PUBLIC HEALTH ASSESSMENT
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- Agency for Toxic Substances and Disease Registry
Division of Health Assessment and Consultation
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1600 Clifton Road NE, Atlanta, Georgia 30333
APPENDIX C RESPONSE TO PUBLIC COMMENTS
Comment 1. Conclusions 1 and 3 are reasonable and generally correct but do not present a full and accurate representation of the site and the health risks presented by groundwater. The report does not appear to present any basis in fact for item 2.
Response: After statement 1, the health assessment explains why downgradient wells are at risk. In order to determine future risks from site-related chemicals impacting water supplies, monitoring of these supplies is necessary. In addition, as stated in the public health assessment, conditions at the site pose a physical hazard to those who enter the site. Fencing the site may serve to protect people who may be unaware of the hazards. Environmental monitoring represents a one time sampling event and chemical concentrations may increase over time.
Comment 2. The report presents a fairly accurate general description of site conditions, but fails to discuss the potential for contamination of the deep mine aquifer water from materials which were left in the mine due to its previous operation.
Response: A public health assessment is the evaluation of data and information on the release of hazardous substances into the environment in order to assess any current or future impact on public health. It is not the purpose of the public health assessment to determine the source of the contamination, but to ascertain the potential impact on public health.
Comment 3. The report fails to identify site-related chemicals of concern in surface soil, leachate and surface water. Low levels of chemicals in surface sediments in this area only confirms the lack of site-related contamination.
Response: The chemicals in the pathways of potential human exposure are clearly shown in Table 5. The chemicals identified as chemicals of concern are based on concentrations in groundwater, comparisons to health-related standards, and the potential for migration to off-site water supplies. In addition, the public health assessment presented information on contaminants in soil, surface water, and leachate on pages 7-8 of the Environmental Contamination Section.
We do not agree with the statement that low level contamination of sediment confirms the lack of site-related chemicals. It identifies the presence of site-related chemicals at low concentrations.
Comment 4. Although the data on surface soil, leachate, surface water, and sediments indicate minimal migration from the landfill, the report makes the chemicals reported at low concentrations in groundwater from the mine aquifer a concern and relates this concern to the site. Although the reviewer was unable to accurately determine the pattern of chemical distribution in the shallow aquifer, the higher reported concentrations of chemicals appear to be related to perched water. The chemicals reported are typically found in leachate from a sanitary landfill and would be expected in these samples.
Response: The chemicals of concern in groundwater are listed in Tables 4 and 5. The concentrations of these chemicals are not low, and all exceed the chosen comparison values. These chemicals of concern were present in both the shallow and deep aquifer systems. Most of the higher concentrations of metals in the deep mine aquifer occur in areas adjacent to the inferred sites of shallow groundwater infiltration into the deep mine system. While the VOC concentrations were generally low, it does indicate that the landfill has impacted groundwater at the site.
It is not the purpose of the public health assessment to determine the source of the contamination, but to ascertain the impact on public health.
Comment 5. The assumption is then made that the shallow and deep aquifer are connected. The groundwater data for both aquifers is presented in a single table. This is very misleading and gives the impression that there is a comparatively free flow connection between the shallow aquifer groundwater and the deep mine aquifer. The magnitude of the potential for the shallow aquifer to impact the deeper aquifer is never addressed.
Response: The tables in the public health assessment serve as summaries of the chemicals present at the site. Data from the RI report (PRC, 1990) indicated that the two aquifers are connected. Because of site topography and surface coal mining operations, landfill wastes and mine spoil are in contact with the coal unit at the north end of the landfill. Indications of a hydrogeologic connection between the aquifers include the higher hydraulic heads in the shallow aquifer, the groundwater depression in the vicinity of Pond 2, and the occurrence of site-related chemicals in both aquifers. For example, vinyl chloride was present in the perched, bedrock aquifer at the southeast edge of the landfill and also in a deep mine well downgradient of the bedrock well. The presence of fracture systems in roof rock overlying older underground coal mines and the potential for infiltration of shallow groundwater into the deep mine are well documented (Appendix B, FS Report, PRC, 1991 and Harper et al, 1990).
Comment 6. The report states that the public and private wells "did not contain any chemicals of concern" although the chemicals of concern were never identified in a straight forward manner. The carbon tetrachloride reported in the community well was identified as "not found in other media" which suggests that it is not site-related.
Response: It is true that prior to the Human Exposure Pathway Section of the public health assessment, specific Tables listing chemicals of concern were not included in the Environmental Contamination Section. Public health assessments do not follow the same format as a Baseline Risk Assessment, which generally includes lists of "chemicals of concern." The specific chemicals in the human exposure pathways or potential pathways are the focus of the "chemicals of concern." Those chemicals listed in Table 5 of the public health assessment are those chemicals of concern even though they are not labeled as chemicals of concern. In addition, the specific chemicals of concern were discussed in the Toxicological Evaluation Section. As stated previously, the public health assessment serves to identify possible risks to human health and does not focus on the source of the chemicals.
Comment 7. In the Pathway Analysis, the first statement ("The reported disposal of hazardous waste at the Fultz Landfill resulted in the low level contamination of soils, leachate, surface water, sediment, Pond 1A, and groundwater.") does not appear to have any basis in facts presented in the previous sections.
Response: This is a general statement which referred to the environmental monitoring data presented in Tables 2-4, on pages 8-10 of the public health assessment, and in the Remedial Investigation Report. These data clearly indicate that disposal of materials at the Fultz Landfill has impacted various environmental media at the site.
