Dft Rem Investigation PH Sediment study 10.05

Draft

Remedial Investigation Report Pearl Harbor SedimentPEARL HARBOR, HAWAII

October 2005

Commander Naval Facilities Engineering Command, Pacific 258 Makalapa Drive, Suite 100 Pearl Harbor, HI 96860-3134

Comprehensive Long-Term Environmental Action Navy Contract Number N62742-94-D-0048, CTO 0115

Draft

Remedial Investigation Report Pearl Harbor SedimentPEARL HARBOR, HAWAII

October 2005

Prepared for:

Commander Naval Facilities Engineering Command, Pacific 258 Makalapa Drive, Suite 100 Pearl Harbor, HI 96860-3134Prepared by:

Earth Tech, Inc. 841 Bishop Street, Suite 500 Honolulu, HI 96813-3920Prepared under:

Comprehensive Long-Term Environmental Action Navy Contract Number N62742-94-D-0048, CTO 0115

EXECUTIVE SUMMARY Pearl Harbor is located on the south-central coast of Oahu, Hawaii (Figure ES-1). In October 1992, the United States Environmental Protection Agency placed the Pearl Harbor Naval Complex (Figure ES-2), including Pearl Harbor itself, on the National Priorities List. Pearl Harbor is approximately 5 square miles in water surface area and is a natural trap, or sink, for sediment and chemicals present in approximately 110 square miles of watershed, or 20 percent of Oahus land surface (Figure ES-3). The Pearl Harbor Sediment Remedial Investigation (RI) is part of the Navys long-term program to restore the environment at its facilities. The field investigation conducted in 1996 provides data to evaluate whether sediments located within Pearl Harbor are safe for humans and marine life based on an environmental background analysis (EBA) and human health and ecological risk assessments. The study identifies areas that may require further consideration, cleanup, or other response actions. RI OBJECTIVES The objectives of the RI are as follows: Determine the type and location of chemicals in the sediment and harbor marine life from past Navy activities. Determine whether chemical concentrations in the sediment and harbor marine life are safe for humans and marine life. Identify locations in the harbor where sediment may require further consideration, cleanup, or other response actions. The RI is intended to characterize chemical contamination in Pearl Harbor sediment from past Navy activities and numerous natural and man-made sources in the upland environment of the Pearl Harbor watershed that have been, and continue to be, sources of natural and anthropogenic chemicals to the harbor as the result of natural transport processes (e.g., erosion, stormwater runoff, and nonstormwater runoff). These transport processes frequently result in mixing and commingling of chemicals in the sediment from multiple sources. These non-Navy watershed-derived chemicals were evaluated in addition to Navy-derived chemicals for a complete assessment of the harbor. NATURE AND EXTENT OF CONTAMINATION A total of 243 chemicals of potential concern (COPCs) or COPC groups were investigated in Pearl Harbor and include the following general types of chemicals:

Metals Butyltins Polycyclic aromatic hydrocarbons (PAHs) comprised of low molecular weight PAHs (LMWPAHs; 2- and 3-ring PAHs) and high molecular weight PAHs (HMWPAHs; 4-, 5-, and 6-ring PAHs) Non-PAH semivolatile organic analytes Chlorinated pesticides Polychlorinated biphenyls (PCBs) Polychlorinated dibenzo-p-dioxin and furans Organophosphorus pesticides Chlorinated herbicides

iii

October 2005

Draft RI Report, Pearl Harbor Sediment, Pearl Harbor, Hawaii

Executive Summary

Triazine pesticides Carbamate/urea pesticides Ordnance compounds

The RI findings are based on surficial (upper 2 centimeters) sediment samples collected at 219 sediment sampling locations throughout the harbor and wild-caught organisms including burrowing organisms living in the sediment (i.e., macroinfauna, primarily shrimp) and organisms living at the sediment surface (crabs and bottom fish) at 15 sampling locations in the West, Middle, and East Lochs between August and December 1996. ENVIRONMENTAL BACKGROUND ANALYSIS The EBA was performed for metals to determine background concentration ranges to support the risk assessments and identification of COPCs needing further consideration.Metals

The background concentration range for each metal exceeding risk thresholds was estimated using multiple lines of evidence including the spatial distribution of the metal in harbor sediment; population characteristics of sediment concentrations revealed by cumulative probability plots; and the geochemical characteristics of the metal, such as the occurrence of the metal in the sediment source materials in the Pearl Harbor watershed (i.e., rocks and stream sediments). These lines of evidence allow differentiation between metal concentrations likely to represent natural/anthropogenic background conditions and concentrations likely to represent a site-related chemical release to the harbor sediments. Based on this analysis, concentrations of aluminum, cobalt, iron, and manganese measured in Pearl Harbor sediment were determined to be consistent with background concentrations. Background ranges were estimated for other metals and subsequently used in conjunction with risk assessment results to identify harbor locations that may require remedial consideration.Chlorinated Pesticides

Chlorinated pesticides exceed risk thresholds for both the human health and ecological risk assessments. However, due to widespread, decades-long historic application of these chemicals to agricultural and urban areas throughout the Pearl Harbor watershed, these chemicals are considered to have a anthropogenic background and are good examples of nonpoint source pollution on Oahu. For example, dichlorodiphenyltrichloroethane (DDT) was applied over large areas as an agricultural insecticide and chlordane was used for residential termite control, especially as urbanization accelerated on Oahu (Oki and Brasher 2003). DDT concentrations in fish from urban streams on Oahu are similar to levels reported on the mainland, while concentrations of chlordane are much higher at urban Oahu sites compared to mainland sites (Brasher and Anthony 2000). Despite bans on the use of DDT and chlordane in 1972 and 1988, respectively, these and other organochlorine pesticides persist in sediments and animals inhabiting aquatic ecosystems on the island of Oahu. These types of organochlorine chemicals remain long-term environmental concerns because of their widespread historic use, slow rates of environmental breakdown, and documented effects on aquatic invertebrates, fish, birds, and humans. HUMAN HEALTH RISK ASSESSMENT The human health risk assessment identified eight metal (aluminum, antimony, arsenic, chromium, copper, iron, manganese, and nickel) and six organic (total PCB National Oceanic and Atmospheric Administration [NOAA]-18, dieldrin, heptachlor epoxide, total dioxin/furan toxic equivalency

iv

October 2005


Executive Summary

quotient [TEQ] Mammal, 2-(2-Methyl-4-Chlorophenoxy) propionic acid [MCPP], and 2,4,6trinitrotoulene) COPCs and COPC groups that exhibit risk in Pearl Harbor for one or more exposure scenario for humans ingesting fish and crab collected from Pearl Harbor. Three metals (aluminum, iron, and manganese) and two chlorinated pesticides (dieldrin and heptachlor epoxide) exceeding human health risk thresholds were determined to have sediment concentrations within the background concentration range. Specific COPCs are identified in Table ES-1. BASELINE ECOLOGICAL RISK ASSESSMENT The ecological risk assessment identified 13 metal (aluminum, arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury , nickel, selenium, silver, and zinc) and 13 organic (LMWPAHs, HMWPAHs, total DDT series, total Chlordane series, total benzene hexachloride [BHC] series, total Endosulfan series, total Endrin series, dieldrin, total PCB NOAA-18, total PCB TEQ Fish, total PCB TEQ Birds, total dioxin/furan TEQ Fish, and MCPP) COPCs and COPC groups that exhibit risk at one or more of the 219 sediment sampling locations in Pearl Harbor for one or more assessment endpoints (i.e., macroinfauna, blue-clawed stone crab, bottom fish [tilapia and bandtailed goatfish], and water and shore birds). Three metals (aluminum, cobalt, and manganese), and six chlorinated pesticides (total DDT series, total Chlordane series, total BHC series, total Endosulfan series, total Endrin series, and dieldrin) exceeding ecological risk thresholds were determined to be within background concentration ranges. Specific COPCs are identified in Table ES-1. CONCLUSIONS AND RECOMMENDATIONS In conclusion, a total of 20 COPCs and COPC groups that exhibited human health risk above an acceptable threshold for fish and/or crab consumption and/or exhibited ecological risk above an acceptable threshold for one or more assessment endpoints are identified for further consideration. Horizontal and vertical distribution of these chemicals in the sediment at select locations in Pearl Harbor is recommended where COPCs are associated with a Navy release. Table ES-1 identifies the specific chemicals recommended for further consideration. Figure ES-4 shows the total number of COPCs or COPC groups recommended for further consideration at each sediment sampling location.

v

The Hawaiian IslandsNiihau Kauai

OAHUKaula Rock Molokai Maui Lanai Kahoolawe Hawaii

PEARL HARBOR

0

50

100 MILES

N

Pearl Harbor Naval Complex (yellow)

N

0

5 MI.

Figure ES-1: Project Location Map Pearl Harbor Sediment Study Site, Pearl Harbor Naval Complex, Oahu, Hawaii

West Loch Middle Loch

Navigation Channel

East Loch Southeast Loch

Figure ES-2: Pearl Harbor Naval Complex

Schofield Plateau

Koolau MountainsEast Loch Makalapa Crater

Middle Loch West Loch

Honolulu Ewa Plain Southeast Loch Honolulu International Airport

Waianae Mountains

Image Produced by NASA/Jet Propulsion Lab; LANDSAT Data from EROS Data Center USGS

