Hopewell Precision Area Contamination

Summary

The Hopewell Precision Area Contamination site is located in a semi-rural residential area of Dutchess County, New York. Hopewell Precision is an active manufacturer that fabricates and paints sheet metal. The facility, which opened in 1977, originally operated at 15 Ryan Drive but moved its operations to 19 Ryan Drive in 1981. Wastes generated from the Hopewell Precision site include paint thinners and degreasing solvents. Mishandling of these waste products, including dumping 5-gallon buckets containing these wastes on the ground outside the back door, allegedly occurred at the original location (15 Ryan Drive). As a result, area groundwater is contaminated with volatile organic compounds (VOCs), primarily trichloroethene (TCE) and 1,1,1-trichloroethane (1,1,1-TCA). Area soil vapor has also been impacted as a result of the VOC groundwater plume. Exposures to TCE and 1,1,1-TCA have occurred via private drinking water supplies and breathing contaminated indoor air as a result of soil vapor intrusion. For this public health assessment, a maximum exposure duration of 29 years was used to correspond with the start of industrial activity at the Hopewell Precision facility. However, the movement of the contamination to groundwater, private drinking water wells, and soil vapor likely took a significant amount of time, resulting in shorter exposure duration than assumed for this public health assessment. The data presented in this public health assessment were current as of the spring of 2006, prior to the start of the Remedial Investigation being conducted by the US EPA.

Dutchess County Health Department (DCHD) staff initially sampled four nearby private wells in June 1985. None of these wells showed any VOC contamination at that time. New York State Department of Environmental Conservation (NYS DEC) staff sampled two private wells in April 1993. No VOC contamination was identified in private drinking water wells during this sampling round. In February 2003, the United States Environmental Protection Agency (US EPA) conducted an assessment of the site. As part of this assessment, US EPA sampled 75 nearby residential wells. Results of the sampling revealed five residential wells, south and southwest of the site, that were contaminated with TCE. Subsequently, US EPA sampled approximately 450 private drinking water wells to delineate the contaminated area. TCE was detected above the state and federal drinking water standards, referred to as Maximum Contaminant Levels (MCLs) of 5 micrograms per liter (mcg/L) in 36 wells of the approximately 450 wells sampled, or about 8 percent. TCE was detected below the state MCL in 22 of the wells sampled or about 5 percent. 1,1,1-TCA was detected above the state MCL of 5 mcg/L in 15 of the wells sampled, or about 3 percent. 1,1,1-TCA was detected below the state MCL in 47 of the wells sampled, or about 10 percent. Two wells had methyl-tert-butyl-ether (MTBE) at levels above the state MCL. However, this contaminant is not related to the Hopewell Precision site. US EPA and NYS DEC provided water treatment systems, also known as point of entry treatment (POET) systems, for private wells to reduce exposures to TCE and 1,1,1-TCA through drinking water. As of the spring of 2006, 51 treatment systems (37 by US EPA and 14 by NYS DEC) had been installed to address the TCE contamination, 1,1,1-TCA contamination, or both. US EPA and NYS DEC monitor these treatment systems on a quarterly basis to ensure that they are working effectively.

From February 2004 through the spring of 2006, US EPA collected sub-slab soil vapor samples from 206 buildings and indoor air samples from 103 buildings, mainly residential, located over the plume. TCE was detected in the sub-slab soil vapor of 66 buildings and in the indoor air of 70 buildings. 1,1,1-TCA was detected in the sub-slab soil vapor samples of 141 buildings and in the indoor air of 71 buildings. Tetrachloroethene, also known as PCE, was detected in the sub-slab soil vapor of 81 buildings and in the indoor air of 61 buildings. Although PCE is a common degreaser, it is not known to be associated with the Hopewell Precision site and has not been consistently detected in the groundwater. The source of the PCE in soil vapor is unknown. Methyl-tert-butyl ether (MTBE), which is unrelated to the Hopewell Precision site, was detected in the sub-slab vapor of 56 buildings and in the indoor air of 77 buildings.

US EPA installed sub-slab depressurization systems (SSDS) at 46 buildings that were determined by US EPA to currently be impacted or that have the potential to be impacted by vapor intrusion of TCE, thereby minimizing exposures to TCE in indoor air. US EPA chose to use TCE as the determining contaminant when making decisions regarding the need for SSDS.

Public health actions were needed in the past and are still being conducted at the Hopewell Precision Area Contamination site to reduce exposures to site-related VOCs, primarily TCE and 1,1,1-TCA, and the non-site related VOCs, PCE and MTBE. Exposure to TCE, 1,1,1-TCA, and MTBE were occurring via contaminated private well water and via indoor air. Exposure to PCE was occurring via indoor air. Many wells were contaminated with TCE and 1,1,1-TCA at or above the state or federal MCLs; two wells had MTBE at levels above the NYS MCL (promulgated in December 2003) of 10 mcg/L. Long-term exposure of residents to the highest levels of TCE detected in private water supplies is estimated to pose a low increased risk for cancer; the risks for noncancer effects is low to moderate. Long-term exposure to the highest level of MTBE in private wells (which is not related to the Hopewell Precision facility) is estimated to pose a low increased risk for cancer. These exposures have been addressed by installation of treatment systems.

Indoor air of some buildings, mostly residential, was contaminated with TCE and PCE above the US EPA remedial goal of less than 0.38 microgram per cubic meter (mcg/m3) TCE in indoor air and NYS DOH air guidelines of 5 mcg/m3 for TCE and 100 mcg/m3 for PCE. Some residents could have been exposed to TCE in their indoor air for as long as 29 years; however, the movement of contamination to groundwater and soil vapor could have taken a significant period of time, resulting in a shorter exposure duration. The estimated increased cancer risk for exposure to the levels of TCE in indoor air at properties within the contamination area is low, with the exception of one property, where the estimated cancer risk is moderate. The risks for TCE noncancer effects for indoor air are minimal to low. PCE indoor air levels, which are not related to the Hopewell Precision facility, are estimated to pose a low increased risk for cancer and minimal to low risk for noncancer health effects, except for two properties where the estimated noncancer risk is moderate. A single property had significantly elevated PCE levels corresponding to a moderate increased theoretical cancer risk and a high risk for noncancer health effects. These exposures have been addressed by installation of mitigation systems.

The drinking water affected by the site currently poses an indeterminate public health hazard. Although treatment systems have been installed on affected wells and regular monitoring is being implemented, the extent of the groundwater plume is still being defined. In those impacted homes already identified, contaminants in private drinking water wells have been reduced to levels below state MCLs, thereby reducing exposures. Therefore, the site currently poses no apparent public health hazard for the residents in homes with drinking water treatment systems.

Similarly, indoor air affected by the site poses an indeterminate public health hazard. Although mitigation systems have been installed and inhalation exposures have been minimized in those impacted homes already identified, the extent of the soil vapor plume still needs to be defined. The site currently poses no apparent public health hazard for residents in homes with soil vapor mitigation systems, also known as a sub-slab depressurization system (SSDS).

Residents affected by the groundwater and soil vapor contamination have voiced concerns about several issues, including when remediation of the contaminated groundwater will take place, the feasibility and cost of bringing public water to the community, and concerns over the safety of using the carbon filters on their wells, and the sub-slab vapor depressurization systems installed on their homes. Residents exposed to TCE and 1,1,1-TCA in their drinking water and indoor air also have questions concerning the short- and long-term health effects of their exposure. NYS DOH, in conjunction with Agency for Toxic Substances and Disease Registry (ATSDR) and US EPA, held four public meetings and one informational community meeting to address residents' health concerns.

ATSDR and NYS DOH have also provided physician education and training materials on exposures associated with the Hopewell Precision Area Contamination. NYS DOH and ATSDR placed an advertisement in the Dutchess County Medical Associations newsletter, The Decatur, in October of 2004, acknowledging the availability for physicians to obtain educational packets that include information on health effects associated with exposures, how to take a patient's environmental exposure history, and case studies in environmental medicine. These resources are also available at the US EPA information repository in the East Fishkill Community Library for other interested health care providers. NYS DOH and ATSDR have also provided the community several opportunities to have these packets sent to their physicians by having patients provide the names of their physician to NYS DOH or ATSDR representatives.

NYS DOH and ATSDR have recommended actions to protect residents from the contaminated groundwater and indoor air. Recommended actions include proper maintenance and monitoring of the installed treatment systems for both drinking water and indoor air, a permanent, long-term remedy for groundwater users, and VOC exposure education for residents and physicians by ATSDR and NYS DOH. Additional investigation of the source of the contamination and the extent of the contaminant plumes is needed and is currently being conducted by the US EPA as part of the Remedial Investigation. As needed, NYS DOH and ATSDR will evaluate new exposure related information in a future public health assessment document.

NYS DOH and ATSDR will coordinate with the appropriate environmental agencies to implement the recommendations and provide follow-up to the Public Health Action Plan. Included in these recommendations is the need to collect additional data to define the extent of the VOC contaminated groundwater plume and soil vapor plume. NYS DOH and US EPA will evaluate the potential for exposures to TCE and 1,1,1-TCA in groundwater and soil vapor based on these data and perform any follow-up sampling that may be necessary.