Comment 8. There is a statement regarding potential impact of contaminated groundwater from other sources that are upgradient of the site.
Response: As stated previously, the public health assessment serves to identify possible risks to human health and does not focus on the source of the chemicals.
Comment 9. The second to the last paragraph in the Pathway Section does finally allude to the fact that there is a major dilution in the deep mine aquifer which would diminish the potential impact on the community water supply.
Response: While dilution in the deep mine aquifer may occur, there are still uncertainties about the exact pattern of groundwater movement in the deep mine aquifer. It is because of these uncertainties that the public health assessment concluded that there is a potential for the site to impact drinking water supplies.
Comment 10. The final paragraph states, "There does not appear to be a pattern of chemical detection for chemical distribution in the groundwater." This argues against a significant impact from the comparatively limited recharge area between the contaminated shallow aquifer and the deep mine aquifer. They continue to address the "groundwater flow" as if this were a typical underground aquifer instead of an open mine reservoir.
Response: The discussion on patterns of chemical distribution is solely used to describe what is happening and not specifically to address aquifer recharge. In addition, the lack of predicable groundwater flow patterns makes it difficult to assess the potential to impact public health. The discussion of site hydrology was simplified to assist the public in the under-standing of groundwater systems at the site.
Although contaminant concentrations were greatest in the shallow aquifer, the environmental data provides evidence that the deep mine aquifer is also contaminated.
Comment 11. The Human Exposure Pathways essentially limits the potential exposure to the human exposure to well water. Surface soils or surface water are not noted as potential exposure pathways.
Response: The minimal surface soil data does not indicate that surface soils pose a significant risk to humans. However, only ten surface soil samples were taken, which may be insufficient to adequately characterize soil contamination. The available data for Wills Creek also indicate minimal contamination and poses minimal risk. Additional samples from Wills Creek were recommended as part of this public health assessment because only one sediment/surface water sample was actually downgradient from the site. In order to accurately determine if the site has impacted Wills Creek, additional downstream samples are needed.
Comment 13. Where doses are given, it is apparent that the low level environmental concentrations reported at the site are not a concern.
Response: The levels of arsenic, barium, chromium, lead, and PAHs in on-site groundwater exceed health-related comparison values. Comparisons to estimated doses were made in order to assist in the determination of "chemicals of concern." While on-site groundwater is not being used, there is a possibility for off-site groundwater to be affected by site-related chemicals. It must also be understood that the available information on "low level environmental concentrations" through specific pathways are somewhat limited.
Comment 14. The conclusion that the site "represents a public health hazard" is not supported by any present exposures and is only suggested by unsupported claims of potential future exposure. The true potential for meaningful contamination of the community and private wells need to be addressed from a hydrogeological point of view.
Response: Public health hazards can be based on ongoing exposures or the potential for exposures to occur. The public health assessment concluded that the site is a public health hazard because of the potential for drinking water supplies in the area to be affected. In order to determine if a site poses a human health risk, one must consider the chemicals present, the concentration, if the concentration exceeds a health-related standard, and if humans are being exposed or may be exposed. In the Fultz Landfill public health assessment, we concluded that the chemicals in Table 5 are at levels of health concern and that there is a potential for on-site groundwater to impact off-site water supplies.
The public health assessment is written for the lay audience and technical issues are presented in a general manner. The technical description of site hydrogeology can be found in the Remedial Investigation/Feasibility Study Reports.
Comment 15. Recommendation 1. There is not evidence or comment that trespass on-site would result in any exposure.
Response: In addition, as stated in the public health assessment, conditions at the site pose a physical hazard to those who enter the site. Fencing the site may serve to protect people who may be unaware of the hazards. Environmental monitoring represents a one time sampling event and chemical concentrations may increase over time.
Comment 17. Recommendation 3: Since there was no indication of soil contamination there does not appear to be a need for further definition.
Response: The minimal surface soil data does not indicate that surface soils pose a significant risk to humans. One surface soil sample did contain toluene. However, only ten surface soil samples were taken, which may be insufficient to adequately characterize soil contamination.
Comment 18. As in 3., above, the lack of any indication of significant site-related contamination does not suggest that further definition is warranted.
Response: The available data for Wills Creek also indicates minimal contamination and poses minimal risk. Additional samples from Wills Creek were recommended as part of this public health assessment, because only one sediment/surface water sample was actually downgradient from the site. In order to accurately determine if the site has impacted Wills Creek, additional downstream samples are needed.
Comment 19. Recommendation 5. This recommendation has no basis when the minimal potential for exposure and health effects is taken into account. Public health studies are only indicated where the potential exposures are high and reasonably can be expected to cause health effects. Evaluation of health outcome data at this site is not warranted or even advisable.
Response: A health study was not recommended as part of this public health assessment, but will be recommended if deemed necessary as a result of community concern or public health need. ATSDR and ODH must be responsive to a community potentially affected by a Superfund site. In addition, health studies are not only done under high exposure scenarios, but to determine if low level environmental exposure have affected human health.
Comment 20. Recommendation 6. This concludes that the site is not a public health concern, and unless data becomes available of "human exposure to hazardous substances at levels of public health concern" which would call for another ATSDR evaluation, there is no recommendation for follow-up activities.
Response: The reviewer drew an incorrect conclusion based on Recommendation 6. Recommendation 6 did not state that the site is not a public health concern, but at this time people are not being exposed to site-related chemicals. The public health assessment clearly stated in the conclusion that the Fultz Landfill posed a public health hazard because of the potential to impact on drinking water supplies.