil removal and remediation action is planned for mid 2016. The fuel line cleaning, biovent installation, pavement repair, and enhanced bioremediation are estimated to cost approximately $347,500. Remediation of the site should provide response completion by the middle of 2018.


1-1

1.0 INTRODUCTION

1.1 Project Information

The United States Army Garrison-Kwajalein Atoll (USAG-KA) proposes to remediate soil contaminated with petroleum hydrocarbons, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs) at the Former Hotline Refueling System (Hotline) beneath the airport runway apron.

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

1.3, 2.0 2.2 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 6.3 6.4 6.5

(1)(iv) Schedule 6.1, Attachment A (1)(v) Resource damage restoration 6.0 (2) Review by Appropriate Agencies 5.2.1, 6.2 (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 at the USAG-KA/Ronald Reagan Ballistic Missile Defense Test Site (RTS). The two islands are 50 miles apart; multiple other islands used by USAG-KA/RTS are situated between these two islands.


1-2

Hotline runs under the runway apron at the northern end of the airfield. The refueling system consists of a series of 8-inch and 6-inch aviation gas lines. Based on the age and historical use of the installation, aviation gas and the jet fuels JP-4 and JP-5 were likely stored in tanks at the nearby Kwajalein Fuel Farm and conveyed through the system for aircraft refueling operations.

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, 2016). Yearly rainfall totals can vary considerably (59 to 138 inches/year) (Gingerich, 1992). The wettest month on Kwajalein is generally September (11.82 inches), while 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).

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). BKSS has encountered similar conditions during their investigations.


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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 (U.S. Army Environmental Hygiene Agency [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.

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 to USAG-KA/RTS on June 15, 2001.

The USAG-KA/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 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 has supported other DoD training activities as well as commercial space launch operations.

1.3.1 Site History

Schematics of the Kwajalein petroleum, oil, and lubricant (POL) system dated 1964 (Towill, 1964) indicate that the former fuel lines run from the fuel farm, east under Lagoon Road before


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turning to the north, beneath the airfield, and ultimately teeing off just south of Buildings Facility Number (FN) 900, FN 902, FN 949, and FN 901. The fuel lines are no longer in use. The schematic diagram indicates that Hotline consists of a series of 8-inch and 6-inch aviation gas lines (Towill, 1964). See Figure 1-2 and Figure 1-3. It is likely that aviation gas and the jet fuels JP-4 and JP-5 were stored at the Kwajalein Fuel Farm and were conveyed through the system for aircraft refueling operations.

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. Contaminants of concern (COCs), with their respective UES screening levels in milligrams per kilogram (mg/kg) include:

Gasoline range organics (GRO) (100 mg/kg)

Diesel range organics (DRO) (500 mg/kg)

VOCs (cleanup criteria vary by specific compound)

PAHs (cleanup criteria vary by specific compound) Primary considerations are the stability of the contaminants and the potential for public contact with the hazardous materials/wastes. This RAM describes actions to minimize or remove the potential hazards presented by the presence of contaminants in the subsurface.

The soil remediation is considered important but not time critical as the affected area is subsurface with minimal exposure to receptors and not in an area that would impact the island drinking water resource. Additionally, access to the runway apron area is generally limited to authorized airfield personnel. Site access controls and the nature of the airfield construction provide physical barriers, reducing potential exposure pathways. 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.


1-5

Figure 1-1 Former Hotline Refueling System Location


1-6



1-7

Figure 1-2 Kwajalein POL Schematic (R.M. Towill Corporation, 1964)


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1-9

Figure 1-3 Kwajalein POL Schematic Inset of Former Hotline Refueling System (R.M. Towill Corporation, 1964)


1-10



2-1

2.0 PRE-REMOVAL ACTION DESIGN ACTIVITIES TO DATE

2.1 Previous Investigations

With the exception of several geotechnical borings being advanced in the area and a report of petroleum odors from some of the soils removed from the borings, no prior studies have been conducted for Hotline. Figure 2-1 identifies the areas of the Operations Apron that reported petroleum odors at or near the groundwater surface during the geotechnical investigation (Pacific Geotechnical, 2013). The investigation was conducted as part of a runway re-paving study and was not specifically designed to identify or locate contamination.

