RECORD OF DECISION FOR SITE SS024 (REEF TAXIWAY) · 647th Air Base Group, Civil Engineer Squadron/ Environmental Restoration Element (647 CES/CEVR) Prepared By: CH2M HILL, Honolulu,

July 14, 2010

RECORD OF DECISIONFOR SITE SS024 (REEF TAXIWAY)

Project KNMD20087772

Hickam Air Force BaseOahu, Hawaii

United States Air Force647 Air Base GroupCivil Engineer SquadronEnvironmental Restoration Element

SDMS DOCID# 1145060

DEPARTMENT OF THE AIR FORCE THIRTEENTH AIR FORCE

HICKAM AFB, HI

MEMORANDUM FOR DISTRIBUTION

FROM: 647 CES/CEVR 75 H Street Hickam AFB HI 96853-5221

JUL 1 4 Z010

SUBJECT: Final Record of Decision (ROD) for Site SS024 (Reef Taxiway), Hickam Air Force Base, Oahu, Hawaii

I. The attached Record of Decision (ROD) for Site SS024 (ReefTaxiway) is provided for your records.

2. Should you have any questions or concerns, please contact Mr. Brian Whitehouse, Remedial Project Manager, at (808) 449-3176 or by e-mai l at brian. [email protected].

2 Attachments: I. Distribution List 2. Final ROD

Chief, Environmental Restoration

DISTRIBUTION LIST Final Record ofDecsion (ROD) for Site SS024 (Reef Taxiway), Hickam Air Force Base, Oahu, Hawaii

State of Hawaii, Dept. of Health Hazard Evaluation and Emergency Response (HEER) Office Attn: Mrs. Lynn Bailey 919 Ala Moana Blvd., Room 206 Honolulu HI 96814 (1 CD)

15 AMDS/SGGB Attn: Capt Walters (1 CD)

15 AW/JAV Attn: Mr. Peter Lee (1 CD)

Army and Pacific Island Section EPA Region IX (EPA SFD-8-3) Attn: Section Chief 75 Hawthorne Street San Francisco CA 94105 (I CD)

State of Hawaii Dept. of Land & Natural Resources Attn: Laura Thielen, Chairperson P.O. Box 621 Honolulu HI 96809-0621 (8 CDs)

Hickam AFB Restoration Advisorv Board Members (I CD ea)

Mr. Ron Mobley Mr. Kyle Kajihiro

Prepared For: United States Air Force13th Air Force 647th Air Base Group, Civil Engineer Squadron/Environmental Restoration Element (647 CES/CEVR)

Prepared By: CH2M HILL, Honolulu, Hawaiion behalf ofAir Force Center for Engineering and the Environment (AFCEE)Environmental Services OfficeSan Antonio, Texas 78226-1845

Contract FA8903-08-D-8769, Task Order 0052July 14, 2010





RECORD OF DECISION FOR SITE SS024 HICKAM AIR FORCE BASE, OAHU, HAWAII

AFCEE CONTRACT FA8903-08-D-8769, TASK ORDER 0052 JULY 14, 2010

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Contents Abbreviations and Acronyms ......................................................................................................... iii

1.0 Declaration ............................................................................................................................... 1-1

1.1 Site Name and Location ................................................................................................ 1-1 1.2 Statement of Basis and Purpose ................................................................................... 1-1 1.3 Description of Selected Decision .................................................................................. 1-1 1.4 Statutory Determinations .............................................................................................. 1-1 1.5 Authorizing Signatures ................................................................................................. 1-2

2.0 Decision Summary ................................................................................................................. 2-1

2.1 Site Name, Location, and Description ......................................................................... 2-1 2.2 Site History and Enforcement Activities .................................................................... 2-1

2.2.1 Site History ........................................................................................................ 2-1 2.2.2 Enforcement Activities ..................................................................................... 2-2

2.3 Community Participation ............................................................................................. 2-2 2.4 Scope and Role of Response Action ............................................................................ 2-3 2.5 Site Characteristics ......................................................................................................... 2-3

2.5.1 Physiography and Climate .............................................................................. 2-3 2.5.2 Geology .............................................................................................................. 2-4 2.5.3 Hydrogeology.................................................................................................... 2-4 2.5.4 Surface Water .................................................................................................... 2-4 2.5.5 Ecology ............................................................................................................... 2-5 2.5.6 Site Investigations ............................................................................................. 2-5 2.5.7 Nature and Extent of Contamination ............................................................. 2-6 2.5.8 Conceptual Site Model ................................................................................... 2-11

2.6 Current and Potential Future Land and Resource Use .......................................... 2-13 2.6.1 Land Use .......................................................................................................... 2-13 2.6.2 Groundwater and Surface Water Resources ............................................... 2-13

2.7 Summary of Site Risks ................................................................................................. 2-13 2.7.1 Baseline Risk Assessment .............................................................................. 2-14 2.7.2 Environmental Hazard Evaluation .............................................................. 2-18 2.7.3 Basis for No Action ......................................................................................... 2-19

2.8 Documentation of Significant Change from Proposed Plan .................................. 2-19

3.0 Responsiveness Summary .................................................................................................... 3-1

4.0 References ................................................................................................................................ 4-1

RECORD OF DECISION FOR SITE SS024 HICKAM AIR FORCE BASE, OAHU, HAWAII AFCEE CONTRACT FA8903-08-D-8769, TASK ORDER 0052 JULY 14, 2010

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Figures 2-1 Site Location Map 2-2 Site Layout 2-3 Historical Aerial Photographs 2-4 Historical Passive Soil Gas Survey Results 2-5 RI Multi-Increment Surface Soil Sampling Locations 2-6 Historical and RI Subsurface Soil, Soil Gas, and Groundwater Sampling Locations 2-7 Tier 1 EAL Exceedances in Surface Soil 2-8 Tier 1 EAL Exceedances in Subsurface Soil 2-9 Tier 1 EAL Exceedances in Groundwater 2-10 Conceptual Site Model

Tables 2-1 Summary of Chemicals Detected in Surface and Subsurface Soils 2-2 Statistical Evaluation of Replicate Multi-Increment Surface Soil Samples 2-3 Summary of Chemicals Detected in Groundwater 2-4 Summary of Chemicals Detected in Soil Gas 2-5 Exposure Point Concentrations for Soil and Groundwater 2-6 Summary of Human Health Risk Estimates for Soil and Groundwater 2-7 Environmental Hazard Evaluation for Chemicals Detected in Soil 2-8 Environmental Hazard Evaluation for Chemicals Detected in Groundwater



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Abbreviations and Acronyms µg/dL micrograms per deciliter °F Degree Fahrenheit AFB Air Force Base bgs below ground surface CERCLA Comprehensive Environmental Response, Compensation, and

Liability Act CFR Code of Federal Regulations CIP Community Involvement Plan COC chemical of concern COPC chemical of potential concern CSM conceptual site model DERP Defense Environmental Restoration Program DU decision unit EAL Environmental Action Level EcoSSL EPA Ecological Screening Level EHE Environmental Hazard Evaluation ELCR excess lifetime cancer risk EPA U.S. Environmental Protection Agency EPC exposure point concentration ES Engineering Science, Inc. HAR Hawaii Administrative Rules HDOH State of Hawaii Department of Health HI hazard index HQ hazard quotient IEUBK Integrated Exposure Uptake Biokinetic Model for Lead in Children IRP Installation Restoration Program LUC land use control mg/kg milligram per kilogram mg/L milligram per liter MI Multi-Increment msl mean sea level


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NCP National Oil and Hazardous Substances Pollution Contingency Plan NPL National Priorities List PAH polynuclear aromatic hydrocarbon PCB polychlorinated biphenyl PSG passive soil gas RAB Restoration Advisory Board RI Remedial Investigation RSD relative standard deviation SARA Superfund Amendments and Reauthorization Act SI Site Inspection SVOC semi-volatile organic compound TCDD tetrachlorodibenzo-p-dioxin TEQ toxic equivalency quotient TPH total petroleum hydrocarbons TPH-d total petroleum hydrocarbons, diesel-range organics TPH-g total petroleum hydrocarbons, gasoline–range organics TPH-o total petroleum hydrocarbons, oil-range organics UCL upper confidence limit UIC underground injection control USAF U.S. Air Force VOC volatile organic compound



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1.0 Declaration

1.1 Site Name and Location Site SS024, Reef Taxiway Hickam Air Force Base (AFB), Oahu, Hawaii

1.2 Statement of Basis and Purpose This document presents the selected No Action decision for Installation Restoration Program (IRP) Site SS024, Reef Taxiway, Hickam AFB, Hawaii, which was chosen in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986 and, to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). This decision is based on the Administrative Record for this site.

This document is issued by the Department of the U.S. Air Force (USAF), as the lead agency. The USAF is managing remediation of contamination at Site SS024 in accordance with CERCLA as required by the Defense Environmental Restoration Program (DERP).

The State of Hawaii Department of Health (HDOH) concurs with the selected remedy.1

1.3 Description of Selected Decision

The decision for Site SS024 is No Action. Current conditions at Site SS024 are protective of human health and the environment, based on current and anticipated future land use; therefore, no further CERCLA action is necessary for the site.

This decision is based on the results of a Site Inspection (SI) (Earth Tech, March 17, 2008) and a Remedial Investigation (RI) for Site SS024 (CH2M HILL, January 15, 2010).

1.4 Statutory Determinations It has been determined that no remedial action is necessary at Site SS024 because the chemical concentrations at the site do not pose potential unacceptable risks to human health and the environment, based on current and anticipated future land use. No active treatment or monitoring will be required at Site SS024. Because hazardous substances, pollutants, or contaminants have not been detected at the site above levels that would not allow for unlimited use and unrestricted exposure, Five-Year Reviews are not necessary at Site SS024.

1 The U.S. Environmental Protection Agency (EPA) has chosen to defer to the State of Hawaii for regulatory

oversight of the Environmental Restoration Program at Hickam AFB. HDOH provides the primary regulatory oversight for Hickam AFB in accordance with the Defense-State Memorandum of Agreement (1991).

RECORD OF DECISION FOR SITE SS024 HICKAM AIR FORCE BASE, OAHU, HAWAII AFCEE CONTRACT FA8903.08-0.a769. TASK ORDER 0052

1.5 Authorizing Signatures This signature sheet documents the U.S. Air Force and State of Hawaii Department of Health's approval of the decision selected in this Record of Decision for Site SS024 at Hickam AFB, Oahu, Hawaii.

SAM C. BARRETI, Colonel, USAF Commander, 15th Wing

H KAWAOKA, Environmental Program Manager State of Hawaii Department of Health Hazard Evaluation and Emergency Response Office

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1 - Jt.f- ;(J

Date



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2.0 Decision Summary This decision summary provides a description of Site SS024 and summarizes legal and public involvement issues and risk evaluation results. The details of the site investigations conducted at Site SS024 are presented in the Final Remedial Investigation Report for Site SS014 (CH2M HILL, January 15, 2010). Additional related site investigations are documented in the Final Installation Restoration Program Phase II, Stage 3, Remedial Investigation Sites LF01, LF05, and FT07 (Engineering Science, Inc. [ES], March 1996), and the Final Site Inspection Report for Spill Site SS024 (Earth Tech, March 17, 2008). The detailed results of the risk evaluation are presented in the Final RI Report (CH2M HILL, January 15, 2010) and summarized herein. The proposed final decision for Site SS024 was presented in the Proposed Plan for Site SS024 (CH2M HILL, March 2010) and is further described in this document.

2.1 Site Name, Location, and Description Site SS024, also known as the Reef Taxiway site because of its proximity to the Honolulu International Airport Reef Runway Taxiway, occupies approximately 2.5 acres and is located in the southern portion of Hickam AFB in the vicinity of the tee box for Hole No. 4 at the Mamala Bay Golf Course. The Mamala Bay Golf Course maintenance area is located north of the site. The Ahua Lagoon is located approximately 250 feet south of the site and is the nearest surface water feature. With the exception of localized topographic mounds created during golf course construction, the surface topography is relatively flat, with an approximate elevation of 3 to 10 feet above mean sea level (msl) (Earth Tech, March 17, 2008). Figure 2-1 shows the site location and Figure 2-2 shows the site layout.

2.2 Site History and Enforcement Activities This section provides background information and describes the CERCLA response actions undertaken at Site SS024.

2.2.1 Site History Site SS024 was initially identified as an IRP site in 1992, because a soil boring (BKG-SB-31) installed in that area showed that total petroleum hydrocarbons (TPH) were detected in soil at 20,000 milligram per kilogram (mg/kg) (ES, March 1996). In 2007, the study area was expanded for an SI to an approximately one-acre area to evaluate the area surrounding the former soil boring location BKG-SB-31 (Earth Tech, March 17, 2008). The study area was further expanded during the RI to approximately 2.5 acres to better evaluate the nature and extent of contaminants discovered during the SI, particularly metals in soil and groundwater.


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To evaluate historical land use and obtain evidence on potential source(s) of contamination found at the site, historical records were reviewed. The review included newspaper articles documenting the development of the former Tri-Services Landfill, historical aerial photographs, and historical and current inventories of chemicals stored and used in the Mamala Bay Golf Course maintenance shop.

Based on historical information reviewed, the area currently encompassed by Site SS024 was situated at the shoreline before the coastline along the Ahua Lagoon was extended approximately 350 feet seaward by imported fill in the 1940s (see Figure 2-3). From approximately 1950 to 1965, the Site SS024 area was likely used for waste disposal similar to activities at the former Tri-Services Landfill (IRP Site LF05), which is located approximately 3,000 feet east of Site SS024. Historical photographs indicated that burning of landfill material did occur in the vicinity of the site. In the mid 1960s, waste disposal activities ceased and the area was converted to the Mamala Bay Golf Course. During the transition from landfill to golf course, most of the landfill debris was removed. However, some of the debris was likely re-distributed with onsite soils to make contours for the golf course playing area. It is likely that the imported fill and the residual landfill debris are the potential sources of contamination.

Chemical inventory records at the golf course indicate that there have been numerous compounds (such as pesticides and arsenate herbicides) stored and used at the Mamala Bay Golf Course maintenance area. Spills or leaks of these chemicals may also be potential sources of contamination.

2.2.2 Enforcement Activities Hickam AFB was first identified as a potential site for inclusion on the National Priorities List (NPL) in 1980. However, after initial evaluations, it was determined that the Base did not qualify for the NPL. The USAF is continuing to manage the Hickam AFB Environmental Restoration Program in accordance with CERCLA and Executive Order 12580, as required by the DERP.

2.3 Community Participation CERCLA regulations require public participation opportunities before and at the completion of any decision document (40 Code of Federal Regulations [CFR] 300.430[f] [3]). To meet this obligation, the USAF and HDOH regularly provide the community with information regarding the environmental cleanup of sites at Hickam AFB. This information is provided through quarterly meetings of the Restoration Advisory Board (RAB), by maintaining the public information repository, and by publishing various announcements, fact sheets, and public notices in the local newspapers. Hickam AFB also maintains a Community Involvement Plan (CIP) that documents the processes employed by the Environmental Restoration Program to encourage and maintain community participation (USAF, February 10, 2005).

The Hickam RAB was formed in September 1996, and held its first meeting on February 26, 1997 and last meeting on February 16, 2010. The RAB helps increase



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community awareness of and also has a voice in environmental restoration issues at the Base. Information regarding environmental work at Hickam AFB and other environmental issues is regularly available through the RAB process.

Documents related to Site SS024 can be found in the information repository maintained at the Hawaii State Library, Main Branch, 478 South King Street, Honolulu, Hawaii, and on the internet at http://www.adminrec.com/PACAF.asp?Location=Hawaii.

The USAF published a notice of the availability of the Proposed Plan for Site SS024 on March 31, 2010 in the Midweek newspaper. The notice announced the 30-day public comment period from April 1 to April 30, 2010. The USAF’s responses to the comments received during the public comment period are included in the Responsiveness Summary, provided as Section 3.0 of this document.

2.4 Scope and Role of Response Action The selected decision in this document constitutes the planned final action for Site SS024 and is protective of human health and the environment.

2.5 Site Characteristics This section describes the physical characteristics of Hickam AFB and specifically of Site SS024. This description is followed by a summary of site-specific nature and extent of contamination. Environmental sampling data gathered during the SI (Earth Tech, March 17, 2008) and the RI (CH2M HILL, January 15, 2010) were primarily used to describe the nature and extent of the contamination and as input for estimating potential risks to human health and the environment.

2.5.1 Physiography and Climate Hickam AFB is situated on the Pearl Harbor coastal plain on the south flanks of the Island of Oahu. The overall topography of Hickam AFB is relatively flat, and most of the land is less than 10 feet above msl. The majority of Hickam AFB is covered by surface paving and maintained landscaped areas. The topography of Site SS024 is relatively flat and the area is mostly covered with grass and shrubs associated with the Mamala Bay Golf Course.

The climate of Hawaii is generally temperate, influenced by the Pacific Ocean and the trade winds. There are two basic seasons: a dry season from May through September, when the mean temperature is 79 degrees Fahrenheit (°F) and a wet season from October through April, when the mean temperature is 73°F. The average annual precipitation at Hickam AFB is approximately 22 inches per year. The highest precipitation is in December and the lowest in August. Periodic thunderstorms can result in flooding, especially in winter. Evaporation rates are high, approximately 80 to 86 inches annually, as a result of brisk trade winds and high solar radiation.

http://www.adminrec.com/PACAF.asp?Location=Hawaii�


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2.5.2 Geology Hickam AFB lies on the southern coastal plain of the Koolau Volcano, within the near-shore coastal outwash plain at Pearl Harbor. The volcano flanks along the entire southern coast of Oahu and are covered by sedimentary rock originating from terrestrial alluvium, small rejuvenation stage (secondary) volcanic eruptions, marine sediment, and coral reef limestone that were deposited over periods of fluctuating sea level. This sedimentary rock is known as “caprock” because it forms a low-permeability cap over the highly permeable volcanic basalt and acts as a confining layer to the upward flow of groundwater from the deeper volcanic basal aquifer.

