PUBLIC HEALTH ASSESSMENT
PLATTEKILL, ULSTER COUNTY, NEW YORK
A summary of the environmental contamination data collected during the RI for the Hertel Landfill site is presented in Tables 1-7. The listing of a contaminant does not necessarily mean that its presence is a public health concern. Contaminants selected for further evaluation are identified and evaluated in subsequent sections of the public health assessment to determine whether exposure to them has public health significance. When selected as a contaminant of concern in one medium, that contaminant will be reported in all media where it is detected. These contaminants are selected and discussed based upon the following factors:
- Concentrations of contaminants on and off the site.
- Field data quality, laboratory data quality, and sample design.
- Comparison of on-site and off-site concentrations with background concentrations.
- Comparison of on-site and off-site concentrations with public health assessment comparison values for (1) noncarcinogenic endpoints and (2) carcinogenic endpoints. These values include Environmental Media Evaluation Guides (EMEGs), Cancer Risk Evaluation Guides (CREGs), drinking water standards and other relevant guidelines.
- Community health concerns.
The most recent environmental data for the Hertel Landfill site were collected as part of the RI/FS by the environmental engineering firms TAMS Consultants, Inc., and TRC Environmental Consultants, Inc., under contract with the US EPA. Previous on-site investigations, conducted by the NYS DEC, have also generated environmental data.
Air and Soil Gas
Ambient air analysis has not been performed at the Hertel Landfill site.
A generalized soil gas screening survey was conducted over the landfill to identify areas of organic vapors in the soil which may be indicative of wastes. In addition, a specialized soil gas survey was performed in an area which received paint wastes, to identify specific volatile organic compounds (VOCs).
The soil gas screening survey was performed at 50-foot intervals across the site from October 28 through November 23, 1989. The field instruments could detect organic vapors, but could not identify and quantify the soil vapors. The instruments used were an organic vapor analyzer (OVA),photoionization detector (HNu), oxygen (O2)/combustible gas indicator (LEL) and a hydrogen sulfide (H2S) meter.
The screening survey found high organic vapor concentrations throughout the surveyed area. The OVA and LEL readings were constantly off scale. This may be indicative of high methane levels as these instruments are particularly sensitive to methane. This is supported by the fact that HNu readings were generally negligible, except in several select locations, such as near Disposal Area #7.
The specialized soil gas survey was conducted in the paint waste/municipal fill disposal area (Disposal Area #7). Soil gas was sampled at 15 points located on the basis of the soil gas screening survey results with the meter calibrated for benzene, toluene, trichloroethene and tetrachloroethene. Each of these four compounds were detected at various concentrations at one or more sampling points. The specialized soil gas survey results are presented in Table 1.
No soil data, other than the data generated during the RI, are available. During the RI, a total of 22 surface (0 to 6 inch depth) soil samples were collected (not including duplicate and QA/QC samples) and analyzed for VOCs, semi-volatile organic compounds, pesticides, polychlorinated biphenyl compounds (PCBs) and metals. Most of the samples were collected in the landfilling area, focusing on the eight tentatively identified waste disposal areas. Surface soil sampling locations are shown in Figure 4. One background surface soil sample (SS-22) was taken from an upgradient portion of the site. Table 2 is a summary of the analytical data for surface soil. VOCs were not detected in surface soils. A total of 16 semi-volatile organic compounds were detected and consisted primarily of polycyclic aromatic hydrocarbons (PAHs), including fluorene, naphthalene, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene, chrysene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene and pyrene. In general, the concentrations of these PAHs were close to the detection limits. The concentrations detected for bis(2-ethylhexyl)phthalate, and naphthalene exceed the respective health comparison values for these contaminants in soil. As such, these compounds will be recognized as contaminants of concern for this media. The pesticides, 4,4'-DDE and 4,4'-DDT and benzo(a)pyrene were detected in several samples at concentrations that did not exceed their respective background levels in rural soils. Therefore, these compounds will not be recognized as contaminants of concern for this medium.
Of the inorganic compounds (metals) only three (antimony, selenium and thallium) were not detected at any on-site location. Comparisons to typical background ranges (Table 2) for inorganic compounds indicate exceedances for arsenic, barium, cadmium, chromium, copper, iron, lead, magnesium, manganese, nickel and zinc. Therefore, these chemicals will be considered as contaminants of concern. In addition, concentrations of arsenic, barium, cadmium, chromium, and manganese were above available health soil comparison values. Although the majority of surface soil samples collected during the RI were obtained at locations within the landfill, samples SS-22 and SS-25 were collected at locations upgradient of the fill area and, as such, were regarded as background samples in the RI. VOCs were not detected in sample SS-22. All VOC, semi-volatile and pesticide/PCB data for sample SS-25 were rejected by quality assurance/quality control (QA/QC). Of the metals detected in SS-22 and SS-25, only arsenic was found at a concentration which exceeds its soil comparison value. The arsenic concentration in SS-22 is the highest for this compound in surface soils.
