PUBLIC HEALTH ASSESSMENT
AIR AND GROUNDWATER PATHWAYS ANALYSES
AGANA POWER PLANT
MONGMONG, GUAM
September 22, 2004

Prepared by:

Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry

TABLE OF CONTENTS

Foreword

Summary

Introduction

Background

• Site Description and History
• Remedial and Regulatory History
• ATSDR's Involvement at the Agana Power Plant
• Demographics
• Land Use and Natural Resource Use
• Geology and Hydrogeology
• Climate and Meteorology
• Quality Assurance and Quality Control

Evaluation of Environmental Contamination, Exposure Pathways, and Public Health Implications

• Breathing Contaminants From Stack Discharges From the Former APP
• Groundwater and Drinking Water

Community Concerns

• Exposure to Contaminants From Eating Foods Raised Locally
• Breathing Contaminants-PCBs That Might Evaporate From the Agana Swamp
• Breathing Contaminants-Dusts From Roads Near the Former APP
• Breathing Contaminants-Smoke From Fires in the Agana Swamp
• Unearthing Buried Wastes From Various Sources
• Past Occupational Exposures
• Exposure to Chlordane in the Mongmong Area

ATSDR's Child Health Considerations

Conclusions

• Exposure Issues
• Community Concerns

Recommendations

Public Health Action Plan

• Completed Actions
• Ongoing and Planned Actions

Preparers of the Report

References

Appendices

Appendix A: Possible Exposure Situations for PCBs From the Agana Power Plant

Appendix B: ATSDR Hazard Categories

Appendix C: Information on How ATSDR Assesses Exposure

Appendix D: Exposure Evaluation Methodology and Assumptions

Appendix E: ATSDR Glossary of Terms

Appendix F: Other Potential Sources of Pollution in the Mongmong Area

Appendix G: Reducing inhalation exposure during swamp fires.

Appendix H: Difference Between ATSDR's public health assessment process and EPA's risk assessment process.

Appendix I: Additional Information Regarding the Potential Health Effects Associated with Dioxins and PCBs

Appendix J: Response to Public Comments

List of Tables

Table 1. Summary of VOCs, PCBs1, and Pesticides Detected in Drinking Water From GWA Supply Wells Within 1 Mile of APP

Table 2. APP Surface and Subsurface Soil Data-Offsite Locations

Table 3. PCB (Aroclors) Sampled in Fish, Eels, and Snails in Agana Swamp and River

Table 4. Estimated (Modeled) PCB Concentrations in Animals in Sampling Locations Based on Historical PCB Levels Detected in Soils near APP

Table 5. PCB Residues Detected in Domestic Foods

Table 6. PM10 Ambient Air Monitoring Data from Guam (1989-1991)

Table D-1. Estimated Concentrations in Meat, Dairy, and Eggs of Free-Ranging Animals Based on Detected Soil Concentrations

Table D-2. Exposure Dose Assumptions

Table D-3. Estimated PCB Exposure Dose Levels From Eating: Non-cancer Effects

List of Figures

Figure 1: Site Location, Agana Power Plant

Figure 2: Agana Power Plant Surface Geology

Figure 3: Agana Power Plant Surface Soils

Figure 4: Agana Power Plant Drainage Areas

Figure 5: Locations of Drinking Water Supply Wells Within a One-Mile Radius of Agana Power Plant

Figure 6a: Elevation Map Locations

Figure 6b: Elevation Map

Figure 7: 1945 Military Areas Near Agana Power Plant

Figure 8: Selected Former Ambient Air Monitoring Locations on Guam

Figure 9: Agana Swamp Wetlands Map

LIST OF ABBREVIATIONS

AIRS	Aerometric Information Retrieval System
APP	Agana Power Plant
ATSDR	Agency for Toxic Substances and Disease Registry
bgs	below ground surface
BTF	biotransfer factor
CAIS	chemical agent identification set
CERCLIS	Comprehensive Environmental Response, Compensation, and Liability Information System
CV	ATSDR's comparison value
DAWR	Division of Aquatic and Wildlife Resources
EMEG	environmental media evaluation guide
EPA	United States Environmental Protection Agency
FDA	United States Food and Drug Administration
FUDS	formerly used defense sites
GDPHSS	Guam Department of Public Health and Social Services
GEPA	Guam Environmental Protection Agency
GWA	Guam Waterworks Authority
LOAEL	lowest observed adverse effect level
mg/kg	milligram per kilogram
mg/kg/day	milligram per kilogram per day
MCL	maximum contaminant level
MRL	ATSDR's minimal risk level
NAS	Naval Air Station
NPL	National Priorities List
PAH	polycyclic aromatic hydrocarbons
PCBs	polychlorinated biphenyls
PCDDs	polychlorinated dibenzo-p-dioxins
PCDFs	polychlorinated dibenzofurans
PCE	tetrachloroethylene
PHA	public health assessment
PM10	particulate matter smaller than 10 microns
ppb	parts per billion
ppm	parts per million
POI	point of interest
RBC	EPA's risk-based concentration
RfD	reference dose
SDWSs	safe drinking water standards
SVOCs	semi-volatile organic compounds
TCE	trichloroethylene
TPH	total petroleum hydrocarbons
TSP	total suspended particulates
USACE	United States Army Corps of Engineers
UXO	unexploded ordnance
VOCs	volatile organic compounds
WERI	Water and Environmental Research Institute of the Western Pacific

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