PUBLIC HEALTH ASSESSMENT
GBF & PITTSBURG DUMPS
ANTIOCH, CONTRA COSTA COUNTY, CALIFORNIA
During the 1960s and 1970s, numerous complaints were filed by the community about chemical odors from the site and symptoms of burning eyes and irritated lungs. Community concerns have been addressed through community meetings and fact sheets. In the course of preparing this public health assessment, we did not discover any current community health concerns.
Exposure to airborne contaminants to on-site workers and nearby community members did occur in the past, but data are not available to evaluate those exposures. The site currently poses no apparent public health hazard, and conditions are not expected to change in the future. The potential for inhalation exposure from releases of contaminated soil gas does exist, but those possible exposures would be below levels of health concern. No other potential present or future completed exposure pathways have been identified.
Significant future exposure to site-related contaminants is unlikely if: 1) migration of groundwater contamination is controlled; 2) remediation efforts reduce groundwater contamination to below levels of health concern; 3) no future drinking water wells are placed in areas of known contamination until remediation has reduced contaminant concentrations below levels of health concern; 4) any future excavation/construction projects at the site take the necessary precautions to insure that workers are not exposed to contaminants above levels of health concern; 5) deed restrictions restrict future development of the site; 6) the landfill gas collection and destruction system adequately controls the lateral transport of landfill gas; and 7) the cap is strictly maintained.
ATSDR and CDHS has made recommendations to reduce and prevent exposure to contaminants and to better characterize the contamination at and nearby the site. Follow-up health activities are not indicated at this time. As additional data becomes available, ATSDR and the California Department of Health Services may reevaluate this site for any indicated follow-up health activities.
A. Cease/Reduce Exposure Recommendations
- In the areas of known ground water contamination, institutional controls should be implemented to prevent future use of contaminated aquifers for drinking water supplies until remediation has reduced contaminant concentrations to below levels of health concern.
- To minimize exposures during any future excavation or construction on the site, the work site should be limited to authorized personnel using appropriate personal protective equipment and applicable OSHA and NIOSH guidelines should be followed.
- Deed restrictions should be implemented to restrict redevelopment of site.
- The landfill gas collection and destruction system and the landfill cap should be strictly maintained to ensure that releases of landfill gas are controlled.
- The nature and extent of potential contamination of drainage zones adjacent to the site, including the Markley Creek bed, should be more thoroughly evaluated. The remedial investigation concludes that contamination has not migrated into the Markley Creek bed north of the site, although this conclusion is based on only four samples from two sampling locations.
- Data from the new on-site gas probes required by the California Integrated Waste Management Board should be periodically reviewed to evaluate migration of soil-gas off site. If significant off-site migration is identified, additional investigation may be required to determine the potential impact of soil-gas contaminants on the nearby community.
The data and information developed in the GBF/Pittsburg Landfill(s) Public Health Assessment have been evaluated for appropriate follow-up health actions. The ATSDR Health Activities Recommendation Panel (HARP) determined that people have been, but are not currently, exposed to contaminants from the site. Data needed to evaluate those exposures are not available. HARP determined that community education about past exposure was indicated, but has been performed. Because important information needed to evaluate past exposure is lacking and no current allegations or indications of adverse health effects have been identified, no additional follow-up health actions are indicated at this time. ATSDR will reevaluate this site for additional follow-up public health actions if new data become available that indicate a need to do so.
The Public Health Action Plan (PHAP) for GBF/Pittsburg Landfill site contains a description of actions to be taken by ATSDR and or CDHS at and in the vicinity of the site subsequent to the completion of this public health assessment. The purpose of the PHAP is to ensure that this health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. HARP did not identify any public health actions to be taken at this time. The public health actions to be implemented by ATSDR/CDHS are as follows:
- ATSDR and CDHS will coordinate with the appropriate environmental agencies to develop plans to implement the cease/reduce exposure and site characterization recommendations contained in this preliminary public health assessment.
- ATSDR will provide an annual follow up to this PHAP, outlining the actions completed and those in progress. This report will be placed in repositories that contain copies of this health assessment, and will be provided to persons who request it.
ATSDR will reevaluate and expand the PHAP when needed. New environmental, toxicological, or health outcome data, or the results of implementing the above proposed actions may result in the need for additional actions at this site.
A. Environmental and Health Effects Assessors
David J. Borgeson, M.S.
Epidemiologist
Impact Assessment, Inc., Consultant to
Environmental Health Investigations Branch,
California Department of Health Services
Diana M. Lee, M.P.H.
Research Scientist
Environmental Health Investigations Branch
California Department of Health Services
Jane Riggan, M.S.W.