A total of 11 subsurface soil samples were collected from test pits excavated in 7 of the 8 tentatively identified disposal areas. Samples were analyzed for VOCs, semi-volatile organic compounds, pesticides/PCBs and metals. Of the six VOCs detected, xylenes (total) were found at the highest concentration (0.30 mg/kg). The five remaining VOCs were detected at concentrations near or below the respective detection limits and below soil comparison values. A total of 17 semi-volatile organic compounds were detected and consisted primarily of PAHs, including fluoranthene, naphthalene and pyrene, with a range of detection from 0.045 to 1.2 mg/kg. Bis(2-ethylhexyl)phthalate was frequently detected, ranging in concentration from 0.087 to 4.50 mg/kg. This compound was detected at concentrations exceeding the health comparison value in two of 11 samples with an average value of 3.6 mg/kg. Benzo(a)pyrene exceeds the health comparison value, but does not exceed its background level in rural soils. Therefore, this compound will not be recognized as a contaminant of concern for soil.
Of the inorganic compounds analyzed, only selenium was not detected at any of the eleven sampling locations. Comparisons to typical background levels (see Table 2) for inorganic compounds indicate slight exceedances for cadmium, copper, nickel and zinc; however, these compounds do not exceed their health comparison values. Antimony was detected at a concentration above background and slightly exceeded its comparison value; it is included as an additional contaminant of concern for this medium.
Pesticides and PCBs were not detected in any subsurface soil samples.
Surface Water and Sediment
Surface water and sediment were sampled to determine if disposal activities at the site have contaminated sediments and/or surface water through surface runoff and groundwater discharge. Surface water grab samples were collected from 20 locations, including the adjacent wetlands, the creek, a tributary and background and downgradient locations. Sediment samples were collected at each surface water sampling location. Surface water/sediment sampling locations are shown in Figure 6. Table 3 is a summary of the analytical data for compounds detected in surface water, excluding leachate samples. A summary of sediment data (excluding leachate seep sediment samples) is given in Table 4. Typical background ranges and health comparison values for organic compounds and metals in soil are provided in this table.
On-site surface water samples SW-6 through SW-9 were collected from the stream which flows south to north along the toe of the eastern edge of the fill and, as such, are regarded as on-site surface water samples. Pesticides, PCBs and semi-volatile compounds were not detected in these four samples. With the exception of acetone at 8 micrograms per liter (mcg/L), no other VOCs were detected in samples SW-6 through SW-9.
Iron and manganese are the only metals detected in samples SW-6 through SW-9 at concentrations exceeding NYS DEC ambient surface water quality standards/guidelines (Table 8). These compounds will be recognized as contaminants of concern for this medium.
Elevated concentrations of aluminum (up to 4,280 mcg/L in SW-2) were noted in several surface water samples when compared to the US EPA secondary standard for this compound in drinking water. Iron and/or manganese were also detected in the following samples at concentrations exceeding standards/guidelines: SW-2, SW-3, SW-4, SW-10, SW-11, SW-12, SW-13, SW-14, SW-15 and SW-40. In addition to these two metals, cadmium and lead in SW-2 were at levels above the standards/ guidelines. These metals will also be recognized as contaminants of concern for this media. The organic compound, 4-methylphenol, was detected in SW-2 at a concentration which exceeds its respective standard of 1 mcg/L. This standard is based on the potential for 4-methylphenol to cause a taste/odor effect if water is chlorinated for drinking. Since on-site surface water is not a source of drinking water, 4-methylphenol will not be recognized as a contaminant of concern.
Sediment samples SED-5 through SED-9, SED-37 and SED-38 were collected from the stream which flows from the southern wetland area north, along the eastern boundary of the site. SED-4 was collected from the wetlands in the southern portion of the site. With the exception of SED-7, these eight samples showed no detectable concentrations of semi-volatiles, pesticides or PCBs. Several VOCs, including methylene chloride, toluene, and 2-butanone, were detected in one or more of these eight samples. However, only methylene chloride was detected (SED-4 and SED-41) at a concentration above the health comparison value for soil/sediment (Table 4). This compound will also be recognized as a contaminant of concern. Out of all the metals detected in these eight samples, only barium, cadmium and manganese were detected at concentrations that exceed comparison values (for soil). These metals will be recognized as contaminants of concern.
