PUBLIC HEALTH ASSESSMENT
ROWE INDUSTRIES GROUNDWATER CONTAMINATION
SAG HARBOR, SUFFOLK COUNTY, NEW YORK
The environmental contamination data for the Rowe Industries site are summarized in Appendix B, Tables 1-9. 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 for further evaluation 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 environmental 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 contaminant concentrations in environmental media with public health assessment comparison values for (1) noncarcinogenic endpoints and (2) carcinogenic endpoints. Contaminant concentrations above a comparison value do not necessarily represent a health threat but are evaluated further to determine if exposure is of public health significance. Comparison 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 Rowe Industries site were collected as part of the RI by the consulting firm of Leggette, Brashears & Graham, Inc. These data are used to describe the nature and extent of contamination at the site on a media specific basis. The on-site media sampled during the RI were soil gas, ambient air, subsurface and surface soil, groundwater, and pond and drywell sediments.
Soil gas was surveyed beneath and immediately outside the eastern border of the building currently occupied by SHI. The survey encompassed the property, but emphasized the area east of the building towards the pond. The survey did not extend beyond the property boundary. Some of the stations immediately west of the pond, where groundwater was too high, were not surveyed. The two compounds detected at the highest levels were tetrachloroethene and 1,1,1-trichloroethane (see Table 1). The highest concentrations of tetrachloroethane were found east of the building in the paved parking area, up to 24,039 parts per billion (ppb). The values decreased to non-detectable (ND) levels further east, towards the on-site pond. Trichloroethene was generally detected at the same stations as tetrachloroethene, with trichloroethene concentrations generally lower than tetrachloroethene in the paved areas around the SHI building and higher in the wooded area east of the parking lot. Trichloroethene concentrations ranged between ND and 2,922 ppb. 1,1,1-Trichloroethane levels ranged from ND to 10,367 ppb, which was found in the wooded areas between the parking lot and the on-site pond. The soil vapors were highest near the former drum storage area and around Drywell A (see Figure 3).
Two downwind stations and one upwind station were used for air monitoring outside the building. Another station was set up on the ground floor inside the building. Samples were analyzed for tetrachloroethene, trichloroethene, and 1,1,1-trichloroethane by gas chromatograph; nothing was detected at any of the sampling stations.
Eight soil borings were drilled at the Rowe Industries site outside the building; two were drilled inside the building. Six more borings were drilled outside near the former drum storage area. The boring that contained the highest level of contamination is boring number 10, in the area of the former drum storage area (see Table 2). Boring 10 contained 67 milligrams per kilogram (mg/kg) of tetrachloroethene, 66 mg/kg of xylenes, and 1,300 mg/kg of acetone. Those levels were found at a depth of 4 to 12 feet.
Surface soil samples (0-6") were collected in thirteen locations on-site (see Figure 2). 1,2-Dichloroethane was detected in samples S-3 and S-4 at estimated values of 0.005 mg/kg and 0.002 mg/kg respectively (see Table 3). Seven of the thirteen samples contained toluene up to an estimated level of 0.005 mg/kg. Samples S-5 and S-9 had elevated levels of lead, 522 mg/kg and 149 mg/kg respectively. Samples S-5 and S-9 had elevated levels of chromium, 438 mg/kg and 318 mg/kg.
Groundwater monitoring wells were installed on-site in 1983 by the SC DHS and for the RI in 1989 and 1990. The monitoring wells were installed on-site in upgradient and downgradient locations. Upgradient refers to the direction from which the groundwater is flowing towards the site; downgradient refers to the direction in which the groundwater flows away from the site. The results are summarized in Table 4 and include the RI and SC DHS samples. Contamination has increased over time at some locations. The highest level of tetrachloroethene was in on-site well N-28, 12,000 micrograms per liter (mcg/L) in a 1990 sample. The highest level in this well in 1984 was 2,100 mcg/L. Monitoring well N-27 had 5,900 mcg/L of tetrachloroethene in 1984 and had 6,000 mcg/L in 1991.