Most of Site SS024 is covered by maintained grass and shrubs. The site is generally underlain by top soil (up to 2.2 feet thick), imported fill soil (3.2 to 9.8 feet thick), a buried debris layer (1 to 4.5 feet thick), fine-grained soil (0.5 to >2 feet thick), and coralline gravelly sand from top to bottom. The buried debris layer contains man-made debris including glass shards, burned and unburned wood, soot, porcelain, wire, and brick fragments, but does not appear to extend across the entire golf course.

2.5.3 Hydrogeology Previous studies at Hickam AFB have shown that shallow groundwater at the Base occurs under unconfined conditions within the fill, clay, and coral reef deposits that comprise the shallow marine aquifer. Much of the surface soil at Hickam AFB, which consists of either fill or native soil and coral, is sufficiently permeable to allow natural precipitation water to infiltrate directly to the water table (except where the ground surface is paved).

At Site SS024, shallow groundwater occurs under unconfined conditions within the coralline sand and gravel unit at depths ranging between approximately 7 and 10 feet bgs. Because no permanent monitoring wells were installed and no groundwater flow study was conducted at Site SS024, the hydrogeological characteristics are derived from the tidal study performed at adjacent Site LF05 in 2005 (CH2M HILL, May 19, 2006). Based on the proximity of Site SS024 to Site LF05, the net migration of shallow groundwater beneath Site SS024 is assumed to flow south-southwest into the Ahua Lagoon, with an estimated hydraulic gradient of 0.0005 foot per foot.

2.5.4 Surface Water The Pacific Ocean, which includes Mamala Bay, the Ahua Lagoon, and Hickam Harbor, lies to the south of Hickam AFB. Over the past century, the natural drainage of Hickam AFB has been mostly eliminated by the construction of runways, roads, and parking areas. Surface drainage today consists mostly of urban drainage systems, with several shallow manmade canals and ditches. The largest canals, receiving the most runoff, drainage, and groundwater discharge, are the Manuwai and Kumumauu Canals and, to a lesser extent, the Motor Pool Storm Drain.

The nearest surface water body to Site SS024 is the Ahua Lagoon, which is located approximately 250 feet south of the site.



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2.5.5 Ecology Hickam AFB has been constructed over fill, former sugar cane fields, and tidal lowlands. The low annual rainfall and the salinity of the soil support sparse natural vegetation. The plant community along the banks of the lower reaches of the canals and the Ahua Lagoon is dominated by red mangrove. Submergent patches of brown algae are present near the mouths of the canals. Aquatic species or evidence of species observed in the lagoon includes fish, invertebrates, insects, and algae. Marine mammals and endangered species potentially occurring in the marine waters offshore from Hickam AFB include the Hawaiian monk seal, the green sea turtle, and the humpback whale.

Site SS024 is surrounded by outdoor recreational activities, and the surface cover is maintained grass and shrubs. Portions of the site could support viable ecological habitat.

There is no aquatic habitat within Site SS024. However, the nearby Ahua Lagoon serves as local habitat for estuarine resources.

2.5.6 Site Investigations Three environmental investigations have been conducted in the vicinity of Site SS024 between 1992 and 2009. The investigation activities conducted at the site are summarized below.

2.5.6.1 RI at Sites LF01, LF05, and FT07 (ES, March 1996) Site SS024 was initially identified in 1992, during the RI activities for nearby IRP Sites LF01, LF05, and FT07. A soil boring (BKG-SB-31) was advanced near the tee box of Hole No. 4 to 10 feet below ground surface (bgs) to provide background data for the project sites. Glass shards and brick material were noted throughout the fill material observed in the boring. A composite soil sample collected from between 2 and 6 feet bgs exhibited TPH at 20,000 mg/kg2

2.5.6.2 SI (Earth Tech, March 17, 2008)

. In addition, three metals (lead at 211 mg/kg, thallium at 7.6 mg/kg, and zinc at 738 mg/kg) were detected at concentrations above HDOH Tier 1 Environmental Action Levels (EALs) (lead at 200 mg/kg, thallium at 1 mg/kg, and zinc at 600 mg/kg) (HDOH, Summer 2008 updated March 2009).

Between 2006 and 2007, a passive soil gas (PSG) survey was performed at the site to evaluate the presence of volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), polynuclear aromatic hydrocarbons (PAHs), and TPH. The PSG results indicated that low levels of VOCs and PAHs were present in soil gas at small isolated areas (see Figure 2-4). Other detected compounds included acetone, carbon disulfide, 1,1-dichloroethene, ethylbenzene, naphthalene, trichloroethylene, tetrachloroethene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, and xylenes.

2 Note that this TPH analysis was performed using the U.S. Environmental Protection Agency (EPA) method

418.1, which is no longer used for TPH analysis, as it has been recognized that results using this method may be biased by the presence of other non-petroleum related organics.


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Nine soil borings were also advanced to a maximum depth of 15 feet bgs. One soil sample was collected from each borehole at approximately 6 to 9 feet bgs, where a black layer containing debris and ash (0.5 to 2 feet thick) was consistently observed. Five of the nine borings were converted to temporary wells. Groundwater samples were collected from each of the five temporary wells. The soil and groundwater samples were analyzed for VOCs, PAHs, TPH-gasoline-range organics (TPH-g), TPH-diesel-range organics (TPH-d), TPH-oil-range organics (TPH-o), and metals.

The results indicated that neither VOCs nor PAHs were detected in any soil or groundwater samples at concentrations above the corresponding Tier 1 EALs. Five metals (arsenic, cadmium, copper, zinc, and lead) were detected in soil at concentrations above HDOH Tier 1 EALs and the Hickam ambient background levels. Dissolved copper was detected in groundwater at concentrations above the corresponding Tier 1 EAL and the Hickam ambient background level.

2.5.6.3 RI (CH2M HILL, January 15, 2010) Based on the results of the SI, an RI was conducted in 2009 to better characterize the nature and extent of contamination and to assess potential risks to human health and the environment posed by chemicals in site media.

As part of the RI, surface soil samples were collected from two decision units (DUs) using a Multi-Increment (MI) sampling approach. Figure 2-5 shows the MI surface soil sampling areas during the RI. The surface soil samples were analyzed for SVOCs, PAHs, TPH-d, TPH-o, organochlorine pesticides, polychlorinated biphenyl (PCBs), and metals. Fifteen soil borings were advanced to a maximum depth of 18 feet bgs and a total of 30 subsurface soil samples were collected for the analysis of VOCs, SVOCs, PAHs, TPH-g, TPH-d, TPH-o, organochlorine pesticides, and metals. Subsurface soil samples collected from within the buried debris layer at 8 of the 15 soil borings were also analyzed for PCBs and dioxins/furans. Temporary wells were installed in 7 of the 15 soil borings and groundwater samples were collected from each well for the analysis of VOCs, SVOCs, PAHs, TPH-d, TPH-g, TPH-o, organochlorine pesticides, and dissolved metals. Soil gas samples were collected from five locations across Site SS024 and analyzed for VOCs.

Figure 2-6 shows the historical and RI subsurface soil, soil gas, and groundwater sample locations at Site SS024.

2.5.7 Nature and Extent of Contamination The following subsections summarize data collected during the SI and the RI at Site SS0243. To help focus the discussion of nature and extent on those chemicals more important at the site, the results for each sample type (soil, groundwater, and soil gas) were initially screened against the corresponding HDOH Tier 1 EALs4

3 The analytical results from the 1992 background soil boring (BKG-SB-31) were not used in the evaluation of

nature and extent of contamination because the analytical method used for TPH is outdated and more recent site data are available.

(HDOH, Summer 2008 updated

4 The most stringent final EALs reported by HDOH were used for the screening, and may include aesthetic effects such as odor, and pathways that may not exist for this site.



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March 2009). Although the concentrations of some chemicals in soil or groundwater exceeded the screening levels, none of these chemicals were retained as chemicals of concern (COCs) based on the results of the human health and ecological risk evaluation for the site (see Section 2.7). The following subsections describe the nature and extent of contamination in soil, groundwater, and soil gas, respectively.

2.5.7.1 Soil The soil samples collected from Site SS024 were analyzed for a variety of chemical groups, including VOCs, SVOCs, PAHs, TPH-g, TPH-d, TPH-o, organochlorine pesticides, PCBs, dioxins/furans, and total metals. The results were evaluated in terms of surface soil (0.1 to 0.5 foot bgs) and subsurface soil (greater than 3 feet bgs). The analytical data for the chemicals detected in surface soil and subsurface soils are summarized in Table 2-1. Tier 1 EAL exceedances in surface soil and subsurface soil are depicted in Figure 2-7 and Figure 2-8, respectively.

Surface Soil (0.1 to 0.5 foot bgs) Three replicate surface soil samples were collected from each of the two decision units at Site SS024, using the MI sampling approach. The results for chemicals detected in at least one of the triplicate samples from either decision unit are shown in Table 2-2. Mean, standard deviations, and relative standard deviations (RSDs) were calculated for each detected chemical within each decision unit.

The project Work Plan specified a range of 35 to 50 percent or less as reasonable for RSDs, based on a verbal discussion with HDOH representative during the August 14, 2008 Triad Project Planning meeting. An upper range of 50 percent was included in the project Work Plan based on discussions with HDOH during the Triad meeting.

As indicated in Table 2-2, several chemicals detected in DU#1 have RSDs above 35 percent. However, many of the elevated RSDs are associated with low level qualitative detections or at least one non-detected result, the exceptions being benzo[b]fluoranthene and pyrene, PCB-1260, aluminum, chromium, manganese, nickel, vanadium, and zinc. Of those chemicals, benzo[b]fluoranthene, pyrene, PCB-1260, and zinc exceed the project-specific RSD goal of less than 50 percent.

The RSDs for DU#2 are generally lower than those for DU#1, indicating more heterogeneity associated with DU#1. Only four chemicals (4,4’-DDD, antimony, molybdenum, and selenium) exceeded 35 percent RSD. With the exception of selenium, all elevated RSD exceedances were associated with at least one non-detected result.

Table 2-2 summarizes the chemicals detected in surface soil at both DUs, including comparisons to screening levels. Chemicals detected in surface soil samples from the two decision units at Site SS024 included 2 SVOCs, 12 PAHs, TPH-d, TPH-o, 6 pesticides, PCBs, and 23 metals. At each decision unit, as a conservative estimate, the maximum concentration of each analyte from the three replicate samples (primary, duplicate, and triplicate) was used for comparison to screening levels and evaluation of extent. The


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following chemicals were detected at concentrations above the corresponding screening levels (as shown in Figure 2-7):

• Dieldrin. Dieldrin was detected in surface soil samples from both decision units, at maximum concentrations of 0.0055 and 0.0076 mg/kg, above the EAL of 0.0033 mg/kg. The RSD for dieldrin is 55 percent for DU#1 versus 7 percent for DU#2, indicating somewhat higher variability between the replicates in DU#1. However, the mean dieldrin concentrations of each decision unit are very similar (0.0047 versus 0.0051 mg/kg), and both above the EAL.

• Benzo[a]pyrene. Benzo[a]pyrene was detected in surface soil samples from both decision units, at maximum concentrations of 0.2 and 0.092 mg/kg. The benzo[a]pyrene concentration detected in DU#1 (0.2 mg/kg) slightly exceeded the EAL of 0.15 mg/kg. The RSD for benzo[a]pyrene is 80 percent for DU#1 versus 21 percent for DU#2, indicating higher variability between the replicates in DU#1. However, the mean benzo[a]pyrene concentrations of each decision unit are very similar (0.010 mg/kg versus 0.074 mg/kg), and both below the EAL.

• Arsenic. Arsenic was detected in surface soil samples from both decision units, at maximum concentrations of 75 and 120 mg/kg, above both the EAL of 20 mg/kg (based on generic background) and the Hickam ambient background concentration of 27.9 mg/kg. The RSDs for arsenic for both decision units were very low (19 and 18 percent, respectively for DU#1 and DU#2). The mean arsenic concentrations in both decision units (98 and 63 mg/kg, respectively for DU#1 and DU#2) also exceeded the EAL.

• Bioaccessible Arsenic. Bioaccessible arsenic was analyzed for in two of the triplicate samples collected at DU#1 and one of the triplicate samples collected from DU#2 at maximum concentrations of 15.5 and 31.7 mg/kg, respectively. Both the maximum and mean bioaccessible arsenic (30 mg/kg) concentrations in surface soil sample from DU#1 exceeded the EAL of 20 mg/kg.

Based on the results above, the following conclusions were drawn regarding the extent of surface soil contamination:

• Based on similar concentrations detected within and across the decision units, the extent of dieldrin and arsenic contamination in surface soil appears to be widespread, possibly resulting from the routine legal application of materials (for example, pesticides and arsenate herbicides) during golf course maintenance. The results for bioaccessible arsenic were evaluated as part of the Baseline Risk Assessment (Section 2.7).

• PAHs exhibited more variability in DU#1, such that the maximum concentration exceeded the EAL while the mean did not. However, the mean concentrations between the two decision units were similar, suggesting there is no significant source of PAHs at Site SS024.



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Subsurface Soil (>3 feet bgs) Chemicals detected in subsurface soil samples from Site SS024 included 18 VOCs, 1 SVOC, 16 PAHs, TPH-g, TPH-d, TPH-o, 7 pesticides, 2 PCBs, 20 dioxin/furans, and 24 metals. Of these, the following chemicals were detected at concentrations above the corresponding screening levels (as shown in Figure 2-8):

• TPH-d. TPH-d was detected in 37 of the 39 samples analyzed, at concentrations ranging from 1.2 to 760 mg/kg. The TPH-d concentrations in two samples (SS024-BH005 and SS024-BH011) exceeded the EAL of 500 mg/kg.

• Antimony. Antimony was detected in 18 of the 30 samples analyzed, at concentrations ranging from 0.17 to 23 mg/kg. The antimony concentrations in four samples (SS024-BH001, SS024-BH012, SS024-BH013, and SS024-BH014) exceeded both the EAL of 6.3 mg/kg and the Hickam ambient background concentration of 8.7 mg/kg.

• Arsenic. Arsenic was detected in all 39 samples analyzed, at concentrations ranging from 4.3 to 51.7 mg/kg. The arsenic concentrations in five samples (SS24-TW03, SS024-BH005, SS024-BH012, SS024-BH013, and SS024-BH014) exceeded both the EAL of 20 mg/kg and the Hickam ambient background concentration of 27.9 mg/kg.

• Barium. Barium was detected in all 39 samples analyzed, at concentrations ranging from 6.2 to 980 mg/kg. The barium concentration in one sample (SS024-BH011) exceeded both the EAL of 750 mg/kg and the Hickam ambient background concentration of 951 mg/kg.

• Cadmium. Cadmium was detected in 26 of the 39 samples analyzed, at concentrations ranging from 0.15 to 26.7 mg/kg. The cadmium concentrations in three samples (SS24-TW02, SS024-BH006, and SS024-BH013) exceeded both the EAL of 12 mg/kg and the Hickam ambient background concentration of 3.6 mg/kg.

• Copper. Copper was detected in all 39 samples analyzed, at concentrations ranging from 1.4 to 5,600 mg/kg. The copper concentrations in 10 samples (see Figure 2-8) exceeded both the EAL of 230 mg/kg and the Hickam ambient background concentration of 138 mg/kg.

• Lead. Lead was detected in 33 of the 39 samples analyzed, at concentrations ranging from 0.12 to 2,900 mg/kg. The lead concentrations in eleven samples (see Figure 2-8) exceeded both the EAL of 200 mg/kg and the Hickam ambient background concentration of 226 mg/kg.

• Zinc. Zinc was detected in all 39 samples analyzed, at concentrations ranging from 2 to 3,800 mg/kg. The zinc concentrations in eight samples (see Figure 2-8) exceeded both the EAL of 600 mg/kg and the Hickam ambient background concentration of 421 mg/kg.


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• Dioxins/Furans. Dioxins/furans were detected in all eight samples analyzed. The 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalency quotient (TEQ) ranged from 0.000003 to 0.00011 mg/kg. The TCDD TEQ concentrations in seven samples (see Figure 2-8) exceeded the EAL of 0.0000045 mg/kg.

Based on the results above, the following conclusions were drawn regarding the extent of subsurface soil contamination:

• The occurrences of TPH-d contamination in subsurface soil are limited to two isolated soil boring locations (SS024-BH005 and SS024-BH011) and do not appear to represent a widespread condition.

• The extent of metals contamination in subsurface soil appears to be widespread. Elevated metal concentrations were detected in 16 of the 24 soil boring locations analyzed (see Figure 2-8), at depths ranging from 5.5 to 13.5 feet bgs. It appears that the elevated metal concentrations are directly correlated with the presence of the buried layer. This is evident in that no samples collected from above this layer contained concentrations of metals above their respective screening levels.

• Dioxins/furans were analyzed with soil samples collected from eight soil boring locations (SS024-BH001, SS024-BH006, SS024-BH008, SS024-BH009, and SS024-BH011 through SS024-BH014), at depth intervals where a buried debris layer was uncovered during drilling. Elevated concentrations of dioxins/furans (in terms of 2,3,7,8-TCDD TEQ) were detected in seven of the eight soil borings, indicating that the buried debris layer is the potential source of the dioxins/furans contamination.

• Although the extent of the metals and dioxins/furans contamination in subsurface soil has not been delineated, no further step-out sampling is recommended because the subsurface contamination appears to be a regional rather than site-specific issue. The subsurface soil contamination seems to be limited to the buried debris layer present at or below the capillary fringe zone, to which human or ecological exposure is highly unlikely.

2.5.7.2 Groundwater The groundwater samples from Site SS024 were analyzed for a variety of chemicals, including VOCs, SVOCs, PAHs, TPH-g, TPH-d, TPH-o, pesticides, and dissolved metals. Tier 1 EAL exceedances in groundwater at Site SS024 are depicted in Figure 2-9.

Chemicals detected in groundwater samples included 6 VOCs, 9 PAHs, TPH-g, TPH-d, TPH-o, 1 pesticide, and 21 dissolved metals (see Table 2-3). Of these, the following chemicals were detected at concentrations above the corresponding screening levels.