Samples SED-33 and SED-34 were collected at depths of 6 to 12 inches and 12 to 18 inches, respectively, at sample location SED-8. VOCs, PCBs, semi-volatile compounds and pesticides were not detected. With the exception of nickel, metals in these two samples were at concentrations below typical background ranges and public health assessment guidance values. The nickel concentration in SED-34 exceeds the typical background range. Nickel will therefore be recognized as a contaminant of concern.
Other metals which were detected in sediment samples at concentrations exceeding typical background ranges include barium, cadmium, copper, iron and manganese. The highest concentration of copper was detected in SED-31 which was collected at a depth of between 6-12 inches. The highest concentration of iron was detected in SED-17. Therefore, copper and iron will also be recognized as additional contaminants of concern.
Groundwater (monitoring wells)
A total of 19 groundwater monitoring wells were installed at the Hertel Landfill site to investigate the hydrogeology of the site and to collect groundwater samples. The wells were installed at 12 locations, including 7 well clusters. Each well cluster had one well screened in the shallow, unconsolidated overburden deposits and one well completed in the shallow, sedimentary bedrock (if present at depths less than 50 feet) or in the deep, unconsolidated overburden deposits (at about 45 feet below grade) when bedrock was not encountered. The remaining five wells were installed in the shallow, unconsolidated overburden interval. The locations of the monitoring wells are shown in Figure 7. Two rounds of groundwater sampling were conducted. The first sampling round was conducted in June 1990 and round two was conducted in August 1990. Both rounds included samples obtained from the 19 wells installed during the RI and, in addition, from the 5 existing monitoring wells. Samples were analyzed for VOCs, semi-volatile compounds, pesticides/PCBs and metals (filtered and unfiltered). A summary of groundwater data are given in Tables 5 and 6.
Pesticides and PCBs were not detected in on-site groundwater in either sampling round. Samples obtained from the shallow wells contained several VOCs, primarily petroleum hydrocarbons, during both sampling rounds. In sampling round one, the VOCs which exceeded NYS DOH drinking water standards (Table 8) include benzene, toluene, chlorobenzene, ethylbenzene, and xylenes. Semi-volatile compounds detected in round one and which also exceed drinking water standards include benzoic acid, phenol, bis(2-ethylhexyl)phthalate and di-n-octylphthalate. These VOCs and semi-volatile compounds will be recognized as contaminants of concern and will be discussed further in subsequent sections of this public health assessment.
In sampling round one, metals (unfiltered) which were detected at concentrations exceeding drinking water standards include barium, chromium, cobalt, iron, lead, and manganese. Also, sodium exceeds the level for individuals on severely restricted sodium diets and aluminum exceeds the secondary standard proposed by US EPA (Table 8). All these inorganic compounds will be recognized as contaminants of concern and will be discussed further in subsequent sections of this public health assessment.
In the second sampling round, the VOCs which were detected at concentrations exceeding the NYS DOH drinking water standards include benzene, toluene, chlorobenzene, ethylbenzene, and xylenes. These same VOCs were detected at similar concentrations during sampling round one. Semi-volatile compounds detected in round two which exceed drinking water standards include 4-methylphenol, bis(2-ethylhexyl)phthalate, 2,4-dimethylphenol, and diethylphthalate. These semi-volatile compounds will also be considered as contaminants of concern for later discussion in this public health assessment. These compounds were also detected in the first sampling round, but at lower concentrations.
In sampling round two, metals (unfiltered) which were detected at concentrations exceeding drinking water standards include chromium, cobalt, iron, lead, manganese, and silver. Also, sodium exceeds the level for individuals on severely restricted sodium diets and aluminum exceeds the secondary standard proposed by US EPA (Table 8). All these metals will be considered as contaminants of concern and will be discussed further in subsequent sections of this public health assessment.
Air and Soil Gas
Off-site ambient air and soil gas have not been analyzed.
Surficial soil samples were not collected at off-site locations.
Subsurface soil samples were not collected at off-site locations.
Surface Water and Sediment
A total of five downgradient surface water samples (SW-16 through SW-20) were collected from the stream which drains the site to the east. No VOCs, pesticides/PCBs or semi-volatile compounds were detected in these samples. However, iron and/or manganese were present in SW-16, 17 and 18 at concentrations exceeding NYS DEC ambient surface water quality standards/guidelines. Of the metals detected in sediment samples SED-16 through SED-20, manganese is the only compound detected at concentrations (in SED-17 and SED-18) above the public health assessment comparison values. The contaminant levels generally decrease with increasing distance from the site.