Persons known to have been exposed to site-related contaminants in either groundwater or soil vapor at this site are being offered enrollment in the NYS VOC Exposure Registry established by NYS DOH. The VOC Exposure Registry is a tool for long-term follow-up for communities with documented exposures to VOCs. Future analysis of VOC Exposure Registry information will involve combining information from multiple sites with similar exposures into a multi-site study, increasing our ability to detect effects. People who are enrolled in the Registry will be kept informed of any research results that come from the Registry data.

NYS DOH is conducting a health statistics review for the Hopewell Junction Contamination Area. The review will use existing data from statewide databases on cancer diagnoses, congenital malformations, and low birth weight births to determine whether these outcomes are occurring at a higher, lower, or about the same level in the Hopewell Junction study area compared to the rest of New York State. The results of the review will be discussed in a future public health assessment document.

This public health assessment was distributed for public comment from November 17th 2006 until January 19th 2007. A public meeting was held on January 22nd 2007 to discuss the document with the community and the deadline was extended until February 23rd 2007. NYS DOH received multiple written comments, and verbal comments from the meeting. A summary of these comments and NYS DOH's responses are included in Appendix E.

In addition to those educational materials distributed thus far, NYS DOH and ATSDR will distribute a draft of this public health assessment to concerned residents and local physicians in the area who expressed an interest in the site.

Purpose and Health Issues

The purpose of this public health assessment (PHA) is to evaluate human exposure pathways for contaminants related to the Hopewell Precision Area Contamination site. This PHA also fulfills the congressional mandate for public health assessment activities for each site being proposed to the National Priorities List (NPL). The Hopewell Precision Area Contamination site was proposed to the NPL on September 23, 2004 and added on April 27, 2005. In addition, this public health assessment responds to a petition for a public health assessment that ATSDR received from a local resident. This public health assessment will focus on exposure to volatile organic compounds (VOCs), mainly trichloroethene (TCE) and 1,1,1-trichloroethane (1,1,1-TCA) in private wells and soil vapor, which are the only known site-related exposure pathways in the contamination area. The public health actions taken to date include identifying exposed and potentially exposed residents and providing treatment and mitigation systems to homeowners with private drinking water wells contaminated with TCE and 1,1,1-TCA above New York State (NYS) public drinking water standard of 5 micrograms per liter (mcg/L), or with TCE sub-slab vapor concentration of greater than US EPA action and screening levels. In addition, evaluation of contaminants not related to the Hopewell Precision Area Contamination site have been included in this report to provide a thorough evaluation of the potential risks and hazards from environmental contamination in the community. The United States Environmental Protection Agency (US EPA), New York State Department of Health (NYS DOH), and Agency for Toxic Substances and Disease Registry (ATSDR) conducted four public meetings to address public health concerns.

Background

A. Site Description and History

The Hopewell Precision Area Contamination site is in the Hamlet of Hopewell Junction, Dutchess County, New York. The source of contamination is believed to be the Hopewell Precision facility, an active sheet metal fabrication and painting business. The facility, which opened in 1977, originally operated at 15 Ryan Drive but moved to its current location, 19 Ryan Drive, in 1981. Since 1981, a moving company has occupied the property at 15 Ryan drive. The combined size of these two adjacent properties is 5.7 acres. The facility and the associated groundwater and soil vapor contamination plumes are in a semi-rural mostly residential area. The area impacted by the groundwater and soil vapor contamination extends approximately 1.4 miles in a southwestern direction from the Hopewell Precision site, generally following NYS Route 82. The streets with one or more impacted private wells include NYS Route 82, Oakridge Road, Lenart Drive, Creamery Road, Hamilton Road, Clove Branch Road, Baris Lane, Cavelo Road, and West Old Farm Road (Appendix A, Figure 1). About 670 people live in the affected area. All residents in the affected area rely on private wells as their primary source of potable water. Impacted wells in the study area are contaminated with VOCs, primarily TCE and to a lesser extent 1,1,1-TCA. The streets with one or more soil vapor impacted buildings include Ryan Drive, NYS Route 82, Lenart Drive, Creamery Road, Hamilton Road, Oakridge Road, Maple Place, Baris Lane, and Canterberry Court. TCE is the primary site-related soil vapor contaminant.

Waste products associated with the Hopewell Precision Facility include paints, thinners, and degreasing solvents. Allegedly, these waste products were dumped directly to the ground outside of the building at 15 Ryan Drive. Waste paints and thinners were allegedly dumped outside the backdoor on a daily basis and waste degreasing solvents were dumped on a biweekly basis. US EPA first investigated this site in response to a letter written by a concerned citizen. US EPA confirmed the allegations of dumping during a site inspection in November 1979. At this time, several punctured and leaking 55-gallon drums of various chemicals, empty paint, and solvent cans were identified on-site. Proper disposal of the TCE used in site operations could not be documented due to missing waste manifest documents. In March of 1980, US EPA sampled the on-site process well and found low level VOC contamination. The site was subsequently referred to NYS DEC for further investigation.

NYS DEC completed an investigation of the site in 1984 and again in 1987 (NYS DEC, 1987). As part of these investigations, NYS DEC installed three on-site groundwater monitoring wells in May of 1985. Subsequent sampling of these wells identified one with 1,1,1-TCA at 23 mcg/L and trace levels of other VOCs. In June 1985, the Dutchess County Health Department (DCHD) sampled four private wells (2 residential and 2 business, including the on-site well). No VOCs were detected in any of the samples.

In April 1993, the site owners completed a limited site investigation which included sampling of the three previously installed groundwater monitoring wells and two residential private wells. NYS DEC collected samples at the same time during this investigation. TCE was only detected in one on-site monitoring well at levels below state MCL. In 1994, based on the results of these investigations, NYS DEC decided to remove the Hopewell Precision site from the New York State Registry of Inactive Hazardous Disposal Waste Sites.

In February 2003, as part of US EPA's effort to make decisions on historic sites, US EPA sampled 75 residential wells near the Hopewell Precision site. Analyses of the samples revealed that five residential wells were contaminated with TCE ranging from 1.2 mcg/L to 250 mcg/L. At that time, NYS DEC, on behalf of the NYS DOH, requested US EPA conduct a removal action at the site (i.e., installation of carbon filter systems on residential wells). A removal action is a short-term measure taken to reduce human exposures.

US EPA initiated a removal action at the site in March 2003. Since the time of initiation, US EPA has expanded the scope of their investigation to include additional drinking water wells and sub-slab soil vapor and indoor air sampling. The results of the expanded investigation have confirmed that some homes were impacted by contaminated drinking water and contaminated soil vapor intrusion as a result of the site-related TCE and 1,1,1-TCA groundwater plume.

B. Actions Implemented During the Public Health Assessment Process

US EPA installed point of entry treatment systems (referred to as POETS) on those private drinking water wells that had VOC contamination that exceeded or approached the federal and state Maximum Contaminant Level (MCL) for TCE of 5 mcg/L. NYS DEC installed carbon filters at those locations where 1,1,1-TCA was detected at levels below the federal MCL of 200 mcg/L but above the state MCL of 5 mcg/L. US EPA and NYS DEC will continue to provide regular sampling and maintenance for these carbon filters until such time that they are no longer needed (i.e., analysis shows that groundwater is consistently below the federal and state MCLs) or an alternative water source for the area is secured.

US EPA has also installed active sub-slab depressurization systems (SSDS) in those buildings found to be impacted or have the potential to be impacted by soil vapor intrusion. US EPA's action level (i.e., a SSDS is automatically installed) for TCE in sub-slab soil vapor is 50 mcg/m3. US EPA's screening level for soil vapor (i.e., indoor air sampling will be conducted) is a concentration greater than 2.7 mcg/mL, and the US EPA post-mitigation goal for TCE in indoor air is less than 0.38 mcg/m3. Outdoor air was not considered in the establishment of US EPA action levels. US EPA is providing post-installation indoor air sampling to confirm the effectiveness of the systems in minimizing vapor intrusion of TCE contaminated soil vapor. US EPA will provide monitoring and maintenance of each of the SSDS until such time that they are no longer needed.

US EPA, NYS DOH, ATSDR, and NYS DEC conducted four public meetings (July 10, 2003, May 5, 2004, December 1, 2005, and January 22, 2007) to answer health concerns, to explain in greater detail the VOC registry, and to discuss the current activities taking place at the site. NYS DOH and ATSDR also requested resident assistance in identifying their health care providers so that educational outreach to the health care providers could be targeted. US EPA has mailed out six update newsletters to the community.

NYS DOH and ATSDR physician outreach activities included the placement of an advertisement in the Dutchess County Medical Society Newsletter, The Decatur, informing area physicians of the availability of a "Physician Outreach Packet" which contains several ATSDR documents including ATSDR's 2004 Toxicological Profiles CD, "Case Studies in Environmental Medicine," and other reference information. NYS DOH and ATSDR also included a notice in the October 2004 US EPA community update newsletter informing the public of the opportunity to request that a packet be sent to their physician.

C. Site Visit

The initial site visit by NYS DOH was completed on January 16, 1986. Since that time, NYS DOH, NYS DEC, and US EPA have completed multiple visits to this area. US EPA's work at the site is on-going. Access is restricted to the Hopewell Precision property. NYS DOH, NYS DEC, DCHD, and US EPA have all sampled private well water in homes in the area. NYS DOH last visited the site on December 1, 2005.

A public meeting was held on January 22, 2007 and no changes in site characteristics were noted. In addition, the US EPA project manager visits the site periodically, and no significant changes in site conditions have been reported.