Sediment was sampled from 0-6" at three locations in the on-site pond. Ethylbenzene was the only compound detected, in one location, sample number 2 (see Table 5). No elevated inorganic compounds were found.
Six drywells are located on the Rowe Industries property. Three are currently in use by SHI. Sediment from four of the six drywells were taken by hand auguring into the top 6 inches of the sediment. The results of the samples are summarized in Table 6. Tetrachloroethene was detected as high as 9.1 mg/kg, 1,1,1-trichloroethane was detected as high as 5.3, trichloroethene was detected as high as 27.0 mg/kg, and 1,2-dichloroethane was detected as high as 28.0 mg/kg. Some of the drywells continue to be a source of groundwater contamination.
Groundwater monitoring wells were installed off-site in 1983 by the SC DHS and in 1989 and 1990 for the RI. Private residential water supply wells have also been used in this investigation as off-site monitoring wells. All of the private residential wells in the plume area have been replaced by a public water supply. Other homes which could be monitored are upgradient or outside the plume boundary. These results are summarized in Table 7. Two of the private wells sampled (House No. 6 and House No. 1 - see Figure 4) had the highest off-site concentrations of site related contaminants. Levels of tetrachloroethene up to 1,900 mcg/L were found in 1984 samples by the SC DHS in a downgradient private water supply well. That same well had 510 mcg/L of tetrachloroethene in 1989. Most other off-site wells had levels that were generally the same as in 1984, particularly for tetrachloroethene. The concentrations of trichloroethene and 1,1,1-trichloroethane have decreased throughout the off-site area.
The monitoring wells installed off-site for the RI are clusters of three wells, which access different levels of contamination: one shallow, one intermediate and one deep. The data for these wells indicate the plume leaving the Rowe Industries site has the highest concentrations in the intermediate zone, about 25 feet below the water table. Off-site, the highest concentrations stay in the upper 50-60 feet of the aquifer. The deep well installed near Sag Harbor Cove, on the opposite side of the cove from the site, is screened so that it should intercept any contaminated water that could flow beneath the cove. Since no contaminants were found in this well, the plume probably discharges into the cove and into the ocean.
The upgradient monitoring and homeowner wells did not contain site related contamination. The upgradient groundwater is not contributing contaminants to the plume.
Sixteen surface water samples were collected in five locations in Ligonee Brook and Sag Harbor Cove (see Figure 6). Low levels, up to 30 mcg/L of 12 organic compounds were detected, all of which were identified as constituents of the plume from Rowe Industries (see Table 8).
Nineteen sediment samples were collected in five locations in Ligonee Brook and Sag Harbor Cove directly under the location where the surface water samples were taken (see Figure 5). Levels of organic chemicals up to 0.34 mg/kg were detected (see Table 9).
Surface and Subsurface Soil
Off-site surface or subsurface soil was not sampled during the site investigations.
Off-site soil gas was not sampled during the site investigations.
The RI performed at this site was done in accordance with US EPA Quality Assurance and Quality Control (QA/QC) guidelines. The previous investigation performed by SC DHS did not necessarily meet these guidelines; however, these data were used in this public health assessment. US EPA data quality summaries indicated minor QA/QC problems in the RI data; however, these problems were not sufficient to alter the interpretations of the data.
There are no known physical or other hazards present at the site.
To identify possible facilities that could contribute to
environmental contamination at or near the Rowe Industries site
and/or could create health threats unrelated to the site, the NYS
DOH searched the 1990 Toxic Chemical Release Inventory (TRI). TRI
is developed by the US EPA from the chemical release (air, water)
information provided by certain industries. The search of the TRI
facilities list was to identify emissions from those industries
near the Rowe Industries site (within 2.5 miles) to which citizens
(living near the site) may also be exposed. No TRI facilities were
identified using a screening method developed by the NYS DOH as
reporting 1990 air or water releases.