2.1.1 BKSS Investigation 2015

BKSS performed a subsurface investigation in 2015 to evaluate the nature and extent of fuel-related contamination in the vicinity of the underground lines associated with Hotline. Using existing drawings of former fuel systems on Kwajalein (Figures 1-2 and 1-3; Towill 1964), BKSS established proposed boring locations along the abandoned fuel line system and provided the field team coordinates for the proposed locations. The investigation consisted of membrane interface probe (MIP) screening to groundwater or refusal and the subsequent advancement of 28 Geoprobe borings to collect soil samples at depths of 18 to 24 inches below the fuel lines, or where signs of petroleum impact were noted in the boring cores (i.e., staining or odor).

To initially screen for petroleum contamination, a Geoprobe direct push platform outfitted with a MIP was deployed (ASC, 2015). The MIP uses a flame ionization detector (FID) and photoionization detector (PID) to volatilize organic compounds. The MIP screening results were used to identify areas of contamination, and consequently, to guide soil sampling efforts. The MIP FID results were more conclusive and are presented in Table 2-1 and Attachment B Membrane Interface Probe Field Services Report (ASC, 2015).

Table 2-1 Former Hotline Refueling System MIP Results (ASC, 2015)

MIP Location Detector Used

Detector Response (millivolts) Comparison to Average 100

mg/kg Standard Response

Minimum Maximum Average

006-0715-SB04 006-0715-SB05

006-0715-SB05A 006-0715-SB05B 006-0715-SB03 006-0715-SB07 006-0715-SB08 006-0715-SB09 006-0715-SB10

006-0715-SB10A 006-0715-SB10B 006-0715-SB06 006-0715-SB11 006-0715-SB12

FID

4.43E+04 8.16E+04 7.93E+04 7.78E+04 5.80E+04 5.49E+04 5.26E+04 5.04E+04 5.26E+04 5.11E+04 5.26E+04 4.96E+04 4.81E+04 4.65E+04

6.42E+05 1.11E+05 8.85E+04 8.85E+04 1.13E+05 2.54E+05 6.10E+04 5.95E+04 5.80E+04 5.87E+04 5.72E+04 2.54E+05 6.26E+04 5.42E+04

1.94E+05 9.32E+04 8.37E+04 8.40E+04 8.07E+04 7.49E+04 5.56E+04 5.38E+04 5.43E+04 5.46E+04 5.39E+04 8.06E+04 5.06E+04 4.87E+04

> 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100


2-2

Table 2-1 Former Hotline Refueling System MIP Results (ASC, 2015) (Continued)

MIP Location Detector Used

Detector Response (millivolts) Comparison to Average 100

mg/kg Standard Response

Minimum Maximum Average

006-0715-SB13 006-0715-SB14

006-0715-SB14A 006-0715-SB15 006-0715-SB16 006-0715-SB17 006-0715-SB18 006-0715-SB19 006-0715-SB20 006-0715-SB44 006-0715-SB45 006-0715-SB46 006-0715-SB43 006-0715-SB42 006-0715-SB41 006-0715-SB40

4.73E+04 4.27E+04 4.04E+04 3.97E+04 3.81E+04 3.89E+04 3.74E+04 4.27E+04 3.97E+04 3.89E+04 3.97E+04 3.97E+04 3.81E+04 3.81E+04 3.81E+04 3.74E+04



< 100 < 100 < 100 < 100 < 100 < 100 < 100 < 100 > 100 > 100 < 100 < 100 < 100 > 100 < 100 > 100

Yellow highlights indicate detector responses greater than the UES Screening Level of 100 mg/kg for GRO

Soil samples were collected from 28 Geoprobe borings and analyzed for lead, VOCs, PAHs, DRO, and GRO in an off-island laboratory. Following is a summary of the analytical exceedances identified when compared to the UES screening criteria, which are also presented in Table 2-2:

Twelve samples exceeded the UES screening level of 500 mg/kg for DRO; ranging from 1,900 to 23,000 mg/kg

Seven samples exceeded the UES screening level of 100 mg/kg for GRO; ranging from 120 to 4,300 mg/kg

One sample exceeded the UES screening level of 0.28 mg/kg for 4-Methyl-2-pentanone (MIBK), with a concentration of 0.3 mg/kg

One sample exceeded the UES screening level of 0.00023 mg/kg for benzene, with a concentration of 0.0011 mg/kg

Eleven samples exceeded the UES screening level of 0.00017 mg/kg for ethylbenzene; ranging from 0.0014 to 18.0 mg/kg

Five samples exceeded the UES screening level 0.0013 mg/kg for methylene chloride; ranging from 0.0016 to 0.0047 mg/kg

Seven samples exceeded the UES screening level of 0.0058 mg/kg for 1-methylnaphthalene; ranging from 0.81 to 11.0 mg/kg