• TPH-d. TPH-d was detected in all 12 samples analyzed, at concentrations ranging from 0.041 to 0.97 milligram per Liter (mg/L). The TPH-d concentration in three samples (SS024-GW002, SS024-GW003, and SS024-GW007) exceeded the EAL of 0.64 mg/L.



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• Dissolved Copper. Dissolved copper was detected in 5 of the 12 samples analyzed, at concentrations ranging from 0.00033 to 0.02 mg/L. The dissolved copper concentration in groundwater sample from well SS24-TW02 exceeded both the EAL of 0.0029 mg/L and the Hickam ambient background concentration of 0.007 mg/L. This sample was collected during the SI and the dissolved copper result was flagged with “M”, indicating the presence of a matrix effect.

• Dissolved Zinc. Dissolved zinc was detected in 5 of the 12 samples analyzed, at concentrations ranging from 0.0027 to 0.026 mg/L. The dissolved zinc concentration in groundwater sample from well SS024-GW001 exceeded both the EAL of 0.022 mg/L and the Hickam ambient background concentration of 0.0198 mg/L.

Based on the results above, the following conclusions were drawn regarding the extent of groundwater contamination:

• Overall, the extent of TPH-d and dissolved metals contamination in site groundwater appears to be limited and does not represent a widespread condition. In particular, TPH-d in groundwater is not considered a concern because the TPH-d concentrations in site soil are relatively low (with a maximum of 760 mg/kg) and no free petroleum product or strong hydrocarbon odors were noticed in any soil borings installed.

• The elevated dissolved zinc concentrations in site groundwater likely represent ambient background levels in groundwater at Hickam AFB, which range from 0.002 to 0.0198 mg/L.

2.5.7.3 Soil Gas The soil gas samples collected from Site SS024 were analyzed for VOCs. Chemicals detected in soil gas samples included 23 VOCs (see Table 2-4); however, none of these chemicals were detected at concentrations above the corresponding screening levels.

2.5.8 Conceptual Site Model A conceptual site model (CSM) was developed to depict the potential relationship or exposure pathway between chemical sources and receptors. An exposure pathway describes the means by which a receptor can be exposed to the chemicals in the environmental media. These pathways are summarized below, based upon current and potential future land uses and the potential beneficial use of groundwater and surface water at Site SS024. The general CSM for Site SS024 is illustrated in Figure 2-10.

2.5.8.1 Potential Human Receptors and Exposure Pathways Populations potentially exposed to chemicals in site media at Site SS024 consist of occupational workers, excavation/construction workers, and hypothetical future residents5

5 Residential land use at Site SS024 is not anticipated. Risks to hypothetical future residents were calculated

to assist the Air Force in determining whether land use controls (LUCs) are needed.

. The exposure pathways by which receptors may be exposed to soil, soil gas, and


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groundwater are identified as incidental ingestion, dermal contact, and inhalation of dust and vapors. As indicated in Section 2.6.2 below, groundwater is not suitable as a drinking water source or for other domestic or industrial purposes. Therefore, future human contact with chemicals in groundwater is not expected.

Potentially complete human exposure pathways exist for the following receptors and exposure routes:

• Incidental ingestion, dermal contact, and inhalation of dust and vapors from soil (less than 3 feet bgs) by occupational workers. Potential exposure of indoor workers by inhalation following vapor intrusion was also evaluated. It is assumed that an occupational worker would be exposed to soil and indoor vapors for 250 days per year for 25 years.

• Incidental ingestion, dermal contact, and inhalation of dust and vapors from soil and shallow groundwater (less than 10 feet bgs) by excavation/construction workers. It is assumed that an excavation/construction worker would be exposed to soil and shallow groundwater for 20 days per year for 6.6 years.

• Incidental ingestion, dermal contact, and inhalation of dust and vapors from soil (less than 10 feet bgs) by hypothetical future residents. Potential exposure of indoor residents by inhalation following vapor intrusion was also evaluated. It is assumed that a hypothetical future resident would be exposed to soil and indoor vapors for 350 days per year for 30 years. This evaluation assumes that residential exposure to soil occurs onsite, but also addresses the possibility that subsurface soil is removed from the site and re-deposited in another area with potential residential-type exposure frequency and duration.

2.5.8.2 Potential Ecological Receptors and Exposure Pathways Ecological pathways at Site SS024 are considered complete for avian or mammalian terrestrial wildlife because portions of the site could support viable ecological habitat. Therefore, risks to terrestrial ecological receptors are evaluated. The exposure routes of potential terrestrial ecological receptors include 1) direct ingestion of surface soil by avian terrestrial species; and 2) bioaccumulation of chemicals in surface soil through ingestion of food items such as prey.

A potentially complete exposure pathway also exists for the discharge of site groundwater into the Ahua Lagoon, where aquatic receptors reside. The exposure routes for potential aquatic and benthic ecological receptors include ingestion, direct uptake through gills, or food-chain transfer. Therefore, the groundwater-to-surface water-discharge pathway is evaluated as part of the ecological screening assessment.



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2.6 Current and Potential Future Land and Resource Use 2.6.1 Land Use Currently, approximately 60 percent of the land at Hickam AFB is used for military and public facilities. Honolulu International Airport, contiguous to the eastern boundary of Hickam AFB, is the major public facility in the area. The third major land use in this area is residential, including communities within Hickam AFB and in Aliamanu, located north of Hickam AFB and the H-1 Freeway. Industrial, commercial, and recreational facilities are also located in this area.

Site SS024 is located at the western edge of the Mamala Bay Golf Course, approximately 250 feet north of the Ahua Lagoon. The current land use plan classifies land use at Site SS024 as outdoor recreation. The nearest on-Base residential area is across the flight line and over a mile to the north and west of Site SS024. There are no known plans for redevelopment and it is anticipated that the future land use will remain outdoor recreation.

2.6.2 Groundwater and Surface Water Resources Groundwater generally occurs at approximately 7 to 10 feet bgs beneath Site SS024. The shallow aquifer beneath Site SS024 is within the Moanalua System of the Pearl Harbor aquifer (Classification code 30104116) (Mink and Lau, February 1990). According to the State aquifer code that indicates developability, utility, quality, uniqueness, and vulnerability to contamination of the groundwater resources, the aquifer (aquifer status code 23321) beneath Site SS024 has potential developability; is ecologically important; has moderate salinity; is replaceable; and is highly vulnerable to contamination. The aquifer is not considered a drinking water source. Site SS024 is also makai (seaward) from the underground injection control (UIC) line; aquifers makai from the UIC line are not a drinking water source (Hawaii Administrative Rules [HAR] Section 11-23-05). In addition, groundwater is not likely to be used for industrial purposes, based on the current and reasonably anticipated future uses of Site SS024.

The nearest surface water body to Site SS024 is the Ahua Lagoon, which is located approximately 250 feet south of the site.

2.7 Summary of Site Risks A baseline risk assessment was performed for Site SS024 to characterize the current and potential risks posed to human health and the environment by the detected chemicals. Additionally, an Environmental Hazard Evaluation (EHE) was conducted for Site SS024 to consider the broader range of potential environmental hazards associated with any contaminated media at the site, in accordance with the HDOH guidance Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, Summer 2008 updated March 2009). While the baseline risk assessment focuses on cumulative risks resulting from chemical toxicity for various site-specific scenarios (such as human direct exposure, terrestrial ecotoxicity concern, and protection of aquatic habitats), the EHE


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provides a conservative screening mechanisms for identifying the potential for environmental hazards resulting from both chemical exposures and non-risks endpoints (such as gross contamination, nuisance, leaching, and explosion potential) by comparing chemical data to HDOH EALs.

The results of the baseline risk assessment and EHE are summarized in the following subsections.

2.7.1 Baseline Risk Assessment The baseline risk assessment consisted of both a human health risk assessment and an ecological screening assessment.

2.7.1.1 Human Health Risk Assessment The process for selection of COCs based on human health risk consisted of the following steps:

• Chemical of Potential Concern (COPC) Selection. The COPC selection process consisted of compiling all analytical data and identifying all the chemicals that were detected at least once in a particular exposure medium with the exception of essential nutrients (that is, calcium, iron, magnesium, potassium, and sodium).

• Exposure Point Concentration (EPC) Calculation. EPCs are estimated chemical concentrations with which a receptor may come into contact, and are specific to each exposure medium. The EPCs for exposure pathways associated with soil at Site SS024 were estimated by aggregating concentration data from soil samples collected from the entire site. The EPCs were calculated for each analyte using the EPA’s statistical program ProUCL, Version 4.00.04 (EPA, May 14, 2009). The maximum detected concentration is used in place of the 95 percent UCL when the calculated 95 percent UCL is greater than the maximum detected value. For ecological exposure pathways associated with groundwater, EPCs were identified on a sample-specific basis, rather than aggregating data spatially. The EPCs calculated for COPCs identified for surface soil, subsurface soil, and groundwater at Site SS024 are listed in Table 2-5.

• COC Selection. The COC selection process consisted of calculating EPCs for each COPC, estimating daily exposure to each COPC via the identified exposure pathway, estimating the hazard index (HI) by summing the hazard quotients (HQs) for all of the non-carcinogenic COPCs, and calculating an excess lifetime cancer risk (ELCR) by summing the values for each carcinogenic COPC. For an exposure pathway with an estimated HI greater than 1, each major contributing COPC would be identified as a COC. If the cumulative ELCR for the exposure pathway was greater than the upper limit of the EPA target risk range of 1 x 10-6 to 1 x 10-4, each major contributing COPC would be identified as a COC.

• Risk Estimation Method for Lead. Potential risks posed by lead in soil were evaluated using methods different from those described above. For direct contact pathways, the EPC for lead in soil was compared to the residential EAL



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of 400 mg/kg, derived using EPA’s Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK) (EPA, 2004). This model identifies what percentage of the potentially exposed population would be expected to have a blood lead level greater than 10 micrograms per deciliter (µg/dL). A soil concentration that is below 400 mg/kg results in a calculated blood lead level below 10 µg/dL in 95 percent of the potentially exposed population, and therefore is considered to pose no unacceptable risk. Potential risks to workers were evaluated by comparing the EPC for lead in soil to the commercial/industrial EAL of 800 mg/kg.

2.7.1.1.1 Summary of Risk Estimates by Exposure Scenario This section summarizes the risk estimates for the three exposure scenarios evaluated at Site SS024: occupational workers, excavation/construction workers, and hypothetical future residents. The cancer and non-cancer risk estimates for each exposure scenario are summarized in the following subsections. Estimated risks to human health were calculated using the SI and RI data for each exposure scenario and the cumulative risk estimates are summarized in Table 2-6.

Occupational Workers6

Potential exposure to COPCs in surface soil was evaluated under this scenario.

• Surface Soil (0 to 0.5 foot bgs). The cumulative ELCR from all carcinogenic COPCs in surface soil is 2 x 10-5, which is within the EPA target risk range of 1 x 10-6 to 1 x 10-4. The HI for non-cancer effects is 0.3, which is below the EPA threshold value of 1.

Potential exposure to COPCs in subsurface soil and shallow groundwater was evaluated under this scenario.

Excavation and Construction Workers

• Subsurface Soil (0 to 10 feet bgs). The cumulative ELCR from all carcinogenic COPCs in subsurface soil is 6 x 10-7, which is below the EPA target risk range of 1 x 10-6 to 1 x 10-4. The HI for non-cancer effects is 0.1, which is below the EPA threshold value of 1.

• Groundwater. The cumulative ELCR from all carcinogenic COPCs in shallow groundwater is 3 x 10-6, which is within the EPA target risk range of 1 x 10-6 to 1 x 10-4. The HI for non-cancer effects is 0.4, which is below the EPA threshold value of 1.

6 Golfers are potential receptors at Site SS024. They were semi-quantitatively evaluated as part of the

baseline risk assessment. Assuming that a realistic exposure frequency of the golfers is one tenth of the occupational worker scenario, the potential risks to the golfers from exposure to surface soil would be approximately 2×10-6, within the EPA target risk range of 1×10-6 to 1×10-4.


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Potential exposure to COPCs in subsurface soil was evaluated under this scenario. The ELCR and HI for the hypothetical future resident exposure scenario were calculated for the two exposure cases (using surface soil from less than 0.5 foot bgs and using subsurface soil from less than 10 feet bgs). The risk calculation results for each case are discussed below.

Hypothetical Future Residents

• Subsurface Soil (0 to 10 feet bgs). The cumulative ELCR from all carcinogenic COPCs in subsurface soil is 4 x 10-5, which is within the EPA target risk range of 1 x 10-6 to 1 x 10-4. The HI for non-cancer effects is 1, which is at the EPA threshold value of 1. The primary contributors to HI are cobalt (26 percent; HQ=0.4) and 2,3,7,8-TCDD TEQ (22 percent; HQ=0.3), and manganese (14 percent; HQ=0.2). However, the EPC for cobalt and manganese were detected below the Hickam ambient background levels.

• Surface Soil (0 to 0.5 foot bgs). The cumulative ELCR from all carcinogenic COPCs in surface soil is 9 x 10-5, which is within the EPA target risk range of 1 x 10-6 to 1 x 10-4. The HI for non-cancer effects is 1, which is at the EPA threshold value of 1. The primary contributor to the HI is bioaccessible arsenic (31 percent contribution; HQ=0.4). Other COPCs contributing to the total non-cancer risk were below the Hickam ambient background levels. These included, vanadium (21 percent contribution; HQ=0.3), cobalt (19 percent contribution; HQ=0.3), and manganese (15 percent contribution; HQ=0.2).

2.7.1.1.2 Lead Risk Evaluation The EPC calculated for lead in soil using all samples was 825 mg/kg, which exceeds both the residential and occupational action levels of 400 mg/kg and 800 mg/kg, respectively. Based on these results, a more careful review of the potential risk from lead exposure in soil was conducted in accordance with HDOH guidance (HDOH, Summer 2008 updated March 2009), by only considering sample data above the groundwater table and the capillary fringe. The EPC for lead in soil samples situated above the capillary fringe zone is 225 mg/kg, which is below both the residential and occupational action levels (400 mg/kg and 800 mg/kg, respectively).

2.7.1.1.3 Human Health Risk Assessment Conclusions The results of the human health risk assessment for soil and groundwater exposure scenarios indicate that there are no unacceptable risks to occupational workers, excavation/construction workers, or hypothetical future residents. Therefore, no COCs are identified for soil or groundwater based on human health risk at Site SS024.

2.7.1.2 Ecological Screening Assessment Ecological pathways at Site SS024 are considered complete for terrestrial wildlife because portions of the site could support viable ecological habitat. Therefore, risks to terrestrial ecological receptors were evaluated using surface soil data, where terrestrial receptors are most likely to reside.



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A potentially complete exposure pathway also exists for the discharge of site groundwater into the Ahua Lagoon, where aquatic receptors reside. The exposure routes for potential aquatic and benthic ecological receptors include ingestion, direct uptake through gills, or food-chain transfer. Therefore, the groundwater-to-surface water-discharge pathway is evaluated as part of the ecological risk evaluation.

2.7.1.2.1 Ecological Screening Assessment Results The ecological screening assessment was conducted using surface soil and shallow groundwater data. The results for each medium are summarized below.

All of the chemicals detected in surface soil were at levels below the EALs for ecotoxicity, except for arsenic. The levels of bioaccessible arsenic in surface soil ranged from 15.5 to 31.7 mg/kg (see Table 2-1), with an average of 23.6 mg/kg, slightly exceeding the ecotoxicity EAL of 20 mg/kg. However, these levels are below the EPA Ecological Screening Levels (EcoSSLs) of 34 mg/kg for avian receptors and 36 mg/kg for mammalian receptors (EPA, March 2005).

Surface Soil (0 to 0.5 foot bgs)

Groundwater COPC concentrations were compared to the EALs that incorporate aquatic habitat goals (because groundwater is not a current or potential drinking water resource at these locations). The results indicate that all of the shallow groundwater concentrations were detected at levels below the aquatic habitat EALs, with the exception of dissolved copper, dissolved zinc, and TPH-d.

Shallow Groundwater

The dissolved copper concentrations in 2 of 12 well locations exceeded both the EAL of 0.0029 mg/L and the Hickam ambient background level of 0.007 mg/L. The maximum dissolved copper concentration was 0.02 mg/L. However, the dissolved copper levels at all well points closest to Ahua Lagoon were below the aquatic habitat goal. These results indicate that dissolved copper in groundwater is not migrating offsite.

The dissolved zinc concentrations in 1 of 7 well locations sampled exceeded both the EAL of 0.022 mg/L and the Hickam ambient background level of 0.0198 mg/L. The maximum dissolved zinc concentration was 0.026 mg/L. However, the dissolved zinc levels at all well points closest to Ahua Lagoon were below the aquatic habitat goal. These results indicate that dissolved zinc in groundwater is not migrating offsite.

The groundwater concentrations of TPH-d in 3 of 12 well locations exceeded the EAL of 0.64 mg/L, with a maximum detect of 0.97 mg/L. However, the 95 percent UCL concentration of 0.56 mg/L was below the EAL for aquatic habitat concern.

2.7.1.2.2 Ecological Screening Assessment Conclusions The results of the ecological screening assessment for soil and groundwater exposure scenarios indicate that, based on the available data, there are no unacceptable risks to terrestrial or aquatic receptors. Therefore, no COCs are identified based on ecological risk at Site SS024.


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2.7.2 Environmental Hazard Evaluation In addition to the baseline risk assessment, an EHE was conducted to identify the potential risks and hazards to human health and the environment. The EHE was conducted in general accordance with guidance provided in the Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, Summer 2008 updated March 2009).

The results of the EHE for soil and groundwater are summarized in Tables 2-7 and 2-8, respectively. No environmental hazards were identified for soil gas at Site SS024.