Groundwater (monitoring wells)
No monitoring wells have been installed at off-site locations.
Groundwater (private supply wells)
In June 1990, tap water samples were collected from 11 residences, identified as PW-1 through PW-11, located between 500 and 1,700 feet from the site. Sample PW-12 is a resample of PW-8. Samples were analyzed for VOCs, semi-volatile compounds, pesticides/PCBs and metals. Analytical results reveal that VOCs, semi-volatile compounds and pesticides/PCBs were not present at the detection limits used. An elevated level (30.7 mcg/L) of lead was detected in sample PW-11, however confirmatory sampling was not performed to confirm this finding. Sodium was detected in PW-11 and PW-12 at concentrations slightly above the NYS DOH guidance value for public drinking water supplies and may be naturally occurring. Slightly elevated levels of iron were detected in the samples PW-07 and PW-11 and probably is naturally occurring. Results of analysis for lead and zinc were not provided for all samples due to QA/QC rejection. A summary of compounds detected in private wells is provided in Table 7.
On April 8, 1991, NYS DOH collected tap water samples from 9 of the same 11 residences. Preliminary results indicated a trace (less than 1 mcg/L) of 1,1,1-trichloroethane in one sample (PW-03). This same compound was also detected in this well at 2 mcg/L when sampled by NYS DOH in February 1987. VOCs and semi-volatile compounds were not detected in the remaining eight samples. In addition, another sample indicated the presence of sodium at 28,900 mcg/L. Iron was also slightly elevated in two samples at 633 and 584 mcg/L. The residence PW-11 was resampled and lead was not present (above the detection limit of 10 mcg/L). However, in one home, the lead concentration was elevated (56 mcg/L) in the collected tap water sample. This sample may have been obtained before completely flushing the household plumbing lines. On June 25, 1991, NYS DOH collected samples from the two residences previously sampled (PW-03 and PW-05), to confirm the presence of 1,1,1-trichloroethane and lead. These sampling results indicate that 1,1,1-trichloroethane is not present (above the detection limit). Furthermore, this VOC has not been detected in on-site groundwater. The testing for lead show that the concentration detected is below the respective detection limit.
On September 16, 1991 the Ulster County Department of Health collected tap water samples from eight homes located near the landfill. Individual wells supply tap water to these homes on Bedell Avenue and Tucker Corners Road. NYS DOH records do not indicate that these residences have been previously tested. Sampling results indicate that no VOCs were detected above the detection limits. Samples were not analyzed for semi-volatile compounds nor pesticides/PCBs. The testing for metals show that the results are below comparison values.
Groundwater (public supply wells)
Public drinking water supply wells are not present in the area surrounding the site.
In preparing this public health assessment, NYS DOH relied on the information provided in the referenced documents and assumed that adequate quality control measures were followed with regard to chain of custody, laboratory procedures and data reporting. The analyses and conclusions of this public health assessment are valid only if the referenced information is complete.
There are no known physical or other hazards present at the site.
To identify possible facilities that could contribute to the groundwater or soil contamination near
the Hertel site and/or create health threats unrelated to the site, NYS DOH searched the 1989 TRI.
TRI is developed by the US EPA from the chemical release (air, water and soil) information
provided by certain industries. TRI did not contain information on toxic chemical releases in the
Town of Plattekill.
To determine whether nearby residents and persons on-site are exposed to contaminants migrating from the site, an evaluation was made of the environmental and human components that lead to human exposure. This pathway analysis consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and an exposed population.
An exposure pathway is categorized as a completed or potential exposure pathway if the exposure pathway cannot be eliminated. A completed exposure pathway occurs when the five elements of an exposure pathway link the contaminated source to a receptor population. Should a completed exposure pathway exist in the past, present, or future, the population is considered exposure. A potential exposure pathway exists when one or more of the five elements are missing, or if modeling is performed to replace real sampling data. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present. The discussion that follows incorporates only those pathways that are important and relevant to the site.
No completed exposure pathways have been identified for this site.
Air and Soil Gas Exposure Pathway
Existing ambient air data are not sufficient to evaluate this environmental pathway. Field instruments indicated high levels of VOCs, primarily methane, in the soil gas phase in the landfill. Compounds identified as contributing to the elevated organic vapor concentration detected near disposal area #7 include benzene, toluene, trichloroethene and tetrachloroethene. With the exception of disposal area #7, the presence and concentration of soil gas constituents were not verified by compound-specific sampling and analysis.