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Seven samples exceeded the UES screening level of 0.19 mg/kg for 2-methylnaphthalene; ranging from 0.99 to 10.0 mg/kg

Five samples exceeded the UES screening level of 0.012 mg/kg for benzo(a)anthracene; ranging from 0.024 to 0.18 mg/kg

Five samples exceeded the UES screening level of 0.041 mg/kg for benzo(b)fluoranthene; ranging from 0.056 to 0.48 mg/kg

Seven samples exceeded the UES screening level of 0.004 mg/kg for benzo(a)pyrene; ranging from 0.004 to 0.31 mg/kg

Two samples exceeded the UES screening level of 0.013 mg/kg for dibenz(a,h)anthracene; ranging from 0.036 to 0.073 mg/kg

One sample exceeded the UES screening level of 0.24 mg/kg for indeno[1,2,3-cd]pyrene, with a concentration of 0.26 mg/kg

Seven samples exceeded the UES screening level of 0.00054 mg/kg for naphthalene; ranging from 0.0042 to 2.0 mg/kg

Table 2-2 Former Hotline Refueling System Screening Level Exceedances

Sample ID Analyte/ Compound Detected Result

(mg/kg) UES Screening Level (mg/kg)

006-0915-SB32

DRO

8,600

500

006-0915-SB33 8,600 006-0915-SB34 2,100 006-0915-SB24 2,700 006-0915-SB31 9,400 006-0915-SB35 11,000

006-1115-SB24A-01 1,900 006-1115-SB32A-01 10,000 006-1115-SB33A-01 15,000 006-1115-SB34A-01 23,000 006-1115-SB36A-01 2,200 006-1115-SB40A-01 2,200

006-0915-SB32

GRO

910

100

006-0915-SB33 120 006-0915-SB34 170 006-0915-SB31 130

006-1115-SB32A-01 4,300 006-1115-SB34A-01 140 006-1115-SB40A-01 170


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Table 2-2 Former Hotline Refueling System Screening Level Exceedances (Continued)



VOCs 006-1115-SB34A-01 MIBK 0.3 0.28

006-0915-SB24 Benzene 0.0011 0.00023 006-0915-SB32

Ethylbenzene

0.79

0.00017

006-0915-SB33 0.048 006-0915-SB34 0.47 006-0915-SB24 0.0017 006-0915-SB31 0.43 006-0915-SB35 0.1

006-1115-SB32A-01 18.0 006-1115-SB33A-01 0.32 006-1115-SB34A-01 1.3 006-1115-SB35A-01 0.002 006-1115-SB36A-01 0.0014 006-1115-SB24A-01

Methylene Chloride

0.0033

0.0013 006-1115-SB33A-01 0.0047 006-1115-SB35A-01 0.0016 006-1115-SB36A-01 0.0016 006-1115-SB40A-01 0.0017

PAHs 006-0915-SB32

1-Methylnaphthalene

11.0

0.0058

006-0915-SB34 4.3 006-0915-SB31 3.1 006-0915-SB35 2.0

006-1115-SB32A-01 9.8 006-1115-SB34A-01 8.5 006-1115-SB40A-01 0.81

006-0915-SB32

2-Methylnaphthalene

8.0

0.19

006-0915-SB34 4.3 006-0915-SB31 2.6 006-0915-SB35 1.2

006-1115-SB32A-01 10.0 006-1115-SB34A-01 3.3 006-1115-SB40A-01 0.99

006-0915-SB38

Benzo(a)anthracene

0.18

0.012 006-0915-SB25 0.024 006-0915-SB30 0.062

006-1115-SB24A-01 0.087 006-1115-SB32A-01 0.093


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Table 2-2 Former Hotline Refueling System Screening Level Exceedances (Continued)



PAHs (Continued) 006-0915-SB38

Benzo(b)fluoranthene

0.37

0.041 006-0915-SB24 0.34 006-0915-SB25 0.056 006-0915-SB30 0.077

006-1115-SB24A-01 0.48 006-0915-SB29

Benzo(a)pyrene

0.004

0.004

006-0915-SB38 0.22 006-0915-SB24 0.22 006-0915-SB25 0.04 006-0915-SB30 0.065

006-1115-SB24A-01 0.31 006-1115-SB36A-01 0.029

006-0915-SB38 Dibenz(a,h)anthracene 0.036 0.013 006-1115-SB24A-01 0.073 006-1115-SB24A-01 Indeno(1,2,3-cd)pyrene 0.26 0.24

006-0915-SB32

Naphthalene

0.78

0.00054

006-0915-SB34 0.81 006-0915-SB30 0.0042 006-0915-SB31 0.9

006-1115-SB32A-01 2.0 006-1115-SB34A-01 1.9 006-1115-SB40A-01 0.16

The VOC and PAH exceedances have been found to correlate with the DRO and GRO exceedances. As such, addressing the DRO and GRO contamination will address the other COCs identified above.