D. Demographics

NYS DOH estimated, from the 2000 Census (US Bureau of the Census, 2001; 2002), that approximately 670 people live above the area of the plumes. The age distribution of the area is similar to that of the rest of Dutchess County as well as New York State, excluding New York City (NYC). There were approximately 130 females of reproductive age (ages 15-44) in the area. The area is somewhat less racially diverse than the rest of the county or state (excluding NYC) with 97% of the population reported as white. Based on the 2000 Census, less than 1% of people in the area are living below the poverty level compared to 10% in New York State, while the median household income is almost 60% higher than the rest of the state (excluding NYC). These comparisons are provided in the following table. In addition, there are no schools or nursing homes within the area.

2000 Census Demographics New York State excluding NYC Dutchess County Area above plume
Age Distribution
<6 8% 8% 8%
6-19 20% 21% 22%
20-64 58% 60% 58%
>64 14% 12% 12%
Race Distribution
White 85% 84% 97%
Black 8% 9% <1%
Native American <1% <1% <1%
Asian 2% 3% <1%
Pacific Islander <1% 0% 0%
Other 2% 2% <1%
Multi-Racial 2% 6% 1%
Percent Minority* 18% 20% 8%
Ethnicity Distribution
Percent Hispanic 6% 2% 6%
1999 Median Income $47,517 $53,086 $74,547
% Below Poverty Level 10% 8% <1%

* Minority includes Hispanics, African-Americans, Asian-Americans, Pacific Islanders and Native Americans.

Discussion

A. Environmental Contamination

The environmental data presented in this section were gathered during investigations conducted by NYS DOH, NYS DEC, and US EPA. The data discussed here were acquired before US EPA began its remedial investigation of the Hopewell Precision Area under the Superfund Program in 2006. That investigation is ongoing. US EPA expects to report on the results of the remedial investigation in mid-2008. The following sections summarize the results of the investigations of groundwater, surface water, sediment, soil, soil vapor, and indoor air contamination in and around the study area prior to the US EPA's remedial investigation.

Groundwater / Private Drinking Water

Groundwater is known to be contaminated in the investigation area, encompassing approximately one square mile; however, not all private wells within the area are contaminated. The depths of wells in the contaminated area are between 5 feet to 355 feet below ground surface. All of the wells in the area, including wells that contain site-related contamination are drilled into and screened in glacial outwash or bedrock. These two water bearing units are hydraulically interconnected and are considered to be one aquifer. TCE and 1,1,1-TCA were detected in some of the samples collected from wells and were the only site-related VOCs detected consistently above the state MCL of 5 mcg/L. Approximately 450 private drinking water wells were sampled by US EPA to delineate the contamination area (See Table 1 for data summary). TCE was present above state public drinking water standard in 8 percent or 36 of the approximately 450 wells sampled. TCE was detected below the state and federal MCLs in about 5 percent or 22 of the wells sampled. 1,1,1-TCA was present above state MCL in about 3 percent or 15 of the approximately 450 wells sampled. 1,1,1-TCA was detected below the state MCL in about 10 percent or 47 wells of the wells sampled. 1,1,1-TCA was not detected in any well above the federal MCL of 200 mcg/L. In some cases, individual wells showed no contamination in areas where neighbors had elevated levels of TCE or 1,1,1-TCA. Such differences may be the result of differences in depth and construction of individual wells and well water usage per household. Also, contamination from the source area could be following a complicated course through glacial outwash and fractures in the bedrock.

To detect any future migration of the plume and reduce potential exposures, US EPA has been testing private wells beyond the edge of the known plume area. These wells will be sampled regularly as part of a long-term monitoring program. In addition, US EPA has proposed installing additional groundwater monitoring wells as part of the on-going remedial investigation of the Hopewell Precision Area Contamination site.

Two VOCs unrelated to the Hopewell Precision Area Contamination site were detected in several residential wells. Methyl-tert-butyl ether (MTBE), which was a common gasoline additive in NYS prior to January 2004, was detected in drinking water wells at levels below the state MCL of 10 mcg/L with the exception of two wells (up to 28 mcg/L). MTBE was detected in 42 of the approximately 450 wells sampled or about 9 percent. The average concentration of MTBE in wells sampled was 0.37 mcg/L. The detection of MTBE in area wells is most likely the result of gasoline spills in the area. Information on local gasoline spills is available from the NYS DEC Region 3 office at (845) 256-3052 or visit the NYS DEC website.

In addition, styrene was detected at a level (5.3 mcg/L) just slightly above the state MCL in one private drinking water well. The presence of styrene in this sample is not site-related and may be due to the use of styrene in some plumbing adhesives. Therefore, no further evaluation of styrene will be completed in this PHA.

Surface Water and Sediment

In April 2003, US EPA collected surface water samples and sediment samples from two small ponds, Pond 1 and Pond 2 (Appendix A, Figure 2) located approximately 300 feet south-southwest (i.e., downgradient) of Hopewell Precision, the alleged source area. TCE was detected in the surface water at concentrations of 4 mcg/L and 3.4 mcg/L in these two ponds respectively. TCE was detected at a concentration of 88 micrograms per kilogram (mcg/kg) in the sediment sample collected from Pond 1. No TCE was detected in the Pond 2 sediment sample. 1,1,1-TCA was not detected in either surface water or sediment sample. To the best of our knowledge, which is based on site visits and discussions with federal and local agency staff and residents, these ponds are not used for recreation.

In May 2003, US EPA collected additional surface water samples from two ponds located approximately 900 feet (Pond 3) and 4,500 feet southwest of Hopewell Precision (Pond 4). No TCE or 1,1,1-TCA was detected in either surface water sample from the two ponds. TCE was detected in only one sediment sample from Pond 3 at a concentration 3.6 mcg/kg. To the best of our knowledge, which is based on site visits and discussion with federal and local agency staff and residents, these ponds are not used for recreation.

Surface water samples were collected by the Village of Fishkill (May 2004) and DCHD (June 2004) from the nearby Red Wing Park permitted bathing (swimming) facility. Neither TCE nor 1,1,1-TCA were detected in any of the surface water samples collected.

Soil

Although NYS DEC conducted a Phase II investigation at the site in 1986, no soil samples were collected at that time.

In July 2003, US EPA collected 13 on-site and five off-site soil samples. Analysis of these samples indicated that TCE was present in two on-site samples and 1,1,1-TCA was present in one of the on-site samples. Neither contaminant was detected in any of the off-site soil samples.

US EPA collected additional soil samples at the site in December 2003. US EPA focused its investigation between the boundaries of the current and former Hopewell Precision Facilities (15 and 19 Ryan Drive). US EPA installed 14 soil borings down to 12 feet below the ground surface in the suspected source areas and two soil borings to be used as background samples for comparison purposes (i.e., samples collected from upgradient areas not known or expected to be contaminated). US EPA collected 26 soil samples from the 16 soil borings. Low levels of TCE (up to 3.9 mcg/kg) were detected in five of the 26 soil samples collected. TCE was not detected in the background samples. US EPA concluded that the coarse-grained soils at the site have very little ability to hold the organic chemicals. The vertical groundwater recharge through the shallow soils (i.e., precipitation in the form of rain or snow) may have flushed away any contamination remaining in the soils on the Hopewell Precision site.

Soil Vapor / Indoor Air

From February 2004 to the spring of 2006, US EPA collected sub-slab soil vapor samples from 206 buildings and indoor air samples from 103 buildings, mainly residential, located over the plume. The reason for the decreased number of buildings sampled for indoor air compared to the number of buildings sampled for soil vapor is that some homes were eliminated from further investigation since there was minimal potential for vapor intrusion (i.e., the sub-slab concentrations were below the US EPA TCE screening level of greater than 2.7 mcg/m3). In those locations where indoor air was sampled, samples were collected from basement levels (if present) and the first floor living space. Since the amount of exposure can vary based on whether the basement is finished and occupied frequently or a non-occupied area used for storage, laundry, or other infrequent uses, the data for both the basement and first floor are separated as presented in Table 2.

TCE

TCE was detected in the sub-slab vapor samples of 66 buildings or approximately 32% with a range of 2.7 mcg/m3 to 7518 mcg/m3. TCE was detected in the basement air of 51 buildings with an average of 3.6 mcg/m3 and the first floor of 54 buildings with an average of 2.2 mcg/m3. The TCE concentrations in the 70 buildings where the contaminant was detected ranged from 0.37 mcg/m3 to 172 mcg/m3.

1,1,1-TCA

1,1,1-TCA was detected in the sub-slab vapor samples of 141 buildings or approximately 69% with a range of 2.7 mcg/m3 to 486 mcg/m3. 1,1,1-TCA was detected in the basement of 55 buildings with an average of 1.2 mcg/m3 and the first floor of 43 buildings with an average of 0.9 mcg/m3. TCA concentrations in the 71 buildings where the contaminant was detected ranged from 0.36 mcg/m3 to 17 mcg/m3.