Impact Assessment, Inc., Consultant to
Environmental Health Investigations Branch,
California Department of Health Services
ATSDR REGIONAL REPRESENTATIVES
Lynn Berlad
Regional Services, Region IX
Office of the Assistant Administrator
Gwendolyn Eng
Regional Services, Region IX
Office of the Assistant Administrator
William Nelson
Regional Services, Region IX
Office of the Assistant Administrator
ATSDR TECHNICAL PROJECT OFFICER
Gail Godfrey
Division of Health Assessment and Consultation
Remedial Programs Branch, State Programs Section
This GBF/Pittsburg Landfill(s) Public Health Assessment was prepared by the Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.
Gail Godfrey
Technical Project Officer
Remedial Programs Branch
Division of Health Assessment and Consultation (DHAC)
ATSDR
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment, and concurs with its findings.
Robert C. Williams, P.E., DEE
Director, DHAC, ATSDR
- The MARK Group, Engineers & Geologists, Inc., GBF/Pittsburg Landfill(s) Respondents Group Remedial Investigation Report, GBF/Pittsburg Landfill(s), Antioch, California, August, 1991.
- California Department of Health Services (Currently Department of Toxic Substances Control), Preliminary Assessment Summary for GBF/Pittsburg Landfills, July 1987.
- California Department of Health Services (Currently Department of Toxic Substances Control), Memorandum from Allen K. Wolfenden, Chief, Special Projects Unit, Site Cleanup and Emergency Response Section, to Howard Hatayama, North Coast California Section, April 15, 1985.
- California Department of Health Services (Currently Department of Toxic Substances Control) and Contra Costa County Health Services Department, Fact Sheet #5 for GBF/Pittsburg Landfill Site, Contra Costa County, California, June 1991.
- Bay Area Air Quality Management District, letter to Wendel Brunner, M.D., Contra Costa County Health Services Department, reporting results of ambient air and soil gas testing at GBF/Pittsburg Landfills during December 1986. January 8, 1987.
- Contra Costa County Health Services Department, Current Status Report of GBF Toxic Waste Site in Antioch, prepared by staff from the Public and Environmental Health Divisions for the County Board of Supervisors, January 26, 1987.
- California Department of Health Services (Currently Department of Toxic Substances Control), Community Relations Plan for the GBF/Pittsburg Landfill Site, Contra Costa County, California, Prepared by ICF Technology, Inc., March 1988.
- McCulley, Frick & Gilman, Inc., Preliminary Public Health and Environmental Evaluation, GBF/Pittsburg Landfill(s). Prepared for IT Corporation January 29, 1988, and amended May 11, 1988.
- Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services, Preliminary Health Assessment for GBF, Inc., Dump, Antioch, Contra Costa County, California, CERCLIS Number CAD980498562, July 18, 1990.
- The MARK Group, Engineers & Geologists, Inc., GBF/Pittsburg Landfill(s) Respondents Group Public Health and Environmental Evaluation, GBF/Pittsburg Landfill(s), Antioch, California, December 1991.
- Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services, Health Assessment Guidance Manual, March 1992.
- Memorandum from California Integrated Waste Management Board to Mr. William Q. Nelson, Department of Health and Human Services, March 29, 1993.
- Hydro Geo Chem, Inc., Soil Gas Survey, GBF/Pittsburg Landfill, Antioch, California, Appendix A, April 19, 1990.
- Bay Area Air Pollution Control District (Currently the Bay Area Air Quality Management District), Memorandum describing results of air sampling during a fire involving paper pulp in a former liquid waste disposal pond on August 1 and 2, 1977. Memorandum dated September 29, 1977.
- Radiation Detection Company, report to IT, Inc., describing results of air sampling conducted for IT, Inc. during a fire involving paper pulp in a former liquid waste disposal pond on August 2, 1977. Report dated August 8, 1977.
- Little, J.C., J.M. Daisy, and W.W. Nazaroff, "Transport of Subsurface Contaminants into Buildings, An Exposure Pathway for Volatile Organics", Environmental Science and Technology, Vol. 26, No. 11, 1992.
- Hearey, C.D., J.A. Harris, M.S. Usatin, D.M. Epstein, H.K. Ury, and R.R. Neutra, "Investigation of a Cluster of Anencephaly and Spina Bifida", American Journal of Epidemiology, Vol. 120, No. 4, 1984.
- California Department of Health Services (Currently Department of Toxic Substances Control) and Contra Costa County Health Services Department, Fact Sheet #4 for GBF/Pittsburg Landfill Site, Contra Costa County, California, June 1990.