Detailed review of the chromatograms for the DRO and GRO laboratory analyses indicated the petroleum component fingerprints were mostly representative of diesel or JP-4/JP-5, or hydraulic oil, with two analyses distinctly indicative of JP-4/JP-5, and one that was indicative of Bunker C oil. Table 2-3 lists the DRO components interpreted by the chromatogram reviews from the respective boring samples. The chromatogram signatures for diesel and JP-4/JP-5 are similar, and based on the number of years the fuel products could have been weathered following their release make discerning between diesel and JP-4/JP-5 impracticable; however, the analytical results, in association with the sample locations on the refueling apron, do not suggest there are additional or off-site sources for the contamination other than the Hotline fuel lines and airfield maintenance activities. For example, the detection of hydraulic oil in the subsurface indicates the likelihood hydraulic oil was leaked onto the apron during routine aircraft maintenance and washed through cracks in the pavement by years of precipitation. It is assumed the one Bunker C oil detection is related to a release that likely occurred prior to airfield construction. The DRO and GRO sampling results are shown in Figure 2-2 and Figure 2-3.


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Table 2-3 Former Hotline Refueling System Petroleum Sources

Boring ID Petroleum Source DRO Detected Result (mg/kg) SB-021 Hydraulic oil 5.2 SB-022 Chromatogram not reviewed Non-Detect (ND) SB-023 Diesel or JP-4/JP-5 and hydraulic oil 220 SB-024 Hydraulic oil 2,700 SB-024A Hydraulic oil 1,900 SB-025 Diesel and hydraulic oil 150 SB-026 JP-4/JP-5 23 SB-028 Chromatogram not reviewed 0.89 SB-029 Chromatogram not reviewed 3.9 SB-029A Diesel and hydraulic oil 190 SB-030 Diesel and hydraulic oil 74 SB-031 Diesel or JP-4/JP-5 9,400 SB-032 Diesel or JP-4/JP-5 8,600 SB-032A Diesel or JP-4/JP-5 10,000 SB-033 Diesel or JP-4/JP-5 8,600 SB-033A Diesel or JP-4/JP-5 15,000 SB-034 Diesel or JP-4/JP-5 2,100 SB-034A Diesel and hydraulic oil 23,000 SB-035 Diesel or JP-4/JP-5 11,000 SB-035A Chromatogram not reviewed ND SB-036 Transformer oil and hydraulic oil 53 SB-036A Diesel or JP-4/JP-5 2,200 SB-037 Hydraulic oil 2.1 SB-038 Bunker C and hydraulic oil 140 SB-039 Hydraulic oil 4.8 SB-040A JP-4/JP-5 and hydraulic oil 2,200 SB-042A Chromatogram not reviewed 0.95 SB-044A Chromatogram not reviewed 0.71


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Figure 2-1 Operations Apron Locations of Hydrocarbon Odors (Pacific Geotechnical, 2013)


2-8



2-9

Figure 2-2 Former Hotline Refueling System Soil Boring Locations and DRO Results


2-10



2-11

Figure 2-3 Former Hotline Refueling System Soil Boring Locations and GRO Results


2-12



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2.2 Conceptual Site Model

Based on historical information and data collected during the 2015 BKSS investigation, Figure 2-4 depicts the preliminary Conceptual Site Model (CSM) for the fuel lines associated with Hotline. This CSM is based on the information known about this site as discussed above.

Although no direct human health risks are noted, it cannot be guaranteed that possible remaining contaminated soil and/or groundwater will not be encountered by current or future residents living or working on Kwajalein. The potential COCs are identified and will be remediated as necessary to ensure they do not degrade marine water quality levels defined in Section 3-2 of the UES.