PCE

Tetrachloroethene, also known as PCE, was detected in the sub-slab soil vapor of 81 buildings or 39% with a range of greater than 2.7 mcg/m3 to 4500 mcg/m3. Although PCE is a common degreaser, it is not known to be associated with the Hopewell Precision site. In addition, PCE has not been consistently detected in the groundwater. In the approximately 450 private drinking water wells sampled, PCE was only detected twice at concentrations of 0.22 mcg/L and 0.28 mcg/L, which are below NYS public drinking water standard of 5 mcg/L. The source of the PCE in soil vapor is unknown. Additional investigation is being conducted during the on-going remedial investigation by US EPA. PCE was detected in the basement air of 48 buildings with an average of 7.5 mcg/m3 and the first floor of 40 buildings with an average of 7.6 mcg/m3. PCE concentrations in the 61 buildings where the contaminant was detected ranged from 0.45 mcg/m3 to 2000 mcg/m3. The detection of PCE in indoor air may be the result of vapor intrusion or possibly the presence of products stored or used in the buildings (e.g., dry-cleaned clothes, automotive brake cleaner, etc.). Due to the prevalence of PCE detected in soil vapor and the levels at which PCE was present in indoor air, further evaluation of PCE is included in the Public Health Implications section of this PHA.

MTBE

Methyl-tert-butyl ether (MTBE), which is unrelated to the Hopewell Precision Area Contamination site, was detected in the sub-slab vapor of 56 out of 206 buildings or 27% with a range of 2.7 mcg/m3 to 76.0 mcg/m3. MTBE was detected in the basement of 75 buildings with an average of 7.6 mcg/m3 and the first floor of 60 buildings with an average of 5.6 mcg/m3. MTBE concentrations in the 77 buildings where the contaminant was detected ranged from 0.36 mcg/m3 to 610 mcg/m3. The increased percentage of MTBE detected in the indoor air compared to that detected in the soil vapor suggests that in many situations there is likely an indoor source, such as gasoline, used or stored within a building. However, the possibility of vapor intrusion of MTBE can not be eliminated as a potential exposure pathway. Therefore, due to the prevalence of MTBE detections in soil vapor and the levels at which MTBE was present in indoor air, further evaluation of MTBE is included in the Public Health Implications section of this PHA.

Common Household Contaminants

Several volatile organic compounds such as acetone, 1,1-dichlorobenzene and methylene chloride were detected at levels above background in the indoor air of some buildings. The presence of these compounds in indoor air is most likely the result of products stored and used in the building such as nail polish remover, craft/hobby supplies, mothballs, cleaning/disinfectants, rug cleaners, hairspray, etc. These compounds are not site-related contaminants and, therefore, will not be further evaluated in this public health assessment.

Sub-slab Depressurization Systems

As of early 2006, US EPA had installed sub-slab depressurization systems (SSDS) at 46 buildings (or approximately 70% of buildings where TCE was detected in sub-slab soil vapor) that were determined by US EPA to be impacted or to have the potential to be impacted by vapor intrusion. US EPA has chosen to use TCE as the determining contaminant when making decisions regarding the need for SSDS. US EPA expects that additional systems may be warranted based on the results of the soil vapor investigations being conducted during the Remedial Investigation.

B. Pathways Analysis

This section of the PHA identifies completed exposure pathways associated with past, present, and future uses of the site. An exposure pathway is how an individual could be exposed to contaminants originating from a site. An exposure pathway is comprised of five elements including:

  1. a contaminant source,
  2. environmental media and transport mechanisms,
  3. a point of exposure,
  4. a route of exposure,
  5. a receptor population.

The source of contamination is the place where contaminant release to the environment occurred (any waste disposal area or point of discharge); if the original source is unknown, it is the environmental media, (soil, air, water, biota) which are contaminated at the point of exposure. Environmental media and transport mechanisms carry contaminants from the source area to points where human exposures may occur. The exposure point is a location where actual or potential human contact with a contaminated medium may occur. The route of exposure is the manner in which a contaminant actually enters or contacts the body (ingestion, inhalation, and dermal absorption). The receptors are the people who are exposed or may potentially become exposed to contaminants at a point of exposure.

Completed Exposure Pathways:

For the Hopewell Precision Area Contamination site, there are two known completed site-related exposure pathways, exposure to primarily TCE and 1,1,1-TCA in private drinking water and contaminated soil vapor intruding into indoor air. Exposure to contaminants in drinking water supplies can occur through ingestion, dermal contact, and absorption during showering, bathing or other household water uses, and through inhalation of aerosols and vapors from water used in the household. Exposure to soil vapor contaminated with VOCs can occur when the vapors beneath a building are drawn through cracks and openings in the foundation and mix with indoor air. Inhalation is the route of exposure, or the manner in which the VOCs actually enter the body, once in the indoor air. For an undetermined period of time, some residents were exposed to VOCs in their drinking water supply and/or indoor air. Prior to February 2003, we do not know how long or at what concentration residents were exposed to site-related contaminants in their drinking water. However, limited sampling of private wells in 1985 showed no contamination. Prior to February 2004, we do not know how long or at what concentration residents were exposed to site-related contaminants in their indoor air. The maximum duration for both the drinking water and vapor intrusion exposure pathways could be as long as 29 years for some of the homes in the contamination area, since some of these homes were built and the potential source facility was operational as early as 1977. However, it is quite likely that the movement of the contamination to groundwater, private drinking water wells and soil vapor could have taken a significant period of time, resulting in shorter exposure duration.

Although these pathways were complete in the past, most exposures were eliminated or minimized as contamination was identified through the installation of treatment systems on drinking water wells where VOCs were detected at or above the NYS public drinking water standard of 5 mcg/L and installation of sub-slab depressurization systems on homes where soil vapor intrusion was occurring or has the potential to occur. One property owner has refused the installation of the treatment systems on the property and therefore, exposures may be currently occurring. If treatment systems are not maintained or if TCE or 1,1,1-TCA is detected at or above the state MCL in any wells where contamination was not previously identified or TCE is detected in sub-slab vapor in any additional buildings, additional exposures to these contaminants above standards or guidelines could occur.

C. Public Health Implications

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 exposure pathways identified for the Hopewell Precision Area Contamination site, NYS DOH assessed the risks for cancer and noncancer health effects. The risks for health effects depend primarily on contaminant concentration, exposure route, exposure frequency and exposure duration. For additional information on how NYS DOH determined and qualified health risks applicable to this public health assessment, please refer to Appendix C.

  1. Past ingestion, dermal and inhalation exposure to volatile organic contaminants in private water supply wells

    Exposure to chemicals in drinking water is possible by ingestion, and also by dermal contact and inhalation from water uses such as showering, bathing, and cooking. Although actual exposure varies depending on an individual's lifestyle, each of these exposure routes can contribute to the overall daily intake of contaminants and, thus, may increase the risk for chronic health effects. Several investigations (e.g., Maxwell et. al., 1991; Weisel and Jo, 1996) have indicated that for VOCs in drinking water, exposures by the inhalation or dermal routes may approach the same level as exposure by ingestion. Therefore, the NYS DOH doubled the exposure from ingesting two liters of water per day in the risk calculations to account for non-ingestion VOC exposures from drinking water.

    For an undetermined period of time, possibly for up to 29 years, some of the private water supply wells near the Hopewell Precision facility have been contaminated with VOCs, primarily TCE and 1,1,1-TCA. The estimated exposure duration of 29 years is based on the beginning of industrial activity at the Hopewell Precision facility in 1977, although the movement of contamination to groundwater and private drinking water wells could have taken a significant period of time, resulting in a shorter exposure duration. Some private wells also contained MTBE, which is not considered related to the Hopewell Precision facility. Some concentrations of TCE, 1,1,1-TCA and MTBE detected in private wells exceed the state MCL and/or public health assessment comparison values (see Table 3). Therefore, these chemicals have been selected for further evaluation.

    Trichloroethene (TCE)

    In humans, long-term exposure in the workplace to high levels of TCE in air is linked to effects on the central nervous system and irritation of the mucous membranes. Some studies of people exposed to high levels of TCE in workplace air or in drinking water show an association between exposure to TCE and increased risks for certain types of cancer, including cancers of the kidney, liver, esophagus, and non-Hodgkin's lymphoma. Other studies suggest an association between workplace TCE exposure and reproductive effects (alterations in sperm counts) in men.

    Studies of women exposed to mixtures of chlorinated solvents (including TCE) in drinking water during pregnancy also suggest that TCE may increase the risk of birth defects (e.g., neural tube defects, oral cleft defects, and congenital heart defects) and/or childhood leukemia (ATSDR, 1997b). In each of the drinking water studies, however, there are uncertainties about how much contaminated water the women drank during pregnancy and about how much TCE was in the water the women drank while pregnant. In addition, we do not know if the health effects observed in the studies of human exposure to TCE in workplace air and in drinking water are due to TCE or other factors, including exposure to other chemicals, smoking, alcohol consumption, and lifestyle choices. Since these potential confounding factors were not well controlled, and because there were uncertainties about actual exposures, the studies in humans suggest, but do not prove, that exposure to TCE can cause cancer, developmental effects and reproductive effects in humans.

    In animal studies, exposure to high levels of TCE caused adverse effects on the central nervous system, liver and kidneys. Lifetime exposure to high levels of TCE has caused cancer in laboratory animals. When pregnant animals were exposed by ingestion to large amounts of TCE, adverse effects on the normal development of the offspring were observed (ATSDR 1997b). In most, but not all of these studies, the high amounts of the chemicals also caused adverse health effects on the parent animals. In one set of studies, effects on fetal heart development were observed in the offspring of rats exposed to TCE in drinking water before and during pregnancy (Dawson et al., 1993, Johnson et al., 1998, Johnson et al., 2003).

