MUNISPORT LANDFILL
NORTH MIAMI, DADE COUNTY, FLORIDA
CONCLUSIONS
Based on the available data, we categorize the Munisport Landfill site as an indeterminate public health hazard. Data are either not available or inadequate for all environmental media to which humans may be exposed. Except for coliform bacteria, the available environmental data do not indicate that humans are being or have been exposed to levels of toxic chemicals that would be expected to cause adverse health effects. This conclusion is based on the limited data currently available and may change once the surface soil and landfill material have been adequately characterized. The data are inadequate to determine if there has been an increased rate of cancer in the Highland Village mobile home park.
1. Children and adults frequently trespass across this site. Warning signs exist, but they are too few to meet the requirements of Florida DER Rule 17-736 and Florida Statutes 403.704 and 403.7255. The 10-foot cliff in the mound of soil on the landfill may be a physical hazard to children trespassing on the site.
2. Dense undergrowth along the southwest site boundary next to the Highlands Village mobile home park harbors snakes, scorpions, and spiders that may threaten the health of these residents. Dense undergrowth and debris in Highland Village may also harbor snakes, scorpions, and spiders.
3. Past activities at this site may have exposed nearby residents to contaminated dust. We cannot confirm this exposure or evaluate the health risk since no air samples were collected before landfill operations ceased in 1980 and vegetation covered the site. On-site air quality was only tested during the 1990 landfill fire. This testing was too late, however, to measure the maximum contaminant concentrations and was not located in the nearby neighborhoods where exposure occurred. Currently, exposure to contaminated dust is unlikely since the site is covered with vegetation. Any future remediation, construction, or development at this site that removes vegetation or uncovers landfill material, however, may expose nearby residents to contaminated dust.
4. Sampling on the landfill portion of the site (10 samples from 170 acres; 1 every 17 acres) is inadequate to fully characterize the extent of soil contamination. Additional chemicals may be discovered and the concentrations of previously discovered chemicals may be higher. Fifty additional surface soil samples (0 to 3 inches deep) and sixty additional fill samples (5 to 10 feet deep) will be necessary to fully characterize the extent of soil/fill contamination on the landfill portion of the site.
5. Long-term (> 1 year) consumption of PCB contaminated oysters and fish from Biscayne Bay may affect the immune system and result in a "low" increased risk of cancer. The pattern of fish and oyster contamination suggests that this site is not the source of PCBs in Biscayne Bay. The number of fish and oyster samples collected was too few, however, to characterize the extent of contamination throughout Biscayne Bay.
6. After unusually heavy rains, the southeast lake on the landfill overflows and floods the Highland Village mobile home park. Although skin contact with the water in the on-site lakes is not likely to cause adverse health effects, the stormwater run-off from these lakes has not been tested and may be different due to suspended particulates. Until this stormwater is analyzed, we cannot determine its public health threat.
7. Nearby residents report that children swim in the on-site lakes. Although coliform bacteria are not Superfund hazardous waste, children who swam in the on-site lakes 10 years ago may have been exposed to disease causing bacteria associated with fecal material. As a result of this exposure, these children were at a higher risk of infections such as hepatitis, meningitis, and gastroenteritis. It is not possible to determine the current health threat from swimming in these lakes because they have not been tested for bacterial contamination since 1982.
8. If significant areas of the landfill adjacent to the Highland Village mobile home park are paved, landfill gases that currently migrate upward and dissipate may migrate latterly into Highland Village.
9. Twenty-eight chemicals found in various media at this site lack sufficient toxicological data to determine their public health significance.
10. If radioactive medical waste was disposed of at this landfill, it is unlikely that it was a health threat. Most of the radioactive isotopes used in hospitals and doctor's offices have short half-lives (days or weeks) and the radiation they emit is too weak to penetrate even a thin layer of soil. Florida HRS requires hospitals and doctors to hold this waste until the remaining radioactivity is insignificant.
RECOMMENDATIONS
Cease/Reduce Exposure Recommendations
1. Restrict public access to the site. Post additional hazardous waste warning signs to meet the requirements of Florida DER Rule 17-736 and Florida Statutes 403.704 and 403.7255. Eliminate the 10-foot cliff in the mound of soil in the middle of the landfill. The appropriate local, state, or federal agency should restrict site access to prevent human exposure to contaminated soil via incidental ingestion or to contaminated lake water via incidental ingestion during swimming.
2. Clear and maintain a buffer free of dense undergrowth (15 feet minimum) along the southwest site boundary bordering the Highlands Village mobile home park. The appropriate local, state, or federal agency should clear and maintain a buffer free of dense undergrowth that harbors snakes, scorpions, and spiders. Residents should also clear their property of dense undergrowth or debris.
3. Control dust generation and monitor the air quality on site and in the Highland Village mobile home park. To insure that nearby residents are not exposed to contaminated dust or asbestos, the appropriate local, state, or federal agency should control dust generation during any site remediation, construction, or development that removes vegetation or uncovers landfill material. The appropriate local, state, or federal agency should also monitor the air quality on site and in nearby neighborhoods during any landfill fires or any site remediation, construction, or development that removes vegetation or uncovers landfill material. The air should be sampled for dust (particulates) and analyzed for heavy metals, asbestos, and other site-related contaminants.