2.7.2.1 Soil The soil data were compared to the HDOH Tier 1 EALs for the following environmental hazards: 1) gross contamination; 2) human direct exposure (based on unrestricted land use); 3) terrestrial wildlife exposure; 4) leaching of contaminants from soil to groundwater and surface water; and 5) vapor intrusion into buildings (based on unrestricted land use). The soil metal data were also compared to Hickam AFB ambient background levels. Table 2-7 summarizes the exceedances of both Tier 1 EALs and ambient background levels in site soils. The following summarizes the EHE results associated with the surface and subsurface soil data.

The EHE for surface soil indicate that Tier 1 EALs were exceeded for arsenic (total and bioaccessible) for human direct exposure concern; for arsenic and benzo[a]pyrene for terrestrial ecotoxicity concern; and for dieldrin for groundwater protection concern.

Surface Soil

Overall, the elevated concentrations of these chemicals in surface soil were flagged in the EHE as posing potential environmental threats; however, the results of the baseline risk assessment indicate that they do not pose unacceptable risk to human health or the environment.

The EHE for subsurface soil indicate the following: Subsurface Soil

• Tier 1 EALs for gross contamination concern were exceeded for TPH-d and three metals (copper, lead, and zinc).

• Tier 1 EALs for human direct exposure concern were exceeded for TPH-d, dioxins/furans, and five metals (antimony, arsenic, cadmium, copper, and lead).

• Tier 1 EALs for terrestrial ecotoxicity concern were exceeded for seven metals (antimony, arsenic, barium, cadmium, copper, lead, and zinc).

• Tier 1 EAL for groundwater protection concern was exceeded for TPH-d only.

The detections of TPH-d in the subsurface soil at elevated concentrations are limited to two locations and do not represent a widespread site condition. Overall, the elevated concentrations of metals and dioxins/furans in subsurface were mainly found in the buried debris layer and therefore metals and dioxins were flagged in the EHE as posing potential environmental threats. However, the results of the baseline risk assessment, which included all subsurface soil and groundwater data (except for lead data, see Section 2.7.1.1.2 above for



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explanation), indicate that they do not pose unacceptable risks to human health or the environment. Please refer to Section 7.1 (Summary of Findings) and Appendix I (Buried Debris Layer at Mamala Bay Golf Course) of the RI Report (CH2M HILL, January 15, 2010) for additional details.

2.7.2.2 Groundwater The groundwater data were compared to HDOH Tier 1 EALs for the following environmental hazards: 1) protection of aquatic habitats; and 2) protection against gross contamination conditions. The dissolved metal data for groundwater were also compared to the Hickam AFB ambient background levels. Table 2-8 summarizes the exceedances of both Tier 1 EALs and ambient background levels in site groundwater.

The results indicate that Tier 1 EALs for aquatic habitat concern were exceeded for TPH-d and two dissolved metals (dissolved copper and dissolved zinc). The extent of TPH-d, dissolved copper, and dissolved zinc contamination in site groundwater appears to be limited and does not represent a widespread condition. Overall, the elevated concentrations of metals in groundwater were flagged in the EHE as posing potential threats to aquatic resources; however, results of the baseline risk assessment indicate that they do not pose unacceptable risk to ecological receptors.

2.7.3 Basis for No Action Based on the results of the baseline risk assessment and EHE conducted for Site SS024, no action is required to protect human health or the environment from actual or threatened releases of hazardous substances in soil or groundwater at Site SS024. The buried debris layer will be handled in accordance with administrative procedures described in Appendix I (Buried Debris Layer at Mamala Bay Golf Course) of the RI Report (CH2M HILL, January 15, 2010).

2.8 Documentation of Significant Change from Proposed Plan

There are no significant changes in this document from the Proposed Plan. The Proposed Plan for Site SS024 was issued in March 2010 and information on the Proposed Plan was presented in a Proposed Plan meeting on April 22, 2010. Comments on the Proposed Plan were solicited from interested parties up until April 30, 2010. These comments and associated responses are provided in Section 3.1. However, none of the comments received resulted in changes to the ROD.


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3.0 Responsiveness Summary This section provides a summary of the public comments regarding the Proposed Plan for Site SS024, Hickam AFB. The general public and community stakeholders were provided the opportunity to review and comment on the Proposed Plan. The comment period began on April 1, 2010 and ended on April 30, 2010. A public notice summarizing the Proposed Plan and announcing the availability of the administrative record, the public comment period, and the associated public meeting was printed in the Midweek newspaper on March 31, 2010. The public meeting was held at the Ohana Honolulu Airport Hotel, located at 3401 North Nimitz Hwy, Honolulu, Hawaii, on April 22, 2010. The public meeting was recorded and transcribed. Comments relating to the Proposed Plan that were received from the audience at the public meeting are addressed as below.

Comment #1 (from Mr. Ron Mobley, RAB Member): Mr. Mobley asked the Air Force to explain the terminology “multi-increment surface soil sampling”, which was mentioned several times during the meeting.

Response: During the Remedial Investigation (RI), a multi-increment (MI) soil sampling approach was used to collect surface soil samples from Site SS024 to enhance the sample representativeness. The 2.5-acre study area was divided into two decision units for the MI sampling. Each decision unit was sub-divided into a minimum 30 increments (37 and 40 for the two decision units at Site SS024) as recommended by the State of Hawaii Department of Health (HDOH) guidance. Approximately equal amount of surface soil was collected from each increment and combined into one primary sample for each decision unit. The primary samples were sent to a laboratory for chemical analysis. The results of each primary sample were then compared to applicable HDOH screening levels to determine whether further action is required for each decision unit. Further detail on the MI sampling approach can also be found in Section 4.2 of the “Technical Guidance Manual for the Implementation of the Hawaii State Contingency Plan” (HDOH, November 12, 2008, Interim Final).GM for the Implementation of the Hawai'i State Contingency Plan

Comment #2 (from Mr. Ron Mobley, RAB Member): Mr. Mobley pointed out the discrepancy between the meeting presentation and the Proposed Plan regarding the depths to buried debris layer. The meeting presentation indicated a range of 6.5 to 8.5 feet below ground surface (bgs) while the Proposed Plan showed a range of 5 to 11.6 feet bgs.

Response: The buried debris layer was encountered at Site SS024 at a depth interval ranging from 5 to 11.6 feet bgs, mostly found at the depth interval of 6.5 and 8.5 feet bgs. The Record of Decision (ROD) for Site SS024 has provided the correct information.

Comment #3 (from Mr. Ron Mobley, RAB Member): Mr. Mobley pointed out the discrepancy between the meeting presentation and the Proposed Plan regarding the exposure frequency and


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duration that were used to estimate potential risks to excavation/construction workers. The meeting presentation indicated four weeks a year while the Proposed Plan showed 20 days a year.

Response: The correct exposure frequency and duration should be 20 working days a year. The ROD for Site SS024 has provided the correct information.

Comment #4 (from Mr. Ron Mobley, RAB Member): Mr. Mobley stated a concern about using the terminology “unacceptable risk” and his preference to come up with a different way of phrasing it.

Response: The use of the term "unacceptable risk" is common within state and federal regulatory arenas. The term is important in that it explicitly indicates that risk is a matter of degree, and recognizes that zero risk does not exist. The use of the term and the degree of risk that is considered unacceptable has been dictated by U.S. Environmental Protection Agency (EPA) in “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions” (OSWER Directive 9355.0-30, April 22, 1991).



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4.0 References CH2M HILL. March 2010. Proposed Plan for Site SS024 (Reef Taxiway), Hickam Air Force Base,

Oahu, HI. Prepared for the Air Force Center for Environmental Excellence, Environmental Services Office, Installation-Worldwide Pacific Division (AFCEE/IWP), Brooks City-Base, Texas, and for 15th Airlift Wing CES/CEVR, Hickam Air Force Base, Oahu, Hawaii.

CH2M HILL. January 15, 2010. Final Remedial Investigation for Site SS024 (Reef Taxiway), Hickam Air Force Base, Oahu, HI. Prepared for the Air Force Center for Environmental Excellence, Environmental Services Office, Installation-Worldwide Pacific Division (AFCEE/IWP), Brooks City-Base, Texas, and for 15th Airlift Wing CES/CEVR, Hickam Air Force Base, Oahu, Hawaii.

CH2M HILL. May 19, 2006. Final Tidal Study Report Chlorinated VOCs Plume Area at Site LF05. Prepared for Air Force Center for Environmental Excellence, Environmental Services Office, Installation Worldwide – Pacific Division (AFCEE/IWP), Brooks City-Base, Texas, and for 15th Airlift Wing CES/CEVR, Hickam Air Force Base, Oahu, Hawaii.

Earth Tech, Inc., March 17, 2008. Final Site Inspection for Spill Site SS24 (Reef Taxiway), Hickam Air Force Base, Oahu, Hawaii. Prepared for the AFCEE Environmental Services Office, Environmental Restoration Division, (AFCEE/ERD), Brooks City-Base, Texas, and for 15 CES/CEVR, Hickam Air Force Base, Oahu, Hawaii.

Engineering Science, Inc. (ES). March 1996. Final Installation Restoration Program Phase II, Stage 3, Remedial Investigation Sites LF01, LF05, and FT07, Volume 1: Final Remedial Investigation Report, Hickam Air Force Base, Oahu, Hawaii.

Mink, John F., and L. Stephen Lau. February 1990 (revised). Aquifer Identification and Classification for Oahu: Groundwater Protection Strategy for Hawaii. Water Resources Research Center (WRRC) Technical Report No. 179. University of Hawaii at Manoa, Honolulu, Hawaii.

State of Hawaii Department of Health (HDOH). Summer 2008, updated March 2009. Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater.

U.S. Environmental Protection Agency (EPA). May 14, 2009. Software for Calculating Upper Confidence Limits (UCLs) ProUCL Version 4.00.04 ([Online: http://www.epa.gov/esd/tsc/software.htm]).

U.S. Environmental Protection Agency (EPA). March 2005. Guidelines for Carcinogen Risk Assessment.

U.S. Air Force (USAF). February 10, 2005. 15th Airlift Wing Community Involvement Plan, Hickam Air Force Base, Honolulu, Hawaii. Prepared by Tetra Tech EM Inc.


4-2

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FIGURES





FIGURE 2-1Site Location MapRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

\\Nala\proj\AFCEE_Hickam\376712TO52INC4P08\GIS\MXD\ROD\Figure2-1_SiteLocation_ver1.mxd

VICINITY MAP

0 1,000 2,000500

Feet

$

LEGEND

Area ofDetail

Project LocationSite SS024

Mamala Bay Ahua Lagoon

Hickam Air Force BaseHonolulu International Airport

Pearl Harbor Naval Complex

Boundary of Hickam AFB

Golf Course

Project Location and Boundary

IRP Site LF05

Malama BayGolf Course

Par 3Golf

Course

LEGEND

Figure 2-2Site LayoutRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

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Site SS024 Study AreaHickam AFB BoundaryBuildingFence

0 50 100 150 20025

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Golf Course Maintenance Building/Yard

#4 Tee box

\\Nala\proj\AFCEE_Hickam\376712TO52INC4P08\GIS\MXD\ROD\Figure2-2_SiteLayout_rev1.mxd

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Ahua Lagoon

1941 Aerial Photograph. Site SS024 location appeared to be in a shallow marine environment.

1945 Aerial Photograph. Nearshore sediment was dredged and deposited, extending the shoreline southward. Site SS024 was no longer in a shallow marine environment.

1954 Aerial Photograph. Shoreline alteration and addition of fill soil appeared to be completed. The shoreline visible in this photograph seemed to be in the same location as current. Construction of Mamala Bay Golf Course had not begun.

Figure 2-3 Historical Aerial Photographs Record of Decision for Site SS024 Hickam AFB, Oahu, HI

Approximate Location of Site SS024

Undisturbed ShorelineApproximate Location of Site SS024

Dredging

Depositing Fill Soil

Altered Shoreline

Approximate Location of Site SS024

FIGURE 2-4Historical Passive Soil Gas Survey ResultsRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

CH2MHILL

Meters

0 10 20

Note:This figure has been modified from the originalfigures in Appendix B of the “Final Site Inspection Report for Spill Site SS24 (Reef Taxiway)“(Earth Tech, March 17, 2008)” to show the

locations where volatile organic compounds were detected during the passive soil gas survey conducted at Site SS024.

LEGEND

Passive Soil-Gas Sample LocationVICINITY MAP

\\\\Nala\proj\AFCEE_Hickam\376712TO52INC4P08\GIS\MXD\ROD\Figure2-4_PassiveSoil.ppt

Decision Unit #1Decision Unit #2

LEGEND

Figure 2-5RI Multi-Increment Surface SoilSampling LocationsRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

Multi-Increment Sampling Decision Unit BoundaryIncrement Area BoundaryHickam AFB BoundaryBuildingFence

0 50 10025

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$

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Building/Yard

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#*

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#*

#*

#*

#*

#*

!A#*

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XW

XW

XW

XW

SS024-BH012

SS024-BH004/GW004

SS024-BH011

SS024-BH006/GW006

SS024-BH001/GW001

SS024-SG004

SS024-BH014

SS024-BH007/GW007

SS024-BH015

SS24-TW04

SS024-SG001

SS024-SG003

SS024-SG002

SS024-SG005

SS24-TW03

SS24-SB02

SS24-TW02

SS24-SB04

SS24-TW05

SS24-TW01

SS24-SB03

SS24-SB01

BKG-SB-31

SS024-BH008

SS024-BH009

SS024-BH010

SS024-BH013 SS024-BH003/GW003

SS024-BH005/GW005

SS024-BH002/GW002

FIGURE 2-6Historical and RI Subsurface Soil, Soil Gasand Groundwater Sampling LocationsRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

LEGEND

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!. RI Subsurface Soil Sampling Location

@A RI Subsurface Soil and Groundwater Sampling Location

XW RI Soil Gas Sampling Location

SI Subsurface Soil and Groundwater Sampling Location#*

SI Subsurface Soil Sampling Location#*

Initial 1992 Background Soil Sampling Location@ASite SS024 Study Area

FenceBuilding

Hickam AFB Boundary

Decision Unit #1Decision Unit #2

SS024-MI001-0309 (Primary Sample)Arsenic 84 M mg/kgArsenic, Bioaccessible 31.7 mg/kgDieldrin 0.0076 J mg/kgSS024-MI101-0309 (Duplicate Sample)Arsenic 120 mg/kgArsenic, Bioaccessible 28.8 mg/kgBenzo(a)pyrene 0.2 J mg/kgDieldrin 0.0035 J mg/kgSS024-MI201-0309 (Triplicate Sample)Arsenic 91 mg/kg

SS024-MI002-0309 (Primary Sample)Arsenic 62 mg/kgDieldrin 0.0055 J mg/kgSS024-MI102-0309 (Duplicate Sample)Arsenic 75 mg/kgDieldrin 0.0049 J mg/kgSS024-MI202-0309 (Triplicate Sample)Arsenic 52 mg/kgDieldrin 0.0048 J mg/kg

LEGEND

Figure 2-7Tier 1 EAL Exceedances inSurface SoilRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

Revised Multi-Increment Sampling Decision Unit BoundaryFenceHickam AFB BoundaryBuilding

0 50 10025

Feet

$Note: mg/kg = milligram per kilogram M = A matrix effect was present. J = the analyte was positively identified; the quantitation is an estimate - Displayed values exceed both HDOH EALs and Hickam ambient background concentrations for metals. For the purpose of evaluating risk for each decision unit, the most conservative value (highest concentrations) for each chemical concentrations that exceeded screening levels is used. For risk evaluation in decision unit #1, the total arsenic concentration of 120 mg/kg , bioaccessible arsenic concentration of 31.7 mg/kg, benzo(a)pyrene concentration of 0.2 mg/kg, and dieldrin concentration of 0.0076 mg/kg will be used. For risk evaluation in decision unit #2, the total arsenic concentration of 62 mg/kg , bioaccessible arsenic concentration of 15.5 mg/kg, and dieldrin concentration of 0.0055 mg/kg will be used.

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\\Nala\proj\AFCEE_Hickam\376712TO52INC4P08\GIS\MXD\ROD\Figure2-7_EALExceeds_SurfaceSoil_rev1.mxd

ChemicalTier 1 EAL(most stringent)

Final Screening Level

Hickam AFB Background Metals

Total Arsenic 20 Background 27.9Bioaccessible Arseni 23* Background Not ApplicableBenzo(a)pyrene 0.15 Direct Exposure Not ApplicableDieldrin 0.0033 Leaching Not Applicable* - HDOH Tier 2 Action Level

HDOH Action Level Comparison Concentrations (mg/kg)

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SS024-BH010

SS024-BH004

LEGEND

Figure 2-8Tier 1 EAL Exceedances inSubsurface SoilRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI

!. RI Subsurface Soil Sample Location with HDOH EAL Exceedances

!. RI Subsurface Soil Sample Location with no HDOH EAL Exceedances

GF 1992 "Background" Soil Boring with HDOH EAL Exceedance

#* Historical Subsurface Soil Sample Location with no HDOH EAL Exceedances

#* Historical Subsurface Soil Sample Location with HDOH EAL Exceedances

Site SS024 Study Area

Hickam AFB Boundary

Building

Fence

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SS024-BH001B (7 - 8 ft bgs) Antimony 23 mg/kgLead 470 mg/kg2,3,7,8-TCDD TEQ 2.5E-5 mg/kg

SS024-BH005B (7 - 8 ft bgs) Arsenic 37 mg/kgCopper 350 mg/kgLead 1600 mg/kgTPH-d 540 mg/kg

SS024-BH006B (7 - 8.5 ft bgs) Cadmium 25 mg/kgCopper 1600 mg/kgLead 2600 mg/kgZinc 2000 mg/kg2,3,7,8-TCDD TEQ 9.0E-5 mg/kg

SS024-BH007B (11.5 - 13.5 ft bgs) Copper 1300 mg/kg

SS024-BH009B (7 - 9 ft bgs) Lead 340 M mg/kg2,3,7,8-TCDD TEQ 6.2E-6 mg/kg

SS024-BH011B (5.5 - 8 ft bgs) Barium 980 J mg/gLead 330 J mg/kg2,3,7,8-TCDD TEQ 3.2E-5 mg/kgTPH-d 760 J mg/kg

SS024-BH012B (6 - 8 ft bgs) Antimony 22 mg/kgArsenic 32 mg/kgCopper 1700 J mg/kgLead 660 mg/kgZinc 3000 mg/kg2,3,7,8-TCDD TEQ 8.2E-5 mg/kg

SS024-BH013B (6.5 - 8.5 ft bgs) Antimony 13 mg/kgArsenic 43 mg/kgCadmium 21 mg/kgCopper 870 mg/kgLead 1100 mg/kgZinc 3800 mg/kg2,3,7,8-TCDD TEQ 1.1E-4 mg/kg

SS024-BH014B (8 - 10 ft bgs) Antimony 12 mg/kgArsenic 28 mg/kgCopper 5600 mg/kgLead 2900 mg/kgZinc 1700 mg/kg 2,3,7,8-TCDD TEQ 9.0E-5 mg/kg

SS024-BH015B (7 - 8.5 ft bgs) Copper 260 mg/kgZinc 830 mg/kg

SS24-SB01 (8 - 8.5 ft bgs) Lead 1690 mg/kgZinc 1000 mg/kg

SS24-SB02(7 - 7.5 ft bgs) Copper 458 mg/kg

SS24-SB04 (8.5 - 9 ft bgs) Copper 307 mg/kgLead 560 mg/kgZinc 2550 mg/kg

SS24-TW01(6 - 6.5 ft bgs) Copper 1540 mg/kgLead 800 mg/kgZinc 1410 mg/kg

SS24-TW02 (8.5 - 9 ft bgs) Cadmium 26.7 mg/kg

SS24-TW03 (7 - 8 ft bgs) Arsenic 51.7 mg/kg

Note: mg/kg = milligram per kilogram J = the analyte was positively identified; the quantitaion is an estimate -- Displayed values exceed both HDOH EALs and Hickam ambient background concentrations for metals -- The subsurface soil sample fom the 1992 "Background" soil boring had a TPH concentration of 20,000 mg/kg. However, the method use to analyze for TPH is biased high, therefore, the result will not be used to evaluate the nature and extent of contamination for Site SS024.