An evaluation was made of the environmental and human components that lead to human exposure to determine whether nearby residents and persons on-site are exposed to contaminants migrating from the site. The pathways 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 exposed. A potential exposure pathway exists when one or more of the five elements is 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.
Groundwater was discovered to be contaminated in 1983. At that time, private residences in the plume area used private water supply wells for household water. Wells that drew water from the contaminated groundwater were used by residents in this area prior to 1985. Residents that used these wells were exposed to contaminants through ingestion of water, dermal contact with the water, and inhalation of vapors during showering, cooking, etc. Exposures ceased when residences were connected to a public water supply in 1985.
Groundwater in the area of the plume remains contaminated at levels above drinking water standards. All homes in the area of the plume have been connected to the public water supply. Although the plume appears to be well-defined, changes in groundwater movement and/or quality may cause future contamination of other private water supply wells. Residents that use these wells could be exposed to contaminants through ingestion of water, dermal contact with water, or inhalation of water vapors during showering, cooking, etc.
Although levels or organic contaminants found in on-site surface soil are generally low, there are two areas where inorganic contaminants are elevated. Because these elevated levels exist at the surface, there is potential for trespassers to come into direct contact with these soils, or, in the case of children, for incidental ingestion of these soils to occur. If this site is developed for residential use, there is a potential for direct contact or incidental ingestion of these soils by residents.
Volatile organic compounds were also found in subsurface soils on-site. Although the contaminated subsurface soil is not available for direct contact with people under existing conditions, if site use changes and remedial work is not done, exposures could occur. For example, if the existing industry on-site were to go out of business and the existing structure torn down and replaced with residential buildings, direct contact with contaminated soil by construction workers is possible. During remediation of on-site subsurface soils there is a potential for direct contact with these soils by persons engaged in remedial activities.
During remedial activities, subsurface soils that are contaminated with volatile organic contaminants will be disturbed when excavated. On-site remedial workers and nearby residents could inhale contaminated soil particles or vapors if proper dust and vapor control procedures are not instituted during remedial work.
Surface Water and Sediments
Surface water and sediments in off-site areas contain low levels of volatile organic contaminants. Persons who are engaged in recreational activities in these off-site areas could come into direct contact with these contaminants during wading and/or swimming.
The soil gas survey conducted on-site found high levels of soil
vapors near contaminated areas. No off-site soil gas survey has
been conducted near adjacent residences. There is a potential for
these vapors to infiltrate basement walls of residences, and to
accumulate, particularly in basement areas. Residents could inhale
these vapors when in these areas of their homes.
An analysis of the toxicological implications of the human exposure pathways of concern is presented below. To evaluate the potential health risks from contaminants of concern associated with the Rowe Industries site, the NYS DOH has assessed the risks for cancer and noncancer health effects. The health effects are related to contaminant concentration, exposure pathway, exposure frequency and duration. For additional information on how the NYS DOH determined and qualified health risks applicable to this health assessment, refer to Appendix D.
- Past ingestion, dermal absorption and inhalation exposure to
contaminants in private drinking well water supplies.
For an undetermined period of time (less than 24 years) a number of residential wells near the Rowe Industries Site were contaminated with volatile organic chemicals (Table 7). These wells were sampled between 1984 and 1989. Contaminant levels in drinking water prior to these times are not known. Between August 1984 and March 1985 all affected residences were connected to public water supplies.
Levels of tetrachloroethene, 1,1,1-trichloroethane, trichloro-ethene, 1,1-dichloroethane, 1,1-dichloroethene and 1,2-dichloroethene in these wells exceed New York State and/or US EPA drinking water standards for each of these contaminants (see Table 7). Chronic exposure to these chemicals in drinking water was possible by ingestion, dermal contact and inhalation when water was used for showering, bathing, and cooking. Although exposures vary depending on individual lifestyles, each of these exposure routes contributes to the overall daily uptake of contaminants and thus increases the potential for chronic health effects.