    Based on the available sampling information and data from animal and human studies, long-term exposure (i.e., 29 years) to the highest level of TCE detected in private water supplies (250 mcg/L) is estimated to pose a low increased risk for cancer (i.e., the estimated risk is between one-in-one million and one-in-ten thousand). The available information suggests the risk for noncancer health effects would be moderate for people drinking water from private wells containing TCE levels higher than 130 mcg/L (seven of the 58 wells where TCE was detected) and low for wells containing TCE between about 25 mcg/L and 130 mcg/L (19 of the 58 TCE-containing wells). The noncancer risk for people drinking water from private wells containing less than about 25 mcg/L TCE is estimated to be minimal. Overall, the increase in the health risks for TCE in drinking water is difficult to estimate because we have no information on how long or to what levels people were exposed prior to the time the chemicals were detected in private water supplies.

    1,1,1-Trichloroethane (1,1,1-TCA)

    1,1,1-TCA was present above the state MCL of 5 mcg/L in 15 of the approximately 450 wells sampled (about 3%), and none of the levels exceeded the health comparison value for 1,1,1-TCA based on noncancer effects (Table 3). Exposure to high levels of 1,1,1-TCA can cause adverse effects on the nervous system, liver and cardiovascular system (ATSDR, 1995). The available data suggest the risks for noncancer health effects from past exposure in drinking water are minimal for exposure to the highest detected level of 1,1,1-TCA detected in private wells (12 mcg/L). Available toxicological data are inadequate to assess the carcinogenic potential of 1,1,1-TCA (US EPA IRIS, 2004).

    Methyl-tert-Butyl Ether (MTBE)

    MTBE was detected in 42 of approximately 450 wells sampled (about 9%). It was detected above the state MCL for MTBE in only two wells. MTBE caused cancer in laboratory animals exposed to high levels for most or all of their life (Bird et al., 1997; Belpoggi et al., 1995; 1998). Whether or not MTBE causes cancer in humans is unknown. 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. Long-term exposure to the highest detected level of MTBE in private wells (28 mcg/L) is estimated to pose a low increased risk for cancer; it would be very low for exposure to the levels detected in other private wells (all below the state MCL of 10 mcg/L). The risk for noncancer health effects would be minimal.

    Summary

    The following table summarizes the evaluation of potential health risks for contaminants detected in private drinking water supplies:

    Summary of Cancer and Noncancer Risk Descriptors for Contaminants Detected in Private Wells Near the Hopewell Precision Sitea
    Chemical Drinking Water Concentration in Micrograms per Liter Qualitative Risk Descriptor
    Cancer Risk Evaluation
    trichloroethene (TCE) 250b low
    1,1,1-trichloroethane (1,1,1-TCA) ---c ---c
    methyl-tert-butyl ether (MTBE) 28b low
    Noncancer Risk Evaluation
    trichloroethene (TCE) > 130
    ≥ 25 to 130
    < 25
    moderate
    low
    minimal
    1,1,1-trichloroethane (1,1,1-TCA) 12b minimal
    methyl-tert-butyl ether (MTBE) 28b minimal

    aAdditional information on evaluating the health risks for the contaminants is found in Appendix C. MTBE contamination is not considered related to the Hopewell Precision facility.

    bHighest level detected.

    cToxicological data are inadequate to assess the carcinogenic potential of 1,1,1-TCA.

  2. Past inhalation exposure to volatile organic contaminants in indoor air.

    Several VOCs were detected in indoor air in buildings within the Hopewell Precision contamination area. The primary indoor air contaminants associated with the Hopewell Precision facility are TCE and 1,1,1-TCA. Since operations at the Hopewell Precision facility began in 1977, people could potentially have been exposed to these contaminants for up to 29 years, although this is unlikely considering that migration of contaminants to groundwater, to soil vapor, and then to indoor air could have taken a significant length of time. Tetrachloroethene (PCE) and MTBE, which are not considered related to the Hopewell Precision facility, were also detected in indoor air. Some of the measured indoor air levels of these four contaminants exceed indoor background levels and/or public health assessment comparison values (Table 4). Therefore, these chemicals have been selected for further evaluation.

    Trichloroethene (TCE)

    TCE was detected in the indoor air of 70 homes. The cancer and noncancer health effects for exposure to TCE have been discussed previously. Long-term exposure (29 years) to TCE detected in indoor air near the Hopewell Precision site is estimated to pose a low increased risk for cancer (i.e., the increase cancer risk is between one-in-one million and one-in-ten thousand) for air levels ranging from about 1 mcg/mL to 72 mcg/mL. One of the 359 samples taken had TCE at an air concentration greater than 72 mcg/mL (172 mcg/mL). Long-term exposure to this level is estimated to pose a moderate increased risk for cancer (i.e., the increased risk is between one-in-ten thousand and one-in-one thousand). The available information suggests the risks for noncancer health effects for exposure to TCE in air are low for air levels ranging from greater than 10 mcg/mL to equal to or below 50 mcg/mL, and minimal for air levels equal to or below 10 mcg/mL. Only two locations had TCE air levels greater than 50 mcg/mL. Long-term exposure to the levels at these properties is estimated to pose a moderate risk for noncancer health effects. As noted previously, the increase in health risk is difficult to estimate because we have no information on how long or to what levels people were exposed to prior to the time the contamination was discovered.

    1,1,1-Trichloroethane (1,1,1-TCA)

    1,1,1-TCA was detected in some buildings near the Hopewell Precision facility above indoor air background levels, but none of the air levels (the highest being 17 mcg/m3) exceeded its inhalation public health comparison value based on noncancer health effects (Table 4). The health effects of 1,1,1-TCA have already been discussed. The available information suggests the risks for noncancer health effects for 1,1,1-TCA in indoor air are minimal.

    Tetrachloroethene (PCE)

    PCE was detected in indoor air in 61 of the buildings tested, and some of the highest detected levels exceed indoor air background levels and inhalation public health assessment comparison values (Table 4). The PCE indoor air levels are not considered related to the Hopewell Precision facility.

    Exposure to elevated levels of PCE for short or long periods of time can cause effects on the central nervous system. Very high exposures (700,000 mcg/mL or more) have caused symptoms such as dizziness, headaches, sleepiness, lightheadedness and poor balance, while lower exposures (350,000 mcg/mL for short-term exposure and 1400 mcg/mL to 5000 mcg/mL for long-term exposure) have resulted in lower scores on tests that evaluate central nervous system (CNS) function.

    Studies of workers exposed to PCE and other chemicals and studies of people living in communities with drinking water supplies contaminated with mixtures of VOCs (including PCE) show an association between exposure to high levels of these chemicals and increased risks of cancer (ATSDR 1997a). The role of other factors (e.g., exposure to other chemicals) in causing these cancers is not completely understood; and therefore the studies suggest, but do not prove, that exposure to PCE causes cancer in humans. Studies of people exposed to PCE in the workplace suggest that long-term inhalation exposure may increase the risk of effects on reproduction (reduced fertility, changes in semen quality, increased incidences of menstrual disorders and increased rates of spontaneous abortion), but the studies are not strong enough to conclude that these effects were due solely to PCE. Long-term exposure to high levels of PCE has caused cancer and adverse effects on the central nervous system, kidney and liver in laboratory animals. Based on information from animal and human studies, long-term exposure to levels from 2 mcg/mL to 190 mcg/m3 of PCE measured in the indoor air (the highest level detected, with the exception of one property) is estimated to pose a low increased risk for cancer. The available information suggests the risks for noncancer effects from exposure to PCE in indoor air would be low for PCE levels from greater than 100 mcg/m3 to 190 mcg/m3, and minimal for PCE levels equal to or below 100 mcg/m3.

    One property contained PCE indoor air levels as high as 2000 mcg/mL. Long-term exposure to this level is estimated to pose a moderate increased risk for cancer and a high risk for noncancer health effects. The measured level of 2000 mcg/mL is within the range of PCE air concentrations associated with slightly lower scores on nervous system function tests in people who lived in apartments above dry cleaning shops (1400 mcg/mL to 5000 mcg/mL) (Altmann et al., 1995).

    Methyl-tert-Butyl Ether (MTBE)

    In some buildings, MTBE was detected in the indoor air above background levels and its public health assessment comparison values based on carcinogenic effects (Table 4). As with PCE, the MTBE levels in the buildings are not considered related to the Hopewell Precision facility. The health effects for exposure to MTBE have been discussed previously. Long-term exposure to the highest level of MTBE detected in the indoor air (610 mcg/mL) is estimated to pose a low increased risk for cancer and a minimal risk for noncancer health effects.