Private homes are located as close as 500 feet from the landfill. The release of contaminants to ambient air will likely be diluted to levels below detection limits at unconfined on-site and off-site areas. However, the possibility exists for the migration and intrusion of soil gas into basements of nearby homes. Persons living in these homes may potentially be exposed to elevated levels of soil gas contaminants through inhalation. The lack of ambient air quality data (on-site and off-site) creates uncertainty as to the potential health threat which may confront trespassers and nearby residents.
Soil Exposure Pathways
Contaminants related to the past disposal of wastes at the site are present and are migrating through the soils and into the groundwater beneath the site. Past, current, and future exposure pathways are possible from contamination of surface soils at the site. Surface soil samples from on-site locations are contaminated with several semi-volatile compounds and metals at concentrations which exceed public health assessment comparison values. The extent of contamination detected in on-site surface soil could not be compared to off-site surface soil conditions as the RI study did not include sampling of off-site background surface samples.
Subsurface soil samples obtained from 11 on-site test pits are contaminated with VOCs, semi-volatile compounds and metals. Many of the semi-volatile compounds and metals detected are persistent in the environment. PAHs generally have a very low solubility and readily absorb to organic carbon in soils, which reduces their mobility. Numerous inorganic compounds also have an affinity for soils. However, under certain conditions, some metals can be mobile which may allow for migration to other media. Only the semi-volatile compound, bis(2-hexylethyl)phthalate, and the metal, antimony, are present in subsurface soils at contaminant levels of concern.
Contaminated media at the Hertel site (including soils) have the potential for off-site migration. At this time the transport of contaminated dust (from on-site) to off-site residents is unlikely due to several factors: abundant vegetation covers most of the site; and the surface of the landfill is generally flat which reduces the extent of erosion, thereby limiting off-site transport via wind and/or overland runoff (via precipitation). However, contaminants can migrate from the surface soil through leaching to groundwater or volatilization to ambient air. Since the surface soils at the site are permeable, precipitation can readily percolate through the underlying soils. Contaminants can migrate to groundwater due to the lack of an impervious liner or impermeable material beneath the landfilled areas. Therefore, under the current conditions, the surface and subsurface soils serve as a continuing source of contamination to the groundwater table.
The potential for on-site exposure to contaminated surface soils can occur since site access is possible. Trespassers may be exposed to soil contaminants via ingestion, inhalation of dust and dermal absorption via direct contact with soil. Exposure to contaminated subsurface soils will not occur unless subsequent on-site excavation of soils is conducted.
Based on past and current site conditions, the soil exposure pathway may be categorized as a potential human exposure pathway. The possibility of human exposure to site-related soil contaminants now and in the past is a concern which will be addressed further in this public health assessment.
Surface Water/Sediment Exposure Pathway
As previously mentioned in the background section of this public health assessment, the wetlands area which contains the landfill serves as the watershed for a stream which drains off-site to the east.
On-site and off-site downgradient surface water and sediment are contaminated with several inorganic compounds (cadmium, iron, lead, manganese) at levels of concern. The landfill may be acting as a source of these contaminants from direct discharge of landfill runoff or seepage or groundwater discharge to the surface water. Surface water sediments are also contaminated with several organic compounds at levels of concern. The on-site stream is not likely to support fish since it is narrow, shallow and intermittent. No fish were collected nor were any observed during the ecological investigation of the site. Therefore, the possibility of exposure via consumption of fish will not be considered as a route of exposure.
Nearby residents could be exposed to these surface waters/sediment through dermal contact and ingestion during recreational use of downstream waters and wetlands and other surface waters on the landfill parcel.
Groundwater Exposure Pathway
Groundwater is contaminated in two geologic units at the site. The shallow, water-bearing unit consists of unconsolidated overburden deposits of glacial till. The glacial till is composed of an unsorted mixture of boulders, gravel, sand, silt and clay. The groundwater flow in this aquifer is to the east, where it discharges into the adjacent wetlands. Groundwater contamination in this aquifer has been detected on site. Contaminants which exceed NYS DOH drinking water standards include benzene, toluene, chlorobenzene, ethylbenzene, xylenes, benzoic acid, 4-methylphenol and diethylphthalate. Inorganic compounds which were in shallow monitoring wells at concentrations exceeding NYS drinking water standards include barium, chromium, cobalt, iron, lead, manganese, and sodium.