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ChemicalTier 1 EAL (most stringent) Tier 1 EAL Basis


Antimony 6.3 Background 8.7Arsenic 20 Background 27.9Barium 750 Background 951Cadmium 12 Terrestrial Ecotoxicity 3.6Copper 230 Terrestrial Ecotoxicity 138Lead 200 Background 226Nickel 150 Background 358Zinc 600 Terrestrial Ecotoxicity 421TPH-d 500 Gross Contamination Not applicableBenzo(a)pyrene 0.15 Direct Exposure Not applicableDieldrin 0.0033 Leaching Not applicable2,3,7,8-TCDD TEQ 4.5E-06 Direct Exposure Not applicable

HDOH Action Level Comparison Concentrations (mg/kg)Final ScreeningLevel

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LEGEND

Figure 2-9Tier 1 EAL Exceedances inGroundwaterRecord of Decision for Site SS024Hickam Air Force Base, Oahu, HI0 10050

Feet

$

SS024-GW001 Zinc, dissolved 0.026 J mg/L

Note: mg/L = milligram per Liter J = the analyte was positively identified; the quantitation is an estimate M = a matrix effect was present -- Displayed values exceed both HDOH EALs and Hickam ambient background concentrations for metals

SS024-GW002 TPH-d 0.91 mg/L



SS24-TW02 Copper, dissolved 0.02 M mg/L

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A RI Groundwater Sample Locations with HDOH EAL Exceedance

A RI Groundwater Sample Locations with no HDOH EAL Exceedance

< Historical Groundwater Sampling Location with HDOH EAL Exceedance

Site SS024 Study Area< Historical Groundwater Sampling Location with no HDOH EAL Exceedance

Hickam AFB Boundary

BuildingFence

ChemicalTier 1 EAL (most stringent) Tier 1 EAL Basis


Copper, dissolved 0.0029 Background 0.007Zinc, dissolved 0.022 Aquatic Habitat 0.0198TPH-d 0.64 Aquatic Habitat Not applicable

HDOH Action Level Comparison Concentrations (mg/L)Final ScreeningLevel

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TABLES





Page 1 of 3

TABLE 2-1Summary of Chemicals Detected in Surface and Subsurface SoilsRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI

Chemical Group Analyte Units

Number of Detects

Number of Samples

Frequency of Detection Minimum MDL

Maximum MDL

Minimum Detected Value

Maximum Detected Value EAL

Number of Detects > EAL

Number of Nondetects > EAL Background

Number of Detects > Background

Number of Nondetects > Background

Surface Soil (Multi-Increment Sampling)TPH Diesel C10-C28 mg/kg 2 2 100% -- -- 35 41 500 -- -- -- -- --TPH Motor Oil C28-C36 mg/kg 2 2 100% -- -- 170 220 -- -- -- -- -- --SVOC bis(2-Ethylhexyl)phthalate mg/kg 2 2 100% -- -- 0.068 0.084 35 -- -- -- -- --SVOC Butylbenzylphthalate mg/kg 1 2 50% 0.011 0.011 0.012 0.012 -- -- -- -- -- --PEST 4,4'-DDD mg/kg 1 2 50% 0.0036 0.0036 0.012 0.012 2 -- -- -- -- --PEST 4,4'-DDE mg/kg 2 2 100% -- -- 0.005 0.0078 1.4 -- -- -- -- --PEST 4,4'-DDT mg/kg 2 2 100% -- -- 0.0052 0.0058 1.7 -- -- -- -- --PEST Dieldrin mg/kg 2 2 100% -- -- 0.0055 0.0076 0.0033 2 -- -- -- --PEST Endosulfan sulfate mg/kg 2 2 100% -- -- 0.0033 0.0043 -- -- -- -- -- --PEST gamma-Chlordane mg/kg 2 2 100% -- -- 0.0038 0.0083 7 -- -- -- -- --PCB Aroclor-1260 mg/kg 2 2 100% -- -- 0.31 0.42 1.1 -- -- -- -- --PAH Anthracene mg/kg 1 2 50% 0.0099 0.0099 0.014 0.014 2.5 -- -- -- -- --PAH Benzo(a)anthracene mg/kg 2 2 100% -- -- 0.054 0.14 1.5 -- -- -- -- --PAH Benzo(a)pyrene mg/kg 2 2 100% -- -- 0.092 0.2 0.15 1 -- -- -- --PAH Benzo(b)fluoranthene mg/kg 2 2 100% -- -- 0.14 0.3 1.5 -- -- -- -- --PAH Benzo(g,h,i)perylene mg/kg 2 2 100% -- -- 0.047 0.088 27 -- -- -- -- --PAH Benzo(k)fluoranthene mg/kg 2 2 100% -- -- 0.057 0.11 15 -- -- -- -- --PAH Chrysene mg/kg 2 2 100% -- -- 0.072 0.14 14 -- -- -- -- --PAH Dibenz(a,h)anthracene mg/kg 1 2 50% 0.011 0.011 0.022 0.022 0.15 -- -- -- -- --PAH Fluoranthene mg/kg 2 2 100% -- -- 0.062 0.16 40 -- -- -- -- --PAH Indeno(1,2,3-cd)pyrene mg/kg 2 2 100% -- -- 0.042 0.075 1.5 -- -- -- -- --PAH Phenanthrene mg/kg 2 2 100% -- -- 0.019 0.049 11 -- -- -- -- --PAH Pyrene mg/kg 2 2 100% -- -- 0.16 0.34 56 -- -- -- -- --METAL Aluminum mg/kg 2 2 100% -- -- 21000 22000 -- -- -- 63700 -- --METAL Antimony mg/kg 2 2 100% -- -- 0.44 4 6.3 -- -- 8.7 -- --METAL Arsenic mg/kg 2 2 100% -- -- 75 120 20 2 -- 27.9 2 --METAL Arsenic-Bioaccessible mg/kg 2 2 100% -- -- 15.5 31.7 20 1 -- -- -- --METAL Barium mg/kg 2 2 100% -- -- 93 120 750 -- -- 951 -- --METAL Beryllium mg/kg 2 2 100% -- -- 0.61 0.63 4 -- -- 3.01 -- --METAL Cadmium mg/kg 2 2 100% -- -- 0.62 0.72 12 -- -- 3.6 -- --METAL Calcium mg/kg 2 2 100% -- -- 150000 190000 -- -- -- -- -- --METAL Chromium mg/kg 2 2 100% -- -- 89 93 500 -- -- 273 -- --METAL Cobalt mg/kg 2 2 100% -- -- 18 21 40 -- -- 79.9 -- --METAL Copper mg/kg 2 2 100% -- -- 80 160 230 -- -- 138 1 --METAL Iron mg/kg 2 2 100% -- -- 40000 43000 -- -- -- 124000 -- --METAL Lead mg/kg 2 2 100% -- -- 49 79 200 -- -- 226 -- --METAL Magnesium mg/kg 2 2 100% -- -- 11000 11000 -- -- -- -- -- --METAL Manganese mg/kg 2 2 100% -- -- 810 1200 -- -- -- 4590 -- --METAL Mercury mg/kg 2 2 100% -- -- 0.062 0.091 4.7 -- -- 0.38 -- --METAL Molybdenum mg/kg 2 2 100% -- -- 0.55 3 40 -- -- 9.6 -- --METAL Nickel mg/kg 2 2 100% -- -- 58 63 150 -- -- 358 -- --METAL Potassium mg/kg 2 2 100% -- -- 1300 1500 -- -- -- -- -- --METAL Selenium mg/kg 2 2 100% -- -- 2.4 3.1 10 -- -- 3.6 -- --METAL Sodium mg/kg 2 2 100% -- -- 1600 2000 -- -- -- -- -- --METAL Thallium mg/kg 2 2 100% -- -- 0.083 0.12 1 -- -- 230 -- --METAL Vanadium mg/kg 2 2 100% -- -- 92 95 110 -- -- 246 -- --METAL Zinc mg/kg 2 2 100% -- -- 130 380 600 -- -- 421 -- --Subsurface SoilVOC 1,1-Dichloroethene mg/kg 1 39 3% 0.0003 0.0036 0.0078 0.0078 4.3 -- -- -- -- --VOC 2-Butanone mg/kg 24 39 62% 0.0007 0.0071 0.0039 0.1 14 -- -- -- -- --VOC Acetone mg/kg 33 39 85% 0.0014 0.0033 0.0029 0.66 0.86 -- -- -- -- --VOC Benzene mg/kg 4 39 10% 0.0006 0.0036 0.002 0.015 0.53 -- -- -- -- --VOC Bromomethane mg/kg 4 39 10% 0.0007 0.0036 0.0014 0.0017 0.18 -- -- -- -- --VOC cis-1,2-Dichloroethene mg/kg 1 39 3% 0.0005 0.0036 0.36 0.36 1.2 -- -- -- -- --

EAL a Background b

Page 2 of 3



Number of Detects

Number of Samples


Maximum MDL







EAL a Background b

VOC Ethylbenzene mg/kg 1 39 3% 0.0005 0.0036 0.0019 0.0019 1.6 -- -- -- -- --VOC Isopropylbenzene mg/kg 1 30 3% 0.0011 0.0036 0.0022 0.0022 -- -- -- -- -- --VOC m,p-Xylenes mg/kg 2 39 5% 0.0011 0.0036 0.0018 0.0069 12 -- -- -- -- --VOC Methylene Chloride mg/kg 14 39 36% 0.0023 0.013 0.0036 0.045 0.88 -- -- -- -- --VOC o-Xylene mg/kg 2 39 5% 0.0008 0.0036 0.0018 0.002 12 -- -- -- -- --VOC Tetrachloroethene mg/kg 1 39 3% 0.001 0.0039 0.0025 0.0025 0.07 -- -- -- -- --VOC Toluene mg/kg 2 39 5% 0.0007 0.0036 0.0018 0.002 11 -- -- -- -- --VOC trans-1,2-Dichloroethene mg/kg 1 39 3% 0.0006 0.0036 0.07 0.07 2.1 -- -- -- -- --VOC Trichloroethene mg/kg 1 39 3% 0.0005 0.0036 0.21 0.21 0.21 -- -- -- -- --VOC Trichlorofluoromethane mg/kg 12 30 40% 0.0012 0.0055 0.0025 0.044 -- -- -- -- -- --VOC Vinyl Chloride mg/kg 1 39 3% 0.0006 0.0036 0.012 0.012 0.04 -- -- -- -- --VOC Xylenes, Total mg/kg 2 9 22% 0.0008 0.0012 0.0035 0.01 12 -- -- -- -- --TPH Diesel C10-C28 mg/kg 37 39 95% 1.3 1.3 1.2 760 500 2 -- -- -- --TPH Gasoline C6-C10 mg/kg 20 39 51% 0.021 0.96 0.011 0.5 100 -- -- -- -- --TPH Motor Oil C28-C36 mg/kg 34 39 87% 5.8 6.6 1.8 1700 -- -- -- -- -- --SVOC bis(2-Ethylhexyl)phthalate mg/kg 4 30 13% 0.035 0.091 0.063 0.16 35 -- -- -- -- --PEST 4,4'-DDE mg/kg 3 30 10% 0.00042 0.011 0.00072 0.001 1.4 -- -- -- -- --PEST Aldrin mg/kg 1 30 3% 0.00028 0.007 0.002 0.002 0.029 -- -- -- -- --PEST alpha-BHC mg/kg 1 30 3% 0.00034 0.0085 0.0017 0.0017 -- -- -- -- -- --PEST alpha-Chlordane mg/kg 1 30 3% 0.00023 0.0058 0.00062 0.00062 7 -- -- -- -- --PEST Dieldrin mg/kg 1 30 3% 0.00047 0.012 0.0011 0.0011 0.0033 -- 1 -- -- --PEST Heptachlor mg/kg 1 30 3% 0.00029 0.0073 0.00061 0.00061 0.11 -- -- -- -- --PEST Heptachlor epoxide mg/kg 1 30 3% 0.00028 0.007 0.00077 0.00077 0.0031 -- 1 -- -- --PCB Aroclor-1260 mg/kg 1 8 13% 0.0013 0.0033 0.0074 0.0074 1.1 -- -- -- -- --PCB Aroclor-1262 mg/kg 2 7 29% 0.016 0.017 0.017 0.032 -- -- -- -- -- --PAH 1-Methylnaphthalene mg/kg 4 9 44% 0.0016 0.0062 0.0037 0.0086 -- -- -- -- -- --PAH 2-Methylnaphthalene mg/kg 10 39 26% 0.0024 0.021 0.0059 0.066 1.1 -- -- -- -- --PAH Acenaphthene mg/kg 5 39 13% 0.0016 0.021 0.0067 0.19 23 -- -- -- -- --PAH Anthracene mg/kg 2 39 5% 0.0012 0.026 0.0039 0.04 2.5 -- -- -- -- --PAH Benzo(a)anthracene mg/kg 7 39 18% 0.0012 0.028 0.0036 0.25 1.5 -- -- -- -- --PAH Benzo(a)pyrene mg/kg 2 39 5% 0.0013 0.023 0.039 0.073 0.15 -- -- -- -- --PAH Benzo(b)fluoranthene mg/kg 4 39 10% 0.0012 0.024 0.014 0.29 1.5 -- -- -- -- --PAH Benzo(g,h,i)perylene mg/kg 1 39 3% 0.0013 0.036 0.017 0.017 27 -- -- -- -- --PAH Benzo(k)fluoranthene mg/kg 1 39 3% 0.0006 0.024 0.083 0.083 15 -- -- -- -- --PAH Chrysene mg/kg 7 39 18% 0.0012 0.028 0.0072 0.088 14 -- -- -- -- --PAH Fluoranthene mg/kg 14 39 36% 0.0013 0.026 0.0052 0.27 40 -- -- -- -- --PAH Fluorene mg/kg 6 39 15% 0.0009 0.022 0.0076 0.067 7.3 -- -- -- -- --PAH Indeno(1,2,3-cd)pyrene mg/kg 1 39 3% 0.0017 0.03 0.019 0.019 1.5 -- -- -- -- --PAH Naphthalene mg/kg 12 39 31% 0.0012 0.011 0.025 0.56 4 -- -- -- -- --PAH Phenanthrene mg/kg 16 39 41% 0.0016 0.023 0.0041 0.16 11 -- -- -- -- --PAH Pyrene mg/kg 18 39 46% 0.0016 0.015 0.0062 2.1 56 -- -- -- -- --METAL Aluminum mg/kg 30 30 100% -- -- 560 50000 -- -- -- 63700 -- --METAL Antimony mg/kg 18 30 60% 0.15 0.22 0.17 23 6.3 6 -- 8.7 4 --METAL Arsenic mg/kg 39 39 100% -- -- 4.3 51.7 20 6 -- 27.9 5 --METAL Barium mg/kg 39 39 100% -- -- 6.2 980 750 1 -- 951 1 --METAL Beryllium mg/kg 30 30 100% -- -- 0.042 1.9 4 -- -- 3.01 -- --METAL Cadmium mg/kg 26 39 67% 0.055 0.066 0.15 26.7 12 3 -- 3.6 12 --METAL Calcium mg/kg 30 30 100% -- -- 72000 510000 -- -- -- -- -- --METAL Chromium mg/kg 39 39 100% -- -- 4.5 200 500 -- -- 273 -- --METAL Cobalt mg/kg 39 39 100% -- -- 0.71 54.7 40 5 -- 79.9 -- --METAL Copper mg/kg 39 39 100% -- -- 1.4 5600 230 10 -- 138 11 --METAL Iron mg/kg 30 30 100% -- -- 1400 170000 -- -- -- 124000 4 --METAL Lead mg/kg 33 39 85% 0.059 0.078 0.12 2900 200 11 -- 226 11 --METAL Magnesium mg/kg 30 30 100% -- -- 8900 36000 -- -- -- -- -- --METAL Manganese mg/kg 30 30 100% -- -- 42 2000 -- -- -- 4590 -- --