Review of human receptors for Hotline included current and future Installation Personnel and current and future Residents. Based on the contamination source being primarily beneath 2 feet of concrete and 4 to 7 feet below grade, potentially complete pathways include:

Current / Future Installation Personnel o Dermal contact to groundwater o Dermal contact to and ingestion of subsurface soil

Future Residents o Ingestion of biota o Dermal contact to marine water or sediment o Dermal contact to groundwater o Dermal contact to and ingestion of subsurface soil

There are no complete pathways for current Residents. Access to the runway apron area is generally limited to authorized airfield personnel. Site access controls and the nature of the airfield construction provide physical barriers, eliminating potential exposure pathways.

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

BKSS provided archeological monitoring during their site investigation in 2015. No artifacts were noted by the BKSS archeologist during the exploration work. No cultural resources are anticipated at the site.


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Figure 2-4 Former Hotline Refueling System Conceptual Site Model

Installation Personnel Residents

Current

SOURCE INTERACTION RECEPTORS

Subsurface Fuel Lines

ACTIVITY RELEASE MECHANISM TRANSPORT &

MIGRATION MECHANISMS

EXPOSUREMEDIA

EXPOSUREROUTES

TPH

Figure 2-4: Former Hotline Refueling System Conceptual Site Model

SECONDARY SOURCEPRIMARY SOURCE HUMAN HEALTH

Release of Fuel

Surface Human Activities

Air

Surface Soil

Inland SurfaceWater/Sediment

InhalationDermal Contact

Ingestion

Dermal Contact

Ingestion

Ingestion

Dermal Contact

Ingestion

Dermal Contact

Groundwater

Subsurface Soil

LeachingSubsurface

Current Future Future

Key

Complete PathwayIncomplete Pathway

Subsurface SoilMarine

Water/Sediment

Potentially Complete Pathway

Biota Ingestion

Dermal Contact


3-1

3.0 APPLICABLE REMOVAL ACTION TECHNOLOGIES

3.1 Scope and Purpose of Removal Action

The scope of work for this task is to remove the source of fuel contamination in soil by accessing, draining, cleaning, and capping the Hotline fuel lines and in-situ remediation of the petroleum contaminated soil associated with these fuel lines. The removal action objective focuses on using technologies to access and remove the contamination and mitigate the secondary transport of the contamination within the soil.

Characterization of the soil contamination associated with Hotline through subsurface soil sampling reveals the highest concentration of COCs are in the soils beneath the central northern section of the refueling system. Samples were collected from depths where the highest indications of odor or staining were observed and submitted for laboratory analysis.

Based on sample results, COCs in soil include the following:

GRO

DRO

VOCs (4-methyl-2-pentanone, benzene, ethylbenzene, and methylene chloride)

PAHs (benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenz(a,h)anthracene, indeno(1,2,3-cd)pyrene, 1-methylnaphthalene, 2-methlynaphthalene, and naphthalene)

The VOC and PAH exceedances have been found to correlate with the DRO and GRO exceedances. As such, addressing the DRO and GRO contamination is expected to address the other COCs identified above.

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 technology.

Technologies were selected from the FRTR Screening Matrix primarily based on the ability to remediate DRO and GRO (“Fuels” in the screening matrix). Secondary consideration was given to the ability to remediate VOCs (“nonhalogenated VOCs” in the screening matrix) and PAHs (“nonhalogenated semi-volatile organic compounds [SVOCs]” in the screening matrix). Technologies considered above average for these contaminant groups were researched further before the final technologies were selected for in-depth analysis (described below).

3.2 Justification for the Proposed Action

Sampling of soils during the investigation showed contamination exceeding RBCLs remains from petroleum releases; this is defined as a threat to human health and the environment. In


3-2

accordance with the UES, contamination in soil above acceptable concentrations for DRO and GRO, as well as select VOCs and PAHs, constitute a risk and must be removed. Without intervention, contamination in the soil provides an ongoing threat to the surrounding environment.

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” in soil, with secondary consideration given to “nonhalogenated VOCs” 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 below in Section 4.0.

Table 3-1 FRTR Screening Matrix for Preferred Options

Relative Cost & Performance Green = Above Average

Yellow = AverageOrange = Below Average

Deve

lopm

ent S

tatu

s

Trea

tmen

t Tra

in

Relative Overall Cost & Performance

Ava

ilabi

lity

Fuel

s

Non

halo

gena

ted

SVO

Cs

Non

halo

gena

ted

VO

Cs

Ope

ratio

ns

&M

aint

enan

ce

Cap

ital

Syst

em R

elia

bilit

y &

M

aint

aina

bilit

y

Rel

ativ

e C

osts

Tim

e

In situ Biological Treatment 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 to determine relative effectiveness, comparative cost, and their ability to reduce contaminant loading to soil. 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, soil vapor extraction, landfarming, biopiles, and incineration.