FIGURE 1. SITE LOCATION MAP (6)

FIGURE 2. LAND USE IN THE SITE VICINITY (1)
| Chemical |
|---|
| Acetone |
| Ammonia |
| Arsenic |
| Carbon Tetrachloride |
| Carbonyl Sulfide |
| Catechol |
| Chlorine |
| Chloroform |
| Formaldehyde |
| Freon 113 |
| Glycol Ethers |
| Hydrochloric Acid |
| Hydrogen Fluoride |
| Manganese Compounds |
| Methanol |
| Methylene Chloride |
| Phosphoric Acid |
| Sodium Hydroxide |
| Sodium Sulfate |
| Sulfuric Acid |
| Toluene |
| Titanium Tetrachloride |
| Year | Air Releases (lbs) | Water Releases (lbs) | Land Releases (lbs) | Publicly Owned Treatment Works (lbs) |
|---|---|---|---|---|
| 1987 | 793,616 | 1,752,849 | 2,731 | 796 |
| 1988 | 1,055,457 | 23,124 | 0 | 0 |
| 1989 | 832,072 | 18,553 | 0 | 0 |
| 1990 | 618,610 | 7,054 | 15,000 | 0 |
| Contaminant |
|---|
| Inorganic |
| Beryllium (& beryllium chromate) Calcium hypochlorite Chromium Copper ammonia complex Hexavalent chromium Iron chloride Lead Mercury Phosphoric acid Potassium cyanide Silver nitrate Sulfuric acid & iron sulfate (pickeling liquor) Titanium dioxide Zinc chloride |
| Organic |
| Pesticides & herbicides (picloram, DDT, formaldehyde, malathion, lindane, chlordane, diazinon) Solvents (chlorothene, trichloroethylene, photographic supplies, freon fluorocarbon, and ethyl acetate) Dowtherm (diphenoloxide & dichlorenzine) Polychlorinated biphenols Monoethanolamine Ethanolamines 1,1,1-Trichloroethane |
| Acids |
| Hydrochloric Nitric Acetic Chromic |
| Other |
| M2 Incendiary Oil Thickener Liquid industrial wastes Phosphorus ordinance Outdated medicines & medical equipment |
| Chemical | Maximum Conc. ppb | Location | Comparison Value ppb | Comparison Value Source |
|---|---|---|---|---|
| VOLATILE ORGANIC COMPOUNDS | ||||
| Acetone | 400,000 | MW-23 | 1,000 | Oral RMEG-Child |
| Benzene | 250 | MW-22, MW-23 | 1.2 | Oral CREG-Water |
| Carbon tetrachloride | 210 | MW-21 | 0.3 | Oral CREG-Water |
| Chloroethane | 9 | G-4 | NA | NA |
| Chloroform | 1,500 | MW-23 | 5.7 | Oral CREG-Water |
| 1,1-Dichloroethane | 39 | G-4 | NA | NA |
| 1,2-Dichloroethane | 31 | G-6 | 0.4 | Oral CREG-Water |
| 1,1-Dichloroethylene | 25 | G-6 | 0.06 | Oral CREG-Water |
| 1,2-Dichloroethylene | 160 | G-6 | 70 | LTHA |
| 1,2-Dichloropropane | 3,500 | G-4 | 5 | MCL |
| Methylene Chloride | 500 | MW-23 | 4.7 | Oral CREG-Water |
| 4-Methyl-2-Pentanone | 390 | MW-23 | NA | NA |
| Tetrachloroethylene | 310 | G-6 | 0.7 | Oral CREG-Water |
| Trichloroethylene | 270 | G-6 | 3.2 | Oral CREG-Water |
| Vinyl Chloride | 36 | MW-23 | 0.2 | Chronic Oral EMEG-Child |
| SEMI-VOLATILE ORGANIC COMPOUNDS | ||||
| Isophorone | 69 | G-4 | 8.5 | Oral CREG-Water |
| 4-Methylphenol | 33 | G-4 | NA | NA |
| Phenol | 72,000 | MW-23 | 4,000 | LTHA |
| INORGANIC CHEMICALS | ||||
| Arsenic | 83 | MW-23 | 0.02 | Oral CREG-Water |
| Cadmium | 260 | MW-23 | 2 | Chronic Oral EMEG-Child |
| Chromium | 120 | MW-23 | 50 | Oral RMEG-Child |
| Copper | 4,100 | MW-23 | 1,300 | MCL |
| Nickel | 4,700 | MW-23 | 100 | LTHA |
| Silver | 190 | G-4 | 50 | Oral RMEG-Child |
NA = Not Available
| CONTAMINANT | MAXIMUM CONCENTRATION (ppbv) |
|---|---|
| Benzene | 5,500 |
| Carbon tetrachloride | 0.1 |
| Chloroform | 430 |