    Summary

    The following table summarizes the evaluation of potential health risks for contaminants detected in indoor air:

    Summary of Cancer and Noncancer Risk Descriptors for Contaminants Detected in Indoor Air Near the Hopewell Precision Sitea
    Chemical Air Concentration in Micrograms per Cubic Meter Qualitative Risk Descriptor
    Cancer Risk Evaluation
    trichloroethene (TCE) 1 to 72b low
    1,1,1-trichloroethane (1,1,1-TCA) ---c ---c
    tetrachloroethene (PCE) 2 to 190d low
    methyl-tert-butyl ether (MTBE) 610e low
    Noncancer Risk Evaluation
    trichloroethene (TCE) > 10 to ≤ 50
    ≤ 10
    low
    minimal
    1,1,1-trichloroethane (1,1,1-TCA) 17e minimal
    tetrachloroethene (PCE) > 100 to 190d
    ≤ 100
    low
    minimal
    methyl-tert-butyl ether (MTBE) 610e minimal

    aAdditional information on evaluating the health risks for the contaminants is found in Appendix C. MTBE and PCE contamination is not considered related to the Hopewell Precision facility.

    bOne building had a level of 172 mcg/m3, which is estimated to pose a moderate increased cancer risk.

    cToxicological data are inadequate to assess the carcinogenic potential of 1,1,1-TCA.

    dOne building had a level of 2000 mcg/m3, which is estimated to pose a moderate increased risk for cancer and a high risk for noncancer effects.

    eHighest level detected.

D. Consideration of Interactions among Environmental Chemicals

Most hazardous waste sites contain multiple chemical contaminants. Therefore, the possibility for interactions among the chemicals detected at the Hopewell Precision contamination area was considered when evaluating the potential health risks. The three types of interactions among chemicals that can take place are additivity, synergy and antagonism. Additivity means that the combined effect of the chemicals of a mixture acting together is equal to the sum of the effects of the chemicals acting alone. Synergy takes place when the combined effect of the chemicals acting together is greater than the sum of the effects of the chemicals acting alone. Antagonism refers to the combined effect of the chemicals acting together being less than the sum of the effects of the chemicals acting alone.

Studies that directly evaluate dose-response relationships for exposure to mixtures containing all four of the chemicals that were selected for further evaluation in the Hopewell Precision contamination area (trichloroethene, 1,1,1-trichloroethane, tetrachloroethene, MTBE) are not available. However, in 2004, ATSDR published a document called an Interaction Profile (ATSDR, 2004a), which summarizes the available information on chemical interactions in various mixtures of three of the four chemicals (trichloroethene, 1,1,1-trichloroethane and tetrachloroethene). According to ATSDR's evaluation, trichloroethene, 1,1,1-trichloroethane and tetrachloroethene can all cause CNS effects, and while no studies are available that directly examine the joint toxic action of mixtures of these three chemicals on the nervous system, additivity for CNS effects is plausible.

Studies in laboratory animals show that all three chemicals cause effects on the liver and kidney, and trichloroethene and tetrachloroethene both cause carcinogenic responses (via reactive metabolites) in these organs. In addition, limited studies of interactions of binary (two chemicals) or trinary (three chemicals) mixtures of these chemicals on the liver and kidney provide no evidence of greater than additive effects. According to ATSDR, additive action on the liver and kidney is plausible for binary combinations of each of the components, with the exception of limited evidence that tetrachloroethene may inhibit the toxic action of trichloroethene on the liver and kidney. Therefore, assuming there is general similarity among the four chemicals of concern with respect to toxic endpoints and mode of action, we considered the non-cancer and cancer health effects and health risks to be additive. Based on the ATSDR guidance for evaluating the health risks of mixtures (ATSDR, 2004b), significant interactive effects among these chemicals are unlikely to result in a health hazard, because for most of these properties, the individual chemical exposures are less than one-tenth of each chemicals' reference concentration or reference dose. This means that most of the exposures at the site are well below exposure levels associated with adverse health effects. Significant interactions among carcinogens in mixtures of the chemicals chosen for further evaluation are considered unlikely at low environmental exposure levels (ATSDR, 2004b; NRC, 1989).

E. ATSDR Child Health Considerations

ATSDR emphasizes examining child health issues in all of the agency's activities, including evaluating child-focused concerns through its mandated public health assessment activities. ATSDR and NYS DOH consider children when evaluating exposure pathways and potential health effects from environmental contaminants. We recognize that children are of special concern because of their greater potential for exposure from play and other behavior patterns. Children sometimes differ from adults in their susceptibility to the effects of hazardous chemicals, but whether there is a difference depends on the chemical. Children may be more or less susceptible than adults to health effects from a chemical and the relationship may change with developmental age.

The possibility that children or the developing fetus may have increased sensitivity to TCE (the primary contaminant associated in the Hopewell Precision contamination area) was taken into account when evaluating the potential health risks associated with the contamination of private water supply wells and indoor air.

Human studies suggest that exposure to mixtures of chlorinated solvents (including TCE) in drinking water during pregnancy may increase the risk of birth defects (e.g., neural tube defects, oral cleft defects, and congenital heart defects) and/or childhood leukemia (ATSDR 1997b). As stated previously in this document, the amount of exposure to TCE, the exposure duration, and the role of other factors (e.g., exposure to other chemicals in the water) in causing these effects is not fully known. The studies therefore suggest, but do not prove, that the developing fetus may have increased sensitivity to the effects of trichloroethene.

When pregnant animals were exposed by ingestion and/or inhalation to large amounts of TCE, adverse effects on the normal development of the offspring were observed (ATSDR 1997b). In most, but not all of these studies, the high amounts of the chemicals also caused adverse health effects on the parent animal. One study reported abnormal fetal heart development in the offspring of rats exposed to TCE in drinking water before and during pregnancy (Dawson et al., 1993). Another study in rats reported that exposure to TCE in drinking water before mating, during gestation, and throughout lactation was associated with a significant decrease in the number of myelinated fibers in 21 day old offspring (Isaacson and Taylor, 1989).

The likelihood for site-related TCE exposures to cause developmental health effects (e.g., those on the fetus, infants or children) was evaluated by comparing TCE exposure estimates for the site to levels of exposures known to cause developmental toxicity in the studies described above. The estimated exposures to the highest levels of TCE in drinking water from private wells or in indoor air near the Hopewell Precision facility are about 700 times lower than the lowest TCE exposure levels reported to cause developmental effects in the offspring of animals. It therefore appears unlikely that site-related exposures to TCE will result in developmental effects, although there is some uncertainty associated with this evaluation because of the limitations in the available information on the developmental toxicity of TCE.

F. Health Outcome Evaluation

NYS DOH has not completed an evaluation of health outcome data specifically for the Hopewell Precision site. The number of people known to have been exposed to VOCs is too small to conduct a health study that could successfully detect an unusual disease pattern. However, Hopewell Precision is a site selected for inclusion in the New York State VOC Exposure Registry and NYS DOH will conduct a health statistics review for the Hopewell Junction Contamination Area.

A health statistics review uses existing data from sources such as birth certificates and health registries to determine whether health outcomes in a particular community are occurring at higher, lower, or about the same level compared to statewide levels. A health statistics review takes risk factors commonly found on health records into account such as age and sex. A health statistics review may not be able to take into account certain individual risk factors for health outcomes such as medical history, smoking, genetics and occupational exposures. A health statistics review does not tell us why elevations or deficits in health outcomes exist and cannot prove whether there is a cause and effect relationship between exposures and health outcomes. Rather, a health statistics review may suggest hypotheses and could indicate whether a more rigorous study should be considered.

For the Hopewell Precision Area Contamination site, the review will use existing data from statewide databases on cancer diagnoses, congenital malformations, and low birth weight births to determine whether these outcomes are occurring at a higher, lower, or about the same level in the Hopewell Junction study area compared to the rest of New York State. Diagnoses that occurred in the study area identified from the New York State Cancer Registry from 1980, Congenital Malformations registry from 1983, and birth records from 1978 through the most recent year of available data will be included in the health statistics review even if the person no longer lives in the area.

NYS DOH established the New York State VOC Exposure Registry (Registry) in 1999 as a tool for health status assessment and long-term follow-up for communities and individuals with documented exposures to VOCs. The Registry is currently evaluating exposures and health status of New York State residents at locations where drinking water or indoor air was contaminated with chemicals such as industrial solvents or petroleum products from landfills, industrial sites, spills, or other sources. Individuals and communities are considered for inclusion in the Registry if potential exposures from the contamination of private wells, public water supplies, or indoor air have been verified by sampling results.

For eligible residents in the Hopewell Precision area, enrollment in the Registry currently involves completion of a mailed questionnaire seeking information about exposures during the time period before the contamination was detected and before intervention occurred to prevent exposure. Information about other risk factors such as tobacco and alcohol use, detailed information about registrant health status before and after the potential exposure, and basic demographic information such as age, education and occupation, is also collected. Health status questions seek information about cancer as well as respiratory, neurological, cardiovascular, gastrointestinal, musculo-skeletal, endocrine, and reproductive symptoms and diseases.

The Registry enrollment process for homes with private wells impacted by Hopewell Precision has been underway since 2003. Since that time, additional investigation of groundwater and soil vapor intrusion into the indoor air of residences overlying the groundwater contamination has been ongoing. Residents will be contacted about the Registry as the on-going investigations document exposures to site-related contaminants in either private drinking water wells or indoor air.

Enrollment in the Registry has provided NYS DOH researchers with identifying information for exposed individuals. This information will be maintained to help NYS DOH researchers stay in contact with registrants so that information from any studies resulting from the Registry can be provided to enrollees.

In addition to following people over time, the exposure registry is a tool for combining information from sites with similar exposures so that larger numbers of individuals can be evaluated. The method used to collect data for the VOC Exposure Registry is being changed to maximize this use of the Registry. Statewide comprehensive data from a variety of databases will be used to evaluate health outcomes for groups of individuals from sites with similar VOC exposures. The databases that are currently being used to develop follow-up health outcome data are the Cancer Registry, the Congenital Malformations Registry, and Vital Records (birth and death certificates). Hospital discharge information may also be used in the future.