The deeper, water-bearing unit consists of sedimentary bedrock, composed principally of sandstone. The measured depth to bedrock at the site varies from 28 to greater than 50 feet below grade. Groundwater flow in this aquifer occurs along fractures and joints. The groundwater gradients in this aquifer are to the north-northeast. Groundwater contamination in this deeper aquifer has not been detected on-site. Off-site groundwater lead contamination has been indicated in several private drinking water supply wells. However, the elevated concentrations of lead detected in well water at two nearby homes appear to be attributed to the household plumbing.
Contaminants in on-site monitoring wells (placed in the bedrock) exceeding drinking water standards or guidance values include the semi-volatile compounds, phenol and di-n-octylphthalate and the metals including barium, chromium, cobalt, iron, lead, manganese, silver and sodium. Contaminants which have been identified at concentrations above these standards or guidelines in the off-site private drinking water supply wells include lead, sodium and iron. These wells are located to the north-northeast of the landfill. Well depths for all the nearby private wells are not known; however, most, if not all, of these wells are probably bedrock wells. Although available data do not indicate the presence of groundwater contamination in the bedrock aquifer at the site, the possibility exists that site contaminants could reach the deeper aquifer and migrate off-site, subsequently contaminating local private supply wells.
Lead in drinking water is frequently associated with household plumbing. Confirmation sampling of the affected wells has been conducted, and results indicate the source is from household plumbing and not from the site. As discussed in the Background section of this public health assessment, residents have been informed of measures to follow which will reduce exposure to lead in drinking water.
Guidelines have been established by the NYS DOH for sodium in drinking water. The sodium in two homeowner wells exceeds the lower guideline value of 20,000 mcg/L.
The potential exists for the migration of additional contaminants in on-site groundwater monitoring
wells to nearby private drinking water supply wells.
A toxicological evaluation of the potential human exposure pathways of primary concern related to the Hertel Landfill site is presented below:
- Potential ingestion, dermal and inhalation exposure to contaminants in private wells as a result
of contaminant plume migration.
As indicated in Tables 5 and 6, on-site groundwater is contaminated with volatile and semi-volatile organic compounds and metals at concentrations that exceed New York State groundwater and/or drinking water standards or guidelines (Table 8). There is a potential for oral (ingestion), dermal and inhalation exposure to contaminants in residential well water from contaminant groundwater. This pathway is incomplete since no off-site migration has been identified and therefore no known exposure is occurring.
Volatile Organic Compound Contaminants
Benzene is a known human carcinogen (ATSDR, 1991b). Chlorobenzene causes cancer in laboratory animals exposed to high levels over their lifetime (ATSDR, 1989a). Chemicals that cause cancer in laboratory animals may also increase the risk of cancer in humans who are exposed to lower levels over long periods. Chronic exposure to benzene and chlorobenzene found in on-site groundwater would pose a low increased cancer risk over a lifetime of exposure. Toxicological data are inadequate to assess the carcinogenic potential of ethylbenzene (ATSDR, 1989b), toluene (ATSDR, 1989d) and xylenes (ATSDR, 1990e) in humans.
Chlorobenzene, ethylbenzene, toluene and xylene produce a variety of noncarcinogenic toxicities (primarily liver, kidney and nervous system effects) at exposures several orders of magnitude greater than potential exposures from on-site groundwater. Exposure to benzene has been associated with damage to blood cell-forming tissues and the immune system. Chemicals that cause effects in humans and/or animals after high levels of exposure may also pose a risk to humans who are exposed to lower levels over long periods of time. Although the risks of noncarcinogenic effects from these exposures aren't completely understood, the existing data suggest that they would be minimal.
Semi-volatile Organic Compound Contaminants
Bis(2-ethylhexyl)phthalate, found in on-site groundwater causes cancer in laboratory animals exposed to high levels over their lifetime (ATSDR, 1991e). Based on the result of animal studies and the limited sampling of on-site groundwater, we estimate that exposure to bis(2-ethylhexyl)phthalate at levels found in on-site groundwater would pose a low increased cancer risk over a lifetime of exposure. Toxicological data are inadequate to assess the carcinogenic potential of 2,4-dimethylphenol (US EPA, 1990), 4-methylphenol, benzoic acid (US EPA, 1990), diethylphthalate (US EPA, 1990), di-n-octylphthalate (US EPA, 1990), and phenol (ATSDR, 1989c) in humans.
These semi-volatile organic compounds also produce a variety of noncarcinogenic toxicities (primarily nervous system and/or blood system effects by the phenolic contaminants; damage to the male reproductive system by the phthalates and malaise by benzoic acid) at exposures several orders of magnitude greater than exposure from on-site groundwater. Although the risks of noncarcinogenic effects from these potential exposures aren't completely understood, the existing data suggest that the risks would be minimal.