Tetrachloroethene, trichloroethene and 1,1-dichloroethene cause cancer in laboratory animals exposed to high levels over their lifetimes (ATSDR, 1989a; 1990a; 1990e,f). 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 of time. Whether or not these chemicals cause cancer in humans is not known. Based on the results of animal studies and limited sampling of private water supply wells in 1984, it is estimated that persons exposed to drinking water contaminated with tetrachloroethene, trichloroethene, and 1,1-dichloroethene at the highest levels found in homeowner well samples could have a high increased risk of developing cancer. Toxicological data are inadequate to assess the carcinogenic potential of 1,1-dichloroethane, 1,2-dichloroethene and 1,1,1-trichloroethane (ATSDR, 1990b,d).
1,1,1-Trichloroethane can cause damage to the nervous system, liver and cardiovascular system at exposure concentrations several orders of magnitude greater than those measured in these private water supply wells (ATSDR, 1990d). Tetrachloroethene, trichloroethene, 1,1-dichloroethane, 1,1-dichloroethene and 1,2-dichloroethene (ATSDR, 1989a; 1990a,b; 1991e,f) also produce a variety of noncarcinogenic toxicities (primarily nervous system, liver and kidney effects) at exposures several orders of magnitude greater than past exposure from these private water supply wells. 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. In addition, since these organic contaminants all have very similar toxic effects, it is not unreasonable to assume that they can act in an additive manner. Although the risks of noncarcinogenic effects from past exposures are not completely understood, the existing data from sampling in 1984 suggest that they could have been high.
- Potential ingestion, dermal absorption and inhalation exposure to contaminants in drinking water as a result of contaminant
As indicated in Table 4, on-site and off-site groundwater is contaminated with organic chemicals and metals at concentrations that exceed New York State groundwater and/or drinking water standards or guidelines. Private drinking water supply wells close to the site, therefore, could become contaminated with on-site and off-site groundwater by plume migration.
Tetrachloroethene, trichloroethene and 1,1-dichloroethene cause cancer in laboratory animals exposed to high levels over their lifetimes (ATSDR, 1989a, 1990a, 1991d,e,f). Based on the results of animal studies, chronic exposure to drinking water contaminated at the highest levels of tetrachloroethene, trichloroethene and 1,1-dichloroethene found in on-site and off-site groundwater could pose a high increased cancer risk. Toxicological data are inadequate to assess the carcinogenic potential of ethylbenzene, xylene, toluene, acetone, total 1,2-dichloroethene and trichloro-1,2,2-trifluoroethane (Freon 113) (ATSDR, 1989b, 1990b,c,e; US EPA, 1991, 1992).
These contaminants can produce a variety of noncarcinogenic toxicities (primarily nervous system, liver, and kidney effects) at exposures several orders of magnitude greater than those from potential exposures to on-site and/or off-site groundwater. The existing data suggest that the risks from noncarcinogenic effects could be high for tetrachloroethene, trichloroethene, and 1,1,1-trichloroethane.
Metal contaminants of potential concern in on-site and/or off-site groundwater include lead, chromium and cadmium. Chronic exposure to lead is predominantly associated with neurological and hematological effects (ATSDR, 1991c). The developing fetus and young children are particularly sensitive to lead-induced neurological effects. 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, 1991b). Chronic exposure to cadmium can lead to kidney damage and may cause adverse effects on bone, the gastrointestinal tract, liver, blood and reproduction (ATSDR, 199a). Exposure to drinking water contaminated with these metals at the highest levels found in on-site and/or off-site groundwater could pose a high increased risk of adverse health effects.
- Past, present and potential ingestion, inhalation and dermal
exposure of persons coming in contact with on-site soil.
The potential for exposure to contaminated surface soils on-site exists since the site is accessible to workers and trespassers. As shown in Table 3, some samples of on-site surface soils contain levels of lead which slightly exceed typical background levels and contain chromium at levels exceeding the public health assessment comparison value for this metal. The toxicological effects of lead and chromium have been discussed previously. Because of the limited number of surface soil samples with slightly elevated levels of lead and chromium, any increased risk of adverse health effects would be minimal for incidental ingestion of on-site surface soils.