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Table 3-2 Initial Evaluation of Removal Action Options for the Former Hotline Refueling System

Option Description Effectiveness Rationale Relative Cost

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. None Yes

In-Situ Technologies

Enhanced Bioremediation

Add nutrients and oxygen to enhance the existing naturally-occurring biodegradation of contaminants. Use Geoprobe or constructed delivery system to apply nutrients at depth.

Good

Studies have shown that indigenous microorganisms on Kwajalein Atoll have the ability to degrade the COCs. The addition of nutrients and oxygen to the subsurface will enhance this natural bioremediation and contaminant desorption from subsurface materials. Because the site is paved, a delivery system will be necessary to provide delivery of nutrients to deeper soils.

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

Soils vapors are extracted to an aboveground remediation system. Does not work with PAHs. Requires installation, operation, and maintenance of system and piping throughout contaminated area to provide air injection and extraction. Extracted vapors may require treatment. The secondary effect of adding oxygen will enhance in-situ naturally-occurring biodegradation.

High No


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Table 3-2 Initial Evaluation of Removal Action options for the Former Hotline Refueling System (Continued)

Option Description Effectiveness Rationale Cost

Qualification (Reason)

Recommended for Further Evaluation

Ex-Situ Technologies

Landfarming

Excavate fuel contaminated soil from around fuel lines and transport to a surface containment area. Use tilling or plowing to deliver nutrients to and oxygenation of the soil ex-situ.

Good

Contamination source area removal will lessen potential public contact, as well as decrease contamination available to migrate to soil or groundwater. Remaining contamination may require additional in situ treatment. Requires excavation and transport of soil to a suitable area in another location for treatment.

Medium-High Yes

Biopiles

Excavate fuel contaminated soil from around fuel lines and transport to a surface containment area. Install injection systems to provide nutrients and air flow (oxygenation) through the ex-situ biopile.

Good

Contamination source area removal will lessen potential public contact, as well as decrease contamination available to migrate to soil or groundwater. 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 system and piping in biopiles to provide nutrient delivery and oxygenation.

Medium-High Yes

Incineration

Excavate soil from around fuel lines and transport to another location. Incinerate soil to remove fuel contamination.

Good

Contamination source area removal will lessen potential public contact, as well as decrease contamination available to migrate to soil or groundwater. 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 on natural processes to perform degradation of contamination. This alternative is included to establish a baseline for relative costs of other alternatives and 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 injected microorganisms degrade organic contaminants found in a specific matrix, converting them to innocuous end products. Nutrients are added to the matrix 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 a specific matrix 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 mixing or injecting nutrients into the layers of the contaminated soil, bioventing uses passive or 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

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 an 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 and oxygenation. This technology typically involves spreading excavated contaminated soils in a thin layer on a liner or


3-6

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, the enhanced microbial activity results in degradation of adsorbed petroleum product constituents through microbial respiration (U.S. Environmental Protection Agency [EPA], 1994a).

3.3.1.6 Biopiles

Biopiles are 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, 1994b).

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, 1994b).

3.3.1.7 Incineration

High temperatures (870 to 1,200 degrees Celsius [°C]) 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 on 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. The costs are relative to each other in order to compare technologies and can be used for comparative purposes since they are based on 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, as well. Access to and removing residual fuel from the fuel lines themselves is an essential step of the remediation process for all technologies discussed below.

4.1 Enhanced Bioremediation

4.1.1 Effectiveness

For enhanced bioremediation systems, the EPA recommends an initial screening for effectiveness before a more detailed analysis is conducted (EPA, 2004). 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. There is a possibility free mobile product will be found within the abandoned fuel lines. This product will be removed as part of the remediation activities and containerized to prevent it from getting into the soils. While concentrations of contaminants in some places 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 on Kwajalein, a more detailed analysis of effectiveness was conducted.

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


4-2

Table 4-1 Enhanced Bioremediation Effectiveness Evaluation

Parameter Effective Reason

Indigenous microbial populations / population density

Yes

A 1992 study to evaluate bioremediation potential for 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 Kwajalein 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; thereby increasing the speed of remediation.