Chronic exposure to elevated lead levels is predominantly associated with neurological and hematological effects (ATSDR, 1991f). The developing fetus and young children are particularly sensitive to lead-induced neurological effects, with symptoms ranging from delayed mental development and behavioral effects at low blood lead levels to frank ataxia, stupor, coma and convulsions at high blood levels. At high exposure levels, lead can cause kidney damage, gastrointestinal distress, and reproductive effects including abortion and damage to the male reproductive system.
The primary toxicities associated with ingestion of large amounts of chromium have been kidney damage, birth defects and adverse effects on the reproductive system (ATSDR, 1991d). Exposure to high manganese concentrations primarily causes nervous system effects (ATSDR, 1990a ). Effects observed following ingestion of cobalt include cardiomyopathy (cardiovascular effects), gastrointestinal effects, visual disturbances and thyroid effects (ATSDR, 1990c). Exposure to high silver concentrations primarily causes discoloration of skin, hair and fingernails (ATSDR, 1990d). Ingestion of high concentrations of barium may cause cardiovascular effects, including increased blood pressure, damage to heart muscle and changes in heart rhythm and also has been associated with kidney, neurological and gastrointestinal effects (ATSDR, 1991a). The most sensitive effect from chronic elevated exposure to cadmium is kidney damage (ATSDR, 1991c). The levels of aluminum, iron and manganese in on-site groundwater are over 1,200, 1,600 and 2,000 times the levels, respectively, at which the aesthetic quality of drinking water begins to be affected (WHO, 1984 ). Water containing more than 20,000 mcg/L of sodium should not be used for drinking by people on severely restricted diets and water containing more than 270,000 mcg/L of sodium should not be used for drinking by people on moderately restricted diets. Exposure to drinking water contaminated with these metals, in particular lead, cobalt and manganese, at concentrations found in on-site groundwater would pose a high increased risk of adverse health effects.
- Potential ingestion, dermal and inhalation exposure of persons engaged in recreational
activities in on-site and adjacent streams and wetlands.
As indicated in Table 3, on-site surface water and sediment is contaminated with volatile and semi-volatile organic compounds and metals, some of which exceed New York State surface water standards or guidelines. Whereas none of the organic compounds pose an immediate health concern, lead and manganese are at levels which suggest that they could present a public health threat, especially to children who could play in these areas on a frequent basis.
- Potential inhalation, dermal and ingestion exposure of persons coming in contact with on-site soil/sediment.
The potential for on-site exposure to contaminated surface soils and sediments can occur since site access is possible. This accessibility could pose a high health risk, especially to children who could come in contact with on-site surface soil that is contaminated with cadmium, chromium, and lead and on-site sediment that is contaminated with manganese.
- Potential inhalation, dermal and ingestion exposure of persons engaged in on-site clean-up
activities and nearby residents to contaminated soil.
Persons engaged in on-site clean-up (remediation) activities have a potential for exposure by multiple routes to organic chemicals and metal contaminants (Table 2) and could be at increased risk of adverse health effects. However, use of proper procedures and protective equipment should minimize the chance of any significant health effects. In addition, use of appropriate dust suppression methods and monitoring of ambient air for organic vapors during clean-up would minimize any low level increased risk to nearby residents.
- Potential inhalation exposure to volatile organic compounds in indoor air due to migration of
soil vapors into nearby structures.
Adequate data are not available to assess the toxicological implications of this potential exposure pathway. However, there is some data to suggest (Table 1) that benzene, tetrachloroethene (ATSDR, 1991g) and trichloroethene (ATSDR, 1991h) could pose a public health threat. These volatile organic compounds, which were detected in on-site soil gas, are known or suspected human carcinogens and all are well absorbed by all routes of exposure. In addition, limited data on soil vapor generation indicate that the on-site methane levels could pose a public health threat. One public health threat from methane generation is the potential for explosive levels of methane to accumulate in closed buildings (houses) and hence be a safety problem. Another public health threat is that toxic gases, such as vinyl chloride or other volatile chlorinated hydrocarbons, tend to be carried with methane. These chemicals can pose risk of adverse health effects if nearby residents are exposed. These risks are in addition to the effects that can be caused by large amounts of methane replacing oxygen in the air.