| 1,2-Dichloroethane | 120 |
| Ethylbenzene | 2,500 |
| Ethylene Dibromide | 18 |
| Methane | 260,000,000 (i.e., 26%) |
| Methylene Chloride | 61,000 |
| Tetrachloroethylene | 920 |
| 1,1,1-Trichloroethane | 15,000 |
| Trichloroethylene | 1,600 |
| Vinyl Chloride | 1,200 |
| Toluene | 39,000 |
| Xylenes | 6,400 |
| Chemical | Maximum Conc. ppb | Location | Comparison Value ppb | Comparison Value Source |
|---|---|---|---|---|
| VOLATILE ORGANIC COMPOUNDS | ||||
| Benzene | 36 | MW-14 | 1.2 | Oral CREG-Water |
| Carbon tetrachloride | 140 | MW-36 | 0.3 | Oral CREG-Water |
| Chloroethane | 4.8 | MW-7 | NA | NA |
| Chloroform | 270 | MW-7 | 5.7 | Oral CREG-Water |
| 1,1-Dichloroethane | 9 | MW-14 | NA | NA |
| 1,2-Dichloroethane | 16 | MW-36 | 0.4 | Oral CREG-Water |
| 1,1-Dichloroethylene | 14 | MW-7 | 0.06 | Oral CREG-Water |
| 1,2-Dichloropropane | 1,900 | MW-14 | 5 | MCL |
| Methylene Chloride | 31 | MW-7 | 4.7 | Oral CREG-Water |
| Tetrachloroethylene | 120 | MW-7 | 0.7 | Oral CREG-Water |
| Trichloroethylene | 96 | MW-7 | 3.2 | Oral CREG-Water |
| Vinyl Chloride | 3.6 | MW-8 | 0.2 | Chronic Oral EMEG-Child |
| SEMI-VOLATILE ORGANIC COMPOUNDS | ||||
| Isophorone | 28 | MW-14 | 8.5 | Oral CREG-Water |
| INORGANIC CHEMICALS | ||||
| Cadmium | 30 | MW-29 | 2 | Chronic Oral EMEG-Child |
| Chromium | 140 | MW-29 | 50 | Oral RMEG-Child |
| Nickel | 170 | MW-14 | 100 | LTHA |
| Silver | 70 | MW-7 | 50 | Oral RMEG-Child |
NA = Not Available
| CONTAMINANT | NUMBER OF LOCATIONS TESTED | MAXIMUM CONCENTRATION (ppbv) |
|---|---|---|
| PRINCIPAL ANALYTES | ||
| Carbon Tetrachloride | 87 | 19.4 |
| Trichloroethylene | 87 | 4.7 |
| Tetrachloroethylene | 87 | 6.2 |
| Methylene Chloride | 87 | 0.29 |
| Chloroform | 87 | 7.4 |
| Methane | 35 | 45.7 |
| SECONDARY ANALYTES | ||
| Vinyl Chloride | 51 | 2.0 |
| 1,1-Dichloroethylene | 51 | 0.05 |
| 1,1,1-Trichloroethane | 51 | 0.6 |
| 1,2-Dichloroethane | 51 | 1.5 |
| Benzene | 51 | Not Quantified |
| Toluene | 51 | 1.9 |
| Ethylbenzene | 51 | Not Quantified |
| Xylenes | 51 | 37.6 |
| Freon-113 | 51 | Not Quantified |
| Contaminated Environmental Medium | Time Frame | Exposure Point | Exposure Route at Exposure Point | Potentially Exposed Populations at Exposure Point | Comments |
|---|---|---|---|---|---|
| Soil/Waste | Past | On-site | Direct Contact, incidental ingestion | On-site workers | Nature and magnitude of exposure occurring in the past, especially during the 1960s and 1970s, are unknown. |
| Ambient Air | Past | On-site, Nearby residences | Inhalation | On-site workers and nearby residents | Nature and magnitude of exposure occurring in the past, especially during the 1960s and 1970s, are unknown. |
| Contaminated Environmental Medium | Time Frame | Exposure Point | Exposure Route at Exposure Point | Potentially Exposed Populations at Exposure Point | Comments: |
|---|---|---|---|---|---|
| Ambient Air | Current, Future | On-site, nearby community | Inhalation | On-site workers, nearby residents | Significant exposure is not expected as long as cap is maintained. |
| Indoor Air | Current, Future | Nearby community | Inhalation | Nearby residents | Significant exposure is not expected. |