Contaminant constituents and concentration Yes

DRO, GRO, and associated compounds are generally amenable to biodegradation. Concentrations are below 25,000 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

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


4-3

Requires additional oxygen as well as nutrients

May require periodic reapplications

Paved areas will not have precipitation to help disperse added nutrients or organic compounds and provide moisture

May not be able to reduce contaminants to very low concentrations

Typically requires long-term monitoring of residual contamination

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

4.1.3 Relative Cost

Enhanced bioremediation has the potential to be a low-cost option. Costs for this technology could be as limited as the price of the nutrients and the addition of those nutrients while accessing the fuel lines. It is possible that natural subsurface oxygen levels will not be enough to sustain the nutrient enhanced remediation. In this case, additional oxygen will be required in the form of vents (bioventing), chemicals, or another oxygen source.

4.2 Bioventing

4.2.1 Effectiveness

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

Table 4-2 Bioventing Effectiveness Evaluation



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.


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 Bioventing will enhance the supply of oxygen. 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 Kwajalein tends to have a neutral to slightly alkaline pH.

Depth to groundwater Yes Groundwater depths encountered at the Kwajalein airfield ranged from 5.0 to 7.0 feet bgs.

Nutrient supply Yes




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


4-4


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

Advantages:

Enhances natural biodegradation through native microorganisms

Proven effective at a wide range of sites


Requires a low amount of energy

Works well with moist and sandy soils

Uses readily available equipment; easy to install

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

Has simple operation and monitoring requirements

Requires short treatment times (i.e., 6 months to 2 years)

Easily combinable with other technologies

Very effective on fuels, nonhalogenated VOCs, and nonhalogenated SVOCs

Does not require soil removal

Disadvantages:

Not effective with excessive moisture content in soil

May require off-gas treatment

High constituent concentrations may initially be toxic to microorganisms

Cannot always achieve very low cleanup standards

Typically requires long-term monitoring of residual contamination

Requires system installation and maintenance

Regular and continued system monitoring and maintenance required

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 and construction, the number of vents, and the depth of vents. Due to the high water table on Kwajalein and the proximity to local roads, the vents would be constructed horizontally rather than vertically, reducing the total number required.


4-5

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 Kwajalein made up of sand and gravel.

Soil structure Yes Soil on Kwajalein is free of impermeable layers or other conditions that would disrupt air flow. Moisture content Yes Soils on Kwajalein are well drained and have a moderate moisture content.


Depth to groundwater Yes Groundwater depths encountered at the Kwajalein airfield ranged from 5.0 to 7.0 feet bgs.

Contaminant constituents and concentration 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, 1994d).

Advantages:

Proven performance; readily available equipment; easy installation

Short treatment times (i.e., 6 months to 2 years)

May provide oxygen to enhance natural bioremediation

Easily combined with other technologies (e.g., enhanced 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 remediation

Concentration reductions greater than approximately 90% are difficult to achieve


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May require costly treatment for atmospheric discharge of extracted vapors

Air emission permits may be required

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

Due to high water table, special controls could 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

Requires system installation and maintenance


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, 1994d). 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 typically requires treatment prior to disposal. Due to the high water table on Kwajalein, the vents would be constructed horizontally rather than vertically, reducing the total number required, and the impact on local traffic.

4.4 Biopiles

4.4.1 Effectiveness

Because the majority of contaminated soils are beneath the airfield, excavation of all the soils with contamination levels above the remedial goals is unlikely; therefore, the effectiveness of biopiles as a removal action technology is contingent on 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 supplemental to the biopiles action. Table 4-4 summarizes the factors of effectiveness of biopiles for known on-site conditions.

Table 4-4 Biopile Effectiveness Evaluation



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. Additionally, bacteria can be introduced as necessary in the biopile.

Moisture content Yes Soil moisture is amenable to bacterial growth. Additionally, moisture can be regulated within the biopile as necessary.



4-7

Table 4-4 Biopile Effectiveness Evaluation (Continued)


Oxygen availability Yes A 1992 study (ORNL, 1992) on bioremediation on Kwajalein found addition of air/oxygen to be important in maintaining microbial density. Additionally, oxygen concentrations would be supplemented through the biopile system.

Soil texture Yes Soils on Kwajalein made up of sand and gravel. Soil pH Yes Soil on Kwajalein tends to have a neutral to slightly alkaline pH.

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; thereby increasing the speed of remediation. Nutrients can be regulated within the biopile.