Page 3 of 3



Number of Detects

Number of Samples


Maximum MDL







EAL a Background b

METAL Mercury mg/kg 26 39 67% 0.0051 0.0086 0.0072 0.783 4.7 -- -- 0.38 1 --METAL Molybdenum mg/kg 23 30 77% 0.082 0.094 0.091 25 40 -- -- 9.6 2 --METAL Nickel mg/kg 39 39 100% -- -- 2.3 160 150 2 -- 358 -- --METAL Potassium mg/kg 30 30 100% -- -- 91 5800 -- -- -- -- -- --METAL Selenium mg/kg 12 30 40% 0.11 0.16 0.21 4.8 10 -- -- 3.6 3 --METAL Silver mg/kg 23 30 77% 0.043 0.05 0.068 16 20 -- -- 4.9 2 --METAL Sodium mg/kg 30 30 100% -- -- 2500 8100 -- -- -- -- -- --METAL Thallium mg/kg 8 30 27% 0.026 0.1 0.036 0.36 1 -- -- 230 -- --METAL Vanadium mg/kg 30 30 100% -- -- 6 150 110 3 -- 246 -- --METAL Zinc mg/kg 39 39 100% -- -- 2 3800 600 8 -- 421 9 --DIOX/FURN 1,2,3,4,6,7,8,9-OCDD mg/kg 8 8 100% -- -- 0.0000326 0.00475 -- -- -- -- -- --DIOX/FURN 1,2,3,4,6,7,8,9-OCDF mg/kg 8 8 100% -- -- 0.00000335 0.000547 -- -- -- -- -- --DIOX/FURN 1,2,3,4,6,7,8-HpCDD mg/kg 8 8 100% -- -- 0.0000052 0.00148 -- -- -- -- -- --DIOX/FURN 1,2,3,4,6,7,8-HpCDF mg/kg 8 8 100% -- -- 0.00000685 0.00149 -- -- -- -- -- --DIOX/FURN 1,2,3,4,7,8,9-HpCDF mg/kg 8 8 100% -- -- 0.000000397 0.0000234 -- -- -- -- -- --DIOX/FURN 1,2,3,4,7,8-HxCDD mg/kg 7 8 88% 0.000000583 0.000000583 0.000000801 0.0000231 -- -- -- -- -- --DIOX/FURN 1,2,3,4,7,8-HxCDF mg/kg 8 8 100% -- -- 0.00000316 0.0000804 -- -- -- -- -- --DIOX/FURN 1,2,3,6,7,8-HxCDD mg/kg 7 8 88% 0.00000057 0.00000057 0.00000198 0.0000534 -- -- -- -- -- --DIOX/FURN 1,2,3,6,7,8-HxCDF mg/kg 8 8 100% -- -- 0.00000222 0.0000777 -- -- -- -- -- --DIOX/FURN 1,2,3,7,8,9-HxCDD mg/kg 8 8 100% -- -- 0.000000665 0.0000454 -- -- -- -- -- --DIOX/FURN 1,2,3,7,8,9-HxCDF mg/kg 8 8 100% -- -- 0.00000082 0.0000246 -- -- -- -- -- --DIOX/FURN 1,2,3,7,8-PeCDD mg/kg 8 8 100% -- -- 0.000000513 0.0000246 -- -- -- -- -- --DIOX/FURN 1,2,3,7,8-PeCDF mg/kg 8 8 100% -- -- 0.00000155 0.0000622 -- -- -- -- -- --DIOX/FURN 2,3,4,6,7,8-HxCDF mg/kg 8 8 100% -- -- 0.00000354 0.000117 -- -- -- -- -- --DIOX/FURN 2,3,4,7,8-PeCDF mg/kg 8 8 100% -- -- 0.00000345 0.000107 -- -- -- -- -- --DIOX/FURN 2,3,7,8-TCDD mg/kg 7 8 88% 0.000000164 0.000000164 0.000000607 0.00000877 0.0000045 3 -- -- -- --DIOX/FURN 2,3,7,8-TCDF mg/kg 8 8 100% -- -- 0.00000253 0.0000804 -- -- -- -- -- --DIOX/FURN Total HpCDD mg/kg 8 8 100% -- -- 0.0000114 0.00335 -- -- -- -- -- --DIOX/FURN Total HpCDF mg/kg 8 8 100% -- -- 0.00000997 0.00192 -- -- -- -- -- --DIOX/FURN Total HxCDD mg/kg 8 8 100% -- -- 0.00000316 0.000813 -- -- -- -- -- --DIOX/FURN Total HxCDF mg/kg 8 8 100% -- -- 0.0000282 0.000832 -- -- -- -- -- --DIOX/FURN Total PeCDD mg/kg 8 8 100% -- -- 0.00000286 0.000366 -- -- -- -- -- --DIOX/FURN Total PeCDF mg/kg 8 8 100% -- -- 0.0000334 0.00129 -- -- -- -- -- --DIOX/FURN Total TCDD mg/kg 8 8 100% -- -- 0.00000221 0.000475 -- -- -- -- -- --DIOX/FURN Total TCDF mg/kg 8 8 100% -- -- 0.000043 0.00206 -- -- -- -- -- --DIOX/FURN Toxic Equivalence mg/kg 8 8 100% -- -- 0.00000303 0.000105 0.0000045 7 -- -- -- --

Notes:mg/kg = milligram(s) per kilogramMDL = method detection limit

VOC = volatile organic compoundsTPH = total petroleum hydrocarbonsSVOC = semivolatile organic compoundsPEST = pesticidesPCB = polychlorinated biphenylsPAH = polynuclear aromatic hydrocarbonsDIOX/FURN = dioxins/furansa EAL = State of Hawaii Department of Health Environmental Action Level (HDOH, October 2008 updated March 2009) for sites where drinking water is not threatened and less than 150 meters from surface water. The EALs listed here are "Final Groundwater Action Levels", representing the most stringent values. Sceening the subsurface soil data in this table against EALs is considered conservative, since the samples were collected from either the capillary fringe, or from beneath the water table.b Background = Hickam ambient background metal concentrations were established in the Final Technical Memorandum Base-Wide Ambient Metals Study, Hickam Air Force Base, Oahu, Hawaii (CH2M HILL, January 6, 2006)

= exceeds EAL and Hickam ambient background metals concentration, if applicable.

Page 1 of 2

TABLE 2-2Statistical Evaluation of Replicate Multi-Increment Surface Soil SamplesRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


SS024-MI001-

0309

SS024-MI101-

0309

SS024-MI201-

0309 Mean STD RSD%

SS024-MI002-0309

SS024-MI102-0309

SS024-MI202-0309 Mean STD RSD%

TPH Diesel C10-C28 mg/kg 35 26 27 29 4.9 17% 41 33 37 37 4.0 11%TPH Motor Oil C28-C36 mg/kg 170 130 140 147 21 14% 220 180 190 197 21 11%SVOC Anthracene mg/kg 0.01 U 0.014 F 0.0098 U 0.011 0.0024 21% 0.0099 U 0.0099 U 0.0099 U 0.0099 0 --SVOC Benzo(a)anthracene mg/kg 0.03 F 0.14 J 0.041 F 0.070 0.061 86% 0.038 F 0.054 J 0.033 J 0.042 0.011 26%SVOC Benzo(a)pyrene mg/kg 0.053 J 0.2 J 0.059 J 0.10 0.083 80% 0.069 J 0.092 J 0.062 J 0.074 0.016 21%SVOC Benzo(b)fluoranthene mg/kg 0.075 J 0.3 J 0.091 J 0.16 0.13 81% 0.11 J 0.14 J 0.096 J 0.12 0.022 19%SVOC Benzo(g,h,i)perylene mg/kg 0.022 J 0.088 J 0.024 J 0.045 0.038 84% 0.031 J 0.047 J 0.029 J 0.036 0.0099 28%SVOC Benzo(k)fluoranthene mg/kg 0.033 J 0.11 J 0.036 J 0.060 0.044 73% 0.041 J 0.057 J 0.033 J 0.044 0.012 28%SVOC bis(2-Ethylhexyl)phthalate mg/kg 0.084 F 0.035 U 0.035 U 0.051 0.028 55% 0.052 F 0.068 J 0.049 J 0.056 0.010 18%SVOC Butylbenzylphthalate mg/kg 0.011 U 0.012 J 0.011 U 0.011 5.77E-04 5% 0.011 U 0.011 U 0.011 U 0.011 2.12E-18 --SVOC Chrysene mg/kg 0.04 F 0.14 J 0.046 F 0.075 0.056 74% 0.055 F 0.072 J 0.048 J 0.058 0.012 21%SVOC Dibenz(a,h)anthracene mg/kg 0.011 U 0.022 J 0.011 U 0.015 0.0064 43% 0.011 U 0.011 U 0.011 U 0.011 2.12E-18 --SVOC Fluoranthene mg/kg 0.038 F 0.16 0.055 F 0.084 0.066 78% 0.048 F 0.062 F 0.046 F 0.052 0.0087 17%SVOC Indeno(1,2,3-cd)pyrene mg/kg 0.018 F 0.075 J 0.02 F 0.038 0.032 86% 0.025 F 0.042 J 0.025 J 0.031 0.0098 32%SVOC Phenanthrene mg/kg 0.014 F 0.049 F 0.012 F 0.025 0.021 83% 0.016 F 0.019 F 0.012 F 0.016 0.0035 22%SVOC Pyrene mg/kg 0.084 J 0.34 J 0.081 J 0.17 0.15 88% 0.11 0.16 J 0.079 J 0.12 0.041 35%PEST 4,4'-DDD mg/kg 0.0036 U 0.0036 U 0.0036 U -- -- -- 0.0036 U 0.012 J 0.0073 U 0.0076 0.0042 55%PEST 4,4'-DDE mg/kg 0.0078 F 0.0035 J 0.005 J 0.0054 0.0022 40% 0.0039 J 0.005 J 0.0059 U 0.0049 0.0010 20%PEST 4,4'-DDT mg/kg 0.0035 U 0.0052 J 0.0048 J 0.0045 8.89E-04 20% 0.0049 J 0.0057 J 0.0058 J 0.0055 4.93E-04 9%PEST Dieldrin mg/kg 0.0076 J 0.0035 J 0.0029 J 0.0047 0.0026 55% 0.0055 J 0.0049 J 0.0048 J 0.0051 3.79E-04 7%PEST Endosulfan sulfate mg/kg 0.0026 U 0.0026 U 0.0033 J 0.0028 4.04E-04 14% 0.0043 J 0.0035 J 0.0051 U 0.0043 8.00E-04 19%PEST gamma-Chlordane mg/kg 0.004 F 0.0083 J 0.0023 J 0.0049 0.0031 64% 0.0035 J 0.0038 J 0.0024 U 0.0032 7.37E-04 23%PCB Aroclor-1260 mg/kg 0.42 J 0.11 J 0.22 J 0.25 0.16 63% 0.31 0.18 0.27 0.25 0.067 26%METAL Aluminum mg/kg 11000 J 11000 J 21000 J 14,333 5,774 40% 12000 15000 22000 16,333 5,132 31%METAL Antimony mg/kg 1.1 M 4 J 0.12 UJ 1.7 2.0 116% 0.44 F 0.12 U 0.12 U 0.23 0.18 82%METAL Arsenic mg/kg 84 M 120 91 98 19 19% 62 75 52 63 12 18%METAL Arsenic-Bioaccessible mg/kg 31.7 M 28.8 -- 30 2.1 7% 15.5 F -- -- 16 -- --METAL Barium mg/kg 54 M 86 93 78 21 27% 120 97 110 109 12 11%METAL Beryllium mg/kg 0.38 0.54 0.61 0.51 0.12 23% 0.59 0.63 0.62 0.61 0.021 3%METAL Cadmium mg/kg 0.44 0.72 0.63 0.60 0.14 24% 0.59 0.62 0.54 0.58 0.040 7%METAL Calcium mg/kg 150000 J 190000 150000 163,333 23,094 14% 140000 150000 130000 140,000 10,000 7%METAL Chromium mg/kg 47 M 49 J 89 J 62 24 38% 60 72 93 75 17 22%METAL Cobalt mg/kg 9.5 J 12 18 13 4.4 33% 16 18 21 18 2.5 14%METAL Copper mg/kg 84 160 110 118 39 33% 69 80 66 72 7.4 10%METAL Iron mg/kg 23000 26000 40000 29,667 9,074 31% 28000 34000 43000 35,000 7,550 22%METAL Lead mg/kg 40 M 79 59 59 20 33% 42 49 37 43 6.0 14%METAL Magnesium mg/kg 8200 J 11000 J 9100 J 9,433 1,429 15% 10000 11000 10000 10,333 577 6%METAL Manganese mg/kg 340 J 460 J 810 J 537 244 46% 720 830 1200 917 251 27%METAL Mercury mg/kg 0.059 J 0.091 J 0.064 J 0.071 0.017 24% 0.056 J 0.062 J 0.047 J 0.055 0.0075 14%METAL Molybdenum mg/kg 0.79 J 3 J 0.23 J 1.3 1.5 109% 0.28 F 0.55 F 0.065 U 0.30 0.24 81%METAL Nickel mg/kg 30 M 36 58 41 15 36% 42 49 63 51 11 21%METAL Potassium mg/kg 1100 M 1500 1500 1,367 231 17% 1200 1300 1300 1,267 58 5%METAL Selenium mg/kg 1.1 J 0.093 UJ 2.4 J 1.2 1.2 97% 1.3 J 2 J 3.1 J 2.1 0.91 43%METAL Sodium mg/kg 1400 M 2000 1600 1,667 306 18% 1500 1600 1300 1,467 153 10%METAL Thallium mg/kg 0.12 F 0.067 U 0.067 U 0.085 0.031 36% 0.083 F 0.066 U 0.068 U 0.072 0.0093 13%METAL Vanadium mg/kg 50 M 56 J 95 J 67 24 36% 68 80 92 80 12 15%

Decision Unit #1 Decision Unit #2

Page 2 of 2

TABLE 2-2Statistical Evaluation of Replicate Multi-Increment Surface Soil SamplesRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


SS024-MI001-

0309

SS024-MI101-

0309

SS024-MI201-

0309 Mean STD RSD%

SS024-MI002-0309

SS024-MI102-0309

SS024-MI202-0309 Mean STD RSD%

Decision Unit #1 Decision Unit #2

METAL Zinc mg/kg 150 J 380 J 130 J 220 139 63% 120 130 110 120 10 8%

Notes:

mg/kg = milligram(s) per kilogram

TPH = total petroleum hydrocarbonsPEST = pesticidesPAH = polynuclear aromatic hydrocarbonsPCB = polychlorinated biphenylsSVOC = semi-volatile organic compoundsSTD = standard deviationRSD = relative standard deviationRPD = relative percent difference

Data Qualifiers

F The analyte was positively identified but the associated numerical value is below the reporting limit (RL).J The analyte was positively identified; the quantitation is an estimation.M A matrix effect was present.U The analyte was analyzed for, but not detected. The associated numerical value is at or below the sample-

specific method detection limit (MDL).

Bold indicates RSD is greater than 35 percent but the associated data are low level qualitative detections of include at least one non-detected result; therefore higher RSDs reflect higher uncertainty.Bold and shade indicates RSD is greater than 35 percent, which is considered reasonable by HDOH. Note that the QAPP specified RSDs between 35 and 50 percent are considered acceptable.

Page 1 of 2

TABLE 2-3Summary of Chemicals Detected in GroundwaterRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


Number of Detects

Number of Samples

Frequency of Detection

Minimum MDL

Maximum MDL







VOC Acetone ug/L 5 12 42% 1 1 1.1 14 1500 -- -- -- -- --VOC Benzene ug/L 4 12 33% 0.1 0.12 0.1 3.6 46 -- -- -- -- --VOC cis-1,2-Dichloroethene ug/L 7 12 58% 0.1 0.32 0.1 1.4 590 -- -- -- -- --VOC Freon 12 ug/L 1 7 14% 0.2 0.2 1.6 1.6 -- -- -- -- -- --VOC para-Isopropyl Toluene ug/L 1 7 14% 0.1 0.1 0.6 0.6 -- -- -- -- -- --VOC Vinyl Chloride ug/L 2 12 17% 0.1 0.27 0.3 0.3 21 -- -- -- -- --TPH Diesel C10-C28 mg/L 12 12 100% -- -- 0.041 0.97 0.64 3 -- -- -- --TPH Gasoline C6-C10 mg/L 3 12 25% 0.012 0.016 0.018 0.026 0.5 -- -- -- -- --TPH Motor Oil C28-C36 mg/L 10 12 83% 0.096 0.096 0.037 0.58 -- -- -- -- -- --PEST beta-BHC ug/L 2 7 29% 0.004 0.004 0.004 0.005 -- -- -- -- -- --PAH 1-Methylnaphthalene ug/L 4 12 33% 0.013 0.02 0.02 0.33 -- -- -- -- -- --PAH 2-Methylnaphthalene ug/L 3 12 25% 0.014 0.02 0.02 0.12 2.1 -- -- -- -- --PAH Acenaphthene ug/L 3 12 25% 0.011 0.02 0.05 0.97 23 -- -- -- -- --PAH Anthracene ug/L 2 12 17% 0.012 0.02 0.05 0.46 0.73 -- -- -- -- --PAH Fluoranthene ug/L 1 12 8% 0.014 0.02 0.82 0.82 8 -- -- -- -- --PAH Fluorene ug/L 2 12 17% 0.014 0.02 0.03 0.48 3.9 -- -- -- -- --PAH Naphthalene ug/L 5 12 42% 0.013 0.02 0.03 0.93 24 -- -- -- -- --PAH Phenanthrene ug/L 2 12 17% 0.02 0.027 0.04 3.3 4.6 -- -- -- -- --PAH Pyrene ug/L 1 12 8% 0.015 0.02 0.64 0.64 2 -- -- -- -- --METAL Aluminum, dissolved mg/L 5 7 71% 0.015 0.015 0.021 0.079 -- -- -- 2.33 -- --METAL Antimony, dissolved mg/L 6 7 86% 0.00014 0.00014 0.0002 0.0021 0.03 -- -- 0.028 -- --METAL Arsenic, dissolved mg/L 12 12 100% -- -- 0.0014 0.0057 0.036 -- -- 0.0261 -- --METAL Barium, dissolved mg/L 12 12 100% -- -- 0.013 1.7 2 -- -- 0.173 4 --METAL Cadmium, dissolved mg/L 2 12 17% 0.000069 0.00047 0.0001 0.00027 0.003 -- -- 0.002 -- --METAL Calcium, dissolved mg/L 7 7 100% -- -- 7.7 70 -- -- -- -- -- --METAL Chromium, dissolved mg/L 7 12 58% 0.000079 0.0006 0.00011 0.0018 0.074 -- -- 0.012 -- --METAL Cobalt, dissolved mg/L 6 12 50% 0.00014 0.00016 0.00022 0.00075 0.003 -- -- 0.005 -- --METAL Copper, dissolved mg/L 5 12 42% 0.00018 0.0026 0.00033 0.02 0.0029 1 -- 0.007 1 --METAL Iron, dissolved mg/L 6 7 86% 0.016 0.016 0.02 0.28 -- -- -- 4.27 -- --METAL Lead, dissolved mg/L 6 12 50% 0.00011 0.00014 0.00028 0.002 0.0056 -- -- 0.03 -- --METAL Magnesium, dissolved mg/L 7 7 100% -- -- 16 320 -- -- -- -- -- --METAL Manganese, dissolved mg/L 7 7 100% -- -- 0.005 0.29 -- -- -- 0.592 -- --METAL Molybdenum, dissolved mg/L 7 7 100% -- -- 0.0043 0.021 0.24 -- -- 0.0483 -- --METAL Nickel, dissolved mg/L 12 12 100% -- -- 0.00021 0.036 0.005 1 -- 0.077 -- --METAL Potassium, dissolved mg/L 7 7 100% -- -- 37 150 -- -- -- -- -- --METAL Selenium, dissolved mg/L 6 7 86% 0.00016 0.00016 0.00027 0.0011 0.005 -- -- 0.0375 -- --METAL Sodium, dissolved mg/L 7 7 100% -- -- 600 4500 -- -- -- -- -- --METAL Thallium, dissolved mg/L 2 7 29% 0.000032 0.000032 0.000052 0.00038 0.02 -- -- 0.0022 -- --METAL Vanadium, dissolved mg/L 6 7 86% 0.00015 0.00015 0.00054 0.0026 0.019 -- -- 0.106 -- --METAL Zinc, dissolved mg/L 5 12 42% 0.00069 0.009 0.0027 0.026 0.022 1 -- 0.0198 1 --