Site Characterization Recommendations
4. Collect 50 surface soil samples (0 to 3 inches deep) and 60 fill samples (5 to 10 feet deep) from the 170 acre landfill portion of the site. The number of samples is based on an average of one sample for every 3 acres; ten surface soil samples have already been collected and analyzed. Analyze these samples for the chemicals analyzed in the remedial investigation, plus asbestos. The appropriate local, state, or federal agency should collect and analyze these samples.
5. Investigate PCB contamination in Biscayne Bay fish, oysters, and other aquatic species eaten by humans. The appropriate local, state, or federal agency should investigate the extent of PCB contamination in Biscayne Bay fish, oysters, and other aquatic species eaten by humans.
6. Test the quality of stormwater run-off from this site. The appropriate local, state, or federal agency should analyze the stormwater run-off quality in Highland Village the next time heavy rains cause the southeast lake to overflow.
7. Test the bacteriological quality of the on-site lakes. Although coliform bacteria are not a Superfund hazardous waste, the appropriate local, state, or federal agency should measure the current levels of bacterial contamination in the on-site lakes.
8. Monitor soil gases along the southeast boundary of the site if significant areas of the landfill are paved. If significant areas of the landfill adjacent to the Highland Village mobile home park are paved, the appropriate local, state, or federal agency should monitor the soil gases along the southwest corner of the landfill.
ATSDR Health Activities Recommendation Panel (HARP) Recommendations
The information in this public health assessment has been evaluated by the ATSDR Health Activities Recommendation Panel (HARP) for follow-up health activities. HARP determined the following actions are needed: community education to inform the community about health risks from exposure to site-related contaminants; community education to inform the community about the relationships between exposure and risk, and between dose and response; a disease symptom and prevalence study to define and validate site-related health complaints; and research to derive a minimal risk level for lead and fill toxicological data gaps for dibenzofuran, tetrahydrofuran and alkyl benzene sulfonamides. After consulting with EPA, and state and local environmental agencies, ATSDR will determine if additional follow-up health actions are needed.
PUBLIC HEALTH ACTIONS
The Public Health Action Plan for the Munisport Landfill site contains a description of actions to be taken by ATSDR, Florida HRS, and other governmental agencies subsequent to the completion of this assessment. The purpose of this plan is to ensure that this assessment not only identifies public health hazards, but provides a plan of action designed to mitigate hazardous substances in the environment. ATSDR and Florida HRS are committed to ensuring this plan is implemented.
A. ATSDR, Division of Toxicology, will develop a chronic oral Minimal Risk Level for lead.
B. ATSDR, Division of Toxicology, will consider developing Toxicological Profiles for the 28 chemicals listed in Appendix B.
C. Florida HRS, Toxicology and Hazard Assessment and the Dade County Public Health Unit, Environmental Health will warn residents of Highland Village of the dangers of trespassing on this site, including incidental ingestion of the soil and incidental ingestion of water from swimming in the lakes.
D. Florida HRS will apply for funding to perform a disease and symptom prevalence study.
E. Florida HRS, Toxicology and Hazard Assessment will coordinate with the appropriate environmental agencies to develop plans to implement the cease/reduce exposure and site characterization recommendations contained in this public health assessment.
F. The Dade County Public Health Unit will test the bacteriological quality of the eight on-site lakes.
G. The Southeast District Office of the Florida DER will sample the stormwater run-off from the site the next time it floods the Highland Village mobile home park. Since the nearest Florida DER office is in West Palm Beach about 60 miles north of the site, they must rely on residents or local officials to notify them when flood conditions exist in Highland Village.
H. The Florida DER will address the closure of the landfill portion of the site under the landfill closure requirements in Chapter 17-701, Florida Administrative Code.
I. EPA will continue to monitor the design and implementation of the ground water remediation.
J. EPA will continue to monitor state closure of the landfill portion of the site to insure that it is compatible with the ground water remediation.
K. EPA will require additional air monitoring where appropriate.
ATSDR and/or Florida HRS will reevaluate the Public Health Action Plan when new environmental, toxicological, or health outcome data are available.
PREPARERS OF REPORT
E. Randall Merchant, M.S.
Biological Administrator
Office of Toxicology and Hazard Assessment
Florida Department of Health and Rehabilitative Services
Bruce J. Tuovila, M.S.
Environmental Specialist
Office of Toxicology and Hazard Assessment
Florida Department of Health and Rehabilitative Services
H. Joseph Sekerke, Jr., Ph.D.
Biological Scientist
Office of Toxicology and Hazard Assessment
Florida Department of Health and Rehabilitative Services
ATSDR TECHNICAL PROJECT OFFICER
Richard Kauffman
Remedial Programs Branch
Division of Health Assessment and Consultation
ATSDR REGIONAL REPRESENTATIVE
Bob Saffay
Regional Services
Office of the Assistant Administrator
CERTIFICATION
The Florida Department of Health and Rehabilitative Services prepared this public health assessment under a cooperative agreement with the Agency for Toxic Substances and Disease Registry. It complies with approved methodology and procedures existing when the assessment was started.
Richard R. Kaufmann
Technical Project Officer, SPS, RPB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment and concurs with its findings.
Robert C. Williams
Director, DHAC, ATSDR
REFERENCES