Figure ES-3: Pearl Harbor and Southern Oahu with Approximate Boundary of the 110-Square-Mile Pearl Harbor Watershed (red outline)

anal

Wa iNational Wildlife Refuge Waiawa Unit

im Wa

awa

Drain

Wa i ke le

o an

a ge C

Oil Spill Site

#

alu aim WBlaisdell Park

Makalena Golf Course

ala u

ao

#

K

Old Pearl City Peninsula Landfill McGrew Pt. Housing

aka

hiNaval Inactive Ship Maintenance Facility

Ka

p

Fire Fighting Training Area

LegendCity / County Landfill

Number of COPCs or COPC GroupsRichardson RecreationGolf Course

Recommended for Further Consideration at Each Sediment Sampling Location

nouliuli

Beckoning Pt. Walker Bay

Ford IslandFord Island Landfill

Center

Naval Supply Center

1 2 3 4 5

[39 locations] [17 locations] [14 locations] [18 locations] [14 locations] [9 locations] [9 locations] [2 locations] [1 locations] [1 locations]

Waipio PeninsulaNational Wildlife Refuge Honouliuli Unit

6

SUBASE Naval Shipyard Naval Station PWC Main Complex

7 8 9

10-11

0

[95 locations]

Pearl Harbor Naval Complex Landfill Wildlife Refuge Park Golf Course Other Land Features Stream Mouth Coral Streams

Naval Magazine Lualualei West Loch

Bishop Pt.Ft. Kam Sewage Treatment Plant

Stratum Boundary Substratum Boundary Ford Island BridgeSite of sample collection, stratum, and substratum boundaries

Hickam Air Force Base

as presented in the Pearl Harbor Sediment RI Final Work Plan (Ogden1996c)

NMap Projection based on State Plane Coordinate System (NAD 83) Zone 3 Iroquois Pt. Housing

0

1000

2000

3000

4000

Scale in Feet

Figure ES-4: Total Number of COPCs or COPC Groups Recommended for Further Consideration at Each Sediment Sampling Location in Pearl Harbor

Halaw

Pearl City Peninsula

Ai

ea

Old FLETRAGRU

a

Ho

Table ES-1: Summary of RI Findings and Recommendations for Pearl Harbor SedimentAre Sediment Exceeds BERA Concentrations Consistent With Human Health PRG or Risk the Background Threshold Risk Driver Range? (Section 9)? (Section 8)?

COPCs Metals Aluminum Antimony Arsenic

Recommendation No Further Consideration Further Consideration Further Consideration Further Consideration Further Consideration No Further Consideration Further Consideration No Further Consideration Further Consideration No Further Consideration Further Consideration Further Consideration Further Consideration Further Consideration Further Consideration

Spatial Distribution of COPC Figure

Locations for Further Consideration Rationale for Recommendation Figure Human Health: no exceedance of upper bound background range Ecological: no exceedance of upper bound background range Human Health: exceeds HHRA risk threshold and exceeds upper bound background range Ecological: no exceedance of PRG Human Health: exceeds HHRA risk threshold and exceeds upper bound background range Ecological: exceeds PRG and exceeds upper bound background range Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG and exceeds upper bound background range Human Health: exceeds HHRA risk threshold and exceeds upper bound background range Ecological: exceeds PRG and exceeds upper bound background range Human Health: no exceedance of HHRA risk threshold and no exceedance of upper bound background range Ecological: exceeds PRG and no exceedance of upper bound background range Human Health: exceeds HHRA risk threshold and exceeds upper bound background range Ecological: exceeds PRG and exceeds upper bound background range Human Health: exceedance of HHRA risk threshold and no exceedance of upper bound background range Ecological: no exceedance of upper bound background range Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG and exceeds upper bound background range Human Health: no exceedance of upper bound background range Ecological: no exceedance of upper bound background range Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG and exceeds upper bound background range Human Health: exceedance of HHRA risk threshold and exceeds upper background range Ecological: no exceedance of PRG Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG and exceeds upper bound background range Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG and exceeds upper bound background range Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG and exceeds upper bound background range

yes yes yes

yes no yes

yes no no

10-1 10-2

10-21 10-22

Cadmium

no

yes

no

10-3

10-23

Chromium

yes

yes

no

10-4

10-24

Cobalt

no

yes

yes

-

-

Copper

yes

yes

no

10-5

10-25

Iron

yes

no

yes

-

-

Lead

no

yes

no

10-6

10-26, 10-27

Manganese

yes

yes

yes

-

-

Mercury

no

yes

no

10-7

10-28

Nickel

yes

no

no

10-8

10-29

Selenium

no

yes

no

10-9

10-30

Silver

no

yes

no

10-10

10-31

Zinc Polycyclic Aromatic Hydrocarbons (PAHs) total LMWPAHs

no

yes

no

10-11

10-32

no

yes

N/A

Further Consideration Further Consideration

10-12

10-33

Human Health: no exceedance of HHRA risk threshold Ecological: BERA HQ>=1 Human Health: no exceedance of HHRA risk threshold Ecological: exceeds PRG

total HMWPAHs Polychlorinated Biphenyls (PCBs) total PCB NOAA-18

no

yes

N/A

10-13

10-34

yes

yes

N/A

Further Consideration Further Consideration Further Consideration

10-14

10-35

Human Health:HHRA risk threshold exceeded Ecological: exceeds PRG Human Health: not applicable to human health risk considerations Ecological: BERA HQ>=1 Human Health: not applicable to human health risk considerations Ecological: BERA HQ>=1 Human Health: evaluated as individual COPCs; see Acronyms list for individual COPCs in series Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Human Health: evaluated as individual COPCs; see Acronyms list for individual COPCs in series Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Human Health: evaluated as individual COPCs; see Acronyms list for individual COPCs in series Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Human Health: evaluated as individual COPCs; see Acronyms list for individual COPCs in series Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Human Health: evaluated as individual COPCs; see Acronyms list for individual COPCs in series Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Human Health: exceeds HHRA risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Human Health: exceeds HHRA risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range Ecological: exceeds screening level risk threshold; sediment concentrations determined to be within the anthopogenic background concentration range

total PCB TEQ Fish

N/A

yes

N/A

10-15

10-36

total PCB TEQ Bird Chlorinated Pesticides total DDT series

N/A

yes

N/A

10-16

10-37

no

yes

yes

No Further Consideration

-

-

total Chlordane series

no

yes

yes


-

-

total BHC series

no

yes

yes


-

-

total Endosulfan series

no

yes

yes


-

-

total Endrin series

no

yes

yes


-

-

Dieldrin

yes

yes

yes


-

-

Heptachlor epoxide (also part of total Chlordane series)

yes

yes

yes


-

-

Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/PCDF) total Dioxin/Furan TEQ - Fish N/A yes N/A Further Consideration Further Consideration 10-17 10-38 Human Health: not applicable to human health risk considerations Ecological: BERA HQ>=1 Human Health: HHRA risk threshold exceeded, no sediment PRG currently available Ecological: Not applicable to ecological risk considerations

total Dioxin/Furan TEQ - Mammal Chlorinated Herbicides 2-(2-Methyl-4-Chlorophenoxy) propionic acid (MCPP) Ordnance Compounds 2,4,6-trinitrotoulene (TNT) Acronyms: COPC = Chemical of Potential Concern BERA = Baseline Ecological Risk Assessment FS = Feasibility Study HQ = Hazard Quotient HHRA = Human Health Risk Assessment N/A = not applicable PCB = Polychlorinated Biphenyl PRG = Preliminary Remediation Goal TEF = Toxic Equivalency Factor to 2,3,7,8-TCDD TEQ = Toxicity Equivalent Quotient to 2,3,7,8-TCDD

yes

N/A

N/A

10-18

-

yes

no

N/A

Further Consideration

10-19

-

Human Health: HHRA risk threshold exceeded, no sediment PRG currently available Ecological: no exceedance of PRG

yes

no

N/A

Further Consideration

10-20

-

Human Health: HHRA risk threshold exceeded, no sediment PRG currently available Ecological: no BERA HQ because all samples non-detect in sediment

total HMWPAH = total High Molecular Weight Polycyclic Aromatic Hydrocarbon (sum of 4-ring, 5-ring, and 6-ring PAHs) total LMWPAH = total Low Molecular Weight Polycyclic Aromatic Hydrocarbon (sum of 2-ring and 3-ring PAHs) total DDT series = 2,4'-DDD + 4,4'-DDD + 2,4'-DDE + 4,4'-DDE + 2,4'-DDT + 4,4'-DDT total Chlordane series = alpha-chlordane + gamma-chlordane + cis-nonachlor + trans-nonachlor + heptachlor + heptachlor epoxide + oxychlordane total BHC series = alpha-BHC + beta-BHC + delta-BHC + gamma-BHC(lindane) total Endosulfan series = endosulfan I + endosulfan II + endosulfan sulfate total Endrin series = endrin + endrin aldehyde + endrin ketone

CONTENTS Executive Summary Acronyms and Abbreviations 1. Introduction 1.1 Site Background 1.1.1 Site Description 1.1.2 Site History 1.1.3 Previous Investigations Chemicals of Potential Concern for Harbor Sediments 1.2.1 Metals 1.2.2 Butyltins 1.2.3 Semivolatile Organics (including PAHs) 1.2.4 PCBs 1.2.5 Polychlorinated PCDDs and PCDFs 1.2.6 Chlorinated Pesticides 1.2.7 Organophosphorus and Carbamate/Urea Pesticides 1.2.8 Herbicides 1.2.9 Ordnance-related Compounds RI Objectives Characteristics of the Pearl Harbor Watershed 2.1.1 Terrestrial Environment 2.1.2 Marine Environment Locations and Nature of Potential Sources of Chemicals to Pearl Harbor 2.2.1 Navy Sources 2.2.2 Watershed Non-Navy, Nonpoint Sources 2.2.3 Watershed Non-Navy Point Sources 2.2.4 Summary of Results for Navy and Non-Navy Sources of Chemicals Fate and Transport Pathways CSM for Ecological Risk Assessment CSM for Human Health Risk Assessment Sediment Samples for COPC Measurements 4.1.1 Sampling Design 4.1.2 Selection of Sampling Strata 4.1.3 Field Sample Collection and Processing Sediment Samples for Toxicity Measurements Wild-Caught Biota Tissue Samples for COPC Measurements 4.3.1 Whole-body Samples 4.3.2 Fish Fillet Samples Surface Seawater Samples for COPC Measurements Investigation Derived Waste iii xxv 1-1 1-1 1-1 1-1 1-2 1-5 1-5 1-5 1-6 1-6 1-7 1-7 1-8 1-8 1-8 1-9 2-1 2-1 2-1 2-14 2-17 2-17 2-22 2-27 2-33 3-1 3-1 3-1 3-2 4-1 4-1 4-1 4-2 4-19 4-21 4-22 4-22 4-22 4-23 4-23

1.2

1.3 2. 2.1

Environmental Setting of the Study Area

2.2

3.