People who are enrolled in the Registry will be kept informed of any research results that come from the Registry data. Information gathered for the Registry is strictly confidential. This means that information that could reveal specific enrollees or any information about their health status can not be provided to anyone other than NYS DOH researchers evaluating the data. In addition, privacy of individual health information is protected in all reports that use Registry data. Reports provide information that is grouped so that no individual information is revealed.

Community Health Concerns

Community health concerns have been expressed at public meetings and meetings with local elected officials, through correspondence to government agencies, and telephone calls to the county and state health departments. The major concerns and responses to those concerns are summarized below. This public health assessment was distributed for public comment from November 17th 2006 until January 19th 2007. A public meeting was held on January 22nd 2007 to discuss the document with the community and the deadline was extended until February 23rd 2007. NYS DOH received multiple written comments, and verbal comments from the meeting. A summary of these comments and NYS DOH's responses is included in Appendix E.

Concern: The primary concern expressed is about the possible health effects in exposed individuals. Part of this concern is the uncertainty about the length of time people may have been exposed and whether the levels of contaminants have varied (increased or decreased) during that time.

Answer: Potential health effects from past exposure to contaminants in drinking water are evaluated and discussed in the Public Health Implications section. We do not have enough information to accurately estimate people's potential duration of exposure. Initial contamination of the groundwater may have occurred 29 years ago. Therefore, in the public health assessment, we used an exposure duration of 29 years to evaluate risks for site-related chemicals. As described elsewhere in this document, this is likely an over-estimate.

Concern: People who were exposed to the contaminated water in the past are interested in what, if any, medical monitoring would be recommended for themselves and their families.

Answer: Volatile organic compounds, such as TCE and 1,1,1-TCA that were detected in drinking water near the Hopewell Precision Area Contamination site, do not persist in the body for very long after the exposure stops. Because people are no longer exposed to these chemicals from the Hopewell Precision Area Contamination site, biological monitoring for these VOCs or their metabolites is not useful.

Research studies have not identified specific medical tests to look for effects from these chemicals. However, biological tests such as urinalysis or blood chemistry analyses are useful tools for finding health problems early. An individual's physician may have already used these routine tests when giving periodic checkups in the past. Physicians evaluate test results by comparing them to normal ranges for a person's gender and age. A wide range of medical conditions can cause abnormal findings in these tests. Each physician also interprets an individual's results in relation to individual medical histories. Residents may wish to tell their physician about their exposure to VOCs because the physician will consider their patient's personal health history when deciding the types of tests needed and how frequently their patients need to be seen. If your physician would like to talk with a NYS DOH environmental health nurse or physician, they should contact NYS DOH at 518-402-7950 or 1-800-458-1158.

Concern: Some residents suspect that illnesses in the family (e.g., cancer, headaches, dizziness, etc.) were caused by exposure to the contaminated groundwater.

Answer: Potential cancer and non-cancer health effects are discussed in the Public Health Implications section. Whether these contaminants or some other factors caused the symptoms or illnesses mentioned is not known.

Concern: Some residents have requested that NYS DOH and ATSDR conduct a health study of the people in Hopewell Junction who were exposed to contaminants from the Hopewell Precision site.

Answer: Hopewell Precision is a site selected for inclusion in the VOC Exposure Registry, and NYS DOH will conduct a health statistics review for the Hopewell Precision Contamination Area.

The Registry and health statistics review are discussed more fully in the Health Outcome Evaluation Section.

Concern: Some residents are worried about the reliability of the water treatment systems and sub-slab depressurization systems installed at their homes.

Answer: Both types of system use well-established, reliable technologies to reduce exposures to contamination. Similar systems have been used successfully at many other sites. The US EPA and NYS DEC are currently responsible for maintaining the systems they have installed. If these systems become part of the final remedy for the site, a formal maintenance and monitoring plan would ensure that the systems are maintained until they are no longer needed.

Concern: Some residents have asked when the groundwater contamination will be remediated, and whether it would be feasible to provide a public water supply to the community.

Answer: The US EPA estimates that they will propose a remedy for this site in 2008. The proposed remedy will be based on a feasibility study, which will examine a number of possible ways to clean up and reduce the potential for exposure to the contamination. The provision of a public water supply would be one of the measures considered in the study. The proposed remedy will include an approximate timetable for remediation.

Conclusions

Public health actions were needed in the past and may be needed in the future at the Hopewell Precision Area Contamination site to reduce exposures to site-related VOCs, primarily TCE and 1,1,1-TCA and the non-site related VOCs, PCE, and MTBE. Exposure to TCE, 1,1,1-TCA and MTBE were occurring via contaminated private well water and via soil vapor intrusion impacts to indoor air. Exposure to PCE was occurring via soil vapor intrusion impacts to indoor air. Several wells were contaminated with TCE and 1,1,1-TCA at or above the state or federal MCLs; one well had MTBE at levels above the state MCL. Long-term exposure (up to 29 years) of residents to the highest levels of TCE detected in private water supplies is estimated to pose a low increased risk for cancer; the risks for noncancer effects is low to moderate. Long-term exposure to the highest level of MTBE in private wells (which is not related to the Hopewell Precision facility) is estimated to pose a low increased risk for cancer. These exposures have been addressed by installation of treatment systems.

Indoor air of some buildings, mostly residential, was contaminated with TCE and PCE above US EPA screening levels and New York State air guidelines. Some residents could have been exposed to TCE in their indoor air for as long as 29 years. With the exception of measured levels at one property, (for which the estimated cancer risk was moderate), the estimated increased cancer risk for exposure to the levels of TCE measured in indoor air is low. The risks for TCE noncancer effects for indoor air are minimal to low. PCE air levels, which were not related to the Hopewell Precision facility, are estimated to pose a low increased risk for cancer and minimal to low risk for noncancer health effects. A single property had significantly elevated PCE levels corresponding to a moderate increased cancer risk and a high risk for noncancer health effects. These exposures have been addressed by installation of mitigation systems.

The drinking water affected by the site currently poses an indeterminate public health hazard. Although treatment systems have been installed and regular monitoring is being implemented in those impacted homes already identified, the extent of the groundwater plume still needs to be defined. Exposures to contaminants have been reduced to levels below state and federal MCLs in those wells already identified. However, if treatment systems are not maintained, or if TCE or 1,1,1-TCA are detected in any potentially threatened wells, or if new wells are installed in the contaminated plume, exposures could be occurring or occur in the future.

Similarly, soil vapor and indoor air affected by the site poses an indeterminate public health hazard. Although mitigation systems have been installed and exposures have been reduced to levels below US EPA screening levels and NYS DOH air guidelines in those impacted homes already identified, the extent of the soil vapor plume still needs to be defined. Also, if the treatment systems are not maintained, or if TCE or 1,1,1-TCA is detected in the soil vapor in additional buildings overlying the contaminated plume, exposures could be occurring or occur in the future.

Sampling data indicate that the contamination plume has moved primarily to the southwest, underneath and beyond Route 82. The extent of the plume will be delineated as part of US EPA's on-going Remedial Investigation of the site. The source of contamination is believed to be the former Hopewell Precision facility located at 15 Ryan Drive, that was used to manufacture and paint sheet metal, and the current Hopewell Precision facility at 19 Ryan Drive that continues these activities.

Recommendations

  1. Continue actions to minimize human exposure to the contaminated water.
  2. Maintain installed treatment systems and monitor the quality of the treated water until contamination levels are below federal and state MCLs or until an alternative water supply is provided.
  3. Maintain installed soil vapor mitigation systems until the contamination levels are below US EPA site-specific target levels.
  4. Through the US EPA's ongoing remedial investigation, define the nature and extent of the groundwater and soil-vapor contamination from the Hopewell Precision site.
  5. Continue monitoring of potentially affected private wells, soil vapor and indoor air in the area, with treatment systems/mitigation systems added as appropriate.
  6. Consider a permanent, long-term remedy for groundwater users.
  7. Undertake additional investigation of the source(s) of MTBE in groundwater, although not site-related. Information on local gasoline spills can be obtained from the NYS DEC Region 3 office at (845) 256-3052 or visit the NYS DEC website
  8. Complete additional investigation of the source(s) of PCE found in soil vapor, although not site-related. This should be done by the US EPA during the on-going Remedial Investigation.
  9. Complete additional investigations of the source of the contamination and the extent of the contamination.