NYS DOH has not evaluated health outcome data for the Hertel Landfill site. The available data do not indicate that humans have been exposed to levels of contamination that would be expected to cause adverse health effects. Therefore, health outcome databases will not be searched at this time. An elevated level of lead detected in the well water at two nearby homes is not believed to be related to the site. To date, no other primary contaminants have been detected in local drinking water supply wells above drinking water standards. A Health Survey Questionnaire administered to community residents who live within two miles of the site include information about various adverse health effects experienced by participants in the survey. Although various health problems are indicated in the survey, it is not possible to develop any reliable indication as to disease trends solely based on this information. A search of pertinent databases may be considered in the future if additional community health concerns are received which warrant the need.
We have addressed each of the community concerns about health as follows:
- Local residents are concerned about present and future contamination of private
drinking water supply wells.
To date, testing of local homeowner wells conducted by TAMS Consultants, Inc., NYS DOH, and UC DOH, has not indicated the presence of contamination attributed to the site. Furthermore, sampling data indicate that the individual water supplies are of satisfactory quality (State and Federal primary standards) for the analytical tests that were performed. Residents' concern about future contamination of drinking water supply wells, due to the migration of contaminants from the site, has been addressed in the selected remedial remedy for the site. The selected remedy is intended to minimize and reduce the downgradient migration of contaminants in groundwater. Specifically, the planned extraction and treatment of on-site groundwater will prevent the off-site groundwater from being contaminated above drinking water standards, thereby ensuring that the community continues to have a potable supply of drinking water. The effectiveness of this treatment remedy will be monitored and evaluated using a groundwater monitoring program.
- Residents are concerned about the flow of leachate away from the site, into the Black
Creek, and past the Highland High School three miles downstream.
The test results for the samples collected in the adjacent wetlands indicate that contaminants have migrated to the wetlands and that the continued migration of contaminants to the wetlands may have potential adverse effects. Recreational use of the wetlands and surface waters adjacent to and on the landfill parcel should be minimized due to the elevated concentrations of several metals which could pose a significant risk of adverse health effects to individuals who incidently ingest these contaminated surface waters. Surface water contamination is anticipated to be greatly diluted downstream of the site so that recreational use of these waters (near the school) would not be expected to pose any increased health risks.
- Concerns have been raised regarding the relationship between the Hertel Landfill site
and the incidence and location of cancer-related deaths, miscarriages and birth defects
in the population that live downgradient of the site.
The source of these concerns has been traced to a health survey questionnaire administered in 1984 (by a local resident) to community residents who live near the Hertel Landfill site. A review of the information and responses contained in the questionnaires has been completed by Dr. Fred L. Stallings in ATSDR's Division of Health Studies. The material consisted of 87 questionnaires from which information on 89 recognizable respondents was provided. Of the 89 respondents, 37 (42%) reported at least one symptom or disease. The survey contained 75 responses that did not report any symptoms. The information was examined for patterns of adverse health as indicated by symptom and disease histories that were reported on each completed questionnaire. The symptom complaints most commonly described were rash and itching (12), kidney disease (2), lung disease (2), heart disease (6), and hair loss (2).
The design of the survey questionnaire and other factors severely limited ATSDR's ability to develop any reliable conclusion about disease trends. According to ATSDR, the design and instructions were not explicit enough to guide the respondent toward adequate completion of the forms. In addition, the questionnaires were not completed consistently by respondents, the number of respondents per household was not apparent, and the number of households represented in the survey could not be determined. Because of this limitation in knowing the number of participants, symptom rates could not be calculated for this survey. Also, due to the lack of information in the surveys concerning the potential for exposure, no association with exposure to hazardous materials could be evaluated.
- Concerns have been raised about the lack of a fence around the site and that new people
in the town may enter the landfill and be exposed to serious health hazards.
As a first step towards implementing site security, signs have been posted at various locations, noting that the site is a Superfund site. The proposed remedy includes fencing the perimeter of the landfill to be capped. Currently, vehicular access to the landfill site is limited due to the presence of a locked gate and fence placed across the entrance road leading to the disposal areas.
- Concerns have been raised including the potential fire and explosive hazard of chemicals
and drums landfilled at the site and that this risk may increase if the contents of the
landfill are disturbed during remedial activities. Furthermore, the local Fire
Department has raised concerns as to what hazards firefighters may face if they have to
fight a fire on he landfill.
Extensive sampling and trenching of the landfill was performed during the RI. The investigation did not reveal any evidence of buried drums or "hot spots" at the site. According to US EPA, available data does not indicate that firefighters would be placed at increased risk by going onto the site (to fight a fire), above and beyond those that they might be subjected to at another municipal landfill. Adequate health and safety plans and practices will help to address potential fire and explosion problems during remediation activities.