Conceptual Site Model 3.1 3.2 3.3

4.

Field Investigation 4.1

4.2 4.3

4.4 4.5

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5.

Nature and Extent of Contamination 5.1 5.2 5.3 Sediment Samples for Chemical Measurements Sediment Samples for Toxicity Measurements Wild-Caught Biota Tissue Samples for Chemical Measurements Definitions Chemical-Specific Criteria and Benchmarks 6.2.1 Environmental/Ecological 6.2.2 Human Health Location-Specific Criteria and Benchmarks Action-Specific Criteria and Benchmarks Potential Chemical Sources EBA Methods and Procedure Pearl Harbor Sediment Dataset EBA Lines of Evidence 7.4.1 Spatial and Population Evidence 7.4.2 Sediment Source and Geochemical Evidence 7.4.3 Upper 5 Percent Evaluation Summary and Conclusions 8.1.1 Exposure Pathways 8.1.2 Contaminant Screening and Identification of Chemicals of Potential Concern 8.1.3 Toxicity Assessment 8.1.4 Risk Characterization 8.1.5 Uncertainty Assessment 8.1.6 Conclusions Step 1 and 2 - Ecological Screening Risk Assessment Step 3a - Baseline Ecological Risk Assessment Step 3b/4 - Problem Formulation and Data Quality Objectives for the Step 7 BERA Step 5 - Field Sampling Design Step 6 - Site Investigation and Data Analysis Step 7 Risk Characterization for Baseline Ecological Risk Assessment 9.6.1 Summary and Conclusions 9.6.2 Problem Formulation 9.6.3 Risk Estimation 9.6.4 Step 7 BERA Results

5-1 5-1 5-1 5-1 6-1 6-1 6-1 6-2 6-3 6-4 6-5 7-1 7-1 7-1 7-1 7-1 7-2 7-3 7-4 8-1 8-1 8-1 8-1 8-2 8-2 8-6 8-6 9-1 9-1 9-1 9-2 9-5 9-5 9-5 9-5 9-5 9-6 9-7 10-1 10-1 10-2 10-2 10-2

6.

ARARs and TBCs 6.1 6.2

6.3 6.4 7. 7.1 7.2 7.3 7.4

Environmental Background Analysis

8.

Human Health Risk Assessment 8.1

9.

Ecological Risk Assessment 9.1 9.2 9.3 9.4 9.5 9.6

10.

Summary of Conclusions and Recommendations 10.1 Nature and Extent of Contamination 10.2 Environmental Background Analysis 10.2.1 Metals 10.2.2 Chlorinated Pesticides

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10.3 Human Health Risk Assessment 10.4 Baseline Ecological risk Assessment 10.5 Conclusions and Recommendations 11. References

10-2 10-2 10-3 11-1

APPENDIXES Appendix A Planning Documents (CD-ROM Only) Appendix B Storm Drain Maps (CD-ROM Only) Appendix C Field Data Sheets and Notebooks (CD-ROM Only) Appendix D Chemistry Data (CD-ROM Only) Appendix E Sediment Grain Size Data (CD-ROM Only) Appendix F Amphipod Survival Report (CD-ROM Only) Appendix G Echinoderm Fertilization Report (CD-ROM Only) Appendix H Environmental Background Analysis Appendix I Human Health Risk Assessment Appendix J Step 1 and 2 Ecological SRA (CD-ROM Only) Appendix K Step 3a BERA (CD-ROM Only) Appendix L Step 3b/4 Problem Formulation and DQOs for the Step 7 BERA (CDROM Only) Appendix M Step 7 BERA (includes Steps 5 and 6) (CD-ROM Only) FIGURES 1-1 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 3-1 3-2 Project Location Map Pearl Harbor and Southern Oahu with Approximate Boundary of the 110Square-Mile Pearl Harbor Watershed (Red Outline) Pearl Harbor Naval Complex Bathymetry of Pearl Harbor Generalized Geology Eight Sub-Watersheds Comprising the Overall 110-Square-Mile Pearl Harbor Watershed Geographic Study Areas (GSAs), Pearl Harbor Naval Complex Oahu, Hawaii Approximate Locations of Agricultural Activity in the Pearl Harbor Watershed Locations and Nature of Sites in the Watershed that May be Potential Sources of Chemicals to Pearl Harbor Fate and Transport Pathways for Chemicals to Sediments in Pearl Harbor Conceptual Site Model for Chemicals from Sediments to Biological Receptors for Pearl Harbor 1-3 2-3 2-5 2-7 2-9 2-11 2-19 2-25 2-29 3-3 3-5

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3-3 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 9-1 10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9

Conceptual Site Model (CSM) for Human Health Risk Assessment for Pearl Harbor Regional Sampling Areas of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 1 Southeast Loch of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 2 Inner Navigation Channel of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 2 Outer Navigation Channel of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 3 Inner West Loch of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 3 Outer West Loch of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 4 Middle Loch of Pearl Harbor Sediment and Toxicity Sampling Locations in Region 5 East Loch of Pearl Harbor Wild-Caught Biota Tissue Sampling Locations in Pearl Harbor Seawater Sampling Locations in Pearl Harbor Combined 8-Step Process Concentration of Antimony (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Arsenic (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Cadmium (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Chromium (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Copper (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Lead (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Mercury (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Nickel (Detect) in Sediment at Selected Locations in Pearl Harbor Concentration of Selenium (Detect) in Sediment at Selected Locations in Pearl Harbor

3-7 4-3 4-5 4-7 4-9 4-11 4-13 4-15 4-17 4-25 4-27 9-3 10-7 10-9 10-11 10-13 10-15 10-17 10-19 10-21 10-23

10-10 Concentration of Silver (Detect) in Sediment at Selected Locations in Pearl Harbor 10-25

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10-11 Concentration of Zinc (Detect) in Sediment at Selected Locations in Pearl Harbor 10-12 Concentration of Total LMWPAHs (Detect) in Sediment at Selected Locations in Pearl Harbor 10-13 Concentration of Total HMWPAHs (Detect) in Sediment at Selected Locations in Pearl Harbor 10-14 Concentration of Total PCB NOAA-18 (Detect) in Sediment at Selected Locations in Pearl Harbor 10-15 Concentration of Total PCB TEQ - Fish (Detect) in Sediment at Selected Locations in Pearl Harbor 10-16 Concentration of Total PCB TEQ - Bird (Detect) in Sediment at Selected Locations in Pearl Harbor 10-17 Concentration of Total Dioxin/Furan TEQ - Fish (Detect) in Sediment at Selected Locations in Pearl Harbor

10-27 10-29 10-31 10-33 10-35 10-37 10-39

10-18 Concentration of Total Dioxin/Furan TEQ - Mammal (Detect) in Sediment at Selected Locations in Pearl Harbor 10-41 10-19 Concentration of 2-(2-Methyl-4-Chlorophenoxy) propionic acid (MCPP) (Detect) in Sediment at Selected Locations in Pearl Harbor 10-20 Concentration of 2,4,6-trinitrotoluene (TNT) (Detect) in Sediment at Selected Locations in Pearl Harbor 10-21 Antimony Locations in Pearl Harbor Recommended for Further Consideration 10-22 Arsenic Locations in Pearl Harbor Recommended for Further Consideration 10-23 Cadmium Locations in Pearl Harbor Recommended for Further Consideration 10-24 Chromium Locations in Pearl Harbor Recommended for Further Consideration 10-25 Copper Locations in Pearl Harbor Recommended for Further Consideration 10-43 10-45 10-47 10-49 10-51 10-53 10-55

10-26 Lead Locations in Pearl Harbor Recommended for Further Consideration (Anthropogenic + Natural Lead) 10-57 10-27 Lead Locations in Pearl Harbor Recommended for Further Consideration (Natural Lead Only) 10-59 10-28 Mercury Locations in Pearl Harbor Recommended for Further Consideration 10-29 Nickel Locations in Pearl Harbor Recommended for Further Consideration 10-30 Selenium Locations in Pearl Harbor Recommended for Further Consideration 10-31 Silver Locations in Pearl Harbor Recommended for Further Consideration 10-61 10-63 10-65 10-67