Notes:mg/L = milligram(s) per literug/L = microgram(s) per literMDL = method detection limit

VOC = volatile organic compoundsTPH = total petroleum hydrocarbonsPEST = pesticidesPAH = polynuclear aromatic hydrocarbons

EAL a Background b

Page 2 of 2

TABLE 2-3Summary of Chemicals Detected in GroundwaterRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


Number of Detects

Number of Samples


Minimum MDL

Maximum MDL







EAL a Background b

CONV = conventional dataa EAL = State of Hawaii Department of Health Environmental Action Level (HDOH, October 2008 updated March 2009) for sites where drinking water is not threatened and less than 150 meters from surface water. The EALs listed here are "Final Groundwater Action Levels", representing the most stringent values.b Background = Hickam ambient background metal concentrations were established in the Final Technical Memorandum Base-Wide Ambient Metals Study, Hickam Air Force Base, Oahu, Hawaii (CH2M HILL, January 6, 2006)


Page 1 of 1

TABLE 2-4Summary of Chemicals Detected in Soil GasRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


Number of Detects

Number of Samples


Minimum MDL

Maximum MDL


Maximum Detected Value

aEAL Residential

Number of Detects > Residential

Number of Nondetects > Residential

aEAL Commercial

Number of Detects > Commercial

Number of Nondetects > Commercial

TO-15 1,1,2-TRICHLORO-1,2,2-TRIFLUOROETHANE ug/m3 5 5 100% -- -- 0.79 1.7 210 -- -- 210 -- --TO-15 1,2,4-TRIMETHYLBENZENE ug/m3 5 5 100% -- -- 0.41 3.3 3.4 -- -- 14 -- --TO-15 1,2-DICHLOROPROPANE ug/m3 1 5 20% 0.17 0.17 0.39 0.39 99 -- -- 420 -- --TO-15 1,3,5-TRIMETHYLBENZENE (MESITYLENE) ug/m3 2 5 40% 0.18 0.18 0.39 0.64 95,000 -- -- 270,000 -- --TO-15 1,4-DICHLOROBENZENE ug/m3 4 5 80% 0.18 0.18 0.2 0.35 310 -- -- 1,300 -- --TO-15 BENZENE ug/m3 5 5 100% -- -- 0.24 0.58 250 -- -- 1,100 -- --TO-15 BROMOMETHANE ug/m3 2 5 40% 0.17 0.17 0.24 0.31 5,100 -- -- 14,000 -- --TO-15 CHLOROBENZENE ug/m3 1 5 20% 0.17 0.17 0.29 0.29 62,000 -- -- 170,000 -- --TO-15 CHLOROFORM ug/m3 4 5 80% 0.17 0.17 2.3 5 83 -- -- 350 -- --TO-15 CHLOROMETHANE ug/m3 5 5 100% -- -- 0.58 0.99 95,000 -- -- 270,000 -- --TO-15 DICHLORODIFLUOROMETHANE ug/m3 5 5 100% -- -- 2.4 3.3 210 -- -- 210 -- --TO-15 ETHYLBENZENE ug/m3 4 5 80% 0.17 0.17 0.18 1.1 1,100,000 -- -- 3,000,000 -- --TO-15 m,p-Xylene ug/m3 5 5 100% -- -- 0.65 1.8 -- -- -- -- -- --TO-15 METHYL ISOBUTYL KETONE ug/m3 5 5 100% -- -- 0.37 2 3,100,000 -- -- 8,800,000 -- --TO-15 NAPHTHALENE ug/m3 4 5 80% 0.17 0.17 0.58 18 3,100 -- -- 8,800 -- --TO-15 n-BUTYLBENZENE ug/m3 3 5 60% 0.18 0.18 0.72 1.7 150 -- -- 150 -- --TO-15 n-HEXANE ug/m3 2 5 40% 0.18 0.18 0.45 2.6 -- -- -- -- -- --TO-15 n-PROPYLBENZENE ug/m3 3 5 60% 0.17 0.17 1.3 1.6 150 -- -- 150 -- --TO-15 o-Xylene ug/m3 5 5 100% -- -- 0.22 0.57 110,000 -- -- 300,000 -- --TO-15 TETRACHLOROETHYLENE(PCE) ug/m3 3 5 60% 0.29 0.29 0.49 2.5 320 -- -- 1,400 -- --TO-15 TOLUENE ug/m3 5 5 100% -- -- 0.37 1.1 400,000 -- -- 1,100,000 -- --TO-15 TRICHLOROETHYLENE (TCE) ug/m3 1 5 20% 0.17 0.17 0.22 0.22 170 -- -- 720 -- --TO-15 TRICHLOROFLUOROMETHANE ug/m3 5 5 100% -- -- 1.2 1.3 730 -- -- 730 -- --

Notes:

ug/m3 = micrograms per cubic meter of air

MDL = method detection limit

aMost stringent of State of Hawaii Department of Health Environmental Action Levels for shallow soil gas for residential and commercial scenarios (HDOH, October 2008 updated March 2009).

1 of 5

TABLE 2-5Exposure Point Concentrations for Soil and GroundwaterRecord of Decision for Site SS024, Hickam AFB, Oahu, HI

Chemical Units Number

of Detects Number of

Samples Maximum

Detected ValueCalculated 95%

UCL Final EPC BasisSurface Soil4,4'-DDD mg/kg 1 2 1.20E-02 2.00E+00 1.20E-02 Max Detect4,4'-DDE mg/kg 2 2 7.80E-03 2.00E+00 7.80E-03 Max Detect4,4'-DDT mg/kg 2 2 5.80E-03 2.00E+00 5.80E-03 Max DetectAluminum mg/kg 2 2 2.20E+04 2.00E+00 2.20E+04 Max DetectAnthracene mg/kg 1 2 1.40E-02 2.00E+00 1.40E-02 Max DetectAntimony mg/kg 2 2 4.00E+00 2.00E+00 4.00E+00 Max DetectAroclor-1260 mg/kg 2 2 4.20E-01 2.00E+00 4.20E-01 Max DetectArsenic mg/kg 2 2 1.20E+02 2.00E+00 1.20E+02 Max DetectArsenic-Bioaccessible mg/kg 2 2 3.17E+01 2.00E+00 3.17E+01 Max DetectBarium mg/kg 2 2 1.20E+02 2.00E+00 1.20E+02 Max DetectBenzo(a)anthracene mg/kg 2 2 1.40E-01 2.00E+00 1.40E-01 Max DetectBenzo(a)pyrene mg/kg 2 2 2.00E-01 2.00E+00 2.00E-01 Max DetectBenzo(b)fluoranthene mg/kg 2 2 3.00E-01 2.00E+00 3.00E-01 Max DetectBenzo(g,h,i)perylene mg/kg 2 2 8.80E-02 2.00E+00 8.80E-02 Max DetectBenzo(k)fluoranthene mg/kg 2 2 1.10E-01 2.00E+00 1.10E-01 Max DetectBeryllium mg/kg 2 2 6.30E-01 2.00E+00 6.30E-01 Max Detectbis(2-Ethylhexyl)phthalate mg/kg 2 2 8.40E-02 2.00E+00 8.40E-02 Max DetectButylbenzylphthalate mg/kg 1 2 1.20E-02 2.00E+00 1.20E-02 Max DetectCadmium mg/kg 2 2 7.20E-01 2.00E+00 7.20E-01 Max DetectChromium mg/kg 2 2 9.30E+01 2.00E+00 9.30E+01 Max DetectChrysene mg/kg 2 2 1.40E-01 2.00E+00 1.40E-01 Max DetectCobalt mg/kg 2 2 2.10E+01 2.00E+00 2.10E+01 Max DetectCopper mg/kg 2 2 1.60E+02 2.00E+00 1.60E+02 Max DetectDibenz(a,h)anthracene mg/kg 1 2 2.20E-02 2.00E+00 2.20E-02 Max DetectDieldrin mg/kg 2 2 7.60E-03 2.00E+00 7.60E-03 Max DetectDiesel C10-C28 mg/kg 2 2 4.10E+01 2.00E+00 4.10E+01 Max DetectEndosulfan sulfate mg/kg 2 2 4.30E-03 2.00E+00 4.30E-03 Max DetectFluoranthene mg/kg 2 2 1.60E-01 2.00E+00 1.60E-01 Max Detectgamma-Chlordane mg/kg 2 2 8.30E-03 2.00E+00 8.30E-03 Max DetectIndeno(1,2,3-cd)pyrene mg/kg 2 2 7.50E-02 2.00E+00 7.50E-02 Max DetectIron mg/kg 2 2 4.30E+04 2.00E+00 4.30E+04 Max DetectLead mg/kg 2 2 7.90E+01 2.00E+00 7.90E+01 Max DetectManganese mg/kg 2 2 1.20E+03 2.00E+00 1.20E+03 Max DetectMercury mg/kg 2 2 9.10E-02 2.00E+00 9.10E-02 Max DetectMolybdenum mg/kg 2 2 3.00E+00 2.00E+00 3.00E+00 Max Detect

2 of 5




Samples Maximum


UCL Final EPC BasisMotor Oil C28-C36 mg/kg 2 2 2.20E+02 2.00E+00 2.20E+02 Max DetectNickel mg/kg 2 2 6.30E+01 2.00E+00 6.30E+01 Max DetectPhenanthrene mg/kg 2 2 4.90E-02 2.00E+00 4.90E-02 Max DetectPyrene mg/kg 2 2 3.40E-01 2.00E+00 3.40E-01 Max DetectSelenium mg/kg 2 2 3.10E+00 2.00E+00 3.10E+00 Max DetectThallium mg/kg 2 2 1.20E-01 2.00E+00 1.20E-01 Max DetectVanadium mg/kg 2 2 9.50E+01 2.00E+00 9.50E+01 Max DetectZinc mg/kg 2 2 3.80E+02 2.00E+00 3.80E+02 Max DetectSubsurface Soil1-Methylnaphthalene mg/kg 4 9 8.60E-03 6.27E-03 6.27E-03 Nonparametric2-Butanone mg/kg 23 37 1.00E-01 1.61E-02 1.61E-02 Nonparametric2-Methylnaphthalene mg/kg 10 39 6.60E-02 1.53E-02 1.53E-02 Nonparametric4,4'-DDE mg/kg 3 30 7.80E-03 1.83E-03 1.83E-03 Nonparametric4,4'-DDT mg/kg 2 30 5.80E-03 5.27E-03 5.27E-03 NonparametricAcenaphthene mg/kg 5 39 1.90E-01 2.19E-02 2.19E-02 NonparametricAcetone mg/kg 31 37 6.60E-01 1.50E-01 1.50E-01 NonparametricAluminum mg/kg 30 30 5.00E+04 2.87E+04 2.87E+04 NonparametricAnthracene mg/kg 3 39 4.00E-02 7.05E-03 7.05E-03 NonparametricAntimony mg/kg 19 30 2.30E+01 6.38E+00 6.38E+00 NonparametricAroclor-1260 mg/kg 3 10 4.20E-01 1.70E-01 1.70E-01 NonparametricAroclor-1262 mg/kg 2 7 3.20E-02 2.39E-02 2.39E-02 NonparametricArsenic mg/kg 39 39 1.20E+02 3.30E+01 3.30E+01 NonparametricArsenic-Bioaccessible mg/kg 2 2 3.17E+01 3.17E+01 3.17E+01 Max DetectBarium mg/kg 39 39 9.80E+02 3.71E+02 3.71E+02 GammaBenzene mg/kg 4 37 1.50E-02 3.03E-03 3.03E-03 NonparametricBenzo(a)anthracene mg/kg 9 39 2.50E-01 3.04E-02 3.04E-02 NonparametricBenzo(a)pyrene mg/kg 4 39 2.00E-01 5.38E-02 5.38E-02 NonparametricBenzo(b)fluoranthene mg/kg 6 39 3.00E-01 5.15E-02 5.15E-02 NonparametricBenzo(g,h,i)perylene mg/kg 3 39 8.80E-02 1.72E-02 1.72E-02 NonparametricBenzo(k)fluoranthene mg/kg 3 39 1.10E-01 6.21E-02 6.21E-02 NonparametricBeryllium mg/kg 30 30 1.90E+00 1.07E+00 1.07E+00 Nonparametricbis(2-Ethylhexyl)phthalate mg/kg 6 30 1.60E-01 7.40E-02 7.40E-02 NonparametricBromomethane mg/kg 4 37 1.70E-03 1.44E-03 1.44E-03 NonparametricCadmium mg/kg 26 39 2.67E+01 5.62E+00 5.62E+00 NonparametricChromium mg/kg 39 39 2.00E+02 1.19E+02 1.19E+02 NonparametricChrysene mg/kg 9 39 1.40E-01 2.50E-02 2.50E-02 Nonparametric

3 of 5




Samples Maximum


UCL Final EPC BasisCobalt mg/kg 39 39 5.47E+01 3.14E+01 3.14E+01 NonparametricCopper mg/kg 39 39 5.60E+03 1.04E+03 1.04E+03 NonparametricDieldrin mg/kg 3 30 7.60E-03 2.02E-03 2.02E-03 NonparametricDiesel C10-C28 mg/kg 37 39 7.60E+02 2.24E+02 2.24E+02 NonparametricEndosulfan sulfate mg/kg 2 30 4.30E-03 3.42E-03 3.42E-03 NonparametricFluoranthene mg/kg 16 39 2.70E-01 3.73E-02 3.73E-02 NonparametricFluorene mg/kg 6 39 6.70E-02 1.38E-02 1.38E-02 Nonparametricgamma-Chlordane mg/kg 2 30 8.30E-03 4.30E-03 4.30E-03 NonparametricGasoline C6-C10 mg/kg 19 37 5.00E-01 7.27E-02 7.27E-02 NonparametricIndeno(1,2,3-cd)pyrene mg/kg 3 39 7.50E-02 2.42E-02 2.42E-02 NonparametricIron mg/kg 30 30 1.70E+05 9.12E+04 9.12E+04 NonparametricLead mg/kg 33 39 2.90E+03 8.52E+02 8.52E+02 Nonparametricm,p-Xylenes mg/kg 2 37 6.90E-03 2.26E-03 2.26E-03 NonparametricManganese mg/kg 30 30 2.00E+03 1.22E+03 1.22E+03 NonparametricMercury mg/kg 26 39 7.83E-01 9.93E-02 9.93E-02 NonparametricMethylene Chloride mg/kg 13 37 4.50E-02 9.31E-03 9.31E-03 NonparametricMolybdenum mg/kg 23 30 2.50E+01 6.45E+00 6.45E+00 NonparametricMotor Oil C28-C36 mg/kg 34 39 1.70E+03 5.27E+02 5.27E+02 NonparametricNaphthalene mg/kg 12 39 5.60E-01 7.15E-02 7.15E-02 NonparametricNickel mg/kg 39 39 1.60E+02 1.04E+02 1.04E+02 Nonparametrico-Xylene mg/kg 2 37 2.00E-03 1.82E-03 1.82E-03 NonparametricPhenanthrene mg/kg 18 39 1.60E-01 2.75E-02 2.75E-02 NonparametricPyrene mg/kg 19 39 2.10E+00 2.02E-01 2.02E-01 NonparametricSelenium mg/kg 13 30 4.80E+00 1.61E+00 1.61E+00 NonparametricSilver mg/kg 22 30 1.60E+01 3.77E+00 3.77E+00 NonparametricThallium mg/kg 10 30 3.60E-01 9.53E-02 9.53E-02 NonparametricToluene mg/kg 2 37 2.00E-03 1.82E-03 1.82E-03 NonparametricToxic Equivalence mg/kg 8 8 1.05E-04 8.22E-05 8.22E-05 NormalTrichlorofluoromethane mg/kg 10 28 1.70E-02 4.65E-03 4.65E-03 NonparametricVanadium mg/kg 30 30 1.30E+02 9.41E+01 9.41E+01 NonparametricXylenes, Total mg/kg 2 9 1.00E-02 6.01E-03 6.01E-03 NonparametricZinc mg/kg 39 39 3.80E+03 8.70E+02 8.70E+02 GammaGroundwaterAcetone ug/L 5 12 1.40E+01 - 1.40E+01 Max DetectBenzene ug/L 4 12 3.60E+00 - 3.60E+00 Max Detectcis-1,2-Dichloroethene ug/L 7 12 1.40E+00 - 1.40E+00 Max Detect