Public Health Action Plan

The Public Health Action Plan (PHAP) for the Hopewell Precision Area Contamination site describes actions to be taken by ATSDR and/or NYS DOH following completion of this PHA. For those actions already taken at the site, please refer to the Background section of this PHA. The purpose of the PHAP is to provide a plan of action designed to outline measures to be taken to mitigate exposures and minimize the potential for adverse human health effects resulting from the past, present, and/or future exposures to hazardous substances at or near the site. Included is a commitment on the part of ATSDR and/or NYS DOH to follow up on this plan to ensure that it is implemented. The public health actions to be implemented by ATSDR and/or NYS DOH are as follows:

  1. NYS DOH will coordinate with the appropriate environmental agencies to develop a plan to implement the recommendations contained in this PHA.
  2. NYS DOH will review all data generated from the US EPA Remedial Investigation of the site to evaluate potential public health implications and implement necessary measures to protect public health. The evaluation of additional information about exposures will be the subject of a future public health assessment document.
  3. ATSDR will provide a follow-up report on this PHAP, as needed, outlining the actions completed and those in progress. This report will be placed in repositories that contain copies of this PHA and will be provided to people who request it.
  4. NYS DOH will continue to distribute information on the NYS VOC Exposure Registry to residents with exposures documented by sampling results. Results of any new research that become available will be shared with Registry participants.
  5. NYS DOH will proceed with a health statistics review for the area. Any follow-up activities will take into consideration the findings of the health statistics review, the feasibility of additional action, and input from community members. The findings of the review will be the subject of a future public health assessment document.
  6. ATSDR and NYS DOH will provide future updates of the PHA to local physicians and concerned residents who expressed an interest in the draft PHA. They will be encouraged to contact the agencies if they have additional questions or concerns.

ATSDR and NYS DOH will reevaluate and expand the PHAP when needed. New environmental, toxicological, or health outcome data, or the results of implementing the proposed actions may determine the need for additional actions at this site.

References

  1. ATSDR (Agency for Toxic Substances and Disease Registry). 2004a. Interaction Profile for: 1,1,1-Trichloroethane, 1,1-Dichloroethane, Trichloroethylene and Tetrachloroethylene. Atlanta, GA: Division of Toxicology, Agency for Toxic Substances and Disease Registry, Public Health Service, US Department of Health and Human Services.
  2. ATSDR (Agency for Toxic Substances and Disease Registry). 2004b. Guidance Manual for the Assessment of Joint Toxic Action of Chemical Mixtures. Atlanta, GA: Division of Toxicology, Agency for Toxic Substances and Disease Registry, Public Health Service, US Department of Health and Human Services.
  3. ATSDR (Agency for Toxic Substances and Disease Registry) . 1995. Toxicological Profile for 1,1,1-Trichloroethane. Atlanta, GA: U.S. Public Health Service. U.S. Department of Health and Human Services.
  4. ATSDR (Agency for Toxic Substances and Disease Registry). 1997a. Toxicological Profile for Tetrachloroethene (Update). Atlanta, GA: U.S. Public Health Service. U.S. Department of Health and Human Services.
  5. ATSDR (Agency for Toxic Substances and Disease Registry). 1997b. Toxicological Profile for Trichloroethene (Update). Atlanta, GA: U.S. Public Health Service. U.S. Department of Health and Human Services.
  6. Altmann, L., A. Bottger and H. Weigand. 1990. Neurophysiological and psychophysical measurements reveal effects of acute low-level organic solvent exposure in humans. Int. Arch. Occup. Environ. Health : 493-499
  7. Altmann, L., H. Wiegand, A. Bottger, F. Elstermeier and G. Winneke. 1992. Neurobehavioral and neurophysiological outcomes of acute repeated perchloroethylene exposure. Appl. Psych. 41: 269-279.
  8. Altmann, L., H.-Florian Neuhann, U. Kramer, J. Witten and E. Jermann. 1995. Neurobehavioral and neurophysiological outcomes of chronic low-level tetrachloroethene exposure measured in neighborhoods of dry cleaning shops. Environ. Res. 69: 83-89.
  9. Belpoggi, F., M. Soffritti and C. Maltoni. 1995. Methyl-tertiary-butyl ether (MTBE) - A
  10. gasoline additive - Causes testicular and lymphohaematopoietic cancer in rats. Toxicol.
  11. Indust. Health. 11:119-149.
  12. Belpoggi, F., M. Soffritti and C. Maltoni. 1998. Pathological characterization of testicular tumours and lymphomas-leukemia, and their precursors observed in Sprague-Dawley rats exposed to methyl-tertiary-butyl ether (MTBE). Eur. J. Oncol. 3:201-206.
  13. Bird, M.G., H.D. Burleigh-Flayer, J.S. Chun, J.F. Douglas, J.J. Kneiss and L.S. Andrews. 1997. Oncogenicity studies of inhaled methyl tertiary-butyl ether (MTBE) in CD-1 mice and F-344 rats. J. Appl. Toxicol. 17: S45-S55.
  14. Cavalleri, A., F. Gobba, M. Paltriinieri, G. Fantuzzi, E. Righi and G. Aggazzotti. 1994. Perchloroethylene exposure can induce colour vision loss. Neuroscience Lett. 179: 162-166.
  15. Dawson, V., P.D. Johnson, S.J. Goldberg and J.B. Ulreich. 1993. Cardiac teratogenesis of halogenated hydrocarbon-contaminated drinking water. J. Am. Coll. Cardiol. 21: 1466-72.
  16. Fredriksson, A., B.R.G. Danielsson and P. Eriksson. 1993. Altered behavior in adult mice orally exposed to tri- and tetrachloroethylene as neonates. Toxicol. Lett. 66: 13-19.
  17. Hake, C.L. and R.D. Stewart. 1977. Human exposure to tetrachloroethylene: Inhalation and skin contact. Environ. Health Persp. 21: 231-239.
  18. Isaacson L.G. and D.H. Taylor. 1989. Maternal exposure to 1,l,2-trichloroethene affects myelin in the hippocampal formation of the developing rat. Brain Res. 488:403-407.
  19. Johnson, P.D., B.V. Dawson, and S.J Goldberg,. 1998. A Review: Trichloroethylene metabolites: Potential cardiac teratogens. Environ. Health. Perspect. 106, Supplement 4, August 1998.
  20. Johnson, P.D., S.J Goldberg, M.Z Mays, and B.V Dawson,. 2003. Threshold of trichloroethylene contamination in maternal drinking waters affecting fetal heart development in the rat. Environ. Health Persp. 111:289-292.
  21. Maxwell, N.I., D.E. Burmaster and D. Ozonoff. 1991. Trihalomethanes and maximum contaminant levels: the significance of inhalation and dermal exposures to chloroform in household water. Regul. Toxicol. Pharmacol. 14: 297-312 (review).
  22. NRC (National Research Council). 1989. Drinking Water and Health. Selected Issues in Risk Assessment. Vol. 9. Mixtures. Washington, D.C: National Academy Press.
  23. NYS DEC (New York State Department of Environmental Conservation), 1987. Engineering Investigations at Inactive Hazardous Waste Sites in the State of New York Phase II Investigations – Hopewell Precision Site. Wehran Engineering P.C.
  24. NYS DOH (New York State Department of Health). 2000. New York State Cancer Surveillance Improvement Initiative.
  25. Stewart, R.D., E.D. Baretta, H.C. Dodd and T.R. Torkelson. 1970. Experimental human exposure to tetrachloroethylene. Arch. Environ. Health. 20: 224-229.
  26. US Bureau of the Census 2001. 2000 Census of population and housing summary file 1(SF1). US Department of Commerce.
  27. US Bureau of the Census 2002. 2000 Census of population and housing summary file 3 (SF3). US Department of Commerce.
  28. US EPA IRIS (United States Environmental Protection Agency Integrated Risk Information System). 2004. Washington, DC: Office of Research and Development, National Center for Environmental Assessment.
  29. US EPA (United States Environmental Protection Agency). 2004. Hazard Ranking System Documentation Package Hopewell Precision Area Contamination Hopewell Junction, Dutchess County, New York. Edison, NJ: Weston Solutions Inc..
  30. Weisel, C.P. and W.K. Jo. 1996. Ingestion, inhalation, and dermal exposures to chloroform and trichloroethene from tap water. Environ. Health Persp. 104: 48-51.

References for Summary of Public Comments and Responses

  1. NAS (National Academy of Sciences). 2006. Assessing the Human Health Risks of Trichloroethylene: Key Scientific Issues. Washington, DC: National Academy Press.
  2. NYS DEC (New York State Department of Environmental Conservation). 1997. Combined Regulatory Impact and Draft Environmental Impact Statement; Human Health Fact Sheet for Trichloroethene. Albany, NY: Division of Water.
  3. NYS DOH (New York State Department of Health). 2006a. Trichloroethene Air Criteria Document. Final Report. Troy, NY: Center for Environmental Health, Bureau of Toxic Substance Assessment.
  4. NYS DOH (New York State Department of Health). 2006b. Guidance for Evaluating Soil Vapor Intrusion in the State of New York. Final Draft. Troy, NY: Center for Environmental Health, Bureau of Environmental Exposure Investigation.
  5. US EPA (United States Environmental Protection Agency). 2006. A framework for Assessing Health Risks of Environmental Exposures to Children. External Review Draft. EPA/600/R-05/093A. Washington DC: National Center for Environmental Assessment, Office of Research and Development.
  6. US EPA (United States Environmental Protection Agency). 1989. Exposure Factors Handbook. Office of Health and Environmental Assessment. Washington, DC. EPA/600/8-89/043.
  7. US EPA (United States Environmental Protection Agency). 2001. Trichloroethylene Health Risk Assessment: Synthesis and Characterization, External Review. EPA/600/P-01/002A. Washington, DC: Office of Research and Development.

For more information on the work of ATSDR, please contact

NCEH/ATSDR Office of Communication, Information Services Center
1600 Clifton Road, N.E. (MS E-29)
Atlanta, GA 30333
Telephone: 1-888-422-8737