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10-32 Zinc Locations in Pearl Harbor Recommended for Further Consideration 10-69 10-33 Total LMWPAHs Locations in Pearl Harbor Recommended for Further Consideration 10-34 Total HMWPAHs Locations in Pearl Harbor Recommended for Further Consideration 10-35 Total PCB NOAA-18 Locations in Pearl Harbor Recommended for Further Consideration 10-36 Total PCB TEQ Fish Locations in Pearl Harbor Recommended for Further Consideration 10-37 Total PCB TEQ Bird Locations in Pearl Harbor Recommended for Further Consideration 10-38 Total Dioxin/Furan TEQ Fish Locations in Pearl Harbor Recommended for Further Consideration 10-39 Total Number of COPCs or COPC Groups Recommended for Further Consideration at Each Sediment Sampling Location in Pearl Harbor TABLES 2-1 2-2 2-3 2-4 2-5 2-6 2-7 4-1 4-2 4-3 5-1 5-2 5-3 Summary of Environmental Assessment at the Pearl Harbor Naval Complex (DON 2002) Summary of 303(d) Impaired Waterbodies in the Peal Harbor Watershed Summary of EPA-Designated Sites of the Pearl Harbor Watersheds Summary of Sites of Concern and Releases in Communities in the Pearl Harbor Watersheds Summary of UST and LUST Sites in Communities in the Pearl Harbor Watersheds Summary of Non-Navy NPDES Permitted Discharges to Pearl Harbor and Streams that Discharge to Pearl Harbor Summary of Potential Sources of Chemicals from Navy and Non-Navy Sources in Pearl Harbor Watersheds Sediment Sampling Locations for Pearl Harbor and Rationale for Selection Sediment Sampling Locations for Pearl Harbor and Specific COPCs Sampled at Each Location Wild-Caught Biota Tissue Sampling Locations for Pearl Harbor and Specific COPCs Sampled at Each Location Sediment Maximum and Minimum Concentrations for Detect and Nondetect Values for All COPCs Amphipod Survival and Echinoderm Fertilization Success (Negative Control or Criteria Corrected) in Pearl Harbor Sediment Samples Macroinfauna Maximum and Minimum Concentrations for Detect and Non-detect Values for All COPCs 2-21 2-27 2-27 2-28 2-31 2-31 2-33 4-29 4-33 4-39 5-3 5-7 5-9 10-71 10-73 10-75 10-77 10-79 10-81 10-83

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Contents

5-4 5-5 6-1 6-2 6-3 7-1 8-1 9-1 9-2

Epibenthic Crab Maximum and Minimum Concentrations for Detect and Non-detect Values for All COPCs Benthic Fish Maximum and Minimum Concentrations for Detect and Nondetect Values for All COPCs Chemical-specific Criteria and Benchmarks Location-specific Criteria and Benchmarks Action-specific Criteria and Benchmarks Maximum Detected Concentrations, Estimated Background Concentration Ranges, and 95th Percentiles, Pearl Harbor Sediments Risk Drivers Contributing to the Overall Exceedances of EPAs Upper Bound Limit for Excess Cancer Risk and Non-Cancer Hazards Summary of Risk Results for the Step 7 BERA Detailed Risk Results for the 17 COPCs or COPC Groups Exhibiting Unacceptable, Indeterminate, and Acceptable Risk for Each Assessment Endpoint Summary of Risk-Based Preliminary Remediation Goals for Sediment Concentrations of Step 7 BERA COPCs for the Assessment Endpoints Evaluated in Pearl Harbor. Summary of RI Findings and Recommendations for Pearl Harbor Sediment

5-13 5-17 6-2 6-4 6-5 7-4 8-3 9-8

9-10

9-3

9-15 10-5

10-1

xxiii

ACRONYMS AND ABBREVIATIONS C AE ARAR As AST ASTM BAFs BERA BHC Cd CERCLA CLEAN cm Co COPC Cr CSM CT Cu CWA DDT DGPS DLNR DOH DON DQO EBA Eco-SSL EFA West EPA EPC ERA ER-L ERV ESA FLETRAGRU GPS GSA HAR HEER HHRA HI HMWPAH HQ IAS IDW degrees Celsius assessment endpoint applicable or relevant and appropriate requirement arsenic aboveground storage tank American Society for Testing and Materials biota-to-sediment-accumulation-factor (tissue dry weight to sediment dry weight) baseline ecological risk assessment benzene hexachloride cadmium Comprehensive Environmental Response, Compensation, and Liability Act Comprehensive Long-Term Environmental Action Navy centimeter cobalt chemical of potential concern chromium conceptual site model central tendency copper Clean Water Act dichlorodiphenyltrichloroethane Differential Global Positioning System Department of Land and Natural Resources, State of Hawaii Department of Health, State of Hawaii Department of the Navy data quality objective Environmental Background Analysis ecological soil screening level Engineering Field Activity, West Environmental Protection Agency, United States exposure point concentration ecological risk assessment effects range-low ecotoxicity reference value Endangered Species Act Fleet Training Group Global Positioning System geographic study area Hawaii Administrative Rules Hazard Evaluation and Emergency Response human health risk assessment hazard index high molecular weight polynuclear aromatic hydrocarbon hazard quotient Initial Assessment Study investigation-derived waste

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Acronyms

IR LMWPAH LOAEL LUST MCPP mg/kg mgd mL Mn MPN NEESA NFA NGPC Ni NISMO NOAA NOAEL NPDES NPL NR NRWQC PAH Pb PCB PCDD PCDF PETN PHNC ppb ppm PRG PWC RCRA RDX RI RME SARA SMDP SRA SRR SSR SVOA TCDD TEF TEQ TMDL TNT UCL

installation restoration low molecular weight polynuclear aromatic hydrocarbon lowest observed adverse effects level leaking underground storage tank 2-(2-Methyl-4-Chlorophenoxy) propionic acid milligram per kilogram million gallons per day milliliter manganese most probable number Naval Energy and Environmental Support Activity no further action Notice of General Permit Coverage nickel Naval Sea Systems Command Inactive Ship On-Site Maintenance Office National Oceanic and Atmospheric Administration no observed adverse effects level National Pollutant Discharge Elimination System National Priorities List normalized ingestion rate National Recommended Water Quality Criteria polycyclic aromatic hydrocarbon lead polychlorinated biphenyl polychlorinated dibenzo-p-dioxin polychlorinated dibenzofuran pentaerythrite tetranitrate and picric acid Pearl Harbor Naval Complex part per billion part per million preliminary remediation goal Public Works Center Resource Conservation and Recovery Act hexahydro-1,3,5-trinitro-1,3,5-triazine remedial investigation reasonable maximum exposure Superfund Amendments and Reauthorization Act scientific management decision point screening ecological risk assessment sediment risk range site summary report semivolatile organic analyte 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalency factor toxic equivalency quotient total maximum daily load 2,4,6-trinitrotoluene upper confidence limit

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Acronyms

U.S. U.S.C. USACE USFWS UST WP WQS Zn

United States United States Code U.S. Army Corps of Engineers U.S. Fish and Wildlife Service underground storage tank work plan Water Quality Standards zinc

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Introduction

1.

Introduction

Pearl Harbor is located on the south-central coast of Oahu, Hawaii (Figure 1-1). In October 1992, the United States (U.S.) Environmental Protection Agency (EPA) placed the Pearl Harbor Naval Complex (PHNC), including Pearl Harbor itself, on the National Priorities List (NPL). The Navy, in cooperation with the EPA, the State of Hawaii Department of Health (DOH), U.S. Fish and Wildlife Service (USFWS), National Oceanic and Atmospheric Administration (NOAA), State Department of Land and Natural Resources (DLNR), and members of the public, initiated a study to investigate Pearl Harbor sediment. The sediment study was initiated in accordance with the Federal Facilities Agreement, which was completed in 1994 among the Navy, the EPA, and the DOH. The Pearl Harbor Sediment Remedial Investigation (RI) is part of the Navys long-term program to restore the environment at its facilities. The investigation provides data to evaluate whether sediments located within Pearl Harbor are safe for humans and marine life. The study identifies areas that may require further evaluation, cleanup, or other response actions. This RI report was prepared for the Naval Facilities Engineering Command, Pacific (NAVFAC Pacific), under the U.S. Navy Comprehensive Long-Term Environmental Action (CLEAN) Navy II program; contract number N62742-94-D-0048, contract task order no. 0115. 1.1 SITE BACKGROUND

This section presents a brief site description, site history, and results of previous investigations for Pearl Harbor.1.1.1 Site Description

Pearl Harbor is approximately 5 square miles in water surface area and is a natural trap, or sink, for sediment and chemicals present in approximately 110 square miles of watershed, or 20 percent of Oahus land surface. During the last century, a wide variety of human activities have been concentrated along the shoreline and within the watersheds that drain into Pearl Harbor. These include industrial and operational activities of the Department of the Navy (DON); private industrial operations; agriculture, municipal, and commercial activities; and the general urbanization of shoreline areas. These activities may have released many types of chemicals into the air, water, and soil along the shoreline and within the watersheds that drain into Pearl Harbor. Consequently, any natural or man-made surface water runoff from these watersheds potentially transports chemicals into Pearl Harbor where they are deposited in the sediment. In addition to acting as a natural trap for chemicals entering the harbor, sediments are the natural habitat for many types of marine life, such as crabs and fish that live on the bottom of the harbor and are part of the food web for many waterbird species and humans.1.1.2 Site History

The present-day PHNC is an outgrowth of more than 100 years of peacetime and wartime development. This development has resulted in dredging to construct a channel and berthing area of sufficient depth to allow passage of large ships and construction of extensive shoreside facilities to meet the changing needs of the U.S. Fleet. Military vessels using the harbor on a regular basis include Navy surface ships, submarines, and harbor craft; Army cargo transport vessels; Coast Guard buoy tenders and patrol vessels; and foreign naval vessels. Harbor navigation channels and mooring areas at piers and wharves supporting these vessels are maintained at water depths necessary for safe navigation through a program of routine maintenance dredging. Shoreside facilities include ship mooring and repair facilities; fuel storage, handling, transfer, and recycling facilities; and operations, maintenance, and support facilities. New facilities are developed as needed and may involve in-water construction and project-specific dredging.