4 of 5




Samples Maximum


UCL Final EPC BasisFreon 12 ug/L 1 7 1.60E+00 - 1.60E+00 Max Detectpara-Isopropyl Toluene ug/L 1 7 6.00E-01 - 6.00E-01 Max DetectVinyl Chloride ug/L 2 12 3.00E-01 - 3.00E-01 Max DetectDiesel C10-C28 ug/L 12 12 9.70E-01 - 9.70E-01 Max DetectGasoline C6-C10 ug/L 3 12 2.60E-02 - 2.60E-02 Max DetectMotor Oil C28-C36 ug/L 10 12 5.80E-01 - 5.80E-01 Max Detectbeta-BHC ug/L 2 7 5.00E-03 - 5.00E-03 Max Detect1-Methylnaphthalene ug/L 4 12 3.30E-01 - 3.30E-01 Max Detect2-Methylnaphthalene ug/L 3 12 1.20E-01 - 1.20E-01 Max DetectAcenaphthene ug/L 3 12 9.70E-01 - 9.70E-01 Max DetectAnthracene ug/L 2 12 4.60E-01 - 4.60E-01 Max DetectFluoranthene ug/L 1 12 8.20E-01 - 8.20E-01 Max DetectFluorene ug/L 2 12 4.80E-01 - 4.80E-01 Max DetectNaphthalene ug/L 5 12 9.30E-01 - 9.30E-01 Max DetectPhenanthrene ug/L 2 12 3.30E+00 - 3.30E+00 Max DetectPyrene ug/L 1 12 6.40E-01 - 6.40E-01 Max DetectAluminum, dissolved mg/L 5 7 7.90E-02 - 7.90E-02 Max DetectAntimony, dissolved mg/L 6 7 2.10E-03 - 2.10E-03 Max DetectArsenic, dissolved mg/L 12 12 5.70E-03 - 5.70E-03 Max DetectBarium, dissolved mg/L 12 12 1.70E+00 - 1.70E+00 Max DetectCadmium, dissolved mg/L 2 12 2.70E-04 - 2.70E-04 Max DetectCalcium, dissolved mg/L 7 7 7.00E+01 - 7.00E+01 Max DetectChromium, dissolved mg/L 7 12 1.80E-03 - 1.80E-03 Max DetectCobalt, dissolved mg/L 6 12 7.50E-04 - 7.50E-04 Max DetectCopper, dissolved mg/L 5 12 2.00E-02 - 2.00E-02 Max DetectIron, dissolved mg/L 6 7 2.80E-01 - 2.80E-01 Max DetectLead, dissolved mg/L 6 12 2.00E-03 - 2.00E-03 Max DetectMagnesium, dissolved mg/L 7 7 3.20E+02 - 3.20E+02 Max DetectManganese, dissolved mg/L 7 7 2.90E-01 - 2.90E-01 Max DetectMolybdenum, dissolved mg/L 7 7 2.10E-02 - 2.10E-02 Max DetectNickel, dissolved mg/L 12 12 3.60E-02 - 3.60E-02 Max DetectPotassium, dissolved mg/L 7 7 1.50E+02 - 1.50E+02 Max DetectSelenium, dissolved mg/L 6 7 1.10E-03 - 1.10E-03 Max DetectSodium, dissolved mg/L 7 7 4.50E+03 - 4.50E+03 Max DetectThallium, dissolved mg/L 2 7 3.80E-04 - 3.80E-04 Max DetectVanadium, dissolved mg/L 6 7 2.60E-03 - 2.60E-03 Max Detect

5 of 5




Samples Maximum


UCL Final EPC BasisZinc, dissolved mg/L 5 12 2.60E-02 - 2.60E-02 Max Detect

Notes:EPC = exposure point concentrationmg/kg = milligram per kilogramUCL = upper confidence limit

Page 1 of 1

TABLE 2-6Summary of Human Health Risk Estimates for Soil and GroundwaterRecord of Decision for Site SS024, Hickam AFB, Oahu, HI

Exposure Scenario Exposure Route ELCR HI Primary Contributors a

Occupational Worker -Direct Contact with Soil (0-3 ft bgs)

IngestionDermalInhalationTotal

1.8x10-54.2x10-62.8x10-72x10-5

0.280.020.030.3

None

Excavation/Construction Worker -Direct Contact with Soil (0-10 ft bgs)


6.0x10-74.1x10-87.2x10-96x10-7

0.10.0020.002

0.1

None

Excavation/Construction Worker -Trench Groundwater (0-15 ft bgs)


4.3x10-72.0x10-62.1x10-73x10-6

0.0020.20.20.4

None

Hypothetical Future Resident -Direct Contact with Soil (0-10 ft bgs)


3.9x10-54.1x10-67.2x10-74x10-5

10.040.06

1

None

Hypothetical Future Resident -Direct Contact with Soil (0-3 ft bgs)


7.9x10-59.0x10-65.9x10-79x10-5

10.4

0.051

None

Notes:a Primary contributors to the total risk are listed when ELCR > 10-4 or HI > 1. ELCR = excess lifetime cancer riskHI = hazard index

Page 1 of 2

TABLE 2-7Environmental Hazard Evaluation for Chemicals Detected in SoilRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI

Location SampleIDDepth From

Depth To

Depth Units

Sample Date

Chemical Group Analyte Result Units Background

Ceiling Value (Gross Contamination)

Direct Exposure

Urban Area Ecotoxicity Criteria

Groundwater Protection

Multi-Increment Surface SoilSS24MI001 SS024-MI001-0309 0.1 0.5 FT 03-Mar-09 METAL Arsenic 120 mg/kg 27.9 1000 0.43 20 --SS24MI002 SS024-MI002-0309 0.1 0.5 FT 03-Mar-09 METAL Arsenic 75 mg/kg 27.9 1000 0.43 20 --SS24MI001 SS024-MI001-0309 0.1 0.5 FT 03-Mar-09 METAL Arsenic-Bioaccessible 31.7 M mg/kg 27.9 1000 0.43 20 --SS24MI001 SS024-MI001-0309 0.1 0.5 FT 03-Mar-09 PAH Benzo(a)pyrene 0.2 J mg/kg -- 500 0.15 40 7.6SS24MI001 SS024-MI001-0309 0.1 0.5 FT 03-Mar-09 PEST Dieldrin 0.0076 J mg/kg -- 1000 0.03 4 0.0033SS24MI002 SS024-MI002-0309 0.1 0.5 FT 03-Mar-09 PEST Dieldrin 0.0055 J mg/kg -- 1000 0.03 4 0.0033Subsurface SoilSS24BH009 SS024-BH009B-0309 7 9 FT 04-Mar-09 DIOX/FURN Toxic Equivalence 6.2007E-06 mg/kg -- 1000 0.0000045 -- 0.19SS24BH011 SS024-BH011B-0309 5.5 8 FT 04-Mar-09 DIOX/FURN Toxic Equivalence 3.18007E-05 mg/kg -- 1000 0.0000045 -- 0.19SS24BH006 SS024-BH006B-0309 7 8.5 FT 09-Mar-09 DIOX/FURN Toxic Equivalence 9.00976E-05 mg/kg -- 1000 0.0000045 -- 0.19SS24BH001 SS024-BH001B-0309 7 8 FT 23-Mar-09 DIOX/FURN Toxic Equivalence 2.54724E-05 mg/kg -- 1000 0.0000045 -- 0.19SS24BH012 SS024-BH012B-0309 6 8 FT 23-Mar-09 DIOX/FURN Toxic Equivalence 8.21743E-05 mg/kg -- 1000 0.0000045 -- 0.19SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 DIOX/FURN Toxic Equivalence 0.000105477 mg/kg -- 1000 0.0000045 -- 0.19SS24BH014 SS024-BH014B-0309 8 10 FT 24-Mar-09 DIOX/FURN Toxic Equivalence 8.97701E-05 mg/kg -- 1000 0.0000045 -- 0.19SS24BH001 SS024-BH001B-0309 7 8 FT 23-Mar-09 METAL Antimony 23 mg/kg 8.7 1000 6.3 20 --SS24BH012 SS024-BH012B-0309 6 8 FT 23-Mar-09 METAL Antimony 22 mg/kg 8.7 1000 6.3 20 --SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 METAL Antimony 13 mg/kg 8.7 1000 6.3 20 --SS24BH014 SS024-BH014B-0309 8 10 FT 24-Mar-09 METAL Antimony 12 mg/kg 8.7 1000 6.3 20 --SS24BH005 SS024-BH005B-0309 7 9 FT 09-Mar-09 METAL Arsenic 37 mg/kg 27.9 1000 0.43 20 --SS24BH012 SS024-BH012B-0309 6 8 FT 23-Mar-09 METAL Arsenic 32 mg/kg 27.9 1000 0.43 20 --SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 METAL Arsenic 43 mg/kg 27.9 1000 0.43 20 --SS24BH014 SS024-BH014B-0309 8 10 FT 24-Mar-09 METAL Arsenic 28 mg/kg 27.9 1000 0.43 20 --SS24-TW03 SS24-TW03-SB-A-01-7 7 8 FT 24-Jul-07 METAL Arsenic 51.7 mg/kg 27.9 1000 0.43 20 --SS24BH011 SS024-BH011B-0309 5.5 8 FT 04-Mar-09 METAL Barium 980 J mg/kg 951 1000 3100 750 --SS24BH006 SS024-BH006B-0309 7 8.5 FT 09-Mar-09 METAL Cadmium 25 mg/kg 3.6 1000 14 12 --SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 METAL Cadmium 21 mg/kg 3.6 1000 14 12 --SS24-TW02 SS24-TW02-SB-A-01-8.5 8.5 9 FT 24-Jul-07 METAL Cadmium 26.7 mg/kg 3.6 1000 14 12 --SS24BH005 SS024-BH005B-0309 7 9 FT 09-Mar-09 METAL Copper 350 mg/kg 138 1000 630 230 --SS24BH006 SS024-BH006B-0309 7 8.5 FT 09-Mar-09 METAL Copper 1600 mg/kg 138 1000 630 230 --SS24BH007 SS024-BH007B-0309 11.5 13.5 FT 09-Mar-09 METAL Copper 1300 mg/kg 138 1000 630 230 --SS24BH012 SS024-BH012B-0309 6 8 FT 23-Mar-09 METAL Copper 1700 J mg/kg 138 1000 630 230 --SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 METAL Copper 870 mg/kg 138 1000 630 230 --SS24BH014 SS024-BH014B-0309 8 10 FT 24-Mar-09 METAL Copper 5600 mg/kg 138 1000 630 230 --SS24BH015 SS024-BH015B-0309 7 8.5 FT 24-Mar-09 METAL Copper 260 mg/kg 138 1000 630 230 --SS24-SB02 SS24-SB02-SB-A-01-7 7 7.5 FT 24-Jul-07 METAL Copper 458 mg/kg 138 1000 630 230 --SS24-SB04 SS24-SB04-SB-A-01-8.5 8.5 9 FT 24-Jul-07 METAL Copper 307 mg/kg 138 1000 630 230 --SS24-TW01 SS24-TW01-SB-A-01-6 6 6.5 FT 24-Jul-07 METAL Copper 1540 mg/kg 138 1000 630 230 --SS24BH009 SS024-BH009B-0309 7 9 FT 04-Mar-09 METAL Lead 340 M mg/kg 226 1000 400 200 --SS24BH011 SS024-BH011B-0309 5.5 8 FT 04-Mar-09 METAL Lead 330 J mg/kg 226 1000 400 200 --SS24BH005 SS024-BH005B-0309 7 9 FT 09-Mar-09 METAL Lead 1600 mg/kg 226 1000 400 200 --SS24BH006 SS024-BH006B-0309 7 8.5 FT 09-Mar-09 METAL Lead 2600 mg/kg 226 1000 400 200 --SS24BH001 SS024-BH001B-0309 7 8 FT 23-Mar-09 METAL Lead 470 mg/kg 226 1000 400 200 --SS24BH012 SS024-BH012B-0309 6 8 FT 23-Mar-09 METAL Lead 660 mg/kg 226 1000 400 200 --SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 METAL Lead 1100 mg/kg 226 1000 400 200 --SS24BH014 SS024-BH014B-0309 8 10 FT 24-Mar-09 METAL Lead 2900 mg/kg 226 1000 400 200 --SS24-SB01 SS24-SB01-SB-A-01-8 8 8.5 FT 24-Jul-07 METAL Lead 1690 mg/kg 226 1000 400 200 --SS24-SB04 SS24-SB04-SB-A-01-8.5 8.5 9 FT 24-Jul-07 METAL Lead 560 mg/kg 226 1000 400 200 --SS24-TW01 SS24-TW01-SB-A-01-6 6 6.5 FT 24-Jul-07 METAL Lead 800 mg/kg 226 1000 400 200 --SS24BH006 SS024-BH006B-0309 7 8.5 FT 09-Mar-09 METAL Zinc 2000 mg/kg 421 1000 4700 600 --

Page 2 of 2

TABLE 2-7Environmental Hazard Evaluation for Chemicals Detected in SoilRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


Depth To

Depth Units

Sample Date



Direct Exposure

Urban Area Ecotoxicity Criteria

Groundwater Protection

SS24BH012 SS024-BH012B-0309 6 8 FT 23-Mar-09 METAL Zinc 3000 mg/kg 421 1000 4700 600 --SS24BH013 SS024-BH013B-0309 6.5 8.5 FT 23-Mar-09 METAL Zinc 3800 mg/kg 421 1000 4700 600 --SS24BH014 SS024-BH014B-0309 8 10 FT 24-Mar-09 METAL Zinc 1700 mg/kg 421 1000 4700 600 --SS24BH015 SS024-BH015B-0309 7 8.5 FT 24-Mar-09 METAL Zinc 830 mg/kg 421 1000 4700 600 --SS24-SB01 SS24-SB01-SB-A-01-8 8 8.5 FT 24-Jul-07 METAL Zinc 1000 mg/kg 421 1000 4700 600 --SS24-SB04 SS24-SB04-SB-A-01-8.5 8.5 9 FT 24-Jul-07 METAL Zinc 2550 mg/kg 421 1000 4700 600 --SS24-TW01 SS24-TW01-SB-A-01-6 6 6.5 FT 24-Jul-07 METAL Zinc 1410 mg/kg 421 1000 4700 600 --SS24BH011 SS024-BH011B-0309 5.5 8 FT 04-Mar-09 TPH Diesel C10-C28 760 J mg/kg -- 500 500 -- 500SS24BH005 SS024-BH005B-0309 7 9 FT 09-Mar-09 TPH Diesel C10-C28 540 mg/kg -- 500 500 -- 500

Notes:

Data Qualifiers Abbreviations

J = The analyte was positively identified; the quantitation is an estimation. FT = feetM = A matrix effect was present. mg/kg = milligrams per kilogram

Chemical GroupsTPH = total petroleum hydrocarbonsPEST = pesticidesPAH = polynuclear aromatic hydrocarbonsDIOX/FURN = dioxins/furansa EAL = State of Hawaii Department of Health Environmental Action Level (HDOH, October 2008 updated March 2009) for sites where drinking water is not threatened and less than 150 meters from surface water. The EALs listed here are "Final Groundwater Action Levels", representing the most stringent values. Sceening the subsurface soil data in this table against EALs is considered conservative, since the samples were collected from either the capillary fringe, or from beneath the water table.b Background = Hickam ambient background metal concentrations were established in the Final Technical Memorandum Base-Wide Ambient Metals Study, Hickam Air Force Base, Oahu, Hawaii (CH2M HILL, January 6, 2006)


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TABLE 2-8Environmental Hazard Evaluation for Chemicals Detected in GroundwaterRecord of Decision for Site SS024, Hickam Air Force Base, Oahu, HI


Depth To

Depth Units

Sample Date



Aquatic Habitat Goal

SS24-TW02 SS24-TW02-GW-AZ-01 5 15 FT 25-Jul-07 METAL Copper, dissolved 0.02 M mg/L 0.007 50 0.0029SS24GW001 SS024-GW001-0409 4 14 FT 01-Apr-09 METAL Zinc, dissolved 0.026 J mg/L 0.0198 50 0.022SS24GW002 SS024-GW002-0309 3 13 FT 31-Mar-09 TPH Diesel C10-C28 0.91 mg/L -- 2.5 0.64SS24GW003 SS024-GW003-0309 4 14 FT 31-Mar-09 TPH Diesel C10-C28 0.67 mg/L -- 2.5 0.64SS24GW007 SS024-GW007-0309 4 14 FT 31-Mar-09 TPH Diesel C10-C28 0.97 mg/L -- 2.5 0.64

Notes:

Data Qualifiers

J = The analyte was positively identified; the quantitation is an estimation.F = The analyte was positively identified but the associated numerical value is below the reporting limit (RL).M = A matrix effect was present.

Chemical GroupsTPH = total petroleum hydrocarbonsAbbreviationsFT = feetmg/L = milligrams per litera EAL = State of Hawaii Department of Health Environmental Action Level (HDOH, October 2008 updated March 2009) for sites where drinking water is not threatened and less than 150 meters from surface water. The EALs listed here are "Final Groundwater Action Levels", representing the most stringent values.b Background = Hickam ambient background metal concentrations were established in the Final Technical Memorandum Base-Wide Ambient Metals Study, Hickam Air Force Base, Oahu, Hawaii (CH2M HILL, January 6, 2006)