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 operations and maintenance (O&M)

Short treatment times (i.e., 6 to 18 months)

USAG-KA already has an available, working biopile or landfarm cell in place on Kwajalein

Effective on organic constituents with slow biodegradation rates

Requires less land area than landfarming

Utilizes indigenous microorganisms to accomplish bioremediation

Can be a closed system (i.e., vapor emissions can be controlled)

Would reduce the risk of in-situ contaminant migration

Disadvantages:

Excavation and transport of contaminated soil is required

Requires backfilling of excavation and removal and replacement of concrete

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 soil below the water table and between utilities

Requires system construction and installation of piping



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4.4.3 Relative Cost

The biopile technology has the potential to be a medium-high cost option. Biopiles are relatively simple and require few personnel for O&M. 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 soil and providing backfill will result in a significant cost increase to this relatively simple alternative. The soil at the airfield is covered by up to 2 feet of concrete, and removing and replacing the concrete would also result in a significant additional expense.

4.5 Landfarming

4.5.1 Effectiveness

Because the majority of contaminated soils are beneath the airfield, excavation of all the soils with contamination levels above the remedial goals is unlikely; therefore, the effectiveness of landfarming as a removal action technology is contingent on 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


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 aerobic microbes. Additionally, bacteria can be introduced as necessary in the landfarm cell.

Moisture content Yes Soil moisture is amenable to bacterial growth. Additionally, moisture can be regulated within the landfarm cell as necessary.


Oxygen availability Yes A 1992 study (ORNL, 1992) on bioremediation on Kwajalein found addition of air/oxygen to be important in maintaining microbial density. Additionally, oxygen concentrations would be supplemented through tilling the landfarm cell.

Soil texture Yes Soils on Kwajalein made up of sand and gravel. Soil pH Yes Soil on Kwajalein tends to have a neutral to slightly alkaline pH. Temperature Yes Soil temperatures are between 10° and 45°C.

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; thereby increasing the speed of remediation. Nutrients can be regulated within the landfarm cell.


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


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Advantages:

Relatively simple to design and implement

Does not require extensive O&M

Short treatment times (i.e., 6 to 18 months)

Effective on organic constituents with slow biodegradation rates


USAG-KA already has an available, working biopile or landfarm cell in place on Kwajalein

May reduce the risk of in-situ contaminant migration

Disadvantages:

Excavation and transport of contaminated soil is required

Requires backfilling of excavation and removal and replacement of concrete

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 soil below the water table and between utilities

Regular and continued landfarm cell monitoring and maintenance required

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 O&M 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 soil and providing backfill will result in a significant cost increase to this relatively simple alternative. The soil at the airfield is covered by up to 2 feet of concrete, and removing and replacing the concrete would also result in a significant additional expense.

4.6 No-Action

4.6.1 Effectiveness

The no-action alternative would rely on natural attenuation of contaminants to accomplish the cleanup goals for the site. It is possible that the natural attenuation of contaminants on Kwajalein would be efficient enough to negate the need for any additional removal action efforts; however, it is approximated the DRO and GRO contamination in the soil have been in place for a while and concentrations are still relatively high. A 1992 study (ORNL, 1992) showed that native microorganisms on Kwajalein Atoll are capable of degrading the COCs naturally. While being capable, this natural process was found to be relatively inefficient as oxygen levels were exceptionally low where remediation had occurred, negatively affecting the bacteria populations.


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It was determined that if elevated or even normal oxygen levels could be sustained, remediation rates could be increased. Table 4-6 summarizes the effectiveness of the no action alternative for known on-site conditions.

Table 4-6 No Action Effectiveness Evaluation



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.



Oxygen availability No 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 Kwajalein 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 No




Intrinsic permeability Yes Bioremediation 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 the no-action alternative are described below.

Advantages:

The most cost-effective alternative to implement; no cost

Effective on organic constituents with high to moderate biodegradation rates


No construction or additional infrastructure required


Requires no energy

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

Causes minimal disturbance to site operations

Has no operation and monitoring requirements


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Disadvantages:

Possibility that contamination levels never reach minimum cleanup criteria

Much slower remediation time-frame (existing contamination is likely decades old and remains above cleanup levels)

Potential for contamination to migrate

Increased risk for human interaction with contaminants

4.6.3 Relative Cost

There is no cost associated with this alternative.

4.7 Comparative Analysis of Alternatives

4.7.1 Implementability Comparison

The majority of Hotline lies beneath the airfield. The highest concentrations of contaminants were found beneath the airfield operations apron. The construction of the airfield presents a unique challenge when considering remediation alternatives; the surface of the operations apron consists of asphaltic concrete from 10 to 24 inches thick (Pacific Geotechnical, 2013). Additionally, this area of the airfield is used frequently during normal base operations, c

hotline refueling ram final 061317 · ues u.s. army kwajalein atoll environmental standards u.s....

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