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Introduction

Like the present-day PHNC, the area in the vicinity of Pearl Harbor (which includes Honolulu and its suburbs) encompasses and reflects more than 100 years of peacetime and wartime development. Over this period, land uses in private and public areas adjacent to the harbor and in the watersheds have shifted from primarily agricultural (sugarcane, pineapple, taro, and watercress farming) to commercial, industrial, and residential activities. For example, since 1970, a marked increase in urban development on leeward Oahu is reflected in extensive housing development in the Pearlridge, Waimalu, and Waiawa areas of Pearl City. The Waipahu and Ewa Beach regions have also experienced rapid residential growth in recent years. Commercial and light industrial complexes accompanied this growth. These past and recent activities have produced a range of mixed land uses, including light industrial, municipal, commercial, urban, and agricultural activities. Collectively, these activities are potential sources of a broad range of chemicals, which enter the watersheds that drain into Pearl Harbor.1.1.3 Previous Investigations

The Navy has actively undertaken a program to identify, characterize, evaluate, and address contaminated sites within the PHNC. As a result of these activities, many sites within the PHNC have been identified, characterized, and in some cases, remediated. These activities included a preliminary assessment of the PHNC, referred to as the Initial Assessment Study (IAS), conducted by Naval Energy and Environmental Support Activity (NEESA) in 1983. In addition to the IAS, the EPA conducted a Resource Conservation and Recovery Act (RCRA) Facility Assessment of the more highly industrialized areas located within the PHNC in 1987. The EPA concluded that many of the sites identified as a result of these studies were believed to pose little or no threat to human health and/or the environment. Although these studies focused on upland areas of the PHNC and not harbor sediment, the information is relevant to this investigation because harbor sediments are a major trap for chemicals that may have been transported to the harbor from these upland activities through natural and man-made transport pathways (e.g., stormwater runoff).1.1.3.1 INITIAL ASSESSMENT STUDY

Potential contamination of Pearl Harbor sediments was listed as Site 19 in the NEESA IAS (1983). The IAS recommended no further action (NFA) for harbor sediments. EPA Region 9 took exception to the NFA determination. Consequently, the Navy conducted a Preliminary Assessment/Site Investigation in 1992 (Grovhoug 1992) to further evaluate sediment contamination.1.1.3.2 PRELIMINARY ASSESSMENT/SITE INVESTIGATION

Grovhoug (1992) reviewed existing information on Pearl Harbor compiled from numerous studies conducted over several years and concluded that the environmental risks from contamination of sediment, water, and organisms in Pearl Harbor is considered moderately low, and risk to human health is considered low. This RI was initiated to more definitively evaluate these conclusions and identify any contaminated areas that pose a risk to human health or the environment. In 1996 the Navy, the EPA, DOH, USFWS, NOAA, and DLNR developed comprehensive sampling plans (Ogden 1996a,b,c; see Appendix A on CD-ROM) to develop a synoptic set of data specifically designed to characterize chemicals in Pearl Harbor sediment, evaluate the potential risk of chemicals in sediments to human health and the environment, and identify areas that may require remediation. Consequently, this RI presents results of a study considerably more extensive and comprehensive than conducted by Grovhoug (1992).

1-2

The Hawaiian IslandsNiihau Kauai

OAHUKaula Rock Molokai Maui Lanai Kahoolawe Hawaii

PEARL HARBOR

0

50

100 MILES

N

Pearl Harbor Naval Complex (yellow)

N

0

5 MI.

Figure 1-1: Project Location Map Pearl Harbor Sediment Study Site, Pearl Harbor Naval Complex, Oahu, Hawaii

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Introduction

1.2

CHEMICALS OF POTENTIAL CONCERN FOR HARBOR SEDIMENTS

Present-day and historical information for Navy and private land use in the Pearl Harbor watershed were used to identify chemicals of potential concern (COPCs). Because it is not possible to separate present-day and historical sources of chemicals to harbor sediment (e.g., Johnston et al. 1989; Grovhoug 1992; Ogden 1996c) the RI for sediments in Pearl Harbor addresses both present-day and historical sources. Due to the diversity of sources, COPCs investigated in Pearl Harbor include the following broad range of chemical groups: Metals Butyltins Polycyclic aromatic hydrocarbons (PAHs) comprised of low molecular weight PAHs (LMWPAHs; 2- and 3-ring PAHs) and high molecular weight PAHs (HMWPAHs; 4-, 5-, and 6-ring PAHs) Non-PAH semivolatile organic analytes (SVOAs) Polychlorinated biphenyls (PCBs) Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) Chlorinated pesticides Organophosphorus pesticides Herbicides Triazine pesticides Carbamate/urea pesticides Ordnance compounds The following paragraphs describe characteristics of each chemical group.1.2.1 Metals

Certain metals are required for physiological processes by all living organisms. However, metals can be toxic when present at concentrations above the level of homeostatic regulation in an organism. In addition, certain metals may have similar chemical properties to other essential metals, but be toxic to organisms. Following exposure and uptake, metals can exert toxic effects by disrupting functional groups in enzymes, altering conformation of biomolecules, or displacing essential metals in metaloenzymes.1.2.2 Butyltins

Butyltins considered for the Pearl Harbor Sediment RI include mono-, di-, tri-, and tetrabutyltins. Butyltins are used for stabilization of polyvinyl chloride plastics. Tin stabilizers are effective in preventing degradation of the plastic during processing and during prolonged exposure to light or heat. In addition, butyltins can be used as pesticides. Certain types of trialkyltin and triaryltin compounds possess potent biocidal properties and are used as fungicides, insecticides, and pest control in agriculture applications. Tributyltin oxide or tributyltin fluoride organotin-impregnated elastomers are used in wood preservatives, fungicides for textiles, paper pulp, rope fibers, and certain marine antifouling paints for use on hulls of ships and seaway navigational markers.

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Introduction

1.2.3

Semivolatile Organics (including PAHs)

Semivolatile organics comprise a broad range of chemicals representing numerous types of organic compounds and sources to the environment. As noted in the Final Work Plan (WP) for the Pearl Harbor Sediment RI, semivolatile organics considered for the RI include a range of petrochemicals, oils, and lubricants; solvents and degreasers; and plasticizers (e.g., 3-2 in Ogden 1996c). A major component of the semivolatile organics includes the broad group of petrochemicals. Petrochemicals are compounds produced from petroleum or natural gas. A major focus in the petroleum industry for petrochemicals is the production of broad ranges of (refined) products including liquid fuels, oils, lubricants, solvents, and degreasers. Crude oils, which are the starting petrochemicals for many of the preceding groups of petrochemicals, are a complex mixture of thousands of hydrocarbon and nonhydrocarbon compounds (Albers 1995). A hydrocarbon is a molecule consisting solely of hydrogen and carbon. Hydrocarbons in petroleum are divided into the following four major classes: straight-chain alkanes (n-alkanes or n-paraffins), branched alkanes (isoparaffins), cycloalkanes (cycloparaffins), and aromatics. Aromatics in petroleum have carbon atoms arranged on one- to six-ring structures with each ring containing six carbon atoms. Nonhydrocarbons in petroleum are compounds containing oxygen, sulfur, nitrogen, or metals in addition to hydrogen and carbon, and can range from an open-chain structure to a molecule containing 10 to 20 fused carbon rings. Hydrocarbons comprise more than 75 percent of most crude and refined oils, whereas heavy crude oils can contain more than 50 percent nonhydrocarbons. For environmental considerations, PAHs warrant particular consideration for sediments in Pearl Harbor. PAHs are compounds with two or more fused carbon rings, which can have substituted groups attached to the rings. PAHs range from naphthalene (two rings) to coronene (seven rings), and can include compounds with nitrogen, sulfur, or oxygen. In general, PAHs have low solubility in water, high melting and boiling points, and low vapor pressures, which will favor accumulation in sediments. Furthermore, solubility decreases, melting and boiling points increase, and vapor pressure decrease with increasing molecular volume (and weight). Natural sources for PAHs include forest and grass fires, oil seeps, volcanoes, and certain types of micro-organisms. Anthropogenic sources include petroleum spills and discharges, electric power generation, refuse incineration, home heating, coke, carbon black, coal tar, asphalt production, and internal combustion engines. The primary mechanism for atmospheric contamination by PAHs is incomplete combustion of organic matter. Aquatic contamination is caused by petroleum spills, discharges, and seepages; industrial and municipal wastewater; urban and suburban stormwater runoff; and atmospheric deposition.1.2.4 PCBs

PCBs are compounds with a biphenyl ring structure and substituted chlorines on the rings that vary in number from 1 to 10. Congeners refer to individual PCB compounds that have a specified number of chlorine atoms at specific positions on the parent biphenyl structure. A total of 209 congeners are possible for the entire range of PCB compounds. The environmental transport and fate of PCBs is complex, in large part to the fact that releases generally involve commercial mixtures. Commercial production of PCBs began in 1929, although production throughout the world was reduced or stopped in the 1970s. Some production continued through at least 1983. Commercial mixtures of PCBs have been utilized in a variety of applications including dielectric fluids in capacitors and transformers, heat transfer fluids, hydraulic fluids, lubricating and cutting oils, and additives in pesticides, paints, copying paper, carbonless copy (no carbon required) paper, adhesives, sealants, and plastics. PCBs are not known to occur naturally. The differing physical and chemical properties of congeners comprising commercial mixtures (i.e., different water solubilities, vapor pressures, and octanol-water partition coefficients for individual