Tetrachloroethene was found in subsurface soils in one area (soil boring 10) at levels that could pose a low increased cancer risk to residents should the site be excavated and developed for residential use. The increased risk to workers through incidental ingestion during excavation would be minimal.
- Potential exposure to volatile organic contaminants in indoor
air as a result of vapor migration to off-site residences.
The data are inadequate to assess the toxicological implications of this potential pathway since no data exist on levels of volatile organic contaminants in nearby residences. However, the on-site soil gas survey detected high levels of tetrachloroethene, 1,1,1-trichloroethane, and trichloroethene vapors in on-site soil. The toxicological properties of these contaminants have been discussed previously. Although it is not known what levels could potentially impact air quality in nearby buildings, the levels of these three volatile organic contaminants found in soil vapor would pose a high risk of adverse health effects if found in indoor air (see Table 1).
- Present and potential ingestion, dermal and inhalation
exposure of persons engaged in recreational activities in
As indicated in Table 8, some samples of surface water from Ligonee Brook contained tetrachloroethene, 1,1,1-trichloroethane, trichloroethene, 1,1-dichloroethane, 1,1-dichloroethene, and benzene at levels exceeding New York State standards and/or public health assessment comparison values for drinking water. However, due to the limited number of samples containing these contaminants and the incidental nature of recreational activities, which would result in estimated doses considerably lower than those resulting from drinking water exposure, none of these contaminants would be expected to cause adverse health effects.
The NYS DOH has not evaluated health outcome data specifically for the Rowe Industries site. Breast cancer incidence rates have been examined for small geographic areas of Nassau and Suffolk Counties for the years 1978-1987. No association was found between breast cancer incidence patterns and contaminated drinking water wells or hazardous waste sites.
The cancer and non-cancer health risks associated with drinking contaminated groundwater are high. The ability of the health outcome data bases to detect an increase in disease is, however, limited due to the small size of the population affected. Therefore, health outcome databases will not be searched at this time. The site and the people exposed to the contaminated drinking water will be considered for addition to the NYS DOH registry being developed for VOC exposures from drinking water. Periodically, this registry will be matched with the cancer registry to evaluate possible adverse health outcome.
We have addressed the community health concerns as follows:
- Local residents have been concerned about private well water
quality and the protection of the aquifer since the
contamination was discovered.
When groundwater contamination was discovered, the Suffolk County Department of Health Services tested all area wells to determine the extent of contamination. County, state, and federal officials moved quickly to provide public water to all affected residences. Residents' concern about future contamination of drinking water supply wells, due to continued migration of contaminants from the site, should be addressed in the selected remedy for the site. The selected remedy should include removal of on-site source areas and installation of a groundwater extraction and treatment system. The selected remedy should address elimination of contaminant sources and prevent further migration of groundwater contaminants.
- Several residents of the area requested their wells be
The NYS DOH coordinated sampling of these wells with the Suffolk County Department of Health Services. All residents whose well had the potential for impacts were sampled. None of these wells sampled in october 1992 were found to contain site-related contamination.
- Residents were concerned about the potential health effects of
past exposures from ingesting contaminated water.
NYS DOH staff discussed the potential health effects of ingestion of water contaminated with chemicals from the site. Staff informed residents that a NYS DOH physician is available to discuss potential health effects or problems with the residents' physicians. The potential health effects related to past exposures to contaminated drinking water are summarized in the Public Health Implications section (Toxicological Evaluation).
- Residents near the plume, but not affected by the
contamination, wanted to be connected to the public water
supply using government funds.
NYS DOH and US EPA staff explained that these funds are used only to connect residences where the water supply has become contaminated above drinking water standards.
- There were concerns regarding the release of treated water
into local marine waters.
NYS DOH and US EPA staff explained that treated water to be released in local marine waters would be tested on a regular basis and would cause no adverse effects on local marine life.