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Introduction

congeners) affect the composition of PCBs in environmental samples. For example, lowermolecular-weight congeners (i.e., lower numbers of chlorine atoms) generally exhibit greater evaporation and dissolution losses in aqueous systems because of their greater vapor pressures and water solubilities, respectively. In turn, this can result in residual PCBs in sediments and biological tissues being preferentially enriched in higher-molecular-weight congeners. Congeners with higher chlorine numbers also generally exhibit higher octanol-water partition coefficients, which favor preferential sorption and retention on or in solid and lipid phases (e.g., sediments and organisms, respectively). Lower-chlorinated congeners are generally more susceptible to microbial degradation, which is responsible for lower environmental half-life values (Erickson 1986). In summary, the physical, chemical, and microbiological properties of individual congeners will influence the composition of PCBs in environmental samples, which may not reflect the composition of the starting commercial mixture that was released to the environment. The potential for environmental effects varies among congeners. Commercial production of PCBs began in 1929, although production throughout the world was reduced or stopped in the 1970s. Some production continued through at least 1983. Commercial mixtures of PCBs have been utilized in a variety of applications including dielectric fluids in capacitors and transformers, heat transfer fluids, hydraulic fluids, lubricating and cutting oils, and additives in pesticides, paints, copying paper, carbonless copy (no carbon required) paper, adhesives, sealants, and plastics. PCBs are not known to occur naturally.1.2.5 Polychlorinated PCDDs and PCDFs

PCDDs (dioxins) and PCDFs (furans) are chlorinated aromatic compounds comprised of two benzene rings with cross-bridge connections at two points. Oxygen intermediates occur in one of the cross-bridge connections for PCDFs and both of the cross-bridge connections for PCDDs. The level of chlorine substitutions on the aromatic rings can vary from 1 to 10, with chlorine atoms occurring at different positions on the rings to yield congeners and isomers that total 75 and 135 for PCDDs and PCDFs, respectively (Safe 1990, 1991). In general, compounds comprising PCDDs and PCDFs have very low water solubilities (e.g., 12-20 nanograms per liter for 2,3,7,8-tetrachlorodibenzo-pdioxin [TCDD]; Cook et al. 1993) and high lipid solubilities, which favor their uptake and concentration in biota. Toxicities vary among congeners in the PCDD and PCDF groups, with toxicity differences being functions of stereo selective interactions for individual compounds. The most potent toxicant in the overall suite of compounds is TCDD. Neither PCDDs nor PCDFs are produced commercially, except in very small amounts for analytical standards. However, these compounds are released to the environment as not only trace chemicals in mixtures of other chlorinated aromatics, but also byproducts of combustion when chlorinated compounds or other materials are burned in association with inorganic chloride (Safe 1990, 1991; Hansen 1994). PCDDs and PCDFs occur as impurities in biphenyl ether, chlorinated peony herbicides (e.g., 2,4,5-T, a component in the defoliant Agent Orange), and hexachlorophene. PCDDs and PCDFs also occur as byproducts in production processes for hexachlorobenzene; chlorides of iron, aluminum, and copper; technical hexachlorocyclohexanes; and commercial PCBs. PCDDs and PCDFs occur in effluents from pulp and paper mills as byproducts of the chlorine bleaching process. In combustion processes, PCDDs and PCDFs occur as trace chemicals in fly ash and flue gas emissions from municipal and industrial waste incinerators that have a source of chlorine during the burn reaction.1.2.6 Chlorinated Pesticides

Pesticides encompass a diverse group of chemicals that are used for pest control in agricultural and urban/suburban settings. They are designed to be highly toxic to their intended target organisms,

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Introduction

although many nontarget organisms can also suffer adverse effects associated with misuse or unintended release of these chemicals. Chlorinated (or organochlorine) pesticides include chemicals such as dichlorodiphenyltrichloroethane (DDT) and its analogues, hexachlorocyclohexane, cyclodienes and similar compounds (including aldrin, dieldrin, endrin, heptachlor, chlordane, and endosulfan), toxaphene and related chemicals, and mirex (Blus 1995). One of the best known characteristics of organochlorine pesticides is their persistence in the environment. Environmental half-lives generally range from months to years, with some chemicals persisting for decades and possibly centuries. Furthermore, many organochlorine pesticides are characterized by low water solubilities and high tendencies to adsorb to solid matrices and accumulate in lipid phases (e.g., organisms).1.2.7 Organophosphorus and Carbamate/Urea Pesticides

Organophosphorus and carbamate/urea pesticides are used to control a large variety of insects and other invertebrates, fungi, birds, mammals, and herbaceous plants (Hill 1995). Over 100 different organophosphorus and carbamate/urea chemicals are registered in the U.S. alone for use in thousands of products applied to widely diverse habitats including agricultural crops, forests, rangelands, wetlands, towns, and cities. Organophosphorus and carbamate/urea pesticides are comparatively short-lived under most neutral-to-basic environmental conditions. They are rapidly metabolized or excreted by most organisms and do not bioconcentrate in food webs. These factors and their broadspectrum insecticidal efficacy favor their use as replacements for the more persistent and problematic organochlorine compounds.1.2.8 Herbicides

Herbicides are chemicals that destroy or inhibit plant growth, especially of weeds or other undesirable vegetation (McGraw-Hill Inc. 1994). Wide varieties of organic herbicides have been developed and have received widespread usage in agriculture, forestry, and other industries. Modern usage often combines two or more herbicides to provide the desired weed control. Applications can include objectives, such as improving agricultural yields; reducing labor and machinery energy required for weed control; minimizing exposure of livestock and humans to irritating and/or poisonous plants; reducing irrigation costs; reducing insect and disease control costs through removal of host weeds for undesirable organisms; minimizing the presence of undesirable plants from recreational areas, roadsides, forests, parks, and home lawns; and prolonging the life of asphalt and concrete surfaces by preventing weed penetration of those surfaces.1.2.9 Ordnance-related Compounds

Ordnance, munitions, and propellants may result from Navy-related activities in the vicinity of Pearl Harbor. As described in McGraw-Hill Inc. (1994), most military explosives are relatively simple compositions that are formulated for high explosive-energy densities, loading in munitions plants, and long storage lives. Most are based on explosive chemicals that incorporate oxidizer and fuel components in the same molecule. An examples of the type of ordnance compounds that may have been unintentionally introduced over time to sediments in the harbor is 2,4,6-trinitrotoluene (TNT), which was once used extensively as a military explosive and is a relatively insensitive and inexpensive explosive of moderate energy. At the present time, it is mainly used in combination with more powerful explosives, such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and pentaertthritol tetranitrate and picric acid (PETN). RDX is a fairly insensitive explosive of high density and melting point, and has the highest detonation pressure of any compound in common use. PETN has moderate sensitivity, a small critical diameter, and a high detonation pressure. Tetryl is a relatively insensitive explosive, but is easier to press into pellets for use as booster charges. Booster charges are detonated with a still smaller charge of an even more sensitive explosive, such as lead azide. Lead azide is a socalled primary explosive because small charges of it are easily detonated by a spark or flame. In

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Introduction

addition to being used as a yellow dye for silk, picric acid has been used as an explosive that can be detonated by both heat and shock. Many salts of picric acid are even more readily detonated than free acid and must be handled with great care. 1.3 RI OBJECTIVES Determine the type and location of chemicals in the sediment and harbor marine life from past Navy activities. Determine whether chemicals in the sediment and harbor marine life are safe for humans and marine life, and. Identify locations in the harbor where sediment may require further consideration, cleanup, or other response actions. The RI is intended to characterize potential chemical contamination in Pearl Harbor sediment from past Navy activities. The RI also included evaluation of numerous natural and man-made sources in the upland environment of the Pearl Harbor watershed that have and continue to be sources of natural and anthropogenic chemicals to the harbor as the result of natural transport processes (e.g., erosion, stormwater runoff, and non-stormwater runoff). These watershed-derived chemicals were evaluated in addition to Navy-derived chemicals to ensure a complete assessment of the harbors. A stratified random sampling design was employed for the harbor-wide assessment to ensure complete coverage of the harbor, with greater emphasis in nearshore areas that are likely to pose greater risk to target receptors. The resulting database of measurements can allow for quantitative selection of the least impacted areas of the harbor as site-specific reference areas. Particular areas for focused sampling in the stratified random sampling design include locations that: (1) were expected to exhibit elevated chemical loading, (2) are important habitats for special status species and/or recreational or commercial fishing activity, and/or (3) are anticipated to be characterized by higher levels of exposure for special status species of interest or humans (e.g., nearshore sediment environments and stream mouths). For the purpose of characterizing sediment contamination and the goal of addressing such contamination (i.e., remediation of chemicals and their source), the holistic approach considers phenomena, such as movements of sediments and their associated chemicals in the harbor, as well as inherent mobilities of various aquatic and/or special interest organisms relative to chemical sources in sediments.

The objectives of the RI are as follows:

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Environmental Setting

2.

Environmental Setting of the Study Area

Pearl Harbor, one of the largest estuaries in Hawaii, and its upland watershed is a productive and complex ecosystem of interconnected habitats and living resources with complex relationships among the living resources. An estuary is a semi-enclosed body of water that has free connection with the open sea and within which seawater is measurably diluted by freshwater from land drainage. Within an estuary, freshwater mixes with seawater, with each water type contributing its own chemical and physical characteristics. This creates a range of environments that support a wide variety of plants and animals. The spectrum of aquatic environments in the harbor, from freshwater to seawater, creates a unique estuarine ecosystem abundant with life. 2.1 CHARACTERISTICS OF THE PEARL HARBOR WATERSHED

This section characterizes the upland or terrestrial environment in the Pearl Harbor watershed (Section 2.1.1) and the marine environment (Section 2.1.2) within Pearl Harbor. An understanding of the upland environment around Pearl Harbor is relevant to this investigation of harbor sediments because the sediments in Pearl Harbor are a major trap, or repository, for chemicals that may have been transported to the harbor from upland activities in the Pearl Harbor watershed through natural and man-made transport pathways.2.1.1 2.1.1.1 Terrestrial Environment GEOLOGY

Four major geomorphic provinces exist on the Island of Oahu: the Koolau Range, Waianae Range, Schofield Plateau, and Coastal Plain (Stearns 1985). The island of Oahu was initially formed by two massive shield volcanoes, the Waianae and Koolau Volcanoes, rising from the floor of the Pacific Ocean. The eroded remnants of these shield volcanoes, the Koolau and Waianae Ranges, compose the island and are exposed as long, narrow, nearly parallel mountain ridges, which are separated by the Schofield Plateau (Figure 2-1). The Waianae and Koolau Volcanics are primarily tholeiitic and alkalic basalts, with minor amounts of more acidic rocks (e.g., rhyodacite). Banking of the younger Koolau flows against the older Waianae Range and erosion of the two mountain ranges formed the Schofield Plateau in the central portion of Oahu. The Coastal Plain overlies the Koolau Volcanics at the north and south ends of the Schofield Plateau (Stearns 1985). The PHNC is located on the coastal plain south of the Schofield Plateau (Figure 2-2). The PHNC area is underlain by interbedded marine and terrestrial sediments that were deposited over the shield lavas during periods of sea-level transgression and regression (Stearns and Chamberlain 1967). The Pearl Harbor basin is a drowned river system with several tributaries that form the three main lochs (West Loch, Middle Loch, and East Loch) that join to form a single channel entrance (Figure 2-1 and Figure 2-2). Harbor bathymetry is characterized by shallow areas at the head of each loch grading to deeper waters toward the center of the loch and in the main navigation channels. This change in depth is gentle in upper West Loch, but more abrupt in Middle and East Lochs where extensive dredging has been used to maintain navigation depths necessary for the operation of naval vessels (Figure 2-3). The geology of the Pearl Harbor area is the result of processes including sea level fluctuations, stream erosion, alluvial deposits, and volcanism. A cluster of overlapping volcanic tuff cones (Aliamanu, Salt Lake, and Makalapa Craters) comprising the Honolulu Volcanics occurs east of Pearl Harbor. Volcanic tuff deposits dominate the area immediately east of the harbor. The Ewa Plain on the west side of the harbor is underlain by an extensive coralline limestone reef formation. Koolau basalts underlie most of the area north of the harbor. Caprock sediments overlie the Koolau

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basalts in some areas near the shoreline north of the harbor. A geologic map of the area near Pearl Harbor is presented in Figure 2-4.2.1.1.2 HYDROLOGY

Surface Water The Pearl Harbor watershed is characterized by a very steep precipitation gradient from the harbor to the crest of the Koolau Range. Pearl Harbor is relatively dry with a mean annual rainfall of 64.8 centimeters (25.5 inches) compared to the crest of the Koolau range where the mean annual rainfall may exceed 699 centimeters (275 inches). Rainfall is seasonal, varying from 10.2 centimeters (4 inches) per month during the winter (December to February) to 2.54 centimeters (1 inch) per month during the summer (June to July) (Giambelluca et al. 1986). The 110 square miles of overall watershed for Pearl Harbor is subdivided into eight distinct subwatersheds: Aiea, Halawa, Honouliuli, Kalauao, Kapakahi, Waiawa, Waikele, and Waimalu (Waimalu and Waimano Streams) (Figure 2-5). These watersheds contain the headwaters of nine streams that drain into Pearl Harbor. Seven are perennial (Halawa, Kalauao, Kapakahi, Waiawa, Waikele, Waimalu, and Waimano) and two are intermittent (Aiea and Honouliuli). Aiea, Halawa, Kalauao, Waimalu, and Waimano Streams drain steep, relatively narrow valleys of the Koolau Range and therefore transport substantial coarse sediment loads during storm events (WET 1991, Oki and Brasher 2003). Waikele and Honouliuli Streams drain the Schofield Plateau and typically transport large amounts of fine-grained sediment. The Waikele watershed is the largest and comprises approximately 40 percent of the overall Pearl Harbor watershed and discharges the heaviest sediment load of any of the Pearl Harbor Basin streams (Grovhoug 1992). All streams drain forested and agricultural lands and pass through highly urban areas before entering Pearl Harbor. The volume of freshwater entering Pearl Harbor has been estimated at 50 million gallons per day (mgd) during dry periods and greater than 100 mgd during rainy periods (Cox and Gordon 1970; B-K Dynamics 1972). Groundwater Groundwater movement in the Pearl Harbor area is controlled by local and regional hydrologic conditions that influence the supply and distribution of water in the sedimentary deposits and volcanic rocks (basalts) that underlie the harbor area (Youngberg 1973). Unconfined near-surface caprock groundwater occupies sediments that overlie and confine groundwater at lower levels within the basaltic bedrock that underlies the Pearl Harbor area. The caprock groundwater occurs in permeable sediments (sands and gravels) that overlie impermeable sediments (clays) that confine the deeper groundwater within the underlying fractured basalts. The caprock groundwater is recharged by water that infiltrates the near-surface sediments and percolates downward to the saturated zone below the water table. Both the near-surface caprock groundwater and the deeper, confined groundwater flow toward the ocean, and are recharged by infiltration from rainfall, streams, and irrigation. In the northern Pearl Harbor area, groundwater discharge supports perennial stream flows and springs, while farther to the south, groundwater within the confined Koolau basalt aquifer exists under artesian conditions and discharges to Pearl Harbor or the Pacific Ocean (NEESA 1983). Groundwater flow toward the harbor may act as a transport pathway for chemicals present in upland soils to reach Pearl Harbor. Chemicals present in upland soils may enter the groundwater by leaching through highly permeable overlying soils except in areas overlain by sedimentary caprock. Once in the groundwater, chemicals may be transported to streams that discharge to the harbor or to the harbor directly.

2-2

Schofield Plateau

Koolau MountainsEast Loch Makalapa Crater


Honolulu Ewa Plain Southeast Loch Honolulu International Airport

Waianae Mountains

Image Produced by NASA/Jet Propulsion Lab; LANDSAT Data from EROS Data Center USGS

Figure 2-1: Pearl Harbor and Southern Oahu with Approximate Boundary of the 110-Square-Mile Pearl Harbor Watershed (red outline)

West Loch Middle Loch

Navigation Channel

East Loch Southeast Loch

Figure 2-2: Pearl Harbor Naval Complex


East Loch

Southeast Loch

Navigation Channel

Figure 2-3: Bathymetry of Pearl Harbor

LegendHonolulu Volcanics Kolekole Volcanics

Koolau Basalt No Data

Sedimentary Deposits

Waianae Volcanics

Watershed Boundaries

Pearl Harbor Naval Complex Landfill Wildlife Refuge Park Golf Course Other Land Features Stream Mouth Coral Streams Stratum Boundary Substratum Boundary Ford Island BridgeSite of sample collection, stratum, and substratum boundaries as presented in the Pearl Harbor Sediment RI/FS Final Work Plan (August 1996)Naval Magazine Lualualei Waikele BranchRoyal Kunia Golf Course II Waikele Golf Course

Manana Storage Area

Royal Kunia Golf Course I

Pearl City Junction

Map Projection based on State Planema

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Waiau Power

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Naval Shipyard

Naval Station

PWC Main Complex

Naval Magazine Lualualei West Loch

Naval Housing

Bishop Pt.

Ft. Kam Sewage Treatment Plant

Hickam Air Force Base

Iroquois Pt. Housing

Figure 2-4: Generalized Geology

Kapakahi

Waikele

Kalauao Waiawa

Waimalu Honouliuli Halawa

Aiea

Figure 2-5: Eight Sub-Watersheds Comprising the Overall 110-Square -Mile Pearl Harbor Watershed

October 2005



2.1.1.3

SEDIMENTATION

Sedimentation is a major natural process defining the physical characteristics of Pearl Harbor. Freshwater streams in the Pearl Harbor watershed transport an estimated 96,300 tons (180,000 cubic yards) of naturally occurring terrigenous sediment, annually, (Nystedt 1977) to the depositional environment of Pearl Harbor, which acts as a natural trap, or sink, for the sediment. These terrigenous sediments are the product of physical and chemical weathering of rock and soil in the Pearl Harbor watershed. Once the streams discharge sediments to the harbor, the distribution of sediment is influenced by hydrographical (i.e., water depths) conditions, sediment particles (i.e., grain size), and harbor currents. Larger sediment particles discharged to the harbor by streams are deposited rapidly in the vicinity of stream mouths, while smaller particles remain in suspension and are transported greater distances from a stream mouth before settling to the bottom of the harbor. Turner (1975) characterized sediments near stream mouths as comprising basaltic minerals, such as plagioclase, augite, magnetite, and olivine. Secondary weathering products of basalt, such as hematite, kaolinite, montmorillonite, and gibbsite, are distributed in the harbor mostly as clay-sized material. Carbonate sediment, which occurs in the outer portion of the harbor and navigation channels far from the stream mouths, is likely derived from ancient coral deposits. Although transport of sediment is a natural part of the watershed ecosystem, the transport process can carry toxic chemicals from upland areas to Pearl Harbor (Oki and Brasher 2003). Individual sediment particles (particularly clays) have a large surface area, and molecules of toxic chemicals easily adsorb, or attach, to them. As a result, natural sediment particles can act as transport agents for chemicals present in upland soils and streambed sediment by adsorbing metals, nutrients, oil, pesticides, and other potentially toxic chemicals. The overall process allows chemicals of both natural (e.g., metals in volcanic soils and parent rock) and anthropogenic (e.g., pesticides, herbicides, and metals) origins in watershed soils that originate miles from Pearl Harbor to migrate into the harbor by means of natural transport processes. For example, chemicals from automobile exhaust (e.g., lead and PAHs) or oil and grease from parking lots and streets can be washed into urban storm drains by stormwater runoff, transported into an urban stream or drainage channel, and eventually discharged into Pearl Harbor. Similarly, stormwater runoff from the unpaved land areas can transport chemicals, such as pesticides or herbicides that have been applied to agricultural areas and urban lawns. These types of diffuse or nonpoint source pollution are difficult to control. The rapid urbanization of Oahu that began during the 1950s has increased nonpoint source pollution. In addition, urbanization has facilitated the natural transport of chemicals to the harbor by changing the land cover from porous soils and vegetation, which inhibit and reduce transport, to impervious pavement that facilitates transport and increases stormwater runoff and runoff velocities to the streams that drain into the harbor. Two groups of organochlorine pesticides are good examples of nonpoint source pollution on Oahu: Dichlorodiphenyltrichloroethane (DDT) and chlordane. DDT was applied over large areas as an agricultural insecticide; chlordane was used for residential termite control, especially as urbanization accelerated on Oahu (Oki and Brasher 2003). DDT concentrations in fish from urban streams on Oahu are similar to levels reported on the mainland, while concentrations of chlordane are much higher at urban Oahu sites compared to mainland sites (Brasher and Anthony 2000). Despite bans on the use of DDT and chlordane in 1972 and 1988, respectively, these and other organochlorine pesticides persist in sediments and animals inhabiting aquatic ecosystems on the island of Oahu. These types of organochlorine chemicals remain long-term environmental concerns because of their widespread historical use, slow rates of environmental breakdown, and documented effects on aquatic invertebrates, fish, and birds.

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Several metals occur naturally in Hawaiian volcanic soils and are also examples of nonpoint sources of chemicals. Substantial loads of both naturally occurring and anthropogenic metals are discharged to Pearl Harbor with sediments eroded from rock and soil in the watershed. As noted previously, the basaltic rocks that provide the bulk of the sediments deposited in the harbor contain relatively high concentrations of metals including cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), and zinc (Zn), in addition to minor amounts of other trace metals. Anthropogenic sources have contributed variable quantities of trace metals including arsenic (As), cadmium (Cd), Cu, lead (Pb), and Zn to the soils and sediments (De Carlo and Anthony 2002, De Carlo et al. 2004). Background concentrations of these metals are therefore likely to reflect anthropogenic enrichment in some areas. Conversely, although concentrations of Co, chromium (Cr), and Ni are elevated in some areas of Oahu, soil concentration ranges for these metals typically reflect greater contributions from natural sources than from anthropogenic sources (De Carlo and Anthony 2002, De Carlo et al. 2004).2.1.2 2.1.2.1 Marine Environment CHARACTERISTICS OF MARINE ENVIRONMENT

Pearl Harbor contains approximately 5 square miles of soft-bottom (e.g., mud and sand) benthic or harbor bottom habitat. Although specific species in the benthic, or bottom-dwelling, community may change with water depth and location in the harbor, the major biotic components in the community generally include infaunal organisms that burrow and live in sediments (e.g., amphipods, worms, clams, snails, and shrimp) and epifauna that live on or in proximity to the sediment surface (e.g., crabs, snails, and bottom fish). These benthic organisms are a major link between the primary producers and the upper trophic levels of the harbor food web. In particular, the benthic invertebrates are a major food source to other benthic species, such as fish and crabs that consume epifaunal and infaunal invertebrates and may ultimately be consumed by humans. The benthic community also provides a food source to primarily terrestrial species, such as shorebirds (e.g., stilts) and diving birds that may forage on intertidal mudflats and on the bottom in shallow water. Estuaries such as Pearl Harbor are important habitats because of their generally high productivity; their use as nursery and rearing areas by numerous birds, motile fish, and crustacean species; and the ability of these motile species to export the energy fixed in the estuary to other (terrestrial and offshore) environments (e.g., Deegan 1993; McClintock et al. 1993). Pearl Harbor supports the types of organisms that produce these benefits (e.g., fish and portunid crabs such as Thalamita) and the fishes observed in the harbor appear to be dominated by juvenile year classes (Evans et al. 1974; Grovhoug 1992). Because of its relatively large size, Pearl Harbor comprises a significant proportion of the estuarine habitat in the main Hawaiian Islands. It is therefore important to protect its biological productivity and its functionality as a rearing and nursery area for a variety of important fish and indigenous bird species. Grovhoug (1992) summarized past biological investigations on Pearl Harbor and reported the harbor is characterized by high biological complexity and productivity for plankton, fouling (i.e., organisms that live on pier pilings and ship hulls), benthic, and fish assemblages. More than 90 species of marine fishes, 114 species of benthic organisms, 71 species of micromollusks, and 88 species of piling organisms were identified from the harbor ecosystem during comprehensive field studies conducted by Evans et al. (1974). The estuary is expected to provide important nursery areas for many marine fish species. Several wetland areas are located adjacent to Pearl Harbor in East Loch, Middle Loch, West Loch, and on the Waipio Peninsula. The Pearl Harbor National Wildlife Refuge has two units located at Honouliuli in West Loch and at Waiawa on Pearl City Peninsula (DLNR 1990). These areas are known habitats for several endemic and endangered waterbird species including the Hawaiian stilt,

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Aeo (Himantopus mexicanus knudseni), the Hawaiian coot, Alae Keokeo (Fulica americana alai), the Hawaiian duck, Koloa (Anas wyvilliana), and the Hawaiian moorhen or gallinule, Alae ula (Gallinula chloropus sandvicensis) (USN 1982 and 1989). Hawaii has the largest number of threatened or endangered species of any state in the U.S. The pressures on the indigenous flora and fauna are intense. Several of these species are limited in their distribution to wetland and estuarine habitats (e.g., Hawaiian coot and Hawaiian stilt). The survival of these species is heavily dependent upon both the nesting and rearing areas and the benthic food items available in these habitats. As mentioned, Pearl Harbor is one of the largest estuaries in Hawaii and is therefore extremely important to the preservation of these species. Several natural marine resources in the Pearl Harbor estuary are harvested by local residents for consumption (e.g., goatfish, mullet, crabs, oysters, and algae) (personal communication with J. G. Grovhoug 1995). Fish and wildlife resources on lands and waters within the PHNC are managed under a cooperative agreement among the DON, USFWS, NOAA Fisheries, and DLNR.2.1.2.2 ECOLOGICAL RESOURCES OF CONCERN FOR COPCS IN HARBOR SEDIMENTS

Organisms that live in and on bottom sediments in Pearl Harbor form complex natural communities. Known as benthos, these bottom-dwelling organisms include a wide range of animals and plants. Benthic organisms are often differentiated by their habitat, which includes organisms living in sediments (infauna) as well as those living on the sediments surface (epifauna). Detailed descriptions of characteristics and differences in feeding habits and habitats for the organisms discussed below are provided in Appendix C of the Step 3b/4 baseline ecological risk assessment (BERA) document for Pearl Harbor Sediment RI (AMEC 2002). Infauna are often further differentiated by their general size. For the RI, the focus for infauna is directed at larger organisms with sizes generally greater than approximately 1 millimeter. These larger infauna are referred to as macroinfauna (Mare 1942). In Pearl Harbor, macroinfauna are primarily comprised of crustacea, such as ghost shrimp (Callianassa spp.) and pistol or snapping shrimp (Alpheus spp.) with lesser amounts of other organisms, such as polychaete worms, clams, and gobid fishes (i.e., gobies). Collectively, macroinfauna form their own community structures in sediments and are connected to the overlying water column by tubes and tunnels that they build in sediments. In general, macroinfauna in Pearl Harbor include deposit feeders that ingest and process sediments in their digestive tracts, detritivores that ingest detritus such as excrement or waste products of other organisms in the sediments (including dead organisms), and carnivores that actively hunt and feed on other organisms in the sediments. Epifauna may be either attached to the sediments surface and stationary (e.g., oysters) or capable of moving on the surface (e.g., crabs). Epifauna, such as crabs, are mobile and may enter the water column for brief excursions. Blue-clawed stone crabs (Thalamita crenata) are representative epifauna in Pearl Harbor. These crabs are omnivores that consume a variety of food items including other animals associated with sediments (e.g., shrimp, clams, snails, worms, and small fish), algae, and detritus including dead organisms. Other aquatic organisms associated with harbor sediments include bottom fish. Examples in the Pearl Harbor ecosystem include the bandtail goatfish (Upeneus taeniopterus) and tilapia (Oreochromis mossambicus). Goatfish are carnivores that actively search for food items, such as shrimp, crabs, worms, and small fish, by probing into surface sediments. Tilapia are omnivores that ingest a wide range of food items including epifauna, larval fish, detritus, decomposing organic matter, and aquatic

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plants. As part of their reproductive activities, tilapia actively excavate and maintain nests in bottom sediments. Bottom fish are considered harbor residents and have lifelong exposure to COPCs in sediment compared to transient fish in the harbor, such as papio and mullet. Therefore, exposure estimates to sediment-based COPCs for resident bottom fish are greater than those for fish living higher in the water column (i.e., more removed from the sediment interface) and/or transient fish in the harbor. Macroinfauna, epifauna, and bottom fish in Pearl Harbor affect the physical and chemical conditions of sediments and the overlying water. For example, macroinfauna (e.g., especially ghost shrimp and pistol or snapping shrimp) actively pump water through tubes and burrows that they build in the sediment. Digging associated with the building of tubes or burrows by macroinfauna results in mixing of deeper sediments with surface sediments, a process known as bioturbation. In addition, infaunal deposit feeders, such as polychaete worms, promote mixing of sediments by plowing through and ingesting sediments in their search for food. Epibenthic predators, such as crabs and bottom fish including goatfish, actively move across and manipulate or probe into bottom sediments while searching for food. Tilapia promote mixing of sediments during the building and maintenance of nests for reproductive activities. All of the preceding actions result in mixing or stirring of sediments, which increases exchange of materials including COPCs between deeper and surface sediments and the overlying